复杂环境下风冷柴油机工作及冷却性能研究  

Research on the Working and Cooling Performance of An Air Cooled Diesel Engine in Complex Environments

作　　者：张乐 向建华[1] ZHANG Le;XIANG Jianhua(School of Mechanical Engineering,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京理工大学机械与车辆学院,北京100081

出　　处：《内燃机工程》2023年第6期46-53,共8页Chinese Internal Combustion Engine Engineering

摘　　要：针对一款V型风冷柴油机,研究其在不同海拔、温度环境下的工作性能及冷却散热能力,进而提高柴油机热效率。为充分考虑动力舱下柴油机的冷却散热,提出一种将动力舱模型一维离散,以此搭建柴油机冷却系统模型的方法,并与柴油机工作模型进行耦合仿真。结果表明:柴油机在2000 r/min外特性工况条件下,外界环境海拔、温度的升高使得柴油机缸内燃烧工作曲线后移,海拔每增加1000 m,放热峰值点后移2°,缸内燃气温度升高;一定转速下的风扇空气质量流量会随海拔、温度的增大而减小,柴油机冷却能力下降,缸盖燃气侧表面平均温度升高;柴油机热效率随海拔、温度的升高而降低,高海拔、高温环境下,增大风扇转速可提升柴油机热效率,随着风扇转速提高,海拔4000 m、温度20℃环境下,柴油机热效率从29.7%升至35.7%。Taking a V-type air-cooled diesel engine as the research object,the working performance and heat dissipation ability of the engine were studied under different altitude and temperature environments,in order to improve its thermal efficiency.The power cabin model was discretized to build the cooling system model,and the cooling system model was coupled with the diesel engine working model to simulate the process of engine cooling and heat dissipation.Results show that under the conditions of 2000 r/min external characteristic of the diesel engine,the increase of altitude and temperature of the external environment causes the working curve of combustion in the diesel engine cylinders to shift backward.For every 1000 m increase in altitude,the peak point of heat release moves back by 2°,and the gas temperature in the cylinder increases.At a certain speed,the air mass flow of the fan decreases with the increase of altitude and temperature,meanwhile the cooling capacity of the diesel engine decreases,and the average temperature of cylinder head fire surface increases.The thermal efficiency of the diesel engine decreases with the increase of altitude and temperature.At high altitudes and high temperatures,the increase of fan speed can improve the thermal efficiency of the diesel engine.With the increase of the fan speed,the thermal efficiency of the diesel engine changes from 29.7% to 35.7% at the altitude of 4000 m and the temperature of 20℃.

关 键 词：风冷柴油机 一维离散 耦合仿真 复杂环境 热效率 

分 类 号：TK414.2[动力工程及工程热物理—动力机械及工程]