Abstract
The paper presents a new approach to the formation of a system of equations -the nodal pressure model, which is based on the inverse characteristics of passive and active elements of pipeline networks developed during the study, the closing system of equations of stationary isothermal modes of the heat supply system, interpreted in terms of typical regime situations, fixing their state according to the content of the initial data.The solution of which made it possible to create an effective algorithm and computer implementation of simulation modeling of modes of large-size heat supply systems of variable technological structure.