Process Operation And Control Philosophy

OSE571 Ocean Plant Design

Process Operation and Control Philosophy

Daejun CHANG ([email protected]) Division of Ocean System Engineering

Korea Advanced Institute of Science and Technology

Design Procedure and Key deliverables Concept Consolidation Production Availability

Design Basis (Philosophy)

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System Description Process Flow Diagram

Equipment Specification

Process Simulation

Equipment Design

Process Operation and Control Philosophy P&ID Layout Safety Studies

Risk Assessment HAZOP Caution: Not universally applicable -1-

Ocean Systems Engineering

Hazards and Safety Systems Emergency Response (Escape Route, TR, Evacuation Means, Rescue Equipment, Emergency Power) Accident Mitigating Protection (Active/Passive Fire Protection, Fire/Blast Walls)

Accident: Fire/Explosion

Accident Controlling Protection (F&G Detection, ESD, Depressurization, Alarm)

Potential Accident: Gas Leak

Preventive Protection (Structural & Machinery Integrity, Relief, PSV) Basic Process Control (P, T, F, Surge, Back Pressure) Inherent Safety Design (Layout, Inventory, Leak, Ignition)

Layered Structure of Safety Systems against Fire and Explosion -2-

Ocean Systems Engineering

Workflow for Process Control System Description (W4) Process Operation and Control Philosophy (W9) P&ID (W11) Functional Design Specification (W11) Logic Diagram Field Implementation -3-

Ocean Systems Engineering

What is in the process operation and control philosophy Ø The key document for operation and control Ø Operation Philosophy § Big picture of operation § Operation modes defined § Operation philosophy for each mode § Safety instrumentations Ø Control Philosophy § Detailed feature § Unit-by-unit description § Control loops defined

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Ocean Systems Engineering

Operation Philosophy

Ø Big picture of operation § Working principles § Degree of automation § Number of operators required § Control system architecture

Ø Operation modes defined Ø Operation philosophy for each mode Ø Safety instrumentations

-5-

Ocean Systems Engineering

Operation Philosophy Ø Big picture of operation Ø Operation modes defined § Steady - Operational cases: loading, offloading, etc. - Capacity: Max, Normal, Min (turndown) § Dynamic - Start-up - Shutdown - Emergency shutdown Ø Operation philosophy for each mode Ø Safety instrumentations

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Ocean Systems Engineering

Operation Philosophy

Ø Big picture of operation Ø Operation modes defined Ø Operation philosophy for each mode § Governing philosophy only § Details deferred to Control Philosophy

Ø Safety instrumentations

-7-

Ocean Systems Engineering

Operation Philosophy

Ø Big picture of operation Ø Operation modes defined Ø Operation philosophy for each mode Ø Safety instrumentations § What if an unwanted emergency occurs? § Causes and counter measures

-8-

Ocean Systems Engineering

Control Philosophy Ø Detailed feature § Subsystems (units), equipment, components § Control targets and variables § Set points § Control and operation procedure

Ø Unit-by-unit description Ø Control loops defined

-9-

Ocean Systems Engineering

Control Philosophy Ø Detailed feature Ø Unit-by-unit description § Follow the main stream § Describe the situation and circumstance where control is required § Describe how to manipulate the components

Ø Control loops defined

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Ocean Systems Engineering

Control Philosophy Ø Detailed feature Ø Unit-by-unit description Ø Control loops defined § Controlled variables with set point § Manipulated variables § Disturbances § Working mechanism

-11-

Ocean Systems Engineering

Some Questions Ø Why about control of other subsystems like power generation? § Utility: well proven, repeated design à Well established control § Process: specific to the facility à New design à Need to establish the control algorithm Ø Who will take care about the followings tasks including P&ID and logic diagram? § P&ID à process engineers § Logic diagram à electrical engineers § Functional design specification (W11) to bridge them Ø Can we make it without knowledge of control theory? § Advanced controls à very rare in real process industry (Why?) § Fundamental understanding of the process control à enough

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Ocean Systems Engineering