Research On Cascade Phase Change Energy Storage System And Its Key Technologies

The phase change energy storage is a hot spot in the research of energy storage because of its advantages such as large storage heat of unit volume,constant temperature of heat storage and heat release process and so on.In this paper,cascade experimental phase change thermal storage platform as the research object,according to the phase change heat exchanger heat transfer and flow characteristics of the numerical simulation,and develop a set of suitable for the experimental platform of control strategy,build complete control system and experiment.Firstly,the internal of the low temperature heat storage device for heat transfer research,establish the corresponding mathematical model,and put forward the effective heat capacity method simplified the phase change process.The simulation results can reflect the effects of different mass flux and different heat transfer time on the heat transfer and heat release process.According to the phase change energy storage experimental platform,the overall control scheme and the control mode of the phase change energy storage platform are given.In this study,a detailed study is made on the heat storage operation mode and the heat release mode,and the system diagram,flow chart and control strategy are given.The hardware equipment and the key parameters of the experimental system are introduced in detail,and the AI,DI,AO and DO signal of the platform are analyzed,According to different signals,select different control acquisition boards,and how to realize the communication of the various types of signals are introduced in detail,through the LABVIEW software programming to achieve the automatic control function of the experimental platform.In the end,the experimental study on the phase change thermal storage system is carried out.The experimental results show that the total heat storage heat of the phase change is 64.5KWh,and the phase change heat is 53.5KWh.The total heat release rate is 82.9%.The temperature of the outlet of each heat exchanger can be achieved at the time of the heat release and the temperature can be maintained for a period of time.Compared with the single heat storage and heat storage,the combined heat storage is more heat,and the heat storage rate is faster.It is showed that the cascade phase change thermal storage system has a positive significance for the realization of thermal energy utilization of the target.