사무소 건물의 중앙 열원 공급식 공기열 히트펌프 냉난방 시스템의 에너지 절감 가능성 분석

Abstract

This study proposes and evaluates an air-conditioning system for office buildings that utilizes a central air-source heat pump (ASHP) to supply heating and cooling water to individual heat pumps. The proposed system aims to overcome the limitations of conventional decentralized air-to-air heat pumps, whose performance varies significantly with outdoor air temperature. To assess its performance, a thermodynamic cycle analysis and annual energy simulation were conducted using TRNSYS 18 and Engineering Equation Solver (EES) program, considering a typical office building model. Results show that the proposed system achieved higher isentropic efficiency for both individual and central heat pumps, with values of approximately 0.66 and 0.80, respectively, due to the reduced compression ratio. The coefficient of performance (COP) of the individual heat pumps in the proposed system improved by about 45% compared to the conventional system, reaching an average COP of 5.77. Moreover, the total annual energy consumption of the proposed system, including the central unit and circulation pumps, was approximately 99.4 MWh, which represents an 18% reduction compared to the reference central system (115.29 MWh). These findings indicate that the proposed central-source integrated ASHP system can significantly enhance overall energy efficiency by stabilizing heat source temperatures and optimizing the operation of distributed heat pumps.