How Vapour Compression Cycle Works ?

How Vapour Compression Cycle Works ?
by

1 Answer

Answer :

The Vapor-Compression Refrigeration Cycle is comprised of four steps. ... The condenser is in contact with the hot reservoir of the refrigeration system. (The gas releases heat into the hot reservoir because of the external work added to the gas.) The refrigerant leaves as a high pressure liquid.
by

Related questions

What is the use of flash chamber in a vapour compression refrigeration cycle to improve the COP of refrigeration cycle ?

Description : What is the use of flash chamber in a vapour compression refrigeration cycle to improve the COP of refrigeration cycle ?

Last Answer : When liquid refrigerant as obtained from condenser is throttled, there are some vapours. These vapours if carried through the evaporator will not contribute to refrigerating effect. Using a flash ... out in stages. Similarly compression process is also done in two separate compressor stages.

Most of the domestic refrigerators work on the following refrigeration system (a) vapour compression (b) vapour absorption (c) carnot cycle (d) electrolux refrigerator

Description : Most of the domestic refrigerators work on the following refrigeration system (a) vapour compression (b) vapour absorption (c) carnot cycle (d) electrolux refrigerator

Last Answer : Ans: a

In vapour compression cycle using NH3 as refrigerant, initial charge is filled at (a) suction of compressor (b) delivery of compressor (c) high pressure side close to receiver (d) low pressure side near receiver

Description : In vapour compression cycle using NH3 as refrigerant, initial charge is filled at (a) suction of compressor (b) delivery of compressor (c) high pressure side close to receiver (d) low pressure side near receiver

Last Answer : Ans: c

The lower horizontal line of the refrigeration cycle plotted on pressure-enthalpy-diagram represents (a) condensation of the refrigerant vapour (b) evaporation of the refrigerant liquid (c) compression of the refrigerant vapour (d) metering of the refrigerant liquid

Description : The lower horizontal line of the refrigeration cycle plotted on pressure-enthalpy-diagram represents (a) condensation of the refrigerant vapour (b) evaporation of the refrigerant liquid (c) compression of the refrigerant vapour (d) metering of the refrigerant liquid

Last Answer : Ans: b

Where does the lowest temperature occur in a vapour compression cycle ? (a) condenser (b) evaporator (c) compressor (d) expansion valve

Description : Where does the lowest temperature occur in a vapour compression cycle ? (a) condenser (b) evaporator (c) compressor (d) expansion valve

Last Answer : Ans: b

The value of COP in vapour compression cycle is usually (a) always less than unity (b) always more than unity (c) equal to unity (d) any one of the above

Description : The value of COP in vapour compression cycle is usually (a) always less than unity (b) always more than unity (c) equal to unity (d) any one of the above

Last Answer : Ans: b

The higher temperature in vapour compression cycle occurs at (a) compressor discharge. (b) expansion valve (c) evaporator (d) condenser discharge

Description : The higher temperature in vapour compression cycle occurs at (a) compressor discharge. (b) expansion valve (c) evaporator (d) condenser discharge

Last Answer : Ans: a

In a vapour compression cycle, the refrigerant immediately after expansion valve is (a) liquid (b) sub-cooled liquid (c) saturated liquid (d) wet vapour

Description : In a vapour compression cycle, the refrigerant immediately after expansion valve is (a) liquid (b) sub-cooled liquid (c) saturated liquid (d) wet vapour

Last Answer : Ans: d

Domestic refrigerator working on vapour compression cycle uses the following type of expansion device (a) electrically operated throttling valve (b) manually operated valve (c) thermostatic valve (d) capillary tube

Description : Domestic refrigerator working on vapour compression cycle uses the following type of expansion device (a) electrically operated throttling valve (b) manually operated valve (c) thermostatic valve (d) capillary tube

Last Answer : Ans: d

The vapour compression refrigerator employs the following cycle (a) Rankine (b) Carnot (c) Reversed Carnot. (d) Brayton

Description : The vapour compression refrigerator employs the following cycle (a) Rankine (b) Carnot (c) Reversed Carnot. (d) Brayton

Last Answer : Ans: c

In vapour compression cycle the condition off refrigerant is dry saturated vapour (a) after passing through the condenser (b) before passing through the condenser (c)before entering the expansion valve (d) before entering the compressor

Description : In vapour compression cycle the condition off refrigerant is dry saturated vapour (a) after passing through the condenser (b) before passing through the condenser (c)before entering the expansion valve (d) before entering the compressor

Last Answer : Ans: D

In vapour compression cycle the condition of refrigerant is superheated vapour (a) after passing through the condenser (b) before passing through the condenser (c) after passing through the expansion or throttle valve (d) beforeentering the expansion valve

Description : In vapour compression cycle the condition of refrigerant is superheated vapour (a) after passing through the condenser (b) before passing through the condenser (c) after passing through the expansion or throttle valve (d) beforeentering the expansion valve

Last Answer : Ans: b

In vapour compression cycle, the condition of refrigerant is high pressure saturated liquid (a) after passing through the condenser (b) before passing through the condenser (c) after passing through the expansion or throttle valve (d) before entering the expansion valve

Description : In vapour compression cycle, the condition of refrigerant is high pressure saturated liquid (a) after passing through the condenser (b) before passing through the condenser (c) after passing through the expansion or throttle valve (d) before entering the expansion valve

Last Answer : Ans: d

In vapour compression cycle, the condition of refrigerant is very wet vapour (a) after passing through the condenser (b) before passing through the condenser (c) after passing through the expansion or throttle valve (d) before entering the expansion valve

Description : In vapour compression cycle, the condition of refrigerant is very wet vapour (a) after passing through the condenser (b) before passing through the condenser (c) after passing through the expansion or throttle valve (d) before entering the expansion valve

Last Answer : Ans: c

In vapour compression cycle, the condition of refrigerant is saturated liquid (a) after passing through the condenser (b) before passing through the condenser (c) after passing through the expansion throttle valve (d) before entering the expansion valve

Description : In vapour compression cycle, the condition of refrigerant is saturated liquid (a) after passing through the condenser (b) before passing through the condenser (c) after passing through the expansion throttle valve (d) before entering the expansion valve

Last Answer : Ans: a

Ammonia-absorption refrigeration cycle requires (a) very little work input (b) maximum work input (c) nearly same work input as for vapour compression cycle (d) zero work input

Description : Ammonia-absorption refrigeration cycle requires (a) very little work input (b) maximum work input (c) nearly same work input as for vapour compression cycle (d) zero work input

Last Answer : Ans: a

Vapour compression refrigeration is some what like (a) Carnot cycle (b) Rankine cycle (c) reversedCamot cycle (d) reversed Rankine cycle

Description : Vapour compression refrigeration is some what like (a) Carnot cycle (b) Rankine cycle (c) reversedCamot cycle (d) reversed Rankine cycle

Last Answer : Ans: C

Which of the following has the minimum value of COP for a given refrigeration effect? (A) Reverse Carnot cycle (B) Ordinary vapour-compression cycle (C) Vapour-compression process with a reversible expansion engine (D) Air refrigeration cycle

Description : Which of the following has the minimum value of COP for a given refrigeration effect? (A) Reverse Carnot cycle (B) Ordinary vapour-compression cycle (C) Vapour-compression process with a reversible expansion engine (D) Air refrigeration cycle

Last Answer : (D) Air refrigeration cycle

Out of the following refrigeration cycles, which one has the minimum COP (Co-efficient of performance)? (A) Air cycle (B) Carnot cycle (C) Ordinary vapour compression cycle (D) Vapour compression with a reversible expansion engine

Description : Out of the following refrigeration cycles, which one has the minimum COP (Co-efficient of performance)? (A) Air cycle (B) Carnot cycle (C) Ordinary vapour compression cycle (D) Vapour compression with a reversible expansion engine

Last Answer : A) Air cycle

Describe with a neat diagram the working of a simple vapour compression refrigeration system. Represent the cycle on P–V and T–S diagram.

Description : Describe with a neat diagram the working of a simple vapour compression refrigeration system. Represent the cycle on P–V and T–S diagram. 

Last Answer : Vapour compression refrigeration cycle: The vapor-compression uses a circulating liquid refrigerant as the medium which absorbs and removes heat from the space to be cooled and subsequently rejects that heat elsewhere. Figure shows ... the compressor. P-V Diagram T-S diagram: 

Domestic refrigerator usually works on the __________ refrigeration cycle. (A) Carnot (B) Air (C) Absorption (D) vapour-ejection

Description : Domestic refrigerator usually works on the __________ refrigeration cycle. (A) Carnot (B) Air (C) Absorption (D) vapour-ejection

Last Answer : (C) Absorption

What Is Vapor Compression Cycle?

Description : What Is Vapor Compression Cycle?

Last Answer : Vapor-Compression Refrigeration or vapor-compression refrigeration system (VCRS), in which the refrigerant undergoes phase changes, is one of the many refrigeration cycles and is the most widely used method for air-conditioning of buildings and automobiles.

It is used for gas turbines which operates on an open cycle where both the compression and expansion processes take place in rotating machinery.  a. Dual Cycle  b. Otto Cycle  c. Carnot Cycle  d. Brayton Cycle

Description : It is used for gas turbines which operates on an open cycle where both the compression and expansion processes take place in rotating machinery.  a. Dual Cycle  b. Otto Cycle  c. Carnot Cycle  d. Brayton Cycle

Last Answer : Brayton Cycle

Executes the entire cycle in just two strokes the power stroke and the compression stroke.  a. One-stroke engine  b. Two-stroke engine  c. Four-stroke engine  d. Eight-stroke engine

Description : Executes the entire cycle in just two strokes the power stroke and the compression stroke.  a. One-stroke engine  b. Two-stroke engine  c. Four-stroke engine  d. Eight-stroke engine

Last Answer : Two-stroke engine

The efficiency of Diesel cycle depends upon  A. temperature limits  B. pressure ratio  C. compression ratio  D. cut-off ratio and compression ratio

Description : The efficiency of Diesel cycle depends upon  A. temperature limits  B. pressure ratio  C. compression ratio  D. cut-off ratio and compression ratio

Last Answer : Answer: D

Otto cycle efficiency is higher than Diesel cycle efficiency for the same compression ratio and heat input because in Otto cycle  A. combustion is at constant volume  B. expansion and compression are isentropic  C. maximum temperature is higher  D. heat rejection is lower

Description : Otto cycle efficiency is higher than Diesel cycle efficiency for the same compression ratio and heat input because in Otto cycle  A. combustion is at constant volume  B. expansion and compression are isentropic  C. maximum temperature is higher  D. heat rejection is lower

Last Answer : Answer: D

During which of the following process does heat rejection takes place in Carnot cycle?  A. Isothermal expansion  B. Isentropic expansion  C. Isothermal compression  D. Isentropic compression

Description : During which of the following process does heat rejection takes place in Carnot cycle?  A. Isothermal expansion  B. Isentropic expansion  C. Isothermal compression  D. Isentropic compression

Last Answer : Answer: C

For same compression ratio and for same heat added  (a) Otto cycle is more efficient than Diesel cycle  (b) Diesel cycle is more efficient than Otto cycle  (c) efficiency depends on other factors  (d) both Otto and Diesel cycles are equally efficient  (e) none of the above.

Description : For same compression ratio and for same heat added  (a) Otto cycle is more efficient than Diesel cycle  (b) Diesel cycle is more efficient than Otto cycle  (c) efficiency depends on other factors  (d) both Otto and Diesel cycles are equally efficient  (e) none of the above.

Last Answer : Answer : a

In order that a cycle be reversible, following must be satisfied  (a) free expansion or friction resisted expansion/compression process should not be encountered  (b) when heat is being absorbed, temperature of hot source and working sub¬stance should be same  (c) when beat is being rejected, temperature of cold source and working sub-stance should be same  (d) all of the above  (e) none of the above.

Description : In order that a cycle be reversible, following must be satisfied  (a) free expansion or friction resisted expansion/compression process should not be encountered  (b) when heat is being absorbed, temperature of hot ... sub-stance should be same  (d) all of the above  (e) none of the above.

Last Answer : Answer : d

Thermal power plant works on  (a) Carnot cycle  (b) Joule cycle  (d) Rankine cycle  (d) Otto cycle  (e) Brayton cycle.

Description : Thermal power plant works on  (a) Carnot cycle  (b) Joule cycle  (d) Rankine cycle  (d) Otto cycle  (e) Brayton cycle.

Last Answer : Answer : c

The condition of refrigerant before entering the expansion or throttle valve, in a vapour compression system (a) dry vapour (b) wet vapour (c)liquid-vapour mixture (d) high pressure saturated liquid

Description : The condition of refrigerant before entering the expansion or throttle valve, in a vapour compression system (a) dry vapour (b) wet vapour (c)liquid-vapour mixture (d) high pressure saturated liquid

Last Answer : Ans: d

The COP of a vapour compression plant in comparison to vapour absorption plant is (a) more (b) less (c) same (d) more/less depending on size of plant

Description : The COP of a vapour compression plant in comparison to vapour absorption plant is (a) more (b) less (c) same (d) more/less depending on size of plant

Last Answer : Ans: a

In vapour compression refrigeration system, refrigerant occurs as liquid between (a) condenser and expansion valve (b) compressor and evaporator (c) expansion valve and evaporator (d) compressor and condenser

Description : In vapour compression refrigeration system, refrigerant occurs as liquid between (a) condenser and expansion valve (b) compressor and evaporator (c) expansion valve and evaporator (d) compressor and condenser

Last Answer : Ans: c

Lowering of condenser temperature (keeping the evaporator temperature constant) in case of vapour compression refrigeration system results in (A) Increased COP (B) Same COP (C) Decreased COP (D) Increased or decreased COP; depending upon the type of refrigerant

Description : Lowering of condenser temperature (keeping the evaporator temperature constant) in case of vapour compression refrigeration system results in (A) Increased COP (B) Same COP (C) Decreased COP (D) Increased or decreased COP; depending upon the type of refrigerant

Last Answer : (A) Increased COP

Which of the following is a widely used refrigerant in vapour compression refrigeration system (using large centrifugal compressor)? (A) Freon (B) Liquid sulphur dioxide (C) Methyl chloride (D) Ammonia

Description : Which of the following is a widely used refrigerant in vapour compression refrigeration system (using large centrifugal compressor)? (A) Freon (B) Liquid sulphur dioxide (C) Methyl chloride (D) Ammonia

Last Answer : (A) Freon

The effect of changing the evaporator temperature on COP as compared to that of changing the condenser temperature (in vapour compression refrigeration system) is (A) Less pronounced (B) More pronounced (C) Equal (D) Data insufficient, can't be predicted

Description : The effect of changing the evaporator temperature on COP as compared to that of changing the condenser temperature (in vapour compression refrigeration system) is (A) Less pronounced (B) More pronounced (C) Equal (D) Data insufficient, can't be predicted

Last Answer : (B) More pronounced

Adiabatic compression of a saturated water vapour makes it (A) Supersaturated (B) Superheated (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : Adiabatic compression of a saturated water vapour makes it (A) Supersaturated (B) Superheated (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : B) Superheated

In vapour compression refrigeration system, if the evaporator temperature and the condenser temperatures are -13°C and 37°C respectively, the Carnot COP will be (A) 5.2 (B) 6.2 (C) 0.168 (D) Data insufficient, can't be found out

Description : In vapour compression refrigeration system, if the evaporator temperature and the condenser temperatures are -13°C and 37°C respectively, the Carnot COP will be (A) 5.2 (B) 6.2 (C) 0.168 (D) Data insufficient, can't be found out

Last Answer : A) 5.2

The benchmarking parameter for a vapour compression refrigeration system is a) kW / kg of refrigerant used b) kcal / m3 of chilled water c) BTU / Ton of Refrigeration d) kW / Ton of Refrigeration

Description : The benchmarking parameter for a vapour compression refrigeration system is a) kW / kg of refrigerant used b) kcal / m3 of chilled water c) BTU / Ton of Refrigeration d) kW / Ton of Refrigeration

Last Answer : d) kW / Ton of Refrigeration

Effect Of Superheating of suction Vapour-(before compression)

Description : Effect Of Superheating of suction Vapour-(before compression)

Last Answer : Effect Of Superheating of suction Vapour-(before compression) A vapour compression cycle with superheated vapour before compression is shown on T-s and p-h diagrams respectively. In this cycle, the ... . Thus, to avoid this, a 5 to 20 K superheat of the refrigerant is always desirable. 

Vapour which is at a pressure smaller than the saturation pressure for the temperature involved is called a __________ vapour. (A) Superheated (B) Desuperheated (C) Non-condensable (D) None of these

Description : Vapour which is at a pressure smaller than the saturation pressure for the temperature involved is called a __________ vapour. (A) Superheated (B) Desuperheated (C) Non-condensable (D) None of these

Last Answer : (A) Superheated

If a gas vapour is allowed to expand through a very minute aperture, then such a process is known as  (a) free expansion  (b) hyperbolic expansion  (c) adiabatic expansion  (d) parabolic expansion  (e) throttling.

Description : If a gas vapour is allowed to expand through a very minute aperture, then such a process is known as  (a) free expansion  (b) hyperbolic expansion  (c) adiabatic expansion  (d) parabolic expansion  (e) throttling.

Last Answer : Answer : e

Superheated vapour behaves  (a) exactly as gas  (b) as steam  (c) as ordinary vapour  (d) approximately as a gas  (e) as average of gas and vapour.

Description : Superheated vapour behaves  (a) exactly as gas  (b) as steam  (c) as ordinary vapour  (d) approximately as a gas  (e) as average of gas and vapour.

Last Answer : Answer : d

Which of the following can be regarded as gas so that gas laws could be applicable, within the commonly encountered temperature limits.  (a) 02, N2, steam, C02  (b) Oz, N2, water vapour  (c) S02, NH3, C02, moisture  (d) 02, N2, H2, air  (e) steam vapours, H2, C02.

Description : Which of the following can be regarded as gas so that gas laws could be applicable, within the commonly encountered temperature limits.  (a) 02, N2, steam, C02  (b) Oz, N2, water vapour  (c) S02, NH3, C02, moisture  (d) 02, N2, H2, air  (e) steam vapours, H2, C02.

Last Answer : Answer : d

Reducing suction pressure in refrigeration cycle (a) lowers evaporation temperature (b) increases power required per ton of refrigeration (c) lowers compressor capacity because vapour is lighter (d) all of the above.

Description : Reducing suction pressure in refrigeration cycle (a) lowers evaporation temperature (b) increases power required per ton of refrigeration (c) lowers compressor capacity because vapour is lighter (d) all of the above.

Last Answer : Ans: d

Pick up the incorrect statement (a) lithium bromide used in vapour absorption cycle is nonvolatile (b) lithium bromide plant can't operate below 0°C (c) a separator is used in lithium bromide plant to remove the unwanted water vapour by condensing (d) concentration of solution coming out of lithium bromide generator is more in comparison to that entering the generator

Description : Pick up the incorrect statement (a) lithium bromide used in vapour absorption cycle is nonvolatile (b) lithium bromide plant can't operate below 0°C (c) a separator is used in lithium ... of solution coming out of lithium bromide generator is more in comparison to that entering the generator

Last Answer : Ans: c

During which of following process does heat rejection take place in Carnot vapour cycle? [IES-1992] (a) Constant volume (b) constant pressure (c) Constant temperature (d) constant entropy

Description : During which of following process does heat rejection take place in Carnot vapour cycle? [IES-1992] (a) Constant volume (b) constant pressure (c) Constant temperature (d) constant entropy

Last Answer : (c) Constant temperature

Rotation is simply---------object w.r.t origin or centre point. a.Turn b.Shift c.Compression d.Drag element

Description : Rotation is simply---------object w.r.t origin or centre point. a.Turn b.Shift c.Compression d.Drag element

Last Answer : a.Turn

A truss element a.107 dynes b.resists lateral forces c.is a two-force body d.is a three force body e.resist forces in compression only

Description : A truss element a.107 dynes b.resists lateral forces c.is a two-force body d.is a three force body e.resist forces in compression only

Last Answer : c. is a two-force body

TIES : STRUTS : a.purlins : piers b.angle : tee c.rolle support : hinge d.compression : tension e.107 dynes

Description : TIES : STRUTS : a.purlins : piers b.angle : tee c.rolle support : hinge d.compression : tension e.107 dynes

Last Answer : d. compression : tension