Modeling method for low-capacity hot water boiler plants and their thermal loads

The paper presents a novel method for modeling autonomous low-capacity hot water boiler plants and their thermal loads. The proposed approach is based on representing the main elements of the thermal circuit (boiler, heat exchanger, heating, and domestic hot water consumers) as a group of interacting thermal masses and on using a system of differential equations to describe the heat transfer dynamics. The heat transfer coefficients between thermal masses are determined through steady-state analysis, taking into account boundary conditions on external energy flows. The computational implementation of the model was carried out in the MATLAB Simulink environment, with parameter identification based on real operational data from a boiler plant with two 1 MW boilers and 90% efficiency. In the computational experiment, both steady-state and dynamic tests were performed: heating of the boiler under nominal load and cooling after shutting off the heat carrier flow. The modeling results demonstrated a high degree of agreement with operational data (mean absolute temperature error was less than 0.5 °C), confirming the adequacy and reliability of the proposed method. The universality of the approach allows the model to be scaled to various equipment types and operating modes without significant increase in computational load. The proposed method can serve as an effective tool for engineering analysis, design, and subsequent optimization of heat supply systems, providing reductions in time and resource expenditures for experimental verification.