Device for reducing flue gas temperature of boiler and improving productivity of coal mill

Abstract

The utility model discloses a device for reducing boiler flue gas temperature and improving coal mill productivity, and belongs to the technical field of boiler flue gas temperature control. The device comprises a grate cooler, a coal mill, a power station boiler and a kiln head dust collector, a wind-shield wall is arranged in the grate cooler, and the interior of the grate cooler is divided into a grate cooler front section, a grate cooler middle section and a grate cooler tail section by the wind-shield wall according to the temperature from high to low; the grate cooler middle section is connected with a power station boiler through a boiler air inlet pipeline and connected with a coal mill through a coal mill air inlet pipeline. An air taking pipeline is connected between the boiler air inlet pipeline and the coal mill air inlet pipeline; the tail section of the grate cooler is connected with a boiler air inlet pipeline through a boiler air supplement pipeline and connected with a kiln head dust collector through a boiler bypass pipeline. The device solves the problem that a large amount of energy is consumed under the condition that the flue gas temperature is reduced, and is used for protecting safe operation of equipment.

Description

Technical Field

[0001] The utility model belongs to the technical field of boiler flue gas temperature control, in particular to a device for reducing boiler flue gas temperature and improving coal mill production capacity. Background Art

[0002] In order to prevent the boiler and its thermal system from overheating, tube bursting, and equipment damage, it is necessary to control the flue gas temperature within a certain range while increasing the coal mill production capacity to ensure that the boiler steam temperature requirement does not affect the operation of the turbine; higher temperatures will cause stress softening of the internal pipes of the boiler and the valve materials in the thermal system, thereby causing serious wear of components such as the valve core in the pipes and valves. In severe cases, it may also cause accidents such as equipment tube bursting, which is not conducive to the safe operation of the equipment.

[0003] In order to make the flue gas temperature entering the boiler meet the boiler's design temperature requirements, cooling treatment is required. The general method is to leave one or more natural air vents in the boiler air inlet duct for forced cooling. However, this will reduce the flue gas flow rate and increase the fan load and power consumption, resulting in a large amount of energy loss. Utility Model Content

[0004] The utility model overcomes the deficiencies of the prior art and proposes a device for reducing boiler flue gas temperature and increasing coal mill production capacity, thereby solving the problem of large energy loss caused by reducing flue gas temperature and protecting the safe operation of equipment.

[0005] In order to achieve the above-mentioned purpose, the present invention is implemented through the following technical solutions.

[0006] A device for reducing boiler flue gas temperature and increasing coal mill production capacity comprises a grate cooler, a coal mill, a power station boiler and a kiln head dust collector; a windbreak wall is provided in the grate cooler, which divides the grate cooler into a grate cooler front section, a grate cooler middle section and a grate cooler end section according to temperature from high to low; the grate cooler middle section is connected to the power station boiler through a boiler air inlet duct, and the grate cooler middle section is connected to the coal mill through a coal mill air inlet duct; the boiler air inlet duct is located on a side close to the grate cooler front section, and the coal mill air inlet duct is located on a side close to the grate cooler end section; an air intake duct is connected between the boiler air inlet duct and the coal mill air inlet duct; the grate cooler end section is connected to the boiler air inlet duct through a boiler supply air duct, and the grate cooler end section is connected to the kiln head dust collector through a boiler bypass duct.

[0007] Furthermore, the coal mill air inlet duct is provided with a coal mill air inlet valve, and the air intake duct is located behind the coal mill air inlet valve; the air intake duct is provided with a coal mill air intake valve.

[0008] Furthermore, the boiler air supply pipe is provided with a boiler air supply valve, and the boiler bypass pipe is provided with a bypass valve.

[0009] Furthermore, the power station boiler is connected to the boiler bypass pipe through the boiler outlet pipe.

[0010] Furthermore, the boiler air outlet pipe is provided with a boiler outlet valve.

[0011] Furthermore, the boiler air inlet duct is connected to two natural cooling cold air outlets, and the two natural cooling cold air outlets are respectively provided with cold air valves.

[0012] The beneficial effects of the present invention compared to the prior art are as follows:

[0013] The utility model sets a windbreak wall in the grate cooler, and divides the grate cooler into the front section, the middle section and the end section according to the temperature distribution from high to low, which can effectively prevent the flue gas in the high temperature zone and the low temperature zone from circulating with each other and affecting the stable operation of the subsequent equipment. When the flue gas temperature entering the boiler is higher than the specified value, the low-temperature flue gas from the low-temperature zone of the end section of the grate cooler enters the boiler air supply duct and mixes with the high-temperature flue gas in the boiler air inlet duct before entering the boiler, which can reduce the boiler flue gas temperature, that is, play a cooling role and increase the air intake of the boiler, and can avoid causing unnecessary power loss to the kiln head system exhaust fan; and the utility model introduces the boiler air intake into the coal mill air inlet duct, which can simultaneously increase the coal mill production capacity, which not only increases the power generation of the power station, but also reduces unnecessary energy loss, and can also increase the production capacity of the kiln system.

[0014] When the boiler temperature is higher than the specified value, affecting the safe operation of the boiler equipment, or the coal mill temperature is too low to dry the pulverized coal moisture, this device can be used to improve the situation. It not only achieves the flue gas temperature required by the boiler, but also meets the temperature requirements of the coal mill, making it easier for operators to operate flexibly. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the connection structure of the device for reducing boiler flue gas temperature and increasing coal mill production capacity described in the present invention;

[0016] In the picture:

[0017] 1. Middle section of grate cooler; 2. End section of grate cooler; 3. Windbreak wall; 4. Coal mill; 5. Kiln head dust collector; 6. Power station boiler; 7. Boiler air inlet duct; 8. Coal mill air inlet duct; 9. Boiler bypass duct; 10. Boiler air outlet duct; 11. Air intake duct; 12. Boiler supply air duct; 13. Boiler outlet valve; 14. Bypass valve; 15. Coal mill air intake valve; 16. Second cold air valve; 17. Boiler supply air valve; 18. First cold air valve; 19. Coal mill air inlet valve; 20. Grate cooler; 21. Front section of grate cooler. DETAILED DESCRIPTION

[0018] In order to make the technical problems, technical solutions, and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail with reference to the embodiments and accompanying drawings. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. The technical solutions of the present invention will be described in detail below with reference to the embodiments and accompanying drawings, but the scope of protection is not limited thereto.

[0019] See also Figure 1 This embodiment proposes a device for reducing boiler flue gas temperature and increasing coal mill production capacity, including a grate cooler 20, a coal mill 4, a power station boiler 6, and a kiln head dust collector 5; a windbreak wall 3 is provided in the grate cooler 20, and the windbreak wall 3 divides the grate cooler 20 into a grate cooler front section 21, a grate cooler middle section 1, and a grate cooler end section 2 according to temperature from high to low; the top of the grate cooler middle section 1 is connected to a boiler air inlet duct 7 and a coal mill air inlet duct 8, the boiler air inlet duct 7 is located on the side close to the grate cooler front section 21, and the coal mill air inlet duct 8 is located on the side close to the grate cooler end section 2; the grate cooler middle section 1 is connected to the power station boiler 6 through the boiler air inlet duct 7, and the grate cooler middle section 1 is connected to the coal mill 4 through the coal mill air inlet duct 8. The coal mill air inlet duct 8 is provided with a coal mill air inlet valve 19 , and an air intake duct 11 is connected between the boiler air inlet duct 7 and the coal mill air inlet duct 8 . The air intake duct 11 is located behind the coal mill air inlet valve 19 ; a coal mill air intake valve 15 is provided on the air intake duct 11 .

[0020] The top of the grate cooler end section 2 is connected to the boiler supply air duct 12 and the boiler bypass duct 9; the boiler supply air duct 12 is provided with a boiler supply air valve 17, and the boiler bypass duct 9 is provided with a bypass valve 14; the grate cooler end section 2 is connected to the boiler air inlet duct 7 through the boiler supply air duct 12, and the grate cooler end section 2 is connected to the kiln head dust collector 5 through the boiler bypass duct 9; the power station boiler 6 is connected to the boiler bypass duct 9 through the boiler outlet air duct 10, and the boiler outlet air duct 10 is provided with a boiler outlet valve 13.

[0021] Among them, the windbreak wall 3 is used to separate the high-temperature area and the low-temperature area inside the grate cooler 20, and the boiler air supply duct 12 is used to direct the low-temperature flue gas in the low-temperature area of ​​the grate cooler 20 to the boiler air inlet duct 7 to mix with the high-temperature flue gas and cool it before entering the power station boiler 6.

[0022] After the windbreak wall 3 is added to the grate cooler 20, the bypass valve 14 is opened by about 30%, and the low-temperature cold air from the last section 2 of the grate cooler is directly conveyed from the boiler bypass pipe 9 to the kiln head dust collector 5. The temperature of the middle section 1 of the grate cooler is higher than that when the windbreak wall 3 is not added, thereby not affecting the air intake temperature of the power station boiler 6 and the coal mill 4.

[0023] After the windbreak wall 3 is added, the boiler air inlet duct 7 is close to the high-temperature area of ​​the front section 21 of the grate cooler. In order to prevent the power station boiler 6 from operating at high temperature, it is necessary to use the boiler air supply duct 12 at the end 2 of the grate cooler to extract hot air of about 150-200 degrees and mix it with the high-temperature hot air of more than 400 degrees from the boiler air inlet duct 7 before entering the power station boiler 6. This not only avoids the power station boiler 6 from operating at high temperature, but also replenishes the air volume of the power station boiler 6, thereby increasing power generation.

[0024] After the windbreak wall 3 is added, the coal mill air inlet duct 8 is close to the low-temperature area of ​​the grate cooler end 2, so the coal mill temperature is relatively low. Therefore, the coal mill production needs to extract some high-temperature hot air from the boiler air inlet duct 7 to assist the coal mill 4 in increasing production and reducing moisture. In this case, the air inlet temperature in the power station boiler 6 can also be reduced to prevent the temperature from exceeding the preset value. The first cold air valve 18 and the second cold air valve 16 on the two natural ventilation ports originally provided on the boiler air inlet duct 7 can be closed by this device, so that the temperature can be reduced without using the ventilation ports on the boiler air inlet duct 7. This increases the air intake of the boiler, does not cause unnecessary power loss to the kiln head system exhaust fan, and improves the coal mill production capacity.

[0025] The above content is a further detailed description of the present invention in combination with a specific preferred embodiment. It cannot be determined that the specific embodiments of the present invention are limited to this. For ordinary technicians in the technical field to which the present invention belongs, they can make several simple deductions or substitutions without departing from the present invention, which should be regarded as belonging to the present invention and the scope of patent protection determined by the submitted claims.

Claims

1. A device for reducing boiler flue gas temperature and increasing coal mill production capacity, characterized in that: The invention comprises a grate cooler (20), a coal mill (4), a power station boiler (6) and a kiln head dust collector (5); a windbreak wall (3) is provided in the grate cooler (20), and the windbreak wall (3) divides the grate cooler (20) into a grate cooler front section (21), a grate cooler middle section (1) and a grate cooler end section (2) according to the temperature from high to low; the grate cooler middle section (1) is connected to the power station boiler (6) through the boiler air inlet duct (7), and the grate cooler middle section (1) is connected to the power station boiler (6) through the coal mill air inlet duct (8). The coal mill (4) is connected; the boiler air inlet duct (7) is located on a side close to the front section (21) of the grate cooler, and the coal mill air inlet duct (8) is located on a side close to the end section (2) of the grate cooler; an air intake duct (11) is connected between the boiler air inlet duct (7) and the coal mill air inlet duct (8); the end section (2) of the grate cooler is connected to the boiler air inlet duct (7) through the boiler air supply duct (12), and the end section (2) of the grate cooler is connected to the kiln head dust collector (5) through the boiler bypass duct (9).

2. The device for reducing boiler flue gas temperature and increasing coal mill production capacity according to claim 1, characterized in that: The coal mill air inlet duct (8) is provided with a coal mill air inlet valve (19), and the air extraction duct (11) is located behind the coal mill air inlet valve (19); the air extraction duct (11) is provided with a coal mill air extraction valve (15).

3. The device for reducing boiler flue gas temperature and increasing coal mill production capacity according to claim 1, characterized in that: The boiler air supply pipe (12) is provided with a boiler air supply valve (17), and the boiler bypass pipe (9) is provided with a bypass valve (14).

4. The device for reducing boiler flue gas temperature and increasing coal mill production capacity according to claim 1, characterized in that: The power station boiler (6) is connected to the boiler bypass pipe (9) via the boiler air outlet pipe (10).

5. The device for reducing boiler flue gas temperature and increasing coal mill production capacity according to claim 4, characterized in that: The boiler air outlet pipe (10) is provided with a boiler outlet valve (13).

6. The device for reducing boiler flue gas temperature and increasing coal mill production capacity according to claim 1, characterized in that: The boiler air inlet duct (7) is connected to two natural cooling cold air inlets, and the two natural cooling cold air inlets are respectively provided with cold air valves.

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