Archives of Thermodynamics最新文献_第10页

A case study of working fluid selection for a small-scale waste heat recovery ORC system 小型余热回收ORC系统工质选择实例研究

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ATHER.2019.129999

P. Klimaszewski, D. Zaniewski, Ł. Witanowski, T. Suchocki, P. Klonowicz, P. Lampart

{"title":"A case study of working fluid selection for a small-scale waste heat recovery ORC system","authors":"P. Klimaszewski, D. Zaniewski, Ł. Witanowski, T. Suchocki, P. Klonowicz, P. Lampart","doi":"10.24425/ATHER.2019.129999","DOIUrl":"https://doi.org/10.24425/ATHER.2019.129999","url":null,"abstract":"The paper illustrates a case study of fluid selection for an internal combustion engine heat recovery organic Rankine cycle (ORC) system having the net power of about 30 kW. Various criteria of fluid selection are discussed. Particular attention is paid to thermodynamic performance of the system and human safety. The selection of working fluid for the ORC system has a large impact on the next steps of the design process, i.e., the working substance affects the turbine design and the size and type of heat exchangers. The final choice is usually a compromise between thermodynamic performance, safety and impact on natural environment. The most important parameters in thermodynamic analysis include calculations of net generated power and ORC cycle efficiency. Some level of toxicity and flammability can be accepted only if the leakages are very low. The fluid thermal stability level has to be taken into account too. The economy is a key aspect from the commercial point of view and that includes not only the fluid cost but also other costs which are the consequence of particular fluid selection. The paper discusses various configurations of the ORC system – with and without a regenerator and with direct or indirect evaporation. The selected working fluids for the considered particular power plant include toluene, DMC (dimethyl carbonate) and MM (hexamethyldisiloxane). Their advantages and disadvantages are outlined. ∗Corresponding Author. Email: pklimaszewski@imp.gda.pl 160 P. Klimaszewski, et al.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41673982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Generalized thermal microstretch elastic solid with harmonic wave for mode-I crack problem 具有谐波的广义热微拉伸弹性固体I型裂纹问题

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ATHER.2020.133626

K. Lotfy, A. El-Bary, M. Allan, M. H. Ahmed

引用次数: 2

Passive cooling through the atmospheric window for vehicle temperature control 通过大气窗进行被动冷却以控制车辆温度

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2021.138108

U. Khan, R. Zevenhoven

{"title":"Passive cooling through the atmospheric window for vehicle temperature control","authors":"U. Khan, R. Zevenhoven","doi":"10.24425/ather.2021.138108","DOIUrl":"https://doi.org/10.24425/ather.2021.138108","url":null,"abstract":"One of the most energy-intensive activities for a vehicle is space air conditioning, for either cooling or heating. Considerable energy savings can be achieved if this can be decoupled from the use of fuel or electricity. This study analyzes the opportunities and eﬀectiveness of deploying the concept of passive cooling through the atmospheric window (i.e. the 8– 14 µ m wavelength range where the atmosphere is transparent for thermal radiation) for vehicle temperature control. Recent work at our institute has resulted in a skylight (roof window) design for passive cooling of building space. This should be applicable to vehicles as well, using the same materials and design concept. An overall cooling eﬀect is obtained if outgoing (long wavelength greater than 4 µ m) thermal radiation is stronger than the incoming (short wavelength less than 4 µ m) thermal radiation. Of particular interest is to quantify the passive cooling of a vehicle parked under direct/indirect sunlight equipped with a small skylight, designed based on earlier designs for buildings. The work involved simulations using commercial computational ﬂuid dynamics software implementing (where possible) wavelength-dependency of thermal radiation properties of materials involved. The ﬁndings show that by the use of passive cooling, a temperature diﬀerence of up to 7–8 K is obtained with an internal gas ﬂow rate of 0.7 cm/s inside the sky-light. A passive cooling eﬀect of almost 27 W/m 2 is attainable for summer season in Finland. Comparison of results from Ansys Fluent and COMSOL models shows diﬀerences up to about 10 W/m 2 in the estimations.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49517077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

A universal model for solar radiation exergy accounting: Case study of Tunisia 太阳辐射火用计算的通用模型:以突尼斯为例

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2022.141980

D. Lounissi, N. Bouaziz

{"title":"A universal model for solar radiation exergy accounting: Case study of Tunisia","authors":"D. Lounissi, N. Bouaziz","doi":"10.24425/ather.2022.141980","DOIUrl":"https://doi.org/10.24425/ather.2022.141980","url":null,"abstract":"The global solar radiation is the origin for all environmental processes on the earth and the majority of energy sources are derived from it. The data of solar radiation are required for the design and the study of solar application systems. The more important is the quality of the solar radiation which is deﬁned by the maximum work can be provided by the solar radiation. This quality is measured by the exergy content of a solar radiation. In the present work, a universal pattern has been built to provide a prediction of solar exergy dependently to the geographic location. Fitting models have been developed for exergy account depending on geographic location, based on the linear, quadratic, cubic, logarithmic, exponential, power regression. The Petela model is adopted from literature for exergetic eﬃciency accounting of solar radiation. The global solar radiation according to ASHRAE model is expressed dependently of the cosine of zenith angle. The developed model is applied on Tunisia regions to predict exergy solar potential. The studied regions are classiﬁed regarding the exergy account, high, medium and low solar exergy locations. Results show that generally the solar radiation shows a low degree of exergy content, about 7% of diﬀerence.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43652475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

An experimental study of solar air heater using arc shaped wire rib roughness based on energy and exergy analysis 基于能量和火用分析的弧形丝肋粗糙度太阳能空气加热器实验研究

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2021.138112

Harish Kumar Ghritlahre

{"title":"An experimental study of solar air heater using arc shaped wire rib roughness based on energy and exergy analysis","authors":"Harish Kumar Ghritlahre","doi":"10.24425/ather.2021.138112","DOIUrl":"https://doi.org/10.24425/ather.2021.138112","url":null,"abstract":"In the present study, energy and exergy analysis has been evaluated for roughened solar air heater (SAH) using arc shaped wire ribs. To achieve this aim, two diﬀerent types of ﬂow arrangement have been considered. These arrangements are: apex upstream ﬂow and apex downstream ﬂo. In addition to this, a smooth duct SAH has been used for comparative study. The experiments were performed using the mass ﬂow rate of 0.007– 0.022 kg/s on outdoor condition at Jamshedpur city of India. The absorber plate roughness geometry has been designed with relative roughness height 0.0395, rib size 2.5 mm, relative roughness pitch 10 and arc angle 60 ◦ . The energetic and exergetic performances have been examined on the basis of the ﬁrst and second law of thermodynamics. According to the results, there is observed to be the maximum thermal eﬃciency and exergy eﬃciency as 73.2% and 2.64%, respectively, for apex upstream ﬂow SAH at 0.022 kg/s, while, at same mass ﬂow rate the maximum thermal eﬃciency and exergy ef-ﬁciency is obtained as 69.4% and 1.89%, respectively, for apex downstream ﬂow SAH. In addition to this, results reported that the maximum outlet temperature and temperature diﬀerence observed at lower mass ﬂow rate. Also examined the outlet air temperature of SAH with various mass ﬂow rates is very important for both analysis.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47027594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Research on oxy-fuel combustion power cycle using nitrogen for turbine cooling 利用氮气进行涡轮冷却的全氧燃烧动力循环研究

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2020.135859

V. Kindra, Rogalev, O. Zlyvko, A. Zonov, M. Smirnov, Ilya

引用次数: 4

Implementation of turbulence damping in the OpenFOAM multiphase flow solver interFoam 湍流阻尼在OpenFOAM多相流求解器interFoam中的实现

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2022.140923

J. Polansky, S. Schmelter

{"title":"Implementation of turbulence damping in the OpenFOAM multiphase flow solver interFoam","authors":"J. Polansky, S. Schmelter","doi":"10.24425/ather.2022.140923","DOIUrl":"https://doi.org/10.24425/ather.2022.140923","url":null,"abstract":"In the presented work Egorov’s approach (adding a source term to the ω -equation in the k - ω model, which mimics the damping of turbulence close to a solid wall) was implemented in on the subclass of shear stress transport models. Hence, turbulence damping is available for all shear stress transport type models, including hybrid models that are based on the ω -equation. It is shown that turbulence damping improves the prediction of the axial velocity proﬁle not only for Reynolds-averaged Navier–Stokes simulation but also for detached eddy simulation and delayed detached eddy simulation models. Furthermore, it leads to a more realistic estimation of the pressure drop and, hence, to a more correct prediction of the liquid level. In this paper, simulation results for four diﬀerent turbulence models are presented and validated by comparison with experimental data. Furthermore, the inﬂuence of the magnitude of the damping factor on the pressure drop in the channel is investigated for a variety of diﬀerent gas-to-liquid ﬂow rate ratios. These investigations show that higher gas-to-liquid ﬂow rate ratios require higher damping factors to correctly predict the pressure drop. In the end, advice is formulated on how an appropriate damping factor can be determined for a speciﬁc test case.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42402623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Development of flow and efficiency characteristics of an axial compressor with an analytical method including cooling air extraction and variable inlet guide vane angle 轴流压气机的流动和效率特性的分析方法，包括冷却空气抽取和可变进口导叶角

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2021.138121

Paweł Trawiński

{"title":"Development of flow and efficiency characteristics of an axial compressor with an analytical method including cooling air extraction and variable inlet guide vane angle","authors":"Paweł Trawiński","doi":"10.24425/ather.2021.138121","DOIUrl":"https://doi.org/10.24425/ather.2021.138121","url":null,"abstract":"The development of a reliable mathematical model of an axial compressor requires applying ﬂow and eﬃciency characteristics. This approach provides performance parameters of a machine depending on varying conditions. In this paper, a method for developing characteristics of an axial compressor is presented, based on general compressor maps available in the literature or measurement data from industrial facilities. The novelty that constitutes the core of this article is introducing an improved method describing the performance lines of an axial compressor with the modiﬁed ellipse equation. The proposed model is extended with bleed air extraction for the purposes of cooling the blades in the expander part of the gas turbine. The variable inlet guide vanes angle is also considered using the vane angle correction factor. All developed dependencies are fully analytical. The presented approach does not require knowledge of machine geometry. The set of input parameters is based on reference data. The presented approach makes it possible to determine the allowed operating area and study the machine’s performance in variable conditions. The introduced mathematical correlations provide a fully analytical study of optimum operating points concerning the chosen criterion. The ﬁnal section presents a mathematical model of an axial compressor built using the developed method. A detailed study of the exemplary ﬂow and eﬃciency characteristics of an axial compressor operating with a gas turbine is also provided.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42500312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Reduction of carbon footprint from spark ignition power facilities by the dual approach 通过双重方法减少火花点火电力设施的碳足迹

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2021.137559

K. Janusz-Szymańska, K. Grzywnowicz, G. Wiciak, L. Remiorz

{"title":"Reduction of carbon footprint from spark ignition power facilities by the dual approach","authors":"K. Janusz-Szymańska, K. Grzywnowicz, G. Wiciak, L. Remiorz","doi":"10.24425/ather.2021.137559","DOIUrl":"https://doi.org/10.24425/ather.2021.137559","url":null,"abstract":"Power generation units, suitable for individual users and small scale applications, are mainly based on spark ignition engines. In recently performed research, reductions of emissions coming from such units, especially considering carbon dioxide emissions, are deemed as the issue of particular importance. One of solutions, postponed to reduce impact of spark ignition engine-based units on the natural environment, is transition from fossil fuels into renewable gaseous fuels, as products of organic digestion. Nonetheless, development of new solutions is required to prevent further carbon dioxide emissions. The paper presents a novel dual approach developed to reduce carbon dioxide emissions from stationary power units, basing on spark ignition engine. The discussed approach includes both reduction in carbon content in the fuel, which is realized by its enrichment with hydrogen produced using the solar energy-supported electrolysis process, as well as application of post-combustion carbon dioxide separation. Results of the performed analysis suggest proﬁtability of transition from fossil into the hydrogen-enriched fuel mixture, with signiﬁcant rise in operational parameters of the system following increase in the hydrogen content. Nevertheless, utilization of the carbon dioxide separation leads to vital soar in internal energy demand, causing vital loss in operational and economical parameters of the analyzed system.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41265082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Challenges in operating and testing loop heat pipes in 500–700 K temperature ranges 在500-700 K温度范围内操作和测试环路热管的挑战

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2022.141978

P. Szymański

{"title":"Challenges in operating and testing loop heat pipes in 500–700 K temperature ranges","authors":"P. Szymański","doi":"10.24425/ather.2022.141978","DOIUrl":"https://doi.org/10.24425/ather.2022.141978","url":null,"abstract":"The potential applications of loop heat pipes (LHPs) are the nuclear power space systems, fuel cell thermal management systems, waste heat recovery systems, medium temperature electronic systems, medium temperature military systems, among others. Such applications usually operate in temperature ranges between 500–700 K, hence it is necessary to develop an LHP system that will meet this requirement. Such a thermal management device require to meet various technical problems and challenges currently existing in the development of LHP working in medium temperatures, including: (1) selection of appropriate working ﬂuid; (2) selection of appropriate LHP construction material; (3) construction of suitable test rig capable of testing at elevated temperatures; (4) development of new testing methods. Currently, there are no proven working ﬂuids that can be used in LHPs in medium temperature ranges. Water can be applicable only at temperatures up to 570 K. Caesium can be applicable at temperatures above 670 K. Organic ﬂuids usually tend to generate non-condensable gasses and/or decompose at elevated temperatures and their viscosity dramatically increases. For halides, most of them are very reactive or toxic and their full property data are not available or the majority of the physical properties are predicted, also live tests and their environmental impact data are not adequate. As for casing/LHP construction material, there are no full chemical compatibility tables with most of the medium temperature working ﬂuids and the reactivity of ﬂuids signiﬁcantly limits the potential materials. Also, testing such an LHP is an endeavour as the reactivity of medium temperature ﬂuids and the use of obscure metals create new chal-∗","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41323524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2