Modeling of characteristics of heat exchangers of heat supply systems in variable operating modes

Heat exchangers used in heating systems usually operate under conditions of variable flow rates and temperatures of heat carriers. However, the theory for calculating the variable modes of operation of such devices is based on the use of constant parameters of heat exchangers. At the same time it is clear that the parameter of the heat exchanger can be affected by all quantities that determine the change of the heat transfer coefficient. In addition, the groups of heat exchangers with a tied supply of heat, i.e. with redistribution of the heat flow in a variable mode of operation, are used. A new method for calculating the variable modes of operation of heat points with a tied heat supply has been developed. The method of mathematical modeling defines the dependencies that determine the change in the heat exchanger parameters in variable operating modes. The obtained expressions can be used to configure programmable regulators which will allow the correction of inefficient modes of operation of the heating system.