The Design And Experimental Studies On The Exhaust Turbine Power Generation System Of Vehicle Engine

According to the heat balance of engine, the heat removed by exhaust gas of total calories about 30 percent in ideal conditions. Therefore, the potential for recovering exhaust gas energy is relatively high. Recycling exhaust energy of the engine exhaust gas through turbine power generation system, is an important way to improve the thermal efficiency of engine and achieve energy saving.In this paper, designing and constructing the test bench of the engine power turbine to energy recovery based on a type of naturally aspirated diesel engine test stand. The test data was analyzed by Matlab software, the result could show the change regularity about exhaust parameters, residual pressure energy, residual kinetic energy and residual heat energy of exhaust in different conditions. The influence of the exhaust gas state parameter on the three forms of energy and power turbine exhaust output power were researched. Meanwhile, the economy of energy recovery test system in diesel- power turbine was analyzed. Finally, the overall scheme about turbine power testing system using engine exhaust was designed.The results indicated that exhaust state parameters and the three exhaust gas energy were increased with the increase of engine load and speed. In general, the potential of recovery energy of the exhaust gas was large, the minimum and maximum value was 2.219 kW and 28.95 kW respectively. In contrast, the residual kinetic energy of exhaust was smaller, the maximum value was 0.0954 kW. The minimum of residual pressure energy was 0.2071 kW, and the maximum value of 3.9397 kW. Compared to residual kinetic energy and pressure energy, the residual heat energy was much higher, the minimum and maximum value was 2kW and 24.9193 kW respectively. In short, the residual heat energy was the main target of energy recovery, the residual pressure energy was considered only in the condition of high-speed and high-load area, and kinetic energy could be negligible. In addition, the exhaust state parameters had a certain influence on the three forms of the exhaust gas energy. The exhaust flow rate had a great effect on the kinetic energy, the exhaust pressure could affect the residual pressure energy largely and the exhaust temperature had greatest impact on the kinetic energy.The output power and speed of power turbine increased as the engine load and speed increasing. The minimum and maximum output power was 0.4218 kW and 5.593 kW, the maximum speed was 75800 RPM. The exhaust temperature was the greatest of four exhaust parameters influence on output power of turbine. Power turbine recovered exhaust energy was only 17.34 percent to 23.56 percent, most of the exhaust energy wasted into the atmosphere.Compared to the diesel engine without driving force, the energy recovery test system of diesel power turbine improved thermal efficiency of an average 10.6%. From the economic point of view, the diesel engine with a power turbine energy recovery system or have a certain feasibility.Finalization of the overall design of the exhaust gas turbine power generation test systems, and related components for selection or design. Test system consists of three components: the power turbine, transmission, high speed generator. Power turbine as the prime mover testing system, high speed generator select rare earth permanent magnet generator, the transmission mechanism is a single-stage helical gear drive.