Measurement and Control of the Gas Turbine Inlet Air Cooling System
As a constant-column power generating machine, the combustion turbine has a direct proportion of its output to the quantity of input air. Therefore, when the ambient air temperature rises higher in summer, the effect of combustion turbine is decreasing. In order to enhance the efficiency of combustion turbine in summer, two sets of inlet air cooling system (IACS) were installed in PG6551(B) combustion turbines in Jinhua, Zhejiang, China. Two low-pressure evaporators were installed in the caudal flue of the waste heat boiler, therefore, the produced saturation steam drives a single-effect lithium bromide absorption chiller to cool the input air of combustion turbines to raise the output power of combustion turbine in summer; or supplies the low-pressure heater to heat the condensated water from the deaerator of the steam turbine in winter. A measurement and control system (MCS) of the new-added inlet air cooling equipments was developed. Based on the framework of DCS (Distributed Computer System), the M&C system has the IACS work correctly and easily. The structure and functions of the M&C is described in detail.