Here are some of the desirable properties of refrigerant explained in detail. Why does greg gutfeld wear a ring on the middle finger on his left hand. In the last two centuries, human ingenuity made it. The hydrofluorocarbons are refrigerants that contain no chlorine and are not harmful to the ozone layer odp 0, see section 5. The refrigerants have a thermodynamic property charge. The replacement of materials with noxious properties such as ammonia toxic and ethylene flammable with nontoxic, nonflammable cfcs has been arrested by the environmental harm which the latter cause. Important refrigerants and its properties free download as word doc. The storage conditions of perishable commodities, design conditions of various cities of the world, relevant data for design. So, a tradeoff has to be done in order to achieve as high a cop as possible. Usually, a fluid, used in a heat pump and refrigeration cycle that can extract heat from another body or substance. Refrigerants are widely used in refrigeration cycle where cooling effect below the atmospheric temperatures are needed.
Howmechanismworks refrigerants and its classification. Physical properties of refrigerants molecular weight, boiling, freezing and critical points engineering toolbox resources, tools and basic information for engineering and design of technical applications. Freon refrigerants r11, r12, and r22, plus ammonia and water, will be discussed in terms of the abovementioned categories. In most cycles it undergoes phase transitions from a liquid to a gas and back again. Policylegislation on fgases and alternatives two environmental frameworks one goal the montreal protocol and the kyoto protocol. The specific volume of the refrigerant is the number of cubic feet of gas, which is formed when one pound of refrigerant evaporates. Ashrae position document on refrigerants and their responsible use 2 executive summary refrigerants are the working fluids in refrigeration, airconditioning, and heatpumping systems. Jul 17, 2017 if there is toxicity identified in this small amount, the substance is a class b refrigerant. One way of reducing the amount of these refrigerants and the risk of leakage is to chill a secondary refrigerant, such as glycol or brine, in a centralized plant room and circulate this rather than the primary refrigerant. The toxicity depends upon the concentration and exposure limits. The liquid has to vapourise at the evaporator coil to cause cooling. Globally, there is a growing interest in ammonia as a refrigerant, both by itself, and in cascade refrigeration systems with carbon dioxide and other secondary system designs. Influence of those properties, which is of the utmost significance on the vapor compression process effi. The good properties of a refrigerant are as follows.
They absorb heat from one area, such as an airconditioned space, and reject it into another, such as outdoors, usually through evaporation and condensation. The refrigerants are expensive and have negative environmental impacts when released to the atmosphere. Refrigerants and their application presented by thomas e. This refrigerant was introduced commercially in the early 1960s for low temperature applications and is particularly suitable for hermetic compressors.
Blends of reduced gwp include in addition to r4a, r1234yf and r1234zee primarily the refrigerants r32, r125 and r152a. The specific heat of liquid should be as small as possible and of vapour should be as high as possible to give less superheating of vapour. 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. Characteristics of hfc refrigerants purdue university. Thermodynamic and transport properties of refrigerants are necessary for predicting system behaviour and performance of components. Whenever we choose them for particular use properties of refrigerants also plays a vital role in economic and environmental friendly application. This unit is intended to serve as an introductory guide to the study of refrigerants. The earliest mechanical refrigeration used air as a working fluid. It is consistent with and is intended to complement iso 817. R22 will soon be phased out, so you will not see it as much as you do other refrigerants in the future. Hence, new synthetic ester lubricants were developed for this application.
A refrigerant is a substance or mixture, usually a fluid, used in a heat pump and refrigeration cycle. 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. 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. R22 light green r4a light sky blue r404a orange the name label of the gases are given on the cylinder. Following are the desirable properties of a primary refrigerant. Mar 28, 2005 abstract this chapter presents data for the thermodynamic and transport properties of refrigerants. The flood of the airconditioner, that is, the refrigerants, their properties, merits. The second generation of refrigerants included chlorofluorocarbons cfcs and hydrochlorofluorocarbons hcfcs, which became widely used because they were efficient, nonflammable, and nontoxic.
These properties are pressure, temperature, volume, density, enthalpy, flammability, ability to mix with oil, moisture reaction, odor, toxicity, leakage tendency, and leakage detection. Desirable properties of refrigerants chemical engineering site. This article describes thermodynamic properties of the refrigerants the ideal refrigerant. Hfc refrigerants are not miscible with the mineral oils used in cfc refrigeration systems. These properties pressure, temperature, volume, density, enthalpy, flammability, the opportunity to mix with vegetable oil, moisture reaction, smell, toxicity, leakage trend, and leak detection. All terms in this document will follow the standard industry definitions in the ashrae terminology website. Apr 12, 2020 refrigerants are widely used in refrigeration cycle where cooling effect below the atmospheric temperatures are needed. Fellow ashrae mcquay international staunton, virginia usa 1 what is a refrigerant. However, all other refrigerant tables work essentially the same way as the r22 example. The purpose of this international standard is to address the differing performance ratings due to the differences between multiple property formulations, which is a problem especially in international trade. Mclinden physical and chemical properties division national institute of standards and technology 325 broadway, mailstop 838. Ideal refrigerant properties, explanations of nomenclature, various types of refrigerant mixtures, ozone depletion factors and global warming impact are given, together with a worked example of a tewi calculation. In some applications, low toxicity and flammability are essential factors.
Volkmar hasse, gtz proklima, germany preface volkmar hasse, gtz proklima i. However, important practical issues such as the system design, size, initial and operating costs, safety, reliability, and serviceability etc. Table a16 properties of the atmosphere at high altitude table a17 idealgas properties of air table a18 idealgas properties of nitrogen, n 2 table a19 idealgas properties of oxygen, o 2 table a20 idealgas properties of carbon dioxide, co 2 table a21 idealgas properties of carbon monoxide, co table a22 idealgas. Thermodynamic properties of duponttm freonr 22 refrigerant. 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. However, their impact on global warming is very large compared with traditional refrigerants. Class 1 refrigerants are completely nonflammable, class 2 types are moderately flammable and class 3 substances are highly flammable. Pdf depletion of ozone layer in the stratosphere and global warming caused due to the use of different cfc and hcfc refrigerants have. Physical properties of refrigerants molecular weight, boiling, freezing and critical points. This information is based on values calculated using the nist refprop database mclinden, m. Comparison of specific volumes up to 5 degrees f five refrigerants we chose. Box 1053 morristown, new jersey 079621053 for more information call us at 180063188 or visit us at.
Refrigerants r402a, r402b, and r404a properties, uses. Table a1 molar mass, gas constant, and criticalpoint properties table a2 idealgas specific heats of various common gases table a3 properties of common liquids, solids, and foods table a4 saturated watertemperature table table a5 saturated waterpressure table table a6 superheated water table a7 compressed liquid water table a8 saturated icewater vapor. New tables of the thermodynamic properties of dupont. Toxicity classification of refrigerants is assigned to classes a or b. The desirable properties of refrigerants used in the refrigerant systems on board the ship are as follows. After studying this unit, you should be able to learn the different classifications of refrigerants, naming convention for refrigerants, properties of. For pure refrigerants, the virial, cubic, martinhou, benedictwebbrubin, and helmholtz nist equations of state and the extended corresponding states model are discussed. Pdf refrigerant types, issues, trends and future options. The flood of the airconditioner, that is, the refrigerants, their properties, merits and demerits are summarized to map the various types and their classifications. Their thermodynamic characteristics constitute as ideal replacement for r502 for refrigeration sector in new facilities at low and medium temperatures. Uses the freon hp refrigerants can be used in virtually all r502based applications, either as a result of retrofitting existing equipment that uses r502 or following development of new equipment designed to use freon hp products.
Single state selection of the single state option opens a window that allows the calculation of pressuretemperature, specific volume, enthalpy, entropy. The production and use of cfcs is restricted by the montreal protocols. Besides halogenated refrigerants, ammonia nh 3 and hydrocarbons are considered as. A comparison between refrigerants used in air conditioning. This is an important factor to consider when choosing the size of refrigeratorssystem components. Info refrigerants option screen properties calculation selection of properties on the main menu at the top left of the screen will reveal three options. The ashrae position document on ammonia as a refrigerant was. Influence of those properties, which is of the utmost significance on.
This site is like a library, use search box in the widget to get ebook that you want. The refrigerants have a fullpage thermodynamic property chart on pressureenthalpy coordinates with tabular data for the saturated liquid and vapor on the facing page. 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. Refrigerants should have high latent heat, otherwise the mass flow rate will be high. This primary refrigerant has long been used as refrigerant in large icemaking and cold storage plants. Environmental protection agency epa issued regulations under the clean air act to phase out the one of the constant themes throughout the history of the hvac industry is the search for a better refrigerant. Class a signifies refrigerants for which toxicity has not been identified. Thermodynamic properties for the alternative refrigerants nist. This paper presents the investigation results of hfc refrigerants r125, r143a, r152a and r32 which prevent the ozone layer. Refrigerant tables and charts download ebook pdf, epub. Guidelines for the use of hydrocarbon refrigerants in. This document, prepared by isotc 86sc 8wg 7, is a new international standard.
Refrigerant property an overview sciencedirect topics. The most common hfc refrigerants available since the ban on hcfcs are presented in table 5. Loss certain physical properties of refrigerants r11. The refrigerants should be non poisonous to humans and food stuff. A comparison between refrigerants used in air conditioning derya ozkan, ozden agra and ozlem cetin university of yildiz technical university, turkey corresponding email. The properties of some of the common refrigerants in use are given below. Table 1, on pages 4 and 5, shows the properties of r22 at satur ation. Vapours of refrigerants should be easily condensable. Ashrae position document on refrigerants and their. Engineering toolbox resources, tools and basic information for engineering and design of technical applications. New refrigerants to replace cfcs comprise an active area of development. It is much less expensive than some other refrigerants.
Regulatory oversight on cfc, hcfc, and other synthetic refrigerants, have refocused attention on ammonia to. Following this the requirement to move from cfcs to hfcs, and now to longerterm natural refrigerants and hfos. Properties of azeotropic refrigerants are entirely different from those of their components and may be conveniently treated as a single chemical compound. 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. Technical information at22 thermodynamic properties of dupontz freon. Safety properties of refrigerants considering flammability and toxicity are defined by ashrae standard 34 1.
Natural refrigerants sustainable ozone and climatefriendly alternatives to hcfcs introduction dr. This handy book contains properties of refrigerants, insulating materials, saturated air, some liquids and gases. 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. Refrigerants thermodynamic, physical, chemical, safety related and environmental properties have been presented and discussed in the first part of the paper. A good refrigerant has the right combination of safety and functionality. Nextgeneration low global warming potential refrigerants. The thermodynamic efficiency of a refrigeration system depends mainly on its operating temperatures. Refrigerant these properties are practically not found in any refrigerant. Refrigerant properties refrigerants can be characterized by a number of properties. Abstract models commonly used to calculate the thermodynamic properties of refrigerants are summarized. View and download powerpoint presentations on refrigerants ppt. Honeywell genetron refrigerants pressure temperature chart. 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. 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.
Thermophysical properties of refrigerants t his chapter presents data for thermodynamic and transport properties of refrigerants, arra nged for the occasional user. This class includes refrigerants that cool by phase change typically boiling, using the refrigerant s latent heat. To enable the use of smaller compressors and other equipment the refrigerant should have smaller vapor density. Guidelines for the use of hydrocarbon refrigerants in static refrigeration and air conditioning systems. Find powerpoint presentations and slides using the power of, find free presentations research about refrigerants ppt. For more comprehensive data the refrigerant supplier or. The thermodynamic properties are interrelated and mainly depend on normal boiling point, critical temperature, molecular weight and structure. Click download or read online button to get refrigerant tables and charts book now. Refrigerants may be divided into three classes according to their manner of absorption or extraction of heat from the substances to be refrigerated. Although properties of nearazeotropic refrigerants are nearer to azeotropic than to non. This section presents data for the thermodynamic and transport properties of refrigerants, arranged for the occasional users. After studying this unit, you should be able to learn the different classifications of refrigerants, naming convention for refrigerants, properties of individual refrigerants, and.
The paper on refrigerants has been divided in two parts. Toxicity is the important properties of refrigerants. Inforefrigerants option screen properties calculation selection of properties on the main menu at the top left of the screen will reveal three options. Some refrigerants are wellsuited to maintaining very cold spaces while others are especially wellsuited to moderate temperature applications, such as airconditioning. Effects of refrigerant properties on refrigerant performance citeseerx. Comparison of environmental impacts and physical properties of refrigerants ko matsunaga executive summary even before the invention of refrigeration, people wanted to improve their life by using ice to provide cold drinks and preserve food. Important refrigerants and its properties atmospheric.
However, hcfc refrigerants r123 and r22 do not completely prevent the ozone layer depletion. Development of the refprop database and transport properties of refrigerants final report mark o. Chapter 20, thermophysical properties of refrigerants, ashrae. What are the desirable properties of refrigerants primary. High critical temperature to have large isothermal energy transfer. The first generation of refrigerants included substances such as hydrocarbons, ammonia, and carbon dioxide. Predominantly 350 kw 10,000 kw cooling capacity range in which the centrifugal water chiller unit chiller is used. Originally the title given was new and alternative refrigerants but i was also asked to. Nearazeotropic refrigerants are blends whose characteristics are near to azeotropic.