How to Prevent Crystallization in Lithium Bromide Absorption Chiller?
In addition to using a U-shaped tube as an automatic crystal dissolving device, certain internal control elements must be configured in the lithium bromide absorption refrigerator to prevent the occurrence of crystallization.
(1) Install a temperature relay on the concentrated solution pipeline at the outlet of the generator. When the temperature of the concentrated solution is higher than a given value (the temperature depends on the design parameters of the refrigerator), the temperature relay will act, turn off or turn off the heating steam, and issue an alarm to prevent the occurrence of crystallization accidents. The alarm signal enables the operator to find and eliminate the cause of crystallization in time.
(2) A liquid level controller is installed in the evaporator liquid bag towel. When the liquid level of the cold water exceeds the given value, the liquid level controller will act to open the solenoid valve installed on the refrigerant water bypass pipe, so that the refrigerant water will pass into the absorber from the evaporator liquid sac bypass, reducing the desalinated lithium The concentration of the solution prevents crystallization due to the high concentration of the solution. When the liquid level controller acts, an alarm is issued, so that the operator can troubleshoot in time.
(3) The cooling water is cut off or the flow is too low to protect the device. When the cooling water pump fails, or the cooling water volume is significantly reduced due to other reasons, the absorption effect of the absorber is greatly weakened, which may cause the concentration of the solution at the outlet of the generator to be too high and crystallize. To this end, a pressure (or differential pressure) relay is installed on the cooling water pipeline of the absorber. When the cooling water pressure (or differential pressure) is lower than a given value, the relay will act to turn off the heating steam and issue an alarm, so that the operator can find out in time. and troubleshooting.
(4) Anti-crystallization device when parking. When the refrigerator is just stopped, because the concentration of the solution in the generator is relatively high, if it is not mixed with the dilute solution in the absorber, it may crystallize due to the temperature drop after stopping. The anti-crystallization device during shutdown can use a delay relay to control the solution pump and the evaporator pump, so that the two pumps continue to run for a period of time (10-15 minutes) after the steam valve is closed, so that the dilute solution of the absorber and The concentrated solution of the generator is fully mixed and the refrigerant vapor of the evaporator is fully absorbed. In this way, the solutions in each part of the system are mixed and diluted, which can prevent crystallization from occurring due to temperature drop after shutdown. In addition, the temperature relay installed on the outlet pipe of the generator can also make the solution pump and the evaporator pump continue to run for a period of time after the refrigerator is stopped, until the temperature of the mixed solution is lower than the specified value.
