锅炉燃烧系统

燃烧系统 combustion system 燃烧系统是燃料燃烧的场所，主要部件包括炉膛、分离器、返料系统 The combustion system is the place where fuel be combusted, mainly consists of furnace, cyclone separator, material returning device

循环流化床锅炉三大核心部件

循环流化床锅炉三大核心部件 —燃烧室、分离器、回料阀

分离器

燃烧室

回料阀

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? 1.炉膛。 ? 也叫流化床燃烧室，是供燃料燃烧的地方。由炉墙和水冷壁围成的空间，燃料在其内呈现流化状态燃烧。炉膛包括下部锥段和上部直段两部分，分为密相区、过渡区和稀相区。流化床燃烧室是流化床燃烧系统的主体,完成大约50 ％燃料释热量的传递吸收过程。它既是一个燃烧设备，也是一个热交换器和脱硫、脱氮装置，集流化过程、燃烧、传热与脱硫、脱硝反应于一体。

? 1. Furnace. ? It is also called the fluidized bed combustion chamber where the fuel burns. The fuel burns in the fluidized state in the chamber surrounded by the insulated wall and water wall. The furnace includes the lower conical section and the upper straight section, which are divided into the dense region, transition region and dilute region by the difference of consistence of material. The CFB combustion chamber is the main part of CFB combustion system, and about 50% of heat releasing, heat transferring and absorbing process are finished in it. It is not only a combustion device, but also a heat exchanger, desulfurization and denitration device, and it concentrates all the technologies of the fluidization, combustion, heat transfer, desulphurization, and denitration.

分离后烟气过热器过热器烟囱

稀相区
高温旋风分离

省煤器省煤器空预器空预器尾部受热面二次风

CFBB 炉膛

料腿

除尘器引风机

煤石灰石

密相区
一次风室 U型阀返料装置一次风一次风机一次风二次风机二次风

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燃烧装置：流化床布风板采用水冷布风板结构，有效面积为9.1m2 ; 布风板上布置了299只钟罩式风帽，风帽间风板上填保温混凝土和耐火混火混凝土。空气分为一次风及二次风，http:///
一、二次风之比为55：45，一次风从炉膛水冷风室二侧进入，经布风板风帽小孔进入燃烧室。二次风在布风板上高度方向分二层送入。布风板上布置了二只Ф219的放渣管（每只放渣管另接一只Ф219事故放渣管），可接冷渣机（用户自理）。建议：运行时，冷渣机可根据压差，断续排渣。水冷风室底部还布置了二只Ф108的放灰管，用于定期清除水冷风室中的积灰

The combustion device:
The fluidized air distributors adopt the water-cooling air distributor structure, and the effective area is 9.1m2. The air distributor is equipped with 299 bell wind caps, the insulating concrete and the ref

ractory concrete could be filled on the air plates. Air is divided into the primary air and the secondary air. PA: SA is about 55: 45. The primary air is sent from two sides of the water-cooled wind chamber, then it goes into the combustion chamber through the hood holes on the air distributors. The secondary air is distributed by two layers on height direction of the air distributor. Two(Ф219) slag-discharging tubes are arranged on the air distributor (besides, every slagdischarging tube is connected with one (Ф219 ) accident slag-discharging tube), and the slag cooler can be linked here (supplied by the user). Suggestion: During the operation process, the slag cooler can discharge slag discontinuously according to differential pressures. Bottom of the water-cooling air chamber is equipped with two (Ф108) slag- discharging tubes, so that the fouling in the water-cooling air chamber could be removed regularly.

? 炉膛底部是布风板，布风板上嵌有大量的风帽，风帽上开有许多小孔。布风板下面是风室。布风板一方面保证一次风均匀穿过布风板进入炉膛对炉内物料进行均匀流化，另一方面将固体颗粒限制在炉膛布风板以上，将物料与风分隔开来，并对固体颗粒（床内物料）起支撑作用。下图是典型的布风板结构图。 ? The bottom of furnace is an air-distributor on which a lot of air caps are embedded. There are many orifices opened on the air caps. An air chamber is under the air-distributor. The air-distributor has not the only function that makes the primary air passes through it and enters into the furnace evenly so as to get a uniform fluidization, but also has the function to support the solid particles and also act as a separating board between the furnace and the air chamber. The following figure is a typical structure of the air-distributor:

? 1—内管 2—外罩 3—环形底板 ? 1—inner pipe 2-external cover 3-annular base plate ? 图水冷布风板及钟罩式风帽 ? Figure Water-cooled distributor and bell covered air cap ? 风帽是保证床内物料正常流化和隔绝固体颗粒向风室倒流的关键部件，主要通过特殊的风帽及风帽小孔结构设计来实现。布风板及风帽设计的好坏直接影响床内颗粒的流化情况，它应当有一定的阻力以保证整个床面流化的均匀同时应尽量控制阻力不致过大以减小阻力损失，同时，风帽设计还特别强调防止炉膛内向风室的漏渣。从风帽的功能出发，实际采用的风帽有多种型式，如钟罩型、蘑菇型、T型、7字型定向风帽等，目前应用最广泛效果相对较好的是钟罩型风帽）。

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? Air cap is a critical part which ensures the normal material fluidization on the bed and prevents the solid particles from flowing reversal into the air chamber. This function is mainly realized through a design of a special structure of the air c

ap and orifices on it. The design of air distributor and air cap influences directly the fluidized status of material on the bed. Therefore, it should have a proper resistance to ensure the even fluidization of the material on bed and avoid the resistance from becoming too big so as to reduce much pressure head of the PA fan. At the same time, the designer should pay more attention to prevent material from dropping into air chamber. For the different function and discriminating characteristics slightly, the are many kind of caps used in industry, such as bell covered type, mushroom type, T type, figure 7 shaped oriented air cap. Nowadays, the most widely used and has the best effect is bell covered type.

? 大型CFB锅炉布风板及其下的风室往往由水冷壁管弯制而成，形成水冷风室和水冷布风板结构，以防止其高温变形（尤其是采用床下点火方式时）。 ? The big capacity CFB boiler will has a large size in structure, which provides a possibility to manufacture the air distributor and air chamber with curved water wall, so as to form the water cooled air chamber and air distributor which can reduce the possibility of distortion in high temperature (especial when adapting the belowbed igniting system).

? 炉膛内燃料的燃烧以二次风入口为界分为两个区。二次风入口以下为大粒子还原气氛燃烧区，二次风入口以上为小粒子氧化气氛燃烧区。燃料的燃烧过程、脱硫过程、NOx 和N2O的生成及分解过程主要在燃烧室内完成。炉膛下部锥段以下及炉内其它易磨损部位敷设耐火浇筑料，以保护受热面。 ? The fuels burned inside the furnace are divided into two zones, with the boundary line of secondary air inlet. Below the secondary air inlet is reducing atmosphere combustion zone for big particle. Above the secondary air inlet is oxidizing atmosphere combustion zone. The process of combustion, desulphurization, formation and decomposition of NOx and N2O are mainly finished in combustion chamber. The lower part, the conical section of the furnace and other fray easily area are covered with refractory to protect the heating surface.

? 炉膛上部一般还悬挂部分受热面（水冷屏、过热屏或再热屏），以吸收炉膛内燃烧释放的部分热量。 ? Some heating surfaces (water-cooled screen, superheated screen or reheated screen) are hanged on the upper area of the furnace to absorb partial heat released by fuel burned in furnace.

? 2.旋风分离器 ? 旋风分离器是循环流化床锅炉的关键部件，它的作用是将烟气中的固体颗粒分离出来，通过回料系统将其送回炉膛继续燃烧，从而维持炉膛内的物料平衡，降低飞灰含碳量。 ? 2. Cyclone Separator ? The cyclone separator is the crucial component of a CFB boiler. The function of the cyclone separator is to separates the solid particles which are not burnt out from t

he flue gas and sends them return back to the furnace through the material returning device to combust again, so as to maintain the material balance in the furnace and reduce the carbon content in the fly ash.