Reliable and safe heat supply of residential buildings in transitional conditions with independent connection of the heating system

Abstract

The arrangement for heat supply of residential buildings with indirect connection to external heating systems is considered, providing reliability of heat input and required comfort in case of cold snaps after the official end of the heating season or before its beginning by supplying water from the return main of the heating system downstream the hot water supply heat exchangers. The calculations have been made to determine the amount of the main components of heat balance of a residential building on an example of one of standard projects being currently used in the climatic conditions of Moscow, subject to the structural characteristics of the building and its occupancy level. It is established that the actual heat output of the heating system when using the system of chilled water downstream the hot water supply heat exchangers as a heat source enables to main-tain an indoor temperature required for safe living conditions with the average daily outdoor air temperature above +2°C, the heat gain from solar radiation being moderate. It is proven that, tak-ing into account the thermal stability of the enclosing structures, the daily flow rate fluctuations do not significantly affect the stability of the temperature conditions of residential buildings or the comfort of their indoor microclimate at high outdoor air temperatures. It is noted that, in terms of reliability of heat supply of the main group of residential buildings and ensuring the life safety, the proposed arrangement is not inferior to the standard two-stage arrangement of connection of DHW heat exchangers with restriction of the total consumption of delivery water and with the associated regulation of heat supply for DHW, heating and ventilation. It is shown that the use of this arrangement involves virtually no extra costs, provides hydraulic resistance of the heating system and ensures a system-wide effect in the form of higher electricity generation at thermal consumption when using cogeneration.