Intelligent transformation method of ash conveying system in thermal power plant

Abstract

The invention discloses an intelligent transformation method for an ash conveying system of a thermal power plant, including hardware transformation of a process pipeline, hardware transformation of a control system, optimization of a control program, intelligent determination of an ash blockage position, and an automatic ash cleaning system. The hardware transformation of the process pipeline includes: S1. a pressure regulating valve is respectively added to a compressed air inlet pipeline of each ash removal unit; S2. a pneumatic ash conveying assisting device is installed at the ash conveying pipeline; S3. the ash conveying pipeline of a silo pump unit is changed from parallel to series; the hardware transformation of the control system includes: R1. a low material level detection switch is added to the first and second electric fields and the economizer silo pump; R2. a pneumatic valve is added to the first and second electric fields and the fluidizing gas pipeline of the economizer silo pump; R3. a compressed air storage tank or a high-pressure fan is respectively added to the compressed air inlet of the first and second electric fields and the economizer ash removal pipeline. The invention relates to the technical field of ash removal systems in thermal power plants. This transformation has low investment, short construction period, and quick effect, and has a qualitatively superior effect compared with previous energy-saving projects.

Description

Technical Field

[0001] The invention relates to the technical field of ash removal systems in thermal power plants, and in particular to an intelligent transformation method for ash conveying systems in thermal power plants. Background Art

[0002] In the thermal power industry, the pneumatic ash conveying system has always been at a disadvantage compared to other devices in terms of energy saving due to many limiting factors. The intelligent ash conveying system achieves almost perfect coordination through the improvement of the ash conveying process and the intelligent logic program. This transformation requires low investment, short construction period, and quick results. Compared with previous energy-saving projects, it has a qualitative leap and is of great promotion value.

[0003] The pneumatic ash removal system is an auxiliary treatment facility for thermal power plants. Whether it can maintain long-term continuous and stable operation is an important link related to the safe production of the entire generator set.

[0004] 1. At present, in order to reduce production costs, domestic thermal power plants seriously burn different coal qualities, resulting in large changes in ash quality and ash volume, unstable ash-gas ratio, and frequent ash blockage failures. In order to ensure the normal operation of the ash conveying system, the gas volume has to be increased and the ash conveying time has to be extended, resulting in excessive consumption of energy, accelerated wear of the ash conveying pipeline, and increased equipment maintenance frequency and cost.

[0005] 2. Pneumatic ash handling control generally adopts PLC+host computer distributed control system, which has a high degree of automation and safe and reliable control. However, since energy saving and intelligent requirements were not considered in the original design, the control program only adopted sequential control logic, which was simple and rough. It did not optimize the order and frequency of ash delivery of each unit and the ash delivery time of each unit according to the ash volume and ash falling speed of each ash handling unit. Often, several units deliver ash at the same time, and the ash delivery time is fixed, which increases the consumption of compressed air for no reason, which not only wastes energy but also accelerates the wear of pipelines.

[0006] 3. If a serious ash blockage occurs, the location of the blockage can only be found by manually knocking on the ash removal pipeline one by one. After finding the blockage location, the pipeline is manually opened and cleaned. This not only increases the labor intensity of the workers, but also seriously affects the safe operation of the unit due to the failure to eliminate the ash blockage in time. Summary of the invention

[0007] In view of the deficiencies of the prior art, the present invention provides an intelligent transformation method for an ash conveying system of a thermal power plant, which solves the problem that the prior device is inconvenient to use.

[0008] To achieve the above objectives, the present invention is implemented by the following technical methods: an intelligent transformation method of the ash conveying system of a thermal power plant, including process pipeline hardware transformation, control system hardware transformation and control program optimization, as well as intelligent ash blockage position determination and automatic ash cleaning system, the process pipeline hardware transformation includes: S1. adding a pressure regulating valve to the compressed air intake pipeline of each ash removal unit, S2. installing a pneumatic ash conveying assist device at the ash conveying pipeline, S3. changing the ash conveying pipeline of the silo pump unit from parallel to series, the control system hardware transformation includes: R1. One, The second electric field and economizer bin pump add low material level detection switches, R2. The first and second electric fields and economizer bin pump fluidizing gas pipelines add pneumatic valves, R3. The first and second electric fields and economizer ash removal pipelines add compressed air storage tanks or high-pressure fans at the compressed air inlets, R4. Add PLC remote racks and modules and control boxes or add new control systems to network with the original control system. The control program optimization includes: T1. Add intelligent optimization sorting program, T2. The first and second electric fields and economizer bin pump fluidizing gas inlet valves automatically adjust according to the material level of the bin pump. Automatic opening and closing, T3. The original control function is specified as "parallel control", and the newly added intelligent optimization function is "sequential control". T4. Since only one air compressor needs to be turned on in "sequential control" and two air compressors need to be operated in "parallel control", when the two control modes are switched, a VB program is written in the upper computer configuration software. T5. The added intelligent judgment of ash blocking position and automatic ash cleaning system are connected to the control program. The transformation of the intelligent judgment of ash blocking position and automatic ash cleaning system includes A1. On each ash conveying main pipeline, every 30-50 A new pressure sensor, a set of cleaning bypass valve and ash-gas separation device are installed. A2. When a blockage occurs, the blockage position is accurately determined based on the difference in pressure data before and after the blockage section, and then the cleaning bypass valves before and after the blockage section are automatically opened according to the clearing procedure to perform clearing operations. A3. The pressure data of the ash conveying pipeline is collected at all times, the opening and closing of the cleaning bypass valve is automatically controlled, and it is connected to the original ash removal control system. A4. The intelligent judgment of the blockage position and the automatic cleaning control monitoring operation screen and parameter setting screen are added to the original upper computer monitoring system.

[0009] Preferably, the control program optimizes and retains the control functions and logic of the original program.

[0010] Beneficial Effects

[0011] The present invention provides an intelligent transformation method for the ash conveying system of a thermal power plant, which has the following beneficial effects: In view of the technical difficulties and pain points encountered in the actual operation of the above thermal power plant ash removal system, our technical transformation method is: process pipeline hardware transformation; increase control system hardware; optimize the original control software; increase intelligent judgment of ash blockage position and automatic ash cleaning system, so as to achieve the effect of energy saving, energy saving and intelligent operation and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of the present invention.

[0013] Figure 2 It is a partially enlarged schematic diagram of the control system of the present invention. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical methods in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0015] See also Figure 1-2The present invention provides a technical method: an intelligent transformation method for the ash conveying system of a thermal power plant, including the hardware transformation of the process pipeline, the hardware transformation of the control system, the optimization of the control program, the intelligent determination of the ash blockage position and the automatic ash cleaning system. The hardware transformation of the process pipeline includes: S1. The compressed air intake pipeline of each ash removal unit is respectively increased with a pressure regulating valve, S2. A pneumatic ash conveying assist device is installed at the ash conveying pipeline, S3. The ash conveying pipeline of the silo pump unit is changed from parallel to series, and the hardware transformation of the control system includes: R1. The first and second electric fields and the economizer silo pump are increased with low material Position detection switch, R2. Add pneumatic valves to the fluidizing gas pipelines of the first and second electric fields and economizer silo pumps, R3. Add compressed air storage tanks or high-pressure fans to the compressed air inlets of the first and second electric fields and economizer ash removal pipelines, R4. Add PLC remote racks and modules and control boxes or add new control systems to network with the original control system. The control program optimization includes: T1. Add intelligent optimization sorting program, T2. The fluidizing gas inlet valves of the first and second electric fields and economizer silo pumps are automatically opened and closed according to the material level of the silo pump, T3. The original control function is specified as " The newly added intelligent optimization function is "sequential control". T4. Since only one air compressor needs to be turned on in "sequential control" and two air compressors need to be operated in "parallel control", when switching between the two control modes, a VB program is written in the upper computer configuration software. T5. The added intelligent ash blockage position detection and automatic ash cleaning system is connected to the control program. The modification of the intelligent ash blockage position detection and automatic ash cleaning system includes A1. A pressure sensor and a set of ash cleaning bypass valves and valves are newly installed every 30-50 meters on each ash conveying main pipeline. Ash-gas separation device, A2. When an ash blockage failure occurs, the ash blockage position is accurately determined based on the difference in pressure data before and after the ash blockage section, and then the ash cleaning bypass valve before and after the ash blockage section is automatically opened according to the clearing procedure to perform clearing operations. A3. The pressure data of the ash conveying pipeline is collected at all times, the opening and closing of the clearing bypass valve is automatically controlled, and it is connected to the original ash removal control system. A4. The intelligent judgment of the ash blockage position and the automatic ash cleaning control monitoring operation screen and parameter setting screen are added to the original upper computer monitoring system. The control program optimizes and retains the control functions and logic of the original program.

[0016] By those skilled in the art, the components in this case are connected in sequence. The specific connection and operation sequence should refer to the following working principle. The detailed connection means are well-known technologies in the field. The following mainly introduces the working principle and process.

[0017] Example:

[0018] 1. Hardware transformation of process pipelines

[0019] 1) Each ash removal unit’s compressed air inlet pipeline is equipped with a pressure regulating valve to adjust the ash conveying pipeline pressure and optimize the conveying speed, thereby achieving the purpose of saving air and preventing wear.

[0020] 2) Install a pneumatic ash conveying assist device at the part of the ash conveying pipeline that is prone to clogging. When the pressure in the ash conveying pipeline increases and is close to reaching the pipe blocking pressure, the pneumatic ash conveying assist device will automatically open to replenish air into the ash conveying pipeline, thereby enhancing the fluidization effect in the ash removal pipeline and reducing the chance of clogging.

[0021] 3) According to the current status of ash conveying operation on site, the ash conveying pipelines of the silo pump unit are changed from parallel to series to reduce the use of compressed air for ash conveying and the frequency of ash conveying.

[0022] 2. Control system hardware transformation

[0023] 1) Low material level detection switches are added to the first and second electric fields and economizer bin pumps to accurately control the fluidizing gas inlet valve.

[0024] 2) Add pneumatic valves to the fluidizing gas pipelines of the first and second electric fields and economizer silo pumps. Automatically open and close the air inlet valve according to the ash content of the silo pump to achieve precise control. During the ash conveying process, when a silo pump has a low material level, close the fluidizing gas valve of the silo pump in time to achieve the purpose of saving air.

[0025] 3) Compressed air storage tanks or high-pressure fans are added to the compressed air inlets of the first and second electric fields and economizer ash removal pipelines to supplement the insufficient compressed air pressure during the ash conveying process or to clear blockages.

[0026] 4) If the original PLC control system does not have enough I / O points, add PLC remote racks and modules and control boxes. Or add a new control system to network with the original control system to access the control points added after the transformation.

[0027] 3. Control program optimization

[0028] 1) Keep the control functions and logic of the original program.

[0029] 2) Add intelligent optimization sorting program to arrange the ash delivery order according to the ash removal capacity and ash falling amount of each ash removal unit. The ash delivery order is: the big order is divided into three levels: T1, T2, and T3:

[0030] (1) T1: Side A and B of the first and second electric fields of electrostatic precipitator

[0031] The internal "ash delivery" priority order is:

[0032] (a) Side A of the first electric field; (b) Side B of the first electric field; (c) Side A of the second electric field; (d) Side B of the second electric field.

[0033] (2) T2: Economizer

[0034] The internal "ash delivery" priority order is:

[0035] (a) Unit B of the No. 3 and No. 4 silo pumps; (b) Unit C of the No. 5 and No. 6 silo pumps; (c) Unit A of the No. 1 and No. 2 silo pumps; (d) Unit D of the No. 7 and No. 8 silo pumps.

[0036] (3) T3: Side A and B of the third, fourth and fifth electric fields of electrostatic precipitator

[0037] The internal "ash delivery" priority order is:

[0038] (a) Three-electric field A side; (b) Three-electric field B side; (c) Four-electric field A side; (d) Four-electric field B side;

[0039] (e) Side A of the five electric fields; (f) Side B of the five electric fields.

[0040] Among them, the T2 and T3 levels are "connected in parallel", that is, any unit of the economizer and any unit of the third, fourth, and fifth electric fields of the electrostatic precipitator can "transmit ash" at the same time.

[0041] The triggering condition for sorting is when any silo pump of each unit triggers a high material level or the feeding time of the unit is up. When a unit is in manual mode, the unit exits the sorting. The internal units of each level are interlocked in sequence. In each sorting level, only one unit can be in the ash feeding state at the same time.

[0042] The unit load signal and the new signal are connected to the system, and the gas consumption and the number of air compressors in operation are automatically adjusted according to the unit load changes, thus achieving energy-saving control to the greatest extent.

[0043] 3) The fluidizing gas inlet valves of the first and second electric fields and economizer silo pumps are automatically opened and closed according to the material level of the silo pump.

[0044] 4) The original control function is defined as “parallel control”, and the newly added intelligent optimization function is “sequential control”. The two functions can be switched without disturbance at any time through the control button on the host computer.

[0045] 5) Since only one air compressor needs to be turned on in "sequential control" and two air compressors need to be operated in "parallel control", a VB program is written in the upper computer configuration software to realize automatic start and stop of the air compressor when switching between the two control modes, so as to meet the disturbance-free switching between the two control modes. 6) The added intelligent detection of the ash blockage position and the automatic ash cleaning system are connected to the control program.

[0046] 4. Add intelligent detection of ash blockage position and automatic ash cleaning system

[0047] 1) Install a pressure sensor and a set of ash cleaning bypass valve and ash gas separation device every 30-50 meters (the specific data depends on the site conditions) on each ash conveying main pipeline. The newly installed pressure sensor is used to detect the pressure changes inside the ash conveying pipeline, and the ash cleaning bypass valve and ash gas separation device are used to automatically clear the ash blockage fault when ash is blocked.

[0048] 2) When a ash blockage failure occurs, the ash blockage location is accurately determined based on the difference in pressure data before and after the ash blockage section, and then the ash cleaning bypass valves before and after the ash blockage section are automatically opened according to the clearing procedure to perform the clearing operation.

[0049] 3) Add a set of intelligent detection of ash blockage position and automatic ash cleaning control system to collect pressure data of the ash conveying pipeline, automatically control the opening and closing of the clearing bypass valve, and connect it to the original ash removal control system to realize information interconnection and control logic linkage and interlocking.

[0050] 4) Add intelligent detection of dust blockage position and automatic dust cleaning control monitoring operation screen and parameter setting screen to the original upper computer monitoring system.

[0051] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants 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. In the absence of further restrictions. The sentence "includes an element defined by ... does not exclude the existence of other identical elements in the process, method, article or device including the element".

[0052] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Intelligent transformation method of ash conveying system in thermal power plant, characterized in that: It includes the hardware transformation of process pipelines, the hardware transformation of control systems, the optimization of control programs, the intelligent determination of ash blockage positions and the automatic ash cleaning system. The hardware transformation of process pipelines includes: S1. The compressed air intake pipelines of each ash removal unit are respectively equipped with pressure regulating valves; S2. The ash conveying pipelines are equipped with pneumatic ash conveying assist devices; S3. The ash conveying pipelines of the silo pump unit are changed from parallel to series; The hardware transformation of the control system includes: R1. The first and second electric fields and economizer silo pumps are equipped with low material level detection switches; R2. The first and second electric fields and economizer silo pumps are equipped with low material level detection switches; Pneumatic valves are added to the fluidizing gas pipeline of the coal burner silo pump. R3. Compressed air storage tanks or high-pressure fans are added to the compressed air inlets of the first and second electric fields and economizer ash removal pipelines. R4. PLC remote racks and modules and control boxes are added or new control systems are added to network with the original control system. The control program optimization includes: T1. Adding intelligent optimization sorting program. T2. The fluidizing gas inlet valves of the first and second electric fields and economizer silo pumps are automatically opened and closed according to the material level of the silo pump. T3. The original control function is specified as "parallel control" , the newly added intelligent optimization function is "sequential control", T4. Since only one air compressor needs to be turned on in "sequential control" and two air compressors need to be operated in "parallel control", when switching between the two control modes, a VB program is written in the upper computer configuration software, T5. The added intelligent judgment of ash blockage position and automatic ash cleaning system are connected to the control program. The transformation of the intelligent judgment of ash blockage position and automatic ash cleaning system includes A1. Install a pressure sensor and a set of ash cleaning bypass valve and ash gas separation device every 30-50 meters on each ash conveying main pipeline, A2. When ash blockage occurs, the ash blockage position is accurately determined according to the difference in pressure data before and after the ash blockage section, and then the ash cleaning bypass valve before and after the ash blockage section is automatically opened according to the cleaning program to perform the cleaning operation A3. The pressure data of the ash conveying pipeline is collected at all times, the opening and closing of the cleaning bypass valve is automatically controlled, and it is connected to the original ash removal control system, A4. Add the intelligent judgment of ash blockage position and automatic ash cleaning control monitoring operation screen and parameter setting screen in the original upper computer monitoring system.

2. The intelligent transformation method of the ash conveying system of a thermal power plant according to claim 1 is characterized in that: The control program optimization retains the control functions and logic of the original program.

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