Chillers are divided into air-cooled chillers and water-cooled chillers in the industry. Chillers are divided into low-temperature chillers and normal temperature chillers in terms of temperature control. The normal temperature is generally controlled within the range of 0-35 degrees. The temperature control of cryocooler is generally in the range of 0-100 ℃. It is a kind of water cooling equipment, and the chiller is a kind of cooling water equipment that can provide constant temperature, constant current and constant pressure.

The editing of the working principle of the chiller is to inject a certain amount of water into the water tank in the chiller, cool the water through the cooling system of the chiller, and then send the low-temperature cooling water to the equipment to be cooled by the water pump. After the cooling water of the chiller takes away the heat, the temperature rises and then flows back to the water tank to achieve the cooling effect.

(1) The cooling water temperature is too high and the condensation effect is poor. The rated working condition of cooling water required by chiller is 30 ~ 35 ℃, high water temperature and poor heat dissipation will inevitably lead to high condensation pressure, which often occurs in high temperature season. The reasons for the high water temperature may be: the cooling tower fails, such as the fan is not turned on or even reversed, and the water distributor does not turn, which shows that the temperature of the cooling water is very high, and it rises rapidly; the external temperature is high, the water path is short, and the amount of water that can be recycled is small, in this case, the temperature of the cooling water is generally maintained at a higher level, which can be solved by increasing the storage tank.

(2) The cooling water flow is insufficient to reach the rated water flow. The main performance is that the pressure difference between the inlet and outlet water of the unit becomes smaller (compared with the pressure difference at the beginning of system operation), and the temperature difference becomes larger. The reason for the insufficient water flow is the lack of water or air in the system. The solution is to install the exhaust valve at the high place of the pipeline for exhaust; the pipeline filter is blocked or selected too fine, and the water permeability is limited, so the appropriate filter shall be selected and the filter screen shall be cleaned regularly; the selection of the water pump is small, which is not matched with the system.

(3) , condenser scaling or clogging. Generally, tap water is used for condensate water, which is easy to scale when the temperature is above 30 ℃. Moreover, because the cooling tower is open and directly exposed to the air, dust and foreign matters are easy to enter the cooling water system, resulting in dirty and blocked condenser, small heat exchange area, low efficiency, and also affecting water flow. Its performance is that the pressure difference and temperature difference between the water in and out of the unit become large, the temperature of the condenser is very high when touching it by hand, and the liquid outlet copper tube of the condenser is hot. The unit shall be backwashed regularly, and chemical cleaning and descaling shall be carried out if necessary.

(4) . too much refrigerant filling. This kind of situation generally occurs after maintenance, which shows that the suction and discharge pressure, balance pressure are high, and the running current of compressor is also high. The air shall be discharged under rated working conditions according to the suction and discharge pressure, balance pressure and operating current until normal.

(5) The refrigerant is mixed with air, nitrogen and other non condensable gases. This kind of situation usually occurs after maintenance, and the vacuumizing is not complete. It can only be drained, vacuumized and filled with refrigerant again.