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How To Calculate The Cooling Capacity Of Chiller?

Apr 10, 2017

A, the conversion of a variety of refrigeration units are as follows:

1, 1 kcal / h (kcal / h) = 1.163W, 1 W = 0.8598 kcal / h;

2, Btu / h (/ h) = 0.2931W, 1 W = 3.412 Btu / h;

3, 1 USRT (US ton) = kW = = 0.28434 kW = 3.517 USRT;

4, 1 kcal / h = Btu / h, 1 Btu / h = 0.252 kcal / h;

5, USRT = 3024 kcal / h, 10000 kcal / h = = 3.3069 USRT;

6, 1 = 2.5 kW (for air-cooled units), 1 (kW = 3 for water-cooled unit)


B, refrigeration equipment selection formula:

1, through the cooling water (oil) inlet and outlet temperature difference to calculate calorific value

Q = SH * De * F * / 60 DT

Q: calorific value KW

SH: specific heat ratio of hot water is 4.2KJ/Kg*C (4 thousand and 200 MJ / kg * C). The specific heat of the oil is 1.97KJ/Kg*C (1 thousand and 970 MJ / kg * C).

De: specific gravity 1Kg/L (1 kg / L) oil specific gravity 0.88Kg/L (0.88 kg / L)

F: flow LPM (L/min L / min)

DT: cooling water (oil) inlet and outlet temperature difference (outlet temperature - inlet temperature)

Note: "/ 60" is used to increase the flow rate / min to L / S; 1kW = 1kJ/s;

Example 1: cooling water inlet is 20 degrees, water is 25 degrees, flow rate of 10 L / min

Calorific value Q = 4.2 * 1 * * (25-20) / 60 = 3.5KW

Select the cold water chiller can be appropriately increased 20%-50% can choose AYD-02 HP

Example 2: cooling oil inlet is 25 degrees, water is 32 degrees, flow rate of 8 L / min

Calorific value Q = 1.97 * 0.88 * * (32-25) / 60 = 1.62KW

Select the cold oil cooling capacity can be appropriately increased 20%-50% can choose AYD-01 HP

2, through the water (oil) temperature calculation of heat Shenglai box

Q = SH * De * V * / 60 DT

Q: calorific value KW

SH: specific heat ratio of hot water is 4.2KJ/Kg*C (4 thousand and 200 MJ / kg * C). The specific heat of the oil is 1.97KJ/Kg*C (1 thousand and 970 MJ / kg * c)

De: specific gravity 1Kg/L (1 kg / L) oil specific gravity 0.88Kg/L (0.88 kg / L)

V: water capacity L (L) including the water tank and the total water capacity of the pipeline

DT: water (oil) maximum temperature rise in one minute

Note: "/ 60" is used to convert the Wen Sheng degree / minute to Celsius / sec; 1kW = 1kJ/s;

Note: when measuring, the temperature of the water (oil) tank should be slightly lower than the ambient temperature.

Example: tank volume 1000L maximum water temperature 0.2 degrees / min

Calorific value Q = 4.2 * 1 * 1000 * 0.2 / 60 = 14KW

Select the cold water chiller can be appropriately increased 20%-50% can choose AYD-05HP or AYD-06HP

3, through the power of the equipment, calorific value estimation

A, such as for spindle cooling, according to the spindle motor power of 30% to estimate the cooling capacity of the cooling unit.

Example: 7.5KW motor, with 2.2kW or 2.8KW cooling capacity of refrigeration units, you can choose AYD-01 HP;

B, injection molding machine according to 80T clamping force =1HP, 1HP=3KW cooling capacity estimation

Example: injection molding machine model: MA1200/370, clamping force is 1200T, 1200/80=15. AYD-15HP can be used for cold water chiller, chiller is 47KW.

molding machine chiller


C, cold water machine how to choose: we hope to buy cold water machine is helpful. First of all, we have to find out which types of chillers are divided into: general manufacturers, will produce two kinds of water and air cooling.

1, air-cooled chiller, in which the body contains a thermal insulation water tank and pump, no need to add cooling towers to heat. Installation and movement is very convenient. However, it requires a higher working environment, first, because it is to cool the hot air circulation, so if the installation of the ventilation effect is not good, it will directly affect the cooling effect of the chiller. In addition, if you want to put cold water machine in the humidity requirements of the dust-free workshop, then I advise you to modify the water cooling. Because of air-cooled chillers, water vapor will be set at the top of the heat.

2, water-cooled chiller, can be divided into open, sealed (some known as the box type) and screw type. First of all, to declare that water-cooled chillers are to be installed in addition to cooling towers and pumps, for the extraction of hot water cooling. To achieve good cooling effect.

3, open type cold water machine, but also with a water tank. It doesn't have to be sealed, because he has a water tank in itself. Open general will be installed in the workshop somewhere, he convenient maintenance, but because is not beautiful, therefore it has a sealed water cooling type cold water machine, because it is a structure of the box, so popular. But if you are on the refrigerating capacity requirements are very large, it is necessary to choose a screw type cold water machine, then we will call the chiller, most of the manufacturers, if you of the chiller compressor is required to reach above 60HP, they will recommend that you use the screw type refrigerator.

4.Chiller selection warm tips:

First, the standard cold water temperature difference of 5 degrees, (down to 20 degrees Celsius), if a AYD-10HP of cold water chiller per hour standard flow rate of 3.5 cubic meters of water.

Secondly, so when you try this cold water machine not only chiller flow, but also see how much you need if you try the temperature, temperature is from 28 degrees down to 7 degrees, if you try cold water machine, large temperature difference, it will reduce the flow of cold water per hour. From 3.5 cubic meters reduced to 1 parties. So what you want is 3.5 cubic meters per hour, you have to choose a larger model.

Finally, in the trial of the chiller, to see you are a direct or indirect cooling, cooling, cooling water is directly put directly into the cold water machine, cold water directly out of the products you need inside cooling, so the effect will be better, so the indirect cooling like put water in a pot, the pot in the above put a small basin, a small pot inside to cool the product, so the effect will certainly be worse, when you choose the machine, must consider this problem to affect the size of.


D, the selection of industrial chillers / oil cooler selection:

1, the cooling capacity of industrial chillers and environmental temperature and outlet temperature of different surface changes;

2, the actual heating capacity of the equipment will be different because of different parts, mold, parameters, etc.;

3, the use of cold water after the temperature drop, connecting pipes, water tanks, fuel tanks, mold, spindle, the surface temperature of the device will be lower than the ambient temperature, so the absorption of heat will lead to increased load;

4, in the actual application of industrial cooling in many cases can not be accurately calculated using the above method, this can only be estimated by empirical data, similar equipment analogy method.

5, any calculation methods are likely to appear deviation, so that the actual use of the chiller is too large or too small, so the above method for reference only.