LAUSR

Abstract This study proposes a stepless variable speed driving technology for the refrigeration equipment of the air conditioning system, to realize the energy saving strategies by using the Variable Refrigerant Volume (VRV). The developed technology was applied to the Air Cooled Packaged Water Chiller Unit (ACH). In this study, a Stepless Variable Refrigerant Output (SVRO) technology was developed for the ACH. The proposed technology, SVRO, is a plug-in device attached to the ACH controller. The SVRO is divided into two modes, using the temperature and the pressure sensors as the feedback signals. The signals are transmitted to the control module for calculation by the feedback of different sensors and then regulate the output frequency of the inverter. Therefore, the ACH was tested in a single zone, and the experiment is divided into two types: closedown experiments and non-stop experiments. Moreover, three different case tests were performed and compared by applying the conventional control method and the proposed stepless variable speed driving technology. The results show that the cumulative energy consumption of the developed control technology is lower than that of the conventional method. The experimental results also show that the energy accumulated by the pressure sensor is lower than that of the temperature sensor, which is more energy-efficient. Furthermore, the experimental results of using the pressure sensor combined with the SVRO technique indicate that at least 20% of the energy saving rate was achieved. This verified the energy saving effect of the ACH with the proposed stepless variable speed driving technology.