Improving Comfort and Air Conditioner Performance by Optimizing Controllers under Actual Usage Conditions

Taebyoung Park,Yulho Kang,Inwon Lee,Byungsoon Kim,Gilun Hwang,Youngchull Ahn

doi:10.3390/app11114818

Abstract

This study is to increase the efficiency of the air conditioning system under actual conditions of use. In order to improve the increase in energy consumption due to control without considering indoor cooling load fluctuations, we review it compared to conventional control methods in two respects. First, we examined the control method to reduce energy consumption by varying the evaporative pressure of the system according to the cooling load, and secondly, further reducing energy consumption by controlling the revolutions per minute (RPM) of the fan of the indoor unit at the same time as the pressure fluctuation under the cooling load. We found that changing the target pressure depending on the difference between the target temperature and room temperature can control temperature more efficiently and save energy than using fixed target pressure, and that the effect increases when applying the control of the air volume of the indoor air. Cleaning up the resulting values, the fan-load-control condition of the cooling-load-estimation control method showed an energy savings effect of 16.1–48.7% compared with the fixed-pressure control method and 1.2–37.7% compared with the cooling-load-estimation control method.

Highlights

As temperatures are rising owing to global warming and living standards are improving, the use of air conditioners is increasing rapidly
An inverter air conditioner can control the amount of circulating refrigerant by varying compressor driving frequency, thereby modulating cooling ability according to heat load and maintaining room temperature while reducing deviation
With regard to compressor operating frequency fluctuations resulting from an outdoor temperature of 30 ◦C, the operating frequency fluctuation range decreased in the fixed-pressure control, cooling-load-estimation control, and cooling-load-estimation-with-interlockingfans control methods

Summary

Introduction

As temperatures are rising owing to global warming and living standards are improving, the use of air conditioners is increasing rapidly. Research on ways to improve indoor-space comfort and air conditioner efficiency in actual conditions should be followed by research on energy efficiency. An inverter air conditioner can control the amount of circulating refrigerant by varying compressor driving frequency, thereby modulating cooling ability according to heat load and maintaining room temperature while reducing deviation. Unnecessary energy loss can be reduced, and seasonal energy efficiency ratio, which is an energy efficiency index considering environmental temperature changes, is higher in inverter air conditioners than in conventional constant-speed-type air conditioners [1,2]. Kinab et al [4] examined the characteristics of compressor efficiency and power consumption and compared the effect of cooling load changes on the energy efficiency ratio. Luis et al [5] summarized the energy regulations of major countries and emphasized the importance of system efficiency

Methods

Results

Conclusion