本文選題：氣液兩相流 + 參數(shù)測(cè)量��； 參考：《浙江大學(xué)》2017年博士論文

【摘要】：氣液兩相流在工業(yè)過程中涉及范圍十分廣泛,其參數(shù)的有效測(cè)量是一個(gè)具有重大意義但仍未得到較好解決的課題�；诘刃щ妼�(dǎo)檢測(cè)的氣液兩相流參數(shù)檢測(cè)方法具有結(jié)構(gòu)簡(jiǎn)單和實(shí)時(shí)響應(yīng)快等優(yōu)點(diǎn)而得到廣泛關(guān)注,但該方法仍然存在兩方面不足:在測(cè)量機(jī)理方面,現(xiàn)有的電導(dǎo)檢測(cè)方法主要是接觸式的,其檢測(cè)電極直接與被測(cè)流體接觸,會(huì)引起電極極化和電化學(xué)腐蝕等問題;在測(cè)量信息方面,現(xiàn)有的電導(dǎo)檢測(cè)方法以獲取流體等效電導(dǎo)信號(hào)為目的,但對(duì)復(fù)雜的氣液兩相流體而言,包含更多流動(dòng)特征的完整電阻抗信息(實(shí)部、虛部和幅值)的獲取將更有利于氣液兩相流參數(shù)檢測(cè)。本學(xué)位論文針對(duì)以上兩個(gè)問題,對(duì)現(xiàn)有的電容耦合式非接觸電導(dǎo)檢測(cè)(Capacitively Coupled Contactless Conductivity Detection,C4D)技術(shù)存在的問題進(jìn)行改進(jìn),研發(fā)了新型非接觸式電阻抗傳感器,利用完整電阻抗信息實(shí)現(xiàn)氣液兩相流參數(shù)測(cè)量。本學(xué)位論文中的主要?jiǎng)?chuàng)新點(diǎn)和貢獻(xiàn)如下:1、為克服本課題組已有工業(yè)型C4D傳感器存在的輸入輸出特性呈現(xiàn)非單調(diào)性的不足,提出了一種基于雙電感串聯(lián)諧振的非接觸式電導(dǎo)檢測(cè)新方法,研發(fā)了一種工業(yè)型雙電感結(jié)構(gòu)C4D傳感器。該方法在激勵(lì)電極和檢測(cè)電極端各串聯(lián)一個(gè)電感器件,不僅克服了耦合電容對(duì)測(cè)量的不利影響,還解決了已有工業(yè)型C4D傳感器輸入輸出特性的非單調(diào)性的問題。實(shí)驗(yàn)結(jié)果表明,所提出的基于雙電感串聯(lián)諧振的非接觸式電導(dǎo)檢測(cè)新方法是有效的,所研發(fā)的工業(yè)型雙電感結(jié)構(gòu)C4D傳感器是成功的。在四種管道(內(nèi)徑分別為1.8 mm、3.3 mm、5.0 mm和7.6mm)中,電導(dǎo)測(cè)量最大相對(duì)誤差均小于4%。2、針對(duì)實(shí)際電感存在電感可調(diào)范圍窄、大電感制造困難和體積較大等問題,引入模擬電感技術(shù),提出了基于模擬電感串聯(lián)諧振的非接觸式電導(dǎo)檢測(cè)新方法。研發(fā)了對(duì)稱浮置模擬電感以及基于對(duì)稱浮置模擬電感的C4D傳感器。研究結(jié)果表明,對(duì)稱浮置模擬電感和該新型C4D傳感器的設(shè)計(jì)是成功的,稱浮置模擬電感等效電感值調(diào)節(jié)大并可實(shí)現(xiàn)較大電感值,采用對(duì)稱浮置模擬電感的C4D傳感器的性能和電導(dǎo)測(cè)量精度令人滿意。在三種管道(內(nèi)徑分別為3.0 mm、4.6 mm和6.4 mm)中,電導(dǎo)測(cè)量最大相對(duì)誤差均小于5%。3、針對(duì)對(duì)稱浮置模擬電感存在的結(jié)構(gòu)復(fù)雜、運(yùn)行穩(wěn)定性需重點(diǎn)考慮等問題,研發(fā)了兩種基于接地模擬電感的C4D傳感器:A(利用電流轉(zhuǎn)電壓的原理)和B(測(cè)量分壓電阻兩端電壓差的原理)。在三種管道(內(nèi)徑分別為3.0mm、4.6mm和6.4 mm)中利用C4D傳感器A和C4D傳感器B進(jìn)行電導(dǎo)測(cè)量實(shí)驗(yàn)。實(shí)驗(yàn)結(jié)果表明,接地模擬電感和新型C4D傳感器的設(shè)計(jì)是成功的。與對(duì)稱浮置模擬電感相比,接地模擬電感具有結(jié)構(gòu)簡(jiǎn)單和運(yùn)行穩(wěn)定性較好等優(yōu)點(diǎn)�；诮拥啬M電感的C4D傳感器的電導(dǎo)測(cè)量精度也令人滿意(三種管徑下,新型C4D傳感器A和B的電導(dǎo)測(cè)量最大相對(duì)誤差分別為4.5%和5.0%),且C4D傳感器A的整體測(cè)量性能較C4D傳感器B更好。4、結(jié)合接地模擬電感阻抗相消技術(shù)和數(shù)字相敏解調(diào)(DPSD)技術(shù)提出了一種非接觸式電阻抗測(cè)量新方法,研發(fā)了一種新型非接觸式電阻抗傳感器。該非接觸式電阻抗測(cè)量方法根據(jù)阻抗相消原理克服耦合電容對(duì)電阻抗測(cè)量的不利影響,利用DPSD技術(shù)獲取氣液兩相流的完整電阻抗(實(shí)部、虛部和幅值)信息。模擬和實(shí)際流體測(cè)量實(shí)驗(yàn)表明:所提出的非接觸式電阻抗測(cè)量方法是有效的,所研發(fā)的新型非接觸式電阻抗傳感器是成功的。模擬測(cè)量實(shí)驗(yàn)中,電阻測(cè)量和電容測(cè)量的最大相對(duì)誤差分別為3.7%和2.4%,電阻-電容組合測(cè)量實(shí)驗(yàn)中,電阻和電容測(cè)量的最大相對(duì)誤差分別為2.1%和5.1%;實(shí)際流體測(cè)量實(shí)驗(yàn)中,KC1溶液電導(dǎo)率測(cè)量和有機(jī)溶劑介電常數(shù)測(cè)量的最大相對(duì)誤差分別為3.7%和5.8%。5、將所研發(fā)的新型非接觸式電阻抗傳感器與小波分析和k均值聚類方法相結(jié)合提出了一種基于非接觸電阻抗測(cè)量的氣液兩相流流型辨識(shí)新方法。該方法采用小波分析提取所獲電阻抗信號(hào)各部分的頻域特征,結(jié)合電阻抗信號(hào)的統(tǒng)計(jì)特征構(gòu)成特征向量,利用以馬氏距離作為距離度量指標(biāo)的k均值聚類方法進(jìn)行流型分類。三種管徑(3.0mm、4.0mm和7.0mm)下的流型辨識(shí)實(shí)驗(yàn)結(jié)果表明,所提出的流型辨識(shí)新方法是有效的。利用實(shí)部、虛部、幅值和完整電阻抗信號(hào)對(duì)泡狀流和段塞流進(jìn)行辨識(shí)的最低準(zhǔn)確率分別為91.1%和90.9%、90.2%和87.9%、92.7%和87.0%及91.1%和93.5%。采用完整電阻抗信號(hào)的整體流型辨識(shí)效果略優(yōu)于單獨(dú)采用實(shí)部、虛部或幅值信號(hào)的流型辨識(shí)效果。6、提出了一種基于非接觸電阻抗測(cè)量的氣液兩相流相含率測(cè)量新方法。該方法充分利用電阻抗各部分信息,結(jié)合最小二乘法,建立不同流型相含率測(cè)量模型,實(shí)際測(cè)量時(shí)根據(jù)流型判別結(jié)果選擇相應(yīng)的相含率測(cè)量模型并最終實(shí)現(xiàn)相含率測(cè)量。三種不同管徑(3.0mm、4.0mm和7.0mm)泡狀流和段塞流下的實(shí)驗(yàn)研究結(jié)果表明所提出的相含率測(cè)量新方法是可行的和有效的,充分利用氣液兩相流完整電阻抗信息(實(shí)部,虛部和幅值)有助于相含率測(cè)量精度的提高。
[Abstract]:Gas-liquid two-phase flow is widely involved in the industrial process. The effective measurement of its parameters is a subject which is of great significance but is still not well solved. The method of gas liquid two-phase flow parameter detection based on equivalent conductance detection has been paid wide attention to the advantages of simple structure and fast real-time response, but the method still exists. The two aspects are insufficient: in the measurement mechanism, the current conductance detection method is mainly contact type. The detection electrode directly contacts with the measured fluid, causes electrode polarization and electrochemical corrosion. In the measurement information, the current conductance detection method is aimed at obtaining the fluid equivalent conductance signal, but the complex gas-liquid two phases are used. For fluid, the acquisition of integrated electrical impedance information (real part, virtual part and amplitude) containing more flow characteristics will be more conducive to the detection of gas-liquid two-phase flow parameters. In this dissertation, the existing Capacitively Coupled Contactless Conductivity Detection (C4D) technology exists for the existing capacitive coupling non-contact conductivity detection (Capacitively Detection, C4D). The main innovation points and contributions in this dissertation are as follows: 1, in order to overcome the inadequacy of the input and output characteristics of the existing industrial C4D sensors in our research group, a new method is proposed. Based on a new method of non contact conductance detection based on double inductor series resonance, an industrial dual inductor C4D sensor is developed. This method is connected with an inductor at the exciting electrode and the detection electrode. It not only overcomes the negative influence of the coupling capacitance on the measurement, but also solves the input and output characteristics of the existing industrial type C4D sensors. The experimental results show that the new method of non-contact conductivity detection based on double inductance series resonance is effective. The developed industrial dual inductor structure C4D sensor is successful. The maximum relative error of the conductance measurement is less than 4%. in four kinds of pipes (1.8 mm, 3.3 mm, 5 mm and 7.6mm respectively). 2, in view of the narrow inductance of the inductor, the difficulty in producing large inductors and the larger size of the inductor, a new method of non contact conductance detection based on the analog inductor series resonance is proposed. The symmetrical floating analog inductor and the C4D sensor based on the symmetrical floating inductance are developed. The design of the symmetrical floating analog inductor and the new C4D sensor is successful. It is said that the equivalent inductance value of the floating analog inductor can be adjusted greatly and the inductance value can be realized. The performance and the conductivity measurement precision of the C4D sensor with symmetrical floating analog inductance are satisfactory. In the three kinds of pipes (3 mm, 4.6 mm and 6.4 mm respectively), the conductance measurement The maximum relative error is less than 5%.3. In view of the complex structure of the symmetrical floating analog inductor and the operation stability, two kinds of C4D sensors based on grounding analog inductors are developed: A (using the principle of current transfer voltage) and B (the principle of measuring voltage difference at the two end of the voltage divider). In the three kinds of pipes, the internal diameter is 3.0m, respectively. M, 4.6mm and 6.4 mm) use C4D sensor A and C4D sensor B to carry out conductance measurement experiments. Experimental results show that the design of ground Analog inductors and new C4D sensors is successful. Compared with symmetric floating analog inductors, the ground Analog inductors have the advantages of simple structure and good operation stability. The conductivity measurement accuracy of the sensor is also satisfactory (the maximum relative error of the electrical conductivity measurement of the new C4D sensor A and B is 4.5% and 5% respectively), and the overall measurement performance of the C4D sensor A is better than that of the C4D sensor B, and a non contact with the grounding analog inductance impedance cancellation technique and the digital phase sensitive demodulation (DPSD) technology is proposed. A new non contact electrical impedance sensor is developed. The non-contact impedance measurement method overcomes the adverse effect of the coupling capacitance on the impedance measurement based on the impedance cancellation principle. The DPSD technology is used to obtain the complete impedance (real part, imaginary part and amplitude) information of the gas-liquid two phase flow. The measurement experiments show that the proposed non-contact impedance measurement method is effective and the new type of non-contact electrical impedance sensor developed is successful. The maximum relative error of resistance measurement and capacitance measurement is 3.7% and 2.4% respectively in the simulated measurement experiment. The maximum phase of resistance and capacitance measurement in the resistance capacitance measurement experiment The errors are 2.1% and 5.1% respectively. In the actual fluid measurement experiments, the maximum relative errors of the measurement of KC1 solution conductivity and the dielectric constant of organic solvents are 3.7% and 5.8%.5 respectively. A new type of non-contact electrical impedance sensor, combined with wavelet analysis and K mean clustering, is put forward based on the non contact resistance measurement. A new method for identifying the flow pattern of gas-liquid two phase flow is used. This method uses the wavelet analysis to extract the frequency domain characteristics of all parts of the impedance signal, and combines the statistical characteristics of the electrical impedance signal to form the characteristic vector. The flow pattern classification is carried out by using the K means clustering method which takes martensitic distance as a distance measure. Three kinds of pipe diameter (3.0mm, 4.0mm and 7.0mm) are used. The flow pattern identification results show that the proposed flow pattern identification method is effective. The minimum accuracy of identification of bubbly flow and slug flow using real parts, imaginary parts, amplitude and integrated impedance signals is 91.1% and 90.9%, 90.2% and 87.9%, 92.7% and 87%, 91.1% and 93.5%. are identified as the integral flow pattern identification of integrated electrical impedance signals. The effect is slightly better than the flow pattern identification effect of the real part, the imaginary part or the amplitude signal.6. A new method for measuring the phase holdup of gas-liquid two-phase flow based on the non contact impedance measurement is proposed. This method makes full use of the information of the electrical impedance and the least square method to establish the measurement model of the phase holdup of different flow patterns, and the actual measurement is based on the flow. The phase holdup measurement model is selected and the phase holdup measurement is finally realized. The experimental results of three different pipe diameter (3.0mm, 4.0mm and 7.0mm) bubbly flow and slug flow show that the proposed phase holdup method is feasible and effective, and fully utilizes the integrated electrical impedance information (real part, virtual part and the virtual part) of the gas liquid two phase flow. The amplitude is helpful to the improvement of the measurement accuracy of the phase holdup.

【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類號(hào)】：O359.1
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本文編號(hào)：1850516