Ash removal device for air pre-heater

Abstract

The utility model provides an ash removal device for an air pre-heater, which comprises the air pre-heater, an air outlet of the air pre-heater is communicated with an air inlet of a boiler through a first pipeline, a smoke inlet of the air pre-heater is communicated with a smoke outlet of the boiler through a smoke inlet pipe, and a smoke outlet of the air pre-heater is communicated with a smoke outlet pipe; the ash removal assembly comprises two annular pipes arranged close to the two ends of the air pre-heater respectively and a plurality of horizontal pipes communicated between the two annular pipes; each annular pipe and each horizontal pipe are communicated with the air pre-heater through a plurality of connecting pipes, the first pipeline is communicated with one annular pipe through a second pipeline, and a temperature sensor and an electric heating wire electrically connected with the temperature sensor are arranged on the second pipeline. According to the method, the situation that the air pre-heater is blocked due to the fact that the liquid ammonium bisulfate adheres to fly ash particles in the smoke to form viscous accumulated ash on the heating surface of the air pre-heater is avoided as much as possible, and therefore the ash removal efficiency is improved, and the operation economical efficiency of the generator set is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of air preheaters, and in particular to a dust cleaning device for air preheaters. Background Art

[0002] Air preheater is generally referred to as air preheater. It is a heat exchanger that uses the exhaust heat of boilers and other equipment to preheat. The purpose is to reduce the exhaust temperature of boilers and other equipment, improve thermal efficiency, make fuel easier to ignite, burn stably and improve combustion efficiency.

[0003] In recent years, due to the sharp increase in coal costs, in order to ensure overall economic benefits, power plants have to burn a large amount of low-quality coal with high sulfur content, high ash content, high moisture content and low calorific value, resulting in a significant increase in sulfur oxides such as SO2 and SO3 in boiler flue gas and dust content in flue gas. SO3, excess NH3 and H2O at the outlet of the denitrification device react in the range of 146-207°C to generate liquid ammonium bisulfate. Liquid ammonium bisulfate has extremely strong adhesion and is easy to adhere to the fly ash particles in the flue gas to form sticky ash deposits on the heating surface of the air preheater, thereby causing blockage of the air preheater. If the heating surface of the air preheater is severely blocked, it will lead to increased operating resistance, poor boiler ventilation effect, increased fan power consumption, increased boiler exhaust temperature, and reduced boiler efficiency, which will seriously affect the economic operation of the generator set. Therefore, in order to avoid the above problems, a dust cleaning device for air preheater is urgently needed. Utility Model Content

[0004] The present application provides a dust cleaning device for an air preheater, which is used to solve the technical problems described in the above background technology.

[0005] In order to solve the above technical problems, this application adopts the following technical solutions:

[0006] The present application provides a dust cleaning device for an air preheater, comprising:

[0007] An air preheater, wherein the air outlet of the air preheater is connected to the air inlet of the boiler through a first pipe, the smoke inlet of the air preheater is connected to the smoke outlet of the boiler through a smoke inlet pipe, and the smoke outlet of the air preheater is connected to a smoke outlet pipe;

[0008] A cleaning component, the cleaning component includes two annular tubes respectively arranged near the two ends of the air preheater and a plurality of horizontal tubes connected between the two annular tubes; each of the annular tubes and each of the horizontal tubes are connected to the air preheater through a plurality of connecting tubes, the first pipe is connected to one of the annular tubes through a second pipe, and the second pipe is provided with a temperature sensor and an electric heating wire electrically connected to the temperature sensor.

[0009] Optionally, a compressed gas pipeline is connected to the pipe body of the second pipe close to the annular pipe connected thereto, and an end of the compressed gas pipeline away from the second pipe is connected to a gas compressor.

[0010] Optionally, an induced draft fan is provided on the smoke outlet pipe.

[0011] Optionally, one end of each connecting pipe connected to the air preheater is provided with a high-pressure nozzle for injecting high-temperature air into the air preheater.

[0012] Optionally, the high-pressure nozzle is made of stainless steel.

[0013] Optionally, an ultrasonic vibrator is provided on the outer wall of the air preheater.

[0014] Optionally, a first flow regulating valve and a second flow regulating valve are respectively provided on the pipe body of the first pipe between the second pipe and the boiler and on the pipe body of the second pipe close to the first pipe.

[0015] The cleaning device for an air preheater provided in the present application allows the flue gas discharged from the boiler to enter the air preheater and undergo heat exchange with the air entering the air preheater, so that the flue gas temperature is reduced and the air temperature is increased. The temperature of the air entering the second pipe from the air outlet of the air preheater and the first pipe is then detected by a temperature sensor. If the temperature detected by the temperature sensor is lower than the temperature at which ammonium bisulfate is converted into a gas, the hot air in the second pipe is heated by an electric heating wire to ensure that the temperature of the hot air entering the air preheater from the second pipe is higher than the temperature at which ammonium bisulfate is converted into a gas. The purpose is to convert the liquid ammonium bisulfate in the flue gas entering the air preheater into a gas and discharge it from the smoke outlet pipe to the outside of the air preheater along with the flue gas entering the air preheater. In addition, since each annular tube and each horizontal tube are connected to the air preheater through multiple connecting tubes, that is, the air preheater is evenly spaced in the axial and radial directions with multiple connecting tubes for introducing high-temperature air therein, the hot air entering the air preheater can be quickly and evenly distributed in the air preheater and vaporize the liquid ammonium bisulfate in the flue gas entering the air preheater, thereby avoiding as much as possible the liquid ammonium bisulfate adhering to the fly ash particles in the flue gas to form sticky ash deposits on the heating surface of the air preheater and causing blockage of the air preheater, thereby improving the cleaning efficiency and ensuring the economic operation of the generator set. 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, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. 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 A schematic diagram of the structure of a dust cleaning device for an air preheater provided in one embodiment of the present application;

[0018] Figure 2 A schematic structural diagram of a dust cleaning device for an air preheater provided in another embodiment of the present application;

[0019] Figure 3 A schematic structural diagram of a high-pressure nozzle disposed at one end of a connecting pipe connected to an air preheater provided in an embodiment of the present application;

[0020] Figure 4 A schematic structural diagram of an annular tube provided in one embodiment of the present application being connected to an air preheater via a connecting pipe.

[0021] In the figure: 100, air preheater; 101, ultrasonic vibrator; 200, first pipeline; 201, first flow regulating valve; 300, boiler; 400, smoke inlet pipe; 500, smoke outlet pipe; 501, induced draft fan; 600, ash cleaning component; 601, annular pipe; 602, horizontal pipe; 603, connecting pipe; 6031, high-pressure nozzle; 700, second pipeline; 701, temperature sensor; 702, second flow regulating valve; 800, compressed gas pipeline; 801, gas compressor. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application is clearly and completely described below. 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 also fall within the scope of protection of the present application.

[0023] refer to Figures 1 to 4 The present application provides a dust cleaning device for an air preheater, comprising:

[0024] The air preheater 100, the air outlet of the air preheater 100 is connected with the air inlet of the boiler 300 through the first pipe 200, the smoke inlet of the air preheater 100 is connected with the smoke outlet of the boiler 300 through the smoke inlet pipe 400, and the smoke outlet of the air preheater 100 is connected with the smoke outlet pipe 500; wherein, the air preheater 100 is also provided with an air inlet for introducing air therein, the exhaust gas temperature of the boiler 300 is generally between 120°C and 350°C, the smoke in the boiler 300 enters into the air preheater 100 through the air outlet and the smoke inlet pipe 400 thereon, and heat exchanges with the air entering into the air preheater 100 from the air inlet of the air preheater 100, after the heat exchange, the smoke temperature decreases and the air temperature increases.

[0025] The ash cleaning component 600 includes two annular tubes 601 respectively arranged near the two ends of the air preheater 100 and a plurality of horizontal tubes 602 connected between the two annular tubes 601; each annular tube 601 and each horizontal tube 602 are connected to the air preheater 100 through a plurality of connecting tubes 603, the first pipe 200 is connected to one of the annular tubes 601 through the second pipe 700, and the second pipe 700 is provided with a temperature sensor 701 and an electric heating wire electrically connected to the temperature sensor 701. The specifications and models of the temperature sensor 701 and the electric heating wire can be selected according to actual needs, so as to ensure that the electric heating wire wound on the second pipe 700 can quickly heat the air in the second pipe 700 in a short time, so as to ensure that the temperature of the hot air entering the flue gas space in the air preheater 100 from the second pipe 700 is greater than the temperature at which the ammonium bisulfate in the flue gas is converted into a gaseous state. Therefore, the present application does not specifically limit it here. The air with increased temperature in the air preheater 100 enters the second pipe 700 through the air outlet thereon and the first pipe 200, and the temperature of the hot air entering the second pipe 700 is detected by the temperature sensor 701. If the temperature detected by the temperature sensor 701 is lower than the temperature at which ammonium bisulfate is converted into gas, the hot air in the second pipe 700 is heated by the electric heating wire to ensure that the temperature of the hot air entering the air preheater 100 from the second pipe 700 is higher than the temperature at which ammonium bisulfate is converted into gas. The purpose is to convert the liquid ammonium bisulfate in the flue gas entering the air preheater 100 into gas and discharge it from the flue gas outlet pipe 500 to the outside of the air preheater 100 along with the flue gas entering the air preheater 100, thereby avoiding the liquid ammonium bisulfate from bonding to the fly ash particles in the flue gas to form sticky ash accumulation on the heating surface of the air preheater 100 and causing blockage of the air preheater 100. In addition, since each annular tube 601 and each horizontal tube 602 are connected to the air preheater 100 through multiple connecting tubes 603, that is, the air preheater 100 is evenly spaced in the axial and radial directions with multiple connecting tubes 603 for introducing high-temperature air therein, the hot air entering the air preheater 100 can be quickly and evenly distributed in the air preheater 100 and vaporize the liquid ammonium bisulfate in the flue gas entering the air preheater 100, thereby avoiding as much as possible the liquid ammonium bisulfate adhering to the fly ash particles in the flue gas to form sticky ash deposits on the heating surface of the air preheater 100 and causing blockage of the air preheater 100, thereby improving the cleaning efficiency and ensuring the economic operation of the generator set.

[0026] The present application provides a cleaning device for an air preheater. The flue gas in the boiler 300 enters the air preheater 100 through the air outlet and the smoke inlet pipe 400 thereon, and undergoes heat exchange with the air entering the air preheater 100. After the heat exchange, the flue gas temperature decreases and the air temperature increases. A portion of the air with the increased temperature in the air preheater 100 enters the second pipe 700 through the air outlet and the first pipe 200 thereon (a portion of the air with the increased temperature in the air preheater 100 will enter the boiler 300 through the first pipe 200 to provide the hot air required for combustion of the boiler 300, so that high-temperature flue gas is generated in the boiler 300, and heat exchange occurs between the high-temperature flue gas and the air in the air preheater 100, thereby obtaining hot air for cleaning the air preheater 100). The hot air entering the second pipe 700 is sensed by the temperature sensor 701. The temperature is detected. If the temperature detected by the temperature sensor 701 is lower than the temperature at which ammonium bisulfate is converted into a gas, the hot air in the second pipe 700 is heated by the electric heating wire to ensure that the temperature of the hot air in the second pipe 700 is higher than the temperature at which ammonium bisulfate is converted into a gas. After the hot air comes out of the second pipe 700, it enters the annular pipe 601, the horizontal pipe 602 and another annular pipe 601 connected thereto in sequence. The hot air entering each annular pipe 601 and each horizontal pipe 602 enters the air preheater 100 through the connecting pipe 603 connected thereto and vaporizes the liquid ammonium bisulfate in the flue gas entering the air preheater 100, thereby preventing the liquid ammonium bisulfate from adhering to the fly ash particles in the flue gas to form sticky ash accumulation on the heating surface of the air preheater 100 and causing blockage of the air preheater 100.

[0027] In some embodiments, reference Figure 2 In the present application, the second pipeline 700 is connected to a compressed gas pipeline 800 on the pipe body close to the annular pipe 601 connected thereto, and the end of the compressed gas pipeline 800 away from the second pipeline 700 is connected to a gas compressor 801. The compressed gas outlet of the gas compressor 801 is connected to one end of the compressed gas pipeline 800, and the end of the compressed gas pipeline 800 away from the gas compressor 801 is connected to the second pipeline 700. Specifically, the gas (which may be air, nitrogen, inert gas, etc.) enters the gas compressor 801 through the air inlet on the gas compressor 801, and after being compressed by the gas compressor 801, enters the second pipeline 700 from the compressed gas outlet on the gas compressor 801, thereby increasing the air pressure in the second pipeline 700, and is mixed with the hot air in the second pipeline 700 and applies a certain power to the hot air, so that the hot air is quickly rushed into the air preheater 100, and while gasifying the liquid ammonium bisulfate in the air preheater 100, a certain impact force can be applied to the heating surface in the air preheater 100, thereby flushing away the fly ash on the heating surface in the air preheater 100, further improving the cleaning efficiency in the air preheater 100.

[0028] In some embodiments, reference Figure 2 In the present application, an induced draft fan 501 is provided on the smoke outlet pipe 500. The induced draft fan 501 accelerates the circulation rate of the hot air and flue gas in the air preheater 100 through the gravitational force of the induced draft fan 501, thereby improving the gasification efficiency of the liquid ammonium bisulfate in the flue gas by the hot air, and further improving the ash cleaning efficiency in the air preheater 100.

[0029] In some embodiments, reference Figure 3 In the present application, one end of each connecting pipe 603 connected to the air preheater 100 is provided with a high-pressure nozzle 6031 for injecting high-temperature air into the air preheater 100. The high-pressure nozzle 6031 is provided with a plurality of jet holes, that is, the hot air is dispersed through the plurality of jet holes on the high-pressure nozzle 6031, so that the hot air entering the air preheater 100 is fully dispersed, thereby increasing the contact area between the hot air and the flue gas, so that the liquid ammonium bisulfate in the flue gas can be quickly gasified, thereby improving the cleaning efficiency in the air preheater 100.

[0030] In some embodiments, the high-pressure nozzle 6031 in the present application is made of stainless steel. According to the definition in GB / T20878-2007, stainless steel is steel with stainless and corrosion-resistant properties as the main characteristics, and the chromium content is at least 10.5%, and the carbon content is no more than 1.2%. The flue gas discharged from the boiler contains acidic gases (for example: sulfur oxides) and alkaline gases (nitrogen oxides). The high-pressure nozzle 6031 made of stainless steel can avoid the flue gas in the air preheater 100 from corroding the high-pressure nozzle 6031 after long-term use in the air preheater 100, and the heat-resistant temperature of the stainless steel material can be as high as 1300°C, thereby increasing the service life of the high-pressure nozzle 6031 in the air preheater 100.

[0031] In some embodiments, reference Figure 2 , an ultrasonic vibrator 101 is arranged on the outer wall of the air preheater 100 in the present application. Among them, the ultrasonic vibrator 101 is a device, also known as an ultrasonic vibrator, and the whole after the transducer and the horn are connected is called a vibrator. There can be multiple ultrasonic vibrators 101 in the present application, and the multiple ultrasonic vibrators 101 are evenly arranged on the outer wall of the shell of the air preheater 100, and the vibration force generated by the multiple ultrasonic vibrators 101 during the vibration process acts on the shell of the air preheater 100, so that the fly ash attached to the inner wall of the shell of the air preheater 100 is shaken off, further improving the cleaning efficiency of the air preheater 100. Specifically, the number, specifications and models of the ultrasonic vibrators 101 can be set according to actual needs. Therefore, this application does not make specific limitations on them.

[0032] In some embodiments, reference Figure 2In the present application, the first pipeline 200 is provided with a first flow regulating valve 201 and a second flow regulating valve 702 on the pipe body between the second pipeline 700 and the boiler 300 and on the pipe body of the second pipeline 700 close to the first pipeline 200. The specifications and models of the first flow regulating valve 201 and the second flow regulating valve 702 can be selected according to actual needs, so the present application does not specifically limit them.

[0033] In the above embodiment, before the air preheater 100 is cleaned, the second flow regulating valve 702 is closed, and the first flow regulating valve 201 is opened, that is, the hot air in the air preheater 100 that has increased in temperature after heat exchange with the flue gas only enters the boiler 300 through the air outlet of the air preheater 100, the first pipeline 200 and the air inlet of the boiler 300, and provides the boiler 300 with the air required for the combustion of the fuel therein, and the high-temperature flue gas generated by the combustion of the fuel and the hot air in the boiler 300 enters the air preheater 100 through the air outlet of the boiler 300 and the smoke inlet pipe 400 and enters the air preheater 100 and the air preheater 300. The air in the air preheater 100 undergoes heat exchange, so that the air temperature rises (the air temperature is greater than the temperature at which ammonium bisulfate is converted into gas). After the air temperature in the air preheater 100 rises, the second flow regulating valve 702 is opened to start cleaning the air preheater 100, so that the air after the temperature rises passes through the second pipe 700 and then enters the air preheater 100 to convert the liquid ammonium bisulfate in the flue gas in the air preheater 100 into gas and is discharged from the flue gas outlet pipe 500 to the outside of the air preheater 100 together with the flue gas entering the air preheater 100, thereby achieving the purpose of cleaning the air preheater 100. In the above-mentioned cleaning process, the amount of hot air entering the boiler 300 can be accurately adjusted by the first flow regulating valve 201, so that the hot air entering the boiler 300 fully reacts with the fuel therein, avoiding the excessive hot air entering the boiler 300, which causes a large air pressure in the boiler 300 and affects the normal operation of the boiler 300. The second flow regulating valve 702 can be used to adjust the flow rate of hot air entering the second pipeline 700, so as to control the amount of hot air used in the process of cleaning the air preheater 100.

[0034] 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, ordinary technicians in the field should understand that they can still modify the technical solutions recorded 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. A dust cleaning device for an air preheater, characterized in that: include: An air preheater (100), wherein an air outlet of the air preheater (100) is connected to an air inlet of a boiler (300) via a first pipe (200), a smoke inlet of the air preheater (100) is connected to a smoke outlet of the boiler (300) via a smoke inlet pipe (400), and a smoke outlet of the air preheater (100) is connected to a smoke outlet pipe (500); A cleaning component (600), the cleaning component (600) comprising two annular tubes (601) respectively arranged near the two ends of the air preheater (100) and a plurality of horizontal tubes (602) connected between the two annular tubes (601); each of the annular tubes (601) and each of the horizontal tubes (602) are connected to the air preheater (100) via a plurality of connecting tubes (603), the first pipeline (200) is connected to one of the annular tubes (601) via a second pipeline (700), and a temperature sensor (701) and an electric heating wire electrically connected to the temperature sensor (701) are arranged on the second pipeline (700).

2. The dust cleaning device for air preheater according to claim 1, characterized in that: The second pipeline (700) is connected to a compressed gas pipeline (800) on the pipe body close to the annular pipe (601) connected thereto, and the compressed gas pipeline (800) is connected to a gas compressor (801) at one end away from the second pipeline (700).

3. The dust cleaning device for air preheater according to claim 1, characterized in that: The smoke outlet pipe (500) is provided with an induced draft fan (501).

4. The dust cleaning device for air preheater according to claim 1, characterized in that: One end of each connecting pipe (603) that is in communication with the air preheater (100) is provided with a high-pressure nozzle (6031) for injecting high-temperature air into the air preheater (100).

5. The dust cleaning device for air preheater according to claim 4, characterized in that: The high-pressure nozzle (6031) is made of stainless steel.

6. The dust cleaning device for air preheater according to claim 1, characterized in that: An ultrasonic vibrator (101) is arranged on the outer wall of the air preheater (100).

7. The dust cleaning device for air preheater according to any one of claims 1 to 6, characterized in that: The first pipeline (200) is provided with a first flow regulating valve (201) and a second flow regulating valve (702) on the pipeline body between the second pipeline (700) and the boiler (300) and on the pipeline body of the second pipeline (700) close to the first pipeline (200), respectively.

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