Table of Contents
What is the formula of refrigeration effect?
i = isentropic. m = refrigerant flow, kW. W = work of compression, kW.
How do you calculate the cooling effect of a refrigerator?
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 refrigerant flow rate?
Basic Calculations
- Refrigerant mass flow rate (kg/s) (9.6) r = Q e / h 1 − h 4.
- Compressor isentropic power (kW) (9.8) r h 2 − h 1.
- Heat rejected in condenser (kW) (9.9) h 2 − h 3.
How is refrigerator COP calculated?
For a refrigerator the coefficient of performance is COP = Qlow/(-W). Details of the calculation: (a) COP = Qlow/(-W). (-W) = Qlow/COP = 120/5 J = 24 J.
How is refrigerant number calculated?
Divide the quantity of refrigerant that the heat pump moves by the time it takes to move it. If it pumps 3.6 kilograms of refrigerant in 10 seconds: 3.6 / 10 = 0.36 kilograms per second. Divide the answer to step 1 by the answer to step 2: 51.2 / 0.36 = 142.2 kilojoules per kilogram.
How do I calculate freezer cooling capacity?
Q = changes x volume x energy x (Temp out – Temp in ) / 3600
- Q = kWh/d.
- changes = number of volume changes per day.
- volume = the volume of the cold store.
- energy = energy per cubic meter per degree Celsius.
- Temp out is the air temperature outside.
- Temp in is the air temperature inside.
- 3600 is just to convert from kJ to kWh.
What is the COP formula?
COP is defined as the relationship between the power (kW) that is drawn out of the heat pump as cooling or heat, and the power (kW) that is supplied to the compressor. For example: A given heat pump used for air cooling has a COP = 2.
How do you calculate police?
Coefficient of Performance: This coefficient of performance (COP) calculator calculates the ratio of heating or cooling provided to work required. The most basic formula to COP is Q/W, where Q is the heat supplied to or removed from the reservoir and W is the work done by the heat pump.
How do you calculate refrigerant charge in a refrigeration system?
The refrigerant charge is obtained by multiplying the density of gas (ρg) and liquid (ρl) refrigerants by integral along length of the tube. The calculation of refrigerant charge in the low pressure tubes is the same as that in high-pressure tube, which includes the refrigerant charge of A/D (mA/D).
What is the dryness fraction of refrigerant?
Dryness fraction of Refrigerant to be compressed at entrance of compressor. It has to be increased, as dryness fraction denotes the amount of vapour refrigerant present in mixture of liq and dry vapour refrigerant. Dryness fraction can be increased by using a superheating the vapour refrigerant before entering the compressor.
How to calculate the dryness fraction of steam from calorimeter?
Formula: The dryness fraction of steam from separating and throttling calorimeter is calculated by the equation: x = x1. x2 where, x1 = Dryness fraction of steam measured by separating calorimeter, x2 = Dryness fraction of steam measured by throttling calorimeter
What is the minimum dryness fraction required for superheating?
For example, the wet steam at 40 bar pressure requires minimum 93.5\% dryness fraction before throttling to reach 5°C superheating at pressure slightly above atmospheric pressure after throttling (the minimum dryness fraction required for 40 bar pressure can be find by a process ‘1-2’ as shown in Fig. 26.2).
How can we reduce the amount of refrigerant in a compressor?
It can be reduced by using a sub cooler. Dryness fraction of Refrigerant to be compressed at entrance of compressor. It has to be increased, as dryness fraction denotes the amount of vapour refrigerant present in mixture of liq and dry vapour refrigerant.