制冷装置中膨胀阀的对比研究

Comparison Research of Expansion Valve in Refrigeration Machines

为验证自行开发的电子膨胀阀和采用单片机开发的实时控制器的控制效果 ,针对热力膨胀阀、步进电机型膨胀阀、电磁阀型膨胀阀 ,进行了多个制冷系统冷启动和稳定工况下变负荷控制的实验研究。结果表明相对于传统的热力膨胀阀 ,电子膨胀阀更适用于系统综合控制器 ;连续调节型的执行机构比离散调节型的执行机构更容易使过热度稳定 ;积分环节大大改善了过热度的控制品质。自行开发的电子膨胀阀和控制器 ,性能价格比高 ,与国外同类产品相比 。

To test control performance of the present electronic expansion valve and real-time controller developed with MCU, the experimental research of refrigeration systems was performed in cool startup or cooling load variation under a steady operating conditions. These systems were individually assembled with three kinds of expansion valves: thermostatic, electric driven by the stepmotor and electromagnetic. Results show that compared with conventional thermostatic expansion valves, electronic expansion valves are more suitable to integral controller and superheat controlled by continuous devices is more stable than that controlled by discrete devices; the integral element promotes control quantity greatly. The present electronic expansion valve and controller are of high-performance and low-cost. Compared with similar products of foreign companies, their control effectiveness is also obvious.