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UDC 697.34
Rafal’skaia Tat’iana, Mansurov R. Sh.
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
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UDC 628.147.22
DOI 10.35776/VST.2026.05.06
Prirez Denis, Prorekhin Sergei, Tusheva Mariia, Butakova Mariia
Chemical treatment of heat transfer medium to prevent corrosion under conditions of the zinc coating polarity reversal in hot water supply systems
Summary
While operating galvanized main pipelines in hot water supply systems, problems associated with accelerated pipe corrosion arise. Under normal operating conditions, the zinc coating is anodic and provides for both mechanical and electrochemical steel protection. Zinc coating damage or presence of pores in it do not cause steel corrosion, but rather expedite destruction of the coating itself. Changing environmental conditions can cause a polarity shift in the zinc coating resulting in the increased steel dissipation in pores, cracks, and scratches. Possible using chemical treatment of the heat transfer agent to prevent corrosion under conditions of polarity shifts in the zinc coating of pipes is discussed.
Key words
reagent treatment , water treatment , hot water supply system , zinc coatings , scale inhibitor , corrosion rate , zinc plated steel
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UDC 696.46.001.5
Serov S. F., Degtyarev N. S.
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
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UDC 628.144+620.193
DOI 10.35776/VST.2025.08.06
Chukhin Valentin, Makisha Nikolai
Factors affecting accelerated corrosion of galvanized pipes in hot water supply systems
Summary
The results of inspecting hot water supply systems of residential buildings in Moscow and other cities of Russia are summarized. The examined buildings had a wide range of hot water supply systems: single-zone and dual-zone, with the number of sections from 1 to 10, with the number of floors from 8 to 31, with risers up to 32 in number and combined into sectional units. A distinctive feature of all the buildings was the short service life of hot water supply systems (before time of rusty water and holes appearing in the pipes), amounting to 3–7 years instead of the period of 25 years provided for in CP 30.13330.2020 (clause 11.2). The causes of accelerated corrosion of galvanized pipes were identified by the degree of their effect. The determining factors causing accelerated corrosion are high oxygen concentration in raw cold water and disregard of the real protective capacity of the zinc coating while designing, installing and operating the systems. Particular attention is paid to cases where the causes of corrosion unevident. In order to clarify the effect of some factors causing accelerated corrosion, the results of additional studies are presented.
Key words
hot water supply system , corrosion , steel galvanized pipes , electrolytic potential
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