Study on Thermal Optimization of Heat Driven Type Compact MH Refrigeration System

Abstract

In order to optimize the heat driven type MH refrigeration system thermally, the calculation model based on one-dimensional thermal diffusion equation and the experimental using demonstrational system were made. At first, we investigated the thermal optimized driving temperature condition and the best MH alloy's mass ratio. But even though under the thermal optimization condition, the refrigeration performance of this system was not good to compare with traditional one. The reason of it is that the effective thermal conductivity of MH alloy bed is extremely low (about 1 W/m ・K). Then, in order to enhance the refrigeration performance, the mixing carbon fiber into the MH bed is used in this study. The effect of adding the carbon fiber on the refrigeration performance is also analyzed by the above-mentioned calculation model and demonstrational system. As shown in the results of these analyses, we are able to increase the cooling load by carbon fiber mixing. Furthermore, the decrease of COP by adding carbon fiber is not remarkable. Eventually, the mixing carbon fiber is good refrigeration performance enhancement method for this system.