Does ideal vapor compression refrigeration cycle involve any internal irreversibility? Notes: The ideal compression refrigeration cycle is
not an internally reversible cycle
, since it involves throttling which is an irreversible process.
Does that ideal vapor-compression refrigeration cycle?
In an ideal vapor-compression refrigeration cycle, the refrigerant enters the compressor as a saturated vapor and is cooled to the saturated liquid state in the condenser. It is then throttled to the evaporator pressure and vaporizes as it absorbs heat from the refrigerated space.
What are the assumptions for an ideal vapor-compression refrigeration cycle?
Also, we have to make some assumptions for ideal vapor-compression cycle:
Irreversibilities within the evaporator, condenser and compressor are ignored
. No frictional pressure drops. Refrigerant flows at constant pressure through the two heat exchangers (evaporatorand condenser)
What is the difference between ideal and actual Vapour compression cycle?
Which equipment is involved in the ideal vapor-compression refrigeration cycle?
The Vapor Compression Refrigeration Cycle involves four components:
compressor, condenser, expansion valve/throttle valve and evaporator
.
Which part of the vapor-compression refrigeration cycle produces the refrigeration effect?
The evaporator
produces the cooling or refrigerating effect.
How does vapor-compression refrigeration work?
The Vapor Compression Refrigeration Cycle
As the refrigerant circulates through the system, it is alternately compressed and expanded, changing its state from a liquid to a vapor
. As the refrigerant changes state, heat is absorbed and expelled by the system, lowering the temperature of the conditioned space.
What is ideal vapor compression?
The ideal vapor-compression refrigeration cycle
involves an irreversible (throttling) process to make it a more realistic model for the actual systems
. Replacing the expansion valve by a turbine is not practical since the added benefits cannot justify the added cost and complexity.
Which one of the following is not an assumption in theoretical Vapour compression cycle?
4. Which one of the following is not an assumption in theoretical vapour compression cycle? Explanation:
There are no mechanical or fluid friction losses
, is one of the assumptions made in theoretical vapor compression cycle.
Which ideal heat engine cycle is the vapor-compression refrigeration system based on?
More details. An ideal refrigeration cycle looks much like a
reversed Carnot heat engine or a reversed Rankine cycle heat engine
. The primary distinction being that refrigeration cycles lack a turbine, using a throttle instead to expand the working fluid.
Is the ideal vapor compression cycle reversible?
The ideal compression refrigeration cycle is
not an internally reversible cycle
, since it involves throttling which is an irreversible process.
What is an ideal vapor?
Analysis (a) In an ideal vapor-compression refrigeration cycle, the compression process is isentropic,
the refrigerant enters
.
the compressor as a saturated vapor at the evaporator pressure, and leaves the condenser as saturated liquid at the condenser
.
pressure
.
Why do we study the reversed Carnot cycle even though it is not a realistic model for refrigeration cycles?
As reverse Carnot cycle has highest possible COP of a refrigeration cycle or it is a ideal refrigeration cycle. hence we study reverse Carnot cycle
to compare COP of the other realistic refrigeration cycle with it
.
What are the four major components of a vapor compression refrigeration system?
3.4. 2 Vapor compression refrigerators. A detailed description of the vapor compression refrigeration is available in any basic thermodynamics textbook. All vapor compression refrigerators are made of four main components:
a compressor, a condenser, an expansion orifice, and an evaporator
.
Which is not the main part of Vapour compression system?
Compressor the
process equipment
is usually not used during the vapour compression refrigeration system and absorption compression refrigeration system.
What are the advantages and disadvantages of vapor compression refrigeration system over air refrigeration system?
- Size is small when compared to an air refrigeration system for a given capacity of refrigeration.
- Volume of refrigerant circulated is low. …
- High coefficient of performance.
- The operating temperature range is huge.
In which stage the heat is rejected by the refrigerant in vapour compression refrigeration cycle?
Solution. During refrigeration cycle, heat is rejected by the refrigerant in
the condenser
. Explanation: In the condenser, the heat is rejected by the refrigerant into the atmosphere, and then the refrigerant goes to the expansion valve.
What is a Vapour compression refrigeration system discuss the conditions to improve the performance of the Vapour compression refrigeration system?
What is simple Vapour compression refrigeration system?
What components in a compression refrigeration system maintain the pressure difference in the system?
To maintain the difference in pressure between the condenser and the evaporator caused by the compressor,
an expansion valve
is needed in the cycle. The expansion valve separates the high-pressure part of the system from the low-pressure part. Only a small trickle of refrigerant liquid flows through the valve.
Which of the following is not an advantage of vapour compression refrigeration system?
Which of the following is not an advantage of vapor compression refrigeration system over air refrigeration system? Explanation: In vapor compression refrigeration system the
prevention of leakage of the refrigerant
is a major problem.
Which of the following best describes the process of vapour compression refrigeration *?
Which of the following best describes the process of vapour compression refrigeration? Explanation: In vapour compression refrigerator,
warm air is first evaporated and then passed into a compressor
. This compresses the vapour which is then passed through a condenser to obtain a liquid.
Why the wet compression in vapour compression refrigeration systems are avoided?
Why refrigeration cycle is commonly called reversed heat engine?
Reversed cycles are used either
to extract heat from bodies colder than the surroundings
(cooling effect), referred to as refrigeration cycles, or to heat spaces by extracting heat from low-temperature sources (heating effect), called heat pump cycles.
Which of the following components is the reverse Carnot cycle?
Explanation: The reversed Carnot cycle has 4 processes namely,
isothermal compression process, isentropic compression process, isentropic expansion process and isothermal expansion process
.
What is the reverse Rankine Cycle?
An ideal thermodynamic cycle consisting of heat addition at constant pressure, isentropic expansion, heat rejection at constant pressure, and isentropic compression
; used as an ideal standard for the performance of heat-engine and heat-pump installations operating with a condensable vapor as the working fluid, such as …
What is Carnot’s ideal refrigerator?
How does cooling occur in a direct expansion vapor-compression refrigeration system?
During which component of Vapour compression refrigeration system the enthalpy remains constant?
How do you create a vapor compression cycle?
Which of the following is an example of a reversed Carnot cycle?
A refrigerator
operates on Reversed Carnot cycle. What is the power required to drive the refrigerator between temperatures of 42°C and 4°C, if heat at the rate of 2 kJ/s is extracted from the low-temperature region? Q4.
What is the coefficient of performance of the refrigeration system working on reversed Carnot cycle?
What are the difference between actual and theoretical COP?
theoretical COP is greater than the actual COP for all cases
. Also Fig. (4) shows that the values of COP increases when the system was charging by the compositions of S 2 , S 3 and S 4 about 19.1%, 11.6% and 7.3% respectively in comparison with of S 1 . … … of Performance (COP) Fig.
Which of the following is not the difference between theoretical and actual VCR?
1. Which of the following is not the difference between theoretical and actual VCR cycle? Explanation: Entropy is the randomness of molecules.
Change in entropy cannot be kept constant
.
What is simple vapour compression cycle?
The vapour compression cycle
relies on the condensation temperature increasing with increase in pressure
. A vapour from the evaporator when compressed will condense at a higher temperature, corresponding to the new higher pressure.
What is Bell Coleman cycle?
The Bell Coleman Cycle (also called as the Joule or “reverse” Brayton cycle) is
a refrigeration cycle where the working fluid is a gas that is compressed and expanded, but does not change phase
. Air is most often this working fluid.
