Downward guiding type ash conveying control system
By adopting the design of the lower lead fluidization chamber and ash conveying main pipe in the ash conveying system, the problems of ash blockage and poor powder suspension status of the medium lead-in series ash conveying system are solved, and more efficient ash conveying is achieved, ensuring the safe and stable operation of the boiler.
Patent Information
- Application Number
- CN202421941320.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-12
- Publication Date
- 2025-05-13
- Estimated Expiration
- 2034-08-12
AI Technical Summary
The existing medium-induction series ash transport system is prone to blockage of ash, and the powder is suspended poorly, resulting in ash bucket full of ash, affecting the safe and stable operation of the boiler.
The lower-pull ash conveying control system is adopted, including a pneumatic ash conveying chamber pump, a down-pull fluidization chamber and ash conveying main pipe. The powder naturally falls into the ash conveying main pipe through gravity, and uses high-pressure airflow to push the powder into a suspended shape, improving the conveying efficiency of the powder.
It effectively solves the problems of ash blockage and poor suspension status of powder in the ash conveying system, improves the ash conveying effect, avoids ash full of ash, and ensures the safe and stable operation of the boiler.
Smart Images
Figure CN222860558U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of power generation equipment, in particular to a down-drawing type ash conveying control system. Background Art
[0002] like Figure 1 As shown, the existing pneumatic ash conveying system of Changsha Power Plant is a center-inducted series ash conveying system. The operation process of this system is: exhaust valve 3 opens to release pressure → delay → feed valve 2 opens, ash is fed → feeding time is up → feed valve 2 closes → exhaust valve 3 closes to release pressure → air source pressure reaches the pressure setting value of 450Kpa → open discharge valve 1, prepare to discharge ash → open air intake valve (valve before flow regulating valve, between 6 and 7) → open flow regulating valve 6 → discharge timing starts, ash in the pneumatic ash conveying silo pump is discharged from the start discharge valve through the ash conveying main pipe → the pressure of the pneumatic ash conveying silo pump reaches the lower limit of the pressure setting → close discharge valve 1 → open exhaust valve 3, release pressure → delay 20S → close flow regulating valve 6 → close air intake valve (valve before flow regulating valve, between 6 and 7) → close exhaust valve 3 → enter the next cycle of work.
[0003] When the above system is actually running, the powder in the pneumatic ash conveying silo pump cannot be stably discharged, especially the pneumatic ash conveying silo pumps of the economizer and denitrification are blocked for a long time and cannot convey ash, causing the ash hopper to be full of ash, affecting the safe and stable operation of the boiler. The specific reasons are analyzed as follows:
[0004] 1. The existing ash conveying system uses the early middle-introduction series pump ash conveying system. The ash conveying main pipe 5 is installed at a high position, the diameter of the ash inlet branch pipe (the pipe in the box 6 in the attached figure) is small, and the bottom fluidization effect is not good. When the system is actually running, the main ash conveying air source and the powder produce material-gas separation, and the powder is not completely discharged.
[0005] Second, the existing ash conveying system is controlled by pressure conveying. When the discharge valve 1 is turned on, the ash-gas mixture will scour and wear the discharge valve 1 to a certain extent.
[0006] 3. At present, the ash conveying procedure of our company is that after pressurization, the ash conveying main pipe 5 is sprayed to generate negative pressure flow to suck the powder into the ash conveying main pipe 5. However, due to the unsatisfactory bottom fluidization, the powder cannot be suspended and sucked into the ash conveying main pipe 5, and the powder and air are completely separated without the action of pressure difference. Utility Model Content
[0007] In view of the above problems, the utility model provides a down-drawing ash conveying control system for solving the problems of easy ash blockage and poor powder suspension state in the existing middle-drawing series ash conveying system.
[0008] In order to achieve the above purpose, the technical solution adopted by the utility model is:
[0009] A down-drawing ash conveying control system comprises at least one pneumatic ash conveying silo pump, a down-drawing fluidizing chamber is arranged at the bottom of the pneumatic ash conveying silo pump; the down-drawing fluidizing chamber is connected in series with the ash conveying main pipe; one end of the ash conveying main pipe is connected to the ash bin, and the other end is connected to the high-pressure gas source; the outlet of the ash conveying main pipe is provided with a discharge valve, and the inlet is provided with an ash conveying air intake valve; the ash conveying main pipe at the output end of each down-drawing fluidizing chamber is connected to the air source pipe through an air source branch pipe, and the air source branch pipe is provided with an air supply valve; the end of the air source pipe is connected to the high-pressure gas source;
[0010] The upper side wall of the pneumatic ash conveying silo pump is connected with an exhaust branch pipe and a pressurized pipe; the end of the exhaust branch pipe is connected to the exhaust main pipe, and the end of the exhaust main pipe is connected to the outlet of the ash conveying main pipe; the other end of the pressurized pipe is connected to the air source pipe; a pressurized valve is arranged on the pressurized pipe; and an exhaust valve is arranged on the exhaust branch pipe.
[0011] As a further improvement of the above solution, a plurality of pneumatic ash conveying bin pumps are arranged side by side, and the downdraft fluidizing chambers are connected in series through the ash conveying main pipe.
[0012] As a further improvement of the above solution, a flow regulating valve is provided between the ash conveying main pipe and the high-pressure gas source.
[0013] As a further improvement of the above scheme, the upper side wall of the pneumatic ash conveying silo pump is connected to an exhaust main pipe, and the output end of the pressurized pipeline is connected to the exhaust branch pipe.
[0014] As a further improvement of the above solution, a pressure gauge is provided on the ash conveying main pipe.
[0015] As a further improvement of the above solution, a drain valve is provided at the connection between the exhaust main pipe and the ash conveying main pipe.
[0016] Compared with the prior art, the beneficial effects of the utility model are:
[0017] 1. The original pressurized mode of transportation caused great wear on valves and accessories, and it was also unable to adapt to the modified transportation mode. The procedure was changed from pressurized transportation to non-pressurized transportation to reduce the wear on the ash conveying valve.
[0018] 2. When the ash conveying system is blocked, the ash conveying system will be automatically stopped. The valve on the air supply valve will be manually opened to allow compressed air to bypass the discharge valve and pressurize the ash conveying main pipe alone to clear the powder in the ash conveying pipe. After the cleaning is completed, the automatic mode will be turned on again.
[0019] After the transformation, the ash conveying pipeline before the discharge valve was introduced. At the same time, the program was modified to add the action of cleaning the exhaust main pipe after the empty pump to prepare for smooth feeding. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 It is a schematic diagram of the structure of the existing center-drawn ash conveying system.
[0021] Figure 2This is a schematic diagram of the structure of the down-drawing ash conveying control system of the utility model.
[0022] In the figure: 1. discharge valve; 2. feed valve; 3. exhaust valve; 4. fluidizing chamber; 5. ash conveying main pipe; 6. flow regulating valve; 7. ash conveying air inlet valve; 8. air source pipe; 9. air supply valve; 10. pressurizing valve; 11. air source pipe air inlet valve; 12. pneumatic ash conveying silo pump; 13. pressurizing pipeline; 14. exhaust main pipe; 15. drain valve; 17. air source branch pipe; 18. exhaust branch pipe. DETAILED DESCRIPTION
[0023] In order to enable those skilled in the art to better understand the technical solution, the utility model is described in detail below in conjunction with embodiments. The description in this section is only exemplary and explanatory and should not have any limiting effect on the protection scope of the utility model.
[0024] Embodiment 1:
[0025] like Figure 2 As shown, the specific scheme of this embodiment is: a down-drawing ash conveying control system, comprising at least one pneumatic ash conveying bin pump 12, a down-drawing fluidizing chamber 4 is arranged at the bottom of the pneumatic ash conveying bin pump 12; the fluidizing chamber 4 is connected in series with the ash conveying main pipe 5; one end of the ash conveying main pipe 5 is connected to the ash bin, and the other end is connected to the high-pressure gas source; the outlet of the ash conveying main pipe 5 is provided with a discharge valve 1, and the inlet is provided with an ash conveying air intake valve 7; the ash conveying main pipe 5 at the output end of each fluidizing chamber 4 is connected to the air source pipe 8 through the air source branch pipe 17, and the air source branch pipe 17 is provided with an air supply valve 9; the end of the air source pipe 8 is connected to the high-pressure gas source;
[0026] The upper side wall of the pneumatic ash conveying silo pump 12 is connected with an exhaust branch pipe 18 and a pressurized pipe 13; the end of the exhaust branch pipe 18 is connected to the exhaust main pipe 14, and the end of the exhaust main pipe 14 is connected to the outlet of the ash conveying main pipe 5; the other end of the pressurized pipe 13 is connected to the air source pipe 8; a pressurized valve 10 is arranged on the pressurized pipe 13; and an exhaust valve 3 is arranged on the exhaust branch pipe 18.
[0027] As a preferred embodiment of the above embodiment, a plurality of pneumatic ash conveying bin pumps 12 are arranged side by side, and the fluidizing chambers 4 are connected in series through the ash conveying main pipe 5 .
[0028] As a preferred embodiment of the above embodiment, a flow regulating valve 6 is provided between the ash conveying main pipe 5 and the high-pressure gas source.
[0029] As a preferred embodiment of the above embodiment, the upper side wall of the pneumatic ash conveying silo pump 12 is connected to an exhaust main pipe 14 , and the output end of the pressurized pipeline 13 is connected to the exhaust branch pipe 18 .
[0030] As a preferred embodiment of the above embodiment, a pressure gauge is provided on the ash conveying main pipe 5 .
[0031] As a preferred embodiment of the above embodiment, a drain valve 15 is provided at the connection between the exhaust main pipe 14 and the ash conveying main pipe 5 .
[0032] The specific working principle of this utility model:
[0033] like Figure 2 As shown in the figure, the operation process of this down-drawing ash conveying control system is as follows:
[0034] The high-pressure gas source is generally a gas storage tank, which provides compressed air to form a main jet airflow that enters the ash conveying main pipe 5 and the gas source pipe 8; and enters the ash conveying main pipe 5 through the flow regulating valve 6.
[0035] Overall process:
[0036] Exhaust valve 3 opens, pressure relief → delay → feed valve 2 opens, ash feeding starts → feeding time is up → feed valve 2 closes → exhaust valve 3 closes → air source pressure reaches the set pressure value of 450Kpa;
[0037] Open the discharge valve 1 to discharge ash → open the ash conveying air inlet valve 7 → open the flow regulating valve 6 to adjust the air inlet flow → the discharge timing starts, the powder is transported to the ash conveying main pipe 5 in the pneumatic ash conveying silo pump 12, and comes out from the discharge valve 1 → the pressure of the pneumatic ash conveying silo pump 12 reaches the lower limit of the pressure setting → close the discharge valve 1 to end the ash discharge;
[0038] The exhaust valve 3 is opened to release the pressure → delay 20S → close the flow regulating valve 6 → close the ash conveying air inlet valve 7 → close the exhaust valve 3 → enter the next cycle.
[0039] 1.1 The feeding stage is as follows:
[0040] 1.1.1 Prepare for feeding: When the air source pressure reaches the set value of 450Kpa, open the exhaust valve 3. When the exhaust valve 3 opening instruction is issued, the timing starts. When the minimum cycle time setting value (manually set by the operator) is reached, the feeding stage begins.
[0041] 1.1.2 Start feeding: open feed valve 2 and start feeding timing. When the economizer feeding timing reaches the feeding time setting value (manually set by the operator), the feeding end stage begins.
[0042] 1.1.3 End of feeding: Close feed valve 2 and enter the discharge preparation stage.
[0043] 1.2 The discharging stage is as follows:
[0044] 1.2.1 Prepare for discharging: Close the exhaust valve 3 and enter the discharging stage.
[0045] 1.2.2 Start discharging: open the discharge valve 1; open the ash conveying air inlet valve 7, open the flow regulating valve 6 (the opening is manually set by the operator) to enter the start of the air intake stage; the flow regulating valve 6 opening command is issued to start the discharging timing. When the silo pump pressure reaches the set lower limit of the silo pump pressure (manually set by the operator), close the discharge valve 1 and enter the end of the discharging stage. After a delay of 1 second, the exhaust valve 3 is opened. After a delay of 20 seconds, the flow regulating valve 6 is closed, followed by a delay of 1 second, the air inlet valve is closed, and after another 3 seconds, the exhaust valve 3 is closed to enter the end of the discharging stage.
[0046] 1.2.3 Discharging is completed: open exhaust valve 3.
[0047] The economizer ash conveying sequential control logic only works when the ash conveying system is in automatic mode. In the manual mode, the exhaust valve 3, feed valve 2, pre-feed valve 2, air intake valve, flow regulating valve 6 and discharge valve 1 can all be operated individually.
[0048] The utility model replaces the original middle-drawn fluidizing plate with a bottom-drawn fluidizing chamber 4, i.e., the cavity at the bottom of the pneumatic ash conveying bin pump 12. The ash conveying system is changed from the middle-drawn series pump conveying to the bottom-drawn series pump conveying process, solving the fluidization method with unsatisfactory boiling effect.
[0049] The powder in the pneumatic ash conveying silo pump 12 naturally falls into the ash conveying main pipe 5 under the action of gravity, and the main jet airflow only needs to push the powder falling into the ash conveying main pipe 5.
[0050] In order to adjust the delivery concentration of the ash conveying main pipe 5, the opening size of the flow regulating valve 6 is changed, so that the ratio of ash and compressed air in the pneumatic ash conveying bin pump 12 and the ash conveying main pipe 5 is changed to change the ash concentration. When the pressure valve 10 is not opened, the powder falls into the ash conveying main pipe 5 by gravity, and the ash delivery concentration is low. When the pressure valve 10 is opened, the ash delivery concentration will gradually increase with the opening size.
[0051] The ash is transported out from the discharge valve 1. In order to ensure that the ash conveying main pipe 5 is not blocked, the system adds a total concentration adjustment device at the front end of the discharge valve 1 of the ash conveying main pipe 5, which is composed of an air supply valve 9 and a pressurizing valve 10; they work together to adjust the concentration, open the air source pipe inlet valve 11, and the high-pressure airflow enters the air source pipe 8 and the pressurized pipe 13.
[0052] The main functions of the air supply valve 9 are twofold. First, it is used as a concentration regulator for the ash conveying main pipe 5. It can be opened when the concentration is adjusted. The larger the opening, the lower the dust concentration in the ash conveying main pipe 5. Second, it is used to clean the ash conveying main pipe 5 when the pipe is blocked. When a pipe blockage alarm occurs, the system will automatically shut down, all valves will be closed and wait for manual processing. At this time, the system enters the manual state, and the valve on the air supply valve 9 is manually opened to allow compressed air to bypass the discharge valve 1 and pressurize the ash conveying main pipe 5 alone to empty the powder in the ash conveying pipe. After cleaning, turn on the automatic mode again.
[0053] The system program needs to be further optimized. The original pressurized mode of delivery causes great wear and tear on valves and accessories, and is also unable to adapt to the modified delivery mode. The program needs to be changed from pressurized delivery to non-pressurized delivery.
[0054] The exhaust pipe system was renovated. The original exhaust pipe was laid horizontally for a long time. When the pneumatic ash conveying silo pump 12 was exhausted, fine powder entered the exhaust pipe. Due to the short valve opening and closing time, the dust was not easy to be emptied from the pipe and was easily deposited in the exhaust pipe, causing the exhaust to be blocked and affecting the feeding. After the renovation, the pressurized pipe 13 was introduced. At the same time, the program was modified to add the action of cleaning the exhaust main pipe 14 after the empty pump to prepare for smooth feeding.
[0055] 1. Operation Procedures
[0056] Operation mode: combination of automatic and manual.
[0057] 1. Automatic operation procedure
[0058] Exhaust valve 3 opens, pressure relief → delay → feed valve 2 opens, ash feeding starts → feeding time is up → feed valve 2 closes → exhaust valve 3 closes → air source pressure reaches the set pressure value of 450Kpa;
[0059] Open the discharge valve 1 to discharge ash → open the ash conveying air inlet valve 7 → open the flow regulating valve 6 to adjust the air inlet flow → the discharge timing starts, the powder is transported to the ash conveying main pipe 5 in the pneumatic ash conveying pump and comes out from the discharge valve 1 → the pressure of the pneumatic ash conveying silo pump 12 reaches the lower limit of the pressure setting → close the discharge valve 1 to end the ash discharge;
[0060] The exhaust valve 3 is opened to release the pressure → delay 20S → close the flow regulating valve 6 → close the ash conveying air inlet valve 7 → close the exhaust valve 3 → enter the next cycle.
[0061] 2. Manual operation procedure
[0062] Exhaust valve 3 opens, pressure relief → delay → feed valve 2 opens, ash feeding starts → feeding time is up → feed valve 2 closes → exhaust valve 3 closes → air source pressure reaches the set pressure value of 450Kpa;
[0063] Open the discharge valve 1 to discharge ash → open the ash conveying air inlet valve 7 → open the flow regulating valve 6 to adjust the air inlet flow → the discharge timing starts, the powder is transported to the ash conveying main pipe 5 in the pneumatic ash conveying pump and comes out from the discharge valve 1 → the pressure of the pneumatic ash conveying silo pump 12 reaches the lower limit of the pressure setting → close the discharge valve 1 to end the ash discharge;
[0064] Open the exhaust valve 3 to release the pressure → delay 20S → close the flow regulating valve 6 → close the ash conveying air inlet valve 7 → close the exhaust valve 3 → the transportation is completed.
[0065] 3. Start the machine
[0066] Ensure that the working pressure of the main gas source is above 0.45MPa, and control the working pressure of the high-pressure gas source to be above 0.6MPa. First check whether the control working signal indications are normal, whether the manual and automatic procedures are correct, and then manually open the discharge valve, air inlet valve, and flow regulating valve; blow for 1 to 2 minutes, and only after the pipeline is unblocked can feeding and transportation be carried out.
[0067] 4. Shutdown
[0068] The machine can be stopped only after all materials have been delivered and it is confirmed that there is no residual material in the pipeline and hopper, and then the machine can be manually blown for 5 to 10 minutes to ensure that there is no material in the pipeline, pump and hopper.
[0069] After the transformation, the ash conveying effect was ideal, and the economizer ash conveying system was restored to a normal ash conveying state from its original long-term paralysis state.
[0070] It should be noted that, in this article, the terms include, contain or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article 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, article or device. Specific examples are used in this article to illustrate the principle and implementation of the technical solution of the utility model. The above examples are only used to help understand the method and core idea of the utility model. The above is only a preferred implementation of the utility model. It should be pointed out that due to the limited expression of words, there are objectively infinite specific structures. For ordinary technicians in this technical field, without departing from the principle of the utility model, several improvements, modifications or changes can be made, and the above technical features can also be combined in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the concept and technical solution of the utility model to other occasions without improvement, should be regarded as the protection scope of the utility model.
Claims
1. A down-drawing ash conveying control system, comprising at least one pneumatic ash conveying silo pump (12), characterized in that: A downward-drawn fluidizing chamber (4) is arranged at the bottom of the pneumatic ash conveying silo pump (12); the fluidizing chamber (4) is connected in series with the ash conveying main pipe (5); one end of the ash conveying main pipe (5) is connected to the ash bin, and the other end is connected to the high-pressure gas source; the outlet of the ash conveying main pipe (5) is provided with a discharge valve (1), and the inlet is provided with an ash conveying air intake valve (7); the ash conveying main pipe (5) at the output end of each fluidizing chamber (4) is connected to the gas source pipe (8) through the gas source branch pipe (17), and the gas source branch pipe (17) is provided with an air supply valve (9); the end of the gas source pipe (8) is connected to the high-pressure gas source; The upper side wall of the pneumatic ash conveying silo pump (12) is connected to an exhaust branch pipe (18) and a pressurizing pipe (13); the end of the exhaust branch pipe (18) is connected to an exhaust main pipe (14), and the end of the exhaust main pipe (14) is connected to the outlet of the ash conveying main pipe (5); the other end of the pressurizing pipe (13) is connected to an air source pipe (8); a pressurizing valve (10) is provided on the pressurizing pipe (13); and an exhaust valve (3) is provided on the exhaust branch pipe (18).
2. A down-drawing ash conveying control system according to claim 1, characterized in that: A plurality of pneumatic ash conveying bin pumps (12) are arranged side by side, and the fluidizing chambers (4) are connected in series through an ash conveying main pipe (5).
3. A down-drawing ash conveying control system according to claim 1, characterized in that: A flow regulating valve (6) is provided between the ash conveying main pipe (5) and the high-pressure gas source.
4. A down-drawing ash conveying control system according to claim 1, characterized in that: The upper side wall of the pneumatic ash conveying silo pump (12) is connected to an exhaust main pipe (14), and the output end of the pressurized pipeline (13) is connected to an exhaust branch pipe (18).
5. The down-drawing ash conveying control system according to claim 1 is characterized in that: A pressure gauge is provided on the ash conveying main pipe (5).
6. A down-drawing ash conveying control system according to claim 1, characterized in that: A drain valve (15) is provided at the connection between the exhaust main pipe (14) and the ash conveying main pipe (5).