Why do we need to compress refrigerant?
we need a compressor to compress the vapor to convert it to liquid. At high presser the temperature of the refrigerant increases and reject heat through the condenser. the compressed liquid is expanded to absorve the latent heat of vaporization in the evaporator.
How does a compressor work in a refrigeration system?
In the first stage of the refrigeration cycle, refrigerant enters a compressor as a low-pressure vapor. The compressor compresses the refrigerant to a high-pressure vapor, causing it to become superheated. Once the refrigerant is compressed and heated, it leaves the compressor and enters the next stage of the cycle.
Which type of compressor is best for refrigerator?
reciprocating compressor
What is meant by refrigerating effect?
Refrigeration effect is the amount of heat that each pound of refrigerant retains from the refrigerated space to deliver helpful cooling. In the gas cycle, the refrigeration effect is equivalent to the result of the particular warmth of the gas and the ascent in temperature of the gas in the low temperature side.
How do you increase refrigeration effect?
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.
How can we increase the efficiency of an evaporator?
The steam economy of an evaporator can be improved by adding more effects. The first effect has the highest boiling temperature, while the last effect has the lowest. Each successive effect uses the vapor from the previous effect as a heat source.
How can you increase the efficiency of a refrigeration cycle?
To improve the coefficient of performance, it is to require that compressor work should decrease and refrigerating effect should increase. Modifications in condenser are meant to increase degree of sub-cooling of refrigerant which increased refrigerating effect or more cooling water is required in condenser.
What is the effect of cooling medium on the average refrigeration cop?
The COP can be increased by using water as a cooling medium because water has more heat carrying capacity than air. In this experiment the air cooled condenser of a domestic refrigerator has been replaced by a water cooled condenser.
What is the effect on the Copref as the load is increased Why?
Why? The effect of the condenser temperature is when the load is increase, the temperature also increased. When the more load is added, the more heat is rejected from the system. When more heat is rejected, the temperature is more cooled do to the increases of the load.
How do you calculate refrigeration effect?
Refrigeration Formulas
- Compression Work. Compressor work can expressed as.
- Compression Horsepower. Compression horsepower can be expressed as.
- Compression horsepower per Ton. p = 4.715 / COP (2c)
- COP – Coefficient of Performance. COP = NRE / h (3)
- Net Refrigeration Effect.
- Capacity.
- Compressor Displacement.
- Heat of Compression.
How do you calculate TR on a compressor?
One short ton = 2000 lb, Heat extracted = 2000 x 144/24 hr = 288000 Btu/24 hr = 12000 Btu/hr = 200 Btu/min, 1 ton refrigeration = 200 Btu/min = 3.517 kJ/s = 3.517 kW = 4.713 HP .
What is the refrigeration capacity?
the amount of heat removed from an object to be cooled per unit time by a refrigerating machine. Refrigerating capacity is measured in watts or in kilocalories per hour. The refrigerating capacities of present-day refrigerating machines range from several hundred watts to ten or more megawatts. …
What is a good cooling capacity?
Air Conditioner Cooling Needs Calculator
| Area to be Cooled (Square Feet) | Capacity Needed (BTUs per Hour) |
|---|---|
| 450 to 550 | 12,000 |
| 550 to 700 | 14,000 |
| 700 to 1000 | 18,000 |
| 1000 to 1200 | 21,000 |
How do you calculate cooling capacity?
Using the energy equation of Q = ṁ x Cp x ΔT we can calculate the cooling capacity. We add 273.15K to the celcius to convert it to units of Kelvin. The Specific heat capacity (Cp) is measured in units of kJ per kg per Kelvin. This gives us a final answer of Q = 2,500kW of cooling.
How many BTUs do I need for a 1000 sq ft garage?
Calculating the number of BTUs needed to heat an area For example, a 300 square foot room typically requires 7,000 BTUs to maintain a comfortable temperature, while a 1,000 square foot room requires 18,000 BTUs.