Journal of Non-Equilibrium Thermodynamics最新文献_第2页

Exergy-based efficient ecological-function optimization for endoreversible Carnot refrigerators 内可逆卡诺冰箱基于火用的高效生态功能优化

IF 6.6 3区工程技术

Journal of Non-Equilibrium Thermodynamics Pub Date : 2025-03-12 DOI: 10.1515/jnet-2024-0099

Yanju He, Yanlin Ge, Lingen Chen, Huijun Feng

{"title":"Exergy-based efficient ecological-function optimization for endoreversible Carnot refrigerators","authors":"Yanju He, Yanlin Ge, Lingen Chen, Huijun Feng","doi":"10.1515/jnet-2024-0099","DOIUrl":"https://doi.org/10.1515/jnet-2024-0099","url":null,"abstract":"Based on the definition of exergy-based efficient ecological-function (EEF) proposed in the existing literature, which is the product of energy conversion coefficient-of-performance (ɛ) and exergy-based ecological-function (E), this paper will introduce the exergy-based EEF into performance optimization for Carnot refrigerator cycle. Via endoreversible Carnot refrigerator model established in previous literature, expression of the exergy-based EEF of refrigerator is derived based on finite-time thermodynamic theory, relationships of dimensionless exergy-based EEF versus ɛ and cooling load (R) are studied, and performance differences of refrigerator cycles at the maximum exergy-based EEF, at the maximum E, and at the maximum efficient cooling-load conditions are compared. The results demonstrate that relationships of dimensionless exergy-based EEF versus R and ɛ are parabolic-like ones; in actual design, the refrigerator should be designed at the larger R and ɛ points. When exergy-based EEF is taken as optimization-objective, although R decreases slightly, ɛ is increased, and entropy-generation-rate (σ) is greatly decreased, so exergy-based EEF does not only reflect the compromise between the R and σ, but also reflect the compromise between the R and ɛ.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"21 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143599507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Energetic analysis of a non-isothermal linear energy converter operated in reverse mode (I-LEC): heat pump 反向模式下非等温线性能量转换器（I-LEC）的能量分析：热泵

IF 6.6 3区工程技术

Journal of Non-Equilibrium Thermodynamics Pub Date : 2025-03-06 DOI: 10.1515/jnet-2024-0065

Saul Gonzalez-Hernandez

{"title":"Energetic analysis of a non-isothermal linear energy converter operated in reverse mode (I-LEC): heat pump","authors":"Saul Gonzalez-Hernandez","doi":"10.1515/jnet-2024-0065","DOIUrl":"https://doi.org/10.1515/jnet-2024-0065","url":null,"abstract":"In this paper, we perform an energetic analysis of a non-isothermal linear energy converter operated in inverse mode (refrigerator and heat pump). This is done within the framework of linear irreversible thermodynamics (LIT), starting from the model of an inverse linear energy converter (I-LEC) proposed by S. Gonzalez et al. (S. Gonzalez-Hernandez and L.-A. Arias-Hernandez, “Thermoelectric thomson relations revisited for a linear energy converter,” J. Non-Equilibrium Thermodyn., vol. 44, no. 3, pp. 315–332, 2019). We extend this model to the case of heat pumps, considering different objective functions and performing their respective analyses. We particularly focus on the coefficient of performance (COP) of heating, ϵ H . Additionally, we propose other energetic functions that may be of interest in the analysis of heat pumps, drawing analogies with the well-known functions for refrigerators and heat engines. Finally, we present a brief description of thermoelectric phenomena, focusing primarily on the Peltier effect. A brief analysis of the results obtained in the context of thermoelectric cooling and heating is presented for a non-isothermal LEC.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"212 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143570377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Heat transfer at nano-scale and boundary conditions: a comparison between the Guyer-Krumhansl model and the Thermomass theory 纳米尺度和边界条件下的传热：Guyer-Krumhansl模型与热质理论的比较

IF 6.6 3区工程技术

Journal of Non-Equilibrium Thermodynamics Pub Date : 2025-03-06 DOI: 10.1515/jnet-2024-0098

Carmelo F. Munafó, Patrizia Rogolino, Antonio Sellitto

引用次数: 0

Thermodynamic characterization of transient valve temperatures in diesel engines using probabilistic methods 用概率方法对柴油机瞬态气门温度进行热力学表征

IF 6.6 3区工程技术

Journal of Non-Equilibrium Thermodynamics Pub Date : 2025-02-27 DOI: 10.1515/jnet-2024-0052

Pardeep Kumar, Anikate Gupta, Dinesh Kumar, Vipin Kumar Sharma, Santosh Kumar Rai

{"title":"Thermodynamic characterization of transient valve temperatures in diesel engines using probabilistic methods","authors":"Pardeep Kumar, Anikate Gupta, Dinesh Kumar, Vipin Kumar Sharma, Santosh Kumar Rai","doi":"10.1515/jnet-2024-0052","DOIUrl":"https://doi.org/10.1515/jnet-2024-0052","url":null,"abstract":"This investigation aimed to predict the temperature distribution in the inlet and exhaust valve and isotherms to the cooling media at a given load of a diesel engine. For the analysis that has been done a Tata- Mercedes diesel engine with 90 mm bore diameter and Stroke length of 120 mm was analysed using FEM through Ansys workbench 15.0. Steady as well as transient cases were considered in combination. The temperature distribution and isotherms are computed and plotted using Ansys. The results obtained by Ansys workbench 15.0 were satisfactory and were in line when compared with finite differential analysis. There is a large temperature variation along the length of the valve. It may vary from 560 °C to 110 °C from tip to valve head in the exhaust valve while this variation is less in the case of inlet valve from 540 °C to 100 °C from the face to the tip. The linear temperature difference between the nodes at the base of the stem to the node at the center of the face increases with time and acquires the maximum value of about 120 °C at about 10 s then it decreases till the valve attains a steady state value. Thus, was observed from analysis that during this time there is a maximum probability of failure of valves due to linear differences in temperature.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"85 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143517942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Performance comparison of water towers and combined pumped hydro and compressed gas system and proposing a novel hybrid system to energy storage with a case study of a 50 MW wind farm 水塔与抽水蓄能和压缩气体联合系统的性能比较，并以50mw风电场为例，提出一种新型的混合系统用于储能

IF 6.6 3区工程技术

Journal of Non-Equilibrium Thermodynamics Pub Date : 2025-02-27 DOI: 10.1515/jnet-2024-0102

Amin Hadidi

{"title":"Performance comparison of water towers and combined pumped hydro and compressed gas system and proposing a novel hybrid system to energy storage with a case study of a 50 MW wind farm","authors":"Amin Hadidi","doi":"10.1515/jnet-2024-0102","DOIUrl":"https://doi.org/10.1515/jnet-2024-0102","url":null,"abstract":"In general, the most important method of energy storage at the power plant scale is the pumped hydro method, which has been developed in two main models to improve its performance, which is pumped hydro combined with compressed gas (PHCCG) and pumped hydro in closed towers (PHWT). In this research, to answer which of these methods is more suitable, in the form of a case study, both systems were designed to store the generated energy in the Aghkand wind farm with a nominal power of 50 (MW), and the performance of both was completely compared with each other. The findings indicated that the efficiency of the PHWT method was higher, but on the other hand, the water requirement of the PHCCG method was much lower than the PHWT method. Also, in an innovative way, the PHWT system was presented with a combination of towers of different classes and the performance of each was investigated. Finally, by combining both PHWT and PHCCG systems, a new hybrid system (HPHWTCG) was proposed. By using this hybrid system, the advantages of both methods can be used at the same time and the disadvantages of each method can be eliminated to a great extent. The efficiency of PHWT and PHCCG is 65 % and 45 % respectively. The efficiency of HPHWTCG is between these two values based on its structure.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"23 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143517943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Existence of the Chapman–Enskog solution and its relation with first-order dissipative fluid theories Chapman-Enskog解的存在性及其与一阶耗散流体理论的关系

IF 6.6 3区工程技术

Journal of Non-Equilibrium Thermodynamics Pub Date : 2025-02-27 DOI: 10.1515/jnet-2024-0086

Ana Laura García-Perciante, Alma Rosa Méndez, Olivier Sarbach

引用次数: 0

Is there a need for an extended phase definition for systems far from equilibrium? 对于远离平衡的系统是否需要一个扩展的相定义？

IF 6.6 3区工程技术

Journal of Non-Equilibrium Thermodynamics Pub Date : 2025-02-13 DOI: 10.1515/jnet-2024-0063

Fernando Bautista, Juan Paulo García-Sandoval, Octavio Manero

{"title":"Is there a need for an extended phase definition for systems far from equilibrium?","authors":"Fernando Bautista, Juan Paulo García-Sandoval, Octavio Manero","doi":"10.1515/jnet-2024-0063","DOIUrl":"https://doi.org/10.1515/jnet-2024-0063","url":null,"abstract":"Phase diagrams out of equilibrium have been the subject of intense research. An essential concept in these diagrams is the phase definition. Currently, that definition is well established for systems at classic thermodynamic equilibrium conditions. However, such phase definition is inadequate for systems that are not at equilibrium in the classic thermodynamic sense, like fluid systems under flowing conditions. Complex fluids may exhibit instabilities like shear-banding flow and a non-equilibrium critical point where banding flow ends. At this point, the fluid undergoes a phase transition from heterogeneous to homogeneous states. An extended thermodynamic space of variables is considered to adequately address this situation, which includes non-conservative variables such as stress and shear rate. Hence, the current phase definition based on conservative variables does not apply to non-equilibrium phase diagrams. On this basis, a broader definition of phase is required. We propose that this broader definition considers the thermodynamic variables space of Extended Irreversible Thermodynamics and the mathematical conditions that ensure compatibility between equilibrium and non-equilibrium conditions for systems where phases are well described by thermodynamic potentials even out of equilibrium.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"67 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143417792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical simulation of binary convection within the Soret regime in a tilted cylinder 倾斜圆柱体Soret区二元对流的数值模拟

IF 6.6 3区工程技术

Journal of Non-Equilibrium Thermodynamics Pub Date : 2025-02-10 DOI: 10.1515/jnet-2024-0064

Arantxa Alonso, Isabel Mercader, Oriol Batiste, Alvaro Meseguer

{"title":"Numerical simulation of binary convection within the Soret regime in a tilted cylinder","authors":"Arantxa Alonso, Isabel Mercader, Oriol Batiste, Alvaro Meseguer","doi":"10.1515/jnet-2024-0064","DOIUrl":"https://doi.org/10.1515/jnet-2024-0064","url":null,"abstract":"This study computationally investigates the time-dependent patterns emerging in the Soret regime for binary fluid convection in slightly inclined cylinders heated from below, with a particular focus on positive Soret coefficient thermophobic mixtures (S T > 0) and aspect ratios Γ = 5.2, Γ = 5.3, and Γ = 5.4. By varying the Rayleigh number (Ra) and smoothly adjusting its increments, we capture a range of spatio-temporal behaviours, revealing the coexistence of large-scale shear flows (LSF) and superhighway convection (SHC) patterns. SHC-like structures, characterised by a high base frequency, involve oscillating plumes arranged in adjacent lanes, moving in opposite directions along the inclination. Remarkably, this frequency remains nearly constant across different Ra values. Some of the observed coherent structures, such as periodic and modulated solutions, exhibit equivariance with respect to some elements of the <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <m:msub> <m:mrow> <m:mi mathvariant=\"double-struck\">D</m:mi> </m:mrow> <m:mrow> <m:mn>2</m:mn> </m:mrow> </m:msub> </m:math> ${mathbb{D}}_{2}$ symmetry group inherent to the physical system. In the case of Γ = 5.4, we identify three-frequency orbits, with modulations up to two orders of magnitude smaller than the base frequency. The observed dynamics is highly sensitive to small variations of Γ, with different patterns being stabilized depending on the aspect ratio of the cell. The bifurcation scenarios are complex and case-specific, and their precise determination is computationally demanding.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"44 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143385205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Entropy as Noether charge for quasistatic gradient flow 准静态梯度流的诺特电荷熵

IF 6.6 3区工程技术

Journal of Non-Equilibrium Thermodynamics Pub Date : 2025-02-06 DOI: 10.1515/jnet-2024-0054

Aaron Beyen, Christian Maes

引用次数: 0

Efficient ecological function optimization for endoreversible Carnot heat pumps 内可逆卡诺热泵高效生态功能优化

IF 6.6 3区工程技术

Journal of Non-Equilibrium Thermodynamics Pub Date : 2025-01-03 DOI: 10.1515/jnet-2024-0061

Yiwen Su, Lingen Chen, Yanlin Ge, Huijun Feng

引用次数: 0