Wet cooling tower based on three-zone collaborative optimization under crosswind effect

Abstract

The utility model discloses a wet cooling tower based on three-zone collaborative optimization under the crosswind effect, which belongs to the technical field of cooling towers and comprises a water distribution zone with an oval partition, a filler zone with an oval partition is arranged at the bottom of the water distribution zone with the oval partition, and a dry-wet mixed rain zone with non-centrosymmetric arrangement is arranged at the bottom of the filler zone with the oval partition; the water distribution area of the oval subarea comprises an inner water distribution oval area and an outer water distribution area, and the short half axis of the oval of the inner water distribution oval area faces the windward side and the leeward side; the filler area of the oval partition comprises a filler inner oval area and a filler outer area; a plurality of different splitter plates are arranged in the dry-wet mixed rain area which is arranged in a non-centrosymmetric mode, and the splitter plates are distributed in a non-centrosymmetric mode with the cooling tower as the center. Therefore, an aerodynamic field in the tower is reconstructed, gas-water distribution is improved, heat and mass transfer is enhanced, the influence of crosswind deterioration is relieved, and the cooling performance of the cooling tower is deeply improved.

Description

Technical Field

[0001] The utility model relates to the technical field of cooling towers for thermal (nuclear) power plants and industrial cooling equipment, and in particular to a wet cooling tower based on three-zone collaborative optimization under a crosswind effect. Background Art

[0002] The statements in this section merely provide background technical information related to the present invention and do not necessarily constitute prior art.

[0003] Cooling towers are a crucial component of the cold-end system of thermal (nuclear) power plants, and their performance significantly impacts unit output, safe operation, and economic efficiency. Research has shown that for a 660MW supercritical unit's wet cooling tower, a 1.6°C increase in outlet water temperature increases coal consumption by 1.14g / kWh. Furthermore, increased outlet water temperature reduces condenser vacuum, seriously impacting unit safety. Therefore, optimizing cooling tower performance can improve unit power generation efficiency, achieve efficient energy utilization, and reduce carbon emissions.

[0004] As thermal power generation units continue to develop towards larger capacities, higher parameters, and higher efficiencies, such as supercritical and ultra-supercritical units, the capacity of natural draft wet cooling towers is increasing. However, due to the excessively large base diameter of large wet cooling towers, outside air has difficulty reaching the tower core, resulting in uneven radial ventilation distribution within the tower, low utilization of the tower core filler, and reduced cooling efficiency.

[0005] To address these issues, research has been conducted on energy conservation and efficiency improvements in wet cooling towers, focusing on a single heat and mass transfer zone (or two of these zones), and corresponding efficiency-enhancing measures have been proposed. For example, patent CN116123887A discloses a three-zone synergistically efficient wet cooling tower and power generation equipment. This system achieves synergistic efficiency by providing a two-zone water distribution zone, two-zone packing zones with unequally spaced packing, and a centrally symmetrically distributed dry-wet mixed rain zone.

[0006] But in actual operation, Figure 1 and Figure 2 As shown, under crosswind, the flow field in the tower in the above-mentioned prior art no longer presents an axisymmetric distribution (Y=0m section) or a center-symmetrical distribution (Z=12.5m section), and a large area of ​​low wind speed area appears on the windward side, and the air flow rate in the main heat and mass transfer area on the windward side is relatively low. This is because the air flow rate entering the tower on the windward side is relatively high, and after the air enters the tower, it is difficult to turn and flow upward due to inertia, resulting in a large area of ​​low wind speed area above the windward side air inlet. At the same time, according to Bernoulli's equation, there is a low-pressure area at the windward side air inlet, which will force part of the wet air on the windward side to flow back, and in particularly severe cases, a longitudinal vortex will be generated. In addition, the low wind speed area in the center of the tower appears to be approximately elliptical, and moves toward the leeward side as a whole. As shown Figure 3 and Figure 4As shown in the figure (Note: Y axis is the crosswind direction, X axis is the vertical crosswind direction, and Z axis is the height direction), it can be seen from the temperature field cloud map that the temperature field in the tower in the prior art no longer presents an axisymmetric distribution (Y = 0m section) or a center-symmetric distribution (Z = 12.5m section). The central high-temperature area of ​​the entire tower shifts to the windward side, and a large area of ​​low-temperature area appears on the leeward side; the central high-temperature area of ​​the tower in the filling area ( Figure 4 The cross section (Z = 12.5m, in the fill area) shifts toward the leeward side and takes on a nearly elliptical shape. This indicates that the presence of crosswinds further disrupts the uniformity of the air flow field within the tower, inducing vortices and severely degrading the cooling tower's performance. Utility Model Content

[0007] In response to the above problems, the utility model provides a wet cooling tower based on the coordinated optimization of three zones under the crosswind effect, which can solve the problems of uneven air-water ratio distribution in the tower, high water temperature in the center area of ​​the tower, and poor ventilation in the wet cooling tower in the existing technology under crosswind environment.

[0008] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0009] A wet cooling tower based on three-zone coordinated optimization under crosswind effect, comprising an elliptical partitioned water distribution zone, an elliptical partitioned filler zone at the bottom of the elliptical partitioned water distribution zone, and a non-center-symmetrically arranged dry-wet mixed rain zone at the bottom of the elliptical partitioned filler zone;

[0010] The elliptical partitioned water distribution area includes an inner water distribution elliptical area and an outer water distribution area, and the elliptical semi-axis of the inner water distribution elliptical area faces the windward side and the leeward side;

[0011] The elliptical partitioned filling area includes an inner elliptical filling area and an outer filling area, wherein the elliptical semi-axis of the inner elliptical filling area faces the windward side and the leeward side;

[0012] A plurality of different diverter plates are arranged in the non-centrally symmetrically arranged dry-wet mixed rain zone, and each diverter plate is distributed non-centrally symmetrically with respect to the center of the cooling tower.

[0013] Preferably, the outer water distribution area is arranged around the inner water distribution elliptical area; the midpoints of the two foci of the inner water distribution elliptical area and the center of the outer water distribution area are the same point.

[0014] Preferably, the elliptical partitioned water distribution area adopts an elliptical two-partition water distribution form; specifically: the water sprinkling density of the inner elliptical area of ​​the water distribution is reduced, and the water sprinkling density of the outer area of ​​the water distribution is increased.

[0015] Preferably, the outer area of ​​the filler is arranged around the inner elliptical area of ​​the filler; the midpoints of the two foci of the inner elliptical area of ​​the filler and the center of the outer area of ​​the filler are the same point.

[0016] Preferably, the minor semi-axis of the ellipse in the inner elliptical area of ​​the filler is coaxial with the minor semi-axis of the ellipse in the inner elliptical area of ​​the water distribution.

[0017] Preferably, the filler area of ​​the elliptical partition adopts an elliptical two-partition filler non-uniform arrangement form; specifically: the filler is arranged in the inner elliptical area with a large sheet spacing, and the filler is arranged in the outer area with a small sheet spacing.

[0018] Preferably, the lower part of the diverter plate is a dry area, and the rain area outside the dry area is a wet area; a gap is left between each diverter plate and the filling area of ​​the elliptical partition to ensure that there is ventilation space on the upper part of the diverter plate.

[0019] Preferably, the diverter plate is installed obliquely in the tower, with the higher side of the diverter plate being the upper edge; the diverter plate is installed at the periphery of the rain zone in a manner that the upper edge of the diverter plate is parallel to the radial direction of the cooling tower.

[0020] Preferably, when the diverter plate is located on the windward side, the dry area volume and the dry area inlet area are smaller than the dry area volume and the dry area inlet area of ​​the diverter plate located on the leeward side; the closer the diverter plate is to the windward side, the smaller its length and width are, and the closer the diverter plate is to the leeward side, the larger its length and width are.

[0021] Preferably, the non-centrosymmetrically arranged dry-wet mixed rain zone adopts a non-centrosymmetrical dry-wet mixed rain zone mode.

[0022] Compared with the prior art, the advantages and positive effects of this utility model are:

[0023] The utility model sets an elliptical partitioned water distribution area, an elliptical partitioned filling area and a non-center-symmetrically arranged dry-wet mixed rain area; the water distribution area adopts an elliptical two-partitioned water distribution form, the filling area adopts an elliptical two-partitioned filling non-uniform arrangement form, and the rain area adopts a non-center-symmetrical dry-wet mixed rain area mode, forming a three-zone collaborative optimization technology under a crosswind environment; accurately optimizes the deteriorated heat and mass transfer in the central area of ​​the tower, and enhances the cooling performance; reconstructs the aerodynamic field in the tower, improves the air-water distribution, strengthens the heat and mass transfer, alleviates the impact of crosswind deterioration, and deeply improves the cooling performance of the cooling tower. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0025] Figure 1 This is the air velocity field cloud diagram of the wet cooling tower at Y=0m in the prior art when the crosswind speed is v=5m / s;

[0026] Figure 2This is the air velocity field cloud diagram of the cross section Z=12.5m of the wet cooling tower in the prior art when the crosswind speed is v=5m / s;

[0027] Figure 3 This is the air temperature field cloud diagram of the wet cooling tower at Y=0m in the prior art when the crosswind speed is v=5m / s;

[0028] Figure 4 This is the temperature field cloud diagram of the circulating water in the wet cooling tower at Z=12.5m in the prior art when the crosswind speed is v=5m / s;

[0029] Figure 5 1. It is a schematic diagram of the three-zone coordinated optimization of a wet cooling tower under the crosswind effect of an embodiment of the present invention;

[0030] Figure 6 It is a schematic diagram of the water distribution area of ​​the elliptical partition of the embodiment of the utility model;

[0031] Figure 7 Schematic diagram of the elliptical partitioned filling area of ​​an embodiment of the present invention;

[0032] Figure 8 Schematic diagram of dry-wet mixed rain area arranged non-centrosymmetrically in an embodiment of the present utility model;

[0033] Figure 9 This is the air velocity field cloud diagram of the cross section Z=12.5m of the wet cooling tower in the embodiment when the crosswind speed is v=5m / s;

[0034] Figure 10 This is the temperature field cloud diagram of the circulating water in the wet cooling tower at Z=12.5m in the embodiment when the crosswind speed is v=5m / s;

[0035] In the picture:

[0036] 1. Elliptical partitioned water distribution area; 2. Elliptical partitioned filler area; 3. Non-centrally symmetrically arranged dry-wet mixed rain area; 4. Inner elliptical area of ​​water distribution; 5. Outer water distribution area; 6. Inner elliptical area of ​​filler; 7. Outer filler area; 8. Diverter plate; 9. Dry area; 10. Wet area. DETAILED DESCRIPTION

[0037] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0038] The present invention is described in detail below with reference to the accompanying drawings. This embodiment discloses a wet cooling tower based on the coordinated optimization of three zones under the crosswind effect. Figure 5As shown, it includes an elliptically partitioned water distribution area 1, an elliptically partitioned filling area 2 and a non-center-symmetrically arranged dry-wet mixed rain area 3; the elliptically partitioned water distribution area 1 is above the elliptically partitioned filling area 2, and the elliptically partitioned filling area 2 is above the dry-wet mixed rain area 3 which is non-center-symmetrically arranged.

[0039] like Figure 6 、 Figure 7 、 Figure 8 As shown, the elliptical partitioned water distribution area 1 adopts an elliptical two-partition water distribution form, the elliptical partitioned filling area 2 adopts an elliptical two-partition filling non-uniform arrangement form, and the non-center-symmetrical dry-wet mixed rain area 3 adopts a non-center-symmetrical dry-wet mixed rain area mode.

[0040] The elliptical bipartition is chosen because, for example, Figure 2 and Figure 4 As shown, the low wind speed area and high water temperature area in the center of the tower are both elliptical in distribution. Therefore, based on this, the utility model adopts an elliptical partition configuration mode in both the water distribution area and the filling area to accurately optimize the deteriorated heat and mass transfer in the central area of ​​the tower and enhance the cooling performance.

[0041] like Figure 6 As shown, in this embodiment, the implementation plan of the elliptical partitioned water distribution area 1 is as follows: the elliptical partitioned water distribution area 1 includes an inner water distribution elliptical area 4 and an outer water distribution area 5. The outer water distribution area 5 is arranged around the inner water distribution elliptical area 4 to redistribute the water sprinkling density of the inner water distribution elliptical area 4 and the outer water distribution area 5; specifically: under the rated total circulating water flow rate, the water sprinkling density of the inner water distribution elliptical area is appropriately reduced, and the water sprinkling density of the outer water distribution area is increased. The purpose of this setting is that appropriately reducing the water distribution in the inner area can reduce the ventilation resistance in the inner area. It should be noted that the short semi-axis of the ellipse of the inner water distribution elliptical area 4 needs to face the windward side and the leeward side, that is, parallel to the direction of the wind speed.

[0042] It can be understood that the midpoints of the two foci of the inner water distribution elliptical area 4 and the center of the circle of the outer water distribution area 5 are the same point.

[0043] like Figure 7 As shown, in this embodiment, the implementation plan of the elliptical partitioned filler area 2 is as follows: the elliptical partitioned filler area 2 includes an inner elliptical filler area 6 and an outer filler area 7. The outer filler area 7 is arranged around the inner elliptical filler area 6, and the filler sheet spacing of the inner elliptical filler area 6 and the outer filler area 7 is reconfigured; specifically: the filler inner elliptical filler area is arranged with large-sheet-pitch filler, and the filler outer filler area is arranged with small-sheet-pitch filler. Among them, the ventilation performance of the filler with large sheet spacing is better, but the thermal performance is poor; the thermal performance of the filler with small sheet spacing is better, but the resistance performance is poor. It should be noted that the minor semi-axis of the ellipse in the inner elliptical filler area 6 needs to face the windward side and the leeward side, that is, parallel to the direction of the wind speed.

[0044] It can be understood that the midpoints of the two foci of the inner elliptical area 6 of the filler and the center of the circle of the outer area 7 of the filler are the same point.

[0045] like Figure 8 As shown, in this embodiment, the implementation scheme for the non-center-symmetrical arrangement of dry-wet mixed rain zones 3 is as follows: multiple different diverter plates 8 are installed within the non-center-symmetrical arrangement of dry-wet mixed rain zones 3. Each diverter plate 8 is installed at the periphery of the rain zone in a direction parallel to the radial direction of the cooling tower. The lower portion of the diverter plate 8 constitutes a dry zone 9, and the rain zone area outside the dry zone 9 constitutes a wet zone 10. Note that a gap is left between each diverter plate 8 and the elliptical partitioned filler area 2 to ensure ventilation space above the diverter plate.

[0046] like Figure 8 As shown, in this embodiment, the number of the diverter plates 8 is six, and the diverter plates are installed in the tower at a certain angle, with the higher side of the diverter plates being the upper edge, that is, the diverter plates are installed obliquely in the tower. The reason for the inclined setting is to allow water to flow down along the inclined diverter plates; the diverter plates are installed on the periphery of the rain zone in a manner such that the upper edge of the diverter plates is parallel to the radial direction of the cooling tower.

[0047] like Figure 8 As shown, all diverter plates are distributed non-symmetrically with respect to the center of the cooling tower. Specifically, a diverter plate is provided on the windward side facing the crosswind direction, and the upper edge of the diverter plate is installed on the Y-axis (parallel to the crosswind direction), and the upper edges of the other diverter plates are evenly installed at intervals of 60° along the circumferential direction.

[0048] It must be pointed out that the parameters of the six diverter plates are not identical: first, the diverter plate on the windward side is the smallest in length and width; second, two diverter plates of different sizes are provided on each side of Side I and Side II, with the smaller diverter plate closer to the windward side and the larger diverter plate closer to the leeward side, and the corresponding diverter plates on both sides have the same length and width; finally, the diverter plate on the leeward side is the largest in length and width. The overall trend is that the closer to the windward side, the smaller the length and width of the diverter plate, and the closer to the leeward side, the larger the length and width of the diverter plate. In some embodiments, the number of diverter plates can be set to a larger number according to actual needs, and they must be evenly spaced.

[0049] like Figure 8 As shown, the diverter plate shape is rectangular, for example. Each diverter plate 8 is non-centrosymmetrically distributed about the center of the cooling tower. Specifically, the dry area volume and dry area inlet area of ​​the diverter plate on the windward side are smaller than those on the leeward side, and the dry area volume and dry area inlet area on sides I and II are equal. In other words, along the minor semi-axis of the ellipse, in accordance with the crosswind direction, the length and width of the diverter plate closer to the windward side decreases, while the length and width of the diverter plate closer to the leeward side increases.

[0050] The reason for this setting is: Figure 1As shown, the air inlet velocity on the windward side of the rain area is larger, while the air flow velocity on the leeward side is smaller. In order to comprehensively optimize the air intake effect of the dry area, the utility model reduces the dry area volume and the dry area inlet area on the windward side, increases the dry area volume and the dry area inlet area on the leeward side, and reasonably configures the diverter plate to achieve the purpose of precise optimization under crosswind.

[0051] In this embodiment, the water distribution area adopts an elliptical two-zone water distribution form, the filling area adopts an elliptical two-zone filling non-uniform arrangement form, and the rain zone adopts a non-centrally symmetric dry-wet mixed rain zone mode, thereby forming a three-zone collaborative optimization technology for the wet cooling tower in a crosswind environment.

[0052] In this embodiment, the working principle of the three-zone collaborative optimization technology of the wet cooling tower in a crosswind environment is as follows:

[0053] In a crosswind environment, the outside air on the windward side enters the tower from the dry area. At this time, the air velocity is relatively fast. A shorter splitter plate is configured to slow down the air's growth rate, allowing it to conduct heat and mass transfer with the water droplets and flow all the way to the edge of the short semi-axis of the elliptical partition of the packing in the center of the tower.

[0054] like Figure 3 As shown in the figure, the distance between the leading edge of the windward splitter in the length direction and the edge of the short semi-axis of the elliptical partition is large, which can fully utilize the high-speed and low-temperature air to cool the water droplets;

[0055] When the airflow reaches the elliptical partition in the center of the tower, the water density in the elliptical area of ​​the water distribution is reduced, and the elliptical area of ​​the filler uses large-pitch fillers, that is, the flow resistance in the center of the tower is significantly reduced, which can fully carry out heat and mass transfer and cool the circulating water;

[0056] The outside air on the leeward side enters the tower from the dry area. At this time, the air flow rate is slow. A longer diverter plate is configured to increase the air speed. After that, it contacts and exchanges heat with the water droplets and flows all the way to the edge of the short semi-axis of the elliptical partition of the packing in the center of the tower.

[0057] like Figure 3 As shown in the figure, the distance between the leading edge of the leeward side splitter plate in the length direction and the edge of the short semi-axis of the elliptical partition is small, which allows the air to enter the center area of ​​the tower with a higher flow rate;

[0058] When the airflow reaches the elliptical partition at the center of the tower, the process is the same as that described on the windward side;

[0059] On sides I and II, the outside air enters the tower from the dry area. At this time, the air flow rate is also slow. Properly configuring a longer diverter plate can increase the air speed. Since sides I and II face the edge of the long semi-axis of the elliptical partition, the diverter plate length can be appropriately increased.

[0060] When the airflow reaches the elliptical partition at the center of the tower, the process is the same as that described on the windward side;

[0061] Based on the above analysis, in a crosswind environment, the cooling tower simultaneously implements elliptical two-zone water distribution, elliptical two-zone non-uniform filling, and non-center-symmetric dry-wet mixed rain zone. The three optimization technologies of the three zones (water distribution zone, filling zone, and rain zone) are coordinated and matched with each other to synergistically enhance the cooling circulating water.

[0062] like Figure 9 、 Figure 10 As shown, a wet cooling tower that implements elliptical two-zone water distribution, elliptical two-zone non-uniform packing, and a non-center-symmetric dry-wet mixed rain zone reduces the low wind speed area on the windward side and in the center of the rain zone, significantly increases the air velocity on the leeward side and in the main heat and mass transfer area, and reduces the high water temperature area in the center, sides I, and II of the tower, achieving a more uniform water temperature distribution throughout the tower. This new design comprehensively optimizes the air velocity field and circulating water temperature field within the tower.

[0063] The utility model focuses on the coordinated optimization of efficiency-enhancing technologies in the water distribution area, filler area and rain area under crosswind environments, strengthens heat and mass transfer, alleviates the effects of crosswind deterioration, and deeply improves the cooling performance of the cooling tower.

[0064] Although the above description of the specific implementation methods of the present invention is combined with the accompanying drawings, it does not limit the scope of protection of the present invention. Technical personnel in the relevant field should understand that on the basis of the technical solution of the present invention, various modifications or deformations that can be made by technical personnel in this field without creative work are still within the scope of protection of the present invention.

Claims

1. A wet cooling tower based on three-zone collaborative optimization under crosswind effect, characterized in that: The water distribution area includes an elliptical partition, the bottom of the water distribution area is an elliptical partition filling area, and the bottom of the elliptical partition filling area is a dry-wet mixed rain area arranged non-centrally symmetrically; The elliptical partitioned water distribution area includes an inner water distribution elliptical area and an outer water distribution area, and the elliptical semi-axis of the inner water distribution elliptical area faces the windward side and the leeward side; The elliptical partitioned filling area includes an inner elliptical filling area and an outer filling area, wherein the elliptical semi-axis of the inner elliptical filling area faces the windward side and the leeward side; A plurality of different diverter plates are arranged in the non-centrally symmetrically arranged dry-wet mixed rain zone, and each diverter plate is distributed non-centrally symmetrically with respect to the center of the cooling tower.

2. A wet cooling tower based on three-zone collaborative optimization under crosswind effect according to claim 1, characterized in that: The outer water distribution area is arranged around the inner water distribution elliptical area; the midpoints of the two foci of the inner water distribution elliptical area and the center of the outer water distribution area are the same point.

3. A wet cooling tower based on three-zone collaborative optimization under crosswind effect according to claim 1, characterized in that: The water distribution area of ​​the elliptical partition adopts an elliptical two-partition water distribution form; specifically: the water sprinkling density of the inner elliptical area of ​​the water distribution is reduced, and the water sprinkling density of the outer area of ​​the water distribution is increased.

4. A wet cooling tower based on three-zone collaborative optimization under crosswind effect according to claim 1, characterized in that: The outer area of ​​the filler is arranged around the inner elliptical area of ​​the filler; the midpoints of the two foci of the inner elliptical area of ​​the filler and the center of the outer area of ​​the filler are the same point.

5. The wet cooling tower based on three-zone coordinated optimization under crosswind effect according to claim 1, characterized in that: The minor semi-axis of the ellipse in the inner elliptical area of ​​the filler is coaxial with the minor semi-axis of the ellipse in the inner elliptical area of ​​the water distribution.

6. A wet cooling tower based on three-zone collaborative optimization under crosswind effect according to claim 1, characterized in that: The elliptical partitioned filler area adopts an elliptical two-partitioned filler non-uniform arrangement form; specifically, the inner elliptical area of ​​the filler is arranged with a large-particle-pitch filler, and the outer area of ​​the filler is arranged with a small-particle-pitch filler.

7. A wet cooling tower based on three-zone coordinated optimization under crosswind effect according to claim 1, characterized in that: The lower part of the diverter plate is a dry area, and the rain area outside the dry area is a wet area; a gap is left between each diverter plate and the filling area of ​​the elliptical partition to ensure that there is ventilation space on the upper part of the diverter plate.

8. The wet cooling tower based on three-zone coordinated optimization under crosswind effect according to claim 1, characterized in that: The diverter plate is installed obliquely in the tower, with the higher side of the diverter plate being the upper edge; the diverter plate is installed outside the rain zone in a manner that the upper edge of the diverter plate is parallel to the radial direction of the cooling tower.

9. The wet cooling tower based on three-zone coordinated optimization under crosswind effect according to claim 1, characterized in that: When the diverter plate is located on the windward side, the dry area volume and the dry area inlet area are smaller than those of the diverter plate located on the leeward side; the length and width of the diverter plate closer to the windward side are smaller, and the length and width of the diverter plate closer to the leeward side are larger.

10. The wet cooling tower based on three-zone coordinated optimization under crosswind effect according to claim 1, characterized in that: The non-centrosymmetrically arranged dry-wet mixed rain area adopts a non-centrosymmetrical dry-wet mixed rain area mode.

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