Cleaning device for air pre-heater of thermal power plant and using method

Abstract

The invention relates to the technical field of thermal power generation, in particular to a thermal power plant air pre-heater cleaning device and a using method. The cleaning assembly comprises a driving part, a moving part arranged on the outer wall of the driving part and a spraying part arranged on the outer wall of the moving part; wherein the driving piece can enable the moving piece to move in the main body assembly, so that the spraying piece cleans the inner wall of the main body assembly; the steam supply pressure is controlled through the arrangement of the high-pressure steam pressure reducing valve, meanwhile, the on-way water conveying and water conveying pipe is opened to conduct pipe heating and impurity flushing on the whole system, and the phenomenon that the gun head is blocked by impurities is avoided. After pipe warming and impurity cleaning of the whole system are finished, the pressure reducing valve is adjusted, the pressure of cleaning equipment is set, the high-pressure steam control valve is controlled through the PLC, high-pressure steam flushing of the air pre-heater is achieved, the air pre-heater continuously rotates when the air pre-heater is flushed, the cleaning efficiency is improved, and compared with traditional manual cleaning, the workload is greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of thermal power generation, in particular to a thermal power plant air preheater cleaning device and a use method thereof. Background Art

[0002] Air preheater, also referred to as air preheater, is mainly used in boilers of thermal power plants. It is a preheating device that improves the heat exchange performance of boilers and reduces heat loss. It can transfer the heat carried in the flue gas discharged from the tail flue of the boiler to the air before entering the boiler through the heat sink, and preheat the air to a certain temperature.

[0003] However, air preheaters often encounter blockage during use, mainly due to the adhesion of NH4HSO4 formed by ammonia escape during the denitrification process to the cold end wall. Blockage factors include inaccurate flue gas volume measurement, decreased catalyst activity, and uneven flue gas flow distribution. In addition, low-temperature corrosion and ash accumulation promote each other, forming a vicious cycle and aggravating blockage.

[0004] Currently, low-pressure soot blowing guns are mostly used to clean the flue gas side of the air preheater, but this method is less effective and cannot effectively clean the hardened ash in the gap between the corrugated plates, and the cleaning efficiency is low; in addition, after the boiler is shut down and the air preheater temperature is lowered, the air preheater flue gas side differential pressure can be reduced by external high-pressure water flushing, which is the most direct and fastest way to deal with air preheater ash blockage. However, it is necessary to shut down the machine for flushing, otherwise the air preheater will be scrapped.

[0005] Based on the above problems, we proposed a cleaning device and a method for using an air preheater in a thermal power plant. Summary of the invention

[0006] In view of the above-mentioned technical problem of blockage on the flue gas side of the existing air preheater, a cleaning device for an air preheater of a thermal power plant in the present invention is proposed.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: a cleaning device for an air preheater of a thermal power plant, which includes a main body component; a cleaning component, including a driving member arranged outside the main body component, a moving member arranged on the outer wall of the driving member, and an injection member arranged on the outer wall of the moving member; wherein the driving member can make the moving member move inside the main body component, so that the injection member cleans the inner wall of the main body component.

[0008] As a preferred solution of the thermal power plant air preheater cleaning device of the present invention, the main body component includes an air preheater, a flue gas side and an air side are arranged inside the air preheater, and a flue is arranged inside the air preheater.

[0009] As a preferred solution of the air preheater cleaning device for a thermal power plant of the present invention, the outer wall of the flue is provided with a first fixed bracket, and the inner wall of the flue is provided with a second fixed bracket.

[0010] As a preferred solution of the thermal power plant air preheater cleaning device of the present invention, the driving member includes a motor, and the output end of the motor is drivingly connected to an internal steam supply pipe.

[0011] As a preferred solution of the air preheater cleaning device of a thermal power plant of the present invention, an external steam supply pipe is sleeved inside the internal steam supply pipe, a high-pressure steam control valve is provided on the outer wall of the internal steam supply pipe, and a high-pressure steam pressure reducing valve is provided on the outer wall of the external steam supply pipe.

[0012] As a preferred solution of the thermal power plant air preheater cleaning device of the present invention, the movable part includes a branch pipe arranged on the side wall of the internal steam supply pipe, and the outer wall of the branch pipe is provided with a steam supply main pipe.

[0013] As a preferred solution of the thermal power plant air preheater cleaning device of the present invention, a water inlet is provided on the lower side wall of the steam supply mother pipe, and a water pipe is connected to the outside of the water inlet.

[0014] As a preferred solution of the thermal power plant air preheater cleaning device of the present invention, the injection member includes a steam supply port opened on the outer wall of the steam supply main pipe, and the lower part of the cleaning gun is arranged outside the steam supply port.

[0015] As a preferred solution of the thermal power plant air preheater cleaning device of the present invention, wherein: the lower outer wall of the cleaning gun is movably provided with an upper part of the cleaning gun, and the outer wall of the upper part of the cleaning gun is provided with a gun head.

[0016] In order to solve the above technical problems, the present invention provides the following technical solutions: S1: by increasing the temperature of the cold end of the air preheater, the ammonium hydrogen sulfate is gasified to reduce blockage; S2: using cleaning equipment to flush the air preheater with high-pressure steam.

[0017] The beneficial effects of the present invention are: the steam supply pressure is controlled by setting the high-pressure steam pressure reducing valve, and the water supply and water supply pipes along the way are opened to warm the pipes and flush the impurities of the entire system, so as to avoid the impurities blocking the gun head. After the whole system pipes are warmed up and the impurities are cleaned, the pressure reducing valve is adjusted, the pressure of the cleaning equipment is set, and the high-pressure steam control valve is controlled by PLC to realize the high-pressure steam flushing of the air preheater. When flushing the air preheater, the air preheater is also continuously rotating, which improves the cleaning efficiency and greatly reduces the workload compared with traditional manual cleaning. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0019] Figure 1 It is a schematic diagram of the air preheater in the present invention.

[0020] Figure 2 It is a schematic diagram of the connection structure of the cleaning components in the present invention.

[0021] Figure 3 It is a schematic diagram of the connection structure of the moving parts in the present invention.

[0022] Figure 4 It is a schematic diagram of the injection piece connection structure in the present invention. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0024] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0025] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0026] Example 1, reference Figure 1 , which is the first embodiment of the present invention, provides a cleaning device for an air preheater of a thermal power plant, including a main component 1; a cleaning component 2, including a driving member 21 arranged outside the main component 1, a moving member 22 arranged on the outer wall of the driving member 21 and an injection member 23 arranged on the outer wall of the moving member 22.

[0027] Specifically, the driving member 21 can make the moving member 22 move inside the main assembly 1 , so that the injection member 23 cleans the inner wall of the main assembly 1 .

[0028] Preferably, the cleaning components 2 are preferably divided into two groups, which are arranged on both sides of the cold end flue on the flue gas side; the moving part 22 is arranged inside the main component 1, and the driving part 21 is connected to the moving part 22, and the driving part 21 can make the moving part 22 perform reciprocating translational motion inside the main component 1; the injection part 23 is connected to the moving part 22, and the moving part 22 provides steam to the injection part 23, which can clean the inner wall of the main component 1.

[0029] In summary, the high-pressure steam flushing of the air preheater 11 is achieved through the cleaning component 2, and when the air preheater 11 is flushed, the air preheater 11 is also continuously rotating, which improves the cleaning efficiency and greatly reduces the workload compared to traditional manual cleaning.

[0030] Example 2, reference Figure 1 to Figure 4 , which is the second embodiment of the present invention, provides an air preheater cleaning device for a thermal power plant, including a main component 1 including an air preheater 11, a flue gas side 111 and an air side 112 are provided inside the air preheater 11, and a flue 113 is provided inside the air preheater 11.

[0031] Among them, the air preheater 11 is a three-compartment air preheater, and two cleaning components are arranged on both sides of the cold end flue 113 on the flue gas side 111. When arranged, the gap part of the gun head on one side, that is, the area not covered by the gun head on this side, is just located within the coverage range of the gun head on the other side, ensuring that the gun head can cover the entire heating surface when the air preheater rotates, and the gun heads on both sides are radially distributed to cover the entire heating surface of the air preheater.

[0032] Specifically, a first fixing bracket 114 is provided on the outer wall of the flue 113 , and a second fixing bracket 115 is provided on the inner wall of the flue 113 .

[0033] Among them, the first fixed bracket 114 is fixed to the outer wall of the flue 113, and plays the role of connecting the external steam supply pipe 213 and the internal steam supply pipe 212; the second fixed bracket 115 is connected to the inner wall of the flue 113 by welding, and plays the role of supporting the cleaning component 2.

[0034] Preferably, the driving member 21 comprises a motor 211 , and an output end of the motor 211 is drivingly connected to an internal steam supply pipe 212 .

[0035] Among them, the motor 211 is transmission connected with the internal steam supply pipe 212, and the internal steam supply pipe 212 penetrates the outer wall of one side of the flue 113 and extends into the interior of the flue 113; when the motor 211 is started, the internal steam supply pipe 212 can make translational motion inside the flue 113; the motor 211, the high-pressure steam control valve 2121 and the high-pressure steam reducing valve 2131 are all connected to switches through wires, and the switch is connected to a PLC controller through wires, and the PLC controller is connected to a power supply through wires and connected to a DCS control system, which is convenient for the operator to operate and control.

[0036] Preferably, an external steam supply pipe 213 is sleeved inside the internal steam supply pipe 212 , a high-pressure steam control valve 2121 is provided on the outer wall of the internal steam supply pipe 212 , and a high-pressure steam reducing valve 2131 is provided on the outer wall of the external steam supply pipe 213 .

[0037] Among them, the high-pressure steam control valve 2121 can control the time when steam enters the high-pressure cleaning component 2; the high-pressure steam pressure reducing valve 2131, composed of a manual door, an electric door and an electric lifting valve, controls the high-pressure steam temperature at 200-300°C and the pressure at 3-5MPa by reducing pressure, which meets the requirements for cleaning the air preheater 11; the external steam supply pipe 213 and the internal steam supply pipe 212 are set to deliver water according to the actual situation on site to ensure that the pipeline does not vibrate when put into operation.

[0038] Preferably, the moving member 22 includes a branch pipe 221 arranged on the side wall of the internal steam supply pipe 212 , and a steam supply main pipe 222 is arranged on the outer wall of the branch pipe 221 .

[0039] Among them, one end of the branch pipe 221 is fixedly connected to the internal steam supply pipe 212, and the other end is fixedly connected to the steam supply mother pipe 222; the steam supply mother pipe 222 is placed above the second fixed bracket 115, and the steam supply mother pipe 222 is connected to the internal steam supply pipe 212 through the branch pipe 221.

[0040] Preferably, a water delivery port 223 is provided on the side wall below the steam supply mother pipe 222 , and a water delivery pipe 224 is connected to the outside of the water delivery port 223 .

[0041] The water delivery pipe 224 is welded to the water delivery port 223 to ensure that dirty water in the steam supply mother pipe 222 can be quickly discharged to avoid vibration caused by internal water accumulation.

[0042] Preferably, the injection member 23 includes a steam supply port 231 opened on the outer wall of the steam supply main pipe 222 , and a cleaning gun lower part 232 is provided outside the steam supply port 231 .

[0043] There are multiple steam supply ports 231 , which are evenly opened on the steam supply main pipe 222 to provide steam for the cleaning gun; the bottom of the cleaning gun lower part 232 is connected to the steam supply main pipe 222 .

[0044] Preferably, an outer wall of the cleaning gun lower part 232 is movably provided with a cleaning gun upper part 233 , and an outer wall of the cleaning gun upper part 233 is provided with a gun head 234 .

[0045] Among them, the lower part 232 of the cleaning gun is connected to the upper part 233 of the cleaning gun by internal and external threads to prevent the gun head 234 from being blocked and facilitate replacement; the opening of the gun head 234 is relatively small to meet the requirements of outlet steam pressure and speed; since the gun head 234 and the flue gas flow are arranged in opposite directions, in order to prevent the gun head 234 from being blocked, the steam pressure can be appropriately reduced to ensure low-pressure steam operation, and the system is in hot standby for a long time.

[0046] Furthermore, the motor 121 is started to move the internal steam supply pipe 212 inside the flue 113 , and further move the steam supply mother pipe 222 above the second fixed bracket 115 , so that the gun head 234 sprays steam to clean the inner wall of the flue 113 .

[0047] In summary, when the air preheater 11 is found to be blocked, the steam supply pressure is controlled by setting the high-pressure steam pressure reducing valve 2131, and the water pipe 224 is opened at the same time to warm up the pipes of the entire system and flush the impurities to prevent the impurities from clogging the gun head 234; after the whole system is warmed up and the impurities are cleaned, the high-pressure steam pressure reducing valve 2131 is adjusted, the cleaning equipment pressure is set, and the high-pressure steam control valve 2121 is controlled by the PLC to realize the high-pressure steam flushing of the air preheater 11.

[0048] Example 3, reference Figure 1 to Figure 4 , which is the third embodiment of the present invention, provides a thermal power plant air preheater cleaning device, including S1: by increasing the cold end temperature of the air preheater, ammonia hydrogen sulfate is gasified to reduce blockage; S2: using the cleaning equipment to perform high-pressure steam flushing on the air preheater.

[0049] Specifically, the gasification temperature of ammonium bisulfate is 150°C to 230°C. After increasing the temperature at the cold end of the air preheater, the ammonium bisulfate changes from solid to liquid or gaseous, and the blockage of the air preheater will be significantly alleviated.

[0050] The heat storage element in the low temperature section of the air preheater is a Corten steel heat storage element, which can withstand high temperatures above 300°C, so it has no effect on the heat storage element of the air preheater;

[0051] After increasing the exhaust gas temperature of the air preheater, the temperature difference between the hot and cold ends of the air preheater becomes smaller. Controlling the temperature rise rate of the exhaust gas temperature of the air preheater will control the deformation of the air preheater mushroom and avoid the jamming of the air preheater due to friction between the moving and static parts of the air preheater.

[0052] Preparation before operation:

[0053] S1: The test oil gun is normal.

[0054] S2: Check that the air preheater, supply fan, exhaust fan and primary fan are operating normally and all parameters are qualified. Check on-site that the equipment is operating normally.

[0055] S3: Stop blowing the furnace chamber and flue soot, adjust the soot blowing pressure of the air preheater to above 2Mpa, and put the soot blower at the cold end of the air preheater into continuous operation.

[0056] S4: The boiler air heater is in normal operation and the air temperature after the heater is not less than 30℃.

[0057] S5: The unit load is maintained above 400MW and the unit operating conditions are stable.

[0058] S6: Inform the desulfurization duty officer to pay attention to the flue gas temperature at the inlet of the desulfurization absorption tower and the flue gas temperature at the outlet of the clean flue gas. When the temperature is high, spray water to reduce the temperature according to the regulations.

[0059] S7: Notify the ash removal attendant to monitor the operation of the electrostatic precipitator.

[0060] Implementation steps:

[0061] S1: All preparatory work before inspection is completed, all personnel are in place and the briefing is completed.

[0062] S2: Exit boiler RB protection and large interlock protection.

[0063] S3: Slowly change the load to above 400MW.

[0064] S4: After the unit load is stable, adjust the fan blades on both sides, close the standby side and open the other side to increase the exhaust temperature of the standby side. Control the exhaust temperature of the air preheater to be treated to rise by about 0.5℃ per minute, and stabilize for 5 minutes for every 10℃ increase in temperature. Pay attention to monitoring the current of the two air preheaters and the combustion of the boilers.

[0065] S5: Raise the exhaust gas temperature at the outlet of the standby air preheater to 170℃, control the exhaust gas temperature of the standby air preheater to rise by about 0.5℃ per minute, and keep it stable for 5 minutes for every 10℃ increase in temperature. Pay attention to monitoring the current of the two air preheaters and the combustion of the boilers, and check on-site that the air preheaters rotate smoothly, without friction or abnormal sound.

[0066] S6: The exhaust gas temperature at the outlet of the standby air preheater is above 170℃. After checking that all systems are operating normally and ensuring that all operating parameters are stable, the air preheater cleaning system at the standby air preheater end is put into operation: the steam supply pressure is controlled by the high-pressure steam pressure reducing valve 09, and at the same time, the water supply pipe 04 along the way and the cleaning equipment water supply pipe 04 are opened to warm up the pipes and flush impurities in the entire system to avoid impurities blocking the gun head. After the whole system is warmed up and the impurities are cleaned, adjust the pressure reducing valve 09, set the cleaning equipment pressure, and control the high-pressure steam control valve 08 through the PLC to achieve high-pressure steam flushing of the air preheater. Run for 3-6 hours. Pay attention to monitoring the current of the two air preheaters and the combustion of the boilers.

[0067] S7: Record the changes in the flue gas side differential pressure at the inlet and outlet of the standby air preheater, and the primary and secondary air differential pressure.

[0068] S8: After 3-6 hours of continuous operation, it slowly returns to normal operating conditions

[0069] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), installation arrangement, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure of performing the function described herein, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other replacements, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to numerous modifications still falling within the scope of the appended claims.

[0070] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0071] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0072] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A thermal power plant air preheater cleaning device, characterized in that: include, Main body component (1); A cleaning component (2), comprising a driving member (21) arranged outside the main component (1), a moving member (22) arranged on the outer wall of the driving member (21), and a spraying member (23) arranged on the outer wall of the moving member (22); The driving member (21) can cause the moving member (22) to move inside the main body component (1), thereby causing the injection member (23) to clean the inner wall of the main body component (1).

2. The thermal power plant air preheater cleaning device according to claim 1, characterized in that: The main body component (1) comprises an air preheater (11), a flue gas side (111) and an air side (112) are provided inside the air preheater (11), and a flue (113) is provided inside the air preheater (11).

3. The thermal power plant air preheater cleaning device according to claim 2, characterized in that: The outer wall of the flue (113) is provided with a first fixing bracket (114), and the inner wall of the flue (113) is provided with a second fixing bracket (115).

4. The thermal power plant air preheater cleaning device according to claim 3, characterized in that: The driving member (21) comprises a motor (211), and an output end of the motor (211) is drivingly connected to an internal steam supply pipe (212).

5. The thermal power plant air preheater cleaning device according to claim 4, characterized in that: An external steam supply pipe (213) is sleeved inside the internal steam supply pipe (212), a high-pressure steam control valve (2121) is provided on the outer wall of the internal steam supply pipe (212), and a high-pressure steam pressure reducing valve (2131) is provided on the outer wall of the external steam supply pipe (213).

6. The thermal power plant air preheater cleaning device according to claim 5, characterized in that: The moving part (22) comprises a branch pipe (221) arranged on the side wall of the internal steam supply pipe (212), and the outer wall of the branch pipe (221) is provided with a steam supply main pipe (222).

7. The thermal power plant air preheater cleaning device according to claim 6, characterized in that: A water delivery port (223) is provided on the lower side wall of the steam supply main pipe (222), and a water delivery pipe (224) is connected to the outside of the water delivery port (223).

8. The thermal power plant air preheater cleaning device according to claim 7, characterized in that: The injection member (23) comprises a steam supply port (231) opened on the outer wall of the steam supply main pipe (222), and a cleaning gun lower part (232) is arranged outside the steam supply port (231).

9. The thermal power plant air preheater cleaning device according to claim 8, characterized in that: The outer wall of the cleaning gun lower part (232) is movably provided with a cleaning gun upper part (233), and the outer wall of the cleaning gun upper part (233) is provided with a gun head (234).

10. A method for using a thermal power plant air preheater cleaning device, characterized in that: It comprises the thermal power plant air preheater cleaning device as claimed in any one of claims 1 to 8; and S1: By increasing the temperature of the cold end of the air preheater, the ammonium hydrogen sulfate is gasified to reduce blockage; S2: Use cleaning equipment to flush the air preheater with high-pressure steam.

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