An experimental study of the behavior of a high efficiency residential heat pump in cooling mode with common installation faults imposed

• Published in: Applied thermal engineering 2021-02, Vol.184, p.116116, Article 116116
• Main Authors: Hu, Yifeng, Yuill, David P., Ebrahimifakhar, Amir, Rooholghodos, Ali
• Format: Article
• Language: English
• Subjects: Accumulators; Air conditioners; Air flow; Compensators; Cooling capacity; COP; Driving conditions; Evaporators; Fault impacts; Fault intensity; Fault tolerance; Faults; Heat exchangers; Heat pumps; Heat transfer; Laboratory tests; Pumps; Refrigerants; Residential air source heat pump; Studies
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2020.116116

•Experimental data of a high efficiency residential heat pump.•Installation faults’ impacts on the performance of the system.•Liquid line restrictions reduced efficiency up to 18%.•Refrigerant charge, indoor airflow and non-condensable gas faults were also tested.•High performance system had overall robust performance with faults. Faults are believed to be common in split system air-conditioner and heat pump systems, due to operating degradation or installation problems. Common faults include improper refrigerant charge, reduced evaporator airflow, liquid line restrictions, and the presence of non-condensable gas. Laboratory tests were used to quantify fault impacts on performance of a heat pump system, and impacts on indicator variables such as refrigerant temperatures and pressures. This paper describes a large set of laboratory tests implemented on a high efficiency heat pump operating in cooling mode. This system uses R-410A refrigerant and has a rotary compressor, TXV, two accumulators, and a compensator. A small number of previous experimental studies have been done previously to study the effects of some operating faults, but none has examined a modern system with these components. The tests were conducted with a range of fault intensities and driving conditions. The results are compared to previous researchers’ experimental results. The system’s performance was found to be quite robust in the presence of faults. The TXV, accumulators, and compensator significantly reduce sensitivity to refrigerant charge and liquid line restriction faults, and other faults to a lesser extent.