Research on Performance of Metal Hydride Cooling System

摘要

Present situation and status of research of metal hydride heat pumps were introduce. The thermodynamics process of hydride cooling system was analyzed. A 2-dimensional model were made respectively. The dynamic mass and heat transfer process in hydride bed was analyzed. The performance parameters, such as cooling power and refrigeration coefficient of performance were calculated and analyzed. The trends along with time of various calculated parameters, such as hydrogen concentration and temperature in reaction bed, pressure and temperature of hydrogen gas, heat exchanged between reaction bed and heat transfer fluid were analyzed. The effects on system coefficient of performance of all kinds of design parameters, such as thickness and conductivity of reaction bed, cycle time, were studied. It can be seen that low conductivity in hydride bed limits the performance of system evidently. Different measures should be taken to enhance the conductivity in bed, such as thinner bed, metal foam, mixing hydride powder with copper or aluminum powder sintered into small balls. Continuous cooling capacity can be produced by two hydride systems. Regenerative heat exchange between pre-heating and pre-cooling process of hydride systems was considered. The results show that the system coefficient of performance was increased by proper duration of regenerative heating.