Method for transforming modularized combustion chamber of solid-state deslagging boiler for peak regulation of thermal power plant

Abstract

The invention discloses a transformation method for a modularized combustion chamber of a solid-state deslagging boiler for peak regulation of a thermal power plant, and belongs to the technical field of peak regulation of thermal power plants. Comprising a boiler main combustion chamber which is formed by assembling a plurality of modularized split independent combustion chambers. And each split independent combustion chamber is separated by a water cooling wall to form an independent combustion cavity. And a plurality of split pulverized coal burners are mounted on the outer side of the pulverized coal distributor and are connected with a pulverized coal balancing distributor through pipelines. In addition, the multiple modularized independent combustion chambers share an original smoke pipeline, and efficient smoke exhaust of the whole system is achieved. According to the transformation method, different combustion areas can be better isolated, the combustion efficiency is improved, emission is reduced, loads can be flexibly adjusted, and fluctuation changes of power requirements are adapted.

Description

Technical Field

[0001] The invention belongs to the technical field of peak regulation of thermal power plants, and in particular relates to a method for transforming a modular combustion chamber of a solid slag discharge boiler used for peak regulation of a thermal power plant. Background Art

[0002] Under the background of deep peak regulation, coal-fired units are in low-load operation for a long time. At present, this will lead to a series of technical problems in the boiler: (1) Poor combustion stability. When operating at low load, the combustion process is unstable, resulting in slow feedback adjustment of the unit and causing sudden flameout in the furnace. This not only affects the continuity of power supply, but also may cause damage to the boiler structure. (2) The working environment of the equipment is harsh. The working environment of key components such as superheaters, reheaters, and air preheaters becomes harsh when operating at low load. Uneven heating of the pipes causes metal fatigue, increasing the risk of safety accidents such as pipe bursts, thereby affecting the service life of the boiler. (3) The combustion efficiency decreases, the coal powder is incompletely burned, the furnace temperature decreases, and the thermal efficiency of the boiler decreases. This not only increases fuel consumption, but may also cause ash accumulation and slagging in the furnace, increasing maintenance costs. (4) Pollutant emissions exceed the standard. The reduction in exhaust gas temperature will affect the normal operation of the denitrification system, resulting in excessive outlet pollutant concentrations. This not only violates environmental protection regulations, but also damages the social image of the power plant.

[0003] Although existing technical methods have achieved certain results in dealing with power demand fluctuations and peak load problems, they each have obvious advantages and disadvantages. Although flexible adjustment of unit operating load can adapt to changes in power demand, the response speed is slow and inefficient. Auxiliary backup power sources such as gas turbines and energy storage systems have rapid response capabilities, but they are expensive and have limited resource supply. Optimizing combustion control technology improves combustion stability and efficiency, but the technology is complex and has limited effects at extremely low loads. Strengthening equipment maintenance and upgrades can help improve equipment operation reliability, but it increases operating costs and downtime risks. The use of cogeneration systems can balance loads when power demand is low, but its application is limited by the thermal energy demand market and the load adjustment flexibility is insufficient. Smart grid technology achieves comprehensive monitoring and optimized scheduling, but its implementation is difficult and there are network security risks.

[0004] Existing thermal power plant boilers have problems of low efficiency, high energy consumption and high emissions during the peak load regulation process; the traditional coal-fired boiler structure is not easy to adapt to frequent load changes, resulting in unstable operation, fuel waste and high pollution emissions. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a method for modifying the modular combustion chamber of a solid slag discharge boiler for peak load regulation in a thermal power plant, so as to solve the problem in the prior art that thermal power plant boilers are difficult to adapt to frequent load changes during peak load regulation, resulting in unstable operation, fuel waste and high pollution emissions.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A method for transforming a modular combustion chamber of a solid slag removal boiler for peak load regulation in a thermal power plant comprises the following steps: Step 1, dismantle the main combustion chamber between the flue and the ash hopper in the solid slag discharge boiler, place four modular combustion chambers at the original main combustion chamber, separate and connect the four modular combustion chambers by partitions, and connect the bottom of each modular combustion chamber to the ash hopper; Step 2, installing an independent pulverized coal burner for each modular combustion chamber; Step 3, each modular combustion chamber electrical signal is connected to a combustion chamber sub-control system; Step 4, the upper ends of the four modular combustion chambers are connected to the flue, and the smoke exhaust fan connected to the flue is improved to a variable frequency smoke exhaust fan.

[0007] A further improvement of the present invention is: Preferably, in step 1, the four modular combustion chambers are assembled symmetrically with equal volumes.

[0008] Preferably, in step 1, the partition is a detachable structure, and the cross-section of the partition is cross-shaped.

[0009] Preferably, in step 1, the partition is a water-cooled wall.

[0010] Preferably, the pulverized coal burner is installed on the outer side wall of the modular combustion chamber.

[0011] Preferably, in step 2, a fan is provided at the installation location of each of the pulverized coal burners.

[0012] Preferably, in step 1, the pulverized coal burner is connected to a pulverized coal balancing distributor.

[0013] Preferably, the input end of the pulverized coal equalizer is connected to a pulverized coal input pipeline and an air pipeline, and the output end is respectively input into each pulverized coal burner.

[0014] Preferably, in step 5, the superheater in the flue and the water cooling system in the partition are connected to a steam-water system.

[0015] Preferably, in step 5, a flue gas recirculation system is installed in the flue.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a modular combustion chamber transformation method for a solid slag discharge boiler for peak load regulation in a thermal power plant. The transformation method designs the main combustion chamber of the boiler into a plurality of modular split independent combustion chambers, each of which is separated by a partition to form four independent modular combustion chambers. Each modular combustion chamber is equipped with an independent pulverized coal burner, so that the pulverized coal combustion chamber is an independent combustion chamber. When operating at low load, on the one hand, the combustion process of the independent combustion chamber is more stable, the instability of the combustion process is reduced, and the sudden flameout in the furnace caused by unstable combustion is avoided. On the other hand, the modular design enables the combustion chamber to be flexibly adjusted according to the load demand, and each module can operate independently and can be dynamically adjusted according to the load demand. Such a design enables the coal-fired unit to quickly respond to the situation of insufficient power supply from new energy sources and quickly increase the load to ensure stable power supply. The present invention improves the combustion stability and efficiency through the design of the modular combustion chamber device, adapts to the fluctuation of power demand, reduces pollutant emissions, and prolongs the service life of the equipment, and has significant technical progress and practical value.

[0017] Furthermore, each modular combustion chamber is separated by a water-cooled partition, and can be cooled by a corresponding water-cooled wall when burning independently.

[0018] Furthermore, the existing combustion control system is upgraded to enable it to independently control the operating status of each combustion chamber module. Advanced automated operation technology and intelligent operation algorithms are used to ensure that the combustion status of each combustion chamber module can be monitored and adjusted in real time. The operating system has flexible adjustment capabilities to adapt to different load requirements, thereby achieving optimal combustion efficiency and lowest emissions.

[0019] Furthermore, independent fuel nozzles and fans are installed outside each independent combustion chamber to ensure the combustion efficiency of each module, reduce the generation of nitrogen oxides, and do not cause additional load on the tail SCR denitrification system. The improvement of combustion efficiency not only reduces fuel consumption, but also reduces ash accumulation and slagging in the furnace, reducing maintenance costs.

[0020] Furthermore, a plurality of modular independent combustion chambers share the original flue gas pipeline, and a flue gas recirculation system is introduced into the upper part of the split combustion chamber space to maintain the flue gas temperature.

[0021] Furthermore, a variable frequency controlled smoke exhaust fan is installed in the flue, which is adjusted according to the actual smoke flow rate to ensure effective smoke exhaust at both low and high loads, thereby ensuring the normal operation of the smoke exhaust system. This design effectively reduces pollutant emissions and ensures compliance with environmental regulations.

[0022] Furthermore, by optimizing the steam-water circulation system and matching it with the improved modular combustion chamber equipment, the working environment of key components during low-load operation can be improved, reducing metal fatigue caused by uneven heating of pipes and the risk of safety accidents such as pipe bursts, thereby extending the service life of the boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a flow chart of the method for transforming the modular combustion chamber of a solid slag discharge boiler for peak load regulation in a thermal power plant according to the present invention; Figure 2 It is a front view of the overall structure of the solid slag discharge boiler after the transformation in the present invention; Figure 3 It is a top view of the modular combustion chamber of the solid slag discharge boiler after the transformation in the present invention; Figure 4 It is a schematic structural diagram of the modular combustion chamber assembly of the present invention.

[0024] Among them: 1. Modular combustion chamber; 2. Pulverized coal burner; 3. Pulverized coal balance distributor; 4. Ash hopper; 5. Superheater; 6. Reheater; 7. Economizer; 8. Flue gas circulation device; 9. Steam-water system; 10. Flue; 11. Partition; 12. Inner wall; 13. Outer wall. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with the accompanying drawings: Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0026] The present invention discloses a method for transforming a modular combustion chamber of a solid slag removal boiler for peak load regulation in a thermal power plant, comprising the following steps: Step 1, dismantle the main combustion chamber between the flue 10 and the ash hopper 4 in the solid slag discharge boiler, place four modular combustion chambers 1 at the original main combustion chamber, separate and connect the four modular combustion chambers 1 by partitions 11, and connect the bottom of each modular combustion chamber 11 to the ash hopper 13; In this step, the original main combustion chamber needs to be dismantled first, and then multiple modularized separate combustion chambers are gradually assembled according to the design. Each separate combustion chamber is separated by a partition 11 to form an independent combustion chamber, ensuring isolation and high efficiency of the combustion process.

[0027] Step 2, each modular combustion chamber 1 is equipped with a pulverized coal burner 2; In this step, a plurality of split pulverized coal burners 3 are installed outside the modular combustion chamber 1, and are connected to the output pipelines corresponding to the pulverized coal balanced distributor 3 through pipelines.

[0028] Step 3, each modular combustion chamber 11 is connected to a combustion chamber sub-control system; In this step, the existing combustion control system is modified so that each combustion chamber sub-control system can independently control the operating status of each combustion chamber module; at the same time, advanced automated operation technology is introduced to monitor and adjust the combustion status of each combustion chamber module in real time to ensure the stability and efficiency of the combustion process.

[0029] Step 4: The upper ends of the four modular combustion chambers 11 are commonly connected to a flue, and the smoke exhaust fan connected to the flue is improved to a variable frequency smoke exhaust fan.

[0030] See also Figure 2 and Figure 3 , which is a schematic diagram of the structure of the solid slag discharge boiler for peak load regulation in thermal power plants after modification according to the present invention, including a flue 10, a combustion chamber and an ash hopper 4 arranged from top to bottom.

[0031] The combustion chamber includes four modular combustion chambers 1, which are of equal volume and are symmetrically assembled in pairs. The upper ends of the four modular combustion chambers 1 are connected to the flue 10 so that the flue 10 can discharge the smoke from each modular combustion chamber 1, and the lower ends are connected to the ash hopper 4 so that the solid slag generated during the combustion process can be discharged through the ash hopper 4.

[0032] In some embodiments of the present invention, the four modular combustion chambers 1 are separated by a partition 11, which is cross-shaped and has the shape of two cross-arranged plate-like structures. The partition 11 can be two fixed water-cooled walls fixed perpendicularly to each other, or can be a detachable water-cooled wall.

[0033] As a preferred solution, when the partition 11 is a vertically fixed water-cooled wall, each water-cooled wall is shared by two modular combustion chambers 1 as the inner wall of each modular combustion chamber 1, that is, the two mutually perpendicular inner walls 12 of each modular combustion chamber 1 belong to two modular combustion chambers 1 respectively. When installing the modular combustion chamber 1, the two outer walls 13 of the modular combustion chamber are directly connected to the corresponding water-cooled wall to form a modular combustion chamber 1. The setting of this structure makes disassembly and assembly more convenient and can simplify the water cooling system.

[0034] As a preferred solution, see Figure 4When the partition 11 is a detachable water-cooled wall, each modular combustion chamber 1 has an independent water-cooled wall as the inner wall 12, and each outer wall 13 is fixedly connected to the inner wall 12. During installation, the modular combustion chamber 1 is directly installed between the flue 10 and the ash hopper 4. At the same time, the water-cooled walls of the four modular combustion chambers 1 as the inner walls 12 are connected to each other to stabilize the structure. This connection method is convenient for disassembly and assembly, and makes each water cooling system more independent, so that the corresponding modular combustion chambers 1 can be better cooled.

[0035] Preferably, the existing combustion chamber is designed as a plurality of independent modules, each module including complete combustion facilities, such as fuel supply, air supply, ignition system, etc. Each module is designed to operate independently and can be dynamically adjusted according to load demand.

[0036] In some embodiments of the present invention, each modular combustion chamber 1 is equipped with a pulverized coal burner 2, the number of which can be one or two, and each pulverized coal burner 2 is installed on the outer wall 13. Preferably, each pulverized coal burner 2 is equipped with an independently set fan, and the corresponding fan is installed in the modular combustion chamber 1 to ensure the combustion efficiency of each module and the coal combustion efficiency during low-load operation.

[0037] As a preferred solution, all modular combustion chambers 1 are distributed with coal through a pulverized coal equalizer 3. The output section of the pulverized coal equalizer 3 is a plurality of output pipelines, which are respectively connected to the pulverized coal burners 3 in the modular combustion chambers 1. A corresponding valve is provided on each output pipeline to manage the on-off of the output pipeline. The input end of the pulverized coal equalizer 3 is respectively connected to an air conveyor and a pulverized coal conveyor. The air conveyor and the pulverized coal conveyor are provided with corresponding flow regulating devices to adjust the corresponding flow rates. The pulverized coal equalizer 3 can deliver pulverized coal to each modular combustion chamber 1 individually to ensure a stable supply and sufficient combustion of pulverized coal. The pulverized coal equalizer 3 is then connected to the blower through the air preheater via the conveyor to ensure a stable supply and sufficient combustion of pulverized coal.

[0038] In some embodiments of the present invention, the flue 10 includes an economizer 7, a reheater 6 and a superheater 5 arranged in sequence from top to bottom. The high-temperature flue gas generated by combustion passes through the superheater 5, the reheater 6 and the economizer 7 in sequence. Each device uses the waste heat of the flue gas to heat the steam and air respectively, thereby improving the overall thermal efficiency.

[0039] In some embodiments of the present invention, a steam-water system 9 is provided inside the combustion chamber and the flue, and the steam-water system 9 is connected to the water cooling system in the partition screen and the superheater 8. The water-cooled wall evaporator tube absorbs the high-temperature heat in the furnace and converts water into steam to ensure the stable operation of the boiler under high load conditions. This allows water to be converted from liquid to superheated steam to drive the steam turbine to do work. When used in conjunction with the upgraded modular combustion chamber equipment, the working environment of key components during low-load operation is improved, reducing metal fatigue caused by uneven heating of pipes and reducing the risk of safety accidents such as pipe bursts, thereby extending the service life of the boiler.

[0040] In some embodiments of the present invention, the flue 10 is connected to the variable frequency smoke exhaust fan. Since the number of working units of the modular combustion chamber 1 in the solid slag discharge boiler can be adjusted according to the peak demand, the amount of exhaust flue gas changes. The variable frequency smoke exhaust fan can adjust the power according to the actual flue gas flow rate to ensure effective exhaust during low load and high load operation, thereby ensuring the normal operation of the smoke exhaust system. The variable frequency fan maintains the appropriate flue gas flow and pressure by adjusting the speed, thereby ensuring the normal operation of the smoke exhaust system. This design effectively reduces pollutant emissions and ensures compliance with environmental regulations. In this step, attention should be paid to the connection between the variable frequency fan and the original flue gas pipeline to ensure the smooth operation of the smoke exhaust system.

[0041] In some embodiments of the present invention, the block-type split independent combustion chamber uses the original flue gas pipeline, and introduces a flue gas circulation system 8 into the upper part of the split combustion chamber space of the flue 10 to maintain the flue gas temperature.

[0042] The flue 10 of the present invention is a straight smoke pipe type flue, and the main structure of the flue is a vertical structure. During the smoke exhaust process, the radiation heating surface and the convection heating surface are heated evenly, and when multiple furnaces stop operating, the impact on the boiler unit is relatively small.

[0043] In some embodiments of the present invention, each modular combustion chamber 1 is provided with an independent combustion chamber sub-control system, which is simultaneously connected to the coal powder balanced distributor 7, the coal powder burner 2 corresponding to the modular combustion chamber 1, and the variable frequency smoke exhaust fan by electrical signals. Specifically, the sub-control system can control the ratio and flow of air and coal powder input into the coal powder balanced distributor 7, and at the same time, the on-off of any output pipeline in the coal powder balanced distributor 7 of the sub-control system provides coal powder for any modular combustion chamber 1; the combustion chamber sub-control system can also control the start and stop of the coal powder burner 2 in the coal powder combustion chamber 2 in any modular combustion chamber 1 and the start and stop of the corresponding fan, and the coal powder is ignited and burned in the combustion chamber through the coal powder balanced distributor 7 and the fan 5 through the burner 6. The sub-system is also connected to the variable frequency smoke exhaust fan and can control the working frequency of the variable frequency smoke exhaust fan. The existing combustion control system is upgraded so that it can independently control the operating status of each combustion chamber module; and advanced automatic operation technology is adopted to ensure that the combustion status of each combustion chamber module can be monitored and adjusted in real time. The operating system needs to have flexible adjustment capabilities to adapt to different load requirements; introduce intelligent operation algorithms to automatically adjust the start and stop status of each combustion chamber module according to actual load requirements. The intelligent operating system needs to be able to make dynamic adjustments based on real-time data (such as load requirements, flue gas composition, temperature, etc.) to ensure optimal combustion efficiency and lowest emissions.

[0044] The present invention discloses a modular combustion chamber reconstruction method for flexible load adjustment of a solid-state boiler in a thermal power plant, comprising a main combustion chamber of a boiler, wherein the main combustion chamber of the boiler is assembled from a plurality of modular split independent combustion chambers. Each split independent combustion chamber is separated by a water-cooled wall to form an independent combustion chamber. A plurality of split pulverized coal burners are installed on the outside thereof, and these pulverized coal burners are connected to a pulverized coal equalizing distributor through a pipeline. The pulverized coal equalizing distributor is then connected to a conveyor through a pipeline, and the conveyor is connected to a blower passing through an air preheater through a pipeline. In addition, a plurality of modular independent combustion chambers share the original flue gas pipeline, thereby realizing efficient smoke exhaust of the overall system. This design can not only better isolate different combustion areas, improve combustion efficiency and reduce emissions, but also flexibly adjust the load to adapt to fluctuations in power demand.

[0045] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In the description of the present invention, the first feature "above" or "below" the second feature may include the first and second features being in direct contact, or the first and second features not being in direct contact but being in contact through another feature between them.

[0046] In the description of the present invention, “on”, “over” and “above” a first feature from a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0047] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0049] Although the 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 claims and their equivalents.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for transforming a modular combustion chamber of a solid slag removal boiler for peak load regulation in a thermal power plant, characterized in that: The following steps are involved: Step 1, dismantling the main combustion chamber between the flue (10) and the ash hopper (4) in the solid slag discharge boiler, placing four modular combustion chambers (1) at the original main combustion chamber, separating and connecting the four modular combustion chambers (1) via partitions (11), and connecting the bottom of each modular combustion chamber (1) to the ash hopper (13); Step 2, installing an independent pulverized coal burner (2) for each modular combustion chamber (1); Step 3, each modular combustion chamber (1) is electrically connected to a combustion chamber sub-control system; Step 4: The upper ends of the four modular combustion chambers (1) are connected to the flue (10) and the smoke exhaust fan connected to the flue is improved to a variable frequency smoke exhaust fan.

2. The method for transforming a modular combustion chamber of a solid slag removal boiler for peak load regulation in a thermal power plant according to claim 1, characterized in that: In step 1, the four modular combustion chambers are symmetrically assembled with equal volumes.

3. The method for transforming a modular combustion chamber of a solid slag removal boiler for peak load regulation in a thermal power plant according to claim 1, characterized in that: In step 1, the partition is a detachable structure, and the cross-section of the partition is cross-shaped.

4. The method for transforming a modular combustion chamber of a solid slag removal boiler for peak load regulation in a thermal power plant according to claim 1, characterized in that: In step 1, the partition is a water-cooled wall.

5. According to the method for reconstructing a modular combustion chamber of a solid slag removal boiler for peak load regulation in a thermal power plant as claimed in claim 1, the pulverized coal burner (2) is installed on the outer side wall (13) of the modular combustion chamber (1).

6. The method for transforming a modular combustion chamber of a solid slag removal boiler for peak load regulation in a thermal power plant according to claim 1, characterized in that: In step 2, a fan is provided at the installation location of each of the pulverized coal burners (2).

7. The method for transforming a modular combustion chamber of a solid slag removal boiler for peak load regulation in a thermal power plant according to claim 1, characterized in that: In step 1, the pulverized coal burner (2) is connected to a pulverized coal balancing distributor (3).

8. The method for transforming a modular combustion chamber of a solid slag removal boiler for peak load regulation in a thermal power plant according to claim 7, characterized in that: The input end of the pulverized coal equalizer (3) is connected to a pulverized coal input pipeline and an air pipeline, and the output end is respectively input into each pulverized coal burner (2).

9. The method for transforming a modular combustion chamber of a solid slag removal boiler for peak load regulation in a thermal power plant according to claim 7, characterized in that: The combustion chamber sub-control system is simultaneously connected to the pulverized coal balance distributor (7), the pulverized coal burner (2) and the variable frequency smoke exhaust fan by electrical signals.

10. The method for transforming a modular combustion chamber of a solid slag removal boiler for peak load regulation in a thermal power plant according to any one of claims 1 to 9, characterized in that: In step 5, the superheater in the flue (10) and the water cooling system in the partition (11) are connected to the steam-water system (9).

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