COMPARISON OF HOT WATER HEATER CONNECTION SCHEMES FOR DISTRICT HEATING STATIONS IN INSULATED BUILDINGS

One way to improve efficiency micro-district centralized heat supply systems - transition from group thermal substations, where water is prepared for consumption of hot water supply, distribution of heat transfer by types of water supply, regulation of hydraulic and thermal regimes in microdistrict thermal limits, the volume of accumulated heat, up to individual district heating stations. The technological scheme of the individual district heating stations transfers all the necessary functions for the heat supply of the surrounding area construction. One of the advantages of such an approach is the possibility of transition to a two-pipe split thermal boundaries and changes in heat consumption by pipelines microdistrict boundaries A comparison was performed of the network water flow rates through individual district heating stations and the heat transfer surface area of domestic hot water heating installations in insulated buildings. The study analyzed two-stage mixed and two-stage sequential connection schemes of hot water heaters to district heating networks. It was shown that the use of two-stage schemes, as opposed to single-stage schemes, significantly reduces the network water flow through individual district heating stations. This effect is achieved by increasing the heat transfer surface area of heat exchangers in domestic hot water heating systems installed in individual district heating stations compared to single-stage schemes. For heating installations using the two-stage mixed connection scheme, larger heat transfer surface areas are expected compared to the two-stage sequential connection scheme. The excess surface area ranges from 10% to 70%, depending on the building's insulation efficiency and the design temperature for water heating at the first stage of the domestic hot water heating system. A formula was proposed to determine the water heating temperature at the first stage of the heating installation, at which the network water flow rate through the individual district heating station in the two-stage mixed scheme is lower than that in the two-stage sequential scheme. At a significant temperature rise, water heating at the first stage of the heating installation for individual district heating stations with insulation increased to more than 25℃, as a result of the increase in the total heat transfer area of the heat exchangers. installation equipment.