Technical Physics最新文献_第4页

The Use of the Axial Heat Conduction of the Wall for Increasing the Effectiveness of Heat Exchangers 利用壁面轴向导热来提高换热器的效率

IF 1.1 4区物理与天体物理

Technical Physics Pub Date : 2025-02-13 DOI: 10.1134/S1063784224700762

E. P. Valueva, Yu. V. Sabirov

{"title":"The Use of the Axial Heat Conduction of the Wall for Increasing the Effectiveness of Heat Exchangers","authors":"E. P. Valueva, Yu. V. Sabirov","doi":"10.1134/S1063784224700762","DOIUrl":"10.1134/S1063784224700762","url":null,"abstract":"The effect of heat transfer in the wall in the direction of the flow of heat carriers on the effectiveness of heat exchangers is considered for the cases when the wall ends are not thermally insulated from the environment. Use is made of the analytic solution to the problem of parallel-plane flow of heat carriers, which has been considered earlier. The solution depends on the following parameters: ratio of coefficients α of heat transfer from heat carriers; ratio of thermal equivalents β of heat carriers (it is assumed that α = β = 1); number Ntu of heat-transfer units; parameter CA characterizing the axial heat conduction of the wall; the Biot number determining the relative heat transfer from the wall ends to the environment, and the temperatures of the media contacting the wall ends. The effect of the heat conduction the wall increases with decreasing CA. The following two cases are considered: (case I) the temperatures of the environment are assumed to be equal to the inlet and outlet temperatures of the hot heat carrier; (case II) these temperatures are equal to the inlet and outlet temperatures of the cold heat carrier. It is shown that for large Biot numbers (Bi > 1), the effectiveness of using of one of heat carriers can be elevated due to the effect of the axial heat conduction of the wall; in this case, the temperature of the other heat carrier during its flow in the heat exchanger varies insignificantly. The boundaries of the beginning of the effect of the axial heat conduction of the wall on the effectiveness of the heat exchanger are determined.","PeriodicalId":783,"journal":{"name":"Technical Physics","volume":"69 9","pages":"2488 - 2494"},"PeriodicalIF":1.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143404197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Recommendations for the Estimation of Heat Transfer and Critical Heat Fluxes on Boiling Surfaces with Fiber Brush Coatings 用纤维刷涂层估算沸腾表面的传热和临界热通量的建议

IF 1.1 4区物理与天体物理

Technical Physics Pub Date : 2025-02-13 DOI: 10.1134/S1063784224700890

I. A. Popov, Yu. S. Stepanova, R. A. Aksyanov, Yu. F. Gortyshov

引用次数: 0

Production of Biodiesel Fuel from Shea Butter 用乳木果油生产生物柴油

IF 1.1 4区物理与天体物理

Technical Physics Pub Date : 2025-02-13 DOI: 10.1134/S1063784224700907

S. V. Mazanov, A. O. Solovyova, A. U. Aetov, I. M. Mubarakshin, R. Z. Musin, A. V. Tarasova

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Analysis of the Thermal Conditions in a Lithium-Ion Battery Pack at Reduced Heat Exchange Rate with the Environment 降低与环境热交换率时锂离子电池组的热条件分析

IF 1.1 4区物理与天体物理

Technical Physics Pub Date : 2025-02-13 DOI: 10.1134/S106378422470083X

G. V. Kuznetsov, E. V. Kravchenko

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Study of Heat Transfer of a Concave Surface of Short Annular Channels under Impact Jets 冲击射流作用下短环形通道凹表面传热研究

IF 1.1 4区物理与天体物理

Technical Physics Pub Date : 2025-02-13 DOI: 10.1134/S1063784224700920

Yu. L. Leukhin, P. D. Alekseev

{"title":"Study of Heat Transfer of a Concave Surface of Short Annular Channels under Impact Jets","authors":"Yu. L. Leukhin, P. D. Alekseev","doi":"10.1134/S1063784224700920","DOIUrl":"10.1134/S1063784224700920","url":null,"abstract":"By means of physical and mathematical modeling, convective heat transfer and resistance of an annular channel under jet air impingement on the outer concave surface were investigated. It has been established that, in the studied ranges of variation of geometric and mode characteristics, heat transfer and aerodynamics of short annular channels are determined by the dimensionless parameter Af, which is the ratio of the total area of the blowout holes to the area of the blown surface. To ensure uniform heat transfer on the concave surface of the channels, it is advisable to use internal perforated pipes with a value of the parameter Af less than 0.01, and to control heat transfer and intensify it in the required zones, it is possible to use pipes with its higher values. The resistance coefficient of the device decreases with increasing parameter Af and increases slightly with decreasing Reynolds number. An equation has been obtained for calculating the average heat transfer over the surface, the dimensionless total pressure drop in the device, and the total resistance coefficient in the following ranges of variation of mode and geometric parameters: Re = 873–19.7 × 103, Af = (0.94–42.57) × 10–3, S/dc = 3.49–24.92, and h/dc = 4.5–8.1. Assessment of the heat exchange device using the energy efficiency coefficient showed that its optimal value is observed at values of the parameter Af approximately equal to 0.035–0.040.","PeriodicalId":783,"journal":{"name":"Technical Physics","volume":"69 10","pages":"2535 - 2546"},"PeriodicalIF":1.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143404221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Vortices Formation and the Condensate Film Surface Shape in Heat Pipes 热管中涡流的形成与冷凝膜表面形状

IF 1.1 4区物理与天体物理

Technical Physics Pub Date : 2025-02-13 DOI: 10.1134/S1063784224700841

A. V. Seryakov

引用次数: 0

Analysis of the Oxide Target Cooling Modes in the Production of Iodine Isotopes 碘同位素生产中氧化物靶冷却模式的分析

IF 1.1 4区物理与天体物理

Technical Physics Pub Date : 2025-02-13 DOI: 10.1134/S1063784224700816

S. S. Salodkin, Yu. I. Tyurin, V. V. Sokhoreva

引用次数: 0

Investigation of MHD Heat Exchange in a Liquid Metal Flow through a Tube-in-Channel System under Conditions Close to the Thermonuclear Reactor Blanket Module 接近热核反应堆包层模块条件下管道系统液态金属流动MHD换热研究

IF 1.1 4区物理与天体物理

Technical Physics Pub Date : 2025-02-13 DOI: 10.1134/S1063784224700774

N. A. Luchinkin, N. G. Razuvanov, O. N. Polyanskaya, I. O. Teplyakov

{"title":"Investigation of MHD Heat Exchange in a Liquid Metal Flow through a Tube-in-Channel System under Conditions Close to the Thermonuclear Reactor Blanket Module","authors":"N. A. Luchinkin, N. G. Razuvanov, O. N. Polyanskaya, I. O. Teplyakov","doi":"10.1134/S1063784224700774","DOIUrl":"10.1134/S1063784224700774","url":null,"abstract":"Heat exchange in a liquid metal upward flow through a tube-in-channel system has been studied experimentally and analytically. The system consists of a vertical tube passing along the axis of a square heated channel that is connected to a natural circulation loop. Experiments have been conducted in the presence of a transverse magnetic field and without it. Probe measurements using longitudinal microthermocouple probes placed both in the tube and in the channel gap have been applied. Heat exchange averaged characteristics have been numerically simulated for experimental conditions. Three basic operating conditions of the cooling loop have been considered: the loop is shut off, the loop is open allowing free circulation in the gap without cooling, and the loop is open and provides cooling. In experiments, the profiles of averaged temperature, the distributions of heat transfer local coefficients, and the pulsation characteristics of flow temperature both in the tube and in the channel gap have been obtained. Calculation data have been compared with experimental results. It has been found that the configuration and structure of the flow significantly depend on the presence of transverse magnetic field and on whether the natural circulation loop is connected and provides cooling.","PeriodicalId":783,"journal":{"name":"Technical Physics","volume":"69 9","pages":"2461 - 2471"},"PeriodicalIF":1.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143404157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Specific Features of the Breakup of Hot Liquid Metal Droplets Falling into Cold Water 热液态金属液滴落入冷水破裂的具体特征

IF 1.1 4区物理与天体物理

Technical Physics Pub Date : 2025-02-13 DOI: 10.1134/S1063784224700828

Yu. P. Ivochkin, S. M. Yudin, T. I. Borodina

引用次数: 0

Impact of Subcooled Liquid Jet on the Dynamics of Transition from Steady Film Boiling to Intense Heat Transfer Regime 过冷射流对稳定膜沸腾向强传热过渡动力学的影响

IF 1.1 4区物理与天体物理

Technical Physics Pub Date : 2025-02-13 DOI: 10.1134/S1063784224700804

T. A. Gubanova, P. K. Kanin, V. V. Yagov, A. R. Zabirov, I. A. Molotova, M. M. Vinogradov

{"title":"Impact of Subcooled Liquid Jet on the Dynamics of Transition from Steady Film Boiling to Intense Heat Transfer Regime","authors":"T. A. Gubanova, P. K. Kanin, V. V. Yagov, A. R. Zabirov, I. A. Molotova, M. M. Vinogradov","doi":"10.1134/S1063784224700804","DOIUrl":"10.1134/S1063784224700804","url":null,"abstract":"The properties of the cooled surface and of liquid coolant significantly affect the heat transfer intensity during film boiling and the temperature of transition to the intense regime. As a result, many current studies are devoted to unsteady cooling of vertical cylinders and balls made of various metals with and without coating. The impact of an effectively point source of perturbation (such as, for example, a submerged jet) on the vapor film during film boiling is also of genuine interest. This paper presents experimental results of cooling a stainless steel ball in a liquid when exposed to a submerged jet of the same liquid. The aim of the study is to experimentally measure the surface temperature during the transition from steady film boiling to the intense heat transfer regime of boiling. Different cooling liquids were used in the experiments including water, ethanol, water-ethanol mixtures, and perfluorohexane. It is shown that the transition to the intense mode of heat transfer occurs in aqueous liquids significantly earlier than in liquids with high alcohol content. Despite the influence of the submerged jet, there was no intense heat transfer regime during film boiling in perfluorohexane.","PeriodicalId":783,"journal":{"name":"Technical Physics","volume":"69 10","pages":"2510 - 2516"},"PeriodicalIF":1.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143404226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0