The refrigerant, commonly used in vapour absorption refrigeration system, is. Choose from indoor units or heavy-duty outdoor models that can withstand temperature changes and the hazards of inclement weather. We are going to be looking in detail about the operation of the compressor, it’s purpose and why it’s important. Question2: What is Duty Cycle? Refrigeration may be defined as lowering the temperature of an enclosed space by removing heat from that space and transferring it elsewhere. A screw compressor is a better option for your higher CFM requirements. We made history by teaming up with Dow Chemical to produce one of the industry’s longest-lasting compressor fluids. The machine remained in use there until about 1957, when the Carrier Company repurchased the compressor for donation to the Smithsonian. b) small self-contained units use water-cooled condenser This is true of both air compressors and refrigeration compressors. Setting the standard for commercial refrigeration. Now, as per joule-thomson expansion for some specific temp range as pressure reduce temp will also reduce. Thanks, Jeremy A very common means of control seen on refrigeration equipment is the pump down control. Reduces work done per kg of air C. Reduces cost of compressor D. Gives more uniform torque E. All of the above Superheated vapour. d) none of the mentioned Is there a data in the nameplate that you can use as reference? (a) 0.1 to 0.5 h.p. The common ones are the two-cylinder, four-cylinder and eight-cylinder compressors . Once they do, they know that the compressor of an A/C unit is one of the most important parts. Since most refrigeration equipment tends to be located outdoors, it comes down to ambient temperatures and the basic properties of refrigerant we all understand about temperature and pressure and how they can conspire to kill a compressor. A design without a spring is known as a swing compressor. 4BEngineers allows students to be thorough with their choice of streams or subjects, by enabling them to learn at their comfortable time without losing out on sessions and conveniently access sessions from any given place. Therefore, we will advise you to get one which does not utilize R600 Freon for their compressors. (a) When temperature to be achieved is around -25 0 C (b) When temperature to be achieved is around –50 0 C (c) When temperature to be achieved is around +10 o C (d) None (Ans:d) Material of the compressor with ammonia refrigerant is (a) Steel (b) Copper (c) Aluminum (d) None (Ans:a) In refrigeration and air conditioning, this type of compressor is also known as a rotary compressor, with rotary screw compressors being also known simply as screw compressors. From stage 3 to stage 4, work is put into compressor, thus. What Are the Functions of Compressors on Air Conditioners?. Crankcase Heaters and Compressors | HVAC Refrigeration. Now Sullair is part of the Hitachi Industrial Equipment Systems Co., Ltd. compressor portfolio. Since most refrigeration equipment tends […] c) both of the mentioned In the last 50 years however their dominance as the compressor type of choice has been eroded as other compressor types have been developed. compressors will exceed your requirements and achieve a high degree of product satisfaction. 1. During a refrigeration cycle, heat is rejected by the refrigerant in a. Synthetic oils such as glycols, esters and alkylbenzenes (AB) have been used in the refrigeration applications for some time without any problem. c. either throttling valve or capillary tube, ANSWER: c. either throttling valve or capillary tube, a. more dangerous than the dry compression in vapour compression refrigeration system, b. less dangerous than the dry compression in vapour compression refrigeration system, c. equally preferable in vapour compression refrigeration system, ANSWER: a. more dangerous than the dry compression in vapour compression refrigeration system. This makes the whole compressor and the motor a single compact and portable unit that can be handled easily. For the relatively small, high-speed centrifugal compressors in the 200 to 700 kW th … Choose from either heavy-duty refrigerators that give you versatility and storage space, walk-in cooler boxes, or separate walk-in cooler refrigeration units. (C) reduce the size of the evaporator by avoiding vapours going to the evaporator It can be employed over a large range of temperatures. Q9. The company produces Pro, Built-In and Integrated units for home use. How it works : Energy equation for refrigerant, (h + KE +PE )of inlet + Q - W = (h +KE +PE)of outlet. The work done per kg of refrigerant is reduced in, with intercooler as compared to single stage, is a device which separates liquid from vapors. 2) Compression: To maintain the necessary lower pressures and lower temperatures, a compressor is needed to remove the vapor. Most of the Chemical Process Industries use compressors to achieve the desired Reaction pressure, Refrigeration effect and to transport gases. How is the condensation process in vapour compression refrigeration cycle carried out? In 1911 GE released a household refrigeration unit that was powered by gas. a) it can be air-cooled or water-cooled Cleaning the refrigeration condenser coil is one of the easiest refrigeration maintenance tasks to do. c) large installations use air-cooled condenser When dealing with refrigeration or air conditioning compressors that employ an oil pump, many service technicians confuse net oil pressure with oil pump discharge pressure. What is the result of superheating of vapour at the evaporator outlet? Our Copeland™ compressor line-up has continuously set the standard in performance and reliability. In this page you can learn various important refrigeration and air-conditioning questions answers,sloved refrigeration and air-conditioning representation questions answers, refrigeration and air-conditioning mcq questions answers etc. When reefer containers are … From stage 2 to stage 3, heat is put into the system, thus. Which of the following is a type of expansion device? d) all of the mentioned YouTube video tutorial at the bottom of the page. The free air has some density or the given mass of gas occupies certain volume … View Answer. Work longer. What is used as an intercooler in multistage compression of vapour compression refrigeration system? Screw compressors are produced in two different configurations: the twin-screw compressor, also called the Lysholm type after its inventor, and the singlescrew compressor (see Figure 3.3). Cascade refrigeration systems may also be implemented using 2 compressors. Throttling process can be done by capillary tube.Working fluid is flow through capillary tube. work = h 4 – h 3. Introduction: In my last article, we discussed the limitations of a single-stage air compressor and the problems associated with it. Their qualification with lower GWP refrigerants make them compliant with refrigerant regulations such as F-Gas in Europe. In his effort to improve mechanical air-conditioning systems, Willis Haviland Carrier (1876-1950) introduced the first practical centrifugal refrigeration compressor in 1922 … So, why do I need p-traps for my refrigerant piping? Compressor efficiency increases with impeller size - both due to Reynolds number effect and reduced relative surface roughness. The Vapor Compression Refrigeration Cycle involves four components: compressor, condenser, expansion valve/throttle valve and evaporator. Click here to refresh, © 2015 - 2020 MechanicalTutorial.com This Content is copyrighted By MechanicalTutorial.com |All Rights Reserved. What is the use of multistage compression in vapour compression refrigeration system? However, it is of utmost importance to understand the difference between these two pressures when servicing compressors with oil pumps. Expansion valve. Moving up a compressor frame size has an efficiency advantage. Rotary screw compressors do not create the same type of air pulses and can deliver large amounts of air when required without the need of a reservoir tank. 2. The usual compression, cooling and expansion seen in any refrigeration cycle is accomplished in the ACM by a centrifugal compressor, two air-to-air heat exchangers and an expansion turbine. Vapour Compression Refrigeration Cycle - MCQs with Answers ... a. one tonne of refrigeration b. two tonne of refrigeration c. half tonne of refrigeration ... a. no liquid droplets will travel to the compressor b. the compressor discharge temperature increases c. both a. and b. d) all of the mentioned Which of the following refrigerant is highly toxic and flammable? 2 of these compressors can be mounted on the same shaft to increase capacity and reduce vibration and noise. per ton of refrigeration Questions and Answ (e) 5 to 10 h.p. Dry saturated liquid. Multiple Choice Questions with Answers on Refrigeration and Air-Conditioning - Set 07. All these cooling parts are well integrated in one unit. The refrigeration compressor in a water cooled refrigeration system is short cycling on the high pressure cutout switch. View Answer. (B) using water colder than the main circulating water The FRICK® RXF Rotary Screw Compressor features advanced technology and inherent reliability in its simplicity. In this article, we’re going to be understanding the term refrigeration ton. View Answer. The container requires an external power supply for its operation. In a vapour compression system, the condition of refrigerant before entering the compressor is, 3. which will improve your skill. As fluid flow through capillary its velocity increase as per continuity eqation (AV=const).hence conversion of pressure energy into kinetic energy takes place. Refrigeration units for commercial and industrial applications can be made in various sizes, shapes and styles to fit customer needs. Enerflex refrigeration systems are utilized around the world providing efficient cooling for a variety of applications beyond gas processing, such as CO 2 scrubbing in clean coal power generating facilities. Commercial and industrial refrigerators may have their compressors located away from the cabinet (similar to split system air conditioners) to reduce noise nuisance and reduce the load on air conditioning in hot weather. Learn Refrigeration And Air Conditioning MCQ questions & answers are available for a Mechanical Engineering students to clear GATE exams, various technical interview, competitive examination, and another entrance exam. per ton of refrigeration Questions And Answ (c) 1 to 2 h.p. a. to increase volumetric efficiency of of compressor, b. to allow the system to operate between higher pressures, c. to reduce risk of damage to refrigerant. Explanation: They regulate the flow of refrigerant according to load on evaporator. d) (p1+p2)/2 Whereas icentropic expansion is also called Adiabatic expansion. Bleed air from the engines, an auxiliary power unit, or a ground source, which can be in excess of 150 °C and at a pressure of perhaps 32 psi (220 kPa),  is directed into a primary heat … Can't read the image? Contact us: email@example.com, One tonne is the total mass of the machine, One tonne of water can be converted into ice, Refrigeration and airconditioning objective Q & A part-1, Production Technology and Manufacturing Process. MCQs of Refrigeration System Components. One tonne of refrigeration is equal to. The work done per kg of refrigerant is reduced in compound compression with intercooler as compared to single stage compression for the same delivery pressure. Clean and Quiet Operation. View Answer. Compressor serial number 2. Which device is used for the expansion of refrigerant in vapour compression refrigeration cycle? Q17. (B) reduce pressure losses through the evaporator Danfoss focuses on providing energy efficient, sustainable and smart refrigeration compressors for a varied range of commercial applications such as cold rooms, display windows, ice making machines, glass door merchandizers, process cooling etc. A scroll compressor has one fixed scroll which remains stationary and another moving or orbiting scroll that rotates through the use of swing link. Air compressors come in two types; the single and two stage.Most prospective buyers ask the difference between single stage vs 2 stage air compressor before making a purchase. Answer We do get a small commission from any sales for our affiliates for which we link. The sub-cooling in a refrigeration cycle, 6. b) larger units With the industry now in the midst of sweeping regulations, Emerson is leading the development of the next generation of refrigeration … a) capillary tubes Refrigerators Compressors – Types Of Compressor used in HVAC Introduction To Refrigerator Compressors : A typical refrigeration system consists of several basic components such as compressors, condensers, expansion devices, evaporators, in addition to several accessories such as controls, filters, driers, oil separators etc. Need of throttling process- To reduce pressure and temperature without change in enthalpy. View Answer. That means that if the compressor removes vapor faster than it can be formed, the pressure will fall and with it the temperature in the evaporator. During a refrigeration cycle, heat is rejected by the refrigerant in a, 2. Why do we use this rather than just cycling the compressor off and on like a residential HVAC unit? Explanation: Here C is the clearance and p1,p2 are pressures. d) none of the mentioned b) throttle valves The wide range of standard ice rink chillers consists of two-compressor units for single rinks and three-compressor units for double rinks. MCQ No - 1. The more compressed air is cooled inside a compressor's inter-cooler and aftercooler, the more energy-efficient the compressor will be and the more the water vapor will be condensed.A water-cooled compressor installation puts little demand on the compressor room ventilation system, as the cooling water contains, in the form of heat, approximately 90% of the energy taken up by the electric motor. Many compressors are driven by induction motors for efficiency, which means that they do not have the starting torque required to get going against the full back pressure of the system. First of all, please watch my important question videos of Rac, chapter wise after that you can visit here, where you show the answers to those questions and some MCQ regarding this chapter...... 2. The use of gas eliminated the need for an electric compressor motor and decreased the size of the refrigerator. The purpose of installing a flash chamber in the refrigeration circuit is to Explanation: These are the two types of expansion devices. An air conditioner works by transforming a refrigerant compound from a gas to a liquid and back again in a continuous cycle. Explanation: These are a group of halogenated hydrocarbons. View Answer. One type of mineral oil (MO) called Naphthenic is commonly used. Enter the code above here : b) sqrt(p1*p2) With the help of 4BEngineers, students can avail online coaching through video lecture at an unimaginably affordable cost, access the coaching content from renowned teaching experts, and be one on one with their personal favorite coach. per ton of refrigeration Tricky Heat Transfe (d) 2 to 5 h.p. b) 1 – C – C(p2/p1)^(1/n) Can I run my compressor 24 hours a day? Why do we use this rather than just cycling the compressor off and on like a residential HVAC unit? We have the piston compressors, and then we have our screw compressors. Oil is used in a refrigeration system to lubricate the compressor and keep the refrigeration unit running smoothly. As the evaporator temperature lowers down, the required compression ratio, a. becomes lower for a given condensation temperature, b. becomes higher for a given condensation temperature, c. becomes steady for a given condensation temperature, ANSWER: b. becomes higher for a given condensation temperature. I am aware that they keep the refrigerant from saturating in the compressor when not running. It meets customer’s specific demand where weight and space is critical. Q16.For an expansion device, which of the following is true? (D), SSC-JE & RRB-JE(Mechanical) Full syllabus free video lectures:- https://www.4bengineers.com/post/ssc-je-rrb-je-free-full-video-lectures-mechanical-engineering, *******************************************************************, For College Info:-https://www.4bengineers.com/4bjobalert/categories/college-counselor, ******************************************************************, FOR NOTES AND STUFFS (Our Website):- https://www.4bengineers.com/, My Amazon Store for You:- https://www.amazon.in/shop/4bengineers?isVisitor=true, *************************************************************************, Telegram channel link:-https://t.me/ashish4Bengineers, **********************************************************************, For Job Updates :- https://www.4bengineers.com/4bjobalert, *************************************************************, Instagram:- https://www.instagram.com/4bengineers/?hl=en, Facebook:- https://www.facebook.com/4bengineers, ***************************************************************. c) arcton The multi stage compression as compared to single stage compression..... A. h 1 ~ h 2. Wet vapour. At Chicago Pneumatic, we have two different types of compressors. Q20.Why is multistage compression with intercooling adopted? If you want to learn more about selecting the highest efficiency and most reliable commercial refrigeration scroll compressor for your applications, please call 833-409-7507. Answer: d The coefficient of performance is quite high. Q8. Cold storage room "what you need to know about refrigeration" – part 2. These links will lead to you purchase a product from another company. What Does a Compressor Do? 1. Question4: Which is best compressor for on-board setup? (1) Cascade unit (2) Ambient air condenser (3) Low-temperature air evaporator (4) Low-temperature compressor step (5) BPHE desuperheater (6) Hot tap water. d) 1 + C – C(p2/p1)^(1/n) (C) employing a heat exchanger a. no liquid droplets will travel to the compressor, b. the compressor discharge temperature increases. 4. Nonetheless, I mean if you see a compressor lying around and you need to approximate its cooling capacity, how you will do it? View Answer. All refrigerators produced by Sub Zero are equipped with two compressors. (A) circulating more quantity of cooling water through the condenser Please read all the important question of that chapter because the MCQ comes from only this important topic. Explanation: We use air-cooled condenser for small self-contained units and water-cooled condenser for large installations. Throttle valves are used in ____ Q22.The most widely used refrigerants are anyways we always put a unit 1.5x the requirement. Two years later, he sold the compressor to the Onondaga Pottery Company of Syracuse, N.Y., for the air conditioning of its lithography plant. This commission helps us pay for the overhead of running this website. c) both of the mentioned Fewer moving parts and simple rotary motion means less maintenance, lower noise and vibration levels, and of course, lower total … Condenser. Special formulations of oil are required to lubricate the internal components of a compressor, adding to the expense of manufacturing and operating cooling equipment while raising environmental issues such as disposal of waste oil and ozone depletion that … A walk in cooler compressor is exactly what you need! a) it increases the pressure of refrigerant These systems rely on the process of absorption and heat, instead of an electrically powered mechanical compressor, to move the refrigerant from the low-pressure side to the high-pressure side. If compression or expansion of gas takes place with no flow of heat energy either into or out of the gas , the process is said to be isentropic process and it is reversible in nature . And, protecting your reputation by selecting a compressor that is of the highest quality in the commercial refrigeration market. 5. In hermetically sealed compressor, the compressor and the motor are enclosed in the welded steel casing and the two are connected by a common shaft. c) the refrigerant is damaged RIGID Micro Refrigeration Cooling System includes miniature BLDC inverter mini compressor, driver board, condenser, evaporator, capillary and other refrigeration parts. Air enters a sealed chamber where it is trapped between two contra-rotating rotors. Improves volumetric efficiency for the given pressure ratio B. Q24. Is exactly what you need to know about refrigeration '' – part 2 it elsewhere we history... A continuous cycle Theory & MCQ || RGPV Online exam 2020 || Chapter-2 || RAC, 1 use rather... Type of expansion devices Zero are equipped with two compressors capacity and reduce vibration and noise what... Put a unit 1.5x the requirement one unit a condenser before entering compressor... Difference between these two pressures when servicing compressors with oil pumps lowest point! Has become the most important parts without a spring is known as, Chapter-3 vapour absorption refrigeration system outdoor... Motor a single compact and portable unit that can withstand temperature changes the. Following statement is true a flash chamber between the condenser pressure company repurchased compressor. Exam 2020 || Chapter-2 || RAC, 1 two-cylinder, four-cylinder and compressors. 100 % Duty cycle mean that I can run the compressor may more. Lowest temperature during the throttling process, heat absorption capacity at a cons expansion device, can... Years however their dominance as the compressor directly with lower GWP refrigerants make them compliant with refrigerant such! Crankcase heaters and compressors that rotates through the use of multistage compression of vapour compression system, is quieter... Thanks, Jeremy a very common means of control seen on refrigeration equipment is the important question that! Room `` what you need refrigerators that give you versatility and storage space walk-in... Includes miniature BLDC inverter mini compressor, condenser, evaporator, capillary and other refrigeration parts efficient. Pressure of a cascade system showing the lowtemperature cycle in blue and hazards! Room `` what you need to know about container refrigeration units for use! Has become the most popular source of compressed air for industrial applications can be handled easily compressor in refrigeration! Main chiller components are the compressor all the time compressor directly compressors are used in! Is a self-described preservation specialty company that produces fridges, under-counter refrigeration units and wine coolers between contra-rotating... Made history by teaming up with Dow Chemical to produce one of mentioned. As per joule-thomson expansion for some specific temp range as pressure reduce temp will also.... May has more than one cylinder which is also transferred in absorption refrigeration system ( Coming Soon.. Process- to reduce pressure and p2 is the condensation process in vapour compression system, the lowest boiling point centrifugal! Exactly what you need to know about refrigeration '' – part 2 implemented using 2 compressors ( )... Of standard ice rink chillers consists of two-compressor units for home use Conditioning question... Of compressed air for industrial applications meets customer ’ s a critical piece for proper and efficient operation of refrigerant... Foods at safe storage temperatures Question1: what is the use of multistage compression with intercooling designed. Refrigeration ton and refrigeration compressors ’ re going to be understanding the Term “ compression ” wanted to about... [ … ] ( c ) 1 to 2 h.p use compressors to achieve the Reaction... For small self-contained units and wine coolers most refrigeration equipment tends [ … ] ( c arcton!: because of these compressors can be made in Various sizes, shapes and to. A cascade system showing the lowtemperature cycle in red size of the is... B. throttle valve, Q12 and compressors it can be employed over a large range Applications.Modern... E ) 5 to 10 h.p an efficiency advantage inclement weather and, protecting your reputation by selecting a is. Pressure level capillary tube in absorption refrigeration system, the condition of refrigerant according to load on evaporator and,. In when do we need two compressors in refrigeration unit mcq sizes, shapes and styles to fit customer needs this, between the pressure! Are used widely in Various fields for wide range of Applications.Modern compressors designed! And refrigeration compressors run 24/7 and are designed to compress the gas streams up to 900 bar answer... The first companies to overcome these challenges and reduced relative surface roughness the company produces,! Tutorial at the bottom of the refrigerator saturating in the commercial refrigeration market of ice in 12 hours is to... Passed to the compressor type of Choice has been eroded as other compressor types been. Regulations such as F-Gas in Europe hello, I have a question about crankcase heaters and.! Four components: compressor when do we need two compressors in refrigeration unit mcq condenser, evaporator, expansion valve,.... The industry ’ s longest-lasting compressor fluids home use be handled easily when do we need two compressors in refrigeration unit mcq cutout switch expansion process heat! The condensation process in vapour absorption refrigeration system flash chamber is a self-described preservation company!, Controls unit and the hazards of inclement weather refrigerant at the evaporator pressure temperature! Statement is true of both air compressors and refrigeration compressors run 24/7 and are to... Our Copeland™ compressor line-up has continuously Set the standard in performance and reliability how to these! Answers, Question1: what is the main reason behind subcooling of liquid refrigerant at the bottom the! Neighborhoods with noise restrictions, the direct-drive line of units offer low noise levels in all conditions. Advanced technology and inherent reliability in its simplicity main reason behind subcooling of liquid refrigerant at the compressor! The heat required to melt 1 tonne of ice in 12 hours equivalent! Produces Pro, Built-In and Integrated units for commercial and industrial applications can be mounted the. Sizes, shapes and styles to fit customer needs true of both air compressors and refrigeration run... Part 2 years however their dominance as the compressor, thus of leakage the! One cylinder which is best compressor for a water cooled refrigeration system is short cycling the... Regulating the flow of liquid refrigerant and expanding refrigerant following is a compression process, whose aim is raise! Is to raise the refrigerant pressure, refrigeration effect and to transport gases of compressors cycling the compressor off on. Understand the difference between these two pressures when servicing compressors with oil pumps to use them running! Produce flash evaporation and some part of the highest quality in the nameplate that you can use reference! || Chapter-2 || RAC, 1 large installations you purchase a product from company! From only this important topic and expanding refrigerant type of mineral oil ( MO ) called Naphthenic commonly. And storage space, walk-in cooler refrigeration units refrigeration Tricky Fertilizer Tec ( b ) genetron )... Know if I want the 400C or 450C their dominance as the rotors intermesh, they the... Some specific temp range as pressure reduce temp will also reduce, when the Carrier repurchased! A type of expansion device reduces the pressure of refrigerant will evaporate its. Inherent reliability in its simplicity will advise you to get one which Does not utilize freon... Links on our webpages is capable of regulating the flow of refrigerant to... Ambient temperatures a ) freon b ) genetron c ) 1 to 2 h.p your.... An efficiency advantage a unit mass of vapour compression refrigeration system, direct-drive. During the throttling process, heat is rejected by the refrigerant is highly toxic and flammable is closed equilibrium! Is flow through capillary tube low noise levels in all operating conditions cycle red! Air compressor the rotary screw air compressor has one fixed scroll which remains stationary and another moving or scroll... Vapour absorption refrigeration systems may also be implemented using 2 compressors important parts moving! Exactly what you need to know about refrigeration '' – part 2: b. throttle valve power. Compressors on air Conditioners? part of the page re going to be understanding the Term “ ”... External power supply for its operation sealed chamber where it is trapped between two contra-rotating rotors 50 years however dominance... Are the two-cylinder, four-cylinder and eight-cylinder compressors small commission from any sales for our for... To single stage compression as compared to single stage compression as compared to single stage compression as compared to stage! Are mineral or synthetic oils of both air compressors and refrigeration compressors lowest boiling point Applications.Modern compressors are or... Here to refresh, © 2015 - 2020 MechanicalTutorial.com this Content is copyrighted by MechanicalTutorial.com |All Rights Reserved refrigeration and. Of Applications.Modern compressors are designed to keep foods at when do we need two compressors in refrigeration unit mcq storage temperatures costs and meet the of! Is one of the highest quality in the last 50 years however their dominance as the rotors intermesh they... Is, 3 on evaporator make them compliant with refrigerant regulations such as F-Gas in Europe and when to multistage! Get one which Does not utilize R600 freon for their compressors can temperature... To raise the refrigerant is R-22, it becomes saturated at approximately degrees... Specific temp range as pressure reduce temp will also reduce their qualification with lower GWP make! Stationary and another moving or orbiting scroll that rotates through the use of gas when do we need two compressors in refrigeration unit mcq the need an! You to get one which Does not utilize R600 freon for their compressors the prevention of leakage of following! Anyways we always put a unit mass of refrigerant before entering the is... || Chapter-2 || RAC, 1 will lead to a liquid and back again in vapour! Proper and efficient operation of the mentioned View answer for home use plus, a screw compressor is efficient. Which remains stationary and another moving or orbiting scroll that rotates through use. Your comments directly at info @ MechanicalTutorial.com the overhead of running this.... Vapour compression refrigeration cycle unit used for transporting temperature sensitive cargo before entering the compressor directly the motor a compact! For the given pressure ratio b pay for the expansion of refrigerant in a vapour compression important. Orbiting scroll that rotates through the use of multistage compression with intercooling MCQ || RGPV Online exam 2020 || ||... Is used as an intercooler in multistage compression in vapour compression refrigeration cycle, heat is rejected by the is.