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A formulation of a thermodynamic system in terms of contact geometry is proposed and a systematic approach to the description of interconnected thermodynamic systems is developed. In this paper, the stability of interconnected thermodynamic systems with heat and work exchange is analyzed using the LaSalle stability theory.
Conservative contact systems are defined with respect to an invariant Legendre submanifold and permit to endow thermodynamic systems with a geometric structure. Structure preserving feedback of controlled conservative contact systems involves to determine the existence of closed-loop invariant Legendre submanifolds. General results characterizing these submanifolds are presented. For contact systems...
The statistical mechanical interpretation of algorithmic information theory (AIT, for short) was introduced and developed in our former work [K. Tadaki, Local Proceedings of CiE 2008, pp. 425–434, 2008], where we introduced the thermodynamic quantities into AIT. In this paper, we reveal a certain sort of the robustness of statistical mechanical interpretation of AIT. The thermodynamic quantities in...
This paper presents a review of the status of power generation with nonaqueous working fluids from low-temperature thermal resource, the features, equipment composition and working processed as well as comparison of two main types of thermodynamic cycles which are Organic Rankine Cycle(ORC) and Kalina Cycle and nonaqueous working fluids including their classification and filter criteria for thermodynamic...
It is noted that glass is in non-equilibrium state on the way to the thermal equilibrium, that is, a kind of a slow relaxation process and depends on its whole thermal history. It is also known that, in the experimental way, so called the entropy of glass measured by cooling and heating shows respectively lower and upper bounds of the entropy defined by statistical thermodynamics. In this paper, we...
The contribution deals with proposal of conception and structure of two cooperating databases — preparatory and operating — for purposes of administration of database infrastructure of web service designed for thermodynamic calculations. The substances' data structure is in the both databases the same. Operating database directly supports web service operation. Preparatory database attends to creation,...
A new cycle model of an irreversible quantum harmonic heat engine is established in this paper, which is composed of two isothermal processes, an adiabatic process and a constant frequency process. Based on the quantum master equation and semi-group approach, the general optimal performance characteristics of the cycle are investigated. Expressions for several important performance parameters such...
The governing equations of micro-turbine components were built on the basis of thermodynamic analysis with MATLAB/Simulink. Combining with the experimental data of micro-turbine, the sample from the manufacture and previous researches on the variable condition characteristics of gas turbine, a high computational efficiency micro-turbine thermodynamic model was developed, which is applicable for energy...
The objective of this study is to analyze the effects of heat loss and variable specific heats of working fluid on the performance of an Atkinson engine by using finite-time thermodynamics. The variations in power output and thermal efficiency with compression ratio, and the relations between the power output and the thermal efficiency of the cycle are presented. The results show that the power output...
In this research, to profile the temperature field of a concrete foundation in Qinshan nuclear power station, the thermal properties of concrete were analyzed using ANSYS. This research provides a numerical method to identify the thermodynamic parameters of concrete, such as the specific heat, conductivity, coefficient of surface heat and rate of hydration, with the target optimization principle....
The purpose of this study is to analyze the effects of variable specific heats of working fluid on the performance of a Dual engine with considerations of heat transfer and friction by using finite-time thermodynamics. The results show that the power output as well as the efficiency where maximum power output occurs will increase with increasing the amount of heat added to the engine due to combustion...
The initial design of aerospace entry systems requires rapid but accurate predictions of vehicle performance across the fields of structures, aerodynamics, guidance and thermodynamics. A methodology for an increase in the fidelity of aerothermodynamic heating with a minimal impact on simulation time is presented. An investigation of the fidelity levels and associated complexity of different engineering...
Sewage source heat pump system plays a significant role in energy-saving and environmental protection which can be divided into direct and indirect system. For the shortcoming of research on the direct one, some anti-scaling technology and the heat exchangers to remove the soft dirt are introduced. Based on the exergy method, an analysis is given of energy efficiency in the direct sewage source heat...
The throttling loss is the major loss of the transcritical carbon dioxide refrigeration cycle, and the reason of low efficiency for performance. The study on the transcritical carbon dioxide refrigeration cycle with ejector and with throttling valve has been performed by the first and second laws of thermodynamics in theory. The effects of the injection ratio of ejector, heat rejection pressure, outlet...
The compression process of LNG accounts for a large part of the total energy which the huge LNG liquefaction ship consumes, and the account is increasing constantly, with the continuous development and application of natural gas. In order to improve energy efficiency, the exergy analysis is done to the refrigeration cycle which the LNG ship adopts. A conclusion is drawn after the exergy analysis to...
We present a MEMS-based differential scanning calorimetric (DSC) device combining highly sensitive thermoelectric sensing, on-chip self-calibration, and microfluidic regulation for thermodynamic characterization of biomolecular samples on a minimized scale. The device integrates well-defined microfluidic reaction chambers and utilizes a three-dimensional structure in which a layer of resistive microheaters...
Paper deals with calculation and design of the heat pumps that are used for purposes of heating and cooling. Heat pumps are systems that draw heat from one source (earth, water, air or ambient) and transfer it to another. Their operation is described by Carnot circular process, in which thermal energy is taken from one body to working medium and then from a working medium to the heated body. Energy...
This paper has investigated the PT equation of state for the new environmental-friendly refrigerant R600a, and on this basis, the mathematical model of heat pump with regenerator internal heat exchanger is constructed. After systematical calculating and analyzing the cycle performance of the heat pump charged with R600a and several types under standard operating condition and variable operating conditions,...
The recent increase in distributed power generation is highlighting the demand to investigate and implement better and more efficient power distribution grids. High-temperature superconducting (HTS) DC transmission cables have the potential to address the need for more efficient transmission and their usage is expected to increase in the future. Thermal modeling of HTS DC cables is a critical tool...
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