小缸径风冷柴油机热负荷的研究

Research on Thermal Loads of Small-bore Air-cooling Diesel Engines

分析了解决小缸径风冷柴油机热负荷问题的技术难点。指出在计算散热及温度场时,应考虑双金属汽缸体铸造时在结合面上存在的附加接触热阻,铸铁铝合金汽缸体的接触热阻约为3.7×10-4m2·K/W。给出了温度场测量及测量电路布置的技术方案。研究结果表明:导风罩和散热片的形状位置及尺寸、散热片表面质量、汽缸盖底板厚度对热负荷影响较大,采用金属模压铸、对散热表面进行机加工、偏置散热片等均可降低热负荷。

It was pointed out that the attached thermal resistance existing on the contacting surfaces of the dual-metal cylinder body should not be neglected when calculating the heat conduction and temperature field. For the casting iron and aluminum dual-metal cylinder body, the thermal resistance was about 3.7×10-4 m2·K/W. The technical sketch of measuring the temperature field was presented. It was also pointed out that the shape and the position of the cooling air hood and cooling radiator, the size and the surface quality of the cooling radiator, and the ground wall thickness of the cylinder head were the main factors affecting thermal loads. Casting the cylinder body and head with the metal die, machining the cooling radiator surface, making the cylinder center inclined to the center of the cooling radiator could relax the problem of thermal loads.