本文選題：高速氣體 + 流量計校準　； 參考：《東華理工大學》2015年碩士論文

【摘要】：為了解決標準表法校準系統(tǒng)無法進行高速氣體流量校準的問題,本文依據(jù)正壓標準表法設計了一套高速氣體流量計校準系統(tǒng)。通過對系統(tǒng)的不確定度理論分析,并借助計算機流體仿真技術(shù)CFD對系統(tǒng)的結(jié)構(gòu)進行了仿真分析,論證了系統(tǒng)設計方案的可行性。本系統(tǒng)通過空壓機提供氣源,氣體通過前儲氣罐后流向標準表區(qū),其后經(jīng)由后儲氣罐流向待測表區(qū)。通過改變?nèi)饭軓椒謩e為DN20、DN50和DN50的標準管道閥門開度,選通三路管徑分別為DN20、DN32和DN50的待測表管道,實現(xiàn)氣體流量計從低速到高速的流量校準,其中三路標準表和三路待校準表的安裝位置為通過CFD仿真確定的。系統(tǒng)采用PLC-CPU224作為主控制器,以電動調(diào)節(jié)閥為被控對象,通過PID算法和閥門開環(huán)控制調(diào)節(jié)閥門開度進而實現(xiàn)管道流速的控制,其中系統(tǒng)的閉環(huán)控制傳遞函數(shù)及整定參數(shù)為通過機理法和階躍響應法結(jié)合使用,并借助于Matlab工具Simulink仿真得出的。在實際運行過程中將系統(tǒng)的過程量利用組態(tài)軟件MCGS進行實時顯示,并實時改變流量設定量和閥門開度值。經(jīng)過對系統(tǒng)的校準范圍、控制相對誤差、不確定度、重復性和穩(wěn)定性的實驗研究,結(jié)果表明:校準系統(tǒng)的擴展不確定度為0.76%;流量校準范圍為10-910m3/h(對應的在DN50管道內(nèi)的流速范圍為1.4-128.7m/s);系統(tǒng)的控制相對誤差和校準相對誤差都在1%以內(nèi)。
[Abstract]:In order to solve the problem that the calibration system of standard meter can not carry out high speed gas flow calibration, a calibration system of high speed gas Flowmeter is designed according to the positive pressure standard meter method in this paper.By analyzing the uncertainty theory of the system and using the computer fluid simulation technology CFD, the structure of the system is simulated and analyzed, and the feasibility of the system design scheme is proved.The system provides the air source through the air compressor, the gas flows through the front tank to the standard meter area, and then through the rear gas storage tank to the area to be measured.By changing the opening degree of the standard pipe valve with the diameter of DN20 / DN50 and DN50 respectively, and selecting the pipeline to be measured with the diameter of DN20 / DN32 and DN50 respectively, the flow calibration of gas Flowmeter from low speed to high speed can be realized.The installation positions of three standard tables and three channels to be calibrated are determined by CFD simulation.The system adopts PLC-CPU224 as the main controller and the electric regulating valve as the controlled object. Through the PID algorithm and the valve open loop control the valve opening to realize the control of the pipeline velocity.The closed-loop control transfer function and tuning parameters of the system are obtained by the combination of mechanism method and step response method, and by means of Simulink simulation with Matlab tool.The process quantity of the system is displayed in real time by configuration software MCGS, and the flow setting and valve opening value are changed in real time.After an experimental study of the calibration range of the system, the control of relative error, uncertainty, repeatability and stability,The results show that the extended uncertainty of the calibration system is 0.76, the flow calibration range is 10-910m3 / h (the corresponding velocity range in the DN50 pipeline is 1.4-128.7 m / s ~ (-1)), and the control relative error and the calibration relative error are within 1%.
【學位授予單位】：東華理工大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TH814

【參考文獻】

相關期刊論文 前1條

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本文編號：1767693