The following faults may occur during the use of REFRIGERATION UNIT. The following simple analysis of the causes of the faults:
1. Abnormal temperature of cooling water inlet and outlet: the inlet water temperature of the condenser of the chiller is too high, first check whether the fan of the cooling tower is reversed; then through technical demonstration, and if feasible, adjust the angle of the blades of the cooling fan to increase the air volume of the fan . There is also a phenomenon that often occurs in a system where multiple Yantai cooling towers are used in parallel. When part of the load is running, the water temperature difference between the inlet and outlet of the condenser is small. It is necessary to check whether each cooling tower has an electric valve or an electric valve that has been set. Whether the failure causes the cooling water to be bypassed and not completely cooled.
2. The pressure difference between the inlet and outlet of the cooling water is constant: the heat release of the condenser directly affects the cooling capacity. Therefore, the cooling water system should be checked first. Based on the pressure loss value on the nameplate of the main engine, if the pressure difference value from the reading of the pressure gauge at the inlet and outlet greatly exceeds the normal value, it means that the inlet of the condenser is blocked by debris. Open the water seal head at the inlet end, it can be seen that the diameter of the copper pipe is small. Since the cooling water is an open system, the sundries are scattered in the water collecting pan and enter the system with the water flow. Once the water filter mesh is broken down, it will be collected to the inlet of the condenser place, so remove debris. A large number of projects do not monitor the differential pressure of the water filter, which makes it difficult to analyze the problem. When the REFRIGERATION UNIT is at the pressure outlet of the cooling pump, if the pressure difference between the inlet and outlet of the condenser is too small but the water temperature at the outlet of the condenser is too high, the cooling pump is working normally, indicating that the cooling water flow is not enough. This is because the water filter at the inlet of the cooling pump The debris caused by the blockage should be removed.
3. Abnormal temperature of cold water inlet and outlet: REFRIGERATION UNIT evaporator outlet water temperature is too high (higher than 7), the reason may be that the cooling water system is not working properly, resulting in insufficient cooling capacity; another situation is that the main engine cooling cannot meet the demand due to the expansion of the load side . If the water temperature at the outlet of the evaporator is 7, the refrigerator always runs intermittently, and the air-conditioning effect on the load side is not good, indicating that the cold water flow does not meet the design requirements, whether it is a primary pump system or a secondary pump system. This is the reason , should look for system air blockage and water filter blockage.
4. The pressure difference between the inlet and outlet of the cold water is often different: in a system equipped with an air source heat pump type cold (hot) water unit, there is a situation where the position of the constant pressure point is set at the inlet of the water filter. If the filter is blocked, then the filter Negative pressure will be formed in the pipe section between the rear of the pump and the inlet of the pump, causing the system to work abnormally.
5. Analysis of air blockage: Solving the problem of air blockage is more complicated than dealing with water filter blockage, because the latter has a specific location. Some air blockages often result in a large area of water flow reduction, which is no less harmful than a water filter blockage. The pipeline on the load side is long, and it is a hidden project. The installation elevation of the same horizontal pipeline is also unavoidable. As long as an automatic exhaust valve is installed at the inverted U-shape, there is generally no problem. The following are several common and dangerous gas blockage phenomena.
In a project with multiple sub-systems, if air blockage occurs at the top of each water supply and return riser, the consequence is that the water flow of the top layers is seriously insufficient, and the air must be drained. The other is that the air blockage occurs at the expansion tank, and the air in the REFRIGERATION UNIT system cannot be discharged to the atmosphere through it, and there is even a mistake in setting the valve on the expansion pipe, resulting in a serious shortage of water flow in the top layers.