Development and performance evaluation of a high solar contribution resorption-compression cascade heat pump for cold climates
File(s)
Accepted version
Author(s)
Jia, Teng
Dou, Pengbo
Chu, Peng
Dai, Yanjun
Markides, Christos N
Type
Journal Article
Abstract
Absorption-resorption heat pumps (ARHPs) have great potential in utilizing low-temperature solar heat for efficient winter heating, but are limited by their weak adaptability to cold climates relative to absorption heat pumps (AHPs) and vapor compression heat pumps (VCHPs). In this work, a resorption-compression cascade system consisting of ARHP and VCHP subsystems is proposed and investigated, with the goal of achieving efficient winter heating with improved solar contribution in cold climates. Thermodynamic models of the two subsystems and of the whole cascade system are developed for system feasibility verification and performance evaluations. Feasible operation temperature and pressure conditions are identified in terms of internal subsystem matching. Based on these operation conditions, the primary energy ratio (PER) – which is a key performance evaluation index – is investigated over a range of solar fractions (f). The results show that for cases without solar contribution, the PER can be generally >0.95 under feasible operating conditions. In addition, the primary energy saving ratio (PESR) and heating capacity lift ratio (εlift), as well as the heat source temperature (Th) and ambient temperature (Tamb) restriction, are all investigated and compared to those of other, competing heating systems. The results show that the proposed system can reduce the Th demand to 69 °C (with a minimum Tamb of −21 °C) and extend the operational Tamb to −31 °C (with a minimum Th of 90 °C), while importantly achieving PESR > 0.20 and εlift > 20 % under the above extreme conditions. Moreover, when integrating the system with solar heat with f > 43 %, the proposed solar-assisted system has a clear PER advantage over an equivalent VCHP system in the Tamb range from −31 °C to 10 °C, highlighting the possibility of achieving higher solar contribution in cold climates.
Date Issued
2024-09-01
Date Acceptance
2024-05-25
Citation
Energy, 2024, 302
ISSN
0360-5442
Publisher
Elsevier
Journal / Book Title
Energy
Volume
302
Copyright Statement
Copyright © 2024 Elsevier Ltd. This is the author’s accepted manuscript made available under a CC-BY licence in accordance with Imperial’s Research Publications Open Access policy (www.imperial.ac.uk/oa-policy)
License URL
Identifier
https://www.sciencedirect.com/science/article/pii/S0360544224015792
Subjects
ABSORPTION
Cascade heat pump
Cold climates
CYCLES
Energy & Fuels
Heating
Physical Sciences
RECOVERY
Resorption-compression
Science & Technology
solar contribution
SYSTEM
Technology
Thermodynamics
Publication Status
Published
Article Number
131806
Date Publish Online
2024-05-25