Heat-transfer coefficients classification

Surfactant additives have been studied intensively in recent years because of the self-reparability or self-assembly of their micro structures after degradation by mechanical or extensional stresses. This ability has led to many studies of their applications in DHC recirculation systems. Classifications of surfactant DR As and their self-assembly nature are described. Also discussed in this section are the main research results on microstructures, rheological properties, HTR of surfactant DR solutions, and approaches to enhance heat transfer coefficients. Significant field tests around the world are reviewed. 

CLASSIFICATION OF INDIVIDUAL HEAT-TRANSFER COEFFICIENTS. The problem of predicting the rate of heat flow from one fluid to another through a retaining wall reduces to the problem of predicting the numerical values of the individual coefficients of the fluids concerned in the overall process. A wide variety of individual cases is met in practice, and each type of phenomenon must be considered separately. The following classification will be followed in this text ... 

Recall the mathematical classification of boundary conditions summarized in Table 3.5. For example, in energy transport, the first type corresponds to the specified temperature at the boundary the second type corresponds to the specified heat flux at the boundary and the third type corresponds to the interfacial heat transport governed by a heat transfer coefficient. 

Ideal reactors can be classified in various ways, but for our purposes the most convenient method uses the mathematical description of the reactor, as listed in Table 14.1. Each of the reactor types in Table 14.1 can be expressed in terms of integral equations, differential equations, or difference equations. Not all real reactors can fit neatly into the classification in Table 14.1, however. The accuracy and precision of the mathematical description rest not only on the character of the mixing and the heat and mass transfer coefficients in the reactor, but also on the validity and analysis of the experimental data used to model the chemical reactions involved. 

Heat transfer in gas-fluidized bed can occur by conduction, convection, and radiation depending on the operating conditions. The contribution of the respective modes of heat transfer to the coefficient of heat transfer depends on particle classification, flow condition, fluidization regimes, type of distributor, operating temperature, and pressure. Heat transfer between a single particle and gas phase can be defined by the conventional equation of heat transfer ... 

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