Why Carnot is not possible?
Carnot cycles are not encountered in reality since achieving isothermal heat transfer is very difficult (needs very large heat exchangers and long time). Also process 3-4 requires a pump or compressor that can handle two phase mixture (liquid and vapor) which is impractical.
How does Carnot refrigerator work?
A refrigerator or a heat pump that operates on the reversed Carnot cycle is called a Carnot refrigerator or a Carnot heat pump. The basic idea behind a household refrigerator is simple: it uses the evaporation of the refrigerant to absorb heat from the cooling space in the refrigerator.
What is Carnot ideal refrigerator?
An ideal Carnot’s refrigerator is completely opposite to the Carnot engine that extracts heat from a hotter body to produce work and rejects heat to the cooler body.
What is COP in Carnot cycle?
The efficiency of a refrigerator or heat pump is given by a parameter called the coefficient of performance (COP). is the useful heat supplied or removed by the considered system.
How is Carnot police refrigerator calculated?
At an average temperature of −19°C, the COP for a Carnot refrigerator would be (273 − 19)/(25 − (-19)) = 5.772. Since the COP = Qc/W, the minimum work can be calculated as W = Qc/COP = 1,604/5.772 = 184.3 kJ. Thus, the total work is 685 + 184.3 = 869.3 kJ/kg.
How efficient is a chiller?
In general, centrifugal chillers with variable speed drives can typically see a 10 percent to 13 percent efficiency gain for every 5 degrees of condenser water temperature relief. Constant speed chillers also benefit, but only about 5 percent efficiency gain for every 5 degrees of chilled water relief.
How much does a 100 ton chiller cost?
Air-cooled chiller costs vary by manufacturer, location, and technology options. A survey of the major manufacturers shows an average cost for the chiller itself of approximately $350 to $1,000 per ton, depending on capacity (see Table 2).
What is Chiller EER?
The EER is the relationship between the cooling capacity of chiller and the total power consumption of the refriger- ation unit (compressors + fans). This chart above refers to an air cooled chiller with R-134A refrigerant, with inlet wa- ter temperature of 12°C and outlet water temperature of 7°C.
What is EER in refrigeration?
A room air conditioner’s efficiency is measured by the energy efficiency ratio (EER). The EER is the ratio of the cooling capacity (in British thermal units [Btu] per hour) to the power input (in watts). The higher the EER rating, the more efficient the air conditioner.
What is meant by EER?
EER or Energy-Efficiency Ratio is an energy performance rating for, primarily, cooling devices. Definition: EER rating provides you with a ratio of useful cooling output (in BTU/h) to electricity input (measured in W).
How do you convert EER to kW?
Electric motor driven chillers are rated in kilowatts per ton cooling.
- kW/ton = 12 / EER.
- kW/ton = 12 / (COP x 3.412)
- COP = EER / 3.412.
- COP = 12 / (kW/ton) / 3.412.
- EER = 12 / (kW/ton)
- EER = COP x 3.412.
What is EER in HVAC?
The Energy Efficiency Ratio (EER) of an HVAC cooling device is the ratio of output cooling energy (in BTU) to input electrical energy (in watts) at a given operating point. EER is normally calculated with a 95 °F outside temperature and an inside (return air) temperature of 80 °F and 50% relative humidity.