Xiang Zhang, Hadi Keramati, Martinus Arie, Farah Singer, Ratnesh Tiwari, Amir Shooshtari, Michael Ohadi^*

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-14, 2018, DOI:10.5098/hmt.11.18

Abstract Heat exchangers are key components of most power conversion systems, a few industrial sectors can particularly benefit from high temperature heat exchangers. Examples include conventional aerospace applications, advanced nuclear power generation systems, and high efficiency stationary and mobile modular fossil fuel to shaft power/electricity conversion systems. This paper provides a review of high temperature heat exchangers in terms of build materials, general design, manufacturing techniques, and operating parameters for the selected applications. Challenges associated with conventional and advanced fabrication technologies of high temperature heat exchangers are discussed. Finally, the paper outlines future research needs of More >

K.N. Song¹, S. D. Hong¹

Structural Durability & Health Monitoring, Vol.9, No.2, pp. 155-165, 2013, DOI:10.32604/sdhm.2013.009.155

Abstract The IHX (Intermediate Heat Exchanger) of a VHTR (Very High Temperature Reactor) transfers 950° heat generated from the VHTR to a hydrogen production plant. The Korea Atomic Energy Research Institute (KAERI) has manufactured a lab-scale PCHE (Printed Circuit Heat Exchanger) prototype made of SUS316L under consideration as a candidate. In this study, as a part of a hightemperature structural integrity evaluation of the lab-scale PCHE prototype, a macroscopic structural behavior analysis including structural analysis modeling and a thermal/elastic structural analysis was carried out under the test conditions of a helium experimental loop (HELP) as a More >

Sanjeev Saxena¹, Raghvendra Singh², Geeta Agnihotri²

CMC-Computers, Materials & Continua, Vol.36, No.3, pp. 257-270, 2013, DOI:10.3970/cmc.2013.036.257

Abstract The present numerical study is an attempt to understand the dependency of characteristic distance on the fracture specimen thickness and temperature. The presented work will be useful to establish the characteristic distance prediction methodology using three dimensional FEM model. Based on the methods proposed for the numerical prediction of characteristic distance, it comes out that it depends on fracture specimen thickness and finally it converges after a specified thickness of fracture specimen. In Armco iron material, characteristic distance varies in temperature ranges where dynamic strain ageing phenomenon is observed, initially decrease and then increases again. More >

He XY^1,2, H Ye¹, JL Ma^1,2, RQ Zhang², GC Chen¹, YY Xia¹

Phyton-International Journal of Experimental Botany, Vol.81, pp. 177-180, 2012, DOI:10.32604/phyton.2012.81.177

Abstract Annual leaf segments of eight Camellia species were used to study the heat tolerance by an electrical conductivity method, in combination with a Logistic equation to ascertain the semi-lethal high temperature by fitting the cell injury rate curve. The relationship between the processing temperature and the cell injury rate in Camellia showed a typical "S" shaped curve, following the Logistic model. The correlation coefficient was above 0.95. The semi-lethal high temperature LT₅₀ of the eight Camellia species, determined by the inflection point on the curve, varied from 50 to 57 LT₅₀ / °C, following the descending order: Camellia oleifera More >

K.N. Song¹

Structural Durability & Health Monitoring, Vol.8, No.3, pp. 209-222, 2012, DOI:10.32604/sdhm.2012.008.209

Abstract A PHE (Process Heat Exchanger) is a key component in transferring the high temperature heat generated from a VHTR (Very High Temperature Reactor) to the chemical reaction for the massive production of hydrogen. A performance test on a small-scale PHE prototype made of Hastelloy-X is currently under way a small-scale gas loop at the Korea Atomic Energy Research Institute. Previous research on the elastic high-temperature structural analysis of the small-scale PHE prototype has been performed using the parent material properties over the whole region. In this study, an elastic-plastic high-temperature structural analysis considering the mechanical More >

F. De Rosa¹, A. Esposito¹

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.1, pp. 107-128, 2012, DOI:10.3970/fdmp.2011.008.107

Abstract An investigation was conducted to evaluate the feasibility and the performance of an electrically heated composite leading edge for aircraft anti-icing applications. A prototype was designed, manufactured and equipped with a High Temperature composite leading edge with embedded Ni alloy resistance fed by a DC power supply unit. Running wet and fully evaporative functional modes have been verified both analytically and experimentally with reasonable agreement. A room temperature thermal endurance test has been run for 10⁴ cycles aiming to preliminary verify the integrity of the composite laminate after the imposed thermal stress. The EHCLE system (Electrical More >

Menezes LCCR de¹, MN Rossi²

Phyton-International Journal of Experimental Botany, Vol.80, pp. 153-160, 2011, DOI:10.32604/phyton.2011.80.153

Abstract After a fire event, germination of seeds with hard coats can be enhanced. In the present study, we investigated whether germination of Mimosa bimucronata (DC.) Kuntze (Fabaceae) seeds, which present hard coats, is increased after fire, even though these trees usually occur in damp areas, where fire is a transient event. Fire events were manipulated in trays filled with soil covered with different amounts of dry grasses, characterizing three treatments: a) 0g (control group); b) 300g, and c) 450g of dry grass. Burning treatments were applied to seeds positioned either on the soil surface or buried… More >

K.N. Song¹

Structural Durability & Health Monitoring, Vol.7, No.4, pp. 297-306, 2011, DOI:10.3970/sdhm.2011.007.297

Abstract The IHX (Intermediate Heat Exchanger) of a VHTR (Very High Temperature Reactor) transfers 950° heat generated from the VHTR to a hydrogen production plant. The Korea Atomic Energy Research Institute (KAERI) has manufactured a small-scale prototype of a PCHE (Printed Circuit Heat Exchanger) under consideration as a candidate of the IHX. In this study, as a part of high-temperature structural integrity evaluation of the small-scale PCHE prototype, we carried out a macroscopic structural behavior analysis including structural analysis modeling and thermal/elastic structural analysis under small-scale gas loop test conditions as a precedent study to a More >

Liangchi Zhang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.3, pp. 93-94, 2011, DOI:10.3970/icces.2011.017.093

Abstract Understanding the deformation mechanisms of metals under the coupled attack of high strain, high strain rate and high temperature (coupled H3 effect) has become more and more important to the development of new manufacturing technologies. High speed machining (HSM), a new technology to cut high hardness materials, is a typical example, as HSM has become an essential process in making ultra-precision, high-integrity components for devices and structures in the automotive, aeronautical, aerospace and biomedical industries. Nevertheless, due to the high machining speed in HSM, many problems which do not appear in conventional machining will take… More >

Xue Feng^*, Xiang Wang, Guobing Zhang, Huimin Xie, Helong Yu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.4, pp. 115-116, 2011, DOI:10.3970/icces.2011.020.115

Abstract Most ceramic materials, because of their inherent brittleness, are susceptible to catastrophic failure under conditions of thermal shock. A novel method for measuring the dynamical deformation is proposed by using of high speed digital image correlation in high temperature environment. The nature texture of ceramic materials can be used as speckle while filters and monochrome produced by LED are applied to suppress black-body radiation and enhance the luminous intensity.

The light from the heated material can alter the Grayscale of material surface and the recognition for material surface will become more and more difficult with More >