| Title |
Effect of Outdoor Temperature on the Refrigerant Behavior in the Compressor of a Heat Pump Operating at Heating Mode |
| Keywords |
Heat pump ; 열펌프 ; Oil film thickness ; 오일막 두께 ; Bottom shell super heat ; 오일 과열도 ; Dilution ; 희석도 ; Oil viscosity ; 오일점도 ; Heating mode ; 난방모드 |
| Abstract |
The major cause of compressor failure is the decrease of oil viscosity due to floodback. In most previous researches on the compressor reliability, the relationship between oil circulation rate and performance or oil viscosity has been studied. Another research topic is flow visualization by using a sight glass on the bottom of a compressor sump area and accumulator. Both oil film thickness and oil level through the sight glass should be assessed for compressor reliability if the oil content of the mixture is small and low viscosity raise poor lubrication of pump bearing. In this study, the compressor reliability was assessed by measuring the viscosity of the mixture and calculating oil film thickness. The analysis of the relationship between bottom shell super heat and oil film thickness at heating operation was performed. It is concluded that bottom shell superheat does not perfectly stand for the mixture's behavior for a low ambient heating operation and oil film thickness can give more detailed and direct criteria for compressor reliability. |