Numerical Calculation and Prediction of the Water Temperature in Reservoir of a Hydropower Station in Laos

2022 ◽  
Vol 904 ◽  
pp. 35-41
Author(s):  
Hua Zhou ◽  
Jian Xin Ding ◽  
Zhi Cheng Zhang ◽  
Zhan Jun Wang
Keyword(s):  
Temperature Distribution ◽  
Water Temperature ◽  
Great Influence ◽  
Shortwave Radiation ◽  
Hydropower Station ◽  
Analysis Model ◽  
Concrete Dam ◽  
Factors Affecting ◽  
Temperature Boundary ◽  
Spatio Temporal

The water temperature distribution and spatio-temporal variation law of the reservoir have a great influence on the water quality and ecological environment of the reservoir, and it is also an important temperature boundary condition for the design of concrete dam of hydropower station project, which is of great significance for the optimal design and operation of the reservoir. There are many factors affecting the water temperature of the reservoir, and it is difficult to predict the water temperature distribution accurately because of the lack of data and experience. In this paper, a numerical analysis model is established for the reservoir of a hydropower station on the Nam Ngum in Laos, and the water temperature of the reservoir is calculated and predicted, and the water temperature distribution in the reservoir and the water temperature distribution in front of the dam are analyzed and discussed. The results show that the solar shortwave radiation is the main factor affecting the temperature stratification of the reservoir. The stable low temperature layer of the reservoir is not obvious, but there is a tendency to form stratification. The research results can provide water temperature value for the design of concrete dam of the hydropower station and provide reference for the prediction of the water temperature of other similar reservoirs.

FACTORS AFFECTING LONGITUDINAL WATER TEMPERATURE DISTRIBUTION DOWNSTEAM FROM A POWER STATION

1974 ◽  
Vol 5 (2) ◽  
pp. 77-97 ◽  
Author(s):  
CHARLES G. AMATO
Keyword(s):  
Temperature Distribution ◽  
Water Temperature ◽  
Sensible Heat ◽  
Power Station ◽  
Factors Affecting ◽  
Heat Effects

The magnitude of reject heat, the distances to which sensible heat effects may be experienced in a river and alternate means of rejecting heat are discussed.

Temperature Stress Analysis for Concrete Dam of Jiangya Hydropower Station

2014 ◽  
Vol 556-562 ◽  
pp. 683-686
Author(s):  
Yan Yan Zhang ◽  
Cai Ying Chen
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Water Level ◽  
Great Influence ◽  
Element Model ◽  
High Water ◽  
Hydropower Station ◽  
Concrete Gravity Dam ◽  
Concrete Dam ◽  
Temperature Load

Temperature is one of the main loads of concrete dam, adverse temperature load can lead to the dam body cracks, this paper study temperature load’s influence on concrete gravity dam. This paper use finite element method, it adopts finite element calculation software to establish concrete gravity dam’s finite element model of Jiangya hydropower station. Based on monitoring data of water temperature, air temperature, dam body temperature, foundation temperature about Jiangya hydropower station, calculates and analyzes temperature field of dam during operation period, researches stress variation law of dam under the influence of temperature field. The results showe that, temperature load has a great influence on the dam operation, but dam still meet code design requirements; when continuous high temperature during summer, dam should avoid operate under high water level; when continuous low temperature during winter, dam should avoid operate under low water level. Research results provide theoretical according for concrete gravity dam’s safe operation of Jiangya hydropower station.

scholarly journals Spatio-Temporal Characteristics and Obstacle Factors of the Urban-Rural Integration of China’s Shrinking Cities in the Context of Sustainable Development

2021 ◽  
Vol 13 (8) ◽  
pp. 4203
Author(s):  
Bin Du ◽  
Ying Wang ◽  
Jiaxin He ◽  
Wai Li ◽  
Xiaohong Chen
Keyword(s):  
Sustainable Development ◽  
Economic Efficiency ◽  
Formation Mechanisms ◽  
Shrinking Cities ◽  
The Sustainable Development ◽  
Factors Affecting ◽  
Temporal Characteristics ◽  
The North ◽  
Urban Rural ◽  
Spatio Temporal

Based on the fundamental concept of sustainable development, this study empirically analyzes the spatio-temporal characteristics, formation mechanisms and obstacle factors of the urban-rural integration of shrinking cities in China, from 2008 to 2018. The conclusions are as follows: the overall level of the urban-rural integration of shrinking cities in China is low; the internal differences of urban-rural integration are also small, and the changes are slow. Next, the space difference is high in the east and low in the west, high in the south and low in the north. Moreover, differences exist among different levels of urban agglomerations. Urban economic efficiency, urban resources and environment, urban social equity and rural economic efficiency are the main factors affecting the urban-rural integration of shrinking cities in China. Urban and rural economic efficiency are the two most prominent shortcomings that restrict the urban-rural integration of shrinking cities. The spatial resistance mode of each city is more than the two-system resistance; the main resistance of shrinking cities with a higher level of urban-rural integration also comes from the non-economic field. This study expands the research scope that up till now has ignored the discussion of urban-rural issues in the research of shrinking cities at home and abroad, and provides practical guidance for the sustainable development of shrinking cities in China.

Spatio-temporal interpolation of soil water, temperature, and electrical conductivity in 3D + T: The Cook Agronomy Farm data set

2015 ◽  
Vol 14 ◽  
pp. 70-90 ◽  
Author(s):  
Caley K. Gasch ◽  
Tomislav Hengl ◽  
Benedikt Gräler ◽  
Hanna Meyer ◽  
Troy S. Magney ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Water Temperature ◽  
Soil Water ◽  
Data Set ◽  
Temporal Interpolation ◽  
Spatio Temporal

scholarly journals Long-Term Changes in Solar Shortwave Irradiance Due to Different Atmospheric Factors According to Measurements and Reconstruction Model in Northern Eurasia

2020 ◽  
Vol 4 (1) ◽  
pp. 5
Author(s):  
Elena Volpert ◽  
Natalia Chubarova
Keyword(s):  
Optical Thickness ◽  
Cloud Amount ◽  
Shortwave Radiation ◽  
Northern Eurasia ◽  
Factors Affecting ◽  
Meteorological Observatory ◽  
Cloud Optical Thickness ◽  
Reconstruction Model ◽  
Good Agreement

The temporal variability of solar shortwave radiation (SSR) has been assessed over northern Eurasia (40°–80° N; 10° W–180° E) by using an SSR reconstruction model since the middle of the 20th century. The reconstruction model estimates the year-to-year SSR variability as a sum of variations in SSR due to changes in aerosol, effective cloud amount and cloud optical thickness, which are the most effective factors affecting SSR. The retrievals of year-to-year SSR variations according to different factors were tested against long-term measurements in the Moscow State University Meteorological Observatory from 1968–2016. The reconstructed changes show a good agreement with measurements with determination factor R2 = 0.8. The analysis of SSR trends since 1979 has detected a significant growth of 2.5% per decade, which may be explained by its increase due to the change in cloud amount (+2.4% per decade) and aerosol optical thickness (+0.4% per decade). The trend due to cloud optical thickness was statistically insignificant. Using the SSR reconstruction model, we obtained the long-term SSR variability due to different factors for the territory of northern Eurasia. The increasing SSR trends have been detected on most sites since 1979. The long-term SSR variability over northern Eurasia is effectively explained by changes in cloud amount and, in addition, by changes in aerosol loading over the polluted regions. The retrievals of the SSR variations showed a good agreement with the changes in global radiance measurements from the World Radiation Data Center (WRDC) archive. The work was supported by RFBR grant number 18-05-00700.

Investigation of Airflow and Temperature Distribution in the Freezer Cabinet of a Domestic No-Frost Refrigerator

2009 ◽  
Author(s):  
Melike Nikbay ◽  
M. Berkay Acikgoz ◽  
Husnu Kerpicci
Keyword(s):  
Energy Consumption ◽  
Temperature Distribution ◽  
Uniform Temperature ◽  
Flow Conditions ◽  
Piv Measurements ◽  
Factors Affecting ◽  
Flow And Heat Transfer ◽  
Cfd Analyses ◽  
Off Time ◽  
Laminar Flow Conditions

Uniformity of temperature distribution in a loaded freezer cabinet is one of the most important factors affecting energy consumption of a refrigerator. Present study focuses on the airflow behavior and the temperature distribution inside the freezer compartment of a domestic no-frost refrigerator. Energy consumption increases in a freezer cabinet if the temperature difference between the warmest load package and average of all packages is high. The objective is to reduce the energy consumption by providing a uniform temperature distribution and also to keep the food fresh for a longer time. In this study, the air flow and heat transfer during on-time and off-time periods inside the freezer compartment is modeled by considering turbulent and laminar flow conditions in 3D transient CFD analyses. The initial and boundary conditions are provided from temperature controlled room and PIV measurements. The CFD analyses obtained are verified by experimental measurements.

scholarly journals Spatio-temporal characteristics of the sea-ice volume of the Bohai Sea, China, in winter 2009/10

2013 ◽  
Vol 54 (62) ◽  
pp. 97-104 ◽  
Author(s):  
Chengyu Liu ◽  
Wei Gu ◽  
Jinlong Chao ◽  
Lantao Li ◽  
Shuai Yuan ◽  
...  
Keyword(s):  
Sea Ice ◽  
Bohai Sea ◽  
Shortwave Radiation ◽  
Laizhou Bay ◽  
Bohai Bay ◽  
Temporal Characteristics ◽  
The Bohai Sea ◽  
Ice Volume ◽  
Radiation Theory ◽  
Spatio Temporal

AbstractTo investigate the spatio-temporal characteristics of sea-ice resource, we used sea-ice volume to measure the amount of sea-ice resource in the Bohai Sea, China. The sea-ice area was extracted from Advanced Very High Resolution Radiometer (AVHRR) remote-sensing images using the zonal threshold method. The sea-ice thickness was estimated using a sea-ice model based on shortwave radiation theory and field measurements. The spatio-temporal characteristics of sea-ice volume were then analysed using GIS technology. The results indicate that the Bohai Sea experienced two sea-ice volume peaks in winter 2009/10. The largest sea-ice volume was in Liaodong Bay (∼80.26% of the entire sea-ice volume of the Bohai Sea). Bohai Bay had the second largest ice volume, and Laizhou Bay the smallest. The relationship between sea-ice volume and distance from shore is essentially exponential. The proportion of total sea-ice volume that is 0–10 km from shore is ∼42.43%, whereas the proportion that is 100–110 km from shore is only 0.002%.

Block Treatment of Multi-Layer Wafers for the Development of a Numerical Model of a 300mm Batch Heat Treatment Furnace

2006 ◽  
Vol 15-17 ◽  
pp. 537-542
Author(s):  
Eun Yi Ko ◽  
Kyung Woo Yi
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Numerical Model ◽  
Thermal Treatment ◽  
Radiation Heat Transfer ◽  
Great Influence ◽  
Vertical Direction ◽  
Treatment Furnace ◽  
Numerical Experimentation ◽  
Modeling Strategy

Of all the processing stages for wafers, interior temperature distribution in thermal treatment furnaces has a great influence on wafer properties. Therefore, internal temperature distribution is a key factor for operating a furnace. However, it is practically impossible to directly measure temperatures within the furnace, and consequently the need for a reliable numerical model to analyze temperature distribution is becoming increasingly urgent. Exact modeling of the processing is very difficult because the structure of the furnace used for thermal treatment is very complex, with large numbers of Si wafers stacked within. Therefore, simplified modeling is necessary. The modeling strategy of the present study is to reduce the radiation calculation domain and simplify the model by replacing the wafer stack region with a single block. It is necessary to determine the vertical and horizontal effective thermal conductivities of the block to reflect radiation heat transfer between wafers. In this study, calculations were performed through numerical experimentation, using r k as the heat transfer coefficient in the direction of the radius, and v k for the vertical direction. Using these calculated property values, the temperature distribution within a 300mm thermal treatment furnace can be obtained.

scholarly journals Factors impacting on adoption of international education standards: an empirical study using factor analysis

2021 ◽  
Vol 5 (1) ◽  
pp. 25-44
Author(s):  
Adel BOULDJENIB
Keyword(s):  
International Education ◽  
Original Data ◽  
Economic Governance ◽  
Analysis Model ◽  
Accounting Profession ◽  
Education Standards ◽  
Factors Affecting ◽  
Econometric Approach ◽  
Political Economic ◽  
Ordinal Logistic Regression Model

The aim of this study is to determine the factors affecting International Education Standards (IESs) adoption, by using an econometric approach based on a sample of 64 Countries. To do that, data about legal, political, economic and cultural environment of each country was summarized using factorial analysis model. This model extracts four common factors from original data that’s likely to affect IESs adoption, those factors are legal, political and economic governance, opening of accounting profession to the outside world, initiative degree of the society, and accepting change and differences. The study concludes, using an ordinal logistic regression model (logit model), that legal, political and economic governance, opening of accounting profession to the outside world, initiative degree of the society has a significant effect on IESs adoption, while accepting change and differences have no effect.

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