外文翻譯---在全面微油點火燃燒器中給煤率對煙煤燃燒的影響

1、<p><b>　　本科畢業(yè)論文</b></p><p><b>　　外文文獻及譯文</b></p><p>　　文獻、資料題目：Influence of Coal-feed Rates on Bituminous Coal Ignition in A Full-scaleTiny-oil Ignition Burner</p&g

2、t;<p>　　文獻、資料來源：期 刊</p><p>　　文獻、資料發(fā)表（出版）日期：2009.8.5</p><p>　　院 （部）： 熱能工程學院</p><p>　　專 業(yè)： 熱能與動力工程</p><p>　　班 級： 熱動073</p><p>　　姓 名： 仲明凱<

3、/p><p>　　學 號： 2007031271</p><p><b>　　指導教師： 楊冬</b></p><p>　　翻譯日期： 2011.3.31</p><p><b>　　外文文獻</b></p><p>　　Influence of Coal-feed Rat

4、es on Bituminous Coal Ignition in A Full-scale</p><p>　　Tiny-oil Ignition Burner</p><p>　　A B S T RACT</p><p>　　A tiny-oil ignition burner has been proposed to reduce oil consumptio

5、n during the firing-up process and partial-load operations. To investigate the influence of different feed rates on bituminous coal ignition in the tiny-oil ignition burner, full-scale reacting-flow experiments were

6、performed on an experimental setup.The ignition burner was identical to that normally used in an 800-MWe utility boiler. Gas temperature distributions in the burner were obtained at coal-feed rates of 2, 3, 4, a</p>

7、;<p>　　Key words: Tiny-oil ignition burner ；Coal-burning utility boiler；Coal-feed rates</p><p>　　1. Introduction</p><p>　　To fire-up a boiler, oil is primarily used to pre-heat the combus

8、tion chamber of a furnace bringing it to its operating temperature.Generally, oil is delivered under high pressure by an oil-gun with a delivery capacity of about 1 tonne/h. Therefore, in the initial firingup process of

9、a bituminous coal-fired 300 MWe utility boiler, about 100 tonnes of fuel oil would be consumed. Concerns over increasing economic costs in pulverized coal-fired power stations arising from oil consumed in the firing</

10、p><p>　　An alternative tiny-oil ignition burner has been developed and tiny-oil ignition, centrally fuel-rich burners proposed (see Fig. 1). The burner features two oil-guns arranged in the central pipe and the

11、 firing-up process is summarized as follows. Atomized oil from one oil-gun, called the main oil-gun, ignites and burns in an adiabatic chamber. Subsequently, an oil flame ignites the atomized oil from the other oil-gun,

12、called the auxiliary oil-gun. Cone separators are installed in the primary air</p><p>　　2. Experimental set-up</p><p>　　Fig. 1 shows the tiny-oil ignition apparatus. The ignition burner was iden

13、tical to the burner that had been used in an 800-MWe utility boiler and its operation is briefly described as follows. The feeder supplies pulverized coal by primary air from the blower. The pulverized coal is then carri

14、ed to the tiny-oil ignition burner by primary air. Oil is drawn from the oil tank and sent to the main and auxiliary oil-guns atomizing the oil mechanically and by air. Although compressed air enters the oi</p>&l

15、t;p>　　All gas temperatures were measured at the center of the burner as well as the exits of the first and the second combustion chambers. Ash samples were sampled at the exit of the tiny-oil ignition burner. Gases we

16、re sampled using a water-cooled stainless steel probe and analyzed online on a Testo 350M instrument [5]. The probe, consisting primarily of a water-inlet pipe, water-outlet pipe, sampling tube, outer pipe and supporting

17、 components, was bracket-mounted</p><p>　　at the exit of the burner. A sample of the high-temperature gas is collected in the sampling tube and cooled by high pressure cool water delivered through the water-

18、inlet pipe cooling the sampling tube and after heat change flows out via the water-outlet pipe. A water pump provided continuous water circulation. When gas enters the sampling tube, temperatures decease rapidly and the

19、pulverized coal stops burning. Samples are drawn up by a pump through filtrating devices into a Testo 350M gas anal</p><p>　　The difference in pressure before and after ignition is called the burner resistan

20、ce. A static pressure method was used to measure ignition resistance at the position of the straight section (See Fig. 1). One end of the u-tube differential manometer was connected with a static pressure hole, and the o

21、ther end was open to atmospheric conditions.</p><p>　　Table 1 lists equipment used along with their technical characteristics. Table 2 lists operating parameters. Table 3 lists the final analysis and other c

22、haracteristics of 0 # light diesel oil used in</p><p>　　the experiments. Table 4 records the characteristics of the bituminous pulverized coal used in the experiments. The methods used to measure calorific v

23、alue, proximate analysis and ultimate analysis were in accordance with 213-2003, 212-2001 and 476-2001 of the Chinese standards code, respectively. The pulverized coal fineness was R90 = 9.2%, i.e. 90.8% of all particles

24、 pass through a 90 lm aperture sieve.</p><p>　　3. Result and discussion</p><p>　　3.1. The gas temperature distribution</p><p>　　Fig. 2 depicts gas temperature profiles measured alon

25、g the burner center line; here x is the measured distance from the central pipe exit (See Fig. 1). Using the two oil-guns in the absence of coal during firing-up, gas temperatures decreased from 1044 _C to 856 _C with in

26、creasing distance. Most of the oil from both main and auxiliary oil-guns burnt out in the central pipe. High-temperature gas was then formed. As the gas flowed toward the burner nozzle, cold air diffuses into it resultin

27、g in a </p><p>　　Fig. 3 shows the gas temperature profile measured at the exits of the first and second combustion chambers, at a radius of r1 and r2, respectively, from the center line of the burner (See Fi

28、g. 1). During firing-up with the two oil-guns operating in theabsence and then later in the presence of coal, gas temperatures were observed to be largest along the center line. As the radius increased, gas temperatures

29、decreased gradually. Wall temperatures of the first and the second combustion chambers wer</p><p>　　During firing-up with the two oil-guns operating in the absence of coal, gas temperature distributions were

30、 similar at the exits of the first and the second combustion chamber. The oil-flow rate of auxiliary and main oil-guns was 65 and 35 kg/h, respectively (See Table 2). The oil-flow rate of auxiliary oil-gun was higher tha

31、n that main oil-gun. The released heat on the side of the auxiliary oilgun (r1 < 0 and r2 < 0) was higher than that on the side of the main oil-gun (r1 > 0 and r2 > 0). Henc</p><p>　　burned out i

32、n the central pipe. As the gas flowed from the first combustion chamber to the second, it mixed with cold air, thus gradually decreasing gas temperatures.</p><p>　　During firing-up with the two oil-guns in t

33、he presence of coal, the pulverized coal burned adequately releasing heat in the process. Gas temperatures at the second combustion chamber exit</p><p>　　were higher than those at the first combustion chambe

34、r exit. By increasing coal-feed rates, more heat was absorbed by the pulverized coal thereby decreasing its temperature. At the same time,</p><p>　　much more coal ignited; the released heat of combustion the

35、reby increased and in the process the temperature of the pulverized coal would then increase. When coal-feed rates increased from 2 to</p><p>　　4 tonnes/h, the released heat of combustion is more than the ab

36、sorbed heat. Thus at equivalent measuring points at the exits of the first and second combustion chambers and on the burner center line (see Fig. 2) gas temperatures gradually increased. When the coal-feed rate was incre

37、ased to 5 tonnes/h, the released heat from coal combustion was less than the absorbed heat. Thus gas temperatures at equivalent points decreased. However, pulverized coal can be successfully ignited. </p><p>

38、;　　Oil from the main oil-gun was ignited by a high-energy igniter and burnt in an adiabatic chamber. Subsequently, the oil flame formed by the main oil-gun ignited the atomized oil from the auxiliary oil-gun. Afterward,

39、the igniter was closed, and the oil flamewas maintained by the two oil-guns and burned steadily. During firing-up using the two oil-guns in the presence of coal, instantaneous ignition was achieved by the oil flame and a

40、 steady burn of the pulverized coal developed. The flame formed</p><p>　　3.2. Char burnout and release rate of C and H at the exit of the burner</p><p>　　Fig. 5 shows the char burnout and releas

41、e rate of C and H at the exit of the tiny-oil ignition burner. Char burnout was calculated using</p><p>　　ψ=[1-（wk/wx）]/(1-wk)</p><p>　　where w is the coal burnout factor, wk is the ash weight f

42、raction in the input coal, and wx is the ash weight fraction in the char sample.</p><p>　　βis the percentage release of components (C and H), which was</p><p>　　calculated by</p><p>

43、;　　β=1-[(wix/wik)(wk/wx)</p><p>　　where wix is the weight percentage of the species of interest in the char sample and wik is the weight percentage of the species of interest in the input coal [6].</p>

44、<p>　　The distributions of char burnout and release rates of C and H were similar at the different coal-feed rates. The char burnout and the release rates of C and H were largest along the burner center; as the ra

45、dius increased, they decreased with the increase of coal-feed rates. At the center of the burner (r2 = 0), char burnout and release rates of C and H decreased from 83%, 81%, 95% to 75%, 72%, 87% as coal-feed rates increa

46、sed from 2 to 5 tonnes/h.</p><p>　　3.3. Gas compositions and the burner resistance</p><p>　　Table 5 lists gas compositions at the center of the burner exit as well as the burner resistance. For

47、coal-feed rates of 2, 3, 4, 5 tonnes/ h, O2 concentrations were in the range 0.01–0.04% and CO concentrations were more than 10,000 ppm. The O2 concentration at the center point of the burner exit was almost exhausted. W

48、hen the primary air temperature and velocity were 15 _C and 23 m/s, respectively, with oil-flow rate at 100 kg/h, the burner resistance while the two oil-guns were in operation i</p><p>　　3.4. Consumed oil&l

49、t;/p><p>　　Using the tiny-oil ignition burner, total oil-flow rate decreased from 1000 to 100 kg/h, thus saving 90% of the oil usually consumed in the firing-up process.</p><p>　　4. Conclusion</

50、p><p>　　(1) When the primary temperature and velocity air were 15 _C and 23 m/s, respectively, ignition was successful with an oil-flow rate of 100 kg/h and the bituminous coal-feed rate was increased from 2 to

51、 5 tonnes/h. Wall temperatures of the first and the second combustion chambers were less than 116 _C and 127 _C, respectively. At the low temperature, the burner wall was safe. O2 concentrations at the exit of the burner

52、 were 0.01–0.04%. During firing-up, the burner resistance increased to 190 Pa </p><p>　　(2) Temperatures along the center line of the burner gradually increased along the direction of the primary air flow in

53、 the presence of coal. As coal-feed rates increased from 2 to 4 tonnes/h, gas temperatures at equivalent points at the exits of the first and second combustion chambers and on the center line increased gradually. A furth

54、er increase of the coal-feed rate to 5 tonnes/h decreased temperatures at these points.</p><p>　　(3) Distributions of char burnout and release rates of C and H were similar for different coal-feed rates; as

55、the radius increased, they decreased with the increase of coal-feed rates. Finally, increasing coal-feed rates decreased char burnout and release rates of C and H at equivalent points at the exits.</p><p>　　

56、Acknowledgements </p><p>　　This work was supported by the Hi-Tech Research and Development Program of China(Contract No.2007AA05Z301), Post-doctoral Foundation of Heilongjiang Province (LRB07-216), Heilongji

57、ang Province via 2005 Key Projects (Contract No. GC05A314), and the Hi-Tech Research and Development Program of China (863 program) (Contract No.2006AA05Z321).</p><p>　　References</p><p>　　[1] M

58、asaya S, Kaoru M, Koichi T, Oleg PS, Masao S, Masakazu N. Stabilization of pulverized coal combustion by plasma assit. Thin Solid Films 2002;407:186–91.</p><p>　　[2] Kanilo PM, Kazanesev VI, Rasyuk NI, Schun

59、emann K, Vavriv DM. Microwave plasma combustion of coal. Fuel 2003;82:187–93.</p><p>　　[3] Zhang XY, Luo ZB, Zhang SK, Zou GW, Jiang BH. Application testing and study of plasma combustion technology in coal

60、fired boilers with double inlet and outlet tube mill and whirl burner. China Power 2003;36:25–9 [in Chinese].</p><p>　　[4] Li WJ, Cen KF, Zheng CG, Zhou JH, Cao XY. Induction-heating of pulverized coal strea

61、m. Fuel 2004;83:2103–7.</p><p>　　[5] Li ZQ, Jing JP, Chen ZC, Ren F, Xu B, Wei HD, et al. Combustion characteristics and NOx emissions of two kinds of swirl burners in a 300-MWe wall-fired pulverized-coal ut

62、ility boiler. Combust Sci Technol 2008;180(7):1370–94.</p><p>　　[6] Costa M, Silva P, Azevedo JLT. Measurements of gas species, temperature, and char burnout in a low-NOx pulverized-coal-fired utility boiler

63、. Combust Sci Technol 2003;175:271–89.</p><p><b>　　中文譯文：</b></p><p>　　在全面微油點火燃燒器中給煤率對煙煤燃燒的影響</p><p><b>　　摘要：</b></p><p>　　微油點火燃燒器在冷爐啟動和低負荷穩(wěn)燃中減少油

64、耗的方法已經被建議。為了研究不同給煤率對微油燃燒器點燃煙煤的影響，在設計的實驗臺上對燃燒器全面流場進行了實驗研究。點火燃燒器同樣的被廣泛應用于800WMe的電站鍋爐。分別得到了在給煤速率為2t/h、3t/h、4t/h、5t/h時燃燒器內的溫度分布。焦炭燃燒和揮發(fā)分的析出能在燃燒器噴嘴出口被觀測到。對燃燒器中心的氣體成份像O2、CO2進行了測量，獲得了燃燒器內的阻力變化情況。通過使用新型的油槍技術，使得在點火過程中相對原來的油耗量可以減少

65、百分之九十。</p><p>　　關鍵詞：微油點火燃燒器、燃煤電站鍋爐、給煤率</p><p><b>　　1簡介</b></p><p>　　點燃鍋爐時，油主要被用來預熱燃燒室的內壁，以使之達到其相應的運行溫度。通常來說，油通過輸送容量為1噸/小時的油槍在高壓下被釋放出來。因此，在最初的點火過程中，300MWe的燃煤鍋爐大約有100噸的燃料油

66、將會被消耗掉。在燃煤電廠中，鍋爐冷爐啟動和低負荷穩(wěn)燃中的石油消耗使得經濟成本增加，這就增加了我們在開發(fā)無油和微油點火燃燒器方面的興趣。Masaya以及許多科研人員已經研究并報道了有關無油點火燃燒器的不同成果。</p><p>　　【1】研究煤粉通過使用活性組分燃燒器的穩(wěn)定燃燒情況</p><p>　　【2】使用微波煤粉鍋爐來研究煤粉的點火和燃燒</p><p>　　

67、【3】描述在煤粉燃燒鍋爐中關于等離子點火技術的應用。然而，對于這些燃燒器，存在著在擴大燃燒器容積和運行期間需要經常維修這兩個主要的問題</p><p>　　【4】研究感應加熱點燃煤粉流。感應加熱可以提供可靠的、方便的能源去點燃煤粉流，但是這種技術先前還沒有報道過被應用于任何的電站鍋爐中。</p><p>　　另一種微油點火燃燒器已經被開發(fā)并用來點火，并計劃應用于中心燃料豐富的燃燒器內（見圖

68、1）。燃燒器在中央導管處安置的兩條油槍的作用很大。點火過程依下列各項被總結出來：霧化的油從一個油槍中噴出，這個油槍叫做主油槍。在絕熱室內進行點火和燃燒。隨后，燃油被點燃。從另一個油槍中噴出霧化的石油，這根油槍叫做輔助油槍。錐形燃燒器安裝在輸送空氣和煤的主管道中，以用來聚集煤粉使之進入燃燒器的中心區(qū)域。燃料豐富的一次風煤混合物進入第一燃燒室，據(jù)此，富燃料一次風煤混合物被來自主油槍和輔助油槍的高溫火焰所點燃。然后，來自第一燃燒室的燃燒著的煤

69、粉和石油火焰直接進入第二燃燒室，在這里煤被點燃。在鍋爐被點燃后，主油槍和輔助油槍關閉。與此同時，燃燒器調整開關，成為一個富燃料中心燃燒器。</p><p>　　【5】燃燒效率高和低氮氧化物排放的特點在全面微油點火燃燒器中給煤率對煙煤燃燒的影響已經被研究。</p><p><b>　　圖1 實驗裝置</b></p><p><b>　　

70、2．實驗裝置</b></p><p>　　圖1表示微油點火裝置，點火燃燒器同樣的已經被應用于800MWe的電站鍋爐的中。同時，它的操作被簡述如下：給煤機通過送風機提供的一次風補給煤粉，與此同時，煤粉被一次風攜帶到微油點火燃燒器內。油從油箱內被帶出到主油槍和輔助油槍，在這里通過空氣機械霧化。壓縮空氣雖然進入油槍，但一小部分的油在燃燒中還是被消耗掉。主體則通過另一臺送風機提供。煤粉在一次風管道中被點燃，實

71、驗裝置中沒有分離進入內部和外部的二次風。</p><p>　　所有氣體溫度都在燃燒器的中心以及第一燃燒室和第二燃燒室的出口被測量出?；覙悠吩谖⒂土奎c火燃燒器的出口被提取。氣體通過使用水冷不銹鋼探針在Testo350M儀器上在線分析，抽取樣品探針，主要包括一個進水管、出水管、收集管、外管以及支持組件，在燃燒器的出口展開。被抽取的高溫氣體被收集到收集管內，并被高壓冷卻水冷卻。通過進水管冷卻收集管，同時熱量改變后通過出

72、水管導出，水泵提供連續(xù)的水循環(huán)。當氣體進入收集管，溫度快速下降，同時煤粉停止燃燒。樣品通過過濾設備進入Testo350M氣體分析儀進行分析整合。對于每種物質準確測量分析包括百分之一的氧氣和百分之五的一氧化碳。每種傳感器在測量前已經被校準。在這個試驗中二氧化碳的含量為10000ppm。</p><p>　　燃燒器點火之前和點火之后所表現(xiàn)出的不同壓力稱為燃燒器阻力。一種靜壓力的方法被用來測量直區(qū)段位置的點火阻力（見圖

73、1）。微分壓力計U型導管的一端與一個靜壓力孔連接，而另一端則是直接與大氣相通。</p><p><b>　　表1</b></p><p><b>　　設備使用的技術特點</b></p><p>　　表1列出了所用到的設備連同他們的設備技術特點。表2列出了其操作參數(shù)。表3列出了在實驗中所用到的輕柴油的最終分析以及其他特性。表

74、4記錄了被應用于實驗中的煙煤煤粉的性質。這種方法被用來測量發(fā)熱量，先前的分析和最終分析分別都符合213-2003,212-2001和476-2001的國家標準。煤粉細度為百分之九點二的粒子能通過90微米的篩子。</p><p><b>　　表2</b></p><p><b>　　操作參數(shù)</b></p><p><

75、b>　　表3</b></p><p>　　試驗用0號輕柴油的最終分析及其他特點</p><p><b>　　表4</b></p><p>　　試驗用煙煤煤粉的特性</p><p><b>　　3．結果和討論</b></p><p><b>　　3.

76、1氣體溫度分布</b></p><p>　　圖2描述了沿著燃燒器中心線所測量的氣體溫度的分布狀態(tài)。這里x代表從中心管出口所測量的距離（見圖1）。在無煤點火時使用的兩條油槍，隨著距離的增加，氣體的溫度從1044攝氏度降至856攝氏度。來自主油槍和輔助油槍中的大部分油在中心管中燃燒。高溫氣體在此形成了。當氣體流動到燃燒器噴嘴處，冷空氣隨之摻混到氣體中，使氣體的溫度逐漸的降低。冷爐啟動中有煤時使用兩個油槍，

77、高溫油火焰持續(xù)燃燒點燃煤粉使之放出熱量。研究結果：氣體溫度沿著一次風流動的方向及沿著燃燒器中心線的方向增加。</p><p>　　圖3表示：氣體從燃燒器中心線處半徑分別為r1和r2時第一、第二燃燒室出口處被測量的溫度變化曲線（見圖1）。在點火期間，隨著兩條油槍在無煤狀態(tài)下運行以及在有煤狀態(tài)下運行時，觀察氣體的溫度沿著中心線方向一直變至最大。隨著半徑增加，氣體溫度逐漸的減小，第一、第二燃燒室的墻壁溫度不到116攝氏

78、度和127攝氏度。在低溫時，燃燒器的墻體是安全的。</p><p>　　兩支油槍在缺煤運行操作時點火期間，氣體溫度在第一和第二燃燒器出口處的分布時相近的。油在輔助油槍和主油槍里的流量分別為65千克/小時和35千克/小時（見表2）。油在輔助油槍的流量要比在主油槍中的流量大。輔助油槍附近所釋放出的熱量要比主油槍附近多釋放出的熱量要多。因此，在輔助油槍附近的溫度要比主油槍附近的溫度高。例如：在第一燃燒室出口處輔助油槍打

79、開了，在r1分別為-57毫米和-114毫米處的溫度分別為1005攝氏度和767攝氏度，與此同時，在半徑r1分別為57毫米和114毫米處，主油槍被打開，氣體的溫度分別為601攝氏度和203攝氏度。氣體溫度在第二燃燒室出口處要比第一燃燒室出口處低一些。主油槍和輔助油槍內大部分的油都在中心導管處被燃燒。當氣體從第一燃燒室進入到第二燃燒室時，它們與冷空氣混合，如此，氣體的溫度逐漸的減小。</p><p>　　圖2 沿燃燒

80、器中心線測量的氣體溫度的分布曲線</p><p>　　兩支油槍在缺煤狀態(tài)下點火，煤粉充分燃燒并釋放出熱量。第二燃燒室出口處的這些氣體溫度要高于第一燃燒室出口處的氣體溫度。通過增加給煤率，更多的熱量在煙煤燃燒中被吸收，以用來減小其溫度，與此同時，點燃更多的煤，燃燒所釋放的熱量增加，同時在這個過程中煤粉的溫度也會增加。當給煤率從2噸/小時增加到4噸/小時時，燃燒所釋放的熱量大于其所吸收的熱量。從而，在第一和第二燃燒室

81、出口處以及燃燒器中心線處相同的測量點處，氣體的溫度逐漸增加。當給煤率增加到5噸/小時，煤燃燒所釋放出的熱量要比其所吸收的熱量要少。盡管如此，煙煤也可成功點火。</p><p>　　來自主油槍中的燃油通過一個高能量點火器點火，并在一個絕熱燃燒器內燃燒，隨后，通過主油槍點燃來自輔助油槍的霧化油，同時形成油狀火焰。然后，關閉點火器。燃油火焰通過兩支油槍的穩(wěn)定燃燒被保持。在冷爐啟動時使用兩條在缺煤狀態(tài)下的油槍。冷爐啟動和

82、低負荷穩(wěn)燃過程被完成了。通過兩支油槍和煤粉所形成的火焰是明亮穩(wěn)定的。圖4分別表示燃油和煤的燃燒火焰。</p><p>　　圖3 第一燃燒室（a）和第二燃燒室（b）出口處氣體溫度的分布曲線</p><p>　　3.2燃燒器出口處焦炭以及C、H的釋放率</p><p>　　圖5顯示在微油量燃燒器出口處焦炭以及C、H的釋放率。焦炭燃燒計算：</p><

83、p>　　ψ=[1-（wk/wx）]/(1-wk)</p><p>　　這里ψ表示焦炭燃燒因素，Wk表示輸入煤灰質量分數(shù)，Wx表示灰炭樣品的質量分數(shù)。</p><p>　　β表示釋放的氣體成分的百分數(shù)</p><p>　　β=1-[(wix/wik)(wk/wx)</p><p>　　這里wix表示焦炭中各成分的質量分數(shù)，wik表示輸入煤

84、灰各成分的質量分數(shù)。</p><p>　　在不同的給煤率下，焦炭和C、H的釋放率的分布狀態(tài)時相近的。沿著燃燒器的中心，焦炭和C、H的釋放率都是最大的；當半徑增加，釋放率隨著給煤率的增加而減少。在燃燒器的中心處（r2=0），當給煤率從2噸/小時增加到5噸/小時，焦炭和C、H的釋放率從83%、81%、95%減小到75%、72%、87%。</p><p>　　圖4在無煤狀態(tài)下（a）和給煤率為4噸

85、/小時狀態(tài)下（b）點燃兩條油槍時的所產生的火焰</p><p>　　3.3氣體成分和燃燒器阻力</p><p>　　表5列出了在燃燒器出口中心以及燃燒器的阻氣組成。對于2，3，4，5噸/小時煤進給速度，氧氣濃度范圍在0.01-0.04％和二氧化碳濃度大于10,000 ppm。在燃燒器出口中心點氧氣濃度幾乎為零。當一次空氣溫度和速度分別為15攝氏度和23米/ 秒，油流率在100公斤/小時，燃

86、燒器的阻力，兩個油槍在無煤和有煤狀態(tài)下運行時壓力增加190帕，在壓力為500,600,600,550帕時，給煤率分別2,3,4,5噸/小時。</p><p>　　圖5 燃燒器出口處焦炭燃燒以及碳、氫揮發(fā)的分布圖</p><p><b>　　3.4 油耗</b></p><p>　　使用微油點火燃燒器，總的燃油流速從1000公斤/小時減小到100

87、公斤/小時，從而節(jié)省通常在點火過程中所消耗的90％的油。</p><p>　　表5 燃燒器出口中心點處的氣體組成以及燃燒器出口阻力</p><p><b>　　4結論</b></p><p>　?。?）當主空氣溫度和速度分別為15攝氏度和23米/秒，燃油流速為100千克/小時時點火成功，煙煤的給煤率從2噸/小時增加到5噸/小時。第一和第二燃燒室

88、的燃燒溫度分別低于116攝氏度和127攝氏度。在低溫下，燃燒器墻體是安全的。在燃燒器出口處的氧濃度分別為0.01-0.04％。在冷爐啟動期間，燃燒器的阻力在無煤時增加到190帕，有煤時增加到500-600帕。在冷爐啟動中可以節(jié)約百分之九十的通常油耗，顯示出顯著的經濟效益。</p><p>　　（2）在有煤且沿著主空氣流動的方向，沿中心線方向燃燒溫度逐漸升高。由于給煤率從2噸/小時增加到4噸/小時，在第一和第二燃燒

89、室的出口和中線等值點位置處，氣體的溫度逐漸升高。在溫度下降到該點時，給煤率進一步增加到5噸/小時。</p><p>　　（3）在不同給煤率下，焦炭與氫的釋放率分布狀態(tài)類似。隨著半徑的增加，給煤率的增加量將隨之下降。最后，在出口的等值點處，分別增加給煤率同時減小焦炭和碳、氫的釋放率。</p><p><b>　　致謝</b></p><p>　　

90、這項工作得到了中國國家高技術研究發(fā)展計劃（No.2007AA05Z301）、黑龍江省博士后基金會的支持。是2005黑龍江年重點項目（No. GC05A314)、國家高技術研究發(fā)展計劃項目（863計劃）（No.2006AA05Z321）。</p><p><b>　　參考文獻</b></p><p>　　[1] Masaya S, Kaoru M, Koichi T,

91、Oleg PS, Masao S, Masakazu N. Stabilization of</p><p>　　pulverized coal combustion by plasma assit. Thin Solid Films 2002;407:186–91.</p><p>　　[2] Kanilo PM, Kazanesev VI, Rasyuk NI, Schunemann

92、K, Vavriv DM. Microwave</p><p>　　plasma combustion of coal. Fuel 2003;82:187–93.</p><p>　　[3] Zhang XY, Luo ZB, Zhang SK, Zou GW, Jiang BH. Application testing and study ofplasma combustion tech

93、nology in coal fired boilers with double inlet and outlettube mill and whirl burner. China Power 2003;36:25–9 [in Chinese].</p><p>　　[4] Li WJ, Cen KF, Zheng CG, Zhou JH, Cao XY. Induction-heating of pulveri

94、zed coal</p><p>　　stream. Fuel 2004;83:2103–7.</p><p>　　[5] Li ZQ, Jing JP, Chen ZC, Ren F, Xu B, Wei HD, et al. Combustion characteristics</p><p>　　and NOx emissions of two kinds o

95、f swirl burners in a 300-MWe wall-fired</p><p>　　pulverized-coal utility boiler. Combust Sci Technol 2008;180(7):1370–94.</p><p>　　[6] Costa M, Silva P, Azevedo JLT. Measurements of gas species,