Variable-flow inter-tower flow equalizer of cooling tower

Abstract

The utility model provides a variable flow cooling tower inter-tower flow equalizer which comprises an outer pipe and an inner pipe, the lower side of the outer pipe is provided with a water inlet communicated with a cooling tower water inlet pipe, the upper side of the outer pipe is provided with an overflow port, the overflow port is connected with an overflow pipe, the upper portion and the lower portion of the inner pipe are not sealed, the inner pipe is located in the lower half portion of the outer pipe, and the lower end of the inner pipe extends out of the outer pipe. The bottom of the outer pipe and the outer side of the inner pipe are closed, so that inflow water cannot flow out from the bottom of the outer pipe, the overflow pipe extends into a cooling tower water distribution disc, and the bottom end of the overflow pipe is higher than the highest water surface which the water distribution disc possibly reaches. The utility model can effectively eliminate the siphon advantage of the water inlet pipe of the cooling tower, can ensure the balance of the water volume of the system when the cooling tower is started and the water volume suddenly becomes large and small, adapts to the continuous change of the cooling water flow, and continuously keeps the balance of the water volume between the cooling towers under the condition of variable flow, thereby improving the cooling efficiency. Therefore, high efficiency of the cross-flow type cooling tower can be guaranteed, and the cross-flow type cooling tower is suitable for most common cross-flow type cooling towers in the current market.

Description

Technical Field

[0001] The utility model belongs to the technical field of air-conditioning refrigeration, and particularly relates to a variable-flow cooling tower inter-tower flow equalizer. Background Art

[0002] A cooling tower is a key device in the technical field of air-conditioning refrigeration, mainly used to dissipate the condensation heat of a water-cooled refrigeration unit to ensure the normal and efficient operation of the refrigeration unit. Generally, an air-conditioning refrigeration system consists of multiple cooling towers. Each cooling tower has at least two symmetrically arranged water distribution trays in the front and back. Each water distribution tray has a water inlet pipe with an inverted U-shaped structure. The water outlet of the water inlet pipe is connected to the inside of the water distribution tray. When the flow rate is large, the water level in the water tray rises and submerges the water outlet, thus generating a siphon.

[0003] During the actual operation process, each time when starting up, since the water flow reaching each cooling tower is sequential and the resistance is also different, the water level in the water tray will rise at different speeds. For the water tray with a faster rising water level, when the water level exceeds the water inlet, a siphon is formed and a siphon advantage is obtained. The formation process of the siphon advantage and its influence on the hydraulic balance between cooling towers are as follows: Figure 4 is a schematic diagram of the water inlet pipe of the cooling tower. This figure shows the state when the cooling water pump is stopped. At this time, the water levels in the two water trays are 0. If the cooling water pump is started to supply water at this time, the bottom water pressure of the left and right water inlet pipes must reach above H1 to send water into the water tray. Figure 5 is the situation after the cooling water pump is started. At this time, the water volume in the right water inlet pipe is larger, resulting in the water level in the right water tray rising first and exceeding the water inlet, causing a siphon to form in the right pipe. Due to the existence of the siphon, the bottom water supply pressure on the right only needs to reach H2 to send water into the water tray, while the left still needs to reach H1. At this time, in order to balance the flow between the two water trays, V2 needs to be closed to increase a certain resistance h so that H2 + h = H1, thereby re-establishing a rough balance between the two. One situation after balance can be seen in Figure 6 , in the figure, it is assumed that the water level on the left still has not exceeded the water inlet and the right still maintains the siphon state. This situation often exists in actual operation. However, this rough balance state is also temporary. When the system is shut down and started again, since the right valve is closed and the resistance becomes larger, the advantage then comes to the left pipe, as shown in Figure 7 , when the cooling water pump is started again, the left side only needs a pressure of H1 to send water into the water tray, while the right side needs to reach H1 + h to send water into the water tray. Obviously, the left side will form a siphon first at this time. In order to balance the flow between the two water trays, the valve has to be adjusted again, opening V2 and closing V1, and a new balance is formed, as shown in Figure 8 and Figure 9 .

[0004] Due to the existence of an inverted U-shaped elbow in the inlet pipe, siphon may be formed in the inlet pipe, and the pipes forming siphon are not in the same order. The inlet pipe that forms siphon first will gain siphon advantage, while a part of the lagging pipes will not be able to form siphon, and in severe cases, there may even be no water flowing out. For the inlet pipe with siphon advantage, its water volume is much larger than that of the inlet pipe without siphon, which leads to uneven water volume distribution among the cooling towers. Although the siphon advantage can be temporarily eliminated through valve adjustment to achieve approximate balance, when the system water volume changes or the machine stops and starts again, a new siphon advantage will be formed, and the distribution of the pipes with siphon advantage may be very different from the situation after the previous adjustment to balance. This is also the greatest harm of siphon advantage, that is, the distribution of siphon advantage is dynamically changing. During each start-up or the period of increasing or decreasing the number of water pumps, the number and position of the inlet pipes that form or lose siphon advantage are uncertain, which brings great trouble to daily management. Utility Model Content

[0005] In order to eliminate the harm of siphon advantage and facilitate the daily management of the cooling tower, the present utility model proposes a variable water volume cooling tower inter-tower flow equalizer capable of eliminating siphon advantage, which replaces the outlet section of the inlet pipe. See Figure 3 ., which can fundamentally eliminate the siphon advantage of the cooling tower inlet pipe and maintain the water volume balance among the cooling towers under variable flow conditions.

[0006] The technical solution of the present utility model is realized as follows: A variable flow cooling tower inter-tower flow equalizer includes an outer pipe and an inner pipe. An inlet connected to the cooling tower inlet pipe is provided on the lower side of the outer pipe, and an overflow port is provided on the upper side. The overflow port is connected with an overflow pipe. The inner pipe is not sealed at the top and bottom, is located inside the lower half of the outer pipe, and the lower end extends out of the outer pipe. The bottom of the outer pipe is closed with the outside of the inner pipe, so that the inlet water cannot flow out from the bottom of the outer pipe. The overflow pipe extends into the cooling tower water distribution tray, and its bottom end is higher than the highest water surface that the water distribution tray may reach.

[0007] Further, a flow limiting plate is provided between the top end of the inner pipe and the overflow port inside the outer pipe, and a flow limiting hole is opened on the flow limiting plate.

[0008] Further, a plurality of water inlet slits are opened on the upper side of the inner pipe.

[0009] Preferably, the lengths of the water inlet slits are different, the tops are aligned, the bottoms are staggered in height, and the lowest point is higher than the inlet.

[0010] The beneficial effects of the present utility model:

[0011] 1. The flow equalizer is always in communication with the atmosphere. Water flow must pass through the flow equalizer before entering the water distribution tray, during which the siphon phenomenon can no longer form, thus fundamentally eliminating the siphon advantage and ensuring that each tower has the same water pressure condition when the cooling tower is started each time, so as to ensure the balanced distribution of water flow among the cooling towers.

[0012] 2. The inner pipe adopts a side slit type water inlet. The water output corresponds to the water level height. When the water volume of a certain tower is large, the water level height rises, and the water inlet pressure of the outer pipe increases. The increased pressure in turn inhibits the water inflow, and finally reaches balance, which can achieve the water volume balance among the towers when the water volume is small.

[0013] 3. The function of the flow limiting plate is to limit the water volume of several cooling towers with excessive water volume when the water volume is large, and balance the overflow water volume among the towers. Because the larger the overflow volume, the greater the resistance, and vice versa, thus ensuring the balance among the towers during the period of excessive water volume.

[0014] 4. The functions of the overflow port and the overflow pipe are, on the one hand, to play a role in ventilation when the water volume is small, and on the other hand, to directly introduce the water flow into the water tray when the water volume is large, so as not to splash outside the water distribution tray.

[0015] 5. The utility model can effectively eliminate the siphon advantage of the water inlet pipe of the cooling tower, ensure the balance of the system water volume during the startup period of the cooling tower and when the water volume suddenly becomes large or small, and adapt to the continuous change of the cooling water flow. Under the condition of variable flow, continuously maintain the balance of the water volume among the cooling towers, so as to ensure the high efficiency of the cross-flow cooling tower and be applicable to most cross-flow cooling towers commonly found in the current market. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic structural diagram of the utility model;

[0017] Figure 2 is a schematic structural diagram of the flow limiting plate;

[0018] Figure 3 is a schematic connection diagram of the flow equalizer and the cooling tower;

[0019] Figure 4 is a schematic diagram of the principle of the generation of the siphon advantage of the cooling tower Figure 1 ;

[0020] Figure 5 is a schematic diagram of the principle of the generation of the siphon advantage of the cooling tower Figure 2 ;

[0021] Figure 6 is a schematic diagram of the principle of the generation of the siphon advantage of the cooling tower Figure 3 ;

[0022] Figure 7Schematic diagram of the principle for generating the siphon advantage of the cooling tower Figure 4 ;

[0023] Figure 8 Schematic diagram of the principle for generating the siphon advantage of the cooling tower Figure 5 ;

[0024] Figure 9 Schematic diagram of the principle for generating the siphon advantage of the cooling tower Figure 6 ;

[0025] Figure 10 Schematic diagram of the small water volume embodiment;

[0026] Figure 11 Partial enlarged view of the small water volume embodiment;

[0027] Figure 12 Schematic diagram of the medium water volume embodiment;

[0028] Figure 13 Partial enlarged view of the medium water volume embodiment;

[0029] Figure 14 Schematic diagram of the large water volume embodiment;

[0030] Figure 15 Partial enlarged view of the large water volume embodiment;

[0031] In the figure: 1 - outer pipe, 11 - water inlet, 12 - overflow port, 2 - inner pipe, 21 - water inlet slot, 3 - overflow pipe, 4 - current limiting plate, 41 - current limiting hole, A - water inlet pipe, B - water distribution tray. Specific embodiments

[0032] Next, the technical solutions of the present utility model will be clearly and completely described in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts belong to the scope of protection of the present utility model.

[0033] Such as Figure 1-3The variable flow rate cooling tower inter-tower flow equalizer shown includes an outer pipe 1 and an inner pipe 2. The lower side of the outer pipe 1 is provided with a water inlet 11 communicating with the cooling tower water inlet pipe A, and the upper side is provided with an overflow port 12. The overflow port 12 is connected to an overflow pipe 3. The inner pipe 2 is not sealed at the top and bottom, is located in the lower half of the outer pipe 1, and the lower end extends out of the outer pipe 1. The bottom of the outer pipe 1 and the outside of the inner pipe 2 are closed by a bottom plate, so that the inlet water cannot flow out from the bottom of the outer pipe 1. The overflow pipe 3 extends into the cooling tower water distribution tray B, and its bottom end is higher than the highest water surface that the water distribution tray B may reach. A flow limiting plate 4 is arranged inside the outer pipe 1 between the top end of the inner pipe 2 and the overflow port 12. The flow limiting plate 4 is provided with a flow limiting hole 41. A plurality of water inlet slits 21 are opened on the upper side of the inner pipe 2. The lengths of the water inlet slits 21 are different, the tops are aligned, the bottoms are staggered in height, and the lowest point is higher than the water inlet 11.

[0034] Working principle and process:

[0035] The flow equalizer is vertically installed above the cooling tower water distribution tray B. The water inlet 11 of the outer pipe is connected to the outlet of the cooling tower water inlet pipe A, and the water outlet of the inner pipe 2 and the overflow pipe 3 are connected into the water distribution tray B. The water outlet of the inner pipe 2 can be directly placed into the water distribution tray B, or a water distributor can be connected, such as our another patented technology, the linear water distributor. The overflow pipe 3 is placed in the water distribution tray, and the outlet is higher than the highest water level that the water distribution tray can reach. The working process is as follows:

[0036] After the water pump is initially started, the water flow inside the flow equalizer gradually rises until it reaches the bottom end of the longest water inlet slit 21 of the inner pipe. At this time, the water level height of all cooling towers is H11, and the heights of all cooling towers are the same, that is, the water flow lift height of each tower is the same. When the flow rate continues to increase, the water begins to flow into the inner pipe from the water inlet slit and flows out from the outlet into the cooling tower water distribution tray. Because the flow equalizer is directly connected to the atmosphere, siphon will not be formed. When the water flow increases, the water level between the outer pipe 1 and the inner pipe 2 of the flow equalizer continues to rise, so the amount of water entering the inner pipe 2 will also increase, and finally a balance will be reached at a certain height. When the water volume is small, at this time, the water level between the inner and outer pipes of the flow equalizer is between the water inlet slit 21 of the inner pipe and the top. Figure 10 This is the case of less water volume. Figure 11 This is a partial enlarged view. Due to the different distances between each cooling tower and the different pipe lengths, the frictional resistance along each tower is also different, and the flow rate entering each tower is different, which will be reflected in the water surface height difference between the inner and outer pipes of the flow equalizer. By adjusting the cooling tower water inlet valve, the water surface height of each tower can be adjusted until the height of each tower is basically the same. It can be seen that siphon phenomenon will not occur during the whole process. Because there is no siphon phenomenon, during each start-up period, as long as the water volume is the same, the hydraulic lift height of the cooling tower will be the same, and the advantage transfer will not occur again, thus fundamentally eliminating the problem that the water volumes of the cooling towers between towers are different and not the same each time due to the siphon advantage.

[0037] As the water volume continues to increase, the water level between the inner and outer pipes of the flow equalizer will gradually rise until it submerges the top of the inner pipe 2. This is Figure 12 the situation shown in Figure 13 the partial enlarged view. At this time, the water level is between the top of the inner pipe 2 and the flow limiting plate 4. The hydraulic lift height of each tower is H12. Since there is no siphon phenomenon, the lift height will not change suddenly. Also, since the balance has been achieved among the towers through valve adjustment, the lift height remains the same for each tower. This is because the flow in the air-conditioning cooling water pipe is generally in the hydraulically rough zone, where the resistance coefficient is not affected by the water flow velocity but only related to the geometric characteristics of the pipe such as the hydraulic radius and relative roughness. In this zone, as long as the balance is adjusted at a certain water volume, the balance can still be maintained at other water volumes. When the system water flow suddenly changes, such as stopping one water pump or starting one more water pump, resulting in water level fluctuations, for the cooling tower with an increased flow rate, the water level inside its flow equalizing pipe will rise. After the water level rises, it will in turn inhibit the increase in water volume. Through this mechanism, the flow equalizer has the ability of self-adjustment and can always maintain the balance of water volume under variable water volume conditions.

[0038] The design of the overflow pipe 3 has two functions: breathing and overflow. Through reasonable calculation, in most cases, the water level of the flow equalizer will not reach the overflow port 12. However, in special cases, such as hydraulic fluctuations or when the load reaches the maximum, at this time, the water level of the flow equalizer may reach the overflow port 12 and flow out from the overflow port 12 into the cooling tower water distribution tray B. Figure 14 That is, the situation where the water level is higher than the overflow port 12. Figure 15 is the partial enlarged view. At this time, the flow limiting plate 4 will play a role, increasing the resistance of the water flowing through the flow limiting hole 41 and "pressing" most of the water flow at the bottom, flowing out from the inner pipe 2. The water volume exceeding the flow capacity of the inner pipe 2 will enter the upper part of the flow limiting plate 4 and flow out from the overflow pipe 3. Through appropriate design, it can be ensured that the overflow pipe 3 is always in a semi-flow state, and its function as a breathing pipe is always effective, thus ensuring that the siphon phenomenon of the water inlet pipe A can be eliminated within all water volume ranges. And the flow limiting plate 4 can further balance the flow among the towers when the water volume is large or when the water flow suddenly fluctuates.

[0039] The above description is only the preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A variable-flow cooling tower inter-tower flow equalizer, characterized in that, It includes an outer pipe (1) and an inner pipe (2). A water inlet (11) communicating with the cooling tower water inlet pipe (A) is provided on the lower side of the outer pipe (1), and an overflow port (12) is provided on the upper side. The overflow port (12) is connected with an overflow pipe (3). The inner pipe (2) is not sealed at the top and bottom, is located in the lower half of the outer pipe (1), and its lower end extends out of the outer pipe (1). The bottom of the outer pipe (1) is closed with the outside of the inner pipe (2) so that water cannot flow out from the bottom of the outer pipe (1). The overflow pipe (3) extends into the cooling tower water distribution tray (B), and its bottom end is higher than the highest water surface that the water distribution tray (B) may reach.

2. The flow equalizer according to claim 1, wherein A flow limiting plate (4) is provided inside the outer pipe (1) between the top end of the inner pipe (2) and the overflow port (12), and a flow limiting hole (41) is opened on the flow limiting plate (4).

3. The flow equalizer according to claim 1 or 2, characterized in that, A plurality of water inlet slits (21) are opened on the upper side of the inner pipe (2).

4. The flow equalizer according to claim 3, wherein The lengths of the water inlet slits (21) are different, the tops are aligned, the bottoms are staggered in height, and the lowest point is higher than the water inlet (11).

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