Design of a Model of Energy Exchange Running between the Building Envelope and the Surroundings: Free Energy Potential

2015 ◽  
pp. 90-115
Keyword(s):  
Free Energy ◽  
Energy Exchange ◽  
Building Envelope ◽  
Energy Potential

scholarly journals The Physical and Thermodynamic Functions of Borides

2017 ◽  
Vol 18 (1) ◽  
pp. 58-63
Author(s):  
N.Yu. Filonenko
Keyword(s):  
Free Energy ◽  
Physical Properties ◽  
Thermodynamic Functions ◽  
Point Of View ◽  
Energy Potential ◽  
High Temperature Expansion ◽  
Temperature Dependences ◽  
Function Calculation ◽  
First Time ◽  
Good Agreement

In the paper the physical properties and thermodynamic functions of borides Х2В (Х=W, Mo, Mn, Fe, Co, Ni та Cr) are studied with accounting for fluctuation processes. We use the microstructure analysis, the X-ray structural and the durometric analyses to determine the physical properties of alloys. In the paper it is determined the phase composition and physical properties of borides. In this paper for the first time it is determined the thermodynamic functions of borides using the Hillert and Staffansson model with accounting for the first degree approximation of high-temperature expansion for the free energy potential of binary alloys. We obtain the temperature dependences for such thermodynamic functions as Gibbs free energy, entropy, enthalpy and heat capacity Ср along with their values at the formation temperature for Х2В (Х=W, Mo, Mn, Fe, Co, Ni та Cr). The approach under consideration enables to give more thorough from the thermodynamic point of view description of borides formed from the liquid. The outcomes of the thermodynamic function calculation for borides are in good agreement with experimental data and results of other authors.

scholarly journals EN Energy efficiency projects deployment for Ukrainian industry. Efficiency assessment method for energy exchange and the ratio of temperature change in heat exchangers

2020 ◽  
Vol 56 (1-2) ◽  
pp. 54-59
Author(s):  
O. Yakovleva ◽  
O. Ostapenko ◽  
V. Trandafilov
Keyword(s):  
Energy Efficiency ◽  
Heat Exchange ◽  
Heat Exchangers ◽  
Energy Exchange ◽  
Development Process ◽  
Assessment Method ◽  
Environmental Benefits ◽  
Energy Potential ◽  
Heat Exchange Network ◽  
Exchange Network

Energy efficiency projects deployment for Ukraine is one of the challenging task today. Ukrainian in­dustry faces very complex environment for project development as well as its deployment within organization nowadays. UA Policy struggle to keep place on the European market to have possibility not only be a part of global policy but to go forward and to bring benefits for macro and micro economy. Fresh breath by integration energy systems within project management into business model of organization let to move closer to hold under control energy efficiency projects realization and avoid financial risks. Environmental policy and energy policy play crucial role for Ukrainian transformation into European pla­yer. Presented proactive plan provides possibilities to deliver the intended economic and environmental benefits of the Ukrainian energy labelling and ecological design directives. These directives are in use or are under development process by increasing the rates of compliance with their energy efficiency requirements. To start from the energy efficiency development process investigation in order to have possibilities to make corrections on the stage of modeling and design can bring benefits and reduce costs for end users. To evaluate the efficiency of heat exchangers, there are over 40 different private integral energy efficiency criteria. Such a number makes the estimation of heat exchangers not always objective and sufficiently definite, which does not allow to algorithmize the task of determining the efficiency of heat exchangers. On the foundation of the system element representation for the heat exchange network, the concepts of energy potential and energy efficiency of energy exchange are proposed. The obtained equations allow us to determine the efficiency of energy exchange not only for an element of the heat exchange network, but also for a complex system as a whole with a minimum of information about the system

Efficient numerical algorithms for the phase field crystal equation

2021 ◽  
pp. 2150042
Author(s):  
Qingqu Zhuang ◽  
Shuying Zhai ◽  
Zhifeng Weng
Keyword(s):  
Free Energy ◽  
Lower Bound ◽  
Numerical Simulations ◽  
Lagrange Multiplier ◽  
Phase Field ◽  
Numerical Algorithms ◽  
Energy Potential ◽  
Energy Stable ◽  
2D And 3D ◽  
Phase Field Crystal

In this paper, based on the Lagrange Multiplier approach in time and the Fourier-spectral scheme for space, we propose efficient numerical algorithms to solve the phase field crystal equation. The numerical schemes are unconditionally energy stable based on the original energy and do not need the lower bound hypothesis of the nonlinear free energy potential. The unconditional energy stability of the three semi-discrete schemes is proven. Several numerical simulations in 2D and 3D are demonstrated to verify the accuracy and efficiency of our proposed schemes.

scholarly journals Free energy versus internal energy potential for heavy quark systems at finite temperature

2014 ◽  
Vol 931 ◽  
pp. 607-611
Author(s):  
Taesoo Song ◽  
Su Houng Lee ◽  
Kenji Morita ◽  
Che Ming Ko
Keyword(s):  
Free Energy ◽  
Heavy Quark ◽  
Internal Energy ◽  
Finite Temperature ◽  
Energy Potential

A Two-Dimensional Free Energy Model for Single Crystalline Ferroelectrics

2005 ◽  
Vol 881 ◽  
Author(s):  
Sang-Joo Kim ◽  
Stefan Seelecke ◽  
Brian L. Ball ◽  
Ralph C. Smith ◽  
Chang-Hoan Lee
Keyword(s):  
Free Energy ◽  
Evolution Equations ◽  
Saddle Points ◽  
Ferroelectric Materials ◽  
Energy Model ◽  
Two Dimensions ◽  
Two Dimensional ◽  
Energy Potential ◽  
Single Crystalline ◽  
Free Energy Model

AbstractThe one-dimensional free energy model for ferroelectric materials developed in [1-3] is general-ized to two dimensions. The proposed two-dimensional energy potential consists of four energy wells corresponding to four variants of the material, four saddle points representing the barriers for 900 switching processes, and a local energy maximum across which 1800-switching processes take place. The free energy potential is combined with the evolution equations based on the theory of thermally activated processes. The prediction of the model is compared with the recent measurements on a Ba- TiO3 single crystalline ferroelectric in [4]. The responses of the model at various loading frequencies are calculated and the kinetics of 900 and 1800 switching processes are discussed.

A Modified Microplane Model Using Transformation Surfaces to Consider Loading History on Phase Transition in Shape Memory Alloys

2014 ◽  
Author(s):  
Milad Shirani ◽  
Reza Mehrabi ◽  
Masood Taheri Andani ◽  
Mahmoud Kadkhodaei ◽  
Mohammad Elahinia ◽  
...  
Keyword(s):  
Free Energy ◽  
Constitutive Model ◽  
Three Dimensional ◽  
Constitutive Models ◽  
Phenomenological Approach ◽  
Material Point ◽  
Loading History ◽  
Energy Potential ◽  
Microplane Model ◽  
Thermodynamic Driving Force

In most of the existing SMA constitutive models, it is assumed that transformation starts when a thermodynamic driving force reaches a specified amount regardless of loading history. In this work, a phenomenological approach is used to develop an enhanced one-dimensional constitutive model in which loading history is directly considered as one of the main parameters affecting the transformation start conditions. To generalize the model to three-dimensional cases, a microplane formulation based on volumetric-deviatoric is employed. A free energy potential is defined at the microplane level, integrated over all orientations at a material point to provide the macroscopic free energy. Experiments are carried out on Nitinol superelastic tubes to validate the newly proposed constitutive model. In these experiments, interruptions are applied during transformations to show the effects of loading history on transformation start conditions. Numerical results are compared with the experimental data to demonstrate the accuracy of the enhanced model.

Research of Solar Energy Potential of Photovoltaic Installations on Enclosing Structures of Buildings

2021 ◽  
Vol 10 (4) ◽  
pp. 18-34
Author(s):  
Yuliia Daus ◽  
Valeriy Kharchenko ◽  
Igor Yudaev
Keyword(s):  
Solar Energy ◽  
Spatial Orientation ◽  
Power Plants ◽  
Electric Energy ◽  
Building Envelope ◽  
Energy Potential ◽  
Photovoltaic Modules ◽  
Photovoltaic Power ◽  
Inclination Angles ◽  
New Consumer

Under conditions of limited space for the placement of photovoltaic modules, exploitation of rooftop and facade photovoltaic power plants are highly relevant. One of their main advantages is the possibility to integrate them into both existing and new consumer infrastructures, regardless of their configuration, using the building envelope. On the example of the specific tilt angles relative to the horizon of the receiving surfaces of the modules when they are placed on the enclosing structures of the building for southern spatial orientation, analysis of the utilization level of solar energy potential of the region is carried out. The inclination angles of the enclosing structures, which are characterized by the closest electric energy generation to the generation by modules of optimal spatial orientation, are revealed. There were also determined spatial orientations of the enclosing structures, for which the installation of modules of photovoltaic power plants is not recommended.

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