The application of plate exchange in the field of refrigeration is a cooler or air conditioner evaporator, which has become the development trend in the field of refrigeration. The plate of heat exchanger will change along with the use of years, and it will occur leakage, leaching, freezing crack and other problems. This is due to the large number of safe passage of machinery and equipment, it is necessary to have many years of work experience to find the precise reason, today to give you the chiller plate heat exchanger freezing crack causes.
In the specific application of the whole process, because the unit control system design is not sound or customer error operation, it is very easy to cause the failure mode of the plate for freezing and cracking, chiller plate heat exchanger freezing and cracking its actual causes are as follows.
1, the plate exchange inlet pipe filtering device is invalid, the filtering device is invalid, it will cause the residue in the inlet pipe to enter the heat exchanger, which will cause the heat exchanger to be blocked, so that the amount of water discharged from the plate exchange to participate in the heat exchange is less than the minimum amount of water discharged set by the unit, thus making the circulation poor and the temperature difference larger parts of the plate ice blocking condition, causing the plate to expand and crack.
2、Refrigerant saturated suction temperature is too low.
3、The protection failure of electric heater of plate exchange in winter. In general, the chiller will be shut down in winter, because of the unique structure of the plate exchange, the internal refrigerated water cannot be emptied completely, or the refrigerated temperature is too low under the condition that the customer does not consume much heat, in this case, the electric heater on the surface of the plate exchange starts to work to warm up the internal refrigerated water to prevent the plate exchange from freezing and cracking.
4, flow switch maintenance invalid, the flow switch in the chiller, the key effect is to alarm shutdown when the total flow of cool water is less than the preset value, to avoid the unit plate for freezing and cracking. Generally installed in the water outlet channel. If the flow switch equipment fails or the flow switch is shielded by human factors, the management program of the unit cannot immediately issue an audible shutdown, causing the unit to continue to operate when the water output is less than the set rated current, and the refrigerant cools the refrigerated water again in the internal air of the plate swap, thus causing the plate to freeze and crack.
Secondly, when the plate exchange is used as the air conditioning evaporator in the refrigeration unit, the saturation state of the refrigerant in the plate exchange evaporates at a temperature of less than -10 ℃ for no more than 20 seconds, otherwise, it is easy to cause the plate to penetrate and crack in an instant, resulting in freezing and cracking. The freezing and cracking condition of chiller plate heat exchanger is very common, we should find out the reason of freezing and cracking in time, for this reason, we can carry out purposeful prevention, and then prevent the freezing and cracking condition.