Cooling air-secondary air collaborative energy-saving drying system based on slag dryer of thermal power generating unit

Abstract

The invention relates to the technical field of slag drying machines of thermal power generating units, in particular to a cooling air-secondary air collaborative energy-saving drying system based on a slag drying machine of a thermal power generating unit, which comprises a slag discharging case and an air bellow, and a drying system is arranged above an inclined section of the slag discharging case. The drying system comprises a secondary air pipe, a dehumidification structure arranged in the middle section of the secondary air pipe, a conversion structure used for driving the dehumidification structure to rotate and a moisture discharging structure used for discharging moisture. According to the device, the dehumidification structure is arranged, cooling air can be guided to heat and dry secondary air, recycling of the cooling air is achieved, and the energy-saving effect is improved; meanwhile, by arranging the conversion structure, when secondary air is introduced, the dehumidification structure is continuously driven to rotate, so that the position of the dehumidification plate is changed, uninterrupted dehumidification is achieved, and the dehumidification efficiency and effect are improved; in addition, by arranging a moisture discharging structure, when secondary air is introduced, water vapor generated by drying can be rapidly discharged, and the drying effect is prevented from being affected.

Description

Technical Field

[0001] The present invention belongs to the technical field of slag dryers for thermal power plants, and in particular relates to a cooling air-secondary air coordinated energy-saving drying system based on a slag dryer for a thermal power plant. Background Art

[0002] A slag dryer is a device used to treat boiler slag, and is generally divided into dry and wet slag dryers. A dry slag dryer is usually connected directly to the bottom of the boiler. Since the slag is directly discharged, it generates a lot of heat. To facilitate handling and reuse the slag heat, cooling air is usually introduced during the slag dryer's discharge process to cool the slag.

[0003] For example, the invention application with publication number CN117927958A in the field of pollutant control technology in thermal power plants discloses a dust removal device and a dust removal method for a slag bin of a thermal power plant dry slag machine. The dust removal device includes a dust collecting hood installed on the slag discharge port of the slag bin. The dust collecting hood is connected to the horizontal section of the air-cooled dry slag machine through a pipeline. The negative pressure generated by the horizontal section of the air-cooled dry slag machine is used to provide the dust collecting hood with the suction force required for dust collection; the dust-containing gas collected by the dust collecting hood is used as cooling air for the air-cooled dry slag machine, and is sent into the furnace after cooling the slag on the conveyor belt; a pipeline damper is installed on the pipeline. When the slag is unloaded from the slag bin, the opening of the pipeline damper is adjusted according to the unloading amount of slag and the dust situation to adjust the air volume of the dust collecting hood.

[0004] Combining the above cases and actual conditions, we found the following problems: When cooling air is introduced into the slag dryer, since the furnace and the slag dryer are directly connected and the furnace is generally under negative pressure, the cooling air will be directly sucked into the furnace. Although the heat of the sucked-in cooling air can be reused, the sucked-in cooling air will disrupt the flame inside the furnace and affect combustion. At the same time, the cooling air is usually natural wind with a high oxygen content. After being sucked in, it affects the oxygen content at the bottom of the furnace, increases NOx compounds, and affects subsequent exhaust. Based on the above problems, we found that when the furnace load is low, the humidity of the sucked-in cooling air and secondary air has a greater impact on the furnace combustion. Therefore, we invented a cooling air-secondary air collaborative energy-saving drying system based on the slag dryer of a thermal power unit to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a cooling air-secondary air collaborative energy-saving drying system based on a slag dryer of a thermal power unit, which dries the secondary air through a dehumidification plate, and drives the dehumidification plate to change position for uninterrupted drying under the action of the secondary air force. At the same time, the heated cooling air is guided to the heat pipe to heat the dehumidification plate, so that the dehumidification plate can be reused, reducing the direct interference of the cooling air on the furnace, so as to solve the above-mentioned problems of the prior art.

[0006] To achieve the above objectives, the present invention provides a cooling air-secondary air collaborative energy-saving drying system based on a slag dryer of a thermal power unit, comprising a slag discharge box connected to the thermal power unit at its upper right end, and a wind box located within the slag discharge box for introducing cooling air to cool the slag. A drying system for drying the secondary air is provided above the inclined section of the slag discharge box. The drying system comprises a secondary air duct, a dehumidification structure provided in the middle section of the secondary air duct, a conversion structure for driving the dehumidification structure to rotate, and a dehumidification structure for discharging moisture. In this setting, dehumidification is carried out through the dehumidification structure. The conversion structure is set to drive the dehumidification structure to rotate so that the dehumidification structure is always working. The moisture absorbed by the dehumidification structure can be discharged by setting the moisture discharge structure to prevent moisture residue from affecting the drying effect. The dehumidification structure includes a rotating shaft coaxially arranged with the secondary air duct, two dehumidification plates symmetrically arranged above and below the rotating shaft, and a plurality of heat conduction pipes located behind the upper dehumidification plate. The front end of the rotating shaft is fixedly connected to a rotating ring through a connecting rod. In this configuration, the moisture in the secondary air is absorbed by the hygroscopic material on the dehumidification plate to dry the secondary air. At the same time, the heat pipe heats the dehumidification plate above, heating and evaporating the moisture absorbed by the dehumidification plate above. The conversion structure includes a fan blade arranged at the rear air inlet of the secondary air duct and two pulleys respectively fixed to the front and rear ends of the right side of the secondary air duct, the two pulleys are connected by a belt transmission, and the belt is provided with a lever for driving the rotating ring to rotate; In this setting, the secondary air drives the fan blades to rotate, which in turn drives the pulley to rotate the belt, and then drives the lever and belt to move synchronously counterclockwise. When the lever contacts the rotating ring, it drives the upper and lower dehumidification plates to rotate 180 degrees and exchange positions, so that the upper dehumidification plate that has been dried rotates to the bottom to dry the secondary air; The dehumidification structure includes a dehumidification pipe whose bottom end is connected to the middle section of the secondary air duct and a fan arranged in the dehumidification pipe for extracting moisture; In this setting, the fan rotates to draw air and expel the water vapor evaporated from the dehumidification plate above.

[0007] In the technical solution of the present invention, a slag inlet is provided on the top surface of the horizontal section of the slag discharge box near the front end, and the slag inlet is connected to the bottom end of the combustion furnace of the thermal power unit. A conveyor belt for conveying slag is provided in the slag discharge box, and the wind box is arranged in the middle of the conveyor belt and along the conveyor belt. The wind box air inlet is arranged on the right side wall of the inclined section of the slag discharge box near the top, and a slag outlet is provided on the bottom surface of the inclined section of the slag discharge box near the top.

[0008] In this setup, the slag is transported by a conveyor belt and cooled by cooling air introduced through a wind box.

[0009] In the technical solution of the present invention, the left and right sides of the horizontal section of the slag discharge box are connected to the upper half with a first connecting pipe, the rear end of the first connecting pipe is connected to a bag dust collector, the air outlet of the bag dust collector is connected to a second connecting pipe, the first connecting pipe and the bag dust collector are provided with a suction fan, the bottom outlet of the bag dust collector is connected to the middle part of the inclined section of the slag discharge box, and the bottom outlet of the bag dust collector is provided with an air lock.

[0010] In this arrangement, the suction fan sucks air, and the cooling air heated by the slag enters the bag dust collector through the first connecting pipe for dust removal. An air lock is provided to prevent the cooling air from escaping from the bottom outlet of the bag dust collector.

[0011] In the technical solution of the present invention, a dehumidification chamber is provided in the middle of the secondary air duct, the dehumidification plate and the heat conduction pipe are arranged in the dehumidification chamber, baffles are provided on the front and back sides of the dehumidification chamber, first openings are symmetrically provided on the left and right sides of the middle of the front baffle, and second openings that are adapted to the shape of the dehumidification plate are provided near the bottom of the front and rear baffles, and the size of the second opening is smaller than the size of the dehumidification plate.

[0012] In this arrangement, by setting a first opening, the cooling air introduced is discharged from the first opening and mixed with the secondary air after drying. By setting a second opening, the secondary air can enter through the second opening on the rear side and be discharged through the second opening on the front side.

[0013] In the technical solution of the present invention, an air guide cover is provided in the secondary air duct behind the dehumidification chamber. The rear end of the air guide cover has the same diameter as the secondary air duct, and the front end has the same size and shape as the second opening, and the front end of the air guide cover is connected to the second opening on the rear side.

[0014] In this setting, an air guide cover is provided to guide the secondary air to enter from the second opening on the rear side, so as to prevent the secondary air from failing to effectively contact the dehumidification plate and affecting the drying effect.

[0015] In the technical solution of the present invention, a heating chamber adapted to the first opening is provided in the dehumidification chamber, the heating chamber is located on the rear side of the dehumidification plate, the rear side of the heating chamber is connected to the second connecting pipe, the heat conducting pipe is in an arc shape adapted to the dehumidification plate, and both ends of the heat conducting pipe are respectively fixed in the heating chamber on the corresponding side.

[0016] In this arrangement, the cooling air heated by the slag enters the heating chamber through the second connecting pipe to heat the heat pipe, and the heat conduction of the heat pipe heats the dehumidification plate above, causing the water vapor to evaporate and be reused.

[0017] In the technical solution of the present invention, limiting rings are fixed on the front and rear sides of the rotating ring, and the secondary air duct wall is provided with limiting grooves adapted to the limiting rings at the front and rear sides of the rotating ring. The limiting rings are arranged in the corresponding limiting grooves and the two are rotatably connected.

[0018] In this setting, the support swivel is limited by setting a limit groove and a limit ring, and air leakage is avoided at the same time.

[0019] In the technical solution of the present invention, a first transmission rod is coaxially fixed to the left side of the pulley at the rear end, and the left end of the first transmission rod passes through the outer wall of the secondary air duct and is connected to the fan blade transmission through two bevel gears. The outer wall of the rotating ring is located outside the secondary air duct, and two upper and lower lever grooves are provided on the rotating ring. The lever groove is arranged along the outer ring wall of the rotating ring. The upper lever groove is a counterclockwise spiral from right to left, and the lower lever groove is a counterclockwise spiral from left to right. The size of the lever groove is adapted to the lever.

[0020] In this setting, when the secondary air is introduced, the fan blades are blown and the rear end pulley is driven to rotate counterclockwise through the first transmission rod, thereby driving the belt to rotate counterclockwise. When the lever moves to contact the lever groove, the rotating ring is pushed to rotate 180° counterclockwise, causing the rotating shaft to drive the upper and lower dehumidification plates to exchange positions. The upper drying dehumidification plate rotates to the bottom to continue drying the secondary air.

[0021] In the technical solution of the present invention, the bottom end of the dehumidification pipe is connected to the dehumidification chamber, the front end of the fan blade is connected to the second transmission rod through two mutually meshing bevel gears, the top end of the second transmission rod is connected to the third transmission rod through two mutually meshing bevel gears, and the front end of the third transmission rod is connected to the fan transmission through two mutually meshing bevel gears.

[0022] In this arrangement, when the secondary air is introduced, the fan blades are blown through the second transmission rod and the third transmission rod to drive the fan to rotate and inhale air, thereby expelling the evaporated water vapor.

[0023] In the technical solution of the present invention, a mounting box is fixed to the top of the outer wall of the secondary air duct near the rear end, and the second transmission rod and the third transmission rod are arranged in the mounting box.

[0024] In this configuration, the second transmission rod and the third transmission rod are supported by providing a mounting box.

[0025] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. In the present invention, a dehumidification structure is provided so that the cooling air is heated when passing through the slag on the conveyor belt and then enters the heating chamber to heat the heat pipe. The upper dehumidification plate is heated under the heat conduction of the heat pipe to evaporate the water vapor and is discharged from the first opening after heating. The secondary air enters the dehumidification chamber, is dehumidified by the dehumidification plate below, and is discharged from the second opening on the front side. The heated cooling air is then mixed with the secondary air, and the secondary air is preheated to a certain extent. The secondary air is then accelerated by the booster fan and preheated by the preheater and then passed into the furnace. The heated cooling air is used to dry the secondary air, which not only saves energy but also prevents the cooling air from directly entering the furnace and affecting the combustion in the furnace.

[0026] 2. In the present invention, by setting a conversion structure, the secondary air introduced blows the fan blades to drive the rear end pulley to rotate counterclockwise and drive the belt to rotate counterclockwise. When the lever moves to contact the lever groove, it will push the rotating ring to rotate 180° counterclockwise, and the rotating shaft will drive the upper and lower dehumidification plates to exchange positions, so that the upper drying dehumidification plate rotates to the bottom to continue drying the secondary air, achieving uninterrupted drying and improving the drying effect.

[0027] 3. In the present invention, when the fan blades rotate, the second transmission rod and the third transmission rod drive the fan to rotate and inhale air, thereby discharging evaporated water vapor, thereby preventing water vapor backflow from affecting the drying effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a cross-sectional view of the dry slag machine of the present invention; Figure 3 Schematic diagram of the drying system in the present invention; Figure 4 This is a schematic diagram of the interior of the secondary air duct in the present invention; Figure 5 This is a cross-sectional view of the secondary air duct in the present invention; Figure 6 This is an exploded diagram of the dehumidification structure of the present invention; Figure 7 This is another exploded view of the dehumidification structure of the present invention; Figure 8 Schematic diagram of the heat pipe in the present invention; Figure 9 Schematic diagram of the conversion structure in the present invention; Figure 10 This is a schematic diagram of the rear side of the transfer ring of the present invention; Figure 11 Schematic diagram of the moisture removal structure of the present invention; Description of reference numerals: 100, slag discharge box; 101, slag inlet; 102, conveyor belt; 103, bellows; 200, drying system; 201, secondary air duct; 201a, limiting groove; 201b, baffle; 201c, first opening; 201d, second opening; 202, first connecting pipe; 203, bag filter; 204, second connecting pipe; 205, installation box; 206, air guide cover; 207, dehumidification chamber; 208, heating chamber; 210, dehumidification structure; 211, dehumidification plate; 212, rotating shaft; 213, heat pipe; 214, connecting rod; 215, rotating ring; 216, limiting ring; 217, lever slot; 220, conversion structure; 221, fan blade; 222, first transmission rod; 223, pulley; 224, belt; 225, lever; 230, dehumidification structure; 231, dehumidification pipe; 232, fan; 233, second transmission rod; 234, third transmission rod. DETAILED DESCRIPTION

[0029] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0030] Unless expressly stated otherwise, throughout the specification, the term “comprise” or variations thereof such as “include” or “comprising” will be understood to include the stated elements or components but not to exclude other elements or components.

[0031] Reference Figures 1-11 As shown, this embodiment provides a technical solution: The cooling air-secondary air collaborative energy-saving drying system based on the slag dryer of the thermal power unit in the present invention comprises a slag discharge box 100 connected to the thermal power unit at the upper right end and a wind box 103 located in the slag discharge box 100. The wind box 103 is fed with cooling air through a fan. The cooling air cools the slag after passing through the slag, while the cooling air heats up. Usually, the temperature of the cooling air after heating is 300°C-400°C. A drying system 200 for drying the secondary air is provided above the inclined section of the slag discharge box 100. When the furnace load is low, the humidity of the secondary air has a great influence on the furnace combustion. By setting up the drying system 200, the heated cooling air is introduced to dry the secondary air. Not only is it energy-saving and environmentally friendly, but the cooling air can also be mixed with the secondary air later to preheat the secondary air to further save energy. The drying system 200 includes a secondary air duct 201, a dehumidification structure 210 provided in the middle section of the secondary air duct 201, a conversion structure 220 for driving the dehumidification structure 210 to rotate, and a dehumidification structure 230 for discharging moisture. Dehumidification is performed by the dehumidification structure 210. The conversion structure 220 is provided to drive the dehumidification structure 210 to rotate so that the dehumidification structure 210 is always working. The dehumidification structure 230 can discharge the moisture absorbed by the dehumidification structure 210 to prevent residual moisture from affecting the drying effect. The dehumidification structure 210 includes a rotating shaft 212 coaxially arranged with the secondary air duct 201, two dehumidification plates 211 symmetrically arranged above and below the rotating shaft 212, and a plurality of heat conducting pipes 213 located behind the upper dehumidification plate 211. The front end of the rotating shaft 212 is fixedly connected to a rotating ring 215 via a connecting rod 214. The dehumidification plates 211 are made of a hygroscopic material, such as reusable water-absorbing silica gel. The secondary air passes through the lower dehumidification plate 211, where the hygroscopic material absorbs the water vapor in the secondary air and dries the secondary air. At the same time, the heat conducting pipes 213 heat the upper dehumidification plate 211, heating and evaporating the water vapor absorbed by the upper dehumidification plate 211. The conversion structure 220 includes a fan blade 221 provided at the air inlet at the rear end of the secondary air duct 201 and two pulleys 223 fixed to the front and rear ends of the right side of the secondary air duct 201. The two pulleys 223 are connected by a belt 224. The belt 224 is provided with a lever 225 for driving the rotating ring 215 to rotate. The secondary air entering drives the fan blade 221 to rotate, which drives the pulley 223 to drive the belt 224 to rotate, thereby driving the lever 225 and the belt 224 to move counterclockwise synchronously. When the lever 225 contacts the rotating ring 215, it drives the upper and lower dehumidification plates 211 to rotate 180 degrees to exchange positions, so that the upper dried dehumidification plate 211 rotates to the lower side to dry the secondary air. The dehumidification structure 230 includes a dehumidification pipe 231 whose bottom end is connected to the middle section of the secondary air duct 201 and a fan 232 arranged in the dehumidification pipe 231 for extracting moisture. The fan 232 rotates to absorb air and discharges the water vapor evaporated from the dehumidification plate 211 above.

[0032] See also Figure 1-Figure 2 As shown, a slag inlet 101 is provided on the top of the horizontal section of the slag discharge box 100 near the front end, and the slag inlet 101 is connected to the bottom end of the combustion furnace of the thermal power unit. The combustion furnace is usually located above the horizontal section of the slag discharge box 100, and the bottom is connected to the slag discharge box 100. The specific connection method is the existing technology of the combustion furnace and the dry slag discharger, which will not be described here. A conveyor belt 102 for conveying slag is provided in the slag discharge box 100, and a vertical support plate is fixed on the conveyor belt 102 to drive the slag to move. This is the existing technology of the dry slag discharger. , I will not go into details here. The bellows 103 is arranged in the middle of the conveyor belt 102 and along the conveyor belt 102. The air inlet of the bellows 103 is arranged on the right side wall of the inclined section of the slag discharge machine box 100 near the top. The cooling air is transported by the bellows 103 to cool the slag. This is the existing technology of the dry slag discharger and I will not go into details here. A slag outlet is provided on the bottom surface of the inclined section of the slag discharge machine box 100 near the top. When the slag is transported to the top of the inclined section of the slag discharge machine box 100, the slag is discharged from the slag outlet and falls into the slag crusher for processing. This is the existing technology and I will not go into details here.

[0033] Furthermore, the left and right sides of the horizontal section of the slag discharge box 100 are connected to the upper half with a first connecting pipe 202, the rear end of the first connecting pipe 202 is connected to the bag dust collector 203, the first connecting pipe 202 and the bag dust collector 203 are provided with a suction fan, the suction fan sucks air, and the cooling air heated by the slag enters the bag dust collector 203 through the first connecting pipe 202 for dust removal, so as to avoid the fine slag carried by the cooling air from mixing with the secondary air and affecting the subsequent secondary combustion effect. The air outlet of the bag dust collector 203 is connected to the first connecting pipe 202. The second connecting pipe 204, the cooling air after dust removal enters the second connecting pipe 204, the bottom outlet of the bag dust collector 203 is connected to the middle of the inclined section of the slag discharge box 100, and the fine dust slag carried by the cooling air re-enters the slag discharge box 100 from the bottom of the bag dust collector 203. The bottom outlet of the bag dust collector 203 is provided with an air lock to prevent the cooling air from escaping from the bottom outlet of the bag dust collector 203. The bag dust collector 203 and the air lock are both commonly used equipment in thermal power units and are existing technologies. The details will not be repeated here.

[0034] See also Figure 3-Figure 8 As shown, a dehumidification chamber 207 is provided in the middle of the secondary air duct 201, a dehumidification plate 211 and a heat conducting pipe 213 are provided in the dehumidification chamber 207, baffles 201b are provided on both the front and rear sides of the dehumidification chamber 207, the dehumidification plate 211 is fitted with the inner wall of the front baffle 201b, and the arc-shaped outer wall of the dehumidification plate 211 is fitted with the wall of the dehumidification chamber 207 to avoid air leakage and affect the drying of the secondary air, and first openings 201c are symmetrically provided on the left and right sides of the middle of the front baffle 201b, through which the air is introduced. The cooling air is discharged from the first opening 201c and mixed with the dried secondary air. The front and rear baffles 201b are provided with a second opening 201d at the bottom that is adapted to the shape of the dehumidification plate 211. By providing the second opening 201d, the secondary air can enter through the second opening 201d on the rear side and be discharged through the second opening 201d on the front side. The size of the second opening 201d is smaller than that of the dehumidification plate 211, so as to avoid the secondary air inlet area being too large to cause it to be unable to contact the dehumidification plate 211, thereby affecting the drying effect.

[0035] Furthermore, an air guide hood 206 is provided in the secondary air duct 201 at the rear of the dehumidification chamber 207. The rear end of the air guide hood 206 has the same diameter as the secondary air duct 201, and the front end has the same size and shape as the second opening 201d. By providing the air guide hood 206, the secondary air is guided to enter from the second opening 201d on the rear side, thereby preventing the secondary air from being unable to effectively contact the dehumidification plate 211 and affecting the drying effect, and the front end of the air guide hood 206 is connected to the second opening 201d on the rear side.

[0036] Specifically, a heating chamber 208 adapted to the first opening 201c is provided in the dehumidification chamber 207. The heating chamber 208 is located at the rear side of the dehumidification plate 211. The rear side of the heating chamber 208 is connected to the second connecting pipe 204. The cooling air heated by the slag enters the heating chamber 208 through the second connecting pipe 204 to heat the heat pipe 213. Under the heat conduction action of the heat pipe 213, the upper dehumidification plate 211 is heated to evaporate water vapor for reuse. The heat pipe 213 is in an arc shape adapted to the dehumidification plate 211 to ensure that the contact area between the heat pipe 213 and the dehumidification plate 211 is large enough to ensure the heating and evaporation effect. The two ends of the heat pipe 213 are respectively fixed in the corresponding side heating chamber 208.

[0037] See also Figure 9-10 As shown, limiting rings 216 are fixed on the front and rear sides of the rotating ring 215, and limiting grooves 201a adapted to the limiting rings 216 are provided on the walls of the secondary air duct 201 at the front and rear sides of the rotating ring 215. The limiting rings 216 are arranged in the corresponding limiting grooves 201a and the two are rotatably connected. The limiting grooves 201a and the limiting rings 216 are provided to limit and support the rotating ring 215, while avoiding air leakage and affecting the drying effect.

[0038] Furthermore, a first transmission rod 222 is coaxially fixed to the left side of the rear end pulley 223. The left end of the first transmission rod 222 passes through the outer wall of the secondary air duct 201 and is connected to the fan blade 221 through two bevel gears. The outer wall of the rotating ring 215 is located outside the secondary air duct 201. The rotating ring 215 is provided with two upper and lower lever grooves 217. The lever groove 217 is arranged along the outer ring wall of the rotating ring 215. The size of the lever groove 217 is adapted to the lever 225. When the secondary air is introduced , blowing the fan blades 221 and driving the rear end pulley 223 to rotate counterclockwise through the first transmission rod 222, thereby driving the belt 224 to rotate counterclockwise, so that the lever 225 and the belt 224 move synchronously. When the lever 225 moves to contact the lever groove 217, it will push the rotating ring 215 to rotate 180 degrees counterclockwise, causing the rotating shaft 212 to drive the upper and lower dehumidification plates 211 to exchange positions, so that the upper drying dehumidification plate 211 rotates to the bottom to continue drying the secondary air.

[0039] Specifically, since the upper lever groove 217 is a counterclockwise spiral from right to left, and the lower lever groove 217 is a counterclockwise spiral from left to right, when the rotating ring 215 rotates 180 degrees, the original lower lever groove 217 rotates to the upper side again, so that the lever 225 can contact the lever groove 217 again after rotating one circle with the belt 224, and drive the rotating ring 215 to rotate 180 degrees again, thereby realizing the reuse of the dehumidification structure 210. At the same time, the lever 225 moves synchronously with the belt 224. The thickness of the rotating ring 215 is small, so that the contact time between the lever 225 and the lever groove 217 is short, and the lever 225 drives the rotating ring 215 to rotate quickly, that is, the upper and lower dehumidification plates 211 exchange positions quickly, thereby avoiding a large amount of secondary air being undried when exchanging positions. In addition, the lever 225 stays in a position without contacting the lever groove 217 for a long time, which ensures that the dehumidification plate 211 below has enough time to dry the secondary air and avoids the upper and lower dehumidification plates 211 exchanging positions too quickly.

[0040] It should be noted that the fan blades 221 are fixed in the secondary air duct 201 through vertical rods. The fan blades 221 are coaxially rotatably connected to the vertical rods. The fixing of the fan blades 221 is a conventional technology and is not shown in the figure.

[0041] See also Figure 11 As shown, the bottom end of the dehumidification pipe 231 is connected to the dehumidification chamber 207, the front end of the fan blade 221 is connected to the second transmission rod 233 through two mutually meshing bevel gears, the top of the second transmission rod 233 is connected to the third transmission rod 234 through two mutually meshing bevel gears, and the front end of the third transmission rod 234 is connected to the fan 232 through two mutually meshing bevel gears. A mounting box 205 is fixed to the top of the outer wall of the secondary air duct 201 near the rear end, and the second transmission rod 233 and the third transmission rod 234 are arranged in the mounting box 205. When the secondary air is introduced, the fan blade 221 is blown through the second transmission rod 233 and the third transmission rod 234 to drive the fan 232 to rotate and inhale air, thereby discharging the evaporated water vapor.

[0042] The working principle of the cooling air-secondary air collaborative energy-saving drying system based on the slag dryer of the thermal power unit in the present invention is as follows: When the furnace discharges slag, cooling air is introduced from the wind box 103, and secondary air is introduced from the rear end of the secondary air duct 201 at the same time. The cooling air is heated when passing through the slag on the conveyor belt 102, and then passes through the first connecting pipe 202, the bag dust collector 203 and the second connecting pipe 204 in sequence to enter the heating chamber 208 to heat the heat conducting pipe 213. Under the heat conduction action of the heat conducting pipe 213, the upper dehumidification plate 211 is heated to evaporate water vapor. After heating, it is discharged from the first opening 201c. The secondary air is guided by the air guide cover 206 to enter the dehumidification chamber 207 from the second opening 201d on the rear side, and is dehumidified by the dehumidification plate 211 below and discharged from the second opening 201d on the front side. The heated cooling air is then mixed with the secondary air, and the secondary air is preheated to a certain extent. The secondary air is then accelerated by the booster fan and preheated by the preheater before entering the furnace. At the same time, the secondary air blows the fan blades 221 and drives the rear pulley 223 to rotate counterclockwise through the first transmission rod 222, thereby driving the belt 224 to rotate counterclockwise, so that the lever 225 and the belt 224 move synchronously. When the lever 225 moves to contact the lever groove 217, it pushes the rotating ring 215 to rotate 180 degrees counterclockwise, causing the rotating shaft 212 to drive the upper and lower dehumidification plates 211 to exchange positions, so that the upper drying dehumidification plate 211 rotates to the lower side to continue drying the secondary air. Next, the fan blades 221 rotate and are driven by the second transmission rod 233 and the third transmission rod 234 to drive the fan 232 to rotate and inhale air, thereby discharging the evaporated water vapor.

[0043] The foregoing descriptions of specific exemplary embodiments of the present invention are for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many variations and modifications are possible in light of the foregoing teachings. The exemplary embodiments have been selected and described for the purpose of explaining the specific principles of the invention and their practical application, thereby enabling those skilled in the art to make and utilize a variety of exemplary embodiments of the invention and various options and modifications. The scope of the invention is intended to be defined by the description and its equivalents.

Claims

1. A cooling air-secondary air cooperative energy-saving drying system based on a slag dryer of a thermal power unit, comprising a slag discharge box (100) connected to the thermal power unit at the upper right end and a wind box (103) located in the slag discharge box (100) for introducing cooling air to cool the slag, characterized in that: A drying system (200) for drying secondary air is provided above the inclined section of the slag discharge box (100), the drying system (200) comprising a secondary air duct (201), a dehumidification structure (210) provided in the middle section of the secondary air duct (201), a conversion structure (220) for driving the dehumidification structure (210) to rotate, and a dehumidification structure (230) for discharging moisture; The dehumidification structure (210) comprises a rotating shaft (212) coaxially arranged with the secondary air duct (201), two dehumidification plates (211) symmetrically arranged above and below the rotating shaft (212), and a plurality of heat conduction pipes (213) located behind the upper dehumidification plate (211); the front end of the rotating shaft (212) is fixedly connected to a rotating ring (215) via a connecting rod (214); The conversion structure (220) comprises a fan blade (221) arranged at the rear air inlet of the secondary air duct (201) and two pulleys (223) respectively fixed to the front and rear ends of the right side of the secondary air duct (201), the two pulleys (223) being connected by a belt (224), and a lever (225) for driving the rotating ring (215) to rotate is provided on the belt (224); The dehumidification structure (230) comprises a dehumidification pipe (231) whose bottom end is connected to the middle section of the secondary air pipe (201), and a fan (232) disposed in the dehumidification pipe (231) for extracting moisture.

2. The cooling air-secondary air collaborative energy-saving drying system based on a slag dryer of a thermal power unit according to claim 1, characterized in that: A slag inlet (101) is provided on the top surface of the horizontal section of the slag discharge box (100) near the front end, and the slag inlet (101) is communicated with the bottom end of the combustion furnace of the thermal power unit. A conveyor belt (102) for conveying slag is provided in the slag discharge box (100). The wind box (103) is arranged in the middle of the conveyor belt (102) and along the conveyor belt (102). The air inlet of the wind box (103) is arranged on the right side wall of the inclined section of the slag discharge box (100) near the top, and a slag outlet is provided on the bottom surface of the inclined section of the slag discharge box (100) near the top.

3. The cooling air-secondary air collaborative energy-saving drying system based on the thermal power unit slag dryer according to claim 2, characterized in that: The left and right sides of the horizontal section of the slag discharge box (100) are connected to the upper half thereof with a first connecting pipe (202), the rear end of the first connecting pipe (202) is connected to a bag dust collector (203), the air outlet of the bag dust collector (203) is connected to a second connecting pipe (204), the first connecting pipe (202) and the bag dust collector (203) are provided with a suction fan, the bottom outlet of the bag dust collector (203) is connected to the middle of the inclined section of the slag discharge box (100), and the bottom outlet of the bag dust collector (203) is provided with an air lock.

4. The cooling air-secondary air collaborative energy-saving drying system based on a slag dryer of a thermal power unit according to claim 3, characterized in that: A dehumidification chamber (207) is provided in the middle of the secondary air duct (201), the dehumidification plate (211) and the heat conducting pipe (213) are arranged in the dehumidification chamber (207), baffles (201b) are provided on both the front and rear sides of the dehumidification chamber (207), first openings (201c) are symmetrically provided on the left and right sides of the middle of the front baffle (201b), and second openings (201d) that are adapted to the shape of the dehumidification plate (211) are provided near the bottom of the front and rear baffles (201b), and the size of the second opening (201d) is smaller than that of the dehumidification plate (211).

5. The cooling air-secondary air collaborative energy-saving drying system based on a slag dryer of a thermal power unit according to claim 4, characterized in that: An air guide cover (206) is provided in the secondary air duct (201) at the rear of the dehumidification chamber (207); the rear end of the air guide cover (206) has the same diameter as the secondary air duct (201), the front end has the same size and shape as the second opening (201d), and the front end of the air guide cover (206) is in communication with the second opening (201d) at the rear.

6. The cooling air-secondary air collaborative energy-saving drying system based on a slag dryer of a thermal power unit according to claim 5, characterized in that: A heating chamber (208) adapted to the first opening (201c) is provided in the dehumidification chamber (207); the heating chamber (208) is located at the rear side of the dehumidification plate (211); the rear side of the heating chamber (208) is connected to the second connecting pipe (204); the heat conducting pipe (213) is in an arc shape adapted to the dehumidification plate (211); and both ends of the heat conducting pipe (213) are respectively fixed in the heating chamber (208) on the corresponding side.

7. The cooling air-secondary air collaborative energy-saving drying system based on a slag dryer of a thermal power unit according to claim 6, characterized in that: Limiting rings (216) are fixed on the front and rear sides of the rotating ring (215); limiting grooves (201a) adapted to the limiting rings (216) are provided on the wall of the secondary air duct (201) at the front and rear sides of the rotating ring (215); the limiting rings (216) are arranged in the corresponding limiting grooves (201a), and the two are rotatably connected.

8. The cooling air-secondary air collaborative energy-saving drying system based on a slag dryer of a thermal power unit according to claim 7, characterized in that: A first transmission rod (222) is coaxially fixed to the left side of the pulley (223) at the rear end. The left end of the first transmission rod (222) passes through the outer wall of the secondary air duct (201) and is connected to the fan blade (221) through two bevel gears. The outer wall of the rotating ring (215) is located outside the secondary air duct (201). The rotating ring (215) is provided with two upper and lower lever grooves (217). The lever grooves (217) are arranged along the outer ring wall of the rotating ring (215). The upper lever groove (217) is in a counterclockwise spiral shape from right to left, and the lower lever groove (217) is in a counterclockwise spiral shape from left to right. The size of the lever groove (217) is adapted to the lever (225).

9. The cooling air-secondary air collaborative energy-saving drying system based on a slag dryer of a thermal power unit according to claim 8, characterized in that: The bottom end of the dehumidification pipe (231) is in communication with the dehumidification chamber (207); the front end of the fan blade (221) is connected to a second transmission rod (233) via two mutually meshing bevel gears; the top end of the second transmission rod (233) is connected to a third transmission rod (234) via two mutually meshing bevel gears; the front end of the third transmission rod (234) is connected to the fan (232) via two mutually meshing bevel gears.

10. The cooling air-secondary air collaborative energy-saving drying system based on a slag dryer of a thermal power unit according to claim 9, characterized in that: A mounting box (205) is fixed to the top of the outer wall of the secondary air duct (201) near the rear end, and the second transmission rod (233) and the third transmission rod (234) are arranged in the mounting box (205).

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