Isoentropic Efficiency of the Air-to-Air Heat Pump Compressor
Keywords:
air-to-air heat pump, energy efficiency assessment methodology, conversion coefficient, isentropic efficiencyAbstract
It is noted that the problem of energy-efficient heat supply in winter and air conditioning in summer is one of the key problems in the global energy sector, as this industry consumes more than half of primary energy resources. Under such conditions, air-source reversible heat pumps are considered as a promising solution for residential and commercial buildings due to their versatility, high energy efficiency, and use of a renewable energy source – the heat of atmospheric air.
Since the key indicator of the efficiency of a heat pump is the conversion coefficient, it becomes important to reliably determine the isentropic efficiency of the compressor, which significantly affects the consumption of electrical energy and the thermodynamic performance of the cycle. In real operating conditions, the compressor operates at variable loads, pressures, and temperatures, which makes it impossible to use a constant value of isentropic efficiency for a correct assessment of the energy characteristics of the system. Factors that affect the isentropic efficiency of the heat pump compressor are analyzed.
The article presents an experimental stand and a methodology for determining the energy efficiency of an air-to-air heat pump, taking into account the energy consumption of the fans of the indoor and outdoor units. Based on the measured values of pressures and temperatures of the refrigerant R410a and air in the evaporator and condenser, experimental data on the isentropic efficiency of the rotary compressor of the reversible air-to-air heat pump were obtained. A comparison of the obtained results with polynomial correlations published by other authors was carried out, it allowed to establish that these polynomial models have a satisfactory correspondence to the obtained experimental results, but the accuracy of the model depends on the type of refrigerant, compressor design, and operating conditions.
References
H. Oliinyk, “Study of the efficiency of using a heat pump in the heat supply system of a private house,” Вісник Тернопільського національного технічного університету, № 3, c. 14-20, 2022. https://doi.org/10.33108/visnyk_tntu2022.03.014 .
G. Murano, et al., “Energy Potential of Existing Reversible Air-to-Air Heat Pumps for Residential Heating,” Sustainability, vol. 6047, no. 16 (14), 2024. https://doi.org/10.3390/su16146047 .
Z. Xinhui, et al., “Experimental Study on Heating Performance of Air – source Heat Pump with Water Tank for Thermal Energy Storage,” in 2017 10th International Symposium on Heating, Ventilation and Air Conditioning, 2017, vol. 205. pp. 2055-2062. https://www.researchgate.net/publication/320762602 .
V. Andreas, et al., “Data-driven compressor performance maps and cost correlations for small-scale heat-pumping applications,” Energy, vol. 291. March 2024. https://doi.org/10.1016/j.energy.2023.130171 .
Handbook of Energy Efficiency in Buildings. 2019. https://doi.org/10.1016/B978-0-12-812817-6.00040-1 .
Chunling Wu, et al. “Low-temperature air source heat pump system for heating in severely cold area: Long-term applicability evaluation,” Building and Environment, vol. 208. January 2022. https://doi.org/10.1016/j.buildenv.2021.108594 .
Д. В. Степанов, і Д. М., Резидент, «Експериментальний стенд для дослідження енергетичної ефективності теплового насоса типу «повітря-повітря,» на Енергоефективність в галузях економіки України, Міжнар. наук.-техн. конф. Вінниця, 2023. https://conferences.vntu.edu.ua/index.php/egeu/egeu2023/paper/view/19406/16085 .
D. Gibb, et al., “Coming in from the cold: Heat pump efficiency at low temperatures,” Joule, vol. 7. рр. 1939-1942, September 2023. https://doi.org/10.1016/j.joule.2023.08.005 .
F. Ransy, et al., “Performances of a simple exhaust mechanical ventilation coupled to a mini heat pump: modeling and experimental investigations,” in 36th AIVC Conference, 2015. https://www.researchgate.net/publication/289442374 .
C Keith Rice, “The ORNL Modulating Heat Pump Design Tool – Mark IV User’s Guide,” Technical Report. May 1991. http://doi.org/10.2172/814355 .
Published
How to Cite
Issue
Section
License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgment of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).
