overall coefficient of heat transfer

简明释义

总传热系数

英英释义

例句

1.The overall coefficient of heat transfer will vary depending on the materials used in construction.

建筑中使用的材料会影响整体热传递系数。

2.By analyzing the overall coefficient of heat transfer, we can identify areas that need better thermal management.

通过分析整体热传递系数，我们可以识别出需要更好热管理的区域。

3.In order to improve insulation, we need to reduce the overall coefficient of heat transfer in the building.

为了改善绝缘，我们需要降低建筑物的整体热传递系数。

4.The overall coefficient of heat transfer is crucial for designing energy-efficient HVAC systems.

对于设计节能的暖通空调系统来说，整体热传递系数至关重要。

5.The engineer calculated the overall coefficient of heat transfer to determine the efficiency of the heating system.

工程师计算了整体热传递系数以确定加热系统的效率。

作文

In the field of thermodynamics and heat transfer, understanding various parameters is crucial for engineers and scientists. One such important parameter is the overall coefficient of heat transfer, which plays a significant role in determining how efficiently heat is transferred between different mediums. This coefficient is particularly relevant in systems involving heat exchangers, HVAC (heating, ventilation, and air conditioning) systems, and thermal insulation. The overall coefficient of heat transfer is defined as the total heat transfer rate per unit area per unit temperature difference between two fluids or between a fluid and a solid surface. It combines the effects of conduction, convection, and sometimes radiation, depending on the situation. To fully grasp this concept, it is essential to break down its components. Conduction refers to the transfer of heat through a solid material due to a temperature gradient. For instance, when one end of a metal rod is heated, the other end gradually becomes warm due to the conduction of heat through the rod. The rate of heat transfer by conduction can be described using Fourier's law, which states that the heat transfer rate is proportional to the temperature difference and the area through which heat is being conducted.Convection, on the other hand, involves the transfer of heat between a solid surface and a fluid moving over it. This process can be natural, driven by buoyancy forces, or forced, where an external force like a fan or pump enhances the fluid movement. The convective heat transfer coefficient is influenced by several factors, including the fluid's velocity, properties, and the nature of the surface. Understanding these factors is essential for optimizing systems that rely on convective heat transfer.When we consider the overall coefficient of heat transfer, we often encounter the concept of thermal resistance. Just as electrical resistance impedes current flow, thermal resistance hinders heat flow. In many cases, the total thermal resistance can be modeled as a series of resistances associated with conduction and convection. By calculating the individual resistances and summing them, one can derive the overall coefficient of heat transfer. This coefficient is not only critical for theoretical calculations but also has practical applications. For example, in designing a heat exchanger, engineers must ensure that the overall coefficient of heat transfer is maximized to enhance efficiency. This may involve selecting appropriate materials with high thermal conductivity, optimizing fluid flow rates, and minimizing fouling on heat transfer surfaces. Moreover, the overall coefficient of heat transfer can vary significantly based on operating conditions. Changes in temperature, pressure, and fluid properties can all impact this coefficient. Therefore, engineers must conduct thorough analyses and experiments to determine the most effective design parameters for their specific applications.In conclusion, the overall coefficient of heat transfer is a fundamental concept in the study of heat transfer that encapsulates the efficiency of thermal energy transfer in various systems. By understanding its components—conduction, convection, and thermal resistance—engineers can design more efficient systems that meet the demands of modern technology. As we continue to seek improvements in energy efficiency and sustainability, mastering the principles surrounding the overall coefficient of heat transfer will remain a priority in engineering education and practice.

在热力学和热传递领域，理解各种参数对工程师和科学家至关重要。其中一个重要的参数是整体热传递系数，它在确定不同介质之间热量传递的效率方面发挥着重要作用。这个系数在涉及热交换器、暖通空调（HVAC）系统和热绝缘的系统中尤其相关。整体热传递系数被定义为单位面积上单位温度差下的总热传递率。它结合了导热、对流，有时还包括辐射，具体取决于情况。要充分理解这一概念，必须分解其组成部分。导热是指由于温度梯度而通过固体材料传递热量。例如，当金属棒的一端被加热时，由于热量通过棒的导热，另一端逐渐变暖。导热的热传递速率可以用傅里叶定律来描述，该定律指出，热传递速率与温度差和热量传递面积成正比。另一方面，对流涉及固体表面与流体之间的热量传递。这个过程可以是自然的，由浮力驱动，或是强制的，即外部力量（如风扇或泵）增强流体的运动。对流热传递系数受到多种因素的影响，包括流体的速度、性质和表面的特性。理解这些因素对于优化依赖对流热传递的系统至关重要。当我们考虑整体热传递系数时，通常会遇到热阻的概念。就像电阻阻碍电流流动一样，热阻会阻碍热流。在许多情况下，总热阻可以建模为与导热和对流相关的多个热阻的串联。通过计算各个热阻并将其相加，可以推导出整体热传递系数。这个系数不仅对理论计算至关重要，还有实际应用。例如，在设计热交换器时，工程师必须确保整体热传递系数最大化以提高效率。这可能涉及选择具有高导热性的适当材料，优化流体流速，并最小化热传递表面的污垢。此外，整体热传递系数可能会根据操作条件显著变化。温度、压力和流体性质的变化都可能影响该系数。因此，工程师必须进行全面分析和实验，以确定其特定应用的最有效设计参数。总之，整体热传递系数是热传递研究中的一个基本概念，它概括了各种系统中热能传递的效率。通过理解其组成部分——导热、对流和热阻，工程师可以设计出更高效的系统，以满足现代技术的需求。随着我们继续寻求能源效率和可持续性的改善，掌握围绕整体热传递系数的原则将始终是工程教育和实践的重点。