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 into and out of the condenser. Under standard working conditions, the pressure drop of the inlet and outlet water of the condenser is adjusted to 68.6 kPa (0, 7kg/cm:).
In the actual operation of the cooling water system, there are often the following misoperations:
⑴ The water inlet valve of the condenser on the unit that does not need to be opened is not closed before starting up, causing water leakage. Part of the cooling return water flows away from the condenser of the unit that is not turned on, 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. The cooling capacity of the unit decreases, and it will cause the unit to be seriously affected. Stop running. It wastes electricity, reduces the cooling effect, and easily damages the equipment.
⑵Due to the previous misoperation, the condensing pressure of the host and the temperature of the cooling water outlet have increased. Cause misjudgment to the operator. It is mistaken that the condenser water inlet valve and the cooling water pump outlet valve are opened large because the cooling water volume is not enough, and some also increase the cooling tower fan, which causes the power consumption of the water pump and the cooling tower fan to increase.
⑶ Even 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 electric energy of a water pump is wasted. So it is the wrong way to add the wrong cooling water system. The correct operation method is:
⑴ Before starting up, close the condenser water inlet valve of the unit that does not need to be operated to prevent water leakage.
⑵Open 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. Adjust the condenser inlet and outlet. The water outlet pressure drops to about 68.6kPa (0.7 kg/cm:) (the pressure drop is based on the principle that it can overcome the resistance of the pipeline. A lower value is better for energy saving).
(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. The air needs to be exhausted and the pressure gauge indicates normal to continue the next step.
During the operation of ⑷, no matter how many units are turned on, there is one cooling water pump to one host (the matching must be the same).
