Diagnosis of abnormal temperature rise observed on a 275 kV oil-filled cable surface — A case study

To compensate for the shortcomings of the existing point detection methods for grouting defects in prestressed tendon ducts, such as low detection efficiency, stringent detection environment, and easy omission of grouting defects, this article presents a distributed detection approach to detect the grouting defects in tendon ducts. The main objective of the research pertained to the development of a method for accurate identification and location of grouting defects and qualitative evaluation of the size of grouting defects using distributed fiber optic sensors with active heating. Using the thermal analysis of grouting defects in the tendon duct and the research on distributed fiber optic sensors measurement characteristics, our work proposed a method for identifying and locating grouting defects and explored the effect of the grouting defect length and the grouting compactness on the temperature rise of distributed fiber optic sensors. The feasibility of the proposed approach is evaluated through an experimental program. The experimental program involved use of heating distributed fiber optic sensors for the distributed measurement of temperature after the heating and detection of grouting defects in tendon ducts in a concrete beam. The results indicate that distributed fiber optic sensors can monitor the temperature distribution of the tendon duct during a temperature rise in real time. Grouting defects in the tendon duct can be quickly detected and located by identifying temperature anomalies in the temperature contour of the distributed fiber optic sensors. Furthermore, there is a linear relationship between the defect length and the abnormal temperature length on the distributed fiber optic sensors, and the defect length can be identified based on the abnormal temperature length obtained by the measurement. Plane-equivalent thermal conductivity can be used to evaluate the grouting compactness of the tendon duct. When the grouting compactness is greater than 70%, the smaller the plane-equivalent thermal conductivity is, the lower the grouting compactness is. The plane-equivalent thermal conductivity is basically the same when the grouting compactness is less than 70%.

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Environmental effects of temperature rise and long periods without precipitation on soil processes – case study for southern Slovakia

Annals of Warsaw University of Life Sciences – SGGW Land Reclamation ◽

10.2478/sggw-2018-0022 ◽

2018 ◽

Vol 50 (3) ◽

pp. 273-287

Author(s):

Luboš Jurík ◽

Peter Halaj ◽

Tatiana Kaletová ◽

Józef Mosiej ◽

Jozefína Pokrývková ◽

...

Keyword(s):

Water Content ◽

Soil Water ◽

Environmental Effects ◽

Temperature Rise ◽

Extended Period ◽

River Basin Management ◽

Soil Processes ◽

Soil Water Retention ◽

Effects Of Temperature

Abstract Environmental effects of temperature rise and long periods without precipitation on soil processes - case study for southern Slovakia. The general purpose of the article is to evaluate the environmental effects of temperature rise and long periods without precipitation on soil processes in southern Slovakia. Observed climate change (increase in average temperature) can cause changes in the fertility of the soil, especially in the direction of faster mineralization of organic matter. As an example, very accurate measurements of air temperature, rainfall and water content in the soil profile to a depth of 1 m are used. The more specific objective of the study was to evaluate the formation of soil water retention resources under high temperature conditions and over 30 days without rainfall. Based on the measured values, they were created graphs for extended period of time without precipitation. The graph shows the average daily soil moisture in each layer, which is measured at the hydrological network of stations in operation by Centre of Excellence for Integrated River Basin Management at SUA in Nitra. The final evaluation for the stations Žirany and Dolné Naštice, soil water content is showing the vulnerability of crops due to changes in water content, especially in layers from 0.3 to 0.5 m.

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Review on characteristics, heating sources and evolutionary processes of the operating composite insulators with abnormal temperature rise

CSEE Journal of Power and Energy Systems ◽

10.17775/cseejpes.2019.02790 ◽

2020 ◽

Cited By ~ 3

Keyword(s):

Temperature Rise ◽

Evolutionary Processes ◽

Abnormal Temperature

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On investigations of the observed thermal anomaly in earthquake precursors: A case study from the 1993 Latur earthquake prone area in western India

10.21203/rs.3.rs-67573/v1 ◽

2020 ◽

Author(s):

Vijay P Dimri ◽

Simanchal Padhy ◽

N C Mondal ◽

G K Reddy ◽

G G. Ramacharyulu ◽

...

Keyword(s):

Temperature Rise ◽

Seismic Hazard Assessment ◽

Thermal Anomaly ◽

Atmospheric Temperature ◽

Research Area ◽

Western India ◽

Monsoon Period ◽

Helium Gas ◽

Prone Area

Abstract We report and discuss monitoring of short-term variations of widely used multi-geophysical parameters in Latur-Killari area in western India, the region that faced a major devastating earthquake in 1993. An abnormal rise in atmospheric temperature of more than 20 ° C at 11200 m height was observed in the air-flight just 100 km away from Latur during a monsoon period. To investigate the causes of such temperature rise, we studied seismicity of the area in relation to the 1993 Latur event, and continuously monitored ground-water level and soil Helium gas for one week immediately following this observation under a precursory ‘quick please’ operation in the study area. There are no precursory seismic signals associated with this temperature rise; hence the operation was suspended after one week time. Although this thermal anomaly is not followed by any major earthquake over the area, it has larger implications in atmosphere research area. While a detailed investigation of such anomaly is beyond the scope this paper, we report here the possibility that the satellite thermal sensor cannot penetrate thick clouds to accurately retrieve the temperature. We are cautious of arriving at a firm conclusion, but the findings of this study certainly call for continuous monitoring of temperature over the earthquake prone areas to gain insight into the physics of short-lived variation in temperature over spatially limited extent, especially over the earthquake prone areas for improved seismic hazard assessment.

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Effects of High Temperature and Overpressure on Deep Reservoir in Qiongdongnan Basin, Northwestern South China Sea

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.356-360.3033 ◽

2011 ◽

Vol 356-360 ◽

pp. 3033-3037

Author(s):

Jun Xiao ◽

Bei Zhu ◽

Ji Hua Liao

Keyword(s):

High Temperature ◽

Geothermal Gradient ◽

Qiongdongnan Basin ◽

Petroleum Geology ◽

Reservoir Properties ◽

Deep Reservoir ◽

Temperature And Pressure ◽

Full Consideration ◽

Abnormal Temperature

Abnormal temperature and pressure with their effects on deep reservoir is the frontier in petroleum geology. Taking Qiongdongnan basin as a case study, the geological settings of this basin are primarily analyzed in this paper. Then, based on the full consideration of sedimentation and diagenesis, effects of abnormal temperature and pressure on deep reservoir are discussed. Main conclusions are drawn as following: (1) high geothermal or geothermal gradient accelerates the reduction of sandstone porosity, (2) high geothermal or geothermal gradient can improve the reservoir properties by promoting the dissolution of carbonate minerals, the filling of hydrocarbon and the development of overpressure, (3) overpressure can preserve partial primary pores, (4) overpressure can inhibit the growth of some cements and slow down the destruction of diagenesis on deep reservoir, and (5) overpressure can generate some secondary pores by enhancing dissolution.

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