高压共轨柴油机不同海拔(大气压力)适应性试验研究

Experimental Study on Adaptability of High Pressure Common-rail Diesel Engine at Different Altitudes(Air Pressure)

利用柴油机高海拔（低气压）模拟试验系统,开展了高压共轨柴油机不同海拔（大气压力）适应性试验研究,分析了不同海拔对柴油机动力性、经济性以及热平衡性能的影响,为进一步改善柴油机高海拔适应性提供了理论依据。结果表明：柴油机低转速区动力性和经济性随海拔升高的恶化程度比高转速区大,海拔5500 m与0 m相比,低转速区（1000-1300 r/min）时,功率和转矩平均下降了67.4%,燃油消耗率平均增加了50.7%;而高转速区（1800-2100 r/min）时,功率和转矩平均下降了31.8%,燃油消耗率平均增加了8.4%;随着海拔的升高,转矩适应性系数基本不变,但转速适应性系数下降明显;柴油机经济运行区转速范围随海拔升高逐渐变窄且向高转速区偏移,从0 m对应的1200-1900r/min偏移至5500 m对应的1500-2000 r/min;与0 m相比,海拔5500 m时有效功率、冷却液散热量、排气散热量占总热量百分比分别下降了17%、2%和14%,余项损失占比增加了31%。

An experimental study on adaptability of high pressure common-rail diesel engine at different altitudes （air pressure） was conducted based on high altitude （low air pressure） simulation experimental system, the effects of altitude on the power, economy and heat balance performance of diesel engine were studied, which provide theoretical basis for further improve the high altitude adaptability of diesel engine. The results show that： with the increase of altitude, the deterioration degree of diesel engine power and economy performance at low speed regions are greater than high speed regions, compared the performance at altitude of 5500 m with that at 0 m, engine torque and power decrease by 67.4%, and specific fuel consumption increases by 50.7% at engine speed of 1000-1300 r/rain; engine torque and power decrease by 31.8%, and specific fuel consumption increases by 8.4% at engine speed of 1800-2100 r/rain; the torque adaptive coefficient is basically unchanged, but the speed adaptive coefficient decreases obviously; the speed range of economic operation zone narrows gradually and moves to the high speed regions, which shifts from the 1200-1900 r/min at 0m to the 1500-2000 r/min at altitude of 5500 m; compared with 0 m, the percentage of effective power, coolant heat and exhaust heat account for total heat at altitude of 5500 m decrease by 17%, 2% and 14% respectively, and the percentage of residual loss account for total heat increases by 31%.