The Optimization Model of Effective Thermal Conductivity for Metal Hydride Heat Pump of Refrigeration Cycle

The main challenge for the practical application of metal hydride heat pump (MHHP) is the relatively poor system performance, which is mainly caused by the undesirable heat transfer performance of reaction bed. However, there is no significant improvement of system performance when enhancing the effective thermal conductivity (E.T.C) of reaction bed. In order to identify the relationship between the E.T.C and system performance, a numerical model has been carried out first in this research. The effect of E.T.C on cooling temperature, cycle time, the coefficient of performance (C.O.P) and cooling power is investigated according to the numerical results, which indicate that the variation trend of C.O.P and cooling power is opposite when E.T.C increasing. There therefore exists an optimum value of (E.T.C), which is 0.7-0.8 W/mK in this research. The experimental confirmation is conducted eventually, and the comparison of results shows a reasonable agreement with an acceptable error range.