The Generalized Thermodynamics And Its Application Study On Compressor With Vapor Injection

After hundreds years of theoretical development and numerous engineering practices,the classical thermodynamics theory has been proved correct.But,there are still some different understandings about some basic conceptions and meanings.For example,the twine definition of the temperature and heat,the limit of entropy when the thermodynamic temperature is near OK,figuring these problems out is positive to the development of thermodynamics.For long distance transport of natural gas,the loss of pressure is ineluctable.LNG has high quality of cold energy and the vapor injection technology of compressor is a reliable energy-saving technology.This paper raised that using LNG in vapor-injection to improve the efficiency of the natural gas compressors.It is significant to the energy-saving and emission-reduction.According to the phenomenon "the twine of temperature and heat",this paper put forward that the thermodynamic temperature is not unique.Based on the classical thermodynamics,according to the strict mathematical derivation,this paper defined new and widely applicable generalized conceptions of temperature and heat,and called them generalized thermodynamic temperature and generalized heat.Depending on these,generalized entropy,generalized thermodynamic energy and more parameters were defined and classical thermodynamics was proved merely a special example of the generalized thermodynamics.The generalized thermodynamics obeys the basic laws of the classical thermodynamics.In this paper,three laws of generalized thermodynamics were newly explained to fit the generalized thermodynamics system context.According to the generalized thermodynamics,this paper proved that when the classical thermodynamic temperature tends to 0K,the thermodynamic entropy's limit of anything is 0,which solves the problem of entropy's minimum limit and even many basic problems of entropy calculation in thermodynamics,chemistry and physics.And the conception of absolute entropy was raised.A new thermodynamic quantity was also proposed,which is called Jk(kTS).The transformation formulae of Jk is gived,the meaning of it is discussed.The generalized law of entropy production was proved.This paper also proved the two dimensional total differential expressions of generalized thermodynamic parameters,gave the characteristic functions of some generalized thermodynamic parameters,provided the Maxwell relation expressions in same and different generalized thermodynamic systems,rasied the transformation expressions and computational methods of specific heat,Joule Thompson coefficient and some other physical property parameters.The differential expressions of generalized entropy,generalized thermodynamic energy,generalized enthalpy were given.The matrix transformation expressions of different parameters in different generalized thermodynamic systems were studied.This paper also gave the integral expressions of entropy,thermodynamic energy,enthalpy and some other parameters in generalized thermodynamic systems.This paper raised that using liquid nitrogen for vapor-injection of scroll compressor to simulate LNG vapor-injection in natural gas compression,introduced the basic structure,working principle and geometry of scroll compressor,gave the method to calculate the performance parameters of the scroll compressor and the governing equations in generalized thermodynamics,analysed the three-section of the compression process.Using generalized thermodynamic theory,this paper also analysed the relation of the adiabatic efficiency,vapor-injection pressure and relative injection flow ratio in the vapor-injection of scroll compressor,obtained the best optimum condition.The change of generalized heat and generalized enthalpy inthe compression process of the scroll compressor were analyzed and calculated.The generalized enthalpy adiabatic efficiency,generalized absorbing heat adiabatic efficiency,Jk adiabatic efficiency and generalized free energy adiabatic efficiency were defined.These prove that it can be used generalized thermodynamic theory to analyse the actual thermodynamic processes.