Study On Energy Saving Mechanism Of Elliptic Coil Cold Storage System

Cold storage technology has become one of the hot research topics in many countries of theworld and used more and more widely because of its shifting power from on-peak loads tooff-peak periods. Cold storage technology can balance power grid, and fully use the valley powerto adjust power peaking, and transfer part of peak power demand to the valley, and cut the powersupply, and reduce the power construction investment, and protect theatmospheric environment.Coil cold storage system has the advantages of good heat transfer, and releasing coldrelatively stable, and less requirements of cold storage, and low cost of unit, so it is one of themost popular ice storage system. This paper summarizes the current research situation ofdomestic and foreign on coil storage system, and summaries the question of low heat transferefficiency and high energy consumption of the system because of big thermal resistance betweenthe Coolant and the ice and low heat transfer efficiency, so the elliptic coil tube cold storagesystem is provided to improve the heat transfer efficiency and reduce energy consumption bystudying and optimizing of the elliptic tubecold storage device.Firstly, the traditional mathematical model by Enthalpy and temperature method can notevaluate heat transfer characteristics accurately of circular tube and elliptical coil tube, soEnthalpy resistance method is proposed which can describe flow resistance parameters andevaluate heat transfer characteristics of elliptic coil tube comprehensively. Enthalpy resistancemethod is established based on Enthalpy, and Enthalpy resistance mathematical model of icestorage and melting ice of elliptical coil is established, and studies the change of the elliptic heattransfer coefficient, and variation rate of ice storage, and the Coolant temperature change, andthe water temperature change, et al.. Based on the study, verify the correctness of Enthalpyresistance method by experiment of ice storage and ice melting.Secondly, establish mathematical model of elliptical tube based on enthalpy resistancemethod, and simulate flow field of the circular tube and three kind elliptical pipe bundles toobtain their velocity distribution and pressure contour. Based on this, analyze the enthalpyresistance convection flow of different tubular, and study variation of resistance coefficient and comprehensive performance of heat transfer. The results show that the elliptic tubetemperature distribution of the elliptic tube is more uniform, and their vortex area is smaller, andflow resistance is lower, and heat convection effect is better under the same heat transfer area andoutdoor temperature. And conclude the result that there exists an optimal heat transferperformanceof elliptic tube in a certain range of Reynolds number.Thirdly，establish mathematical model of ice storage and ice melting in elliptic cold storagesystem based enthalpy resistance method, and analyze the influence different structuralparameters and operating conditions on the heat transfer performance of ice storage tank, andobtain the best energy-saving point of elliptic ice storage tank theoretically， which providestheoretical guidance for the optimization and calculation analysis of elliptic cold storage system.Last, design and optimize the experimental system of ice storage and ice meltingof elliptic coil storage system to test enthalpy resistance. For the problem of control lingthe storage coil pipe cold output difficultly, design the adaptive control system based on opendisplay cabinet elliptic coil cold storage system, and realize the high efficient use of energythrough controlling of water pump flow and cooling capacity. By the experiment, verifyenthalpy resistance model, and analysis of the characteristics of heat transfer, and the optimizeddesign of ice melting elliptic coil cold storage system.