Heat Transfer Model of Roller Quench in Strip Continuous Heat Treatment Process

Abstract

Roller quench is a rapid cooling technique used in strip continuous heat-treatment process, which is one of the most important processes in producing cold-rolled strip steel. Heat transports by contact heat transfer in roller quench, for the complex characteristics of contact heat transfer, roller quench is very difficulty to simulate. In this paper a roller quench heat transfer model is build based on Fourier-Kirchhoff differential equations. A new correlation function of contact conductance is developed from statistical mechanics model results by least square method. This correlation function solves the heat transfer boundary condition in contact region between strip and roller. In this model the contact radiation is also considered. The roller quench model predicts the heat transfer characteristics of roller quench. The model is useful for the designing and controlling of the roller quench system.

Mathematical Model and Parameter Analysis of the Sintering Process for Ternary Cathode Materials

“…During the calculation of view factors, the number of emitted rays from each surface is 10 6 , and the calculated angular coefficient has an accuracy of 0.1% with 95% confidence. [26] After ob-taining the view factors, the radiative thermal resistance network method is used to establish the equation for the radiosity J j , as given in Equation (8).…”

“…During the calculation of view factors, the number of emitted rays from each surface is 10 6 , and the calculated angular coefficient has an accuracy of 0.1% with 95% confidence. [ 26 ] After obtaining the view factors, the radiative thermal resistance network method is used to establish the equation for the radiosity J j , as given in Equation (8). $$$$\begin{eqnarray} && \sum_{i = 1}^N \left[{\delta_{ki} - (1 - {\varsigma }_k{\varepsilon }_k)(1 - {A}_g){f}_{k - i}} \right]{J}_i \nonumber\\ &&\quad = {\varsigma }_k{\varepsilon }_k\sigma T_k^4 + (1 - {\varsigma }_k{\varepsilon }_k){\varepsilon }_g\sigma T_g^4 + (1 - {\varsigma }_k)\frac{{{Q}_k}}{{{F}_k}}, \end{eqnarray}$$$$where σ is the Stefan–Boltzmann constant; ε k , T k , Q k , and F k are the emissivity, temperature (K), net radiative heat flux (W), and surface area (m 2 ) of surface k , respectively; J i represents the radiosity of surface i (W·m −2 ); δ ki and ζ k are binary functions, as shown in Equations (9) and (10).…”