Experimental Study On The Performance Of A Humid Air Turbine

Humid Air Turbine Cycle,which is an advanced power cycle, is known as a very promising thermodynamic cycle of the twenty-first century because it has simple structure and good thermal performance and can effectively reduce NOx emissions. Currently studies on HAT cycle at home and abroad are mainly in the theoretical calculations. Therefore, it is significant to carry out experimental studies with a complete HAT cycle test device. Based on a micro two-shaft gas turbine, this paper constitutes a micro two-shaft gas turbine testing device by joining the saturator and carries out experiments on the HAT cycle performance. On this basis, simulation calculations and analysis of the experiments are done.This paper introduces the establishment of the micro two-shaft gas turbine test device, as well as the main measurement system and the PLC data acquisition system. Through the experiments, the operating conditions of the two-shaft gas turbine from climbing to a higher operating condition are studied and the performance parameters of the various components of the two-shaft gas turbine are acquired on stable operating conditions. Results show that the ambient temperature and the outlet pressure loss have great impact on the output specific work of the two-shaft gas turbine. Limited due to experimental conditions, simulations demonstrate that, if the turbine inlet temperature is 650°C and pressure ratio is 2.6, the cycle specific work fell by 53.6 percent, while cycle efficiency decreased by 49% when the ambient temperature increased from 10°C to 50°C.Based on preliminary experiments, a micro two-shaft gas turbine test device on the performance of HAT Cycle is constituted by adding a saturator. Experiments are carried out on the device when the fuel is constant or the turbine inlet temperature is constant. In experiments when the fuel is constant, humidification amount changes from 0.0362 to 0.0475(kg/kg(DA)). The results show that air humidification has obvious impact on the performances of gas turbine. The power and efficiency have been greatly improved relative to the simple cycle, and the improvement is especially significant for the micro turbine at low conditions. However, when the gas turbine is at a low operating condition, as the gas temperature is low, combustion efficiency will decrease if humidity is too high, resulting in reducing of gas turbine specific work. The emission measurement results show that the content of NOX in the exhaust after the combustor is significantly reduced , proving good emissions performance of the HAT cycle.The results of simulation on gas turbine performance for the test conditions agree well with the experiments. Meanwhile simulation results also show that the power and efficiency are higher and the consumption of fuel is lower when the temperature ratio is greater; in certain humidification amount, there is an optimal pressure ratio related to some temperature ratio, in which the power and efficiency are the largest; greater temperature ratio, greater optimal pressure ratio. Simulation on the micro two-shaft gas turbine with recuperator is done. The results show that in the case that the turbine inlet temperature does not change, the loss of pressure increases, resulting in reduction of the power by about 10% to 16%. But at the same time, Speed of fuel consumption decreases by 20% to 45% and efficiency increases by 30% to 80%, which shows the performances have been significantly improved.