EFFECT OF INLET AIR COOLING ON THE GAS TURBINE PERFORMANCE USING EVAPORATOR AND VAPOUR ABSORPTION COOLERS AT THE HQ-2 DAUR SSGCL GAS COMPRESSION STATION

Abstract

A gas turbine is a device that converts the energy of fuel into mechanical energy and is used to derive several types of rotating equipment. One of the major drawbacks of a gas turbine is that the performance (power output and thermal efficiency) of a gas turbine decreases instantly with the rise of ambient temperature. At Daur SSGCL Gas Compression Station, gas turbines are used to derive centrifugal type gas compressors to raise the pressure of natural gas where ambient temperature varies between 70 to 500C which decreases the performance of gas turbines. Inlet air cooling is a method through which the effect of ambient temperature on the performance of gas turbines can be decreased. This technique of cooling intake air increases the performance of gas turbines by increasing air density. There are various types of inlet air cooling but, in this study, two types of inlet air cooling techniques are discussed, one of which is wetted media evaporative type and the other one is vapour absorption type. The Evaporative type inlet air cooling technique is suitable for sites with high ambient temperature and low relative humidity and vapour absorption type is used for a wide range of ambient air temperature. In this study, thermodynamic models of the gas turbine have been developed without inlet air cooling (base case/cycle) with inlet air cooling for analyzing the effects of ambient conditions (temperature and relative humidity) on the performance of the gas turbine. The simulated results obtained from Engineering Equation Solver with inlet air cooling systems (vapour absorption and wetted media evaporator cooler) are compared without inlet air cooling (base cycle) gas turbine. On comparison of results of a gas turbine with inlet air cooling systems to without inlet air cooling at ambient conditions, T_0=298.15K (250C) and ∅=60% it is found that gas turbine with evaporator cooler produces 289kW more power than base case/cycle and 390kW more output power with vapour absorption inlet air cooling.