Phase Change Material Thermal Storage for HRSG Heat Recovery
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Solution Overview
Problem
Combined cycle power generation systems face heat loss during gas turbine shutdowns, leading to increased energy consumption and operational costs due to the need for auxiliary heating to maintain optimal temperatures in heat recovery steam generation (HRSG) systems.
Innovation Solution
The integration of phase change materials around key components in the HRSG system to absorb and store heat during operation, releasing it during shutdowns and reducing the need for auxiliary heating by maintaining higher temperatures for extended periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If auxiliary heating system is used to maintain high operating temperatures during gas turbine shutdown, then the HRSG system can return to optimal operating temperature, but energy consumption and operating costs increase
Solution Approach 1:
The phase change material absorbs and stores thermal energy from the HRSG system during operation, performing a preliminary action of heat accumulation before shutdown occurs. This stored energy is then released during shutdown to maintain temperatures, eliminating the need for auxiliary heating and reducing energy consumption during restart operations
Solution Approach 2:
The invention utilizes phase change material that transitions between solid and liquid phases at specific temperatures. During HRSG operation, the material absorbs heat and transitions phase, storing thermal energy. During shutdown, the material releases this stored energy as it transitions back, maintaining system temperature without requiring additional energy input
2Temperature
If auxiliary heating system is used to elevate temperatures during startup, then the HRSG system reaches optimal operating temperature, but operating costs increase due to additional heat input
Solution Approach 1:
The phase change material performs preliminary heat accumulation during the operational phase, storing thermal energy that will be needed during subsequent shutdown and restart periods. This eliminates or reduces the need for costly auxiliary heating during startup operations
Solution Approach 2:
The phase change material undergoes phase transitions at temperatures relevant to HRSG operation, absorbing heat during operation and releasing it during shutdown. This thermal energy recycling reduces the operating costs associated with restarting the system after shutdown
3Productivity
If gas turbine is shutdown during low demand periods, then electricity demand is reduced, but heat loss to environment increases and requires additional heating on restart
Solution Approach 1:
The phase change material performs preliminary heat storage during periods when the gas turbine is operating, accumulating thermal energy that would otherwise be lost during shutdown. This allows the system to quickly restart without significant heat loss penalties
Solution Approach 2:
The phase change material absorbs thermal energy during operation and releases it during shutdown through phase transitions, effectively capturing and retaining heat that would otherwise be lost to the environment. This reduces the energy penalty associated with shutdown and restart cycles
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
This approach allows for 'hot restart' without additional heat input, reducing energy consumption, minimizing thermal stress on components, and extending their lifespan by maintaining higher temperatures and reducing startup times.
Implementation Method 1
a phase change material disposed around an external surface of the power generation system component
Implementation Method 2
the phase change material may be designed to retain heat within the combined cycle power generation systems
Implementation Method 3
the phase change materials may enable HRSG system components to remain at a higher temperature for an extended period by utilizing the heat of fusion between liquid and solid phases
Data Source
Figure 1
Figure 2~3
AI summary
In one embodiment, a component (66) for a power generation system (2) includes an interior volume (68) for containing steam condensate or gas turbine exhaust gas (22). A phase change material (72) is disposed around an external surface of the combined cycle power generation system component (66).