• Md Nasar Equbal

The selection as working fluid of the optimal commercial oil to be used as lubricant in a carbon dioxide (CO2) refrigeration system is not yet solved, although POE and PAG oils give acceptable results. The oil structure and the thermodynamic activity of the oil refrigerant mixture allow for proper lubricant selection. Then at our laboratory, a comprehensive analysis on the solubility of CO2 in certain industrial POE oils and their precursors is ongoing, and several tests have been carried out so far.Application of the CO2 as a refrigerant in air conditioning of vehicle requires development of an applicable lubricant for quick rotation of the compressor. Phase behaviour of the different lubricants that is synthetic in nature, when comes in contact with CO2 forms a basis for developing a carbon-dioxide cooling circuit. Moreover, the influence of carbon-dioxide on the viscosity of oil is crucial for evaluation of the lubricant. These evaluated data of binary mixtures have been calculated and measured at temperatures ranging between 5°C and 100°C under a pressure up to 150 bars. The phase behaviour is qualitatively observed which takes place in the high-pressure view cell and complete content of the high-pressure view cell is monitored. The phase of equilibrium has been measured in an autoclave based static-analytical method. Lubricant’s viscosity which is saturated with carbon-dioxide has been calculated and measured with the integrated quartz viscometer. Carbon-dioxide with the phase behaviour of oils can be sub grouped into three different systems: systems with open miscibility gaps, binary systems with closed miscibility gaps, and the systems that show a barotropic phenomenon. Oils which show barotropic phenomenon coming in contact with compressed CO2 are not advisable and are not used as lubricants, but the oils with limited or completed miscibility with the carbon-dioxide may be used as lubricants. The awareness of phase behaviour and resulting viscosity of a gas-saturated lubricant allow an individual for evaluation of the applicability of lubricants in the car climatization systems. An analysis on the solubility of CO2 in industrial POE lubricants with specific ISO normal viscosity is described here on the basis of measurements conducted at 283 K and 343 K temperatures. In view of the development of thermodynamic models able to predict the properties of the oil refrigerant mixture, the results are discussed and compared with the solubility of precursors.

Autoclave, Barotropic, car climatization, Gas-saturated lubricant, High pressure cell,Static analytical method, Viscometer.

"Thermodynamic and Fluid Dynamic Characteristics of Carbon-Dioxide with Different Lubricants in AutomobileApplication", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 1, page no.1-5, January-2019, Available :http://www.jetir.org/papers/JETIREQ06001.pdf

"Thermodynamic and Fluid Dynamic Characteristics of Carbon-Dioxide with Different Lubricants in AutomobileApplication", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 1, page no. pp1-5, January-2019, Available at : http://www.jetir.org/papers/JETIREQ06001.pdf