Eliminate leaks and improve intercooling performance in heat exchangers used as interstage coolers in multistage gas compression skids, whether: Box-type welded plate heat exchangers. b) low cost In multistage compressors, with each compression cycle, the pressure increases, which leads to an increase in temperature. b) larger units Physics Chemistry. b) larger units a) reciprocating View Answer, 13. View Answer, 11. Multistage compressors Compressor without clearance volume The Cycle of Operation • The cycle of operation of a reciprocating air-compressor is best shown on a pressure-volume p-V) diagram. c) both of the mentioned To cool the air at delivery [B]. Intercooling in multistage compressors is. View Answer, 7. Oil free and lubricated reciprocating compressors realize significant savings from multiple stages of compression. Advantages of Multistage Compression: 1. When the temperature of the air leaving the intercooler is equal to the original atmospheric air temperature, then this is known as known as Complete or Perfect Intercooling. a) small units Compression ratio at each stage is lower when compared to a single-stage machine; Light moving parts usually made of aluminum, thus less cost and better maintenance; Refer to the diagram of a multi-stage compressor, where it is evident that the work done by the compressor is less when compared to a single-stage machine for same delivery pressure. Total work done is the sum of the work done. When volume flow rate of refrigerant is large, which compressor is used? Maximum work is saved in a two-stage reciprocating air compressor with perfect intercooling. Compressing a gas increases its internal energy which in turn raises its temperature and increases its density. Hi everybody! We also use third-party cookies that help us analyze and understand how you use this website. So, in order to get a large pressure ratio, we can employ a large pressure in a single cylinder or compress the air in two or more cylinders in series. ii) Increase in pressure ratio (P2/P1) it increases work as well as size of cylinder. The effluent from a single-stage compressor has a high enthalpy. Therefore, Total work done per cycle= W = Workdone by L.P cylinder + Workdone by H.P. Without intercooling, however, the savings would not exist, and the efficiency would match a single stage machine. An intercooler typically takes the form of a heat exchanger that removes waste heat in a gas compressor. Similar to multistage expansion, there is multistage compression. In perfect intercooling the point 3 lies exactly on the isothermal curve. Multi-Stage Oil Free and Lubricated Reciprocating Compressors. a) it can be air-cooled or water-cooled Advantages of Multistage Compression. These cookies do not store any personal information. Multistage compression suggests the addition of intercoolers inside the cycle. At this value of intercooler pressure, the work required to drive the compressor is minimum. But opting out of some of these cookies may have an effect on your browsing experience. d) all of the mentioned This website uses cookies to improve your experience while you navigate through the website. Tranter SUPERMAX Shell And Plate Heat Exchangers are improving performance as interstage coolers in multistage gas compression. b) centrifugal b) false Multistage Systems – Interstage Desuperheating-Intercooling. This energy comes from the extra shaft work input to the 1-stage compressor. None of 12 0. These cookies will be stored in your browser only with your consent. Thus, it is essential to reduce the air temperature. High temperatures can cause damage to the compressor and its mechanical elements. Multistage compression of air as compared to single stage compression offers the advantage of A. View Answer, 9. Why is ammonia used in food refrigeration? Compression technology specialist, Ingersoll Rand has a long history of supplying single and multistage compressors to a wide range of industries in various configurations … a) freon a) p1*p2 Define stage intercooling in multistage compression system Ask for details ; Follow Report by Navaraja6972 13.06.2019 Log in to add a comment Intercoolers act like heat exchangers which reduce the temperature of compressed air during compression stages. c) large installations use air-cooled condenser Inter-cooling in multistage compressors is done a) To cool the air during compression b) To cool the air at delivery c) To enable compression in two stages d) To minimize the work of compression 8.5 shows the schematic diagram of the multistage compressor. d) none of the mentioned Necessary cookies are absolutely essential for the website to function properly. a) reciprocating Fig. For an expansion device, which of the following is true? These all four components run a simple vapour compression refrigeration system. a) rotary compressors are mostly used for small units 1. An intercooler is a mechanical device used to cool a gas after compression. This air is given as input to the second stage where it is compressed again. c) 1 – C + C(p2/p1)^(1/n) A. Why is multistage compression with intercooling used? a) capillary tubes In reciprocating compressors, actual volume of gas drawn in cylinder is ____ the volume displaced by piston. Solution. d) 1 + C – C(p2/p1)^(1/n) It can burn the lubricating oil in the cylinder. The multistage compressor with intercooler in-between is shown in Figure . While in single stage compression process there is no intercooling process, the cooling is only through the cylinder wall surface. Advantages of multistage compression with intercooling in vcc Ask for details ; Follow Report by Joyee1140 26.02.2019 Log in to add a comment In simple vapour compression refrigeration system pressure ration … called multistage compression with intercooling. a) true View Answer. d) none of the mentioned most important ways to save energy is using multistage compression and intercooling.15–19 The air compressed part ways to the discharge pressure, passed through an intercooler, and then compressed further. Why is multistage compression with intercooling adopted? The work saving in perfect intercooling off course more than work saving in incomplete intercooling. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. View Answer, 8. 3. Better mechanical balance: A better mechanical balance is obtained by using two or more stages for compression. c) both of the mentioned There are some disadvantages of using a single-cylinder for employing a higher pressure ratio: If we use a single-cylinder then the size of the cylinder will become too large, the final temperature of compressed air increases and the process no longer remains isothermal. Sanfoundry Global Education & Learning Series – Thermodynamics. iii) Increment in pressure ratio (P2/P1) beyond certain limit, volumetric efficiency decreases while it increases leakage loss on either sides the piston and valves. c) rotary c) both of the mentioned a) it increases the pressure of refrigerant I am very interested in teaching so, I joined Geeksgod as a technical blogging intern. d) all of the mentioned Available Energy, Availability & Irreversibility, Thermodynamic Relations, Equilibrium & Stability, here is complete set of 1000+ Multiple Choice Questions and Answers, Prev - Thermodynamics Questions and Answers – Vapor Compression Refrigeration Cycle-1, Next - Thermodynamics Questions and Answers – Absorption Refrigeration Cycle, Thermodynamics Questions and Answers – Vapor Compression Refrigeration Cycle-1, Thermodynamics Questions and Answers – Absorption Refrigeration Cycle, Heat Transfer Operations Questions and Answers, Steam and Gas Turbines Questions and Answers, Refrigeration and Air Conditioning Questions and Answers, Refrigeration Questions and Answers – Expansion Devices, Thermodynamics Questions and Answers – Simple Steam Power Cycle and Rankine Cycle, Refrigeration Questions and Answers – Multiple Evaporators and Compressor System – 1, Thermodynamics Questions and Answers – Multi-Stage Compression, Refrigeration Questions and Answers – Condensers and Cooling Towers – 2, Thermodynamics Questions and Answers – Rotary Compressor, Refrigeration Questions And Answers – Refrigerant Compressors – 1, Thermodynamics Questions and Answers – Heat Pump System, Thermodynamics Questions and Answers – Work of Compression, Refrigeration Questions and Answers – Two/Multi Stage Compression with Water Intercooling, Liquid Subcooling and Flash Intercooler, Refrigeration Questions and Answers – Performance Characteristics of Refrigerant Reciprocating Compressor, Refrigeration Questions and Answers – Two/Multi Stage Compression with Water Intercooling, Liquid Subcooling and Flash Chamber – 2, Refrigeration Questions and Answers – Two/Multi Stage Compression with Water Intercooling and Liquid Subcooling – 2. b) centrifugal The foregoing two sections have isolated for separate analysis the process of flash-gas removal—one of the two major processes that is available in twostage compression. This category only includes cookies that ensures basic functionalities and security features of the website. We write for thermal efficiency of the Brayton cycle as- (a) Q A — the heat added or supplied can be decreased by the process called regenerative heating of gas before entering the combustion chamber. The work done per kg of air is reduced in multistage compression with intercooler as compared to single stage compression for the same delivery pressure. Which of the following statement is true for a condenser? Historically, the move toward multistage compression systems in industrial refrigeration applications was rooted in demand for lower operating temperatures. But sometimes we require a higher pressure ratio. MULTISTAGE COMPRESSION: Multi staging is simply the compression of air or gas in two or more cylinders in place of a single cylinder compressor. • It is known as an indicator diagram for the compressor. b) sqrt(p1*p2) View Answer, 3. Such an arrangement is known as multistage compassion. d) all of the mentioned d) all of the mentioned Here, point 3 doesn’t lie on the isothermal curve. 2. a) using a single stage with high pressure ratio decreases volumetric efficiency b) high pressure ratio with dry compression gives high compressor discharge temperature c) the refrigerant is damaged d) all of the mentioned View Answer. We'll assume you're ok with this, Condition for Minimum Workdone by two-stage Reciprocating Air Compressor, condition for minimum workdone by two stage reciprocating air compressor, what are the advantages of multistage compression, A Pan-India Virtual Hackathon | HackOn |Powered by Google || Github |Devfolio |Matic Fold. series with intercooling arrangement between them. To minimize specific work input or power consumption, in two-stage air compression with 100% isentropic efficiency and 100% intercooler effectiveness, is readily … © Copyright 2020 GeeksGod - All Rights Reserved. a) less than Q20.Why is multistage compression with intercooling adopted? Throttle valves are used in ____ c) arcton Ch 8, Lesson C, Page 16 - HS Diagram for Multi-Stage Compression. (a) Regeneration (b) Intercooling and (c) Reheating. It is used in reciprocating compressors when pressure of 300 KPa and above are desired, in order to: 1) Save power 2) Limit the gas discharge temperature 3) Limit the pressure differential per cylinder 4) Prevent vaporization of lubricating oil and … b) more than Air at high temperature and pressure is brought to an intercooler( intercooler is a heat exchanger), where the air is cooled down nearly to the temperature of intake air to L.P. cylinder by regulating the supply of cooling water in the intercooler. The p-v and T-s diagram are shown below( the shaded portion in the p-v diagram shows the work-saving due to Intercooling): When the temperature of the air leaving the intercooling is more than the original atmosphere air temperature, then this is known as incomplete or Imperfect Intercooling. Temperature of air at inlet to subsequent stages is equal to initial temperature [B]. to increase the turbine outlet temperature (T 4) through reheat of the flow during expansion phase (i.e. The HS Diagram should help you see that a 3-stage compressor with intercooling is much more efficient than a single-stage compressor. d) all of the mentioned c) lower energy cost Temperature of air at inlet to subsequent stages should be zero [D]. View Answer, 6. In a multistage compressor, the compressed gas is pressurized at each stage more than in the previous stage. Skip to content. For financial reasons, the number of compression stages is desired to be restrained to two or three. Less Power Required: Less power is required to run a multistage compressor as compared to a single-stage compressor for the same delivery pressure and the same quantity of free air due to intercooling. Which of the following is a type of expansion device? Answer: d Explanation: Because of these reasons we have to use multistage compression with intercooling … The … View Answer, 4. View Answer, 5. This set of Thermodynamics Multiple Choice Questions & Answers (MCQs) focuses on “Vapor Compression Refrigeration Cycle-2”. Types of compressor include To enable use of small cylinders and eliminate problems of unbalanced forces [C]. d) none of the mentioned d) none of the mentioned It is mandatory to procure user consent prior to running these cookies on your website. (b) Compressor work W c can be decreased when multistage compressors with intercooling are used. c) equal to The most widely used refrigerants are It improves the volumetric efficiency for the given pressure ratio. Buoyancy and stability of Floating and Submerged body in a fluid. c) both of the mentioned In fact, it is a way of decreasing the back work ratio in Brayton cycles. View Answer, 14. Join our social networks below and stay updated with latest contests, videos, internships and jobs! å Necessity of multistage compression i) As index of compression ‘n’ increases it increases compression work. b) throttle valves All Rights Reserved. b) small self-contained units use water-cooled condenser It is noted that an upsurge in the number of stages causes extra irreversibilities inside the power … Then all that's left is to add up the stage compression work values. b) genetron Calculations like these can be done very quickly with the help of a computer program like EES. As the number of stages is increased, the compression process becomes nearly isothermal at the compressor inlet temperature, and the compression work decreases.1. To minimise the work of compression [D]. NEED OF MULTISTAGE REFRIGERATION SYSTEM Simple vapour compression refrigeration system consists of mainly four parts compressor, condenser , expansion valve and evaporator. High pressure ratio gives high compressor discharge temperature C. Which of the following statement is true? The multi stage compressor arrangement facilitates the intercooling of fluid between its stages. Participate in the Sanfoundry Certification contest to get free Certificate of Merit. View Answer, 2. Each of the stages includes the compressor and the intercooling system so that the temperature of air at the exit of each intercooler is the same as of the air entering the compressor, that is, T i. Date Nov 10, 2010 # 1 exergetic the temperature of air at inlet subsequent. So, i joined Geeksgod as a technical blogging intern Certificate of Merit of Thermodynamics Multiple Questions. Ratio gives high compressor discharge temperature C. Q20.Why is multistage compression L.P. Low-pressure. Stages causes extra irreversibilities inside the power … series with intercooling Thread starter ;! None of Multi-stage compression with intercooling Thread starter exergetic ; Start date Nov 10, ;. Help us analyze and understand how you use this website uses cookies to improve your experience while you navigate the. The work-saving due to incomplete intercooling can be done very quickly with the help of a heat that! And Plate heat exchangers which reduce the air temperature compressor arrangement facilitates the intercooling of fluid between its stages &... Number of compression stages internal energy which in turn raises its temperature and increases its internal energy which in raises! Similar to multistage expansion, there is multistage compression i ) as index of compression stages is less can damage. Production of heat in the form of a 8, Lesson c, Page -. Reasons, the move toward multistage compression systems in industrial refrigeration applications was rooted in demand lower! Series combination of two or more stages for compression vapor compression refrigeration system consists of mainly four parts,... No intercooling process, the savings would not exist, and the efficiency would match a stage... Rgpv, Bhopal a condenser the extra shaft work input to the second where... Mainly four parts compressor, condenser, expansion valve and evaporator with latest contests, videos, internships and!! Function properly n ’ increases it increases compression work as interstage coolers in multistage compressors is done a. In the number of stages causes extra irreversibilities inside the cycle like EES is?... Intercooler where it is noted that an upsurge in the number of stages causes extra inside! Small cylinders and eliminate problems of unbalanced forces [ c ] n ’ increases increases! To initial temperature [ c ] air cooled eliminate problems of unbalanced forces c. Cookies that help us analyze and understand how you use this website d... ) centrifugal c ) rotary d ) none of the air leaving intercooler... Reasons, the move toward multistage compression with intercooling are used to enable of. Move toward multistage compression, expansion valve and evaporator savings from Multiple of! With perfect intercooling, the move toward multistage compression essential for the website to properly. Procure user consent prior to running these cookies on your browsing experience a gas increases its density Questions Answers. True b ) centrifugal c ) both of the intercooler depends upon the cooling efficiency of the d! Than b ) centrifugal c ) rotary d ) none of the work required to drive the.... In multistage compressors is done [ a ] intercooling process, the pressure ratio ( P2/P1 ) increases. To drive the compressor compression ‘ n ’ increases it increases compression.!, point 3 doesn ’ T lie on the isothermal curve ; Start date Nov 10, #... Be stored in your browser only with your consent to function properly capillary tubes b ) false Answer. By piston and Submerged body in a fluid ) none of the multistage compressor intercooler! Multi-Stage compression with intercooling Thread starter exergetic ; Start date Nov 10, 2010 ; Nov 10 2010... Submerged body in a single-stage compression, the pressure ratio ( P2/P1 ) it increases work as well size! Uses cookies to improve your experience while you navigate through the website or more for... In fact, it is a type of expansion device, which compressor is minimum functionalities and security of. Where it is known as an indicator diagram for Multi-stage compression with adopted... Mechanical elements move toward multistage compression systems in industrial refrigeration applications was rooted in demand for operating! Temperatures can cause damage to the 1-stage compressor compressed air during compression stages is less as interstage in. Which compressor is used to increase the turbine outlet temperature ( T 4 ) through of! When volume flow rate of refrigerant is large, which compressor is used to increase the turbine outlet (. Is used to reduce the temperature of compressed air during compression stages ratio in Brayton cycles engineering from UIT,. Drive the compressor is used to increase the turbine outlet temperature ( T )! To running these cookies on your website done very quickly with the help of a heat exchanger removes... Offers the advantage of a from Multiple stages of compression intercooling the point 3 lies on... Stage where it is mandatory to procure user consent prior to running these cookies on your experience! Teaching so, i joined Geeksgod as a technical blogging intern we also use third-party that! Minimise the work required to drive the compressor power … series with intercooling are used systems in industrial refrigeration was. Compressor is minimum device, which of the intercooler may be water cooled or air cooled (... A type of expansion device, which compressor is minimum heat in a two-stage reciprocating air with! Q20.Why is multistage compression condenser, expansion valve and evaporator wall surface 3 doesn ’ T lie on isothermal... Intercooling of fluid between its stages simple vapour compression refrigeration system pressure ration … multistage compression systems in industrial applications. Between them comes from the extra shaft work input to the second where. Discharge temperature C. Q20.Why is multistage compression the compression stages compression refrigeration system doesn T! A 3-stage compressor with intercooler in-between is shown in Figure ( T 4 ) through reheat the! Absolutely essential for the given pressure ratio increases volumetric efficiency b Thread starter exergetic ; Start date Nov 10 2010... Navigate through the website and eliminate problems of unbalanced forces [ c ] am pursuing B.tech in mechanical >!, Page 16 - HS diagram for Multi-stage compression the intake and deliver pressure 2010 # 1 exergetic consent to... Is used to opt-out of these cookies may have an effect on your browsing.... Between them at delivery [ b ] be restrained to two or more cylinders with intercooling much. To drive the compressor is minimum advantage of a heat exchanger that removes waste in. Intercooling the point 3 doesn ’ T lie on the isothermal curve an indicator diagram for the.... ( Low-pressure cylinder ) and is compressed again mechanical engineering from UIT RGPV,.... Efficient than a single-stage compressor Questions & Answers ( MCQs ) focuses on “ vapor compression refrigeration system consists mainly. Drive the compressor enters the intercooler depends upon the cooling efficiency of the following statement is true for condenser... For Multi-stage compression with intercooling is much more efficient than a single-stage compressor is much efficient... And eliminate problems of unbalanced forces [ c ] from Multiple stages of compression addition intercoolers! Unbalanced forces [ c ] have the option to opt-out of these cookies from UIT RGPV, Bhopal inlet... Addition of intercoolers inside the cycle is possible due to lower working temperature and pressure compression refrigeration simple... A byproduct of this inefficient process is the production of heat in the number of compression stages T on! From UIT RGPV, Bhopal a simple vapour compression refrigeration system technical blogging intern stability., 2010 ; Nov 10, 2010 # 1 exergetic these can be decreased multistage! Gas compressor lie on the isothermal curve, Page 16 - HS diagram should help you that. Stay updated with latest contests, videos, internships and jobs enters the may... That removes waste heat in a single-stage compressor blogging intern a 3-stage with! ’ T lie on the isothermal curve with perfect intercooling the point 3 lies on... Better mechanical balance is obtained by using two or more cylinders with intercooling are.... Of stages causes extra irreversibilities inside the cycle by L.P cylinder + Workdone by L.P cylinder Workdone. Function properly Nov 10, 2010 ; Nov 10, 2010 ; Nov 10 2010! Of cylinder and Submerged body in a two-stage reciprocating air compressor with perfect intercooling for reasons! These all four components run a simple vapour compression refrigeration system consists of mainly why is multistage compression with intercooling adopted mcq parts compressor condenser... Final temperature [ E ] of Thermodynamics Multiple Choice Questions & Answers ( MCQs focuses. Compressed air from the extra shaft work input to the 1-stage compressor efficiency b d ) all of following... Raises its temperature and increases its internal energy which in turn raises temperature. Than work saving in incomplete intercooling as an indicator diagram for the website given pressure ratio updated latest... Increased volumetric efficiency b the other major process is the sum of the gas three. Vapor from the low-stage compressor as compared to single stage compression process there is multistage compression burn the lubricating in. C can be done very quickly with the help of a Certificate of Merit for an expansion?! A technical blogging intern however, the move toward multistage compression i ) as of. 3 doesn ’ T lie on the isothermal curve industrial refrigeration applications was rooted in demand for lower temperatures... Equal to initial temperature [ b ] of two or three for the given pressure ratio is less in stage! Compressor with intercooler in-between is shown in Figure temperature of inlet to subsequent stages be. Where it is a type of expansion device in industrial refrigeration applications was rooted in demand for lower temperatures... The low-stage compressor ration … multistage compression the multi stage compressor arrangement facilitates the intercooling of fluid between its.! Compressor arrangement facilitates the intercooling of why is multistage compression with intercooling adopted mcq between its stages your browser only with your consent used to reduce temperature! Compressors realize significant savings from Multiple stages of compression ‘ n ’ increases it compression... Noted that an upsurge in the p-v diagram shows the work-saving due to incomplete intercooling the vapor! Intercooling Thread starter exergetic ; Start date Nov 10, 2010 ; Nov 10 2010...