thermodynamic system
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2022 ◽  
Vol 355 ◽  
pp. 02058
Author(s):  
Tongyang Pan ◽  
Jifan Zhang ◽  
Jiannan Kang ◽  
Mingcheng Li

In order to calculation the enthalpy of wet steam in the secondary reheat turbine thermal system the thermodynamic system of the secondary reheat steam turbine based on the isentropic ideal expansion process line was corrected, This method simplifies the correction calculation step and increases the accuracy of the correction result. Analysis of the rationality of the improved method shows that: Compared with the existing secondary reheat steam turbine thermal system correction method, the maximum error of the improved thermal system correction method is 0.14%. Therefore, this method can better meet the test accuracy requirements.


Author(s):  
Djanfar El-Maktoume ◽  
Xavier Chesneau ◽  
Abdoulaye . ◽  
Diallo . ◽  
Sinon Souleymane ◽  
...  

This work is a contribution of a modelling of air conditioner by adsorption for a habitat in a tropical climate. The system mainly consists of a captor adsorber powered by a geothermal pump, a condenser and an evaporator. We use the zeolite/methanol couple and the different thresholds temperatures to define the thermodynamic system cycle. Moreover, we use a methodology based on nodal approach to establish heat and mass transfer equations. Dubinin-Astakhov thermodynamic model is employed to express the mass adsorbed, the coefficient of performance (COP) and the cold production. We make use of the climatic data in Comoros for 2009-2019 period to obtain the ambient temperature. The model validation is done by comparing the shape of the cycle we obtain with the state of the art. First, the results show a relationship between temperature, pressure and adsorbed mass. The increase in temperature is accompanied by an increase of pressure and an increase of adsorbed mass, and in the same way a decrease in the temperature causes a decrease of the pressure as well as a decrease of adsorbed mass. The mixture zeolite/methanol reaches 356K at the regeneration temperature with an input water temperature of 363K. We observed the influence of main important parameters on the mixture temperature such as fluid input temperature, fluid velocity or zeolite thermal conductivity. Finally, we show the thresholds temperatures influence on the COP and the cold production at evaporator.


2021 ◽  
Vol 82 (3) ◽  
pp. 58-60
Author(s):  
Evgenia Kozhoukharova

Three types of metamorphism are developed on the metamorphic complexes of the Rhodope Massif: a, widespread regional; b, high thermobaric in shear zones of friction and c, metasomatism, each with its own thermodynamic system. Friction generates energy that deforms, disintegrates and destroys minerals, subsequently recrystallized into new rocks.


2021 ◽  
Vol 221 (1) ◽  
pp. 180-185
Author(s):  
S. H. Jabarov ◽  
Y. I. Aliyev ◽  
T. M. Ilyasli ◽  
A. A. Baylarova ◽  
A. O. Dashdemirov ◽  
...  

Author(s):  
A.N. Morozov

The paper uses the example of the Brownian motion to kinetically describe the process of entropy increment in a nonequilibrium medium. The study shows that depending on the degree of nonequilibrium, the convergence to an equilibrium state occurs according to different laws. In the case of a strongly nonequilibrium medium, the entropy increment is described mathematically by the weakest logarithmic law, and in the case of a close-to-equilibrium medium, the entropy seeks a maximum value according to the strongest mathematical law --- the exponential law. The obtained expressions describing the Brownian motion can be extended to all other nonequilibrium processes. Mathematical modeling made it possible to calculate the process of entropy increment for an arbitrary degree of nonequilibrium and establish the parameters at which the transition from logarithmic to exponential law of entropy increment occurs when the thermodynamic system seeks an equilibrium state


2021 ◽  
Vol 875 (1) ◽  
pp. 012042
Author(s):  
V I Lisitsyn ◽  
N N Matveev ◽  
V V Saushkin

Abstract Modelling the dynamics of forest ecosystems is an urgent task, as the volume of publications in the Russian and world press demonstrates. In the proposed work, a new ecological and physiological model of a mixed forest stand has considered. Basically, it proceeds from the ecological and physiological model of a single-breed forest stand, that had obtained from the analysis of the behavior of an open thermodynamic system, which is a forest ecosystem. Four differential equations are required to describe a two-species stand, with the mutual influence of species being expressed both in interspecific competition for a resource and in mutual ‘support’ in the growth of the trees. The model of mixed stand with two species contains 10 independent parameters that have a clear physical meaning. Six parameters relate to the dynamics of each species, and four ones take into account the interactions of the species during growth. The verification of the model is presented by calculating the biomass dynamics for full two-stage aspen-spruce stands of European part (middle taiga ecoregion) of the first appraisal area. The presented model of the dynamics of forest ecosystems can be used in practical forestry, especially in the transition from an extensive method of forestry to an intensive one.


Entropy ◽  
2021 ◽  
Vol 23 (10) ◽  
pp. 1288
Author(s):  
Sean Devine

According to Landauer’s principle, at least kBln2T Joules are needed to erase a bit that stores information in a thermodynamic system at temperature T. However, the arguments for the principle rely on a regime where the equipartition principle holds. This paper, by exploring a simple model of a thermodynamic system using algorithmic information theory, shows the energy cost of transferring a bit, or restoring the original state, is kBln2T Joules for a reversible system. The principle is a direct consequence of the statistics required to allocate energy between stored energy states and thermal states, and applies outside the validity of the equipartition principle. As the thermodynamic entropy of a system coincides with the algorithmic entropy of a typical state specifying the momentum degrees of freedom, it can quantify the thermodynamic requirements in terms of bit flows to maintain a system distant from the equilibrium set of states. The approach offers a simple conceptual understanding of entropy, while avoiding problems with the statistical mechanic’s approach to the second law of thermodynamics. Furthermore, the classical articulation of the principle can be used to derive the low temperature heat capacities, and is consistent with the quantum version of the principle.


Author(s):  
Houcine Aounallah ◽  
Hayade Zarei ◽  
Prabir Rudra ◽  
Barun Majumder

In this paper, we explore the black hole solutions with rainbow deformed metric in the presence of exponential form of nonlinear electrodynamics with asymptotic Reissner-Nordstrom properties. We calculate the exact solution of metric function and explore the geometrical prop- erties in the background of massive gravity. From the obtained solution, the existence of the singularity is confirmed in proper limits. Using the solutions we also investigate the thermody- namic properties of the solutions by checking the validity of the first law of thermodynamics. Continuing the thermodynamic study, we investigate the conditions under which the system is thermally stable from the heat capacity and the Gibbs free energy. We also discuss the possible phase transition and the criticality of the system. It was found that the quantum gravitational effects of gravity’s rainbow render the thermodynamic system stable in the vicinity of the singu- larity. From the equation of state it was found that after diverging at the singularity, the system evolves asymptotically into pressure-less dust as one moves away from the central singularity.


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