Mobile QR Code QR CODE : Korean Journal of Air-Conditioning and Refrigeration Engineering
Korean Journal of Air-Conditioning and Refrigeration Engineering

Korean Journal of Air-Conditioning and Refrigeration Engineering

ISO Journal TitleKorean J. Air-Cond. Refrig. Eng.
  • Open Access, Monthly
Open Access Monthly
  • ISSN : 1229-6422 (Print)
  • ISSN : 2465-7611 (Online)
Title Thermodynamic Modeling of Refrigerant Cycle in an Air-Source Heat Pump Boiler and Performance Validation
Authors Habin Jo ; Wonjun Choi
DOI https://doi.org/10.6110/KJACR.2026.38.11.608
Page pp.608-618
ISSN 1229-6422
Keywords 건물 전기화; 건물 에너지 시뮬레이션; 급탕 시스템; 히트펌프 모델; 냉매 사이클 Building electrification; Building energy simulation; Domestic hot water system; Heat pump model; Refrigerant cycle
Abstract Building electrification has driven growing interest in domestic hot water (DHW) systems based on air-source heat pump boilers (ASHPBs). However, heat pump performance regression models based on manufacturer-specific data have limited applicability to alternative refrigerants and off-design conditions. This study develops a physics-based dynamic ASHPB model that couples a thermodynamic analysis of the refrigerant cycle with the effectiveness-number of transfer units (ε-NTU) method and incorporates an optimization routine to determine the refrigerant evaporation and condensation temperatures that minimize total power input. The model performance is validated against manufacturer data over leaving water temperatures of 40-65℃ and outdoor air temperatures of -10 to 30℃. The results show satisfactory agreement, with a mean absolute percentage error (MAPE) of 10.1% and a mean absolute error (MAE) of 0.35 for the coefficient of performance (COP). The proposed framework thus supports the manufacturer-independent evaluation of heat pump systems without relying on proprietary empirical curve fits.