The process is not easy, and although there are alternatives to old refrigerants, the new ones are usually not flawless. The potential for a single molecule of the refrigerant to destroy the ozone layer. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of airconditioning and refrigeration equipment. Refrigerants are widely used in refrigeration cycle where cooling effect below the atmospheric temperatures are needed. Tables of the thermodynamic properties of dupont freon. Freon refrigerants r11, r12 and r22, plus ammonia and water, will be discussed in terms. Most automotive air conditioning systems except in australia and possibly other countries use r4a as a refrigerant. The refprop database for the thermophysical properties of. This liquid, sweet, colorless refrigerant has a nonirritating odor, is nonflammable and nontoxic. The thermodynamic properties of refrigerants columbushoa. Distinguish between the refrigerants that have been in used in vapor compression systems up to now 2. The publication presents a set of equations and constants for calculating thermodynamic properties of refrigerants.
Explain the concepts of ozone depletion and global warming and the contribution of cfchcfchfc refrigerants to both issues 4. However, hcfc refrigerants r123 and r22 do not completely prevent the ozone layer depletion. R4a is a common refrigerant used in residential refrigerators around the world, and in automobiles. Describe the basic chemical compositions of refrigerants and the numbering system used to classify refrigerants 3. 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. An additional alternative for those same systems could be the r404a blend, a very lowglide mixture with properties close to those of hcfc22 and therefore requiring minor redesigns. It covers foundation knowledge of refrigerants to underpin their safe handling and the safety of operators. Mixtures of r12 vapor and air, in all proportions, will not. Thermophysical properties of refrigerants t his chapter presents data for thermodynamic and transport properties of refrigerants, arra nged for the occasional user. Positively innovative refrigerants r32 daikin chemical europe. All refrigerants use r11 as a datum reference where r11 has an odp 1. Compressor has to be operated at high vacuum if the boiling point of the refrigerant is high at atmospheric pressure.
Refrigerants are divided into groups according to their chemical composition. If there is toxicity identified in this small amount, the substance is a class b refrigerant. Refrigerants thermodynamic, physical, chemical, safe ty related and environmental properties have been presented and discussed in the first part of the paper. Main properties of typical refrigerants used in different application. After studying this unit, you should be able to learn the different classifications of refrigerants, naming convention for refrigerants, properties of. Annex 18 reports the comprehensive evaluations of the available equations of state and recommended formulations for r123, r4a, r32.
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. Here are some of the desirable properties of refrigerant explained in detail. In the last two centuries, human ingenuity made it. The importance of specifying high quality products pdf. Thermodynamic properties of refrigerants r11, r12, r. This project was made possible with american recovery and reinvestment act of 2009 funds.
The predictions of system behavior and performance are aided by the known thermodynamic and transport properties of the refrigerant. Version 7 of the nist refprop reference fluid thermodynamic and transport properties database is described. Characteristics of some new generation refrigerants with. Classification can be divided into class 1, class 2, class 3. The boiling point is most important because it is a direct indicator of the temperature level at which a refrigerant can be used. Refrigerants are classified according to their way of absorption or extraction of heat from substances stored in the refrigerator. 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. New refrigerants for vapour compression refrigeration and.
State equation, equation of saturated vapor pressure, equation of liquid volume, equation of specific heat capacity, enthalpy and entropy for r11, r12. Title demonstrate knowledge of refrigerants and their management level 3 credits 5 purpose this unit standard is for people who work or intend to work in the refrigeration and air conditioning sector of the engineering industry. A refrigerant is a substance or mixture, usually a fluid, used in a heat pump and refrigeration. Whenever we choose them for particular use properties of refrigerants also plays a vital role in economic and environmental friendly application. Natural refrigerants was developed as a joint effort between the national renewable energy laboratory nrel and cta architects engineers. These properties pressure, temperature, volume, density, enthalpy, flammability, the opportunity to mix with vegetable oil, moisture reaction, smell, toxicity, leakage trend, and leak detection. Download natural refrigerants overview brochurepdf. The most promising refrigerants to be used in future are the hfes, hfos and hfcs with lowgwp, natural refrigerants and blends between hcshfcs and hfcshfos refrigerants.
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. Without being pressureregulated, primary refrigerants absorb all available heat. Low boiling temperature at atmospheric of the refrigerant is desirable. It has long been used in a variety of airconditioning and refrigeration applications in a variety of markets. It has the highest refrigeration effect per kilogram of all refrigerants and comes at a low cost. The refrigerants are arranged in increasing order of atmospheric boiling point, from air at 194. The properties of r 600a differ from other refrigerants commonly used in household applications, as shown in table 1. Refrigerants properties pdf product data summary and thermodynamic tables. This section presents data for the thermodynamic and transport properties of refrigerants, arranged for the occasional users. It was chosen as the preferred equation of state because it provided the most accurate. The thermodynamic properties are interrelated and mainly depend on normal boiling point, critical temperature, molecular weight and structure. R22 light green r4a light sky blue r404a orange the name label of the gases are given on the cylinder.
Duponttm refrigerants, technical information keywords. Please consult the msds for more comprehensive information. The simulator used an equation of state to predict the thermodynamic properties of the refrigerant mixtures. Ashrae thermodynamic properties of refrigerants stewart, richard b. 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. Ecofriendly refrigerants as substitutes for hfc4a a. The conditions include 1 the use of unique fittings, 2 the use of descriptive labels, and. Because of the similarities between r22, r11, and r12, only r12 is discussed. For full table with properties and applications rotate the screen. Thermodynamic properties of duponttm freonr 22 refrigerant author. Usually, a fluid, used in a heat pump and refrigeration cycle that can extract heat from another body or substance. Xoj 9617 sltlvd l l09l seqjeselolt\\l phll l thermophysical properties of.
Class 1 refrigerants used in the standard compression type cooling system. R32 has a gwp about one third that of r410a, and it has excellent properties as a refrigerant. R407cpsltt r407cpsvtt r407c t sl p p r407c t s vp p r407cdsltt r407cdsvtt r407chsltt r407chsvtt r407cssltt r407cssvtt r407ccpsltt r407ccpsvtt r407ccvsltt r407ccvsvtt r407csurftenstt. Thermophysical properties of liquid secondary refrigerants. Fluids suitable for refrigeration purposes can be classified. No companies have listed products specifically related to this chapters topic. Click below to go to the master list of all commercial resources. Compared with previous versions, the database includes additional fluids and mixtures including ammoniawater mixtures, improved property models, additional properties, increased calculational speed, an enhanced user interface, and. Hfc refrigerants are not miscible with the mineral oils used in cfc refrigeration systems.
Refrigerants can be characterized by a number of properties. Pdf current and future trends of refrigerants development. Ammonia is highly toxic but it has excellent thermal properties and low volumetric displacement. Refrigerant selection criteria based on thermodynamic, thermophysical, environmental and economic properties. Selection tips for environmentally safe refrigerants. This paper presents the investigation results of hfc refrigerants r125, r143a, r152a and r32 which prevent the ozone layer. Color codes of refrigerants easy recognize gas cylinder different refrigerant has different color coding few examples are given below. Primary refrigerants change states to absorb heat from surrounding areas or substances. Pdf properties of refrigerants from cubic equations of state. Synthetic and organic refrigerants are classified under two main categories, primary and secondary. A good refrigerant has the right combination of safety and functionality. R22 chc1f425 and r11 cc1435f are colorless, nonexplosive, nonpoisonous refrigerants with many properties similar to those of r12. Thermodynamic properties of duponttm freonr 22 refrigerant. Refrigerants are chemicals used for cooling in automobile air conditioners.
Class 1 refrigerants are completely nonflammable, class 2 types are moderately flammable and class 3 substances are highly flammable. 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. Selection tips for environmentally safe refrigerants a refrigerant is a fluid used in a refrigeration system to extract heat at low temperature and low pressure during evaporation and reject heat at high temperature and high pressure during condensation. This unit is intended to serve as an introductory guide to the study of refrigerants. Refrigerant data comparison raefrigerant ra600 r24 r 1 neame isobutan 1,1,1,2tetraflouroethane dichlorodifluoromethane fhormula c 3 3 cfh. Refrigerant r4a thermodynamic properties eng units 2 equations the mbwr equation of state was used to calculate the tables of thermodynamic properties. The desired thermodynamic properties are a boiling point somewhat below the target temperature, a high heat of vaporization, a moderate density in liquid. These physical properties of refrigerants help us select the proper refrigerant for the application as per our requirement. 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.
Following are the desirable properties of a primary refrigerant. The refrigerants have a thermodynamic property charge. 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. This information is based on values calculated using the nist refprop database mclinden, m. The use of natural refrigerants generally leads to lower operating costs. This leads to a different design of details in many cases. This article describes thermodynamic properties of the refrigerants the ideal refrigerant. Download limit exceeded you have exceeded your daily download allowance. This program is based on the most accurate pure fluid and mixture models currently available.301 982 927 1071 1602 82 997 1559 1277 229 1453 1429 476 480 453 258 1127 894 374 1186 216 374 1309 983 742 962 1223 923 939