What Is Vapor Compression Cycle?

1 Answer

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.

Related questions

Description : Water vapor at 100 KPa and 150°C is compressed isothermally until half the vapor has condensed. How much work must be performed on the steam in this compression process per kilogram?  a) -1384.7 kJ  b) 1384.7 kJ  c) -2384.7 kJ  d) 2384.7 kJ

Last Answer : -1384.7 kJ

Description : Out of the following refrigeration cycles, which one has maximum COP? (A) Air cycle (B) Carnot cycle (C) Ordinary vapor compression cycle (D) Vapor compression with a reversible expansion engin

Last Answer : (B) Carnot cycle

Description : Which of the following cycle is used in vapor cycle power plant?  a. Brayton cycle  b. Diesel cycle  c. Ericson cycle  d. Rankine cycle

Last Answer : Rankine 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.

Description : How Vapour Compression Cycle Works ?

Last 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.

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

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

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

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

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

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

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

Description : Pick out the wrong statement: (A) The capacity of an evaporator is reduced by the boiling point elevation (B) Corrosive liquid is normally passed through the tubes in a ... recompression evaporator (D) Heat sensitive materials should be concentrated in high pressure evaporators

Last Answer : (D) Heat sensitive materials should be concentrated in high pressure evaporators

Description : Which of the following units is not present in both the vapor compression refrigeration system and absorption refrigeration system? (A) Expansion valve (B) Condenser (C) Refrigerator (D) Compressor

Last Answer : (D) Compressor

Description : The changing of solid directly to vapor without passing through liquid state is called  a. Evaporation  b. Vaporization  c. Sublimation  d. Condensation

Last Answer : Sublimation

Description : Occurs when the vapor pressure equals the atmospheric pressure  a. Boiling  b. Melting  c. Freezing  d. Vaporizing

Last Answer : Boiling

Description : A 0.064 kg of octane vapor (MW = 114) is mixed with0.91 kg of air (MW = 29.0) in the manifold of an Engine. The total pressure in the manifold is 86.1 kPa, and a temperature is 290 K. assume octane behaves ideally. What is ... of the air in the mixture in KPa?  a. 46.8  b. 48.6  c. 84.6  d. 64.8

Last Answer : 84.6

Description : What is the temperature when water and vapor are in equilibrium with the atmospheric pressure?  a. Ice point  b. Steam point  c. Critical point  d. Freezing point

Last Answer : Steam point

Description : At steam point, the temperature of water and its vapor at standard pressure are:  a. Extremes or maximum  b. unity  c. in equilibrium  d. undefined

Last Answer : in equilibrium

Description : What is the temperature when water and vapor are in the equilibrium with the atmospheric pressure?  a. Ice point  b. Steam point  c. Critical point  d. Freezing point

Last Answer : Steam point

Description : ___________ is the percent by weight that is saturated liquid.  a) Quality, x  b) Percent Moisture, y  c) Vapor  c) Liquid

Last Answer : Percent Moisture, y

Description : ___________ is the percent by weight that is saturated vapor.  a) Quality, x  b) Percent Moisture, y  c) Vapor  d) Liquid

Last Answer : Quality, x

Description : _____________ is the difference between the actual temperature of superheated vapor and the saturation temperature for the existing pressure.  a) Degrees of Superheat, °SH  b) Degrees of Sub cooled, °SB  c) Both a and b  d) None of the above

Last Answer : Degrees of Superheat, °SH

Description : __________________ represents the highest pressure and highest temperature at which liquid and vapor can coexist in equilibrium.  a) Critical Point  b) Boiling Point  c) Quality Point  d) None of the above

Last Answer : Critical Point

Description : _________________ is a combination of saturated vapor and saturated liquid.  a) Vapor  b) Saturated Vapor  c) Superheated Vapor  d) Wet Vapor

Last Answer : Wet Vapor

Description : __________________ is a vapor having a temperature higher than the saturation temperature corresponding to the existing pressure.  a) Vapor  b) Saturated Vapor  c) Superheated Vapor  d) Wet Vapor

Last Answer : Superheated Vapor

Description : ___________________ is a vapor at the saturation conditions (saturation temperature and saturation pressure).  a) Vapor  b) Saturated Vapor  c) Superheated Vapor  d) Wet Vapor

Last Answer : Saturated Vapor

Description : _________________ is the name given to a gaseous phase that is in contact with the liquid phase, or that is in the vicinity of a state where some of it might be condensed.  a) Vapor  b) Saturated Vapor  c) Superheated Vapor  d) Wet Vapor

Last Answer : Vapor

Description : Is define as the ratio of the actual pressure of the vapor  a. Relative Humidity  b. Humidity Ratio  c. Dew Point  d. Adiabatic Saturation

Last Answer : Relative Humidity

Description : A vessel with a volume of cubic meter contains liquid water and water vapor ion equilibrium at 600 kPa. The liquid water has mass of1kg. Using the steam table, calculate the mass of the water vapor.  A. 0.99kg  B. 1.57 kg  C ... / kg vg = 0.3157 m^3 / kg Vtot = mƒ vƒ + mg vg mg = (tot-mƒ vƒ) / vg

Last Answer : 3.16 kg

Description : A 10m^3 vessel initially contains 5 m^3 of liquid water and 5 m^3 of saturated water vapor at 100 kPa. Calculate the internal energy of the system using the steam table.  A. 5 x10^5 kJ  B. 8x10^5 kJ  C. 1 ... 3 kJ/kg ug= 2506kJ/kg formula: Mvap = V vap/vg M liq = Vliq/ vƒ u =uƒM liq + ug M vap

Last Answer : 2 x10^6 kJ

Description : The temperature at which the vapor pressure exactly equals one atm is called _________.  a. boiling temperature  b. normal boiling point  c. triple point  d. point of infliction

Last Answer : normal boiling point

Description : On a day when the partial pressure of water vapor remains constant, what happens as the temperature rises?  a. the relative humidity increases  b. the relative humidity decreases  c. the relative humidity remains constant  d. the air would eventually become saturated

Last Answer : the relative humidity decreases

Description : _________is the partial pressure of water vapor at the existing temperature divided by the equilibrium vapor pressure of water at the existing temperature.  a. vacuum pressure  b. relative humidity  c. absolute pressure  d. vapor pressure

Last Answer : relative humidity

Description : Vapor pressure depends only on _________.  a. pressure  b. force  c. volume  d. temperature

Last Answer : temperature

Description : The pressure of the vapor phase of a substance that is in equilibrium with the liquid or solid phase.  a. Phase Pressure  b. Equilibrium Vapor Pressure  c. Specific Pressure  d. Equilibrium Phase Pressure

Last Answer : Equilibrium Vapor Pressure

Description : Which is NOT a correct statement?  A. A superheated vapor will not condense when small amount of heat re removed  B. An ideal gas is a gas that is not a superheated vapor  C. A saturated ... absorb as much heat as it can without vaporizing  D. Water at 1 atm and room temperature is subcooled

Last Answer : An ideal gas is a gas that is not a superheated vapor

Description : Water boils when:  A. Its saturated vapor pressure equals to the atmospheric pressure  B. Its vapor pressure equals 76cm of mercury  C. Its temperature reaches 212 degree Celsius  D. Its vapor pressure is 1 gram per sq. cm

Last Answer : Its saturated vapor pressure equals to the atmospheric pressure

Description : The ratio of the mass of vapor to the total mass of the mixture is called ______.  A. Vapor ratio  B. Vapor content  C. Vapor index  D. Quality

Last Answer : Quality

Description : What is defined as the direct conversion of a substance from the solid to the vapor state or vice versa without passing the liquid state?  A. Condensation  B. Vaporization  C. Sublimation  D. Cryogenation

Last Answer : Sublimation

Description : What refers to the point at which the saturated liquid and saturated vapor states are the same or identical?  A. Triple point  B. Inflection point  C. Maximum point  D. Critical point

Last Answer : Maximum point

Description : A vapor that is not about to condense is called _____ vapor.  A. Saturated  B. Compressed or subcooled  C. Superheated  D. Unsaturated

Last Answer : Superheated

Description : A vapor that is about to condense is called ______ vapor.  A. Saturated  B. Compressed or subcooled  C. Superheated  D. Unsaturated

Last Answer : Saturated

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

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

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

Last Answer : d. compression : tension

Description : As compression ratio increases, thermal n increases. How is thermal n affected by weak and rich mixture strength ?

Last Answer : Thermal n is high for weak mixture and it decreases as mixture strength becomes rich.

Description : If piston displacement is deducted from the total volume of cylinder the remaining volume is known as 1. piston displacement 2. Clearance volume 3. displacement volume 4.compression ratio

Last Answer : ans 2

Description : Knapsack hand compression sprayer covers b. 1-2 ha/day c. 1-3 ha/day d. None of above

Last Answer : Ans-    a. 0.5-1 ha/day.