Development of marketable solar assisted heat pumps. Phase II. Summary report, technical results

A water source heat pump has been designed that is capable of operating over the range from 40 to 110/sup 0/F entering water temperature and has a heating coefficient of performance greater than six in the upper portion of this range. A computerized heat pump balance program was written to allow the performance of either a water-to-water or a water-to-air heat pump to be predicted in either the heating or cooling mode. A detailed program description, flow charts, and sample outputs are appended. The balance program was used to specify components for a high efficiency water-to-water and a high efficiency water-to-air heat pump. Performance predictions for both units in heating and in cooling are included. The water-to-water and water-to-air performance predictions were compared. The water-to-air approach was clearly superior. A detailed design and layout was done for the three solar-assisted water-to-air heat pump. A horizontal configuration was chosen for marketability reasons. The design was made consistent with high quantity production equipment available in our factories and should result in the lowest possible manufacturing cost. A key question to be answered in this project is whether a reciprocating compressor can operate without damage at the high suction pressures characteristic to the inline SAHP. Reciprocating compressors are normally applied in applications with maximum suction pressures equal to a 55/sup 0/F saturated suction temperature. An accelerated life test was performed on low speed at 85/sup 0/F saturated suction temperature and 100/sup 0/F saturated condensing temperature. After 465 hours at these severe conditions no performance degradation or physical damage was noted. Tests on high speed at 70/sup 0/F saturated suction temperature are in progress and should define the limits where the compressor may be safely operated