Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Fast detection study of foreign object intrusion on railway track

Niu H., Hou T.

Archives of Transport

2018

Vol. 47, iss. 3

79--89

The foreign objects intrusion on railway track has seriously affected the safe operation of the train, and it is extremely urgent to monitor them in real time. In order to improve the detection accuracy and rapidity of foreign objects intrusion on railway track, the new detection method of foreign object intrusion on railway track based on multi-background modeling, multi-difference and proportion method of black and white pixels is put forward in this paper. The multi-background modeling method that includes the historical background modeling, the multi-frame average background modeling and the previous frame of current frame background modeling method is used to model background modeling, and the three backgrounds are updated respectively to achieve background updating. The improved Canny method and Hough transform method is used to extract track edge, and get the final track edge image. Based on track edge image, the railway track dangerous area was established through the image segmentation method to reduce the amount of information in image processing and improve the processing speed. And then, according to the structure method of multi-background modeling, the detection method that fuses the historical background difference, average background difference and interframe difference is used to detect foreign object intrusion on track, and the detection result was processed by the morphological open processing. Finally, for the foreign objects intrusion, the decision is done by the quantitative proportion method of black and white pixels of image. The experimental results show that this method has better noise immunity performance and environmental adaptability, and the accuracy and rapidity of foreign objects intrusion detection is improved effectively.

Experimental investigation of a high temperature resistant and low friction fracturing fluid

Xiao B., Zhang S., Zhang J., Hou T., Guo T.

Physicochemical Problems of Mineral Processing

2015

Vol. 51, iss. 1

37--47

The performance of a hydraulic fracturing fluid (HFF) system directly determines the efficiency of stimulation. Since the targeted formations of most oil fields in China are characterized by large depth (~5000 m), high temperature (160 to 180 °C) and tight lithology, newer and suitable HFFs have to be developed. Based on a newly synthetized organo-boron/-zirconium cross-linking agent (Gh-g), a composite temperature stabilizer (WJ-6) and other optimized additives via indoor evaluation, this study introduced a novel HFF, which is thermally stable at high temperature (HT) up to 180 °C and exerted low friction pressures. The performance of HFF was evaluated in the laboratory. The experimental results showed that the HFF system performed well at HTs. It maintained a viscosity of 100 mPa•s or more after 90 min of shearing (170 s−1) at 180 °C. Furthermore, the system exhibited delayed cross-linking. It took 120 s for the cross-linking reaction to complete; therefore, the tube friction was reduced to a large extent. Another characteristic feature of the formulated HFF system was the low friction pressures, where the drag reduction percentage was in the range from 35% to 70%. Moreover, only minor damage was caused by the fluid to the formation core samples. The average core permeability damage was 19.6%. All these qualities ensure that this fluid system is in full compliance with the requirements of the fracturing treatment.