Coal power unit peak regulation system capable of rapidly increasing load in short time

Abstract

The utility model relates to the technical field of flexible adjustment of coal power units, in particular to a coal power unit peak shaving system capable of rapidly increasing load in a short time. Comprising a bypass flue and a high-pressure heater bypass pipeline, the vertical shaft flue is connected with the bypass flue in parallel; the original boiler shaft flue comprises an economizer, and the newly-added bypass flue comprises a gas combustion system installed on the top and a bypass heat exchanger installed on the lower portion. The bypass heat exchanger is serially connected with the water side of the original boiler economizer through a pipeline; the fuel gas combustion system comprises a fuel gas pipeline, fuel gas combustor combustion-supporting air and cooling flue gas, and the cooling flue gas is communicated with the upper part of a boiler shaft flue through a flue; the high-pressure heater system and the high-pressure heater bypass pipeline are connected in parallel, and flow regulating valves are arranged on the two paths. Through a bypass high-pressure heater coupling external heat source heating water supply mode, the unit rapidly and stably raises the load in a short time, and the peak regulation requirement of a power grid is met.

Description

Technical Field

[0001] The utility model relates to the technical field of flexible peak regulation of coal-fired power generation units, in particular to a peak regulation system of coal-fired power generation units capable of quickly increasing load in a short time. Background Art

[0002] Under the current dual-carbon policy background, the traditional power system is gradually shifting to a "new power system" with new energy as the main body, aiming to achieve carbon peak and carbon neutrality goals and meet the power needs of economic and social development. However, due to the increasing proportion of power sources lacking regulation capabilities of new energy, the flexibility resources of the power grid are in short supply. For quite a long time, coal-fired power is the only flexible resource with large-scale economic deep peak regulation capabilities, that is, it is a major demand to significantly improve the adaptability of coal-fired power units.

[0003] However, traditional coal-fired power units lack flexible peak-shaving capabilities and cannot meet the peak-shaving needs of coal-fired power units for rapid load increases under the current situation. Utility Model Content

[0004] In view of the problem that the existing coal-fired power units have insufficient flexible peak-shaving capacity, the utility model proposes a coal-fired power unit peak-shaving system with short-term rapid load increase, comprising a bypass flue and a high-pressure heater bypass pipeline; a bypass flue is newly added to the boiler shaft flue, a gas burner is arranged at the top of the bypass flue, a bypass heat exchanger is arranged at the bottom, combustion-supporting air and cooling flue gas of the gas burner are received by the gas burner, and a third flow regulating valve is arranged at the input end of the high-pressure heater bypass pipeline, and a third stop valve is arranged at the output end, so as to ensure that the total flow of the two routes is basically consistent during operation, and by adopting a coupling external heat source method, the problem of insufficient subsequent heat on the steam side of the system after the bypass high-pressure heater increases the load is effectively solved, and the load increase lasts longer and is more stable.

[0005] The specific implementation contents of the utility model are as follows:

[0006] A peak-shaving system for coal-fired power units with short-term rapid load increase, comprising a bypass flue and a high-pressure heater bypass pipeline;

[0007] The bypass flue is connected in parallel with the vertical shaft flue at the rear of the boiler;

[0008] A gas burner is provided at the top of the bypass flue, and a bypass heat exchanger is provided at the bottom of the bypass flue;

[0009] A gas pipeline is arranged above the gas burner; the gas pipeline is used to receive combustion-supporting air and cooling flue gas from the gas burner;

[0010] The high pressure heater bypass pipeline is connected in parallel with the high pressure heater system;

[0011] The input end of the high-pressure heater bypass pipeline is provided with a third flow regulating valve, and the output end of the high-pressure heater bypass pipeline is provided with a third stop valve.

[0012] In order to better realize the utility model, further, the bypass flue includes an upper flue, a flue joint, and a lower flue;

[0013] The upper flue is a circular flue, and the gas burner is vertically arranged in the upper flue;

[0014] The lower flue is a rectangular flue, and the bypass heat exchanger is arranged in the lower flue;

[0015] The upper flue is connected with the lower flue through a flue joint.

[0016] In order to better realize the utility model, further, a cooling flue is provided on the side of the upper flue, and is connected to the upper part of the vertical shaft flue at the rear of the boiler through the cooling flue.

[0017] In order to better realize the utility model, further, a cooling flue flow regulating baffle is provided in the cooling flue.

[0018] In order to better implement the utility model, further, a fourth flow regulating valve is provided at the input end of the gas pipeline;

[0019] A combustion-supporting air regulating baffle for a gas burner is arranged in the gas pipeline; the combustion-supporting air regulating baffle for the gas burner is used for regulating the volume of the combustion-supporting air.

[0020] In order to better realize the utility model, further, an economizer is arranged in the vertical shaft flue at the tail of the boiler;

[0021] The economizer and the bypass heat exchanger are operated in series;

[0022] A first flow regulating valve is provided at the input end of the water supply pipe of the economizer;

[0023] The first flow regulating valve is connected in parallel with the bypass heat exchanger;

[0024] The input end of the bypass heat exchanger is provided with a second flow regulating valve and a first stop valve, and the output end of the bypass heat exchanger is provided with a second stop valve.

[0025] In order to better realize the utility model, further, a smoke mixer is provided at the output end of the bypass pipe;

[0026] The output end of the bypass pipe is connected to the boiler tail shaft flue through the flue gas mixer.

[0027] In order to better implement the utility model, further, a water supply pump is provided at the input end of the high-pressure heating system, and the water supply pump is connected to the input end of the bypass pipeline;

[0028] The high pressure heating system is provided with a flow control valve.

[0029] The specific implementation contents of the utility model are as follows:

[0030] The utility model adopts a coupling external heat source method, which effectively solves the problem of insufficient subsequent heat on the steam side of the system after the bypass high-pressure heater increases the load. The load increase lasts longer and is more stable. Compared with the traditional energy storage peak-shaving method using heat storage tanks to store energy, it has the characteristics of simple system, simple control method and lower cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the boiler side bypass flue structure provided by the utility model.

[0032] Figure 2 This is a schematic diagram of the structure provided by the utility model connected to the high-pressure heating system.

[0033] Among them, 1. economizer, 2. bypass heat exchanger, 3. first flow regulating valve, 4. second flow regulating valve, 5. first stop valve, 6. bypass heat exchanger inlet pipe, 7. bypass heat exchanger outlet pipe, 8. second stop valve, 9. high pressure heating system, 10. flow control valve, 11. third flow regulating valve, 12. third stop valve, 13. high pressure heating bypass pipe, 14 feed water pump, 15. bypass flue, 16. flue joint, 17. gas burner, 18. cooling flue, 19. cooling flue flow regulating baffle, 20. gas pipeline, 21. fourth flow regulating valve, 22. gas burner combustion-supporting air, 23. gas burner combustion-supporting air regulating baffle, 24. boiler economizer outlet flue, 25. boiler tail shaft flue. DETAILED DESCRIPTION

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. It should be understood that the described embodiments are only part of the embodiments of the utility model, not all of the embodiments, and therefore should not be regarded as limiting the scope of protection. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technical personnel in this field without creative work are within the scope of protection of the utility model.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] Embodiment 1:

[0037] This embodiment proposes a coal-fired power unit peak load regulation system with short-term rapid load increase, such as Figure 1 As shown, it includes a bypass flue 15 and a high pressure heater bypass pipe 13;

[0038] The bypass flue 15 is connected in parallel with the boiler tail shaft flue 25;

[0039] A gas burner 17 is disposed at the top of the bypass flue 15, and a bypass heat exchanger 2 is disposed at the bottom of the bypass flue 15;

[0040] A gas pipeline 20 is arranged above the gas burner 17; the gas pipeline 20 is used to receive combustion-supporting air and cooling flue gas from the gas burner;

[0041] The high pressure heater bypass pipeline 13 is connected in parallel with the high pressure heater system 9;

[0042] A third flow regulating valve 11 is provided at the input end of the high-pressure heater bypass pipeline 13 , and a third stop valve 12 is provided at the output end of the high-pressure heater bypass pipeline 13 .

[0043] Working principle: The coal-fired power unit peak-shaving system with short-term rapid load increase proposed in this embodiment includes a boiler shaft flue 25, a newly added bypass flue 15, a steam turbine high-pressure heating system 9, and a newly added high-pressure heating bypass pipeline 13; the boiler shaft flue 25 and the bypass flue 15 are connected in parallel in the flue gas flow; the boiler shaft flue 25 includes an economizer 1, and the newly added bypass flue 15 includes a gas combustion system 17 installed on the top thereof, and a bypass heat exchanger 2 installed at the bottom; when the first flow regulating valve 3 of the inlet pipeline of the economizer 1 is closed, the bypass heat exchanger 2 is connected in series with the water side of the economizer 1 through a pipeline; the gas burner 17 includes a gas pipeline 20, a gas burner combustion-supporting air 22 and cooling flue gas, and the cooling flue gas is connected to the upper part of the boiler shaft flue 25 through the flue 18; the high-pressure heating system 9 is connected in parallel with the high-pressure heating bypass pipeline 13, and both routes are provided with flow regulating valves, and the high-pressure heating bypass pipeline 13 is provided with a third stop valve 12.

[0044] In this embodiment, a bypass flue 15 is newly added to the boiler shaft flue 25, and a gas burner 17 is arranged on the top of the bypass flue 15, and a bypass heat exchanger 2 is arranged at the bottom. The gas burner 17 receives the gas burner combustion air 22 and the cooling flue gas, and combines the third flow regulating valve 11 arranged at the input end of the high-pressure bypass pipe 13 and the third stop valve 12 arranged at the output end to ensure that the total flow of the two routes is basically consistent during operation. By adopting the method of coupling external heat source, the problem of insufficient subsequent heat on the steam side of the system after the high-pressure heating system 9 increases the load is effectively solved, and the load increase lasts longer and is more stable.

[0045] Embodiment 2:

[0046] This embodiment is based on the above embodiment 1. Figure 2 The specific structure of the bypass flue 15 is illustrated in FIG.

[0047] The bypass flue 15 includes an upper flue, a flue joint 16, and a lower flue;

[0048] The upper flue is a circular flue, and the gas burner 17 is vertically arranged in the upper flue;

[0049] The lower flue is a rectangular flue, and the bypass heat exchanger 2 is arranged in the lower flue;

[0050] The upper flue is connected to the lower flue through a flue joint 16 .

[0051] Working principle: In this embodiment, the gas burner 17 on the bypass flue 15 is installed vertically downward, and the distance between the gas burner 17 and the heat exchanger 2 is sufficiently reserved. The distance selection takes into account the expansion of the combustion torch and the sufficient mixing of the combustion products and the cooling flue gas; the cooling flue gas process annularly wraps the combustion product of the gas burner 17, that is, the high-temperature flue gas, and the two are fully mixed with the flow, and after the temperature is evenly mixed, they countercurrently exchange heat with the bypass heat exchanger 2; the upper part of the bypass flue 15 is a circular flue, and the lower part is a rectangular flue, and the upper joint and the lower joint are connected by a flue joint 16 that changes from round to square.

[0052] The other parts of this embodiment are the same as those of the above-mentioned embodiment 1, and thus will not be described in detail.

[0053] Embodiment 3:

[0054] This embodiment is based on any one of the above embodiments 1 to 2. Figure 1 , Figure 2 As shown, a cooling flue 18 is provided on the side of the upper flue, and is connected to the upper part of the boiler tail shaft flue 25 through the cooling flue 18.

[0055] Furthermore, a cooling flue flow regulating baffle 19 is provided in the cooling flue 18 .

[0056] A fourth flow regulating valve 21 is provided at the input end of the gas pipeline 20;

[0057] A gas burner combustion-supporting air regulating baffle 23 is disposed in the gas pipeline 20; the gas burner combustion-supporting air regulating baffle 23 is used to adjust the combustion-supporting air volume.

[0058] Working principle: In this embodiment, the vertical shaft flue 25 at the rear of the boiler and the bypass flue 15 are connected through the cooling flue 18. The cooling flue 18 is provided with a cooling flue flow regulating damper 19. The damper opening of the cooling flue flow regulating damper 19 is controlled according to the output of the gas burner 17. The output of the gas burner 17 is regulated by the fourth flow regulating valve 21 provided on the gas pipeline, and the air used for gas combustion is provided by the gas burner combustion air 22. The combustion air volume is controlled by the gas burner combustion air regulating damper 23 on its air duct.

[0059] The other parts of this embodiment are the same as any one of the above-mentioned embodiments 1-2, so they will not be repeated here.

[0060] Embodiment 4:

[0061] This embodiment is based on any one of the above embodiments 1 to 3. Figure 1 , Figure 2 As shown, an economizer 1 is provided in the vertical flue 25 at the tail end of the boiler;

[0062] The economizer 1 and the bypass heat exchanger 2 are operated in series;

[0063] A first flow regulating valve 3 is provided at the input end of the water supply pipe of the economizer 1;

[0064] The first flow regulating valve 3 is connected in parallel with the bypass heat exchanger 2;

[0065] The input end of the bypass heat exchanger 2 is provided with a second flow regulating valve 4 and a first stop valve 5 , and the output end of the bypass heat exchanger 2 is provided with a second stop valve 8 .

[0066] Furthermore, a flue gas mixer is provided at the output end of the bypass pipe 15;

[0067] The output end of the bypass pipe is connected to the boiler tail shaft flue 25 through the flue gas mixer.

[0068] Working principle: A first flow regulating valve 3 is provided on the water supply pipe at the inlet of the economizer 1. The first flow regulating valve 3 and the newly added bypass heat exchanger 2 are connected in parallel. When the first flow regulating valve 3 is closed, the newly added bypass heat exchanger 2 and the economizer 1 operate in series, that is, the water supply from the steam turbine high-pressure heating system 9 is first heated by the bypass heat exchanger 2, and then enters the economizer 1 to continue heating; the first stop valve 5 and the second stop valve 8 are provided before and after the bypass heat exchanger 2, and the system can be isolated under special circumstances.

[0069] The other parts of this embodiment are the same as any one of the above-mentioned embodiments 1 to 3, so they will not be repeated here.

[0070] Embodiment 5:

[0071] This embodiment is based on any one of the above embodiments 1 to 4. Figure 1 , Figure 2 As shown, the working principle of peak regulation is described in detail with a specific embodiment.

[0072] When the unit needs to increase the load quickly, the flow control valve 10 of the feed water before the high-pressure heater is gradually closed, and the third flow regulating valve 11 is gradually opened, and the total flow of the two routes is kept basically the same during the operation. Due to the bypass high-pressure heater system 9, the extraction steam volume of the high-pressure heater is gradually reduced, and the exhausted extraction steam continues to work in the turbine, which increases the power generation load of the unit in a short time and meets the rapid demand of the power grid for power load.

[0073] After bypassing the high-pressure heater, the feed water temperature drops, and the dropped water temperature is heated by the bypass heat exchanger 2 in the bypass flue 15. The heat absorbed by the bypass heat exchanger 2 comes from the operation of the gas burner 17. The operating output of the gas burner 17 is coordinated with the bypass high-pressure heater 9. The control target is to keep the inlet water temperature of the economizer 1 constant or increase the outlet water temperature of the economizer 1. The increase in water temperature is restricted by the temperature difference between the outlet water temperature of the economizer 1 and the saturated water, that is, to meet the safety of the heating surface of the economizer 1. After the peak-shaving cycle ends, the bypass flue 15 and the high-pressure heater bypass gradually exit operation, waiting for the next load increase peak-shaving.

[0074] In this embodiment, all parts in contact with the environment except the original coal-fired power unit equipment are reasonably insulated, and the insulation surface temperature meets the requirements of the specifications.

[0075] The bypass heat exchanger 2 on the bypass flue 15 of this embodiment preferably adopts a serpentine tube bundle, and the medium in the tube and the flue gas exchange heat in countercurrent, that is, the flue gas flows from top to bottom and the water flows from bottom to top, wherein the bypass heat exchanger 2 is an air-water heat exchanger.

[0076] The other parts of this embodiment are the same as any one of the above-mentioned embodiments 1 to 4, so they are not repeated here.

[0077] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A coal-fired power unit peak load regulation system with short-term rapid load increase, characterized in that: It includes a bypass flue (15) and a high pressure heater bypass pipe (13); The bypass flue (15) is connected in parallel with the boiler tail shaft flue (25); A gas burner (17) is arranged at the top of the bypass flue (15), and a bypass heat exchanger (2) is arranged at the bottom of the bypass flue (15); A gas pipeline (20) is arranged above the gas burner (17); the gas pipeline (20) is used to receive combustion-supporting air from the gas burner and cool flue gas; The high pressure heater bypass pipeline (13) is connected in parallel with the high pressure heater system (9); The input end of the high-pressure heater bypass pipeline (13) is provided with a third flow regulating valve (11), and the output end of the high-pressure heater bypass pipeline (13) is provided with a third stop valve (12).

2. A coal-fired power generation unit peak load regulation system with short-term rapid load increase according to claim 1, characterized in that: The bypass flue (15) comprises an upper flue, a flue joint (16), and a lower flue; The upper flue is a circular flue, and the gas burner (17) is vertically arranged in the upper flue; The lower flue is a rectangular flue, and the bypass heat exchanger (2) is arranged in the lower flue; The upper flue is connected to the lower flue via a flue joint (16).

3. A coal-fired power generation unit peak load regulation system with short-term rapid load increase according to claim 2, characterized in that: A cooling flue (18) is provided on the side of the upper flue, and is connected to the upper part of the vertical shaft flue (25) at the rear of the boiler via the cooling flue (18).

4. A coal-fired power generation unit peak load regulation system with short-term rapid load increase according to claim 3, characterized in that: A cooling flue flow regulating baffle (19) is arranged in the cooling flue (18).

5. A coal-fired power generation unit peak load regulation system with short-term rapid load increase according to claim 1, characterized in that: A fourth flow regulating valve (21) is provided at the input end of the gas pipeline (20); A gas burner combustion-supporting air regulating baffle (23) is arranged in the gas pipeline (20); the gas burner combustion-supporting air regulating baffle (23) is used to regulate the volume of the combustion-supporting air.

6. A coal-fired power generation unit peak load regulation system with short-term rapid load increase according to claim 1, characterized in that: An economizer (1) is arranged in the vertical flue (25) at the rear of the boiler; The economizer (1) and the bypass heat exchanger (2) are operated in series; A first flow regulating valve (3) is provided at the input end of the water supply pipe of the economizer (1); The first flow regulating valve (3) is connected in parallel with the bypass heat exchanger (2); The input end of the bypass heat exchanger (2) is provided with a second flow regulating valve (4) and a first stop valve (5), and the output end of the bypass heat exchanger (2) is provided with a second stop valve (8).

7. A coal-fired power generation unit peak load regulation system with short-term rapid load increase according to claim 1, characterized in that: A flue gas mixer is provided at the output end of the bypass flue (15); The output end of the bypass flue (15) is connected to the boiler tail shaft flue (25) via the flue gas mixer.

8. A coal-fired power generation unit peak load regulation system with short-term rapid load increase according to claim 1, characterized in that: A water supply pump (14) is provided at the input end of the high-pressure heating system (9), and the water supply pump (14) is connected to the input end of the bypass pipeline (13); The high pressure heating system (9) is provided with a flow control valve (10).

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