Long circular type twisted tube falling film closed cooling tower

Abstract

An oblong twisted tube falling film closed cooling tower relates to the technical field of cooling towers and comprises a tower body, a plurality of vertical heat exchange tube groups are arranged in the tower body in parallel along the horizontal direction, each vertical heat exchange tube group comprises tube bundles which are arranged in parallel from top to bottom, and a plurality of oblong twisted heat exchange tubes are fixedly connected between the two tube bundles. The problems that in the prior art, fluid in a heat exchange pipe and the inner wall can be layered, heat exchange is affected, and the heat exchange efficiency is low are solved; according to the horizontal heat exchange tube bundle, cooling water collides with the heat exchange round tube for heat exchange, and noise generated by resonance of the coil tube is large; most of the filler and the heat exchange tube bundle are arranged up and down, and wind resistance is large. And a spray water pipe and a spray nozzle are arranged in the equipment, so that the spray nozzle is easy to block.

Description

Technical Field

[0001] The invention relates to the technical field of cooling towers, in particular to an oblong twisted tube falling film closed cooling tower. Background Art

[0002] As a high-efficiency cooling equipment, conventional closed cooling tower uses the latent heat of water evaporation to remove the heat of the medium, completes the cooling of the medium, and uses the recycling of cooling water to achieve the effect of water saving and cooling. Its basic structural type is that the heat exchange tube bundle is mostly a circular steel tube structure, the heat exchange tube bundle is placed horizontally (the medium flows horizontally), the filler is placed at the bottom of the heat exchange tube bundle, and the water sprayed on the heat exchange tube bundle by the spray water on the upper part of the heat exchange tube bundle is sprayed downward. The airflow driven by the axial flow fan flows upward from the bottom of the filler, and the cooling water outside the tube forms a water film on the outer wall of the heat exchange tube. Under the action of the airflow, through evaporation, a heat exchange process of heat transfer and mass transfer occurs outside the heat exchange tube, thereby realizing heat transfer.

[0003] A patent with a publication number of CN218821764U is disclosed in the prior art. The solution includes: an outer shell; a water collecting tank located in the lower part of the outer shell, used to hold cooling water; a heat exchange tube group installed in the outer shell, located above the water collecting tank, wherein the heat exchange tube group is composed of twisted tubes, and the horizontal spacing of the twisted tubes is the maximum diameter of the twisted tubes; a sprayer, located above the heat exchange tube group to spray cooling water on the heat exchange tube group, wherein the sprayer is composed of a spray water tank, a spray pipe and a plurality of basket-type nozzles fixed under the spray pipe, the spray water tank is installed on the outside of the outer shell, and the spray pipe and the plurality of nozzles are installed in the outer shell, and the spray pipe is connected to the spray water tank and the plurality of nozzles respectively; and a pumping system, installed on the outside of the outer shell, used to pump the cooling water in the water collecting tank to the spray water tank of the sprayer. The closed cooling tower has a compact structure, high heat exchange efficiency and low cost.

[0004] As the existing devices are used, the shortcomings of the technology are gradually exposed, mainly in the following aspects:

[0005] First, the existing heat exchange tube bundles generally use horizontal coils as heat exchange equipment, and most of the heat exchange tubes are smooth metal round tubes. The fluid in the heat exchange tubes will be stratified with the inner wall, affecting the heat exchange, resulting in low heat exchange efficiency; in addition, there are many heat exchange tubes and the manufacturing cost is high. These factors limit the use and promotion of traditional evaporative coolers in some occasions.

[0006] Second, in the horizontal heat exchange tube bundle, the cooling water collides with the heat exchange circular tube for heat exchange, and the coil is prone to resonance, generating a lot of noise. In addition, the cooling water flows from top to bottom, and the cooling water in the tube flows horizontally. The two flow in an alternating manner, and the logarithmic mean temperature difference is much smaller than that in pure countercurrent.

[0007] Third, most of the conventional closed cooling tower fillers are arranged up and down with the heat exchange tube bundle, with a larger size in the air inlet direction and a larger wind resistance, which in turn increases the fan power and reduces the heat dissipation efficiency.

[0008] Fourth, uneven water spraying is a common problem of conventional closed cooling towers. Due to the uneven water spraying, the required water spraying flow rate is larger, the water pump power is also increased, and the spray water pipe and nozzle are placed inside the equipment, the nozzle is easy to be blocked.

[0009] As can be seen from the above, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Summary of the invention

[0010] In view of the defects in the prior art, the present invention provides an oblong twisted tube falling film closed cooling tower to solve the problems in traditional technology that the fluid in the heat exchange tube will be stratified with the inner wall, affecting the heat exchange, resulting in low heat exchange efficiency; in the horizontal heat exchange tube bundle, the cooling water collides with the heat exchange circular tube for heat exchange, and the noise generated by the coil resonance is relatively large; most of the fillers are arranged up and down with the heat exchange tube bundle, and the wind resistance is also relatively large; and the spray water pipe and nozzle are placed inside the equipment, and the nozzle is easily blocked.

[0011] To achieve the above object, the present invention provides the following technical solutions.

[0012] The oblong twisted tube falling film closed cooling tower comprises a tower body, in which a plurality of vertical heat exchange tube groups are arranged in parallel in the horizontal direction, each of the vertical heat exchange tube groups comprises tube bundles arranged in parallel from top to bottom, and a plurality of oblong twisted heat exchange tubes are fixedly connected between two tube bundles.

[0013] As an optimized solution, cross-flow fillers are provided between adjacent vertical tube heat pipe groups and between the vertical tube heat pipe group on one side close to the inner wall of the tower body and the inner wall of the tower body.

[0014] As an optimized solution, a water spraying plate is provided above the cross-flow filler, and filler water spraying holes are opened on the water spraying plate corresponding to the filler.

[0015] As an optimized solution, the water spray pan is located below the tube bundle above, and is provided with a heat exchange tube water spray hole for avoiding the oblong twisted heat exchange tube. The spray water in the water spray pan flows downward along the outer surface of the tube bundle and forms a descending water film.

[0016] As an optimized solution, an air inlet hole is opened on the outer wall of the tower body near the cross-flow filler.

[0017] As an optimized solution, there are several contact points between adjacent oblong twisted heat exchange tubes along the length direction.

[0018] As an optimized solution, a water collector is provided on one side of the vertical heat exchange tube group close to the center of the tower body.

[0019] As an optimized solution, an axial flow fan is provided at the center of the top of the tower body, and the vertical heat exchange tube groups are arranged on both sides of the axial flow fan.

[0020] As an optimized solution, several tube bundles at the top are commonly connected to a medium inlet pipeline.

[0021] As an optimized solution, several tube bundles at the bottom are commonly connected to a medium outlet pipeline.

[0022] As an optimized solution, a water collecting tank is provided at the bottom of the tower body, a circulating water pump connected to the water collecting tank is provided on the tower body, and an outlet end of the circulating water pump is connected to the water spray tray through a pipeline.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The water holes of the heat exchange tubes of the water spraying plate are set on the outside of the oblong twisted heat exchange tubes. Under the action of gravity, the cooling water can evenly flow from the annular gap from top to bottom, forming a descending water film along the outer surface of the tube bundle. At the same time, under the action of a part of the airflow coming from the top, the flow rate of the cooling water forming the water film can be accelerated under the condition of the same water volume, so as to achieve the effect of heat exchange more efficiently;

[0025] 2. The long round twisted heat exchange tube can make the fluid circulate alternately in the lateral and longitudinal directions inside the tube. The twisted inner tube wall generates centrifugal force when the fluid flows inside the tube. Under the action of centrifugal force, the fluid fits tightly with the inner wall of the heat exchange tube, avoiding stratification between the fluid and the inner wall of the heat exchange tube when the fluid flows, thereby obtaining a higher heat exchange efficiency; the cooling water flows spirally from top to bottom along the outer tube wall outside the tube, enhancing the heat transfer inside the tube and completing the falling film cooling process;

[0026] 3. The filler and the vertical tube bundle of the long round twisted tube are arranged crosswise, so that the medium in the tube is cooled step by step, which can achieve a better cooling effect than the conventional closed cooling tower. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required in the specific embodiments or the prior art description. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual scale.

[0028] Figure 1 It is a structural schematic diagram of the present invention;

[0029] Figure 2 It is a schematic diagram of the structure of the present invention in a side view direction;

[0030] Figure 3 It is a schematic diagram of the structure of the oblong twisted heat exchange tube of the present invention;

[0031] Figure 4 for Figure 3 Schematic diagram of the cross section along A-A;

[0032] Figure 5 It is a schematic structural diagram of the water spraying plate of the present invention.

[0033] In the figure: 1-tube bundle; 2-water spraying plate; 3-axial flow fan; 4-packing; 5-water collector; 6-long round twisted heat exchange tube; 7-water collecting tank; 8-circulating water pump; 9-packing water spraying hole; 10-heat exchange tube water spraying hole. DETAILED DESCRIPTION

[0034] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0035] like Figures 1 to 5 As shown, the oblong twisted tube falling film closed cooling tower includes a tower body, in which a plurality of vertical heat exchange tube groups are arranged in parallel in the horizontal direction, each vertical heat exchange tube group includes tube bundles 1 arranged in parallel from top to bottom, and a plurality of oblong twisted heat exchange tubes 6 are fixedly connected between the two tube bundles 1.

[0036] Cross-flow fillers 4 are respectively arranged between adjacent vertical heat pipe groups and between the vertical heat pipe group on one side close to the inner wall of the tower body and the inner wall of the tower body.

[0037] A water spraying plate 2 is arranged above the cross-flow filler 4 , and filler water spraying holes 9 are opened on the water spraying plate 2 corresponding to the filler 4 .

[0038] The water spray pan 2 is located below the tube bundle 1 above, and is provided with a heat exchange tube water spray hole 10 for avoiding the oblong twisted heat exchange tube 6. The spray water in the water spray pan 2 flows downward along the outer surface of the tube bundle 1 and forms a descending water film.

[0039] An air inlet hole is provided on the outer wall of the tower body near the cross-flow filler 4 .

[0040] When the center distance between two adjacent oblong twisted heat exchange tubes 6 is equal to the outer major axis distance of the oblong twisted heat exchange tubes 6 , there are several contact points between the two oblong twisted heat exchange tubes 6 in the length direction.

[0041] In detail, the horizontal cross-section of the oblong twisted heat exchange tube 6 is an oblong shape, and the oblong shape includes a long end and a short end. Since the twisted tube is an oblong twisted heat exchange tube 6, when the center distance between two adjacent oblong twisted heat exchange tubes 6 is equal to the distance between the long axes of the tubes outside the oblong twisted heat exchange tubes 6, there are a number of contact points between the two oblong twisted heat exchange tubes 6, that is, when the center distance between the adjacent oblong twisted heat exchange tubes 6 is equal to the distance between the long axes of the tubes outside the oblong twisted heat exchange tubes 6, the long ends of the adjacent oblong twisted heat exchange tubes 6 are in contact with each other to form a number of contact points. The vibration of the tube bundle 1 when the flow rate of cooling water is large can be reduced through the number of contact points, thereby increasing the flow rate of the air outside the tube bundle 1, achieving the effect of strengthening the heat transfer performance of the air side outside the tube bundle 1, and reducing the collision noise between adjacent tube bundles 1 when the tube bundle 1 vibrates.

[0042] A water collector 5 is provided on one side of the vertical heat exchange tube group close to the center of the tower body.

[0043] An axial flow fan 3 is provided at the center of the top of the tower body, and the vertical heat exchange tube groups are arranged on both sides of the axial flow fan 3, and can be arranged on one side of the axial flow fan 3.

[0044] Several tube bundles 1 at the top are commonly connected to a medium inlet pipeline.

[0045] Several tube bundles 1 at the bottom are commonly connected to a medium outlet pipeline.

[0046] The medium inlet pipeline and the medium outlet pipeline are connected to both sides of the equipment through the inlet manifold and the outlet manifold respectively, which is convenient for connection with the user pipeline.

[0047] A water collecting tank 7 is provided at the bottom of the tower body, and a circulating water pump 8 connected to the water collecting tank 7 is provided on the tower body. The outlet end of the circulating water pump 8 is connected to the water spraying plate 2 through a pipeline.

[0048] The oblong twisted heat exchange tube 6 can be arranged in the same manner as the traditional horizontal coil, that is, a triangular difference arrangement, or can be arranged in an aligned manner (the present solution takes the example of an aligned arrangement), and the air inlet direction is a horizontal and vertical mixed air inlet. Due to the large air inlet area, the required fan static pressure is small, and the fan motor power is also small;

[0049] Therefore, more tube bundles 1 and fillers 4 can be arranged on both sides or one side of the transverse fan to increase the heat exchange area and improve the heat exchange capacity of the equipment;

[0050] Since the heat exchange tubes of the oblong twisted heat exchange vertical tube bundle 1 are placed vertically, a larger heat exchange surface can be obtained by increasing the height of the oblong twisted heat exchange vertical tube bundle 1, so that the oblong twisted tube falling film closed cooling tower occupies a smaller area for equipment with the same heat exchange area;

[0051] The long round twisted heat exchange tube 6 allows the fluid to circulate alternately in the lateral and longitudinal directions inside the tube. The twisted inner tube wall generates centrifugal force when the fluid flows inside the tube. Under the action of centrifugal force, the fluid fits tightly with the inner wall of the heat exchange tube, avoiding stratification between the fluid and the inner wall of the heat exchange tube when the fluid flows, thereby obtaining a higher heat exchange efficiency. The cooling water flows spirally from top to bottom along the outer tube wall outside the tube, strengthening the heat transfer inside the tube and completing the falling film cooling process;

[0052] The water holes of the water spray plate 2 are divided into two parts. One part is a large water spray hole, which is sleeved on the upper end of the oblong twisted heat exchange tube 6. The annular cooling water flows down from the large hole of the water spray plate 2 along the outer tube wall in a spiral, and finally flows to the water collecting tank 7, thereby strengthening the heat transfer in the tube and completing the falling film cooling process. The other part is a densely distributed small water spray hole, which is placed above the filler 4. The columnar cooling water flows from the water spray plate 2 to the upper end of the filler 4, and flows down along the inner surface of the filler 4 to the water collecting tank 7. The cooling water in the water collecting tank 7 is led to the upper water spray plate 2 by the circulating water pump 8 through the circulating pipeline, thus completing a cooling cycle. Since the water spray plate 2 is a uniform water spray hole through the static pressure of the cooling water in the water spray plate 2, the water spraying is very uniform, so the required water spraying amount is also small, and the power of the circulating water pump 8 is also relatively small. The water spray plate 2 is placed above the equipment, which is easy to observe and clean dirt;

[0053] The filler 4 is a cross-flow filler 4, which is placed side by side with the tube bundle 1 and staggered above the water collecting tank 7. Its function is to mix the cooling water flowing vertically with the cross-wind introduced by the axial flow fan 3, thereby reducing the temperature of the cooling water, and then the circulating water pump 8 leads it to the water spraying plate 2 above through the circulating pipeline to complete a cooling cycle. Since the size in the air inlet direction is thin, the air inlet resistance is very small, and the motor power of the axial flow fan 3 is small, so it is more energy-saving;

[0054] The water collecting tank 7 is placed below the tube bundle 1 and the filler 4 to collect cooling water. Since the required amount of cooling water is small, the volume of the water tank can be reduced while meeting the function of the equipment base.

[0055] The medium flows in the tube bundle 1 from top to bottom. When the cooling water forms a descending water film on the outer surface of the tube bundle 1 from top to bottom, the water film absorbs the heat of the medium in the tube bundle 1 to exchange heat and moisture and heat up. Part of the water vapor is taken away by the air, and the temperature of the cooling water is reduced, achieving a highly efficient cooling effect through the vertical falling film. Compared with the horizontal coil in the prior art, under the action of gravity, the cooling water forms a descending water film on the outer surface of the tube bundle 1 from top to bottom. At the same time, under the action of the cooling water, the flow rate of the cooling water forming the water film can be accelerated under the condition of the same water volume, and the cooling effect can be achieved more efficiently;

[0056] In detail, the direction of cooling water outside the tube bundle 1 is consistent with the direction of a part of air flow, and the descending water film flows along the axial direction of the tube bundle 1. Since the air and cooling water flow through the outer surface of the tube bundle 1 in the same direction, the water can be well covered on the outer surface of the tube bundle 1 by the wind force and form a descending water film, ensuring that the outer surface of the tube bundle 1 is completely wetted. This same-direction flow can reduce the possibility of dry spots or scaling formed on the windward surface of the tube bundle 1 due to air and water; at the same time, when in use, since the descending water film is consistent with the direction of a part of air flow, the flow speed of the descending water film is accelerated by the drive of the air flow, so that the outer surface of the tube bundle 1 is in a turbulent state, and then the boundary layer of the descending water film on the outer surface of the tube bundle 1 is thinner, which can not only make the heat exchange effect between the descending water film and the tube bundle 1 better, but also save the use rate of cooling water.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. Long round twisted tube falling film closed cooling tower, characterized by: It comprises a tower body, wherein a plurality of vertical heat exchange tube groups are arranged in parallel in the horizontal direction, each of the vertical heat exchange tube groups comprises tube bundles (1) arranged in parallel from top to bottom, and a plurality of oblong twisted heat exchange tubes (6) are fixedly connected between two tube bundles (1).

2. The oblong twisted tube falling film closed cooling tower according to claim 1 is characterized in that: Cross-flow fillers (4) are respectively provided between adjacent vertical tube heat pipe groups and between the vertical tube heat pipe group on one side close to the inner wall of the tower body and the inner wall of the tower body.

3. The oblong twisted tube falling film closed cooling tower according to claim 2 is characterized in that: A water spraying plate (2) is provided above the cross-flow filler (4), and filler water spraying holes (9) are provided on the water spraying plate (2) corresponding to the filler (4).

4. The oblong twisted tube falling film closed cooling tower according to claim 3 is characterized in that: The water spraying plate (2) is located below the tube bundle (1) located above, and a heat exchange tube water spraying hole (10) is provided on the water spraying plate (2) to avoid the oblong twisted heat exchange tube (6). The spraying water in the water spraying plate (2) flows downward along the outer surface of the tube bundle (1) to form a descending water film.

5. The oblong twisted tube falling film closed cooling tower according to claim 2 is characterized in that: An air inlet hole is provided on the outer wall of the tower body near the cross-flow filler (4).

6. The oblong twisted tube falling film closed cooling tower according to claim 1 is characterized in that: There are a number of contact points between adjacent oblong twisted heat exchange tubes (6) along the length direction.

7. The oblong twisted tube falling film closed cooling tower according to claim 1 is characterized in that: A water collector (5) is provided on one side of the vertical heat exchange tube group close to the center of the tower body.

8. The oblong twisted tube falling film closed cooling tower according to claim 1, characterized in that: An axial flow fan (3) is provided at the center of the top of the tower body, and the vertical heat exchange tube groups are arranged on both sides of the axial flow fan (3).

9. The oblong twisted tube falling film closed cooling tower according to claim 1, characterized in that: The plurality of tube bundles (1) at the top are commonly connected to a medium inlet pipeline, and the plurality of tube bundles (1) at the bottom are commonly connected to a medium outlet pipeline.

10. The oblong twisted tube falling film closed cooling tower according to claim 3, characterized in that: A water collecting tank (7) is provided at the bottom of the tower body, and a circulating water pump (8) connected to the water collecting tank (7) is provided on the tower body, and an outlet end of the circulating water pump (8) is connected to the water spraying plate (2) through a pipeline.

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