An Experimental Study On Low-temperature Cool Storage Systems And Characteristics Of Cool Charge And Discharge

Developing cool thermal energy storage technology is an important measure to realize shifting electrical energy demand from peak period to off-peak period. At present, cool storage technology is applied mainly to air-conditioning in buildings, but it's potential to extend its application range with the development of technology. Therefore, the research and development of low-temperature cool storage has important theoretical and practical significance.A sort of binary eutectic salt was found by experiments with phase change temperature -10.7C and merits of phase change performance stabilization, large latent, no phase segregation and so on. The results show that this cool storage material is hopeful to been applied in the field of beer freeze plant, freezer and some chemical industry as cool storage material.A cool storage experimental apparatus with internal melt ice-on-coil was set up, and on which the heat-transfer characteristics have been determined. The effects of inlet temperature and flow rate of coolant on the heat-transfer characteristics have been primarily studied, the experimental results show as follow:(1) The charging and discharging properties are strongly affected by the inlet temperature of coolant in the cool storage tank, but weakly influenced by the flow rate. After analyzing the process of cool charging, the reasonable inlet temperature and flow rate is ?17.5 C and 1.23 m3/h separately.(2) It's a dominant part of the total thermal resistance for the one of the ice layer in the charging process and the solution layer in the discharging process outside the coils. So the emphasis of heat transfer enhancement lies in increasing the conduction coefficient of the cool storage material outside the coil.(3) The calculated value of the heat-transfer coefficient outside of the tube form experiment is compared with from conduction theory. The results show that the natural convection strengthens heat transfer, especially in the cool discharging process.(4) The concentric cylinders model is built without ice overlap during the process of icing. The thermal resistance method is used, and the phase-change interface immobilization law is found.(5) The amounts of cool charging have been correlated in terms of Fourier, Stefan andReynolds number: Q/Qmax =0.043Fo0.7401Ste0.5595Re0.3366, 0