logarithmic mean temperature difference

简明释义

对数平均温差

英英释义

例句

1.When designing a district heating system, the logarithmic mean temperature difference (对数平均温度差) can significantly impact energy efficiency.

在设计区域供热系统时，对数平均温度差 (logarithmic mean temperature difference) 可以显著影响能源效率。

2.The calculation of the heat exchanger's efficiency relies heavily on the logarithmic mean temperature difference (对数平均温度差) to determine the temperature gradient.

热交换器效率的计算严重依赖于对数平均温度差 (logarithmic mean temperature difference) 来确定温度梯度。

3.In HVAC design, the logarithmic mean temperature difference (对数平均温度差) is essential for calculating the required heat transfer area.

在暖通空调设计中，对数平均温度差 (logarithmic mean temperature difference) 对于计算所需的热传递面积至关重要。

4.To optimize the cooling system, engineers must accurately measure the logarithmic mean temperature difference (对数平均温度差) between the inlet and outlet streams.

为了优化冷却系统，工程师必须准确测量进出口流之间的对数平均温度差 (logarithmic mean temperature difference)。

5.The formula for the logarithmic mean temperature difference (对数平均温度差) helps in understanding the thermal performance of a heat exchanger.

用于计算对数平均温度差 (logarithmic mean temperature difference) 的公式有助于理解热交换器的热性能。

作文

In the field of thermodynamics and heat transfer, the concept of logarithmic mean temperature difference plays a crucial role in the design and analysis of heat exchangers. Understanding this concept is essential for engineers and scientists who work with thermal systems. The logarithmic mean temperature difference (often abbreviated as LMTD) is defined as the temperature difference between the hot and cold fluids at each end of a heat exchanger, averaged in a specific logarithmic manner. This method provides a more accurate representation of the average temperature difference that drives heat transfer between two fluids compared to a simple arithmetic mean.To appreciate the significance of logarithmic mean temperature difference, one must first recognize the principles of heat transfer. Heat exchangers are devices designed to transfer heat from one fluid to another without mixing them. The efficiency of a heat exchanger largely depends on the temperature difference between the two fluids. A greater temperature difference typically results in more efficient heat transfer. However, the temperature difference is not constant throughout the heat exchanger; it varies along its length. This is where the logarithmic mean temperature difference becomes useful.The formula for calculating the logarithmic mean temperature difference is given by:LMTD = (ΔT1 - ΔT2) / ln(ΔT1 / ΔT2)where ΔT1 is the temperature difference at one end of the heat exchanger, and ΔT2 is the temperature difference at the other end. The natural logarithm function (ln) is used in this formula to ensure that the average accounts for the exponential nature of heat transfer. By using the LMTD, engineers can more accurately determine the required surface area of the heat exchanger needed to achieve a desired heat transfer rate.One of the primary advantages of using the logarithmic mean temperature difference is that it simplifies the calculations involved in heat exchanger design. When engineers know the inlet and outlet temperatures of both the hot and cold fluids, they can easily compute the LMTD and use it to size the heat exchanger appropriately. This calculation is particularly important in industries such as power generation, chemical processing, and HVAC systems, where efficient heat exchange is critical for operational performance and energy conservation.Moreover, the logarithmic mean temperature difference also helps in analyzing the performance of existing heat exchangers. By comparing the actual heat transfer rate to the expected rate based on the LMTD, engineers can identify potential issues such as fouling or scaling that may be affecting the heat exchanger’s efficiency. If the actual performance deviates significantly from the expected performance, it may indicate that maintenance or cleaning is required to restore optimal function.In conclusion, the logarithmic mean temperature difference is a fundamental concept in heat transfer that provides a more accurate way to assess the temperature differences driving heat exchange in thermal systems. Its application not only aids in the design of new heat exchangers but also serves as a valuable tool for evaluating and maintaining the efficiency of existing systems. As industries continue to seek ways to improve energy efficiency and reduce operational costs, understanding and utilizing the logarithmic mean temperature difference will remain an essential skill for engineers and scientists alike.

在热力学和传热领域，对数平均温差的概念在热交换器的设计和分析中起着至关重要的作用。理解这一概念对于从事热系统工作的工程师和科学家来说是必不可少的。对数平均温差（通常缩写为LMTD）被定义为在热交换器两端热流体与冷流体之间的温差，以特定的对数方式进行平均。这种方法比简单的算术平均值提供了更准确的温差表示，从而驱动两种流体之间的热传递。要理解对数平均温差的重要性，首先必须认识到热传递的基本原理。热交换器是设计用来将热量从一种流体转移到另一种流体的设备，而不混合这两种流体。热交换器的效率在很大程度上取决于两种流体之间的温差。较大的温差通常会导致更高效的热传递。然而，温差并不是在整个热交换器中保持不变；它沿着热交换器的长度变化。这就是对数平均温差变得有用的地方。计算对数平均温差的公式为：LMTD = (ΔT1 - ΔT2) / ln(ΔT1 / ΔT2)其中ΔT1是热交换器一端的温差，ΔT2是另一端的温差。该公式中使用自然对数函数（ln），以确保平均值考虑到热传递的指数特性。通过使用LMTD，工程师可以更准确地确定所需的热交换器表面积，以实现期望的热传递率。使用对数平均温差的主要优点之一是简化了热交换器设计中的计算。当工程师知道热流体和冷流体的入口和出口温度时，他们可以轻松计算LMTD，并利用它来适当调整热交换器的尺寸。这一计算在发电、化工处理和暖通空调系统等行业中尤为重要，因为高效的热交换对于操作性能和节能至关重要。此外，对数平均温差还有助于分析现有热交换器的性能。通过比较实际热传递率与基于LMTD的预期热传递率，工程师可以识别潜在问题，例如可能影响热交换器效率的污垢或结垢。如果实际性能明显偏离预期性能，则可能表明需要进行维护或清洁，以恢复最佳功能。总之，对数平均温差是传热中的一个基本概念，提供了一种更准确的方法来评估驱动热交换的温差。其应用不仅有助于新热交换器的设计，也为评估和维护现有系统的效率提供了宝贵的工具。随着各行业继续寻求提高能源效率和降低运营成本，理解和利用对数平均温差将始终是工程师和科学家的基本技能。