Derivation of the equations of regulation and analysis of the hydraulic modes of open heat supply systems without flow regulators at the service connection

Energy efficiency and improved quality are currently very relevant issues in the housing and communal sector. These can be addressed, first of all, by introducing automated control systems and implementing optimized algorithms for monitoring and regulating heating and heat supply processes in general. The task of studying the features of the hydraulic regime of open heat supply systems without flow controllers at subscriber inputs is considered. Since a significant number of heating networks are open, the ban on their operation was reversed by Federal Law No. 438-F3 of December 30, 2021. Existing literature on open heating networks was analyzed and summarized. The hydraulic regime of open heating networks is very complex; its characteristic features are not sufficiently detailed and not clearly explained in the literature. This introduces difficulties in improving the quality of operation of open networks and university educational programs. In this paper, a detailed derivation of the main relationships characterizing the hydraulic regime is provided, with the assumption that the analyzed heat network is configured according to S.A. Chistovich’s horizontal track principle. This makes it possible to reduce the calculation of a real operating network to a calculation of the hydraulic regime of a single-loop equivalent heat network using Kirchhoff’s laws for hydraulic circuits, which, unlike electrical circuits, are always non-linear circuits. The obtained solutions for specific cases were analyzed; in particular, the influence of the water intake on the heating mode of consumers was studied for various characteristics of the heat supply system and outdoor temperature. The aforementioned algorithms can be used both for the algorithmic support of automated heat supply control systems and for educational purposes.