EVAPORATOR PROCESS-CONTROL USING COMPUTER-MODELS

Model-based control is the concept of using a real-time mathematical m odel to adjust inputs to a process in order to achieve control objecti ves. The current study of its application to evaporators was conducted in conjunction with two Australian food processing factories. The pot ential benefits include greater process flexibility and better respons e to setpoint variation. Data from the two evaporation systems collect ed over two years included evaporator design and configuration, produc t thermophysical data, and system performance data. Two computer model s based on heat and mass balance and heat transfer were constructed us ing a modular programming style which allowed system reconfiguration. The model was validated using plant data from one factory, the differe nce with the simulation model being not significant at the 5% level. M ethods for combining the predictive capacity of the model with a stand ard control algorithm are discussed, as well as the validity of this c ontrol approach for dynamic situations such as start-up.