Simulation And Optimization Of Engine Performance For Gas Generator Set

As the country is vigorously promoting distributed energy,the number of electrified mobile charging power supply equipment for automobiles has increased.Simultaneously,the demand for data centers,5G base stations,and building backup power sources has gradually increased,and the demand for internal combustion engines for generator sets has increased.Due to the high development cost of gas-fired internal combustion engines,to reduce research and development costs,the current domestic gas-fired power generation internal combustion engines are directly converted from vehicle gas internal combustion engines.Operating surface conditions of automotive gas engines.The overall performance of high,medium,and low speeds needs to be considered in the design.The speed range is 800r/min-2100r/min,and the maximum torque point or maximum power point is usually the optimal design condition.,The performance of other speeds cannot be optimally exerted.However,in the operating conditions of the gas-fired power generation internal combustion engine,the speed of the power generation internal combustion engine is constant(usually 1500r/min).Therefore,it is necessary to use advanced simulation optimization methods to optimize and analyze the structural parameters of the original vehicle gas engine and the flow of the intake manifold,and to comprehensively improve the effective thermal efficiency of the power generation internal combustion engine,reduce gas consumption and improve reliability.The main contents of this article are as follows:(1)based on physical model calibration,use the experimental data of the original vehicle engine bench test to model the one-dimensional model of the gas engine,and calibrate the external characteristics of the model at 1500r/min.The errors of all parameters are all Less than 2%,indicating that the one-dimensional performance simulation model can truly show the working characteristics of the gas engine,and subsequent optimization studies are based on this calibration model.(2)Comparing the impact of two different compression ratio change methods on engine performance,it is found that the engine performance improvement is greater when the combustion chamber volume is changed,and the intake duration,valve timing,and ignition advance angle under different compression ratios are optimized.,And re-select and match the turbocharger of the engine.The study found that the change of the combustion chamber volume and the change of the piston stroke to increase the compression ratio by two different control methods have great differences in engine performance.With the increase of the angle multiplication factor of the intake duration,the performance of the internal combustion engine under different compression ratios also declines.Using the DoE method to optimize the valve timing of internal combustion engines at different compression ratios is feasible.The results show that the intake cam timing angle is 326℃A,and the exhaust cam timing angle is 120℃A at different compression ratios.The performance is optimized,and at the same time,the ignition advance angle is appropriately delayed to 12.25℃A,which can increase the power and reduce the gas consumption rate.(3)The supercharger used in the original engine is too large,and a higher supercharge ratio cannot be obtained under the same flow at low speed.According to the matching requirements of the engine and the supercharger,choosing a smaller supercharger will not only improve Improved efficiency and improved engine performance.After optimizing the structural parameters of the engine,compared with the original engine,the engine power is increased by 3.01%,the gas consumption rate is reduced by 2.80%,the effective thermal efficiency is increased by 2.76%,the pumping loss is reduced by 1.56%,and the overall engine performance is significantly optimized.(4)Next,perform three-dimensional modeling of the gas engine intake manifold,and use a three-dimensional coupling method to simulate the gas flow of the engine intake manifold,and analyze the original engine intake manifold pressure distribution diagram and streamline diagram,And put forward an optimization plan.Compared with the original intake manifold,the pressure difference between the three-cylinder and four-cylinder of the improved intake manifold has been reduced by 0.37%and 0.40%,respectively,and the uniformity of the intake manifold has been reduced by 0.36%...