【正文】 el and air among the tiers of burners, as well as other operations written in the boiler operational chart, are used during boiler , the effect they have on the process is limited in nature. On the other hand, control of the furnace process in a boiler implies the possibility of making substantial changes in the conditions under which the bustion and heat transfer proceed in order to considerably expand the range of loads, minimize heat losses, reduce the extent to which the furnace is contaminated with slag, decrease the emissions of harmful substances, and shift to another fuel. Such a control can be obtained by making use of the following three main factors: (i) the flows of oxidizer and gases being set to move in the flame in a desired aerodynamic manner。 this made it possible not only to raise or lower the flame, but also to concentrate or disperse the release of heat in it [1]. A very tangible effect was obtained from installing multifuel (operating on coal and openhearth, coke, and natural gases) flatflame burners in the boilers of cogeneration stations at metallurgical plants in Ukraine and Russia. Unfortunately, we have to state that, even at present, those in charge of selecting the type, quantity, and layout of burners in a furnace sometimes adopt technical solutions that are far from being optimal. This problem should therefore be considered in more detail. If we increase the number of burners nb in a furnace while retaining their total crosssectional area (ΣFb=idem) and the total flowrate of air through them, their equivalent diameters deq will bee smaller, as willthe jet momentums Gbwb, resulting in a corresponding decrease in the jet throw distance hb and the mass they eject. The space with high velocity gradients also bees smaller, resulting in poorer mixing in the furnace as a whole. This factor bees especially important when the emissions of NOx and CO are suppressed right inside the furnace using staged bustion (at αb 1) under the conditions of a fortiori nonuniform distribution of fuel among the burners. In [1], a quantitative relationship was established between the parameters characterizing the quality with which once through jets mix with one another as they flow into a limited space with the geometrical parameter of concentration = with nb = idem and Gb = idem. By decreasing this parameter we improve the mass transfer in the furnace。 as a consequence, the flame es closer to the waterwalls and the latter are contaminated with slag. One method by which the tangential bustion scheme can be improved consists of organizing the socalled concentric admission of large jets of airdust mixture and secondary air with the fuel and air nozzles spaced apart from one another over the furnace perimeter, acpanied by intensifying the ventilation of mills [9, 10]. Despite the fact that the temperature level in the flame decreases, the bustion does not bee less stable because the fuel mixes with air in a stepwise manner in a horizontal plane. Vortex furnace designs with large vortices the rotation axes of which are arranged transversely with respect to the main direction of gas flow have wide possibilities in terms of controlling the furnace process. In [1], four furnace schemes with a controllable flame are 大連交通大學(xué) 2020 屆本科生畢業(yè)設(shè)計(jì)外文翻譯 6 described, which employ the principle of large jets colliding with one another。第一階段包括發(fā)展燃燒技術(shù)和當(dāng)新裝置設(shè)計(jì)時高爐的設(shè)計(jì)。當(dāng)然，火爐燃燒進(jìn)程的調(diào)整方法有諸如改變空氣過剩系數(shù)，煙氣再循環(huán)率，燃料和空氣在鍋爐空間內(nèi)的分配，以及其它在鍋爐運(yùn)行期間書面的控制圖表。流化床燃燒的方法可以實(shí)施三個設(shè)計(jì)版本：帶有密集床的機(jī)械爐，流化床鍋爐，以及噴動床爐。 同樣重要的是，對于鍋爐燃燒控制過程，當(dāng)固體燃料燃燒時，也要優(yōu)化將燃料碾磨精化。與此同時，鍋爐空氣動力學(xué)的關(guān)鍵在于混合中心（集中的傳遞），這一過程的可估計(jì)的定量參數(shù)，只能間接或特殊的測量。顯然，越大的噴射距離（和其勢頭），造成的在爐膛內(nèi)持續(xù)存在的速度梯度的時間越長，一個參數(shù)，確定如何流動中完全混合。 第一輪曾經(jīng)是密集射流與周圍介質(zhì)以其最初的形式混合的熔爐，在這里噴氣軸的流速仍然是等于在噴嘴孔半徑 r0 的速度 W2。第二種模型描述的是混合氣體燃燒器，第三種模式描述的是在爐膛內(nèi)的混合。一旦通過燃燒器，這一值將接近于基于鍋爐設(shè)備 的實(shí)際值。顯然，如果層之間的距離比較小，斷開或連接的行為對整個過 大連交通大學(xué) 2020 屆本科生畢業(yè)設(shè)計(jì)外文翻譯 10 程的影響可以忽略。一個非常明顯的效果，是在烏克蘭和俄羅斯的聯(lián)產(chǎn)鍋爐冶金產(chǎn)業(yè)中安裝萬能（用于煤炭和平爐，焦化，自然氣體）平面燃燒器。帶有高流速梯度的空間也變小，導(dǎo)致作為整體的爐子混合性變差。然而，這需要我們在相同的 Fb 下，增加流體速度和能源的支出。 為便于說明，我們將估計(jì)當(dāng) ?f Σ Fb/Ff=idem是混合爐數(shù)量的影響。根據(jù)有關(guān)數(shù)據(jù)，以低于額定的量混合并通過燃燒器進(jìn)入爐體內(nèi)為特點(diǎn)的空氣指數(shù)β air，可用公式進(jìn)行估計(jì)：β air=15f ，這一公式范圍已經(jīng)被核實(shí) ?f ，為爐膛配備了兩個前沿使其一次性通過燃燒器。nb =1） — 其中一個安排在反向表面 — 不得傾向下調(diào)超過 50度。然而，帶有線路和小的當(dāng)量直徑的燃燒器，經(jīng)常被用作引燃水份含量較高的低熱量褐煤。盡管火焰的溫度會下降，燃燒卻依然穩(wěn)定，這時因?yàn)槿剂虾涂諝獾幕旌线^程是在一個循序漸進(jìn)的水平上進(jìn)行的。這種鍋爐的測試表明了，在爐子的出口處，氣體的溫度在沿爐子的深度和寬度上都是不均勻分布的。蒸汽能力從501650噸 /小時這樣的氣動方案鍋爐已經(jīng)被 ZiO 和 Sibener gomash 制造，并在俄羅斯等一些國外的發(fā)電站得到應(yīng)用。帶有火焰控制爐的鍋爐已經(jīng)在電力工業(yè)中得到了應(yīng)用，由于在它們的內(nèi)部存在兩個區(qū)，這些設(shè)備可以被看做在某種程度上具有可控性。發(fā)展?fàn)t技術(shù)所用到的所謂 VIR 技術(shù)（音譯縮寫俄羅斯引進(jìn)，創(chuàng)新和改造），可以被視為這方面的曙光。離心除塵技術(shù)已經(jīng)在點(diǎn)燃高活性煤炭方面得到了應(yīng)用，在這一計(jì)劃中，采用粉球制造裝置用以優(yōu)化燃料分配，以及其流量和組分。這一設(shè)計(jì)思想，對鍋爐進(jìn)程控制有著很深刻的影響。圖表三顯示的是燃料流量在燃燒器的四個不同層次中分配最佳的一個。我們認(rèn)為，這些困難是由于這樣一個事實(shí)，即燃料的分配比例超過一定分?jǐn)?shù)，導(dǎo)致可以優(yōu)化程度有限，流體在主爐容體中有著相當(dāng)緩慢的空氣動力學(xué)結(jié)構(gòu)。計(jì)算這種爐的例子已經(jīng)在書中第二頁給出了。在這種爐燃燒低質(zhì)