absorption chiller capacity control?

Answer 1

Abstract: A feedforward control method for an absorption chiller includes determining the disturbance transfer function, determining the capacity valve transfer function, measuring the actual disturbance, and implementing the feedforward control function in a feedforward controller. The feedforward control function is represented by the ratio of the disturbance transfer function divided by the capacity valve transfer function. The disturbance transfer function and the capacity valve transfer function are measured by applying a known amplitude input perturbation to the disturbance or capacity valve and recording the resulting perturbation in the output leaving chilled water temp. The disturbance transfer function is then the ratio of the delta leaving chilled water temperature divided by the delta change in the disturbance. The capacity transfer function is the ratio of the delta leaving chilled water temperature divided by the delta change in the capacity valve.