Multi-unit parallel type pilot pneumatic conveying integrated system of ash conveying system

Abstract

The invention discloses a multi-unit parallel type pilot pneumatic conveying integrated system of an ash conveying system, and relates to the technical field of pneumatic conveying. The multi-unit parallel conveying module comprises three ash conveying main pipelines, each pipeline is connected with 300 pure mechanical pilot valves in series at intervals of 3-5 meters, ceramic wear-resistant elbows and expansion joints are adopted, and bin pumps are connected in series through Y-shaped tee joints; the pilot gas source module is provided with a DN80 auxiliary gas main pipe along a pipeline, is provided with a pressure regulating valve group, a filter and a bypass valve group, cancels an original fluidizing valve and the like, and only remains a main gas inlet valve; the linkage control module is simplified into a blanking-conveying two-step sequence based on a PLC (Programmable Logic Controller) and configures a picture to display a state in real time; the ash blocking protection module comprises a large ash blocking device and a special one-way valve, and an ash pipe is sealed by double O-shaped rings; and the state monitoring module is provided with a pressure gauge and a flowmeter and triggers alarm when abnormity occurs. Pipe blockage and abrasion are reduced, energy consumption and maintenance cost are reduced, ash conveying efficiency and stability are improved, the energy-saving policy is met, and safe operation of a unit is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of pneumatic conveying technology, in particular to a multi-unit parallel pilot pneumatic conveying integrated system of ash conveying system. BACKGROUND

[0002] The ash conveying system of No. 1 unit of Changchun Thermal Power Branch of Jilin Electric Power Co., Ltd. adopts traditional positive pressure dense phase suspension flow conveying technology, which is supplied by Clyde and includes 3 ash conveying pipelines connecting different specification bins of dust collectors (V3.0 m³, V1.5 m³, V0.5 m³, V0.3 m³) and having a conveying distance of 295 meters. The system operation relies on compressed air mixed with fly ash to form a suspension flow, which is significantly affected by factors such as fly ash density and pipeline distance, and has many problems. The high flow rate at the rear of the pipeline causes severe wear and tear, frequent plugging needs to be repaired every month, and the maintenance cost is high; the ash-gas mixing system has multiple air inlet points and a large amount of instantaneous air, and 4-5 air compressors (exhaust capacity 66 Nm³ / min, power 315 KW) need to be operated at full load, the plant power consumption rate is high, and there is insufficient standby equipment, which poses a hidden danger to the safe production of the boiler.

[0003] With the changes in the coal electricity market, the fluctuation of coal ash content makes it difficult for the traditional system to adapt to the conveying of large particles and large specific gravity materials, resulting in frequent pipe blockage and frequent leakage points, which not only affects the ash conveying efficiency, but also easily causes emission pollution and a poor working environment. The system output is insufficient to meet the subsequent ash conveying demand, and the high material level fault of the dust collector is difficult to predict, which may cause a short circuit of the high-voltage power supply, resulting in unit load reduction or shutdown. In addition, large air volume operation causes waste of compressed air, which does not meet the national energy saving and emission reduction policy, and also restricts the enterprise's cost reduction and profit increase, and the above problems need to be solved by technical upgrading.

[0004] Existing pneumatic conveying technologies such as dense phase and double sleeve pipe, although widely used in a certain period, have defects such as rear wear caused by one-way air flow introduction, high noise, high energy consumption, poor adaptability, etc. When the density of fly ash increases, the friction between gas and fly ash increases, and the air volume and pressure need to be increased, further intensifying the vicious cycle of high flow rate, severe wear and tear, and rising energy consumption. Although there are plug flow conveying technologies in the industry, there is still room for improvement in multi-unit cooperation, low consumption, high efficiency, and integration of anti-blocking and wear resistance, which cannot fully meet the transformation needs of the ash conveying system of the unit. SUMMARY

[0005] The multi-unit parallel pilot pneumatic conveying integrated system of ash conveying system proposed in the present application solves the problems mentioned in the above prior art.

[0006] In order to achieve the above purpose, the present application adopts the following technical scheme: a multi-unit parallel pilot pneumatic conveying integrated system of ash conveying system, comprising:

[0007] Unit parallel conveying module: contains 3 independent ash conveying main pipelines, each pipeline is connected with 100 pure mechanical pilot valves in series along the pipeline for 3-5 meters; the pipeline uses Φ219*8mm and Φ159*8mm seamless steel pipes meeting the Q345 material requirement, the elbow is 90° / 45° ceramic composite wear-resistant part, one corrugated expansion joint is arranged every 50 meters, and the warehouse pump is connected in series through a Y-shaped wear-resistant tee joint;

[0008] Pilot gas source module: DN80 accompanying gas main pipe is laid along the ash conveying pipeline in parallel, 3 groups of pressure regulating valve groups, 8 accompanying gas pipeline filters and 3 groups of bypass valve groups are configured; all warehouse pump fluidization valves, pipeline secondary air supply valves and anti-blocking purge valves in the original system are cancelled, only the main air inlet valve at the top of the warehouse pump is reserved, and 6 DN25 automatic drain valves are arranged in the accompanying gas main pipe;

[0009] Linkage control module: the control core modification program is constructed to simplify the original five-step sequence of material falling-fluidization-pressure increase-conveying-purge into two-step sequence of material falling-conveying, the logic modification of the linkage control module needs to be completed by the original DCS system configuration debugging manufacturer to ensure the compatibility with the existing system; the WinCC configuration picture displays the pressure curve of each unit, the red / green indication of the pilot valve action state and the electromagnetic flowmeter data in real time, and the built-in timing optimization algorithm makes the conveying start interval of the three main pipelines ≥30 seconds;

[0010] Ash blocking protection module: the system is configured with 5 DN80 ash blocking devices and 300 special one-way valves; the ash pipe connection part adopts double O-ring + metal check ring sealing structure, and a 3mm thick stainless steel anti-backflow baffle is arranged at the intersection of the pilot pipeline and the ash conveying pipeline;

[0011] State monitoring module: one local pressure gauge, two DN200 electromagnetic flowmeters and one DN150 electromagnetic flowmeter are installed at the beginning, middle and end of the pipeline to collect pressure and flow data in real time; when the pressure exceeds the set value ±15% or the flow fluctuation is >20%, the audible and visual alarm is triggered and the configuration picture is prompted to flash, and the abnormal time and parameters are recorded automatically.

[0012] Further, it further comprises:

[0013] Conveying cycle optimization module: the conveying cycle of each unit is calculated by the formula wherein T is the conveying cycle, is the fly ash bulk density, K=0.9 is the full bin coefficient, and Q is the average ash conveying amount, which is used to dynamically adjust the unit start-stop timing.

[0014] Energy consumption monitoring module: the gas saving rate is calculated by the formula to monitor the energy saving effect in real time; wherein S is the gas saving rate, is the unit ash consumption gas consumption after the transformation, is the unit ash consumption gas consumption before the transformation.

[0015] Further, the ceramic wear-resistant elbow of the unit parallel conveying module adopts a gradually changing wall thickness design, the wall thickness at the curvature center is 8-10 mm, the inner wall is a 20x20 mm honeycomb ceramic inlaid structure, and the ceramic inlaid structure is combined with the pipeline body through a high-temperature-resistant adhesive.

[0016] Further, the pilot gas source module is provided with a three-stage cyclone + membrane filter combined structure, the first-stage cyclone separates liquid water, the second-stage active carbon adsorbs oil, and the third-stage PTFE membrane filters dust, and the filter element is provided with a differential pressure monitoring device.

[0017] Further, the linkage control module is internally provided with a pipe blockage prediction and self-unblocking logic, when the pressure of a section of pipeline suddenly rises by greater than or equal to 0.08 MPa and the flow decreases by 30%-50% within 5 seconds, the linkage control module automatically triggers high-frequency pulse purging of the three pilot valves before and after the section of pipeline, and simultaneously closes the upstream unit feeding valve, thereby preferentially ensuring the release of the pressure in the pipeline.

[0018] Further, the special one-way valve of the ash blocking protection module adopts a double-flap elastic sealing structure, the valve flap is made of wear-resistant nitrile rubber, a 316L stainless steel ring is embedded in the valve seat, the opening pressure is less than or equal to 0.02 MPa, the closing response time is less than 0.1 second, and the backflow of ash is controlled to be less than or equal to 0.5 kg per hour.

[0019] Further, the flow meter of the state monitoring module adopts an inserted V-cone + temperature and pressure compensation design, the V-cone throttling piece is made of hastelloy, and the real-time density correction function is realized.

[0020] Further, the bunker pump discharge port of the unit parallel conveying module is provided with a Venturi acceleration section, the length of the Venturi acceleration section is three times the diameter of the pipeline, the inlet taper angle is 15°±1°, the outlet taper angle is 8°±1°, the local flow field is accelerated, and the ash gas mixture forms an initial plug before entering the main pipeline, thereby reducing the wear of the pipeline inlet section.

[0021] Further, the pressure regulating valve group of the pilot gas source module is provided with a self-adaptive pressure stabilizing device, when the total gas source pipeline pressure fluctuates by ±0.05 MPa, the opening degree of the valve core of the PID regulating valve is adjusted, the output pressure is stabilized in the range of the set value ±0.02 MPa, and the consistency of the pilot valve action is ensured.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] The ceramic composite wear-resistant elbow and the gradually changing wall thickness design of the multi-unit parallel conveying module, in combination with the "upper outlet and lower inlet" connection mode of the bunker pump and the Venturi acceleration section, greatly reduce the wear of the pipeline, reduce the maintenance frequency, prolong the service life of the equipment, and solve the problem of frequent leakage of the traditional system. The multi-stage ash blocking design of the pure mechanical pilot valve and the ash blocking protection module effectively avoids the backflow of ash and gas, cooperates with the pipe blockage self-unblocking logic, fundamentally solves the pipe blockage problem, and improves the stability of the system.

[0024] The pilot gas source module cancels the redundant fluidization, air supplement device, only retains the main air inlet path, combines three-stage purification filtering and self-adaptive pressure stabilizing adjustment, significantly reduces the gas source consumption, reduces the number of air compressors in operation, reduces the plant power rate, and meets the energy saving and emission reduction policy. The linkage control module simplifies the control step sequence, avoids the gas source pressure fluctuation through the time sequence optimization algorithm, improves the conveying efficiency, and simultaneously reduces the burden of the control system. The state monitoring module collects the pressure and flow data in real time, timely alarms in the case of abnormality, facilitates the operation and maintenance personnel to quickly respond, and reduces the fault risk.

[0025] The system has strong overall adaptability, can cope with fly ash materials with different densities and particle sizes, meets the full load fly ash conveying demand of the unit, avoids the unit load reduction or shutdown caused by the high material level failure of the dust collector, guarantees the safe production, improves the fly ash conveying efficiency, reduces the emission pollution, improves the working environment, has economic benefits and social benefits, and provides a reliable solution for efficient, energy-saving and safe operation of the fly ash conveying system of the thermal power plant. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 A schematic block diagram of the fly ash conveying system multi-unit parallel pilot pneumatic conveying integrated system is provided for the present application;

[0027] Figure 2 A pipe blocking frequency comparison schematic diagram of the fly ash conveying system multi-unit parallel pilot pneumatic conveying integrated system is provided for the present application;

[0028] Figure 3 A comparison schematic diagram of the number of air compressors in operation of the fly ash conveying system multi-unit parallel pilot pneumatic conveying integrated system is provided for the present application. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0030] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0031] Furthermore, the terms "first", "second", etc. are used only for descriptive purposes and do not connote or imply relative importance or an ordering between or among the indicated technical features. Thus, a feature defined with "first", "second", etc. can include one or more of the features implicitly or explicitly. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly specifically defined otherwise. Furthermore, the terms "mounting", "connected", "connection" should be interpreted broadly, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances, and the present application will be further described in detail below with reference to the drawings.

[0032] Reference Figures 1 to 3 : A specific embodiment of a multi-unit parallel pilot pneumatic conveying integrated system of an ash conveying system.

[0033] I. Overall deployment of the system

[0034] The system of the present application is aimed at the modification of the ash conveying system of No. 1 unit, and the original 3 ash conveying main pipelines are retained: DN200 pipelines connect 4 V3.0m³ silo pumps of an electric field A side and 4 V0.5m³ silo pumps of a coal economizer, and two DN150 pipelines respectively connect 4 V3.0m³ silo pumps of an electric field B side + 8 V0.3m³ series silo pumps of denitration + 4 V1.5m³ silo pumps of each of bag area I and II. The pipelines adopt Φ219x8mm (DN200) and Φ159x8mm (DN150) seamless steel pipes, 1 pure mechanical pilot valve (300 in total) is connected in series along the pipeline every 3-5 meters, the valve body integrates 0-0.6MPa pressure gauges and 4 sets of spring type anti-ash components, and the valves are connected through Φ8mm pilot pipes to realize interlocking control. The elbows adopt 90° / 45° ceramic composite wear-resistant parts (composite structure of base body wall thickness 10mm + ceramic wear-resistant layer 5mm, total wall thickness ≥15mm, wall thickness at the center of curvature ≥10mm, and inner wall adopts 20x20mm honeycomb ceramic inlay), 1 corrugated expansion joint (compensation amount ±100mm) is arranged every 50 meters, the silo pumps are connected in series through Y-shaped wear-resistant tees (branch angle 30°), the overall layout is consistent with the original ash conveying path, and no additional land occupation is required.

[0035] II. Running mechanism of core module

[0036] Multi-unit parallel conveying module:

[0037] The ash conveying system comprises three independent ash conveying main pipes (DN200 pipes correspond to four V3.0 m3 tank pumps and four coal economizers V0.5 m3 tank pumps on the side of one electric field A, and DN150 pipes correspond to four V3.0 m3 tank pumps and eight denitration V0.3 m3 series tank pumps on the side of one electric field B, four V1.5 m3 tank pumps in the first and second bag areas respectively), 300 pure mechanical pilot valves (valve body with 0-0.6 MPa pressure gauge, four sets of spring type ash blocking components are arranged in the valve, and the valves are connected through Φ8 mm pilot pipes) are connected in series along the pipes at a distance of 3-5 meters; the pipes are Φ219*8 mm (DN200) and Φ159*8 mm (DN150) seamless steel pipes, the elbows are 90° / 45° ceramic composite wear-resistant parts (5 mm alumina ceramic lining, Q235 steel sleeve on the outer wall), one corrugated expansion joint (compensation amount ±100 mm) is arranged every 50 meters, and the tank pumps are connected in series through Y-shaped wear-resistant tees (branch angle 30°);

[0038] A venturi acceleration section (length is 3 times the diameter of the pipe, inlet taper angle is 15°±1°, and outlet taper angle is 8°±1°) is arranged at the discharge port of the tank pump to form an initial material plug. The ceramic wear-resistant elbow is designed with a gradually changing wall thickness, the wall thickness at the curvature center is 8-10 mm (the straight section is 5-6 mm), the inner wall is 20*20 mm honeycomb ceramic which is combined with the pipe through a high-temperature adhesive resistant to temperatures above 200 DEG C, and the impact speed of ash particles is less than or equal to 12 m / s.

[0039] The pilot gas source module comprises:

[0040] A DN80 accompanying gas main pipe (20# seamless steel pipe) is arranged in parallel along the ash conveying pipe, three groups of ZDTY.ZL-80 type pressure regulating valve groups (import pressure 0.6-0.8 MPa, outlet pressure 0.2-0.35 MPa continuously adjustable), eight accompanying gas pipe filters (DN80 / L500, filter element is stainless steel sintered mesh, precision 5 μm) and three groups of bypass valve groups (comprising a DN80 pneumatic butterfly valve and a manual ball valve) are arranged, all the tank pump fluidization valves, pipe secondary air valves and anti-blocking purge valves in the original system are cancelled, only the tank pump top main air valve (DN100 pneumatic ball valve) is reserved, and one DN25 automatic drain valve (drainage capacity 1.5 t / h) is arranged every 100 meters of the accompanying gas main pipe;

[0041] Along the ash pipeline parallel laying DN80 gas mother pipe (20# seamless steel pipe), configuration 3 groups of ZDTY.ZL-80 type pressure regulating valve group (import 0.6-0.8 MPa, outlet 0.2-0.35 MPa adjustable), 8 sets of gas filter (three-stage purification: cyclone water removal ≥95%, activated carbon oil removal to ≤0.01 mg / m³, PTFE membrane filtration 0.1-0.5 μm), 3 groups of bypass valve group (DN80 pneumatic butterfly valve + manual ball valve). Cancel the original system fluidization valve, air supply valve, only keep DN100 warehouse pump main air valve, and set up DN25 automatic drain valve (drainage 1.5 t / h) every 100 meters of gas mother pipe.

[0042] Linkage control module:

[0043] Based on the control core compatible with the original ash control PLC system, add hardware (card, cabinet) and original system type consistent control core, modify the program to simplify the original "material- fluidization- boost- conveying- purge" five-step sequence to "material (material level meter full signal trigger, time 30-60 seconds)- conveying (warehouse pump pressure reaches 0.2 MPa to start, to ash storage pressure <0.05 MPa stop)" two-step sequence; Configuration picture (WinCC) real-time display of each unit pressure curve (sampling period 100 ms), pilot valve action state (red / green indication) and electromagnetic flowmeter data, built-in timing optimization algorithm makes 3 main pipeline conveying start interval ≥30 seconds, avoid gas source pressure fluctuation superimposed ±0.05 MPa;

[0044] Based on S7-1200 PLC, simplify the control to "material- conveying" two-step sequence: material stage (material level meter full signal trigger, 30-60 seconds), conveying stage (warehouse pump pressure reaches 0.2 MPa to start, to ash storage pressure <0.05 MPa stop). WinCC configuration picture real-time display of pressure curve (sampling 100 ms), pilot valve state and flow, built-in algorithm makes 3 pipeline start interval ≥30 seconds, avoid gas source fluctuation superimposed ±0.05 MPa. When the pipe is blocked (5 seconds pressure rises ≥0.08 MPa and flow decreases 30%-50%), trigger the high-frequency pulse purge (4-6 Hz, 2-3 seconds) of the three pilot valves before and after this section, and close the upstream feeding valve at the same time.

[0045] Ash prevention module:

[0046] Each main pipeline is provided with one XDZR-80 large dust arrestor (passage diameter 80 mm, built-in double-layer filter screen: outer layer 10-mesh stainless steel screen + inner layer 50-mesh ceramic fiber screen) and 300 ZDXD-ZH / 25 special one-way valves (opening pressure 0.02 MPa, closing leakage <0.1 L / min); the dust pipe connection part adopts double O-ring (fluorine rubber, Φ200 / 150×8 mm) + metal check ring sealing structure, and a 3 mm thick stainless steel anti-backflow baffle (inclination angle 45°) is arranged at the intersection of the pilot pipeline and the dust conveying pipeline;

[0047] Each pipeline is provided with one XDZR-80 large dust arrestor (double-layer filter screen: 10-mesh stainless steel screen + 50-mesh ceramic fiber screen) and 300 ZDXD-ZH / 25 one-way valves (double-flap nitrile rubber valve flap, Shore hardness 85±5, closing response <0.1 second, backflow ≤0.5 kg / h). The dust pipe connection adopts double O-ring (fluorine rubber Φ200 / 150×8 mm) + metal check ring sealing, and a 3 mm thick 45° stainless steel anti-backflow baffle is arranged at the intersection of the pilot pipe and the dust conveying pipe.

[0048] State monitoring module:

[0049] One Y-100 on-site pressure gauge (accuracy 1.6 level), two DN200 electromagnetic flowmeters (measurement range 0-300 Nm³ / h) and one DN150 electromagnetic flowmeter (0-150 Nm³ / h) are installed at the start, middle and end of the pipeline to collect pressure and flow data in real time; when the pressure exceeds the set value ±15% or the flow fluctuation is >20%, the audible and light alarm (buzzer + red warning light) is triggered and the configuration screen is prompted to flash, and the abnormal time and parameters are recorded automatically;

[0050] Y-100 pressure gauge (accuracy 1.6 level), plug-in V-cone flowmeter (Hastelloy material, DN200 range 0-300 Nm³ / h, DN150 range 0-150 Nm³ / h, temperature and pressure compensation suitable for 120-180℃, accuracy ±0.5%) are installed at the start, middle and end of the pipeline; when the pressure exceeds ±15% or the flow fluctuation is >20%, the buzzer + red warning light alarm is triggered, and the abnormal parameters are recorded.

[0051] III. Application of key formulas

[0052] Transportation cycle optimization: wherein T is the cycle (min), V is the total volume of the silo pump (m³), For fly ash density (1000-1200 kg / m³), K=0.9, Q is the average ash conveying amount (kg / min). For example, the total volume of the pump of the silo on the A side of the electric field is 14 m³, and the fly ash density is 1100 kg / m³, and the average ash conveying amount is 200 kg / min. According to the calculation, T=(14*1100*0.9) / 200≈69.3 minutes, which indicates that the unit should be started once every 70 minutes.

[0053] The gas saving rate is calculated as: Wherein , are the gas consumption (Nm³ / t) of the unit before and after the transformation, respectively. If 80 Nm³ of gas is needed for conveying 1 t of ash before the transformation, and 35 Nm³ of gas is needed after the transformation, then directly reflects the energy saving effect.

[0054] Four, effect data representation

[0055] Indicator Before modification After modification Daily average pipe blocking times 5-8 times 0-1 times Pipeline life 6-8 months 36-48 months Air compressor operation number 4-5 units 2-3 units Monthly maintenance cost 80-100 thousand yuan 1-2 thousand yuan

[0056] The above data is based on continuous operation monitoring for 3 months after the transformation. The number of pipe blockages is significantly reduced after the transformation, which benefits from the pilot valve pulse purge and the anti-dust design, avoiding the pipe blockage caused by the accumulation of dust particles in the traditional system; the pipe life is extended by more than 6 times, due to the ceramic wear-resistant elbow and the gradual wall thickness design, which greatly reduces the wear rate; the number of air compressors running is reduced, combined with the improvement of the gas saving rate, which directly reduces the consumption of auxiliary power; the monthly maintenance cost is reduced by more than 80%, mainly due to the reduction of pipe wear, the decrease of leakage frequency and the extension of spare parts replacement cycle. Overall, the system realizes the core goals of "blockage treatment, wear prevention and gas saving" through structural optimization and intelligent control, and improves the operation stability and economy.

[0057] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any skilled person in the art can make equivalent replacements or changes to the technical solutions and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A multi-unit parallel type pilot pneumatic conveying integrated system of a fly ash conveying system, characterized in that, Comprise: Unit parallel conveying module: contains 3 independent conveying main pipeline, each pipeline along the way every 3-5 meters in series pure mechanical pilot valve, each elbow before and after each add a pilot valve, a total of 300; pipeline adopts Φ219x8mm and Φ159x8mm seamless steel pipe, elbow is 90° / 45° ceramic composite wear-resistant parts, every 50 meters sets up 1 corrugated expansion joint, through Y type wear-resistant tee realizes bin pump series communication; Pilot gas source module: along each gas mother pipe starting end installs pressure regulating valve group, pneumatic cut-off valve and drainage pipeline, end installs manual ball valve, configures 3 groups of pressure regulating valve group, 8 gas pipeline filters and 3 groups of bypass valve group; cancel all bin pump fluidization valve, pipeline secondary air supply valve and anti-blocking purge valve of original system, only keep bin pump top main air inlet valve, gas mother pipe is arranged with 6 DN25 automatic drain valve; Linkage control module: the control core modification program is constructed to simplify the original five-step sequence of feeding-fluidizing-pressurizing-conveying-purging into two-step sequence of feeding-conveying, the linkage control module needs to be modified by the original DCS system configuration debugging manufacturer to ensure compatibility with the existing system; the WinCC configuration picture displays the pressure curve of each unit, the red / green indication of the pilot valve action state and the electromagnetic flowmeter data in real time, and the built-in timing optimization algorithm makes the conveying start interval of the three main pipelines ≥30 seconds; Ash blocking protection module: the system is configured with 5 DN80 ash blockers and 300 special one-way valves; the ash pipe connection part adopts double O-ring + metal check ring sealing structure, and a 3mm thick stainless steel anti-backflow baffle is arranged at the intersection of the pilot pipeline and the ash conveying pipeline; State monitoring module: one local pressure gauge, two DN200 electromagnetic flowmeters and one DN150 electromagnetic flowmeter are installed at the starting end, middle end and end of the pipeline to collect pressure and flow data in real time; when the pressure exceeds the set value ±15% or the flow fluctuation is >20%, the audible and visual alarm is triggered and the configuration picture is prompted to flash, and the abnormal time and parameters are recorded automatically.

2. The multi-unit parallel type pilot pneumatic conveying integrated system of the ash conveying system according to claim 1, characterized in that, Also include: Transport cycle optimization module: by formula Calculate the unit transport cycle, where T is the transport cycle, is the fly ash bulk density, K=0.9 is the full bin coefficient, Q is the average fly ash transport amount, which is used to dynamically adjust the unit start-stop timing.

3. The multi-unit parallel type pilot pneumatic conveying integrated system of the ash conveying system according to claim 1, characterized in that, Also include: Energy consumption monitoring module: by formula Calculate the energy-saving rate and monitor the energy-saving effect in real time. where S is the turndown ratio, gas consumption per unit of ash after revamping, gas consumption per unit of ash before revamping.

4. The multi-unit parallel type pilot pneumatic conveying integrated system of the ash conveying system according to claim 1, characterized in that, The ceramic wear-resistant elbow of the unit parallel conveying module adopts a gradually changing wall thickness design, the wall thickness at the curvature center is 8-10mm, the inner wall is a 20x20mm honeycomb ceramic inlaid structure, and the pipeline base body is combined through a high-temperature resistant adhesive.

5. The multi-unit parallel pilot pneumatic conveying integrated system of the ash conveying system according to claim 1, characterized in that, The gas filter of the pilot gas source module adopts a three-stage cyclone + membrane filter combined structure, the first-stage cyclone separates liquid water, the second-stage activated carbon adsorbs oil, and the third-stage PTFE membrane filters dust, and the filter element is provided with a differential pressure monitoring device.

6. The multi-unit parallel pilot pneumatic conveying integrated system of the ash conveying system according to claim 1, wherein, The linkage control module is provided with a pipe blocking prediction and self-unblocking logic, when the pressure of a section of pipeline suddenly rises by ≥0.08MPa and the flow decreases by 30%-50% within 5 seconds, the three pilot valves before and after the section are automatically triggered for high-frequency pulse purging, and the upstream unit feeding valve is closed, thereby giving priority to the release of the pipeline pressure.

7. The multi-unit parallel pilot pneumatic conveying integrated system of the ash conveying system according to claim 1, characterized in that, The special one-way valve of the ash blocking protection module adopts a double-flap elastic sealing structure, the valve flap is made of wear-resistant nitrile rubber, the valve seat is embedded with a 316L stainless steel ring, the opening pressure is ≤0.02MPa, the closing response time is <0.1 second, and the backflow ash amount is controlled to be ≤0.5kg per hour.

8. The multi-unit parallel pilot pneumatic conveying integrated system of the ash conveying system according to claim 1, characterized in that, The flow meter of the state monitoring module adopts plug-in V-cone + temperature and pressure compensation design, the V-cone throttling member is made of hastelloy, and the real-time density correction function is realized.

9. The multi-unit parallel pilot pneumatic conveying integrated system of the ash conveying system according to claim 1, wherein, The venturi accelerating section is arranged at the discharge port of the bin pump of the unit parallel conveying module, the length is 3 times of the pipe diameter, the inlet taper angle is 15°±1°, the outlet taper angle is 8°±1°, and the initial material plug is formed in the ash gas mixture before entering the main pipe through local flow field acceleration, so that the abrasion of the pipe inlet section is reduced.

10. The multi-unit parallel pilot pneumatic conveying integrated system of the ash conveying system according to claim 1, characterized in that, The pressure regulating valve group of the pilot gas source module is equipped with a self-adaptive pressure stabilizing device, when the gas source main pipe pressure fluctuates ±0.05MPa, the output pressure is stabilized in the range of the set value ±0.02MPa through the PID adjusting valve core opening, and the consistency of the pilot valve action is ensured.

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