The coefficient of performance or COP (sometimes CP or CoP) of a heat pump, refrigerator or air conditioning system is a ratio of useful heating or cooling provided to work (energy) required . Higher COPs equate to higher efficiency, lower energy (power) consumption and thus lower operating costs.
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. ... Therefore, the produced heat and the supplied power employ the same units during COP calculation.
What is tonne of refrigeration and coefficient of performance?
1 TR is defined as the heat removal rate so as to freeze 1 ton (1000 kg) of water at 0°C into ice at 0°C in twenty-four hours. In actual practice, one TR is equivalent to 210 kJ/min or 3.5 kJ/s.
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 a good coefficient of performance?
Test results of the best systems are around 4.5 . When measuring installed units over a whole season and accounting for the energy needed to pump water through the piping systems, seasonal COP’s for heating are around 3.5 or less. This indicates room for further improvement.
Can coefficient of performance be greater than 1?
COP of refriegeration is always greater than one . 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.
How is ikW TR calculated?
Performance Assessment Of Chiller
Main performance parameter is ikW/TR and it is define by ratio of power input to compressor divided by tons of cooling produced . Lower ikW/TR indicates higher efficiency. COP (Co – efficient of Performance) is define by ratio of EER by 3.413.
How can coefficient of performance be improved?
To improve the coefficient of performance, its requires that the compressor work should decrease and refrigeration effect should increase . It means that decrease in condenser pressure and temperature so the refrigeration effect will increase and compressor input work due to this cop will increase.
What is SI unit of refrigeration?
Explanation: KJ/s or KW is the S.I. unit of refrigeration, which is converted to Tonnes as commercial unit.
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 the relation between coefficient of performance and efficiency?
Coefficient of Performance (COP) is the efficiency ratio of the amount of heating or cooling provided by a heating or cooling unit to the energy consumed by the system . The higher the Coefficient of Performance the more efficient the system.
Can the coefficient of performance be smaller than 1?
Coefficient Of Performance (COP) is the ratio of “Coldness” produced to the “Heat” or ” Work” supplied. In the case of vapour compression system, it is the mechanical or electrical work , which is the Input to the machine. ... So, the answer to your query is that, yes, the COP can be less than 1 .
What is the relative coefficient of performance?
Relative coefficient of performance
A cooling system usually has heat loss during the operation. So its C.O.P is always slightly different from its theoretical C.O.P., the new C.O.P. is known as Actual C.O.P. Relative coefficient of performance defined as the ratio of actual C.O.P. to the theoretical C.O.P.
What is a good COP value?
Air source heat pumps tend to be less efficient, and a COP over 3 is considered good . Comparing different air source heat pumps, it is worth bearing in mind that a heat pump with a higher CoP / SPF will cost more, and the same is true when comparing ground source heat pumps with one another.
Why COP of heat pump is more than refrigerator?
The heat rejected to the hot sink is greater than the heat absorbed from the cold source , so the heating COP is 1 greater than the cooling COP. applies to heat pumps and applies to air conditioners or refrigerators.
What is the maximum coefficient of performance?
Maximum Coefficient of Performance
is the temperature of the environment to which the heat is dispelled to . is the temperature of the space to cool off. is the maximum coefficient of performance.
