EXPERIMENTAL INVESTIGATION OF THE POTENTIAL OF LIQUIFIED  PETROLEUM GAS IN VAPOUR COMPRESSION REFRIGERATION SYSTEM

O. A. Adeaga; O. O. Alabi; S. A. Akintola

O. A. Adeaga Department of Mechanical and Mechatronics Engineering, First Technical University, Ibadan
O. O. Alabi Department of Mechanical Engineering, University of Ibadan
S. A. Akintola Department of Petroleum Engineering, University of Ibadan

Keywords: Refrigerant, Global Warming Potential, Vapor Compression, LPG, COP, Flammability

Abstract

The essence of refrigeration systems cannot be overemphasized especially in this part of the globe. Perishable items are to be preserved for some periods before usage while human comfort should also be also be paramount since we are in the northern hemisphere of the globe. The device hat doe this uses refrigerants as working fluids which are traditional harmful to human beings through depletion of the ozone layer. Majorly Ozone layer protects the earth from warming which could lead to flooding. Common economical refrigerants like CFCs (Chlorofluorocarbons) have been discovered to be harmful to the earth. This article therefore, experimented the quantity replacement of CFCs with Liquefied Petroleum Gas in various mixes. The LPG (Liquefied Petroleum Gas) used consists a mixture of propane and butane in the ratio 6:4 by mass. The blend of the two refrigerants were shaped essentially by blending at least two single-part refrigerants, the GWP (Global Warming Potentials) of a refrigerant mix is the mass-weighted normal of GWPs of individual parts in the mix. That is, to compute the GWP of a mix, one essentially adds the GWP of the singular parts with respect to their (GWP (LPG) x M (LPG)) + (GWP(R-134a) x M(R-134a)) = GWP (blend). From the evaluated GWP of the 6 different % mass composition, the % mass of (100%/0%) was the only refrigerant to adhere to the preferred GWP<150. The mass composition of blend (100%/0%) LPG/R-134a was first performed. In-order to achieve this, 8kg of each of the refrigerant was used. The blend was formed in an empty cylinder which was measured as 2482g with the aid of a digital beam balance, by gradually injecting LPG into the empty cylinder till the mass percentage of the 2000g entered, making the mass read as 4,482g (i.e., 2482g of the empty cylinder + 2000g of LPG). Based on the above observations, it could be inferred that the COP (Coefficient of Performance) of mixed refrigerants blends was higher than that of R-134a indicating that each of the blend exhibit higher performance. The experiment discovered that LPG could be used in the place of R134a without affecting the operation efficiency of a vapor compression refrigeration system. The study concludes that LPG offers the best alternative when the COP and flammability are combined as performance metrics