Experimental Study On Performance Of Diesel Exhaust Gas Turbine Power Generation System

The vigorous development of the automobile industry consumes a lot of petroleum resources,and the energy is becoming increasingly scarce.At present,the heat balance of vehicle engine shows that the energy carried by engine exhaust accounts for about 1/3 of the heat generated by fuel combustion,which has great potential for recovery.Utilizing power turbine to recover waste gas energy for power generation is an effective way to improve engine fuel utilization and thermal efficiency.In this paper,a test bench for diesel exhaust gas turbine power generation system is built.The exhaust state parameters,power turbine air speed,load speed,system output voltage,load current,electric power,engine fuel consumption and thermal efficiency are collected through the test.The performance of exhaust gas turbine power generation system is studied by the data obtained from the test.Firstly,the variation of exhaust state parameters and exhaust energy of diesel engine in power generation system and the energy loss of exhaust gas are studied.Then,the load-carrying capacity of power turbine with generator and without generator is evaluated and the energy recovery characteristics and influencing factors of power generation system are analyzed by comparing the rotational speeds of power turbine with generator and without generator.Finally,the energy recovery from exhaust gas and the thermal efficiency of system cycle are discussed.The economy of the system is analyzed from different angles.The results show that in the whole test range,the exhaust energy of the engine is between 10.19 kW and 20.35 kW when the power generation system is running.The main form of exhaust energy loss is waste heat energy.The exhaust energy loss accounts for about 30%～50% of the total exhaust energy.The available exhaust energy of the power turbine is between 4.42 kW and 10.76 kW.The speed of turbine with generator is obviously lower than that without generator.The load capacity of turbine with generator is not very strong,and there is still much room for improvement.The maximum recovery efficiency of power turbine for exhaust gas energy is 17.5%.The generator starting can be realized by controlling the output power of the engine at 13 kW.The maximum output power of the corresponding system can reach 84 W.The power generation efficiency of the system ranges from 2.3% to 5.0%.By comparing the fuel consumption rate and thermal efficiency of the system engine with that of the original engine,the economy of the system engine has not deteriorated significantly.The maximum net recovery energy of waste exhaust is 70.97 W.Under each working condition,the thermal efficiency of the system cycle is higher than that of the original engine,at 2200 r/min engine speed,the average thermal efficiency improvement rate reached the highest 2.6%.