Research On Heat Transfer Characteristics Of Solid Electric Heat Storage Device

With the gradual expansion of the scale of wind power generation in China, theproblem of grid connection and power consumption has become the most importantfactor in the sustained and stable development of it, causing the substantial declineof average utilization hours, and affecting the economy of wind power seriously. Tosolve the problems above, in recent years, some domestic and foreign researchinstitutions present a solid electric heat storage technology that can transformabandoned wind energy in wind farm or conventional valley power, into sensibleheat storage which has significantly higher temperature through the appropriate heatstorage device. The technology can be applied to heating in winter or other energyuses, Which to some extent, solve the problem of large-scale energy losses causedby power rationing in wind farm. Furthermore, in the areas of TOU imple mentation,the technology can save running costs by heat storage of high temperature, whileovercoming a series of defects of traditional water heat storage.The theory of solid electric heat storage technology and thermal properties ofits device are in-depth studied in this dissertation. Firstly, the heat storage materialand structure form of solid electric heat storage device are determined. Taking aheat storage unit as research object, on the basis of reasonable simplifications inmathematical modeling, the temperature field analytical solutions in the process ofheat transfer with uniform initial temperature are solved by using variableseparation method combined with the characteristics of Bessel equation, and threedifferent working conditons are simulated to conduct the research of influence byrelated structural parameters and operating parameters.Based on temperature field analytical solution above, the combinations indifferent working conditions with non-uniform initial temperature of heat storageunit are classified, and the initial temperature conditions are approximatelyprocessed by integral average method, acquiring the theoretical solution expressionsof the temperature fie ld separately. A typical period is selected to simulate operatingprocesses under influences combined with different initial conditions and boundaryconditions, obtaining the changing properties of temperature fie ld and relevant thermal parameters of heat storage unit in different moments and relative positions.Eventually, according to the whole solid electric heat storage device, amathematical model of heat process between a cluster of heat storage units and thefluid is built, and the differential equation is simp lified by analyzing magnitude ofall items, the expressions of temperature distribution for the fluid and a single-rowcluster of heat storage unit’s surface are solved. The temperature field and thermalparameters of a cluster of heat storage units and fluid are analyzed by a specificcase in a heat release stage, revealing the heat transfer characteristics of solidelectric heat storage device, and providing a theoretical basis and computationalmethods for designing and running simulation.The research establishes theoretical basis for the detailed design of solidelectric heat storage and reasonable matching of various operating parameters,while providing technical references for application and promotion of the system.