Design And Optimization Of Gas Recirculation Structure On Parking Heaters

The parking heater is an auxiliary heating device installed on the vehicle,which can solve the problem of starting the vehicle in the cold and assist the heating of the cab.The parking heater is widely used in the northern region due to its small size,low fuel consumption,high thermal efficiency and easy installation and use.In order to better reduce the emission of nitrogen oxides and improve the stability and reliability of the initial combustion under low load conditions,we will continue to optimize the structure and strive to reduce pollutant emissions as much as possible without adding external catalysts.Start-up performance under low load conditions.In this paper,a two-stage combustion test bench with adjustable flue gas recirculation rate in the range of 0~40% is designed.The design and numerical simulation are carried out by reference to the Venturi ejector principle.The preferred structure is processed and tested to verify the structure in the station.The results of two-stage combustion test show that flue gas recirculation is beneficial to improve the initial combustion stability problem under low load conditions,and is beneficial to reduce nitrogen oxide emissions under high load conditions.The numerical simulation results show that the designed structure can achieve a 5.6% gas recirculation rate.The flue gas recirculation rate has a large influence on the flow field and temperature field of the combustion chamber after being added to the flue gas recirculation structure.Finally,the gas recirculation structure was processed and tested to investigate the effect of the recirculating structure on combustion under high load.Through experiments,we found that the recirculating structure can effectively increase the speed of flue gas temperature rise in both the combustion chamber test and the whole machine test,which is beneficial to the temperature rise of the combustion chamber during initial ignition.