It is essential that systems be charged with liquid from the cylinder. These properties are pressure, temperature, volume, density, enthalpy, flammability, ability to mix with oil, moisture reaction, odor, toxicity, leakage tendency, and leakage detection. Usually, a fluid, used in a heat pump and refrigeration cycle that can extract heat from another body or substance. It was invented in 1991 but did not begin to see real popularity until the 2000s. Please note that not all products are available in all markets. Thermal properties of each refrigerant 32 table 14. Ammonia is an efficient and popular refrigerant due to its superior thermodynamic properties and low cost. Comparative evaluation of refrigerant properties full ul, performance, operating maps and reliability testing thermophysical similarity of r448a and r449a has been verified the thermophysical properties of r448a are much closer to r407a than r404a r404a is much denser than r448a. A next generation refrigerant properties database purdue epubs. This paperback is dedicated to those who are eager to learn the hvacr trade and refrigerant chargingtroubleshooting practices. The refrigerant, a vaporliquid mixture at a low pressure point 1 on figure 6. Find the properties at point 4, the pressure drop across the expansion device, the quality of the refrigerant and properties at point 1. The flood of the airconditioner, that is, the refrigerants, their properties, merits and demerits. These detailed properties can be used by the students of polytechnics, undergraduate and postgraduate engineering students and for a.
R404a refrigerant is an established alternative to r22 and r502. 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. Therefore, problems should be solved using all property data. Refrigerant fluid an overview sciencedirect topics. 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. Fellow ashrae mcquay international staunton, virginia usa 1 what is a refrigerant. All properties have been compiled together for each refrigerant for conveniece of usepref. All of the thermodynamic properties can be computed from eqs.
The tables are also useful for practising and research engineers. Table aesuperheated refrigerant4a figure a14eph diagram for refrigerant4a table a16eproperties of the atmosphere at high altitude table a17eidealgas properties of air table a18eidealgas properties of nitrogen, n 2 table a19eidealgas properties of oxygen, o 2 table a20eidealgas properties of carbon dioxide, co 2. International standard formulation for the thermodynamic properties of 1,1,1. Here are some of the desirable properties of refrigerant explained in detail. As such, there is no refrigerant that can be advantageously used under all operating conditions and in all types of refrigeration systems. Reference states used for most refr igerants correspo nd to the inter. The present tables and charts of important properties of refrigerants and also psychrometrics have been. Hfo 1234 yf article pdf available in current science 11508. Cooling efficiency of each refrigerant 25 table 11. Thank you for using refrigerantcode and making it a highly accepted refrigerant properties software. 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. It also provides a closer match to r500 at airconditioning temperatures. New refrigerants to replace cfcs comprise an active area of development. These requirements apply for all refrigerants that contain ozonedepleting substances, e.
Properties of a good refrigerants mechanical engineering. Freon refrigerants r11, r12, and r22, plus ammonia and water, will be discussed in terms of the abovementioned categories. It is hazardous when released in large quantities due to its toxicity. For example, ammonia might be an acceptable refrigerant for largescale industrial refrigeration applications where the extra cost to mitigate its toxicity and flammability risks is justified. Pressuretemperature table for r502, r404a, and r452a is shown in figure 1. The efficiencies and capacity changes shown are based on the theoretical properties of the refrigerant alone, with all design variables held constant for objective comparison. Isobutane r 600a is a possible refrigerant for this application, with good energy efficiency, but with a very different characteristic in several points, which implies the design to be made or adopted for this refrigerant. Refrigerant charging and service procedures for air. Refrigerant 12 dichlorodifluoromethane properties of saturated liquid and saturated vapor. Upon a change of seals the risk is low as all refrigerant is removed. Refrigerants are widely used in refrigeration cycle where cooling effect below the atmospheric temperatures are needed. Refrigerants and their application presented by thomas e. 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. This refrigerant was designed to be a safe, nontoxic, nonflammable, and reliable alternative to the hcfc r22.
However, ammonia does exhibit a unique refrigerant characteristic due to its irritating odor. The most common way of doing work on the refrigerant is to compress it when it is in the vapor or gas state, as illustrated in figure 6. Their thermodynamic characteristics constitute as ideal replacement for r502 for refrigeration sector in new facilities at low and medium temperatures. However, all fluids other than air can be called as toxic as they will cause. Considerations for next generation hvac refrigerants. Energy consumption and environmental impacts 26 of each refrigerant during operation table 12.
Tables of the thermodynamic properties of dupont freon. 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. If possible, the refrigerant must be odorless, but easy detection in the air is. Sustainability safeguards longterm investments and ensures compliance with corporate social responsibility csr. The refrigerants have a thermodynamic property charge. R410a is an hfc refrigerant that is a blend of the hfc r32 and the hfc r125.
Refrigerant choices this table compares various properties of both current and nextgeneration refrigerants. Vapour charging solstice n40 may result in the wrong refrigerant composition and could damage the system. In this book, you will find step by step procedures for preparing an air conditioning and heat pump system for refrigerant, reading the manifold gauge set, measuring the refrigerants charge level, and troubleshooting problems with the systems refrigerant flow. Effects of refrigerant properties on refrigerant performance citeseerx.
Understanding applications for alternate refrigerants. These pressures have accelerated the development of alternative refrigerants. R414b is a dropin replacement not requiring system adjustments, oil changes, or retrofit procedures. A refrigerants thermophysical properties and other characteristics should be matched to the conditions encountered in the application.
A familiarity with these diagrams will make this chapter easier. Pdf refrigerant types, issues, trends and future options. High critical temperature to have large isothermal energy transfer. For the same amount of subcooling, r404a and r452a produce. The production and use of cfcs is restricted by the montreal protocols. Reclaim to reprocess refrigerant to at least the purity specified in the ari standard 700, specifications for fluorocarbon refrigerants, and to verify this purity using specified analytical methods. It can be blended with hfos to improve performance. Just complete your repair and replace the r12 with r414b. Refrigerant properties refrigerants can be characterized by a number of properties. The risk of malfunction or leakage lies in the ability of the retrofit refrigerant to act similar to the former refrigerant to maintain the overall system chemistry. A throttling valve should be used to control the flow. In spite of that, we can state certain desirable properties that a refrigerant should posses. Epa requires proper refrigerant management practices by those who buy or sell refrigerant, technicians, owners and operators of ac and refrigeration systems, and others.
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. This information is based on values calculated using the nist refprop database mclinden, m. R404a and r452a possess similar energy efficiency and capacity characteristics to r502. List important thermodynamic and environmental properties influencing refrigerant. Technical r404a data sheet features and uses of r404a r404a is a ternary mixture consisting of r125, r143a and r4a. This section presents data for the thermodynamic and transport properties of refrigerants, arranged for the occasional users. Ebook refrigerant tables and charts as pdf download. R22 when all are operating under the same capacity. Refrigerant options now and in the future white paper. This article describes thermodynamic properties of the refrigerants the ideal refrigerant. The refrigerant is a heat carrying medium which during their cycles i. R1234yf may require about a 5% increase in refrigerant vs. R414b utilizes 4 refrigerant components which when blended together, result in low and high pressure readings.
The next generation of refrigerants are olefinbased and have properties similar to hcfcs and hfcs, but with minimal direct environmental impact. This blend refrigerant is similar to r401a except, it is higher in r22 content. Figure 2 shows the comparison of some properties of r502, r404a, and r452a. Whenever we choose them for particular use properties of refrigerants also plays a vital role in economic and environmental friendly application. Refrigerant tables and charts download ebook pdf, epub. Find, read and cite all the research you need on researchgate.
The current hfc4a pag oil will not work with hfo 1234yf. Ammonia is environmentally benign, having zero gwp and zero odp. The temperature of the refrigerant at this point is lower than that of the process stream requiring cooling. Thermodynamic properties of duponttm freonr 22 refrigerant author. Thermal properties of each refrigerant 24 table 10. Summary of environmental impacts of each refrigerant 28 table.
734 1393 1157 1271 827 384 1037 893 754 676 1502 934 668 600 734 1176 1131 1250 731 165 161 178 768 694 155 422 1401 1559 72 643 1142 199 447 1439 486 212 714 718 951 655 1150 948