二级可调增压柴油机变海拔热平衡试验

Thermal Balance Test of Regulated Two-Stage Turbocharged Diesel Engine at Variable Altitude

中文关键词: 二级可调增压柴油机  高海拔  热平衡

英文关键词: regulated two-stage turbocharged diesel engine  high altitude  thermal balance

中文摘要:

      进行二级可调增压柴油机热平衡性能研究,有助于评价发动机在不同工况下的热量分配情况,合理控制发动机热负荷,解决高海拔发动机开锅问题,提高热效率。利用自主设计的柴油机高海拔热平衡试验系统,进行不同模拟海拔(0m、3500、5500m)二级可调增压柴油机全负荷热平衡试验,研究了海拔高度对二级可调增压柴油机热平衡性能的影响。结果表明：随海拔升高,发动机热负荷升高,具体表现为高速区域涡前排温增大、1500r/min全负荷工况下缸内最高燃烧温度峰值升高且对应曲轴转角减小；随海拔升高,有效功和排气带走热量占总热量百分比均呈下降趋势,发动机冷却液带走热量和余项损失占总热量百分比增加,相较于平原工况,海拔5500m时,有效功率和排气散热量占比减小1.8%、16.8%,冷却液带走热量和余项损失占比增加2.9%、15.7%；二级增压技术对柴油机高原性能恢复具有明显效果,5500m海拔环境条件下,柴油机中、高转速下的热效率恢复情况明显优于低速工况。

英文摘要:

      The research on thermal balance of regulated two-stage turbocharged diesel engine is helpful to assess the heat distribution of the engine under different working conditions, control the heat load of the engine reasonably, solve the boiling problem of the engine at high altitudes and improve the thermal efficiency. The full load thermal balance test of regulated two-stage turbocharged diesel engine at different simulated altitudes (0m, 3500m, 5500m) was carried out on the self-designed high altitudes thermal balance test system for, and the influence of altitudes on thermal balance of regulated two-stage turbocharged diesel engine was studied. The results indicated that the heat load of engine increased with the increase of altitudes, which was manifested by that the exhaust temperature at high speed and the maximum combustion temperature at 1500r/min increased with the increase of altitudes, while the crankshaft angle corresponding to maximum combustion temperature decreased with it. The percentage of heat taken away by brake power and exhaust showed a downward trend, and the percentage of heat taken away by coolant and remainder heat lost increased, in particular, compared with the altitude of 0 m, the percentage of power and heat taken away by exhaust decreased by 1.8% and 16.8%, respectively, and the percentage of heat taken away by coolant and remainder heat lost increased by 2.9%、15.7% ,respectively,at 5500 m. The technology regulated two-stage turbocharging had a significant effect on the recovery of diesel engine performance at high altitude, in particular, the thermal efficiency recovery of diesel engine under medium and high speed was obviously better than that under low speed at 5500m altitude.