Construction of methods to improve operational efficiency of an intermittent heat supply system by determining conditions to employ a standby heating mode

Abstract

In the course of this study we defined conditions for the rational utilization of intermittent heat supply for public buildings of various types: administrative and educational institutions, and other public buildings. Known results of theoretical and experimental research do not take into consideration the dynamics of cooling a building and the appropriateness of employing a standby heating mode. And this is very important for a model of control over a heat supply system. We modeled mathematically a change in temperature indoors for various types of buildings under variable climatic parameters, of different levels of modernization and operating parameters of buildings, all of which defines the appropriateness of employing a standby regime. By cancelling a standby mode, it becomes possible to achieve an additional energy saving effect. This paper shows the impact of enclosing structures of buildings on the dynamics of heating and cooling premises under variable climatic conditions for various operational modes. A mathematical model has been proposed for the basic operational modes when an intermittent heating supply is used. A structure of the mathematical model consists of two inertial links: low­inertial and highly­inertial. The first link reflects the process of heating air indoors. The second link reflects the process of heating a premise’s enclosing structures. Parameters of the proposed model are the coefficients of the transfer of an object along the channel “heating power – change in air temperature”, as well as the time constants for each of the links. The input variables for a given model are the ambient temperature and the premises’ utilization mode (switch time of alternating regimes). The output change is a room temperature in accordance with the current mode. We have defined boundary conditions for employing a standby mode of an intermittent heating system for various types of buildings at different degrees of thermal modernization. The results of this research could be used when designing new public buildings and while modifying heating systems at existing administrative and educational institutions. In this case, it is necessary to take into consideration the degree of thermal modernization of a building, the type of heating systems, as well as modes of utilization