How to operate the chiller correctly

How to operate the chiller correctly

For an operating chiller. Environmental conditions, the load has become a fixed value. At this time, the condensing heat load is also a fixed value. It is stipulated that the temperature difference between the inlet and outlet water is 5℃, the cooling water volume must also be a certain value and the flow rate is inversely proportional to the temperature difference between the inlet and outlet water. Therefore, the operation of the chiller. As long as the temperature difference between the inlet and outlet of the cooling water is specified, this flow is usually controlled by the pressure drop of the cooling water in and out of the condenser. Under standard conditions, the pressure drop of the condenser inlet and outlet water is set to 68.6kPa (0, 7kg/cm:).

　　In the actual operation of the cooling water system, there are often the following misoperations:

　　1. The inlet valve of the condenser on the unit that does not need to be opened is not closed before the chiller is turned on, causing water leakage. Part of the cooling return water flows away from the condenser of the unit that is not started, reducing the cooling water flow in the condenser of the running unit, causing the condensing pressure to rise, the operating current of the main unit increases, and the cooling capacity of the unit decreases. Stopping the operation will waste electricity, reduce the cooling effect, and easily damage the equipment.

　　2. Due to the previous misoperation, the condensing pressure of the chiller and the cooling water outlet temperature have increased. Cause misjudgment to the operator, mistakenly think that the amount of cooling water is not enough to open the condenser water inlet valve and the cooling water pump outlet valve, and some even increase the cooling tower fan, causing the water pump and cooling tower fan to increase power consumption

　　 3. What's more, blindly open a cooling water pump. Although adding the cooling water pump can indeed reduce the cooling water temperature and condensing pressure, after all, the electrical energy of a water pump is wasted, so it is a mistake.

　　 The correct operation method of the cooling water system is:

　　 1. Before starting the machine, close the condenser water inlet valve of the unit that does not need to be operated to prevent water leakage.

2. Open the inlet and outlet valves on the condenser of the unit to be operated (generally, the outlet valve is normally open, and the inlet valve is opened and closed as required. The condenser and evaporator are the same). Turn on the corresponding cooling water pump and adjust the condenser inlet and outlet pressure It is reduced to about 68.6kPa (0.7kg/cm:) (the pressure drop is based on the principle of overcoming the resistance of the pipeline, and the lower the energy saving effect is better).

　　3. If the pointer of the condenser water inlet and outlet pressure gauge swings too much, it indicates that there is air in the cooling water system, and the air needs to be exhausted. After the pressure gauge indicates normal, continue to the next step.

　　 4. In operation, no matter how many chillers are opened, one cooling water pump corresponds to one host (the matching must be the same).