Evaluation of the water temperature in the hot water system effect on the indoor temperature conditions

Summary

In the modern centralized heat supply systems two breakpoints of the central control heating curve are used. According to the effective regulative documents on ensuring the quality of hot water the temperature of supplied hot water should be raised in order to improve its microbiological characteristics. For this purpose the lower breakpoint of the central control heating curve was raised. At the same time in view of the impossibility of maintaining high temperature heating curves of the heat sources the upper breakpoint of the heating curve is used. However in the present day schemes of heat supply stations coordinated heat supply to the systems of hot water and heat supply is used. The effect of temperature breakpoints on the indoor conditions was studied. A comparative checking calculation of the heating curves of a heat supply station in 2011–2012 was carried out when two breakpoints of the heating curve were used and in 2014–2015 when the upper breakpoint was raised (the lower breakpoint was raised too). The indoor temperature was determined with account of various building heat accumulation coefficients at different outdoor temperatures and variable water consumption in the hot water system. The calculations showed that raising the lower breakpoint produced more significant effect on the indoor heat conditions compared to the effect of raising the upper breakpoint. Raising the temperature in the hot water system can cause unfavorable heat conditions in the heated space; therefore raising the lower breakpoint cannot be considered as an energy efficient solution of the problem. Eliminating the drawbacks in the operation of hot water systems as well as carrying out regular thermal water disinfection can ensure meeting the requirements of the effective regulative documents eliminating deterioration of the heat supply quality.

Key words

hot water supply system , heat supply system , heating system , indoor heat conditions , heating curve of the central control , heat supply station , building heat accumulation coefficient

Heat Accumulating Systems in Heat Supply of Private Dwelling Houses

Summary

An innovation design of a heat accumulator differing qualitatively from known domestic and foreign analogues has been developed. The principle of operation of the heat accumulator is based on a phase transition (solid substance – liquid) of a heat accumulating material – paraffin. Paraffin heat accumulators can be used in the systems of heat supply, heating and hot water supply of private dwelling houses and small blocks of flats. Owing to the high effective design and up-to-date materials the heat accumulator can reduce significantly expenditure of heat and electric energy. In many cases heat accumulating electric systems of the heat supply can prove to be economically attractive.

Key words

hot water supply system , heating system , regulating device , heat accumulator , phase transition