USE OF A TWO-STAGE COMBINED SCHEME FOR HEAT EXCHANGERS CONNECTION IN HEATING POINTS FOR HOT WATER SUPPLY OF INSULATED BUILDINGS

Authors

  • O. Aleksakhin V.N. Karazin Kharkiv National University
  • O. Boblovskyi O.M. Beketov National University of Urban Economy in Kharkiv
  • O. Kruhliakova National Technical University “Kharkiv Polytechnic Institute”

DOI:

https://doi.org/10.33042/2522-1809-2024-3-184-93-98

Keywords:

centralised heat supply, individual heating point, water heaters, hot water supply

Abstract

The article addresses the features of the functioning of centralised heat supply systems of residential micro-districts considering the improvement of thermal insulation of existing buildings. It also analyses the performance characteristics of hot water supply heaters installed on individual heat points of insulated buildings. The authors compared the heat transfer surface area of heaters and network water flow rate through the heating point for one-stage and two-stage combined schemes of connection of heat exchangers and heat networks.

The analysis of calculation results showed that using a two-stage combined connection scheme reduces the consumption of network water through the individual heat supply unit compared to the one-stage scheme. However, the two-stage scheme causes the necessity to increase the heat transfer surface area compared to the one-stage connection scheme. We generalised the results by formulas for calculating water flow rate from distribution heat networks and heat transfer surface area. It is possible to use the obtained results to develop a strategy for reforming micro-district centralised heating systems.

Using a two-stage combined connection scheme for hot water supply heat exchangers installed on individual heating points (IHP) of additionally insulated buildings reduces network water consumption through the individual heating point by 8–16% compared to a one-stage connection scheme. The device of a two-stage combined scheme in comparison with a one-stage scheme causes the increase of heat transfer surface area of heat exchangers of the hot water supply of individual heating points from one and a half to two times depending on the accepted design temperature of heating of cold water at the first stage of the heating unit. The results of calculations are approximated by equations, allowing, with acceptable accuracy, to compare the indicators of two-stage combined and one-stage schemes of connection of water heaters for individual heating points of insulated buildings.

Author Biographies

O. Aleksakhin, V.N. Karazin Kharkiv National University

Candidate of Technical Sciences, Associate Professor at the Department of Physics of Alternative Energy Technologies and Ecology

O. Boblovskyi, O.M. Beketov National University of Urban Economy in Kharkiv

Assistant at the Department of Oil and Gas Engineering and Technology

O. Kruhliakova, National Technical University “Kharkiv Polytechnic Institute”

Candidate of Technical Sciences, Associate Professor at the Department of Heat Engineering and Energy-efficient Technologies

References

Tovazhnyansky L., Kapustenko Р., Khavin G. et al (2004) Plate heat exchangers in industry; red. by L. L. Tovazhnyansky. Kharkov: NTU "KhPI", 232 p.

Taradai A.M. (1998) Fundamentals of plate heat exchang-ers design for heat supply systems. Kharkov: Osnova, 192 p.

Zinger N. M., Bestolchenko V. G., Zhidkov A. A. (1998) Improving the efficiency of heat supply stations. Мoscow: Stroyizdat, 185 p.

Lee, J., & Lee, K.-S. (2014). Flow characteristics and thermal performance in chevron type plate heat exchangers. International Journal of Heat and Mass Transfer, 78, 699–706.

Saha, S. K., & Haaris Khan, A. (2020). Numerical Study on the Effect of Corrugation Angle on Thermal Performance of Cross Corrugated Plate Heat Exchangers. Thermal Science and Engineering Progress, 100711. doi:10.1016/j.tsep.2020.100711.

Collis, D. C., & Williams, M. J. (1959). Two-dimensional convection from heated wires at low Reynolds numbers. Journal of Fluid Mechanics, 6(03), 357. doi:10.1017/s0022112059000696

Patrick Mitchell: Central Heating, Installation, Maintenance and Repair. Writers Print Shop, 196 (2008).

Domestic Water Heating Design Manual (2nd Edition), American Society of Plumbing Engineers (ASPE) (2003).

International Code Council. International Energy Conservation Code. Falls Church, VA, 2018.

Malyarenko V. (2006) Fundamentals of buildings thermal physics and energy saving. Kharkiv: SAGA, 484 p.

Malyarenko V., Redko А., Chaika Yu., Povolochko V. (2001) Technical thermophysics of buildings and structures envelopes. Kharkov: Rubicon, 280 p.

Aleksahin A., Boblovskiy A. (2012) Evaluation of energy-saving potential of functioning residential buildings. Energy saving. Power engineering. Energy audit. № 1(95). P. 10–15.

Aleksahin О.О. (2010) Thermal calculations of district heating systems. Kharkov: KNАME, 138 p.

Wong H.Y. (1977) Handbook of Essential Formulae and Data on Heat Transfer for Engineers. Longman, London and New York.

Published

2024-06-07

How to Cite

Aleksakhin, O., Boblovskyi, O., & Kruhliakova, O. (2024). USE OF A TWO-STAGE COMBINED SCHEME FOR HEAT EXCHANGERS CONNECTION IN HEATING POINTS FOR HOT WATER SUPPLY OF INSULATED BUILDINGS. Municipal Economy of Cities, 3(184), 93–98. https://doi.org/10.33042/2522-1809-2024-3-184-93-98