Performance and Operating Characteristics of Micro Gas Turbine Driven by Pulse, Pressure Gain Combustor

Abstract

Abstract This paper presents the experimental results of a micro gas turbine driven by pulse, pressure gain combustor. The aim of this study is to demonstrate the improvement of the engine performance by applying the pressure gain combustion. The micro gas turbine is composed of a combustor having two combustion chambers and an automotive turbocharger which is used as a compressor and a turbine. The outlets of two combustion chambers are joined by a confluence part to connect with the turbine. By changing the combustion methods of each combustion chamber, the gas turbine was operated in three modes; normal combustion mode, pulse combustion augmented mode, and fully pulse combustion mode. In the normal combustion mode, two combustion chambers were operated under continuous, constant-pressure combustion. In the pulse combustion augmented mode, one combustion chamber was operated under continuous, constant-pressure combustion and the other was operated under pulse combustion. In the fully pulse combustion mode, two combustion chambers were operated under pulse combustion. The pulse combustion applied in this study was the forced-ignition type, active pulse combustion. Although the pressure increase was attained by the pulse combustion comparing with the normal combustion, the mass-averaged pressure in the combustor showed that the net pressure gain in the combustor was not attained. The engine performance such as thermal efficiency and work and operating characteristics of gas turbine were investigated for two operation modes. In the pulse combustion augmented mode, the gas turbine could successfully sustain its operation as well as normal operation mode. The increase in the combustor pressure affected the air mass flow rate and the compressor performance, resulted in the decrease of performance comparing with the normal combustion mode.