While analyses and system performance tools have shown that hfc refrigerant blends offer certain performance, capacity. Sep 17, 2014 color codes of refrigerants easy recognize gas cylinder different refrigerant has different color coding few examples are given below. These physical properties of refrigerants help us select the proper refrigerant for the application as per our requirement. This refrigerant was introduced commercially in the early 1960s for low temperature applications and is particularly suitable for hermetic compressors. The refrigerants have a fullpage thermodynamic property chart on pressureenthalpy coordinates with tabular data for the saturated liquid and vapor on the facing page. Safety rules for the application of hydrocarbon refrigerants. Many different refrigerants have been used in the past and are in use today with good ability to transfer heat from one place to another. Getting physical exploring the physical properties of these refrigerants is a good place to start.
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. Synthetic and organic refrigerants are classified under two main categories, primary and secondary. Investigation into the fractionation of refrigerant blends. After studying this unit, you should be able to learn the different classifications of refrigerants, naming convention for refrigerants, properties of individual refrigerants, and. In fact, from the thermodynamic or heatcarrying standpoint, differences among refrigerants with similar. Refrigerants and their application presented by thomas e.
Usually, a fluid, used in a heat pump and refrigeration cycle that can extract heat from another body or substance. The process is not easy, and although there are alternatives to old refrigerants, the new ones are usually not. R22 light green r4a light sky blue r404a orange the name label of the gases are given on the cylinder. Pdf refrigerant types, issues, trends and future options. Thermodynamic properties of duponttm freonr 22 refrigerant. A comparison between refrigerants used in air conditioning derya ozkan, ozden agra and ozlem cetin university of yildiz technical university, turkey corresponding email.
R22 chc1f425 and r11 cc1435f are colorless, nonexplosive, nonpoisonous refrigerants with many properties similar to those of r12. Refrigerants with higher boiling points tend to be more efficient and may work well in a smaller machine. A familiarity with these diagrams will make this chapter easier. A number of materials have physical and thermodynamic properties suitable for their use as refrigerants. Thermophysical properties of refrigerants t his chapter presents data for thermodynamic and transport properties of refrigerants, arra nged for the occasional user. The following is a list of refrigerants with their typeprefix, ashrae designated numbers, iupac chemical name, molecular formula, cas registry number blend name, atmospheric lifetime in years, semiempirical ozone depletion potential, net global warming potential over a 100year time horizon, occupational exposure limitpermissible exposure. It would not cause ozone depletion or climate change. This unit is intended to serve as an introductory guide to the study of refrigerants. Here are some of the desirable properties of refrigerant explained in detail. This article presents a comparison of the properties and performance of hydrocarbons as refrigerants in smallsize heat pump and refrigeration systems apr 12, 2020 refrigerants are widely used in refrigeration cycle where cooling effect below the atmospheric temperatures are needed. This information is based on values calculated using the nist refprop database mclinden, m. The refrigerants have a thermodynamic property chart on pressureenthalpy coordinates with an abbreviated set of tabular data for saturated liquid and vapor on the faci ng page.
Refrigerants are widely used in refrigeration cycle where cooling effect below the atmospheric temperatures are needed. A refrigerant is a substance or mixture, usually a fluid, used in a heat pump and refrigeration cycle. Fellow ashrae mcquay international staunton, virginia usa 1 what is a refrigerant. Nist standard reference database 23, refprop thermo dynamic properties of refrigerants and refrigerant mixtures, version 3. Refrigerants and read with me bible pdf refrigerating systems which are practicable but which do not at. The facts on hydrocarbon refrigerants hydrocarbons are natural, non toxic, non ozone depleting replacements for cfc refrigerants, importation and production of which were banned from december 31st 1995. This section presents data for the thermodynamic and transport properties of refrigerants, arranged for the occasional users. In fact, from the thermodynamic or heatcarrying standpoint, differences among refrigerants with similar boiling points are small. R11, r12, r22, r4a, r744, r718 are least hazardous, while refrigerants belonging to group b3 e.
Pdf properties of refrigerants from cubic equations of state. Refrigerants color codes refrigerants and their color codes. The refrigerant in any refrigerator or air conditioner flows continuously through the vapor compression cycle, absorbing the heat in the evaporator and releasing it in the condenser. Jul 17, 2017 a refrigerant with a lower boiling point tends to have a better ability to cool. In most cycles it undergoes phase transitions from a liquid to a gas and back again. Mie would allow greater charge sizes to be used for refrigerants with lower 2l burning velocities or for refrigerants that approach the nonflammable limit. 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. Because of the similarities between r22, r11, and r12, only r12 is discussed. Duponttm refrigerants, technical information keywords. If possible, the refrigerant must be odorless, but easy detection in the air is desirable. Refrigerant safety significant new alternatives policy. Although this number is very small, especially com. Mar 28, 2005 abstract this chapter presents data for the thermodynamic and transport properties of refrigerants. Examples of secondary refrigerants include water, air, hydrocarbons, ammonia and carbon dioxide, which are more environmentally benign than traditional refrigerants such as hcfcs.
Primary refrigerants change states to absorb heat from surrounding areas or substances. However, hfcs still dominate the market outright and natural refrigerants, despite their superior properties, still. 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. Incorporating product design into the development of new. In addition, it is sometimes helpful to classify some blends as nearazeotropes. Chapter 6 introduction to refrigerants flashcards quizlet. Many working fluids have been used for such purposes. Hydrocarbon refrigerants are natural replacements for cfc, hfc and hcfc refrigerant gases, and are. A numerical value assigned to refrigerants to compare the destructive potential each refrigerant poses to the ozone layer compared to r11, which has an odp of 1.
In terms of its properties, it should be considered a highclass refrigerant. A comparison between refrigerants used in air conditioning. Without being pressureregulated, primary refrigerants absorb all available heat from perishable goods until theyre frozen solid. Secondary refrigerants allow the amounts of environmentally harmful primary refrigerants to be minimized and contained in a restricted area. As demonstrated in figure 4, the higher the mie, the. Since different fluids have the desired traits in different degree, choice is a matter of. R22 is an hcfc and contains a small amount of chlorine, which gives it an odp of greater than 00. Whenever we choose them for particular use properties of refrigerants also plays a vital role in economic and environmental friendly application. 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. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of airconditioning and refrigeration equipment. In todays world, other properties of the refrigerant are more important. In many instances, the driving factors for alternative refrigeration system decisions are marketing exposure and demonstrating good environmental stewardship. Refrigerants properties pdf product data summary and thermodynamic tables. 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 n low cost.
Download limit exceeded you have exceeded your daily download allowance. Chapter 20, thermophysical properties of refrigerants, ashrae. The properties examined in this study were toxicity, flammability, explosion potential, global warming potential, ozone depletion potential and efficiency. R407cpsltt r407cpsvtt r407c t sl p p r407c t s vp p r407cdsltt r407cdsvtt r407chsltt r407chsvtt r407cssltt r407cssvtt r407ccpsltt r407ccpsvtt r407ccvsltt r407ccvsvtt r407csurftenstt r407cwsltt r407cwsvtt. Refrigerant safety the risks associated with the use of refrigerants in refrigeration and airconditioning equipment can include toxicity, flammability, asphyxiation, and physical hazards. An understanding of the pressuretemperature relationship of refrigerants as theypass through the refrigeration compression cycle also will help you as you study this chapter on refrigerant tables.
The refrigerant used should preferably be inexpensive and easily available. Refrigerants are divided into groups according to their chemical composition. This article describes thermodynamic properties of the refrigerants the ideal refrigerant. Thermodynamic properties of duponttm freonr 22 refrigerant author. Although refrigerants can pose one or more of these risks, system design, engineering controls, and other techniques mitigate this risk for the use of. It has long been used in a variety of airconditioning and refrigeration applications in a variety of. The method used to solve for new refrigerants was achieved using an iterative method based on group contribution theory. Annex 18 reports the comprehensive evaluations of the available equations of state and recommended formulations.
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