Integration of booster heat pumps in ultra-low temperature district heating network: Prototype demonstration and refrigerant charge investigation

Tingting Zhu, Yanjun Du, Jierong Liang*, Wilko Rohlfs, Jan Eric Thorsen, Brian Elmegaard

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

79 Downloads (Pure)

Abstract

Decentral booster heat pumps (BHPs) integrated in ultra-low temperature district heating (ULTDH) systems are deemed a sustainable solution for low-carbon building systems. The performance of BHPs is critical for the implementation of ULTDH systems. In this study, we experimentally investigate the effect of refrigerant charge on temperature, pressure, system coefficient of performance (COP), and heating capacity to evaluate the operability and sensitivity of ULTDH. A performance-guaranteed range of refrigerant charge is proposed to ensure the feasibility of the system. We also analyse the component-level exergy destruction and the system-level exergetic efficiency of a BHP prototype. The exergetic efficiencies range from 24.9 % to 33.4 % under operational conditions for ULTDH. The condenser and evaporator's exergy destruction is influenced by the temperature profiles on both sides, suggesting the potential to improve BHP performance by tailoring operating parameters. Additionally, the return water temperature significantly affects the system COP when the domestic hot water supply temperature is fixed. Within the allowable range of return water temperature, BHP operation with high evaporator outlet water temperature can improve the overall efficiency of the ULTDH system.
Original languageEnglish
Article number113516
JournalEnergy and Buildings
Volume298
Number of pages14
ISSN0378-7788
DOIs
Publication statusPublished - 2023

Keywords

  • Booster heat pump
  • COP
  • District heating
  • Domestic hot water
  • Exergy analysis

Fingerprint

Dive into the research topics of 'Integration of booster heat pumps in ultra-low temperature district heating network: Prototype demonstration and refrigerant charge investigation'. Together they form a unique fingerprint.

Cite this