Performance Analysis of Water-to-Air Heat Pump System under Water Temperature and Load Ratio

열원 및 부하조건에 따른 물-공기 히트펌프 시스템의 성능분석

  • Published : 2011.05.26

Abstract

Heating and cooling performance has been analyzed for the water-source heat pump system using raw water from Daechung reservoir. During heating operation from March to May, water temperature is not good condition for a heat source due to the higher atmospheric temperature. Avearged heating load ratio is only 14.3%, and the averaged unit COP and system COP are estimated to be 2.46 and 2.15 respectively. The COP is affected considerably by the water temperature, and the unit COP is increased from 2.16 at $5^{\circ}C$ to 2.95 at $11^{\circ}C$. Cooling performance is analyzed with the measured data from June to August. During cooling operation, raw water has lower temperature by 4. $5^{\circ}C{\sim}4.7^{\circ}C$ than the atmosphere. The load ratio is 39.2%, and the averaged unit COP and system COP are estimated to be 7.25 and 6.13 respectively. The heating COP is affected by the load ratio rather than water temperature. The COP is increased for 20%~40% load ratio, while is decreased for 40%~60% load ratio. It is estimated that the compressor operation combination for 3 (two constant speed and one inverter) compressors is changed for the load ratio.

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