典型的秸秆气化发电工艺流程,主要由进料装置、燃气发生系统、燃气净化系统、燃气发电系统、控制系统和废水处理系统六大部分组成。
The typical straw gasification power generation process is mainly composed of six parts: feed device, gas generation system, gas purification system, gas power generation system, control system and wastewater treatment system.
(1)进料装置;进料装置一般采用螺旋进料器,依靠电磁调速电机驱动并调节秸秆物料的进料量,螺旋进料器不仅能够保证连续均匀地进料,而且能够有效地将气化炉与外部隔绝密闭起来,使气化所需空气只能由鼓风机控制进入气化炉。
(1) Feeding device; The feeding device generally adopts a screw feeder, which is driven by an electromagnetic speed-regulating motor and regulates the feeding amount of straw materials. The screw feeder can not only ensure continuous and uniform feeding, but also effectively isolate and seal the gasifier from the outside, so that the air required for gasification can only be controlled by the blower to enter the gasifier.
(2)燃气发生系统;燃气发生系统主要由进风机、气化炉和排渣螺旋装置构成。气化炉有固定床气化炉、流化床气化炉等不同形式,但主要采用循环流化床气化炉。农作物秸秆在气化炉中转化为可燃气体,气化后产生的灰分由排渣螺旋装置及时排出炉外。
(2) Gas generation system; The gas generation system is mainly composed of inlet fan, gasifier and slag removal screw device. The gasifier has different forms, such as fixed bed gasifier and fluidized bed gasifier, but mainly uses circulating fluidized bed gasifier. Crop straw is converted into combustible gas in the gasifier, and the ash generated after gasification is timely discharged from the furnace by the slag removal screw device.
(3)燃气净化系统;秸秆气化后产生的可燃气含有大量的粉尘、灰分、焦油等,需经过净化处理后才能用于发电。对于固体颗粒和细粉尘的去除一般选用多级除尘技术,如惯性除尘器、旋风除尘器、文丘里洗涤器、电除尘器等。可燃气中焦油的去除一般采用吸附和水洗的方法,主要设备是两个串联的喷淋洗气塔。
(3) Gas purification system; The combustible gas produced after straw gasification contains a large amount of dust, ash, tar, etc., which can be used for power generation only after purification. For the removal of solid particles and fine dust, multi-stage dust removal technology is generally adopted, such as inertial dust collector, cyclone dust collector, venturi scrubber, electric dust collector, etc. Tar in combustible gas is generally removed by adsorption and water washing, and the main equipment is two spray gas washing towers in series.
(4)燃气发电系统;燃气发电系统主要有内燃机发电系统、燃气轮机发电系统和燃气内燃机组发电系统三种。内燃机发电系统以简单的内燃机组为主,可以单独燃用低热值燃气,也可以燃气、油两用,其设备技术成熟可靠,乃常用设备。燃气轮机发电系统对燃气的质量要求较高,而且需要较高的自动化控制水平和燃气轮机改造技术水平,所以单用燃气轮机的秸秆发电技术较少。燃气-蒸汽联用混合发电技术是在内燃机、燃气轮机发电的基础上增加余热蒸汽的联合循环,可以有效提率,燃气-蒸汽联合循环的秸秆发电系统一般采用燃气轮机发电设备。
(4) Gas power generation system; Gas power generation system mainly includes internal combustion engine power generation system, gas turbine power generation system and gas internal combustion unit power generation system. The internal combustion engine power generation system is mainly composed of simple internal combustion units, which can be used to burn low calorific value gas alone or both gas and oil. Its equipment technology is mature and reliable, and it is a common equipment. Gas turbine power generation system requires high quality of gas, and requires high automation control level and gas turbine transformation technology level, so straw power generation technology of gas turbine alone is less. Gas-steam combined hybrid power generation technology is a combined cycle that adds waste heat steam on the basis of internal combustion engine and gas turbine power generation, which can effectively improve efficiency. The straw power generation system of gas-steam combined cycle generally uses gas turbine power generation equipment.
(5)控制系统;控制系统主要由电控柜、热电偶、温度显示仪、压力表以及风量控制阀构成,有需要时还可以增加电脑自动化监控系统。
(5) Control system; The control system is mainly composed of electric control cabinet, thermocouple, temperature indicator, pressure gauge and air volume control valve. If necessary, computer automatic monitoring system can also be added.
(6)废水处理系统;秸秆气化发电产生的废水一般采用过滤吸附、生物法处理或者化学混凝法等处理,然后循环利用。
(6) Wastewater treatment system; The wastewater from straw gasification and power generation is generally treated by filtration adsorption, biological treatment or chemical coagulation, and then recycled.