TEMPERATURE DYNAMIC-MODELS OF HEAT-EXCHAN GER FOR PHOTOSENSITIVE MATERIAL COATING AND DRYING PROCESSES

Nonlinear and linear temperature dynamic models of a heat exchanger we re investigated for air conditioning control of coating and drying pro cesses for photosensitive materials. The nonlinear model was derived f rom heat balance based on the assumption of lumped parameter system th at the heat exchanger is divided into small parts in the direction of flow (divided cell model). In each part, the temperature of the heatin g fluid, heated fluid and heat transfer tube with fin are assumed to b e uniform. Parameters involved in this model were estimated from exper imental data of the step response characteristics of temperature. The linear model is obtained by linearizing this nonlinear model. It was c onfirmed that the dynamic behavior of temperature can be successfully expressed by both nonlinear and linear models. Both models are conside red to be utilizable for process analysis and control system design of the air conditioning system under consideration.