Anti-blocking device for steam on-line air preheater

Abstract

The utility model relates to the technical field of air preheaters, in particular to a steam online air preheater anti-blocking device which comprises a steam gun barrel and a steam source, the steam source is communicated with the steam gun barrel and used for supplying high-temperature and high-pressure steam into the steam gun barrel, a nozzle is arranged on the steam gun barrel, and the nozzle is communicated with the steam gun barrel. And the nozzle is used for spraying high-temperature and high-pressure steam into the air preheater. The air preheater has the effect of reducing blockage of the air preheater.

Description

Technical Field

[0001] The present application relates to the technical field of air preheaters, and in particular to a steam online air preheater anti-blocking device. Background Art

[0002] Since the late 1990s, the air preheaters of coal-fired power units have basically adopted rotary air preheaters, which have the characteristics of small size and high heat exchange efficiency. However, the ash blockage at the cold end of the air preheater has always been a difficult problem to solve, especially the ash blockage at the cold end of the air preheater in the SCR denitrification system has gradually increased. The main reason is that the flue gas produced by the combustion of pulverized coal in coal-fired power plants contains SO3, and the catalyst of the SCR device has enhanced the SO3 conversion rate by nearly 1%. At the same time, in order to meet the national environmental protection requirements for NOx emissions, the amount of ammonia injection is increased, and SO3 will react with NH3 in the SCR device to form ammonium bisulfate (NH3+SO3+H2O→(NH4)HSO4). Ammonium bisulfate is sticky and adsorbs and adheres to the fly ash in the flue gas to block the channels of the air preheater heat exchange elements, increase the flue gas resistance, thereby increasing the power consumption of the three major fans, and affecting the heat exchange efficiency of the air preheater.

[0003] At present, the main measures for dealing with ash blockage are steam soot blowing and ultrasonic soot blowing during operation. However, since ammonium bisulfate has strong adhesion after solidification and is difficult to clean, the cleaning effect is not very obvious. Utility Model Content

[0004] The purpose of the present application is to provide a steam online air preheater anti-blocking device, which can reduce the blockage of the air preheater.

[0005] The present application provides a steam online air preheater anti-blocking device adopts the following technical solution:

[0006] A steam in-line air preheater anti-blocking device comprises a steam gun barrel and a steam source, wherein the steam source is connected to the steam gun barrel and is used to supply high-temperature and high-pressure steam into the steam gun barrel, and a nozzle is arranged on the steam gun barrel, and the nozzle is used to spray high-temperature and high-pressure steam into the air preheater.

[0007] By adopting the above technical solution, high-temperature and high-pressure steam is sprayed into the air preheater to decompose NH4HSO4 into gas and discharge it, thereby reducing the situation where NH4HSO4 is adsorbed and adhered to fly ash in the flue gas and blocks the channels of the air preheater heat exchange elements.

[0008] Optionally, it further includes a bracket and a driving member, the steam gun barrel is rotatably connected to the bracket, and the driving member is installed on the frame and is used to drive the steam gun barrel to rotate.

[0009] By adopting the above technical solution, when the nozzle does not spray high-temperature and high-pressure steam, the driving member drives the steam gun barrel to rotate so that the nozzle's spray direction is perpendicular to the flue gas entry direction, thereby reducing the situation where the spray is blocked by flue gas.

[0010] Optionally, a cooling box is provided between the steam source and the steam gun barrel, the cooling box is connected to the steam source and the steam gun barrel respectively, and the cooling box is connected to a condenser pipe for supplying condensed water into the cooling box.

[0011] By adopting the above technical solution, in order to save energy, the steam source adopts the high-temperature and high-pressure steam produced by the power plant boiler. Since the temperature of the high-temperature and high-pressure steam generated by the power plant boiler is greater than 450°C, by introducing condensed water into the cooling box, the temperature of the high-temperature and high-pressure steam is conveniently adjusted to ensure the temperature of the high-temperature and high-pressure steam entering the steam gun barrel.

[0012] Optionally, a nozzle is provided in the cooling box, and the condensing pipe is connected to the nozzle.

[0013] By adopting the above technical solution, the condensed water is converted into small water droplets through the nozzle and sprayed into the cooling box, so that the contact area between the condensed water and the high-temperature and high-pressure steam is increased, thereby increasing the cooling speed of the high-temperature and high-pressure steam.

[0014] Optionally, a check valve is installed on the condenser.

[0015] By adopting the above technical solution, the occurrence of back-steam is reduced by setting the check valve.

[0016] Optionally, a first regulating valve is installed on the condenser.

[0017] By adopting the above technical solution, a first regulating valve is installed on the condenser pipe, and the amount of condensed water sprayed from the nozzle is adjusted by the first regulating valve, thereby controlling the cooling amount of the high-temperature and high-pressure steam.

[0018] Optionally, a manual valve is installed on the condenser.

[0019] By adopting the above technical solution, when the anti-blocking device needs to be repaired, the manual valve is closed to increase the safety of the repair.

[0020] Optionally, a second regulating valve is provided between the steam source and the steam gun barrel, and the second regulating valve is used to adjust the gas supply of the steam source.

[0021] By adopting the above technical solution, the second regulating valve is used to adjust the supply amount of high-temperature and high-pressure steam from the steam source, thereby adjusting the pressure of the high-temperature and high-pressure steam to ensure that the pressure of the high-temperature and high-pressure steam supplied to the steam gun barrel is appropriate.

[0022] Optionally, the gas pressure of the high-temperature and high-pressure steam is 3-4MP.

[0023] By adopting the above technical solution, the gas pressure is 3-4MP, the decomposition effect of NH4HSO4 is better and the decomposition is more complete.

[0024] Optionally, the temperature of the high-temperature and high-pressure steam is 400-450°C.

[0025] By adopting the above technical solution, the decomposition effect of NH4HSO4 is better and more complete at a temperature of 400-450°C.

[0026] In summary, the present application includes at least one of the following beneficial technical effects:

[0027] 1. By injecting high-temperature and high-pressure steam into the air preheater, NH4HSO4 is decomposed into gas and discharged, thereby reducing the situation where NH4HSO4 adsorbs and adheres to fly ash in the flue gas and blocks the channels of the air preheater heat exchange elements;

[0028] 2. When the nozzle does not spray high-temperature and high-pressure steam, the driving member drives the steam gun barrel to rotate so that the nozzle's spray direction is perpendicular to the flue gas entry direction, thereby reducing the situation where the spray is blocked by the flue gas;

[0029] 3. In order to save energy, the steam source uses high-temperature and high-pressure steam produced by the power plant boiler. Since the temperature of the high-temperature and high-pressure steam generated by the power plant boiler is greater than 450°C, by introducing condensed water into the cooling box, it is convenient to adjust the temperature of the high-temperature and high-pressure steam to ensure the temperature of the high-temperature and high-pressure steam entering the steam gun barrel. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the overall structure of a steam online air preheater anti-blocking device according to an embodiment of the present application.

[0031] In the figure, 1, steam source; 2, steam gun barrel; 21, nozzle; 3, bracket; 4, driving member; 5, condenser; 51, check valve; 52, first regulating valve; 53, manual valve; 6, cooling box; 7, second regulating valve. DETAILED DESCRIPTION

[0032] The following is combined with Figure 1 , further details of this application are given.

[0033] A steam online air preheater anti-blocking device, referring to Figure 1, comprising a steam gun barrel 2 and a steam source 1. The steam gun barrel 2 is arranged in the air preheater and is located at the cold air inlet of the air preheater. The steam source 1 is connected to the steam gun barrel 2 and is used to supply high-temperature and high-pressure steam into the steam gun barrel 2. The pressure of the high-temperature and high-pressure steam is 3-4MP, and the temperature of the high-temperature and high-pressure steam is 400-450°C. Preferably, in this embodiment, the pressure of the high-temperature and high-pressure steam is 4MP, and the temperature is 450°C.

[0034] The steam gun barrel 2 is provided with a nozzle 21, which can be arranged toward the flue gas inlet of the air preheater. In this embodiment, the steam gun barrel 2 is provided with a plurality of nozzles 21, which are all arranged toward the flue gas inlet of the air preheater, and the surface of the nozzle 21 is treated with anti-wear, and the nozzle 21 is made of a high temperature and impact resistant material such as stainless steel or ceramic. When high temperature and high pressure steam is introduced into the steam gun barrel 2, it is sprayed toward the flue gas inlet through the nozzle 21, and mixed with the flue gas at the flue gas inlet. At about 200°C: NH4HSO4=NH3+ H2SO4; if it is suddenly heated to a high temperature of 400°C or violently impacted, explosive decomposition will occur: NH4HSO4=NH3↑+H2O+SO3↑, so NH4HSO4 will decompose into gas and be discharged, thereby reducing the situation where ammonium bisulfate and fly ash in the flue gas are adsorbed and bonded to block the channel of the heat exchange element of the air preheater.

[0035] In order to reduce the situation that the nozzle 21 is blocked by flue gas when not spraying high-temperature and high-pressure steam, a bracket 3 is fixedly connected in the air preheater, and the steam gun barrel 2 is rotatably connected to the bracket 3. A driving member 4 is installed on the bracket 3. The driving member 4 is used to drive the steam gun barrel 2 to rotate. When the nozzle 21 does not spray high-temperature and high-pressure steam, the driving member 4 drives the steam gun barrel 2 to rotate so that the spray direction of the nozzle 21 is perpendicular to the flue gas entry direction, thereby reducing the situation that the spray is blocked by flue gas. In this embodiment, the driving member 4 is a motor.

[0036] In order to save energy, the steam source 1 uses high-temperature and high-pressure steam produced by the power plant boiler. Since the temperature of the high-temperature and high-pressure steam generated by the power plant boiler is greater than 450°C, a cooling box 6 is provided between the steam source 1 and the steam gun barrel 2. The cooling box 6 is connected to the steam source 1 and the steam gun barrel 2 respectively. The high-temperature and high-pressure steam produced by the power plant boiler flows into the cooling box 6 for cooling, so that the temperature of the high-temperature and high-pressure steam entering the steam gun barrel 2 is appropriate.

[0037] The cooling box 6 is connected with a condenser pipe 5, through which condensed water is introduced into the cooling box 6, so that the condensed water contacts the high-temperature and high-pressure steam, thereby cooling the high-temperature and high-pressure steam. In this embodiment, in order to increase the cooling speed of the high-temperature and high-pressure steam, a nozzle is fixedly connected in the cooling box 6, and the condenser pipe 5 is connected with the nozzle. The nozzle converts the condensed water into small water droplets and sprays them into the cooling box 6, so that the contact area between the condensed water and the high-temperature and high-pressure steam is increased, thereby increasing the cooling speed of the high-temperature and high-pressure steam.

[0038] In order to save energy, the condensed water uses the condensed water of the power plant, because the temperature of the condensed water of the power plant is usually kept unchanged. In order to facilitate the adjustment of the temperature of the high-temperature and high-pressure steam, a first regulating valve 52 is installed on the condenser 5. The first regulating valve 52 is used to adjust the amount of condensed water sprayed from the nozzle, thereby controlling the cooling amount of the high-temperature and high-pressure steam.

[0039] In order to reduce the backflow of high-temperature and high-pressure steam, a check valve 51 is installed on the condenser 5. The backflow is reduced by setting the check valve 51. In order to increase the safety during maintenance, a manual valve 53 is installed on the condenser 5. When the anti-blocking device needs to be repaired, the manual valve 53 is closed to increase the safety of maintenance.

[0040] Since the high-temperature and high-pressure steam pressure generated by the power plant boiler is greater than 4MP, a second regulating valve 7 is provided between the steam source 1 and the steam gun barrel 2. The second regulating valve 7 is used to adjust the supply amount of the high-temperature and high-pressure steam of the steam source 1, thereby adjusting the pressure of the high-temperature and high-pressure steam. In this embodiment, the second regulating valve 7 is provided between the steam source 1 and the cooling box 6 to adjust the amount of the high-temperature and high-pressure steam delivered by the steam source 1 into the cooling box 6, thereby adjusting the pressure in the cooling box 6 to ensure that the pressure output to the steam gun barrel 2 meets the decomposition requirements of NH4HSO4.

[0041] The implementation principle of the embodiment of the present application is as follows: high-temperature and high-pressure steam is output from the power plant boiler and flows into the cooling box 6. The amount of high-temperature and high-pressure steam flowing into the cooling box 6 is adjusted by the second regulating valve 7, thereby controlling the pressure of the high-temperature and high-pressure steam flowing into the steam gun barrel 2. Condensed water is sprayed into the cooling box 6 to cool the high-temperature and high-pressure steam.

[0042] The regulated high-temperature and high-pressure steam is ejected through the nozzle 21 to react with NH4HSO4 in the flue gas, thereby decomposing NH4HSO4 to reduce the blockage of the air preheater.

[0043] When there is no need to spray high-temperature and high-pressure steam, the steam gun barrel 2 is driven to rotate by the driving member 4 so that the air outlet direction of the nozzle 21 is perpendicular to the flue gas inlet direction, thereby reducing the occurrence of nozzle 21 blockage.

[0044] The embodiments of this specific implementation are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. The same components are represented by the same figure marks. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A steam in-line air preheater anti-blocking device, characterized in that: The invention comprises a steam gun barrel (2) and a steam source (1), wherein the steam source (1) is connected to the steam gun barrel (2) and is used to supply high-temperature and high-pressure steam into the steam gun barrel (2), and the steam gun barrel (2) is provided with a nozzle (21), and the nozzle (21) is used to spray high-temperature and high-pressure steam into the air preheater.

2. The anti-blocking device for steam in-line air preheater according to claim 1 is characterized in that: It also comprises a bracket (3) and a driving member (4), wherein the steam gun barrel (2) is rotatably connected to the bracket (3), and the driving member (4) is mounted on the frame and is used to drive the steam gun barrel (2) to rotate.

3. The anti-blocking device for steam in-line air preheater according to claim 1 is characterized in that: A cooling box (6) is provided between the steam source (1) and the steam gun barrel (2); the cooling box (6) is connected to the steam source (1) and the steam gun barrel (2) respectively; and the cooling box (6) is connected to a condensation pipe (5) for supplying condensed water into the cooling box (6).

4. The anti-blocking device for steam in-line air preheater according to claim 3 is characterized in that: A nozzle is provided in the cooling box (6), and the condensing pipe (5) is connected to the nozzle.

5. The anti-blocking device for steam in-line air preheater according to claim 3 is characterized in that: A check valve (51) is installed on the condenser pipe (5).

6. The anti-blocking device for steam in-line air preheater according to claim 3 is characterized in that: A first regulating valve (52) is installed on the condenser tube (5).

7. The anti-blocking device for steam in-line air preheater according to claim 3 is characterized in that: A manual valve (53) is installed on the condenser tube (5).

8. A steam in-line air preheater anti-blocking device according to any one of claims 1 to 7, characterized in that: A second regulating valve (7) is provided between the steam source (1) and the steam gun barrel (2), and the second regulating valve (7) is used to adjust the gas supply volume of the steam source (1).

9. The anti-blocking device for steam in-line air preheater according to claim 1, characterized in that: The gas pressure of the high-temperature and high-pressure steam is 3-4MP.

10. The anti-blocking device for steam in-line air preheater according to claim 1, characterized in that: The temperature of the high-temperature and high-pressure steam is 400-450°C.

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