Assembled boiler air pre-heater anti-blocking device

Abstract

The embodiment of the utility model relates to an assembly type boiler air pre-heater anti-blocking device, and belongs to the technical field of boiler environmental protection. The assembled boiler air pre-heater anti-blocking device comprises a reheat steam main pipe, the reheat steam main pipe is sequentially connected with a primary air bellow and a primary air main pipe, and first reheaters are arranged in the primary air bellow and the primary air main pipe; the primary air mother pipe is connected with an air feeder, a second reheater is arranged in an outlet air box of the air feeder, the air feeder is further connected with a body drain flash tank of the steam turbine, and the body drain flash tank is connected with a condenser. According to the anti-blocking device provided by the embodiment of the invention, the air pre-heater is prevented from being blocked by ammonium hydrogen sulfate, the differential pressure of the air pre-heater is controlled, the input rate of a soot blower is reduced, steam is saved, and the service life of the air pre-heater is prolonged.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of boiler environmental protection, and in particular to an assembled boiler air preheater anti-blocking device. Background Art

[0002] In recent years, thermal power plants have been affected by the coal market, with the calorific value of coal entering the furnace dropping significantly and the ash content rising significantly, sometimes with the air dry basis ash content >50%. In addition, after the ultra-low emission transformation, the air preheater is frequently blocked, seriously affecting the load capacity and safety of the unit. Especially for low calorific value and low volatile coal, the flexibility of the unit is effectively improved, which facilitates the wide peak regulation of the unit. Utility Model Content

[0003] In view of this, an embodiment of the present application provides an assembled boiler air preheater anti-blocking device to solve the technical problems raised in the above-mentioned background technology.

[0004] An embodiment of the present application provides an assembled boiler air preheater anti-blocking device, comprising a reheat steam main pipe, wherein the reheat steam main pipe is connected to a primary wind box and a primary air main pipe in sequence, wherein a first reheater is arranged in each of the primary wind box and the primary air main pipe; wherein the primary air main pipe is connected to an air supply fan, wherein a second reheater is arranged in an outlet wind box of the air supply fan, wherein the air supply fan is also connected to a main body drain expansion tank of a steam turbine, and wherein the main body drain expansion tank is connected to a condenser.

[0005] In some embodiments that may include the above-mentioned embodiments, the reheat steam main pipe is provided with a manual door in front of the regulating door, a regulating door and a manual door behind the regulating door in sequence, the regulating door regulates the flow rate of the reheat steam, and the manual door in front of the regulating door and the manual door behind the regulating door are used for maintenance isolation.

[0006] In some embodiments, which may include the above embodiments, the first reheater and the second reheater are both packaged platen reheaters.

[0007] In some embodiments that may include the above embodiments, the size of the primary air main pipe is Φ1802mm×3mm.

[0008] In some embodiments that may include the above embodiments, the assembled platen reheater has a size of 1500 mm×1500 mm.

[0009] In some embodiments that may include the above embodiments, the primary air box has a size of 2000 mm×1400 mm×8800 mm.

[0010] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0011] 1. Increasing the primary air temperature is beneficial to increasing the temperature of the primary air-powder mixture, facilitating the precipitation of volatile matter in coal powder and igniting coal powder; increasing the temperature of the primary air-powder mixture is beneficial to reducing the ignition heat of coal powder, facilitating early ignition of coal powder, increasing the combustion time, reducing the carbon content of fly ash and large slag, and improving furnace efficiency.

[0012] 2. When the outlet air temperature of the blower is increased, it is helpful to prevent ammonium bisulfate from clogging the air preheater, control the differential pressure of the air preheater, reduce the investment rate of the soot blower, save steam, and extend the service life of the air preheater.

[0013] 3. Arrange assembled screen superheaters in the primary wind box, primary air main pipe, and blower outlet air duct. Arrange 3 screens in the primary wind box, 3 screens in the primary air main pipe, and 3 screens in the blower outlet air duct to reduce the damage to the air duct caused by primary and secondary air.

[0014] 4. Since the primary air heating temperature can be controlled by adjusting the amount of reheat steam and is not affected by the volatile matter of the coal entering the furnace, the temperature can be high or low, which is flexible and convenient.

[0015] 5. Due to the increase in the temperature of the primary and secondary air, the laying of the fire protection belt can be effectively reduced, the thermal resistance of the furnace can be reduced, the furnace outlet temperature can be lowered, and the coking of the boiler can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is a schematic structural diagram of an air preheater anti-blocking device according to an embodiment of the present application.

[0018] Description of reference numerals:

[0019] 1. Reheat steam main pipe; 101. Manual door in front of regulating door; 102. Regulating door; 103. Manual door behind regulating door; 2. Primary wind box; 3. Primary air main pipe; 4. First reheater; 5. Air blower; 6. Second reheater; 7. Main body drain expansion tank; 8. Condenser; 9. Reheater; 10. Boiler. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0021] First, those skilled in the art should understand that these implementations are only used to explain the technical principles of the present application and are not intended to limit the scope of protection of the present application. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios.

[0022] Secondly, it should be noted that in the description of the present application, terms such as "up", "down", "left", "right", "front", "back", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present application.

[0023] refer to Figure 1 The assembled boiler air preheater anti-blocking device of the embodiment of the present application includes a reheat steam main pipe 1. The reheat steam enters the reheat steam main pipe 1 through a reheater 9, and enters the primary air box 2 and the primary air main pipe 3 of the boiler 10 in sequence after coming out of the reheat steam main pipe 1. The primary air box 2 and the primary air main pipe 3 are both provided with a first reheater 4. The temperature of the reheat steam is higher than the temperature of the primary air in the primary air box 2 and the primary air main pipe 3, so that the reheat steam heats the primary air. The steam after heat release enters the outlet air box of the blower 5 through the primary air main pipe 3. The outlet air box of the blower 5 is provided with a second reheater 6. The temperature of the steam after heat release is higher than the temperature of the secondary air in the blower 5, so as to heat the secondary air in the blower 5. After heat release, the steam enters the main body drain expansion tank 7 of the steam turbine and returns to the condenser 8.

[0024] It should be noted that the primary air at the air preheater outlet is clean air, which causes less wear and tear on the tube screen and is conducive to the long-term stable operation of the equipment.

[0025] In a specific embodiment, the reheat steam main pipe 1 is provided with a manual door 101 in front of the regulating door, a regulating door 102 and a manual door 103 behind the regulating door in sequence. The regulating door 102 adjusts the flow of the reheat steam, controls the pressure and the heating temperature; the manual door 101 in front of the regulating door and the manual door 103 behind the regulating door are used for maintenance and isolation.

[0026] Exemplarily, the first reheater 4 and the second reheater 6 are both assembled screen-type reheaters, which are assembled as needed and arranged in parallel in a countercurrent staggered row in the air duct, which will not be described in detail in the embodiments of the present application.

[0027] In a specific embodiment, the size of the primary air main pipe 3 is Φ1802mm×3mm (corresponding to the inner diameter and length respectively); the size of the assembled screen reheater is 1500mm×1500mm; the size of the primary air box 2 is 2000mm×1400mm×8800mm (corresponding to the length, width and height respectively). The size can be adjusted according to actual needs, and this application does not limit this.

[0028] The working principle of the device in the embodiment of the present application:

[0029] The reheated steam at 540°C is drained from the reheated steam main pipe 1 at 6.3m of the steam turbine and introduced into the primary air box 2 and the primary air main pipe 3 of the boiler 10. An assembled screen-type reheater is installed in the primary air box 2 and the primary air main pipe 3. The primary air at 320°C is heated by the steam at 540°C to increase the temperature of the primary air to 360-380°C. The heated steam is drawn out from the primary air main pipe 3 and enters the inlet air duct of the blower 5. An assembled screen-type reheater is installed in the outlet air box of the blower 5. The secondary air delivered by the blower 5 is heated by steam to increase the temperature of the secondary air at the inlet of the air preheater. The steam after releasing heat enters the main body drain expansion tank 7 of the steam turbine and returns to the condenser 8. It should be noted that the intermediate pressure cylinder is a component of the steam turbine. The reheated steam is sent to the intermediate pressure cylinder (not shown in the figure) to impulse the rotor to drive the generator to rotate and generate electricity.

[0030] The hollow preheater anti-blocking device of the present application fully utilizes existing equipment and will not affect the safety of the unit; the tube screens can be prepared and the pipelines can be arranged during the operation of the unit, and it can be implemented during the shutdown period, with a short construction period.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An assembled boiler air preheater anti-blocking device, characterized in that: It includes a reheat steam main pipe, which is connected to a primary wind box and a primary air main pipe in sequence, and a first reheater is arranged in each of the primary wind box and the primary air main pipe; the primary air main pipe is connected to a blower, and a second reheater is arranged in the outlet wind box of the blower, and the blower is also connected to a main body drain expansion tank of a steam turbine, and the main body drain expansion tank is connected to a condenser.

2. The assembled boiler air preheater anti-blocking device according to claim 1 is characterized in that: The reheat steam main pipe is provided with a manual door in front of the regulating door, a regulating door and a manual door behind the regulating door in sequence. The regulating door regulates the flow of the reheat steam, and the manual door in front of the regulating door and the manual door behind the regulating door are used for maintenance isolation.

3. The assembled boiler air preheater anti-blocking device according to claim 1 is characterized in that: The first reheater and the second reheater are both assembled platen reheaters.

4. The assembled boiler air preheater anti-blocking device according to claim 1 is characterized in that: The size of the primary air main pipe is Φ1802mm×3mm.

5. The assembled boiler air preheater anti-blocking device according to claim 3 is characterized in that: The size of the assembled platen reheater is 1500mm×1500mm.

6. The assembled boiler air preheater anti-blocking device according to claim 1 is characterized in that: The dimensions of the primary air box are 2000mm×1400mm×8800mm.

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