Work output and thermal efficiency of an endoreversible entangled quantum Stirling engine with one dimensional isotropic Heisenberg model

2020 ◽  
Vol 547 ◽  
pp. 123856 ◽  
Author(s):  
Yong Yin ◽  
Lingen Chen ◽  
Feng Wu ◽  
Yanlin Ge
Keyword(s):  
Thermal Efficiency ◽  
Heisenberg Model ◽  
Stirling Engine ◽  
Work Output ◽  
One Dimensional

First and second law analysis of a Stirling engine with imperfect regeneration and dead volume

2009 ◽  
Vol 223 (11) ◽  
pp. 2595-2607 ◽  
Author(s):  
J Harrod ◽  
P J Mago ◽  
K Srinivasan ◽  
L M Chamra
Keyword(s):  
Entropy Generation ◽  
Thermal Efficiency ◽  
Engine Performance ◽  
Stirling Engine ◽  
Dead Volume ◽  
Second Law ◽  
Work Output ◽  
Volume Percentage ◽  
Stirling Cycle ◽  
Second Law Analysis

This article discusses the thermodynamic performance of an ideal Stirling cycle engine. This investigation uses the first law of thermodynamics to obtain trends of total heat addition, net work output, and thermal efficiency with varying dead volume percentage and regenerator effectiveness. Second law analysis is used to obtain trends for the total entropy generation of the cycle. In addition, the entropy generation of each component contributing to the Stirling cycle processes is considered. In particular, parametric studies of dead volume effects and regenerator effectiveness on Stirling engine performance are investigated. Finally, the thermodynamic availability of the system is assessed to determine theoretical second law efficiencies based on the useful exergy output of the cycle. Results indicate that a Stirling engine has high net work output and thermal efficiency for low dead volume percentages and high regenerator effectiveness. For example, compared to an engine with zero dead volume and perfect regeneration, an engine with 40 per cent dead volume and a regenerator effectiveness of 0.8 is shown to have ∼60 per cent less net work output and a 70 per cent smaller thermal efficiency. Additionally, this engine results in approximately nine times greater overall entropy generation and 55 per cent smaller second law efficiency.

scholarly journals Toeplitz algebras and spectral results for the one-dimensional Heisenberg model

2006 ◽  
Vol 47 (8) ◽  
pp. 082107 ◽  
Author(s):  
Mondher Damak ◽  
Marius Măntoiu ◽  
Rafael Tiedra de Aldecoa
Keyword(s):  
Heisenberg Model ◽  
One Dimensional ◽  
The One

Optimum Performance of a Regenerative Gas Turbine Power Plant Operating With/Without a Solid Oxide Fuel Cell

2011 ◽  
Vol 8 (5) ◽  
Author(s):  
Y. Haseli
Keyword(s):  
Fuel Cell ◽  
Pressure Drop ◽  
Solid Oxide Fuel Cell ◽  
Hybrid System ◽  
Thermal Efficiency ◽  
Pressure Ratio ◽  
Solid Oxide ◽  
Work Output ◽  
Oxide Fuel ◽  
Optimum Pressure

Optimum pressure ratios of a regenerative gas turbine (RGT) power plant with and without a solid oxide fuel cell are investigated. It is shown that assuming a constant specific heat ratio throughout the RGT plant, explicit expressions can be derived for the optimum pressure ratios leading to maximum thermal efficiency and maximum net work output. It would be analytically complicated to apply the same method for the hybrid system due to the dependence of electrochemical parameters such as cell voltage on thermodynamic parameters like pressure and temperature. So, the thermodynamic optimization of this system is numerically studied using models of RGT plant and solid oxide fuel cell. Irreversibilities in terms of component efficiencies and total pressure drop within each configuration are taken into account. The main results for the RGT plant include maximization of the work output at the expenses of 2–4% lower thermal efficiency and higher capital costs of turbo-compressor compared to a design based on maximum thermal efficiency. On the other hand, the hybrid system is studied for a turbine inlet temperature (TIT) of 1 250–1 450 K and 10–20% total pressure drop in the system. The maximum thermal efficiency is found to be at a pressure ratio of 3–4, which is consistent with past studies. A higher TIT leads to a higher pressure ratio; however, no significant effect of pressure drop on the optimum pressure ratio is observed. The maximum work output of the hybrid system may take place at a pressure ratio at which the compressor outlet temperature is equal to the turbine downstream temperature. The work output increases with increasing the pressure ratio up to a point after which it starts to vary slightly. The pressure ratio at this point is suggested to be the optimal because the work output is very close to its maximum and the thermal efficiency is as high as a littler less than 60%.

scholarly journals Topology and the one-dimensional Kondo-Heisenberg model

2020 ◽  
Vol 101 (16) ◽  
Author(s):  
Julian May-Mann ◽  
Ryan Levy ◽  
Rodrigo Soto-Garrido ◽  
Gil Young Cho ◽  
Bryan K. Clark ◽  
...  
Keyword(s):  
Heisenberg Model ◽  
One Dimensional ◽  
The One

scholarly journals Exact two-spinon dynamical correlation function of the one-dimensional Heisenberg model

1996 ◽  
Vol 54 (18) ◽  
pp. R12669-R12672 ◽  
Author(s):  
A. H. Bougourzi ◽  
M. Couture ◽  
M. Kacir
Keyword(s):  
Correlation Function ◽  
Heisenberg Model ◽  
Dynamical Correlation ◽  
One Dimensional ◽  
The One
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