Cooling tower anti-freezing adaptive control system and method based on temperature field measurement

Abstract

This invention discloses an adaptive control system and method for cooling tower antifreeze based on temperature field measurement, including a controller, a cooling tower circulating water inlet pipe, a circulating water pump, a cooling tower circulating water return pipe, and several sets of adjustable antifreeze devices installed at the air inlet of the cooling tower. The outlet of the cooling tower circulating water inlet pipe is connected to the inlet of the cooling tower via the circulating water pump, and the outlet of the cooling tower is connected to the cooling tower circulating water return pipe. A cooling tower outlet water temperature measuring point is installed at the inlet of the cooling tower, and a cooling tower ambient temperature measuring point is installed at the lower edge of the air inlet of the cooling tower. The controller is connected to the cooling tower ambient temperature measuring point, the cooling tower outlet water temperature measuring point, the circulating water pump, and the adjustable antifreeze devices. This system and method can alleviate the pressure of cooling tower antifreeze in winter and avoid problems such as ice buildup and damage to the packing layer.

Description

Technical Field

[0001] This invention belongs to the field of steam turbine operation technology, and relates to an adaptive control system and method for cooling tower antifreeze based on temperature field measurement. Background Technology

[0002] With the high proportion of intermittent and highly volatile clean energy being integrated into the power grid, improving the deep peak-shaving capacity and load change response speed of thermal power units has become a hot topic in the flexible retrofitting of thermal power units. The cooling towers of wet-cooled units are designed based on the maximum heat exchange capacity under summer conditions. This leads to a significant reduction in the circulating water volume in the cooling towers during winter peak-shaving operations in northern regions, especially after heating system retrofitting. This results in immense pressure on the cooling towers to prevent freezing in winter, easily causing problems such as ice buildup and damage to the packing layer. Furthermore, the extremely high time responsiveness requirements for flexible control during peak-shaving operations further increase the difficulty of adjusting cooling tower antifreeze measures. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a cooling tower antifreeze adaptive control system and method based on temperature field measurement. This system and method can alleviate the antifreeze pressure of circulating water on the cooling tower in winter and avoid the problems of ice buildup and damage to the packing layer.

[0004] To achieve the above objectives, the cooling tower antifreeze adaptive control system based on temperature field measurement of the present invention includes a controller, a cooling tower circulating water inlet pipe, a circulating water pump, a cooling tower circulating water return pipe, and several sets of adjustable antifreeze devices installed at the air inlet of the cooling tower.

[0005] The outlet of the cooling tower circulating water inlet pipe is connected to the cooling tower inlet via a circulating water pump, and the cooling tower outlet is connected to the cooling tower circulating water return pipe. A cooling tower outlet water temperature measuring point is installed at the cooling tower inlet, and a cooling tower ambient temperature measuring point is installed at the lower edge of the cooling tower air inlet.

[0006] The controller is connected to the ambient temperature measurement point of the cooling tower, the outlet water temperature measurement point of the cooling tower, the circulating water pump, and the adjustable antifreeze equipment.

[0007] The adjustable antifreeze device includes an antifreeze folding curtain installed at the air inlet of the cooling tower and an antifreeze device drive motor for driving the antifreeze folding curtain to unfold or retract, wherein the controller is connected to the antifreeze device drive motor.

[0008] During operation, the antifreeze equipment drives the motor to control the antifreeze folding curtain to expand or contract, thereby adjusting the opening of the cooling tower air inlet and thus the air intake area of ​​the cooling tower air inlet.

[0009] The adjustable antifreeze device also includes a stroke displacement sensor for detecting the displacement of the antifreeze folding curtain, and the stroke displacement sensor is connected to the controller.

[0010] The adaptive control method for cooling tower antifreeze based on temperature field measurement described in this invention includes the following steps:

[0011] The water output from the cooling tower circulating water inlet pipe is pumped into the cooling tower for cooling, and the water output from the cooling tower is discharged through the cooling tower circulating water return pipe.

[0012] The outlet water temperature of the cooling tower is measured through the outlet water temperature measuring point, and the ambient temperature at the lower edge of the air inlet of the cooling tower is measured through the ambient temperature measuring point.

[0013] Calculate the average ambient temperature within the detection period Δt to obtain the average ambient temperature; calculate the average outlet water temperature within the detection period Δt to obtain the average outlet water temperature; preset ambient temperature T1℃; preset safe outlet water temperature T2℃.

[0014] The circulating water pump and the drive motor of the antifreeze equipment are controlled according to the average ambient temperature and the average outlet water temperature to achieve adaptive control of the cooling tower for antifreeze.

[0015] The specific operation of controlling the circulating water pump and the antifreeze equipment drive motor according to the average ambient temperature and average outlet water temperature is as follows:

[0016] When the average ambient temperature is greater than T1℃ and the average outlet water temperature is greater than T2℃, it indicates that the antifreeze pressure of the cooling tower is relatively low. Increase the opening of the antifreeze folding curtain by P1% and reduce the flow rate of the circulating water pump by Q%.

[0017] When the average ambient temperature is greater than T1℃ and the average outlet water temperature is less than T2℃, it indicates that the antifreeze pressure of the cooling tower is moderate. Since the average outlet water temperature is low, the opening of the antifreeze folding curtain is reduced by P2%. The average cooling water outlet temperature of the next detection cycle Δt is then tracked until the average outlet water temperature is greater than or equal to T2℃.

[0018] When the average ambient temperature is <T1℃ and the average outlet water temperature is >T2℃, it indicates that the cooling tower has moderate antifreeze pressure and maintains its current state.

[0019] When the average ambient temperature is <T1℃ and the average outlet water temperature is <T2℃, it indicates that the cooling tower is under greater antifreeze pressure. The opening of the antifreeze folding curtain should be reduced by P2%, and the flow rate of the circulating water pump should be increased by Q%. The average outlet water temperature of the next temperature measurement period Δt should be tracked until the average outlet water temperature is greater than or equal to T2℃.

[0020] T1 = 0.

[0021] T2 = 10.

[0022] The present invention has the following beneficial effects:

[0023] The cooling tower antifreeze adaptive control system and method based on temperature field measurement described in this invention obtains the average ambient temperature and average outlet water temperature of the cooling tower during operation, and uses this to determine the current circulating water antifreeze pressure. Then, it controls the circulating water pump and the drive motor of the antifreeze equipment to ensure that the outlet water temperature of the cooling tower is above the safe range, reduce the risk of the circulating water freezing in winter, alleviate the antifreeze pressure of the circulating water on the tower in winter, avoid the problems of ice buildup and damage to the packing layer in the cooling tower, and achieve safe, stable and flexible operation. Attached Figure Description

[0024] Figure 1 This is a structural diagram of the present invention.

[0025] Among them, 1 is the cooling tower, 2 is the adjustable antifreeze equipment, 3 is the antifreeze equipment drive motor, 4 is the antifreeze folding curtain, 5 is the stroke displacement sensor, 6 is the cooling tower ambient temperature measuring point, 7 is the cooling tower circulating water inlet pipe, 8 is the circulating water pump, 9 is the cooling tower outlet water temperature measuring point, and 10 is the cooling tower circulating water return pipe. Detailed Implementation

[0026] To enable those skilled in the art to better understand the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, not all embodiments, and are not intended to limit the scope of the present invention. Furthermore, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion regarding the concepts disclosed in the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should fall within the scope of protection of the present invention.

[0027] The accompanying drawings show structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not drawn to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0028] Example 1

[0029] refer to Figure 1The cooling tower antifreeze adaptive control system based on temperature field measurement described in this invention includes several sets of adjustable antifreeze devices 2 installed at the air inlet of the cooling tower 1, wherein the opening of the air inlet of the cooling tower 1 is adjusted by the adjustable antifreeze devices 2.

[0030] Specifically, the adjustable antifreeze device 2 includes a cooling tower ambient temperature measuring point 6 installed at the lower edge of the air inlet of the cooling tower 1, an antifreeze folding curtain 4 set at the air inlet of the cooling tower 1, an antifreeze device drive motor 3 for driving the antifreeze folding curtain 4 to unfold or retract, and a stroke displacement sensor 5 for detecting the displacement of the antifreeze folding curtain 4. The antifreeze device drive motor 3 drives the antifreeze folding curtain 4 to unfold and retract, thereby controlling the air intake area of ​​the air inlet of the cooling tower 1 and adjusting the opening of the air inlet of the cooling tower 1. At the same time, the stroke displacement sensor 5 detects the displacement of the antifreeze folding curtain 4 to reflect the air intake area of ​​the air inlet of the cooling tower 1.

[0031] Preferably, it should be noted that the cooling tower antifreeze adaptive control system based on temperature field measurement of the present invention further includes a circulating water pump 8, a cooling tower circulating water inlet pipe 7, and a cooling tower circulating water return pipe 10. The outlet of the cooling tower circulating water inlet pipe 7 is connected to the inlet of the cooling tower 1 via the circulating water pump 8, and the outlet of the cooling tower 1 is connected to the cooling tower circulating water return pipe 10. A cooling tower outlet water temperature measuring point 9 is provided at the inlet of the cooling tower 1, and the outlet water temperature of the cooling tower 1 is measured through the cooling tower outlet water temperature measuring point 9.

[0032] During operation, the water output from the cooling tower circulating water inlet pipe 7 is sent into the cooling tower 1 for cooling via the circulating water pump 8. The water output from the cooling tower 1 is discharged through the cooling tower circulating water return pipe 10. During this process, the outlet water temperature of the cooling tower 1 is measured through the cooling tower outlet water temperature measuring point 9, and the upper tower circulating water flow rate of the cooling tower 1 is adjusted by the circulating water pump 8.

[0033] This invention measures the ambient temperature and the outlet water temperature of the cooling tower 1 based on the ambient temperature measuring point 6 and the outlet water temperature measuring point 9 of the cooling tower to determine the current antifreeze operation status of the cooling tower 1. Based on this, the antifreeze equipment drives the motor 3 to drive the antifreeze folding curtain 4 to unfold or retract. It should be noted that the ambient temperature measuring point 6 measures the ambient temperature at the lower edge of the air inlet of the cooling tower to reflect the current ambient temperature, and the outlet water temperature measuring point 9 measures the outlet water temperature of the cooling tower 1 to determine the antifreeze pressure for the circulating water to freeze.

[0034] Example 2

[0035] refer to Figure 1 The adaptive control method for cooling tower antifreeze based on temperature field measurement described in this invention includes the following steps:

[0036] The water output from the cooling tower circulating water inlet pipe 7 is sent into the cooling tower 1 for cooling via the circulating water pump 8, and the water output from the cooling tower 1 is discharged through the cooling tower circulating water return pipe 10.

[0037] The outlet water temperature of cooling tower 1 is measured through cooling tower outlet water temperature measuring point 9, and the ambient temperature at the lower edge of the air inlet of cooling tower 1 is measured through cooling tower ambient temperature measuring point 6.

[0038] Calculate the average ambient temperature within the detection period Δt to obtain the average ambient temperature; calculate the average outlet water temperature within the detection period Δt to obtain the average outlet water temperature; preset ambient temperature T1℃, preset safe outlet water temperature T2℃; preferably, T1=0; T2=10.

[0039] When the average ambient temperature is greater than T1℃ and the average outlet water temperature is greater than T2℃, it indicates that the antifreeze pressure of cooling tower 1 is relatively low. Increase the opening of the antifreeze folding curtain 4 by P1% and reduce the flow rate of circulating water pump 8 by Q%.

[0040] When the average ambient temperature is greater than T1℃ and the average outlet water temperature is less than T2℃, it indicates that the antifreeze pressure of cooling tower 1 is moderate. Since the average outlet water temperature is low, the opening of the antifreeze folding curtain 4 is reduced by P2%. The average cooling water outlet temperature of the next detection cycle Δt is tracked until the average outlet water temperature is greater than or equal to T2℃.

[0041] When the average ambient temperature is <T1℃ and the average outlet water temperature is >T2℃, it indicates that the antifreeze pressure of cooling tower 1 is moderate and the current state can be maintained.

[0042] When the average ambient temperature is <T1℃ and the average outlet water temperature is <T2℃, it indicates that the antifreeze pressure of cooling tower 1 is relatively high. The opening of the antifreeze folding curtain 4 is reduced by P2%, and the flow rate of the circulating water pump 8 is increased by Q%. The average outlet water temperature of the next temperature measurement period Δt is tracked until the average outlet water temperature is greater than or equal to T2℃.

[0043] The overall control logic is shown in Table 1.

[0044] Table 1

[0045]

[0046] It should be noted that this invention overcomes the defect that the circulating water volume of cooling tower 1 is significantly reduced during peak-shaving operation in northern regions during winter, which easily causes ice buildup and damage to the packing layer of cooling tower 1. It realizes adaptive control and adjustment of the temperature field measurement of cooling tower 1, ensuring that cooling tower 1 operates safely, stably and flexibly in winter.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A cooling tower antifreeze adaptive control method based on temperature field measurement, characterized in that, The cooling tower antifreeze adaptive control system based on temperature field measurement includes a controller, a cooling tower circulating water inlet pipe (7), a circulating water pump (8), a cooling tower circulating water return pipe (10), and several sets of adjustable antifreeze devices (2) installed at the air inlet of the cooling tower (1). The outlet of the cooling tower circulating water inlet pipe (7) is connected to the inlet of the cooling tower (1) via the circulating water pump (8), and the outlet of the cooling tower (1) is connected to the cooling tower circulating water return pipe (10). A cooling tower outlet water temperature measuring point (9) is set at the inlet of the cooling tower (1), and a cooling tower ambient temperature measuring point (6) is set at the lower edge of the air inlet of the cooling tower (1). The controller is connected to the ambient temperature measuring point (6) of the cooling tower, the outlet water temperature measuring point (9) of the cooling tower, the circulating water pump (8) and the adjustable antifreeze device (2); The adjustable antifreeze device (2) includes an antifreeze folding curtain (4) installed at the air inlet of the cooling tower (1) and an antifreeze device drive motor (3) for driving the antifreeze folding curtain (4) to unfold or retract, wherein the controller is connected to the antifreeze device drive motor (3); Includes the following steps: The water output from the cooling tower circulating water inlet pipe (7) is sent into the cooling tower (1) for cooling via the circulating water pump (8), and the water output from the cooling tower (1) is discharged through the cooling tower circulating water return pipe (10). The outlet water temperature of the cooling tower (1) is measured by the outlet water temperature measuring point (9), and the ambient temperature at the lower edge of the air inlet of the cooling tower (1) is measured by the ambient temperature measuring point (6). Calculate the detection cycle The average ambient temperature is obtained by calculating the average ambient temperature within t; the detection cycle is then calculated. The average value of the outlet water temperature within t is used to obtain the average outlet water temperature, the preset ambient temperature T1℃, and the preset safe outlet water temperature T2℃. Based on the average ambient temperature and average outlet water temperature, the circulating water pump (8) and the antifreeze equipment drive motor (3) are controlled to achieve adaptive control of cooling tower antifreeze.

2. The adaptive control method for cooling tower antifreeze based on temperature field measurement according to claim 1, characterized in that, The specific operation of controlling the circulating water pump (8) and the antifreeze equipment drive motor (3) based on the average ambient temperature and average outlet water temperature is as follows: When the average ambient temperature is greater than T1℃ and the average outlet water temperature is greater than T2℃, it indicates that the antifreeze pressure of the cooling tower (1) is relatively low. The opening of the antifreeze folding curtain (4) is increased by P1%, and the flow rate of the circulating water pump (8) is reduced by Q%. When the average ambient temperature is greater than T1℃ and the average outlet water temperature is less than T2℃, it indicates that the antifreeze pressure of the cooling tower (1) is moderate. Since the average outlet water temperature is low, the opening of the antifreeze folding curtain (4) is reduced by P2%; and the next detection cycle is continued. The average cooling water outlet temperature of t is calculated until the average outlet water temperature is greater than or equal to T2℃. When the average ambient temperature is <T1℃ and the average outlet water temperature is >T2℃, it indicates that the antifreeze pressure of the cooling tower (1) is moderate and the current state is maintained. When the average ambient temperature is <T1℃ and the average outlet water temperature is <T2℃, it indicates that the antifreeze pressure of the cooling tower (1) is relatively high. The opening of the antifreeze folding curtain (4) is reduced by P2%, and the flow rate of the circulating water pump (8) is increased by Q%; and the temperature measurement period is continued. The average outlet water temperature is calculated until the average outlet water temperature is greater than or equal to T2℃.

3. The adaptive control method for cooling tower antifreeze based on temperature field measurement according to claim 2, characterized in that, T1=0。 4. The adaptive control method for cooling tower antifreeze based on temperature field measurement according to claim 2, characterized in that, T2=10。 5. The adaptive control method for cooling tower antifreeze based on temperature field measurement according to claim 1, characterized in that, During operation, the antifreeze folding curtain (4) is expanded or contracted by the antifreeze equipment driven motor (3) to adjust the opening of the air inlet of the cooling tower (1) and thus adjust the air inlet area of ​​the cooling tower (1).

6. The adaptive control method for cooling tower antifreeze based on temperature field measurement according to claim 1, characterized in that, The adjustable antifreeze device (2) also includes a stroke displacement sensor (5) for detecting the displacement of the antifreeze folding curtain (4), and the stroke displacement sensor (5) is connected to the controller.

Images