阅读说明：本技术 超临界锅炉启动期间节油控制方法 (Oil-saving control method during supercritical boiler starting period ) 是由 张同喜 麻建中 梁银河 崔庆伟 于 2021-08-23 设计创作，主要内容包括：本发明涉及热电厂技术领域,公开了一种超临界锅炉启动期间节油控制方法,所述方法包括：在锅炉的C层投入C层全部油枪和D层全部大油枪并点火；投入辅助蒸汽至除氧器加热,提高除氧器内水温；启动C层磨煤机；待C层燃烧器煤火检强度高于特定值后,撤出D层油枪；投入C层等离子燃烧器释放等离子拉弧开启与汽轮机中压缸连通的抽气电动阀、抽气逆止阀,将中压缸内蒸汽投入到2号高压加热器汽侧,提高给水温度；C层磨煤机增加至特定煤量以上后,保留煤火检强度低于特定值的燃烧器的油枪外,撤出煤火检强度高于特定值的燃烧器的油枪。通过上述技术方案的设置能够稳定燃烧,提高油枪中燃油燃烧的效率,达到节油的效果,节约节油成本。(The invention relates to the technical field of thermal power plants, and discloses an oil-saving control method during the starting period of a supercritical boiler, which comprises the following steps: putting all oil guns on the layer C and all large oil guns on the layer D in the boiler and igniting; adding auxiliary steam to the deaerator for heating, and increasing the water temperature in the deaerator; starting a coal mill on the layer C; after the coal fire detection intensity of the combustor in the layer C is higher than a specific value, the oil gun in the layer D is withdrawn; throwing the C-layer plasma burner to release plasma, arcing, opening an air exhaust electric valve and an air exhaust check valve which are communicated with a steam turbine intermediate pressure cylinder, throwing steam in the intermediate pressure cylinder to the steam side of the No. 2 high pressure heater, and increasing the water supply temperature; and after the coal pulverizer on the layer C is increased to a specific coal amount, keeping the oil guns of the burners with the coal fire detection strength lower than the specific value, and withdrawing the oil guns of the burners with the coal fire detection strength higher than the specific value. Through the arrangement of the technical scheme, the fuel can be stably combusted, the efficiency of fuel combustion in the fuel gun is improved, the fuel saving effect is achieved, and the fuel saving cost is saved.)

1. The oil-saving control method during the starting period of the supercritical boiler is characterized by comprising a boiler, wherein the boiler is provided with a plurality of layers, each layer is matched with a coal mill and a burner, the burner is internally provided with a plurality of oil guns, a layer C and a layer D are horizontally arranged and positioned at the bottommost layer of the boiler, the burner at the layer C is a plasma burner, and the oil guns of the layer D are large oil guns; the method comprises the following steps:

s1, putting all oil guns on the layer C and all large oil guns on the layer D in the boiler and igniting;

s2, adding auxiliary steam to the deaerator for heating, and increasing the water temperature in the deaerator;

s3, starting a coal mill on the layer C; after the coal fire detection intensity of the combustor in the layer C is higher than a specific value, the oil gun in the layer D is withdrawn;

s4, putting the carbon plasma burner into the plasma burner to release plasma and arcing;

s5, opening an air extraction electric valve and an air extraction check valve which are communicated with a steam turbine intermediate pressure cylinder, and throwing steam in the intermediate pressure cylinder to the steam side of the No. 2 high pressure heater to increase the water supply temperature;

and S6, after the coal mill on the layer C is increased to a specific coal amount, keeping the oil gun of the combustor with the coal fire detection strength lower than the specific value, and withdrawing the oil gun of the combustor with the coal fire detection strength higher than the specific value.

2. The method for controlling fuel saving during the startup of a supercritical boiler according to claim 1, wherein the auxiliary steam comes from a plant-wide auxiliary steam main pipe.

3. The fuel saving control method during the start-up of the supercritical boiler according to claim 1, characterized in that 6 layers are provided in the boiler.

4. The method for controlling fuel saving during startup of a supercritical boiler according to claim 1, characterized in that there are 6 oil guns in the burners of each layer.

5. The method for controlling fuel saving during the startup period of a supercritical boiler according to claim 1, wherein the time interval between S2 and S3 is 10 minutes to give S2 sufficient time to increase the temperature of the water wall step by step.

6. The method for controlling fuel economy during startup of a supercritical boiler according to claim 1, wherein the specific value of the coal fire detection intensity in S4 is 70% or more.

7. The fuel saving control method during startup of a supercritical boiler according to claim 1, characterized in that the specific coal amount is 25t/h in S5.

8. The method for controlling fuel saving during the start-up of a supercritical boiler according to any one of claims 1 to 7, characterized in that after the grid connection of the unit generator, an oil gun in a burner of a D level is thrown into the D level, a coal mill of the D level is started, and the coal grinding amount of a coal mill of a C level and a coal mill of the D level is adjusted.

9. The method of claim 8, wherein the adjusting the amount of coal ground for the layer C coal mills and the layer D coal mills comprises reducing the amount of coal ground for the layer C coal mills and gradually reducing the amount of coal ground for the layer D coal mills.

Technical Field

The invention relates to the technical field of thermal power plants, in particular to an oil-saving control method during the starting period of a supercritical boiler.

Background

The deep peak regulation of the thermal power generating unit becomes a normal state, and the peak regulation of the starting and stopping of the unit is more and more frequent. The starting times of the unit in the factory are 12 times in 2018, 16 times in 2019, 15 times in 30 days in 10 and month in 2020, and the starting oil is more and more. The boiler low-load operation and the start-stop process need to be oiled for combustion supporting, and the coal mill on the layer C of the boiler in our factory is provided with a plasma burner, so that the boiler low-load operation and start-stop process has certain combustion supporting capacity and has a space for reducing combustion supporting oil.

Disclosure of Invention

The invention aims to provide an oil-saving control method during the starting period of a supercritical boiler, which can solve the problem of large oil consumption in the low-load operation and start-stop process of the boiler in the prior art.

In order to achieve the aim, the invention provides an oil-saving control method during the starting period of a supercritical boiler, which comprises a boiler, wherein the boiler is provided with a plurality of layers, each layer is matched with a coal mill and a burner, the burner is provided with a plurality of oil guns, a layer C and a layer D are horizontally arranged and positioned at the bottommost layer of the boiler, the burner of the layer C is a plasma burner, and the oil guns of the layer D are large oil guns; the method comprises the following steps:

s1, putting all oil guns on the layer C and all large oil guns on the layer D in the boiler and igniting;

s2, adding auxiliary steam to the deaerator for heating, and increasing the water temperature in the deaerator;

s3, starting a coal mill on the layer C; after the coal fire detection intensity of the combustor in the layer C is higher than a specific value, the oil gun in the layer D is withdrawn;

s4, putting the carbon plasma burner into the plasma burner to release plasma and arcing;

s5, opening an air extraction electric valve and an air extraction check valve which are communicated with a steam turbine intermediate pressure cylinder, and throwing steam in the intermediate pressure cylinder to the steam side of the No. 2 high pressure heater to increase the water supply temperature;

and S6, after the coal mill on the layer C is increased to a specific coal amount, keeping the oil gun of the combustor with the coal fire detection strength lower than the specific value, and withdrawing the oil gun of the combustor with the coal fire detection strength higher than the specific value.

Through the arrangement of the technical scheme, the auxiliary steam can improve the temperature of water supply, so that the temperature of a water-cooled wall is improved, and the large oil guns in the adjacent layers are used for assisting ignition, so that the medium and small oil guns in the layer are prevented from extinguishing, the oil guns are withdrawn according to the flame intensity condition in the hearth, and the subsequent combustion in the hearth is maintained through a plasma arc; through the measures, the fuel can be stably combusted, the combustion efficiency of the fuel in the fuel gun is improved, the fuel-saving effect is achieved, and the fuel-saving cost is saved.

Further, the auxiliary steam comes from a whole plant auxiliary steam main pipe.

Further, 6 layers are provided in the boiler.

Further, there are 6 oil guns in the burner of each tier.

Further, the time interval between S2 and S3 is 10 minutes, so that sufficient time is given to S2 to gradually increase the temperature of the water wall.

Further, the specific value of the coal fire-detection intensity described in S4 is 70% or more.

Further, the specific coal amount is 25t/h in S5.

And further, after the unit generator is connected to the grid, putting an oil gun in a D-layer combustor in the D layer, starting a D-layer coal mill, and adjusting the coal grinding amount of a C-layer coal mill and a D-layer coal mill.

Further, the adjustment of the coal grinding amount of the C-layer coal mill and the D-layer coal mill comprises the reduction of the coal grinding amount of the C-layer coal mill, and the gradual reduction of the coal grinding amount of the D-layer coal mill.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Detailed Description

The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

In the present invention, the use of the terms of orientation such as "upper and lower" in the case where no description is made to the contrary generally means the orientation in the assembled and used state. "inner and outer" refer to the inner and outer contours of the respective component itself.

The invention provides an oil-saving control method during the starting period of a supercritical boiler, which comprises the boiler, wherein the boiler is provided with a plurality of layers, each layer is matched with a coal mill and a burner, the burner is provided with a plurality of oil guns, a layer D of a layer C is horizontally arranged and is positioned at the bottommost layer of the boiler, the burner of the layer C is a plasma burner, and the oil guns of the layer D are large oil guns; preferably, the boiler has 6 levels, from top to bottom, of EF, AB, CD, respectively, wherein the EF, AB and CD levels are the same and are horizontally disposed. It should be noted that the oil output of the large oil gun is greater than that of other oil guns, such as the oil gun in A, B, C, E, F layers; the large oil gun is specially used for starting the boiler.

The method comprises the following steps:

s1, putting all oil guns on the layer C and all large oil guns on the layer D in the boiler and igniting, so as to avoid Main Fuel Tripping (MFT) caused by flameout of the small oil guns when the boiler is ignited;

s2, adding auxiliary steam to the deaerator for heating, and increasing the water temperature in the deaerator; thereby improving the water wall and temperature and stabilizing the combustion. The auxiliary steam comes from a main auxiliary steam pipe of the whole plant, namely an auxiliary steam header, and the steam source of the auxiliary steam is adjacent unit steam and/or reheat cooling section steam supply and/or steam extraction steam supply of a steam turbine;

s3, starting a coal mill on the layer C; after the coal fire detection intensity of the combustor in the layer C is higher than a specific value, the oil gun in the layer D is withdrawn; preferably, the specific value of the coal fire-detecting intensity described in S4 is 70% or more. Preferably, the time interval between S2 and S3 is 10 minutes, so as to give S2 sufficient time to gradually increase the temperature of the water wall;

s4, putting the carbon plasma burner into the plasma burner to release plasma and arcing; the plasma arc can ignite the coal powder, can replace part of oil guns to ignite, and has the effect of saving oil;

s5, opening an air extraction electric valve and an air extraction check valve which are communicated with a steam turbine intermediate pressure cylinder, and throwing steam in the intermediate pressure cylinder to the steam side of the No. 2 high pressure heater to increase the water supply temperature; it should be noted that the number of the high-pressure heaters is three, namely 3, 2 and 1, and each high-pressure heater is only provided with one steam side and one water side; the steam side of the No. 1 high-pressure heater is connected with a high-pressure cylinder of the steam turbine, the steam side of the No. 2 high-pressure heater is connected with the high-pressure side of a medium-pressure cylinder of the steam turbine, and the steam side of the No. 3 high-pressure heater is connected with the low-pressure side of the medium-pressure cylinder of the steam turbine; the starting of the unit adopts a medium pressure cylinder starting mode, only the high pressure side of the medium pressure cylinder is provided with steam, and the temperature of the feed water in the No. 2 high pressure heater can be improved.

And S6, after the coal mill on the layer C is increased to a specific coal amount, keeping the oil gun of the combustor with the coal fire detection strength lower than the specific value, and withdrawing the oil gun of the combustor with the coal fire detection strength higher than the specific value. Preferably, the specific coal amount is 25t/h in S5. The oil gun is withdrawn according to the flame intensity condition in the hearth, and the subsequent combustion in the hearth is maintained through the plasma arc, so that the fuel consumption in the operation process can be reduced.

By the measures, the method can ensure stable combustion in the hearth, improve the combustion efficiency of fuel oil in the oil gun, achieve the effect of saving oil and save the oil saving cost.

The factory adopts the oil saving measures of assisting the stripping of high feed water temperature, timely removing the oil gun and plasma combustion-supporting without throwing the oil gun to compare the consumed fuel oil amount of the unit in cold starting without adopting the oil saving measures as follows:

the #1 unit is started 16 times in total in 16 days from 2018 to 2020, 5 months and 16 days, wherein two times are started after holiday regulation, the stop time is short, the oil consumption of the hot-state starting unit is less, and the rest is cold-state starting. The average oil consumption of the #1 unit in the cold start of each unit from 2018 to 2020 is 29.47 t.

The cold starting times of the #2 unit from 2018 to 2020 are 12, wherein 3 starting oil consumptions cannot be counted due to the fault of fuel base data before 11 and 5 days in 2019, 11 and 28 days in 2019 and 7 days in 2020, and the average cold starting oil consumption of 7 times in the period from 11 and 28 days in 2019 to 7 months in 2020 is 26.6 t. After the oil saving measures are adopted in cold starting twice in 8 months, 10 days and 9 months, 18 days in 2020, 8.69t and 8.14t of fuel oil are consumed respectively, and the average oil consumption of twice is 8.41 t.

In summary, the average fuel consumption of 21 cold starts during the period from 2018 to 1 month 8 of 2020 in #1 and #2 machines is 28.51t, and after the fuel saving measure is adopted, the fuel is saved by 20t for each cold start. According to the calculation of 15 times of unit starting in the factory in 2020, the fuel oil is saved by about 300t, the unit price is calculated according to 6000 yuan/ton, and the cost is saved by 180 ten thousand yuan.

Further, after the power generator can generate power and the grid is connected to the boiler level C, the boiler level D starts to be burned. And (4) putting an oil gun in the D-layer combustor in the D layer, starting a D-layer coal mill, and adjusting the coal grinding amount of the C-layer coal mill and the D-layer coal mill. Preferably, the adjusting the coal grinding amount of the C-layer coal mill and the D-layer coal mill comprises reducing the coal grinding amount of the C-layer coal mill, and gradually reducing the coal grinding amount of the D-layer coal mill under the condition that the C-layer coal mill can operate under the high-coal-amount working condition. Through the setting of above-mentioned technical scheme, the coal grinding volume that reduces C layer coal pulverizer after opening D layer coal pulverizer can prevent that the buggy from adding in furnace too much thereby the burning excessively leads to the overheated equipment operation that influences of water-cooling wall, has improved the security of equipment and can practice thrift the buggy cost.

After the lowest C layer and the D layer of boiler fully burn, the temperature that includes water-cooled wall in the boiler improves gradually, and the start-up and the pulverized coal burning of EF, AB layer coal pulverizer have possessed sufficient condition, can easily burn according to the mode on D layer to the generating power of boiler improves gradually.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.