| The decrease of atmospheric pressure leads to inadequate air intake when the diesel engine operates at plateau,which results in the drop of power?the rise of fuel consumption and the deterioration of exhaust.By combining the two-stage turbocharging technology and the fuel injection adjustment technology,the power recovery of diesel engine at plateau can be realized.In this paper,variable altitude performance experiment of diesel engine with different turbocharging system is researched based on the plateau simulation system.Results show that the high altitude power recovery is low for diesel engine matched with single-stage turbocharging system due to the limit of the compressor ratio and flow range.By matching adjustable two-stage turbocharging system,the diesel engine power recovery reaches to 100% under 3000 m and 85% at 4500 m.The result shows that the two-stage turbocharging system can satisfy the requirement of the diesel engine air intake at high altitude.Impact of fuel injection timing and injection pressure under different excess air factor condition is researched on high-pressure common rail single cylinder diesel engine.Results show that earlier fuel injection and higher fuel injection pressure can ensure exhaust temperature not exceeding its limit.A model of diesel engine with two-stage turbocharging system was built by using GT-Power.After calibration with experiment data,the cooperative control of oil and air for diesel engine at 4500 m was calculated.The corresponding scope of oil and air was determined according to the recovery target of maximum torque and maximum power.The results show that too much intake air causes excessive maximum pressure and too little intake air causes exhaust temperature when cycle fuel injection quantity is sufficient.In addition,the scope of excess air coefficient which meets diesel engine power recovery requirement decreases with the increase of cycle fuel injection quantity... |
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