Deep peak regulation device for coal power unit

Abstract

The utility model discloses a deep peak regulation device for a coal power unit, which comprises the coal power unit, a high-pressure bypass and a low-pressure bypass, the coal power unit comprises a boiler, a high-pressure cylinder, an intermediate-pressure cylinder and a low-pressure cylinder, and a superheater outlet of the boiler is connected with a steam inlet of the high-pressure cylinder through a main steam pipeline. The main steam pipeline is communicated with a heat control system, a temperature and pressure reducer system is arranged on the main steam pipeline, a plurality of branch steam pipelines are arranged on the main steam pipeline on one side of the temperature and pressure reducer system, and a first stop valve and a first electric valve are arranged on each branch steam pipeline. The branch steam pipelines are connected with the heat control system, and a plurality of drainage pipelines are arranged on the main steam pipeline on the other side of the temperature and pressure reducer system. According to the utility model, the cost investment is greatly reduced, the main steam heat supply transformation is realized while the deep peak regulation operation transformation of the lowest rated load is realized, and the external heat supply capability is greatly improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the peak shaving technology field of coal power unit especially relates to a device for coal power unit deep peak shaving. BACKGROUND

[0002] It is known that carrying out flexible reconstruction of coal power units is a main measure to improve the regulation capacity of the power system and is one of the key supports to promote large-scale and high-proportion development of new energy. In February 2024, the National Development and Reform Commission and the National Energy Administration issued the relevant "Guiding Opinions on Strengthening the Construction of Grid Peak Shaving, Energy Storage and Intelligent Dispatching Capacity" and proposed to further carry out flexible reconstruction of coal power units. By 2027, the existing coal power units will achieve "reconstruction as much as possible", and in areas with high proportion of new energy and insufficient peak shaving capacity, deep peak shaving of coal power units will be explored under the premise of ensuring safety, with minimum power generation output reaching 30% below the rated load.

[0003] According to statistics, at present, Jiangsu has 125 coal power units with a total installed capacity of 7264 million kilowatts, with an average deep peak shaving capacity of 31.4% and a total deep peak shaving capacity of 1348 million kilowatts, ranking in the forefront of the country. In February 2024, the "Supplementary Technical Specifications for Deep Peak Shaving of Grid Dispatched Power Units in Jiangsu" was released, which clearly defined more detailed requirements for the deep peak shaving capacity of coal-fired units below 30% of the rated load. At the same time, with the formation of the power auxiliary service market, deep peak shaving has formed a compensation price ladder with deeper depth and higher price, so the enthusiasm of power generation enterprises participating in peak shaving has been fully mobilized.

[0004] However, the current implementation of deep peak shaving operation of coal-fired units is mainly through boiler side reconstruction, mainly including full-load denitration reconstruction, combustion system reconstruction, water power system optimization, air preheater anti-blocking reconstruction, and control part optimization, etc. On the one hand, the boiler side reconstruction cost is high, with a reconstruction cost of more than 200 million yuan for a 300 megawatt (MW) level unit, on the other hand, through boiler side reconstruction to achieve 20% or less operation, the boiler combustion is unstable, the operation requirements for the operating personnel are high, and the boiler is also prone to boiler blowout, which causes metal fatigue to the boiler metal equipment, reduces the equipment operation reliability, and reduces the unit operation life, therefore it is necessary to improve the existing technology. UTILITY MODEL CONTENTS

[0005] (I) Technical problems to be solved

[0006] In view of the deficiencies in the prior art, the utility model provides a device for coal power unit deep peak shaving, which is reasonable in design, simple in structure, reduces the cost input, and also realizes main steam heat supply reconstruction while realizing minimum rated load deep peak shaving operation reconstruction, greatly improving the external heat supply capacity.

[0007] (ii) Technical solutions to be taken

[0008] To achieve the above object, the technical scheme adopted by the utility model is:

[0009] A device for deep peak regulation of coal power unit, comprising a coal power unit, a high-pressure bypass and a low-pressure bypass, the coal power unit comprising a boiler, a high-pressure cylinder, a medium-pressure cylinder and a low-pressure cylinder, the outlet of the superheater of the boiler is connected with the steam inlet of the high-pressure cylinder through a main steam pipeline, the outlet of the superheater of the boiler is connected with the steam inlet of the medium-pressure cylinder through a heat re-steam pipeline, the exhaust steam of the medium-pressure cylinder is connected with the steam inlet of the low-pressure cylinder through a medium-low pressure communication pipeline, an adjusting valve is arranged on the medium-low pressure communication pipeline, the main steam pipeline is used for communicating with a heat control system, a desuperheater system is arranged on the main steam pipeline, a plurality of branch steam pipelines are arranged on the main steam pipeline on the side of the desuperheater system, a first stop valve and a first electric valve are arranged on each branch steam pipeline, the branch steam pipelines are connected with the heat control system, and a plurality of bleeder pipelines are arranged on the main steam pipeline on the other side of the desuperheater system.

[0010] Preferably, the number of the branch steam pipelines is three, the heat control system is connected with each branch steam pipeline, the first stop valve and the first electric valve are arranged on each branch steam pipeline, the first electric valve is a P91 valve, and the main steam pipeline and the branch steam pipelines are made of P91 pipe material.

[0011] Preferably, the number of the bleeder pipelines is eight, two second stop valves are arranged on each bleeder pipeline, and the bleeder pipelines are made of 15CrMo pipelines.

[0012] Preferably, a first flow meter, a second check valve, a second electric valve and a sixth stop valve are sequentially arranged on the main steam pipeline on the other side of the desuperheater system.

[0013] Preferably, the desuperheater system comprises a first adjusting valve and a desuperheater arranged on the main steam pipeline, a pipeline is arranged on the desuperheater, a third check valve, a third stop valve, a second adjusting valve, a third electric valve, a second flow meter, a first throttling valve, a filter and a fourth stop valve are sequentially arranged on the pipeline, and a fifth stop valve is connected in parallel with the third stop valve, the second adjusting valve and the third electric valve on the pipeline.

[0014] Preferably, a safety valve is arranged on the desuperheater.

[0015] In addition, the utility model also provides a running method of the device for deep peak regulation of coal power unit.

[0016] S1, the main steam pipeline in the coal-fired unit extracts the main steam, and the main steam pipeline supplies heat to the outside through the desuperheater and pressure reducer system;

[0017] S2, by adjusting the pressure in the desuperheater and pressure reducer system, it is beneficial to realize the minimum rated load deep peak shaving operation modification, and at the same time, the main steam heat supply modification is realized, and the external heat supply capacity is greatly improved.

[0018] (Three) technical effects to be achieved

[0019] Compared with the prior art, the utility model has the beneficial effects that:

[0020] The utility model discloses a desuperheater and pressure reducer system is arranged on the main steam pipeline, and a plurality of branch steam pipelines are arranged on the main steam pipeline on the side of the desuperheater and pressure reducer system, a first stop valve and a first electric valve are arranged on each branch steam pipeline, the branch steam pipeline is connected with a heat control system, a plurality of drainage water pipelines are arranged on the main steam pipeline on the other side of the desuperheater and pressure reducer system, the design is reasonable, the structure is simpler, the cost investment is reduced, and at the same time, the minimum rated load deep peak shaving operation modification is realized, the main steam heat supply modification is realized, and the external heat supply capacity is greatly improved. DRAWINGS

[0021] Figure 1 It is a schematic diagram of the utility model for coal-fired unit deep peak shaving device.

[0022] In the drawing: 1, desuperheater and pressure reducer system;2, first stop valve;3, first electric valve;4, second stop valve;5, first flowmeter;6, second check valve;7, second electric valve;8, sixth stop valve;11, first regulating valve;12, desuperheater;13, third check valve;14, third stop valve;15, second regulating valve;16, third electric valve;17, second flowmeter;18, first throttle valve. Specific implementation

[0023] In the description of the utility model, it should be explained that when an element is called "fixed to" or "arranged on" another element, it can be directly on another element or indirectly on another element. When an element is called "connected to" another element, it can be directly connected to another element or indirectly connected to another element.

[0024] In the description of the utility model, it needs to explain, the term "center", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and so on the direction or position relation indicated is based on the direction or position relation shown in the drawing, or it is the direction or position relation that the utility model product uses usually places, just is for the convenience of describing the utility model and simplifying the description, and is not the indication or the implied device or element that the indicated device or element must have a particular direction, constructs and operates, therefore can not be understood as the limitation to the utility model. In addition, the term "first", "second", "third" and so on are only used to distinguish the description, and can not be understood as the indication or the implied relative importance. Therefore, the feature that is limited to "first", "second" can be explicitly or implicitly include one or more features. In the description of the utility model, the meaning of "a plurality of" is two or two or more, unless otherwise specifically limited. The meaning of "several" is one or more, unless otherwise specifically limited.

[0025] In the description of the utility model, it also needs to explain that, unless otherwise specifically defined and limited, the term "set", "installation", "connection", "connection" should be broad sense, for example, can be fixed connection, can also be detachable connection, or integrally connected, can be mechanical connection, can also be electrical connection, can be directly connected, can also be indirectly connected through the intermediate medium, can be the communication inside two elements. For ordinary skilled in the art, the specific meaning of the above-mentioned terms in the utility model can be understood according to the specific circumstances.

[0026] In order to make the purpose, technical scheme and advantages of the utility model more clear and obvious, the utility model is further described in detail below through the drawings and examples. However, it should be understood that the specific examples described herein are only used to explain the utility model, and are not used to limit the scope of the utility model. In addition, in the following description, the description of the known structure and technology is omitted to avoid unnecessary confusion of the concept of the utility model.

[0027] Example one: refer to Figure 1The utility model relates to a kind of coal power unit depth peak shaving device, including coal power unit, high pressure bypass and low pressure bypass, coal power unit includes boiler, high pressure cylinder, middle pressure cylinder and low pressure cylinder, the superheater outlet (steam chamber in this example) of boiler is connected with the steam inlet of high pressure cylinder by main steam pipeline, the superheater outlet of boiler is connected with the steam inlet of middle pressure cylinder by hot re-steam pipeline, the exhaust of middle pressure cylinder is connected with the steam inlet of low pressure cylinder by middle-low pressure communication pipe, adjusting valve is arranged on middle-low pressure communication pipe, main steam pipeline is used to be connected with heat control system (heat control system is prior art, thus no longer specific), it is beneficial to heat control system to heat supply, main steam pipeline is provided with desuperheater system 1, and a plurality of branch steam pipelines (heat supply pipeline) are arranged on the main steam pipeline on the side of desuperheater system 1, first stop valve 2 and first electric valve 3 are arranged on each branch steam pipeline, branch steam pipeline is connected with heat control system, and a plurality of drain water pipelines are arranged on the main steam pipeline on the other side of desuperheater system 1.

[0028] Example two: can be based on example one, branch steam pipeline adopts three, heat control system is connected to each branch steam pipeline, first stop valve 2 and first electric valve 3 are installed on each branch steam pipeline, and first electric valve 3 adopts P91 valve, and correspondingly, main steam pipeline and branch steam pipeline are also made of P91 pipe material, and the temperature and pressure of this kind are suitable, and it is more suitable for this kind of place.

[0029] Example three: can be based on example one or example two, drain water pipeline (SS, representing drain, the project of the utility model is not limited to the number of drain water pipelines, and the following drain water pipelines can be laid according to the site condition) adopts eight, two second stop valves 4 are arranged on each drain water pipeline, and drain water pipeline adopts 15CrMo pipe, which is heat-resistant pipe, can greatly improve equipment reliability.Further illustrate, first flow meter 5, second check valve 6, second electric valve 7 and sixth stop valve 8 are sequentially arranged on the main steam pipeline on the other side of desuperheater system 1, which is more conducive to convenient control.

[0030] Embodiment four: can be based on the embodiment one or embodiment two or embodiment three, the temperature and pressure reducer system 1 includes the first regulating valve 11 and the desuperheater 12 arranged on the main steam pipeline, the pipeline is arranged with the third check valve 13, the third stop valve 14, the second regulating valve 15, the third electric valve 16, the second flow meter 17, the first throttle valve 18, the filter 19 and the fourth stop valve in sequence, and the fifth stop valve is connected in parallel on the pipeline of the third stop valve 14, the second regulating valve 15 and the third electric valve 16, and the pipeline on the fourth stop valve is pumped by the water pump. Further, the safety valve is arranged on the desuperheater 12, which is reasonable and improves the safety of use. The temperature and pressure reducer system 1 in the utility model cannot meet the demand of the heat user due to the high main steam extraction pressure, so it is necessary to adjust the parameters to the appropriate range through the desuperheater 12. The operating pressure of the desuperheater 12 is 7-10 MPa, the operating temperature is 170 DEG C, the design pressure is 11 MPa, and the design temperature is 180 DEG C.

[0031] Embodiment five: can be based on the embodiment one or embodiment two or embodiment three or embodiment four, a kind of for coal power unit depth peak shaving device operating method applied as above, including the following steps:

[0032] S1, main steam is extracted in coal power unit main steam pipeline, and the main steam pipeline is heated externally after passing through temperature and pressure reducer system 1;

[0033] S2, the pressure in temperature and pressure reducer system 1 is adjusted, which is conducive to realizing the lowest rated load depth peak shaving operation modification, and realizing main steam heating modification, greatly improving the external heating capacity.

[0034] The lowest operation condition of the boiler in the prior art is 30% of the rated condition, and the boiler load is greater than 30% of the rated load during deep regulation operation, and the main steam pipeline of the utility model is provided with multiple branch steam pipelines (heat supply pipelines), heat supply is realized through main steam, heat and electricity are decoupled, when the boiler operates under the condition of 30% of the rated load, main steam is extracted for external heat supply, the steam amount entering the steam turbine is reduced, and the generator output is reduced, so that 18% deep peak regulation operation is realized. The key to realizing 20% deep peak regulation operation of the coal-fired unit lies in the stability of the boiler combustion during deep regulation, and the initial design of the general coal-fired unit is that the lowest load for stable operation is 30% of the rated load, the lowest technical output of the boiler is ensured, that is, 30% of the rated load, the steam amount entering the steam turbine is reduced, and the steam turbine output is reduced, so that 20% deep peak regulation operation is realized, and when the unit operates below 20% of the rated load, the unit has a large flow external heat supply capacity, for example, when the 330MW unit boiler operates at 30% of the rated load, the corresponding load is 99MW, when the 300MW unit operates at 30% of the rated load, 10MW of load is corresponding to 30t / h of main steam, in order to realize 20% of the rated load (that is, 66MW), at least 99t / h of main steam needs to be extracted, and finally, 120t / h of main steam is extracted from the main steam pipeline for external heat supply, so that 18% of the rated load deep peak regulation operation is realized, and the unit main steam external heat supply modification is realized. It can be seen that the modification cost is reduced by about 80% compared with the conventional technical route, the modification cost is greatly saved, the workload of modification is small, and the modification equipment is less. Secondly, the boiler can operate above 30% of the rated load, the operation pressure of the operator is reduced, and the influence on the service life of the equipment is also reduced.

[0035] The utility model can have multiple main steam pipelines, when all the main steam pipelines are put into the heat supply pipeline, the operating pressure is 9-10MPa, the operating temperature is 530-538 DEG C, the design pressure of the main steam pipeline is 17.47MPa, and the design temperature is 546 DEG C, one of the main steam pipelines is reduced in temperature and pressure, and the operating pressure of the heat supply pipeline is 2.5MPa, the operating temperature is 390 DEG C, the design pressure is 2.65MPa, and the design temperature is 410 DEG C. The utility model can realize that the boiler meets the lowest design output, realizes main steam external heat supply and 18% rated load deep peak regulation operation.

[0036] The standard parts used in the application file can be purchased in the market, the specific connection mode of each part adopts the conventional means of the existing technology, such as the boiler, the high-pressure cylinder, the medium-pressure cylinder and the low-pressure cylinder, the internal components of the desuperheater adopt the conventional type of the existing technology, and the internal structure belongs to the existing technology structure, workers can complete normal operation according to the existing technology manual, and the circuit connection adopts the conventional connection mode of the existing technology, so specific description is not made here.

[0037] It should be noted that although the above embodiments have been described herein, the patent protection scope of the utility model is not limited thereby. Therefore, based on the innovative concept of the utility model, the changes and modifications of the embodiments described herein, or the equivalent structures or equivalent process transformations made by using the contents of the utility model specification and drawings, directly or indirectly apply the above technical solutions to other related technical fields, are all included in the protection scope of the utility model patent.

Claims

1. A deep peak-shaving device for a coal-fired power unit, comprising a coal-fired power unit, a high-pressure bypass, and a low-pressure bypass. The coal-fired power unit includes a boiler, a high-pressure cylinder, an intermediate-pressure cylinder, and a low-pressure cylinder. The superheater outlet of the boiler is connected to the steam inlet of the high-pressure cylinder via a main steam pipeline. The superheater outlet of the boiler is connected to the steam inlet of the intermediate-pressure cylinder via a hot reheat steam pipeline. The exhaust steam of the intermediate-pressure cylinder is connected to the steam inlet of the low-pressure cylinder via a medium-low pressure connecting pipe. A regulating valve is installed on the medium-low pressure connecting pipe. The main steam pipeline is used to connect to a thermal control system. The device is characterized in that: The main steam pipeline is provided with a desuperheater system (1), and a plurality of branch steam pipelines are arranged on the main steam pipeline at one side of the desuperheater system (1), each of the branch steam pipelines is provided with a first stop valve (2) and a first electric valve (3), the branch steam pipelines are connected with the heat control system, and a plurality of blowdown water pipelines are arranged on the main steam pipeline at the other side of the desuperheater system (1).

2. The apparatus for deep load following of a coal-fired power plant of claim 1, wherein: The branch steam pipelines are three, each of the branch steam pipelines is connected with the heat control system, each of the branch steam pipelines is provided with the first stop valve (2) and the first electric valve (3), the first electric valve (3) is a P91 valve, and the main steam pipeline and the branch steam pipelines are made of P91 pipe materials.

3. The device for deep load modulation of coal-fired power units according to claim 1 or 2, characterized in that: The blowdown water pipelines are eight, each of the blowdown water pipelines is provided with two second stop valves (4), and the blowdown water pipelines are made of 15CrMo pipelines.

4. The apparatus for deep load following of a coal-fired power plant of claim 3, wherein: The main steam pipeline at the other side of the desuperheater system (1) is sequentially provided with a first flow meter (5), a second check valve (6), a second electric valve (7) and a sixth stop valve (8).

5. The device for deep load modulation of coal power units according to claim 1 or 2 or 4, characterized in that: The desuperheater system (1) comprises a first regulating valve (11) and a desuperheater (12) arranged on the main steam pipeline, the desuperheater (12) is provided with a pipeline, the pipeline is sequentially provided with a third check valve (13), a third stop valve (14), a second regulating valve (15), a third electric valve (16), a second flow meter (17), a first throttle valve (18), a filter (19) and a fourth stop valve, and a fifth stop valve is connected in parallel to the pipeline of the third stop valve (14), the second regulating valve (15) and the third electric valve (16).

6. The apparatus for deep load modulation of a coal-fired power unit of claim 5, wherein: The desuperheater (12) is provided with a safety valve.

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