Heat exchange optimization structure of power plant cooling tower

Abstract

The invention discloses a heat exchange optimization structure of a power plant cooling tower, which comprises a cooling tower main body, a water inlet pipe mounted at the top of the cooling tower main body, a water outlet pipe mounted at the bottom of the cooling tower main body, a flow guide fan mounted at the upper part in the cooling tower main body, a filler groove mounted at the lower part in the cooling tower main body, and an air inlet groove formed in the inner wall of the cooling tower main body, an air inlet pipe communicated with the air inlet groove is arranged in the side wall of the cooling tower main body; the flow guide fan comprises a bottom plate, a plurality of arc-shaped vertical plates are annularly fixed to the edge of the bottom plate, flow guide plates are installed on the inner sides of the arc-shaped vertical plates, a first through hole is formed in the center of the bottom plate, and a plurality of fan blades are evenly arranged between the first through hole and the edge of the bottom plate. A plurality of layers of conical screen plates are arranged in the packing groove, the adjacent conical screen plates face opposite directions, and the height of the conical screen plate on the top layer is gradually reduced from the middle to the edge. The defects in the prior art can be overcome, and the cooling efficiency of the cooling tower under all working conditions is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of cooling towers, and in particular to a heat exchange optimization structure for a power plant cooling tower. Background Art

[0002] After the cooling circulating water in a power plant absorbs heat from the unit, it is cooled by a cooling tower. In the cooling tower, cold air flows upward from the bottom of the tower, while the circulating water to be cooled is sprayed downward from the top of the cooling tower, and the temperature of the circulating water is reduced through the heat exchange between water and air in the tower. When designing a desired cooling tower, its structural parameters need to be set according to the circulating water flow rate to achieve the best cooling efficiency.

[0003] Generally, the larger the volume of the cooling tower, the larger its rated circulating water flow rate. However, during the actual operation of a power plant, the cooling circulating water does not always circulate at the rated flow rate. When the load is small, the flow rate of the cooling circulating water will be reduced. However, in order to balance the unit load and the construction and use costs of the cooling tower, generally, the cooling tower is designed according to the average load of the unit. This results in a significant decrease in the cooling efficiency of the cooling tower when the unit operates at full load. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a heat exchange optimization structure for a power plant cooling tower to solve the deficiencies of the existing technology and improve the cooling efficiency of the cooling tower under all working conditions.

[0005] To solve the above technical problem, the technical solutions adopted by the present invention are as follows.

[0006] A heat exchange optimization structure for a power plant cooling tower includes a cooling tower main body. An inlet pipe is installed at the top of the cooling tower main body, and an outlet pipe is installed at the bottom of the cooling tower main body. A guide fan is installed above the interior of the cooling tower main body, and a packing tank is installed below the interior of the cooling tower main body. An air inlet groove is provided on the inner wall of the cooling tower main body, and an air inlet pipe communicating with the air inlet groove is provided inside the side wall of the cooling tower main body. The guide fan includes a bottom plate, and a plurality of arc-shaped vertical plates are annularly fixed at the edge of the bottom plate. The arc-shaped vertical plates bulge outward, and a guide plate is installed inside the arc-shaped vertical plates. A first through hole is provided at the center of the bottom plate, and a plurality of fan blades are evenly arranged between the first through hole and the edge of the bottom plate. A plurality of layers of conical mesh plates are arranged in the packing tank, and the orientations of adjacent conical mesh plates are opposite. The height of the top conical mesh plate gradually decreases from the middle to the edge.

[0007] Preferably, the air inlet groove is located on one side of the guide fan, and the air outlet direction of the air inlet groove is inclined downward and faces the guide fan.

[0008] Preferably, the deflector is pivotally connected to the inner wall of the arc-shaped vertical plate, and a pneumatic push rod is installed between the deflector and the arc-shaped vertical plate. The included angle between the deflector and the arc-shaped vertical plate faces the rotation direction of the deflector fan (that is, if the opening direction between the deflector and the arc-shaped vertical plate is clockwise, the rotation direction of the deflector fan is also clockwise).

[0009] Preferably, a first flow guiding groove is provided on the deflector, and the height of the first flow guiding groove near the arc-shaped vertical plate is lower than the height of the other end of the first flow guiding groove.

[0010] Preferably, a second flow guiding groove is provided at the pivotally connected end of the deflector and the arc-shaped vertical plate. A rotating shaft is installed on the arc-shaped vertical plate through a shaft bracket, and the rotating shaft is fixedly connected to the second flow guiding groove.

[0011] More preferably, an extension piece is installed on the side of the second flow guiding groove facing away from the arc-shaped vertical plate, and the included angle between the extension piece and the deflector is 15 - 25°.

[0012] Preferably, a plurality of parallel partitions are fixed between adjacent conical mesh plates, and a plurality of water permeable grooves are provided on the partitions.

[0013] More preferably, the water permeable grooves on adjacent partitions on the same layer are arranged in a staggered manner.

[0014] Preferably, angle steel bars are fixed between adjacent partitions on the same layer, with the tips of the angle steel bars facing upward. A plurality of second through holes are provided on the surface of the angle steel bars. Mesh plates are installed at the bottom of the angle steel bars and on the second through holes respectively, and no filler is filled in the internal cavity formed by the angle steel bars and the mesh plates.

[0015] Preferably, a plurality of air inlets are provided at the bottom of the cooling tower main body. The air inlets are communicated with the bottom edge of the side wall of the filler tank, and the air inlet direction of the air inlets is tangent to the side wall of the filler tank.

[0016] The beneficial effects brought by adopting the above technical solutions are as follows: By improving the structure of the cooling tower, the efficient cooling working condition range of the cooling tower is expanded, thereby improving the operation efficiency of the entire generator set and reducing the operation cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a structural diagram of a specific embodiment of the present invention.

[0018] Figure 2 is a top view of the deflector fan in a specific embodiment of the present invention.

[0019] Figure 3 is a structural diagram of the deflector in a specific embodiment of the present invention.

[0020] Figure 4 is Figure 3Cross-sectional view in the direction of A-A in [Chinese text].

[0021] Figure 5 It is a partially enlarged view of the inside of the packing tank in a specific embodiment of the present invention.

[0022] Figure 6 It is a structural diagram of the angle steel bar in a specific embodiment of the present invention. Specific Embodiment

[0023] Traditional cooling towers can only control the cooling efficiency by changing the air flow rate. However, the change in air flow rate has a relatively small impact on the water-air heat exchange process, which is the main reason for the narrow high-efficiency cooling range of traditional cooling towers.

[0024] In view of the defects of the prior art, the present invention has improved the structure of the cooling tower. Referring to Figures 1-6 , a specific embodiment of the present invention includes a cooling tower main body 1. An inlet water pipe 2 is installed at the top of the cooling tower main body 1, and an outlet water pipe 3 is installed at the bottom of the cooling tower main body 1. A guide fan 4 is installed above the inside of the cooling tower main body 1, and a packing tank 5 is installed below the inside of the cooling tower main body 1. An air inlet groove 6 is provided on the inner wall of the cooling tower main body 1, and an air inlet pipe 7 communicating with the air inlet groove 6 is provided inside the side wall of the cooling tower main body 1; the guide fan 4 includes a bottom plate 8. A plurality of arc-shaped vertical plates 9 are fixedly arranged in a ring shape at the edge of the bottom plate 8. The arc-shaped vertical plates 9 bulge outwards, that is, towards the outside of the guide fan 4. A guide plate 10 is installed inside the arc-shaped vertical plates 9. A first through hole 11 is provided at the center of the bottom plate 8, and a plurality of fan blades 12 are evenly arranged between the first through hole 11 and the edge of the bottom plate 8; a plurality of layers of conical mesh plates 13 are arranged in the packing tank 5. The orientations of adjacent conical mesh plates 13 are opposite, and the height of the top conical mesh plate 13 gradually decreases from the middle to the edge.

[0025] Circulating water with cooling enters the interior of the cooling tower main body 1 from the water inlet pipe 2 and flows downward. The rotation of the guiding fan 4 causes the air flow to flow upward and be discharged from the cooling tower main body 1, thereby generating a low pressure inside the cooling tower main body 1 relative to the outside. The pressure difference causes external air to enter the cooling tower main body 1 from two directions, namely the bottom of the cooling tower and the air inlet groove 6, forming a complete water-air cycle. The circulating water passes through two cooling mechanisms, namely the guiding fan 4 and the packing tank 5, inside the cooling tower. When the cooling water flows downward to the guiding fan 4, the water flow on the outside is sprayed outward under the agitation of the fan blades 12, while the water flow in the middle directly flows downward through the first through hole 11. The guiding fan 4 disperses the water flow, improving the efficiency of water-air heat exchange here. More importantly, it enables more efficient heat exchange to occur in the packing tank 5 below. The packing tank 5 is filled with packing (not shown in the figure). The multi-layer baffle structure of the packing tank 5 can make the water flow flowing down from the first through hole 11 flow back and forth multiple times in the packing tank 5, increasing the contact heat exchange between the water flow and the air flow in the packing. At the same time, the water flow sprayed on the outside directly covers the entire area of the packing tank 5 to optimize the flow state of the water flow in the packing tank 5.

[0026] The air inlet slot 6 is located on one side of the guiding fan 4. The air outlet direction of the air inlet slot 6 is inclined downward and faces the guiding fan 4. The guiding plate 10 is pivotally connected to the inner wall of the arc-shaped vertical plate 9. An air cylinder push rod 24 is installed between the guiding plate 10 and the arc-shaped vertical plate 9. The included angle between the guiding plate 10 and the arc-shaped vertical plate 9 faces the rotation direction of the guiding fan 4. The first air guiding through slot 25 is arranged on the guiding plate 10. The height of one end of the first air guiding through slot 25 close to the arc-shaped vertical plate 9 is lower than the height of the other end of the first air guiding through slot 25. The second guiding slot 20 is arranged at the pivotally connected end of the guiding plate 10 and the arc-shaped vertical plate 9. A rotating shaft 15 is installed on the arc-shaped vertical plate 9 through a shaft bracket 14. The rotating shaft 15 is fixedly connected to the second guiding slot 20. An extension piece 16 is installed on the side of the second guiding slot 20 facing away from the arc-shaped vertical plate 9. The included angle between the extension piece 16 and the guiding plate 10 is 20°. The air outlet direction of the air inlet slot 6 is inclined downward, and the blown air hits the guiding fan 4. Part of the air flow forms a turbulent flow outside the guiding fan 4, and the other part of the air flow enters the inside of the guiding fan 4, and is accelerated in the area between the guiding plate 10 and the arc-shaped vertical plate 9 and fully mixed and contacted with the water sprayed outward. The outer arc-shaped vertical plate 9 can form a low-pressure area on its inner side during rotation, so as to effectively absorb the external air flow. Part of the water-vapor mixture after mixing between the guiding plate 10 and the arc-shaped vertical plate 9 is ejected at high speed through the first air guiding through slot 25 and the second guiding slot 20, and is secondarily impacted and mixed with the water flow inside the guiding fan 4, so as to complete the first contact cooling of the water flow at the guiding fan 4. The angle of the guiding plate 10 is adjustable (adjusted by the air cylinder push rod 24). When the water inflow increases, the included angle between the guiding plate 10 and the arc-shaped vertical plate 9 is increased, so that the air flow driven inward by the guiding fan 4 is increased, and the water-vapor mixing efficiency is improved. When the water inflow decreases, the included angle between the guiding plate 10 and the arc-shaped vertical plate 9 is decreased, and the water flow sprayed outward by the guiding fan 4 is increased, so as to ensure the uniformity of the spraying on the packing slot 5.

[0027] A number of parallel partitions 17 are fixed between adjacent conical mesh plates 13. A number of water-permeable through slots 18 are provided on the partitions 17, and the water-permeable through slots 18 on adjacent partitions 17 on the same layer are arranged in a staggered manner. Angle steel bars 19 are fixed between adjacent partitions 17 on the same layer, with the tips of the angle steel bars 19 facing upward. A number of second through holes 21 are provided on the surface of the angle steel bars 19. Mesh plates 22 are installed at the bottom of the angle steel bars 19 and on the second through holes 21 respectively. The internal cavity formed by the angle steel bars 19 and the mesh plates 22 is not filled with packing. A number of air inlets 23 are provided at the bottom of the cooling tower main body 1, and the air inlets 23 are communicated with the bottom edge of the side wall of the packing tank 5. The air inlet direction of the air inlets 23 is tangent to the side wall of the packing tank 5. The circulating water has two main flow directions in the packing tank. One is to flow reciprocally along the direction of the conical mesh plates 13, and the other is to flow vertically through the mesh holes (not shown in the figure) on the conical mesh plates 13. When the circulating water flow rate is low, the downward seepage is the main flow in the packing tank. As the circulating water volume increases, the water flow rate flowing reciprocally along the direction of the conical mesh plates 13 increases rapidly, while the seepage through the mesh holes increases at a relatively small speed. Thus, the water flow flowing reciprocally along the direction of the conical mesh plates 13 becomes the main flow mode. At this time, the partitions 17 will block the reciprocating water flow, causing the water flow to form a turbulent flow area between the partitions, effectively improving the mixing efficiency of the water flow and the air flow. A cavity is formed inside the angle steel bars 19 to reserve a fast-flowing channel for air and circulating water, facilitating the flow of the water-vapor mixture in the packing tank 5. By installing the angle steel bars, the circulating water and the air flow can be fully mixed in the packing tank 5 regardless of whether the circulating water is in a large-flow or small-flow state, avoiding the overflow of the circulating water in the packing tank 5 when a large amount of circulating water is injected.

[0028] In addition, the mesh plate 22 at the bottom of the angle steel bar 19 bulges towards the top of the angle steel bar 19, thus forming a cavity with a shape of "higher in the middle and lower at both ends" inside the angle steel bar 19. This shape of the cavity is conducive to the convection of water flow and air flow in the cavity (the water flow is located at the lower part of the cavity, and the air flow is located at the upper part of the cavity), thereby further improving the water-vapor circulation and mixing efficiency in the packing tank 5.

[0029] In the renovation project of a certain unit's cooling tower, this cooling tower structure of the present invention was used. Taking the cooling tower before renovation as the control group and the cooling tower after renovation as the experimental group, the temperature difference between the inlet and outlet water (the larger the temperature difference between the inlet and outlet water, the higher the cooling efficiency) was measured under different circulating water flow rate conditions, and the experimental environmental temperature was 10 - 15°C. The following table shows the cooling water temperature difference data of the experimental group and the control group.

[0030]

[0031] It can be seen from the above comparative experiments that the cooling tower structure of the present invention can have a wider high-efficiency cooling range, improving the cooling efficiency of the cooling tower under all working conditions.

[0032] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A heat exchange optimization structure of a power plant cooling tower, comprising a cooling tower body (1), a water inlet pipe (2) installed at the top of the cooling tower body (1), and a water outlet pipe (3) installed at the bottom of the cooling tower body (1), characterized in that: A guide fan (4) is installed above the interior of the cooling tower body (1), a filling groove (5) is installed below the interior of the cooling tower body (1), an air inlet groove (6) is arranged on the inner wall of the cooling tower body (1), and an air inlet pipe (7) connected to the air inlet groove (6) is arranged in the side wall of the cooling tower body (1); The deflector fan (4) comprises a bottom plate (8), a plurality of arc-shaped vertical plates (9) are annularly fixed to the edge of the bottom plate (8), the arc-shaped vertical plates (9) protrude outward, a deflector plate (10) is installed on the inner side of the arc-shaped vertical plates (9), a first through hole (11) is arranged at the center of the bottom plate (8), and a plurality of fan blades (12) are evenly arranged between the first through hole (11) and the edge of the bottom plate (8); A plurality of layers of conical mesh plates (13) are arranged in the filling groove (5), the adjacent conical mesh plates (13) are oriented in opposite directions, and the height of the conical mesh plates (13) in the top layer gradually decreases from the middle to the edge.

2. The heat exchange optimization structure of a power plant cooling tower according to claim 1, characterized in that: The air inlet slot (6) is located on one side of the air guide fan (4), and the air outlet direction of the air inlet slot (6) is inclined downward and toward the air guide fan (4).

3. The heat exchange optimization structure of a power plant cooling tower according to claim 2, characterized in that: The guide plate (10) is axially connected to the inner wall of the arc-shaped vertical plate (9), and a pneumatic tappet (24) is installed between the guide plate (10) and the arc-shaped vertical plate (9). The angle between the guide plate (10) and the arc-shaped vertical plate (9) faces the rotation direction of the guide fan (4).

4. The heat exchange optimization structure of a power plant cooling tower according to claim 3, characterized in that: The guide plate (10) is provided with a first guide groove (25), and the height of one end of the first guide groove (25) close to the arc-shaped vertical plate (9) is lower than the height of the other end of the first guide groove (25).

5. The heat exchange optimization structure of a power plant cooling tower according to claim 4, characterized in that: A second guide groove (20) is provided at the axial connection end between the guide plate (10) and the arc-shaped vertical plate (9); a rotating shaft (15) is installed on the arc-shaped vertical plate (9) via an axis frame (14); and the rotating shaft (15) is fixedly connected to the second guide groove (20).

6. The heat exchange optimization structure of a power plant cooling tower according to claim 5, characterized in that: An extension piece (16) is installed on the side of the second guide groove (20) facing away from the arc-shaped vertical plate (9), and the included angle between the extension piece (16) and the guide plate (10) is 15-25 degrees.

7. The heat exchange optimization structure of a power plant cooling tower according to claim 3, characterized in that: A plurality of mutually parallel partitions (17) are fixed between adjacent conical mesh plates (13), and a plurality of water-permeable grooves (18) are arranged on the partitions (17).

8. The heat exchange optimization structure of a power plant cooling tower according to claim 7, characterized in that: The water-permeable grooves (18) on adjacent partitions (17) on the same layer are arranged in a staggered manner.

9. The heat exchange optimization structure of a power plant cooling tower according to claim 7, characterized in that: An angle steel bar (19) is fixed between adjacent partitions (17) on the same layer, the tip of the angle steel bar (19) is facing upward, a plurality of second through holes (21) are arranged on the surface of the angle steel bar (19), mesh plates (22) are respectively installed on the bottom of the angle steel bar (19) and the second through holes (21), and the internal cavity formed by the angle steel bar (19) and the mesh plate (22) is not filled with fillers.

10. The heat exchange optimization structure of a power plant cooling tower according to claim 9, characterized in that: A plurality of air inlets (23) are arranged at the bottom of the cooling tower body (1); the air inlets (23) are connected to the bottom edge of the side wall of the filling groove (5); and the air inlet direction of the air inlet (23) is tangent to the side wall of the filling groove (5).

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