解析燃氣烘爐火焰檢測不穩(wěn)定改造

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【摘要】本文是以烘爐燃燒時火焰檢測設備的故障全過程為實例,探討分析影響烘爐火焰檢測穩(wěn)定的各種因素,詳述與之相對應的檢修對策及效果,說明通過改進修檢工藝,可以有效地提高烘爐滅火保護裝置的可靠性。 【 abstract 】 this article is based on oven burning flame detection equipment failure process as an example, analyzes factors which influenced the stability of the oven flame detection, detail and the corresponding repair measures and effect, and that by improving the inspection process, can effectively improve the reliability of oven fire protection device. 　　【關鍵詞】電離電極;火焰監(jiān)測器;程序控制器;穩(wěn)定性 【 key words 】 the ionization electrode; Flame monitor; Program controller; The stability 　　　　 　　1 前言 1 introduction 　　 　　筆者對廣州某公司在運轉的三臺烘爐進行了半年時間的觀察及檢測,發(fā)現(xiàn)了因設計、安裝質量、檢修調整、燃燒工況(調整)等諸多問題,爐膛外火焰檢測信號長期不穩(wěn)定,多次出現(xiàn)保護誤動現(xiàn)象,嚴重影響了機組的安全穩(wěn)定運行。一方面火檢裝置本身存在不穩(wěn)定因素,另一方面燃燒控制設備可控性差;燃燒調整不當又反過來影響火檢的穩(wěn)定,并多次影響工作效率,本文就怎樣對烘爐火焰檢測改造進行探討。 The author a company working in guangzhou three oven for half a year's observation and testing, found due to the quality of design, installation, maintenance adjustment (adjustment), combustion conditions and so on many issues, outside the furnace flame detection signal is not stable for a long time, multiple occurrences of protection misoperation phenomenon, seriously affecting the safe and stable operation of the unit. Fire detection device itself exists unstable factors on one hand, on the other hand, poor combustion control equipment control; Improper combustion adjustment, in turn, influence the stability of the flame detector, and influence work efficiency many times, this article on how to oven flame detection transformation were discussed. 　　 　　2 影響火檢穩(wěn)定的因素分析 Two factors affecting the stability of the flame detector is analyzed 　　 　　從烘爐設備分析火檢不穩(wěn)定原因應從火檢裝置本身和燃燒變化兩個方面進行分析,找出制約火檢光(電)信號傳輸、處理不合理環(huán)節(jié)和燃燒工況變差的因素,并采取有效的檢修對策改進設備、燃燒控制以及改善調整,完全可以消除鍋爐火檢不穩(wěn)定現(xiàn)象,這在1號、2號爐改造后15個火檢的良好運行工況得到了證明。 From oven equipment this paper analyzes the reasons of unstable flame detector should from the device itself and the combustion flame detector changes two aspects carries on the analysis, find the fire detector (electricity) light signal transmission, processing, unreasonable links and combustion condition, and take effective maintenance measures to improve equipment, combustion control, and improve the adjustment, can completely eliminate the phenomenon of boiler flame detector is not stable, after the reform in boiler no. 1, 2, 15 got prove that fire inspection of good operation condition. 　　2.1 火焰監(jiān)測器安裝位置不合理。 2.1 the flame monitor installation position is not reasonable. 　　火焰監(jiān)測器的安裝位置、傾角在導光管中的相對位置兩個問題。由于燃氣燃燒器擴散角、初燃區(qū)范圍大小的差異,所以導光管與燃燒器傾角安裝,并以一定的傾角對準初燃區(qū)中部靠前處,如果導光管沒對準初燃區(qū)或者插入困難而沒有伸到位影響視角,都會嚴重影響檢光效果?；饳z信號偏弱,不能正確反映燃燒的實際工況,燃燒負荷較低時,易誤發(fā)無火信號。(圖1) The installation location, Angle of the flame monitor the relative position of two questions in the light pipe. Due to gas burner diffusion Angle, in the early combustion zone size difference, so the light pipe installation with the burner Angle, and aim at a certain Angle in the early combustion zone in central front place, if the light pipe out early combustion zone or insert difficult without stretch in place influence Angle, will seriously affect the light effect. Fire detection signal is weak, can not correctly reflect the actual working condition of the combustion, combustion at low load, easy to mistakenly send no fire signal. (figure 1) 　　2.2 火焰監(jiān)測器能變差或積灰。 2.2 the flame monitor can worsen or dust. 　　由于導光管冷卻效果不好而造成導光管前端溫度過高,使導光管過早老化,且探頭維護不善易積灰,二者都會嚴重影響通光性能(透光率),使紫外光亮度信號在傳輸過程中大大減弱,從而使火檢信號不穩(wěn)定。 Due to bad cooling effect of the light guide light guide front temperature is too high, make the light guide premature aging, and probe poorly maintained dust easily, both are seriously affecting the optical properties (transmittance) and the ultraviolet luminance signal during transmission greatly reduced, so that the flame detector signal is not stable. 　　2.3 火焰監(jiān)測器參數(shù)調整不合理。 2.3 the flame monitor parameter adjustment is not reasonable. 　　處理好靈敏度和分辨能力兩個方面的問題,既要有足夠的靈敏度保證火檢信號的穩(wěn)定,又要將本身的火焰同與其相鄰、相對的焰區(qū)分開來。火檢參數(shù)調整不當主要表現(xiàn)在如下方面: Handle both sensitivity and resolution of problems, should not only have enough sensitivity to the stability of the flame monitoring signals of guarantee, and flame with adjacent to itself, apart from the relative flame. Improper parameter adjustment of the flame detector is mainly embodied in the following aspects: 　　2.3.1 在燃氣燃燒的工況下調整火檢,由于火焰是離燃燒器19.6mm左右向前燃燒,火焰長度是296mm,經(jīng)監(jiān)測后火檢參數(shù)與檢測實際工況不符。 2.3.1 in gas combustion adjustment under the condition of fire, because fire is around 19.6 mm burner combustion, the flame length is 296 mm, after monitoring the parameters of the flame detector and the detection of actual working condition. 　　2.3.2 在調整單臺火檢時沒有減少給氣量進行試驗、調整。 2.3.2 when adjusting a single fire inspection did not decrease for gas testing and adjustment. 　　2.3.3 中心頻率設定不準,由于初燃區(qū)火焰閃爍的頻率不僅與煤氣質有關,而且與空氣濃度有關,因此中心頻率的設定宜在60%～70%額定負荷下進行試驗、設定,滿負荷和最低負荷下調整、設定中心頻率都是不合理的。 2.3.3 center frequency setting is not allowed, because the early combustion zone flame flicker frequency not only related with the gas quality, and is associated with air concentration, so the center frequency of the set should be under 60% ~ 70% rated load test, the setting, full load and the minimum load adjustment, setting the center frequency is not reasonable. 　　2.3.4 調整后的火檢參數(shù)沒有進行低負荷、變煤氣質(種)的試驗和長時間的考驗,一旦遇到比試驗更差的工況,則可能出現(xiàn)大面積火檢不穩(wěn)而產(chǎn)生保護誤動。 2.3.4 after adjusting the parameters of the flame detector to low load, the gas mass (kind of) test and the length of the test of time, once encounter less than the test conditions, may appear unstable area fire detection and protection misoperation. 　　2.3.5 沒有處理好靈敏度和分辨能力之間的矛盾關系,存在一定的漏檢、誤檢的隱患。 2.3.5 did not deal with the contradiction between the sensitivity and resolving power relations, there is leak and mistakenly identified hazards. 　　2.4 煤氣量的變化及一次風過量。 2.4 the quantity of gas and the wind too much at a time. 　　煤氣量變差或煤氣熱值降低,則會使煤氣著火距離后移,使初燃區(qū)中心偏離原來火檢導光管對準的區(qū)域,亮度、頻率會因此而發(fā)生變化,影響火檢信號的穩(wěn)定,同樣風機一次風量過大,未燃區(qū)會因一次風速增高、煤氣細度增大而加長,也會使煤氣著火距離后移,典型的情況是鍋爐低負荷(低于65%額定負荷)下磨一次風量過大,對火檢有明顯影響,這種運行工況應盡量避免。 Gas quantity difference or gas calorific value is reduced, can make gas ignition distance moved, at the beginning of the combustion zone center deviating from the original light pipe alignment area flame detector, intensity, frequency will change because of this, the stability of the flame monitoring signals of influence, as a fan air volume is too big, not combustion zone due to a higher wind speed and the fineness degree of the gas increases, longer, also can make gas ignition distance backward-shift, typically boiler under low load (less than 65% the rated load) grinding a air volume is too big, had significant effect on the fire inspection, the operation condition should be avoided. 　　2.5 燃燒控制設備可靠性差及擺動異常。 2.5 abnormal combustion control equipment reliability is poor and swing. 　　主要是燃燒器擺角和二次風擋板,燃燒器擺角控制異常,部分擺到最高、最低,特別是同一層擺角,因噴口燒損變形卡住原因,使擺角出現(xiàn)有的上擺到頂、有的下擺到底的情況,烘爐正常切向燃燒遭到破壞,紫外光導向管跟隨擺動,燃燒器初燃區(qū)火焰仍然偏離檢測區(qū),火焰回流效果差,同時紫外光在導光管中的位置會因擺動相對后移,使火檢信號偏弱而不穩(wěn),特別是低負荷更明顯,不但火檢不穩(wěn),還會損壞燃氣閥組。 Mainly swinging Angle of burner and secondary air baffle, the swinging Angle of burner control abnormal, place to the highest and lowest part, especially in the same layer angular, stuck due to the burning of the nozzle deformation reason, make the pendulum Angle appear some on to, in some cases the hem in the end, oven normal tangential combustion destroyed, ultraviolet light pipe run follow swinging, the burner flame combustion zone is still at the beginning of deviating from the detection area, poor flame backflow effect, at the same time uv in the light guide position will due to the relatively backward, make the signal weak and unstable flame detector, especially more obvious under low load, unstable flame detector, not only can damage the gas valve group. 　　二次風擋板開不到位也是嚴重影響燃燒的因素之一,使燃燒器燃燒配風不夠,燃燒工況惡化而使火檢不穩(wěn)。 Secondary air baffle opening does not reach the designated position is one of the serious factors affecting combustion, the combustion burner air distribution is not enough, unstable combustion condition deterioration and make the fire inspection. 3 改造方案 3 retrofit scheme 　　 　　3.1 要改用電離電極重新定位。 3.1 to convert the ionization electrode repositioning. 　　電離電極安裝在噴口前方的火焰口內,火焰要與電極要相互垂直安裝。威索公司根據(jù)燃燒器的尺寸、噴口擴散角、額定工況一次風速和燃氣壓力,空氣壓力,燃氣檢漏確定了火焰的長度為傾角為60°左右,并向前燃燒300mm長火焰,而電離電極要與火焰穩(wěn)焰器垂直并相距20mm。還要做好絕緣和防高溫處理和降溫處理(圖2) Ionization electrode is installed in the flame inside the mouth in front of the nozzle, the flame with electrodes perpendicular to install. Weishaupt company according to the size of the burner, nozzle Angle, the rated working condition of a gas pressure, wind speed and air pressure, gas leak detection to determine the length of the flame inclination to 60 °, and 300 mm long flame combustion, and ionization electrode and the flame stabilizing vertical flame device and 20 mm apart. For insulation and heat treatment and cooling (figure 2) 　　 　　 　　3.2 改造后的工作過程。 3.2 after transforming the work process. 　　烘爐的燃燒是由程序控制器LFL1.333給予一定吹掃時間,并點火在3秒鐘內對火焰檢測電離電極是否有導通電流30~50uA返回程序控制器分析如有30-50uA通過則燃燒器繼續(xù)燃燒,否則熄火和報警,火焰要燃燒充分并有良好藍色和白紅色的火焰,這樣才能保護好電離電極不會結垢而不能正常狀態(tài)工作。 Oven combustion is a program controller LFL1.333 offer certain purging time and ignition of flame ionization detection within 3 seconds if there is a drive electrode current 30 ~ 50 ua return analysis if there is a 30-50 ua program controller through the burner to burn, or shut down and alarm, fire will burn sufficiently and blue and white and red flame is good, in this way can we protect the ionization electrode will not scale and can't normal work. 　　3.3 兩臺爐目前火檢設備改造前后對比。 3.3 two furnace fire inspection comparison before and after the equipment reform at present. 　　電離電極檢測是只要有火焰燃燒就有電流通過,并能安全保護整套設備正常狀態(tài)工作。 Ionization electrode detection is as long as the flame is the current through, and the set safety protection equipment normal work. 　　火焰監(jiān)測器檢測不能有效檢測火焰如導光管有灰和不反光,還有其它光線的干擾和誤動作還有火焰燃燒不穩(wěn)定而做成不能正常工作對火檢設備進行長達一年的對比后,兩臺爐共有15個火檢,設備本身缺陷已完全消除,火檢裝置的參數(shù)改造已全面完善,能比較真實地反映烘爐單個燃燒器的燃燒工況,終于實現(xiàn)兩臺爐火檢設備缺陷“0”目標。 Flame monitor tests are not effective flame detection such as light pipe is grey and not reflective, and other light interference and false action and flame instability and make it can't work normally fire inspection equipment for up to one year after contrast, a total of 15 fire inspection two furnace, the equipment itself defect has been completely eliminated, the parameters of the flame monitoring device has a comprehensive, can more truly reflect the oven single burner combustion condition, finally realize the two fire detection equipment defects "zero" goal. 　　3.4 烘爐改造后火檢效益。 3.4 oven after transforming the fire inspection efficiency. 　　2007年5月～2008年5月,1號、2號機火檢誤動僅0次,已大大降低誤動作,還能提高生產(chǎn)效率,提高工作質量。 In May 2007 to May 2008, no. 1, no. 2 machine maloperation of the flame detector is only 0 times, has greatly reduce misoperation, it can improve the production efficiency, improve the quality of work. 　　通過火檢綜合測檢,調試后一年沒有發(fā)生過烘爐滅火保護誤動,工作一年內沒有發(fā)生保護誤動而造成停產(chǎn),滅火保護裝置的可靠性明顯提高。烘爐運行良好的工作狀態(tài),充分體現(xiàn)了其在技術改良后的穩(wěn)定性,確保了生產(chǎn)效率及工作質量的提高。 By fire inspection comprehensive measurement inspection, debugging after one year there have been no oven fire protection maloperation, working within a year of protection misoperation caused production does not occur, the reliability of the fire protection system has improved significantly. Oven running in good working condition, fully embodies the its stability after technical improvement, to ensure the production efficiency and improve the quality of our work.