THE CO2 HYDRATES PRODUCED IN A COMPREESION CYCLE USED FOR COOL STORAGE ON DIFFERENT INITIAL PRSSURE

A new device was designed to produce CO2 hydrates for cool storage in a compression cycle. The nucleation time, production, hydration ratio, and the cool storage capacity were calculated and analyzed under different initial pressures of CO2 in the circulatory system. Results showed that CO2 hydrates formed during the process of CO2 bubble rising and flocked together on the interface of gas and liquid. And the hydrates floating on the water are porous, and the gaseous CO2 can smoothly pass through the hydrates layer. With the initial pressure increased, the pressure dropped, the mass of hydrates produced and the hydrate ratio also increased and the nucleation time decreased. When initial pressure was 4.2MPa, the nucleation time, production, hydration ratio, and the cool storage capacity were 8min, 8.44kg, 75.1% and 4.22MJ respectively. Additionally, when a large number of the hydrates produced, after the nucleation, abrupt rise of the temperature happened in the kettle.