Feasibility Study of Ebullient Cooling Technology for SiC Power Devices With Extremely High Heat Generation Density of 1000 W/cm2

<p>In this regional heat flow study of New Zealand temperatures have been measured in available boreholes using a specially constructed thermistor probe, and existing temperature information has been incorporated from various sources including oil prospecting boreholes. Thermal conductivity has been measured in the laboratory on 581 samples. Newly determined values of heat flow are given for 105 locations; values for the South Island are here presented for the first time. Most of the heat flow values have been grouped in eight regions based on the level of heat flow. This classification can be related to the occurrence of certain surface manifestations and geophysical anomalies, and to regional plate tectonics. High heat flow in three regions is consistent with melting conditions being reached at depths between 35km and 45km. These are the Taranaki Region, the West Coast Region and the Great South Basin. The average regional heat flow for these regions varies from 86.4 mW/m2 to 110.7 mW/m2. Much lower heat flow is obtained in the Hikurangi and Marlborough-Canterbury Regions; these may possibly be interconnected. Elsewhere the heat flow is low to normal with isolated highs. The broad distribution of heat flow in the North Island is typical for an active subduction region. Radioactive heat generation has been measured on rock types from various localities, and large variations have been found. The heat flow - heat generation relationship has been studied for 42 sites. A linear relationship is found only in the Taranaki and Hikurangi Regions. Temperature calculations show large differences in the deep-seated temperature distribution beneath New Zealand, and this has also been reflected in the distribution of "reduced heat flow". Temperature and heat flow can be correlated with upper mantle inhomogeneity. The inferred variation of radioactive heat generation with depth has been studied for areas beneath the Western Canterbury Region. A mean heat generation of 1.56 plus-minus .07 muW/m3 has been found in a sequence which has been inferred to occur between 17km and 30km in depth under the region; this is very much higher than the usually adopted values for the lower crust. Normal heat flow observed in the Western Cook Strait Region, and the existence of good seismic wave transmission beneath the same region, can be attributed to crustal and lithospheric thickening. The relevance of present study to petroleum occurrences has been examined and it is found that in areas of proven hydrocarbon potential the heat flow is high.</p>

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Terrestrial Heat Flow in New Zealand

10.26686/wgtn.16945981 ◽

2021 ◽

Author(s):

◽

Om Prakash Pandey

Keyword(s):

New Zealand ◽

Heat Flow ◽

Heat Generation ◽

Plate Tectonics ◽

High Heat ◽

The North ◽

Rock Types ◽

Flow Heat ◽

Geophysical Anomalies ◽

First Time

<p>In this regional heat flow study of New Zealand temperatures have been measured in available boreholes using a specially constructed thermistor probe, and existing temperature information has been incorporated from various sources including oil prospecting boreholes. Thermal conductivity has been measured in the laboratory on 581 samples. Newly determined values of heat flow are given for 105 locations; values for the South Island are here presented for the first time. Most of the heat flow values have been grouped in eight regions based on the level of heat flow. This classification can be related to the occurrence of certain surface manifestations and geophysical anomalies, and to regional plate tectonics. High heat flow in three regions is consistent with melting conditions being reached at depths between 35km and 45km. These are the Taranaki Region, the West Coast Region and the Great South Basin. The average regional heat flow for these regions varies from 86.4 mW/m2 to 110.7 mW/m2. Much lower heat flow is obtained in the Hikurangi and Marlborough-Canterbury Regions; these may possibly be interconnected. Elsewhere the heat flow is low to normal with isolated highs. The broad distribution of heat flow in the North Island is typical for an active subduction region. Radioactive heat generation has been measured on rock types from various localities, and large variations have been found. The heat flow - heat generation relationship has been studied for 42 sites. A linear relationship is found only in the Taranaki and Hikurangi Regions. Temperature calculations show large differences in the deep-seated temperature distribution beneath New Zealand, and this has also been reflected in the distribution of "reduced heat flow". Temperature and heat flow can be correlated with upper mantle inhomogeneity. The inferred variation of radioactive heat generation with depth has been studied for areas beneath the Western Canterbury Region. A mean heat generation of 1.56 plus-minus .07 muW/m3 has been found in a sequence which has been inferred to occur between 17km and 30km in depth under the region; this is very much higher than the usually adopted values for the lower crust. Normal heat flow observed in the Western Cook Strait Region, and the existence of good seismic wave transmission beneath the same region, can be attributed to crustal and lithospheric thickening. The relevance of present study to petroleum occurrences has been examined and it is found that in areas of proven hydrocarbon potential the heat flow is high.</p>

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Research on Efficiency Improvement of UPS Based on Silicon Carbide MOSFET

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.842.257 ◽

2020 ◽

Vol 842 ◽

pp. 257-261

Author(s):

Peng Zhang ◽

Xiu Ying Ren ◽

Hong Da Zhang ◽

De Wen Zhang ◽

See Lan ◽

...

Keyword(s):

Silicon Carbide ◽

Breakdown Strength ◽

Research Direction ◽

High Heat ◽

Power Devices ◽

Power Failure ◽

Switching Losses ◽

Core Part ◽

Gap Width

In order to avoid the loss caused by sudden power failure or loss, UPS is very necessary.As the core part of UPS, the efficiency of DC-DC converter improvement has been a long-term research direction in the industry.Switch tube loss are the main factors influencing the DCDC converter efficiency, SI power component is affected by its material, its performance is difficult to further improve, seriously affect the efficiency of the DC-DC converter, SiC semiconductor with high band gap width, the advantages of high heat conductivity and high electric breakdown strength in recent years become a hot research direction at home and abroad, and silicon carbide material improves the device the possibility of high frequency, miniaturization and efficiency.Compared with Si power devices, the advantages of SiC power devices are higher voltage and temperature resistance, higher operating frequency and lower switching losses.

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An Overview of Investigation for Ferrite Magnetic Nanomaterial

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.271.51 ◽

2018 ◽

Vol 271 ◽

pp. 51-63 ◽

Cited By ~ 1

Author(s):

Deleg Sangaa ◽

Baatartsogt Khongorzul ◽

Enkhnaran Uyanga ◽

Narmandakh Jargalan ◽

Namsrai Tsogbadrakh ◽

...

Keyword(s):

Heat Generation ◽

Spinel Ferrite ◽

High Heat ◽

Magnetic Nanomaterials ◽

Ferrite Powder ◽

Ion Distribution ◽

Hyperthermia Treatment ◽

Spinel Type ◽

Powder Samples ◽

Cancer Tumor

In recent time, interest to ferrite magnetic nanomaterials has considerably grown mainly due to their much promising medical and biological applications. The spinel ferrite powder samples having high heat generation ability in AC magnetic field was studied for application to hyperthermia treatment of cancer tumor. These properties of ferrites are strongly depending on their chemical composition, ion distribution, spin orientation and method of preparation in general and crystal structure in particular nature of the material. In this study, several samples of ferrite magnetic structures were investigated by neutron diffraction. The explanation of the mechanism to occurs the heat generation ability in the magnetic materials and the electronic and magnetic states of ferrite-spinel – type structures were theoretically defined by the first-principles calculations within the framework of DFT.

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Variable-viscosity flows in channels with high heat generation

Journal of Fluid Mechanics ◽

10.1017/s0022112077001141 ◽

1977 ◽

Vol 83 (1) ◽

pp. 191-206 ◽

Cited By ~ 53

Author(s):

J. R. A. Pearson

Keyword(s):

Boundary Layer ◽

Heat Generation ◽

Thermal Boundary Layer ◽

Variable Viscosity ◽

Plane Channel ◽

High Heat ◽

Maximum Temperature ◽

Mean Velocity ◽

Channel One ◽

Plane Channel Flow

This paper presents a similarity solution for plane channel flow of a very viscous fluid, whose viscosity is exponentially dependent upon temperature, when heat generation is very large. A dimensionless formulation of the problem involves two length scales (the depthhand lengthl, respectively, of the channel), one velocity scale (the mean velocityVof the fluid along the channel), the thermal conductivityk, thermal diffusivitykand viscosityVof the fluid, and the temperature coefficientbof the viscosity. From these, two important dimensionless groups arise, the Graetz number (Gz = Vh2/kl) and the Nahme–Griffith number (G= μV2b/k). In the case of steady flow withG−1[Lt ]Gz−1[Lt ] 1 a thin thermal boundary layer of thickness proportional toGz−½arises at each wall with an even thinner shear layer, detached from the wall and embedded in the thermal boundary layer, of thickness proportional toGz−½(lnG)−1, coinciding with the region of maximum temperature (lnG)/b. The similarity variable is (Pe½y/x½) wherePeis the Péclet number (Vh/k) andyandxare measured away from and along (either) boundary wall. The analogous unsteady uniform flow solution is also given.

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Review: The thermal regime along the southern Canadian Cordillera Lithoprobe corridor

Canadian Journal of Earth Sciences ◽

10.1139/e95-129 ◽

1995 ◽

Vol 32 (10) ◽

pp. 1611-1617 ◽

Cited By ~ 24

Author(s):

R. D. Hyndman ◽

T. J. Lewis

Keyword(s):

Heat Flow ◽

Heat Generation ◽

Thermal Regime ◽

Volcanic Belt ◽

Normal Fault ◽

High Heat ◽

General Level ◽

Canadian Cordillera ◽

Seismic Structure ◽

Brittle Ductile Transition

This summary article describes the surface heat flow and heat generation data available for the Southern Canadian Cordillera Lithoprobe Transect, and the inferred crustal temperatures. At the western end of the transect, the continental margin has the characteristic heat flow pattern of a subduction zone; there are high heat flows over the young oceanic crust of the deep-sea Cascadia Basin (~120 mW·m−2), decreasing values landward on the continental slope and shelf (90–50 mW·m−2), and very low heat flow and low crustal temperatures in the forearc region of Vancouver Island and the adjacent mainland (30–40 mW·m−2). Very high and irregular heat flow occurs in the Garibaldi Volcanic Belt at the northern end of the Cascade volcanic arc. To the east, across the Intermontane and Omineca belts to the Rocky Mountain Trench, the heat flow and inferred crustal temperatures are high. The highest values are in the east in the Omineca Belt, where the radioactive heat generation is especially great. The crustal thermal regime has important implications for the interpretation of the deep seismic structure: (1) The brittle–ductile transition (~450 °C), which occurs in the mid-crust for most of the transect, is expected to represent a general level of thrust and normal fault detachment. The deeper crust may be mechanically decoupled from that above. (2) Crustal thickness may be related to temperature. If the lithosphere temperature is high and its density decreased by thermal expansion, there can be isostatic equilibrium with a thin crust and high topography. (3) The thermal regime appears to control the depth to the widespread crustal reflectivity and high electrical conductivity in the deep crust.

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