Reaction durability of a magnesium oxide/water chemical heat pump system

Magnesium oxide/water chemical heat pump system was studied experimentally to demonstrate the durability for repetitive operation. The results showed that this heat pump had a practical performance for a heat storage system from viewpoints of durability to repetitive operation and heat output. The reactivity of a reactor bed was kept during ten times of repetitive reactions except a lowering of reactivity in initial three reaction cycles. From the reactivity change during whole cycles, it was surmised that this material had enough durability for dozens of times of repetition. The system was able to store thermal energy at about 430/spl deg/C and to supply thermal energy at about 85-125/spl deg/C as a heat amplifier type heat pump, and the heat output power exceeded 50 W per 1 kg of initial magnesium hydroxide during 40-60 minutes. The results of experiments and simulations showed that the heat pump had enough thermal storage capacity and thermal power as a practical system.