How to save energy in the operation of air conditioning refrigeration units? Regarding this point, I believe everyone is particularly eager to know. In fact, operators of refrigeration units often cause the operating parameters of the units to deviate due to a large number of misoperations, artificially increasing the operating costs of the units. In the operation of air conditioning refrigeration units, the systems that are more prone to misoperations are the chilled water system, cooling water system, cooling tower system, etc. Therefore, today we will introduce energy conservation in the operation of air conditioning refrigeration units from the operation of the chilled water system.

Air conditioning refrigeration units

The operation of air conditioning refrigeration units is all under standard working conditions, that is, what we often say: the return water temperature of chilled water is 12°C, the supply water temperature is 7°C 4, and the temperature difference is 15°C. For the same air conditioning refrigeration unit, if its operating conditions remain unchanged and the external load is certain, the refrigeration capacity of the unit is also certain. At this time, the water supply through the evaporator of the unit is inversely proportional to the temperature difference between the supply and return water. That is to say, the larger the chilled water flow, the smaller the temperature difference. Conversely, the smaller the flow, the larger the temperature difference. The working condition of the air conditioning refrigeration unit is specified as a 5°C temperature difference in the chilled water supply, which is actually the specified chilled water flow. The control of the chilled water flow is manifested in: controlling the pressure drop of water through the evaporator to be positioned at 0.5kg/cm under standard working conditions.

In the operation of the chilled water system of the air conditioning refrigeration unit, the operator should strictly adjust the pressure drop of the chilled water inlet and outlet according to the operating parameters of the unit. Many operators will adjust the pressure drop higher than the operating parameters. Once the pressure drop is too high, instead of closing the outlet valve of the chilled water pump, they open the inlet and outlet valves of the evaporator of another refrigeration unit that is not in operation and discharge excessive water to reduce the pressure drop. Such an operation leads to an artificially increased operating current of the water pump, resulting in waste of electricity.

Also, when starting the refrigeration unit, the inlet and outlet valves of the evaporator of the refrigeration unit that is not in operation are not closed, so that a part of the chilled water flows away from the evaporator of the unit that is not in operation, thereby affecting the refrigeration effect of the refrigeration unit in the operating state.

In fact, the correct operation method of the chilled water system of the air conditioning refrigeration unit is: before starting the machine, first close the inlet valve of the chilled water of the refrigeration unit that is not in operation: then open the inlet and outlet valves of the evaporator of the unit that needs to be operated, and start the corresponding chilled water pump, and adjust the pressure drop of the inlet and outlet of the evaporator to be about 0.5kg/cm.

During installation or use, no matter how many units you start, it should be one chilled water pump corresponding to one unit, and the matching must be the same.