Performance Improvement of an Open Cycle Regenerative Gas Turbine Power Plant Using an Inlet Air Cooling System

In a hot and dry climate country, performance of a gas turbine power cycle is low. Incorporation of a regenerator in the cycle and a spray cooler before compression of inlet air enhances its performance. Accordingly, this study focuses on the effect of regeneration and cooling of the inlet air on performance of an open cycle gas turbine plant, which mainly includes improvement in its thermal efficiency and reduction in specific fuel consumption. In this context, a suitable mathematical model is developed on the basis of fundamental understanding of thermodynamics and gas turbine relations. This model is then used in simulations by developing a code on Java platform where ambient temperature, pressure ratio and regenerator effectiveness are considered as major system parameters. In the simulation, a comparison among a simple Brayton cycle, a regenerative cycle and a regenerative cycle with spray cooler is considered under different system parameters. It is predicted that there is a significant increase in thermal efficiency and a significant decrease in specific fuel consumption on incorporation of regenerator and spray cooler to the cycle. However, addition of a spray cooler is applicable above an optimal pressure ratio (≈6) and in the high temperature environmental condition. As an example, 12.89% increase in thermal efficiency is found at a regenerator effectiveness of 0.85 on addition of spray cooler before compression of inlet air at an ambient temperature of 328K, and subsequent reduction in specific fuel consumption is found as 2.85% at pressure ratio of 10.