Reliability of Methods of Calculation of Heating Systems for Digital Model

The paper focuses on the fact that today's modern digital technologies are a productive tool in the field of energy efficiency and energy conservation of thermal energy complex of the Russian Federation. The paper analyses different methods of hydrodynamic calculation of heating systems. The main task includes the analysis of existing hydraulic regime models to determine the prospects of the need to refine the techniques to build digital twin systems. The results of the calculations of the hydraulic regime of the heating systems are presented by summarising the existing mathematical description approaches, the convergence of which was assessed by comparing the values obtained as a percentage of the adopted basic calculation method. The authors note significant discrepancies in the results obtained, which are explained by the assumptions adopted in a particular method in order to simplify calculations and save time in the course of their implementation. It is suggested to use in calculations the values of local resistance coefficients according to the known dependences presented in scientific literature, where the influence of liquid movement mode on the value of local resistance coefficient is taken into account. It is pointed out that the concept of digital twin construction requires development and validation of mathematical models with high level of adequacy. In this connection it is concluded that the mathematical description of thermal and hydraulic regimes of heating systems requires clarification and additional theoretical and experimental research.