Abstract: When the agricultural diesel engine runs out of fuel and the fuel tank is refueled again, the fuel supply is interrupted, and it is difficult to start due to the gas entering the fuel circuit. To address this issue, a new simple and reliable degassing mechanism for the fuel supply channel of agricultural diesel engines is proposed based on the principle of the medical Murphy tube. Comparative tests were conducted on emission performance, fuel consumption, and starting performance of diesel engines before and after the installation of the degassing mechanism. The results show that the mean values of opacity (N) before and after the installation of the degassing mechanism were 12.89% and 13.246%, respectively. The mean values of the light absorption coefficient (K) were consistent at 0.35 m-1 before and after the installation. The mean values of fuel consumption (G) per hour before and after the installation were 1.324 L and 1.222 L, with a standard deviation of less than 3%. The measured values of N, K, and G decreased with the use of the degassing mechanism, indicating an improvement in emission performance, fuel economy, and operational stability. The diesel engine equipped with degassing mechanism significantly improved starting performance, enabling normal operation of the engine under all working conditions. The degassing mechanism effectively exhausts the gas from the diesel engines fuel supply system, showing practical significance and broad application prospects.

Key words: agricultural diesel engine, degassing mechanism, oil supply passage, Murphys tube

摘要： 农用柴油机在燃料用尽、油箱再次加油时,存在油路进入气体而导致的供油中断以及难以起动问题。针对这一现象，基于医学莫菲氏管原理提出一种简单可靠的农业用柴油机新型供油道除气机构。对比完成安装除气机构前后柴油机的排放性能试验、油耗试验和燃油耗尽后的柴油机启动性能试验。结果显示，各转速下安装除气机构前后不透光度N的均值分别为12.89%和13.246%，安装除气机构前后光吸收系数K的均值均为0.35m-1，安装除气机构前后每小时燃油消耗量G的均值分别为1.324L和1.222L，标准差均小于3%，且N、K和G的测量值均随着除气机构的使用而降低，表明除气机构使柴油机排放性能和经济性能得到改善，运行更稳定。装有除气机构的柴油机在燃油耗尽重新加油后可以正常启动，不影响发动机各工况下的正常运转，启动性能得到显著提升。该除气机构可以有效地排出柴油机燃油供给系统中的气体，具有实际意义和广泛的应用前景。

关键词: 农用柴油机, 除气机构, 供油道, 莫菲氏管