IJSRST173893 | Received : 15 Nov 2017 | Accepted : 30 Nov 2017 | November-December-2017 [(3)8: 457-465] © 2017 IJSRST | Volume 3 | Issue 8 | Print ISSN: 2395-6011 | Online ISSN: 2395-602X Themed Section: Science and Technology 457 Study & Simulation of Co2 Refrigeration System Snehal D. Patil *1 , Prof. S. H. Gupta 2 * 1 Department of Mechanical, Heat Power, G. H. Raisoni College of Engineering & Mang., India 2 Department of Mechanical, Heat Power, G. H. Raisoni College of Engineering & Mang., India ABSTRACT Carbon-dioxide is not new to refrigeration. Its use began in the mid-nineteenth century and steadily increased, reaching a peak in the 1920s. Its use declined with the introduction of chlorofluorocarbons (CFCs) that operated at much lower pressures. Use of CO 2 continued, but chiefly in cascade systems for industrial and process applications. Recently, strong interest has been shown in CO 2 as a refrigerant by vending machine manufacturers. There are also possibilities for other light commercial refrigeration applications, as well as for residential air conditioning also including the industrial sector applications that involves cold storage. Keywords : Compressor, Trans-critical, Sub-critical, Cascade system, Critical point. I. INTRODUCTION Carbon-Di-Oxide (CO 2 ) is a component of our atmosphere that is essential to life. It has no ozone depletion potential and insignificant global warming potential, so CO 2 has no regulatory liability, as do HFCs. There is no need to account for the amount used, and it does not need to be reclaimed. Other principal benefits of CO 2 are that it is a natural substance; it is cheap, readily available, not poisonous in any common concentration, and non-flammable. Currently it is not an easy matter for decision makers in commercial refrigeration to make a definitive choice when it comes to refrigerants and system type. For the last decade, many refrigerant options and system architectures have appeared both on paper and in practice. The sector has been in the environmental spotlight in recent years, especially as the leakage studies have revealed the true effects of HFC emissions in centralized systems. Considerable reductions in emissions are certainly possible, but they do require changes. The challenge that is being faced in implementing this cycle is the trans-critical conditions of the gas which are very difficult to control. But it surely has its advantages and disadvantages as well. Those in detail are being discussed below as a part of the project that we carry out. The major challenges in CO 2 refrigeration involve the relatively high working pressures. R-744 (CO 2 ) is a leading option for environmental reasons, and it can be a winner for power consumption as developments of component technology and application methods continue to reveal potential performance gains. Good experience has been gained with different system configurations over many years, particularly in central and northern Europe. The confidence resulting from this experience ensures that CO 2 will be a long-term option in the foreseeable future. II. PROBLEM STATEMENT In the early days of refrigeration the two refrigerants in common use were ammonia and carbon dioxide. Both were problematic - ammonia is toxic and carbon dioxide requires extremely high pressures (from around 30 to 200 atmospheres) to operate in a refrigeration cycle, and since it operates on a trans-critical cycle the compressor outlet temperature is extremely high (around 160°C). When Freon 12 (dichloro-diflouro-methane) was newly discovered it totally took over as the refrigerant of choice. It is an extremely stable, non-toxic fluid, which does not interact with the compressor lubricant, and operates at pressures always somewhat higher than atmospheric, so that if any leakage occurred, air would not leak into the system, thus one could recharge without having to apply vacuum.