燃煤锅炉 外文翻译 外文文献 英文文献 中英翻译

Controlling the Furnace Process in Coal-Fired Boilers
The unstable trends that exist in the market of fuel supplied to thermal power plants and the situations in which the parameters of their operation need to be changed (or preserved), as well as the tendency toward the economical and environmental requirements placed on them becoming more stringent, are factors that make the problem of controlling the combustion and heat transfer processes in furnace devices very urgent. The solution to this problem has two aspects. The first involves development of a combustion technology and,accordingly, the design of a furnace device when new installations are designed. The second involves modernization of already existing equipment. In both cases,the technical solutions being adopted must be properly substantiated with the use of both experimental and calculation studies.
The experience Central Boiler-Turbine Institute Research and Production Association (Ts KTI) and Zi O specialists gained from operation of boilers and experimental investigations they carried out on models allowed them to propose several new designs of multicell and maneuverable—in other words, controllable—furnace devices that had been put in operation at power stations for several years. Along with this, an approximate zero-one-dimensional, zone wise calculation model of the furnace process in boilers had been developed at the Tsk Ti, which allowed Tsk Ti specialists to carry out engineering calculations of the main parameters of this process and calculate studies of furnaces employing different technologies of firing and combustion modes .
Naturally, furnace process adjustment methods like changing the air excess factor, stack gas recirculation fraction, and distribution of fuel and air among the tiers of burners, as well as other operations written in the boiler operational chart, are used during boiler operation.However, 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 combustion 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;
(ii) the method used to supply fuel into the furnace and the place at which it is admitted thereto;
(iii) the fineness to which the fuel is milled.
The latter case implies that a flame-bed method is used along with the flame method for combusting fuel.The bed combustion method can be implemented in three design versions: mechanical grates with a dense bed, fluidized-bed furnaces, and spouted-bed furnaces.
As will be shown below, the first factor can be made to work by setting up bulky vorticisms transferring large volumes of air and combustion products across and along the furnace device. If fuel is fired in a flame, the optimal method of feeding it to the furnace is to admit it to the zones near the centers of circulating vorticisms, a situation especially typical of highly intense furnace devices. The combustion process in these zones features a low air excess factor (α< 1) and a long local time for which the components dwell in them, factors that help make the combustion process more stable and reduce the emission of nitrogen oxides .
Also important for the control of a furnace process when solid fuel is fired is the fineness to which it is milled; if we wish to minimize incomplete combustion, the degree to which fuel is milled should be harmonized with the location at which the fuel is admitted into the furnace and the method for supplying it there, for the occurrence of unburned carbon may be due not only to incomplete combustion of large-size fuel fractions, but also due to fine ones failing to ignite (especially when the content of volatiles Daff < 20%).
Owing to the possibility of pictorially demonstrating the motion of flows, furnace aerodynamics is attracting a great deal of attention of researchers and designers who develop and improve furnace devices. At the same time, furnace aerodynamics lies at the heart of mixing (mass transfer), a process the quantitative
parameters of which can be estimated only indirectly or by special measurements. The quality with which components are mixed in the furnace chamber proper depends on the number, layout, and momenta of the jets flowing out from individual burners or nozzles, as well as on their interaction with the flow of flue gases, with one another, or with the wall.
It was suggested that the gas-jet throw distance be used as a parameter determining the degree to which fuel is mixed with air in the gas burner channel. Such an approach to estimating how efficient the mixing is may to a certain degree be used in analyzing the furnace as a mixing apparatus. Obviously, the greater the jet length (and its momentum), the longer the time during which the velocity gradient it creates in the furnace will persist there, a parameter that determines how completely the flows are mixed in it. Note that the higher the degree to which a jet is turbulence at the outlet from a nozzle or burner, the shorter the distance which it covers, and, accordingly, the less completely the components are mixed in the furnace volume. Once through burners have advantages over swirl ones in this respect.
It is was proposed that the extent to which once through jets are mixed as they penetrate with velocity w2 and density ρ2 into a transverse (drift) flow moving with velocity w1 and having density ρ1 be correlated with the relative jet throw distance in the following way
Where ks is a proportionality factor that depends on the “pitch” between the jet axes (ks= 1.5–1.8).
The results of an experimental investigation in which the mixing of gas with air in a burner and then in a furnace was studied using the incompleteness of mixing as a parameter are reported in 5.
A round once through jet is intensively mixed with the surrounding medium in a furnace within its initial section, where the flow velocity at the jet axis is still equal to the velocity w2 at the nozzle orifice of radius r0.The velocity of the jet blown into the furnace drops very rapidly beyond the confines of the initial section, and the axis it has in the case of wall-mounted burners bends toward the outlet from the furnace.
One may consider that there are three theoretical models for analyzing the mixing of jets with flow rate G2 that enter into a stream with flow rate G1. The first
model is for the case when jets flow into a “free” space (G1= 0),the second model is for the case when jets flow into a transverse (drift) current with flow rate G1 G2，and the third model is for the case when jets flow into a drift stream with flow rate
G1<G2. The second model represents mixing in the channel of a gas burner, and the third model represents mixing in a furnace chamber. We assume that the mixing pattern we have in a furnace is closer to the first model than it is to the second one, since 0 <G1/G2< 1, and we will assume that the throw distance h of the jet being drifted is equal to the length S0 of the “free” jet’s initial section. The ejection ability of the jet being drifted then remains the same as that of the “free” jet, and the length of the initial section can be determined using the well-known empirical formula of G.N. Amphibrachic [6] ：S0= 0.67r0/a, (2)where a is the jet structure factor and r0 is the nozzle radius.
At a = 0.07, the length of the round jet’s initial section is equal to 10 r0 and the radius the jet has at the transition section (at the end of the initial section) is equal to 3.3 r0. The mass flow rate in the jet is doubled in this case. The corresponding minimum furnace cross-sectional area Ff for a round once through burner with the outlet cross-sectional area Fb will then be equal to and t he ratio Ff/Fb≈20. This value is close to the actual values found in furnaces equipped with once through burners. In furnaces equipped with swirl burners, a= 0.14 and Ff/Fb≈10. In both cases, the interval between the burners is equal to the jet diameter in the transition section d tr , which differs little from the value that has been established in practice and recommended in [7].
The method traditionally used to control the furnace process in large boilers consists of equipping them with a large number of burners arranged in several tiers. Obviously, if the distance between the tiers is relatively small, operations on disconnecting or connecting them affect the entire process only slightly. A furnace design employing large flat-flame burners equipped with means for controlling the flame core position using the aerodynamic principle is a step forward. Additional possibilities for controlling the process in TPE-214 and TPE-215 boilers with a steam output of 670 t/h were obtained through the use of flat-flame burners arranged in two tiers with a large distance between the tiers; 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 multicell (operating on coal and
open-hearth, coke, and natural gases) flat-flame 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 cross-sectional area (ΣFb=idem) and the total flow rate of air through them, their equivalent diameters deq will become smaller, as will the jet momentums GB, resulting in a corresponding decrease in the jet throw distance Hb and the mass they eject. The space with high velocity gradients also becomes smaller, resulting in poorer mixing in the furnace as a whole. This factor becomes especially important when the emissions of Box and CO are suppressed right inside the furnace using staged combustio n (at αb < 1) under the conditions of a Fortinbras 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; however, this entails an increase in the flow velocity and the expenditure of energy (pressure drop) in the burners with the same Fb. At the same time, we know from experience and calculations that good mixing in a furnace can be obtained without increasing the head loss if we resort to large long-range jets. This allows a much less stringent requirement to be placed on the degree of uniformity with which fuel must be distributed among the burners. Moreover, fuel may in this case be fed to the furnace location where it is required from process control considerations.
For illustration purposes, we will estimate the effect the number of burners has on the mixing in a furnace at = = idem. schematically shows the plan views of two furnace chambers differing in the number of once through round nozzles (two and
four) placed in a tier (on one side of the furnace). The furnaces have the same total outlet cross-sectional areas of the nozzles (ΣF b) and the same jet velocities related to these areas (wb). The well-known swirl furnace of the TsKTI has a design close to the furnace arrangement under consideration. According to the data of [1], the air fraction βair that characterizes the mixing and enters through once through burners into the furnace volume beneath them can be estimated using the formula βair = 1 – (3) which has been verified in the range = 0.03–0.06 for a furnace chamber equipped with two frontal once through burners. Obviously, if we increase the number of burners by a factor of 2, their equivalent diameter, the length of the initial section of jets S0 and the area they “serve” will reduce by a factor of Then, for example, at = 0.05, the fraction βair will decrease from 0.75 to 0.65. Thus, Eq. (3) may be written in the following form for approximately assessing the effect of once through burners on the quality of mixing in a furnace:βair = 1 – 3.5f nb ' ,where is the number of burners (or air nozzles) on one wall when they are arranged in one tier both in onesided and opposite manners.
The number of burners may be tentatively related to the furnace depth af (at the same = idem) using the expression (5)
It should be noted that the axes of two large opposite air nozzles ( = 1)—an arrangement implemented in an inverted furnace—had to be inclined downward by more than 50° [8].
One well-known example of a furnace device in which once through jets are used to create a large vortex covering a considerable part of its volume is a furnace with tangentially arranged burners. Such furnaces have received especially wide use
in combination with pulverizing fans. However, burners with channels having a small equivalent diameter are frequently used for firing low-calorific brown coals with high content of moisture. As a result, the jets of air-dust mixture and secondary air that go out from their channels at different velocities(w2/w1 = 2–3) become turbulence and lose the ability to be thrown a long distance; as a consequence, the flame comes closer to the water walls and the latter are contaminated with slag. One method by which the tangential combustion scheme can be improved consists of organizing the so-called concentric admission of large jets of air-dust mixture and secondary air with the fuel
and air nozzles spaced apart from one another over the furnace perimeter, accompanied by intensifying the ventilation of mills [9, 10]. Despite the fact that the temperature level in the flame decreases, the combustion does not become less stable because the fuel mixes with air in a stepwise manner in a horizontal plane.
V ortex furnace designs with large cortices 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 described, which employ the principle of large jets colliding with one another; three of these schemes have been implemented. A boiler with a steam capacity of 230 t/h has been retrofitted in accordance with one of these schemes (with an inverted furnace) . Tests of this boiler, during which air-dust mixture was fed at a velocity of 25–30 m/s from the boiler front using a high concentration dust system, showed that the temperature of gases at the outlet from the furnace had a fairly uniform distribution both along the furnace width and depth . A simple method of shifting the flame core over the furnace height was checked during the operation of this boiler, which consisted of changing the ratio of air flow rates through the front and rear nozzles;this allowed a shift to be made from running the furnace in a
dry-bottom mode to a slag-tap mode and vice Versace. A bottom-blast furnace scheme has received rather wide use in boilers equipped with different types of burners and mills. Boilers with steam capacities ranging from 50 to 1650 t/h with such an aerodynamic scheme of furnaces manufactured by ZiO and Bergomask have been installed at a few power stations in Russia and abroad . We have to point out that, so far as the efficiency of furnace process control is concerned, a combination of the following two aerodynamic schemes is of special interest: the inverted scheme and the bottom-blast one. The flow pattern and a calculation analysis of the furnace process in such a furnace during the combustion of lean coal are presented in [13].
Below, two other techniques for controlling the furnace process are considered. Boilers with flame–stoker furnaces have gained acceptance in industrial power engineering, devices that can be regarded to certain degree as controllable ones owing to the presence of two zones in them . Very different kinds of fuel can be jointly combusted in these furnaces rather easily. An example of calculating such a furnace
device is given in [2]. As for boilers of larger capacity, work on developing controllable two-zone furnaces is progressing slowly . The development of a furnace device using the so-called VIR technology (the transliterated abbreviation of the Russian introduction, innovation, and retrofitting) can be considered as holding promise in this respect. Those involved in bringing this technology to the state of industry standard encountered difficulties of an operational nature (the control of the process also presented certain difficulties). In our opinion, these difficulties are due to the fact that the distribution of fuel over fractions can be optimized to a limited extent and that the flow in the main furnace volume has a rather sluggish aerodynamic structure. It should also be noted that the device for firing the coarsest fractions of solid fuel in a spouting bed under the cold funnel is far from being technically perfect.
Centrifugal dust concentrators have received acceptance for firing high-reactive coals in schemes employing pulverizing fans to optimize the distribution of fuel as to its flow rate and fractions. The design of one such device is schematically shown in [9]. Figure shows a distribution of fuel flow rates among four tiers of burners that is close to the optimum one. This distribution can be controlled if we furnish dust concentrators with a device with variable blades, a solution that has an adequate effect on the furnace process.
燃煤锅炉的燃烧进程控制
存在于火电厂的市场的燃料供应，某些操作参数需要改变（或保留）的情况下，以及经济和环境方面倾向的要求使他们变得更加严格的不稳定趋势是导致使控制燃烧与传热过程炉设备非常紧迫的主要因素。

解决这个问题的办法有两个方面。

第一阶段包括发展燃烧技术和当新装置设计时高炉的设计。

第二阶段包括现有的现代化设备。

在两种情况下，技术精髓的采用必须通过类似试验与计算研究的使用来证实。

有着丰富经验的机组研究和生产协会（ TsKTI ）和齐奥专家取得锅炉操作和实验进行了调查，他们的模式使他们能够提出一些新设计的混和机动性，换言之，可控炉装置已在发电站投入使用多年，与此同时，一种近似零一维，锅炉炉膛燃烧进程总线计算模型在TsKTI 已经研制成功，这一模型允许Tsk-ti 专家获取计算这一进程中的主要参数，计算研究炉膛采用不同技术时的发射与燃烧方式。

当然，火炉燃烧进程的调整方法有诸如改变空气过剩系数，烟气再循环率，燃料和空气在锅炉空间内的分配，以及其它在锅炉运行期间书面的控制图表。

然而，它们对进程的影响自然是有限的。

另一方面，控制锅炉的燃烧进程很可能意味着在某种条件下发成实质性改变，在这种条件下发生燃烧和传热，目的是大幅度扩大负荷量，尽量减少热损失，减少炉渣的污染程度，减少排放的有害物质，并且转型成再燃物。

这种控制，可利用以下三个主要因素:
(i)流动的氧化剂和气体以一种期望的空气动力学方式在火焰中流动
(ii)将燃料供应到火炉的方法并证实燃料已经供应到地方了
(iii)经过研磨的优良燃料
后者意味着火炉床的方法被用作带有火焰的燃料燃烧过程。

流化床燃烧的方法可以实施三个设计版本：带有密集床的机械炉，流化床锅炉，以及喷动床炉。

正如一下所要展示的，第一个因素可以通过在锅炉装置周围建立一些庞大的漩涡转移大量的空气和燃烧产品来实现。

如果燃料进给是在火焰中进行，最佳的进给方式是将其进给到漩涡中心区域附近，这种方式特别适用在高度密集炉设备
α，在这一很长过程时中。

在这一区域的燃烧过程具有较低的空气过剩因数1
π
间内这些成分都要存在于此，这一因素有助于使燃烧过程更稳定和减少排放的氮氧化物。

同样重要的是，对于锅炉燃烧控制过程，当固体燃料燃烧时，也要优化将燃料碾磨精化。

如果我们要尽量减少不完全燃烧，燃料的研磨程度应该与位置相协调，在这一位置上，燃料被送进炉膛，同时供应燃料应讲究方法，因为碳的不完全燃烧不但是因为大型燃料组分不完全燃烧，而且还因为某些经过研磨的细质不燃烧的缘故。

（特别是某些挥发性的成分Vdaf<20%）。

由于存在绘画般的显示流体运动的可能性，锅炉空气动力学吸引了大量研究人员和设计师的关注，他们一直致力于发展和改进锅炉设备。

与此同时，锅炉空气动力学的关键在于混合中心（集中的传递），这一过程的可估计的定量参数，只能间接或特殊的测量。

成分在炉膛内混合的质量严格上取决于数量，布局，还有从个别炉膛和喷嘴喷射出来的流体动力，以及它们与流动的废气或与墙壁的相互作用。

有人建议，气体喷射距离可以作为参数确定气体燃烧器通道中燃料与空气的混合程度。

这种如何估计有效混合的做法可以在一定的程度上用于混合装置的炉的分析。

显然，越大的喷射距离（和其势头），造成的在炉膛内持续存在的速度梯度的时间越长，一个参数，确定如何流动中完全混合。

注意，在喷嘴或燃烧器出口的喷射高度越高，它涵盖的距离越短，因此，组成部分不完全是在炉体内混合。

一旦通过燃烧器便在漩涡这方面具有优势。

还有人提议，因为它们以速度w2和密度ρ2渗透变成横向（漂移）流移动速度w1和密度ρ1，所以在喷嘴混合的程度与气体喷射距离密切相关，以下列方式：公式（1）
Ks是相称的因素，取决于射流轴线之间的距离（Ks= 1.5至1.8）天然气与空气在炉中混合，然后在炉中使用不完整的混合技术的实验研究结果作为一个参数在[5]报告。

第一轮曾经是密集射流与周围介质以其最初的形式混合的熔炉，在这里喷气轴的流速仍然是等于在喷嘴孔半径r0的速度W2。

喷嘴吹入到炉的速度下降非常迅速，超越了最初一节的限制，壁挂式燃烧器的轴弯曲对准炉的出口。

有人可能会认为，有三个理论模型用于分析流量G2和流量G1混流喷射的原理。

第一种模式是喷射流入“自由”空间的情况（ G1= 0 ）；第二个模型是喷射流入横向（漂移）的情况下，当前的流量G1 G2 ；第三个模型是当喷射流入漂移流的情况下，此时流量G1<G2。

第二种模型描述的是混合气体燃烧器，第三种模式描述的是在炉膛内的混合。

我们认为，与第二种模式相比在不久的将来我们
即将拥有的混合模式更接近于第一种模式，因为0 <G1/G2 < 1 ，我们将假定喷射的漂移距离h等同于自由喷射的初始长度S0.正在漂流的喷射的弹射能力等同于自由喷射的长度，初始喷射的长度能够用众所周知的公式确
G.N.Amphibrachic ：S0 = 0.67r0 / a，在这里，a代表喷射结构因数，r0代表喷嘴半径。

在a= 0.07时，喷嘴的初始喷射圆长等同于10倍的r0，喷射过渡段（在初始喷射结束时）的半径等同于3.3倍r0.集中喷射的流量是这种情形的两倍。

相应的最小炉周围的代表性区域Ff一旦通过燃烧器出口区域Fb，这两个区域将相等同，他们的比例是Ff/Fb≈20。

一旦通过燃烧器，这一值将接近于基于锅炉设备的实际值。

带有旋流的锅炉燃烧器，a = 0.14和Ff/Fb≈10。

在两种情况下，燃烧器之间的距离与在过渡阶段的喷射直径dtr相等，这与建立于实践与建议的价值差别很小。

传统的方法来控制大型锅炉的炉内过程包括给他们配备了大量的燃烧器，并将这些燃烧器安排在几个层次。

显然，如果层之间的距离比较小，断开或连接的行为对整个过程的影响可以忽略。

锅炉设计采用大平面火焰燃烧器装备，意味着利用空气动力学原理控制火焰的燃烧中心是锅炉发展历程中先前迈出的一大步。

对于控制蒸汽产量为600吨/小时TPE-214 and TPE-215 型锅炉进程，更多可能性是通过在两个距离较大的层面上采用平面火焰燃烧器。

这使人们有可能不仅提高或降低的火焰，而且还能集中或分散释放的热量。

一个非常明显的效果，是在乌克兰和俄罗斯的联产锅炉冶金产业中安装万能（用于煤炭和平炉，焦化，自然气体）平面燃烧器。

不幸的是，我们必须指出，即使在目前，那些负责选择炉具类型，数量和布局所采用的技术解决方案，还远远没有得到优化。

因此这个问题应考虑更多的细节。

如果我们增加炉具数量，同时保留其总截面积（ΣFb =idem）和通过他们的空气总量，他们的等效直径deq将变得越来越小，而喷射动量Gbwb 也会减小，导致喷射距离的相应减少和集中退出。

带有高流速梯度的空间也变小，导致作为整体的炉子混合性变差。

在燃料分配不均匀的情况下，当采用分级燃烧(atαb<1)时，喷射氮氧化物和碳氧化物的比例很正确的时候，这一因素变得非常重要。

定量关系被建立在以质量和几何参数的浓度为特征的参数上，质量取决于混合喷射进入有限空间的流量，几何参数的浓度为
fΣFb/Ff， nb=idem,Gb=idem。

通
过降低这个参数我们提高炉的传质;然而，这需要我们在相同的Fb下，增加流体速度和能源的支出。

与此同时，我们从经验和计算中得知，良好的混合炉，如果我们采用大型的远程喷射炉，可不增加顶端的损失。

这让很多不是很严格的要求可以置于一致的水平上，在这一水平上，燃料必须被分配在炉内。

此外，燃料可能在这种情况下被传送至该炉的某一位置，这一位置是需要从过程控制方面去考虑。

为便于说明，我们将估计当=fΣFb/Ff=idem是混合炉数量的影响。

图标1显示了两炉膛放置在一层（炉子一侧）的喷嘴数量的不同（2或者4）。

该炉具有相同的喷嘴区域总出口横断面（ΣFb ）和相同的喷射速度联系着这些区域（wb）。

众所周知的TsKTI漩涡炉有一个接近于考虑下的炉具的设计方案。

根据有关数据，以低于额定的量混合并通过燃烧器进入炉体内为特点的空气指数βair，可用公式进行估计：βair=1-5f，这一公式范围已经被核实=f0.03-0.06，为炉膛配备了两个前沿使其一次性通过燃烧器。

显然，如果我们增加燃烧器的数量到因数2，其当量直径，初始喷射区域的长度S0和他们所“服务”的区域因数将减小2，例如，当a=0.05，分数βair将由0.75减少至0.65 ，因此，在通过对经过燃烧器进入炉内混合的质量的影响进行评估后，上述公式可以写成：β
air=1-3.5f nb，在这里nb是在一面墙上燃烧器（或空气喷嘴）的数量，当它们被安排在一样或相反的方式上。

燃烧器的数量可能暂时与炉的深度af联系（同时f=idem），此时用公式。

nb=1）—其中一个安排在应当指出的是，在轴上的两个相对的空气喷嘴，（'
反向表面—不得倾向下调超过50度。

有关炉装备，有一个很有名的案例。

通过喷射用来制造一个很大的漩涡，用来覆盖炉装置的大部分体积，这种装置是在炉膛四角布置燃烧器。

这种装备已经结合研磨鼓风机得到了广泛的采用。

然而，带有线路和小的当量直径的燃烧器，经常被用作引燃水份含量较高的低热量褐煤。

结果，以不同的速度喷射空气粉尘混合物和从各自不同通道出去的二级空气（w2/w1 = 2–3），这些喷射物形成漩涡从而失去可以远距喷射的能力。

因此，火焰接近于水壁，后者被残渣污染。

有一种方法能够使切向燃烧方案得到改进，这种方法是引导所谓的“轴心”吸纳大量的空气粉尘混合物与二次空气，燃料和空气喷嘴彼此不相邻并配有通风机。

尽管火焰的温度会下降，燃烧却依然稳定，这时因为燃料和空气的混合过程是在一个循序渐进的水平上进行的。

带有大涡轮横向旋转轴，和主要气流方向有关的涡炉设计具有广泛的可能性用于控制炉进程。

四个可控火焰的锅炉计划被记述，它们遵循大型喷嘴彼此相喷射的原理，这其中的三个计划已经被实施了。

一个蒸汽能力230吨/小时的锅炉已按照其中的一个计划进行了改装（带有反转炉）。

这种锅炉的测试表明了，在炉子的出口处，气体的温度在沿炉子的深度和宽度上都是不均匀分布的。

在此期间，空气粉尘混合物在高浓缩除尘机的作用下，以25-30米/秒的速度从炉子的前沿喷射。

一个测量炉中火焰高度的简单办法是在操作锅炉的过程中进行，这需要考虑通过炉前后方喷嘴不断变化的空气流量比率；这个过程允许由干底模式替换为液态排渣模式，反之亦然。

一个底喷炉计划已经在锅炉产业上得到了广泛的应用，这一类锅炉配有不同的燃烧器和粉碎器。

蒸汽能力从50--1650吨/小时这样的气动方案锅炉已经被ZiO 和 Sibener gomash制造，并在俄罗斯等一些国外的发电站得到应用。

我们必须指出，迄今为止炉的过程控制效率问题已经受到关注，以下两个气动炉方案格外有趣：反转模式和底喷炉模式。

在这种炉燃烧低质煤的过程中，流量和炉的进程计算分析被提出。

下面，其他两个控制炉过程的技术被考虑。

带有火焰控制炉的锅炉已经在电力工业中得到了应用，由于在它们的内部存在两个区，这些设备可以被看做在某种程度上具有可控性。

各种不同的燃料可以很容易的放到一个炉内一同燃烧。

计算这种炉的例子已经在书中第二页给出了。

至于大容量锅炉，双炉区控制的锅炉发展的一直很缓慢。

发展炉技术所用到的所谓VIR技术（音译缩写俄罗斯引进，创新和改造），可以被视为这方面的曙光。

那些致力于把这一技术带进国家行业标准中的人，遇到了自然运作方面的麻烦（过程控制中也介绍了某些问题）。

我们认为，这些困难是由于这样一个事实，即燃料的分配比例超过一定分数，导致可以优化程度有限，流体在主炉容体中有着相当缓慢的空气动力学结构。

还应该指出，在冷窗下的喷床，用于喷射固体燃料粗糙组分的设备，还远远不够完善。

离心除尘技术已经在点燃高活性煤炭方面得到了应用，在这一计划中，采用粉球制造装置用以优化燃料分配，以及其流量和组分。

设计图标见表二。

图表三显示的是燃料流量在燃烧器的四个不同层次中分配最佳的一个。

如果我们提供一个叶片可变的灰尘集中装置，这种分配是可控的。

这一设计思想，对锅炉进程控制有着很深刻的影响。