Thermophysical properties of refrigerants t his chapter presents data for thermodynamic and transport properties of refrigerants, arra nged for the occasional user. The properties are a combination of the individual component properties, and the vapor composition is different from the liquid, which promotes fractionation and temperature glide effects. Hfc refrigerants are not miscible with the mineral oils used in cfc refrigeration systems. Fundamental and practical flammability properties of 2l refrigerants national institute of advanced industrial science and technology aist kenji takizawa icr2015 workshop on risk assessment of mildly flammable refrigerants,august 20, 2015. Experimental investigation of an alternate refrigerant for. Another example of this interest was that the swedish energy agency in the 1990s funded a three year research program named alternative. A good refrigerant has the right combination of safety and functionality. Refrigerant r123 properties, uses, storage, and handling. Thermodynamic and transport properties of the refrigerant. Synthetic and organic refrigerants are classified under two main categories, primary and secondary. Describe the stages of heat theory and the principles involved in heat transfer, and recognize various components of refrigeration systems and their application. Secondary refrigerants allow the amounts of environmentally harmful primary refrigerants to be minimized and contained in a restricted area.
Refrigerants and read with me bible pdf refrigerating systems which are practicable but which do not at. The present study is concerned with properties of possible alternatives to the fully halogenated chlorofluorcarbons, a class of compounds widely used as working fuids refrigerants in refrigeration and airconditioning. The method used to solve for new refrigerants was achieved using an iterative method based on group contribution theory. The process is not easy, and although there are alternatives to old refrigerants, the new ones are usually not flawless. The liquid has to vapourise at the evaporator coil to cause cooling. The boiling point is most important because it is a direct indicator of the temperature level at which a refrigerant can be used. Without being pressureregulated, primary refrigerants absorb all available heat. Sep 17, 2014 color codes of refrigerants easy recognize gas cylinder different refrigerant has different color coding few examples are given below. Fluorocarbons, especially chlorofluorocarbons, became commonplace in the 20th century, but they are. Mixtures of r12 vapor and air, in all proportions, will not. Compressor has to be operated at high vacuum if the boiling point of the refrigerant is high at atmospheric pressure. The importance of specifying high purity products veronica shiels, barry lyons boc, the priestley centre, 10 priestley road, the surrey research park, guildford, surrey, gu2 7xy, united kingdom boc boc is a member of the linde group. As the blend changes phase, more of one component will transfer to the other phase faster than the rest. Zeotrope a blend that behaves normally as a mixture of refrigerants.
Reference fluid thermodynamic and transport propertiesrefprop, version 9. Fundamental and practical flammability properties of 2l. Class 1 refrigerants used in the standard compression type cooling system. Originally the title given was new and alternative refrigerants but i was also asked to. Thermodynamic properties of duponttm freonr 22 refrigerant. Working fluids in refrigeration cycles undergoes phase transition in cycles mostly before going to subject topic first of all we divide all refrigerants in following categories. Recognize the characteristics and procedures required to service. While having less impact on the environment, flammable. Technical r404a data sheet features and uses of r404a r404a is a ternary mixture consisting of r125, r143a and r4a. Refrigerants are classified according to their way of absorption or extraction of heat from substances stored in the refrigerator. This project was made possible with american recovery and reinvestment act of 2009 funds. Properties of refrigerants n low boiling point and high latent heat of vaporization n dense vapor n low toxicity n non flammable n low miscibility with oil. The desired thermodynamic properties are a boiling point somewhat below. It would not cause ozone depletion or climate change.
Safety rules for the application of hydrocarbon refrigerants. A refrigerant is a substance or mixture, usually a fluid, used in a heat pump and refrigeration cycle. In most cycles it undergoes phase transitions from a liquid to a gas and back again. The thermochemical and physical properties of each refrigerant were used to determine and. Toxicity is the important properties of refrigerants. After studying this unit, you should be able to learn the different classifications of refrigerants, naming convention for refrigerants, properties of individual refrigerants, and. Duponttm refrigerants, technical information keywords. An industrial and speciality gases provider, the company supplies. The refrigerants should be non poisonous to humans and food stuff. This file is licensed under the creative commons attributionshare alike 3. Low boiling temperature at atmospheric of the refrigerant is desirable. The toxicity depends upon the concentration and exposure limits.
Their thermodynamic characteristics constitute as ideal replacement for r502 for refrigeration sector in new facilities at low and medium temperatures. If there is toxicity identified in this small amount, the substance is a class b refrigerant. Selection tips for environmentally safe refrigerants. R22 chc1f425 and r11 cc1435f are colorless, nonexplosive, nonpoisonous refrigerants with many properties similar to those of r12. Airconditioning with natural refrigerants interview with thomas spanich, member of the board at eurammon, the european initiative for natural refrigerants mr. Pdf refrigeration and airconditioning play a vital role in domestic and. Jul 17, 2017 a refrigerant with a lower boiling point tends to have a better ability to cool. In spite of considerable efforts to improve the thermal properties of the alternative fluids and to develop new designs or control strategies for the systems, in some cases, inconsistent experimental results can be found 3. Many working fluids have been used for such purposes. The desirable characteristics of ideal refrigerants are. Natural refrigerants r717 ammonia r744 co 2 hydrocarbon refrigerants fluorocarbon refrigerants. The refrigerants are arranged in increasing order of atmospheric boiling point, from air at 194. Examples of secondary refrigerants include water, air, hydrocarbons, ammonia and carbon dioxide, which are more environmentally benign than traditional refrigerants such as hcfcs.
Physical properties of refrigerant metric and standard physical properties of refrigerant metric. Guiding you through todays and tomorrows refrigerants and technologies, with emphasis on global warming potential, energy consumption. Physical properties of freon 123 physical property unit freon 123 chemical name 2,2dichloro1,1,1trifluoroethane chemical formula cf 3chcl 2 molecular weight gmol 152. The refrigerant used should preferably be inexpensive and easily available. Natural refrigerants was developed as a joint effort between the national renewable energy laboratory nrel and cta architects engineers. Because of the similarities between r22, r11, and r12, only r12 is discussed. Refrigerant is the life blood of the vapor compression cycle. The importance of specifying high purity natural refrigerants. Please consult the msds for more comprehensive information, or contact the hc refrigerant products technical support representative.
R22 light green r4a light sky blue r404a orange the name label of the gases are given on the cylinder. It is desirable to have a service replacement that looks. In real cases, the objects to be ranked are described by. Color codes of refrigerants easy recognize gas cylinder different refrigerant has different color coding few examples are given below. Effects of refrigerant properties on refrigerant performance citeseerx. Environmental consciousness refrigerant options now and in the future. Properties of refrigerants n low boiling point and high latent heat of vaporization n dense vapor n low toxicity n. Class 1 refrigerants are completely nonflammable, class 2 types are moderately flammable and class 3 substances are highly flammable. Refrigerants are widely used in refrigeration cycle where cooling effect below the atmospheric temperatures are needed. The ideal working fluid or often called refrigerant would have favorable thermodynamic properties, be noncorrosive to mechanical components, and be safe, including freedom from toxicity and flammability. Natural refrigerants overview brochure 63895 12 linde gas.
This unit is intended to serve as an introductory guide to the study of refrigerants. The refrigerants have a thermodynamic property charge. Refrigerants color codes refrigerants and their color codes. R11, r12, r22, r4a, r744, r718 are least hazardous, while refrigerants belonging to group b3 e. Refrigerants properties pdf product data summary and thermodynamic tables. While having less impact on the environment, flammable refrigerants are significantly more easily. The alternate refrigerants to be used in the project have very less. Refrigerant selection involves compromises between conflicting desirable properties. It has long been used in a variety of airconditioning and refrigeration applications in a variety of markets.
A refrigerant is a substance or mixture, usually a fluid, used in a heat pump and refrigeration. Classification can be divided into class 1, class 2, class 3. In addition to the desirable properties listed, the refrigerant had a relatively high critical temperature and the ability to improve bearing performance by forming. Environmental consciousness refrigerant options now and in. After studying this unit, you should be able to learn the different classifications of refrigerants, naming convention for refrigerants, properties of. They use r22 as the base refrigerant and blend other refrigerants with it to achieve a desir able property. The properties examined in this study were toxicity, flammability, explosion potential, global warming potential, ozone depletion potential and efficiency. Without being pressureregulated, primary refrigerants absorb all available heat from perishable goods until theyre frozen solid. It was soon evident, though, that the lack of chlorine and that the new ester oils did not have the same good lubrication properties as mineral oil and cfc refrigerants. Thermodynamic properties of duponttm freonr 22 refrigerant author. Zeotropic blends shift in composition during the boiling or condensing process. Spanich, according to the german energy agency, the operation of ventilation and airconditioning systems accounts for around 20 percent of all energy consumed by commercial buildings. In terms of its properties, it should be considered a highclass refrigerant. Apr 12, 2020 refrigerants are widely used in refrigeration cycle where cooling effect below the atmospheric temperatures are needed.
With this in mind, the working group has taken as its starting point the results of annex 18 thermophysical properties of the environmentally acceptable refrigerants of the heat pump programme of the international energy agency mclinden and watanabe. Fluids suitable for refrigeration purposes can be classified. Following the discovery that some of these chemical compounds may be harmful to the environment, they are being replaced with more environmentally friendly alternatives see figure 5. Annex 18 reports the comprehensive evaluations of the available equations of state and recommended formulations for r123, r4a, r32. Second, because of its superior thermodynamic properties, ammonia as a refrigerant requires less energy than other refrigerants when used in large industrial systems. Hence, new synthetic ester lubricants were developed for this application. Mixtures of r12 vapor and air, in all proportions, will not irritate your eyes, nose, throat, or lungs. All refrigerants are dangerous if misused or applied incorrectly.
You may do so in any reasonable manner, but not in. Refrigerants with higher boiling points tend to be more efficient and may work well in a smaller machine. Here are some of the desirable properties of refrigerant explained in detail. New, natural and alternative refrigerants by dr s f pearson of star refrigeration limited introduction it is an honour to be invited to present this paper despite the rather daunting title. Whenever we choose them for particular use properties of refrigerants also plays a vital role in economic and environmental friendly application. Oct 04, 2016 hey guys, refrigerants is nothing but. Selection tips for environmentally safe refrigerants a refrigerant is a fluid used in a refrigeration system to extract heat at low temperature and low pressure during evaporation and reject heat at high temperature and high pressure during condensation.
Desirable properties of refrigerants chemical engineering site. Incorporating product design into the development of new. The liquid at the evaporator coil should therefore vapourise easily, otherwise the compressor will have to create too much of vacuum to cause the liquid to vapourise. Primary refrigerants change states to absorb heat from surrounding areas or substances. Following are the desirable properties of a primary refrigerant. We provide packages from laboratory samples to 15tonne bulk deliveries. This information is based on values calculated using the nist refprop database mclinden, m. Should is used to indicate provisions which are not mandatory but which are desirable as good practice. Boc offers a comprehensive range of natural refrigerants as well as traditional fluorocarbon refrigerants to the refrigeration and air conditioning industry. Indirect systems with secondary refrigerants or coolants have in sweden long been used for ice rinks and heat pumps and are today increasingly used by supermarket chains for cold storage, cooling. The physical properties of a fluid largely determine its suitability for use in a given application. Since different fluids have the desired traits in different degree, choice is a matter of tradeoffs. Commonly used refrigerants are carbon dioxide, sulphur dioxide, ammonia, freon11, freon12 and cryogenic refrigerants.
The properties of zeotropic blends are somewhat different than traditional refrigerants. R404a refrigerant properties pdf r404a is a blend of hfc refrigerants commonly used for medium and low. It is the fluid that flows continuously through the refrigeration cycle or vapor compression cycle absorbing heat from the low temperature reservoir and throwing it to the atmosphere or any other high temperature reservoir. Download limit exceeded you have exceeded your daily download allowance.