| The efficient use of energy has become a particularly important factor for the sustainable development of our economy and society.The utilization of new energy and industrial waste heat possess the characteristics of intermittence,large energy level span and dispersion.These energy sources are scattered and difficult to concentrate on stable supply.In many cases,we can't use unstable energy reasonably.Phase change energy storage technology can well solve the problem of time and space mismatch in the supply and demand of heat energy.It has broad application prospects and practical significance in the field of industrial waste heat utilization.In this paper,we selects62~# paraffin and stearic acid as phase change materials for heat storage,and graphite powder were selected as additives to strengthen phase change materials.Experiment and analyze the performance of samples by differential scanning calorimeter(DSC)and TC3000 universal thermal conductivity tester.Research the effects of additives on phase change temperature,latent heat of phase change,thermal conductivity,latent heat of condensation,sub cooling and cycle stability of phase change materials for the heat storage,so as to optimize the selection of phase change for phase change energy storage heat exchanger device material.A variety of heat exchanger forms are selected for comparative analysis of operation stability,safety,heat transfer effect,manufacturing cost and other factors.Finally,the tubular heat exchanger was selected as the form of phase change heat storage and heat exchange device.Based on the structural design of the heat storage and heat exchange device,the experimental design of the heat storage and heat exchange system,and the determination of experimental conditions,an experimental bench was built to study the heat transfer performance of the phase change heat storage and heat exchange device.Set three adjustment methods to adjust hot water inlet temperature,hot water inlet flow,and heat storage time.Experimental testing and analysis of the temperature change of the change of inlet and outlet water temperature with time during the heat storage process,the change of the heat exchange capacity during the heat storage process,and the change of the inlet and outlet temperature of the radiator with time during the heat release.The research results provide a reference and basis for the use of a phase change heat storage heat exchange device in a low-temperature waste heat recovery operation system. |
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