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Frontiers in Energy

Front. Energy    2019, Vol. 13 Issue (2) : 411-416
Experimental investigation on oil-gas separator of air-conditioning systems
Dianbo XIN(), Shuliang HUANG, Song YIN, Yuping DENG, Wenqiang ZHANG
Qingdao Hisense Hitachi Air-conditioning Systems Co., Ltd. Qingdao 266071, China
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The oil-return system plays an important role in the variable refrigerant flow (VRF) systems because it ensures the reliable operation of the VRF systems. The oil-gas separator is the most essential component of the oil-return system, and the separation efficiency of the separator directly influences the performance of the VRF systems. Therefore, in this paper, a test rig was built to measure the oil discharge ratio of the compressor and the separation efficiency of the oil-gas separator. A sound velocity transducer was used to measure the oil mass concentration instantaneously, because the sound velocity was changed with the mass ratio of oil to refrigerant. The separation efficiency of the separator could be obtained by comparing the mass fraction of oil to refrigerant before and after the separator was connected to the system.

Keywords variable refrigerant flow system      oil-gas separator      separation efficiency     
Corresponding Authors: Dianbo XIN   
Online First Date: 09 February 2017    Issue Date: 04 July 2019
 Cite this article:   
Dianbo XIN,Shuliang HUANG,Song YIN, et al. Experimental investigation on oil-gas separator of air-conditioning systems[J]. Front. Energy, 2019, 13(2): 411-416.
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Dianbo XIN
Shuliang HUANG
Song YIN
Yuping DENG
Wenqiang ZHANG
Fig.1  Schematic diagram of experimental setup
SensorControl rangeAccuracyMeasurement location
Pressure transducer0.1–1.2 MPa±0.15%Suction pipe of compressor
Pressure transducer1.0–4.5 MPa±0.15%Discharge pipe of compressor
Temperature transducer15°C–40°C±0.1°CSuction pipe of compressor
Temperature transducer30°C–60°C±0.1°CBefore the expansion valve
Temperature transducer25°C–45°C±0.2°CEnvironment of the compressor
Sound velocimeter200–1600 m/s±0.01 m/sAfter the sub-cooler
Tab.1  Measurement accuracy and location of sensors
Fig.2  Validation of sound velocity method
Fig.3  Oil discharge ratio at different rotary speeds
Fig.4  Oil flow rate at different rotary speeds
Fig.5  Oil discharge ratio at different pressure ratios
Fig.6  Oil concentration after oil separator at different pressure ratios
Fig.7  Oil separation efficiency at different pressure ratios
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