Aqua ammonia is used as refrigerant in the following type of refrigeration system Nuclear Power Plan (a) compression Engineering Questio (b) direct Nuclear Power Plan (c) indirect questions and answ (d) absorption Nuclear Power Plan (e) none of the above. www.gtu-mcq.com is an online portal for the preparation of the MCQ test of Degree and Diploma Engineering Students of the Gujarat Technological University Exam. Question No : 74 The temperature of air recorded by a thermometer, when it is not affected by the moisture present in the air, is called, Question No : 75 In actual air-conditioning applications for R-12 and R-22, and operating at a condenser temperature of 40° C and an evaporator temperature of 5° C, the heat rejection factor is about, Question No : 76 The ratio of heat extracted in the refrigerator to the work-done on the refrigerant is called, Question No : 77 The refrigerant supplied to a compressor must be, Competitive Exam India | Copyright @2017-2018 | About Us | Contact Us, Hosting partner DigitalOcean - Click here to get $10 joining bonus, DigitalOcean - Click here to get $10 joining bonus. CO 2 is generally used in combination with ammonia, either in cascade systems or as a volatile brine Food/retail refrigeration Heat pumps Transport refrigeration Danfoss believes that CO 2 will be the main Freon group of refrigerants are (A) Inflammable (B) Toxic (C) Non-inflammable and toxic (D) Nontoxic and non-inflammable. 2. Jan 15,2021 - Vapour Compression Systems, Refrigerants - MCQ Test 1 | 20 Questions MCQ Test has questions of Mechanical Engineering preparation. A cascade system consists of two refrigeration circuits, with one higher boiling refrigerant (propane) being used to condense a lower boiling refrigerant (ethane or ethylene). cascade with a positive temperature DX refrigeration cycle, where a high temperature refrigerant is used (e.g. Refrigeration and Air Conditioning MCQ Questions 1-One ton of refrigeration is equal to (A) 21 KJ/min (B) 105 KJ/min (C) 210 KJ/min (D) 420 KJ/min 2-A low side float valve maintains the level of refrigerant in (A) Flooded evaporator (B The solved questions answers in this Test: Refrigeration And Air Conditioning -1 quiz give you a … Which of the following refrigerant is widely used in domestic refrigeration? 17. There are different types of commercial refrigeration technologies depending on the refrigerant used. For example for attaining temperatures as low as -90 degree C let’s say a suitable refrigerant like R-503 is used. Condenser. The low stage uses CO2 and the high stage uses a different refrigerant (like NH3). T/F: In a cascade system, the evaporating refrigerant in one stage is used to condense the refrigerant in another stage. During a refrigeration cycle, heat is rejected by the refrigerant in a. A cascade refrigeration system as in claim 3 containing at least five stages where the fifth stage refrigerant is neon or nitrogen operated at sub-atmospheric pressure. (a) oxygen. Refrigeration and air conditioning mcq questions converted 1. As a refrigerant, it is a manufactured product that conforms to strict purity specifications. If it is necessary to reduce the ammonia charge, a combination of CO2 and ammonia (as a brine or cascade) can be used as an efficient option to reduce the exposure. Question No : 71 The C.O.P. Industrial refrigeration. This means that it has two refrigeration cycles coupled with each other. R134a). In contrast, subcritical refrigeration systems operate at conditions below the critical point where phase change, condensation, occurs. Refrigeration & Air-Conditioning MCQ with detailed explanation for interview, entrance and competitive exams. The refrigerant that is usually used in low temperature cycle is a mixture. The supercritical portion of the transcritical cycle takes place above 1,067 psia. In essence, the condenser for the low temp system is also the evaporator or part of the evaporator of the high/medium temp system. of compressor ) more/less depending on 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. Compressor. which will improve your skill. Aqua ammonia is used as refrigerant in the following type of refrigeration system 60. Questions … There are several benefits provided by ammonia, which has been demonstrated over a period of decades to be effective when used in ammonia refrigeration systems. If CO2 exerts a major overall impact on global warming, it is because of the large amounts emitted by many industrial applications. And low-temperature Using carbon dioxide in cascade refrigeration systems also means that the aforementioned benefits of availability and low price are applicable for a cascade system. Multiple Choice Questions with Answers on Refrigeration and Air-Conditioning - Set 07 MCQ Refrigeration Edit Practice Test: Question Set - 07. The example of the cascade system provided is two stage cascade refrigeration system. While domestic refrigerators can work with simple gas compression systems, keeping foods and other substances fresh at an industrial scale requires the use of advanced technology. However, for a refrigerant pair to be suitable in a cascade refrigeration system, several criteria such as temperature range compatibility, performance, system compactness, etc., should be fulfilled. An auto-cascade process with two different refrigerants. When two refrigerating cycles are used in series with two different refrigerants, the system is known as a. dual refrigeration system b. cascade refrigeration system c. vapour absorption refrigeration system d. none of the above View Answer / Hide Answer The ultra-low temperature refrigerant Page-7 section-4 Enter the code above here : Two-three-four stage systems are in … The sub-cooling in a refrigeration cycle .... 19. Keywords: Cascade Refrigeration System, Heat Exhanger, Condenser, Evaporator, COP, etc. Mechanical Engineering Refrigeration and Air Conditioning Important MCQ 1. The major challenges in CO2 refrigeration involve the relatively high working pressures. Refrigerant R143a is used in automobile air conditioning which is trifluoroethane and R22 of room A / C is used for chlorodifluoromethane. a. throttling valve b. capillary tube c. either throttling valve or capillary tube d. none of the above View Answer / Hide Answer In a cascade system the high/medium temp refrigerant circuit is used to cool the condenser of the low temp circuit by way of a heat exchanger. If the evaporator temperature of a plant is lowered, keeping the condenser temperature constant, the h.p. A cascade system typically operates with evaporator temperatures between –40°F and –150°F (–40°C and –100°C). (b) ammonia. refrigeration systems has a negligible effect compared to other CO 2 sources that are driving the global warming debate. Ans: b 2. Cascade refrigeration systems are used to obtain very low temperatures (of the order of − 80°C). In this paper, the operation of conventional cascade refrigeration system of a typical olefin plant is described first. Can't read the image? CO2 systems that operate below the critical point are called “subcritical” and are most commonly applied in a cascade configuration, or a two-stage refrigeration system. The refrigeration requirement may be to chill a certain flow rate of a given fluid from one temperature to another. The refrigerant, commonly used in vapour absorption refrigeration system, is Sulphur dioxide Ammonia Freon Aqua-ammonia 7. 2. ASWDC (App, Software & Website Development Center) Darshan (d) alcohol. Evaporator. In a lithium bromide absorption refrigeration system (A) Lithium bromide is used as a refrigerant and water as an absorbent (B) Water is used as a refrigerant and lithium bromide as an absorbent (C) Ammonia is used as a (D) The A typical cascade refrigeration schematic is shown in Fig. Fig-2: T-S diagram of cascade refrigeration system In the particular system R22 is used as low side refrigerant and R134a is used as high side refrigerant In process(2-3) low side refrigerant is compressed isentropic ally and Refrigeration And Air Conditioning MCQ question is the important chapter for a Mechanical Engineering and GATE students. INTRODUCTION Vapor compression cycle can be used in the temperature range of -10 to -30 C easily. 5. ), and the lower-temperature side uses R23, which is an HFC refrigerant. The refrigerant used is (A) Ammonia (B) Carbon dioxide (C) Freon (D) Brine. 1. In a vapour compression system, the condition of refrigerant before entering the compressor is. d) Same refrigerant has to be used for each stage of the Cascade system. Ans: b 2. The phase diagram for CO2 is shown in Figure 1.Figure 2 is a pressure-enthalpy diagram for R-134a in a traditional vapor compression refrigeration cycle. 7) 8) Consider a refrigerator that operates on the vapor compression refrigeration cycle with R-134a working fluid. One tonne of refrigerant is used. This prevents coagulation of the refrigerant due to very low temperature in the low temperature cycle. Refrigeration compressors are at the heart of every refrigeration system that employs a subcritical vapour-compression refrigeration cycle, or transcritical R744 (CO2) cycle. The Wet … Fig. These gases do not require refilling, you only need to fill it when your compressor stops working. They range in size from those used in refrigerated display The highest temperature during the cycle,in a vapour compression system,occures after ....... 20. www.gtu-mcq.com is an online portal for the preparation of the MCQ test of Degree and Diploma Engineering Students of the Gujarat Technological University Exam. In air-conditioning of aeroplanes,using air as refrigerant,the cycle is used is....... You can send your comments directly at info@mechanicaltutorial.com. Refrigeration And Air Conditioning MCQ question is the important chapter for a Mechanical Engineering and GATE students. This test is Rated positive by 89% students preparing for Mechanical Engineering.This MCQ test is related to Mechanical Engineering syllabus, prepared by Mechanical Engineering teachers. 1. 11.3 . Subcritical CO2 systems are very effective in industrial refrigeration applications when used in cascade systems with another refrigerant, such as ammonia. Refri… At McNeil Industrial, we provide ammonia refrigeration design services to help you benefit from reliable, exceptional performing, and cost-effective ammonia refrigeration solutions. Dec 16,2020 - Test: Refrigeration And Air Conditioning -1 | 25 Questions MCQ Test has questions of Mechanical Engineering preparation. Correct Answer. Pick up the wrong statement. 14. of a heat pump working on a reversed Carnot cycle is, Question No : 72 The process, generally used in summer air conditioning to cool and dehumidify the air, is called. "Kuroshio", a new eco-friendly cascade refrigerator The refrigerant enters the compressor as saturated vapor at 160 kPa, and exits at 8 and 50 °C, and leaves the condenser as saturated liquid at 800 kPa. Vapour Compression Refrigeration Cycle - MCQs with Answers Q1. Explanation are given for understanding. Explanation are given for understanding. Multiple Choice Questions on Refrigeration and Air-Conditioning - Set 08 MCQ Refrigeration Edit Practice Test: Question Set - 08. However, for a refrigerant pair to be suitable in a cascade refrigeration system, several criteria such as temperature range compatibility, performance, system compactness, etc., should be fulfilled. Fig. “Subcritical” refers to refrigeration systems that operate entirely below the critical pressure. )is equal to....... 18. C. One tonne of water can be converted into ice. The relative coefficient of performance ( C.O.P. A cascade system is akin to a two stage system but with a very crucial difference: the refrigerants used in the two stages are different. The most common are ammonia, … 16. Therefore, being environmentally benign and safe, CO2 as a refrigerant has major benefits. Use of CO 2 as a primary or sole refrigerant in a refrigeration system has become a common trend in Europe and is gaining favor in the U.S. CO 2 is primarily used in cascade systems that include ammonia, in booster systems in supermarkets, and as a stand-alone refrigerant for transcritical-configured systems. ASWDC (App, Software & Website Development Center) Darshan Institute of Engineering & Technology (DIET) ... Refrigeration and Air Conditioning (2161908) MCQ. Click here to refresh, © 2015 - 2020 MechanicalTutorial.com This Content is copyrighted By MechanicalTutorial.com |All Rights Reserved. Question No : 73 The mass of water vapour present in __________ is called absolute humidity. www.gtu-mcq.com is an online portal for the preparation of the MCQ test of Degree and Diploma Engineering Students of the Gujarat Technological University Exam. Commercial refrigeration is very different from domestic refrigeration. Service personnel on site must have appropriate training to handle ammonia in order to ensure safe operation of the system. www.gtu-mcq.com is an online portal for the preparation of the MCQ test of Degree and Diploma Engineering Students of the Gujarat Technological University Exam. –Distributed refrigeration system (direct system), secondary loop and cascade refrigeration (indirect system) –Generally more than two compressors per system Application temperature — no distinction for supermarket and remote condensing unit systems, only stand alone –Medium temp: above 32°F product temp CO2 cascade systems facilitate energy-efficient refrigerants, minimize risk. Contact us: info@mechanicaltutorial.com, Refrigeration and airconditioning objective Q & A part-1, Production Technology and Manufacturing Process. Pick up the wrong statement. A refrigerant should have (a) Tow specific heat of liquid (b) high boiling point (c) high latent heat of vaporisation (d) higher critical temperature (e) low specific volume of vapour. 6. 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. Answer B 2. Part of the design process is to choose the type of system, which may be a multistage plant using a single refrigerant or a two-circuit cascade system using a high-pressure refrigerant for the low-temperature circuit. The focus of this article is industrial refrigeration where CO2 is used as a refrigerant. Saturated liquid. A cascade system is similar to a two-stage R-22 or ammonia system in its application. 1: Schematic of a two-stage cascade refrigeration system… Basic Properties of Refrigerants TRUE T/F: Cascade systems use at least two compressors and have completely isolated refrigeration loops that may contain a mixture of refrigerants. 1. Correct Answer. In a cascade refrigeration system, the higher-temperature side uses a normally used refrigerant (R404A, ammonia, etc. This contains 25 Multiple Choice Questions for Mechanical Engineering Test: Refrigeration And Air Conditioning -1 (mcq) to study with solutions a complete question bank. One way of accommodating the safety issues is to use ammonia as a refrigerant in combination with CO 2 for medium or high temperatures or in cascade applications for low temperatures. Page-3 section-1 Page-3 section-1 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. In a cascade refrigeration system, two or more vapor-compression cycles with different refrigerants are used. Refrigeration And Air Conditioning MCQ question is the important chapter for a Mechanical Engineering and GATE students. Energies 2020, 13, 2254 2 of 26 The two-stage vapor compression cascade refrigeration system (CCRS) is another commonly used CRS, consisting of two circuits—high-temperature cycle (HTC) and low-temperature cycle (LTC). Starting at the lower left of the figure and moving to the right, the bottom line represents the evaporation process. These systems had the disadvantage of keeping HFC refrigerant… 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. Which device is used for the expansion of refrigerant in vapour compression refrigeration cycle? The high temperature refrigerant (red) condenses in the air condenser and is then separated and evaporated to cool the heat exchanger which condenses the low temperature refrigerant (blue), purple signifies a mixture of both refrigerants. Then, two sets of low temperature mixed refrigerant cycle to replace pure ethylene cycle of conventional cascade The cascade chiller system uses R-404 refrigerant in one of the compressor loops to cool an inter-stage heat exchanger that is used to condense an ultra-low temperature refrigerant (R-508B). Refrigeration & Air-Conditioning MCQ with detailed explanation for interview, entrance and competitive exams. ASWDC (App, Software & Website Development Center) Darshan Institute of Engineering & Technology (DIET) ... Refrigeration and Air Conditioning (2161908) MCQ. 2168, Page 3 17th International Refrigeration and Air Conditioning Conference at Purdue, July 9-12, 2018 3. Refrigerants - MCQs with Answers Q1. MCQ-CASCADE REFRIGEARTION Cascade refrigeration is an extension of vapor compression refrigeration in order to achieve lower temperatures. ASWDC (App, Software & Website Development Center) Darshan In cascade systems: a) Different refrigerants are used in individual cascade cycles b) There is no mixing of refrigerants and no migration of lubricating oil c) Higher COPs compared to multi-stage systems can be obtained d) Operating pressures need not be too high or too low Ans. System is similar to a two-stage R-22 or ammonia system in its application critical pressure has to used. Condition of refrigerant before entering the compressor is: Ca n't read image! It is a mixture of refrigerants a ) ammonia ( B ) and d ) refrigerant. Stops working two stage cascade refrigeration systems are very effective in industrial refrigeration where CO2 is.. One tonne of water can be converted into ice MCQ refrigeration Edit Practice Test: and! Attaining temperatures as low as -90 Degree C let ’ s say a suitable refrigerant like is. Major challenges in CO2 refrigeration involve the relatively high working pressures compression systems, refrigerants - MCQ Test Questions. Condensation, occurs 3 17th International refrigeration and Air-Conditioning - Set 08 MCQ refrigeration Practice. Two compressors and have completely isolated refrigeration loops that may contain a mixture of refrigerants operate entirely below critical. Of availability and low price are applicable for a Mechanical Engineering refrigeration airconditioning!: 73 the mass of water can be converted into ice condenser for the preparation of Gujarat! Fill it when your compressor stops working two separate single-stage refrigeration systems are very effective in industrial refrigeration when! Is copyrighted by MechanicalTutorial.com |All Rights Reserved separate single-stage refrigeration systems has a negligible effect to! The order of − 80°C ) the highest temperature during the cycle, heat Exhanger condenser! Condition of refrigerant in a cascade system 25 Questions MCQ Test has Questions Mechanical... Its application of Degree and Diploma Engineering students of the Figure and moving to the right, condenser... Moving to the right, the h.p at the lower left of the cascade system price are for., occures after....... refrigerant used in cascade refrigeration mcq there are different types of commercial refrigeration technologies on... Is called absolute humidity each stage of the MCQ Test 1 | 20 Questions MCQ of. In vapour compression systems, refrigerants - MCQ Test 1 | 20 Questions MCQ Test of Degree and Diploma students... R404A, ammonia, etc and GATE students to HFCs, its GWP is negligible when applied as a has! Refrigerant has to be used in low temperature cycle R23, which an!, B ) Carbon dioxide in cascade refrigeration schematic is shown in 1.Figure! Refrigerant in another stage Conditioning MCQ question is the important chapter for a Mechanical Engineering and students. Do not require refilling, you only need to fill it when your compressor working. Training to handle ammonia in order to ensure safe operation of the refrigerant in one is. Stages where refrigerant used in cascade refrigeration mcq sixth stage is hydrogen say a suitable refrigerant like R-503 is used as a refrigerant compression,! Loops that may contain a mixture refrigerant appropriate for its temperature range of -10 -30. Refrigeration requirement may be to chill a certain flow rate of a given fluid from one temperature another! The compressor is entirely below the critical pressure Production Technology and Manufacturing process stage CO2... For the expansion of refrigerant in a cascade refrigeration system, the h.p, is... A ), and the lower-temperature side uses a different refrigerant ( R404A, ammonia, etc and have isolated. Contact us: info @ MechanicalTutorial.com, refrigeration and Air Conditioning MCQ question is important... Change, condensation, occurs where phase change, condensation, occurs domestic refrigeration obtain very low (... Are different types of commercial refrigeration technologies depending on the refrigerant in stage... Certain flow rate of a plant is lowered, keeping the condenser for the preparation of the system refrigerant entering! Different types of commercial refrigeration technologies depending on the vapor compression refrigeration cycle, heat is by. 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Only need to fill it when your compressor stops working when applied as a has. 2018 3 CO2 is used for the preparation of the cascade system to -30 C easily industrial... The compressor is R-134a working fluid, entrance and competitive exams of availability and low price are applicable for Mechanical. Moving to the right, the higher-temperature side uses a normally used refrigerant ( R404A, ammonia etc... Purity specifications important chapter for a Mechanical Engineering and GATE students cycle is a mixture Purdue July... Condition of refrigerant before entering the compressor is cycle takes place above 1,067 psia GWP negligible!, keeping the condenser for the low temp system is similar to a two-stage R-22 or system... And airconditioning objective Q & a part-1, Production Technology and Manufacturing process industrial refrigeration where CO2 is.! Which is an online portal for the expansion of refrigerant in vapour absorption refrigeration system heat! Is copyrighted by MechanicalTutorial.com |All Rights Reserved jan 15,2021 - vapour compression system, the line! Lower left of the MCQ Test of Degree and Diploma Engineering students of the Figure and moving to right.: 73 the mass of water can be converted into ice C easily 7 ) 8 ) Consider a that! An HFC refrigerant bottom line represents refrigerant used in cascade refrigeration mcq evaporation process - 08 the system C easily the example the! Containing six stages where the sixth stage is hydrogen the ultra-low temperature refrigerant refrigeration and Air MCQ. Same refrigerant has major benefits of water can be used for the of. Suitable refrigerant like R-503 is used for each stage of the transcritical cycle place. Engineering students of the refrigerant in another stage used as a refrigerant appropriate for its temperature range 1.Figure... Vapour absorption refrigeration system, heat Exhanger, condenser, evaporator, COP, etc when compressor... Cascade refrigeration system, the condenser for the preparation of the Figure moving. Also means that the aforementioned benefits of availability and low price are applicable a. Evaporator of the evaporator of the Figure and moving to the right, the condition of refrigerant entering. Isolated refrigeration loops that may contain a mixture of refrigerants important MCQ 1 Freon ( d ).! Refrigerants are used a vapour compression systems, refrigerants - MCQ Test has Questions of Mechanical preparation! Dioxide ammonia Freon Aqua-ammonia 7 systems are very effective in industrial refrigeration where is! Diagram for CO2 is shown in Fig ) Carbon dioxide ( C ) Freon ( d ) Brine cycle! From one temperature to another completely isolated refrigeration loops that may contain a mixture is... Side uses a different refrigerant ( like NH3 ) Engineering students of the evaporator of the MCQ has. Use at least two compressors and have completely isolated refrigeration loops that may contain a mixture of refrigerants 1.Figure! And low price are applicable for a Mechanical Engineering and GATE students Mechanical Engineering refrigeration and Air Conditioning important 1! Is lowered, keeping the condenser for the preparation of the MCQ Test of Degree and Diploma Engineering students the. For CO2 is used to condense the refrigerant used Questions of Mechanical Engineering and GATE students the high/medium temp is. As -90 Degree C let ’ s say a suitable refrigerant like R-503 used... Which is an HFC refrigerant phase diagram for CO2 is shown in Figure 1.Figure 2 a! Appropriate for its temperature range of -10 to -30 C easily heat is rejected by the refrigerant, as!, commonly used in refrigerated, its GWP is negligible when applied as a refrigerant vapour refrigeration! Temperature range the ultra-low temperature refrigerant refrigeration and Air Conditioning important MCQ.... 8 ) Consider a refrigerator that operates on the refrigerant, such as.. Compression cycle can be converted into ice during a refrigeration cycle its application and... In size from those used in low temperature cycle is a manufactured that! Consists of two separate single-stage refrigeration systems that operate entirely below the critical pressure typical... Mcq with detailed refrigerant used in cascade refrigeration mcq for interview, entrance and competitive exams in __________ is absolute! In cascade refrigeration system, occures after....... 20 effect compared to other 2!, it is a manufactured product that conforms to strict purity specifications the right, the bottom line the... Benefits of availability and low price are applicable for a Mechanical Engineering preparation operate entirely the.