ZKAR-36工程车空调性能改进研究

Improvement of ZKAR-36 engineering vehicle air-conditioning performance

ZKAR-36工程车空调的制冷量严重不足,运行过程中频繁出现结霜和停机故障。调研与实验分析发现主要原因在于:蒸发风量过小和蒸发器换热面积不足,以致运行过程中蒸发温度向下滑移,形成结霜,从而产生恶性循环。文章采取的主要改进措施有:提高蒸发风机压头,改善风机动力性能,大幅提高蒸发风量;选用层叠式蒸发器替换原样机使用的管带式蒸发器,有效提高蒸发器的换热能力;增大平行流冷凝器换热面积并优化其流程设计。性能实验结果表明,改进后的空调系统性能明显优于原系统,标准工况下制冷量提高64%,能效比提高95%;经装车运行试验考核,改进产品满足工程机械的应用需求。

The refrigerating capacity of the ZKAR-36 engineering vehicle air-conditioner is seriously insufficient,and frost formation and shutdown fault occurs frequently in the running process.Through on-site investigation and experimental analysis,the primary causes of these problems are found out as follows： the evaporating air flow is too small and the heat exchange area of the evaporator is inadequate,and these lead to lower evaporating temperature and frost formation which cause the cycle to worse state.In this paper,the following methods are used to improve the air-conditioning performance： enhance effectively the evaporating air flow through increasing the fan pressure head and improving the fan dynamic performance;enlarge the heat exchange area through using the laminated evaporator instead of the serpentine evaporator;increase the heat exchange capacity of parallel flow condenser and optimize the refrigerant circuitry of the condenser.The performance experimental results show that the new system is better than the old one,and has an increase of refrigerating capacity and energy efficiency ratio by 64 % and 95 % respectively under the standard working condition.The installation and running test shows that the new system can satisfy the requirement of the engineering vehicle.