Also Energy conservation heat engines

Simultaneous heat and mass transfer also occurs in drying processes, chemical reaction steps, evaporation, crystallisation, and distillation. In all of these operations transfer rates are usually fixed empirically. The process can be evaluated using either the heat- or mass-transfer equations. However, if the process mechanism is to be fully understood, both the heat and mass transfer must be described. Where that has been done, improvements in the engineering of the process usually result (see Process energy conservation). 

This law is also called the Law of Conservation of Energy. The diagram below (Fig. 3.1), after Mackowiak (1966), represents a system of constant mass and energy which is enclosed in the circle. The arrows represent the interconvertability of the various types of energy. For example, heat energy can be converted to mechanical work, which is the basis of internal combustion engines. 

Chemical reactors can liberate or absorb very large amounts of ener, and the handling of this energy is a major concern in reaction engineering. This topic is an application of the First Law of Thermodynamics, which says that mechanical and thermal ener is conserved in ary process. When we describe a chemical reaction, we designate its rate, but we should also be very concerned about the heat of the reaction so we need to specify A and AG for every reaction. 

Conservation Equations. In the above section, the material functions of nonnewtonian fluids and their measurements were introduced. The material functions are defined under a simple shear flow or a simple shear-free flow condition. The measurements are also performed under or nearly under the same conditions. In most engineering practice the flow is far more complicated, but in general the measured material functions are assumed to hold. Moreover, the conservation principles still apply, that is, the conservation of mass, momentum, and energy principles are still valid. Assuming that the fluid is incompressible and that viscous heating is negligible, the basic conservation equations for newtonian and nonnewtonian fluids under steady flow conditions are given by... 

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