Construction Modernization of Heat Accumulators Based on Solid Materials for Electricity Night Tariffs Operation

The use of heat accumulators based on solids in heat supply systems is relevant when using a two- and three-zone electricity tariff. The main advantages of such heat accumulators are simplicity of design and relatively small volume. The main parameters of the heat accumulator, affecting the efficiency of its operation, is the thickness of the accumulating material, the specific heat flux to the surface, and the temperature drop across the thickness of the material. Existing analytical methods for calculating the non-stationary thermal conductivity are practically not applicable for describing the processes of charging and discharging the battery.Based on computer simulation data, the method of calculating solid bodies under boundary conditions of the second kind has been further developed. The process of charging and discharging the heat accumulator with the help of an experimental stand was carried out. The processes of charging and discharging the heat battery under various operating conditions are investigated. It has been proved experimentally that it is permissible to use the theory of a regular thermal regime to describe the process of heating and cooling an accumulating headpiece. On the basis of the data obtained as a result of the experiment, the theory of thermal regular regime was further developed in the part of calculating the cooling and heating of bodies in convective heat exchange in channels and internal sources of heat. An algorithm for determining the design parameters of the heat accumulator in dependence of the operating conditions of the heat supply system is proposed. It is shown that to maximize the use of the storage volume it is necessary that the heating duration significantly exceed the duration of the inertial period. The recommendations on the location of heating elements in the accumulating nozzle and the choice of their number, the procedure for determining the optimum thickness of the accumulating layer, the dimensions of the accumulating nozzle and the specific heat flux to the heating surface are developed.