Gas Turbine Intake Air Heating with Load-Based Heat Source Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The operation efficiency of gas turbines is reduced due to the reduction in the flow rate of combustion gas supplied to the turbine when compressed air is returned from the compressor for intake air heating, as it is used as a heat source.
Innovation Solution
An intake air heating system with a first heating unit that returns compressed air to the intake flow path and a second heating unit using a different heat source, controlled by a control device to heat external air in high-load sections, reducing the reliance on compressed air for heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If compressed air is returned to the intake duct for heating external air, then the external air is heated effectively, but the flow rate of combustion gas supplied to the turbine is reduced
Solution Approach 1:
The heating system is divided into two independent heating units: a first heating unit that uses compressed air as heat source, and a second heating unit that uses a different heat source. This segmentation allows selective operation of heating units based on load conditions, preventing the need to always sacrifice combustion gas flow rate for heating.
Solution Approach 2:
The control device dynamically selects which heating unit to operate based on the gas turbine load. In high-load sections, the second heating unit is activated to avoid reducing combustion gas flow rate. In lower-load sections, the first heating unit can operate. This dynamic adaptation resolves the contradiction by adjusting the heating strategy according to operational conditions.
2Temperature
If compressed air is used as heat source for heating external air, then heating is achieved, but operation efficiency of the gas turbine is reduced
Solution Approach 1:
The system changes the operating parameters by introducing a second heating unit with a different heat source that can operate under specific load conditions. This parameter change (switching heat sources based on load) maintains heating effectiveness while preserving gas turbine operation efficiency during high-load operation.
3Power
If the flow rate of compressed air returned to intake duct is increased for heating, then heating capacity is improved, but the flow rate of combustion gas to turbine is further reduced
Solution Approach 1:
The second heating unit acts as an intermediary heating solution that provides alternative heating capacity without consuming compressed air from the combustion path. This intermediary system allows the first heating unit to operate at full capacity when needed, while the second heating unit compensates during high-load conditions to maintain overall heating capacity without sacrificing combustion gas flow rate.
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
Improves the operation efficiency of gas turbines by minimizing the decrease in combustion gas flow rate and suppressing carbon monoxide generation, particularly in high-load sections.
Implementation Method 1
a heater configured to heat the external air by using a heat source different from the compressed air
Implementation Method 2
The external air is heated by mixing the compressed air flowing through the return line with the external air flowing through the intake duct
Data Source
AI summary
This intake air heating system is configured so as to heat external air flowing in an intake air flow path communicated with a compressor of a gas turbine, the intake air heating system comprising: a first heating unit that includes a return flow path for returning some compressed air discharged from the compressor to the intake air flow path; a second heating unit that includes a heater configured so as to utilize a heat source differing from the compressed air to heat the external air; and a control device that is configured so as to control the second heating unit such that the external air is heated by the heater in a high load segment where the gas turbine load is higher than a first stipulated load.