scholarly journals Properties of a Prototype Corium of Nuclear Reactor

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Mazhyn K. Skakov ◽  
Nurzhan Ye. Mukhamedov ◽  
Ilya I. Deryavko ◽  
Erlan G. Batyrbekov
Keyword(s):  
Heat Capacity ◽  
Phase Composition ◽  
Thermal Diffusivity ◽  
Thermophysical Properties ◽  
Heat Conductivity ◽  
Nuclear Reactor ◽  
Severe Accident ◽  
Structure Phase ◽  
Actual Interaction ◽  
Core Materials

The paper studies structure, phase composition, and thermophysical properties (TPP) (specific heat capacity, thermal diffusivity, and heat conductivity) of a prototype corium of a fast nuclear reactor (melt of core materials of nuclear reactor produced under out-of-pile conditions). The obtained data will be used to get more accurate understanding of main regularities of actual interaction of core materials of a nuclear reactor under a severe accident.

scholarly journals Temperature Dependence of Thermophysical Properties of Full-Scale Corium of Fast Energy Reactor

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Mazhyn K. Skakov ◽  
Nurzhan Ye. Mukhamedov ◽  
Alexander D. Vurim ◽  
Ilya I. Deryavko
Keyword(s):  
Heat Capacity ◽  
Thermal Diffusivity ◽  
Fast Reactor ◽  
Thermophysical Properties ◽  
Heat Conductivity ◽  
Nuclear Reactor ◽  
Reactor Vessel ◽  
Full Scale ◽  
Temperature Fields ◽  
First Time

For the first time the paper determines thermophysical properties (specific heat capacity, thermal diffusivity, and heat conductivity) of the full-scale corium of the fast energy nuclear reactor within the temperature range from ~30°С to ~400°С. Obtained data are to be used in temperature fields calculations during modeling the processes of corium melt retention inside of the fast reactor vessel.

scholarly journals Applying the EDPS Method to the Research into Thermophysical Properties of Solid Wood of Coniferous Trees

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Ľuboš Krišťák ◽  
Rastislav Igaz ◽  
Ivan Ružiak
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Diffusivity ◽  
Moisture Content ◽  
Thermophysical Properties ◽  
Solid Wood ◽  
Plane Source ◽  
Coniferous Trees ◽  
Extended Dynamic ◽  
Dynamic Plane

The results of using the EDPS (extended dynamic plane source) method to determine thermophysical properties of solid wood of coniferous trees growing in Slovakia with 0% and 12% equilibrium moisture content are presented in the paper. Solid wood of two different tree species: Norway spruce (Picea abies L.) and Scots pine (Pinus sylvestris L.) was used in the research. The research was carried out independently in three anatomical planes. Coefficients of thermal conductivity, thermal diffusivity, and specific heat capacity were determined following the research. Comparing the research results to the values determined by other authors and already published models to calculate individual parameters, the fact that the data gathered using the EDPS method can be accepted in case of all studied thermophysical properties can be stated.

scholarly journals Thermophysical properties of BiFeO3/REE multiferroics in a wide temperature range

2020 ◽  
Vol 10 (01n02) ◽  
pp. 2060019
Author(s):  
Sidek Khasbulatov ◽  
Suleiman Kallaev ◽  
Haji Gadjiev ◽  
Zairbek Omarov ◽  
Abumuslim Bakmaev ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Rare Earth ◽  
High Temperature ◽  
Thermal Diffusivity ◽  
Rare Earth Elements ◽  
Wide Temperature Range ◽  
Thermophysical Properties ◽  
Multiferroic Bifeo ◽  
Comprehensive Study

The paper presents the results of a comprehensive study of the thermophysical properties (thermal conductivity, thermal diffusivity, heat capacity) of high-temperature multiferroic BiFeO3 modified with rare-earth elements (REEs) (La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Lu). The regularities of the formation of the mentioned characteristics were established. The assumptions about the nature of the observed phenomena were suggested.

scholarly journals Thermophysical properties of NP2 brand nickel

2021 ◽  
Vol 2119 (1) ◽  
pp. 012135
Author(s):  
D A Samoshkin ◽  
A Sh Agazhanov ◽  
S V Stankus
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Diffusivity ◽  
Thermophysical Properties ◽  
Magnetic Phase ◽  
Laser Flash ◽  
Scanning Calorimetry ◽  
Reference Table ◽  
Laser Flash Technique ◽  
Flash Technique

Abstract The heat capacity and the thermal diffusivity of NP2 brand nickel were investigated in the temperature interval 296–1000…1375 K of the solid-state, including the region of the magnetic phase transformation. Measurements were carried out on samples from one initial ingot by laser flash technique and method of differential scanning calorimetry using LFA-427 and DSC 404 F1 setups, respectively. The thermal conductivity was calculated based on the measured thermophysical properties. The estimated errors of the obtained results were 2–4%, 3–5%, and 2–3% for thermal diffusivity, thermal conductivity, and heat capacity, respectively. For investigated thermophysical properties the fitting equations and the reference table have been received.

scholarly journals Effect of Wheat Straw Biochar on Thermophysical Properties of Loessial Soil

2021 ◽  
Vol 20 (3) ◽  
Author(s):  
B. W. Zhao ◽  
Y. Zhao ◽  
H. Liu ◽  
Y. Q. Li ◽  
K. X. Duan ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Diffusivity ◽  
Water Content ◽  
Thermophysical Properties ◽  
Heat Balance ◽  
Pyrolysis Temperature ◽  
Internal Heat ◽  
Loessial Soil ◽  
Biochar Amendment

Soil thermophysical properties are the key factors affecting the internal heat balance of soil. In this paper, biochars (BC300, BC500 and BC700) were produced with wheat straw at the temperatures of 300, 500 and 700°, respectively. The effects of biochar amendment at the rates of 0%, 1%, 3%, and 5% on the thermophysical properties (thermal conductivity, heat capacity, and thermal diffusivity) of a loessial soil were investigated with and without water content respectively. Although the bulk density of soil significantly decreased with biochar amendment, due to enhancing soil porosity and organic matter content, the thermophysical properties of soil did not change largely with biochar amendment rate and pyrolysis temperature. Water content exhibited significant effects on the thermophysical properties of soils added with biochars, where the thermal conductivity and heat capacity of soil were linearly proportional to water content, the thermal diffusivity initially increased and then decreased with the increase of water content. In the meanwhile, there was no significant correlation between the biochar amendment rate or pyrolysis temperature and thermophysical properties. The results show that water content should be mainly concerned as a factor when the internal heat balance of loess soil is evaluated, even though the soil is amended with biochar.

Experimental Investigation on Critical Heat Flux From Downward-Facing Flat Plate for Different Orientation Angles

2018 ◽  
Author(s):  
K. H. Deng ◽  
Y. Zhang ◽  
C. L. Wang ◽  
Y. P. Zhang ◽  
W. X. Tian ◽  
...  
Keyword(s):  
Heat Flux ◽  
Critical Heat Flux ◽  
Pressure Vessel ◽  
Nuclear Reactor ◽  
Heating Surface ◽  
Severe Accident ◽  
Width Ratio ◽  
Lower Head ◽  
Length Width ◽  
Core Materials

After the severe accident inside a nuclear reactor, the IVR (In-vessel retention) management strategy is an effective way to keep the integrity of pressure vessel and reduce risk of radioactive leakage by holding the damaged core materials through External Reactor Vessel Cooling (ERVS). The damaged core materials aggregate in the lower head of pressure vessel and releasing heat to the lower head. Therefore, it is very important to remove heat timely to keep the integrity of pressure vessel by ERVS. The shape of lower head is hemispherical and the local Critical Heat Flux (CHF) of different parts changed with latitude. In this paper, influence of orientation angles, area and length-width ratio on CHF of plate heating surface for saturated pool boiling is investigate experimentally. The results show that CHF increases with increasing orientation angles and decreasing area, meanwhile, length-width ratio has a significantly effect on CHF.

scholarly journals The effect of artificial forest plantations on the thermophysical properties of chernozems

2019 ◽  
Vol 30 (1) ◽  
pp. 33-38
Author(s):  
V. A. Gorban
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Diffusivity ◽  
Air Temperature ◽  
Thermophysical Properties ◽  
Soil Surface ◽  
Maximum Temperature ◽  
Ordinary Chernozem ◽  
Forest Plantations ◽  
Average Temperature

As a result of a study of the effect of artificial forest plantations formed by Robinia pseudoacacia L. and Quercus robur L., on the thermophysical features of the chernozems of the Komissarovsky reserve (Pyatykhatsky district, Dnepropetrovsk region, Ukraine), it was found that the stand of robinia reduced air temperature by 4, 5 °С, oak – by 9.4 °С in comparison with the open area. The maximum temperature of the soil surface is found in ordinary chernozem. The effect of robinia plantation manifested itself in the form of a decrease in the temperature of the soil surface by 5.4 °C, and the oak surface by 8.0 °C. The maximum soil temperature at a depth of 50 cm is also found in ordinary chernozem. At the same depth, the soil under robinia plantation turned out to be 7.6 °C, under oak – 6.9 °C colder. According to the average temperature of the 50-centimeter layer of all the studied soils, ordinary chernozem is distinguished, the soils under the plantations almost do not differ according to this indicator. The smallest difference between the air temperature and the average temperature of the soil layer 0–50 cm was in the soil under oak plantation, the largest – in the soil under robinia plantation. The smallest difference between the temperature of the soil surface and at a depth of 50 cm was found in the soil under oak plantation, and the greatest difference in the soil under robinia plantations. Based on the analysis of the results obtained, an assumption was made about the thermal features of the upper horizons, which fall within the interval of 0–50 cm, of each of the three studied soils. The soil under robinia plantation is characterized by maximum values of thermal diffusivity, and ordinary chernozem – minimal. The soil under the oak plantation occupies an intermediate value for this indicator. Ordinary chernozem is characterized by maximum values of heat capacity, slightly smaller values are characteristic of soil for robinia plantations. The minimum values of heat capacity are characteristic of oak plantation soil. The soil under robinia plantation is sharply distinguished by the maximum values of thermal conductivity compared to ordinary chernozem and the soil under oak planting. The actual study of thermophysical properties confirmed the correctness of the assumption in only one of the three indicators for each of the studied soils. This indicates a significant limitation of predicting the thermophysical indicators of soils, based only on measuring their temperature. The influence of robinia plantation on the thermal physical properties of ordinary chernozems is manifested in an increase in their thermal diffusivity and thermal conductivity, as well as in a certain decrease in heat capacity. The influence of oak stands is characterized by an increase in thermal diffusivity and heat capacity, as well as a decrease in thermal conductivity of ordinary chernozem.

Determining Thermal Properties of Insulating Sleeves

2010 ◽  
Vol 649 ◽  
pp. 487-491 ◽  
Author(s):  
Witold K. Krajewski ◽  
Józef Szczepan Suchy
Keyword(s):  
Thermal Conductivity ◽  
Mass Transfer ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Boundary Conditions ◽  
Thermophysical Properties ◽  
Mean Values ◽  
Computer Aided ◽  
The Mean

The presented work is aimed at determining thermal diffusivity, thermal conductivity and heat capacity of insulating sleeves used in Polish metallurgical/foundry practice. On basis of the theory elaborated in [1] the mean values of thermophysical properties for temperatures range of about 150-1000 oC were obtained. The results obtained during the examinations presented in the paper can be helpful when formulating boundary conditions during the computer aided simulation of the processes of heat and mass transfer in the system: casting (ingot) – mould riser (ingot head) – ambient, which uses the investigated insulating sleeves [2, 3]. The method of determining thermal properties can be also used for other foundry materials, e.g. sands or cores.

scholarly journals Features of soil thermophysical properties of the southern variant of ravine biogeocenoses of the Ukrainian steppe zone

2020 ◽  
Vol 31 (2) ◽  
pp. 82-86
Author(s):  
V. A. Gorban
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Diffusivity ◽  
Thermophysical Properties ◽  
Organic Matter Content ◽  
Steppe Zone ◽  
Matter Content ◽  
Illuvial Horizon ◽  
Meadow Soil ◽  
The Village

Thermophysical properties are an important characteristic of the general condition of soils, which determine the peculiarities of the distribution of heat flow in them. Today studies of thermophysical properties of soils, including the steppe zone of Ukraine, are practically not performed. This determines the relevance of the work, which is devoted to establishing the characteristics of the thermal properties of various soils. As a result of the study of thermal diffusivity, heat capacity and thermal conductivity of soils of northern and southern exposures, as well as the thalweg of the Voyskovoy Bayrak (located near the village of Voyskovoe Solonyansky district of Dnipropetrovsk region), it was found that the most important soil factors particles of physical clay and organic matter content. It was found that the eluvial horizons of the chernozem of the forest of the northern exposure differ in the reduced values ​​of heat capacity and thermal conductivity in comparison with the illuvial horizons. Eluvial horizons of forest-meadow soil of thalweg are characterized by increased values ​​of thermal diffusivity and thermal conductivity, as well as reduced values ​​of heat capacity compared to illuvial horizons. Eluvial horizons of forest chernozem of southern exposure are characterized by lower values ​​of thermal diffusivity, heat capacity and thermal conductivity compared to illuvial horizons. The most significant boundary between eluvial and illuvial horizons in terms of thermophysical properties is characteristic of the chernozem of forest southern exposure, which is manifested in a sharp increase in the values ​​of thermophysical properties in the first illuvial horizon. Cluster analysis revealed that the most similar in terms of thermal diffusivity are forest chernozems of southern and northern exposures, and in terms of heat capacity and thermal conductivity – forest chernozems of northern exposure and forest-meadow soil of thalweg ravine.

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