The coefficient of performance, COP, of a refrigerator is defined as
the heat removed from the cold reservoir Q
cold
, (i.e. inside a refrigerator) divided by the work W done to remove the heat
(i.e. the work done by the compressor). The COP strongly depends on outside temperature and required indoor temperature.
What is the formula of coefficient of performance?
COP (Coefficient of Performance)
For example: A given heat pump used for air cooling has a
COP = 2
. This means that 2 kW of cooling power is achieved for each kW of power consumed by the pump’s compressor.
What is coefficient of performance of refrigerator Class 11?
Refrigerators will be throwing the heat taking from the T2 (Storage Space) to T1(Room or any exhaust at higher temperature).
COP = (Heat taken from the Storage Space)/ (Work Input) = Q2/W, where W in work input
. applying the reversible refrigerator theory, Q can be replaced by temperature (100% Second Law Efficiency).
What is the coefficient of performance K of the Carnot refrigerator?
To do this conversion, we’ll take our temperatures in degrees Celsius and add 273.15 to it to create a temperature in Kelvin. We do this for both, the cold and the hot temperature. And when we calculate this fraction, we find it’s equal to
0.58
. That’s the coefficient of performance of this Carnot refrigerator.
What is the formula of efficiency of refrigerator?
The efficiency is
e = W/Q
high
. Details of the calculation: Q
high
= 360 J. W = 25 J.
Is coefficient of performance greater than 1?
The coefficient of performance (COP) of
refrigeration is always more than 1
. Hence option (a) is correct. COP is the ratio of heat extracted from the refrigerator to the work done on the refrigerant. It is also called by the name Theoretical coefficient of performance.
What is refrigerator in physics class 11?
A refrigerator works on
the principle of the second law of thermodynamics
. This law is related to the extraction of heat from a body i.e. to lower the temperature of the body. … Hence, a refrigerator is a device which works on the principle that evaporation of a liquid gives a cooling effect.
What is a good coefficient of performance?
A good COP for heat pump units starts at
about 2.0 for an air source heat pump
and about 3.1 for geothermal, but heat pump COP can be well above 4.0 too, as seen in the chart below. A geothermal heat pump is also called a ground source heat pump.
Is coefficient of performance of a refrigerator constant?
Is the COP constant?
No
, the COP strongly depends on outside temperature and required indoor temperature.
What is relative coefficient of performance?
Explanation : The
ratio of the actual C.O.P to the theoretical C.O.P.
is known as relative coefficient of performance. The relative coefficient of performance is equal to (Actual C.O.P.) /(Theoretical C.O.P.)
Are refrigeration cycle is used in?
Explanation: Gas liquefaction is physical conversion of a gas into a liquid state (condensation). The liquefaction of gases is a complicated process that uses various compressions and expansions to achieve high pressures and very low temperatures. Air refrigeration cycle is used in
gas liquefaction process
.
How would you increase the coefficient of performance of an ideal refrigerator?
How would you increase the coefficient of performance of an ideal refrigerator?
Decrease the outside temperature
. Because it is impossible for even a perfect engine to convert heat entirely into mechanical work.
Are heat engines reversible?
The work done by the reversible heat engine is
equal to the heat input minus the heat output
, i.e. The first law of thermodynamics states that the total work done by the system must be equal to the heat supplied by the reservoir, i.e. where the equality holds for a reversible process.
Which cycle is used in refrigeration?
The vapor-compression refrigeration
is the most widely used cycle for refrigerators, air- conditioners, and heat pumps.
Can COPs be less than1?
Coefficient Of Performance (COP) is the ratio of “Coldness” produced to the “Heat” or ” Work” supplied. …
COP can be less than 1
. Usually,COP is more than 1 for VCRS which is actually desirable since VCRS uses high grade electrical energy as the energy input!!…
What is the working principle of refrigerator?
Refrigerators work by
causing the refrigerant circulating inside them to change from a liquid into a gas
. This process, called evaporation, cools the surrounding area and produces the desired effect. … As it evaporates, you should feel a chilling sensation – the same basic principle gives us safe food storage.
