PROCEEDINGS OF THE RUSSIAN HIGHER SCHOOL
ACADEMY OF SCIENCES

On the territory of the Russian Federation, there are a large number of geothermal heat sources with a low, no more than 50 °C, temperature potential, on the basis of which it is possible to create environmentally friendly heat supply systems using heat pumps. Efficiency assessments were made for the use of boost-type absorption heat pumps for these purposes, in which a geothermal or technogenic heat source with a temperature of 40…45 °C is theoretically capable of providing heating of the heat carrier of the heat supply system to 55…63 °C in winter at specific costs of electrical energy for the operation of circulation pumps, automation and control systems - not more than 1.0 % of their useful heat output. The ambient air with negative temperatures sufficient to lower the temperature of the coolant to minus 4°C was considered as a cooling medium. The range of calculated values of the heat transformation coefficients for the considered conditions was α = 0.46…0.47. An analysis of the comparative advantages and disadvantages of using aqueous solutions of LiBr and LiCl salts as working bodies was carried out, on the basis of which the prospects for using the LiCl salt aqueous solutions in absorption heat pumps of a boosting type were shown.

1. Geothermal map of Russia. (In Russian). Available at: https://www.geokniga.org/maps/1009 (accessed 08.09.2023).
2. Geothermal resources of Russia. (In Russian). Available at: https://geographyofrussia.com/ geotermalnye-resursy-rossii/ (accessed 08.09.2023).
3. Goryachii istochnik pos. Belyi Yar [Hot spring of the village Bely Yar]. Available at: http://blog.kob.tomsk.ru/wiki/index.php?title=Горячий_источник_пос._Белый_Яр (accessed 08.09.2023).
4. Tselebnye istochniki [Healing springs]. Available at: https://fanatbaikala.ru/portfolio-view/mineralnye-istochniki (accessed 08.09.2023).
5. Decree of the Gosstroy of the Russian Federation of September 27, 2003 No. 170 "On approval of the Rules and norms for the technical operation of the housing stock". (In Russian). Available at: https://base.garant.ru/12132859/ (accessed 08.09.2023).
6. Baranenko A.V., Timofeevskii L.S., Dolotov A.V., Popov A.V. Absorbtsionnye preobrazovateli teploty [Absorption heat converters]. St. Petersburg, SPbGUNiPT Publ., 2005. 338 p.
7. Cudok F., Giannetti N. Absorption heat transformer – state-of-the-art of industrial applications. Renewable and Sustainable Energy Reviews, 2021, vol. 141, p. 110757. DOI: 10.1016/j.rser.2021.110757.
8. Dzino A.A., Malinina O.S. Otsenka vliyaniya temperatury greyushchego istochnika na energe-ticheskuyu effektivnost' odnostupenchatykh tsiklov absorbtsionnykh termotransformatorov [Estimation of the influence of heating source temperature on energy efficiency of single-stage absorption thermal transformer cycles]. Omskii nauchnyi vestnik. Seriya: Aviatsionno-raketnoe i energeticheskoe mashinostroenie = Omsk Scientific Bulletin. Series Aviation-Rocket and Power Engineering, 2019, vol. 3, no. 3, pp. 33–39. DOI: 10.25206/2588-0373-2019-3-3-33-39.
9. Stepanov K.I., Mukhin D.G., Alekseenko S.V., Volkova O.V. Experimental study of negative temperatures in lithium-bromide absorption refrigerating machines. Thermophysics and Aeromechanics, 2015, vol. 22, no. 4, pp. 481–489. DOI: 10.1134/S0869864315040095.
10. ASHRAE Handbook of Fundamentals. Atlanta, 1997.
11. Ren J., Qian Z., Yao Z., Gan N., Zhang Y. Thermodynamic evaluation of LiCl-H2O and LiBr-H2O absorption refrigeration systems based on a novel model and algorithm. Energies, 2019, vol. 12, p. 3037. DOI: 10.3390/en12153037.
12. Ahmad T., Azhar M., Sinha M.K., Meraj M., Mahbubul I.M., Ahmade A. Energy analysis of lithium bromide-water and lithium chloride-water based single effect vapor absorption refrigeration system: A comparison study. Cleaner Engineering and Technology, 2022, vol. 7, p. 100432. DOI: 10.1016/j.cell.2022.100432.
13. Kim K.J., Ameel T.A., Wood B.D. Performance evaluations of LiCl and LiBr for absorber design applications in the open-cycle absorption refrigeration system. Journal of Solar Energy Engineering, 1997, vol. 119 (2), pp. 165–173. DOI: 10.1115/1.2887898.
14. Conde-Petit M.R. Aqueous solutions of lithium and calcium chlorides: Property formulations for use in air conditioning equipment design. Zurich, Switzerland, M. Conde Engineering, 2014. 29 p. Available at: http://www.mrc-eng.com/Downloads/Aqueous%20LiCl&CaCl2% 20Solution%20Props.pdf (accessed 08.09.2023).
15. Baranenko A.V., Karavan S.V., Pinchuk O.A., Karavan D.V. Vodnye rastvory absor­btsionnykh termotransformatorov [Aqueous