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. This paper presents the investigation results of hfc refrigerants r125, r143a, r152a and r32 which prevent the ozone layer. Guidelines for the use of hydrocarbon refrigerants in. Whenever we choose them for particular use properties of refrigerants also plays a vital role in economic and environmental friendly application. Refrigerants and read with me bible pdf refrigerating systems which are practicable but which do not at. This project was made possible with american recovery and reinvestment act of 2009 funds. 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. Thermodynamic properties of refrigerants r11, r12, r. Natural refrigerants selecting and designing energyefficient commercial refrigeration systems that use low global warming potential refrigerants caleb nelson, chuck reis, eric nelson, james armer, rob arthur, richard heath, and james rono cta architects engineers boise, idaho adam hirsch and ian doebber. Albeit numerous liquids can be utilized as a refrigerant, however in the twentieth century, cfcs turned into the most prevalent refrigerants.
Incorporating product design into the development of new. A comparison between refrigerants used in air conditioning derya ozkan, ozden agra and ozlem cetin university of yildiz technical university, turkey corresponding email. May 01, 2014 following are the desirable properties of a primary refrigerant. A refrigerant is a substance that picks up latent heat when it evaporates from a liquid to a gas. R4a is a common refrigerant used in residential refrigerators around the world, and in automobiles. Boilercastingenergyengineequationforcefuelheatjoining processlaw machinemachiningpropertiessystemthermodynamics cyclestooltypes untagged. 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. Here are some of the desirable properties of refrigerant explained in detail. The test sample of a blend shall not contain more than 40 ppm by weight of halogenated unsaturated volatile impurities, unless listed individually in section 5. Properties of refrigerants n low boiling point and high latent heat of vaporization n dense vapor n low toxicity n. Mixtures of r12 vapor and air, in all proportions, will not irritate your eyes, nose, throat, or lungs. Duponttm refrigerants, technical information keywords. The former and retrofit refrigerants have different properties with respect to the chemical compatibility with the seals.
A good refrigerant has the right combination of safety and functionality. Ammonia is highly toxic but it has excellent thermal properties and low volumetric displacement. The cfcs r12, r11, r114 and r502 together with hcfc r22 became the definitive refrigerants. Natural refrigerants was developed as a joint effort between the national renewable energy laboratory nrel and cta architects engineers. In terms of its properties, it should be considered a highclass refrigerant. 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.
Fundamental and practical flammability properties of 2l. Polyol ester poe generally exhibit excessive solubility with hc refrigerants. Originally the title given was new and alternative refrigerants but i was also asked to. In addition to the desirable properties listed, the refrigerant had a relatively. Because of the similarities between r22, r11, and r12, only r12 is discussed. The choice of perfect refrigerant is made in view of its ideal thermodynamic properties, nondestructive nature, and security nonharmful and noncombustible. At room temperature r410a has a pressure of nearly 200 psi, while r4a is around 70 psi.
These properties pressure, temperature, volume, density, enthalpy, flammability, the opportunity to mix with vegetable oil, moisture reaction, smell, toxicity, leakage trend, and leak detection. Refrigerants are classified according to their way of absorption or extraction of heat from substances stored in the refrigerator. It has the highest refrigeration effect per kilogram of all refrigerants and comes at a low cost. Refrigerants are divided into groups according to their chemical composition. Refrigerants are widely used in refrigeration cycle where cooling effect below the. In fact, from the thermodynamic or heatcarrying standpoint, differences among refrigerants with similar. Properties of oil and refrigerant mixtures lubrication. 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 with higher boiling points tend to be more efficient and may work well in a smaller machine. Download limit exceeded you have exceeded your daily download allowance. The method used to solve for new refrigerants was achieved using an iterative method based on group contribution theory. Class 1 refrigerants are completely nonflammable, class 2 types are moderately flammable and class 3 substances are highly flammable. Refrigerants color codes refrigerants and their color codes. Thermophysical properties of refrigerants t his chapter presents data for thermodynamic and transport properties of refrigerants, arra nged for the occasional user. It would not cause ozone depletion or climate change. Experimental investigation of an alternate refrigerant for. In particular they were nontoxic, nonflammable and with good thermodynamic prop erties and oil miscibility characteristics. A familiarity with these diagrams will make this chapter easier.
Their thermodynamic characteristics constitute as ideal replacement for r502 for refrigeration sector in new facilities at low and medium temperatures. Jul 17, 2017 a refrigerant with a lower boiling point tends to have a better ability to cool. Hydrocarbon refrigerants are natural replacements for cfc, hfc and hcfc refrigerant gases, and are. Class 1 refrigerants used in the standard compression type cooling system. The former and retrofit refrigerants have different properties with respect to the chemical minor 2 hcfc to hfchfo mo to poepve ab to poepve the former and retrofit refrigerants have different properties with respect to the chemical compatibility with the seals.
R4a tables pdf refrigerants and specialities wernervonsiemens str 18 d97076 wuerzburg. Most automotive air conditioning systems except in australia and possibly other countries use r4a as a refrigerant. Thermodynamic properties of duponttm freonr 22 refrigerant. Airconditioning and refrigeration institute arl is foimed through a merger of. Current requirements for a successful blend are that it should.
A number of materials have physical and thermodynamic properties suitable for their use as refrigerants. While r4a and r410a are both environmentally conscious hydrochlorofluorocarbon refrigerants, the two are otherwise dissimilar. They finally chose dichlorodifluoromethane freon as having the most desirable characteristics, thus introducing the first chlorofluorocarbons. 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. Refrigerants can be characterized by a number of properties. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Freon refrigerants r11, r12 and r22, plus ammonia and water, will be discussed in terms. Annex 18 reports the comprehensive evaluations of the available equations of state and recommended formulations for r123, r4a, r32. The liquid has to vapourise at the evaporator coil to cause cooling. If there is toxicity identified in this small amount, the substance is a class b refrigerant. Sep 17, 2014 color codes of refrigerants easy recognize gas cylinder different refrigerant has different color coding few examples are given below. The refrigerants r4a and r410a were both introduced as. Molar mass, gas constant, and criticalpoint properties. Guidelines for the use of hydrocarbon refrigerants in static refrigeration and air conditioning systems foreword with the introduction of the revised eu ozone depleting substances regulation in october 2000 and the introduction of a climate change policy by the uk government in november 2000, it is considered likely that more refrigeration.
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. It has long been used in a variety of airconditioning and refrigeration applications in a variety of markets. Pdf refrigeration and airconditioning play a vital role in domestic and industrial applications. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of airconditioning and refrigeration equipment. Desirable properties and commonly used refrigerants. This information is based on values calculated using the nist refprop database mclinden, m. Which of the following is not a desirable property for new refrigerants high boiling point which of the following refrigerants has a low gwp and can be used as a. 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. Since different fluids have the desired traits in different degree, choice is a matter of tradeoffs. As such, there is no refrigerant that can be advantageously used under all. Color codes of refrigerants easy recognize gas cylinder different refrigerant has different color coding few examples are given below. Which of the following is not a desirable property for new refrigerants high boiling point which of the following refrigerants has a low gwp and can be used as a replacement for r4a in automotive air conditioning. Refrigerants are used in the process of refrigeration, which is a process whereby heat is removed from a sub stance or a space. Technical r404a data sheet features and uses of r404a r404a is a ternary mixture consisting of r125, r143a and r4a.
Refrigerants are widely used in refrigeration cycle where cooling effect below the atmospheric temperatures are needed. 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. A blend of ab and m oils achieving desirable properties for use with hc refrigerants. The thermodynamic properties of refrigerants columbushoa. This is applicable to both refrigeration and air conditioning. A comparison between refrigerants used in air conditioning. The process is not easy, and although there are alternatives to old refrigerants, the new ones are usually not flawless. Apr 12, 2020 refrigerants are widely used in refrigeration cycle where cooling effect below the atmospheric temperatures are needed. Classification can be divided into class 1, class 2, class 3. Desirable properties of refrigerants chemical engineering site. Secondary refrigerants allow the amounts of environmentally harmful primary refrigerants to be minimized and contained in a restricted area. Major when looking at retrofit there are three main cases, retrofit type 1, 2 and 3, which need to be addressed with. With regard to environmental impacts, the preferable refrigerant is butane.
R22 light green r4a light sky blue r404a orange the name label of the gases are given on the cylinder. Properties of common household and commercial refrigerants in a responsive, clear table. Examples of secondary refrigerants include water, air, hydrocarbons, ammonia and carbon dioxide, which are more environmentally benign than traditional refrigerants such as hcfcs. Thermodynamic properties of duponttm freonr 22 refrigerant author. A refrigerant is a substance that picks up latent heat when it evaporates from a liquid to. Safety rules for the application of hydrocarbon refrigerants. State equation, equation of saturated vapor pressure, equation of liquid volume, equation of specific heat capacity, enthalpy and entropy for r11, r12. Polyalkylene glycol pag soluble or partially soluble with hc refrigerants depending upon the conditions. However, hcfc refrigerants r123 and r22 do not completely prevent the ozone layer depletion.
Refrigerants for vapour compression refrigeration systems. The properties examined in this study were toxicity, flammability, explosion potential, global warming potential, ozone depletion potential and efficiency. This liquid, sweet, colorless refrigerant has a nonirritating odor, is nonflammable and nontoxic. R502 together with hcfc r22 became the definitive refrigerants. Mixtures of r12 vapor and air, in all proportions, will not. Guidelines for the use of hydrocarbon refrigerants in static. 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.
Pdf properties of refrigerants from cubic equations of state. The publication presents a set of equations and constants for calculating thermodynamic properties of refrigerants. R22 chc1f425 and r11 cc1435f are colorless, nonexplosive, nonpoisonous refrigerants with many properties similar to those of r12. Refrigerants properties pdf product data summary and thermodynamic tables. R404a is an hfc blend designed for commercial refrigeration where has. However, hfcs still dominate the market outright and natural refrigerants, despite their superior properties, still. 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. Following are the desirable properties of a primary refrigerant.
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