Cooling unit cooling capacity calculation formula

Calculation formula for cooling capacity and water flow of chillers

How to choose the most suitable chiller industrial chillers and small group does, in fact, there is a very simple formula: = cooling capacity of chilled water temperature difference × coefficient × 4.187 ×

1. The chilled water flow refers to the cold water flow required for the operation of the machine, and the unit needs to be converted into liters per second;

2. The temperature difference refers to the temperature difference between the inlet and outlet of the machine;

3. 4.187 is quantitative (specific heat capacity of water);

4. When choosing an air-cooled chiller, multiply the factor by 1.3, and select a water-cooled chiller to multiply by a factor of 1.1.

5. Select the appropriate machine model based on the calculated cooling capacity.

It is customary to use P (pound) to calculate how much chiller should be used, but the most important thing is to know the rated cooling capacity. If the air-cooled 9.07KW looks like a 3P machine, and so on. Therefore , the most important choice for the selection of industrial chillers is to determine the rated cooling capacity.

(2) Formula for calculating the cooling capacity of chiller

The calculation method of chiller cooling capacity, chiller cooling principle, 20kw can be calculated:

1: volume (liter) × liter temperature ÷ heating time (minutes) × 60 ÷ 0.86 (coefficient) = (w)

2: volume (ton or cubic meter) × liter temperature ÷ when heating (time) ÷ 0.86 (coefficient) = (kw)

Your data is calculated with the chiller cooling capacity. The chiller cooling principle can be used for 4 hours 10000l × (15-7) ÷ 4h ÷ 0.86 = 23255w = 23.255kw 5 hours 10 tons × (15-7) ÷ 5h ÷ 0.86=18.604kw

(3) Several common cooling capacity calculation formulas for chillers

1. Temperature difference flow method Q = Cp × r × Vs × △ T

Q: heat load (KW) Cp: constant pressure specific heat (KJ/kg.°C)...4.1868 KJ/kg.°C

r: specific weight (Kg/m3)...1000 Kg/m3 Vs: water flow rate (m3/h) Example: 5.1 m3/h

△T: water temperature difference (°C)...△T=T2 (in and out temperature)-T1 (inlet water temperature) Example:=5°C

Example: Q=Cp.r.Vs.△T=4.1868×1000×5.1×5/3600=29.6565(kw)

When the known cooling capacity is 29.8kw, the temperature difference is 5 degrees, and the specific heat is 4.1868, the water flow rate can also be calculated = 29.8*3.6/(4.1868*5)=5.1247

2. Time rise method Q = Cp × r × V × △ T / H

Q: heat load (KW) Cp: constant pressure specific heat (KJ/kg.°C)...4.1868 KJ/kg.°C

r: specific weight (Kg/m3)... 1000 Kg/m3

V: total water volume (m3) Example: 0.5 m3

△T: water temperature difference (°C)...△T=T2-T1 Example:=5°C H: time (h) Example: 1h

Example: Q= Cp.rV△T/H=4.1868×1000×0.5×5/3600=2.908(kw)

3. Energy conservation method

Q = W in - W out

Q: heat load (KW)

W input: input power (KW) Example: 8KW W output: output power (KW) Example: 3KW

Example: Q=W in-W out=8-3=5(kw)

4. Commonly used method for selecting chillers for chillers : Q = W × C × △ T × S

Q= is the required frozen water energy kcal/h

W = plastic raw material weight KG / H Example: W = 31.3KG / H

C = specific heat of plastic raw material kcal / KG ° C Example: polyethylene PE C = 0.55 kcal / KG ° C

△T= is the temperature difference between the melting temperature and the product mold °C is generally (200 ° C)

S = is the safety factor (take 1.35-2.0) generally takes 2.0

Example: Q=W*C*â–³T*S=31.3*0.55*200*2.0=6886(kcal/h)