A potential approach for reducing the R290 charge in air conditioners and heat pumps. (May 2019)

• Record Type: Journal Article
• Authors: Zhou, Wenjie; Gan, Zhihua
• Is Part Of: International journal of refrigeration. Volume 101(2019)
• Page Start: 47
• Page End: 55
• Publication Date: 2019-05
• Subjects: R290 propane -- Micro bare tube heat exchanger -- Air conditioner -- Heat pump; Propane R290 -- Échangeur de chaleur à micro-tube nu -- Conditionneur d'air -- Pompe à chaleur; Refrigeration and refrigerating machinery -- Periodicals; 621.56
• DOI: 10.1016/j.ijrefrig.2019.02.030
• Languages: English
• ISSNs: 0140-7007

Abstract

Highlights: Micro bare tube heat exchangers have been installed in a split AC unit for the first time. This R290 system COP is 3.40 under ISO-5151:2017 standard. The propane charge is 248 g which is under the EN378-1:2016 regulation. Abstract: This study presents a potential approach for reducing the propane (R290) charge required in air conditioners (ACs) by introducing micro bare-tube heat exchangers as the condenser and evaporator. A theoretical model is developed to predict the performance of a split AC unit, and the unit is tested in an experiment. The split AC unit is tested under the ISO 5151:2017 standard capacity rating test condition in a psychrometric room (outdoor conditions: 35 °C dry bulb/24 °C wet bulb; indoor conditions: 27 °C dry bulb/19 °C wet bulb). The compressor input electricity power is 928 W with 62-W condenser fan power and 82-W evaporator fan power. The test cooling capacity is 3645 W with a system coefficient of performance of 3.40. The stainless steel micro-tube heat exchanger has a 0.58-mm outer diameter and 0.38-mm inner diameter. Owing to the use of micro bare tubes, the optimal propane charge is 248±5 g, which follows the EN378-1:2016 regulation. The use of micro bare-tube heat exchangers in a split AC unit could be a potential approach to reducing the R290 charge required in ACs and heat pumps.