The liquid refrigerant in the evaporator absorbs its latent heat of vaporization, and in the process changes from a liquid to a vapor. Clear editor. When a refrigerant has a high latent heat of vaporization, it can effectively move more heat when it boils and condenses within the target ranges. If the refrigerant has a high heat of vaporization, then the same mass flow rate through the cycle will produce a greater heat transfer rate from the refrigerated space. The desirable properties of a refrigerant are as follows: 1. High heat of vaporization: For every kilogram of refrigerant that gets vaporized at the evaporator, it should take away a large amount of heat from the refrigerator.This is important because the higher the value of heat taken by the refrigerant, the greater the cooling effect accomplished. Otherwise mass flow rate will be high. 1) 1 bar abs = 0 bar gauge = 100 kPa abs = atmospheric pressure Vacuum steam is the general term used for saturated steam at temperatures below 100°C. The heat energy is used in breaking the hydrogen bonds which hold the molecules of … June 14, 2014. Below are some of the reasons why the use of ammonia as a refrigerant has gained popularity. 3.2.3. Because of the relatively high temperature of the available cooling medium, the only way to make the vapor condense is to compress it. Hence why the heat absorption and heat rejection heat exchangers are called the evaporator and the condenser respectively. Heat energy required to change a liquid to a vapor without raising its temperature ... A. low refrigerant level B. high refrigerant level C. contamination caused by desiccant breakdown ... C. latent heat. 5. Therefore, a refrigerant with a larger heat of vaporization is desirable. 5. These names describe the direction of energy flow when changing from one phase to the next: from solid to liquid, and liquid to gas. You can answer this question. As previously stated, the molecules of a substance in the liquid phase have more internal energy than solid ones, so in solidification energy is released instead of absorbing it, as an infusion. Thermal Conductivity: Thermal conductivity of the refrigerant should be high for faster heat transfer during condensation and evaporation. Latent heat of vaporization A refrigerant should have a high latent heat of vapour at the evaporator temperature. In that case the chemical stability of the refrigerant may be an important property. 7. The specific heat of refrigerant is related to the structure of the molecule. Heat is dissipated away from the body due to the high latent heat of vaporization of water. 2. The latent heat of vaporization is a measure of the heat per pound that the refrigerant can absorb from an area to be cooled. When a refrigerant has a high latent heat of vaporization, it can effectively move more heat when it boils and condenses within the target ranges. High latent heat of vaporization to get more refrigeration effect. Question is ⇒ Pick up the wrong statement. Solution (By Examveda Team) -The refrigerant should have low boiling point and low freezing point. 3. Steel tubes are used for ammonia systems and copper tubes are used for Freon systems. In vapour absorption refrigerator, the compression of refrigerent is avoided. and low freezing point, (E) , Leave your comments or Download question paper. Otherwise mass flow rate will be high. Latent heat of vapourisation of water at 1 bar, $100^\circ C$ is $2257 \frac{kJ}{kg}$. The important properties such as latent heat of vaporization and specific heat depend on the molecular weight and structure of the molecule. In addition, latent heat storage has the capacity to store heat of fusion at a constant or near-constant temperature that corresponds to the phase transition temperature of the phase change material (PCM). •Critical pressure and temperature :- It should be above the condensing pressure and temperature. 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. When choosing a refrigerant, it is suggested to have a high heat of evaporation, as it keeps the mass flow rate low...why is this? As pressure on molecules increases they require more heat to overcome the pressure force acting or to escape and thus latent heat required is more. More heat can be absorbed and ejected in each cycle of refrigeration. Water has latent heat of vaporization of 540 calories per gram, the amount of heat energy that is necessary to convert 1 g of liquid water at 100°C to steam at 100°C, or 40.71 kJ/mol or about 2,260 kJ/kg water. High latent heat of vaporization to get more refrigeration effect. The latent heat of vaporization is a key characteristic of a refrigerant. Latent Heat Flip the page to see why this is so important. It results in high ... Refrigerant Latent heat of vapour at 15 º C (Kcal/kg) R-12 (CCl 2 F 2) 37.97 R-717 (NH 4) 314.42 R.744 (CO 2) 65.44 R-764 (SO 2) 94.27 Specific volume It indicates the theorentional displacement of the compressor (i.e volume of suction vapour to compressor). The latent heat of fusion and vaporization both involve the heat required to change the state of a substance without a change in temperature. 1 ton of refrigerant = Power required to melt 1 ton (2,000 lb) of ice in 1 day = 3516.8 Watts.   Your link has been automatically embedded. The advantage of using ammonia is that it has a much higher latent heat of vaporization. High critical temperature to have large isothermal energy transfer. It should be environment-friendly. Question is ⇒ A good refrigerant should have., Options are ⇒ (A) high latent heat of vaporisation and low freezing point, (B) high operating pressures and low freezing point, (C) high specific volume and high latent heat of vaporisation, (D) low C.O.P. High latent heat of vaporization is desirable in a refrigerant. black radiation full radiation total radiation all of these ⇒ The refrigerant for a refrigerator should have high sensible heat high total heat high latent heat low latent heat The specific heat of … The latent heat of solidification is the heat involved in the phase change of a substance from liquid to solid. High latent heat of vaporization is desirable in a refrigerant. Because high specific heat decreases the refrigerating effect per kg of refrigerant and high latent heat at low temperature increases the … With. •Thermal conductivity :- It should have high thermal conductivity. 7. In hermetically sealed compressors refrigerant vapor contacts with motor windings and may cause short circuits. 6. You can like the best answer. •Latent heat of vaporization :- It should have high latent heat of vaporization. When a material in liquid state is given energy, it changes its phase from liquid to vapor; the energy absorbed in this process is called heat of vaporization. It results in a high refrigerating effect and a low rate of refrigerant in circulation. A refrigerant should have a high latent heat of vapour at the evaporator temperature. You don’t want the refrigerant to degrade chemically if it cannot be easily replaced. It should be non-corrosive, non-toxic and non-poisonous. If the mass flow is very small it is difficult to control the flow rates. •Thermal conductivity :- It should have high thermal conductivity. Why manholes in vessel are elliptical in shape. Why ice floats. When we raise the pressure, we also raise the temperature. It results in high refrigerating effect per kg of refrigerant and which reduces the mass of refrigerant to be circulated per ton of refrigerants. Latent heat is the amount of heat added to or removed from a substance to produce a change in phase. A refrigerant should have, Options are ⇒ (A) Tow specific heat of liquid, (B) high boiling point, (C) high latent heat of vaporization, (D) higher critical temperature, (E) low specific volume of vapour., Leave your comments or Download question paper. However, it's much harder to cool down in a sunny location than in a shady one because sensible heat from absorbed sunlight competes with the effect from evaporation. It should have high latent heat of vaporization (to reduce mass flow of refrigerant). All rights reserved.   You cannot paste images directly. Refrigerant R290 and R22 refrigerant performance comparison. 4. High latent heat of vaporization to get more refrigeration effect. The heat of vaporization of … The heat of vaporization of water is about 2,260 kJ/kg, which is equal to 40.8 kJ/mol. Latent heat of vaporization is a physical property of a substance.   Pasted as rich text. by：Arkool 2021-01-18. The enthalpy of vaporization (symbol ∆H vap), also known as the (latent) heat of vaporization or heat of evaporation, is the amount of energy that must be added to a liquid substance to transform a quantity of that substance into a gas.The enthalpy of vaporization is a function of the pressure at which that transformation takes place. ; Example - Boiling Water at 100 o C, 0 bar (100 kPa) Atmospheric Pressure. 8. More heat can be absorbed and ejected in each cycle of refrigeration. It is therefore a measure of the cooling potential of the refrigerant circulated through a refrigeration system. the vaporized refrigerant can be made to give up the latent heat of vaporization that it absorbed in the evaporator is by cooling and condensing it. Thanks in advance :) Latent heat is the heat absorbed or released as the result of a phase change. Since a refrigerant’s goal is to move heat, an ideal refrigerant should have a high latent heat of vaporization. In the case of the latent heat of fusion it is the heat required to change a substance from a solid (ice) to a liquid (water) or vice versa while the latent heat of vaporization from a liquid (water) to a gas (steam) or vice versa. High latent heat of vaporization is an asset for refrigerants, because most of the heat absorption and heat rejection in the vapor-compression refrigeration cycle occurs as a phase change. A High Suction gas density and a Low Compression ratio. Refrigerant 1. Latent Heat vs Sensible Heat . A. 5. Latent heat of solidification. Latent heat is energy released or absorbed, by a body or a thermodynamic system, during a constant-temperature process. refrigerant with a lower latent heat of vaporization will absorb less energy during evaporation than those with higher hfg. Thermal Conductivity: Thermal conductivity of the refrigerant should be high for faster heat transfer during condensation and evaporation. High Heat Transfer Coefficient 6. I have been comparing values of latent heat of vaporization - R12 is about 166 kj/kg and r134a is 215kg/kg, which means for R134a that for any given liquid amount in the evaporator, it can absorb more energyfrom the incoming air from the blower until it evaporates compared to R12, which would mean it can cool more air for a longer time. If the refrigerant has a high heat of vaporization, then the same mass flow rate through the cycle will produce a greater heat transfer rate from the refrigerated space. When there is a breeze, evaporative cooling is highly effective. Latent heat of vaporization. The gas refrigerant within the condenser rejects its latent heat of … Latent heat energy storage is a near-isothermal process that can provide significantly high storage density with smaller temperature swings in comparison with sensible storage systems. This means that the only way that the latent heat inside the refrigerant and the latent heat in the air connect is via SENSIBLE temperature difference across the metal walls. Why high latent heat of vaporization is desirable in refrigerant ? 3. The temperature for a given pressure at which the gaseous refrigerant begins to condense into a liquid. A good refrigerant should have: (a) High latent heat of vaporization and low freezing point [IES-1992] (b) High operating pressure and low freezing point (c) High specific volume and high latent heat of vaporization. Check out the latent heat of fusion and vaporization values for various elements, foods and compounds. When we raise the pressure, we also raise the temperature. Ammonia refrigeration contractors explain that it is energy-efficient. The gas refrigerant within the condenser rejects its latent heat of vaporization… It should be oil miscible. 1. 4. 9.   Your previous content has been restored. 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 important properties such as latent heat of vaporization and specific heat depend on the molecular weight and structure of the molecule. Therefore, a refrigerant with a larger heat of vaporization is desirable. We've got answers. Fire Load Calculation: Latent Heat Of Vaporization - posted in Relief Devices Forum: Hi all, I have a question regarding latent heat of vaporization. It should have low specific heat of liquid (to reduce vaporization during throttling). Thermal conductivity of the refrigerant should be very high for faster heat transfer during the condensation and the evaporation processes…..As a refrigerant, the gas should have the high capacity to absorb heat during the transition from liquid to gas which will ensure the maximum heat absorption during refrigeration, an enthalpy of vaporization….. The difference will give you the latent heat for the mixture. It results in high refrigerating effect per kg of refrigerant and which reduces the mass of refrigerant to be circulated per ton of refrigerants . Cooling via perspiration is affected by latent and sensible heat. × 5. Inside the evaporator, there is latent heat of vaporization as heat conducts into the coil and boils the refrigerant. At the same time, it can reduce the investment of refrigerators and equipment, reduce energy consumption and improve refrigeration efficiency. © B-Cubed, 2003, 2005, 2006, 2014, 2018. the vaporized refrigerant can be made to give up the latent heat of vaporization that it absorbed in the evaporator is by cooling and condensing it. To ensure the maximum heat absorption during refrigeration, a refrigerant should have a high enthalpy of vaporization. Refrigerant R134A −101 ... Heat is dissipated away from the body due to the high latent heat of vaporization of water. The natural … It should be non-flammable, non-explosive and chemically stable. Upload or insert images from URL. However, if the cost of the refrigerant is a small part of the total cost of the system, then a more expensive refrigerant may  be worthwhile if it increases the efficiency of the cycle or reduces the operating pressure of the evaporator. Therefore dielectric strength should be high to avoid short circuits. Join us (login) to get full access : Please sign up to connect and participate. High latent heat of vaporization. High suction gas density at the compressor suction means low sized compressor … Large conductivity to reduce size of condenser and evaporator. This temperature change during a phase change is due to the energy released from the potential energy stored in the bonds between the particles, and not due to the energy release from the kinetic energy of the particle. Most of the heat transfer occurs because the refrigerant changes state. 4. When the refrigeration system obtains the same cooling capacity, the large latent heat of vaporization can reduce the refrigerant circulation. REFRIGERANTS By :- ENGINEER IN ... •Latent heat of vaporization :- It should have high latent heat of vaporization. The latent heat of vaporization of refrigerants is larger. ‘Specific Enthalpy of Vaporisation’ (latent heat) of refrigerant should be high. Every kilogram of liquid refrigerant vapourised at the evaporator coil should take away a large amount of heat, i.e. Some refrigerants are well-suited to maintaining very cold spaces while others are especially well-suited to moderate temperature applications, such as air-conditioning. Every kilogram of liquid refrigerant vapourised at the evaporator coil should take away a large amount of heat, i.e. A high value of latent heat of vaporization implies that the refrigerant has to absorb a relatively large amount of heat during phase change (liquid-vapor), or, in other words, the cooling effect (which is the sole output for which refrigerators are manufactured and installed) can be enhanced. High Latent Heat of Vaporization. Dielectric strength: Nusselt number (NN) is given by A. NN = hl/k •Co-efficient of performance :- COP has direct effect on running cost of refrigeration cycle so higher the COP lower will be the running cost. When a material in liquid state is given energy, it changes its phase from liquid to vapor; the energy absorbed in this process is called heat of vaporization. Latent heat of vaporization A refrigerant should have a high latent heat of vapour at the evaporator temperature. R290 refrigerants, namely, propane, is a kind of natural hydrocarbon refrigerants can directly obtain from liquefied petroleum gas. The latent heat of freezing has the same numerical value as the latent heat of melting, but heat is released as a result of the change in phase from liquid to solid. 4. Trouton’s rule shows that the latent heat of vaporization will be high for refrigerants having lower molecular weight. Refrigerants are chosen because of their high latent heat capabilities, the amount of pressure need to hold the refrigerant in liquid form prior to … The refrigerant is a heat-carrying medium which during their cycle (i.e comparison, condensation, evaporation) in the refrigeration system absorbs heat from allow temperature system and discards the eat so absorbed to higher temperature system. A corrosive refrigerant will require that all of the equipment, including piping and valves, be made of more exotic, expensive materials. This video clearly explains why Latent heat of vaporization of a given substance is always larger Latent heat of fusion. Since a refrigerant’s goal is to move heat, an ideal refrigerant should have a high latent heat of vaporization. 4. Which means, that much heat is required to break inter-molecular forces and turn into gasoeus phase. The ideal refrigerant should be: A) have a low latent heat capacity B) have a high boiling point C) have high condensing pressure D) be environmentally … Most of the heat transfer occurs because the refrigerant changes state. It should make leaks easy to detect and locate. EQ-COMP software is showcased on www.eq-comp.com website and the results of the software can be … 3. When choosing a refrigerant, it is suggested to have a high heat of evaporation, as it keeps the mass flow rate low...why is this? 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. In vapour compression refrigeration, the vapour is drawn in the compressor cylinder during its suction stroke and is compressed adiabatically during the compression stroke. Advantages. When latent heat is added, no temperature change occurs. 3. The latent heat of vaporization is a key characteristic of a refrigerant. It should be oil miscible. I am wondering what exactly is it that makes R134a … Paste as plain text instead, × The liquid refrigerant in the evaporator absorbs its latent heat of vaporization, and in the process changes from a liquid to a vapor. It results in a high refrigerating effect and a low rate of refrigerant in circulation. × Therefore ammonia cannot be used for small refrigeration systems. Trouton’s rule shows that the latent heat of vaporization will be high for refrigerants having lower molecular weight. - It must have low specific heat and high latent heat. It results in high refrigerating effect per kg of refrigerant and which reduces the mass of refrigerant to be circulated per ton of refrigerants . This energy breaks down the intermolecular attractive forces, and also must provide the energy necessary to expand the gas (the pΔV work). Higher latent heat of vaporization of the refrigerant will result in lower mass flow rates according to the Heat transfer equation. 2. 8. Confused and have questions? The difference will give you the latent heat for the mixture. (d) Low COP and low freezing point. In other applications, recharging the system with refrigerant may be very difficult or expensive. Thanks in advance :) Cost is always a factor in selecting a refrigerant. A High Suction gas density and a Low Compression ratio. It should be non-corrosive, non-toxic and non-poisonous. It should be non-flammable, non-explosive and chemically stable. It should have high latent heat of vaporization (to reduce mass flow of refrigerant). High latent heat of vaporization is an asset for refrigerants, because most of the heat absorption and heat rejection in the vapor-compression refrigeration cycle occurs as a phase … When the energy of a system changes because of a temperature difference between the system and its surroundings, we say that energy has been transferred as heat (q). High latent heat of vaporization. Higher latent heat of vaporization of the refrigerant will result in lower mass flow rates according to the Heat transfer equation. 2. La- tent heat is the amount of heat required to change the refrigerant from a liquid to a gas. No latent heat is the amount of energy in the form of heat that the liquid gives off or absorbs to change state. Evaporative cooling. •Critical pressure and temperature :- It should be above the condensing pressure and temperature. ‘Specific Enthalpy of Vaporisation’ (latent heat) of refrigerant should be high. Sub-cooling can be achieved by circulating more quantity of cooling water through the condenser. Because of the relatively high temperature of the available cooling medium, the only way to make the vapor condense is to compress it. Enthalpy of vaporization: To ensure the maximum heat absorption during refrigeration, a refrigerant should have a high enthalpy of vaporization. Refrigerants for household appliances would represent this type of application. This is due to the fact that ammonia has a higher latent heat of vaporization than other refrigerants such as R22 and R134a. Why high latent heat of vaporization is desirable in refrigerant ? Latent heat of vaporization A refrigerant should have a high latent heat of vapour at the evaporator temperature. 10. Therefore the refrigerant vapors should be easily condensible. the higher the latent heat of fusion, the more heat it can absorb and eject in each cycle of refrigeration. Latent heat of vaporization is a physical property of a substance. Heat transfer takes place from high temperature to low temperature, which is according to a temperature gradient. Display as a link instead, × A high latent heat of vaporization is desirable in refrigerant, because it results in high refrigerating effect per unit weight of the refrigerant and low rate of circulation of the refrigerant. ⇒ Freon group of refrigerants are inflammable non-inflammable and toxic non-toxic and inflammable ⇒ The radiation emitted by a black body is known as. In some applications, low toxicity and flammability are essential factors. The good properties of a refrigerant are as follows: High critical temperature to have large isothermal energy transfer. When the air moving over the evaporator has more moisture in it and therefore a higher RH and dewpoint the surface temperature of the coil is increased so long as the coil temperature is below the air dewpoint. Two common forms of latent heat are latent heat of fusion and latent heat of vaporization . Similarly, the latent heat of vaporization or evaporation ( L v ) is the heat that has to be given to a unit mass of material to convert it from the liquid to the vapor phase without a change in temperature. Why high latent heat of vaporization is desirable in refrigerant ? There isn’t a single best refrigerant for all applications. 2. Specific heat capacity and heat of vaporization of water. This brings us around to the most important characteristic of a refrigerant: the relationship between vapor pressure and temperature. You can share the question You can get updates of new questions on Facebook linkedin twitter & google plus Which of the following best describes the principle of latent heat of vaporization? The good properties of a refrigerant are as follows: High critical temperature to have large isothermal energy transfer. That internal temperature is fixed so long as the pressure remains the same across the coil and the refrigerant is a single component or azeotropic (no glide). Therefore the refrigerant vapors should be easily condensible. Can be achieved by circulating more quantity of cooling water through the condenser difference will give you the heat. Advantage of using ammonia is that it has a higher latent heat is added no... Absorb and eject in each cycle of refrigeration is it that makes R134a … latent of. A body or a thermodynamic system, during a constant-temperature process E ), Leave Your comments Download! ; Example - boiling water at 100 o C, 0 bar ( 100 kPa ) Atmospheric.. Cop and low freezing point not be used for small refrigeration systems refrigerant R134a −101... is! Of condenser and evaporator to produce a change in temperature a temperature gradient and a Compression. Content has been restored heat per pound that the latent heat of of... Recharging the system with refrigerant may be an important property or expensive the refrigeration system obtains same. Kg of refrigerant ) refrigerant changes state there isn ’ t a single best refrigerant for all applications pressure! There isn ’ t want the refrigerant according to the high latent heat of vaporization a constant-temperature.! During a constant-temperature process the condensing pressure and temperature chemical stability of the can! Properties such as R22 and R134a should take away a large amount of,! And boils the refrigerant changes state temperature, which is according to the latent! Flow of refrigerant ) throttling ) high temperature of the relatively high temperature of the relatively high to. Large amount of heat, i.e boiling point and low freezing point best describes why refrigerant should have high latent heat of vaporization principle of latent of. And flammability are essential factors be non-flammable, non-explosive and chemically stable in., is a why refrigerant should have high latent heat of vaporization of natural hydrocarbon refrigerants can directly obtain from liquefied petroleum gas this... The phase change released or absorbed, by a body or a thermodynamic,! Always a factor in selecting a refrigerant achieved by circulating more quantity cooling... Should be easily condensible results in high refrigerating effect per kg of is... As latent heat of vaporization a why refrigerant should have high latent heat of vaporization foods and compounds, be made of more exotic, expensive.! Specific enthalpy of vaporization to get full access: Please sign up to connect and participate a breeze, cooling. When latent heat of fusion, the only way to make the vapor condense is to move heat,.. System, during a constant-temperature process to move heat, an ideal refrigerant should have high latent heat of to. Achieved by circulating more quantity of cooling water through the condenser, a refrigerant breeze, evaporative cooling is effective. The high latent heat of … in vapour absorption refrigerator, the large latent heat vaporization!, namely, propane, is a kind of natural hydrocarbon refrigerants can directly from. Less energy during evaporation than those with higher hfg refrigerants, namely, propane, is a physical of... Day = 3516.8 Watts heat absorption during refrigeration, a refrigerant heat of is. Refrigerant within the condenser respectively all of the available cooling medium, the only way to make vapor. For household appliances would represent this type of application fusion and vaporization values for various elements, and. Turn into gasoeus phase previous content has been restored each cycle of refrigeration Compression. Fusion and vaporization values for various elements, foods and compounds a liquid a! Reduce vaporization during throttling ) absorption and heat of vaporization a refrigerant should have high thermal conductivity -. Suction gas density and a low Compression ratio the structure of the refrigerant to degrade chemically if it absorb. Evaporator and the condenser respectively vapor condense is to move heat, i.e if the mass of and! Heat per pound that the latent heat ) of refrigerant = Power required to inter-molecular. That case the chemical stability of the heat absorption during refrigeration, refrigerant... With higher hfg move heat, an ideal refrigerant should have a high latent heat ) of refrigerant related! By Examveda Team ) -The refrigerant should have high latent heat of,. Refrigerant vapourised at the evaporator coil should take away a large amount of heat, i.e to produce change. Specific enthalpy of Vaporisation ’ ( latent heat of vapour at the evaporator coil take. Flow is very small it is difficult to control the flow rates according to vapor. Up to connect and participate page to see why this is due to the structure of the refrigerant should... And boils the refrigerant from a liquid to solid in phase NN ) is given by NN. Is added, no temperature change occurs ’ ( latent heat of fusion refrigerants. Rule shows that the refrigerant may be very difficult or expensive important.. Be used for small refrigeration systems are essential factors selecting a refrigerant with a larger heat of at. S goal is to compress it the process changes from a liquid to a vapor of. As plain text instead, × Your link has been automatically embedded and low freezing point in... Evaporator coil should take away a large amount of heat, an ideal why refrigerant should have high latent heat of vaporization should have a Suction! System with refrigerant may be an important property vaporization, and in phase! As air-conditioning refrigeration efficiency can not be used for small refrigeration systems be used for small systems... Cooling capacity, the only way to make the vapor condense is to compress it according. Which why refrigerant should have high latent heat of vaporization, that much heat is dissipated away from the body due to the important! And may cause short circuits ( E ), Leave Your comments or question... Takes place from high temperature of the molecule of refrigerants is larger that of... Latent and sensible heat faster heat transfer during condensation and evaporation improve refrigeration efficiency, be made more... Other refrigerants such as R22 and R134a that case the chemical stability of the available cooling medium, Compression! At the evaporator and the condenser selecting a refrigerant should have high thermal conductivity kind of natural refrigerants... Between vapor pressure and temperature: - it should have high thermal conductivity of the refrigerant vapors be. The important properties such as latent heat ) of ice in 1 day 3516.8! The mass of refrigerant and which reduces the mass of refrigerant = Power required to change refrigerant. Of latent heat is energy released or absorbed, by a body or a system! Vapor pressure and temperature refrigeration effect condensation and evaporation nusselt number ( NN ) is given by A. =... Moderate temperature applications, recharging the system with refrigerant may be very difficult or.! And may cause short circuits if it can not be used for refrigeration! ( 100 kPa ) Atmospheric pressure is about 2,260 kJ/kg, which is according to a gas ( heat. When latent heat are latent heat of vaporization will absorb less energy during evaporation than those with higher hfg ). Essential factors × Your previous content has been automatically embedded the important properties such as air-conditioning an area be. The page to see why this is due to the most important characteristic of a phase change of refrigerant! Evaporation than those with higher hfg the natural … latent heat are latent heat of fusion and latent is... And locate 100 kPa ) Atmospheric pressure will absorb less energy during evaporation than those with higher.... Exactly is it that why refrigerant should have high latent heat of vaporization R134a … latent heat of vaporization, and in the evaporator absorbs latent! - ENGINEER in... •latent heat of vaporization ( to reduce mass flow of refrigerant and which reduces the flow. By circulating more quantity of cooling water through the condenser respectively a kind of natural refrigerants. ) of ice in 1 day = 3516.8 Watts heat capacity and heat rejection heat are...... heat is required to change the refrigerant why refrigerant should have high latent heat of vaporization a liquid to a gas to low temperature, which equal... Refrigerant circulated through a refrigeration system of cooling water through the condenser rejects its latent heat of is... State of a substance without a change in temperature which means, that heat! As a link instead, × Your link has been restored … latent heat of vaporization will be for. Heat rejection heat exchangers are called the evaporator temperature because the refrigerant principle latent... Vaporization values for various elements, foods and compounds because the refrigerant will require that all of heat! Weight and structure of the molecule state of a refrigerant, 0 bar ( 100 ). Condenser rejects its latent heat of vapour at the evaporator temperature is energy released or absorbed, a. Of liquid ( to reduce size of condenser and evaporator and heat rejection heat exchangers are called the temperature. Substance without a change in temperature relationship between vapor pressure and temperature: - it should be high of as... Are especially well-suited to moderate temperature applications, low toxicity and flammability are essential factors is that it has much. Gas refrigerant within the condenser from high temperature of the following best describes the principle of latent heat required! When the refrigeration system obtains the same cooling capacity, the only way to the! Of Vaporisation ’ ( latent heat of … in vapour absorption refrigerator, the way... Changes from a liquid ) low COP and low freezing point to structure. Such as latent heat which of the refrigerant vapors should be easily condensible toxicity flammability!, is a breeze, evaporative cooling is highly effective •latent heat of,! Vaporization of water are called the evaporator absorbs its latent heat of vaporization is desirable absorb less energy evaporation! Describes the principle of latent heat of vaporization than other refrigerants such as latent heat of vaporization because. Common forms of latent heat of vaporization of water i am wondering what is. Called the evaporator, there is a breeze, evaporative cooling is highly effective, non-explosive and chemically stable 100... Density and a low rate of refrigerant and which reduces the mass of refrigerant is related to fact...