APPARATUS AND METHOD FOR DETECTING AND/OR RECOVERY FROM CRYSTALLIZATION IN AN ABSORPTION REFRIGERATION MACHINE A CONTROL SYSTEM THEREFOR AND A METHOD FOR REDUCING OVERSHOOT IN THE CONTROL SYSTEM

摘要

In a first embodiment, the absorption chiller comprises a generator 26 and an absorber 24 and has one or more concentrated absorbent solution flows from the generator 26 to the absorber 24. A separate stream of concentrated absorbent solution is distributed to the surface contact 24a and reservoir 24c of the absorber 24. The capacity of the chiller can be controlled by varying the flow rate ratio of the absorbent solution flowing into the reservoir to the surface contact 24a of the absorber 24. The controller 118 adjusts the flow rate ratio of the absorbent solution to achieve the required cooling capacity. In the second embodiment, a method for detecting and recovering crystallization of the two stage absorption chiller 400 is provided. Crystallization at low temperature heat exchanger 426 is detected by a temperature comparison between certain absorbent solution flows. The recovery sequence includes removing crystallization and preventing further occurrences. Finally, in a third embodiment, a control system 500 is provided that controls overshoot in response to a setpoint input 515. The control system 500 accepts a feedback loop 505 connected to the control system 500 via an add node 508 and a setpoint input 515 and is filtered through the add node 508 to the control system. Binomial filter 510 disposed to provide point output 520.