制冷系统变容量智能控制的理论及实验研究

为了提高变容量调节制冷系统过热度的控制精度,建立简单易行的过热度控制方法,在考虑各种影响因素的前提下,提出了基于传统PID控制策略的过热度智能控制策略。并以某恒温恒湿冷库为研究对象,验证了所提过热度控制策略的实际控制效果,并与热力膨胀阀的控制效果进行对比分析。实验结果表明:智能控制策略较传统PID控制策略动态响应快,超调量小,振荡时间短;压缩机频率变化作为干扰量提前输入,有利于过热度的稳定;采用智能控制策略对过热度的控制效果明显优于热力膨胀阀,冷库降温时间缩短37.14%。

Theoretical and Experimental Study on Intelligent Control of Variable Capacity Refrigeration System

In order to improve the superheat control precision of the variable capacity refrigeration system, and establish the simple superheat control method, an intelligent superheat control strategy based on the traditional PID control strategy was proposed, with various influencing factors considered. The actual superheat control effect of the intelligent control strategy was checked in a cold store with constant temperature and humidity, and was compared with the control effect of thermostatic expansion valve. The experimental results show that: the intelligent control strategy gives a better performance such as faster dynamic response, lower overshoot, and shorter oscillation time compared with traditional PID control strategy. It is advantageous to superheat stability, if the compressor frequency changes as the interference factors are inputted in advance. The intelligent control strategy is better than the thermal expansion valve on the superheat control effect, and the cold store cooling time is shortened by 37.14%.