Session: 04-18: Pressure Gain Combustion I

Paper Number: 83528

83528 - Evaluation of Pressure Gain and Turbine Inlet Conditions in a Pulse Combustion Gas Turbine 

The pressure-gain combustion has possibility to improve the thermal efficiency and the specific power of gas turbines. The authors developed a 1 kW-class micro gas turbine operated by pulse combustion and demonstrated the successful operation of the gas turbine. Although the instantaneous pressure increase was obtained, the time-resolved flow measurement in the pulse combustor is necessary to evaluate the cycle-averaged pressure gain. The flow measurement at the turbine inlet is also needed to investigate the effect of pulse combustion to the turbine performance. In this study, the pressure, flow velocity, and temperature in the pulse combustor were experimentally measured under gas turbine operation conditions. In our micro gas turbine, the pulse combustor is composed of two combustion chambers. One combustion chamber was operated under pulse combustion, and the other was operated under continuous, constant pressure combustion. The outlets of two combustion chambers are joined by a confluence part, and the burned gases are mixed and flows to the turbine. The gas flow velocities at the chamber inlet and outlet were measured by using a laser doppler velocimeter. The pressures were measured by the fast-response transducers. The gas temperatures were measured by the tunable diode-laser absorption (TDLAS) method. Each measurement was conducted under gas turbine operation, in which the repetitive rate of pulse combustion was 40 cycles per second. It is found that the mass flowed into the combustor largely fluctuated due to intermittent burned gas flow by pulse combustion. The mass-averaged pressure at the turbine inlet showed the increase than that at the compressor outlet, indicating the pressure gain. The gas velocity and temperature at the turbine inlet were also largely fluctuated in one cycle and the values reached the peak at the same time when the pressure reached the peak value.

Presenting Author: Takashi Sakurai Tokyo Metropolitan University

Presenting Author Biography: Dr. Takashi Sakurai is a associate professor at the Tokyo Metropolitan University.<br/>His research topics are pressure-gain combustion and its application to gas turbine, hybrid rocket propulsion, <br/>and hydrogen combustion for gas turbine.<br/>Recent works are :<br/>1. Development of pulse combustion gas turbine<br/>2. Swirling-Oxidizer-Flow-Type (SOFT) Hybrid Rocket (HR) Engine using low-melting point temperature fuel and LOX regenerative-cooling nozzle<br/>3. Dry-Low NOx lean-premixed combustion using lifted flame for hydrogen fuelled gas turbine combustor

Authors:

Takashi Sakurai Tokyo Metropolitan University
Takehiro Sekiguchi Tokyo Metropolitan University
Sora Inoue Tokyo Metropolitan University