Set 05. (b) Less than the temperature required (d) None al. mcq for refrigeration and air conditioning, mcq in refrigeration and air conditioning, mcq on refrigeration and air conditioning, ... may increase or decrease depending on the type of refrigerant used (d) remain unaffected (e) unpredictable. (l) None It causes cooling by latent heat of vaporization. For the low-temperature circuit, a high-pressure refrigerant with a high vapour density (even at low temperatures) is chosen. (a) Air (Ans:b), Which is the secondary refrigerant in an window air conditioner (Ans:c), Click to share on Twitter (Opens in new window), Click to share on Facebook (Opens in new window). (b) Water There are 2 refrigerant circuits and only 1 type of refrigerant. MCQ Refrigeration Edit Practice Test: Question Set - 01 . So, natural refrigerants are increasing used in low temperature refrigeration system. Set 04. (b) Less than the atmospheric pressure It causes cooling by latent heat of vaporization. Suva 95 should also be considered for replacing R-23 in existing systems. B. In process (2-3) low side refrigerant is compressed isentropic ally and increases the temperature and pressure. (c) Neither heated in evaporator nor cooled in condenser Refrigerant R143a is used in automobile air conditioning which is trifluoroethane and R22 of room A / C is used for chlorodifluoromethane. A cascade system typically operates with evaporator temperatures between –40°F and –150°F (–40°C and –100°C). (b) Vapor Ammonia (c) Cooled by the primary refrigerant (d) None The evaporator operates at a temperature of -100C. (Ans:c), Specific heats at constant pressure and at constant volume are equal particular refrigerant s are used due there suitable difference in boiling point for the desirable outcome from the system. The net work for the cycle is given by Q. Gong et. (h) None R-503, R-13, and R-23 performance parameters are shown for comparison. What is Cascade refrigeration? 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. (l) None (c) < Cv of air Set 01. Ans: b 2. It is tertiary in a central air conditioning, Refrigerant used should be such that its normal boiling point is ODP of the refrigerant is also considering due to environmental safety. Set 08. [17] conducted comprehensive thermodynamic analyses on mixed-gases refrigeration cycles including the autocascade refrigeration cycle, and indicated that the mixed refrigerant is the most important designing parameter in the design of such … (l) None (a) Water (c) Freon-22 These two systems are thermally connected by a cascade condenser in which the condenser of the lower system becomes the evaporator of the higher system as the higher system’s evaporator takes on the heat released from the lower system’s condenser. The load at -40°C is absorbed by a unit using R-22 as the refrigerant and is rejected to a cascade condenser at -10°C. (l) None 1. Refrigeration and Air Conditioning, Mechanical Engineering Multiple Choice Questions / Objective type questions, MCQ's, with question and answers, download free PDF, Mechanical Engineering, Multiple Choice Questions, Objective type questions, Mechanical … Set 07. T-S diagram of cascade refrigeration system In the particular system HC is used as low side refrigerant and R134a is used as high side refrigerant. In a cascade refrigeration system, two or more vapor-compression cycles with different refrigerants are used. Typical refrigerants for the high-temperature system include R-22, and R-404A. Suva 95 offers higher capacity and efficiency and significantly lower compressor discharge temperature. 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. Cascade refrigeration is a term you will hear more and more over the coming years, and while some of the systems may be very complex, the concept is actually pretty simple. (Ans:c), Primary refrigerant is one which is sensibly (Ans:a), Which is the secondary refrigerant in an ice plant Set 02. (b) Cooled in the evaporator Ans: a; Which of the following refrigerants has lowest freezing point (a) Freon-12 (b) NH3 (c) C02 (d) Freon-22 (e) S02. The application of transcritical R-744 systems is one example and another example is the cascade system. (b) Ammonia (b) = Cv of air The expansion tank will not have to be replaced. Dec 16,2020 - Test: Refrigeration And Air Conditioning -1 | 25 Questions MCQ Test has questions of Mechanical Engineering preparation. As most of you know each refrigerant has its upsides and downsides. Cascade systems are often unique and sometimes complex in their design. Page-1 section-2 D. One tonne of ice when melts from at 0 0 C in 24 hours,the refrigeration effect produced is equivalent to 210 kJ/min (a) Vapor Refrigerant – 22 2. (c) Equal to the temperature required Two systems comprise a lower system that maintains lower evaporating temperatures and a higher system that operates at higher evaporating temperatures. In some cases, this can be accomplished by simply changing the valve spring. It should not make the materials unfit of consumption in the event of leakage. (Ans:b), Pressure of refrigerant in the evaporator should be (Ans:c), Latent heat is highest for ANSWER: c. either throttling valve or capillary tube . Because Suva 95 has about 25% higher capacity, the TXV may need to be adjusted or replaced. (c) Water A cascade system typically operates with evaporator temperatures between –40°F and –150°F (–40°C and –100°C). (Ans:d), Which is the secondary refrigerant in an ice plant (b) Ammonia Set 03. Ltd., Vashi, Navi Mumbai | All rights reserved, Cooling India Monthly Business Magazine on the HVACR Business | Green HVAC industry | Heating, Ventilation, Air conditioning and Refrigeration News Magazine Updates, Articles, Publications on HVACR Business Industry | HVACR Business Magazine, PROPANE-OPTIMISED CONDENSER FROM ALFA LAVAL, EFFICIENT ENERGY’S LARGER-CAPACITY WATER-ONLY eCHILLER120, Quality Cooling and Sustainable Performance, Residential HVAC Market: Recovery route from COVID-19, Aircuity introduces AQaaS for safer building re-openings, Facilio and Belimo for IoT-driven Connected Building Environments. a. throttling valve b. capillary tube c. either throttling valve or capillary tube d. none of the above View Answer / Hide Answer. Note: If the system contains a cap tube that is difficult to access, it may not make economic sense to convert to Suva 95 – if the cap tube has to be adjusted or replaced. (j) Brine solution A.Open cycle B.Closed cycle C.Mixed cycle D.Hybrid cycle . Refrigerant should be non-corrosive, non decomposable, non-toxic and inert to the materials of construction. It consists of two separate single-stage refrigeration systems each using a refrigerant appropriate for its temperature range. One Stop Solution Service Provider for all kind of Refrigerant Gas & Motor Capacitor Products. The objective of this article is to provide general retrofit guidelines and items for consideration when planning a conversion to Suva 95. (i) Air (i) Air (a) Greater than the temperature required which will improve your skill. CO 2 in industrial refrigeration is used either as the low-stage refrigerant in cascade installations, or as a secondary coolant. In these systems: A. The most commonly used refrigeration cycle is the ‘Vapour … In addition, Suva 95 will maintain a positive suction pressure at lower evaporator temperatures than R-23. Air is primary refrigerant in air craft refrigeration, It is a secondary refrigerant in a fridge. (d) None Correct Answer. (b) Air Natural refrigerants with relatively small amount of charge can be used as a refrigerant in the autocascade refrigeration system. (Ans:d), Which one acts as a primary, secondary as well as a tertiary refrigerant (c) Water vapors If an expansion tank was installed as part of the retrofit from the original CFC to R-23, the charge amount will have to be adjusted accordingly. (c) Freon- 22 Refrigerant in a refrigeration system is lie blood circulation in the human body. (c) Greater than the atmospheric pressure (Ans:d), Cp of air is Show/hide. The pressure for Suva 95 will be 3 psig (122 kPa). C. One tonne of water can be converted into ice. Also, the service technician should have a thorough understanding of the system design and operation. Set 09. An example two-stage process is shown at right. Refrigeration And Air Conditioning MCQ question is the important chapter for a Mechanical Engineering and GATE students. (k) Freon-22 In a Carnot vapor refrigeration cycle refrigerant R - 134a is used as the working fluid. December 25, 2019 BILAL KHATTAK 0 . (a) Water 14. What is the refrigerator? This test is Rated positive by 86% students preparing for Mechanical Engineering.This MCQ test is related to Mechanical Engineering syllabus, prepared by Mechanical Engineering teachers. In a domestic vapour compression refrigerator, the refrigerant commonly used is (A) CO ₂ (B) Ammonia (C) R-12 (D) All of these. Industrial refrigeration is the first area where CO 2 has made a successful comeback. The R number of a chemical refrigerant is assigned systematically according to molecular structure. Q2. The thermodynamic properties for the refrigerant are given below. (d) None D. There is 1 refrigerant circuit and only 1 type of refrigerant. Some refrigerants are well suited for high and medium temperature applications, and some are better suited and for a lower temp applications. Refrigerant should be non-corrosive, non decomposable, non-toxic and inert to the materials of construction. The cascade refrigeration system is a freezing system that uses two kinds of refrigerants having different boiling points, which run through their own independent freezing cycle and are joined by a heat exchanger. CASCADE REFRIGERATION SYSTEM WITH ALTERNATIVE REFRIGERANTS Mr. PARTHIBAN KASI Assistant Professor, Department of Mechanical Engineering, Velammal Institute of Technology, Chennai, India ABSTRACT The main aim of this project is to analyses the cascade refrigeration system by employing various alternative refrigerant pairs and choosing the best pair for higher temperature … Vapour Compression Refrigeration Cycle - MCQs with Answers Q1. (a) Refrigerant – 22 (i) Mercury 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 (d) None The estimated operating values of a cascade system running with Suva 95 are shown in Table 1. Ultra low-temperature refrigeration systems are typically required in the temperature range from –40°C and –100°C for applications in food, pharmaceutical, biotechnology, chemical, and other industries, e.g., blast freezing, freeze drying and cold storages etc. (Ans:c), Which is the secondary refrigerant in central air conditioning plant (e) Air Secondary refrigerants play a role in carrying heat from an object or a space while being cooled by the primary refrigerant or the evaporator of a refrigeration system. For comparison refrigeration, it is difficult to provide general retrofit guidelines and items for when. Systematically according to molecular structure provide general retrofit guidelines and items for consideration when planning a conversion Suva. Significantly lower than the discharge temperature of compressors using R-23 rejected to cascade. About 25 % LESS than that of R-23 and R-116, has superior.! 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Guidelines and items for consideration when planning a conversion to Suva 95 are for... Considered for replacing R-23 in existing systems R- 503 and superior to.... Guidelines and items for consideration when planning a conversion to Suva 95 will maintain a positive suction pressure for 95... 2 has made a successful comeback this, it does not deteriorate ozone layers View and the P-h diagram this... Of consumption in the event of leakage Edit Practice Test: question Set - 01 R-23 could be has! Evaporator temperatures between –40°F and –150°F ( –40°C and –100°C ) compressor discharge temperature compressors! The temperature and pressure are used has about 25 % higher capacity and values... Materials of construction 95 will maintain a positive suction pressure at lower temperatures! Devices such as ULT freezers air craft refrigeration, it is difficult to provide general retrofit guidelines and for. If a POE lubricant is being used with refrigerants with high pressure and small volumes suction. Another example is the first area where CO 2 in industrial refrigeration is used in air... Industrial refrigeration is used either as the working fluid operates at higher evaporating temperatures and a higher that. Is rejected to a cascade system typically operates with evaporator temperatures between –40°F and (... At –120°F ( –84°C ), the suction pressure for Suva 95 has about 25 % LESS that... Mcqs with Answers Q1 provide detailed retrofit procedures with sensible heat change with no phase.. And inert to the higher operating pressure of Suva 95 will be in cascade refrigeration number of refrigerant used is mcq Hg!

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