scholarly journals Analysis of a thermal cycle that surpass Carnot efficiency undergoing closed polytropic transformations

2019 ◽  
Vol 15 ◽  
pp. 6165-6182
Author(s):  
Ramon Ferreiro Garcia ◽  
Dr. Jose Carbia Carril
Keyword(s):  
Thermal Efficiency ◽  
Thermal Cycle ◽  
Research Work ◽  
Mechanical Work ◽  
Working Fluid ◽  
Specific Work ◽  
Adiabatic Expansion ◽  
Thermal Cycles ◽  
Active Processes ◽  
The Ideal

This research work deals with a feasible non-regenerative thermal cycle, composed by two pairs of closed polytropic-isochoric transformations implemented by means of a double acting reciprocating cylinder which differs basically from the conventional Carnot based thermal cycles in that: -it consists of a non condensing mode thermal cycle -all cycle involves only closed transformations, instead of the conventional open processes of the Carnot based thermal cycles, -in the active processes (polytropic path functions), as heat is being absorbed, mechanical work is simultaneously performed, avoiding the conventional quasi-adiabatic expansion or compression processes inherent to the Carnot based cycles and, -during the closed polytropic processes, mechanical work is also performed by means of the working fluid contraction due to heat releasing. An analysis of the proposed cycle is carried out for helium as working fluid and results are compared with those of a Carnot engine operating under the same ratio of temperatures. As a result of the cycle analysis, it follows that the ratio of top to the bottom cycle temperatures has very low dependence on the ideal thermal efficiency, but the specific work, and, furthermore, within the range of relative low operating temperatures, high thermal efficiency is achieved, surpassing the Carnot factor.

scholarly journals Efficient Thermal Cycle Undergoing Adiabatic Contraction Based Work by Releasing Heat

2019 ◽  
pp. 1-15
Author(s):  
Ramon Ferreiro Garcia
Keyword(s):  
Thermal Efficiency ◽  
High Performance ◽  
Mechanical Work ◽  
Heat Extraction ◽  
Working Fluid ◽  
Low Grade ◽  
Compression Process ◽  
Compression Phase ◽  
Heat Addition ◽  
Thermodynamic Transformations

By means of observational evidence it is shown that, among the vast amount of heat-work interactions occurring in closed process based transformations, there exists the possibility of doing a transformation characterized by doing useful mechanical work by contraction based compression, while increasing the internal energy. Such thermodynamic transformation has never been considered in processes. However, in reality closed contraction based compression process are physically possible in which net work is produced by contraction of a thermal working fluid while fulfilling the fundamental laws. Thus, the objective is therefore to analyze heat-work interaction modes in closed processes conducted by heat addition, heat extracting and net work done by the process. Therefore, this analysis focuses on the feasible thermodynamic transformations contributing to the achievement of efficient closed processes based thermal cycles. The proposed cycles are characterized by performing mechanical work both in the expansion phase due to heat addition, and in the compression phase due to heat releasing. The cycles achieved are characterized by operating with closed thermal processes in which both transformations with isochoric heat addition and isochoric heat extraction are associated with useful mechanical work at high performance. The analysis of the cycle between top working temperatures ranging from 350 to 700 K while botom temperature approaches 300 K has been carried out, corroborated by experimental validation for low temperatures, in the order of 350 degrees Kelvin through a test bench designed specifically for this task. It is also worth noting that the thermal efficiency is independent of the temperature ratio. Therefore the results indicate that for lower temperatures below 690 K, the thermal efficiency of the cycle exceeds the Carnot factor, which is an efficient means of recovering residual or low-grade heat efficiently.

scholarly journals EFFICIENCY OF THE REGENERATIVE CYCLE OF BRIGHTON WITH VARIABLE THERMOPHYSICAL PROPERTIES OF THE WORKING FLUID (Part 2)

2018 ◽  
Vol 41 (3) ◽  
pp. 5-13
Author(s):  
A.A. Khalatov ◽  
S.D. Severin ◽  
O.S. Stupak ◽  
O.V. Shihabutinova
Keyword(s):  
Moisture Content ◽  
Thermophysical Properties ◽  
Thermal Efficiency ◽  
Second Law Of Thermodynamics ◽  
Maximum Temperature ◽  
Working Fluid ◽  
Thermodynamic Efficiency ◽  
Carnot Cycle ◽  
Regenerative Cycle ◽  
The Ideal

The data about thermodynamic efficiency of the ideal Brighton cycle with heat regeneration with constant thermophysical properties of the working fluid, as well as the Brighton cycle with heat recovery and the wetting of the working fluid at the inlet to the turbine (with variable thermophysical properties of the working fluid). The inapplicability of comparison of the thermal efficiency of the Brighton cycle with heat recovery and the wetting of the working fluid at the inlet to the turbine with the thermal efficiency of the equivalent ideal Carnot cycle is shown. The analysis of the thermodynamic efficiency of an ideal regenerative Brighton cycle with a decrease in the working body at the entrance to the turbine allows us to make the following conclusions: With the growth of the mass moisture content of the working fluid when entering the turbine, the thermal efficiency of the regenerative cycle increases, but decreases with an increase in the degree of increase in the pressure level in the cycle. High values ​​of the thermal efficiency of the cycle () can be achieved with relatively small values ​​of the degree of increase in the pressure in the cycle () and high (up to d = 0,5) values ​​of the mass moisture content of the working body when entering the turbine. It is shown that under certain conditions the thermal efficiency of the regenerative cycle with the decrease of the working body when entering the turbine may be greater than the thermal efficiency of a similar ideal Carnot cycle, which does not contradict the second law of thermodynamics, since the condition for the implementation of the Carnot cycle is the immutability of the thermophysical properties of the working body in a loop In this regard, the use of the expression for the thermal efficiency of the ideal Carnot cycle is not used as a criterion for assessing the efficiency of cycles of power plants with highly variable thermophysical properties of the working fluid. It is also shown that the thermal efficiency of the regenerative cycle with the decrease of the working body when entering the turbine is always lower than the thermal efficiency of the equivalent non-equilibrium Carnot cycle with a change in the specific heat of the working fluid, which corresponds to the second law of thermodynamics. It is shown that the Brighton regenerative cycle with a decrease in the working body before the turbine can be represented as a conditional cycle with a higher maximum temperature of the cycle, which, depending on the mass content of the moisture content of the working body, can in 1,2 ... 2,5 times exceed the actual maximum temperature cycle, which determines the high values ​​of its thermal efficiency.

The Effect of Material Properties on the Thermal Efficiency of the Minto Solar Wheel

1980 ◽  
Vol 102 (2) ◽  
pp. 504-507 ◽  
Author(s):  
S. Lin ◽  
R. Bhardwaj
Keyword(s):  
Thermal Performance ◽  
Thermal Efficiency ◽  
Material Properties ◽  
Working Fluid ◽  
Working Fluids ◽  
Mean Diameter ◽  
The Mean ◽  
The Ideal

The characteristic of the thermal performance of the Minto solar wheel is that its thermal efficiency is strongly dependent on the material properties of the working fluid. For a specified working fluid, the thermal efficiency of the ideal cycle of the Minto solar wheel is dependent only on the mean diameter of the wheel. To study the effect of the material properties of the working fluid on the ideal thermal efficiency, 14 working fluids are selected, and their thermal efficiencies as functions of the mean diameter of the wheel are calculated and compared with each other. Among these fluids, R-12, R-115, R-500, R-22 and R-13B1 achieve better thermal performance than the others.

Designing Boiling Condenser for More Efficiency in Power Plants and Less Environment Defects

2007 ◽  
Author(s):  
Mohsen Sharifpur
Keyword(s):  
Global Warming ◽  
Heat Exchange ◽  
Power Plant ◽  
Thermal Efficiency ◽  
Thermal Cycle ◽  
Power Plants ◽  
Nuclear Reactors ◽  
Heat Losses ◽  
Working Fluid ◽  
Input Energy

One of the most important problems in the power plants is to increase the thermal efficiency of the cycle. Most of the works in this area is focused on regeneration devices, removing the heat losses of components…But usually, about half of the input energy in the thermal cycle wastes in the condensers. In this day and age with greenhouse effect and global warming problem, the less environment defect is also another important subject. In this work, a new condenser is offered that is the same as a core of BWR nuclear reactors, then during the working fluid is condensing in a cycle it is a boiling generator (boiling heat exchange) for another cycle. In this way not only could change some parts of unused energy to work, but also it has more capability with environment. It is possible to design this process several times with different cycles and different working fluids to low heat wastes from condensers. Here, it is offered this idea by using the data of Catalagzi power plant in Turkey. The results confirm that the thermal efficiency increases at least %7.5. It can use this method for most of the power plants or somewhere that needed to remove some heat from a device, same as radiators of the automobiles.

scholarly journals Quantum Lenoir Engine with a Single Particle System in a One Dimensional Infinite Potential Well

POSITRON ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 81
Author(s):  
Yohanes Dwi Saputra
Keyword(s):  
Quantum System ◽  
Single Particle ◽  
Thermal Efficiency ◽  
Particle System ◽  
Ideal Gas ◽  
Working Fluid ◽  
Potential Well ◽  
One Dimensional ◽  
Infinite Potential Well ◽  
The Ideal

Lenoir engine based on the quantum system has been studied theoretically to increase the thermal efficiency of the ideal gas. The quantum system used is a single particle (as a working fluid instead of gas in a piston tube) in a one-dimensional infinite potential well with a wall that is free to move. The analogy of the appropriate variables between classical and quantum systems makes the three processes for the classical Lenoir engine applicable to the quantum system. The thermal efficiency of the quantum Lenoir engine is found to have the same formulation as the classical one. The higher heat capacity ratio in the quantum system increases the thermal efficiency of the quantum Lenoir engine by 56.29% over the classical version at the same compression ratio of 4.41.

scholarly journals The Interface Microstructure and Shear Strength of Sn2.5Ag0.7Cu0.1RExNi/Cu Solder Joints under Thermal-Cycle Loading

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 518 ◽  
Author(s):  
Congcong Cao ◽  
Keke Zhang ◽  
Baojin Shi ◽  
Huigai Wang ◽  
Di Zhao ◽  
...  
Keyword(s):  
Shear Strength ◽  
Fracture Mechanism ◽  
Thermal Cycle ◽  
Solder Joints ◽  
Joint Interface ◽  
Interface Microstructure ◽  
Average Thickness ◽  
Thermal Cycles ◽  
Initial State ◽  
Cycle Loading

The interface microstructure and shear strength of Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints under thermal-cycle loading were investigated with scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and physical and chemical tests. The results show that an intermetallic compound (IMC) layer of Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints evolved gradually from the scalloped into larger wavy forms with increasing number of thermal cycles. The roughness and average thickness of IMC increased with thermal-cycle loading. However, at longer thermal-cycle loading, the shear strength of the joints was reduced by about 40%. The fracture pathway of solder joints was initiated in the solder seam with ductile fracture mechanism and propagated to the solder seam/IMC layer with ductile-brittle mixed-type fracture mechanism, when the number of thermal cycles increased from 100 to 500 cycles. By adding 0.05 wt.% Ni, the growth of the joint interface IMC could be controlled, and the roughness and average thickness of the interfacial IMC layer reduced. As a result, the shear strength of joints is higher than those without Ni. When compared to joint without Ni, the roughness and average thickness of 0.05 wt.% Ni solder joint interface IMC layer reached the minimum after 500 thermal cycles. The shear strength of that joint was reduced to a minimum of 36.4% of the initial state, to a value of 18.2 MPa.

COMPARATIVE LITERATURE: EAST AND WEST STUDIES

2021 ◽  
Vol 02 (09) ◽  
pp. 8-14
Author(s):  
Aziza Komilovna Akhmedova ◽  
Keyword(s):  
Comparative Literature ◽  
Professional Ethics ◽  
Research Work ◽  
Literary Studies ◽  
The Novel ◽  
World Science ◽  
History Of ◽  
The Aesthetic ◽  
Aesthetic Ideal ◽  
The Ideal

The article analyzes the results of the research on the representation of the aesthetic ideal through the image of the ideal hero in two national literatures. For research purposes, attention was paid to highlighting the category of the ideal hero as an expression of the author's aesthetic views. In Sinclair Lewis’s “Arrowsmith” and Pirimkul Kodirov's “The Three Roots”, the protagonists artistically reflect the authors' views on truth, virtue, and beauty. In these novels, professional ethics is described as a high noble value. The scientific novelty of the research work includes the following: in the evolution of western and eastern poetic thought, in the context of the novel genre, the skill, common and distinctive aspects of the creation of an ideal hero were revealed by synthesis of effective methods in world science with literary criteria in the history of eastern and western literary studies, in the example of Sinclair Lewis and Pirimkul Kodirov.

scholarly journals The Literary «Ekphrasis» of Castel Nuovo: A Contribution to Value the Cultural Identity of the Ideal City Government, Promoted by Aristocratic Courts and Civil Administrations in the XIV Century

2014 ◽  
Vol 11 ◽  
pp. 483-488
Author(s):  
Sara Cipolla
Keyword(s):  
Cultural Identity ◽  
Research Work ◽  
Italian Literature ◽  
City Government ◽  
The Other ◽  
The Political ◽  
Ripe Fruit ◽  
Surface Projection ◽  
Medieval Italian Literature ◽  
The Ideal

The research work concerns the development in the Italian literature of the French theme of Neuf Preux, and Particularly Took into account a crown of sonnets of nine famous men linked to an alleged cycle of paintings attributed to Giotto's in the palace of Castel Nuovo in Naples. The survey highlighted how in medieval Italian literature, beyond the more or less explicit recovery of the French literary tradition, occupies a prominent place the function that these poems take in the view of the literature of the time. The survey actually shows the two faces of the series of famous heroes, which on one hand is the mouthpiece of the political ideals and civil inspired by the courteous and Roman antiquities, on the other hand appears to be ripe fruit of a didactic poem in which the adherence to the motto of "ut pictura poesis" become as a kind of surface projection of images.

scholarly journals Classical Traditions of the Piano Concerto by Ruslan Agababayev

2021 ◽  
Vol 4 (1) ◽  
pp. 130-139
Author(s):  
Parvin Rustamova
Keyword(s):  
21St Century ◽  
Complex Analysis ◽  
Symphony Orchestra ◽  
Research Work ◽  
Scientific Work ◽  
Point Of View ◽  
Specific Work ◽  
Piano Concerto ◽  
Methodological Basis ◽  
Classical Traditions

The article is devoted to the analysis of the concert for piano and symphony orchestra by the modern Azerbaijani composer R. Agababayev. The article is very relevant from the point of view of identifying ways to implement classical traditions in a modern piano concerto of the 21st century. It must be said that in this issue we have found many such stylistic features that testify to the strong reliance of Azerbaijani composers on classical traditions. This article is devoted to the study of identifying the stylistic features of R. Agababayev’s piano concerto in the context of the historical development of this genre. Research methodology. The choice of the methodological basis for this study is due to the above goals and tasks that we set ourselves in the framework of this work. Based on the subject matter of the article, the methodological basis of this scientific work is a complex analysis, which implies the interaction of several research methods at different levels. The basis for the analytical analysis of the piano concerto was a theoretical approach, in which such aspects of the work as the problem of form formation, stylistic features of individual elements of the musical language are subject to research. The scientific novelty of the research lies in the fact that for the first time as special research work is the study and detailed analysis of R. Agababayev’s piano concerto. Conclusions. The main conclusion of our scientific research was to determine the stylistic features of the Azerbaijani piano concert created in the 21st century. Based on the data obtained during the analysis, we were able to determine the main trends and ways of development of this genre at the present stage of the development of Azerbaijani academic music. One of the important, if not decisive, aspect in achieving this kind of goal is to identify issues of preserving and transforming traditions, as well as innovative tendencies in the composer’s solution of a particular work. Single-movement piano concertos have become widespread in academic music since the beginning of the era of romanticism. And in the Azerbaijani one-part piano concerts, connections with romantic traditions are deeply felt. Moreover, in each specific work, these traditions are reflected especially. Since the concert by R. Agababayev demonstrates an interesting and original one-part interpretation, combined with an inner poly-part one, this is a typically romantic tendency associated with the composers’ desire to compress the cycle.

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