广义热力学理论及其在压缩机补气中的应用研究

发布时间：2018-07-05 10:48

本文选题：广义热力学 + 广义热力学温度　；参考：《浙江大学》2017年博士论文

【摘要】：经过百年的理论发展和众多的工程实践,经典热力学已经证明其可靠性,但是对于热力学中的的一些基本概念及其意义仍存在着一些不同的理解。比如温度和热量的定义缠绕问题和熵在温度趋向于0K时的极限值问题,弄清这些问题对热力学发展有积极的意义。长距离运输天然气存在着压力损耗的现象。LNG是一种高质量的冷能,补气压缩机是一种非常可靠的节能技术。本文提出利用LNG补气提高天然气压气机效率,这对节能减排有重大意义。依据本文提出的温热缠绕现象,本文认为热力学温度不唯一。在经典热力学的基础上,通过严格的数学推导,定义了新的、更为普适的温度和热量概念,将它们命名为广义热力学温度和广义热量。以此为基础,定义了广义熵、广义热力学能等物理量。证明了经典热力学中的相应概念仅仅是广义热力学的一个特例,广义热力学遵守经典热力学的基本规律和定理。并在新概念下重新阐述了热力学三大定律,将其推广以适应到广义热力学体系下语境。通过广义热力学体系,证明了当热力学温度趋向于0K时,任何物质的热力学熵趋向于0,即熵具有积分起点。解决了困扰已久的熵的最小极限问题以及热力学,甚至化学和物理上的诸多计算的基础问题。在此基础上,定义了广义热力学体系下绝对熵的概念,定义并命名了新的物理量——火羁(TS),推导了火羁的变换公式,初步探讨了火羁的意义,证明了广义熵产定律。证明了广义热力学各参数的二维全微分关系。给出了广义热力学特性函数的关系以及相同和不同广义热力学系下的麦克斯韦关系式。给出了比热容、焦耳汤普逊系数等物性参数的变换关系和计算方法。给出了广义熵、广义热力学能和广义焓的微分表达式,研究了不同广义热力学系下的矩阵变换关系式。给出了广义热力学系下的熵、火羁、热力学能、焓、自由能、自由焓和火积的积分表达式。本文提出利用液氮补气涡旋压缩机过程来模拟LNG补气天然气压缩机。介绍了涡旋压缩机的基本结构、工作原理和几何结构。给出了涡旋压缩机性能参数的计算方法,广义热力学体系下涡旋压缩机的过程控制方程,以及补气涡旋压缩机内部三段压缩的热力学过程分析。采用广义热力学原理分析了涡旋压缩机补气压缩过程中的绝热指示效率和补气压力以及相对流量比之间的关系,得出了绝热指示效率最大的工况。分析计算了涡旋压缩机压缩过程的广义热量和广义焓的变化;定义了广义焓指示效率、广义吸热指示效率、广义自由焓指示效率和广义火羁指示效率。证明了广义热力学也可以用于实际的过程分析。
[Abstract]:After a hundred years of theoretical development and numerous engineering practices, classical thermodynamics has proved its reliability, but there are still some different understandings of some basic concepts and their meanings in thermodynamics. For example, the problem of the definition of temperature and heat and the limit value of entropy when the temperature tends to be 0 K, it is of positive significance to understand these problems for the development of thermodynamics. LNG is a kind of high quality cold energy, and gas supply compressor is a very reliable energy saving technology. In this paper, the use of LNG gas supply to improve the efficiency of natural gas compressor, which is of great significance for energy saving and emission reduction. According to the thermo-thermal winding phenomenon proposed in this paper, it is considered that the thermodynamic temperature is not unique. On the basis of classical thermodynamics, a new and more general concept of temperature and heat is defined by strict mathematical derivation, which is named generalized thermodynamics temperature and generalized heat. On this basis, generalized entropy, generalized thermodynamic energy and other physical quantities are defined. It is proved that the corresponding concepts in classical thermodynamics are only a special case of generalized thermodynamics, and that generalized thermodynamics obeys the basic laws and theorems of classical thermodynamics. The three laws of thermodynamics are restated under the new concept and generalized to fit the context of the generalized thermodynamic system. Through the generalized thermodynamic system, it is proved that when the thermodynamic temperature tends to 0 K, the thermodynamic entropy of any matter tends to 0, that is, the entropy has an integral starting point. The problem of the minimum limit of entropy and the basic problems of thermodynamics, even chemistry and physics are solved. On this basis, the concept of absolute entropy in the generalized thermodynamic system is defined, a new physical quantity, fire restraint (TS) is defined and named, the transformation formula of fire restraint is derived, the significance of fire restraint is preliminarily discussed, and the law of generalized entropy production is proved. The two-dimensional total differential relation of the parameters of generalized thermodynamics is proved. The relation of generalized thermodynamic characteristic function and Maxwell's relation under the same and different generalized thermodynamic systems are given. The transformation relation and calculation method of physical parameters such as specific heat capacity, Joule Thomson coefficient and so on are given. The differential expressions of generalized entropy, generalized thermodynamic energy and generalized enthalpy are given, and the matrix transformation relations under different generalized thermodynamic systems are studied. The integral expressions of entropy, fire restraint, thermodynamic energy, enthalpy, free energy, free enthalpy and fire product under the generalized thermodynamic system are given. This paper presents a simulation of LNG gas supply natural gas compressor by using liquid nitrogen to replenish gas scroll compressor. The basic structure, working principle and geometric structure of scroll compressor are introduced. The calculation method of the performance parameters of the scroll compressor, the process control equation of the scroll compressor under the generalized thermodynamic system, and the thermodynamic process analysis of the internal three-stage compression of the gas supply scroll compressor are given. The relationship between the adiabatic indicating efficiency, the gas supply pressure and the relative flow ratio in the compression process of the scroll compressor is analyzed by using the generalized thermodynamic principle, and the maximum adiabatic indicating efficiency is obtained. The variation of generalized heat and generalized enthalpy in the compression process of scroll compressor is analyzed and calculated, and the general enthalpy indicating efficiency, generalized endothermic indicating efficiency, generalized free enthalpy indicating efficiency and generalized fire indicating efficiency are defined. It is proved that generalized thermodynamics can also be used in practical process analysis.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O414.1

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