Heat Pump Water Heater Laboratory Test and Design Model Validation

摘要

A residential separated-type heat pump water heater (HPWH) unit was tested in a laboratory under controlled environmental conditions. Steady-state tests were conducted over a range of ambient temperatures, relative humidities, and inlet water temperatures. For the ambient temperature rise from 10 to 38 sup 0 C (50 to 100 sup 0 F), the evaporator capacity increased 62%, the condenser capacity increased 67%, and the coefficient of performance (COP) improved 34% (from 1.89 to 2.54). As the HPWH condenser inlet water temperature increased from 46 to 54 sup 0 C (115 to 130 sup 0 F) while the ambient temperature remained 23 sup 0 C (73 sup 0 F), the condenser capacity decreased 4% and the COP declined 14% (from 2.21 to 1.89). Test data were used to form a data base on HPWH performance which was subsequently used to validate the HPWH design model. The HPWH design model, a computer program derived from the existing ORNL Heat Pump Design Model, was proven to be capable of predicting the performance of the separated-type HPWH system and is intended to be used in studies concerning the improvement of HPWH performance. (ERA citation 11:025785)