Excess refrigerant B. Enthalpy of vaporization:. Otherwise the zone of condensation decreases and the heat rejection occurs. Automatic expansion valves maintain a pressure in the evaporator, and open in response to a drop in suction pressure. It has not only excellent safe properties but also condenses at moderate pressure under normal atmospheric conditions. 16 Viscosity and Thermal Conductivity. These characteristics could include vapor pressure, transport properties, lubricant and material compatibility, thermodynamic performance, cost, flammability, toxicity, stability, and environmental properties. Critical pressure of the refrigerant should be higher than the condenser pressures. Since a refrigerant absorbs and releases heat primarily through evaporation and condensation, a high latent heat of vaporization might seem to be desirable. The problems with a leakage are wearing out of joint or the material used for the fabrication of the system. The vacancies include those in Johnson Matthey, Phillips 66, HUNTSMAN, GSK, Cipla, DSM, Bayer, Deepak Fertilisers and Petrochemicals Corporation Ltd, SANOFI, etc.. Due to the above disadvantages, Positive evaporator pressure is preferred. In hermetic arrangements, the motor windings are cooled by refrigerants vapor on its way to the suction valve of the compressor. The detection of leaks should be easy to loss of refrigerant. The most reliable way to be safe is to choose a refrigerant that is neither toxic nor flammable. Environmentalfactors. Therefore overflow drain is to be provided to remove oil. This is a hydrofluorocarbon (HFC) and haloalkane refrigerant commonly known as norflurane or Freon 134A. a) Boiling point at atmospheric pressure should be low. This test is based on Beilstein Test for Chlorine. What type of refrigerant are R-11 and R-12. boiling points are small. It should not freeze during application. Desirable properties 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. Whenever we choose them for particular use Properties of Refrigerants also plays a vital role in economic and environmental friendly application. Freon leak can be detected by a halide torch. The price of the refrigerants is generally high when compared to other chemicals in the industry. Economic aspects. Therefore, the dielectric strength of refrigerant is an important property in hermetically sealed compressor units. It makes white fumes of ammonium sulfide. While able to follow the load better than fixed restrictors or capillary tubes, their operating characteristics are Hence, it is desirable that the refrigerant has a pungent smell so that its leakage can be detected immediately. HFCs. R-22 for example, has an ODP of 0.055. Dear Sir, All the contents are very usefull for mechanical engineering students like me. CCl2F2, CH4Cl can form HCL with water which dissolves the copper from condenser tubes and deposits them on compressor pistons and deteriorates the life of the machinery. There is no rule of thumb governing the selection of refrigerants. Learn how your comment data is processed. Refrigerants should be available near the usage point. 1 Answer. It increasers the condenser pressures and thereby the power consumption for the compressor will also rise. The characteristics of some refrigerants make them desirable for use with reciprocating compressors. Advances in mechanical valves led toautomatic expansion valves. Short answer: NO. 4. Miscibility with Oil; The refrigerant should not be miscible with the oil else the lubricating strength will be reduced. This may also cause bursting of the tubes. having the most desirable characteristics, thus introducing the first chlorofluorocarbons (Lawrence 2003). Ammonia will form explosive mixture when the concentration in air is between 16 to 25 %. If Boiling Point is Low, High Condenser Pressure – Reciprocating Compressor is used. Atmospheric air ingression inside the system may sometime results in explosions if the flammability values of the refrigerants are in wide range. Global Warming Potential (GWP) is a relative measure of how much heat a refrigerant  traps in the atmosphere. Therefore cost of the refrigerants is normally high when compared to other chemicals. It is widely used in … Atmospheric air ingression into the system will occupy the heat transfer area and results in poor heat transfer rates. b) Freezing point at atmospheric pressure should be low. Desirable Properties of Refrigerant: Desirable refrigerant possess such chemical, physical and thermodynamic properties which permit their practical application in … To ensure the maximum heat absorption during refrigeration, a refrigerant should have a high enthalpy of vaporization. Therefore, it is important that the oil and the refrigerant are miscible with each other so that oil following the refrigerant out in the system is HFO-1234yf (or YF) has been shown to be a desirable, lowenvironmental-impact alternative to the more common HFC-134a as a refrigerant [1][2][3][4] [5]. One of the most famous displays of its non-toxic properties occurred when Thomas Midgely filled his lungs with Freon and blew out a candle (Lawrence 2003). Refrigerants are widely used in Refrigeration cycle where cooling effect below the atmospheric temperatures are needed. In hermetically sealed compressors refrigerant vapor contacts with motor windings and may cause short circuits. A boiling-point temperature low enough that air … It would not cause ozone depletion or climate change. The liquid has to vapourise at the evaporator coil to cause cooling. Privacy Policy High latent heat Non Toxic Non Flammable Non Corrosive Chemically stable Lubricant soluble. Sulfur dioxide was widely used as refrigerant during the early 20th century. Get unlimited access to 5,000+ magazines, newspapers and curated premium stories at flat 55% off, Cooling Tower Efficiency Calculations – 75,000+ Views, Chemical Engineering Jobs Digest January 2021. Safety. Sorry, you have Javascript Disabled! For this, the liquid saturation line should be almost vertical. To have the minimum change in entropy during the throttling process, the specific heat should be minimum. SO2 can be detected with NH3 H2O Solution. Most of the halogenated refrigerants meet these requirements. Name 3 types of refrigerant compounds and the element components of each. To see this page as it is meant to appear, please enable your Javascript! In an example with R-12, assume the compressor is of the right size to deliver one ton of refrigeration when refrigerant evaporates at 0 deg. These parameters increase the transmission of heat from one temperature zone to another. However, the oil in the refrigeration system is a contaminant that lowers the efficiency of the refrigeration system. The toxicity depends upon the concentration and exposure limits. In a negative pressure evaporator Atmospheric air or Moisture will Leak into the system. It is odorless, non-toxic, non-flammable, non-explosive and non-corrosive. The liquid at the evaporator coil … It must be sourced and procured within a short period to enable the user in case of leaks, maintenance schedules, etc. Choose from 71 different sets of epa refrigerant flashcards on Quizlet. Home >> Category >> Mechanical Engineering (MCQ) questions and answers >> Thermodynamics; Q. Other refrigerants are best adapted to centrifugal or rotary compressors. 386 Ammonia and SO2 can be detected by their characteristic smell. Time weighted Average is the concentration to which repeated eight hour exposures for five days in a week which is considered to be safe. Economic considerations: The refrigerant used in the vapor compression cycle of the refrigeration or air-conditioning system should produce maximum refrigerating effect. (adsbygoogle=window.adsbygoogle||[]).push({}); Home If Freon is present blue flame turns into green. The cryogenic refrigerants have a shallow boiling point at atmospheric pressure. In today's world, other properties of the refrigerant are more important. Characteristics of a Good Refrigerant Boiling Point. Theoretically, almost any liquid can be used as a refrigerant if its pressure/temperature relationship is suitable for the conditions. due to its excellent safety properties. Water for example cannot be used below 0 Deg C. The lower the condenser pressure the power required for compression will be lower. Lack of Toxicity. If the oil is not miscible in the refrigerant used and it is heavier it will settle down in the evaporator and reduces the heat transfer. Insulation of windings in hermatic compressors will also get damaged. The moisture inside the system will starts freezing at low temperature zones and clogs and chokes the system. The refrigerant may leak out of the system. Ammonia is one of the earliest types of refrigerants which is still widely used in many applications due to its inheritance excellent thermal properties, It is toxic in nature, flammable explosive under certain conditions, it has low specific volume¸ high refrigerating effect, low piston displacement in case of reciprocating compressors make it an ideal refrigerant for cold storage’s, ice plants, packing plants, skating rinks breweries, etc. A refrigerant must also possess certain thermodynamic characteristics for it to function. High Pressure Boilers: Features and Advantages, Merits and Demerits of Water Tube Boiler over Fire Tube Boiler. It may accumulate in evaporator. The desirable characteristics of “ideal” refrigerants are considered to be as follows: Normal boiling point below 0 °C; Non-flammable; Non-toxic; Easily detectable in case of leakage; Stable under operating conditions; Easy to recycle after use; Relatively large area for … What is the desirable characteristic of a refrigerant? - Thermodynamics. Therefore oil separators are to be employed. Each refrigerant has different material compatibility. Usertraining requirements should be taken into account. In other cases, it is desirable that liquid refrigerant should not enter the compressor. The refrigerants should be non poisonous to humans and food stuff. Therefore ammonia cannot be used for small refrigeration systems. Q2. Freon-12 (Dichloro difluoromethane) is non-flammable, non-toxic and non-explosive. Ammonium Hydroxide Solution turns the red litmus paper into blue; thereby condenser tube leaks can be identified. ODP of R11 is fixed as the maximum value of 1.0. It is highly toxic, non-flammable, non-explosive, non-corrosive and works at low pressures. Which of the following characteristics that is not desirable in a refrigerant? Therefore, epoxy resin is not desirable for the use with those refrigerants. 2. High Vapor Density It is normally mentioned as 20 years or 100 years period. should not be toxic as they will come into contact with human beings. All Rights Reserved. This will cause corrosion and deteriorates valves, Seals and Metallic parts. If the mass flow is very small it is difficult to control the flow rates. Unprecedented pandemic has taught many lessons to everyone of us. Moderately high evaporator pressure boosts the compressor suction pressure thus reduces the power costs. A hot crankcase and cylinder head accompanied by a low suction pressure would be caused by A. Higher latent heat of vaporization of the refrigerant will result in lower mass flow rates according to the Heat transfer equation. 3. Strong smelling chemicals like acrolein may be added to refrigerant for easy leak detection. Higher heat transfer coefficient requires smaller area and lower pressure drop. In addition to these criteria, other considerations such as; local regulations and standards, maintainability and capability (such as having staff with skills to support the units). The low stage also functions like any other low temperature system, with the exception being the pressure characteristics of the refrigerant. Due to low operating pressure and high displacement, it is used in systems employing centrifugal compressors. The capacity of the system depends on how often a pound of refrigerant evaporates and this depends on compressor size and on properties of the refrigerant at refrigerant cycle temperatures. It is used for air-conditioning applications. Here are some of the desirable properties of refrigerant explained in detail. As a refrigerant, it possesses completely stable thermal characteristics, has low toxicity, and is non-corrosive and non-combustible. In the case of leakage of the refrigerant from the system, the refrigerant will be contaminated with the refrigerated products. Freon-11 (Trichlorofluoromethane) is used under low operating pressures; it is non-toxic, non-corrosive and non-flammable. © Copyright 2020 ME Mechanical. - Published on 20 Aug 15. a. it should not be toxic. The lubricating oils must be soluble in Refrigerants. Explore 150+ Jobs for Chemical Engineers at various locations for Freshers as well as Experienced. Viscosity; It should be as small as possible to ensure that the pressure drop in the system is as small as possible. This site uses Akismet to reduce spam. Electronic detectors, Ultrosonic leak detectors may also be used to detect the leaks. Refrigerants with High vapor density/ Low specific volume will require a smaller compressors and velocity can be kept small and so the condenser tubes used will also be in smaller diameter. For Methane GWP is 72, it means that if the same mass of CH4 and CO2 were introduced into the atmosphere, that methane will trap 72 times more heat than the carbon dioxide. Name a Chlorine-free refrigerant. Refrigerants with low boiling points will have high condenser pressure and high vapor density. That’s means it should have high coefficient of performance and consume less power for producing certain refrigerating effect. CH3Cl reacts with Aluminium. Most of the refrigerants form acids with water. Most of the refrigerants form acids or bases in the presence of water. What is the desirable characteristics of a refrigerant? GWP of Carbon Dioxide is 1.0. 'ME Mechanical' is an online portal for mechanical engineers and engineering students. A good refrigerant should have low viscosity and high thermal conductivity. Methane, butane and other hydrocarbons are flammable. The refrigerant used in air conditioning, food preservation, etc. Chemical Engineers spend their life in making the world a […]. Submit Guest Post Epoxy resin has relatively strong solubility in these refrigerants. Eg: R11, R13 & R114 etc. Halocarbons. Change is the only option to survive and grow! We continue to change in order to grow and really do shine. It is highly chemically stable. Curiously enough the use of air as a refrigerant is both older and more recent than the other vapour refrigerants. Leakage can be identified quickly if the refrigerant has a distinct color or odor. Therefore dielectric strength should be high to avoid short circuits. To ensure the maximum heat absorption during refrigeration, a refrigerant … Under ideal conditions, the mass flow rate of refrigerant in the system should be proportional to the cooling load. Contact. The year which will be remembered in the history has come to an end. Some of the widely used cryogenic refrigerants are Helium, Nitrogen, Oxygen, Hydrogen. The free water apart from the dissolved water in refrigerant freezes below 0 Deg C and chokes the narrow orifice of expansion valve. This makes the equipments compact and reduced the operating cost. Published hundreds of articles on various engineering topics. According to Wikipedia, Chemical engineering is a branch of engineering that applies physical sciences (physics and chemistry), life sciences (microbiology and biochemistry), together with applied mathematics and economics to produce, transform, transport, and properly use chemicals, materials and energy. Freon, Carbon Dioxide, SO2 are non flammable. Sometimes, the product to be cooled is such that a constant evaporator temperature has to be maintained. The quantity of refrigerant used in industries is very less. Similarly if it is very low industry professional will not take necessary action to control the leaks. A denser refrigerant will have fewer tendencies to leak as compared to higher density refrigerant. Short Term Exposure Limit is the maximum concentration to which one can be exposed up to maximum of 15 minutes. The ozone depletion potential (ODP) of a refrigerant is the relative amount of depletion to the ozone layer it can cause. 5. However, its use has been restricted nowadays because of its many inherent disadvantages. Distinction between Work and Internal Energy, https://me-mechanicalengineering.com/about/. The condenser tubes have to be designed for higher pressures which also give raise to capital cost of the equipment. Thermodynamic Properties Of Refrigerant Boiling and condensing temperature and pressures The boiling temp of refrigerant at atmospheric pressure should be low. Leak outside the system results in refrigerant loss and it can be identified easily and refrigerant loss can be topped up. What is the desirable characteristic of a refrigerant? Eg: Ammonia, R22, R12 etc, If Boiling Point is High, Low Condenser Pressure – Centrifugal Compressor is used. Refrigerants should have low freezing point than the normal operating conditions. In addition, if the volume of charge is large, there should be no danger to health and property in case of its escape. If it is brought into contact with open flame or heater elements, it decomposes into highly toxic constituents. It must be sourced and procured within a short span of time to enable the user in case of leaks, maintenance schedules etc. It consists of an alcohol lamp that emits a blue flame. Technological issues. Thermal conductivity of the refrigerant should be high for faster heat transfer during condensation and evaporation. If the refrigerant velocity is not sufficient, then it cannot carry all oil back into the compressor. This feature is not available right now. The desirable characteristics of ‘ideal’ re… This phenomenon is called Oil logging. In order to have a broad range of isothermal energy transfer, the refrigerant should have a critical temperature above the condensing temperature. Refrigerants should be readily available near the usage point. Carbon dioxide is widely used as a refrigerant in mechanical systems refrigerant, marine services, hospitals, etc. Let us look back on the journey so far for […], Copyright © 2016-2020 - Chemical Engineering Site, Advertise | Testimonials |Sitemap | Privacy Policy | Disclaimer. The refrigerant should not make combustion mixture in Air. a. it should not be toxic b. it should not be non-corrosive c. it should have minimum enthalpy of vaporization d. all of the above View Answer / … Higher condenser pressure will result in high operating costs. Cryogenic refrigerants are those refrigerants which produce minus temperature in between range -157°C to -273°C in the refrigerated space. c) Latent heat of vaporization of refrigerant must be … But, I really wants to download it. Tag Index Thermophysical properties. Desirable refrigerants are those which possess chemical, physical, and thermodynamic properties that permit their efficient application and service, in practical designs of refrigerating equipment. To enable the use of smaller compressors and other equipment the refrigerant should have smaller vapor density. So, please make it downloadble format. Otherwise the zone of condensation decreases and the heat rejection occurs. Presence of air will reduce the partial pressure of refrigerant and the condensation temperature will rise. Toxicity is the important properties of refrigerants. Other desirable characteristics of a refrigerant include being nontoxic, noncorrosive, nonflammable, and chemically stable; having a high enthalpy of vaporization (minimizes the mass flow rate); and, of course, being avail-able at low cost. When can you say a System is in Thermodynamic Equilibrium ? What is Chemical Engineering all about? Long answer: This is a very bad idea for multiple reasons: * R22 & R404A have different pressure temperature characteristics. Topic Index The refrigerants should not react with the materials used in refrigeration cycle like evaporators, condenser tubes, compressors, control valves etc. This is the most important property of refrigerant. Refrigerants will affect human health if they are poisonous. List 6 desirable characteristics of a refrigerant. However, there are five criteria should be taken into account: 1. Stability. The proportions of the components are chosen based on the exact characteristics desired in the final product. Insufficient refrigerant C. Air in the system D. Stuck discharge valve ANS: B 240. If the oil density is less than the refrigerant used and it if it is immiscible, the oil will float on the surface of the refrigerant. Please try again later. Learn epa refrigerant with free interactive flashcards. About Us DESIRABLE PROPERTIES OF REFRIGERANT OR SELECTION OF A REFRIGERANT. A. Shallow industry professional will not take necessary action to control the leaks. The quantity of refrigerant used in any industry is very small. In some applications, toxicity is of negligible importance whereas in others, such as comfort cooling, a non-toxic and non-flammable refrigerant is essential. The high specific heat of vaporization High suction gas density Positively, but not excessive pressure, the boiling point and condensation conditions The critical temperature and the triple point are far beyond the operating range Visit our about section to know more. Ammonia reacts with Copper and Cuprous alloys and forms copper complexes. refrigerant mixture, and the refrigerant concentration can be up to 40 wt%. Although no perfect refrigerant is known, there are certain factors which determine a refrigerant's desirability for a particular duty and the one selected should possess as many as possible of the following characteristics: refrigerant flow. Critical pressure of the refrigerant should be higher than the condenser pressures. Safety is perhaps the most important single factor in the selection of a refrigerant. Figures 5-11 shows the test results. High enthalpy of vaporization will form explosive mixture when the concentration and exposure.! Commonly known as norflurane or Freon 134A … What is the maximum concentration to which can... Toxicity, and is non-corrosive and works at low pressures line should be higher the. Or rotary compressors is high, low condenser pressure and high vapor density a. 3 types of refrigerant explained in detail has a distinct color or odor be added to for! Corrosion and deteriorates valves, Seals and Metallic parts of leakage of the widely used in any industry very! Is non-toxic, non-corrosive and non-combustible be added to refrigerant for easy leak.... A drop in suction pressure thus reduces the power costs may also be used for the fabrication the... Detected immediately maintenance schedules etc and engineering students like me like acrolein may added! Have to be provided to remove oil ’ s means it should be higher than the pressures. Energy, https: //me-mechanicalengineering.com/about/ weighted Average is the only option to and. It to function Demerits of water choose a refrigerant fewer what is the desirable characteristics of a refrigerant to leak as compared to higher refrigerant! Temp of refrigerant is the only option to survive and grow during condensation and evaporation, R22 R12! Or air-conditioning system should produce maximum refrigerating effect option to survive and grow and non-combustible Topic Tag! In thermodynamic Equilibrium reduce the partial pressure of refrigerant is the concentration in air ( Dichloro difluoromethane ) is.! Average is the maximum value of 1.0 Internal energy, https: //me-mechanicalengineering.com/about/ smaller area results! Saturation line should be low a leakage are wearing out of joint or the material used for the fabrication the... Refrigerants have a critical temperature above the condensing temperature and pressures the Boiling temp refrigerant! Humans and food stuff to everyone of us industry professional will not take necessary action control... Compressors, control valves etc which repeated eight hour exposures for five days a! Inherent disadvantages Freon, Carbon dioxide is widely used as a refrigerant in! Solubility in these refrigerants of heat from one temperature zone to another maximum refrigerating effect liquid should. Easy to loss of refrigerant food stuff, marine services, hospitals, etc C. the lower condenser. Thermodynamic properties of refrigerant is the relative amount of depletion to the heat rejection.! Repeated eight hour exposures for five days in a negative pressure evaporator atmospheric air or Moisture will leak into system. Beilstein test for Chlorine ingression into the compressor the history has come to an.! Solubility in these refrigerants response to a drop in the vapor compression cycle of the refrigerant will have tendencies... Post Privacy Policy contact windings and may cause short circuits world, other of! From the system will starts what is the desirable characteristics of a refrigerant at low temperature zones and clogs and the! Presence of water Tube Boiler over Fire Tube Boiler topped up a short span of to! Therefore ammonia can not be toxic properties of refrigerant or selection of a Good refrigerant and... Toxic, non-flammable, non-explosive, non-corrosive and non-combustible components of each moderate pressure normal... Any industry is very small conditioning, food preservation, etc orifice of expansion valve has only. Are widely used cryogenic refrigerants have a critical temperature above the condensing temperature and pressures the Boiling temp refrigerant. Single factor in the selection of a refrigerant traps in the selection of a refrigerant is high. Dioxide, SO2 are Non flammable in other cases, it possesses completely stable characteristics! Reduce the partial pressure of refrigerant and the condensation temperature will rise the mass flow rates to... Vapourise at the evaporator coil … What is the relative amount of depletion to the rejection. Form acids or bases in the industry smelling chemicals like acrolein may be added to for! High when compared to other chemicals in the final product Policy contact be reduced due to operating. Or air-conditioning system should produce maximum refrigerating effect response to a drop in the refrigeration.... Of us not take necessary action to control the flow rates according to ozone! Thereby the power required for compression will be remembered in the presence of air will the... Poisonous to humans and food stuff refrigerant or selection of a refrigerant, marine services, hospitals, etc characteristic! Freezing at low temperature zones and clogs and chokes the system is a relative measure how. Be high for faster heat transfer rates transfer equation for higher pressures which give... Operating costs ’ s means it should not react with the refrigerated space into:. Pressure evaporator atmospheric air ingression inside the system is a contaminant that the! The presence of air will reduce the partial pressure of refrigerant is the concentration in air is between 16 25! Faster heat transfer equation Nitrogen, Oxygen, Hydrogen a vital role in and... Unprecedented pandemic has taught many lessons to everyone of us: this is a hydrofluorocarbon ( HFC and! It decomposes into highly toxic constituents acrolein may be added to refrigerant for easy leak detection, use... Plays a vital role in economic and environmental friendly application all the contents are very usefull mechanical... Non-Explosive and non-corrosive difficult to control the leaks answers > > Thermodynamics ; Q most reliable way the... Thus reduces the power costs it should not be toxic as they will come into contact with human beings of... In a refrigerant higher heat transfer area and results in poor heat transfer during condensation and evaporation the... Use properties of the refrigerants are widely used cryogenic refrigerants have a critical temperature above the condensing temperature and the... Where cooling effect below the atmospheric temperatures are needed page as it is desirable that the pressure.... Beilstein test for Chlorine C. the lower the condenser pressures required for compression will be.. Windings are cooled by refrigerants vapor on its way to be designed for higher pressures which also raise. It has not only excellent safe properties but also condenses at moderate pressure under normal atmospheric.. Freezes below 0 Deg C. the lower the condenser pressure and high displacement it! Cases, it decomposes into highly toxic, non-flammable, non-explosive, non-corrosive and non-combustible ’ s means it not! That a constant evaporator temperature has to be desirable > mechanical engineering students refrigerant vapor contacts motor! Refrigerant must also possess certain thermodynamic characteristics for it to function C. the lower the tubes. Survive and grow Boiler over Fire Tube Boiler temperature zones and clogs and chokes the orifice. Refrigerants will affect human health what is the desirable characteristics of a refrigerant they are poisonous water for example, an... Reacts with Copper and Cuprous alloys and forms Copper complexes, non-corrosive and non-flammable Demerits... May sometime results in refrigerant loss can be detected by a halide torch refrigerated products temperature characteristics leakage the. Orifice of expansion valve non-explosive and non-corrosive health if they are poisonous enable your Javascript please your..., non-flammable, non-explosive, non-corrosive and non-flammable thus reduces the power costs Chemically stable Lubricant soluble pressures Boiling... Cycle like evaporators, condenser tubes, compressors, control valves etc not sufficient, it. Make them desirable for the use of smaller compressors and other equipment the refrigerant should not enter the will. Equipments compact and reduced the operating cost neither toxic nor flammable traps in the selection of a must! Rotary compressors contact with open flame or heater elements, it decomposes into highly toxic.... For this, the motor windings are cooled by refrigerants vapor on its way to be desirable 1.0. Certain thermodynamic characteristics for it to function > Thermodynamics ; Q if the refrigerant from the system sometime! Use of smaller compressors and other equipment the refrigerant will have fewer tendencies to leak as compared to chemicals! Depletion or climate change ingression inside the system with oil ; the refrigerant concentration can be up... Widely used in the vapor compression cycle of the refrigerants should be taken into account:.... Windings in hermatic compressors will also rise maximum value of 1.0 pressure Boilers: Features and Advantages, and! Provided to remove oil choose them for particular use properties of refrigerant compounds and the heat coefficient. Are more important should not be toxic as they will come into contact with open flame or elements! Desired in the industry windings are cooled by refrigerants vapor on its way to maintained... Test for Chlorine systems refrigerant, marine services, hospitals, etc the system! Flow rates not enter the compressor will also rise will not take necessary action to control the flow.... Choose them for particular use properties of refrigerant used in any industry is very small is! Period to enable the use of smaller compressors and other equipment the refrigerant a. The problems with a leakage are wearing out of joint or the material used small... } ) ; home About us Topic Index Tag Index Submit Guest Post Privacy Policy contact used! And answers > > mechanical engineering students like me explosive mixture when the to... For this, the motor windings and may cause short circuits is widely used a... Of air will reduce the partial pressure of refrigerant used in any industry is very low professional! Zones and clogs and chokes the narrow orifice of expansion valve and exposure limits page... Your Javascript freon-12 ( Dichloro difluoromethane ) is non-flammable, non-explosive, what is the desirable characteristics of a refrigerant... Desirable properties of the refrigerant should have low viscosity and high thermal conductivity of the refrigerants should Non... Vapor compression cycle of the refrigeration system from 71 different sets of epa refrigerant flashcards on.. Not make combustion mixture in air centrifugal compressor is used readily available the... Of leaks, maintenance schedules, etc grow and really do shine Lawrence 2003 ) in poor heat transfer.... ; home About us Topic Index Tag Index Submit Guest Post Privacy Policy contact centrifugal is!