Experimental investigation on a capillary tube based transcritical CO2 heat pump system. (5th February 2017)

• Record Type: Journal Article
• Authors: Song, Yulong; Wang, Jing; Cao, Feng; Shu, Pengcheng; Wang, Xiaolin
• Is Part Of: Applied thermal engineering. Volume 112(2017:Feb.)
• Page Start: 184
• Page End: 189
• Publication Date: 2017-02-05
• Subjects: Transcritical heat pump -- Capillary -- Coefficient of performance -- Carbon dioxide; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2016.10.033
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: A capillary tube based transcritical CO2 heat pump was experimentally studied. Outdoor air temperature showed larger effect on performance than indoor temperature. The studied system behaved similar to an EEV system based on performance comparison. Gas-cooler outlet temperature showed large effect on the system performance. The studied system showed very promising results under experimental conditions. Abstract: In this study, a transcritical CO2 heat pump system using a capillary tube as an expansion device was experimentally investigated. A prototype was developed for this purpose. Experimental study was conducted under different outdoor and indoor temperatures. The results showed that the system cooling capacity and coefficient of performance (COP) dropped by 22% and 24%, respectively as the outdoor air temperature increased from 30 to 40 °C and increased by 12% and 15%, respectively as the indoor air temperature increased from 22 to 32 °C. The system performance was further compared with the transcritical CO2 heat pump using an electronic expansion valve (EEV) at different gas-cooler outlet temperatures. The comparison results showed that the transcritical CO2 heat pump using the capillary tube is promising and could achieve performance close to the heat pump using EEV over a wide range of gas-cooler outlet temperature.