A high efficiency counterflow cooling tower system

Abstract

The application relates to the cooling technical field, in particular to a high-efficiency counterflow cooling tower system which comprises a sub-wet bulb indirect evaporative cooling system, a variable-flow uniform water spraying system and a fan assembly. The sub-wet bulb indirect evaporative cooling system can realize that the outlet water temperature is lower than the ambient wet bulb temperature; the variable-flow uniform water spraying system can keep uniform water spraying under the variable-flow condition, the system further comprises a tower group uniform water distribution device and a double-pipeline switching device; the fan assembly is composed of multiple EC axial flow fans which are distributed in a matrix mode at the tower body air outlets, can provide uniform airflow and reduce energy consumption. The application can improve the cooling efficiency of the counterflow cooling tower, realize uniform water spraying and airflow distribution, reduce energy consumption, can make the outlet water temperature of the cooling tower lower, and makes the cooling tower run efficiently and energy-savingly in the full-flow range.

Description

Technical Field

[0001] This application relates to the field of cooling technology, and in particular to a high-efficiency counterflow cooling tower system. Background Technology

[0002] In the field of cooling technology, traditional open cooling towers are widely used. They exchange heat through direct contact between cooling water and air, reduce water temperature by evaporation, and then allow the cooling water discharged from the cooling tower to absorb heat at the user's heat exchanger for cooling the cold source user, providing effective support for cooling equipment in many industries.

[0003] Therefore, traditional cooling towers are based on the principle of evaporative cooling, and their outlet water temperature can theoretically only reach the ambient wet-bulb temperature at the lowest, resulting in low efficiency of the refrigeration system. Utility Model Content

[0004] In order to enable the refrigeration unit to achieve a lower condensing temperature, improve the system COP (cooling system efficiency), and reduce energy consumption in the refrigeration system, this application provides a high-efficiency counterflow cooling tower system.

[0005] This application provides a high-efficiency counter-flow cooling tower system, which adopts the following technical solution: A high-efficiency counter-flow cooling tower system includes a sub-wet-bulb indirect evaporative cooling system. The sub-wet-bulb indirect evaporative cooling system includes a tower body, air coolers on both sides of the tower body, a fan assembly at the top of the tower body, packing material inside the tower body, a spray system inside the tower body, an outlet chilled water pump and an air cooler pump at the bottom of the tower body, a user heat exchanger, a circulating water supply pipe, and an air cooler supply pipe. The packing material is located below the fan assembly, the spray system is located between the fan assembly and the packing material, the circulating water supply pipe is connected at both ends to the spray system and the bottom of the tower body respectively, and the circulating water supply pipe passes sequentially through the outlet chilled water pump and the user heat exchanger. The air cooler supply pipe connects the air cooler pump and the air cooler, and the air cooler is connected to the spray system. The variable flow uniform spraying system is used to maintain uniform water spraying under variable flow conditions.

[0006] By adopting the above technical solution, the cooling water evaporates and cools on the packing, reducing the water temperature to below the ambient dry-bulb temperature; the ambient air and the cooling water exchange heat through the finned tube bundle in the air cooler, reducing the air temperature and forming pre-cooled air; the pre-cooled air enters the packing, absorbs the heat from the water spray, further reducing the water spray temperature, and finally makes the cooling water temperature exiting the tower lower than the ambient wet-bulb temperature, reaching the "sub-wet-bulb" level. The refrigeration unit can obtain a lower condensation temperature, improve the system COP, save energy and reduce consumption in the refrigeration system, and maintain the requirement of high-efficiency and energy-saving operation when the cooling water flow rate changes.

[0007] Preferably, the system also includes a variable flow uniform water spraying system. The tower body has multiple components. The variable flow uniform water spraying system includes a tower group uniform water distribution device, a dual-pipe switching device, and variable flow uniform water spray nozzles. The spraying components include a main pipe assembly, which includes multiple high-flow-rate spray pipes and multiple low-flow-rate spray pipes. The variable flow uniform water spray nozzles are mounted on the high-flow-rate and low-flow-rate spray pipes. The tower group uniform water distribution device includes an upper tower main pipe, multiple main water supply pipes, and multiple water supply sub-pipes. The main water supply pipes are connected to the upper tower main pipe, the main water supply pipes are connected to the water supply sub-pipes, the main water supply pipes are connected to the high-flow-rate spray pipes, and the water supply sub-pipes are connected to the low-flow-rate spray pipes. The dual-pipe switching device is used to close the main water supply pipes and open the water supply sub-pipes when the external water flow is less than a set flow rate.

[0008] By adopting the above technical solution, the supply of circulating cooling water can be reduced after the atmospheric temperature decreases. At this time, the water pressure of the main water supply pipe decreases. By closing the main pipe valve and opening the branch pipe valve through the dual-pipe switching device, the circulating water is switched to the low-flow spray pipe system and sprayed out from the low-flow nozzles, thereby solving the problem of uneven water spraying under low flow conditions and improving the cooling effect.

[0009] Preferably, the dual-pipeline switching device includes a main pipe valve on the main water supply pipe, a branch pipe valve on the branch water supply pipe, a pipeline booster pump installed on the branch water supply pipe, a pressure relay installed on the main water supply pipe, and a controller. The pressure relay is located upstream of the branch water supply pipe in the main water supply pipe. The pressure relay is used to detect the water pressure in the main water supply pipe and output a low-potential signal when it is lower than a set value. The pipeline booster pump and the pressure relay are both connected to the controller. The controller is used to receive the low-potential signal and control the main pipe valve to close, the branch pipe valve to open, and the pipeline booster pump to start.

[0010] By adopting the above technical solution, the controller automatically adjusts the status of the valves and pipeline booster pump according to the low potential signal. When the water pressure is lower than the set value, the system will automatically close the main valve, open the branch valves and start the pipeline booster pump. After the water is pressurized by the pipeline booster pump, it can flow to each nozzle of the small flow spray pipe, overcome the flow resistance and spray out, so that each nozzle can output basically the same amount of water.

[0011] Preferably, there are multiple upper tower main pipes, each corresponding to a multiple tower body. The tower group uniform water distribution device further includes an inlet main pipe, multiple electric stepping regulating valves installed on each upper tower main pipe, multiple micro differential pressure gauges installed in series downstream of the electric stepping regulating valves, and a reference pressure source connected to each micro differential pressure gauge. The micro differential pressure gauges, reference pressure sources, and electric stepping regulating valves are all connected to a controller. The multiple upper tower main pipes are all connected to the inlet main pipe. The reference pressure source is used to provide a reference pressure. The micro differential pressure gauges are used to measure the pressure difference between the downstream pressure of each upper tower main pipe's corresponding electric stepping regulating valve and the reference pressure source and output a pressure difference signal. The controller receives multiple pressure difference signals, calculates multiple pressure difference values ​​based on the pressure difference signals, and finds the minimum pressure difference value. When the minimum differential pressure value among multiple differential pressure values ​​is not zero, the controller controls the reference pressure source to adjust the reference pressure until the minimum differential pressure value returns to zero. After the minimum differential pressure value is zeroed, the controller sends a stepping signal to each electric stepping regulating valve. Each electric stepping regulating valve adjusts its valve opening according to the stepping signal to adjust the inlet water pressure of multiple upper tower mains until the differential pressure between the inlet water pressure of each upper tower main and the reference pressure is equal, that is, the inlet water pressure of each upper tower main is equal.

[0012] By adopting the above technical solution, the PLC controller sends stepping signals to each electric stepping regulating valve. Each valve adjusts its opening according to the stepping signal to regulate the inlet water pressure of each upper tower main pipe. It should be noted that during the adjustment process, the flow rate in some upper tower main pipes may decrease, while the flow rate in others may increase to maintain a constant total flow rate in the inlet main pipes. The PLC controller continuously monitors the differential pressure signals of each micro-manometer. Based on the dynamic differential pressure signals, the PLC controller dynamically adjusts the positive and negative stepping signals of the electric stepping regulating valves, forming a closed-loop control. The adjustment process continues until the differential pressure between each upper tower main pipe and the reference pressure source is equal, thus achieving uniform water intake in each upper tower main pipe.

[0013] Preferably, the variable flow uniform sprinkler head includes a nozzle seat, a guide tube, a bushing, a water flow pre-swirl device, a shaft, a hub, a sprinkler, and a wind turbine. The nozzle seat is used to install on a high-flow or low-flow sprinkler pipe. The guide tube is installed on the nozzle seat. The bottom of the guide tube is connected to a vertically arranged bushing via a connector. The water flow pre-swirl device is sleeved outside the bushing. The shaft is connected to the bottom of the bushing. The shaft and the central axis of the guide tube are on the same straight line. The hub is rotatably sleeved on the shaft. The sprinkler and the wind turbine are installed on the hub from top to bottom.

[0014] By adopting the above technical solution, cooling water is sprayed out from the nozzle, and the water flow pre-swirl device divides the downward flowing water column into multiple slightly rotating water streams along its peripheral wall, and the rotation direction is consistent with the rotation direction of the sprinkler. This reduces the kinetic energy loss of the downward water column colliding with the sprinkler and converts the energy that might have been lost into the rotational kinetic energy of the sprinkler.

[0015] Preferably, the sprinkler includes a hub and multiple propeller blades, all of which are connected to the outer wall of the hub. The propeller blades are divided into two groups, which are symmetrically distributed around the shaft. The water flow pre-swirl device includes a frustum column and multiple stationary guide vanes. The frustum column is fixedly mounted on a bushing. The multiple stationary guide vanes are arranged circumferentially along the outer curved surface of the frustum column. The stationary guide vanes gradually thicken from top to bottom and gradually twist from top to bottom along the height direction of the frustum column, with the twisting direction consistent with the rotation direction of the propeller blades. Each group of propeller blades is divided into an upper layer, a middle layer, and a lower layer. The angle of depression of the upper layer is smaller than that of the lower layer, and the area of ​​the upper layer is larger than that of the lower layer. The angle of depression of the middle layer is between that of the upper and lower layers, and the area of ​​the middle layer is also between that of the upper and lower layers.

[0016] By adopting the above technical solution, a pre-rotating device for stationary blades is set above the sprinkler, so that the water flow forms a certain rotational momentum before entering the nozzle, thereby improving the uniformity of subsequent distribution; the blades adopt a layered twisted design, with different twisting angles and shapes of different layers of blades, to ensure that the water flow is evenly distributed in the radial and circumferential directions.

[0017] Preferably, the wind turbine includes four wind turbine blades fixedly connected to the hub, and the twisting direction of the wind turbine blades is opposite to that of the propeller blades.

[0018] By adopting the above technical solution, the twisting direction of the wind turbine blades is opposite to that of the propeller blades. The wind turbine blades are driven by the upward wind, while the propeller blades are driven by the falling water, thereby increasing the speed of the hub. The kinetic energy generated by the airflow helps the sprinkler rotate, reducing hydraulic loss and improving the uniformity of water spraying.

[0019] Preferably, the fan assembly includes an axial flow fan, which is installed at the air outlet of the tower.

[0020] By adopting the above technical solution, the axial flow fan removes heat from the cooling tower through the top air outlet, thereby improving cooling efficiency.

[0021] Preferably, the fan assembly includes multiple EC axial flow fans, which are distributed in a matrix at the air outlet of the tower body, and the cross-sectional area of ​​the air outlet of the tower body is the same as the cross-sectional size of the tower body.

[0022] By adopting the above technical solutions, compared with traditional AC motors, EC motors reduce electromagnetic induction losses, have lower starting torque, shorter starting time, and faster transient response, and do not require additional electrical components such as frequency converters and capacitors; the matrix distribution makes the airflow distribution in the cooling tower more uniform, and the uniform weight distribution makes the fan operation more stable; in the event of a single fan failure, the lost airflow can be automatically compensated by other fans; and it supports speed regulation in multiple control modes.

[0023] Preferably, the connector includes two brackets, the tops of which are connected to the bottom of the guide tube, and the two brackets are symmetrically distributed about the central axis of the guide tube, and the bottoms of which are connected to the bushing.

[0024] By adopting the above technical solution, the symmetrical brackets are used to fix the bushings more firmly, thereby making the vertical state of the lower shaft more stable and improving the lower part.

[0025] In summary, this application includes at least one of the following beneficial technical effects: 1. Cooling water evaporates and cools on the packing material, reducing the water temperature to below the ambient dry-bulb temperature; ambient air and chilled water exchange heat through the finned tube bundle partition in the air cooler, reducing the air temperature and forming pre-cooled air; the pre-cooled air enters the packing material, absorbs the heat from the water spray, further reducing the water spray temperature, and ultimately makes the temperature of the cooling water exiting the tower lower than the ambient wet-bulb temperature, reaching the "sub-wet-bulb" level. The refrigeration unit can obtain a lower condensing temperature, improving the system COP and reducing energy consumption in the refrigeration system; 2. When the ambient temperature decreases or the data center load rate decreases, the supply of circulating cooling water can be reduced. At this time, the water pressure of the main water supply pipe decreases. By closing the main pipe valve and opening the branch pipe valve through the dual pipeline switching device, the circulating water is switched to a small flow spray pipe system and sprayed out from small flow nozzles, thereby solving the problem of uneven water spraying under small flow conditions and improving the cooling effect. 3. The controller automatically adjusts the status of valves and pipeline booster pumps based on low potential signals. When the water pressure is lower than the set value, the system will automatically close the main pipe valve, open the branch pipe valves, and start the pipeline booster pump. After the water supply is pressurized by the pipeline booster pump, the reduced flow rate of cooling water can flow to each nozzle of the low flow rate spray pipe, overcome the flow resistance and spray out, so that each nozzle can output water in basically the same amount. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the high-efficiency counterflow cooling tower system in Example 1; Figure 2 This is a schematic diagram of the "mother-daughter pipe" structure consisting of a small-flow spray pipe and a large-flow spray pipe in the variable-flow uniform water sprinkler system of Example 1. Figure 3This is a schematic diagram of the structure of the air guide plate of the main pipe in the variable flow uniform water sprinkler system of Example 1; Figure 4 This is a schematic diagram showing the distribution of multiple main and auxiliary pipes and the distribution of spray water in the variable flow uniform water sprinkler system of Example 1.

[0027] Figure 5 This is a schematic diagram showing the connection relationship between the main water supply pipe and main valve, the water supply branch pipe and branch valve, and the pipeline booster pump in the variable flow uniform sprinkler system of Example 1. Figure 6 This is a schematic diagram of the structure of the variable flow uniform water sprinkler head in the variable flow uniform water sprinkler system of Example 1; Figure 7 This is a schematic diagram of the sprinkler structure in the variable flow uniform watering system of Example 1; Figure 8 This is a schematic diagram of the uniform water distribution device for the cooling tower group in the variable flow uniform water spraying system of Example 1; Figure 9 This is a schematic diagram of the structure of the variable flow uniform water spray nozzle in the variable flow uniform water spray system of Example 2; Figure 10 This is a schematic diagram of the airflow distribution of the fan assembly in Examples 1 and 2.

[0028] Figure 11 This is a partial structural schematic diagram of Example 3; Figure 12 This is a partial structural diagram of Example 3, mainly showing the locking component.

[0029] Explanation of reference numerals in the attached drawings: 10. Tower body; 11. Air inlet; 12. Air outlet; 13. Fan assembly; 14. Air cooler; 15. Packing; 16. User heat exchanger; 20. Outlet chilled water pump; 21. Circulating water supply pipe; 22. Air cooler water pump; 23. Air cooler water supply pipe; 24. Main water supply pipe; 25. Spray system; 30. Non-contact air; 31. Water-contact air; 40. Main water supply pipe; 41. Upper tower main pipe; 42. Cooling tower group; 43. Electric stepper regulating valve; 44. Micro differential pressure gauge; 45. Micro pressure pipe; 46. Reference pressure source; 47. Controller; 50. High-flow spray pipe; 51. High-flow nozzle; 52. Main pipe. 60. Valve; 61. Small flow sprinkler pipe; 62. Small flow nozzle; 63. Air guide plate; 64. Water supply pipe; 65. Branch valve; 70. Pipeline booster pump; 71. Guide cylinder; 72. Support; 72. Bushing; 73. Water flow pre-swirl device; 74. Frustum column; 75. Stationary guide vane; 76. Shaft; 77. Sprinkler; 78. Hub; 79. Wind turbine; 80. Upper blade; 90. Middle blade; 91. Lower blade; 92. EC axial flow fan; 93. Fan frame; 94. Slot; 95. Locking seat; 96. Locking block; 97. Sliding groove. Detailed Implementation

[0030] The present application will be further described in detail below with reference to all the accompanying drawings.

[0031] Example 1 This application discloses a high-efficiency counter-flow cooling tower system. (Refer to...) Figure 1 , Figure 2 A high-efficiency counter-flow cooling tower system includes a sub-wet-bulb indirect evaporative cooling system and a variable-flow uniform water spraying system. Through the coordinated work of these systems, a novel high-efficiency counter-flow cooling tower technology combination solution is formed.

[0032] This utility model's sub-wet-bulb indirect evaporative cooling system includes a tower body 10, a pair of air coolers 14 respectively disposed on both sides of the tower body 10, a fan assembly 13 disposed in the middle of the air outlet 12 at the top of the tower body 10, a user heat exchanger 16, a chilled water pump 20 exiting the tower and an air cooler pump 22, packing material 15 disposed at the top inside the tower body 10, and a spray element 25. The packing material 15 is located below the fan assembly 13, and the spray element 25 is located between the fan assembly 13 and the packing material 15. The fan assembly 13 is a conventional AC fan. The outlet chilled water pump 20 and the air cooler water pump 22 are located at the bottom of the tower. The bottom of the tower body 10 is used for water storage. The two ends of the circulating water supply pipe 21 are connected to the spray unit 25 and the bottom of the tower body 10, respectively. The outlet chilled water pump 20 is connected to the user heat exchanger 16 through the circulating water supply pipe 21. The air cooler 14 is composed of a high-efficiency heat exchange finned tube bundle to realize the heat exchange between the ambient air intake and the chilled water. The air cooler water pump 22 is connected to the air cooler 14 through the air cooler water supply pipe 23. The two water pipes, the circulating water supply pipe 21 and the air cooler water supply pipe 23, are combined to form the upper tower main pipe 41, which is connected to the spray unit 25.

[0033] The specific workflow of the system is as follows: Circulating water passes through the upper tower main pipe 41, and then sprays onto the packing 15 through the spray nozzle 25. After evaporation and cooling on the packing 15, the water temperature drops below the ambient dry-bulb temperature. A portion of the chilled water is transported to the air cooler 14 by the air cooler pump 22. Ambient air enters through the air inlet 11 and exchanges heat with the chilled water through the finned tube bundle partition of the air cooler 14, causing the air temperature to drop and forming non-contact air 30 (pre-cooled air). This non-contact air 30 enters the packing 15, absorbs the heat from the sprayed water, and becomes water-contact air 31, further reducing the sprayed water temperature, ultimately making the outlet water temperature lower than the ambient wet-bulb temperature, reaching the "sub-wet-bulb" level. The cooled chilled water is then transported to the user heat exchanger 16 by the outlet chilled water pump 20 to absorb the user's heat.

[0034] Reference Figure 2 , Figure 3 , Figure 4The variable flow uniform watering system includes a tower group uniform water distribution device, a dual-pipe switching device, and variable flow uniform watering nozzles. The spray component 25 includes a mother-daughter pipe assembly, which consists of a high-flow-rate spray pipe 50 and two low-flow-rate spray pipes 60. The variable flow uniform watering nozzles are installed below the high-flow-rate spray pipe 50 or the low-flow-rate spray pipes 60 and are connected to both the high-flow-rate spray pipe 50 and the low-flow-rate spray pipes 60. Multiple variable flow uniform watering nozzles are arranged along the length of the high-flow-rate spray pipe 50 or the low-flow-rate spray pipes 60, respectively. Each high-flow-rate spray pipe 50 has a low-flow-rate spray pipe 60 closely attached to each side in the horizontal direction, and the low-flow-rate spray pipes 60 are parallel to the high-flow-rate spray pipe 50. The daughter pipes are spot-welded to the mother pipe to reduce wind resistance. Two air guide plates 62 are installed below the high-flow spray pipe 50 of each parent-child pipe. The two air guide plates 62 are inclined and gradually approach the bottom of the high-flow spray pipe 50 from top to bottom. The air guide plates 62 are arranged along the length of the high-flow spray pipe 50. The two ends of the width direction of the air guide plates 62 are connected to the lower part of the high-flow spray pipe 50 and the lower part of the low-flow spray pipe 60, respectively, and are approximately tangent to the high-flow spray pipe 50 and the low-flow spray pipe 60. The tower group uniform water distribution device includes an upper tower main pipe 41, multiple main water supply pipes 24, and multiple branch water supply pipes 63. The main water supply pipes 24 are connected to the upper tower main pipe 41, and each main water supply pipe 24 branches off into a branch water supply pipe 63. Each main water supply pipe 24 is connected to each high-flow-rate spray pipe 50, and each branch water supply pipe 63 is connected to two low-flow-rate spray pipes 60 in the main pipe system. When the weather temperature drops, staff will reduce the cooling water supply. At this time, a dual-pipe switching device is used to close the main water supply pipes 24 and open the branch water supply pipes 63 when the external water flow is less than the set flow rate. The main water supply pipes 24 and branch water supply pipes 63 are connected.

[0035] Reference Figure 1 , Figure 5The dual-pipeline switching device includes a main pipe valve 52 installed on the main water supply pipe 24, a branch pipe valve 64 installed on the water supply branch pipe 63, a pipeline booster pump 65 installed on the water supply branch pipe 63, a pressure relay installed on the main water supply pipe 24, and a controller 47. The main pipe valve 52 and the branch pipe valve 64 can be electric or pneumatic valves. The circulating water volume in the main water supply pipe 24 is positively correlated with the pressure of the main tower pipe 41. When the incoming circulating water volume decreases, the incoming pressure also decreases. For example, if the switching flow rate of the two main water supply pipes 24 is specified as 45% of the rated flow rate, then the main water supply pipe 24 and the main water supply pipe 24 before the branch of the water supply branch pipe 63 have a pressure corresponding to 45% flow rate, which can be denoted as p45. This p45 is a preset value input by the designer in advance. The pressure relay is installed upstream of the water supply branch pipe 63 of the main water supply pipe 24, and the pipeline booster pump 65 is installed on the water supply branch pipe 63. When the inflow of water from outside the tower is greater than or equal to 45% of the rated flow, the water pressure in the main water supply pipe 24 is greater than or equal to p45. The pressure relay outputs a high-potential signal, and the controller 47 opens the main pipe valve 52 and closes the branch pipe valve 64 and the pipeline booster pump 65. The water from outside the tower enters the pipeline system of the high-flow spray pipe 50 inside the tower through the high-flow main pipe. When the inflow of water from outside the tower is less than 45% of the rated flow, the water pressure in the main pipe is less than p45. The pressure relay outputs a low-potential signal to the controller 47, and the controller 47 opens the branch pipe valve 64 and the pipeline booster pump 65, closes the main pipe valve 52, and the water from outside the tower enters the pipeline system of the low-flow spray pipe 60 inside the tower through the water supply branch pipe 63.

[0036] Reference Figure 6 , Figure 7Additionally, the variable flow uniform sprinkler head includes a high-flow-rate sprinkler head and a low-flow-rate sprinkler head, which are respectively installed on the high-flow-rate sprinkler pipe 50 and the low-flow-rate sprinkler pipe 60. Both the high-flow-rate and low-flow-rate sprinkler heads include a nozzle seat, a guide tube 70, a bushing 71, a water flow pre-swirl device 72, a shaft 73, a hub 75, a sprinkler 74, and a wind turbine 76. The nozzle seat is used to install on either the high-flow-rate sprinkler pipe 50 or the low-flow-rate sprinkler pipe 60. The guide tube 70 is installed on the nozzle seat, and the bottom of the guide tube 70 is connected to a vertically arranged bushing 71 via a connector. The connector includes a bracket 701, the top of which is connected to the bottom of the guide tube 70, and the bottom of which is connected to the bushing 71. The water flow pre-swirl device 72 is sleeved outside the bushing 71, and the shaft 73 is connected to the bottom of the bushing 71. The central axis of the shaft 73 and the guide tube 70 is on the same axis. In a straight line, the hub 75 is rotated and mounted on the shaft 73. The sprinkler 74 and the wind turbine 76 are mounted on the hub 75 from top to bottom. The gradually twisted shape and increasing thickness design on the peripheral wall of the water flow pre-swirl device 72 can effectively guide the water flow into the sprinkler 74. The water flow pre-swirl device 72 includes a frustum 721 and multiple stationary guide vanes 722. The frustum 721 is fixedly mounted on the bushing 71. The multiple stationary guide vanes 722 are arranged circumferentially along the outer curved surface of the frustum 721. The stationary guide vanes 722 gradually thicken from top to bottom. The stationary guide vanes 722 gradually twist from top to bottom along the height direction of the frustum 721, and their twisting direction is consistent with the rotation direction of the propeller blades.

[0037] The sprinkler 74 includes six propeller blades fixed to a hub 75. The propeller blades are divided into two groups, symmetrically distributed around the axis of the shaft 73. Each group of propeller blades consists of an upper blade 77, a middle blade 78, and a lower blade 79. The upper blade 77 is relatively flat with a small angle of attack and a large water-receiving area, thus spraying more water and covering a longer distance. The lower blade 79 has a larger angle of attack and a smaller water-receiving area, thus spraying less water and covering a shorter distance. The middle blade 78 has an angle of attack and a surface area between the upper and lower blades, therefore its spray radius and spray volume are also between the upper and lower blades. When viewed from above, the spray radius gradually increases from the center of the sprinkler 74, achieving a relatively uniform water distribution.

[0038] The wind turbine 76 includes four wind turbine blades fixedly connected to the hub 75. The four blades are arranged circumferentially along the rotation direction of the hub 75, and their height is uniform. The twisting direction of the wind turbine blades is opposite to that of the propeller blades of the sprinkler 74. While the falling water flow propels the sprinkler 74 to rotate, the upward wind also drives the wind turbine 76 to rotate, and the direction of rotation of the wind turbine 76 is the same as that of the sprinkler 74. In other words, the wind turbine 76 assists the rotation of the sprinkler 74. This design helps overcome the difficulty of insufficient rotational power of the sprinkler 74 under low-flow conditions, increasing the rotational speed of the sprinkler 74, thereby resulting in a larger spraying area and more uniform water distribution.

[0039] Reference Figure 8 There are generally multiple tower bodies 10, which together form a cooling tower group 42. Uneven water distribution within the cooling tower group 42 can lead to uneven distribution of cooling load among the towers, thus affecting the overall cooling effect and operating efficiency of the system. A tower group uniform water distribution device is used to solve the above problems.

[0040] The tower group uniform water distribution device includes an inlet main pipe 40 and multiple upper tower main pipes 41; an electric stepping regulating valve 43 installed on each upper tower main pipe 41; a detection element installed in series downstream of each electric stepping regulating valve 43; a reference pressure source 46 for providing the system reference pressure; and a controller 47 centrally located in the tower group. The detection element is a micro differential pressure gauge 44, the reference pressure source 46 is a self-stabilizing micro-pressure generator, and the controller 47 is a PLC controller. The inlet main pipe 40 receives the circulating water to be cooled. Each upper tower main pipe 41 is connected at one end to the inlet main pipe 40 and at the other end to the corresponding tower body 10. Specifically, the inlet main pipe 40 divides the circulating water into multiple portions and transports them to the multiple upper tower main pipes 41. Then, the upper tower main pipes 41 transport the water to the main water supply pipe 24, which branches into water supply pipes 63. The main water supply pipe 24 and the water supply pipes 63 respectively transport the water to the high-flow-rate spray pipe 50 or the low-flow-rate spray pipe 60.

[0041] Each differential pressure gauge 44 measures the difference between the inlet water pressure of each upper tower main pipe 41 and the pressure of the self-stabilizing micro-pressure generator, and transmits the differential pressure signal to the PLC controller 47. The PLC controller 47 calculates multiple differential pressure values ​​based on the differential pressure signal, identifies the minimum differential pressure value, and then activates the self-stabilizing micro-pressure generator, causing its pressure to slowly increase until the minimum differential pressure value returns to zero. At this point, the PLC controller 47 shuts down the self-stabilizing micro-pressure generator, and the pressure of the self-stabilizing micro-pressure generator becomes the system's reference pressure.

[0042] Subsequently, the PLC controller 47 sends stepping signals to each electric stepping regulating valve 43. Each electric stepping regulating valve 43 adjusts its valve opening according to the stepping signal to regulate the inlet water pressure of each upper tower main pipe 41. It should be noted that during the adjustment process, the flow rate in some upper tower main pipes 41 may decrease, while the flow rate in others may increase, in order to maintain a constant total flow rate in the inlet main pipe 40. The PLC controller 47 continuously monitors the differential pressure signals of each micro differential pressure gauge 44. Based on the differential pressure signals, the controller 47 dynamically adjusts the positive and negative stepping signals of the electric stepping regulating valves 43, forming a closed-loop control. The adjustment process continues until the differential pressure in each upper tower main pipe 41 is equal, thereby achieving uniform water intake in each upper tower main pipe 41.

[0043] The implementation principle of Example 1 is as follows: Cooling water evaporates and cools on the packing 15, and the water temperature drops below the ambient dry-bulb temperature; ambient air and cooling water exchange heat through the finned tube bundle partition in the air cooler 14, and the air temperature drops to form pre-cooled air; the pre-cooled air enters the packing 15, absorbs the heat of the water spray, further reduces the water spray temperature, and finally makes the cooling water temperature exiting the tower lower than the ambient wet-bulb temperature, reaching the "sub-wet-bulb" level, so that the refrigeration unit obtains a lower condensation temperature, the system COP is improved, and the refrigeration system saves energy and reduces consumption.

[0044] Example 2 Reference Figure 9 , Figure 10 The difference between Embodiment 2 and Embodiment 1 is that the fan assembly 13 in Embodiment 2 includes multiple EC axial flow fans 81, which are installed in a matrix arrangement at the air outlet 12 of the tower body 10. A fan frame 91 is installed inside the air outlet 12 of the tower body 10. The fan frame 91 is rectangular, and the EC axial flow fans 81 are bolted to the fan frame 91. The fan frame 91 is also bolted to the inner wall of the air outlet 12 of the tower body 10. The cross-sectional area of ​​the air outlet 12 of the tower body 10 is the same as the cross-sectional dimension of the tower body 10. Traditional cooling towers typically use a single large fan (Embodiment 1 also uses a single large fan). This single large fan uses an AC motor, and the area of ​​its air outlet 12 is smaller than the cross-sectional dimension of the tower body 10. When the fan is running, the airflow distribution inside the tower body 10 is uneven, and the uneven distribution of large concentrated loads such as the motor may cause the fan to vibrate. Multiple EC axial flow fans 81 replace the traditional single large fan. The multiple EC axial flow fans 81 are distributed in a matrix, and the size and area of ​​the air outlet 12 are comparable to the cross-sectional size of the tower body 10. When the system is running, the airflow distribution in the cooling tower is more uniform, and the uniform weight distribution makes the fan operation more stable.

[0045] In another embodiment 2, the connector includes two brackets 701. The top of each bracket 701 is connected to the bottom of the guide tube 70, and the two brackets 701 are symmetrically distributed about the central axis of the guide tube 70. The bottom of each bracket 701 is connected to the bushing 71.

[0046] The implementation principle of Example 2 is as follows: Compared with traditional AC motors, EC motors reduce electromagnetic induction losses, have low starting torque, short starting time, and fast transient response, and do not require additional electrical components such as frequency converters and capacitors; the matrix distribution makes the airflow distribution in the cooling tower more uniform, and the uniform weight distribution makes the fan operation more stable; in the event of a single fan failure, the missing air volume can be automatically compensated by other fans; and it supports speed regulation in multiple control modes.

[0047] Example 3 Reference Figure 11 , Figure 12 The difference between Embodiment 3 and Embodiment 1 is that: slots 911 are provided at both ends of the fan frame 91, and locking seats 92 are provided on both outer walls of the air outlet 12 of the tower body 10. Locking components for locking the fan frame 91 are provided on the locking seats 92. The locking components include locking blocks 93, locking rods 94, springs 95, and pull blocks 96. The locking blocks 93, locking rods 94, and pull blocks 96 are all cylindrical, and the central axes of the locking blocks 93, locking rods 94, and pull blocks 96 are all on the same straight line. The locking rod 94 is threaded to the locking block 93 and the pull block 96 at both ends. The locking seat 92 has a sliding groove 97 that communicates with the locking groove. The locking block 93 is slidably connected to the sliding groove 97 and its sliding direction is horizontal. When the locking block 93 slides, it is inserted into the slot 911. The locking rod 94 and the spring 95 are both located in the sliding groove 97. The spring 95 is sleeved on the locking rod 94. One end of the spring 95 is bonded to the locking block 93, and the other end of the spring 95 is bonded to the inner wall of the sliding groove 97.

[0048] The implementation principle of Example 3 is as follows: When it is necessary to remove the fan frame 91, simply pull the pull block 96 to move the locking block 93 and separate it from the slot 911, and the fan frame 91 can be removed. The disassembly of the fan frame 91 is more convenient and quick, which facilitates the maintenance and repair of the EC fan.

[0049] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A high-efficiency counter-flow cooling tower system, characterized in that: The system includes a wet-bulb indirect evaporative cooling system and a variable flow uniform spraying system. The wet-bulb indirect evaporative cooling system includes a tower body (10), air coolers (14) installed on both sides of the tower body (10), a fan assembly (13) installed on the top of the tower body (10), packing material (15) installed inside the tower body (10), spray elements (25) installed inside the tower body (10), a tower outlet chilled water pump (20) and an air cooler water pump (22) installed at the bottom of the tower body (10), a user heat exchanger (16), a circulating water supply pipe (21), and an air cooler water supply pipe (23). The packing material... (15) Located below the fan assembly (13), the spray element (25) is located between the fan assembly (13) and the packing (15). The two ends of the circulating water supply pipe (21) are respectively connected to the spray element (25) and the bottom of the tower body (10). The circulating water supply pipe (21) passes through the tower outlet cold water pump (20) and the user heat exchanger (16) in sequence. The air cooler water supply pipe (23) is connected between the air cooler water pump (22) and the air cooler (14). The air cooler (14) is connected to the spray element (25). The variable flow uniform water spraying system is used to maintain uniform water spraying under variable flow conditions.

2. The high-efficiency counter-flow cooling tower system according to claim 1, characterized in that: The tower body (10) has multiple components. The variable flow uniform water spraying system includes a tower group uniform water distribution device, a dual-pipe switching device, and variable flow uniform water spray nozzles. The spraying component (25) includes a mother-daughter pipe assembly, which includes multiple high-flow spray pipes (50) and multiple low-flow spray pipes (60). The variable flow uniform water spray nozzles are installed on the high-flow spray pipes (50) and the low-flow spray pipes (60). The tower group uniform water distribution device includes an upper tower main pipe (4). 1) Multiple main water supply pipes (24) and multiple water supply branches (63), wherein the main water supply pipes (24) are connected to the upper tower main pipe (41), the main water supply pipes (24) are connected to the water supply branches (63), the main water supply pipes (24) are connected to the high flow rate spray pipe (50), and the water supply branches (63) are connected to the low flow rate spray pipe (60). The dual-pipeline switching device is used to close the main water supply pipes (24) and open the water supply branches (63) when the water volume from outside the tower is less than the set flow rate.

3. The high-efficiency counter-flow cooling tower system according to claim 2, characterized in that: The dual-pipeline switching device includes a main pipe valve (52) installed on the main water supply pipe (24), a branch pipe valve (64) installed on the water supply branch pipe (63), a pipeline booster pump (65) installed on the water supply branch pipe (63), a pressure relay installed on the main water supply pipe (24), and a controller (47). The pressure relay is located upstream of the water supply branch pipe (63) in the main water supply pipe (24). The pressure relay is used to detect the water pressure in the main water supply pipe (24) and output a low potential signal when it is less than a set value. The pipeline booster pump (65) and the pressure relay are both connected to the controller (47). The controller (47) is used to receive the low potential signal and control the main pipe valve (52) to close, the branch pipe valve (64) to open, and the pipeline booster pump (65) to open.

4. The high-efficiency counter-flow cooling tower system according to claim 3, characterized in that: There are multiple upper tower main pipes (41), and each upper tower main pipe (41) corresponds to a multiple tower body (10). The tower group uniform water distribution device also includes an inlet main pipe (40), multiple electric stepping regulating valves (43) installed on each upper tower main pipe (41), multiple micro differential pressure gauges (44) installed in series downstream of the electric stepping regulating valves (43), and a reference pressure source (46) connected to each micro differential pressure gauge (44). The micro differential pressure gauges (44), the reference pressure source (46), and the electric stepping valves (43) are all connected to each other. All regulating valves (43) are connected to the controller (47), and all of the upper tower main pipes (41) are connected to the water inlet main pipe (40). The reference pressure source (46) is used to provide reference pressure. The micro differential pressure gauge (44) is used to measure the pressure difference between the downstream pressure of the electric step regulating valve (43) corresponding to each upper tower main pipe (41) and the reference pressure source (46) and output the differential pressure signal. The controller (47) receives multiple differential pressure signals, calculates multiple differential pressure values ​​based on the differential pressure signals, and finds the minimum differential pressure value from them. When the minimum differential pressure value among multiple differential pressure values ​​is not zero, the controller (47) controls the reference pressure source (46) to adjust the reference pressure until the minimum differential pressure value returns to zero; After the minimum differential pressure value is zero, the controller (47) sends a step signal to each electric step regulating valve (43). Each electric step regulating valve (43) adjusts the valve opening according to the step signal to adjust the inlet water pressure of multiple upper tower main pipes (41) until the differential pressure between the inlet water pressure of each upper tower main pipe (41) and the reference pressure is equal, that is, the inlet water pressure of each upper tower main pipe (41) is equal.

5. The high-efficiency counter-flow cooling tower system according to claim 2, characterized in that: The variable flow uniform water spray head includes a nozzle seat, a guide tube (70), a bushing (71), a water flow pre-swirl device (72), a shaft (73), a hub (75), a sprinkler (74), and a wind turbine (76). The nozzle seat is used to install on a high flow spray pipe (50) or a low flow spray pipe (60). The guide tube (70) is installed on the nozzle seat. The bottom of the guide tube (70) is connected to a vertically arranged bushing (71) through a connector. The water flow pre-swirl device (72) is sleeved on the bushing (71). The shaft (73) is connected to the bottom of the bushing (71). The central axis of the shaft (73) and the guide tube (70) are on the same straight line. The hub (75) is rotatably sleeved on the shaft (73). The sprinkler (74) and the wind turbine (76) are installed on the hub (75) from top to bottom.

6. The high-efficiency counter-flow cooling tower system according to claim 5, characterized in that: The sprinkler (74) includes a hub (75) and multiple propeller blades. All propeller blades are connected to the outer wall of the hub (75). The propeller blades are divided into two groups, symmetrically distributed around the shaft (73). The water flow pre-swirl device (72) includes a frustum (721) and multiple stationary guide vanes (722). The frustum (721) is fixedly mounted on a bushing (71). The multiple stationary guide vanes (722) are arranged circumferentially along the outer curved surface of the frustum (721). The stationary guide vanes (722) gradually thicken from top to bottom. The truncated cone (721) is twisted from top to bottom in the height direction, and its twisting direction is consistent with the rotation direction of the propeller blades. Each set of propeller blades is divided into an upper blade (77), a middle blade (78), and a lower blade (79). The angle of depression of the upper blade (77) is smaller than that of the lower blade (79). The area of ​​the upper blade (77) is larger than that of the lower blade (79). The angle of depression of the middle blade (78) is between that of the upper blade (77) and the lower blade (79). The area of ​​the middle blade (78) is also between that of the upper blade (77) and the lower blade (79).

7. A high-efficiency counter-flow cooling tower system according to claim 6, characterized in that: The wind turbine (76) includes four wind turbine blades fixedly connected to the hub (75), and the wind turbine blades are twisted in the opposite direction to the propeller blades.

8. The high-efficiency counter-flow cooling tower system according to claim 1, characterized in that: The fan assembly (13) includes an axial fan for installation at the air outlet (12) of the tower body (10).

9. A high-efficiency counter-flow cooling tower system according to claim 1, characterized in that: The fan assembly (13) includes multiple EC axial flow fans (81), which are distributed in a matrix at the air outlet (12) of the tower body (10). The cross-sectional area of ​​the air outlet (12) of the tower body (10) is the same as the cross-sectional size of the tower body (10).

10. A high-efficiency counter-flow cooling tower system according to claim 5, characterized in that: The connector includes two brackets (701), the tops of which are connected to the bottom of the guide tube (70), and the two brackets (701) are symmetrically distributed about the central axis of the guide tube (70). The bottoms of the two brackets (701) are connected to the bushing (71).

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