Basic knowledge of HRSG

HRSG are boilers that use physical heat or combustibles in various process materials such as waste gas and waste liquid as heat sources. HRSG recover the exhaust gas after the gas turbine has done work, and use the waste heat to generate steam to drive the steam turbine to generate electricity, which can fully improve the efficiency of the gas-steam combined cycle unit and save energy. The exhaust temperature of the simple cycle gas turbine is quite high (generally between 450 and 600°C), and the flow of the gas working medium is very large (for units with larger power, the gas flow rate is often above 300kg/s), so this exhaust gas contains a lot of energy. If a waste heat boiler is installed behind the gas turbine, the waste heat in the high-temperature exhaust gas of the gas turbine is used to heat the condensate of the steam turbine system to produce high-temperature and high-pressure steam, which is then sent to the steam turbine to do work. In this way, more mechanical work can be added, which can not only increase the power of the unit, but also improve the conversion efficiency between the chemical energy and mechanical energy of the fuel. This is the design basis of the waste heat boiler type gas-steam combined cycle solution.