To find the right condensing unit: Box temperature minus split equals suction temperature. APPLY NOW (866) 820-0823. hence it is preferred over icentropic expansion. How does a compressor work? Thermostatic expansion valve or TEV is one of the most commonly used throttling valve for the refrigerator and air conditioning systems. 9. (b) Medium (a) >1.5 bars in order to have a leak free seal when the units leave our plant. (a) >1.5 bars 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. (b) <1.5 bars (b) <1.5 bars Answer: a In a vapour compression system, the lowest temperature during the cycles occurs after, 5. TEV enables safe running of the compressor without flooding and also helps the refrigeration plant run as per the optimum capacity. What is the main reason behind subcooling of liquid refrigerant at the condenser outlet in vapour compression refrigeration system? For an introduction to the workings of a compression refrigeration system, go to Refrigeration 101. Typical refrigerator duty cycle for a ColdMachine or SuperColdMachine with 3" insulation runs the compressor 40% of the time. We’re going to be covering where the term is used, what the term means, where the term came from, how to calculate it, and also some work examples, as well as how to convert it to other common refrigeration units. Vapour Compression Refrigeration Cycle - MCQs with Answers Q1. View Answer: Answer: Option … NORCOLD SCQT Icebox Conversion Kits - YouTube. During periods of low ambient temperatures, if we were to just cycle the compressor off, it can easily get colder at the compressor than it is inside the space. Which of the following statement is true for a condenser? Please read all the important question of that chapter because the MCQ comes from only this important topic. Air trapped in a refrigeration system using a water-cooled condenser is usually indicated by a] unusually high head pressure when compared to the existing temperature of the liquid refrigerant b] higher than normal liquid level in the receiver Another example using a different split: A walk-in meat cooler at 35 ° F, load of 21,600 BTU/hr. Dry saturated liquid. compressors, known as “L” compressors, used refriger-ants 11 and 114 in two frame sizes for air-condi-tioning capacities between 90 and 600 tons. d) none of the mentioned Answer: b Explanation: Here p1 is the evaporator pressure and p2 is the condenser pressure. Which device is used for the expansion of refrigerant in vapour compression refrigeration cycle? Single- and multistage arrangement small compressors, particularly the trunk type, are … d) all of the mentioned One ton of the refrigeration is (a) the standard unit used in refrigeration problems (b) the cooling effect produced by melting 1 ton of ice (c) the refrigeration effect to freeze 1 ton of water at 0°C into ice at 0°C in 24 hours (d) the refrigeration effect to produce 1 ton of ice at NTP conditions During a refrigeration cycle, heat is rejected by the refrigerant in a. What is used as an intercooler in multistage compression of vapour compression refrigeration system? ASWDC (App, Software & Website Development Center) Darshan Institute of Engineering & Technology (DIET) (B) reduce pressure losses through the evaporator a) freon Q16.For an expansion device, which of the following is true? Do not oil the asbestos-free gasket or the flange surface. Do not attempt to open a service valve with an adjustable wrench. (D) all of the above, Q25.The process of undercooling is generally brought about by Expansion valve. Which of the following is a type of expansion device? Q8. at 30 ° F suction temperature. (c) Large Because its function is to absorb heat into the refrigeration system (from where you don't want it), the evaporator is placed in the area to be cooled.The refrigerant is let into and measured by a flow control device, and eventually released to the compressor. Since most refrigeration equipment tends […] B. F – 11. Slide the rotating unit onto the shaft with a turning motion up to the shoulder in the shaft. High critical temperature. They’re more vulnerable against pulsation issues, valve problems, and other reciprocating compressor areas of concern. 1. c) both of the mentioned Proper division can obtain the relationship between refrigerating ability and volume of gas to be handled by the compressor. Evaporator. (d) None (c) >3.5 bars There is a trend toward the use of high-speed reciprocating compressors in all applications, including refrigeration systems. The L compressors were remark-able in that they required only one stage of compres-sion to do what two or three stages had done in all previous centrifugal air-conditioning machines. b) it regulates the flow of refrigerant to evaporator (b) Pressure alone Answer: d (b) <1.5 bars b. to reduce the mass of vapour formed during expansion process, c. to reduce vapour bubbles which obstruct the flow of liquid refrigerant. Q14. The adjustable fan cycling control is set to cut in at the high end of your normal saturated condenser temperature (SCT). C. F – 22. It can be employed over a large range of temperatures. (d) None Step 3. In evaporation process of vapour compression refrigeration system, a. heat is rejected from refrigerant to surroundings, b. heat is rejected from surroundings to refrigerant, ANSWER: b. heat is rejected from surroundings to refrigerant, Q6. View Answer. (B) using water colder than the main circulating water The condensing coil is often placed inside the walk-in refrigerator. Use the right tools! (Ans:a), Centrifugal compressor is used in refrigeration when pressure difference between condenser and evaporator pressures is  c) the refrigerant is damaged As fluid flow through capillary its velocity increase as per continuity eqation (AV=const).hence conversion of pressure energy into kinetic energy takes place. Q22.The most widely used refrigerants are F. Assume use of the same compressor with the same fixed displacement as in the example above and that the temperature of the gas entering the compressor cylinder is 80 deg. A. F – 12. View Answer. In the R-12 example at 0 deg. The sub-cooling in a refrigeration cycle, 6. 2. Another example using a different split: A walk-in meat cooler at 35 ° F, load of 21,600 BTU/hr. The TEV automatically maintains the flow of the refrigerant inside the evaporator as per the load inside it. Answer: d d) 1 + C – C(p2/p1)^(1/n) 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. Liquids are relatively incompressible; while some can be compressed, the main action of a pump is to pressurize and transport liquids. Home MCQ Refrigeration Refrigeration and Air-Conditioning Multiple Choice Questions with Answers - Set 03 Refrigeration and Air-Conditioning Multiple Choice Questions with Answers - Set 03 ... keeping the condenser temperature constant, the h.p. ANSWER: b. throttle valve, Q12. 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. throttling valve b. capillary tube c. either throttling valve or capillary tube d. none of the above View Answer / Hide Answer Q: Why are we putting in Inverted Traps on the liquid and discharge lines? How does a refrigerator work? (a) Temperature a) small units 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. (b) Pressure The desirable property of a refrigerant is. (Ans:a), Reciprocating compressor is used in refrigeration when pressure difference between condenser and evaporator is Explanation: These are a group of halogenated hydrocarbons. - ∆KE= 0 ( velocity will change but it is negligible). You then include your inefficiency and design for 20% or more above what you need as a safety factor. Pick up the wrong statement. a. the mass fraction of liquid in liquid-vapour mixture of refrigerant at inlet to the evaporator, b. the mass fraction of vapour in liquid-vapour mixture of refrigerant at inlet to the evaporator, c. the mass of vapour actually compressed to the mass of vapour should have compressed ideally, ANSWER: b. the mass fraction of vapour in liquid-vapour mixture of refrigerant at inlet to the evaporator, Q5. Q17. c) (p1*p2)/(p1+p2) Choose the letter of the best answer in each questions. Another feature of reciprocating compressors that is somewhat unique when compared to the rest of the compressor family is the number of available drive arrangements, which are almost as complex as the cylinder arrangements. When do we need three compressors in a refrigeration unit? Factors that affect the performance of compressors are the speed of rotation, pressure at suction, pressure at discharge, and type of refrigerant being used. Only liquid is then passed to evaporator and the vapors will be passed to the compressor directly. Latest engineering mcqs refrigeration and air conditioning old question papers and all 100s of new Basic refrigeration test questions Modern refrigeration and air conditioning pdf 2020 download free. Setting the standard for commercial refrigeration. The cut out is adjusted for the lowest end of normal operating SCT. Evaporator: This is the part of the refrigeration system that is doing the actual cooling. Need of throttling process- To reduce pressure and temperature without change in enthalpy. Which device is used for the expansion of refrigerant in vapour compression refrigeration cycle? On average you will not need a compressor larger than 1/4hp and anything 1/6hp or better is above average. When it gets cold out the refrigerant pressures will drop too low … How is the condensation process in vapour compression refrigeration cycle carried out? ... For the same compressor work, COP of the refrigerator as compared to COP of the heat pump is (A) low (B) high (C) same (D) unpredictable. What is the result of superheating of vapour at the evaporator outlet? Compressors are used widely in Various fields for wide range of Applications.Modern compressors are designed to compress the gas streams up to 900 bar. F and has a specific volume of 1.94 cu ft/lb., the weight of refrigerant that the compressor is able to circulate … b) larger units This is the Multiple Choice Questions Part 2 of the Series in Refrigeration Engineering as one of the Mechanical Engineering topic. In this article, we’re going to be looking at the centrifugal compressor for a water cooled chiller. Explanation: Because of these reasons we have to use multistage compression with intercooling. View Answer: Answer: Option … (A) improve overall heat transfer coefficient View Answer. which will improve your skill. pressure of a unit mass of refrigerant remains the same, ie. You will only be able to open a service valve with the appropriately sized service valve wrench. (C) employing a heat exchanger (Ans:c), Compressor in a refrigeration system increases Only liquid is then passed to evaporator and the vapors will be passed to the compressor directly. Explanation: They regulate the flow of refrigerant according to load on evaporator. With 38 models ranging from 71 CFM to 5067 CFM, our gas compressors are available for almost every industrial refrigeration need. C. High … c) large installations use air-cooled condenser d) none of the mentioned Service valves on Copeland® brand condensing units have a torque requirement of 22-25 ft lbs. The heat required to melt 1 tonne of ice in 12 hours is equivalent to. Most of the Chemical Process Industries use compressors to achieve the desired Reaction pressure, Refrigeration effect … 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 . (Ans:c), Reciprocating compressor is used in refrigeration when volume to be compressed Improves volumetric efficiency for the given pressure ratio B. Home MCQ Refrigeration Multiple Choice Questions with Answers on Refrigeration and Air-Conditioning ... Set 07 Multiple Choice Questions with Answers on Refrigeration and Air-Conditioning - Set 07 MCQ Refrigeration Edit ... the pressure range of compressor should be (A) High (B) Low (C) Optimum (D) Any value. c) both of the mentioned Q: Why are we putting in Inverted Traps on the liquid and discharge lines? It improves the volumetric efficiency for the given pressure ratio.. A flash chamber is a device which separates liquid from vapors. d. none of the above In fact, all major industries like foods, chemicals, and technology need refrigerating systems for maintaining cold storage. What Does a Compressor Do? The purpose of installing a flash chamber in the refrigeration circuit is to One of the first things every HVAC/R student learns is that air conditioning units don’t create cool air. (c) Volume alone 151. (d) None Explanation: Here C is the clearance and p1,p2 are pressures. A. F – 12. Explanation: These are the two types of expansion devices. I do not think that you can get below 30 in merc. In simple terms, its function relies on a repeating cycle of increasing and decreasing the pressure of a gaseous refrigerant. 2. With the industry now in the midst of sweeping regulations, Emerson is leading the development of the next generation of refrigeration technology. This may typically be between 120 and 130 degree SCT. 1. The air conditioner component of a building’s HVAC system essentially is a type of refrigerator that cools and dehumidifies the air in the building, ensuring thermal comfort for the occupants. Many compressors can be staged, that is, the fluid is compressed several times in … This, between the condenser and evaporator is known as, Chapter-3 Vapour Absorption Refrigeration system (Coming Soon ). d) all of the mentioned ⇐ MCQ in Refrigeration Engineering Part 3 | ME Board Exam . 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. b) sqrt(p1*p2) Refrigeration compressor units that are installed outdoors must have cold weather controls to operate properly and maintain proper temperature in the cooler or freezer during the cold winter season. Step 2. View Answer. b) genetron The compressor then has to raise the pressure of the refrigerant to a level at which it can condense by rejecting heat to the cooling … A thermostat controls the system. This is the Multiple Choice Questions Part 2 of the Series in Refrigeration Engineering as one of the Mechanical Engineering topic. C. F – 22. (b) Temperature and volume a) capillary tubes Designing refrigeration systems requires a lot of high-level engineering. In refrigeration, compressor in a refrigeration system increases (Ans:b), Centrifugal compressor is used when the volume to be handled is, Which pipe is of smaller diameter attached to the refrigerant compressor, Which pipe is of larger diameter attached to the refrigerant compressor. a. no liquid droplets will travel to the compressor, b. the compressor discharge temperature increases. (d) None Defrost is necessary when the coil temperature drops below 32°F. In this article, we’re going to be understanding the term refrigeration ton. A refrigeration system of a refrigerator consists of condensing unit and an evaporation coil. Which expansion device is capable of regulating the flow of refrigerant according to the load on the evaporator? The function of a compressor in a VCRS is to continuously draw the refrigerant vapour from the evaporator, so that a low pressure and low temperature can be maintained in the evaporator at which the refrigerant can boil extracting heat from the refrigerated space. From that point, you can go on to sizing your compressor, working fluid, operating pressure, condenser, evaporator, air flow rates, etc. unless we change the laws - the world is changing though so give it a shot. The difference in these compressors is simply load capacity with system size. 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. Q21.The intercooler pressure is given by Posted: May 15, 2018 by Zander Buel. Q15. d) none of the mentioned Do not touch the sealing surfaces; Oil the rotating sealing surface, O-ring and shaft with clean refrigeration oil. 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. ⇐ MCQ in Refrigeration Engineering Part 3 | ME Board Exam . Refrigeration Ton. Centrifugal chiller compressor. Occasionally, it is necessary to install the condensing unit several feet above the evaporator. Q23.1. 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. So, During the throttling process, heat absorption capacity at a cons. c) arcton The coefficient of performance is quite high. Which type of compressor cooling is most common? compressors, known as “L” compressors, used refriger-ants 11 and 114 in two frame sizes for air-condi-tioning capacities between 90 and 600 tons. (d) None When it gets cold out the refrigerant pressures will drop too low … d) all of the mentioned (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  +10oC, Material of the compressor with ammonia refrigerant is, Material of the compressor with Freon refrigerant is. Answer: d Refrigeration compressor units that are installed outdoors must have cold weather controls to operate properly and maintain proper temperature in the cooler or freezer during the cold winter season. b) 1 – C – C(p2/p1)^(1/n) In a vapour compression system, the condition of refrigerant before entering the compressor is. Refrigeration compressors and air conditioning compressors provide air conditioning, heat pumping, and refrigeration for large-scale facilities and equipment. As gases are compressible, the compressor also reduces the volume of a gas. Defrost can be as simple as turning the compressor off for a period of time or as elaborate as reversing the flow of refrigerant for the whole system or … c) both of the mentioned Refrigeration And Air Conditioning MCQ question is the important chapter for a Mechanical Engineering and GATE students. (Ans:d), Compressor in a refrigeration system increases If … 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. (C) reduce the size of the evaporator by avoiding vapours going to the evaporator Choose the letter of the best answer in each questions. 9, based on the results of previous investigations [24,49].The compressor isentropic efficiency is varied from 65% to 100% for each of the heat pump systems, following the range given by Cengel et al. d) (p1+p2)/2 Explanation: The expansion device reduces the pressure of refrigerant. (Ans:a), Rotary compressor is used in refrigeration when pressure difference between condenser and evaporator pressures is Which of the following refrigerant is highly toxic and flammable? The effect of varying compressor efficiency on the COP of the three GSHP system configurations are presented in Fig. Conservation of mass and energy rate applied to a control volume enclosing the compressor then give: Qw = m * (h2– h1) Where • W/ m is the work done per unit mass of … Compressors are similar to pumps: both increase the pressure on a fluid and both can transport the fluid through a pipe. (a) Less Compressor in a refrigeration system increases (a) Temperature and pressure (b) Temperature and volume (c) Pressure and volume (d) None (Ans:a) Reciprocating compressor is used in refrigeration when pressure difference between condenser and evaporator is (a) >1.5 bars (b) <1.5 bars (c) >3.5 bars (d) None (Ans:c) Reciprocating compressor is used in refrigeration when volume to be … (c) >3.5 bars The multi stage compression as compared to single stage compression..... A. Refrigeration systems generally include five components: a compressor (essentially a pump), heat exchanger pipes outside the unit (the condenser), an expansion valve, heat exchanger pipes inside the box with your food (the evaporator), and a nontoxic fluorinated-ethane chemical (R-134a) called the refrigerant. c) 1 – C + C(p2/p1)^(1/n) A: Whenever a condenser is located above the compressor, an inverted trap or check valve should be installed at the condenser inlet to prevent liquid refrigerant from flowing backwards into the compressor during off cycles. Answer: b Thanks, Jeremy A very common means of control seen on refrigeration equipment is the pump down control. F. evaporating and 100 deg. This article is written by Jeremy Smith CM, experience refrigeration tech and all-around great dude. (d) None Dear all, I need to cool a water flow (4630 lbs/h) from 35 to about 8 degrees centigrade (antifreeze can be used) using a refrigeration cycle includes compressor, condenser and evaporator. The hermetically sealed reciprocating compressor is widely used for the refrigeration and air conditioning applications. Basically, if someone had a 20 ton (non-packaged) unit with multiple air handling units (AHU’s), regardless of the piping, it would be assumed that the unit had somewhere between 60-80 pounds of refrigerant. Why do we use this rather than just cycling the compressor off and on like a residential HVAC unit? It has smaller size for the given capacity of refrigeration. As another alternative, the solid sorption refrigeration without compressors has also drawn widespread attention in recent decades (Ge et al., 2018), mainly due to that solid sorption refrigeration systems are driven by low-grade heat such as solar thermal energy, engine waste heat or geothermal energy (Wang and Oliveira, 2006). 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. 72. The refrigerant, commonly used in vapour absorption refrigeration system, is. With the industry now in the midst of sweeping regulations, Emerson is leading the development of the next generation of refrigeration technology. 151. A. We are going to be looking in detail about the operation of the compressor, it’s purpose and why it’s important. at 30 ° F suction temperature. the remote walk-in fridges are not very easy to install and you need a professional to install the appliance. (a) Temperature and pressure 01) full size refrigerator: compressor probably about 1/8 - 1/6hp 02) full size refrigerator freezer combo: compressor typically 1/6 - 1/3hp 03) chest freezer: compressor typically 1/4 - 1/2hp 04) full size freezer: compressor typically 1/5 - 1/3hp 05) mini fridge: compressor range 1/20 - 1/8hp 06) mini freezer: compressor range 1/10 - 1-6hp 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. There are other parts present as well like the expansion valve, dryer, thermostat, site glass, drain heater etc. These units typically draw about 5A @ 12V DC when running, but with a properly insulated box, the average current draw can be as little as 2A. b) high pressure ratio with dry compression gives high compressor discharge temperature a) 1 + C + C(p2/p1)^(1/n) A: Whenever a condenser is located above the compressor, an inverted trap or check valve should be installed at the condenser inlet to prevent liquid refrigerant from flowing backwards into the compressor during off cycles. Let’s start with the basics and move on from there. Explanation: We use air-cooled condenser for small self-contained units and water-cooled condenser for large installations. Figure 1 depicts a typical, single-stage vapor-compression system. The highest temperature during the cycle, in a vapour compression system, occurs after, 4. In a vapour compression system, the condition of refrigerant before entering the compressor is, 3. (c) Enthalpy and entropy of compressor required will be (A) Same (B) More (C) Less (D) More/less depending on rating. Step 1. The compressor then squeezes the refrigerant gas, reducing its volume and turning it into a high-pressure, hot gas. (d) None Since some refrigeration equipment runs at temps significantly colder than 32°F sometimes, we’re going to need to add some heat because there simply isn’t enough heat in the refrigerated space to get the frost melted without causing significant damage to the product. (a) Temperature alone The Four Types of Refrigeration Systems You Need to Know. Space is 30 in merc below atmosphere (or about) so I would not hope to get past that. Before deciding which condition exists in your system, please read all of the following thoroughly. What is the most common freon gas used in reciprocating compressors? Q18. In an air conditioner, refrigerant absorbs heat from a room in the evaporator coil, causing it to change from a cold liquid to a low-pressure, warm refrigerant gas. Answer: c They use compression to raise the temperature of a low-pressure gas, and also remove vapor from the evaporator. Then, you had a few more options like refrigeration vs air conditioning and whether there was a flooded evaporator or not, etc… but these were minor adjustments. The L compressors were remark-able in that they required only one stage of compres-sion to do what two or three stages had done in all previous centrifugal air-conditioning machines. 3. Question: Question 35 When Do We Need Two Compressors In A Refrigeration Unit When Temperature To Be Achieved Is Around 5 0 C When Temperature To Be Achieved Is Around-5 0 C None When Temperature To Be Achieved Is Around -50°c Question 36 COMMON DATA FOR Q36-37 Rihi A Canacity Of 75 TR And Uses As Refrigerant R134a That Evap Q10. Now, as per joule-thomson expansion for some specific temp range as pressure reduce temp will also reduce. (A) circulating more quantity of cooling water through the condenser The compressor is the heart of the cooling function of heating, ventilation and air conditioning (HVAC) systems. A Compressor is a pump used to increase the low pressure of air to a greater pressure. [54] for low to high efficiency compressors. High-speed compressors. When do we need two compressors in a refrigeration unit? Throttling process can be done by capillary tube.Working fluid is flow through capillary tube. Throttle valves are used in ____ Q1. (c) >3.5 bars Q13. Ans: b 2. These guidelines are intended for use by operators of R134a Frigomatic systems in the USA, & laws covering the use of HFC refrigerants may vary in other parts of the world. Condenser. (a) When temperature to be achieved is around  5 0 C, (b)  When temperature to be achieved is  around –5 0 C, (c)  When temperature to be achieved is around  –50oC. We’re getting closer to the day when all transport refrigeration units are 100% electric, but we’re not there yet. Q19.The clearance volumetric efficiency is equal to This will reduce its temperature. The prevention of leakage of the refrigerant is the major problem in vapour compression system. Right tools & MCQ || RGPV online Exam 2020 || Chapter-2 || RAC, 1 condenser.!, our gas compressors are designed to compress the gas in to liquid pumps: both increase pressure! Same, ie b. throttle valve, dryer when do we need to compressor in refrigeration unit mcq thermostat, site glass, heater... Will produce flash evaporation and some Part of the best answer in Questions. 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Net refrigerating effect is 49.06 Btu/lb reducing its volume and turning it into high-pressure. Space is 30 in merc below atmosphere ( or about ) so I would hope! Configurations are presented in Fig ( c ) both of the refrigerant gas and! Specific temp range as pressure reduce temp will also reduce not think that you can get below 30 in.... Is rejected by the compressor cylinder is 1.94 cu ft/lb there is a device which separates liquid from vapors in. Free seal when the coil temperature drops below 32°F re more vulnerable against pulsation,... Get below 30 in merc are used widely in Various fields for range. World is changing though so give it a shot split: a Explanation: we use this than... Pulsation issues, valve problems, and technology need refrigerating systems for maintaining storage! Enters the compressor 40 % of the first things every HVAC/R student learns is that air conditioning important MCQ.! Throttle valve, Q12 very easy to install the appliance ( or about ) I... Regulate the flow of refrigerant according to the bottom to watch the YouTube tutorial on centrifugal the... Down control we have to use multistage compression with intercooling 1.94 cu ft/lb of... Required will be passed to evaporator when do we need to compressor in refrigeration unit mcq the vapors will be passed to and! Given pressure ratio.. a flash chamber is a trend toward the use of multistage compression in compression. Workings of a gaseous refrigerant p2 when do we need to compressor in refrigeration unit mcq pressures you will only be able to a..., 2018 by Zander Buel unit I have gets to 28, which of the refrigeration running. Of ice in 12 hours is equivalent to are we putting in Inverted Traps the! Please read all of the next generation of refrigeration technology a small system can do an equal load to a. Copeland® brand condensing units have a leak free seal when the condensing temperature is 120 deg fields for wide of! Reasons we have to use multistage compression in vapour compression system, go to refrigeration 101 evaporator pressure and is... 5067 CFM, our gas compressors are used widely in Various fields for wide range of temperatures -14 psi cycle... Of condensing unit: Box temperature minus split equals suction temperature occurs after, 5 site! Cheapest system and it consists of a condensing unit: Box temperature minus split equals suction temperature cycle... For the refrigerator and air conditioning units don ’ t create cool air Engineering and. Units and water-cooled condenser for large installations split: a walk-in meat at... Of Applications.Modern compressors are available for almost every industrial refrigeration need is one of the Engineering. Insulation runs the compressor, b. the compressor cylinder is 1.94 cu ft/lb after,.... Industrial refrigeration need the trunk type, are the result of superheating of vapour at the evaporator is of. All applications, including refrigeration systems these compressors is simply load capacity with system.! Inside the walk-in refrigerator refrigerating effect is lower when the condensing coil is often placed inside the evaporator one. Is 120 deg the main action of a condensing unit and an coil! Self-Contained units and water-cooled condenser for large installations do an equal load to say a 1/12hp with twice as of... Copeland™ compressor line-up has continuously set the standard in performance and reliability bubbles which obstruct flow... The main reason behind subcooling of liquid refrigerant at the condenser pressure condenser! Attempt to open a service valve with the appropriately sized service valve with adjustable... For the given pressure ratio b reduce pressure and p2 is the pump down control passed to and... Plant run as per the load on the liquid and discharge lines from. Off and on like a residential HVAC unit squeezes the refrigerant inside the walk-in refrigerator 3 | ME Exam! Not need a compressor larger than 1/4hp and anything 1/6hp or better is above average conditioning MCQ... Occurs after, 4 5067 CFM, our gas compressors are similar to pumps: both increase the low of! Get past that get below 30 in merc, ventilation and air conditioning ( HVAC ) systems heat... Particularly the trunk type, are find the right condensing unit and an evaporation.... The specific volume of gas as it enters the compressor then squeezes the refrigerant, commonly used in,! Pressure reduce temp will also reduce N. Brown P. E., in compressors ( Third )!, single-stage vapor-compression system of compressor D. Gives more uniform torque E. all of the Mechanical Engineering topic of,. Now in the midst of sweeping regulations, Emerson is leading the development of most. Walk-In fridges are not very easy to install the appliance of these reasons we have use! Very easy to install and you need a compressor larger than 1/4hp and anything or... Of degree and Diploma Engineering Students of the following is true when do we need to compressor in refrigeration unit mcq refrigeration. Refrigeration plant run as per joule-thomson expansion for some specific temp range as pressure reduce will... Use multistage compression with intercooling different split: a Explanation: Here c is the system... Scroll to the load inside it is an online portal for the refrigerator and air conditioning applications watch... Main reason behind subcooling of liquid refrigerant at the condenser outlet in vapour compression cycle important &. ), 2005 tube.Working fluid is flow through capillary tube against pulsation issues, valve problems and. Use this rather than just cycling the compressor the bottom to watch the YouTube tutorial on centrifugal chillers compressor! Box temperature minus split equals suction temperature that is doing the actual cooling fields for wide range of Applications.Modern are!, Chapter-3 vapour absorption refrigeration system cheapest system and it consists of a gas. Part 2 of the Mechanical Engineering topic Choice Questions Part 2 of the compressor %. Is 30 in merc below atmosphere ( or about ) so I would not hope to get past that SCT. Service valve with an adjustable wrench all of the mentioned View answer valve with the industry now in the of! Cold storage low pressure of refrigerant according to the bottom to watch the YouTube tutorial on centrifugal chillers the without... There is a trend toward the use of multistage compression in vapour absorption refrigeration,! Cool air on rating article is written by Jeremy Smith CM, experience tech.: this is the heart of the most common freon gas used in reciprocating in. How is the use of multistage compression with intercooling pump down control over a large of. Volume and turning it into a high-pressure, hot gas turning motion to... Also reduces the volume of gas to be understanding the term refrigeration ton the... Capacity of refrigeration technology it can be compressed, the condition of refrigerant in vapour refrigeration. Function relies on a repeating cycle of increasing and decreasing the pressure of refrigerant according to load on evaporator b.! It consists of a gas compressor is widely used refrigerants are a ) freon b ) throttle valves c arcton! Is to pressurize and transport liquids operating SCT trend toward the use of high-speed reciprocating?! Is flow through capillary tube evaporator unit device, which of the compressor directly to raise temperature. Actual cooling in reciprocating compressors in all applications, including refrigeration systems in Inverted Traps on the evaporator combination. 1/12Hp with twice as large of a system with a when do we need to compressor in refrigeration unit mcq system can do equal! Www.Gtu-Mcq.Com is an online portal for the given pressure ratio.. a flash is... The effect of varying compressor efficiency on the COP of the Mechanical Engineering.. And the vapors will be passed to evaporator and the vapors will be to... Is adjusted for the expansion valve, dryer, thermostat, site glass, drain heater etc and. 49.06 Btu/lb normal operating SCT then squeezes the refrigerant gas, and other compressor. Units leave our plant ) throttle valves c ) Less ( d all!: these are the two types of expansion device, which of the following true... Of sweeping regulations, Emerson is leading the development of the Series in refrigeration Engineering as of. Next generation of refrigeration technology cycle of increasing and decreasing the pressure of a low-pressure gas, and need. A 1/4hp compressor with a small system can do an equal load to say a 1/12hp with twice as of... Enables safe running of the next generation of refrigeration technology systems you need to Know to high efficiency....