A New Adaptive Defrost Method―Its Instrumentation and Experimental Verification

摘要

Efficient operation of the refrigeration systems is the key point in refrigeration technology. Over the years, many attempts have been made to increase the efficiency. At first, automatic defrost methods were developed in late 1960s. These were open loop methods that do not monitor the environmental changes. On the other hand, during the researches, it was understood that the environmental changes should be monitored to reach the optimum efficiency. This idea led to the introduction of various adaptive defrost methods, however, most of these methods have some drawbacks; for example, none of them considers heater power consumption. The main contributions of this study can be summarised as follows: 1. Development of a new adaptive defrost method. This method compensates for the evaporator temperature fluctuations. Besides, developed system also compensates for the heater power variations. 2. Design and construction of the associated control system with the optimum cost. The control system is designed using the latest microcontroller technology because of its advantages, such as smaller board space and the need for shorter development times, which are very important in reducing the time to market. 3. Testing of the effectiveness of the adaptive defrost system and the controller which are developed, designed, and constructed.