Flue capacity increasing structure

Abstract

The invention 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, each air inducing pipeline is sequentially provided with a flue gas treatment device and a first fan 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 flue capacity increasing structure provided by the invention can resist a certain degree of flue blockage, reduce abnormal shutdown of a generator set and ensure smooth power generation.

Description

Technical Field

[0001] The invention relates to the technical field of power generation equipment, and 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 discharging flue 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 induced draft fan runs at high load for a long time, and the main bearing components are worn, resulting in a shortened maintenance cycle and temporary maintenance, which affects normal power generation. Summary of the invention

[0004] Based on the above problems, the purpose of the present invention is to provide a flue capacity increasing 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 increasing structure comprises 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 arranged on the induced draft ducts along the flue gas flow direction, and the parallel induced draft ducts are connected via a connecting duct, and further comprises:

[0007] A flow combiner is arranged between the induced air duct and the desulfurization device, 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 pipeline, wherein the inlet end of the boosting pipeline is connected to the communicating pipeline and the outlet end of the boosting pipeline is connected to the inlet end of the flow combiner;

[0009] The second fan is arranged on the boosting pipeline, 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 air 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 of the embodiments, the flue gas treatment device includes a denitration reactor, an air preheater and a dust collector assembly which are sequentially arranged on the induced draft duct along the flow direction of the flue gas.

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

[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 pipeline.

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

[0019] 1. By adding a booster duct 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. The second fan and the combiner can cooperate to reduce the flue resistance and achieve smooth confluence of the three flue gases, thereby 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 sucks 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, which 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 accompanying drawings required for use in the description of the embodiments will be briefly introduced below. The accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0022] Figure 1 It is a structural schematic diagram of an embodiment of a flue capacity increasing structure of the present invention;

[0023] Figure 2 It is a structural schematic diagram of a flow combiner in an embodiment of the present invention;

[0024] in:

[0025] 1. Boiler; 2. DeNOx reactor 3. Air preheater; 4. First heat exchanger; 5. First dust collector; 6. Air induced draft duct; 7. First fan; 8. Connecting duct; 9. Booster duct; 10. Second fan; 11. Merger; 11-1. First joint; 11-2. Second joint; 11-3. Third joint; 12. Merging 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 in conjunction with specific examples. It should be understood that these examples are used to illustrate the present invention and are not limited to the scope of the present invention. The implementation conditions adopted in the examples can be further adjusted according to the conditions of the specific manufacturer, and the unspecified implementation conditions are usually the conditions in conventional experiments.

[0027] See also Figure 1 , is a structural schematic diagram of an embodiment of the present invention, which 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 arranged in sequence on the induced draft ducts 6 along the flue gas flow direction, and the parallel induced draft ducts 6 are connected by a connecting pipe 8. Since dust easily accumulates in the flue gas flue and causes blockage, the maintenance cycle is short, which affects the normal power generation of the generator set.

[0028] In order to reduce the blockage of the flue and ensure the normal operation of power generation, the structure of the flue is improved, and a flow combiner 11, a booster pipe 9 and a second fan 10 are added. The flow combiner 11 is arranged between the induced draft pipe 6 and the desulfurization device, the inlet end of the flow combiner 11 is connected to the outlet end of the induced draft pipe 6, and the outlet end of the flow combiner 11 is connected to the desulfurization device. The inlet end of the booster pipe 9 is connected to the connecting pipe 8 and the outlet end is connected to the inlet end of the flow combiner 11. The second fan 10 is arranged on the booster pipe 9, and the wind pressure of the second fan 10 is greater than that of the first fan 7.

[0029] The existing first fan 7 adopts the HA46048-2F single-stage axial flow induced draft fan with stator blade adjustment manufactured by China Power Construction Group Turbine Technology Co., Ltd. The first fan 7 adopts a small steam turbine for speed regulation. The second fan 10 is an electric high-pressure induced draft fan, which adopts a multi-stage axial flow compressor. When the load of the generator set is less than 80% of the maximum load, the second fan 10 can be stopped, and when the load of the generator set is greater than 80% of the maximum load, the second fan 10 can be enabled, which can ensure the flow in the flue gas duct, reduce flue blockage, and ensure 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 the third joint 11-3, and the inner diameter of the second joint 11-2 is smaller than 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, a high dynamic pressure can be generated, and the low-pressure flue gas at the outlet of the first fan 7 can be sucked in, thereby increasing its outlet dynamic pressure. After diffusion, the overall static pressure is increased, the inlet static pressure of the confluence 11 is reduced, and the total pressure at the outlet of the confluence 11 is increased. The 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 shutdown accident caused by it.

[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 from 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 flow direction of the flue gas, 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 which are sequentially arranged along the flue gas flow direction. The flue gas is heated by the second heat exchanger 15 to increase the lifting height and diffusion speed of the flue gas. The second heat exchanger 15 is connected to the first heat exchanger 4 via a circulation pipeline 17. The heat medium in the first heat exchanger 4 is circulated to the second heat exchanger 15 through the circulation pipeline 17 to heat the flue gas, so as to lift and diffuse the flue gas and save energy.

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

[0036] The above examples are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit of the present invention should be included in the protection scope of the present invention.

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 arranged on the induced draft ducts along the flue gas flow direction, and the parallel induced draft ducts are connected via a connecting duct, characterized in that: Also includes: A flow combiner is arranged between the induced air duct and the desulfurization device, 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 pipeline, wherein the inlet end of the boosting pipeline is connected to the communicating pipeline and the outlet end of the boosting pipeline is connected to the inlet end of the flow combiner; The second fan is arranged on the boosting pipeline, and the wind pressure of the second fan is greater than that of the first fan.

2. The flue capacity increasing structure according to claim 1, characterized in that: The confluence device includes a first joint connected to the induced air 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 increasing structure according to claim 2, characterized in that: The inner diameter of the inlet end of the second joint is greater than the inner diameter of the outlet end.

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

5. The flue capacity increasing structure according to claim 4 is 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 increasing 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 draft duct along the flue gas flow direction.

7. The flue capacity increasing 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 first dust collector inlet end.

8. The flue capacity increasing 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 increasing 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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