锅炉燃烧系统(3)

? 3.回料系统。
? 布置在分离器下面，它的作用是将分离下来的燃料送回炉膛中继续燃烧，并保证流化床内的高温烟气不经过返料装置短路流入分离器。返料装置既是一个物料回送器，也是一个锁气器。

? 3. Material returning system ? It is installed below the separator and its effect is to send the separated material back to the furnace to be combusted again. It guarantees that fluidized hot fuel gas doesn’t flow into separator through material returning equipment. Material returning equipment is both a material sending back device and sealing device prevent the flue gas from short circuit.

? 返料装置

? ? ? ? ? ?

典型的U型阀设计返料流畅自动平衡返料小量的高压流化风观察窗温度压力测点

? 回料系统的正常运行对燃烧过程的可控性、对锅炉的负荷调节性能起决定性作用。如果回料系统作用失常，物料的循环燃烧过程建立不起来，锅炉炉膛内将失去循环灰对热量的携带和均匀分配功能，燃料释放的热量会大量集中在炉膛下部，造成运行床温超温，燃烧室内的燃烧工况变差，炉内传热系数下降，难以吸收到额定负荷下需要的热量，锅炉将达不到设计蒸发出力。因此，回料系统的合理设计和运行是非常重要的。

? The normal operation of material circulation system plays a decisive role on controllability of combustion process and load adjusting performance of boiler. If material circulation system doesn’t work normally, then the circulating combustion process can’t be established and the boiler will lose the advantage of heat distribution and transmission by circulating ash in furnace. The heat released by fuel will gather at the bottom of furnace, leading to the over temperature, bad combustion condition in combustion chamber, descending of heat transfer coefficient in furnace. Then its difficult to provide enough heat energy for the boiler to reach the rated load designed. Therefore, the reasonable design and operation of material returning system is very important.

? 流化床燃烧系统中常用的返料装置是非机械式的。设计中采用的返料器主要有两种类型：一种是自动调整型返料器，如流化密封返料器；另一种是阀型返料器，如"L”阀等。自动调整型返料器能随锅炉负荷的变化

，自动改变返料量，不需调整返料风量。阀型返料器要改变返料量则必须调整返料风量，也就是说，随锅炉负荷的变化必须调整返料风量。 ? It is not mechanical equipment for the material returning device in common used in CFB combustion system. There are mainly two types of material returning device: one is adjustment automatically, such as fluidized sealing device, the other is Valve type material returning device, such as “L” valve. The automatically adjusting material returning device can change the amount of returning material with the change of boiler load. It is unnecessary to adjust air flow of returning material. Valve type material returning device has to adjust air flow of returning material to change the amount of returning material. That’s to say, it needs to adjust the air flow of returning material with the change of boiler load.

? 给煤装置 ? 本锅炉炉前布置了三只给煤管，煤通过给煤管送入燃烧室。给煤管上布置有送煤风
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和播煤风，以防给煤堵塞。送煤风接一次冷风，播煤风接一次热风，二股风合计约为总风量的4%，每只送风管、播煤风管应布置一只风门（设计院设计），以调节送煤风量。给煤口在离风帽约1500mm处进入燃烧室。注意事项：为了防止堵煤，应保证煤中全水分≤8%

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Coal-feeding device:

? Three coal-feeding tubes are arranged on boiler front. Coal is sent into the combustion chamber through coal-feeding tube. Coal-sending air and coalspreading air are arranged on coal-feeding tube to avoid clogging. The coalsending air connects to the primary cool air; the coal-spreading air connects to the primary hot air. Totally they take 4 percentage of total air volume. Every air-sending tube or coal-spreading air duct is arranged with one air door (designed by the design institute), so that the coal-sending air volume could be regulated. The coal inlet is linked with the combustion chamber 1500mm far away form the air caps. ? NOTE: To avoid the coal clogging, the percentage of water in coal should not be more than 8%.

给煤系统

采用播煤风，在进入炉膛前的落煤管道内和管道转弯处形成气垫，进煤顺畅，不易堵煤。

给煤系统
落煤管

空气吹扫给煤喷口

煤闸门

炉膛膨胀节

吹扫管吹扫管

给煤口

给煤口在离风帽约1500mm处进入燃烧室。

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床下点火装置
本锅炉采用水冷布风板、床下油枪点火技术，油枪在床下预燃室内先燃烧，然后和冷空气混合成<800℃的高温烟气，再经风室进入燃烧室加热物料，点火初期为了预热锅炉本体，可调节较低的烟气温度，然后视料层温度再逐渐调高温度。油枪前油压2.0MPa，油量100~350Kg/h,采用0#轻柴油；油枪采用机械雾化。

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Under-bed ignition device This technology of “water-cooling air distributo

rs, underbed oil gun ignition” is adopted in this boiler. The oil gun would be burnt in the under-bed pre-combustion chamber. And then, by mixing with the cool air, the high-temperature smoke (<800℃) would form to be. Then it enters into the combustion chamber to heat the material through the air chambers. At the beginning period of ignition, the smoke temperature could be regulated to be relatively low to heat the boiler proper, and it could be increased gradually according to the temperature of material layer. The front oil pressure of oil gun is 2.0MPa, the oil volume would be 100~350Kg/h, the light diesel (0#) is adopted, and the mechanical atomization is adopted by the oil gun.

? 接锅炉点火系统