基于雷诺输运定理的热力学第一定律表达式的探讨

Discussion of the First Law of Thermodynamics Based on the Reynolds Transport Theorem

摘要: 雷诺输运定理是实现拉格朗日方法的“系统”内物质参数变化率到欧拉方法的“控制体”内参数变化率的桥梁。本文引入雷诺输运定理建立了开口系统热力学第一定律表达式，不仅使热力学第一定律具有较统一的数学描述，而且为工程流体力学和传热学的学习奠定了一脉相承、继续延伸应用的基础。通过对高压锅排气和自行车车胎充气过程的分析，研究了充、排气过程的求解方法，有助于学生加深对能量守恒与转化定律的理解与应用，对于热能工程类课程的教学和工程应用具有一定的参考价值。

Abstract: The Reynolds transport theorem provides a bridge between the time rates of change of an extensive property for a system of the Lagrangian approach and for a control volume of the Euler approach. In this paper, the expression of the first law of thermodynamics for an opening system was established by using the Reynolds transport theorem, which not only provides a relatively unified mathematical description of the first law of thermodynamics, but also lays a foundation for the continuous engineering applications of fluid mechanics and heat transfer courses. Through the analysis of the pressure cooker exhaust and bicycle tire inflation processes, the solution method of the charging and exhaust processes was studied, which helps the students to deepen the understanding and application of the energy conservation and conversion law, and has some value for the teaching and engineering applications of the thermal energy engineering courses.