HRSG Electrical Heater for Rapid Fluid Pre-heating
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Solution Overview
Problem
Traditional heat recovery steam generator (HRSG) start-up modes are inefficient and lengthy, leading to resource wastage and excess emissions, as they do not effectively utilize emissions-reducing catalysts at lower temperatures.
Innovation Solution
Incorporating an electrical heating system that pre-heats the fluid during start-up and shutdown modes to quickly reach operating temperatures, allowing for earlier catalyst effectiveness and reducing thermal stress on the HRSG structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional HRSG start-up mode is used, then the system can operate with exhaust gases, but the start-up time is lengthy and inefficient, wasting resources and causing excess emissions
Solution Approach 1:
The electrical heater pre-heats the fluid before the exhaust gases are introduced, performing the heating action in advance. This preliminary heating action reduces the time required for the fluid to reach operating temperature when the exhaust gases are introduced, thereby resolving the contradiction between long start-up time and efficient operation.
Solution Approach 2:
The patent replaces the traditional mechanical/heating system that relies solely on exhaust gas heating with an electrical heating system. This substitution allows for more rapid and controlled heating during start-up, eliminating the lengthy start-up period associated with traditional exhaust gas-only heating methods.
2Object-generated harmful factors
If traditional HRSG start-up mode is used, then the system operates with exhaust gases, but it causes excess emissions that would otherwise be treatable at higher temperatures
Solution Approach 1:
The electrical heater performs preliminary heating of the fluid to higher temperatures before exhaust gas introduction. This preliminary action ensures the fluid reaches temperatures that enable effective catalyst operation from the start, preventing excess emissions that would occur during gradual heating in traditional modes.
Solution Approach 2:
The patent changes the temperature parameter by using electrical heating to rapidly increase fluid temperature to optimal levels for catalyst operation. This parameter change enables the catalyst to function effectively at lower exhaust gas temperatures, reducing emissions while maintaining efficient operation.
3Productivity
If electrical heater is added to HRSG, then start-up efficiency improves and catalyst effectiveness is enhanced, but device complexity increases
Solution Approach 1:
The electrical heater is designed to serve multiple functions: it can heat the fluid during start-up mode, during shutdown mode, and potentially during normal operation if needed. This multi-functionality justifies the added complexity by providing versatile heating capability across different operational states, improving overall system efficiency and flexibility.
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
The electrical heating system improves HRSG efficiency by reducing start-up time, enhancing catalyst utilization, and minimizing emissions, while also generating auxiliary steam for secondary processes during non-normal operating modes.
Implementation Method 1
The electrical heater provides heat to the fluid path during a start-up mode of the HRSG, during a shutdown mode of the HRSG, or both
Implementation Method 2
the HRSG may utilize exhaust gases from a gas turbine engine to heat a fluid (e.g., a liquid, such as water) flowing through the HRSG
Data Source
AI summary
A system includes a turbine system that contains a heat recovery steam generator (HRSG) having a flow path that receives an exhaust gas, and having a fluid path that receives a fluid. The fluid path is adjacent to the flow path such that the fluid is heated by the exhaust gas. The HRSG includes an electrical heater that provides heat to the fluid path during a start-up mode of the HRSG, during a shutdown mode of the HRSG, or both.