International Journal of Engineering Research

Srinivas Pendyala ¹, M. Ravi Kumar ², B. Ravi Kumar ²

Affiliations
1 Department of Mechanical Engineering, GITAM University, Hyderabad, IN
2 Department of Mechanical Engineering, MVSR Engineering College, Hyderabad, IN

Abstract

Early mechanical refrigeration systems employed sulphur dioxide gas or anhydrous ammonia, with small home refrigerators primarily using the former. Being toxic, sulphur dioxide rapidly disappeared from the market with the introduction of CFCs. Refrigerant R12 is one of the most widely used refrigerants used for different applications.R-12 is a CFC and it has unusually high potential to cause the depletion of the ozone layer. Hence it is being replaced by R134a and certain blends. Although R134a is considered as an alternative refrigerant for R12, it has high global warming potential as per the Kyoto protocol it has to be decreased. At present natural refrigerant which is being used is a blend of propane and iso-butane. It operates at similar saturation pressures to R12 or R134A. It is also compatible with most common refrigeration materials and lubricants. HC's are having excellent thermophysical properties, only drawback is the flammability. HC's are not suitable for large cooling capacity plants as it demands more charge of the refrigerant. The present work eliminates the risk of flammable issues of HC refrigerant. Experiments were conducted on two VCR circuits in parallel connection one operating with R134a and the other with HC mixture. Therefore total quantity of the HC charge decreases.

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B. Srinivas ¹, S. Gajanana ², K. Hemachandra Reddy ³, B. Ravi Kumar ²

Affiliations
1 JDA Software India Ltd., Madhapur, Hyderabad-500032, AP State, IN
2 Mechanical Engineering Department, M.V.S.R. Engineering College, Nadergul, Hyderabad-501510, AP State, IN
3 JNTUA, Anantapur, AP State, IN

Abstract

The present work is a contribution of mathematical and operations research models that help in arriving at the best replacement strategies to determine an age of motor vehicle at which the replacement is most economical. Parameters like depreciation, money value, forecasted inflation, nominal interest rate and real interest rate are taken into consideration in model development and for various situations, the replacement period to motor vehicle is suggested.

Keywords

Replacement, Inflation, Forecasting, Interest Rates, and Money Value.

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