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The Simulation of the Risks When a Household Airconditioner Using Flammable Refrigerant Leaks

Author: HaiTengZuo
Tutor: HeGuoGeng
School: Huazhong University of Science and Technology
Course: Refrigeration and Cryogenic Engineering
Keywords: R290 propane leakage of refrigerant concentration simulation
CLC: TB664
Type: Master's thesis
Year: 2013
Downloads: 15
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Abstract

Since1984, the hole of ozone layer has been observed by Halley Bay, Antarcticaobservation station, people began to bring the Earth hazards concerned about the damageto our environment of using chlorine compounds. After the signing of the Treaty of Viennaand Montreal, it is just a matter of time to totally ban the chlorine-containing refrigerant,and in China, the deadline is gradually advanced from the year2020.The reason of the great boom of the world’s Refrigeration industry in the past60years largely depends on the rising of CFCs which has been proved harmless at that time.And now if the CFCs are completely banned, the refrigeration industry will surely suffer agreat impact.Far, the replacement work of the refrigerant is continued, and there are always twovoices, one is led by the United States and Japan, advocating the use of new syntheticrefrigerant to replace the old synthetic refrigerant, while another voice represented byEuropean countries, advocating natural refrigerants to replace those synthetic refrigerant.Though natural refrigerant does not have any short-term or long-term harm to theenvironment, they tend to have toxicity blasting objectionable nature which makes peoplefeel upset when using them.This article concentrates closely to the theme of refrigerant alternative of the times,and analysis the natural refrigerant R290, and by a large number of numerical methods tofind out and give out the detailed filled counters of propane’s concentration when theair-conditioner using it as refrigerant leaks and the possible dangerous areas.After verifying the feasibility of numerical simulation algorithm,5models are used inthis paper: empty bedroom model, the bedroom model with a bed in the middle andwithout desk and chair, the bedroom model with a bed in the middle and a desk and chair;the bedroom model with a bed in the corner and without desk and chair; the bedroommodel with a bed in the corner and a desk and chair. And from the first to the last model, the diffusion region of leaked refrigerants is gradually restricted one by one resulting aincreasing difficulty of diffusion and namely, the danger after leakage increase. And5groups of results are obtained by the simulation.Simulation results show that after the leakage of refrigerant, its concentration willrapidly (about5to10seconds) decrease below the lowest concentration for ignition, andwithin the process of decreasing, high concentration area is very small, and can easily befound out. So if we just pay some little attention or take some preventive measures thehidden dangers of the flammability of propane can be eliminated. At last, this paper finallyprovide the validation of feasibility and safety in using conditioner with R290asrefrigerant.

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