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The Control of Superheat and Capacity for a Variable Speed Refrigeration System Based on PI Control Logic  

Hua, Li (Department of Refrigeration and Air-conditioning Engineering, Graduate School, Pukyong National University)
Jeong, Seok-Kwon (School of Mechanical Engineering, Pukyong National University)
Publication Information
International Journal of Air-Conditioning and Refrigeration / v.15, no.2, 2007 , pp. 54-60 More about this Journal
Abstract
In this paper, we suggest the high efficient control method based on general PI control law for a variable speed refrigeration system. In the variable speed refrigeration system, the capacity and the superheat are mainly controlled by an inverter and an electronic expansion valve, respectively, for saving energy and improving coefficient of performance. Thus, we proposed a decoupling model to eliminate the interfering loop between the capacity and superheat at first. Next, we designed PI controller to control the capacity and superheat independently and simultaneously. Finally, the control performance was investigated through some experiments. The experimental results showed that the proposed PI controller based on the decoupling model can obtain good control performance under the various control references and thermal load.
Keywords
Variable speed refrigeration system(VSRS); PI control; Superheat; Capacity control; Coefficient of performance(COP); Decoupling model; Feedforward compensator;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
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