Oil-gas dual-purpose boiler

Abstract

The utility model relates to an oil-gas dual-purpose boiler which comprises a hearth, an oil-gas dual-purpose burner, a horizontal flue, a vertical shaft flue upper section, a vertical shaft flue lower section, a denitration inlet flue, a denitration flue, a denitration outlet flue and a flue gas discharge port. The vertical shaft flue upper section and the vertical shaft flue lower section are arranged in the same row, the denitration flue is arranged in different rows, and the lower part of the vertical shaft flue upper section and the inlet end of the denitration inlet flue are respectively provided with a flue main flashboard and a flue bypass flashboard which are adjustable in opening degree. When the boiler uses original fuel gas with low NOx emission as fuel, the flue main flashboard is opened, the flue bypass flashboard is closed, flue gas does not need to pass through a denitration flue and directly enters the lower section of the vertical shaft flue from the upper section of the vertical shaft flue, the flue gas side process is simplified, the flue gas side resistance is greatly reduced, and therefore the power consumption of an induced draft fan is reduced, and the purposes of saving energy and reducing consumption are achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of boiler equipment and specifically discloses an oil and gas dual-purpose boiler. Background Art

[0002] With the promulgation and implementation of the national "Emission Standards for Air Pollutants from Thermal Power Plants" (GB13223-2011), it is required that the emissions of smoke, sulfur dioxide, NOx, etc. from boilers must meet the limit values. When the boiler burns fuel gas such as natural gas, its original NOx emissions can generally meet the limit requirements by adopting low-nitrogen combustion technology. However, when burning fuel oil, due to the difference in emission characteristics during fuel combustion, the original NOx cannot meet the limit requirements, and it is generally necessary to arrange a denitrification device in the boiler flue. For oil and gas dual-use boilers, in the conventional layout, the upper section of the shaft flue is arranged in a single row, the denitrification flue is arranged in the same row as the lower section of the shaft flue, and the denitrification device is arranged in the denitrification flue. Whether burning fuel oil or fuel gas, there is no difference in the flue gas side process. The flue gas passes through the upper section of the shaft flue, the denitrification flue, and the lower section of the shaft flue in sequence. That is, no matter what fuel is burned, whether the original NOx emission of the flue gas meets the standard, the flue gas must pass through the denitrification flue. Obviously, when natural gas or other fuel gas is used as fuel, the smoke side resistance is increased unnecessarily, thereby increasing the power consumption of the induced draft fan, which is a huge waste of energy. Summary of the invention

[0003] The utility model aims to overcome the deficiencies in the prior art and to provide an oil and gas dual-purpose boiler which can simplify the flue gas side process when the boiler burns fuel gas, reduce the flue gas side resistance, and reduce the power consumption of the induced draft fan, thereby achieving the purpose of energy saving and consumption reduction.

[0004] According to the technical solution provided by the utility model, the oil-gas dual-purpose boiler includes a furnace, an oil-gas dual-purpose burner, a semi-radiant superheater, a horizontal flue, a high-temperature section convection superheater, an upper section of a vertical shaft flue, a denitrification inlet flue, a denitrification flue, a rectifier, an SCR device, a denitrification outlet flue, a flue gas outlet, an air preheater, a low-temperature section economizer, a lower section of a vertical shaft flue, a flue main damper, a flue bypass damper, a high-temperature section economizer and a low-temperature section convection superheater;

[0005] The top of the furnace is provided with a flue gas outlet, the top of the upper section of the vertical shaft flue is a flue gas inlet, the bottom of the upper section of the vertical shaft flue is a flue gas outlet, the bottom of the denitrification inlet flue is a flue gas inlet, the top of the denitrification inlet flue is a flue gas outlet, the top of the denitrification flue is a flue gas inlet, the bottom of the denitrification flue is a flue gas outlet, the top of the denitrification outlet flue is a flue gas inlet, the bottom of the denitrification outlet flue is a flue gas outlet, the top of the lower section of the vertical shaft flue is a flue gas inlet, and a flue gas outlet is installed at the bottom of the lower section of the vertical shaft flue;

[0006] An oil-gas dual-fuel burner is arranged at the bottom of the furnace. A semi-radiant superheater is arranged at the top of the furnace near the flue gas outlet. The flue gas outlet of the furnace is connected to the flue gas inlet of the horizontal flue. A high-temperature convection superheater is arranged in the horizontal flue. The flue gas outlet of the horizontal flue is connected to the flue gas inlet of the upper section of the vertical flue. A low-temperature convection superheater and a high-temperature economizer are arranged in the upper section of the vertical flue. The low-temperature convection superheater is located above the high-temperature economizer. The flue gas outlet of the upper section of the vertical flue is connected to the flue gas inlet of the lower section of the vertical flue. A main flue damper is arranged at the connection part between the flue gas outlet of the upper section of the vertical flue and the flue gas inlet of the lower section of the vertical flue. A low-temperature economizer and an air preheater are arranged in the lower section of the vertical flue. The low-temperature economizer is located above the air preheater;

[0007] The flue gas inlet of the denitration inlet flue is connected to the flue in the upper section of the vertical flue between the main flue damper and the high-temperature economizer. A bypass flue damper is arranged in the denitration inlet flue near its flue gas inlet. The flue gas outlet of the denitration inlet flue is connected to the flue gas inlet of the denitration flue. A rectifying device and an SCR device are arranged in the denitration flue. The rectifying device is located above the SCR device. The flue gas outlet of the denitration flue is connected to the flue gas inlet of the denitration outlet flue. The flue gas outlet of the denitration outlet flue is connected to the flue in the lower section of the vertical flue between the main flue damper and the low-temperature economizer;

[0008] The upper section of the vertical flue and the lower section of the vertical flue are arranged in the same row, and the upper section of the vertical flue and the denitration flue are arranged in separate rows.

[0009] Preferably, the opening degrees of the main flue damper and the bypass flue damper can be controlled respectively.

[0010] Preferably, the oil-gas dual-fuel burner is arranged singly or in multiple units, and the oil-gas dual-fuel burner can be arranged separately or in combination on the front wall, rear wall or side wall of the furnace.

[0011] Preferably, the SCR device is arranged in a single layer or multiple layers.

[0012] In the utility model, the lower section of the vertical flue is changed from the conventional arrangement in the same row as the denitration flue to the arrangement in the same row as the upper section of the vertical flue, and a main flue damper with an adjustable opening degree and a bypass flue damper are respectively arranged at the lower part of the upper section of the vertical flue and the inlet end of the denitration inlet flue. When the boiler uses fuel gas with a relatively low original NOx emission as fuel, the main flue damper is opened and the bypass flue damper is closed. The flue gas does not need to pass through the denitration flue and directly enters the lower section of the vertical flue through the upper section of the vertical flue. The flue gas side process is simplified and the flue gas side resistance is greatly reduced, so as to reduce the power consumption of the induced draft fan and achieve the purpose of energy conservation and consumption reduction. Description of the Drawings

[0013] Figure 1This is the structural schematic diagram of the present utility model. Detailed implementation manners

[0014] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are only a part rather than all of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0015] An oil-gas dual-fuel boiler, as Figure 1 shown, includes a furnace 1, an oil-gas dual-fuel burner 2, a semi-radiant superheater 4, a horizontal flue 5, a high-temperature convection superheater 7, an upper shaft flue 8, a denitration inlet flue 9, a denitration flue 10, a rectifying device 11, an SCR device 12, a denitration outlet flue 13, a flue gas discharge port 14, an air preheater 15, a low-temperature economizer 16, a lower shaft flue 17, a main flue damper 18, a bypass flue damper 19, a high-temperature economizer 20 and a low-temperature convection superheater 21;

[0016] A flue gas outlet is arranged at the top of the furnace 1. The top of the upper shaft flue 8 is a flue gas inlet, and the bottom of the upper shaft flue 8 is a flue gas outlet. The bottom of the denitration inlet flue 9 is a flue gas inlet, and the top of the denitration inlet flue 9 is a flue gas outlet. The top of the denitration flue 10 is a flue gas inlet, and the bottom of the denitration flue 10 is a flue gas outlet. The top of the denitration outlet flue 13 is a flue gas inlet, and the bottom of the denitration outlet flue 13 is a flue gas outlet. The top of the lower shaft flue 17 is a flue gas inlet, and a flue gas discharge port 14 is installed at the bottom of the lower shaft flue 17;

[0017] An oil-gas dual-fuel burner 2 is arranged at the bottom of the furnace 1, and a semi-radiant superheater 4 is arranged at the top of the furnace 1 near its flue gas outlet. The flue gas outlet of the furnace 1 is connected to the flue gas inlet of the horizontal flue 5. A high-temperature convection superheater 7 is arranged in the horizontal flue 5. The flue gas outlet of the horizontal flue 5 is connected to the flue gas inlet of the upper shaft flue 8. A low-temperature convection superheater 21 and a high-temperature economizer 20 are arranged in the upper shaft flue 8. The low-temperature convection superheater 21 is located above the high-temperature economizer 20. The flue gas outlet of the upper shaft flue 8 is connected to the flue gas inlet of the lower shaft flue 17. A main flue damper 18 is arranged at the connection part between the flue gas outlet of the upper shaft flue 8 and the flue gas inlet of the lower shaft flue 17. A low-temperature economizer 16 and an air preheater 15 are arranged in the lower shaft flue 17. The low-temperature economizer 16 is located above the air preheater 15;

[0018] The flue gas inlet of the denitration inlet flue 9 is connected to the flue of the upper section 8 of the vertical flue between the flue main damper 18 and the high-temperature economizer 20. A flue bypass damper 19 is arranged in the denitration inlet flue 9 near its flue gas inlet position. The flue gas outlet of the denitration inlet flue 9 is connected to the flue gas inlet of the denitration flue 10. A rectifying device 11 and an SCR device 12 are arranged in the denitration flue 10. The rectifying device 11 is located above the SCR device 12. The flue gas outlet of the denitration flue 10 is connected to the flue gas inlet of the denitration outlet flue 13. The flue gas outlet of the denitration outlet flue 13 is connected to the flue of the lower section 17 of the vertical flue between the flue main damper 18 and the low-temperature economizer 16;

[0019] The upper section 8 of the vertical flue and the lower section 17 of the vertical flue are arranged in the same column, and the upper section 8 of the vertical flue and the denitration flue 10 are arranged in separate columns.

[0020] The oil-gas dual-purpose burner 2 is arranged singly or in multiple units.

[0021] The SCR device 12 is arranged in a single layer or multiple layers.

[0022] The opening and closing degrees of the flue main damper 18 and the flue bypass damper 19 can be controlled respectively, and during the working process, the resistance on the flue gas side of the flue main damper 18 and the flue bypass damper 19 is 100 - 200 Pa.

[0023] Above the furnace 1, a steam drum 3 and a steam collecting header 6 are provided.

[0024] The oil-gas dual-purpose burner 2 can burn fuel gas or fuel oil respectively.

[0025] In the present utility model, the boiler steam-water side is composed of the furnace 1, the steam drum 3, the low-temperature economizer 16, the high-temperature economizer 20, the low-temperature convective superheater 21, the high-temperature convective superheater 7, the semi-radiant superheater 4 and the steam collecting header 6.

[0026] During the working process, the total resistance on the flue gas side of the denitration inlet flue 9, the denitration flue 10 and the denitration outlet flue 13 is 1500 - 2500 Pa.

[0027] The working process of the present utility model is as follows:

[0028] The fuel enters the oil-gas dual-fuel burner 2 at the bottom of the furnace 1 and burns. The flue gas generated passes through the furnace 1 and the horizontal flue 5, heating the semi-radiant superheater 4 and the high-temperature convection superheater 7 arranged therein. Then it enters the upper section 8 of the vertical flue, heating the low-temperature convection superheater 21 and the high-temperature economizer 20 arranged therein. After that, the flue gas enters the tail process. When the boiler uses fuel oil with a relatively high original NOx emission as fuel, the flue gas side process is as follows: close the main flue damper 18, open the bypass flue damper 19, and the flue gas enters the denitration flue 10 through the denitration inlet flue 9. The flue gas first passes through the rectifying device 11 to reduce resistance, then passes through the SCR device 12 to remove most of the NOx, and then enters the lower section 17 of the vertical flue, heating the low-temperature economizer 16 and the air preheater 15 arranged therein, and finally discharging from the flue gas outlet 14. When the boiler uses fuel gas with a relatively low original NOx emission as fuel, the flue gas side process is as follows: open the main flue damper 18, close the bypass flue damper 19, and the flue gas directly enters the lower section 17 of the vertical flue without passing through the denitration inlet flue 9, the denitration flue 10 and the denitration outlet flue 13, heating the low-temperature economizer 16 and the air preheater 15 arranged therein, and finally discharging from the flue gas outlet 14. The flue gas side process of the boiler is simplified, and the flue gas side resistance is greatly reduced, thereby reducing the power consumption of the induced draft fan to achieve the purpose of energy conservation and consumption reduction.

[0029] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the examples, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A dual-purpose oil and gas boiler, comprising a furnace (1), a dual-purpose oil and gas burner (2), a semi-radiant superheater (4), a horizontal flue (5), a high-temperature section convection superheater (7), an upper section of a vertical shaft flue (8), a denitration inlet flue (9), a denitration flue (10), a rectifier (11), an SCR device (12), a denitration outlet flue (13), a flue gas outlet (14), an air preheater (15), a low-temperature section economizer (16), a lower section of a vertical shaft flue (17), a flue main damper (18), a flue bypass damper (19), a high-temperature section economizer (20) and a low-temperature section convection superheater (21); The top of the furnace (1) is provided with a flue gas outlet, the top of the upper section (8) of the vertical shaft flue is a flue gas inlet, the bottom of the upper section (8) of the vertical shaft flue is a flue gas outlet, the bottom of the denitrification inlet flue (9) is a flue gas inlet, the top of the denitrification inlet flue (9) is a flue gas outlet, the top of the denitrification flue (10) is a flue gas inlet, the bottom of the denitrification flue (10) is a flue gas outlet, the top of the denitrification outlet flue (13) is a flue gas inlet, the bottom of the denitrification outlet flue (13) is a flue gas outlet, the top of the lower section (17) of the vertical shaft flue is a flue gas inlet, and a flue gas outlet (14) is installed at the bottom of the lower section (17) of the vertical shaft flue; An oil and gas dual-purpose burner (2) is arranged at the bottom of the furnace (1), a semi-radiant superheater (4) is arranged at the top of the furnace (1) near the smoke outlet thereof, the smoke outlet of the furnace (1) is connected to the smoke inlet of the horizontal flue (5), a high-temperature section convection superheater (7) is arranged in the horizontal flue (5), the smoke outlet of the horizontal flue (5) is connected to the smoke inlet of the upper section (8) of the vertical shaft flue, a low-temperature section convection superheater (21) and a high-temperature section economizer are arranged in the upper section (8) of the vertical shaft flue. (20), the low-temperature section convection superheater (21) is located above the high-temperature section economizer (20), the flue gas outlet of the upper section (8) of the vertical shaft flue is connected to the flue gas inlet of the lower section (17) of the vertical shaft flue, a flue main damper (18) is arranged at the connection between the flue gas outlet of the upper section (8) of the vertical shaft flue and the flue gas inlet of the lower section (17) of the vertical shaft flue, a low-temperature section economizer (16) and an air preheater (15) are arranged in the lower section (17) of the vertical shaft flue, and the low-temperature section economizer (16) is located above the air preheater (15); The flue gas inlet of the denitrification inlet flue (9) is connected to the flue of the upper section (8) of the vertical shaft flue between the flue main damper (18) and the high-temperature section economizer (20); a flue bypass damper (19) is arranged in the denitrification inlet flue (9) near its flue gas inlet position; the flue gas outlet of the denitrification inlet flue (9) is connected to the flue gas inlet of the denitrification flue (10); a rectifier (11) and an SCR device (12) are arranged in the denitrification flue (10); the rectifier (11) is located above the SCR device (12); the flue gas outlet of the denitrification flue (10) is connected to the flue gas inlet of the denitrification outlet flue (13); and the flue gas outlet of the denitrification outlet flue (13) is connected to the flue of the lower section (17) of the vertical shaft flue between the flue main damper (18) and the low-temperature section economizer (16); Its characteristics are: The upper section (8) of the vertical shaft flue and the lower section (17) of the vertical shaft flue are arranged in the same row, and the upper section (8) of the vertical shaft flue and the denitrification flue (10) are arranged in separate rows.

2. The oil-gas dual-purpose boiler according to claim 1, characterized in that: The dual-purpose oil and gas burner (2) is arranged in a single unit or in multiple units. The dual-purpose oil and gas burners can be arranged individually or in combination on the front wall, rear wall or side wall of the furnace.

3. The oil-gas dual-purpose boiler according to claim 1, characterized in that: The SCR device (12) is arranged in a single layer or in multiple layers.

4. The oil-gas dual-purpose boiler according to claim 1, characterized in that: The opening and closing degrees of the flue main damper (18) and the flue bypass damper (19) can be controlled independently.

5. The oil-gas dual-purpose boiler according to claim 1, characterized in that: A boiler drum (3) and a steam header (6) are provided above the furnace (1).

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