Chilled Water Unit

GASCO PROJECT NO. 5228

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

Agreement No 13522801

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

Rev. 4

ASAB – 2 ASAB GAS DEVELOPMENT PHASE II PROJECT 5228

OPERATING MANUAL CHAPTER 15 CHILLED WATER - UNIT 266

DOCUMENT CLASS: 2

EASTERN BECHTEL COMPANY LIMITED

THE DESIGN OR PART THEREOF CONTAINED IN THIS DOCUMENT WAS DEVELOPED FOR GASCO FOR THE PROJECT AND REMAINS THE PROPERTY OF GASCO. ALL EASTERN BECHTEL COMPANY LTD (EBCL) PROPRIETARY INFORMATION OR UNDERLYING INTELLECTUAL PROPERTY UTILIZED IN THE CREATION OF THE DESIGN OR INFORMATION CONTAINED HEREIN SHALL REMAIN THE PROPERTY OF EBCL.

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-1

GASCO PROJECT NO. 5228

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

Agreement No 13522801

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

Rev. 4

This page records the revision status of this document. All previous issues are hereby superseded and are to be destroyed. NOTES: Revisions after Rev. 1 are denoted as follows: (a) By a vertical line in the right-hand margin adjacent to the revised text. The revision number is displayed adjacent to the right hand side of the revision line, or (b) By a triangle symbol for graphics, the revision number being denoted within the symbol positioned adjacent to the revision. (c) CHKD = Checked by Project Functional Manager, or nominee; DISC = (Corporate) Functional Manager, or designee; PD = EBCL's Project Director, or designee

REV

DATE

4 3 2

16 May 10 03 Apr 10 08 Nov 08

1 0

19 Oct 08 18 Aug 08

REASON FOR ISSUE

Issued for Implementation Issued for Implementation Re-issued for Implementation Issued for Implementation Issued for Review

DISC

APPROVED PD PMC

FL FL CBM

AMCI AMCI AMCI

MPH MPH IR

CBM CBM

AMCI AMCI

IR IR

BY

CHKD

AJW AJW M&H M&H

GASCO

Signed (Initials)

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-2

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

GASCO PROJECT NO. 5228 Agreement No 13522801

Rev. 4

TABLE OF CONTENTS 15.1

OVERVIEW ....................................................................................................................................... 5

15.2

PROCESS DESCRIPTION .............................................................................................................. 6

15.3

EQUIPMENT DESCRIPTION ........................................................................................................ 8 15.3.1

Chilled Water Return Drum.............................................................................................. 8

15.3.2

Chilled Water Pumps ......................................................................................................... 8

15.3.3

Chilled Water Cooler ......................................................................................................... 9

15.3.4

Chilled Water Compressor ................................................................................................ 9

15.3.5

Compressor Lube Oil System ............................................................................................ 9 15.3.5.1 Lube Oil Pumps .............................................................................................................. 10 15.3.5.2 Lube Oil Cooler .............................................................................................................. 10 15.3.5.3 Lube Oil Filters ............................................................................................................... 11

15.3.6

Compressor Electric Motor ............................................................................................. 11

15.3.7

Motor Lube Oil System .................................................................................................... 11 15.3.7.1 Oil Reservior ................................................................................................................... 11 15.3.7.2 Lube Oil Pumps .............................................................................................................. 12 15.3.7.3 Lube Oil Filters ............................................................................................................... 12 15.3.7.4 Lube Oil Cooler .............................................................................................................. 13

15.3.8

Lube Oil Separator ........................................................................................................... 13

15.3.9

Refrigerant Air Cooler ..................................................................................................... 14

15.3.10 Refrigerant Receiver/Economizer ................................................................................... 14 15.4

OVERPRESSURE PROTECTION DEVICES ............................................................................ 15

15.5

UNIT CONDITIONING ................................................................................................................. 16

15.6

OPERATING VARIABLES AND CONTROLS .......................................................................... 18 15.6.1

Propane Compressor Suction Pressure Control ............................................................ 18

15.6.2

Refrigerant Cooler Pressure Control.............................................................................. 18

15.6.3

Chilled Water Alarms and Shutdowns ........................................................................... 19

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-3

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

GASCO PROJECT NO. 5228 Agreement No 13522801

Rev. 4

15.7

SAFETY PRECAUTIONS ............................................................................................................. 25

15.8

PRE-STARTUP CHECKS ............................................................................................................. 27

15.9

INITIAL STARTUP ........................................................................................................................ 27

15.10 NORMAL STARTUP ..................................................................................................................... 28 15.11 NORMAL OPERATION ................................................................................................................ 29 15.12 NORMAL SHUTDOWN ................................................................................................................ 30 15.13 EMERGENCY OPERATING CONDITIONS ............................................................................. 30 15.14 REFERENCES ................................................................................................................................ 30 15.15 ATTACHMENTS ............................................................................................................................ 31

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-4

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

15.1

GASCO PROJECT NO. 5228 Agreement No 13522801

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

Rev. 4

OVERVIEW The ASAB-2 Chilled Water System is a closed loop recirculation system, which provides cooling water for small, low temperature thermal duties, where air-cooling is inadequate. Warm chilled water is pumped from the Chilled Water Return Drum by motor driven centrifugal pumps. These pumps discharge the water to a kettle type cooler where the warm chilled water is cooled to 13°C by heat exchange with propane refrigerant. Cooled chilled water is distributed to the following users:          

Air Compressor Packages 267-C-101A/B/S Steam Condensate Cooler 261-E-101 Acid Gas Compressor Steam Turbine 153-CT-101A/B Lean Solvent Circulating Pump Seals 130/230-P-101A/S Refrigeration Compressor Motor VSD Chiller Package 141/241-CM-201 Acid Gas Compressor Motor VSD Chiller Package 153-CM-101S-ME-001 Utility Boiler Sample Coolers 262-FH-251 A/B/C/S Booster Compressor GT Sample Coolers 262-HRSG-151 A/B HP Boiler Pump Seal Cooler 262-P-151 A/B/S Propane Compressor Lube Oil Cooler 266- E-103A/B/S

In addition to the above, the AGD-II Chilled Water System will be designed to accommodate a future fourth Air Compressor identical to the first three referenced above. There is a 10°C temperature rise in the above Chilled Water duties and the warm chilled water returns via a collection header to the Chilled Water Return Drum. Make-up water is supplied to the Chilled Water Return Drum from the Demineralised Water System Unit 261. Corrosion inhibitors and biocides are added to the makeup water before topping up the closed Chilled Water circuit. The ASAB-2 Chilled Water System is not integrated with the ASAB-1 Chilled Water System due to the high pressure drop between ASAB-2 and ASAB-1. The high pump head necessary to transfer Chilled Water to ASAB-1 exceeds the design pressure of the ASAB-1 Chilled Water system and is likely to lift the relief valves on the ASAB-1 system if an isolation valve on this system is inadvertently shut. With a separate system for ASAB-2, the necessary pump differential head and the system containment pressure are both reduced to acceptable levels.

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-5

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

15.2

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

GASCO PROJECT NO. 5228 Agreement No 13522801

Rev. 4

PROCESS DESCRIPTION The closed, chilled water loop in Unit 266 uses demineralised water, which is appropriately treated with chemicals, for cooling. The cold chilled water is supplied to users at 13°C and 6.5 barg and returns from users at 23°C and 2.5 barg. Chilled water is stored in a pressurised Chilled Water Return Drum, 266-V-101. The Drum pressure is maintained at approximately 1.25 barg by pressure controller PIC-105A/B, to regulate the nitrogen supply valve, PV-105A, and vent valve, PV-105B. The resulting nitrogen blanket prevents oxygen from entering the system, which reduces the likelihood of internal corrosion. The Chilled Water Pumps, 266-P-101A/S, take suction from the Chilled Water Return Drum (located at the high point of the system). One pump is in service and the other is standby and each pump is equipped with a minimum flow recycle controller, FIC-105/106. The pumps discharge warm chilled water to the refrigeration package integral to the Chilled Water System, 266-ME-101, where it is cooled by propane refrigerant in the Chilled Water Cooler, 266-E-101. The chilled water outflow from the refrigeration package is routed via a distribution header to various users before returning via a collection header to the Chilled Water Return Drum. Chilled Water inventory is topped up in the Chilled Water Return Drum, as required, using demineralised water from the Demineralised Water System, Unit 261. When make-up demineralised water is added to the system, it is first dosed with the necessary corrosion inhibitor, chlorine and appropriate biocide chemicals using a portable injection pump. The Chilled Water System refrigeration package uses a closed loop propane refrigerant system to cool chilled water. The refrigeration package comprises 3x50% compressors, 266-C-101A/B/S. Two compressors are normally in service and one on standby. The Propane Compressors are oil flooded screw compressors and each discharges to a twin chamber separator (Lube Oil Separators 266-V-102A/B/S) where oil is recovered from propane vapour. Recovered oil from the first separator chamber flows to the suction of the Lube Oil Pumps for recirculation via the Propane Compressor Lube Oil System, discussed below. Recovered oil from the second separator chamber returns to the compressor suction. Propane from each separator flows to a single Refrigerant Condenser, 266-E-102A-F, which is a six bay air cooler. Liquid propane exits the condenser and flows to the Refrigerant Receiver/Economizer, 266-V-104, under level control on the receiver/economizer (LIC-805). Flash propane gas from the receiver/economizer flows under pressure control (PIC-801) to the Propane Compressor side stream (economizer) inlet port.

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-6

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

GASCO PROJECT NO. 5228 Agreement No 13522801

Rev. 4

Liquid propane from the receiver/economizer flows under level control, LIC-803 to the shell side of the Chilled Water Cooler (266-E-101). The liquid propane pressure is reduced across LV-803 and two phase flow enters the Cooler. Chilled water flowing through the tube side of the evaporator is cooled by the propane liquid on the shell side. Propane vapour exits the evaporator and flows to the propane compressor suction to complete the loop. The propane pressure in the Cooler shell side controls the chilled water outlet temperature. The Cooler shell side pressure is controlled by PIC-808B controlling hot gas bypass from the Refrigerant Condenser inlet to the Cooler inlet, PIC-808A controlling the Compressors capacity controls, and TIC-811 on the chilled water outlet providing set point reset to PIC-808A. Propane refrigerant make-up is stored in the Propane Storage Drum, 264-V-102 and is pumped into the propane system through a liquid filter dryer. The makeup propane liquid ties into the liquid propane outflow from the Refrigerant Receiver/Economizer, as required. Lube oil, which is separated from propane vapour in the Lube Oil Separators is pumped from each separator by two electric motor driven Lube Oil Pumps, 266-P-101A/B/S and 266-P-101SA/SB/SS. One pump is in service and the other is standby. Each pair of pumps is equipped with a common minimum flow recycle controller (PCV-507/607/707), which discharges back to the relevant Lube Oil Separator. The normal discharge from the pumps is via shell and tube Lube Oil Coolers, 266-E-103A/B/S, where lube oil on the shell side is cooled by chilled water on the tube side. The Lube oil return temperature to the compressor is regulated by an oil cooler bypass circuit using temperature controllers TIC-510/610/710, which act on three port valves TV-510/610/710 located in the respective bypasses. Cooled oil exiting Oil Coolers 266-E-103A/B/S flows to duplex Discharge Lube Oil Filters 266-F-103A/B/S and 266-F-104A/B/S. The filtered oil is distributed to the Propane Compressor bearings, shaft seal, and slide valve. The Propane Compressor drive motors have a separate lube oil system for motor bearing lubrication. Motor driven Lube Oil Pumps 266-P-102A/B/S and 266-P-102SA/SB/SS draw suction from the Oil Reservoirs, 266- TK-101A/B/S. One pump is in service and the other is on standby. Each pair of pumps is equipped with a minimum flow recycle, PCV-520/620/720, which returns lube oil from the outlet of the downstream Lube Oil Cooler back to the Oil Reservoir. In the event of local blocked outlet, there is a local recycle via a PSV from each Lube Oil Pump discharge back to its respective Lube Oil Reservoir. The Lube Oil Pumps discharge to duplex Lube Oil Filters 266-F-105A/B/S and 266-F-106A/B/S. The filtered oil outflow is routed to shell and tube Lube Oil Coolers 266-E-104A/B/S where oil on the shell side is cooled by chilled water on the tube side. The lube oil outlet temperature is controlled by regulating the chilled water flow through the Coolers

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-7

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

GASCO PROJECT NO. 5228 Agreement No 13522801

Rev. 4

using TCV-520/620/720, respectively. Filtered, cool lube oil is delivered to the motor bearings and drains back under gravity from the bearings to the Oil Reservoir. 15.3

EQUIPMENT DESCRIPTION The Chilled Water Unit contains the following major equipment.

15.3.1

Chilled Water Return Drum Chilled Water Return Drum, 266-V-101, is a vertical, carbon steel, insulated vessel measuring 4300 mm ID by 13050 mm T/T. Design pressure is 8.0 barg at 90°C max/5°C min. The vessel is also rated for full vacuum. The Chilled Water Return Drum functions as an expansion tank and provides about 10-minute liquid retention under the maximum recirculation flow. The Drum supplies warm chilled water to the Chilled Water Pumps and receives return water from the chilled water users. The Drum also receives demineralised make-up water from the Demineralised Water System, Unit 261, as required. Chemicals are dosed into the demineralised water to prevent corrosion and biological growth. The Drum is also blanketed with nitrogen to reduce the chance of oxygen leaking into the system that could exacerbate corrosion, and to maintain a constant Chilled Water Pump suction pressure. The Drum has two pressure safety valves PSV-105A/S that are set at 4.0 barg and relieve to atmosphere. There are also local level gauges (LG-105A/B), a local pressure gauge (PG-105), a local nitrogen supply pressure gauge (PG-107), a local return water temperature gauge (TG-105), two 24-inch manways, and provision to drain into the open drain system and vent to atmosphere.

15.3.2

Chilled Water Pumps Chilled Water Pumps, 266-P-101A/S, are horizontal centrifugal pumps driven by 1500 rpm constant speed electric motors. The Pumps draw suction from the bottom outlet of the Chilled Water Return Drum and discharge to the Chilled Water Cooler, 266-E-101. The Pumps are provided with dedicated minimum flow control loops FIC-105/106, which spill back to the Chilled Water Return Drum. The Pumps operate with one Pump in service and one Pump on standby. The standby Pump auto-starts on low pump discharge header pressure. Each pump has the following characteristics: Rated flow: Differential head: Design pressure: Design liquid temperature range: Driver:

780 m3/hr 56.0 m 13.6 barg 5°C to 85°C 200.0 kW

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-8

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

15.3.3

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

GASCO PROJECT NO. 5228 Agreement No 13522801

Rev. 4

Chilled Water Cooler The Chilled Water Cooler (Propane Evaporator), 266-E-101, is a horizontal, insulated shell and tube kettle type exchanger with a design duty of 8.53 MMkcal/hr (9980 kW). The shell and tubes are manufactured in carbon steel with design pressures of 28 and 22 barg, respectively, both at 150°C max/-46°C min. The shell and tubes are both also designed for full vacuum. Chilled water from the Chilled Water Pumps flows through the tubes and is cooled by heat exchange with liquid propane in the shell, which is delivered from the Refrigerant Receiver, 266-V-104, to the shell side of the evaporator under level control using LIC-803. Evaporated propane vapour exits the exchanger shell and flows to the inlet of the Chilled Water Compressors (Propane Compressors), 266-C-101A/B/S. The Chilled Water Cooler pressure (chilled water temperature outlet from the Cooler) controls the Compressor suction pressure. Lube oil accumulating in the kettle flows to the boot where it is recovered by Ejectors J-106 and J-107 that operate on ON/OFF timers. Propane vapour from the inlet of the Refrigerant Air Cooler 266-E-102 is the motive fluid for the ejectors, which discharge to the Propane Compressor suction. The Chilled Water Cooler is protected against over pressure by two pressure safety valves PSV-803A/S, which relieve to the low temperature flare. The kettle includes a local level gauge, LG-802, and a pressure gauge, PG-808. The Chilled Water Cooler also includes provision for draining and venting the tube side and venting the shell side.

15.3.4

Chilled Water Compressor There are 3x50% Chilled Water Compressors (Propane Compressors), 266-C-101A/B/S, which are oil flooded screw type driven by direct coupled electric motors. Lube oil separated from the compressed propane stream is returned to the Compressor suction stream and casing to lubricate the screws. The Compressors are rated to compress 6410 m3/hr of propane at a suction pressure of 4.6 barg and discharge the gas at 22.4 barg. The compressors draw suction from the Propane Evaporator and there is also a side stream inlet from the Refrigerant Receiver/Economizer. The compressors discharge to the Lube Oil Separators, 266-V-102A/B/S. The compressor capacity is adjusted by a hydraulic actuated (lube oil) slide valve, which turn down from 100% to 15%. The compressors include two vibration probes at each shaft bearing.

15.3.5

Compressor Lube Oil System The Compressor Lube Oil System provides pressurised, cooled, and filtered oil for the following services:

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-9

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

GASCO PROJECT NO. 5228 Agreement No 13522801

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15



Bearing lubrication



Shaft seal lubrication



Rotor (Screw) lubrication



Slide valve hydraulic oil

Rev. 4

The Compressor Lube Oil System contains the following major equipment: 15.3.5.1

Lube Oil Pumps Oil separated in the first chamber of the Lube Oil Separator (266- V-102A/B/S) is routed to the Lube Oil Pumps 266-P-101A/B/S and 266-P-101SA/SB/SS, which are horizontal screw type driven by 1450rpm motors, 266-PM-101A/B/S and 266-PM-101SA/SB/SS. One Pump is in service. The other Pump is on standby and will auto start on decreasing oil system differential pressure on PDAL-503/603/703. Minimum pump flow is controlled using a spillback through PCV-507 to the Lube Oil Separator. Each pump includes local discharge pressure gauges (PG-503/603/703 and PG-504/604/704) and local pressure safety valves (PSV-506/606/706 and PSV-507/607/707) that discharge to the Lube Oil Separator. The normal lube oil discharge from the Pumps is routed to the Lube Oil Coolers. Each pump has the following characteristics: Rated flow: Differential head: Design pressure: Design liquid temperature range: Driver:

15.3.5.2

54.0 m3/hr 3.0 barg 40 barg @ 150°C (MAWP is 29 barg @ -46°C/150°C) -46°C to 150°C 18.5 kW

Lube Oil Cooler Lube Oil Coolers, 266-E-103A/B/S, are insulated shell and tube exchangers with a design duty of 439.5 Mkcal/hr (511 kW) each. The carbon steel shell and tubes are designed for 33 barg and 28 barg, respectively, both at 150°C max/-46°C min. The shell and tubes are also both designed for full vacuum. Lube oil from the Lube Oil Pumps flows through the shell and is cooled by chilled water in the tubes. Chilled water from the Chilled Water Pumps, 266-P-101A/S, discharge enters the tube side of the Cooler and warmed Chilled Water exits the Cooler tubes and is sent to the Chilled Water Return Drum, 266-V-101. Some warm lube oil feed bypasses the Cooler under temperature control using TIC-510/610/710. The bypass fluid mixes with cooled lube oil

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-10

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

GASCO PROJECT NO. 5228 Agreement No 13522801

Rev. 4

exiting the Cooler to provide lube oil to users at a regulated temperature. The cooled lube oil flows to the duplex Lube Oil Filters. The Lube Oil Coolers have local shell and tube side vent valves for maintenance, which are blinded but discharge to atmosphere when required. The shell side has a manual drain valve to the oil drain header. The Cooler tube side is equipped with a local pressure gauge, PG-502/602/702 and pressure safety valve, PSV-502/602/702, that relieves to the atmosphere. The shell side has a pressure relief valve PRV-502/603/705 that relieves to the Lube Oil Separator. 15.3.5.3

Lube Oil Filters Discharge Lube Oil Filters, 266-F-103A/B/S and 266-F-104A/B/S, are configured as duplex, horizontal cartridge units, which are located downstream of the Lube Oil Cooler. Each filter is designed for 33 barg and full vacuum at 150°C max/-46°C min. One filter is in service and the other is on standby. The filters include a pressure balance/fill line and manual transfer valves for switching flow between duty and standby units. The Filters have local panel mounted differential pressure indicators, PDI-504A/604A/704A, a vent to atmosphere, and a drain to the oil drain header. Cooled and filtered lube oil flows to the lube oil users.

15.3.6

Compressor Electric Motor Compressor Electric Motors, 266-CM-101A/B/S, are 3100kW, 11kV, 3-phase, 50 Hz, 2978 rpm synchronous motors. The Motor has is a weather proof air cooled enclosure with air supply for motor purging. The motors are equipped with space heaters, winding RTDs, bearing RTDs, radial vibration probes at each shaft bearing, and a shaft key phasor. The motor bearings are forced lubricated by the lube oil system, which is discussed below.

15.3.7

Motor Lube Oil System Each compressor motor has its own lube oil system. The Motor Lube Oil System contains the following major equipment.

15.3.7.1

Oil Reservior The Oil Reservoirs, 266-TK-101A/B/S, are each 500 litre stainless steel tanks, which operate at atmospheric pressure. The reservoir has an electric heater to maintain the lube oil temperature, an atmospheric vent, and a drain valve which is not connected to any permanent drain system.

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-11

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

GASCO PROJECT NO. 5228 Agreement No 13522801

Rev. 4

The oil level is monitored locally on level gauges LG-520/620/720 and LI-520A/620A/720A at the local panel. A DCS indicator LI-520/620/720 activates high and low level alarms. 15.3.7.2

Lube Oil Pumps Lube Oil Pumps, 266-P-102A/S and 266-P-102SA/SS, located in the stainless steel Oil Reservoirs, are submerged vertical sump pumps driven by 1450 rpm electric motors, 266-PM-102A/B/S and 266-PM-102SA/SB/SS. One Pump is in service with the other in standby. The standby Pump will auto start on decreasing oil system pressure, PAL-521/621/721. The lube oil system supply pressure is controlled by backpressure control valves, PCV-520/620/720. These valves are set at 3 barg and the discharge returns to the Oil Reservoir. Each pump is protected by pressure safety valves, PSV-520/620/720 and PSV-521/621/721, which also discharge back to the Oil Reservoir. The pumps also have local discharge pressure gauges, PG-520/620/720 and PG-521/621/721. Lube oil discharging from the Pumps flows to duplex Lube Oil Filters (F-105/106) Each Pump has the following characteristics: Rated flow: Differential head: Design pressure: Design liquid temperature range: Driver:

15.3.7.3

1.2 m3/hr 3 barg (limited by PCV-520) Max 8.0 bar (Limited by PSV 520 & 521 SPt) -46°C to 150°C 1.1 kW

Lube Oil Filters The Lube Oil Filters 266-F-105A/B/S and 266-F-106A/B/S are horizontal stainless steel filters designed for a maximum upstream pressure of 8 barg, which is limited by the set point of PSV-520/620/720 and PSV-521/621/721. The filters contain 10 microns mesh cartridges. One filter is in service and the other is standby. The filters have manual transfer valves for switching flow between duty and standby operations. Local differential pressure indicator PDI-520/620/720 monitors pressure drop across the filter and activates high differential pressure alarm PDAH-520/620/720.

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-12

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

15.3.7.4

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

GASCO PROJECT NO. 5228 Agreement No 13522801

Rev. 4

Lube Oil Cooler Filtered lube oil flows to Lube Oil Cooler 266-E-104A/B/S, a stainless steel shell and tube exchanger. The stainless steel shell is designed for a maximum upstream pressure of 8 barg, which is limited by the set point of PSV-520/520/720 and PSV-521/621/721. The stainless steel tube design condition is compatible with the 22 barg at 150°C max & -46°C min rating of the Chilled Water Cooler tubes. The Lube Oil Cooler tubes are also designed for full vacuum. Lube oil flows through the shell and is cooled by chilled water in the tubes. The Lube oil outlet temperature is controlled by temperature control valves, TCV-520/620/720, which regulate the chilled water flow through the Cooler. The Cooler is equipped with tube side pressure relief valves, PRV-522/622/722, that relieve locally. There are also local oil outlet temperature gauges, TG-520/620/720. Filtered and cooled lube oil flows to the compressor motor bearings and returns by gravity drain to the Oil Reservoir.

15.3.8

Lube Oil Separator Lube Oil Separators, 266-V-102A/B/S, are horizontal carbon steel, insulated vessels measuring 1500 mm ID by 3550 mm T/T. The design pressure is 28 barg at 150°C max and -46°C min and the vessels are also rated for full vacuum. Vapour from the Propane Compressor discharge enters the first chamber of the Lube Oil Separator where the residual lube oil is separated from the propane vapour by flow inversion and gravity. The separated lube oil falls to the bottom of the Separator where it flows to the Lube Oil Pump Suction. The oil is pumped, cooled and filtered by the Compressor lube oil system before return to the Compressor. Reference: Section 15.3.5, "Compressor Lube Oil System" The propane vapour flows from the first chamber of the separator through coalescer cartridges to the second chamber. Coalesced oil separates from the vapour and drops to the bottom of the Separator and flows to the Compressor suction where it mixes with the compressor propane inlet stream. Propane vapour exits the top of the Separator and flows to the Refrigerant Air Cooler, 266-E-102. Vapour temperature is monitored on TI-503A/603A/703A and TI-504B/604B/704B at the local panel. On the DCS, TI-504 activates a high temperature alarm and TI-503 activates a high high temperature alarm.

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-13

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

GASCO PROJECT NO. 5228 Agreement No 13522801

Rev. 4

The Lube Oil Separator has an electric heater to maintain the lube oil temperature within the first chamber. Lube oil temperature is monitored on local panel indicator TI-507A/607A/707A and DCS indicator TI-507/607/707, which activates low low, low, and high high temperature alarms. The separator level is monitored on local level gauge LG-500/600/700, level indicator LI-500A/600A/700A at the local panel and LI-500/600/700 on the DCS, which activates high and low level alarms. Pressure is indicated at local pressure gauges PG-500/600/700. The Lube Oil Separator is equipped with a vent valve to atmosphere, drains from both chambers to the oil drain header and a nitrogen supply. The Separator is protected against overpressure by pressure safety valves PSV-500/600/700, which relieve to the Low Temperature Flare. The Separator discharges propane vapour to the Refrigerant Air Cooler. 15.3.9

Refrigerant Air Cooler The Refrigerant Air Cooler (Propane Condenser), 266-E-102, is a horizontal, induced draft, air cooler with a design duty of 14.065 MMkcal/hr (16375 kW) and 6 x 6.35 m x 13.1 m bays with 12 x constant speed 37 kW motor/belt driven fans (two per bay). The Condenser delivers a liquid propane outlet temperature of 63°C at an inlet propane gas temperature of 86°C and an ambient air temperature of 50°C. Propane vapour from the Lube Oil Separator enters the tube bundle where it is cooled by ambient air passing over the exterior of the tubes. Condenser inlet pressure is controlled by starting and stopping fans to maintain the condenser inlet pressure high enough to circulate liquid propane to the Refrigerant Receiver/Economizer 266-V-104, but as low as possible to limit the Propane Compressor electrical load. Interlock I-805 regulates the inlet pressure on input from PT-805, located on the inlet manifold. There is an inlet pressure gauge, PG-805, to locally monitor the propane pressure. The design pressure is 28 barg at 150°C max and -46°C min. The unit is also designed for full vacuum conditions. The Condenser includes vibration switches on each fan. Condensed propane refrigerant from the Condenser flows to the Refrigerant Receiver/Economizer 266-V-104.

15.3.10

Refrigerant Receiver/Economizer The Refrigerant Receiver/Economizer, 266-V-104, is a horizontal, carbon steel, insulated vessel measuring 1900 mm ID by 7000 mm T/T. The design pressure is 28 barg at 150°C max and -46°C min. The vessel is also rated for a full vacuum condition. The vessel provides a buffer volume for the propane refrigerant and can store the full system liquid propane volume.

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-14

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

GASCO PROJECT NO. 5228 Agreement No 13522801

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

Rev. 4

Liquid propane from the Refrigerant Air Cooler enters the bottom of the Refrigerant Receiver/Economizer vessel under level control using LIC-805 to regulate LV-805 in the feed line. Sub cooled liquid Propane exits the bottom of the vessel and flows to the Chilled Water Cooler (Propane Evaporator) 266-E-101 also under level control. LIC-803 is used to regulate LV-803 in the inlet line to 266-E-101. Propane vapour exits the top of the Refrigerant Receiver/Economizer and flows to the Propane Compressor economizer port. The propane vapour outflow from the Receiver/Economizer is controlled using pressure controller PIC-801 to modulate PV-801. The Receiver/Economizer is protected against overpressure by two pressure safety valves, PSV-801A/S, which relieve to the Low Temperature Flare. Other equipment includes a local level gauge, LG-805, a local pressure gauge PG-800, an atmospheric vent valve, two drain valves and 2 x 24-inch manways. 15.4

OVERPRESSURE PROTECTION DEVICES The chilled water system uses process pressure safety valves (PSV), which discharge to either the low temperature hydrocarbon flare collection (FLC) header or atmosphere. Some PSVs are spared and all have inlet and outlet isolation valves. Discharge isolation valves for all PSVs are locked Open. The duty inlet isolation valves for PSVs are also locked Open position and the inlet valves for spared PSVs out of service are maintained in a locked Close position. A spared PSV has provisions for manual bypass/system blowdown to the FLC header. Overpressure protection devices for Unit 266 process systems and their respective set points, are presented in table 15.4-1. Table 15.4-1: Overpressure Protection Devices, Process Systems Tag No.

Set Pressure (barg)

Location

Discharge To

PSV-105A/S

4.0

266-V-101 Vessel shell (nitrogen blanket)

Atmos

PSV-500/601/704

28.0

266-ME-101-V-102A/B/S Shell

FLC

PSV-502/603/705

28.0

266-ME-101-E-103A/B/S Exchanger tube side

FLC

PSV-801A/S

28.0

266-ME-101-V-104 Shell

FLC

PSV-803A/S

28.0

266-ME-101-E-101 Exchanger shell side

FLC

PSVs for the Propane Compressor and Motor Lube Oil Systems are listed in Table 15.4-2. These PSVs are not spared and do not have inlet and outlet isolation valves. The PSVs discharge back to the source vessel(s) or atmosphere.

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-15

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

GASCO PROJECT NO. 5228 Agreement No 13522801

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

Rev. 4

Table 15.4-2: Overpressure Protection Devices, Auxiliary Systems

PSV-506/606/706

Set Pressure (barg) 26.5

266-ME-101-P-101A/B/S Pump casing

V-102 A/B/S

PSV-507/607/707

26.5

266-ME-101-P-101SA/SB/SS Pump casing

V-102 A/B/S

PRV-502/603/705

26.5

266-ME-101-E-103A/B/S Exchanger shell

V-102 A/B/S

PSV-520/620/720S

8.0

266-ME-101-P-102A/B/S Pump discharge

TK-101A/B/S

PSV-521/621/721

8.0

266-ME-101-P-102SA/SB/SS Pump discharge

TK-101A/B/S

PRV-522/622/722

6.0

266-ME-101-E-104 Exchanger Tube side

Atmos

Tag No.

15.5

Location

Discharge To

UNIT CONDITIONING The activities listed in this section are provided as guidelines. These guidelines are intended for use by the start up team when developing detailed startup procedures. Verify the Unit condition before startup. Confirm construction, mechanical completion, and pre-commissioning activities are complete and signed off. All pre-commissioning activities shall be completed before the Unit is ready for operation. These include, but are not limited to, verifying the following requirements:    

 

    

All safety systems and equipment are in place and fully operable. Required catalysts & chemicals are available. Refer to AGD-II Catalysts & Chemicals Summary, Document Number 999-ZA-E-3422 Temporary filters, construction and commissioning blinds are removed. Pipe work and vessels have undergone pressure testing, cleaning, flushing, draining and drying, as appropriate. This is specifically applicable to Lube Oil systems. Systems containing hydrocarbons are purged of oxygen, All sensing elements which were removed from pipe work prior to hydrotesting have been reinstated. Flow orifices are installed correctly. Actuated valves are installed and correctly tagged, lubricated, and stroked to confirm proper operation. Bypasses are appropriately aligned and locked open/closed, as necessary. Spectacle blinds are positioned for operations. The system has undergone a leak test. Pipe work and equipment may be left at a slightly positive pressure of nitrogen, if appropriate to the nature of the material contained. Test equipment and special tools, if any, and facilities for their operation are available. All functional test procedures are complete. Electrical power systems have been checked out and commissioned and Power is available to all electric drivers, control systems, and panels. Equipment grounding is secure.

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-16

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

 

  

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

GASCO PROJECT NO. 5228 Agreement No 13522801

Rev. 4

All utilities have been commissioned, lined up and are ready for use at the unit battery limit, unless otherwise stated in this document. Motor directions are checked if they have been worked on. All rotating equipment and associated drivers are aligned, run in and lubricated, as required, in accordance with manufacturers' recommended procedures. All instruments have been calibrated, loop checked, and commissioned. Control and shutdown loops are functional and tested All the DCS data links are operational. Initial liquid fills are completed.  Demineralised water (available from the Demineralised Water Storage Tanks, 261-TK-103/104)  Propane (available from Propane Storage Drum, 264-V-102)  Lube oils for compressor and motor  Initial quantities of corrosion inhibitor and biocide chemicals are available.



All Vendor equipment is commissioned and operators are fully acquainted with its use.

  

The plant is punch listed and all critical punch list items have been completed. If an ASAB-2 utility is not available, verify that ASAB-1 crossover is set up More specific safety considerations include, but are not limited to, verifying the following are in place:  Firefighting System and all firefighting equipment and facilities.  Emergency Shutdown System.  Emergency Depressuring Systems.  Fire and Gas Detection System and associated UPS systems.  Unit H2S monitoring systems shall be operation.  Breathing air equipment, if required for use.  Evacuation & Emergency Response procedures in place & team members briefed.  Area audible and visual alarms are in service.  Communications for external interfaces and services must be established.  All pressure safety valves must be in test and correctly lined up. All temporary blinds must have been removed.  All other pressure relief devices, such as rupture discs, must be correctly installed.  All personnel must be fully briefed on the startup procedure and their responsibilities at this time.

Any active alarms associated with any of the above systems must be investigated and rectified prior to startup.

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-17

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

15.6

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

GASCO PROJECT NO. 5228 Agreement No 13522801

Rev. 4

OPERATING VARIABLES AND CONTROLS Chilled water is cooled by a propane refrigeration system. The refrigeration system has three 50% propane compressors (two in service, one standby) with their associated propane/lube oil separators and lube oil systems. The two compressors selected to be in service work in sequence. The process heat load requirements (chilled water temperature) load the first compressor to full capacity and then start and load the second compressor to meet the required heat load. The compressors are also unloaded in sequence. The second compressor is fully unloaded and shutdown before the first compressor starts to unload. The compressors discharge to a single propane condenser, refrigerant receiver/economizer, and evaporator. The chilled water outlet temperature is controlled at 13°C by the evaporator pressure (compressor suction pressure). The heat duty required to condense the propane vapour is controlled by the condenser pressure. The condenser pressure and ambient temperature determine the number of fans that are in service.

15.6.1

Propane Compressor Suction Pressure Control The compressor suction pressure regulates the chilled water operating temperature so any changes to chilled water flow rates/duties will require a corresponding adjustment to the compressor suction pressure to maintain the chilled water temperature at the specified 13°C. The compressor suction pressure is modulated using two loops:  

The first loop comprises the chilled water supply temperature (TIC-811), PIC-808A and the compressor slide valve, which are included in the control loop for normal operation. In the second loop, the chilled water cooler pressure (PIC-808B) and the hot gas bypass (PV-800) provide a control loop for low capacity operation.

These controls are further detailed in “Industrie Technofrigo Dell’Orto S.p.A Operating & Maintenance Manual, Section E-04, Operation/Control Philosophy, Subsection 2, Propane Compressor Suction Pressure, and Subsection 19.4, Capacity control” Reducing the compressor suction pressure (evaporator pressure) reduces the temperature of the boiling propane and lowers the evaporator chilled water outlet temperature. 15.6.2

Refrigerant Cooler Pressure Control The inlet propane pressure to the Refrigerant Cooler (Condenser, 266-E-101) is controlled by the number of condenser fans in service. The DCS uses PT-805 to control the running fans, which regulates the propane temperature and the resultant condenser inlet pressure. PT-805 is set at 16.1 barg, which corresponds to a 50°C propane condensation temperature.

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-18

GASCO PROJECT NO. 5228

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

Agreement No 13522801

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

Rev. 4

For further information refer to the Industrie Technofrigo Dell’Orto S.p.A Operating & Maintenance Manual, Section E-04, Operation/Control Philosophy, Subsection 5.4, Refrigerant Air Cooler pressure regulation. 15.6.3

Chilled Water Alarms and Shutdowns The alarm and shutdown functions for the Chilled Water Unit are listed in the table below. Refer to Unit 266 Cause and Effect Diagrams for an explanation of the trip functions. Table 15.6.3-1: Chilled Water Alarms and Shutdowns Note: 500 series tags are for Train A, 600 for Train B, 700 for Train S, and 800 are common to all Trains. Tag No.

Description

Function

Setpoint

AAH-830

Water in oil return to compressor suction high volume alarm

Activates alarm on increasing % water in oil

0.5% H2O

FAL-105 FAL-106

Chilled Water Pumps discharge low flow alarm

Activates alarm on decreasing flow

350.8 Am3/hr

FAL-115

Low temperature flare header low purge gas flow alarm

Activates alarm on decreasing flow

8 Nm3/hr

FAL-520 FAL-620 FAL-720

Compressor motor drive end bearing low lube oil flow alarm

Activates alarm on decreasing flow

On/Off

FAL-521 FAL-621 FAL-721

Compressor motor non-drive end bearing low lube oil flow alarm

Activates alarm on decreasing flow

On/Off

FALL-830

Chilled water supply low flow shutdown

Initiates I-831 ESD for Unit 266

HA-507 HA-607 HA-707

Chilled Water Compressor Auto/Manual capacity

IAH-585 IAH-685 IAH-785

Chilled Water Compressor motors high amperage alarm

Activates alarm on increasing motor current

178 amps

IAHH-585 IAHH-685 IAHH-785

Chilled Water Compressor motors high-high amperage alarm

Initiates I-585/685/785 closing of solenoids KY-500A/600A/700A and unloads propane compressor on increasing motor current

185 amps

KZA-805

Refrigerant Receiver/Economizer propane outlet sequence valve KV-805 common disagree alarm

Activates alarm when the open and closed limit switches are both open, both closed, or KV-805 is not in trip position within expected travel time

On/Off

KZA-806

Chilled Water Cooler oil boot Ejector J-106 motive fluid supply sequence valve KV-806 common disagree alarm

Activates alarm when the open and closed limit switches are both open, both closed, or KV-806 is not in trip position within expected travel time

On/Off

KZA-807

Chilled Water Cooler oil boot Ejector J-106 oil supply sequence valve KV-807 common disagree alarm

Activates alarm when the open and closed limit switches are both open, both closed, or KV-807 is not in trip position within expected travel time

On/Off

30 Am3/hr On/Off

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-19

GASCO PROJECT NO. 5228

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO) Tag No.

Agreement No 13522801

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

Rev. 4

Description

Function

Setpoint

KZ-808

Chilled Water Cooler oil boot Ejector J-107 motive fluid supply sequence valve KV-808 common disagree alarm

Activates alarm when the open and closed limit switches are both open, both closed, or KV-808 is not in trip position within expected travel time

On/Off

KZ-809

Chilled Water Cooler oil boot Ejector J-107 oil supply sequence valve KV-809 common disagree alarm

Activates alarm when the open and closed limit switches are both open, both closed, or KV-809 is not in trip position within expected travel time

On/Off

LA-106

Chilled Water Return Drum level deviation alarm

Activates alarm when LT-105/ LT-106 deviation occurs

5%

LA-802

Chilled Water Cooler level deviation alarm

Activates alarm when LT-802/ LT-803 deviation occurs

5%

LA-806

Refrigerant Receiver/Economizer level deviation alarm

Activates alarm when LT-805/ LT-806 deviation occurs

5%

LAH-105

Chilled Water Return Drum high water level alarm

Activates alarm on increasing level

87.9% 9994 mm

LAH-500 LAH-600 LAH-700

Lube Oil Separator high oil level alarm

Activates alarm on increasing level

54.5%

LAH-520 LAH-620 LAH-720

Motor oil reservoir high oil level alarm

Activates alarm on increasing level

50%

LAH-803

Chilled Water Cooler high propane level alarm

Activates alarm on increasing level

54.4%

LAH-805

Refrigerant Receiver/Economizer high propane level alarm

Activates alarm on increasing level

38%

LAHH-802

Chilled Water Cooler high propane level shutdown

Initiates I-802 ESD for Unit 266

58.3%

LAHH-806

Refrigerant Receiver/Economizer high propane level shutdown

Initiates I-806 closing ESD valves XV507/607/707 in propane outlet to compressor side stream inlet

42.9%

LAL-105

Chilled Water Return Drum low water level alarm

Activates alarm on decreasing level

8% 1047 mm

LAL-500 LAL-600 LAL-700

Lube Oil Separator low oil level alarm

Activates alarm on decreasing level

22.7%

LAL-520 LAL-620 LAL-720

Compressor motor oil reservoir low oil level alarm

Activates alarm on decreasing level

20%

LAL-805

Refrigerant Receiver/Economizer low propane level alarm

Activates alarm on decreasing level

7.2%

LALL-106

Chilled Water Return Drum low water level shutdown

Initiates I-20 shutdown of Chilled Water Pumps

0% 152 mm

LALL-600

Lube Oil Separator Low Low Level Trip

Diverts lube oil around Lube Oil Cooler

6%

LALL-608

Lube Oil Separator Low Low Level Trip

Diverts lube oil around Lube Oil Cooler

6%

LALL-708

Lube Oil Separator Low Low Level Trip

Diverts lube oil around Lube Oil Cooler

6%

PA-501

Chilled Water Compressor ‘A’ inlet pressure deviation alarm

Activates alarm when PT-500/ PT-501 deviation occurs

5%

PA-506

Chilled Water Compressor ‘A’ discharge pressure deviation alarm

Activates alarm when PT-505/ PT-506 deviation occurs

5%

PA-520

Compressor ‘A’ motor lube oil supply pressure deviation alarm

Activates alarm when PT-520/ PT-521 deviation occurs

5%

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-20

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

GASCO PROJECT NO. 5228 Agreement No 13522801

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

Rev. 4

PA-601

Chilled Water Compressor ‘B’ inlet pressure deviation alarm

Activates alarm when PT-600/ PT-601 deviation occurs

5%

PA-606

Chilled Water Compressor ‘B’ discharge pressure deviation alarm

Activates alarm when PT-605/ PT-606 deviation occurs

5%

PA-620

Compressor ‘B’ motor lube oil supply pressure deviation alarm

Activates alarm when PT-620/ PT-621 deviation occurs

5%

PA-701

Chilled Water Compressor ‘C’ inlet pressure deviation alarm

Activates alarm when PT-700/ PT-701 deviation occurs

5%

PA-706

Chilled Water Compressor ‘C’ discharge pressure deviation alarm

Activates alarm when PT-705/ PT-706 deviation occurs

5%

PA-720

Compressor ‘C’ motor lube oil supply pressure deviation alarm

Activates alarm when PT-720/ PT-721 deviation occurs

5%

PAH-105B

Chilled Water Return Drum nitrogen blanket high pressure alarm

Activates alarm on increasing pressure

2.2 barg

PAH-500 PAH-600 PAH-700

Chilled Water Compressors high inlet pressure alarm

Activates alarm on increasing pressure

9 barg

PAH-505 PAH-605 PAH-705

Chilled Water Compressor high discharge pressure alarm

Activates alarm on increasing pressure

24 barg

PAH-801

Refrigerant Receiver/Economizer high pressure alarm

Activates alarm on increasing pressure

24 barg

PAH-805

Refrigerant Air-cooler high pressure alarm

Activates alarm on increasing pressure. I-805 initiates starting fans.

16.1 barg

PAH-808A

Chilled Water Cooler propane outlet HP alarm. Set alarm at pressure of upstream receiver.

Activates alarm on increasing pressure

14 barg

PAHH-505 PAHH-605 PAHH-705

Chilled Water Compressor high discharge pressure unload

Initiates I-558 unloading Chilled Water Compressor

24.5 barg

PAHH-506 PAHH-606 PAHH-706

Chilled Water Compressor high pressure shutdown

Initiates I-506/606/706 shutdown of Chilled Water Compressor

25 barg

PAL-105A

Chilled Water Return Drum nitrogen blanket low pressure alarm

Activates alarm on decreasing pressure

1.8 barg

PAL-108

Chilled water supply to Chilled Water Cooler low pressure alarm

Activates alarm on decreasing pressure

5.13 barg

PAL-500 PAL-600 PAL-700

Chilled Water Compressors low inlet pressure alarm

Activates alarm on decreasing pressure

3.7 barg

PAL-521 PAL-621 PAL-721

Compressor motor bearings low lube oil pressure alarm

Activates alarm on decreasing pressure and I-581/681/781 start standby lube oil pump

2.5 barg

PAL-801

Refrigerant Receiver/Economizer low pressure alarm

Activates alarm on decreasing pressure

9 barg

PAL-805

Refrigerant Air-cooler low pressure alarm

Activates alarm on decreasing pressure. I-805 initiates stopping fans.

15.6 barg

PAL-808A

Chilled Water Cooler propane outlet LP alarm. Set ca 20% below normal Op Press (4.8 barg)

Activates alarm on decreasing pressure

4 barg

PALL-108

Chilled water supply to Chilled Water Cooler low pressure shutdown

Initiates I-21starting standby Chilled Water Pump and then stopping running Chilled Water Pump

5 barg

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-21

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

GASCO PROJECT NO. 5228 Agreement No 13522801

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

Rev. 4

PALL-501 PALL-601 PALL-701

Chilled Water Compressors low inlet pressure shutdown

Initiates I-501/601/701 shutdown of Chilled Water Compressor

3.2 barg

PALL-520 PALL-620 PALL-720

Compressor motor bearings low lube oil pressure alarm

Initiates I-520/620/720 shutdown of Chilled Water Compressor

2 barg

PDA-502

Chilled Water Compressor ‘A’ lube oil pump differential pressure deviation alarm

Activates alarm when PDT-502/ PDT503 deviation occurs

5%

PDA-602

Chilled Water Compressor ‘B’ lube oil pump differential pressure deviation alarm

Activates alarm when PDT-602/ PDT603 deviation occurs

5%

PDA-702

Chilled Water Compressor ‘S’ lube oil pump differential pressure deviation alarm

Activates alarm when PDT-702/ PDT703 deviation occurs

5%`

PDAH-115 PDAH-116

Chilled Water Pumps suction strainer high differential pressure alarm

Activates alarm on increasing differential pressure

0.02 bar

PDAH-504 PDAH-604 PDAH-704

Chilled Water Compressor lube oil filter high differential pressure alarm

Activates alarm on increasing differential pressure

0.8 barg

PDAH-520 PDAH-620 PDAH-720

Chilled Water Compressor Motor lube oil filter high differential pressure alarm

Activates alarm on increasing differential pressure

TBD

PDAH-521 PDAH-621 PDAH-721

Chilled Water Compressor Motor lube oil filter high differential pressure alarm (local)

Activates alarm on increasing differential pressure

TBD

PDAL-503 PDAL-603 PDAL-703

Chilled Water Compressor lube oil pump low differential pressure alarm

Activates alarm on decreasing differential pressure and initiates I-560 start of the standby lube oil pump

1.5 bar

PDALL-502 PDALL-602 PDALL-702

Chilled Water Compressor lube oil pump low differential pressure shutdown

Initiates I-530/630/730 Chilled Water Compressor shutdown

1 barg

TA-503

Chilled Water Compressor ‘A’ discharge temperature deviation alarm

Activates alarm when TT-503/ TT-504 deviation occurs

5%

TA-603

Chilled Water Compressor ‘B’ discharge temperature deviation alarm

Activates alarm when TT-603/ TT-604 deviation occurs

5%

TA-703

Chilled Water Compressor ‘C’ discharge temperature deviation alarm

Activates alarm when TT-703/ TT-704 deviation occurs

5%

TA-516

Chilled Water Compressor ‘A’ lube oil supply temperature deviation alarm

Activates alarm when TT-510/ TT-516 deviation occurs

5%

TA-616

Chilled Water Compressor ‘B’ lube oil supply temperature deviation alarm

Activates alarm when TT-610/ TT-616 deviation occurs

5%

TA-716

Chilled Water Compressor ‘C’ lube oil supply temperature deviation alarm

Activates alarm when TT-710/ TT-716 deviation occurs

5%

TA-830

Chilled water supply temperature deviation alarm

Activates alarm when TT-811/ TT-830 deviation occurs

5%

TAH-500A/B TAH-600A/B TAH-700A/B

Compressor motor winding R high temperature alarm

Activates alarm on increasing winding temperature

TAH-501A/B TAH-601A/B TAH-701A/B

Compressor motor winding S high temperature alarm

Activates alarm on increasing winding temperature

TAH-502A/B TAH-602A/B TAH-702A/B

Compressor motor winding T high temperature alarm

Activates alarm on increasing winding temperature

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-22

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

GASCO PROJECT NO. 5228 Agreement No 13522801

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

Rev. 4

TAH-504 TAH-604 TAH-704

Chilled Water Compressor high discharge temperature alarm

Activates alarm on increasing temperature

110C

TAH-508 TAH-608 TAH-708

Lube oil separator heater element over temperature alarm

Activates alarm on increasing temperature and initiates shutdown of separator lube heater

On/Off

TAH-509 TAH-609 TAH-709

Compressor motor non-drive end bearing high temperature alarm

Activates alarm on increasing temperature

85C

TAH-510 TAH-610 TAH-710

Chilled Water Compressor lube oil supply high temperature alarm

Activates alarm on increasing temperature

75°C

TAH-512 TAH-612 TAH-712

Compressor motor drive end bearing high temperature alarm

Activates alarm on increasing temperature

85°C

TAH-522 TAH-622 TAH-722

Compressor motor oil reservoir heater element over temperature alarm

Activates alarm on increasing temperature and initiates I-523/623/723 shutdown of heater

TAH-811

Chilled water supply high temperature alarm

Activates alarm on increasing temperature

TAHH-500A/B TAHH-600A/B TAHH-700A/B

Compressor motor winding R high temperature shutdown

Initiates MUILTILIN shutdown of compressor motor

On/Off

TAHH-501A/B TAHH-601A/B TAHH-701A/B

Compressor motor winding S high temperature shutdown

Initiates MUILTILIN shutdown of compressor motor

On/Off

TAHH-502A/B TAHH-602A/B TAHH-702A/B

Compressor motor winding T high temperature shutdown

Initiates MUILTILIN shutdown of compressor motor

On/Off

TAHH-503 TAHH-603 TAHH-703

Chilled Water Compressor high discharge temperature shutdown

Initiates I-503 Chilled Water compressor shutdown

115°C

TAHH-507 TAHH-607 TAHH-707

Lube Oil Separator high oil temperature shutdown

Initiates I-557-657-757 shutdown of separator lube heater

55°C

TAHH-509 TAHH-609 TAHH-709

Compressor motor non-drive end common bearing high temperature shutdown

Initiates I-521/621/721 shutdown of compressor motor

On / Off

TAHH-509A TAHH-609A TAHH-709A

Compressor motor non-drive end bearing high temperature shutdown

Initiates I-521/621/721 shutdown of compressor motor

90°C

TAHH-512 TAHH-612 TAHH-712

Compressor motor drive end common bearing high temperature shutdown

Initiates I-522/622/722 shutdown of compressor motor

On/Off

TAHH-512A TAHH-612A TAHH-712A

Compressor motor drive end bearing high temperature shutdown

Initiates I-522/622/722 shutdown of compressor motor

90°C

TAHH-516 TAHH-616 TAHH-716

Chilled Water Compressor lube oil supply high temperature shutdown

Initiates I-516 shutdown of compressor

85 °C

On/Off

20°C

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-23

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

GASCO PROJECT NO. 5228 Agreement No 13522801

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

Rev. 4

TAHH-521 TAHH-621 TAHH-721

Compressor motor lube oil reservoir high temperature shutdown

Initiates I-523 shutdown of reservoir heater

45°C

TAL-507 TAL-607 TAL-707

Lube Oil Separator low oil temperature alarm

Activates alarm on decreasing temperature - Initiates I-510 and inhibits compressor start

20C

TAL-510 TAL-610 TAL-710

Chilled Water Compressor lube oil supply low temperature alarm

Activates alarm on decreasing temperature

20C

TAL-521 TAL-621 TAL-721

Compressor motor lube oil reservoir low temperature alarm

Activates alarm on decreasing temperature

20°C

TAL-811

Chilled water supply low temperature alarm

Activates alarm on decreasing temperature

8°C

TALL-507 TALL-607 TALL-707

Lube Oil Separator low oil temperature alarm

Activates alarm - Initiates I-557/657/757 start of separator lube heater

20C

TALL-521 TALL-621 TALL-721

Compressor motor lube oil reservoir low-low temperature alarm

Activates alarm - Initiates start of reservoir lube heater

30C

TALL-830

Chilled water supply low temperature shutdown

Initiates I-830 ESD for Unit 266

TDAL-515 TDAL-615 TDAL-715

Chilled Water Cooler propane inlet/outlet low differential temperature alarm

Activates alarm on decreasing differential temperature

VAH-500X VAH-600X VAH-700X

Chilled Water Compressor non-drive end X axis high vibration alarm

Activates alarm on increasing vibration

24 mm/s

VAH-500Y VAH-600Y VAH-700Y

Chilled Water Compressor non-drive end Y axis high vibration alarm

Activates alarm on increasing vibration

24 mm/s

VAH-501X VAH-601X VAH-701X

Compressor motor non-drive end X-axis high vibration alarm

Activates alarm on increasing vibration

128 μm

VAH-501Y VAH-601Y VAH-701Y

Compressor motor non-drive end Y-axis high vibration alarm

Activates alarm on increasing vibration

128 μm

VAH-502X VAH-602X VAH-702X

Compressor motor drive end X-axis high vibration alarm

Activates alarm on increasing vibration

128 μm

VAH-502Y VAH-602Y VAH-702Y

Compressor motor drive end Y-axis high vibration alarm

Activates alarm on increasing vibration

128 μm

VAH-805 VAH-806 VAH-807 VAH-808 VAH-809 VAH-810 VAH-811 VAH-812 VAH-813 VAH-814 VAH-815 VAH-816

Refrigerant cooler fan motor high vibration alarm

Activates alarm on increasing vibration and trips the corresponding fan motor

On/Off

3°C 0.3°C

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-24

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

15.7

GASCO PROJECT NO. 5228 Agreement No 13522801

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

Rev. 4

VAHH-500 VAHH-600 VAHH-700

Chilled Water Compressor non-drive end axial XY common high vibration trip

Initiates I-502/602/702 to shut down compressor

On/Off

VAHH-500X VAHH-600X VAHH-700X

Chilled Water Compressor non-drive end X axis high vibration shutdown

Initiates I-502/602/702 to shut down compressor

35 mm/s

VAHH-500Y VAHH-600Y VAHH-700Y

Chilled Water Compressor non-drive end Y axis high vibration shutdown

Initiates I-502/602/702 to shut down compressor

35 mm/s

VAHH-501 VAHH-601 VAHH-701

Compressor motor non-drive end axial X and Y common high vibration trip

Initiates I-513/613/713 to shut down compressor

On/Off

VAHH-501X VAHH-601X VAHH-701X

Compressor motor non-drive end X axis high vibration shutdown

Initiates I-513/613/713 to shut down compressor

186 mm/s

VAHH-501Y VAHH-601Y VAHH-701Y

Compressor motor non-drive end Y axis high vibration shutdown

Initiates I-513/613/713 to shut down compressor

186 mm/s

VAHH-502 VAHH-602 VAHH-702

Compressor motor drive end axial X and Y common high vibration trip

Initiates I-512/612/712 to shut down compressor

On/Off

VAHH-502X VAHH-602X VAHH-702X

Compressor motor drive end X axis high vibration shutdown

Initiates I-512/612/712 to shut down compressor

186 mm/s

VAHH-502Y VAHH-602Y VAHH-702Y

Compressor motor drive end Y axis high vibration shutdown

Initiates I-512/612/712 to shut down compressor

186 mm/s

XA-502 XA-602 XA-702

Chilled Water Compressor general alarm

Panel Fault Condition – likely to indicate maintenance requirement.

On/Off

XA-503 XA-603 XA-703

Chilled Water Compressor general alarm

Panel Fault Condition – likely to indicate maintenance requirement.

On/Off

XAL-504 XAL-604 XAL-704

Chilled Water Compressor Emergency Stop alarm

Activates alarm indicating emergency stop button triggered

On/Off

XL-105A

Chilled Water Pump P-101A not running status

Initiates I-26 to start Chilled Water Pump P-101S

On/Off

XL-106A

Chilled Water Pump P-101S not running status

Initiates I-26 to start Chilled Water Pump P-101A

On/Off

XA-107

Chilled Water Pump P-101A/S run status

Indicates both pumps are not running and initiates I-25 to shut down Chilled Water Compressor (30 second time delay)

On/Off

XHS-517 XHS-617 XHS-717

Emergency push button (LP)

Initiates I-517/617/717 to shut down Chilled Water Compressor

ZAL-500 ZAL-600 ZAL-700

Chilled Water Compressor slide valve minimum position alarm

Activates alarm when slide valve not working and prevents compressor from starting

---

SAFETY PRECAUTIONS

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-25

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

GASCO PROJECT NO. 5228 Agreement No 13522801

Rev. 4

This chapter contains information on safety systems installed on Unit 266 for protection from plant fires & gas leaks. All hydrocarbons & chemicals can be dangerous if not properly handled so operators should be aware of the hazardous properties of materials in use and trained in the correct procedures for handling these materials. The hazardous nature of hydrocarbons handled in Unit 266 makes it mandatory to carry out regular inspections of all equipment items, piping and valves. Leaks must be reported immediately and remedial actions initiated as soon as possible. All hydrocarbons involve a fire and explosion hazard, the most hazardous petroleum products are those having a flash point below 55°C. Special attention shall be given to operations where there is a risk of contact with these substances, which includes when vessels are drained or during sampling operations. Operators shall wear proper personal protective equipment (PPE) appropriate to any task undertaken and be properly trained in the use and application of this PPE. Examples of PPE include safety glasses and gloves when working around sumps and lift stations. Operators shall familiarize themselves with the location and use of fire fighting and safety equipment and be thoroughly familiar with basic first aid measures and capable of taking appropriate action in the event of an incident. Periodic practice drills, and more specifically fire fighting drills should be carried out to instruct operators in the specific hazards involved and the proper emergency actions to ensure maximum protection for personnel and equipment. Operating personnel shall not endanger themselves while attempting to deal with a fire. Small scale fires may be tackled with hand held extinguishers or steam lances, but major fires should be dealt with from a distance using deluge systems, firewater monitors and fire hoses. The Safety Officer is responsible for periodic checks of fire fighting and safety equipment to ensure they are in full working order. Safety items noted as faulty, non-functional or missing should be immediately reported to the Safety Officer. Entry to a process drum requires a Confined Space Entry Permit. As a minimum the drum must be isolated, purged of gas, and the air quality within the drum confirmed acceptable before entry. Failure to confirm acceptable air quality and monitoring of air quality during the entry could result in serious injury or death. ▲ CAUTION: Company policies and procedures for confined space entry must be followed. Exercise caution when checking pumps that could start automatically at anytime. When preparing pumps for maintenance, exercise caution and maintain proper body position to avoid breathing vapor from pump vents or drains. Avoid contact with liquids present in pumps. Extremely cold temperatures can be present in the propane refrigeration system. Exercise caution when near uninsulated piping and equipment to avoid frostbite and thermal burns to exposed skin. Personal protective equipment (safety glasses, coveralls, and insulated gloves) should be worn.

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-26

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

GASCO PROJECT NO. 5228 Agreement No 13522801

Rev. 4

Nitrogen is a colourless and odourless gas that displaces oxygen in a confined space. Personnel should exercise caution when working near the Chilled Water Return Drum or other locations where nitrogen is vented or discharged. Corrosion inhibitors and biocides are used for the Chilled Water Return Drum. Personnel should avoid breathing vapours and exposing bare skin to chemicals. Use PPE when dispensing chemicals in a confined space. Propane gas is flammable and explosive. Never expose the propane refrigeration system to open flame or sparking devices. Propane is also heavier than air (1.5 times as dense) and therefore sinks and pools at low level. The propane refrigeration system and equipment are protected from overpressure by pressure safety valves (PSVs). Refer to Tables 15.4-1 and 15.4-2 for a list of PSVs. ▲ CAUTION: When draining vessels containing liquid propane always depressurise the vessel to the low temperature flare before draining. Do not drain liquid propane to the open drain header. 15.8

PRE-STARTUP CHECKS Before placing the Unit in service for the first time or after shutdown for maintenance, confirm the Unit is ready for startup. Refer to Section 15.5, "Unit Conditioning." 

     15.9

Verify minimum utilities (fire water, instrument air and electric control power) are available and commissioned to all necessary users. Nitrogen must also be available if containment has been broken and a purge is required. Ensure that treatment chemicals are available and ready to be dosed. Confirm that all safety equipment is in place and is fully operable. If startup follows maintenance, confirm repairs have been completed and Unit has been pressure tested, purged as required and is ready for startup. Confirm vent and drain valves are in their normal operating positions. Verify Lock Open/Lock Close and process manual valves are in their proper positions and locked. Confirm transmitters and controllers are ready for service. Confirm the Chilled Water Return Drum is charged with nitrogen. Confirm Lube Oil Reservoir Heater is energized and check oil temperature

INITIAL STARTUP When starting the Unit for the first time, additional preparations are required to ensure construction and commissioning activities are completed, and the Unit is ready for introduction of propane and demineralised water. Refer to Section 15.5, "Unit Conditioning." The following should be completed for the initial startup:

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-27

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

 



  



  

   15.10

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

GASCO PROJECT NO. 5228 Agreement No 13522801

Rev. 4

Confirm pre-start checks are completed. Refer to Section 15.8, "Pre-Startup Checks." Line up instrument air supply from ASAB-1. Note: Chilled water is required for cooling ASAB-2 Air Compressors before they can be started. Close the chilled water outlet valve to the supply header and open the chilled water bypass valve to the return header. Note: In the event that a user is to be isolated from the chilled water circuit it is important that the isolation valve on the users supply is closed first followed by the isolation valve on the users return line. When re-instated the isolation valve on the users chilled water return line should be opened before the isolation on the supply line. Ensure that the flow orifices upstream of users are installed before the chilled water is circulated as these prevent the Chilled Water Pump from overpressuring the users. Confirm that the Chilled Water temperature is no greater than 46oC. Start a Chilled Water Pump and circulate chilled water. Note: Chilled water circulates through the propane Compressor Motor Lube Oil Cooler and the Chilled Water Cooler. Until the propane compressors are started, the chilled water does not start to cool in the Chilled Water Cooler. Start the Refrigeration Package. For additional information refer to Industrie Technofrigo Dell’Orto S.p.A Operating & Maintenance Manual, Section A-08, Start-Up, Section E-04, Control Philosophy, and Section 19, Unit Start/Stop Operation. During initial start up phase the globe valve at the chilled water outlet of the lube oil coolers will be wide open. After one compressor is started up, the chilled water flow to the lube oil cooler must be throttled to have the lube oil bypass valve TV-501 in a controllable range. After normal operating conditions of chilled water system is established, the chilled water flow must be again adjusted by the outlet globe valve to have oil bypass valve TV510/610/710 in a controllable range. The globe valve will remain in that position till the chilled water system is shutdown. Continue circulating chilled water until the Chilled Water Cooler temperature reaches 13°C. Open the chilled water outlet valve to the supply header and close the chilled water bypass valve to the return header and lock the valves. Chilled water is now available to users. Start ASAB-2 Air Compressors and stop the air supply from ASAB-1.

NORMAL STARTUP Normal startup occurs after the Unit has been in service and is shut down. The Unit internals have not been exposed to the atmosphere for inspection or maintenance and the systems have not been depressurised or drained.

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-28

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

GASCO PROJECT NO. 5228 Agreement No 13522801

Rev. 4

If the Unit is depressurised or drained, fill the Unit using make-up propane and demineralised water. Initiate startup from the DCS or local control panel when authorisation is available. The Startup sequence is the same as the Initial Startup as described in Section 15.9. In addition to this before the compressor is started some lube oil should be drained from the low point on the Lube Oil Cooler, 266-ME-101-E-103A/B/C, and checked to ensure no water is present. 15.11

NORMAL OPERATION During normal operations, the chilled water flow is maintained through the standby equipment to facilitate auto-start. The additional flow to standby equipment does not require additional thermal load once thermal equilibrium is attained. The following list indicates the chilled water users:  Air Compressor Packages 267-C-101A/B/S  Steam Condensate Cooler 261-E-101  Acid Gas Compressor Steam Turbine 153-CT-101A/B  Lean Solvent Circulating Pump Seals 130/230-P-101A/S  Refrigeration Compressor Motor VSD Chiller Package 141/241-CM-201  Acid Gas Compressor Motor VSD Chiller Package 153-CM-101S-ME-001  Utility Boiler Sample Coolers 262-FH-251 A/B/C/S  Booster Compressor GT Sample Coolers 262-HRSG-151 A/B  HP Boiler Pump Seal Cooler 262-P-151 A/B/S  Propane Compressor Lube Oil Cooler 266- E-103A/B/S Refer to the Utility Flow Diagram, Refrigeration Package for CW System, 266-GD-B-03517, for the Chilled Water Unit design parameters The approximate chilled water battery limit conditions are provided in the table below: Table 15.11-1: Battery Limit Conditions Supply / Return Chilled Water Supply

1

Chilled Water Return

1

Temperature

Pressure

13C

6.5 barg

23C

2.5 barg

Propane Refrigerant Supply

2

5 – 35C

5 – 12 barg

Propane Refrigerant Return

2

5 – 35C

5 – 12 barg

1

The supply pressure is downstream of the Chilled Water Chiller 266-E-101, and the return pressure is downstream of the chilled water users.

2

Propane refrigerant supply and return conditions are based on the transfer of Propane Refrigerant to/from the Propane Storage Drum 264-V-102.

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-29

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

GASCO PROJECT NO. 5228 Agreement No 13522801

Rev. 4

During normal operation, one of the two Chilled Water Pumps and two of the three Propane Compressors are in service. Operation of the Units is automated and will not require operator intervention unless an abnormal condition is observed or an alarm sounds. Alarms are provided to alert off design operating conditions as described in Section 15.6.3, "Chilled Water Alarms and Shutdowns." Operations require operator surveillance and specific data should be trended to anticipate potential problems before they result in an unplanned shutdown or equipment damage. 15.12

NORMAL SHUTDOWN For normal shutdown of the Chilled Water Unit, the chilled water users are first shutdown followed by shutdown of the duty Chilled Water Pump at which point the users can be isolated from the chilled water circuit. The exception to this is the Propane Compressor Lube Oil Cooler, 266-E-103A/B/S, which must remain in service until the compressor has been shutdown. The chilled water heat load reduces and both propane compressors are automatically unloaded. One compressor is then shut down. Followed by the other and the system is allowed to settle out. At this point the chilled water side of the Lube Oil Cooler, 266-ME-101-E103A/B/C, should be isolated and drained prior to depressurisation of the propane system and therefore the compressor lube oil circuit. This is to ensure that in the event of leakage in the Lube Oil Cooler no water contaminates the lube oil system. Shutdown of the compressors will also sequentially stop the lube oil systems and the motor lube oil systems. This shutdown can be done from the DCS or locally. For additional information refer to the Industrie Technofrigo Dell’Orto S.p.A Operating & Maintenance Manual, Section E-04, Control Philosophy, Subsection 19.6.

15.13

EMERGENCY OPERATING CONDITIONS The ASAB-2 chilled water system is not integrated with the ASAB-1 system due to the large distance between the two systems and the resultant high pressure drop. If ASAB-2 chilled water is not available to users, is the users shut down on high temperature or the users' operation is altered to compensate for the loss of chilled water until the chilled water system is returned to service. Operation with one of the three propane compressors requires shutdown of some users to maintain the design supply temperature, or the system can deliver chilled water to all users at a higher temperature.

15.14

REFERENCES  

Process Design Basis, Unit 266, Chilled Water, 266-ZA-E-3560 Process Description, Unit 266, Chilled Water, 266-ZA-E-3581

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-30

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

           15.15

GASCO PROJECT NO. 5228 Agreement No 13522801

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

Rev. 4

Safeguarding Narrative, Unit 266, Refrigeration Package for Chilled Water System, 266-GA-E-3625 Utility Safeguarding Flow Diagram, Refrigeration Package for CW System, 266-GG-8-03630 Alarm Summary Report, 999-SA-E-51305 Catalysts and Chemicals Summary for AGD-II, 999-ZA-E-3422 Cause and Effect Diagram, 25179-200-V1A-MCCR-00021 Cause and Effect Diagram, Unit 266, Chilled Water System, 266-SA-D-51185 Chilled Water Cooler, 266-ME-101-E-101 Utility Flow Diagram, Refrigeration Package for CW System, 266-GD-B-03517 Heat and Material Balance, Chilled Water & Refrigeration System, 266-ZA-E-3579 Utility Summary, Chilled Water, 999-ZA-E-3423 Operation & Maintenance Manual, Industrie Technofrigo Dell’Orto S.p.A., 262MIOM

ATTACHMENTS 251797-130-M60-0000-F0202

Chilled Water, Utility Water & DMW Distribution (Absorber)

251797-141-M60-0000-F0304

Refrigeration Compressor Auxiliaries-141-C-201

251797-145-M60-0000-F0202

Utility Water Distribution

251797-153-M60-0000-F0202

Chilled Water & Utility Water Distribution

251797-153-M60-0000-F0303

Acid Gas Compressor Auxiliaries – Train S

251797-191-M60-0000-F0202

Utility, Chilled Water Distribution

251797-230-M60-0000-F0202

Chilled Water, Utility Water & DMW Distribution (Absorber)

251797-261-M60-0000-F0106

Steam Condensate Chiller

251797-262-M60-0000-F0206

Utility Water & Chilled Water Distribution

251797-266-M60-0000-F0101

Refrigeration Compressor Package (CHW System)

251797-266-M60-0000-F0102

Chilled Water Return Drum and Pumps

251797-266-M60-0000-F0103

Refrigeration Air-cooler (CHW System)

251797-267-M60-0000-F0201

Chilled Water, Plant Air, Utility Water & LP Steam Distribution

251797-277-M60-0000-F0106

Water System

251797-277-M60-0000-F0111

BFW, Steam & Condensate Systems

251797-291-M60-0000-F0202

Utility, Chilled Water Distribution

25179-200-V1A-MCCR-00013

Industrie Technofrigo Dell’Orto S.p.A Sheet 1 Compressor

25179-200-V1A-MCCR-00014

Industrie Technofrigo Dell’Orto S.p.A Sheet 2 Oil Circuit

25179-200-V1A-MCCR-00015

Industrie Technofrigo Dell’Orto S.p.A Sheet 3 Refrigerant Air-cooler

25179-200-V1A-MCCR-00016

Industrie Technofrigo Dell’Orto S.p.A Sheet 4 Receiver/Economizer and Evaporator

25179-200-V1A-MCCR-00020

Industrie Technofrigo Dell’Orto S.p.A Sheet 5 Motor Lube Oil System

25179-200-V1A-MCCR-00060

Industrie Technofrigo Dell’Orto S.p.A Sheet 5 Motor Lube Oil System

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-31

ASAB-2 OPERATING MANUAL CHAPTER 15 CHILLED WATER UNIT 266 ABU DHABI GAS INDUSTRIES LTD. (GASCO)

GASCO PROJECT NO. 5228 Agreement No 13522801

COMPANY DOC. 999-ZX-E-09060-C15 DOC. NO. 25179-000-GPP-GSX-00011C15

Rev. 4

25179-200-V1A-MCCR-00063

Industrie Technofrigo Dell’Orto S.p.A Sheet 1 Compressor

25179-200-V1A-MCCR-00064

Industrie Technofrigo Dell’Orto S.p.A Sheet 2 Oil Circuit

25179-200-V1A-MCCR-00070

Industrie Technofrigo Dell’Orto S.p.A Sheet 5 Motor Lube Oil System

25179-200-V1A-MCCR-00073

Industrie Technofrigo Dell’Orto S.p.A Sheet 1 Compressor

25179-200-V1A-MCCR-00074

Industrie Technofrigo Dell’Orto S.p.A Sheet 2 Oil Circuit

ELECTRONIC DOCUMENTS ARE CONTROLLED. ANY PRINTED COPY WILL BE UNCONTROLLED AND MAY BECOME OUTDATED Bechtel_Chilled Water Unit 266_R4

15-32