CO2 Recovery Heat Exchanger Preheating for Thermal Stress Relief

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Solution Overview

Problem

The repeated cycling of heat exchangers between high and low temperature states due to frequent start-ups and shut-downs in carbon dioxide recovery systems leads to premature wear and damage of constituent components.

Innovation Solution

Incorporation of a heat exchange unit with a warm fluid supply system to maintain heat exchange unit temperature during system stoppages, using a warm fluid to preheat the unit before operation, and bypassing liquid flows to avoid immediate temperature changes during start-up.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the carbon dioxide recovery system is repeatedly started and stopped, then the system can adapt to varying operational demands, but the heat exchanger undergoes repeated temperature cycling between high and low states causing premature damage to constituent members

Engineering Contradiction:
Improvesystem operational flexibilityVSAvoidheat exchanger component lifespan
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies preliminary action by introducing a warm fluid supply unit that pre-heats the heat exchanger to a predetermined temperature before the carbon dioxide recovery system starts operation. This preliminary heating action prevents sudden temperature shocks to the heat exchanger during system startup, thereby reducing thermal stress on constituent members like gaskets while maintaining system operational flexibility.

Inventive Principle:
Principle #10Preliminary action

2Use of energy by moving object

If the heat exchanger is maintained at high temperature during operation, then heat exchange efficiency is improved, but the temperature must be reduced to low temperature when operation is stopped causing thermal stress

Engineering Contradiction:
Improveheat exchange efficiencyVSAvoidthermal stress on components
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary anti-action by using the warm fluid supply unit to preheat the heat exchanger before system startup. This counteracts the harmful thermal stress that would otherwise occur when cold fluid enters the heat exchanger during startup, allowing the heat exchanger to maintain high temperature during operation for efficient heat exchange while preventing damage during temperature transitions.

Inventive Principle:
Principle #9Preliminary anti-action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Reduces stress on heat exchanger components by maintaining consistent temperature, preventing damage and extending component lifespan.

Implementation Method 1

The heat exchange unit exchanges the heat of the lean liquid flowing through the lean liquid line with the absorption liquid having a temperature different from that of the lean liquid flowing through the lean liquid line

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

The warm fluid supply unit can supply a warm fluid for warming the heat exchange unit to the heat exchange unit

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP4691602A1Carbon dioxide recovery system
Publication Date: 2026.02.11 MITSUBISHI HEAVY IND LTD
  • EP4691602A1 patent drawingFigure 1
  • EP4691602A1 patent drawingFigure 2~3
  • EP4691602A1 patent drawingFigure 4

AI summary

A carbon dioxide recovery system includes an absorption tower, a regeneration tower, a rich liquid line, a lean liquid line, a heat exchange unit, and a warm fluid supply unit. The absorption tower allows a carbon dioxide containing gas containing carbon dioxide to contact an absorption liquid capable of absorbing carbon dioxide and produces a rich liquid corresponding to an absorption liquid having absorbed carbon dioxide of the carbon dioxide containing gas. The regeneration tower heats the rich liquid to discharge carbon dioxide from the rich liquid and produces a lean liquid corresponding to an absorption liquid having discharged carbon dioxide. The rich liquid line guides the rich liquid from the absorption tower to the regeneration tower. The lean liquid line guides the lean liquid from the regeneration tower to the absorption tower. The heat exchange unit exchanges the temperature of the lean liquid flowing through the lean liquid line with the absorption liquid having a temperature different from that of the lean liquid flowing through the lean liquid line. The warm fluid supply unit can supply a warm fluid for warming the heat exchange unit to the heat exchange unit.