Fire coal conveying device for coal blending combustion of coal-fired power plant

Abstract

The invention provides a fire coal conveying device for coal blending combustion of a coal-fired power plant, a coal conveying unit comprises a plurality of groups of coal crushers and coal conveyors, the rear ends of the groups of coal conveyors are connected with different coal storage areas, and the front ends of the groups of coal conveyors are connected with the coal crushers; the input end of the mixing preparation tank is connected with the coal conveyor, the output end is connected with the combustion furnace, a stirring paddle is arranged in the tank body, and the output end is provided with a speed-adjustable output pump; and the conveying control unit is in control connection with the coal conveying unit and the mixing preparation tank and is used for conveying various types of coal to the mixing preparation tank according to a set proportion through the coal conveying unit, and the coal is conveyed to the combustion furnace according to a set speed after being uniformly mixed by the mixing preparation tank. Uniform and fine mixing of coal of different types and different properties is achieved, dynamic adjustment can be conducted according to the combustion condition, the combustion balance and the combustion efficiency are improved, and the device is suitable for coal blending combustion in which sludge, wood chips and the like are mixed into fire coal.

Description

Technical Field

[0001] The invention relates to coal blending and co-combustion in a coal-fired power plant, and in particular provides a coal conveying device for coal blending and co-combustion in a coal-fired power plant. Background Art

[0002] Blending technology is the process of generating electricity by mixing several different types of coal with different properties in a certain proportion when the coal is burned in the boiler. The basic principle is to use the composition of different types of coal to blend and mix them according to the requirements, so that the final blended coal can reach or approach the design coal requirements of the boiler in terms of performance indicators, so as to make the boiler efficient, sufficient in output and good in environmental performance. Blending coal is one of the important ways to cope with the tight, complex and changeable fuel supply of coal-fired power plant boilers in my country and to improve the safety, economy and environmental protection of the unit operation.

[0003] Domestic power plants generally use a technology that mixes multiple types of coal in a certain proportion in the coal yard, grinds them together, and then transports them to the furnace for blending. The technology only mixes them in the furnace, and it is difficult to evenly and finely mix coal of different types and properties, and it is also difficult to dynamically adjust the proportions of various types of coal in real time according to the combustion situation, which easily leads to problems such as uneven combustion and uneven combustion speed. Moreover, the current coal of various types and properties has the same crushed particle size, which cannot be reasonably and effectively matched, affecting the combustion efficiency. It is unable to cope with the requirements of rapid load changes throughout the day, and it is impossible to burn high calorific value coal at high load and low calorific value coal at low load, and the load response is slow. Summary of the invention

[0004] Based on this, the present invention provides a coal conveying device for blending and burning coal in coal-fired power plants, which can achieve uniform and fine mixing of coal of different types and properties, and can be dynamically adjusted according to the combustion conditions to improve combustion balance and efficiency, and meet the requirements of rapid load changes throughout the day.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a coal conveying device for blending and burning coal in a coal-fired power plant, comprising a coal conveying unit, a mixing and preparing tank, and a conveying control unit. The coal conveying unit comprises a plurality of groups of coal pulverizers and coal conveyors, wherein the rear end of each group of coal pulverizers is connected to different coal storage areas, and the front end is connected to the coal conveyor; the input end of the mixing and preparing tank is connected to the coal conveyor, and the output end is connected to the combustion furnace. A stirring paddle is provided inside the tank body, and an output pump with adjustable speed is provided at the output end, and the output pump is an airflow-driven jet pump. The conveying control unit is control-connected to the coal conveying unit and the mixing and preparing tank, and is configured to convey a plurality of types of coal to the mixing and preparing tank according to a set ratio through the coal conveying unit, and convey the coal to the combustion furnace at a set speed after being evenly mixed in the mixing and preparing tank.

[0006] Furthermore, the coal pulverizers include multiple ones that are radially arranged outside the mixing and preparation tank, the rear end of each coal pulverizer is connected to different coal storage areas, and the front end is connected to the upper end of the mixing and preparation tank, each coal conveyor is provided with a conveying motor with an independently controlled speed, and the conveying control unit is controlled and connected to each conveying motor.

[0007] Furthermore, the coal pulverizer includes a plurality of coal pulverizers respectively connected to the front end of each coal conveyor, and each coal pulverizer is provided with a coal filter screen with different apertures to pulverize different types of coal into different particle sizes.

[0008] Furthermore, a main stirring paddle is provided on the upper part of the tank body of the mixing and preparing tank, and a main stirring motor is drivingly connected to the main stirring paddle. The rotating shaft of the main stirring paddle extends upward along the center of the mixing and preparing tank. The main stirring motor is arranged on the top of the mixing and preparing tank and is connected to the upper end of the rotating shaft of the main stirring paddle. The conveying control unit is provided with a coal conveying speed monitor, and the conveying control unit is control-connected to the main stirring motor, and is configured to control the stirring speed of the main stirring paddle according to the coal conveying amount. When the coal input amount increases, the rotation speed of the main stirring paddle is controlled to increase; when the coal input amount decreases, the rotation speed of the main stirring paddle is controlled to decrease.

[0009] Furthermore, the coal-fired conveying device is also provided with a first batching and conveying unit, which includes a wood chip crusher and a wood chip conveyor. The rear end of the wood chip conveyor is connected to the wood chip crusher, and the front end is connected to the mixing tank. The output end of the wood chip conveyor is provided with a wood chip filter screen. The aperture of the wood chip filter screen is larger than the aperture of each coal filter screen. The conveying control unit is configured to control the conveying speed of the wood chip conveyor to control the weight ratio of wood chips and coal.

[0010] Furthermore, the output port of the wood chip conveyor is connected to the middle part of the mixing and preparing tank, a first auxiliary stirring paddle is arranged in the middle part of the mixing and preparing tank, an auxiliary stirring motor is drivingly connected to the first auxiliary stirring paddle, the auxiliary stirring motor is arranged at the bottom of the mixing and preparing tank and is connected to the lower end of the rotating shaft of the first auxiliary stirring paddle; the conveying control unit is provided with a wood chip conveying speed detector, the conveying control unit is control-connected to the auxiliary stirring motor, and is configured to control the stirring speed of the first auxiliary stirring paddle according to the detected wood chip conveying speed, when the wood chip conveying speed increases, the stirring speed of the first auxiliary stirring paddle is increased; when the wood chip conveying speed decreases, the stirring speed of the first auxiliary stirring paddle is reduced.

[0011] Furthermore, the coal-fired conveying device is also provided with a second batching and conveying unit, which includes a sludge drying and crushing machine and a sludge conveyor. The rear end of the sludge conveyor is connected to the sludge drying and crushing machine, and the front end is connected to the bottom of the mixing tank for conveying. The conveying control unit is configured to control the conveying speed of the sludge conveyor to control the weight ratio of sludge and coal.

[0012] Furthermore, the output port of the sludge crusher is provided with a sludge filter mesh plate, the aperture of the sludge filter mesh plate is larger than the aperture of the coal powder filter mesh plate of the coal crusher, and the aperture of the sludge filter mesh plate is smaller than the aperture of the filter mesh plate of the wood chip crusher, and the output port of the sludge conveyor is connected to the bottom of the mixing preparation tank.

[0013] Furthermore, a second auxiliary stirring paddle is arranged along the central axis in the middle of the mixing and preparing tank, and the auxiliary stirring motor is drivingly connected to the second auxiliary stirring paddle. The output end of the mixing and stirring tank includes an eccentric arrangement at the bottom of the tube body, the second auxiliary stirring paddle is arranged in the output pipe, the auxiliary stirring motor is arranged outside the output pipe and drivingly connected to the second auxiliary stirring paddle. The conveying control unit is provided with a sludge conveying speed detector, and the conveying control unit is control-connected to the auxiliary stirring motor, and is configured to control the stirring speed of the second auxiliary stirring paddle according to the sludge conveying speed. When the sludge conveying speed increases, the stirring speed of the second auxiliary stirring paddle is increased; when the sludge conveying speed decreases, the stirring speed of the second auxiliary stirring paddle is reduced.

[0014] Furthermore, the coal conveying device is also provided with a third batching and conveying unit, and the third batching and conveying unit includes a fuel delivery pump, and a spray head is provided at the output end of the fuel delivery pump. The spray head is arranged at the upper end of the tank body of the mixing tank and the spraying direction is toward the inside of the tank body.

[0015] Compared with the existing technology, the technical advantages of the coal conveying device for coal blending and combustion in coal-fired power plants provided are reflected in:

[0016] 1. The coal conveying unit crushes different types of coal through the coal conveyor, and conveys them to the mixing pipe through the coal conveyor. After being evenly mixed in the mixing tank, they are put into the combustion furnace for combustion, realizing the rapid blending and combustion of different types of coal, improving the overall combustion efficiency, achieving balanced combustion of different types and properties of coal, and improving the economy of coal-fired power generation.

[0017] 2. The coal pulverizer includes multiple ones respectively connected to the front end of each of the coal conveyors. Each coal pulverizer is provided with a coal filter screen with different apertures to pulverize different types of coal into different particle sizes. The pulverized particle sizes of various types and properties of coal are pulverized according to their respective characteristics, so as to achieve reasonable and effective matching, realize the need to change the boiler coal blending in real time, meet the requirements of coal quality for different boiler loads, and improve combustion efficiency.

[0018] 3. The provided coal conveying device for blending and burning coal in a coal-fired power plant is further provided with a batching and conveying unit, so that the provided coal conveying device can be suitable for blending and burning coal with sludge, sawdust, etc., and the coal, sawdust and dry sludge are respectively input at different heights in the mixing tank to avoid long-term storage and co-crushing of coal, sludge and sawdust, avoid sludge easily adhering to the surface of coal and affecting the combustion effect of coal, and avoid wetting problems of sawdust, so as to achieve good combustion effect. This method can not only reduce the demand for coal and reduce costs, but also reduce greenhouse gas emissions from coal combustion.

[0019] 4. Realize accurate and real-time online switching of coal types to meet the requirements of rapid load changes throughout the day. Burn high calorific value coal at high load and low calorific value coal at low load to improve load response. At the same time, increase the blending amount of low calorific coal. It has the characteristics of good load response and high combustion efficiency. It can quickly respond to changes in unit load, completely change the time lag problem in the previous coal blending process, and solve the contradiction between unit load response and accurate coal blending. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0021] Figure 1 It is a schematic diagram of the structure of an embodiment of a coal conveying device for blending and burning coal in a coal-fired power plant;

[0022] Figure 2 It is a schematic diagram of the structure of the provided mixing and preparation tank after removing part of the shell;

[0023] Figure 3 yes Figure 2 Structural diagram of AA viewing direction;

[0024] Figure 4 yes Figure 2 Structural diagram of CC viewing direction;

[0025] Figure 5 It is a schematic diagram of the structure of a group of coal crushers and coal conveyors of the provided coal conveying unit;

[0026] Figure 6 This is a block diagram of the principle of crushing, conveying and mixing different types of coal;

[0027] Figure 7 is a structural schematic diagram of a third batching and conveying unit;

[0028] Figure 8 It is a principle block diagram of a coal conveying device provided for blending and burning coal in a coal-fired power plant.

[0029] Description of the accompanying drawings:

[0030] 1-coal conveying unit, 11-coal pulverizer, 12-coal conveyor, 13-coal conveying pipe;

[0031] 2-first batching and conveying unit, 21-wood chip crusher, 22-wood chip conveyor, 23-wood chip conveying pipe;

[0032] 3-second batching and conveying unit, 31-sludge drying and crushing machine, 32-sludge conveyor, 33-sludge conveying pipe;

[0033] 4-third batching and delivery unit, 41-fuel delivery pump, 42-spraying head;

[0034] 5-mixing tank, 51-main stirring paddle, 52-first auxiliary stirring paddle, 53-second auxiliary stirring paddle, 54-output pump, 55-main stirring motor, 56-auxiliary stirring motor;

[0035] 6-Transport control unit;

[0036] 7- Combustion furnace.

[0037] It should be understood that the size of each part shown in the accompanying drawings is not drawn according to the actual proportional relationship. In addition, the same or similar reference numerals represent the same or similar components. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. 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.

[0039] like Figures 1 to 8As shown, the present invention provides a coal conveying device for blending and burning coal in a coal-fired power plant, comprising a coal conveying unit 1, a mixing and preparing tank 5 and a conveying control unit 6. The coal conveying unit 1 comprises a plurality of groups of coal pulverizers 11 and coal conveyors 12, wherein the rear end of each group of coal pulverizers 11 is connected to a different coal storage area, and the front end is connected to the coal conveyor 12; the mixing and preparing tank 5 has an input end connected to the coal conveyor 12 and an output end connected to the combustion furnace 7, a stirring paddle is provided inside the tank body, and an output pump 54 with adjustable speed is provided at the output end; the conveying control unit 6 is control-connected to the coal conveying unit 1 and the mixing and preparing tank 5, and is configured to convey a plurality of types of coal to the mixing and preparing tank 5 according to a set proportion through the coal conveying unit 1, and convey the coal to the combustion furnace 7 at a set speed after being evenly mixed in the mixing and preparing tank 5.

[0040] A coal conveying device for blending and burning coal in a coal-fired power plant is provided, which can achieve uniform and fine mixing of coal of different types and properties, and can be dynamically adjusted according to the combustion conditions to improve the combustion balance and combustion efficiency. In addition, this coal conveying device can be used for blending and burning coal mixed with sludge, sawdust, etc. It has the advantages of small footprint and convenient operation, but affects the flexibility of unit operation. When the unit is designed to have high calorific value bituminous coal, if a certain proportion of low calorific value coal is blended, the output of the coal mill will increase when it is running at full load. When it exceeds the maximum output of the coal mill, the phenomenon of affecting the unit's load will occur.

[0041] like Figure 1 , Figure 2 , Figure 3 and Figure 6 As shown, the coal pulverizer 11 includes multiple ones and is radially arranged outside the mixed preparation tank. The rear end of each coal pulverizer 11 is connected to different coal storage areas, and the front end is connected to the upper end of the mixed preparation tank through a coal conveying pipe 13. Each coal conveyor 12 is provided with a conveying motor with an independent speed control, and the conveying control unit 6 is connected to each conveying motor control. It realizes accurate and real-time online switching of coal types, responds to the requirements of rapid load changes throughout the day, burns high calorific value coal at high load, burns low calorific value at low load, improves load response, and increases the blending amount of low calorific coal at the same time. It has the characteristics of good load response and high combustion efficiency, and can quickly respond to changes in unit load, completely change the time lag problem in the previous coal blending process, and solve the contradiction between unit load response and accurate coal blending.

[0042] The process of simultaneously increasing the amount of low calorific coal blending refers to:

[0043]

[0044] Wherein, η represents the threshold value of combustion efficiency, q1 represents the calorific value of high calorific value coal, m1 represents the weight of high calorific value coal, q2 represents the calorific value of low calorific value coal, m2 represents the weight of low calorific value coal, Indicates the actual heat release under the ratio of m1:m2, → indicates the Calculate the sign of m2, Indicates from The actual heat release per unit time period identified in , Q2 represents the actual heat demand per unit time period;

[0045] The weight of low calorific value coal is taken as the blending amount of low calorific coal.

[0046] Furthermore, the coal pulverizer 11 includes multiple ones and is respectively connected to the front end of each coal conveyor. Each coal pulverizer 11 is provided with a coal filter screen with different apertures to pulverize different types of coal into different particle sizes, so that the pulverized particle sizes of various types and properties of coal are pulverized according to their respective characteristics, achieving reasonable and effective matching, and realizing the need to change the boiler coal blending in real time, meeting the requirements of coal quality for different boiler loads, and improving combustion efficiency.

[0047] The process of crushing different types of coal into different particle sizes refers to:

[0048] The particle size selection model for different types of coal is constructed using the following formula:

[0049] d=β1x1+β2x2+......+β M x M +C

[0050] Among them, d=β1x1+β2x2+……+β M x M represents the particle size selection model, d represents the actual heat release, x1, x2, ..., x M-1 represents the composition of M-1 coal, x M Indicates particle size, β1, β2, β M represents the regression coefficient, C represents the error parameter;

[0051] The particle sizes of the different types of coal are determined by the particle size selection model.

[0052] Among them, the components of coal include coal type, moisture, ash, volatile matter, fixed carbon, etc.

[0053] Optionally, the process of determining the particle size of the different types of coal through the particle size selection model refers to establishing the particle size selection model based on historical training samples, analyzing the composition of the coal that currently needs to be crushed into different particle sizes, setting multiple random particle sizes, and substituting them into the particle size selection model to calculate the corresponding actual heat release. When the actual heat release reaches the maximum, the random particle size set in the particle size selection model is used as the particle size of the different types of coal.

[0054] The coal conveying unit crushes different types of coal separately through the coal conveyor, and conveys them to the mixing pipe through the coal conveyor, and evenly mixes them in the mixing tank, and then puts them into the combustion furnace 7 for combustion, thereby realizing the rapid blending and combustion of different types of coal, improving the overall combustion efficiency, realizing the balanced combustion of different types and properties of coal, and improving the economy of coal-fired power generation.

[0055] The process of uniformly mixing in the mixing and preparing tank and then putting into the combustion furnace 7 for combustion refers to:

[0056] The mixing uniformity of the mixing preparation tank is calculated using the following formula:

[0057]

[0058] Where S represents the mixing uniformity, y0 represents the total area of ​​particles on the detection plane, y1 represents the total area of ​​newly added particle categories on the detection plane, y3 represents the total area of ​​newly added particle categories in the i-th area, y2 represents the total area of ​​particles in the i-th area, and N represents the number of regions of the same size obtained by segmentation on the detection plane. express The mean of represents the area ratio of particles in the i-th region;

[0059] When the mixing uniformity reaches a preset uniformity, the mixture is put into the combustion furnace 7 for combustion.

[0060] Among them, the detection plane refers to a certain surface of the mixing and preparation tank. It should be noted that the particle recognition on the detection plane is the particle target identified by YOLOV5 target detection technology after the image of a certain surface of the mixing and preparation tank is obtained by taking a camera. The newly added particle category refers to particles of other particle sizes newly added when the materials in the mixing and preparation tank have been evenly mixed. The preset uniformity is set according to the actual scenario and will not be further elaborated here.

[0061] It can provide raw coal adapted to the load in real time to meet the unit's rapid load changes throughout the day. It needs to burn high calorific value coal at high load and low calorific value coal at low load to improve load response. At the same time, it increases the blending amount of low calorific coal, which greatly meets the purpose of rapid response to load requirements while increasing the blending rate of inferior coal.

[0062] Furthermore, a main stirring paddle 51 is provided on the upper part of the tank body of the mixing tank 5, and a main stirring motor 55 is drivingly connected to the main stirring paddle 51. The conveying control unit 6 is provided with a coal conveying speed monitor, and the conveying control unit 6 is control-connected to the main stirring motor 55, and is configured to control the stirring speed of the main stirring paddle 51 according to the coal conveying amount. When the coal input amount increases, the rotation speed of the main stirring paddle 51 is controlled to increase; when the coal input amount decreases, the rotation speed of the main stirring paddle 51 is controlled to decrease.

[0063] The process of controlling the rotation speed of the main stirring blade 51 to increase when the coal input amount increases and controlling the rotation speed of the main stirring blade 51 to decrease when the coal input amount decreases refers to:

[0064] The falling speed of the input coal in the mixed preparation tank 5 is calculated using the following formula:

[0065] V1=V0+gt1

[0066]

[0067]

[0068]

[0069] Among them, V 12 represents the falling speed, V0 represents the throwing speed of the input coal, t1 represents the time length of the input coal reaching the highest plane of the main stirring paddle 51, g represents the proportional coefficient of 9.8N / kg, V1 represents the speed of the input coal when it reaches the highest plane of the main stirring paddle 51, n represents the rotation speed of the main stirring paddle 51, r represents the radius of the main stirring paddle 51, v represents the linear speed of the main stirring paddle 51, t2 represents the time length of the input coal from the highest plane of the main stirring paddle 51 to the highest plane of the mixture in the mixing tank 5, and V2 represents the speed of the input coal from the highest plane of the main stirring paddle 51 to the highest plane of the mixture in the mixing tank 5;

[0070] Based on the falling speed, the target rotation speed of the main stirring paddle 51 is selected using the following formula:

[0071]

[0072] Wherein, n′ represents the target speed, V1 represents the speed when the input coal reaches the highest plane of the main stirring paddle 51, V2 represents the speed of the input coal from the highest plane of the main stirring paddle 51 to the highest plane of the mixture in the mixing tank 5, V3 represents the coal input speed corresponding to the coal delivery amount, ε represents the preset speed error, → represents the speed error of Calculate the sign of n'.

[0073] It should be noted that the starting speed refers to the speed of the input coal at the starting point, the starting point is the position of the input coal outside the mixing tank, the highest plane of the main stirring paddle 51 refers to the plane where the highest horizontal axis of rotation of the main stirring paddle 51 is located, the highest plane of the mixture in the mixing tank 5 refers to the plane where the highest height of the mixed materials in the mixing tank 5 is located, such as the highest horizontal plane of the liquid mixture, and n' is a different n that meets the requirements. The optimal n, ε is used to ensure The value is similar to V3.

[0074] At present, there is a coal blending and burning technology in the industry that adds sludge and sawdust to coal. Coal, sludge and sawdust are directly put into the combustion furnace 7 without mixing outside the furnace. The accumulated sludge will cause the flame to be buried, hindering the full combustion, and the wood chips burn quickly and cannot play the role of internal transmission ignition. Therefore, it is necessary to mix outside the furnace. At present, it is mostly carried out in the coal yard, and the dried sludge and sawdust are put into the coal, and then crushed and stored together with the coal, and then transported to the combustion furnace 7 by a conveying machine. However, the on-site application effect is poor. The reason is that coal, sludge and sawdust are stored for a long time and crushed together, which makes it easy for sludge to adhere to the surface of coal, affecting the combustion effect of coal, and sawdust is also prone to wetting problems, making it difficult to achieve a good combustion effect.

[0075] To this end, based on the above embodiments, the provided coal conveying device for blending coal in a coal-fired power plant is further provided with a batching conveying unit, so that the provided coal conveying device can be used for blending coal with sludge, sawdust, etc.

[0076] like Figure 1 , Figure 2 and Figure 8As shown, during the implementation process, the coal-fired conveying device is also provided with a first batching and conveying unit 2, which includes a wood chip crusher 21 and a wood chip conveyor 22. The rear end of the wood chip conveyor 22 is connected to the wood chip crusher 21, and the front end is connected to the mixing tank 5 through a wood chip conveying pipe 23. The output end of the wood chip conveyor 22 is provided with a wood chip filter screen, and the aperture of the wood chip filter screen is larger than the aperture of each coal filter screen. The conveying control unit 6 is configured to control the conveying speed of the wood chip conveyor 22 to control the weight ratio of wood chips to coal.

[0077] Furthermore, the output port of the wood chip conveyor 22 is connected to the middle part of the mixing and preparing tank 5, and a first auxiliary stirring paddle 52 is provided in the middle part of the mixing and preparing tank 5. The auxiliary stirring motor 56 is drivingly connected to the first auxiliary stirring paddle 52. The conveying control unit 6 is provided with a wood chip conveying speed detector. The conveying control unit 6 is control-connected to the auxiliary stirring motor 56 and is configured to control the stirring speed of the first auxiliary stirring paddle 52 according to the detected wood chip conveying speed. When the wood chip conveying speed increases, the stirring speed of the first auxiliary stirring paddle 52 is increased; when the wood chip conveying speed decreases, the stirring speed of the first auxiliary stirring paddle 52 is reduced.

[0078] like Figure 1 , Figure 2 and Figure 8 As shown, in some embodiments, the coal-fired conveying device is also provided with a second batching and conveying unit 3, which includes a sludge drying and crushing machine 31 and a sludge conveyor 32. The rear end of the sludge conveyor 32 is connected to the sludge drying and crushing machine 31, and the front end is connected to the bottom of the mixing tank 5 through a sludge conveying pipe 33. The conveying control unit 6 is configured to control the conveying speed of the sludge conveyor 32 to control the weight ratio of sludge and coal.

[0079] Furthermore, the output port of the sludge crusher is provided with a sludge filter mesh plate, the aperture of the sludge filter mesh plate is larger than the aperture of the coal powder filter mesh plate of the coal crusher 11, and the aperture of the sludge filter mesh plate is smaller than the aperture of the filter mesh plate of the wood chip crusher 21, and the output port of the sludge conveyor 32 is connected to the bottom of the mixing tank 5.

[0080] Furthermore, a second auxiliary stirring paddle 53 is arranged along the central axis in the middle of the mixing and preparing tank 5, and an auxiliary stirring motor 56 is drivingly connected to the second auxiliary stirring paddle 53. The conveying control unit 6 is provided with a sludge conveying speed detector, and the conveying control unit 6 is control-connected to the auxiliary stirring motor 56, and is configured to control the stirring speed of the second auxiliary stirring paddle 53 according to the sludge conveying speed. When the sludge conveying speed increases, the stirring speed of the second auxiliary stirring paddle 53 is increased; when the sludge conveying speed decreases, the stirring speed of the second auxiliary stirring paddle 53 is reduced.

[0081] like Figure 1 , Figure 7 and Figure 8 As shown, in some embodiments, the coal conveying device is also provided with a third batching conveying unit 4, and the third batching conveying unit 4 includes a fuel delivery pump 41. The output end of the fuel delivery pump 41 is provided with a spray head 42, and the spray head 42 is arranged at the upper end of the tank body of the mixing and preparing tank 5 and the spraying direction is toward the inside of the tank body.

[0082] Furthermore, the rotating shaft of the main stirring paddle 51 extends upward along the center of the mixing and preparing tank 5, the main stirring motor 55 is arranged at the top of the mixing and preparing tank 5 and is connected to the upper end of the rotating shaft of the main stirring paddle 51, and the auxiliary stirring motor 56 is arranged at the bottom of the mixing and preparing tank 5 and is connected to the lower end of the rotating shaft of the first auxiliary stirring paddle 52; the output end of the mixing and stirring tank includes an eccentric arrangement at the bottom of the tube body, the second auxiliary stirring paddle 53 is arranged in the output pipe, the auxiliary stirring motor 56 is arranged outside the output pipe and is driven and connected to the second auxiliary stirring paddle 53, and the output pump 54 is an airflow-driven jet pump.

[0083] The provided coal conveying device for blending and burning coal in a coal-fired power plant is further provided with a batching and conveying unit, so that the provided coal conveying device can be suitable for blending and burning coal with sludge, sawdust, etc., and the coal, sawdust and dry sludge are respectively input at different heights in the mixing and preparing tank to avoid long-term storage and co-crushing of coal, sludge and sawdust, avoid sludge easily adhering to the surface of coal and affecting the combustion effect of coal, and avoid wetting problems of sawdust, so as to achieve good combustion effect. This method can not only reduce the demand for coal and reduce costs, but also reduce greenhouse gas emissions from coal combustion.

[0084] At present, most thermal power technologies have seen declining operating benefits and coal prices continue to rise. The coal-fired power plant coal-mixing and blending device provided by the company has the advantages of low transformation cost, small construction and modification engineering, safety and reliability, and flexible operation mode. It is an effective means to reduce the operating costs of coal-fired power plants, improve operating conditions, and meet the requirements of deep peak regulation of power grids. It can be fully promoted in the coal-fired power plant industry and can also be used in other industries. It is in line with the industry development trend of coal and sludge, sawdust, etc., and can achieve the compound effect of environmental protection and energy saving, with broad application prospects.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A coal conveying device for blending coal in a coal-fired power plant, characterized in that: include: A coal conveying unit (1) comprises a plurality of groups of coal pulverizers (11) and coal conveyors (12), wherein the rear end of each group of coal pulverizers (11) is connected to different coal storage areas, and the front end is connected to the coal conveyor (12); A mixing tank (5), the input end of which is connected to a coal conveyor (12), and the output end of which is connected to a combustion furnace, a stirring paddle is provided inside the tank body, and a speed-adjustable output pump (54) is provided at the output end; and The conveying control unit (6) is connected to the coal conveying unit (1) and the mixing and preparing tank (5) and is configured to convey multiple types of coal to the mixing and preparing tank (5) according to a set ratio through the coal conveying unit (1), and convey the coal to the combustion furnace (7) at a set speed after being evenly mixed in the mixing and preparing tank (5).

2. The coal conveying device for coal blending and combustion in a coal-fired power plant according to claim 1 is characterized in that: The coal pulverizers (11) include a plurality of coal pulverizers (11) which are radially arranged outside the mixing and preparing tank (5). The rear end of each coal pulverizer (11) is connected to a different coal storage area, and the front end is connected to the upper end of the mixing and preparing tank. Each coal conveyor (12) is provided with a conveying motor with an independently controlled speed. The conveying control unit (6) is control-connected to each conveying motor.

3. The coal conveying device for coal blending and combustion in a coal-fired power plant according to claim 2 is characterized in that: The coal pulverizer (11) includes a plurality of coal pulverizers (11) which are respectively connected to the front end of each coal conveyor. Each coal pulverizer (11) is provided with a coal filter screen with different apertures so as to pulverize different types of coal into different particle sizes and transport them to the mixing tank (5) through the coal conveying pipe (13).

4. The coal conveying device for coal blending and combustion in a coal-fired power plant according to claim 3 is characterized in that: A main stirring paddle (51) is arranged on the upper part of the tank body of the mixing and preparing tank (5), and a main stirring motor (55) is drivingly connected to the main stirring paddle (51). The rotating shaft of the main stirring paddle (51) extends upward along the center of the mixing and preparing tank (5). The main stirring motor (55) is arranged on the top of the mixing and preparing tank (5) and is connected to the upper end of the rotating shaft of the main stirring paddle (51). The conveying control unit (6) is provided with a coal conveying speed monitor. The conveying control unit (6) is controllably connected to the main stirring motor (55) and is configured to control the stirring speed of the main stirring paddle (51) according to the coal conveying amount. When the coal input amount increases, the rotation speed of the main stirring paddle (51) is controlled to increase; when the coal input amount decreases, the rotation speed of the main stirring paddle (51) is controlled to decrease.

5. The coal conveying device for coal blending and combustion in a coal-fired power plant according to claim 4 is characterized in that: The coal-fired conveying device is further provided with a first batching conveying unit (2), the first batching conveying unit (2) comprising a wood chip crusher (21) and a wood chip conveyor (22), the rear end of the wood chip conveyor (22) being connected to the wood chip crusher (21), and the front end being connected to the mixing tank (5), the output end of the wood chip conveyor (22) being provided with a wood chip filter screen, the aperture of the wood chip filter screen being larger than the aperture of each coal filter screen, and the conveying control unit (6) being configured to control the conveying speed of the wood chip conveyor (22) so as to control the weight ratio of wood chips to coal.

6. The coal conveying device for coal blending and combustion in a coal-fired power plant according to claim 5 is characterized in that: The output port of the wood chip conveyor (22) is connected to the middle of the mixing and preparing tank (5), a first auxiliary stirring paddle (52) is arranged in the middle of the mixing and preparing tank (5), an auxiliary stirring motor (56) is drivingly connected to the first auxiliary stirring paddle (52), the auxiliary stirring motor (56) is arranged at the bottom of the mixing and preparing tank (5) and is connected to the lower end of the rotating shaft of the first auxiliary stirring paddle (52), the conveying control unit (6) is provided with a wood chip conveying speed detector, the conveying control unit (6) is control-connected to the auxiliary stirring motor (56), and is configured to control the stirring speed of the first auxiliary stirring paddle (52) according to the detected wood chip conveying speed, when the wood chip conveying speed increases, the stirring speed of the first auxiliary stirring paddle (52) is increased; when the wood chip conveying speed decreases, the stirring speed of the first auxiliary stirring paddle (52) is reduced.

7. The coal conveying device for blending coal in a coal-fired power plant according to any one of claim 6, characterized in that: The coal-fired conveying device is also provided with a second batching and conveying unit (3), which comprises a sludge drying and pulverizing machine (31) and a sludge conveyor (32), wherein the rear end of the sludge conveyor (32) is connected to the sludge drying and pulverizing machine (31), and the front end is connected to the bottom of the mixing and preparing tank (5) for conveying, and the conveying control unit (6) is configured to control the conveying speed of the sludge conveyor (32) so as to control the weight ratio of sludge to coal.

8. The coal conveying device for coal blending and combustion in a coal-fired power plant according to claim 7, characterized in that: The output port of the sludge crusher is provided with a sludge filter screen, the aperture of the sludge filter screen is larger than the aperture of the coal powder filter screen of the coal crusher (11), and the aperture of the sludge filter screen is smaller than the aperture of the filter screen of the wood chip crusher (21), and the output port of the sludge conveyor (32) is connected to the bottom of the mixing tank (5).

9. The coal conveying device for blending coal in a coal-fired power plant according to claim 8, characterized in that: A second auxiliary stirring paddle (53) is arranged along the central axis in the middle of the mixing and preparing tank (5), and an auxiliary stirring motor (56) is drivingly connected to the second auxiliary stirring paddle (53). The output end of the mixing and stirring tank includes an eccentric arrangement at the bottom of the tube body, the second auxiliary stirring paddle (53) is arranged in the output pipe, and the auxiliary stirring motor (56) is arranged outside the output pipe and drivingly connected to the second auxiliary stirring paddle (53). The conveying control unit (6) is provided with a sludge conveying speed detector, and the conveying control unit (6) is controllably connected to the auxiliary stirring motor (56) and is configured to control the stirring speed of the second auxiliary stirring paddle (53) according to the sludge conveying speed. When the sludge conveying speed increases, the stirring speed of the second auxiliary stirring paddle (53) is increased; when the sludge conveying speed decreases, the stirring speed of the second auxiliary stirring paddle (53) is reduced.

10. The coal conveying device for blending and burning coal in a coal-fired power plant according to claim 4, 5 or 7, characterized in that: The coal conveying device is further provided with a third batching conveying unit (4), the third batching conveying unit (4) comprising a fuel delivery pump (41), the output end of the fuel delivery pump (41) being provided with a spray head (42), the spray head (42) being arranged at the upper end of the tank body of the mixing and preparing tank (5) and the spraying direction being toward the inside of the tank body.

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