1. Optional Industrial Chiller
According to the resistance losses of R, Q0, t0, tk, liquid lines and valve parts, the steps are as follows: Determine the pressure difference between the two ends of the expansion valve; Determine the form of the valve; Select the type and specification of the valve. 1, determine the pressure difference between the two ends of the valve: ΔP = PK-ΣΔPi-Po (KPa) Where: PK - condensing pressure, KPa, ΣΔPi - is ΔP1 + ΔP2 + ΔP3 + ΔP4 (ΔP1 is the resistance loss of the liquid pipeline; ΔP2 is the resistance loss of the elbow, valve, etc.; ΔP3 is the pressure loss of the liquid pipe rise, ΔP3=ρɡh; ΔP4 is the resistance loss of the liquid separation head and the liquid separation capillary, usually 0.5bar); Po—evaporation pressure ,KPa. Industrial Chillers
2. determine the form of the valve:
The choice of internal or external balance depends on the pressure drop in the evaporator. For R22 systems, when the pressure drop exceeds the corresponding evaporating temperature by 1°C, an externally-balanced thermal expansion valve should be used.
3. choose the valve model and specifications: frequency chiller
According to Q0 and calculated ΔP and evaporating temperature before and after the expansion valve t0 from the relevant table to find the type of valve and valve capacity. In order to simplify the matching procedures, technical measures may be used. The model and specifications of the thermal expansion valve must be based on the type of refrigerant used in the refrigeration system, the range of evaporation temperature, and the heat load of the evaporator. When carrying out the selection, the following requirements shall be met: Screw chiller
(1) The capacity of the selected thermal expansion valve is 20-30% greater than the actual heat load of the evaporator;
(2) When selecting the thermal expansion valve, the pressure drop of the fluid supply line should be calculated to obtain the pressure difference between the valve and the valve. Then the specification of the thermal expansion valve is determined according to the expansion valve calculation capacity table provided by the manufacturer. ="white-space:normal;">;

(3) For refrigeration systems that do not have a cooling water control valve or cold winter cooling water, When selecting a thermal expansion valve, the capacity of the valve should be 70-80% greater than the evaporator load, but the maximum should not exceed 2 times the evaporator heat load.

first, Industrial Chillers installation
1. Check whether it is intact before installation, especially the part of temperature sensing mechanism;
2. The installation location must be close to the evaporator. The valve body should be installed vertically. It can not be tilted or installed upside down; Freezer
3. When installing, care should be taken to keep the temperature of the temperature sensing mechanism within the temperature sensing package. Therefore, the temperature sensing package should be installed lower than the valve body.

4. temperature package must not be placed on the pipeline with fluid;
5. The temperature-sensing package should be installed on the return pipe of the evaporator's outlet level as far as possible. It should generally be more than 1.5m away from the suction port of the compressor;

6. temperature sensor package is usually placed on the evaporator return pipe, and close to the wall tightly packed, the contact area should be cleaned and exposed metal oxide color;

7. If the evaporator outlet has a gas-liquid exchanger, it is generally packaged at the outlet of the evaporator, ie before the heat exchanger;

8. when the return pipe diameter is less than 25mm, the temperature package can be tied in the top of the return pipe; when the diameter is greater than 25mm, can be tied in the lower side of the return pipe 45 °, to prevent the bottom of the pipe accumulation of oil and other factors, affecting Wen Bao's correct temperature.
Second, Industrial chiller debugging
1. Set a thermometer at the evaporator outlet or use suction pressure to check the superheat;
2. When the superheat is too small (too much liquid supply), the adjustment lever rotates half circle or one circle clockwise (that is, increases the spring force and decreases the valve opening), when the refrigerant flow decreases; the adjustment rod thread rotates once The number of turns should not be too much (one turn of the adjusting rod thread, the superheat degree changes by about 1-2°C), and after many adjustments until the requirements are met;

3. Experience adjustment method: Turn the adjusting rod thread to change the opening of the valve so that the evaporator return pipe just happens to be frosted or dew condensation. For a refrigerating device with an evaporating temperature less than 0°C, if it is touched after frosting, there is a feeling of coldness that sticks the hands, and the opening degree is appropriate. When the evaporating temperature is above 0°C, condensation can be considered as condensation. Judgment.

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