University of Tasmania
Browse
145504 - Energy and exergy analysis of the air source transcritical.pdf (839.18 kB)

Energy and exergy analysis of the air source transcritical CO2 heat pump water heater using CO2-based mixture as working fluid

Download (839.18 kB)
journal contribution
posted on 2023-05-21, 01:02 authored by Wang, Y, He, Y, Song, Y, Yin, X, Cao, F, Xiaolin WangXiaolin Wang
Given the large demand nowadays for domestic hot water, and its impact on modern building energy consumption, air source transcritical CO2 heat pumps have been extensively adopted for hot water production. Since their system efficiency is limited by significant irreversibility, a CO2-based mixture could offer a promising drop-in technology to overcome this deficiency without increasing system complexity. Although many CO2 blends have been studied in previously published literature, little has been presented about the CO2/R32 mixture. Therefore, a proposed mixture for use in transcritical CO2 heat pumps was analyzed using energy and exergy analysis. Results showed that the coefficient of performance and exergy efficiency variation displayed an “M” shape trend, and the optimal CO2/R32 mixture concentration was determined as 0.9/0.1 with regard to flammability and efficiency. The irreversibility of the throttling valve was reduced from 0.031 to 0.009 kW⋅kW−1 and the total irreversibility reduction was more notable with ambient temperature variation. A case study was also conducted to examine domestic hot water demand during the year. Pure CO2 and the proposed CO2 blend were compared with regard to annual performance factor and annual exergy efficiency, and the findings could provide guidance for practical applications in the future.

History

Publication title

Energies

Volume

14

Issue

15

Article number

4470

Number

4470

Pagination

1-18

ISSN

1996-1073

Department/School

School of Engineering

Publisher

MDPIAG

Place of publication

Switzerland

Rights statement

Copyright 2021 by the authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/

Repository Status

  • Open

Socio-economic Objectives

Energy systems and analysis

Usage metrics

    University Of Tasmania

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC