The objective of this study is to investigate the performance characteristics of an injection CO2 (carbon dioxide) HPWH (heat pump water heater) at various operating conditions. In the standard and standby heat loss test conditions, the performance of a two-stage CO2 HPWH adopting a SCVI (sub-cooler vapor injection HPWH) cycle was measured and analyzed by varying the compressor frequency, the water flow rate, and the injection ratio at various outdoor temperatures. In the standard tests at the outdoor temperature of-15°C, the COP (coefficient of performance) of the optimized SCVI HPWH was 7.6% higher than that of the non-injection HPWH. During the standby loss tests at the water flow rate of 200kgh-1, the COP of the optimized SCVI HPWH was 7.1% higher than that of the non-injection HPWH.
Bibliographical noteFunding Information:
This work was supported by the Human Resources Development Program (No. 20124010203250 ) of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea Government Ministry of Trade, Industry and Energy .
© 2014 Elsevier Ltd.
- CO heat pump water heater
- Hot water temperature
- Injection ratio
- Vapor injection
- Water heating performance
ASJC Scopus subject areas
- Civil and Structural Engineering
- Building and Construction
- Modelling and Simulation
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Energy Engineering and Power Technology
- Mechanical Engineering
- Industrial and Manufacturing Engineering
- Management, Monitoring, Policy and Law
- Electrical and Electronic Engineering