Gas-Water Heat Exchangers for Cooling Gas Turbine Exhaust Gases

Gas-Water Heat Exchangers for Cooling Gas Turbine Exhaust Gases

Gas-water type heat exchangers play an important role in cooling the exhaust gases of gas turbines. Gas turbines are a common type of power generator, and they generate a large amount of waste heat during operation, including high-temperature exhaust gas streams. The use of gas-water type heat exchangers to cool these exhaust streams helps to improve the efficiency of the power plant and can be used for waste heat recovery. Below are the key roles and working principles of gas-water type heat exchangers in this process:

Key Roles:

1. Waste Heat Recovery: High temperature waste heat from gas turbine exhausts can be recovered through a gas-water type heat exchanger and converted into useful heat energy. This recovery process helps to improve energy efficiency and reduce energy waste.

2. Power Generation Efficiency Improvement: By lowering the temperature of the exhaust gas stream, the gas-water type heat exchanger can increase the thermal efficiency of the gas turbine, thus improving the efficiency of electric power generation.

3. Environmental protection: Waste heat recovery and exhaust gas cooling help to reduce the temperature of gas turbine emissions and reduce the impact on the environment. This helps to comply with environmental regulations and reduce air pollution.

Principle of operation:

1. Exhaust gas flow into the heat exchanger: The high temperature gas turbine exhaust gas flow first enters the gas-water type heat exchanger.

2. Heat exchange: In the heat exchanger, the heat from the exhaust stream is transferred to the cooling water or other cooling medium in it. This causes the temperature of the exhaust air stream to decrease and the temperature of the cooling water to increase.

3. Cooling water circulation: The cooling water is normally channelled back to the cooling unit (e.g. cooling tower) via a circulation system for re-cooling. This ensures that the cooling water in the heat exchanger is always in the proper temperature range.

4. Waste heat recovery: By means of heat exchange, the heat energy in the exhaust air stream is transferred to the cooling water, which rises in temperature. This heat energy can be used for different purposes such as heating water or steam circulation in power generation.

5. Reducing Exhaust Gas Temperature: Ultimately, the role of the air-to-water heat exchanger is to reduce the temperature of the exhaust gas stream to a safe level to meet process requirements and environmental regulations.

Gas-water type heat exchangers play an important role in improving the efficiency and environmental friendliness of gas turbine power plants. Through waste heat recovery and exhaust gas cooling, they maximise the use of waste heat resources, reduce energy wastage and cut emissions. This helps to improve the economics of electric power plants while reducing environmental impact.