PARAMETERS OF HOT WATER SUPPLY HEAT EXCHANGERS FOR HEAT STATIONS OF INSULATED BUILDINGS AT ONE-STAGE CONNECTION SCHEME

The peculiarities of functioning of centralized heat supply systems of residential microdistricts at carrying out works on ‘insulation’ of buildings in operation, namely, parameters of operation of hot water supply heating units are considered. The influence of the heating load reduction due to the works on increasing the heat transfer resistance of the building structures on the flow rate of network water and heat exchange area of hot water supply heaters has been analyzed. Estimates are made for conditions of use of one-stage parallel scheme connection for heat exchangers to heat distribution networks. The known relations for such most widespread in heat supply systems heat exchangers as plate apparatuses are used at calculations of a heat transfer surface. The range of change of the heat transfer surface of hot water heaters and the flow rate of network water depending on the ratio of the maximum heat loads of hot water supply and heating and the degree of insulation efficiency of the building is determined. Formulas for determining the parameters of hot water supply heat exchangers are proposed. The formulas are valid in the range of reduction of heat consumption for heating of the building from 0 to 35 %. Assessment of the heating load reduction is performed on condition that the thermal modernization of a building constructed in accordance with the building requirements in force several decades ago provides modern requirements for the thermal resistance of building structures. The temperature of water in the heating system of the insulated building is determined depending on the building insulation efficiency, provided that the water flow rate through the heating system of the building before and after its insulation is unchanged. The range of variation of the ratio of hot water supply and heating heat loads accepted for consideration is 0,6–1,2. The obtained results can be used at comparison of connection schemes of heat exchangers for hot water heating for installation on individual heat points of insulated buildings.