• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.30 no.3
• /
• pp.107-115
• /
• 2018

A design combining the use of a compressor and expander was introduced in order to improve the cycle performance of a $CO_2$ automotive air conditioning system. Both the compressor and expander used were of rotary vane type and were designed to share a common shaft in a housing. Numerical simulation was carried out to evaluate the merit of the combined unit. In a typical automotive air conditioning operating conditions, the COP of the system was improved by 8.7% by the application of the combined unit. The compressor input was reduced by 5.2% through use of the expander output. In addition, about 3.06% increase in the cooling capacity was obtained through isentropic expansion in the expander. Our study noted that, as the pressure difference between the gas cooler and the evaporator becomes larger, the COP of the system improved increases unless the mass flow rate in the expander exceeds that in the compressor.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.18 no.1
• /
• pp.17-26
• /
• 1998

The specimen with the wear between a roller and a vane and a normal specimen are classified by AE signal pattern recognition method with a neural network classifier in airconditioning operation test. Also the specimen with the scoring between a shaft and a bearing and a normal specimen are classified by the same method. As the internal pressure increases, the wear between the roller and the vane increases. The different pairs of oils and refrigerants five the effect on the wear.

• Proceedings of the SAREK Conference
• /
• 2006.11a
• /
• pp.45-45
• /
• 2006

• 유체기계공업학회:학술대회논문집
• /
• 2002.12a
• /
• pp.221-226
• /
• 2002

One of the serious challenges in developing rotary compressor with HFC refrigerant is the prediction of scuffing times and wear amounts between vane and roller surfaces. In this study, the tribological characteristics of sliding surfaces using vane-roller geometry of rotary compressor were investigated. The sliding tests were carried out under various sliding speeds, normal loads and surface roughness. During the test friction force, wear depth, time to failure and surface temperature were monitored. Because severe wear was occurred on vane surface, TiN coating was applied on sliding surfaces to prolong the wear-life of vane-roller interfaces. From the sliding test it was found that there was the optimum initial surface roughness to break in and to prolong the wear life of sliding surfaces. Depending on the load and speed, the protective layers, which were composed of metallic oxide and organic compound, were formed on sliding surfaces. Those would play an important role in role amounts of friction and wear between miler and vane surfaces.

• Tribology and Lubricants
• /
• v.20 no.6
• /
• pp.337-342
• /
• 2004

One of the serious challenges in developing rotary compressor with HFC refrigerant is the prediction of scuffing times and wear amounts between vane and roller surfaces. In this study, the tribological characteristics of sliding surfaces using vane-roller geometry of rotary compressor were investigated. The sliding tests were carried out under various sliding speeds, normal loads and surface roughness. During the test, friction force, wear depth, time to failure and surface temperature were monitored. Because severe wear occurred on vane surface, TiN coating was applied on sliding surfaces to prolong the wear life of vane-roller interfaces. From the sliding test it was found that there was the optimum initial surface roughness to break in and to prolong the wear life of sliding surfaces. Depending on the load and speed, the protective layers, which were composed of metallic oxide and organic compound, were formed on sliding surfaces. Those would play an important role in the amounts of friction and wear between roller and vane surfaces.