Modeling Thermofluid Systems: An Approach Customized for Optimization

Many technical applications involve the heating and cooling of fluids. In technical terms, the corresponding systems are called thermofluid systems. These systems can be regarded as fluid systems with superimposed heat transfer. However, since both parts mutually depend on each other, they have to be considered simultaneously. As an extension of previous research on fluid systems, we present a mathematical model for the algorithmic system design of thermofluid systems. This includes modeling the physical properties and system components related to heat transfer. Besides that, another issue arises if heat transfer is considered. While it can be reasonable for fluid systems to be assumed as quasi-stationary systems, this does not hold for most thermofluid systems. Although some can be regarded as quasi-stationary, most of them show dynamic behavior. A major reason for this is that when dealing with heat, storage tanks become important. Thus, an appropriate time representation is required. For this purpose, we introduce a continuous-time approach.