Flue capacity increasing structure

Abstract

The utility model discloses a flue capacity increasing structure which comprises a boiler, a desulfurization device, a chimney and at least two air inducing pipelines connected between the boiler and the desulfurization device in parallel, a flue gas treatment device and a first fan are sequentially arranged on each air inducing pipeline in the flue gas flow direction, and the air inducing pipelines connected in parallel are connected through a communicating pipeline. The flow converging device is arranged between the air inducing pipeline and the desulfurization device, the inlet end of the flow converging device is connected with the outlet end of the air inducing pipeline, and the outlet end of the flow converging device is connected with the desulfurization device through a flow converging pipeline; the inlet end of the pressurizing pipeline is connected with the communicating pipeline, and the outlet end of the pressurizing pipeline is connected with the inlet end of the junction station; and the second fan is arranged on the pressurizing pipeline, and the air pressure of the second fan is larger than that of the first fan. The capacity increasing structure for the flue can resist a certain degree of blockage of the flue, reduce abnormal shutdown of a generator set and guarantee smooth power generation.

Description

Technical Field

[0001] The utility model relates to the technical field of power generation equipment, in particular to a flue capacity increasing structure. Background Art

[0002] Coal-fired power generation units use the heat generated by burning coal to heat the water in the boiler, generating a large amount of steam to drive the turbine to rotate, thereby converting thermal energy into mechanical energy. The turbine drives the generator to rotate, and then converts the mechanical energy into electrical energy.

[0003] Coal produces a variety of pollutants during the combustion process. Therefore, it is necessary to install dust removal, desulfurization, denitrification and other devices in the flue for exhaust gas. However, these settings increase the flow of the flue, and the flue and its environmental protection devices are prone to dust accumulation and blockage, making the supporting fans unable to meet the maximum load requirements, and even the maintenance cycle is not reached. The main bearing components of the induced draft fan are worn due to long-term high-load operation, resulting in a shortened maintenance cycle and temporary maintenance, which affects normal power generation. Utility Model Content

[0004] Based on the above problems, the purpose of this utility model is to provide a flue capacity expansion structure, which can reduce flue blockage and ensure normal power generation.

[0005] In order to solve the problems in the prior art, the technical solution provided by the present invention is:

[0006] A flue capacity expansion structure includes a boiler, a desulfurization device, a chimney, and at least two induced draft ducts connected in parallel between the boiler and the desulfurization device, wherein a flue gas treatment device and a first fan are sequentially provided on the induced draft ducts along the direction of flue gas flow, and the parallel induced draft ducts are connected via a connecting duct, and further includes:

[0007] a flow combiner disposed between the induced air duct and the desulfurization device, wherein the inlet end of the flow combiner is connected to the outlet end of the induced air duct, and the outlet end of the flow combiner is connected to the desulfurization device via the flow combiner duct;

[0008] A boosting pipe, wherein the inlet end of the boosting pipe is connected to the communicating pipe and the outlet end of the boosting pipe is connected to the inlet end of the manifold;

[0009] The second fan is arranged on the boosting pipe, and the wind pressure of the second fan is greater than that of the first fan.

[0010] In one embodiment, the confluence includes a first joint connected to the induced draft duct, a second joint connected to the boost duct, and a third joint connected to the confluence duct, the first joint and the second joint are interconnected with the third joint, the second joint is arranged opposite to the third joint and extends into the third joint to form a nozzle, and the first joint is arranged on the side of the second joint.

[0011] In one embodiment, the inner diameter of the inlet end of the second joint is larger than the inner diameter of the outlet end.

[0012] In one embodiment, the outer wall of the second joint transitions from the inlet end to the outlet end in an arc shape.

[0013] In one embodiment, the inner diameter of the first joint is smaller than that of the third joint, and the inner diameter of the second joint is smaller than that of the first joint.

[0014] In one embodiment, the flue gas treatment device includes a denitrification reactor, an air preheater and a dust collector assembly which are sequentially arranged on the induced draft duct along the flue gas flow direction.

[0015] In one embodiment, the dust collector assembly includes a first dust collector and two first heat exchangers connected to an inlet end of the first dust collector.

[0016] In one embodiment, the desulfurization device includes a desulfurization absorption tower, a second dust collector and a second heat exchanger which are sequentially arranged along the flow direction of the flue gas.

[0017] In one embodiment, the second heat exchanger is connected to the first heat exchanger via a circulation pipe.

[0018] Compared with the prior art, the advantages of the present invention are:

[0019] 1. By adding a booster pipe and a second fan, when the unit load is greater than 80% of the maximum load, the second fan can be added and run in parallel to ensure the flue flow. Through the guidance cooperation of the second fan and the combiner, the flue resistance is reduced, and the smooth confluence of the three flue gases can be achieved, reducing the dynamic pressure loss caused by the impact, avoiding the wind rush caused by the imbalance of the fan output, and avoiding the resulting shutdown accidents.

[0020] 2. The structure of the combiner allows the high-pressure flue gas at the outlet of the second fan to flow into the combiner, generating high dynamic pressure, which entrains the low-pressure flue gas at the outlet of the first fan on the induced draft duct, increasing its outlet dynamic pressure. After diffusion, the overall static pressure is increased, reducing the static pressure at the combiner inlet and increasing the total pressure at the booster combiner outlet. This increases the operating differential pressure before and after the fan and reduces the operating differential pressure in the device behind the fan, ensuring the normal output operation of the generator set. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. The drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 This is a structural schematic diagram of an embodiment of a flue capacity expansion structure of the utility model;

[0023] Figure 2 This is a structural diagram of a flow combiner in an embodiment of the present utility model;

[0024] in:

[0025] 1. Boiler; 2. Denitrification reactor; 3. Air preheater; 4. First heat exchanger; 5. First dust collector; 6. Induced draft duct; 7. First fan; 8. Connecting duct; 9. Booster duct; 10. Second fan; 11. Combiner; 11-1. First joint; 11-2. Second joint; 11-3. Third joint; 12. Combiner duct; 13. Desulfurization absorption tower; 14. Second dust collector; 15. Second heat exchanger; 16. Chimney; 17. Circulation duct. DETAILED DESCRIPTION

[0026] The above scheme is further described below with reference to specific examples. It should be understood that these examples are intended to illustrate the present invention and are not intended to limit the scope of the present invention. The implementation conditions used in the examples can be further adjusted according to the conditions of the specific manufacturer. The implementation conditions not specified are generally those used in routine experiments.

[0027] See also Figure 1 , which is a structural schematic diagram of an embodiment of the utility model, provides a flue capacity expansion structure, including a boiler 1, a desulfurization device, a chimney 16 and two induced draft ducts 6 connected in parallel between the boiler 1 and the desulfurization device. A flue gas treatment device and a first fan 7 are sequentially provided on the induced draft ducts 6 along the flue gas flow direction. The parallel induced draft ducts 6 are connected by a connecting pipe 8. Since dust easily accumulates in the flue gas flue, resulting in blockage, the maintenance cycle is short, which affects the normal power generation of the generator set.

[0028] To reduce flue clogging and ensure normal power generation, the flue structure was improved by adding a flow combiner 11, a booster duct 9, and a second fan 10. The flow combiner 11 is located between the induced draft duct 6 and the desulfurization device. The inlet of the flow combiner 11 is connected to the outlet of the induced draft duct 6, and the outlet of the flow combiner 11 is connected to the desulfurization device. The inlet of the booster duct 9 is connected to the connecting duct 8, and the outlet of the flow combiner 11 is connected to the inlet of the flow combiner 11. The second fan 10 is located on the booster duct 9, and its wind pressure is greater than that of the first fan 7.

[0029] The existing first fan 7 is a HA46048-2F single-stage axial-flow induced draft fan with adjustable stator blades, manufactured by China Power Engineering Group Turbine Technology Co., Ltd. It operates with a small steam turbine for speed regulation. The second fan 10 is an electric high-pressure induced draft fan, utilizing a multi-stage axial-flow compressor. When the generator set load is less than 80% of the maximum load, the second fan 10 can be deactivated. When the generator set load exceeds 80% of the maximum load, the second fan 10 can be activated. This ensures flow in the flue gas duct, reduces flue gas obstruction, and ensures normal power generation.

[0030] like Figure 2 As shown, the confluence 11 includes a first joint 11-1 connected to the induced draft duct 6, a second joint 11-2 connected to the boost duct 9, and a third joint 11-3 connected to the confluence duct 12. The first joint 11-1 and the second joint 11-2 are interconnected with the third joint 11-3. The second joint 11-2 and the third joint 11-3 are arranged opposite to each other and extend into the third joint 11-3 to form a nozzle. The two first joints 11-1 are arranged on the side of the second joint 11-2.

[0031] Among them, the inner diameter of the first joint 11-1 is smaller than that of the third joint 11-3, and the inner diameter of the second joint 11-2 is smaller than that of the first joint 11-1. The inner diameter of the inlet end of the second joint 11-2 is larger than the inner diameter of the outlet end. In this way, the second joint 11-2 can form a high-speed airflow at the outlet end of the confluence 11, and at the same time the static pressure drops, thereby increasing the flow rate of the flue gas entering the confluence 11 from the induced draft duct 6, and reducing the lift burden of the first fan 7. When the high-pressure flue gas at the outlet of the second fan 10 flows into the confluence 11, it can generate high dynamic pressure, suck the low-pressure flue gas at the outlet of the first fan 7, increase its outlet dynamic pressure, and increase the overall static pressure after diffusion, thereby reducing the static pressure at the inlet of the confluence 11 and increasing the total pressure at the outlet of the confluence 11. It can also realize the confluence of the three flue gases, reduce the dynamic pressure loss caused by the impact, avoid the wind rush caused by the imbalance of the fan output, and avoid the resulting shutdown accidents.

[0032] In order to further optimize the implementation effect of the present invention, the outer wall of the second joint 11-2 transitions from the inlet end to the outlet end in an arc surface. In this way, when the low-pressure flue gas in the induced draft duct 6 merges with the high-pressure flue gas entering the booster duct 9, the pressure loss of the low-pressure flue gas can be reduced.

[0033] In this example, the flue gas treatment device includes a denitrification reactor 2, an air preheater 3 and a dust collector assembly, which are arranged in sequence on the induced draft duct 6 along the flue gas flow direction, wherein the dust collector assembly includes a first dust collector 5 and two first heat exchangers 4 connected to the inlet end of the first dust collector 5, and the flue gas temperature is reduced by the first heat exchanger 4.

[0034] The desulfurization device includes a desulfurization absorption tower 13, a second dust collector 14, and a second heat exchanger 15, arranged sequentially along the flue gas flow path. The second heat exchanger 15 heats the flue gas, increasing its lift height and diffusion rate. The second heat exchanger 15 is connected to the first heat exchanger 4 via a circulation pipe 17. This circulation pipe 17 circulates the heat medium from the first heat exchanger 4 to the second heat exchanger 15, heating the flue gas and increasing its lift and diffusion rate, saving energy.

[0035] In summary, the flue capacity expansion structure can ensure flue flow, reduce flue resistance, reduce flue blockage, extend flue maintenance cycle, reduce abnormal shutdown of units, and ensure smooth power generation.

[0036] The above examples are intended only to illustrate the technical concepts and features of this utility model. Their purpose is to enable those familiar with the art to understand the content of this utility model and implement it accordingly. They are not intended to limit the scope of protection of this utility model. Any equivalent changes or modifications based on the spirit of this utility model shall be included in the scope of protection of this utility model.

Claims

1. A flue capacity expansion structure, comprising a boiler, a desulfurization device, a chimney, and at least two induced draft ducts connected in parallel between the boiler and the desulfurization device, wherein a flue gas treatment device and a first fan are sequentially provided on the induced draft ducts along the direction of flue gas flow, and the parallel induced draft ducts are connected via a connecting duct, characterized in that: Also includes: a flow combiner disposed between the induced air duct and the desulfurization device, wherein the inlet end of the flow combiner is connected to the outlet end of the induced air duct, and the outlet end of the flow combiner is connected to the desulfurization device via the flow combiner duct; A boosting pipe, wherein the inlet end of the boosting pipe is connected to the communicating pipe and the outlet end of the boosting pipe is connected to the inlet end of the manifold; The second fan is arranged on the boosting pipe, and the wind pressure of the second fan is greater than that of the first fan.

2. The flue capacity expansion structure according to claim 1, characterized in that: The confluence includes a first joint connected to the air induced duct, a second joint connected to the boost duct, and a third joint connected to the confluence duct. The first joint and the second joint are both interconnected with the third joint. The second joint is arranged opposite to the third joint and extends into the third joint to form a nozzle. The first joint is arranged on the side of the second joint.

3. The flue capacity expansion structure according to claim 2, characterized in that: The inner diameter of the inlet end of the second joint is larger than the inner diameter of the outlet end.

4. The flue capacity expansion structure according to claim 3, characterized in that: The outer wall of the second joint transitions from the inlet end to the outlet end in an arc shape.

5. The flue capacity expansion structure according to claim 4, characterized in that: The inner diameter of the first joint is smaller than that of the third joint, and the inner diameter of the second joint is smaller than that of the first joint.

6. The flue capacity expansion structure according to claim 1, characterized in that: The flue gas treatment device comprises a denitration reactor, an air preheater and a dust collector assembly which are sequentially arranged on the induced air duct along the flue gas flow direction.

7. The flue capacity expansion structure according to claim 6, characterized in that: The dust collector assembly includes a first dust collector and two first heat exchangers connected to the inlet end of the first dust collector.

8. The flue capacity expansion structure according to claim 7, characterized in that: The desulfurization device comprises a desulfurization absorption tower, a second dust collector and a second heat exchanger which are sequentially arranged along the flow direction of the flue gas.

9. The flue capacity expansion structure according to claim 8, characterized in that: The second heat exchanger is connected to the first heat exchanger via a circulation pipeline.

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