Analysis and treatment methods of high pressure failure of chiller
1. The cooling water temperature is too high and the condensation effect is poor. Chiller rated operating conditions
is 30~35℃. High water temperature and poor heat dissipation will inevitably lead to condensation.
The pressure is high, which often occurs during high temperature seasons.
Solution: The reason for the high water temperature may be: cooling tower failure, such as the fan not turning on or even reversing.
The water distributor does not rotate, which means the cooling water temperature is high and rises rapidly; external
The temperature is high, the water path is short, and there is less circulating water. In this case, the cooling water temperature
Generally maintained at a high level, this can be solved by adding a water storage tank.
2. Overcharging of refrigerant. This situation usually occurs after maintenance, indicating that the suction and exhaust
The pressure and balance pressure are higher and the compressor operating current is higher.
Solution: It should be carried out according to the suction and exhaust pressure and balance pressure under rated working conditions.
Electric exhaust operation until normal.
3. The condenser is scaled or blocked. Condensed water generally uses tap water, which is prone to scaling above 30°C.
Moreover, since the cooling tower is open and directly exposed to the air, dust and foreign matter can easily enter the cooling water system, causing the condenser to become dirty and blocked, resulting in a small heat exchange area and low efficiency, which also affects the water flow rate. The symptoms are that the pressure difference and temperature difference between the inlet and outlet water of the unit increase, the temperature of the condenser is very high when touched by hand, and the condenser liquid copper pipe is hot to the touch.
Solution: The unit should be backwashed regularly and chemically cleaned and descaled if necessary.
4. The cooling water flow is insufficient and cannot reach the rated water flow. The main manifestations are that the unit enters,
The outlet water pressure difference becomes smaller (compared with the pressure difference at the initial stage of system operation) and the temperature difference becomes larger.
Solution: The reason for insufficient water flow is the lack of water or air in the system. The solution is to install an exhaust valve at the top of the pipeline for exhaust; the pipeline filter is blocked or is too thin, and the water permeability is limited. A suitable filter should be selected. And clean the filter screen regularly; the water pump selection is small and the system does not match.
5. The refrigerant is mixed with non-condensable gases such as air and nitrogen.
Solution: This situation usually occurs after maintenance and incomplete vacuuming. It must be drained, revacuumed and refilled with refrigerant.
6. False alarms caused by electrical faults. False alarms occur due to moisture, poor contact or damage to the high-voltage protection relay, moisture or damage to the unit electronic board, or communication failure.
Solution: For this kind of malfunction, the HP fault indicator light on the electronic board often does not light up or lights up slightly. Manually
The RESET high-voltage protection relay is invalid, the computer displays "HP RESET", or disappears automatically. The compressor operating current is normal, and the suction and exhaust pressures are normal.