Effects of Refrigerant Charge on Cooling Capacity

Effects of Refrigerant Charge on Cooling Capacity Points : effects of refrigerant charge on cooling capacity The variations of the capacity for the capillary tube system as a function of refrigerant charge. When the water temperature entering the condenser was 34°C, the heat pump had the maximum capacity at fullcharge condition. The slope of the capacity with a charge’ amount was much steeper at undercharged cOnditiàns than that at overcharged “conditions. For overcharged conditions, the, capacity was reduced due to a decrease of the temperature difference between the refrigerant and the water with increasing refrigerant charge. For undercharge conditions, the capacity dropped with decreasing refrigerant charge due to a reduction of refrigerant flow rate and compressor efficiency resulting from an increase of suction temperature in addition, since the superheat at undercharged conditions was higher than that at overcharged conditions, the more significant reduction of evaporator efficiency occurred at undercharged conditions. These trends were also reported in previous studies by Houcek & Thedford and Farzard & O’Neal. When the water temperature entering the condenser was 34°C the capacity decreased by 23.7%, as the charge amount was reduced from full charge to —20% of full charge. However, the reduction of the capacity was only by 4.5% as the charge amount increased from full charge +20% of full charge.