R4a has relatively low pressure and therefore about 50% larger compressor displacement is required when compared to r22. However, the compressor must use a synthetic polyester lubricating oil. Both the neat lubricant and a mixture of lubricant and refrigerant 5050 volume ratio were tested. Chlorofluorocarbons cfcs had been phased out under the montreal protocol. It is odorless, nontoxic, nonflammable, nonexplosive and noncorrosive. Vapour charging solstice n40 may result in the wrong refrigerant composition and could damage the system. The toxicity depends upon the concentration and exposure limits. While leakage rates can vary widely among different hvac products, good design and servicing can keep leakage to a minimum. Steve is a distinguish service member of ashrae and is involved in numerous refrigerant safety standard 34 and use standards used globally by the hvacr.
High latent heat of vaporization to get more refrigeration effect. Toxicity is the important properties of refrigerants. Agas au11734 r22 is a single component hcfc refrigerant that has historically been used for air conditioning, medium temperature and low temperature refrigeration. In todays world, other properties of the refrigerant are more important. 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. Key properties of the main refrigerants are given in table 3.
A good refrigerant has the right combination of safety and functionality. After some time the two main refrigerant innovators honeywell and chemours came out with a new refrigerant under their hfo line known as r1234yf. Key properties of the main refrigerants are given in together with their typical application ranges. Note that in most cases, equipment designed for r22 cannot use r410a because of this difference in operating pressures, so retrofitting an existing r22. Carbon dioxide is widely used as a refrigerant in mechanical systems refrigerant, marine services, hospitals, etc. This new refrigerant worked very similar to r4a but had a gwp of only four. 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 ammonia n has good heat transfer properties n not miscible with oil n but n toxic n flammable n corrosive to copper pipes carbon dioxide n non toxic n non flammable n but n higher. Refrigerant tables and charts download ebook pdf, epub. Fellow ashrae mcquay international staunton, virginia usa 1 what is a refrigerant. 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. The use of smaller hoses and 30% increase in control pressure regulations also have to be done to the system. Thermophysical properties of refrigerants t his chapter presents data for thermodynamic and transport properties of refrigerants, arra nged for the occasional user.
In addition, the physical properties of the freon hp refrigerants are listed in table. At first the push to phase out 4a was stalled as there wasnt a good substitute out there. The important properties such as latent heat of vaporization and. For example, in a regular home refrigerator, a class a and class 1 substance are used.
Physical properties of lubricants valvoline technical services page 1 following are the important properties of a lubricant. In the last two centuries, human ingenuity made it. Be preparedremember that good troubleshooting requires a thorough understanding of the basics. Oct, 2015 a lubricant is a substance introduced to reduce friction between surfaces in mutual contact, which reduces the heat generated.
Effects of refrigerant properties on refrigerant performance citeseerx. In some applications it may be necessary to consider other properties of the refrigerant, such as its interaction with. So, a tradeoff has to be done in order to achieve as high a cop as possible. Although the perfect refrigerant with an ideal mix of environmental and physical properties has not yet been developed, some promising candidates exist. The objective of this thesis is to increase the understanding of lubricating rolling element bearings in refrigeration compressors. The choice of refrigerant is becoming more complex and this chapter can only be considered as an introduction. The most reliable way to be safe is to choose a refrigerant that is neither toxic nor flammable. Refrigerant is the life blood of the vapor compression cycle. Because of the availability of isobutane all over the world it has been discussed widely for cfc replacement. Appendix a thermodynamic property tables general because of ammonias widespread use as a refrigerant, comprehensive tables of thermodynamic properties are frequently needed by refrigeration engineers. Physical properties of lubricants valvolinecummins. Jun 02, 2019 properties of commonly used refrigerants a refrigerant is a substance or mixture. The decision to use the low gwp refrigerant r1234yf in mobile air conditioning systems for passenger cars low gwp hfo refrigerant r1234yf also led to the development of alternatives for further mobile applications as well as stationary refrigeration, air conditioning and heat pump systems.
Refrigerant selection designing buildings wiki share your construction industry knowledge. New refrigerants to replace cfcs comprise an active area of development. The earth is surrounded by a thin film of gases which form the atmosphere. The following is a list of refrigerants with their typeprefix, ashrae designated numbers. The desired thermodynamic properties are a boiling point somewhat below the. Part of this chapter deals with a refrigerant r22 that will soon be phased out of production. 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. Thus the normal boiling point is a good indicator of the critical temperature of the refrigerant.
Desirable properties of refrigerants chemical engineering site. Years ago, when chillers used cfcs and service practices were less concerned with minimizing emissions, leak rates. This refrigerant is not 100% compatible with the lubricants and mineralbased refrigerant currently used in r12. Refrigerants have been a key component of air conditioning and refrigeration systems since the 19th century.
A perfect refrigerant with ideal properties for every application does not exist. Jul 12, 2019 a perfect refrigerant with ideal properties for every application does not exist. In the present study, recent research is considered about new generation refrigerant r1234yf and r1234ze e. This section presents data for the thermodynamic and transport properties of refrigerants, arranged for the occasional users. The refrigerants have a thermodynamic property charge. The general conclusion of the thesis is that the refrigerant affects all of the measured properties negatively on the subject of lubrication and life of the rolling element bearing. Refrigerants are widely used in refrigeration cycle where cooling effect below the. Most of the halogenated refrigerants meet these requirements. Visual ratings were obtained on both the liquid solutions and. Refrigerants r402a, r402b, and r404a properties, uses. The good properties of a refrigerant are as follows.
Since different fluids have the desired traits in different degree, choice is a matter of tradeoffs. If possi ble, the refrigerant must be odorless, but easy detection in the air is desirable. Refrigerants and their application presented by thomas e. Some fluids, however, are better than others, as evidenced by the bans placed on ozonedepleting refrigerants. This is a haloalkane refrigerant with thermodynamic properties similar to r12 dichlorodifluoromethane but with insignificant ozone depletion. They also have good energy efficiency, but are flammable and can form an. It would not cause ozone depletion or climate change. Engineering toolbox resources, tools and basic information for engineering and design of technical applications. 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. Update on next generation low gwp refrigerants for. The refrigerants should be non poisonous to humans and food stuff. Whenever we choose them for particular use properties of refrigerants also plays a vital role in economic and environmental friendly application. Refrigerant options now and in the future white paper. Ammonia, r717, is an attractive refrigerant alternative.
Compare performance of multiple refrigerants, learn the line sizing, and much more all for free. Standard thermometers of appropriate range are provided for the refrigerant system. It has been used in refrigeration systems since 1840 and in vapor compression since 1860. Oct 25, 2018 refrigerant trends in thailand have shown improvements in increasing energy efficiency and decreasing globalwarming potential gwp, as shown in figure 3 7,8, which is related to the figure 2. 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. This refrigerant is called freon 404a r404a, and its composition is. Here are some of the desirable properties of refrigerant explained in detail. Suitable for retrofit and original equipment usage. Sustainability safeguards longterm investments and ensures compliance with. Jul 17, 2017 a good refrigerant has the right combination of safety and functionality.
In the last two centuries, human ingenuity made it possible to control fully. A summary of general and environmental properties of refrigerants is given in the icheme guide and more detailed information in the ashrae handbooks. R407c refrigerant has been formulated as a good match to the existing hcfc refrigerant r22 for use in air conditioning, chilling and refrigeration applications and was the first of the r22 alternatives to be used on a commercial scale. In an industrial setting where more safety measures are in place and more refrigeration is needed, a class b and class 2 refrigerant. In terms of its properties, it should be considered a highclass refrigerant. Pdf refrigerant types, issues, trends and future options. Usually, a fluid, used in a heat pump and refrigeration cycle that. With r410a, the same unit will operate under the same conditions with a suction pressure of 118 psi and a discharge pressure of 400 psi, as shown in figure 1 on the next page.
Density density is fundamental physical property of oil. A comparison between refrigerants used in air conditioning. Click download or read online button to get refrigerant tables and charts book now. A throttling valve should be used to control the flow of refrigerant to the suction side to ensure that a liquid. Technical information at22 thermodynamic properties of dupontz freon. Air conditioning and refrigeration industry refrigerant selection guide page 5 seventh edition january 2003 1. Third, ammonia refrigeration has a proven safety record, in part because of the refrigerant s physical properties not the least of which is its.
Physical properties of refrigerants molecular weight, boiling, freezing and critical points. Table 1, on pages 4 and 5, shows the properties of r22 at satur ation. Aside from technological advances, a major change to their use is the increasing focus on reducing the impact on the environment. New refrigerants impact standards and codes the function of refrigerant as a fluid used for heat transfer has not changed since the development of the first refrigerating system. Desirable properties and commonly used refrigerants. The saturated and boiling steam properties of refrigerants r22, r4a, r32, r152a, r290, r1270 and r600a to be analyzed have been taken from the. Aspects on the development of hfo and hfohfc refrigerants. However, as a service technician you maycontinue to come across it for years to come.
R4a is capable to be at temperatures of 28c at room temperatures of 38c, its performance being very similar to that of an r12. R22 will soon be phased out, so you will not see it as much as you do other refrigerants in the future. Properties of a good refrigerants mechanical engineering. This paper contains a summarized look at our experience and knowledge, describing the background, trends, and drivers that frame the scenarios for present and future refrigerant selection. R404a refrigerant is an established alternative to r22 and r502. Of flammable refrigerant in room airconditioners used for human comfort flammability group of the refrigerant occupancy classification location classification of rac equipment 15 for example, r32 group 2l and r290 group 3 have different flammability properties which affect. Everything you need to know about the coming changes in. These refrigerants are primarily used for air conditioning and heat pumps and have replaced r22 in many applications. If possible, the refrigerant must be odorless, but easy detection in the air is desirable. Please note that for reduced gwp, klea 407a offers a good alternative. Review of the thermophysical properties and performance.
Airah wishes to acknowledge the assistance provided by. A refrigerant is a substance or mixture, usually a fluid, used in a heat pump and refrigeration. This site is like a library, use search box in the widget to get ebook that you want. This article describes thermodynamic properties of the refrigerants the ideal refrigerant. For refrigerants this means certain chemicals will be phased out and others restricted. In some applications it may be necessary to consider other properties of the refrigerant, such as its interaction with the process fluid in the event of a pinhole leak.
The refrigerant is a heat carrying medium which during their cycles i. It is essential that systems be charged with liquid from the cylinder. Fundamentals of mechanical refrigeration systems course content introduction mechanical refrigeration is a thermodynamic process of removing heat from a lower temperature heat source or substance and transferring it to a higher temperature heat sink. Thermodynamic properties of refrigerant r4a, also known as 1,1,1,2tetrafluoroethane, r4a, freon 4a, forane 4a, genetron 4a, florasol 4a, suva 4a or hfc4a and norflurane inn. Properties of commonly used refrigerants a refrigerant is a substance or mixture. 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. Everything you need to know about the coming changes in the global, federal, and state refrigerant landscape karim amrane, ph. Refrigeration n changes phase due to change in pressure n most common cryogens are n solid carbon dioxide n liquid carbon cook chill systems n used to replace warm holding of foods n cook chill system. 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. Jun 20, 2015 the refrigerant is a heat carrying medium which during their cycles i. Refrigerant these properties are practically not found in any refrigerant. In fact, from the thermodynamic or heatcarrying standpoint, differences among refrigerants with similar boiling points are small. High critical temperature to have large isothermal energy transfer. Feb 14, 2017 following are properties of a good refrigerant given below.
It is odorless in concentrations of less than 20 percent by volume in air. It is measured at specific temperature by hydrometer or automatic density meter. Design changes to the condenser and evaporator need to be done to use this refrigerant. Today, as in that first system, the refrigerant absorbs heat and transfers it at a higher temperature and a higher pressure, usually with a phase change. In higher concentrations, its odor resembles that of carbon tetrachloride. Gwp of the refrigerant and the rate of refrigerant leakage into the environment. Solstice n40 r448a refrigerant honeywell refrigerants. Usually, a fluid, used in a heat pump and refrigeration cycle that can extract heat from another body or substance. Safety is perhaps the most important single factor in the selection of a refrigerant. The bubble pressure is used for determining the system pressure when the refrigerant is in a saturated liquid or subcooled condition i. The hydrocarbons like r600a, r290 and r1270 are good alternatives to r12. Characteristics of refrigerants pure r12 cc 1425f425 is colorless. Following are properties of a good refrigerant given below.
These properties can be divided into favourable thermodynamic, chemical and physical properties. Physical properties of refrigerants low freezing point. Refrigerants physical properties engineering toolbox. Table 1, on pages 4 and 5, shows the properties of.
These physical properties of refrigerants help us select the proper refrigerant for the application as per our requirement. The production and use of cfcs is restricted by the montreal protocols. Isobutane r 600a is a possible refrigerant for this application, with good energy efficiency. Thermodynamic properties of duponttm freonr 22 refrigerant. 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. To enable the use of smaller compressors and other equipment the refrigerant should have smaller vapor.
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