Wet sludge direct blending coal mill system in coal-fired power generation units

Abstract

This invention provides a wet sludge direct-blending coal mill system for coal-fired power generating units, belonging to the field of power plant technology. It solves the problem of raw coal silo blockage caused by sludge co-firing. The coal-fired power generating unit includes a coal pulverizing system and a conveying device. Each coal pulverizing system includes a raw coal silo, a coal feeder, a coal chute, and a coal mill. This wet sludge direct-blending coal mill system includes a wet sludge storage silo, a plunger pump, and a conveying pipeline. The conveying pipeline includes a front conveying section, a rear main conveying section, and a rear auxiliary conveying section. The inlets of the rear main conveying section and the rear auxiliary conveying section are both connected to the front conveying section. A control valve one is installed on the rear main conveying section, and a control valve two is installed on the rear auxiliary conveying section. The outlet of the rear main conveying section is connected to the coal chute in one of the coal pulverizing systems, and the outlet of the rear auxiliary conveying section is located at the conveying device. It has advantages such as high co-firing efficiency and more flexible wet sludge co-firing methods.

Description

Technical Field

[0001] The invention belongs to the technical field of power plants, relates to a coal-fired generator set, and in particular to a wet sludge direct-blending coal mill system in the coal-fired generator set. Background Art

[0002] Sewage generated in daily life or industrial production is generally treated by sewage treatment plants, and sludge is inevitably produced after treatment. The existing sludge treatment methods mainly include transportation to waste incineration plants for incineration, aerobic composting of sludge, or sanitary landfill after pretreatment. However, since sludge usually contains pathogenic microorganisms, parasite eggs, harmful heavy metals and a large number of difficult-to-degrade substances, no matter which of the above methods is used for treatment, it will cause varying degrees of pollution to the environment. Therefore, in this case, it is often necessary to deal with the secondary pollution caused. With the increasing production of sludge, the current treatment scale or processing capacity can no longer meet the demand.

[0003] Considering that sludge itself has a high calorific value and can be used as fuel after drying, people have proposed to mix sludge with coal in a certain proportion and send it to the boiler of the coal-fired unit of the power plant for coupled power generation. The water content in normal sludge is very high, sometimes even up to about 80%. If the sludge is directly mixed with coal powder in the raw coal bunker and then sent to the coal mill for grinding, it is easy to cause blockage in the raw coal bunker due to excessive water, so that the coal powder cannot be supplied normally and the normal operation of the coal-fired unit of the power plant is affected. Since the moisture in the sludge is the key reason for the blockage in the raw coal bin, in this case, the technical personnel in this field will easily think of or conventionally adopt the method of pre-treating the sludge with drying equipment or dehydration equipment before sending the sludge into the raw coal bin, so as to reduce the moisture content of the sludge and avoid blockage in the raw coal bin. For example, the sludge treatment system using a power plant pulverized coal boiler disclosed in Application No. 200820085305.7, the sludge deep dehydration and resource utilization disposal device disclosed in Application No. 201210177324.3 and the sludge co-combustion system of a thermal power plant disclosed in Application No. 201910967434.1, etc. Summary of the invention

[0004] The purpose of the present invention is to solve the above problems existing in the prior art and propose a wet sludge direct blending coal mill system in a coal-fired power generation unit, which solves the problem that the raw coal bunker is easily blocked when sludge is blended and burned.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A wet sludge direct blending coal mill system in a coal-fired power generation unit, the coal-fired power generation unit includes several groups of parallel coal-fired pulverizing systems and a conveying device that can convey coal to each coal-fired pulverizing system, each group of coal-fired pulverizing systems includes a raw coal bin, a coal feeder, a coal drop pipe and a pulverizer arranged in sequence, the wet sludge direct blending coal mill system includes a wet sludge storage bin, a plunger pump arranged at the outlet of the wet sludge storage bin and a conveying pipeline connected to the outlet of the plunger pump, characterized in that the conveying pipeline includes a front conveying section, a rear main conveying section and a rear auxiliary conveying section, the inlet of the rear main conveying section and the inlet of the rear auxiliary conveying section are both connected to the front conveying section, the rear main conveying section is provided with a control valve 1, the rear auxiliary conveying section is provided with a control valve 2, the outlet of the rear main conveying section is connected to the coal drop pipe in one of the coal-fired pulverizing systems, and the outlet of the rear auxiliary conveying section is arranged at the conveying device.

[0007] The coal is distributed by a conveying device according to the demand and then transported to the raw coal bunker in each coal-fired pulverizing system. Generally speaking, considering the economic benefits, it is not necessary for all coal-fired pulverizing systems to be put into operation at the same time. Basically, 1-2 sets of coal-fired pulverizing systems will be selected for regular use, and the remaining coal-fired pulverizing systems will be used as backup. Therefore, in this wet sludge direct blending coal mill system, the coal-fired pulverizing system where the coal drop pipe connected to the rear main conveying section is located is regarded as regular time use.

[0008] During normal time, the control valve 2 on the rear auxiliary conveying section is controlled to be closed, and the control valve 1 on the rear main conveying section is controlled to be opened. The wet sludge in the wet sludge storage bin is supplied to the plunger pump and pumped into the conveying pipeline by the plunger pump. Since the control valve 1 on the rear auxiliary conveying section is closed, the wet sludge will enter the rear main conveying section from the front conveying section, and then be directly sent to the coal drop pipe from the rear main conveying section and enter the corresponding coal mill together with the coal dropped into the coal drop pipe. The hot primary air in the coal mill directly mixes, crushes and dries the wet sludge and the coal. The dried sludge is mixed with the coal powder and sprayed into the boiler connected to the coal mill for combustion. When the coal mill in the coal-fired pulverizing system needs to be shut down for maintenance, the alternative coal-fired pulverizing system is put into operation. At this time, the control valve 1 on the rear main conveying section is controlled to be closed, and the control valve 2 on the rear auxiliary conveying section is controlled to be opened. The wet sludge is still pumped into the conveying pipeline by the plunger pump. As the control valve on the rear main conveying section is closed, the wet sludge will enter the rear auxiliary conveying section from the front conveying section, and fall into the conveying device from the outlet of the rear auxiliary conveying section and be sent into the raw coal bin in the alternative coal pulverizing system together with the coal. Finally, the corresponding coal feeder will drop the coal mixed with wet sludge into the corresponding coal mill through the corresponding coal drop pipe for processing.

[0009] The conveying pipeline is configured to have a rear main conveying section and a rear auxiliary conveying section. By directly connecting the rear main conveying section with the coal drop pipe, the wet sludge can be directly dried by the hot primary air in the coal mill and used as fuel during normal time. During this period of time, the wet sludge no longer passes through the raw coal bin, which ensures that the raw coal bin will not be blocked, and also improves the rational utilization of resources and reduces environmental pollution; at the same time, there is no need to set up sludge drying equipment, which reduces investment costs. At the same time, when the coal mill matched with the rear main conveying section is repaired, the rear auxiliary conveying section can be used to directly send the wet sludge to the conveying device and distribute it to the remaining coal-fired pulverizing systems for emergency blending, which ensures the blending efficiency and makes the blending method of the wet sludge more flexible. Moreover, the maintenance time of the coal mill will not be too long, so even if the wet sludge is directly mixed into the raw coal bin without pre-drying during this period of time, it is not easy to cause blockage of the raw coal bin.

[0010] In the wet sludge direct blending pulverizer system in the above-mentioned coal-fired power generation unit, the number of raw coal bins, coal feeders, coal drop pipes and pulverizers in each coal-fired pulverizing system is two, and the rear main conveying section includes a mother conveying section and two sub-conveyoring sections connected to the mother conveying section. The two sub-conveyoring sections are both provided with the above-mentioned control valve 1, and the two sub-conveyoring sections are respectively connected to the two coal drop pipes.

[0011] In order to ensure power generation efficiency, two coal mills are generally set up in each coal-fired pulverizing system. By setting the rear main conveying section to include a main conveying section and two sub-conveying sections connected to the main conveying section, and setting control valves on both sub-conveying sections, when any coal mill is under maintenance, the other coal mill can still burn wet sludge normally.

[0012] In the wet sludge direct blending pulverizer system in the above-mentioned coal-fired power generation unit, the conveying device includes a front belt conveyor and a rear belt conveyor, the number of which is the same as the raw coal bin in the entire coal-fired power generation unit, and one end of each rear belt conveyor is arranged at the entrance of the corresponding raw coal bin. The conveying device also includes a transfer station that can connect any front belt conveyor with any rear belt conveyor, and the rear auxiliary conveying section is arranged in the vertical direction and its outlet is bent at 90°, and the outlet of the rear auxiliary conveying section is located above one of the front belt conveyors.

[0013] When the coal mill in the coal-fired pulverizing system coordinated with the rear main conveying section stops running, the wet sludge is transported through the rear auxiliary conveying section to one of the front belt conveyors and mixed with the coal. The front belt conveyor is then connected by the transfer station to the rear belt conveyor coordinated with the raw coal bin in the remaining coal-fired pulverizing systems. In this way, the wet sludge can be sent to the remaining coal-fired pulverizing systems for processing, thereby realizing the blending of wet sludge in special periods.

[0014] In the wet sludge direct-blending pulverizer system in the above-mentioned coal-fired power generation unit, a material plate is vertically arranged above the front belt conveyor corresponding to the outlet of the rear auxiliary conveying section. The material plate is perpendicular to the coal conveying direction of the front belt conveyor, and the lower side of the material plate is in an outwardly convex arc shape.

[0015] Generally speaking, coal will be piled up in a shape similar to a small hill on the front belt conveyor. If wet sludge falls directly on the coal, it will splash around and cause part of the wet sludge to be wasted. Therefore, a material plate is vertically set above the front belt conveyor. Since the lower side of the material plate is in an outward convex arc shape and the material plate is perpendicular to the coal conveying direction of the front belt conveyor, when the front belt conveyor moves forward, the material plate will plow the peak of the coal pile into a pit, so that the wet sludge can fall directly into the pit without splashing around.

[0016] In the wet sludge direct blending coal mill system in the above-mentioned coal-fired power generation unit, a discharge port is provided on the sub-conveying section, and the discharge port is located in front of the inlet of the control valve 1. A lubrication pipe is connected to the front conveying section near the inlet.

[0017] When the unit is operating normally, the discharge port is closed. When the entire coal-fired power generation unit is out of operation, the wet sludge remaining in the conveying pipeline will gradually dry naturally. At this time, the discharge port is opened, and the wet sludge in the wet sludge storage bin is pumped into the conveying pipeline by the plunger pump. The wet sludge remaining in the conveying pipeline will increase the conveying resistance of the fresh wet sludge after drying, and the operating pressure of the plunger pump will naturally increase accordingly. The lubricating pipe can be used to add lubricant to the conveying pipeline, so that the pumping resistance can be reduced, so that the wet sludge that enters the conveying pipeline later squeezes the original residual wet sludge into the discharge pipe for discharge. Performing the above operation during the outage period can continuously replace the residual wet sludge with fresh wet sludge to prevent the conveying pipeline from being blocked, while ensuring the service life of the plunger pump.

[0018] Generally speaking, in order to solve the blockage problem that residual sludge may cause in the conveying pipeline, technicians in this field may easily think of directly passing high-pressure water into the conveying pipeline to flush out the residual sludge with high pressure. However, since the power plant equipment is large in size and the conveying pipeline is very long, a large amount of high-pressure water is required for continuous flushing, which will cause a huge waste of water resources. In the present application, a lubricating medium such as water is added to the conveying pipeline through a lubricating pipe, and then fresh wet sludge is pumped into the conveying pipeline. This not only prevents the blockage of the conveying pipeline by replacing the residual wet sludge with fresh wet sludge, but also does not cause excessive waste of resources (for example, the lubrication method consumes much less water resources than the flushing method, and the replaced residual wet sludge still remains in a muddy state, and can be directly collected and put back into the wet sludge storage bin for recycling).

[0019] In the wet sludge direct blending coal mill system in the above-mentioned coal-fired power generation unit, a pressure gauge is also provided near the inlet position of the front conveying section, and a control valve three is provided on the lubrication pipe.

[0020] When the pumping resistance increases, the pressure gauge will control the opening of control valve 3 on the lubrication pipe according to the detected signal, so that the lubricating fluid (such as water) is automatically injected into the conveying pipeline through the lubrication pipe, realizing intelligent control of the system.

[0021] In the wet sludge direct blending coal mill system in the above-mentioned coal-fired power generation unit, the discharge port is connected to a discharge pipe, a discharge valve is provided at the inlet position of the discharge pipe, and a collecting hopper is provided at the outlet of the discharge pipe.

[0022] By setting up a discharge pipe and a collecting hopper, the discharged old wet sludge can be collected by the collecting hopper for other uses or re-put into the wet sludge storage bin, thus achieving full utilization of resources.

[0023] In the wet sludge direct blending coal mill system in the above-mentioned coal-fired power generation unit, the control valve one, the control valve two and the control valve three are electric ball valves.

[0024] In the wet sludge direct blending coal mill system in the above-mentioned coal-fired power generation unit, the wet sludge direct blending coal mill system also includes a receiving hopper, a shaftless screw conveyor that can deliver the wet sludge in the receiving hopper into the wet sludge storage bin, and a double-shaft screw conveyor arranged between the wet sludge storage bin outlet and the plunger pump, an arch breaking device is arranged in the wet sludge storage bin, and a hydraulic gate valve that can control the opening and closing of the wet sludge storage bin outlet is arranged at the bottom of the wet sludge storage bin.

[0025] Compared with the existing technology, the wet sludge direct blending coal mill system in this coal-fired power generation unit has the following advantages:

[0026] 1. Under normal conditions, the wet sludge is directly sent to the coal drop pipe by the rear main conveying section, and is dried by the hot primary air in the coal mill and used as fuel. The wet sludge no longer passes through the raw coal bunker, which ensures that the raw coal bunker will not be blocked. It also improves the rational use of resources and reduces environmental pollution. At the same time, there is no need to set up special sludge drying equipment, which reduces investment costs;

[0027] 2. When the coal mill matched with the rear main conveying section is under maintenance, the rear auxiliary conveying section can be used to directly send the wet sludge to the conveying device and distribute it to the other coal pulverizing systems for emergency blending. This takes into account both normal blending under normal conditions and emergency blending under maintenance conditions, making the blending method more flexible and the maintenance time of the coal mill will not be too long. Therefore, even if the wet sludge is directly mixed into the raw coal bunker without pre-drying during this period, it is not easy to cause blockage of the raw coal bunker;

[0028] 3. Through the cooperation of the discharge port and the lubrication pipe, the residual wet sludge can be continuously replaced with fresh wet sludge during the shutdown period to prevent the conveying pipeline from being blocked, thus ensuring the service life of the plunger pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a system block diagram of the conveying device and the coal pulverizing system.

[0030] Figure 2 It is a schematic diagram of the first embodiment of the wet sludge direct blending coal mill system in the coal-fired power generation unit.

[0031] Figure 3 It is a schematic diagram between the front belt conveyor and the rear auxiliary conveying section when viewed along the conveying direction of the front belt conveyor.

[0032] Figure 4 It is a schematic diagram between the front belt conveyor and the whole material plate when viewed along the conveying direction of the front belt conveyor.

[0033] In the figure, 1, raw coal bin; 2, coal feeder; 3, coal drop pipe; 4, coal mill; 5, wet sludge storage bin; 6, hydraulic gate valve; 7, double-axis screw conveyor; 8, plunger pump; 9, conveying pipeline; 9a, front conveying section; 9b, rear main conveying section; 9b1, mother conveying section; 9b2, sub-conveying section; 9c, rear auxiliary conveying section; 10, control valve one; 11, control valve two; 12, front end belt conveyor; 13, whole material plate; 14, lubrication pipe; 15, pressure gauge; 16, control valve three; 17, discharge pipe; 18, discharge valve; 19, arch breaking device; 20, control valve four. DETAILED DESCRIPTION

[0034] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0035] Embodiment 1

[0036] like Figure 1 and Figure 2As shown, the wet sludge direct blending coal pulverizer system in the coal-fired power generation unit, the coal-fired power generation unit includes several groups of parallel coal pulverizing systems and a conveying device that can convey coal to each coal pulverizing system. There are four groups of coal pulverizing systems in this embodiment, and each group of coal pulverizing systems includes a raw coal bin 1, a coal feeder 2, a coal drop pipe 3 and a coal pulverizer 4 arranged in sequence. The conveying device can distribute the coal according to demand and then convey it to the raw coal bin 1 in each coal pulverizing system. The coal in the raw coal bin 1 is fed into the coal drop pipe 3 through the coal feeder 2 and finally falls into the coal pulverizer 4. The wet sludge direct blending coal mill system includes a receiving hopper, a wet sludge storage bin 5, a shaftless screw conveyor capable of conveying the wet sludge in the receiving hopper into the wet sludge storage bin 5, a double-axis screw conveyor 7 arranged below the outlet of the wet sludge storage bin 5, a plunger pump 8 arranged below the double-axis screw conveyor 7, and a conveying pipeline 9 connected to the outlet of the plunger pump 8. An arch breaking device 19 is arranged in the wet sludge storage bin 5, and a hydraulic gate valve 6 capable of controlling the opening and closing of the outlet of the wet sludge storage bin 5 is arranged at the bottom of the wet sludge storage bin 5.

[0037] Specifically, if Figure 2 As shown, the conveying pipeline 9 includes a front conveying section 9a, a rear main conveying section 9b and a rear auxiliary conveying section 9c. The inlet of the rear main conveying section 9b and the inlet of the rear auxiliary conveying section 9c are both connected to the front conveying section 9a (specifically, they can be connected by a three-way interface), and the inlet of the front conveying section 9a is connected to the outlet of the plunger pump 8. A control valve 10 is provided on the rear main conveying section 9b, and a control valve 2 11 is provided on the rear auxiliary conveying section 9c. The control valve 10 and the control valve 2 11 are specifically electric ball valves. The outlet of the rear main conveying section 9b is connected to a coal drop pipe 3 in one group of coal-fired pulverizing systems. The coal drop pipe 3 is provided with a control valve 4 20. The connection between the rear main conveying section 9b and the coal drop pipe 3 is located below the control valve 4 20, and the outlet of the rear auxiliary conveying section 9c is arranged at the conveying device.

[0038] The wet sludge is transported by a special vehicle and unloaded into the receiving hopper, and the shaftless screw conveyor inputs the wet sludge into the wet sludge storage bin 5. In normal times, the coal-fired pulverizing system where the coal drop pipe 3 connected to the rear main conveying section 9b is located is used as a regular system, and the remaining coal-fired pulverizing systems are used as backups and are not put into operation. At this time, the control valve 2 11 on the rear auxiliary conveying section 9c is controlled to be closed, and the control valve 1 10 on the rear main conveying section 9b and the control valve 4 20 on the corresponding coal drop pipe 3 are controlled to be opened. The double-axis screw conveyor 7 sends the wet sludge flowing out of the wet sludge storage bin 5 outlet into the plunger pump 8, and the plunger pump 8 pumps it into the corresponding conveying pipeline 9. Since the control valve 2 11 on the rear auxiliary conveying section 9c is closed, the wet sludge will enter the rear main conveying section 9b from the front conveying section 9a, and then be directly sent to the coal drop pipe 3 from the rear main conveying section 9b and enter the corresponding coal mill 4 together with the coal dropped into the coal drop pipe 3. The hot primary air in the coal mill 4 directly mixes, crushes and dries the wet sludge and the coal. The dried sludge is mixed with the coal powder and sprayed into the boiler connected to the coal mill 4 for combustion. When the coal mill 4 in the coal-fired pulverizing system needs to be repaired and shut down, the alternative coal-fired pulverizing system is put into operation. At this time, the control valve 10 on the rear main conveying section 9b is controlled to be closed, and the control valve 2 11 on the rear auxiliary conveying section 9c is controlled to be opened. The wet sludge is still pumped into the conveying pipeline 9 by the plunger pump 8. Since the control valve 10 on the rear main conveying section 9b is closed, the wet sludge will enter the rear auxiliary conveying section 9c from the front conveying section 9a, and fall into the conveying device from the outlet of the rear auxiliary conveying section 9c and be sent into the raw coal bin 1 in the alternative coal pulverizing system together with the coal. Finally, the corresponding coal feeder 2 will drop the coal mixed with wet sludge into the corresponding coal mill 4 through the corresponding coal drop pipe 3 for processing.

[0039] Furthermore, if Figure 1 and Figure 2 As shown, there are two raw coal bins 1, coal feeders 2, coal drop pipes 3 and coal mills 4 in each coal-fired pulverizing system. The rear main conveying section 9b includes a main conveying section 9b1 and two sub-conveying sections 9b2 (specifically, they can be connected by a three-way interface) connected to the main conveying section 9b1. The two sub-conveying sections 9b2 are each provided with a control valve 10, and the two sub-conveying sections 9b2 are respectively connected to the two coal drop pipes 3. In order to ensure power generation efficiency, two coal mills 4 are generally provided in each coal-fired pulverizing system. By setting the rear main conveying section 9b to include a main conveying section 9b1 and two sub-conveying sections 9b2 connected to the main conveying section 9b1, and the two sub-conveying sections 9b2 are each provided with a control valve 10, when any coal mill 4 is under maintenance, the other coal mill 4 can still normally mix and burn wet sludge.

[0040] like Figure 1-Figure 4As shown, the conveying device includes a front belt conveyor 12 and a rear belt conveyor, both of which are the same number as the raw coal bins 1 in the entire coal-fired power generation unit. One end of the rear belt conveyor is arranged at the entrance of the raw coal bin 1. The conveying device also includes a transfer station that can connect any front belt conveyor 12 with any rear belt conveyor. The rear auxiliary conveying section 9c is arranged in the vertical direction and its outlet is bent at 90°. The outlet of the rear auxiliary conveying section 9c is located above one of the front belt conveyors 12. In this embodiment, there are a total of four groups of coal-fired pulverizing systems, and the number of raw coal bins 1 in each group of coal-fired pulverizing systems is two. Therefore, the total number of raw coal bins 1 in the entire coal-fired power generation unit is eight, that is, there are eight front belt conveyors 12 and eight rear belt conveyors. The conveying device is a prior art, and its specific structure and the transfer method between the front belt conveyor 12 and the rear distribution belt are not repeated here. A material plate 13 is vertically arranged above the front belt conveyor 12 corresponding to the outlet of the rear auxiliary conveying section 9c. The material plate 13 is perpendicular to the coal conveying direction of the front belt conveyor 12, and the lower side of the material plate 13 is in an outwardly convex arc shape.

[0041] like Figure 2 As shown, each sub-conveying section 9b2 is provided with a discharge port, which is located in front of the inlet of the control valve 10, and the front conveying section 9a is connected to a lubrication pipe 14 near the inlet. The front conveying section 9a is also provided with a pressure gauge 15 near the inlet, and the lubrication pipe 14 is provided with a control valve 3 16, which is an electric ball valve. The discharge port is connected to a discharge pipe 17, and a discharge valve 18 is provided at the inlet of the discharge pipe 17, and a collecting hopper is provided at the outlet of the discharge pipe 17.

[0042] When the entire coal-fired power generation unit is in shutdown, the wet sludge remaining in the conveying pipeline 9 will gradually dry naturally. At this time, the discharge valve 18 on the discharge pipe 17 is controlled to open, and then the plunger pump 8 pumps the wet sludge in the wet sludge storage bin 5 into the conveying pipeline 9. The wet sludge remaining in the conveying pipeline 9 will increase the conveying resistance of the fresh wet sludge after drying, and the operating pressure of the plunger pump 8 will naturally increase accordingly. The pressure gauge 15 will control the control valve 3 16 on the lubrication pipe 14 to open according to the detected signal, so that the lubricating liquid (such as water) is automatically injected into the conveying pipeline 9 through the lubrication pipe 14, so that the pumping resistance can be reduced, so that the wet sludge that enters the conveying pipeline 9 later squeezes the original residual wet sludge into the discharge pipe 17 for discharge. Performing the above operation during the shutdown period can continuously replace the residual wet sludge with fresh wet sludge to prevent the conveying pipeline 9 from being blocked, while ensuring the service life of the plunger pump 8. In addition, the discharged old wet sludge can be collected by a collecting hopper for other uses or re-put into the wet sludge storage bin 5, thereby achieving full utilization of resources.

[0043] Embodiment 2

[0044] The structure and principle of this embodiment are basically the same as those of the first embodiment, except that: in this embodiment, there are two plunger pumps 8 and two conveying pipes 9, and the rear main conveying section 9b in each conveying pipe 9 is respectively connected to a group of coal drop pipes 3 in the coal pulverizing system.

[0045] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A wet sludge direct blending coal mill system in a coal-fired power generation unit, the coal-fired power generation unit comprising a plurality of parallel coal pulverizing systems and a conveying device capable of conveying coal to each coal pulverizing system, each coal pulverizing system comprising a raw coal bin (1), a coal feeder (2), a coal drop pipe (3) and a coal mill (4) arranged in sequence, the wet sludge direct blending coal mill system comprising a wet sludge storage bin (5), a plunger pump (8) arranged at the outlet of the wet sludge storage bin (5) and a conveying pipeline (9) connected to the outlet of the plunger pump (8), characterized in that: The conveying pipeline (9) comprises a front conveying section (9a), a rear main conveying section (9b) and a rear auxiliary conveying section (9c); the inlet of the rear main conveying section (9b) and the inlet of the rear auxiliary conveying section (9c) are both connected to the front conveying section (9a); a control valve 1 (10) is provided on the rear main conveying section (9b); a control valve 2 (11) is provided on the rear auxiliary conveying section (9c); the outlet of the rear main conveying section (9b) is connected to a coal drop pipe (3) in one of the coal-fired pulverizing systems; the outlet of the rear auxiliary conveying section (9c) is arranged at a conveying device; the conveying device comprises a front belt conveyor (12) and a rear belt conveyor, both of which are the same in number as the raw coal bunker (1) in the entire coal-fired power generation unit; one end of each rear belt conveyor is arranged at the inlet of the corresponding raw coal bunker (1); The device also includes a transfer station capable of connecting any front belt conveyor (12) with any rear belt conveyor. The rear auxiliary conveying section (9c) is arranged in a vertical direction and its outlet is bent at 90 degrees. The outlet of the rear auxiliary conveying section (9c) is located above one of the front belt conveyors (12). When the coal mill (4) in the coal pulverizing system matched with the rear main conveying section (9b) stops running, the wet sludge falls onto one of the front belt conveyors (12) through the rear auxiliary conveying section (9c) and is mixed with the coal. Then, the front belt conveyor (12) is connected to the rear belt conveyor matched with the raw coal bin (1) in the remaining coal pulverizing system by the transfer station. In this way, the wet sludge can be sent to the remaining coal pulverizing system for processing.

2. The wet sludge direct blending coal mill system in the coal-fired power generation unit according to claim 1, characterized in that: Each group of coal-fired pulverizing systems includes two raw coal bins (1), coal feeders (2), coal drop pipes (3) and coal mills (4). The rear main conveying section (9b) includes a main conveying section (9b1) and two sub-conveying sections (9b2) both connected to the main conveying section (9b1). The two sub-conveying sections (9b2) are both provided with the above-mentioned control valve 1 (10). The two sub-conveying sections (9b2) are respectively connected to the two coal drop pipes (3).

3. The wet sludge direct blending coal mill system in the coal-fired power generation unit according to claim 2, characterized in that: A material plate (13) is vertically arranged above the front belt conveyor (12) corresponding to the outlet of the rear auxiliary conveying section (9c); the material plate (13) is perpendicular to the coal conveying direction of the front belt conveyor (12); and the lower side of the material plate (13) is in an outwardly convex arc shape.

4. The wet sludge direct blending coal mill system in the coal-fired power generation unit according to claim 2, characterized in that: The sub-conveyor section (9b2) is provided with a discharge port, which is located in front of the inlet of the control valve 1 (10), and the front conveyor section (9a) is connected to a lubrication pipe (14) near the inlet.

5. The wet sludge direct blending coal mill system in the coal-fired power generation unit according to claim 4, characterized in that: The front conveying section (9a) is also provided with a pressure gauge (15) near the inlet position, and the lubrication pipe (14) is provided with a control valve three (16).

6. The wet sludge direct blending coal mill system in the coal-fired power generation unit according to claim 5, characterized in that: The discharge port is connected to a discharge pipe (17), a discharge valve (18) is provided at the inlet of the discharge pipe (17), and a collecting hopper is provided at the outlet of the discharge pipe (17).

7. The wet sludge direct blending coal mill system in the coal-fired power generation unit according to claim 5, characterized in that: The control valve 1 (10), the control valve 2 (11) and the control valve 3 (16) are electric ball valves.

8. The wet sludge direct blending coal mill system in a coal-fired power generation unit according to claim 1, characterized in that: The wet sludge direct blending coal mill system further comprises a receiving hopper, a shaftless screw conveyor capable of conveying the wet sludge in the receiving hopper into a wet sludge storage bin (5), and a double-shaft screw conveyor (7) arranged between the outlet of the wet sludge storage bin (5) and the plunger pump (8), an arch breaking device (19) being arranged in the wet sludge storage bin (5), and a hydraulic gate valve (6) capable of controlling the opening and closing of the outlet of the wet sludge storage bin (5) being arranged at the bottom of the wet sludge storage bin (5).

Images