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在传热理论中通常把物体的冷却(加热)过程按时间分为两个阶段:不规则过程和正常状态。第一个阶段的特征是物体的初始状态对物体的温度场有强烈影响。随着时间的推移,这种影响逐渐减弱,进入规则热状态阶段。这阶段的特点是物体各点剩余温度对数变化的速度变成常数。在正常热状态下,温度场对时间的变化规律具有简单的指数形式,而剩余温度的对数则按线性规律随时间变化。当物体在具有恒定温度 t_0和恒定传热系数α的介质中冷却时,物体任意点的温度变化用典型函数来描述:v=t-t_0=AU_(?)~(-m(?))(1)式中 v——物体的剩余温度;t——物体在固定点的温度;t_0=常数——周围介质的温度;
In heat transfer theory, the cooling (heating) of an object is usually divided into two phases over time: an irregular process and a normal state. The first phase is characterized by the fact that the initial state of the object has a strong influence on the temperature field of the object. With the passage of time, this effect gradually weakened into the regular state of heat stage. The characteristic of this stage is that the speed of the logarithm of the remaining temperature at each point of the object becomes constant. Under normal thermal conditions, the temperature field has a simple exponential form with respect to time, while the logarithm of the residual temperature changes linearly with time. When the object is cooled in a medium with a constant temperature t_0 and a constant heat transfer coefficient α, the temperature change at an arbitrary point of the object is described by a typical function: v = t -t_0 = AU_ (?) - (-m (?)) 1) Where v - the remaining temperature of the object; t - the temperature of the object at a fixed point; t_0 = constant - the temperature of the surrounding medium;