摘要
小型制冷压缩机性能测试系统中蒸发温度的传统控制方式存在精度低和温度波动大等问题,而蒸发温度控制的精度又直接关系到制冷量的测量精度。为了实现对被测压缩机制冷量的测量精度,需实现蒸发温度的精确控制。通过对蒸发温度控制原理的了解,选取蒸发温度对应的饱和吸气压力为被控对象,以标准工况为目标,设计了蒸发温度控制的硬件平台和脉冲输出控制器,编写了相应控制程序;结合经典PID控制策略,设计了与下位机之间的通信协议,通过软件实现计算机对蒸发温度实时控制;通过实验论证,得出了合理系统响应时间和理想的控制参数。研究结果表明,蒸发温度的PID控制,实现了对膨胀阀的自动调节,系统控制精度明显提高,响应快,使蒸发温度的控制更加精确和稳定。
Traditional control method of the evaporation temperature is poor accurate and the temperature has large fluctuations in the small refrigeration compressor of the performance test system.The control of the evaporation temperature is controlled accurately or not which is directly related to the measurement accuracy of the cooling capacity.In order to accurately measure the cooling capacity,the evaporation temperature needs to be controlled accurately.In the experiment,the suction pressure corresponding evaporation temperature was selected as the controlled object and was based on the target’s condition,with the understanding of the principles of control for evaporation temperature;the hardware platform and the pulse generator was built and controller and the corresponding control program are designed for it;the control of the PID control was selected as the control strategy,communication protocols were designed,so the evaporation temperature can be controlled by the software of the computer in time;the reasonable response time and the ideal control parameters can be drawn by experiment.The results indicate that the PID control of the evaporation temperature which can achieve the automatic adjustment of the expansion valve,can improve the control accuracy of the system and the control of the evaporator temperature can be more precise and stable.
出处
《机电工程》
CAS
2013年第5期596-599,共4页
Journal of Mechanical & Electrical Engineering
关键词
压缩机
温度控制
制冷
蒸发温度
PID
compressor
temperature control
refrigeration
evaporation temperature
PID
