Anti-blocking system of rotary air pre-heater

Abstract

The utility model relates to the technical field of rotary air pre-heaters, and discloses an anti-blocking system of a rotary air pre-heater, which is characterized in that a circulating air sealing sector plate is additionally arranged at the cold end of the rotary air pre-heater to form a circulating air inlet with an original second sealing sector plate; and part of hot secondary air is led out from the hot secondary air mother pipe through the hot secondary air branch pipeline and conveyed to the circulating air inlet, so that the hot secondary air can be utilized to preheat the cold-end heat storage element which is about to enter the smoke side, on one hand, the surface temperature of the cold-end heat storage element can reach the acid dew point or above, formation of acid mist is reduced, and the energy consumption is reduced. Therefore, the formation of sulfate taking CaSO4 as a main component can be reduced; and on the other hand, the ammonium hydrogen sulfate deposition area is promoted to move downwards, the steam soot blowing effect can be improved, and then the air pre-heater blocking risk can be reduced.

Description

Technical Field

[0001] The present application relates to the technical field of rotary air preheaters, and in particular to an anti-clogging system for rotary air preheaters. Background Art

[0002] Rotary air preheater is widely used in coal-fired power plants as an important heat exchange equipment at the tail of the boiler due to its compact structure, high heat exchange efficiency and flexible layout.

[0003] However, since the flue gas introduced into the rotary air preheater contains fly ash, escaped ammonia, SO 3 Gas and water, etc., below the acid dew point, SO 3 The gas will combine with water to form acid mist, which will further react with fly ash to form CaSO 4 Sulfate, mainly composed of sulphate, is adsorbed on the surface of the heat storage element of the rotary air preheater. 3 Ammonium bisulfate generated by the reaction of gas and water also adheres to the surface of the heat storage element of the rotary air preheater. The ammonium bisulfate adhered to the surface of the heat storage element further adsorbs fly ash, causing the fly ash to be deposited on the surface of the heat storage element.

[0004] The above reasons lead to widespread blockage in rotary air preheaters, which in turn causes the power consumption of the three major fans to increase and the heat exchange efficiency of the rotary air preheaters to decrease. When the blockage is severe, it will affect the full load operation of the unit and even the safety and stability of the unit operation. Utility Model Content

[0005] The purpose of the present application is to overcome the problem in the prior art that blockage of a rotary air preheater leads to reduced unit load and unit operation safety, and to provide a rotary air preheater anti-blockage system.

[0006] In order to achieve the above-mentioned purpose, the present application provides a rotary air preheater anti-clogging system, the rotary air preheater anti-clogging system comprising a rotary air preheater, a circulating air sealing fan plate, a hot secondary air main pipe and a hot secondary air branch pipe;

[0007] The rotary air preheater is connected to the hot secondary air main pipe, the flue gas duct of the rotary air preheater is the flue gas side, the primary air duct of the rotary air preheater is the primary air side, and the secondary air duct of the rotary air preheater is the secondary air side;

[0008] The cold end of the rotary air preheater is provided with a first sealing fan plate and a second sealing fan plate, wherein the first sealing fan plate is located between the primary air side and the flue gas side, and the second sealing fan plate is located between the secondary air side and the flue gas side;

[0009] The circulating air sealing sector plate is arranged on the secondary air side of the cold end of the rotary air preheater, and a circulating air inlet is formed between the circulating air sealing sector plate and the second sealing sector plate;

[0010] The inlet of the hot secondary air branch pipeline is connected to the hot secondary air main pipe, and the outlet of the hot secondary air branch pipeline is connected to the circulating air inlet.

[0011] In the embodiment of the present application, the rotary air preheater anti-clogging system further includes a circulating fan, a first valve and a second valve;

[0012] The circulating fan, the first valve and the second valve are all arranged on the hot secondary air branch pipeline, the first valve is located upstream of the circulating fan, and the second valve is located downstream of the circulating fan.

[0013] In the embodiment of the present application, the rotary air preheater anti-clogging system further comprises a cold end hot secondary air leakage introduction pipeline, and the second sealing sector plate is provided with an air extraction port;

[0014] The inlet of the cold-end hot secondary air leakage introduction pipeline is communicated with the air extraction port on the second sealing fan-shaped plate, and the outlet of the cold-end hot secondary air leakage introduction pipeline is communicated with the target position of the hot secondary air branch pipeline.

[0015] In an embodiment of the present application, the rotary air preheater anti-blocking system also includes a third valve, which is arranged on the cold-end hot secondary air leakage introduction pipeline, and the target position is located upstream of the circulating fan.

[0016] In the embodiment of the present application, the rotary air preheater anti-blocking system further comprises a hot end hot primary air leakage introduction pipeline, the hot end of the rotary air preheater is provided with a third sealing fan plate, the third sealing fan plate is located between the primary air side and the flue gas side, and an air extraction port is provided on the third sealing fan plate;

[0017] The inlet of the hot end hot primary air leakage introduction pipeline is connected to the air extraction port on the third sealing fan-shaped plate, and the outlet of the hot end hot primary air leakage introduction pipeline is connected to the target position of the hot secondary air branch pipeline.

[0018] In the embodiment of the present application, the rotary air preheater anti-clogging system further includes a fourth valve;

[0019] The fourth valve is arranged on the hot end hot primary air leakage introduction pipeline, and the target position is located upstream of the circulation fan.

[0020] In the embodiment of the present application, the rotary air preheater anti-clogging system further comprises a hot end hot secondary air leakage introduction pipeline, the hot end of the rotary air preheater is provided with a fourth sealing fan plate, the fourth sealing fan plate is located between the secondary air side and the flue gas side, and an air extraction port is provided on the fourth sealing fan plate;

[0021] The inlet of the hot end hot secondary air leakage introduction pipeline is connected to the air extraction port on the fourth sealing fan-shaped plate, and the outlet of the hot end hot secondary air leakage introduction pipeline is connected to the target position of the hot secondary air branch pipeline.

[0022] In the embodiment of the present application, the rotary air preheater anti-clogging system further includes a fifth valve;

[0023] The fifth valve is arranged on the hot end hot secondary air leakage introduction pipeline, and the target position is located upstream of the circulation fan.

[0024] In the embodiment of the present application, the rotary air preheater anti-blocking system further includes a cold secondary air main pipe and a cold secondary air branch pipe;

[0025] The cold secondary air main pipe is connected to the rotary air preheater, the inlet of the cold secondary air branch pipeline is connected to the cold secondary air main pipe, and the outlet of the cold secondary air branch pipeline is connected to the hot secondary air branch pipeline.

[0026] In an embodiment of the present application, the rotary air preheater anti-blocking system also includes a sixth valve, and the sixth valve is arranged on the cold secondary air branch pipeline.

[0027] Through the above-mentioned rotary air preheater anti-clogging system, the rotary air preheater anti-clogging system includes a rotary air preheater, a circulating air sealing fan plate, a hot secondary air main pipe and a hot secondary air branch pipeline; the rotary air preheater is connected to the hot secondary air main pipe, the flue gas duct of the rotary air preheater is the flue gas side, the primary air duct of the rotary air preheater is the primary air side, and the secondary air duct of the rotary air preheater is the secondary air side; the cold end of the rotary air preheater is provided with a first sealing fan plate and a second sealing fan plate, the first sealing fan plate is located between the primary air side and the flue gas side, and the second sealing fan plate is located between the secondary air side and the flue gas side; the circulating air sealing fan plate is arranged on the secondary air side of the cold end of the rotary air preheater, and a circulating air inlet is formed between the circulating air sealing fan plate and the second sealing fan plate; the inlet of the hot secondary air branch pipeline is connected to the hot secondary air main pipe, and the outlet of the hot secondary air branch pipeline is connected to the circulating air inlet. Based on the solution provided in the embodiment of the present application, part of the hot secondary air is introduced to preheat the heat storage element that is about to enter the flue gas side. On the one hand, the surface temperature of the heat storage element can reach above the acid dew point, reducing the formation of acid mist, thereby reducing the CaSO4 On the other hand, the downward movement of the ammonium bisulfate deposition area can improve the steam soot blowing effect and thus reduce soot accumulation.

[0028] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the accompanying drawings:

[0030] Figure 1 and Figure 2 The structure diagram of a rotary air preheater anti-clogging system according to an embodiment of the present application is schematically shown;

[0031] Figure 3 The schematic diagram shows the structure of another rotary air preheater anti-clogging system according to an embodiment of the present application;

[0032] Figure 4 The structural diagram of another rotary air preheater anti-clogging system according to an embodiment of the present application is schematically shown.

[0033] Description of Reference Numerals

[0034] 101—rotary air preheater; 1011—first sealing fan plate; 1012—second sealing fan plate; 1013—third sealing fan plate; 1014—fourth sealing fan plate; 102—circulating air sealing fan plate; 103—hot secondary air main pipe; 104—hot secondary air branch pipe; 105—circulating air inlet; 106—circulating fan; 107—first valve; 108—second valve; 109—cold end hot secondary air leakage introduction pipe; 110—third valve; 111—hot end hot primary air leakage introduction pipe 112—the fourth valve; 113—the hot end hot secondary air leakage introduction pipeline; 114—the fifth valve; 115—the cold secondary air mother pipe; 116—the cold secondary air branch pipeline; 117—the sixth valve; 118—the first pressure detection device; 119—the second pressure detection device; 120—the third pressure detection device; 121—the fourth pressure detection device; 122—the fifth pressure detection device; 123—the sixth pressure detection device; 124—the control server; 125—the hot end hot air pipeline; 126—the seventh valve. DETAILED DESCRIPTION

[0035] 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 will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the specific implementation methods described herein are only used to illustrate and explain the embodiments of the present application, and are not used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0036] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0037] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0038] As described in the background technology, the rotary air preheater is widely used in coal-fired power plants as an important heat exchange equipment at the tail of the boiler due to its compact structure, high heat exchange efficiency and flexible layout. However, rotary air preheaters are generally blocked. The design pressure drop on the flue gas side of the rotary air preheater is usually 1.0kPa~1.2kPa, but in actual operation, the pressure drop on the flue gas side of the rotary air preheater due to blockage is as high as 1.5kPa~1.8kPa, or even more than 2.0kPa. The reasons for the blockage of the rotary air preheater include: the flue gas introduced into the rotary air preheater contains fly ash, escaped ammonia, SO 3 Gas and water, etc., below the acid dew point, SO 3 The gas will combine with water to form acid mist, which will not only corrode the thermal storage components, but also react with fly ash to form CaSO 4 Sulfate, mainly composed of sulphate, is adsorbed on the surface of the heat storage element of the rotary air preheater. In addition, the escaped ammonia and SO 3Gas and water react to form ammonium bisulfate. Above 207°C, ammonium bisulfate exists in gaseous form, and below 146°C, ammonium bisulfate exists in the form of solid particles. Gaseous and solid ammonium bisulfate can generally be carried away from the rotary air preheater by the flue gas flow, and basically will not cause the rotary air preheater to be blocked. At 146°C to 207°C, ammonium bisulfate exists in the form of a highly viscous liquid, which can adhere to the surface of the heat storage element and further adsorb fly ash in the flue gas and deposit on the surface of the heat storage element. In practical applications, the blockage of the rotary air preheater will lead to insufficient output of the induced draft fan, resulting in a reduction in the unit load and inability to operate at full load. At the same time, the unit is usually equipped with two rotary air preheaters, and the blockage conditions of the two rotary air preheaters are often inconsistent, resulting in inconsistent pressure drops on the flue gas side of each rotary air preheater, resulting in significant fluctuations in furnace pressure and deviation of the flame center, thereby threatening the safe operation of the boiler. In addition, when the rotary air preheater is blocked, in order to achieve sufficient output, the operating current of the induced draft fan and the forced draft fan needs to increase, resulting in an increase in the power consumption rate of the plant. At an operating load of 30%, the power consumption rate of the plant increases to about 10%.

[0039] In view of this, an embodiment of the present application provides a rotary air preheater anti-clogging system, such as Figure 1 and Figure 2 As shown (where Figure 1 This is a schematic diagram of the cold end of the rotary air preheater. Figure 2 Schematic diagram of the hot end of a rotary air preheater), the anti-clogging system of the rotary air preheater may include a rotary air preheater 101, a circulating air sealing fan-shaped plate 102, a hot secondary air mother pipe 103 and a hot secondary air branch pipe 104; the rotary air preheater 101 is connected to the hot secondary air mother pipe 103; the flue gas duct of the rotary air preheater 101 is the flue gas side, the primary air duct of the rotary air preheater 101 is the primary air side, and the secondary air duct of the rotary air preheater 101 is the secondary air side; the cold end of the rotary air preheater 101 is provided with a first sealing fan-shaped plate 1011 and a first sealing fan-shaped plate 1012. Two sealing fan-shaped plates 1012, the first sealing fan-shaped plate 1011 is located between the primary air side and the flue gas side, and the second sealing fan-shaped plate 1012 is located between the secondary air side and the flue gas side; the circulating air sealing fan-shaped plate 102 is arranged on the secondary air side of the cold end of the rotary air preheater 101, and a circulating air inlet 105 is formed between the circulating air sealing fan-shaped plate 102 and the second sealing fan-shaped plate 1012; the inlet of the hot secondary air branch pipeline 104 is connected to the hot secondary air main pipe 103, and the outlet of the hot secondary air branch pipeline 104 is connected to the circulating air inlet 105.

[0040] In the rotary air preheater 101, the flue gas can flow from top to bottom, and the primary air and the secondary air can flow from bottom to top. Figure 1 and Figure 2 The gas flow direction is shown by the arrows.

[0041] The flue gas side can be understood as the air duct for passing flue gas in the rotary air preheater 101, referred to as the flue gas duct; the primary air side can be understood as the air duct for passing primary air in the rotary air preheater 101, referred to as the primary air duct; the secondary air side can be understood as the air duct for passing secondary air in the rotary air preheater 101, referred to as the secondary air duct. The hot end of the rotary air preheater 101 can be the end corresponding to the entrance of hot flue gas, and the cold end of the rotary air preheater 101 can be the end corresponding to the outflow of cold flue gas.

[0042] In the rotary air preheater 101, cold secondary air enters the rotary air preheater 101 and undergoes heat exchange to obtain hot secondary air, and the hot secondary air main pipe 103 can be used to lead hot secondary air from the rotary air preheater 101. The hot secondary air branch pipe 104 can be used to lead part of the hot secondary air from the hot secondary air main pipe 103.

[0043] In the embodiment of the present application, the circulating air inlet 105 formed between the circulating air sealing fan plate 102 and the second sealing fan plate 1012 can correspond to one or more bins. Furthermore, the inlet of the hot secondary air branch pipeline 104 is connected to the hot secondary air mother pipe 103, and the outlet of the hot secondary air branch pipeline 104 is connected to the circulating air inlet 105, which can be understood as: the hot secondary air branch pipeline 104 draws out part of the hot secondary air from the hot secondary air mother pipe 103, and inputs the drawn hot secondary air into the corresponding bin through the circulating air inlet 105. In this way, the hot secondary air can be used to preheat the heat storage element that is about to enter the flue gas side, especially the part of the heat storage element corresponding to the cold end of the rotary air preheater 101.

[0044] Specifically, the preheating process can be: Figure 1 Taking the cold end of the rotary air preheater 101 as an example, the rotation direction of the rotor in the rotary air preheater 101 is clockwise. During the rotation of the rotor, the cells on the secondary air side rotate to the positions corresponding to the circulating air inlet 105 in turn, and the cells that rotate to the circulating air inlet 105 are heated by the hot secondary air introduced by the hot secondary air branch pipe 104, and then the cells rotate to the flue gas side.

[0045] In practical applications, in order to take into account the preheating effect and reduce the hot secondary air drawn out by the hot secondary air branch pipe 104, preferably, the circulating air inlet 105 between the circulating air sealing fan plate 102 and the second sealing fan plate 1012 can correspond to only one compartment. In this way, while reducing the hot secondary air drawn out by the hot secondary air branch pipe 104, each heat storage element that is about to enter the flue gas side can also be preheated.

[0046] In the embodiment of the present application, while a circulating air sealing fan plate 102 is added to the secondary air side of the cold end of the rotary air preheater 101, the sealing fan plate at the hot end of the rotary air preheater 101 may not be adjusted, and no sealing fan plate is added. Figure 3 As shown ( Figure 3 The rotary air preheater 101 rotates clockwise. Then, the hot secondary air entering the rotary air preheater 101 through the circulating air inlet 105 can enter the hot secondary air main pipe 103 again after preheating the heat storage element. Thus, a hot secondary air circulation can be formed in the rotary air preheater 101, the hot secondary air main pipe 103 and the hot secondary air branch pipe 104.

[0047] In a specific implementation, in order to facilitate the introduction of hot secondary air into the circulating air inlet 105 and the above-mentioned circulation process of the hot secondary air, the rotary air preheater anti-blocking system may also include a circulating fan 106, a first valve 107 and a second valve 108; the circulating fan 106, the first valve 107 and the second valve 108 are all arranged on the hot secondary air branch pipeline 104, the first valve 107 is located upstream of the circulating fan 106, and the second valve 108 is located downstream of the circulating fan 106.

[0048] It can be understood that the anti-clogging system for the rotary air preheater provided in the embodiment of the present application includes a rotary air preheater 101, a circulating air sealing fan-shaped plate 102, a hot secondary air mother pipe 103 and a hot secondary air branch pipe 104; the rotary air preheater 101 is connected to the hot secondary air mother pipe 103; the flue gas duct of the rotary air preheater 101 is the flue gas side, the primary air duct of the rotary air preheater 101 is the primary air side, and the secondary air duct of the rotary air preheater 101 is the secondary air side; the cold end of the rotary air preheater 101 is provided with a first sealing fan-shaped plate 101 1 and the second sealing fan-shaped plate 1012, the first sealing fan-shaped plate 1011 is located between the primary air side and the flue gas side, and the second sealing fan-shaped plate 1012 is located between the secondary air side and the flue gas side; the circulating air sealing fan-shaped plate 102 is arranged on the secondary air side of the cold end of the rotary air preheater 101, and a circulating air inlet 105 is formed between the circulating air sealing fan-shaped plate 102 and the second sealing fan-shaped plate 1012; the inlet of the hot secondary air branch pipeline 104 is connected to the hot secondary air main pipe 103, and the outlet of the hot secondary air branch pipeline 104 is connected to the circulating air inlet 105. Based on the scheme provided in the embodiment of the present application, the heat storage element that is about to enter the flue gas side is preheated by drawing out part of the hot secondary air. On the one hand, the temperature of the surface of the heat storage element can be above the acid dew point, reducing the formation of acid mist, thereby reducing corrosion and CaSO 4On the other hand, the downward movement of the ammonium bisulfate deposition area can improve the subsequent steam soot blowing effect, thereby reducing soot accumulation.

[0049] In the prior art, the temperature distribution of the heat storage element that has not been heated by circulating hot secondary air is: the hot end temperature is above 207°C, the middle section temperature is 146°C to 207°C, and the cold end temperature is below 146°C. After being heated by the circulating hot secondary air provided in the embodiment of the present application, the middle section temperature of the heat storage element is above 207°C, and the cold end temperature is 146°C to 207°C, so that the ammonium bisulfate deposition area moves downward. In the prior art, in order to further reduce dust accumulation, high-temperature and high-pressure superheated steam is usually introduced to blow soot on the heat storage element at a regular interval, and the steam is blown from the cold end of the heat storage element to the hot end of the heat storage element. Through the solution provided in the embodiment of the present application, after the ammonium bisulfate deposition area moves downward, the steam soot blowing distance can be reduced, thereby improving the steam soot blowing effect and further reducing dust accumulation.

[0050] In addition, since the solution provided by the above embodiment of the present application uses hot secondary air as circulating air to heat the heat storage element that is about to enter the flue gas side, and the dust content of the secondary air is low, which is much lower than the dust content in the flue gas, the wear on the circulating fan 106 can be reduced. In the solution provided by the above embodiment of the present application, since the sealing fan plate at the hot end of the rotary air preheater 101 is not adjusted, the hot secondary air entering the rotary air preheater 101 through the circulating air inlet 105 will preheat the heat storage element and will be mixed with other hot secondary air on the secondary air side and enter the hot secondary air main pipe 103, and then part of the hot secondary air will be drawn from the hot secondary air main pipe 103 to the hot secondary air branch pipe 104. In this way, the accumulation of dust in the circulating air can be avoided, and the cost of system transformation can be reduced.

[0051] Considering that when the hot secondary air branch pipeline 104 inputs the hot secondary air into the circulating air inlet 105, due to the pressure difference, part of the hot secondary air will leak from the secondary air side to the flue gas side, in order to reduce the leakage rate of the rotary air preheater 101 and further improve the preheating effect of the heat storage element, in one embodiment, the rotary air preheater anti-blocking system provided in the embodiment of the present application also includes a cold-end hot secondary air leakage inlet pipeline 109, and an exhaust port A is opened on the second sealing fan-shaped plate 1012; the inlet of the cold-end hot secondary air leakage inlet pipeline 109 is connected to the exhaust port A on the second sealing fan-shaped plate 1012, and the outlet of the cold-end hot secondary air leakage inlet pipeline 109 is connected to the target position B of the hot secondary air branch pipeline 104.

[0052] Among them, along the flow direction of the secondary air on the secondary air side, the opening size of the air extraction port A can be gradually reduced. Preferably, the air extraction port A can be conical. The number of air extraction ports A opened on the second sealing fan-shaped plate 1012 can be multiple, for example, 3 to 5. These multiple air extraction ports A can be arranged along the bisector of the second sealing fan-shaped plate 1012; more preferably, on the bisector of the second sealing fan-shaped plate 1012, these multiple air extraction ports A can be evenly arranged at equal distances. In this way, the air extraction effect can be improved.

[0053] The target position B can be located upstream of the circulation fan 106, specifically, between the first valve 107 and the circulation fan 106, thereby, one fan can provide power for two pipelines (the hot secondary air branch pipeline 104 and the cold end hot secondary air leakage introduction pipeline 109), thereby reducing the transformation cost.

[0054] In specific implementation, in order to facilitate the control of the gas flowing in the cold-end hot secondary air leakage introduction pipeline 109, the rotary air preheater anti-blocking system can also include a third valve 110, and the third valve 110 is arranged on the cold-end hot secondary air leakage introduction pipeline 109.

[0055] It can be understood that by adopting the above solution, the leaked hot secondary air can be extracted from the air extraction port A and introduced into the hot secondary air branch pipeline 104. In this way, the hot air volume of the preheating heat storage element can be increased, the preheating effect can be improved, and the air leakage of the rotary air preheater 101 can be reduced.

[0056] Taking into account that at the hot end of the rotary air preheater 101, when the hot primary air is output from the primary air side, due to the pressure difference, part of the hot primary air will leak from the primary air side to the flue gas side, in order to further reduce the leakage rate of the rotary air preheater 101 and improve the preheating effect of the heat storage element, in one embodiment, the rotary air preheater anti-blocking system also includes a hot end hot primary air leakage introduction pipeline 111, and the hot end of the rotary air preheater 101 is provided with a third sealing fan plate 1013, and the third sealing fan plate 1013 is located between the primary air side and the flue gas side, and an exhaust port A is opened on the third sealing fan plate 1013; the inlet of the hot end hot primary air leakage introduction pipeline 111 is connected to the exhaust port A on the third sealing fan plate 1013, and the outlet of the hot end hot primary air leakage introduction pipeline 111 is connected to the target position B of the hot secondary air branch pipeline 104.

[0057] Among them, the air exhaust port A on the third sealing fan-shaped plate 1013 can be set with reference to the air exhaust port A on the second sealing fan-shaped plate 1012, and will not be repeated here.

[0058] The target position B can be found in the previous description and will not be described again here.

[0059] In specific implementation, in order to facilitate the control of the gas flowing in the hot end hot primary air leakage introduction pipeline 111, the rotary air preheater anti-blocking system can also include a fourth valve 112; the fourth valve 112 is arranged on the hot end hot primary air leakage introduction pipeline 111.

[0060] It can be understood that by adopting the above solution, the leaked hot primary air can be extracted from the air extraction port A and introduced into the hot secondary air branch pipe 104. In this way, the hot air volume of the preheating heat storage element can be increased, the preheating effect can be improved, and the air leakage of the rotary air preheater 101 can be reduced.

[0061] Taking into account that at the hot end of the rotary air preheater 101, when the hot secondary air is output from the secondary air side, due to the pressure difference, part of the hot secondary air will leak from the secondary air side to the flue gas side, in order to further reduce the leakage rate of the rotary air preheater 101 and improve the preheating effect of the heat storage element, in one embodiment, the rotary air preheater anti-blocking system also includes a hot end hot secondary air leakage introduction pipeline 113, and the hot end of the rotary air preheater is provided with a fourth sealing fan plate 1014, and the fourth sealing fan plate 1014 is located between the secondary air side and the flue gas side, and the fourth sealing fan plate 1014 is provided with an exhaust port A. The inlet of the hot end hot secondary air leakage introduction pipeline 113 is connected to the exhaust port A on the fourth sealing fan plate 1014, and the outlet of the hot end hot secondary air leakage introduction pipeline 113 is connected to the target position B of the hot secondary air branch pipeline 104.

[0062] Among them, the air exhaust port A on the fourth sealing fan-shaped plate 1014 can be set with reference to the air exhaust port A on the second sealing fan-shaped plate 1012, and will not be repeated here.

[0063] The target position B can be found in the previous description and will not be described again here.

[0064] In specific implementation, in order to facilitate the control of the flow of gas in the hot end hot secondary air leakage introduction pipeline 113, the rotary air preheater anti-blocking system can also include a fifth valve 114; the fifth valve 114 is arranged on the hot end hot secondary air leakage introduction pipeline 113.

[0065] It can be understood that by adopting the above solution, the leaked hot secondary air can be extracted from the air extraction port A and introduced into the hot secondary air branch pipeline 104. In this way, the hot air volume of the preheating heat storage element can be increased, the preheating effect can be improved, and the air leakage of the rotary air preheater 101 can be reduced.

[0066] In practical applications, in one embodiment, the rotary air preheater anti-blocking system provided in the embodiment of the present application further includes a cold secondary air main pipe 115 and a cold secondary air branch pipe 116, such as Figure 4As shown; the cold secondary air main pipe 115 is connected to the rotary air preheater 101, the inlet of the cold secondary air branch pipeline 116 is connected to the cold secondary air main pipe 115, and the outlet of the cold secondary air branch pipeline 116 is connected to the hot secondary air branch pipeline 104.

[0067] The cold secondary air enters the secondary air side from the cold end of the rotary air preheater 101 via the cold secondary air main pipe 115. The cold secondary air branch pipe 116 can be used to lead out part of the cold secondary air from the cold secondary air main pipe 115.

[0068] In the implementation of the present application, the inlet of the cold secondary air branch pipeline 116 is connected to the cold secondary air main pipe 115, and the outlet of the cold secondary air branch pipeline 116 is connected to the hot secondary air branch pipeline 104. It can be understood that the cold secondary air branch pipeline 116 draws out part of the cold secondary air from the cold secondary air main pipe 115, and inputs the drawn cold secondary air into the hot secondary air branch pipeline 104.

[0069] In order to facilitate the control of the flow of gas in the cold secondary air branch pipeline 116, the rotary air preheater anti-blocking system may further include a sixth valve 117, which is arranged on the cold secondary air branch pipeline 116. At the same time, in order to realize the independent control of the cold secondary air branch pipeline 116 and the hot secondary air branch pipeline 104, the position where the cold secondary air branch pipeline 116 is connected to the hot secondary air branch pipeline 104 may be located downstream of the second valve 108.

[0070] It can be understood that by adopting the above scheme, when the design selection margin of the rotary air preheater 101 is too small, resulting in limited heat exchange capacity or insufficient power of the blower when the coal-fired unit is running at full load, by setting the cold secondary air branch pipeline 116, when the anti-ash blocking function is not implemented, the cold secondary air can enter the circulating air inlet 105. At this time, the sum of the cross-sectional area of ​​the circulating air inlet 105 and the cross-sectional area of ​​the cold end secondary air duct inlet is basically equivalent to the cross-sectional area of ​​the initial secondary air duct inlet at the cold end of the rotary air preheater 101, thereby minimizing the influence of the heat storage element channel occupied by the circulating air inlet 105 on the secondary air operating parameters, thereby ensuring the safe and stable operation of the unit at the maximum capacity load.

[0071] In practical applications, the rotary air preheater anti-clogging system provided in the embodiment of the present application may also include a first pressure detection device 118, a second pressure detection device 119, a third pressure detection device 120, a fourth pressure detection device 121, a fifth pressure detection device 122 and a sixth pressure detection device 123.

[0072] Among them, the first pressure detection device 118 is arranged under the second sealing sector plate 1012, and the second pressure detection device 119 is arranged on the flue gas side of the cold end of the rotary air preheater 101, and is close to the second sealing sector plate 1012. The first pressure detection device 118 can be used to detect the pressure of the air leakage flow under the second sealing sector plate 1012, and the second pressure detection device 119 can be used to detect the air flow pressure on the flue gas side. Therefore, the opening of the third valve 110 can be controlled according to the pressure difference obtained by the first pressure detection device 118 and the second pressure detection device 119, thereby controlling the air extraction volume.

[0073] The third pressure detection device 120 is arranged under the third sealing sector plate 1013, and the fourth pressure detection device 121 is arranged on the flue gas side of the hot end of the rotary air preheater 101, and is close to the third sealing sector plate 1013. The third pressure detection device 120 can be used to detect the pressure of the air leakage flow under the third sealing sector plate 1013, and the fourth pressure detection device 121 can be used to detect the air flow pressure on the flue gas side. Therefore, the opening of the fourth valve 112 can be controlled according to the pressure difference obtained by the third pressure detection device 120 and the fourth pressure detection device 121, thereby controlling the air extraction volume.

[0074] The fifth pressure detection device 122 is arranged under the fourth sealing sector plate 1014, and the sixth pressure detection device 123 is arranged on the flue gas side of the hot end of the rotary air preheater 101, and is close to the fourth sealing sector plate 1014. The fifth pressure detection device 122 can be used to detect the pressure of the air leakage flow under the fourth sealing sector plate 1014, and the sixth pressure detection device 123 can be used to detect the air flow pressure on the flue gas side. Therefore, the opening of the fifth valve 114 can be controlled according to the pressure difference obtained by the fifth pressure detection device 122 and the sixth pressure detection device 123, thereby controlling the air extraction volume.

[0075] In the above embodiment, the pressure detection device disposed under the sealing sector plate can be understood as being disposed on a side of the sealing sector plate facing the rotor.

[0076] In order to quickly and automatically control each exhaust volume, in one embodiment, the rotary air preheater sealing system also includes a control server 124; the first pressure detection device 118, the second pressure detection device 119, the third pressure detection device 120, the fourth pressure detection device 121, the fifth pressure detection device 122, the sixth pressure detection device 123, the third valve 110, the fourth valve 112 and the fifth valve 114 are all connected to the control server 124.

[0077] In practical applications, in order to further reduce the cost of transformation, the rotary air preheater sealing system may also include a hot-end hot air pipeline 125 and a seventh valve 126. The outlet of the hot-end hot primary air leakage introduction pipeline 111 and the outlet of the hot-end hot secondary air leakage introduction pipeline 113 are both connected to the inlet of the hot-end hot air pipeline 125. The outlet of the hot-end hot air pipeline 125 is connected to the target position B of the hot secondary air branch pipeline 104. The seventh valve 126 is arranged on the hot-end hot air pipeline 125. That is, the hot primary air led out of the hot-end hot primary air leakage introduction pipeline 111 and the hot secondary air leakage introduction pipeline 113 can be gathered in the hot-end hot air pipeline 125, and then transported to the hot secondary air branch pipeline 104. Figure 1 and Figure 2 As shown in Figure 2 The M end of the hot air pipe 125 at the middle hot end is connected to Figure 1 The M end of the hot air pipeline 125 at the hot end is connected. The seventh valve 126 can be used to control the flow of fluid in the hot air pipeline 125 at the hot end.

[0078] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0079] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A rotary air preheater anti-clogging system, characterized in that: The rotary air preheater anti-clogging system comprises a rotary air preheater, a circulating air sealing fan plate, a hot secondary air main pipe and a hot secondary air branch pipe; The rotary air preheater is connected to the hot secondary air main pipe, the flue gas duct of the rotary air preheater is the flue gas side, the primary air duct of the rotary air preheater is the primary air side, and the secondary air duct of the rotary air preheater is the secondary air side; The cold end of the rotary air preheater is provided with a first sealing fan plate and a second sealing fan plate, wherein the first sealing fan plate is located between the primary air side and the flue gas side, and the second sealing fan plate is located between the secondary air side and the flue gas side; The circulating air sealing sector plate is arranged on the secondary air side of the cold end of the rotary air preheater, and a circulating air inlet is formed between the circulating air sealing sector plate and the second sealing sector plate; The inlet of the hot secondary air branch pipeline is connected to the hot secondary air main pipe, and the outlet of the hot secondary air branch pipeline is connected to the circulating air inlet.

2. The rotary air preheater anti-clogging system according to claim 1 is characterized in that: The rotary air preheater anti-clogging system also includes a circulating fan, a first valve and a second valve; The circulating fan, the first valve and the second valve are all arranged on the hot secondary air branch pipeline, the first valve is located upstream of the circulating fan, and the second valve is located downstream of the circulating fan.

3. The rotary air preheater anti-clogging system according to claim 2 is characterized in that: The rotary air preheater anti-clogging system also includes a cold end hot secondary air leakage introduction pipeline, and the second sealing sector plate is provided with an air extraction port; The inlet of the cold-end hot secondary air leakage introduction pipeline is communicated with the air extraction port on the second sealing fan-shaped plate, and the outlet of the cold-end hot secondary air leakage introduction pipeline is communicated with the target position of the hot secondary air branch pipeline.

4. The rotary air preheater anti-clogging system according to claim 3 is characterized in that: The rotary air preheater anti-clogging system also includes a third valve, which is arranged on the cold-end hot secondary air leakage introduction pipeline, and the target position is located upstream of the circulating fan.

5. The rotary air preheater anti-clogging system according to claim 2 is characterized in that: The rotary air preheater anti-clogging system also includes a hot end hot primary air leakage introduction pipeline, the hot end of the rotary air preheater is provided with a third sealing fan plate, the third sealing fan plate is located between the primary air side and the flue gas side, and an air extraction port is opened on the third sealing fan plate; The inlet of the hot end hot primary air leakage introduction pipeline is connected to the air extraction port on the third sealing fan-shaped plate, and the outlet of the hot end hot primary air leakage introduction pipeline is connected to the target position of the hot secondary air branch pipeline.

6. The rotary air preheater anti-clogging system according to claim 5, characterized in that: The rotary air preheater anti-clogging system also includes a fourth valve; The fourth valve is arranged on the hot end hot primary air leakage introduction pipeline, and the target position is located upstream of the circulation fan.

7. The rotary air preheater anti-clogging system according to claim 2, characterized in that: The rotary air preheater anti-clogging system also includes a hot end hot secondary air leakage introduction pipeline, the hot end of the rotary air preheater is provided with a fourth sealing fan plate, the fourth sealing fan plate is located between the secondary air side and the flue gas side, and an air extraction port is opened on the fourth sealing fan plate; The inlet of the hot end hot secondary air leakage introduction pipeline is connected to the air extraction port on the fourth sealing fan-shaped plate, and the outlet of the hot end hot secondary air leakage introduction pipeline is connected to the target position of the hot secondary air branch pipeline.

8. The rotary air preheater anti-clogging system according to claim 7, characterized in that: The rotary air preheater anti-clogging system also includes a fifth valve; The fifth valve is arranged on the hot end hot secondary air leakage introduction pipeline, and the target position is located upstream of the circulation fan.

9. The rotary air preheater anti-clogging system according to claim 2, characterized in that: The rotary air preheater anti-clogging system also includes a cold secondary air main pipe and a cold secondary air branch pipe; The cold secondary air main pipe is connected to the rotary air preheater, the inlet of the cold secondary air branch pipeline is connected to the cold secondary air main pipe, and the outlet of the cold secondary air branch pipeline is connected to the hot secondary air branch pipeline.

10. The rotary air preheater anti-clogging system according to claim 9, characterized in that: The rotary air preheater anti-clogging system also includes a sixth valve, which is arranged on the cold secondary air branch pipeline.

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