Techno-economic analysis of a heat pump cycle including a three-media refrigerant/phase change material/water heat exchanger in the hot superheated section for effi cient domestic hot water generation

Abstract

Integration of a three-media refrigerant/phase change material (PCM)/water heat exchanger (RPW-HEX) in the hot superheated section of a heat pump (HP) system is a promising approach to save energy for domestic hot water (DHW) generation in multi-family houses. The RPW-HEX works as a desuperheater and as a latent thermal energy storage in the system. The latent thermal energy storage is charged during heating and cooling operation and discharged for DHW production. For this purpose, the water side of the RPW-HEX is connected to decentralized DHW storage devices. DHWconsumption, building standards and climate, energy prices, material costs, and production costs are the constraints for the selection of the optimal storage size and RPW-HEX design. This contribution presents the techno-economic analysis of the RPW-HEX integrated into an R32 air source HP. With the aid of experimentally validated dynamic computer models, the optimal sizing of the RPW-HEX storage is discussed to maximize energy savings and to minimize the investment costs. The results are discussed in the context of a return of investment analysis, practical implementation aspects and energetic potential of the novel technology.

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 768824 (HYBUILD). This work is partially supported by ICREA under the ICREA Academia programme. The authors thank C. Köfinger, M. Lauermann, and A. Zottl for critical discussion. Furthermore, we thank A. Bras and S. Hauer for their assistance in generating the data of the different buildings. The authors at the University of Lleida would like to thank the Catalan Government for the quality accreditation given to their research group (2017 SGR 1537). GREiA is certified agent TECNIO in the category of technology developers from the Government of Catalonia.