發(fā)布時(shí)間：2019-05-16 19:50

【摘要】：在管道的生產(chǎn)和建設(shè)過程中,焊縫檢測是必不可少的一道工序。x射線膠片照相法是我國長期采用的管道焊縫檢測方法,但存在檢測效率低、檢測成本高、污染環(huán)境等問題。數(shù)字射線檢測方法的產(chǎn)生為射線檢測提供了新方法,基于非晶硅平板探測器的數(shù)字射線檢測方法在醫(yī)學(xué)領(lǐng)域已得到成功應(yīng)用,但能否應(yīng)用于管道檢測尚未得到統(tǒng)一認(rèn)識(shí)。因此本文ffi點(diǎn)對(duì)該系統(tǒng)的性能評(píng)價(jià)方法、圖像質(zhì)量影響因素及在管道焊縫檢測方面應(yīng)用的有效性進(jìn)行研究。論文通過借鑒國外管道事故統(tǒng)計(jì)數(shù)據(jù),研宄了油氣管道事故的主要引起因素及相關(guān)的安全檢測方法�？偨Y(jié)不同射線檢測方法的發(fā)展、特點(diǎn)及不足,優(yōu)選出適合用于管道焊縫檢測的數(shù)字射線檢測系統(tǒng)。在分析數(shù)字射線檢測系統(tǒng)成像原理的基礎(chǔ)上,對(duì)數(shù)字射線檢測系統(tǒng)的關(guān)鍵組件非晶硅平板探測器的組成、轉(zhuǎn)換機(jī)理進(jìn)行研宄,分析該系統(tǒng)能獲得較好的檢測效果的原因;分析了探測器主要性能參數(shù)對(duì)圖像質(zhì)量的影響。對(duì)圖像對(duì)比度、圖像分辨率等參數(shù)的具體影響因素分別進(jìn)行了試驗(yàn)驗(yàn)證。影響圖像對(duì)比度的主要因素有射線能量、散射線及成像兒何條件,成像兒何條件又包括射線源焦點(diǎn)尺寸、放大倍數(shù)及焦距;影響圖像分辨率的主要因素有探測器像元尺寸、射線源焦點(diǎn)尺寸和放大倍數(shù)等;實(shí)驗(yàn)結(jié)果與理論分析基本一致。從獲得更高圖像對(duì)比度和更高分辨率出發(fā),綜合考慮試驗(yàn)系統(tǒng)組成及相關(guān)影響M素,得出在較優(yōu)條件下的試驗(yàn)參數(shù),在此條件下對(duì)X80鋼管試塊從信噪比、對(duì)比度、分辨率二個(gè)方面進(jìn)行了試驗(yàn)研究,并將獲得的數(shù)字射線檢測圖像與膠片照相檢測圖像進(jìn)行對(duì)比分析。實(shí)驗(yàn)結(jié)果表明:數(shù)字射線檢測圖像質(zhì)量滿足相關(guān)標(biāo)準(zhǔn)要求,檢測結(jié)果是有效的;數(shù)字射線檢測圖像與膠片射線檢測圖像相比具有同等的缺陷發(fā)現(xiàn)能力,某些情況下得到的圖像史加清晰;數(shù)字射線檢測方法可以在很短時(shí)間內(nèi)成像,具有更高的檢測效率;數(shù)字射線檢測方法應(yīng)用于管道焊縫檢測是可行的,實(shí)驗(yàn)結(jié)果及分析為后續(xù)該方法的推廣應(yīng)用提供了理論依據(jù)。
[Abstract]:In the process of pipeline production and construction, weld detection is an indispensable process. X-ray film photography is a long-term pipeline weld detection method in China, but there are some problems, such as low detection efficiency, high detection cost, pollution to the environment and so on. The generation of digital ray detection method provides a new method for ray detection. The digital ray detection method based on amorphous silicon flat plate detector has been successfully applied in the field of medicine, but whether it can be applied to pipeline detection has not been unified. Therefore, the performance evaluation method of the system, the influencing factors of image quality and the effectiveness of its application in pipeline weld detection are studied in this paper. Based on the statistical data of pipeline accidents abroad, the main causes of oil and gas pipeline accidents and the related safety detection methods are studied in this paper. The development, characteristics and shortcomings of different ray detection methods are summarized, and the digital ray detection system suitable for pipeline weld detection is selected. On the basis of analyzing the imaging principle of digital ray detection system, the composition and conversion mechanism of amorphous silicon flat plate detector, which is the key component of digital ray detection system, are studied, and the reasons why the system can obtain better detection effect are analyzed. The influence of the main performance parameters of the detector on the image quality is analyzed. The specific influencing factors of image contrast, image resolution and other parameters are verified by experiments. The main factors affecting the contrast of the image are ray energy, scattered rays and imaging conditions, and the imaging conditions include the focus size of the ray source, magnification and focal length. The main factors affecting the image resolution are the pixel size of the detector, the focus size and magnification of the ray source, and the experimental results are in good agreement with the theoretical analysis. In order to obtain higher image contrast and higher resolution, considering the composition of the test system and the related influence M element, the test parameters under the better conditions are obtained. Under these conditions, the signal-to-noise ratio (SNR) and contrast of the X80 steel pipe test block are obtained. The resolution was studied in two aspects, and the digital radiographic images and film photographic images were compared and analyzed. The experimental results show that the image quality of digital ray detection meets the requirements of relevant standards, and the detection results are effective. Compared with the film ray detection image, the digital ray detection image has the same defect detection ability, and the image history obtained in some cases is clearer. The digital ray detection method can image in a very short time and has higher detection efficiency. It is feasible to apply digital ray detection method to pipeline weld detection. The experimental results and analysis provide a theoretical basis for the subsequent popularization and application of this method.
【學(xué)位授予單位】：西安石油大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TE973.3

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 J.柯斯克能 ,藺春濤,高冬;線陣探測器(LDA)的現(xiàn)狀及發(fā)展趨勢[J];CT理論與應(yīng)用研究;2002年03期

2 王曉香;我國油氣長輸管線用焊接鋼管生產(chǎn)技術(shù)的發(fā)展與展望[J];鋼管;2004年03期

3 程耀瑜,李永紅,張丕壯,郭潔;射線數(shù)字成像檢測系統(tǒng)不均勻性分析與校正[J];光電工程;2005年05期

4 姚海根;;數(shù)字成像設(shè)備的信噪比及其用途[J];出版與印刷;2010年01期

5 蔣太秋;張圣光;王坤顯;劉耀華;;DR平板檢測技術(shù)在螺旋埋弧焊管檢測中的應(yīng)用[J];焊管;2010年02期

6 王功禮,王莉;油氣管道技術(shù)現(xiàn)狀與發(fā)展趨勢[J];石油規(guī)劃設(shè)計(jì);2004年04期

7 鄭世才;第一講 射線照相檢驗(yàn)技術(shù)的基礎(chǔ)[J];無損檢測;2000年01期

8 鄭世才;;不清晰度的測量[J];無損檢測;2006年04期

9 李樹軒;萬詩敏;;射線照相法的缺陷檢出靈敏度[J];無損檢測;2008年11期

10 梁麗紅;;JB/T 4730.11射線數(shù)字成像標(biāo)準(zhǔn)制定的關(guān)鍵技術(shù)探討[J];無損檢測;2011年09期

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本文編號(hào)：2478518