Electronic-grade ultrapure water preparation system and control method

Abstract

According to the ultrapure water preparation system and the control method, to-be-degassed pure water is subjected to heat exchange through a first heat exchange mechanism, is heated to a preset temperature under the control of a first flow regulation execution mechanism, and sequentially flows through a first degassing mechanism, a second degassing mechanism and a third degassing mechanism which are connected in series to form negative pressure to remove dissolved gas; the water enters a second heat exchange mechanism through a third outlet and is controlled by a second flow regulation executing mechanism to be reduced to a preset temperature; a monitoring mechanism containing dissolved oxygen, carbon dioxide and temperature sensors is arranged on a pipeline between the first heat exchange outlet, the first inlet and other stages of inlets and the upstream outlet; the control unit adjusts the vacuum degree of the multiple vacuumizing devices and / or the flow of the first heat exchange mechanism and / or the flow of the second heat exchange mechanism in a linkage mode according to detection results of all the monitoring assemblies so that closed-loop control over the degassing and heat exchange unit can be achieved when the process water quality and the water temperature fluctuate, and dissolved oxygen and carbon dioxide in water can reach the standard. The water supply temperature is within a preset range, and the system energy consumption is low.

Description

Technical Field

[0001] This invention relates to ultrapure water preparation systems, and more particularly to an electronic-grade ultrapure water preparation system and control method. Background Technology

[0002] Electronic-grade ultrapure water is a critical process water in the manufacturing of semiconductor chips, display panels, and other electronic products. As electronic products increasingly demand higher precision and more stringent quality, the standards for electronic-grade ultrapure water are also becoming more stringent, such as the US Standard 1.3, which imposes more stringent requirements on water quality stability and continuous system operation. These requirements not only cover the removal of metal ions, anions and cations, silicon, and boron, but also involve important indicators such as dissolved oxygen and particulate matter. Especially in high-salinity areas, the high hardness, high salt content, and high levels of silicon and boron in the raw water pose greater challenges to ultrapure water preparation. To meet these water quality requirements, ultrapure water preparation systems need to simultaneously address deep desalination, silicon and boron removal, and control carbonate scaling, while effectively managing the effects of organic matter and oxidizing substances on membrane materials and resins. This results in more complex engineering constraints in process configuration, operation control, and energy management.

[0003] Existing electronic-grade ultrapure water production systems typically employ a combination of multi-stage membrane and resin methods. First, raw water undergoes preliminary treatment through pretreatment units such as a raw water tank, multi-media or quartz sand filter, decarbonization tower, and activated carbon filter. It then enters a first-stage reverse osmosis unit and a second-stage reverse osmosis unit for primary desalination and organic matter removal. Next, a specialized EDI module further removes stubborn substances such as silica and boron. Finally, the system uses fine treatment units such as mixed bed, anion exchange bed, and two-stage polishing mixed bed to control metal ions and anions at trace levels. The system's terminal section includes a plate heat exchanger, TOC removal unit, degassing membrane unit, and terminal precision filtration and ultrafiltration units. These devices work together to regulate the supply water temperature, further reduce TOC and dissolved oxygen content, and control particulate matter levels, ensuring that the produced water meets and exceeds US Standard 1.3 requirements.

[0004] Although existing electronic-grade ultrapure water preparation systems structurally meet the requirements for high-purity water production, significant shortcomings remain in the degassing stage in high-salinity regions. Current systems typically control water quality by setting fixed vacuum levels and flow rates during the operation of the degassing membrane unit. However, this reliance on experience-based adjustments leads to difficulties in precisely controlling water quality and temperature when influent water quality and temperature fluctuate. Especially during start-up and shutdown switching, regeneration and rinsing, and load fluctuations in upstream RO, EDI, ion exchange, and mixed-bed units, key parameters such as dissolved oxygen, dissolved carbon dioxide load, and water temperature in the product water can fluctuate significantly, causing instability in the quality and temperature of the purified water to be degassed, thus affecting the efficiency of the degassing membrane unit. Furthermore, existing systems often rely solely on vacuum and flow rate adjustments to avoid insufficient degassing, but this crude control method not only increases energy consumption but may also lead to incomplete degassing, resulting in problems such as excessive dissolved oxygen or dissolved carbon dioxide levels. Furthermore, existing systems lack precise monitoring of key parameters in the degassing process, particularly regarding dissolved oxygen, carbon dioxide, and temperature before and after degassing. Operators must rely on experience for overall adjustments, making it difficult to respond quickly to fluctuations at each stage. Therefore, current technologies have limitations in improving efficiency, reducing energy consumption, and optimizing water quality stability. Optimization of degassing devices and control methods is urgently needed, especially adaptive control under high salinity and fluctuating conditions. Summary of the Invention

[0005] The purpose of this invention is to provide an electronic-grade ultrapure water preparation system and its control method that can perform multi-point online monitoring of water quality and temperature fluctuations caused by pre-degassing processes, and adjust the vacuum degree of multi-stage degassing units and the flow rates of upstream and downstream heat exchange units based on the monitoring results, thereby ensuring stable dissolved oxygen and dissolved carbon dioxide levels while also taking into account the stability of terminal water temperature and energy consumption optimization.

[0006] The technical solution adopted by the present invention to solve the above problems is: an electronic-grade ultrapure water preparation system, characterized in that it comprises: The first heat exchange mechanism includes a first heat exchange channel, a first heat exchange medium channel, and a first flow regulation actuator connected to the first heat exchange medium channel. The first heat exchange channel is provided with a first heat exchange inlet and a first heat exchange outlet in sequence. The first heat exchange medium channel is provided with a first heat exchange medium inlet and a first heat exchange medium outlet in sequence, and is connected to the cooling water outlet of at least one vacuum pump. The cooling wastewater discharged by the vacuum pump is used as the first heat exchange medium to exchange heat with the pure water to be degassed in the first heat exchange channel, so that the pure water flowing out from the first heat exchange outlet reaches a first preset temperature. Multiple degassing mechanisms, namely a first degassing mechanism, a second degassing mechanism, and a third degassing mechanism connected in series, are provided. Each degassing mechanism includes a degassing chamber for pure water to flow through, an inlet and an outlet connected to the degassing chamber, an exhaust port connected to the degassing chamber, and a vacuum pump connected to the exhaust port, so that the pure water entering each degassing chamber flows under negative pressure and is degassed. The inlet and outlet of the first degassing mechanism are the first inlet and the first outlet, respectively; the inlet and outlet of the second degassing mechanism are the second inlet and the second outlet, respectively; and the inlet and outlet of the third degassing mechanism are the third inlet and the third outlet, respectively. The first inlet is connected to the first heat exchange outlet, the first outlet is connected to the second inlet, and the second outlet is connected to the third inlet. The second heat exchange mechanism includes a second heat exchange channel, a second heat exchange medium channel, and a second flow regulation actuator connected to the second heat exchange medium channel. The second heat exchange channel is provided with a second heat exchange inlet and a second heat exchange outlet in sequence. The second heat exchange inlet is connected to a third outlet. The second heat exchange medium channel is provided with a second heat exchange medium inlet and a second heat exchange medium outlet in sequence for introducing cooling water to exchange heat between the pure water in the second heat exchange channel and the cooling water, so that the pure water flowing out of the second heat exchange outlet reaches a second preset temperature. The monitoring mechanism includes several detection components. Each detection component is respectively installed in the pipeline between the first heat exchange outlet and the first inlet, in the pipeline between the first outlet and the second inlet, in the pipeline between the second outlet and the third inlet, and in the pipeline between the third outlet and the second heat exchange inlet. Each monitoring component includes at least a dissolved oxygen sensor, a carbon dioxide sensor, and a temperature sensor, used to detect the dissolved oxygen content, dissolved carbon dioxide content, and temperature of the pure water in the corresponding pipeline. The control unit is electrically connected to the vacuum equipment corresponding to each monitoring component and each degassing mechanism, as well as the first flow regulating actuator and the second flow regulating actuator. The control unit is configured to adjust the vacuum degree of at least two vacuum equipment and / or the flow rate of pure water in the first heat exchange mechanism and the second heat exchange mechanism in conjunction with the detection results of each monitoring component, so that the pure water flowing out from the second heat exchange outlet meets the preset dissolved oxygen and dissolved carbon dioxide indicators while its water temperature is maintained within a preset range.

[0007] Furthermore, the multiple degassing mechanisms only include a first degassing mechanism, a second degassing mechanism, and a third degassing mechanism connected in series. Each of the first, second, and third degassing mechanisms includes: The degassing tube has an inner cavity that forms a degassing chamber, and the tube wall has an inlet and an outlet. An inlet pipe is arranged inside the degassing pipe. One end of the inlet pipe is in fluid communication with the inlet area inside the degassing pipe that is connected to the corresponding inlet. The other end of the inlet pipe is closed. At least one drain outlet is provided on the pipe wall on the side of the inlet pipe near the corresponding inlet. Pure water that enters the degassing pipe through the corresponding inlet enters the inlet pipe through the inlet area and then flows into the corresponding degassing chamber through the drain outlet, forming a ring flow area around the inlet pipe in the degassing chamber. The degassing assembly is arranged inside the degassing pipe and around the water inlet pipe. The degassing assembly includes multiple hollow fiber membrane bundles, as well as fixing members and suction end caps at both ends of the degassing pipe. One end of each hollow fiber membrane bundle is closed and fixed to the fixing member, and the other end is connected to the suction chamber in the suction end cap. The surface of the suction end cap is provided with a suction port that communicates with the suction chamber. The suction port is connected to the corresponding vacuum equipment, so that the pure water flowing through the degassing chamber undergoes transmembrane mass transfer degassing between the outside of the hollow fiber membrane bundle and the negative pressure gas in the suction chamber.

[0008] The outlet is located near the exhaust end cap of the degassing pipe and is used to discharge the pure water that has been degassed by the corresponding degassing chamber.

[0009] Preferably, a first disturbance enhancement flow channel component, a second disturbance enhancement flow channel component, and a third disturbance enhancement flow channel component are respectively provided in the first degassing pipe, the second degassing pipe, and the third degassing pipe. The first disturbance enhancement flow channel component is arranged between the first drain outlet and the first outlet in the first degassing pipe, the second disturbance enhancement flow channel component is arranged between the second drain outlet and the second outlet in the second degassing pipe, and the third disturbance enhancement flow channel component is arranged between the third drain outlet and the third outlet in the third degassing pipe. The first disturbance enhancement channel component, together with the outer wall of the first water inlet pipe and the inner wall of the first degassing pipe, forms a first disturbance channel that extends axially along the first degassing pipe and bends circumferentially. The second disturbance enhancement channel component, together with the outer wall of the second water inlet pipe and the inner wall of the second degassing pipe, forms a second disturbance channel that extends axially along the second degassing pipe and bends circumferentially. The third disturbance enhancement channel component, together with the outer wall of the third water inlet pipe and the inner wall of the third degassing pipe, forms a third disturbance channel that extends axially along the third degassing pipe and bends circumferentially.

[0010] Furthermore, the first disturbance enhancement flow channel component, the second disturbance enhancement flow channel component, and the third disturbance enhancement flow channel component are respectively the first spiral guide vane, the second spiral guide vane, and the third spiral guide vane.

[0011] Specifically, a control method applied to the above-mentioned electronic-grade ultrapure water preparation system includes the following steps: The system collects the dissolved oxygen, dissolved carbon dioxide, and temperature values ​​output by the monitoring components installed on the pipeline between the first heat exchange outlet and the first inlet, the monitoring components installed on the pipeline between the first outlet and the second inlet, the monitoring components installed on the pipeline between the second outlet and the third inlet, and the monitoring components installed on the pipeline between the third outlet and the second heat exchange inlet. The dissolved oxygen and dissolved carbon dioxide detection values ​​of each monitoring component are compared with the preset dissolved oxygen and dissolved carbon dioxide thresholds, respectively, and the temperature detection values ​​of each monitoring component are compared with the preset water temperature range to determine whether there are conditions where dissolved oxygen and / or dissolved carbon dioxide exceed the standard or the water temperature deviates from the preset water temperature range at each monitoring location. When the comparison and judgment step determines that at least one monitoring location has excessive dissolved oxygen and / or dissolved carbon dioxide and / or water temperature deviates from the preset water temperature range, the control unit, based on the correspondence between the corresponding monitoring location and each degassing mechanism and the first heat exchange mechanism and the second heat exchange mechanism, adjusts the vacuum degree of the vacuum equipment corresponding to at least two degassing mechanisms and / or adjusts the opening of the first flow regulating actuator and the second flow regulating actuator, thereby ensuring that the dissolved oxygen content and dissolved carbon dioxide content of the pure water entering the second heat exchange mechanism from the third outlet meet the preset indicators, while controlling the water temperature of the pure water flowing out from the second heat exchange outlet within the preset water temperature range.

[0012] The beneficial effects of the embodiments of the present invention are as follows: 1. By employing a multi-stage series degassing mechanism and a precise online monitoring system, the electronic-grade ultrapure water preparation system of this invention can precisely adjust the operating parameters of the degassing unit, such as vacuum degree and flow rate, based on real-time data of dissolved oxygen, dissolved carbon dioxide, and water temperature. This refined linkage control effectively solves the problem of low degassing membrane efficiency caused by fluctuations in influent water quality and temperature in existing technologies, avoiding the crude control method of using fixed vacuum degree and flow rate in traditional methods. Furthermore, through this refined adjustment, this invention also significantly reduces system energy consumption, ensures that dissolved oxygen and carbon dioxide levels consistently meet standards under complex high-salinity conditions, and maintains the terminal water temperature within a preset range. This optimized control not only improves water quality stability and system operating efficiency but also guarantees the long-term stability of the membrane module, avoids scaling and other problems, and ultimately enhances the overall performance and economy of the ultrapure water preparation system.

[0013] 2. Because the control method of this invention, based on multi-point monitoring, segmented judgment, and linkage adjustment, further employs a technical means of binding control objects to different monitoring locations: when the monitoring component between the first heat exchange outlet and the first inlet exceeds the limit, the first-stage degassing is enhanced by prioritizing the increase of the vacuum degree of the first vacuum pumping device corresponding to the first degassing mechanism and / or increasing the opening of the first flow regulation actuator; when the monitoring component between the first outlet and the second inlet and / or the second outlet and the third inlet exceeds the limit, the vacuum degree is increased only for the vacuum pumping devices corresponding to the second degassing mechanism and / or the third degassing mechanism to enhance the subsequent degassing; and when the monitoring component between the third outlet and the second heat exchange inlet detects that dissolved oxygen and dissolved carbon dioxide have reached the standard but the water temperature is too high, the vacuum degree of at least one vacuum pumping device is reduced and / or increased. By adjusting the opening of the second flow rate actuator, the overall degassing intensity is reduced while the terminal heat exchange intensity is increased. Therefore, it can accurately distinguish whether the problem is insufficient degassing in the upstream stage, insufficient degassing in the downstream stage, or only abnormal water temperature, based on the over-limit position under different operating conditions. This avoids the crude adjustment mode of existing technologies that can only increase the overall vacuum and flow rate. It effectively solves the technical problems of difficulty in accurately locating the source of the problem in the degassing process and the high energy consumption caused by the frequent use of global over-degassing, which still makes it difficult to achieve dual stability of water quality and water temperature. This enables hierarchical closed-loop control of multi-stage degassing processes and synergistic optimization of upstream and downstream heat exchange units. While ensuring that the terminal dissolved oxygen and dissolved carbon dioxide meet the standards for a long time, it significantly reduces unnecessary vacuum load and circulation flow, and enables the terminal water temperature to quickly return to the preset range and improves the overall energy efficiency and operational stability of the system. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the degassing device according to an embodiment of the present invention.

[0015] Figure 2 This is a cross-sectional view of a degassing device according to an embodiment of the present invention.

[0016] Figure 3 This is a schematic diagram of the structure of the first spiral guide plate and the first hollow fiber membrane bundle in a connected state, as shown in an embodiment of the present invention.

[0017] Figure 4 This is a schematic cross-sectional view of a first spiral guide vane and a first hollow fiber membrane bundle in a connected state, as shown in an embodiment of the present invention.

[0018] Figure 5 This is a flowchart illustrating a control method for an electronic-grade ultrapure water preparation system according to an embodiment of the present invention.

[0019] Figure 6 yes Figure 5 A flowchart of the intermediate linkage adjustment steps.

[0020] Wherein: 1. First heat exchange mechanism; 110, first heat exchange inlet; 120, first heat exchange outlet; 130, first heat exchange medium inlet; 140, first heat exchange medium outlet; 2. First degassing mechanism; 210, first degassing pipe; 211, first outlet; 220, first inlet; 230, first water inlet pipe; 231, first drain outlet; 240, first degassing assembly; 241, first fixing member; 242, first suction end cap; 2421, first suction chamber; 2422, first suction port; 243, first hollow fiber membrane bundle; 250, first spiral guide vane; 3. Second degassing mechanism; 310, second degassing pipe; 311, second inlet; 312, second outlet; 320, second water inlet pipe; 321, second drain outlet; 330, second degassing assembly; 331, second fixing member; 332, second hollow fiber membrane bundle; 333, second suction end cap; 3331, second suction port; 3332, second suction chamber; 340, second spiral guide vane; 4, third degassing mechanism; 410, third degassing pipe; 411, third inlet; 412, third outlet; 420, third water inlet pipe; 421, third drain outlet; 430, third degassing assembly; 431, third fixing component; 432, third hollow fiber membrane bundle; 433, third suction end cap; 4331, third suction port; 4332, third suction chamber; 440, third spiral guide vane; 5, first external pipe; 6, second external pipe; 7, second heat exchange mechanism; 710, second heat exchange inlet; 720, second heat exchange outlet; 730, second heat exchange medium inlet; 740, second heat exchange medium outlet; 8, dissolved oxygen sensor; 9, carbon dioxide sensor; 10, temperature sensor. Detailed Implementation

[0021] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0022] See Figures 1 to 2This application discloses a preferred embodiment of an electronic-grade ultrapure water preparation system, including a first heat exchange mechanism 1, multiple degassing mechanisms, a second heat exchange mechanism 7, a monitoring mechanism, and a control unit. The first heat exchange mechanism 1 includes a first heat exchange channel, a first heat exchange medium channel, and a first flow regulation actuator connected to the first heat exchange medium channel. The first heat exchange channel is sequentially provided with a first heat exchange inlet 110 and a first heat exchange outlet 120. The first heat exchange medium channel is sequentially provided with a first heat exchange medium inlet 130 and a first heat exchange medium outlet 140, and is connected to the cooling water outlet of at least one vacuum pump. The cooling wastewater discharged by the vacuum pump serves as the first heat exchange medium to exchange heat with the pure water to be degassed in the first heat exchange channel, so that the pure water flowing out of the first heat exchange outlet 120 reaches a first preset temperature. The multiple degassing mechanisms only include the first degassing mechanism 2 connected in series. The second degassing mechanism 3 and the third degassing mechanism 4 are connected in series. Each degassing mechanism includes a degassing chamber for pure water to flow through, an inlet and an outlet connected to the degassing chamber, an exhaust port connected to the degassing chamber, and a vacuum device connected to the exhaust port, so that the pure water entering each degassing chamber flows under negative pressure and is degassed of dissolved gases. Specifically, the inlet and outlet of the first degassing mechanism 2 are the first inlet 220 and the first outlet 211, respectively; the inlet and outlet of the second degassing mechanism 3 are the second inlet 311 and the second outlet 312, respectively; and the inlet and outlet of the third degassing mechanism 4 are the third inlet 411 and the third outlet 412, respectively. The third outlet 412 is connected to the first inlet 220 and the first heat exchange outlet 120. The first outlet 211 is connected to the second inlet 311, and the second outlet 312 is connected to the third inlet 411. The second heat exchange mechanism 7 includes a second heat exchange channel, a second heat exchange medium channel, and a second flow regulating actuator connected to the second heat exchange medium channel. The second heat exchange channel is provided with a second heat exchange inlet 710 and a second heat exchange outlet 720 in sequence. The second heat exchange inlet 710 is connected to the third outlet 412. The second heat exchange medium channel is provided with a second heat exchange medium inlet 730 and a second heat exchange medium outlet 740 in sequence for introducing cooling water, so that the pure water in the second heat exchange channel is connected to the cooling water. Water heat exchange is used to bring the pure water flowing out of the second heat exchange outlet 720 to a second preset temperature. The monitoring mechanism includes a monitoring component installed on the pipeline between the first heat exchange outlet 120 and the first inlet 220, a monitoring component installed on the pipeline between the first outlet 211 and the second inlet 311, a monitoring component installed on the pipeline between the second outlet 312 and the third inlet 411, and a monitoring component installed on the pipeline between the third outlet 412 and the second heat exchange inlet 710. Each monitoring component includes at least a dissolved oxygen sensor 8, a carbon dioxide sensor 9, and a temperature sensor 10, which are used to detect the dissolved oxygen content, dissolved carbon dioxide content, and temperature of the pure water in the corresponding pipeline.The control unit is electrically connected to each monitoring component, the corresponding vacuum equipment of each degassing mechanism, and the first and second flow regulation actuators. The control unit is configured to, based on the detection results of each monitoring component, adjust the vacuum level of at least two vacuum devices and / or the flow rate of pure water in the first heat exchange mechanism 1 and the second heat exchange mechanism 7, so that the pure water flowing out of the second heat exchange outlet 720 meets the preset dissolved oxygen and dissolved carbon dioxide indicators while maintaining its temperature within a preset range.

[0023] Specifically: The first heat exchange mechanism 1 is a plate heat exchanger body or a shell-and-tube heat exchanger. The interior of the plate heat exchanger is formed by multiple corrugated heat exchange plates stacked to form several mutually spaced flow channels. Adjacent flow channels are separated by sealing gaskets. One part of the flow channels constitutes the first heat exchange channel for the pure water to be degassed to flow through, and the other part of the flow channels constitutes the first heat exchange medium channel for the cooling wastewater of the vacuum pump to flow through. The plate heat exchanger has a first heat exchange inlet 110 and a first heat exchange outlet 120 on its outer side for connection to a pure water pipeline. The first heat exchange inlet 110 is located upstream of the pure water flow direction and is used to receive the pure water to be degassed from the pre-treatment unit. The first heat exchange outlet 120 is located downstream of the pure water flow direction and is used to output the preheated pure water to be degassed. The plate heat exchanger also has a first heat exchange medium inlet 130 and a first heat exchange medium outlet 140 on its outer side for connection to the vacuum pump cooling water outlet and the main discharge pipe. The first heat exchange medium inlet 130 is connected to the cooling water outlet pipeline of at least one vacuum pump, and the first heat exchange medium outlet 140 is connected to the plant cooling water return pipe or centralized discharge pipeline, so that when the cooling wastewater discharged by the vacuum pump flows in the first heat exchange medium channel, it transfers heat with the pure water to be degassed in the first heat exchange channel.

[0024] The first flow regulation actuator is arranged on the inlet or outlet pipeline of the first heat exchange medium channel. It can be an electric regulating valve or a pneumatic regulating valve. Its valve body is connected in series with the vacuum pump cooling wastewater pipeline. By changing the valve core opening, the flow rate of the vacuum pump cooling wastewater in the first heat exchange medium channel is adjusted, thereby controlling the heating degree of the pure water to be degassed in the first heat exchange channel, so that the temperature of the pure water flowing out from the first heat exchange outlet 120 is stabilized near the first preset temperature.

[0025] The first degassing mechanism 2, the second degassing mechanism 3, and the third degassing mechanism 4 can have the same or similar structures, and preferably all adopt the form of hollow fiber membrane contactors. Each stage of the degassing mechanism includes a degassing unit with a shell. The shell has a degassing chamber for pure water to flow through. The axial ends of the shell are respectively provided with inlets and outlets for pure water to enter and exit. The side wall of the shell is provided with an exhaust port communicating with the degassing chamber. The exhaust port is connected to a corresponding vacuum pump through a pipeline. The shell is preferably a cylindrical metal shell, whose inner surface and the hollow fiber membrane bundles filled inside together form the degassing chamber space. The two ends of the hollow fiber membrane bundles are fixed and sealed to the shell by end sealing plates or tube plates. The outer surface of the shell is provided with fixing lugs or support rings for mounting brackets so as to fix each degassing mechanism to a common frame.

[0026] In each degassing mechanism, the inlet and outlet are preferably located on the end caps at both ends of the housing. The inlet end cap has a pure water inlet distribution cavity. After entering through the inlet, the pure water is evenly distributed within the distribution cavity, then flows axially along the degassing chamber through the annular flow channel outside the hollow fiber membrane bundle, and finally collects and exits from the outlet on the outlet end cap. The extraction port is preferably radially located in the middle of the housing or near one end, and is connected to the suction port of a vacuum pump via a short pipe. The vacuum pump can be a vacuum pump or a vacuum unit. The extraction port communicates with the gas phase cavity inside the hollow fiber membrane bundle or inside the housing, allowing dissolved gases in the degassing chamber to be drawn across the membrane and discharged to the vacuum side. By installing a silencer and a condensation unit on the exhaust side of the vacuum pump, noise can be reduced and the released water vapor and impurities can be treated.

[0027] In this embodiment, the inlet and outlet of the first degassing mechanism 2 are named first inlet 220 and first outlet 211, respectively; the inlet and outlet of the second degassing mechanism 3 are named second inlet 311 and second outlet 312, respectively; and the inlet and outlet of the third degassing mechanism 4 are named third inlet 411 and third outlet 412, respectively. The first heat exchange outlet 120 is connected to the first inlet 220 via a short pipe or distribution pipe, allowing the preheated pure water to be degassed to directly enter the degassing chamber of the first degassing mechanism 2 for primary degassing. The first outlet 211 is connected to the second inlet 311 via a connecting pipe, allowing the pure water after coarse degassing by the first degassing mechanism 2 to enter the degassing chamber of the second degassing mechanism 3 for secondary degassing. The second outlet 312 is connected to the third inlet 411 via a connecting pipe, allowing the pure water after secondary degassing to enter the degassing chamber of the third degassing mechanism 4 for tertiary fine degassing, forming a complete multi-stage series system. The connecting pipes are preferably arranged with equal or gradually decreasing diameters to ensure that the inlet and outlet pressures of each degassing unit are within a reasonable range.

[0028] The second heat exchange mechanism 7 is similar in structure to the first heat exchange mechanism 1, including a second heat exchange channel, a second heat exchange medium channel, and a second flow regulation actuator connected to the second heat exchange medium channel. The second heat exchange mechanism 7 is preferably a plate or shell-and-tube heat exchanger, internally configured with a second heat exchange channel for the pure water side and a second heat exchange medium channel for the cooling medium side. The inlet of the second heat exchange channel serves as the second heat exchange inlet 710, which is connected to the third outlet 412 via a pure water pipeline. This allows the pure water, after undergoing multi-stage degassing, to immediately enter the second heat exchange channel after exiting the third degassing mechanism 4, where it exchanges heat with the cooling water flowing within the second heat exchange medium channel. A second heat exchange outlet 720 is located at the downstream end of the second heat exchange channel, used to output electronic-grade ultrapure water that has been cooled to a second preset temperature. The inlet and outlet of the second heat exchange medium channel serve as the second heat exchange medium inlet 730 and the second heat exchange medium outlet 740, respectively connected to the water supply pipe and return pipe of the plant chilled water system or process cooling water system. The second flow regulation actuator is connected in series on the inlet or outlet pipe of the second heat exchange medium channel. By adjusting the valve opening, the cooling water flow rate is changed, and together with the first heat exchange mechanism 1, the pure water temperature is precisely regulated.

[0029] In this embodiment, the monitoring mechanism is a collection of multiple monitoring components, each installed on a corresponding pure water pipeline. Specifically, a short pipe or sampling chamber with a measurement interface is welded onto the pipe section between the first heat exchange outlet 120 and the first inlet 220 to install the first monitoring component (not shown in the figure); a second monitoring component is arranged on the pipe section between the first outlet 211 and the second inlet 311; a third monitoring component is arranged on the pipe section between the second outlet 312 and the third inlet 411; and a fourth monitoring component (not shown in the figure) is arranged on the pipe section between the third outlet 412 and the second heat exchange inlet 710. Each monitoring component includes at least a dissolved oxygen sensor 8, a carbon dioxide sensor 9, and a temperature sensor 10, which are connected to the main pipeline via a tee connector, a measuring cell, or an insertable protective sleeve. The dissolved oxygen sensor 8 is preferably a polarographic or fluorescence-quenched electrode, which contacts the pure water in the pipe through a sensing head to measure the dissolved oxygen concentration in real time. The carbon dioxide sensor 9 is preferably a membrane or optical online analyzer, with the sensing probe placed in a bypass measurement cell and connected to the main pipe through a bypass inlet and outlet. The temperature sensor 10 is preferably a platinum resistance thermometer or thermocouple, which exchanges heat with the pure water fluid through an insert sleeve to measure the water temperature at the corresponding location in real time. The signal cables of all sensors are centrally laid in the control cabinet where the control unit is located.

[0030] The control unit is preferably an automatic control device with a programmable logic controller (PLC) as its core, internally including a central processing module, an analog input / output module, a digital input / output module, and a communication interface module. The analog input terminals of the control unit are connected to the signal output terminals of the dissolved oxygen sensor 8, carbon dioxide sensor 9, and temperature sensor 10 in each monitoring component, respectively, to receive real-time dissolved oxygen, dissolved carbon dioxide, and temperature values ​​at each monitoring location. The analog or digital output terminals of the control unit are connected to the control terminals of the vacuum equipment corresponding to each degassing mechanism, allowing adjustment of the vacuum level and pumping capacity of each degassing mechanism by regulating the output frequency of the vacuum pump inverter, the opening degree of the vacuum regulating valve, or its start / stop status. The output terminals of the control unit are also electrically connected to the actuators of the first and second flow regulation actuators, respectively, changing the flow rate of the heat exchange medium in the first and second heat exchange medium channels by outputting control signals. The control unit has pre-stored control strategies and target parameter ranges for dissolved oxygen, dissolved carbon dioxide and water temperature under different operating conditions. It can realize the linkage adjustment of multi-stage degassing and front and rear heat exchange units, and the set values ​​and control parameters can be set and viewed through human-machine interface or upper-level monitoring system.

[0031] In this embodiment, the working principle and operation process of the electronic-grade ultrapure water preparation system are roughly as follows: The pure water to be degassed from the pre-treatment unit first enters the first heat exchange channel. In the first heat exchange medium channel, it is heated to a first preset temperature conducive to the removal of dissolved gases by the cooling wastewater from the vacuum pump. After exiting the first heat exchange outlet 120, it immediately passes through the first monitoring unit, which monitors its dissolved oxygen content, dissolved carbon dioxide content, and temperature in real time. Subsequently, the preheated pure water enters the first degassing mechanism 2, where it comes into contact with the negative pressure gas generated by the first vacuum pump across the membrane in the first degassing chamber, completing the first stage of degassing. After exiting the first outlet 211, it is monitored online by the second monitoring unit, and then sequentially enters the second degassing mechanism 3 and the third degassing mechanism 4 to complete the second and third stages of degassing. The pure water exiting the third degassing mechanism 4, after being detected by the fourth monitoring unit, enters the second heat exchange channel, where it exchanges heat with the cooling water in the second heat exchange medium channel to cool down. Finally, electronic-grade ultrapure water at a stable temperature is output from the second heat exchange outlet 720. During system operation, the control unit continuously collects detection data from each monitoring unit, compares the dissolved oxygen and dissolved carbon dioxide detection values ​​with the corresponding preset thresholds, and compares the temperature detection values ​​with the preset water temperature range. Based on the exceedance of limits at each monitoring location, it comprehensively judges whether the problem is due to insufficient degassing in the pre-stage, insufficient degassing in the post-stage, or abnormal water temperature. Then, it adjusts the vacuum degree of at least two degassing mechanisms and the flow rate in the first and second heat exchange medium channels in a targeted manner to achieve coordinated closed-loop control of water quality and water temperature.

[0032] In this embodiment, the first heat exchange mechanism 1 uses a vacuum pump to cool wastewater and preheat the pure water to be degassed. The degree of preheating is precisely controlled by the first flow regulating actuator. This is combined with a multi-stage series degassing structure consisting of only the first degassing mechanism 2, the second degassing mechanism 3, and the third degassing mechanism 4, as well as multi-point monitoring components arranged between the first heat exchange outlet 120 and the first inlet 220, between the first outlet 211 and the second inlet 311, between the second outlet 312 and the third inlet 411, and between the third outlet 412 and the second heat exchange inlet 710. The control unit adjusts at least two degassing mechanisms in conjunction with the dissolved oxygen, dissolved carbon dioxide, and temperature detection results output by each monitoring component. The corresponding vacuum level of the vacuum equipment and the flow rate of pure water in the first heat exchanger 1 and the second heat exchanger 7 effectively solve the technical problems in the existing technology where the operating parameters of the degassing device are basically fixed, and global rough adjustments can only be made by relying on a few online points or human experience, making it difficult to respond in a timely manner to fluctuations in the water quality and temperature of the upstream process, easily leading to excessive dissolved oxygen or dissolved carbon dioxide, and making it difficult to stabilize the terminal water temperature and causing high system energy consumption. Thus, it achieves the technical effect of keeping the degassing process of electronic-grade ultrapure water highly efficient and controllable under complex working conditions with high salt content, ensuring that dissolved oxygen and dissolved carbon dioxide meet the standards for a long time, while maintaining the terminal water supply temperature within the preset range and significantly optimizing the overall energy consumption and equipment operating load.

[0033] Furthermore, in some embodiments, the first degassing mechanism 2, the second degassing mechanism 3, and the third degassing mechanism 4 each include a degassing pipe, a water inlet pipe arranged within the degassing pipe, and a degassing assembly arranged within the degassing pipe and circumferentially surrounding the water inlet pipe. The degassing pipe has an inner cavity forming a degassing chamber, and its wall has an inlet and an outlet. One end of the water inlet pipe is in fluid communication with a water inlet area inside the degassing pipe that connects to the corresponding inlet. The other end of the water inlet pipe is closed, and at least one drain outlet is provided on the wall of the water inlet pipe on the side closest to the corresponding inlet. This allows pure water entering the degassing pipe through the corresponding inlet to flow into the water inlet pipe via the water inlet area and then into the corresponding degassing chamber via the drain outlet, forming a ring-shaped flow area around the water inlet pipe within the degassing chamber. The degassing assembly includes multiple hollow fibers. The system includes hollow fiber membrane bundles, fixed components at both ends of the degassing tube, and vacuum end caps. One end of each hollow fiber membrane bundle is sealed and fixed to the fixed component, while the other end is connected to a vacuum chamber located inside the vacuum end cap. The surface of the vacuum end cap is provided with a vacuum port that communicates with the vacuum chamber. The vacuum port is connected to a corresponding vacuum device, allowing pure water flowing through the degassing chamber to undergo transmembrane mass transfer and degassing between the outside of the hollow fiber membrane bundle and the negative pressure gas inside the vacuum chamber. The outlet is located near the vacuum end cap of the degassing tube and is used to discharge the pure water that has been degassed by the corresponding degassing chamber.

[0034] In a specific implementation of the above embodiment, the electronic-grade ultrapure water preparation system further includes a first external pipe 5 and a second external pipe 6; the first degassing mechanism 2 includes a first degassing pipe 210, a first water inlet pipe 230, a first degassing component 240, a first vacuum end cap 242, and a first vacuum device: the inner cavity of the first degassing pipe 210 forms a first degassing chamber, and the first inlet 220 is connected to the first degassing chamber through the first water inlet pipe 230 disposed inside the first degassing pipe 210. One end of the first water inlet pipe 230 is connected to the first inlet 220, and the other end is closed. At least one first drain outlet 231 is provided on the pipe wall near the first inlet 220, allowing water to enter through the first inlet 220. Pure water from the first inlet pipe 230 flows into the first degassing chamber through the first outlet 231. The first degassing assembly 240 includes multiple first hollow fiber membrane bundles 243 arranged circumferentially around the first inlet pipe 230, and first fixing members 241 and first suction end caps 242 disposed at both ends of the first degassing pipe 210. The first suction end cap 242 has a first suction chamber 2421 inside. One end of each first hollow fiber membrane bundle 243 is closed and fixed to the first fixing member 241, and the other end communicates with the first suction chamber 2421 inside the first suction end cap 242. The surface of the first suction end cap 242 is provided with a first suction port 2422 communicating with the first suction chamber 2421. The first suction port 2422 is connected to the first vacuum chamber. The equipment is connected. A first outlet 211 is provided on the pipe wall of the first degassing pipe 210 near the first suction end cap 242, for discharging pure water degassed in the first degassing chamber. The second degassing mechanism 3 includes a second degassing pipe 310, a second water inlet pipe 320, a second degassing component 330, a second suction end cap 333, and a second vacuum device. The inner cavity of the second degassing pipe 310 forms the second degassing chamber. One end of the second degassing pipe 310 is sealed to the side of the first suction end cap 242 of the first degassing mechanism 2 away from the first degassing pipe 210, thus sealing one end of the second degassing pipe 310. A second inlet 311 is provided on the pipe wall of the second degassing pipe 310 near this sealed end. The first external pipe 5 is connected to the first outlet 211, so that the pure water degassed by the first degassing mechanism 2 is introduced into the second degassing pipe 310. The second degassing pipe 310 forms a relatively closed second water inlet space in the area where the second inlet 311 is located. A second connecting port is opened on one side of the second water inlet space. The second water inlet pipe 320 is set in the second degassing pipe 310 and connected to the second connecting port. One end of the second water inlet pipe 320 is connected to the second connecting port, and the other end is closed. At least one second drain port 321 is opened on the pipe wall near the second connecting port, so that the pure water entering the second water inlet space enters the second water inlet pipe 320 through the second connecting port and then flows into the second degassing chamber through the second drain port 321.The second degassing assembly 330 includes multiple second hollow fiber membrane bundles 332 arranged circumferentially around the second water inlet pipe 320, and second fixing members 331 and second suction end caps 333 disposed at both ends of the second degassing pipe 310. A second suction chamber 3332 is formed inside the second suction end cap 333. One end of each second hollow fiber membrane bundle 332 is sealed and fixed to the second fixing member 331, and the other end communicates with the second suction chamber 3332 inside the second suction end cap 333. A second suction port 3331 communicating with the second suction chamber 3332 is provided on the surface of the second suction end cap 333. The second suction port 3331 is connected to a second vacuum device. The second degassing pipe 310 has a pipe wall near the end of the second suction end cap 333. A second outlet 312 is provided for discharging the pure water degassed by the second degassing chamber. The third degassing mechanism 4 includes a third degassing pipe 410, a third water inlet pipe 420, a third degassing component 430, a third suction end cap 433, and a third vacuum device. The inner cavity of the third degassing pipe 410 forms the third degassing chamber. One end of the third degassing pipe 410 is sealed to the side of the second suction end cap 333 of the second degassing mechanism 3 away from the second degassing pipe 310 to close one end of the third degassing pipe 410. A third inlet 411 is provided on the pipe wall of the third degassing pipe 410 near the sealed end. The third inlet 411 is connected to the second outlet 312 through a second external pipe 6, allowing the pure water degassed by the second degassing mechanism 3 to pass through. The water enters the third degassing pipe 410; within the third degassing pipe 410, a relatively enclosed third water inlet space is formed in the area where the third inlet 411 is located. A third connecting port is provided on one side of the third water inlet space. A third water inlet pipe 420 is installed inside the third degassing pipe 410 and connected to the third connecting port. One end of the third water inlet pipe 420 is connected to the third connecting port, and the other end is closed. At least one third drain port 421 is provided on the pipe wall of the third water inlet pipe 420 near the third connecting port, so that pure water entering the third water inlet space enters the third water inlet pipe 420 through the third connecting port and then flows into the third degassing chamber through the third drain port 421. The third degassing assembly 430 includes multiple pipes arranged circumferentially around the third water inlet pipe 420. The third hollow fiber membrane bundle 432, the third fixing member 431 and the third suction end cap 433 are disposed at both ends of the third degassing tube 410. The third suction end cap 433 has a third suction chamber 4332 inside. One end of each third hollow fiber membrane bundle 432 is closed and fixed to the third fixing member 431, and the other end is connected to the third suction chamber 4332 inside the third suction end cap 433. The surface of the third suction end cap 433 is provided with a third suction port 4331 that is connected to the third suction chamber 4332. The third suction port 4331 is connected to the third vacuum equipment. The third degassing tube 410 is provided with a third outlet 412 on the tube wall at the end near the third suction end cap 433 for discharging the pure water after degassing in the third degassing chamber.

[0035] Specifically: The first degassing mechanism 2, the second degassing mechanism 3, and the third degassing mechanism 4 have the same basic structural form. They all adopt a coaxial arrangement of degassing pipes and water inlet pipes, with degassing components arranged circumferentially around the water inlet pipe inside the degassing pipe, thus forming an annular flow area around the water inlet pipe within the degassing chamber. Each stage of the degassing mechanism includes a degassing pipe, a water inlet pipe arranged within the degassing pipe, and degassing components arranged circumferentially around the water inlet pipe. The inner cavity of the degassing pipe forms the degassing chamber as a whole. The pipe wall of the degassing pipe has an inlet and an outlet communicating with the degassing chamber for the entry and exit of pure water. The degassing pipe is preferably a cylindrical shell with one or both ends detachable and closed. Its cross-section can be circular, or it can be designed as an elliptical or polygonal cross-section depending on the arrangement space conditions, in order to optimize the arrangement density within a limited space. The degassing pipe can be made of stainless steel through integral stretching or rolling and welding. Its two ends are connected to end caps through flanges or threaded structures. The inner wall can be polished as needed to reduce flow resistance and contaminant adhesion.

[0036] In each stage of the degassing mechanism, the inlet pipe adopts a slender tubular structure, coaxially arranged inside the degassing pipe. Its outer diameter is smaller than the inner diameter of the degassing pipe, forming an annular space between the outer wall of the inlet pipe and the inner wall of the degassing pipe. This annular space is the main flow channel for pure water in the degassing chamber. The inlet pipe can be a thin-walled circular pipe, preferably made of the same or similar metal material as the degassing pipe to ensure coordinated thermal expansion. In some embodiments, the inlet pipe can also be made of engineering plastic or a plastic-lined metal composite structure to reduce weight and processing costs. One end of the inlet pipe is connected to the water inlet area inside the degassing pipe near the inlet. This water inlet area can be in the form of an annular distribution cavity or an end cavity. By setting a baffle and a flow guiding structure on the inner side of the inlet end of the degassing pipe, the pure water entering from the inlet is first buffered and pressure-equalized in the water inlet area before entering the inlet pipe. The other end of the inlet pipe is a closed structure, such as by welding a cap or end plug, so that the pure water, after flowing axially in the inlet pipe, cannot be directly discharged from the end, but must escape through a drain outlet located on the side of the inlet pipe near the inlet. Several drain outlets are provided on the pipe wall near the corresponding inlet. These drain outlets can be circular holes or elongated holes evenly distributed along the circumference of the pipe, or, as needed, a group of holes arranged in multiple rings, used to evenly distribute the pure water in the inlet pipe into the degassing chamber. With this structure, the pure water entering the degassing pipe through the corresponding inlet first enters the inlet pipe through the inlet area, and then flows into the corresponding degassing chamber through the drain outlet. Within the degassing chamber, a continuous annular flow area is formed around the inlet pipe, ensuring that the pure water flows fully along the axial direction of the degassing pipe outside the hollow fiber membrane bundle.

[0037] In each stage of the degassing mechanism, the degassing assembly is arranged circumferentially within the inlet pipe, forming a ring-shaped structure fitted over the outside of the inlet pipe. The degassing assembly includes multiple hollow fiber membrane bundles, as well as fixing members and extraction end caps located at both ends of the degassing pipe. The hollow fiber membrane bundles are composed of numerous slender hollow fibers, with both ends of each bundle fixed between the end fixing member and the extraction end cap, forming a bundle-like structure. The fixing member is preferably an annular tube sheet or a porous support plate, its outer circumference sealed to the inner wall of the degassing pipe, and its inner circumference arranged around the inlet pipe, forming several through holes for the hollow fiber membrane bundles to pass through. One end of each hollow fiber membrane bundle passes through the fixing member and is sealed at the end, making that end a closed end. The extraction end cap is located at the other end of the degassing pipe, forming an extraction chamber on its inner side. The other end of each hollow fiber membrane bundle passes through the extraction end cap and communicates with the interior of the extraction chamber, so that the hollow channels of the hollow fiber membrane are connected to the gas collection space at this end. The outer surface of the extraction end cap has an extraction port that communicates with the extraction chamber. The extraction port is connected to a corresponding vacuum pump via a pipeline to apply negative pressure to the extraction chamber and the interior of each hollow fiber membrane. The degassing assembly is arranged circumferentially around the water inlet pipe. It can be a single-ring annular bundle or a multi-ring concentric annular bundle to improve membrane area and degassing efficiency. In different embodiments, the hollow fiber membrane bundles can be arranged in a dense hexagonal arrangement, a concentric annular arrangement, or other regular arrays in cross-section to balance membrane flux, pressure drop, and processing difficulty.

[0038] In a specific embodiment of the first degassing mechanism 2, the inner cavity of the first degassing pipe 210 constitutes a first degassing chamber, and the first inlet 220 is connected to the first degassing chamber through a first water inlet pipe 230 disposed inside the first degassing pipe 210. One end of the first water inlet pipe 230 is connected to the first inlet 220. After pure water enters the first degassing pipe 210 through the first inlet 220, it first enters the water inlet area located at the inlet end, and then flows into the interior of the first water inlet pipe 230. The other end of the first water inlet pipe 230 is closed to prevent pure water from flowing out directly from the end. The first water inlet pipe 230 has at least one first drain outlet 231 on the side wall near the first inlet 220. Preferably, it is a plurality of fine holes or elongated holes evenly distributed in the circumferential direction, so that the pure water entering the first water inlet pipe 230 through the first inlet 220 flows evenly into the first degassing chamber through these drain outlets, and flows along the annular channel in the first degassing chamber towards the end of the first degassing pipe 210 near the first suction end cap 242. The first degassing assembly 240 includes multiple first hollow fiber membrane bundles 243 arranged circumferentially around the first water inlet pipe 230, and first fixing members 241 and first suction end caps 242 disposed at both ends of the first degassing pipe 210. The first fixing member 241 is fixed inside the first degassing pipe 210 near the inlet end, its outer circumference is sealed to the inner wall of the first degassing pipe 210, and its inner circumference is arranged around the first water inlet pipe 230. One end of each first hollow fiber membrane bundle 243 is sealed and fixed to the first fixing member 241, and the seal is achieved by potting material or welding process. The first suction end cap 242 is installed at one end of the first degassing pipe 210 near the outlet side, and a first suction chamber 2421 is formed inside. The other end of each first hollow fiber membrane bundle 243 passes through the first suction end cap 242 and communicates with the first suction chamber 2421. The outer surface of the first suction end cap 242 is provided with a first suction port 2422 communicating with the first suction chamber 2421. The first suction port 2422 is connected to the first vacuuming device through a vacuum pipeline. The first degassing pipe 210 is provided with a first outlet 211 on the pipe wall near the first suction end cap 242 for discharging the pure water after degassing in the first degassing chamber. With the above structure, when the pure water flows along the annular channel in the first degassing chamber, it surrounds the first water inlet pipe 230 and covers the outside of the first hollow fiber membrane bundle 243. Dissolved gas can pass through the hollow fiber membrane wall and enter the first suction chamber 2421, and be extracted by the first vacuuming device.

[0039] In a specific embodiment of the second degassing mechanism 3, the inner cavity of the second degassing pipe 310 constitutes a second degassing chamber. One end of the second degassing pipe 310 is sealed to the side of the first suction end cap 242 of the first degassing mechanism 2 away from the first degassing pipe 210. Through this sealed connection structure, one end of the second degassing pipe 310 is directly fixed to the outer wall of the suction end cap or the connecting flange of the first degassing mechanism 2, forming a continuous outer shell structure, thereby sealing that end of the second degassing pipe 310, so that pure water can only enter and flow out from the other end. A second inlet 311 is provided on the pipe wall of the second degassing pipe 310 near the sealed end. The second inlet 311 is connected to the first outlet 211 through the first external pipe 5, so that the pure water degassed by the first degassing mechanism 2 enters the interior of the second degassing pipe 310 from the first outlet 211 through the first external pipe 5. The second degassing pipe 310 forms a relatively enclosed second water inlet space in the area where the second inlet 311 is located. This water inlet space can be constructed by adding an annular baffle or a short inner cylinder inside the second degassing pipe 310, allowing the pure water entering from the second inlet 311 to first diffuse and buffer within the second water inlet space, avoiding direct impact on the inlet of the second water inlet pipe 320. A second connecting port is provided on one side of the second water inlet space, facing one end of the second water inlet pipe 320. The second water inlet pipe 320 is disposed inside the second degassing pipe 310 and connects to the second connecting port, so that one end of the second water inlet pipe 320 is connected to the second connecting port, and the other end is closed. At least one second drain port 321 is provided on the pipe wall of the second water inlet pipe 320 near the second connecting port, so that the pure water entering the second water inlet space enters the second water inlet pipe 320 through the second connecting port, and then flows evenly into the second degassing chamber through the second drain port 321, forming an annular flow area around the second water inlet pipe 320 within the second degassing chamber. The second degassing assembly 330 includes multiple second hollow fiber membrane bundles 332 arranged circumferentially around the second water inlet pipe 320, and second fixing members 331 and second suction end caps 333 disposed at both ends of the second degassing pipe 310. The second fixing members 331 are sealed to the inner wall of the second degassing pipe 310. One end of each second hollow fiber membrane bundle 332 is sealed and fixed to the second fixing member 331, and the other end communicates with a second suction chamber 3332 disposed in the second suction end cap 333 at the other end of the second degassing pipe 310. The outer surface of the second suction end cap 333 is provided with a second suction port 3331 communicating with the second suction chamber 3332. The second suction port 3331 is connected to a second vacuum device through a pipeline. A second outlet 312 is provided on the pipe wall of the second degassing pipe 310 near the second suction end cap 333 for discharging the pure water degassed by the second degassing chamber.

[0040] In a specific embodiment of the third degassing mechanism 4, the inner cavity of the third degassing pipe 410 constitutes a third degassing chamber. One end of the third degassing pipe 410 is sealed to the side of the second suction end cap 333 of the second degassing mechanism 3 away from the second degassing pipe 310. This end is sealed by a similar flange or welded structure, making the third degassing pipe 410 a cylindrical shell with one end closed. A third inlet 411 is provided on the pipe wall of the third degassing pipe 410 near the sealed end. The third inlet 411 is connected to the second outlet 312 through the second outer pipe 6, allowing pure water degassed by the second degassing mechanism 3 to enter the interior of the third degassing pipe 410 from the second outlet 312 through the second outer pipe 6. A relatively closed third water inlet space is formed in the area where the third inlet 411 is located inside the third degassing pipe 410. This third water inlet space is formed by an internal baffle or short cylinder structure to weaken the inlet jet and achieve uniform distribution. A third connecting port is provided on one side of the third water inlet space. The third water inlet pipe 420 is disposed inside the third degassing pipe 410 and connected to the third connecting port, so that one end of the third water inlet pipe 420 is connected to the third connecting port and the other end is closed. At least one third drain port 421 is provided on the pipe wall of the third water inlet pipe 420 near the third connecting port, so that pure water entering the third water inlet space enters the third water inlet pipe 420 through the third connecting port, and then flows into the third degassing chamber through the third drain port 421, forming an annular flow area around the third water inlet pipe 420 in the third degassing chamber. The third degassing assembly 430 includes multiple third hollow fiber membrane bundles 432 arranged circumferentially around the third water inlet pipe 420, as well as third fixing members 431 and third suction end caps 433 disposed at both ends of the third degassing pipe 410. The third fixing member 431 is used to fix and seal one end of the third hollow fiber membrane bundle 432. The third suction end cover 433 has a third suction chamber 4332 inside. The other end of each third hollow fiber membrane bundle 432 is connected to the third suction chamber 4332. The surface of the third suction end cover 433 is provided with a third suction port 4331 that is connected to the third suction chamber 4332. The third suction port 4331 is connected to the third vacuum equipment. The third degassing pipe 410 has a third outlet 412 on the pipe wall near the third suction end cover 433 for discharging the pure water after degassing in the third degassing chamber. Through the above arrangement, the three degassing mechanisms can be integrated in series in terms of shell shape, which reduces the space occupied and the number of external connection pipes and leakage risk.

[0041] In the aforementioned multi-stage degassing structure, the working principles of each stage of the degassing mechanism are basically the same. After pure water enters the corresponding degassing pipe from the upstream inlet, it is first buffered and evenly distributed within the inlet space, and then flows axially into the inlet pipe located inside the degassing pipe. Because the inlet pipe is closed at the tail end, the pure water can only escape through the drain outlet located near the inlet, forming an annular flow band that develops along the axial direction of the degassing pipe, moving closely against the outer side of the hollow fiber membrane bundle. The interior of the hollow fiber membrane bundle is connected to the suction chamber through the suction end cap, and is continuously evacuated by the corresponding vacuum equipment, maintaining a low-pressure or vacuum state inside the membrane. Driven by this pressure, the gaseous components dissolved in the pure water diffuse across the hollow fiber membrane wall into the membrane channels, and then collect in the suction chamber and are finally discharged, thereby achieving efficient removal of gases such as dissolved oxygen and dissolved carbon dioxide. The multi-stage series arrangement allows the first degassing unit 2 to perform coarse degassing, reducing most of the dissolved gas load. The second degassing unit 3 further reduces residual dissolved gas, while the third degassing unit 4 achieves fine degassing, enabling the effluent to meet more stringent gas content standards.

[0042] This multi-stage degassing structure is suitable for installation in the degassing unit of an electronic-grade ultrapure water system. It can be arranged horizontally or vertically depending on the available space. In a horizontal arrangement, the degassing pipes are arranged along a horizontal line, facilitating shared rack space with other equipment and allowing for easy maintenance of end caps and pipe interfaces. In a vertical arrangement, the vertical dimension minimizes the floor space required, and gravity facilitates gas-liquid separation. The system should ideally operate in a clean equipment room with moderate ambient temperature and humidity. The materials used for the degassing pipes and hollow fiber membrane bundles must meet the corrosion resistance and low precipitation requirements of the pure water system.

[0043] In this embodiment, because the degassing pipe and the water inlet pipe are arranged coaxially and a drain outlet is opened on the wall of the water inlet pipe, pure water must first be evenly distributed in the water inlet space before entering the water inlet pipe. Then, it overflows circumferentially into the degassing chamber through the drain outlet and forms a stable annular flow area along the outside of the water inlet pipe. At the same time, hollow fiber membrane bundles are arranged circumferentially inside the degassing pipe, and an extraction chamber and extraction port are integrated at one end. The three degassing mechanisms are sealed and connected to the extraction end cap through an external pipe to form a multi-stage series degassing channel. Therefore, it effectively solves the problems of existing technologies. The single-stage degassing device suffers from uneven internal flow field, short-circuit flow and dead zones, and insufficient degassing efficiency. Furthermore, the dispersed structure of each stage in a multi-stage degassing arrangement leads to complex piping and a large footprint. This invention addresses the technical challenges of constructing a compact, clear flow path, sufficient external membrane shearing, progressive degassing at each stage, and easy modular installation of a multi-stage degassing unit within a limited space. This allows electronic-grade ultrapure water to meet stringent dissolved gas control requirements with higher degassing efficiency, lower energy consumption, and better operational stability after multi-stage degassing.

[0044] Furthermore, to adapt to fluctuations in the parameters of the pure water to be degassed in the previous process, the control unit is configured as follows: When the monitoring component installed on the pipeline between the first heat exchange outlet 120 and the first inlet 220 detects that the dissolved oxygen and / or dissolved carbon dioxide in the pure water in the corresponding pipeline are higher than the first preset threshold, it increases the vacuum degree of the first vacuum pumping device and / or increases the opening degree of the first flow regulating actuator. When the monitoring component installed on the pipeline between the first outlet 211 and the second inlet 311 and / or the monitoring component installed on the pipeline between the second outlet 312 and the third inlet 411 detects that the dissolved oxygen and / or dissolved carbon dioxide in the pure water in the corresponding pipeline are higher than the corresponding preset threshold, the vacuum level of the corresponding second vacuum device and / or third vacuum device is increased. When the monitoring component installed on the pipeline between the third outlet 412 and the second heat exchange inlet 710 detects that the dissolved oxygen and dissolved carbon dioxide in the pure water in the corresponding pipeline both meet the preset indicators and the water temperature is higher than the upper limit of the preset range of outlet water temperature, the vacuum degree of at least one vacuum pumping device is reduced and / or the opening degree of the second flow regulating actuator is increased.

[0045] Specifically: The control unit can be implemented using an industrial controller in conjunction with a touch screen or host computer software, and internally includes a signal acquisition module, a data processing and judgment module, and an execution control output module.

[0046] The signal acquisition module is electrically connected to the monitoring components arranged in the pipeline between the first heat exchange outlet 120 and the first inlet 220, the monitoring components arranged in the pipeline between the first outlet 211 and the second inlet 311, the monitoring components arranged in the pipeline between the second outlet 312 and the third inlet 411, and the monitoring components arranged in the pipeline between the third outlet 412 and the second heat exchange inlet 710. The analog or digital signals output by the dissolved oxygen sensor 8, the dissolved carbon dioxide sensor 9, and the temperature sensor 10 in each monitoring component are sent to the control unit through the signal conditioning circuit to periodically collect the dissolved oxygen detection value, dissolved carbon dioxide detection value, and water temperature detection value of the pure water in the corresponding pipeline.

[0047] The data processing and judgment module pre-stores the upper and lower limits of the dissolved oxygen threshold, dissolved carbon dioxide threshold, and outlet water temperature preset range corresponding to different monitoring locations. Operators can set or adjust the above thresholds according to process requirements through the operation interface.

[0048] The execution control output module is electrically connected to the first vacuum pumping device corresponding to the first degassing mechanism 2, the second vacuum pumping device corresponding to the second degassing mechanism 3, the third vacuum pumping device corresponding to the third degassing mechanism 4, as well as the first flow regulating actuator and the second flow regulating actuator, respectively. It adjusts the vacuum target value of each vacuum pumping device and the opening degree of each flow regulating actuator by outputting control signals.

[0049] During operation, the control unit continuously acquires the current dissolved oxygen, dissolved carbon dioxide and water temperature values ​​from each monitoring component according to the preset sampling cycle, and filters the collected data to suppress instantaneous interference and noise fluctuations.

[0050] The data processing and judgment module first compares the dissolved oxygen detection value output by the monitoring component arranged on the pipeline between the first heat exchange outlet 120 and the first inlet 220 with the corresponding dissolved oxygen threshold, and simultaneously compares the dissolved carbon dioxide detection value at that location with the corresponding dissolved carbon dioxide threshold. When either detection value is higher than the corresponding threshold, it is determined that the dissolved gas load of the pure water to be degassed before entering the first degassing mechanism 2 is too high. At this time, the control unit generates an adjustment command, which increases the target vacuum setting of the first vacuum equipment by executing the control output module, thereby deepening the suction negative pressure inside the first degassing mechanism 2. At the same time, it may also increase the opening of the first flow rate regulating actuator, thereby increasing the flow rate of the pure water to be degassed through the first heat exchange mechanism 1. Thus, while ensuring that the preheating temperature is not lower than the first preset temperature, the temperature and flow rate matching degree entering the first degassing mechanism 2 is improved, thereby improving the first-stage degassing intensity and gas mass transfer efficiency.

[0051] The above-mentioned adjustment actions can adopt a gradual adjustment strategy, such as gradually increasing the vacuum degree or opening degree according to the preset step size, and supplemented by the setting of hysteresis zone to avoid frequent small start-stops causing equipment fatigue.

[0052] For the monitoring components arranged on the pipeline between the first outlet 211 and the second inlet 311, and the monitoring components arranged on the pipeline between the second outlet 312 and the third inlet 411, the control unit monitors the dissolved oxygen and dissolved carbon dioxide values ​​of the pure water after the first and second degassing processes, respectively. The data processing and judgment module compares the respective detection values ​​with preset thresholds at the corresponding locations. When dissolved oxygen and / or dissolved carbon dioxide exceed the corresponding threshold at any location, the control unit determines whether the degassing effect of the first degassing mechanism 2 or the second degassing mechanism 3 is insufficient, and then increases the target vacuum level of the vacuum pumping equipment corresponding to the second degassing mechanism 3 and / or the third degassing mechanism 4, respectively. Specifically, when the threshold is exceeded at the location between the first outlet 211 and the second inlet 311, the control unit prioritizes increasing the vacuum level of the second vacuum pumping equipment, so that the second degassing mechanism 3 can bear more degassing load; when the threshold is exceeded at the location between the second outlet 312 and the third inlet 411, the vacuum level of the third vacuum pumping equipment is prioritized, so that the third degassing mechanism 4 can strengthen the fine degassing effect.

[0053] In some implementations, the control unit can also select different adjustment ranges according to different levels of exceedance. For slight exceedances, a small and slow adjustment is used, while for severe exceedances, a larger and faster adjustment is used, in order to balance response speed and system stability.

[0054] For the monitoring component located on the pipeline between the third outlet 412 and the second heat exchange inlet 710, the control unit compares the dissolved oxygen detection value at this location with the corresponding threshold, and also compares the dissolved carbon dioxide detection value with the corresponding threshold. When both are lower than or equal to the preset threshold, it is determined that the multi-stage degassing has met the dissolved gas control requirements. At this time, the data processing and judgment module further compares the water temperature detection value at this location with the upper limit of the preset range of outlet water temperature. If the water temperature is higher than the upper limit of the preset range of outlet water temperature, it indicates that even though the degassing effect has met the standard, there is still redundancy in the degassing process or the front-end preheating process, resulting in a higher terminal water temperature. To this end, the control unit generates a combined load reduction and temperature reduction regulation command. By executing the control output module, it appropriately reduces the target vacuum level of at least one vacuum pump, thereby slightly reducing the overall degassing intensity. At the same time, it may increase the opening of the second flow regulation actuator to increase the flow rate of pure water entering the second heat exchange mechanism 7 and enhance the heat exchange with the cooling water. This effectively reduces the terminal outlet water temperature without significantly affecting the dissolved oxygen and dissolved carbon dioxide indices, so that the pure water temperature flowing out of the second heat exchange outlet 720 returns to the preset outlet water temperature range.

[0055] In some implementations, the control unit may set certain adjustment priorities, such as prioritizing reducing vacuum pump energy consumption by lowering the vacuum level, and then increasing the flow rate of the second heat exchange mechanism 7 to enhance cooling capacity when it is difficult to further reduce the vacuum level.

[0056] In the aforementioned control process, the control unit can employ a periodic cyclic scanning method for judgment and adjustment. This means that within each control cycle, sensor data acquisition, threshold comparison, operating condition judgment, and actuator output update are completed sequentially. To avoid frequent switching due to short-term fluctuations, the data processing and judgment module can perform time averaging or sliding filtering on the raw detection values ​​of the monitoring components. During comparison, upper and lower hysteresis limits and a minimum adjustment interval are set to ensure the control action has a certain degree of stability and anti-interference capability. Operators can observe real-time data and historical trends at each monitoring point through a touchscreen or host computer interface, record and analyze changes in dissolved oxygen, dissolved carbon dioxide, and water temperature, and appropriately adjust the threshold values ​​and preset outlet water temperature ranges at each location when the process is updated or the raw water quality changes over a long period. This ensures that the control strategy meets current operating requirements while avoiding excessively conservative energy waste.

[0057] This control strategy is suitable for applications where upstream processes in electronic-grade ultrapure water systems exhibit significant fluctuations, such as frequent start-ups, shutdowns, regenerations, or load changes in reverse osmosis units, continuous electrodeionization units, or mixed-bed units. Before operation, the system can automatically learn and record the distribution of dissolved oxygen, dissolved carbon dioxide, and water temperature at various monitoring points under typical operating conditions, using this data to set initial thresholds and adjustment ranges. During operation, when load changes or raw water quality fluctuations cause the parameters of the degassed pure water to deviate from the normal range, the control unit can classify and determine the source of the problem based on monitoring results from different locations. It prioritizes adjusting the vacuum level of the corresponding degassed mechanism and the flow rates of the upstream and downstream heat exchange units to correct the operating conditions, rather than performing a one-size-fits-all global adjustment of the entire degassed system, thus improving the targetedness and accuracy of the adjustment.

[0058] In this embodiment, monitoring components are arranged between the first heat exchange outlet 120 and the first inlet 220, between the first outlet 211 and the second inlet 311, between the second outlet 312 and the third inlet 411, and between the third outlet 412 and the second heat exchange inlet 710. A control unit continuously collects data on dissolved oxygen, dissolved carbon dioxide, and water temperature. Simultaneously, based on the correspondence between each monitoring location and each stage of the degassing mechanism and the preceding and following heat exchange units, the vacuum level of the corresponding vacuuming equipment is selectively increased or decreased, and the first and second flow regulation actuators are adjusted accordingly. By adjusting the opening degree, a segmented closed-loop control system covering key nodes before and after degassing is constructed. Therefore, it effectively solves the problem in existing technologies where the operating parameters of the degassing unit are basically fixed, and global rough adjustments can only be made based on limited online points or manual experience, making it difficult to respond in a timely manner to fluctuations in the parameters of the pure water to be degassed caused by the previous process. This enables fine and coordinated adjustment of the degassing mechanisms at all levels and the heat exchange mechanisms before and after the process under complex working conditions, so that the multi-stage degassing process can not only meet the strict dissolved oxygen and dissolved carbon dioxide control indicators for a long time, but also keep the terminal water temperature within the preset range and take into account the system energy consumption optimization.

[0059] To increase the shear rate near the surface of the water-side membrane and reduce concentration polarization, please refer to [link / reference needed]. Figures 3 to 4 In some embodiments, a first disturbance-enhancing flow channel component, a second disturbance-enhancing flow channel component, and a third disturbance-enhancing flow channel component are respectively provided in the first degassing pipe 210, the second degassing pipe 310, and the third degassing pipe 410. The first disturbance-enhancing flow channel component is arranged between the first drain outlet 231 and the first outlet 211 in the first degassing pipe 210, the second disturbance-enhancing flow channel component is arranged between the second drain outlet 321 and the second outlet 312 in the second degassing pipe 310, and the third disturbance-enhancing flow channel component is arranged between the third drain outlet 421 and the third outlet 412 in the third degassing pipe 410. The first disturbance enhancement channel component, together with the outer wall of the first water inlet pipe 230 and the inner wall of the first degassing pipe 210, forms a first disturbance channel that extends axially along the first degassing pipe 210 and bends circumferentially. The second disturbance enhancement channel component, together with the outer wall of the second water inlet pipe 320 and the inner wall of the second degassing pipe 310, forms a second disturbance channel that extends axially along the second degassing pipe 310 and bends circumferentially. The third disturbance enhancement channel component, together with the outer wall of the third water inlet pipe 420 and the inner wall of the third degassing pipe 410, forms a third disturbance channel that extends axially along the third degassing pipe 410 and bends circumferentially.

[0060] In specific implementation, the above embodiment is characterized by the first disturbance enhancement flow channel component, the second disturbance enhancement flow channel component, and the third disturbance enhancement flow channel component being a first spiral guide vane 250, a second spiral guide vane 340, and a third spiral guide vane 440, respectively. The first spiral guide vane 250 extends spirally along the axial direction of the first water inlet pipe 230. The inner spiral edge of the first spiral guide vane 250 is attached to and sealed against the outer wall of the first water inlet pipe 230, and the outer spiral edge is attached to and sealed against the inner wall of the first degassing pipe 210, thereby forming a first spiral channel between the outer wall of the first water inlet pipe 230, the first spiral guide vane 250, and the inner wall of the first degassing pipe 210. The second spiral guide vane 340 and the third spiral guide vane 440 extend along the second water inlet pipe 320 and the third water inlet pipe 420, respectively. The first spiral guide plate 250, the second spiral guide plate 340, and the third spiral guide plate 440 are respectively attached to and sealed with the outer walls of the second water inlet pipe 320 and the third water inlet pipe 420 and the inner walls of the second degassing pipe 310 and the third degassing pipe 410, so that the outer wall of the second water inlet pipe 320, the second spiral guide plate 340 and the inner wall of the second degassing pipe 310 form a second spiral channel, and the outer wall of the third water inlet pipe 420, the third spiral guide plate 440 and the inner wall of the third degassing pipe 410 form a third spiral channel; the first spiral guide plate 250, the second spiral guide plate 340 and the third spiral guide plate 440 are each provided with multiple through holes along the thickness direction, and each first hollow fiber membrane bundle 243, the second hollow fiber membrane bundle 332 and the third hollow fiber membrane bundle 432 respectively pass through the through holes of the corresponding spiral guide plate and extend into the corresponding spiral channel.

[0061] Specifically: Each disturbance enhancement flow channel component is set between the drain port and the outlet of the corresponding degassing pipe, extending along the axial direction of the corresponding degassing pipe and bending or spiraling in the circumferential direction. This allows the pure water to be treated flowing into the degassing chamber from the drain port to be guided to flow along the curved flow channel as it flows toward the outlet, thereby forming a flow field with strong disturbance characteristics around the outer periphery of the water inlet pipe and around the hollow fiber membrane bundle.

[0062] Structurally, the first disturbance enhancement flow channel component is preferably a first spiral guide vane 250 disposed within the first degassing pipe 210. This guide vane is a strip-shaped sheet that spirally unwound along the axial direction of the first water inlet pipe 230. The inner edge of the first spiral guide vane 250 has an arc-shaped or zigzag profile, the curvature of which matches the outer circumference of the first water inlet pipe 230. During installation, it adheres to the outer wall of the first water inlet pipe 230 and is sealed by welding, snapping, sleeve clamping, or adhesive bonding, ensuring that there is essentially no radial gap between the outer wall of the water inlet pipe and the inner side of the guide vane. The outer edge of the first spiral guide vane 250 also has an arc-shaped or zigzag profile, the curvature of which matches the inner wall of the first degassing pipe 210. The outer edge adheres to the inner wall of the first degassing pipe 210 and forms a circumferential seal. If necessary, a sealing ring or sealing adhesive layer can be provided at the contact point to prevent water from bypassing and leaking through the gap between the spiral guide vane and the pipe wall. The thickness of the guide vane can be a uniform plate thickness, or it can be appropriately varied in the radial or axial direction to balance structural strength and flow channel cross-sectional shape. The first spiral guide vane 250 extends at both ends in the axial direction to the position downstream of the first drain outlet 231 and upstream of the first outlet 211, so that the water flowing into the first degassing chamber from the first drain outlet 231 must flow along the first spiral channel formed by the outer wall of the first inlet pipe 230, the first spiral guide vane 250 and the inner wall of the first degassing pipe 210 before it can be discharged from the first outlet 211.

[0063] The structural layout of the second and third disturbance-enhancing flow channel components is basically the same as that of the first disturbance-enhancing flow channel component. They are a second spiral guide vane 340 and a third spiral guide vane 440 respectively, installed inside the second degassing pipe 310 and the third degassing pipe 410. The second spiral guide vane 340 extends spirally along the axial direction of the second water inlet pipe 320, with its inner edge attached to and sealed to the outer wall of the second water inlet pipe 320, and its outer edge attached to and sealed to the inner wall of the second degassing pipe 310, forming a continuous second spiral channel between the second drain outlet 321 and the second outlet 312. The third spiral guide vane 440 extends spirally along the axial direction of the third water inlet pipe 420, with its inner edge attached to and sealed to the outer wall of the third water inlet pipe 420, and its outer edge attached to and sealed to the inner wall of the third degassing pipe 410, forming a continuous third spiral channel between the third drain outlet 421 and the third outlet 412. To facilitate processing and installation, each spiral guide vane can be integrally rolled from stainless steel plate, engineering plastic plate or composite material plate, or multiple arc-shaped plates can be spliced ​​together circumferentially and then arranged in a zigzag or approximately spiral manner along the axial direction, thereby simplifying the manufacturing process while ensuring the formation of curved flow channels.

[0064] To ensure the synergistic relationship between the degassing component and the disturbance enhancement flow channel structure, the first spiral guide vane 250, the second spiral guide vane 340, and the third spiral guide vane 440 are each provided with multiple through holes along their thickness direction. The axis of each through hole is preferably parallel to the axis of the corresponding degassing tube. The cross-section of the hole can be circular, elliptical, or polygonal, and the hole diameter is slightly larger than the outer diameter of the corresponding hollow fiber membrane bundle, so that the membrane bundle can be inserted through the guide vane during assembly, while ensuring that the membrane bundle has a certain installation margin in the guide vane and is not excessively squeezed. Each first hollow fiber membrane bundle 243 originates from the first fixing member 241, passes through multiple through holes in the first spiral guide plate 250, and extends to the first suction chamber 2421 region within the first suction end cap 242, and is distributed axially within the first spiral channel; each second hollow fiber membrane bundle 332 passes through multiple through holes in the second spiral guide plate 340 and extends into the second spiral channel; each third hollow fiber membrane bundle 432 passes through multiple through holes in the third spiral guide plate 440 and extends into the third spiral channel. Through the above structural arrangement, the water flow within the spiral channel is forced to form a spiral upward or spiral downward flow state around each hollow fiber membrane bundle while advancing axially, significantly enhancing the tangential velocity component and shearing effect of the water body outside the membrane bundles.

[0065] In practical use, pure water entering the degassing chamber through the corresponding drain outlets first collects in the cross-sectional area near the drain outlet under the influence of gravity and pressure difference. Then, guided by the spiral guide vanes, it flows along the spiral channel towards the outlet. Because the flow channel is continuously curved circumferentially and generally has a narrow cross-section, the fluid in the spiral channel generates significant secondary flow and vortex structures, continuously renewing the water near the outer surface of the hollow fiber membrane, reducing the boundary layer thickness near the membrane surface, and thus improving the transmembrane mass transfer flux. In the multi-stage degassing structure, the first three degassing tubes each form an independent spiral disturbance flow channel, providing a high shear environment for each degassing unit, which is beneficial for achieving sufficient degassing within a shorter residence time.

[0066] The disturbance enhancement channel component in this embodiment can be modified in various ways according to different operating conditions. For example, in some application scenarios, the pitch of the spiral guide vane can be designed to gradually decrease along the axial direction, so that the flow velocity of the water is appropriately increased near the outlet end, thereby further improving the terminal degassing efficiency; the pitch of the guide vane can also be designed to vary in segments, forming denser disturbances in certain sections to correspond to areas with high water quality loads. In other embodiments, the disturbance enhancement channel component can also take the form of multiple parallel deflection ribs, corrugated or zigzag guide plates, etc., as long as they together with the outer wall of the corresponding inlet pipe and the inner wall of the degassing pipe form a disturbance channel that extends axially and bends circumferentially, a similar disturbance enhancement effect can be achieved. The arrangement of the through holes can also be optimized according to the number and arrangement of the membrane bundles, for example, by using a ring or multi-ring ring array, so that the water flow in the spiral channel is more uniformly distributed in the radial and circumferential directions, reducing local dead zones.

[0067] To avoid damage to the hollow fiber membrane, the edges of the through holes of the flow guide can be chamfered or rounded, and polished or surface-treated after processing to make the hole edge surface smooth and burr-free. When necessary, flexible sealing rings or buffer gaskets can also be fitted at the through holes to further reduce friction and wear between the membrane bundle and the hole wall.

[0068] In this embodiment, by employing a first disturbance enhancement flow channel component, a second disturbance enhancement flow channel component, and a third disturbance enhancement flow channel component respectively installed in the first degassing pipe 210, the second degassing pipe 310, and the third degassing pipe 410, and by having each disturbance enhancement flow channel component, together with the outer wall of the corresponding inlet pipe and the inner wall of the degassing pipe, form a spiral disturbance flow channel that extends axially and bends circumferentially, and by opening through holes on the spiral guide plate to allow hollow fiber membrane bundles of each stage to pass through and extend into the corresponding spiral channel, the technical means effectively solve the problems in the prior art where the water flow in the degassing membrane module is mostly axially straight or weakly disturbed, the shear rate near the membrane surface is low, the mass transfer efficiency is limited, and concentration polarization and local scaling are easily generated. Thus, it achieves the technical effects of significantly improving the shear strength and disturbance degree of the water body outside the membrane within a limited degassing pipe length, enhancing the transmembrane mass transfer rate, reducing energy consumption under unit degassing load, delaying membrane fouling, and extending the service life of the hollow fiber membrane module.

[0069] It should be noted that, firstly, the aforementioned three-fluid thermodynamic coupling structure introduces heat recovery from the vacuum pump cooling water and thermal coupling with the process water. Its main function is to increase the temperature of the water to be degassed through temperature regulation in the early stages, thereby improving the removal efficiency of dissolved gases. During system operation, the vacuum pump cooling water, under the action of the first heat exchange channel and the first heat exchange medium channel, transfers heat from the cooling water to the water to be degassed. This increases the temperature of the water to be degassed on the one hand, and avoids the use of external heating equipment on the other, thus improving the system's energy efficiency.

[0070] Secondly, building upon the three-fluid thermo-coupling structure which increases water temperature, the multi-stage negative pressure gradient degassing chamber technology further optimizes the degassing process. This technology involves setting up multiple independent degassing zones in series within the degassing device, each employing different vacuum and flow rate adjustment strategies to degas different gas components (such as dissolved oxygen and dissolved carbon dioxide) in stages. Specifically, the gradient vacuum and gas flow rate of each degassing section ensure that different dissolved gases are preferentially removed at each stage, avoiding overheating or over-degassing during the degassing process and optimizing the efficiency of the entire process.

[0071] Finally, the inter-stage online monitoring and adaptive control technology monitors water quality parameters (dissolved oxygen, dissolved carbon dioxide, and temperature) in real time and adjusts the operating status of each degassing stage based on detected changes. This control strategy ensures a rapid response to water quality fluctuations throughout the degassing process. For example, when upstream processes such as RO and EDI cause fluctuations in water quality or temperature, the control unit can automatically adjust parameters such as vacuum, flow rate, and temperature in each degassing stage to maintain water quality stability and prevent dissolved oxygen or carbon dioxide levels from exceeding limits.

[0072] In summary, combining these three aspects forms a highly optimized control system. First, the three-fluid thermo-coupling structure increases the temperature of the water to be degassed, enhancing gas removal capacity and providing a more efficient operating environment for the multi-stage degasing chambers. Subsequently, the multi-stage negative pressure gradient degasing chambers, through reasonable negative pressure control and flow regulation, prioritize the removal of dissolved oxygen, dissolved carbon dioxide, and other gases at different stages, ensuring maximum degasing effect. Finally, inter-stage online monitoring and adaptive control technology precisely adjusts the vacuum and flow rate of each degasing stage based on real-time monitoring data to cope with process fluctuations and ensure water quality stability. The combination of these three elements enables the entire system to maintain efficient and precise degasing performance even under conditions of high salinity and complex water quality. Specifically, the combination of thermo-coupling and negative pressure gradient regulation effectively improves water degasing efficiency, and real-time monitoring and fine control avoid overheating and unnecessary energy consumption common in traditional systems, thus achieving higher energy efficiency and more stable system operation. Compared with traditional degassing membranes, the degassing device in a preferred embodiment of this application can better adapt to dynamic fluctuations in water quality, while reducing energy consumption and maintaining stable system operation. Therefore, this synergistic effect is difficult for technicians to achieve directly through conventional methods.

[0073] To better control the vacuum level and heat exchange rate, a control method for the aforementioned electronic-grade ultrapure water preparation system is proposed. Please refer to [link to relevant documentation]. Figures 5 to 6 Specifically, it includes the following steps: Step S100: Collect the dissolved oxygen detection value, dissolved carbon dioxide detection value, and temperature detection value output by the monitoring components installed on the pipeline between the first heat exchange outlet 120 and the first inlet 220, the monitoring components installed on the pipeline between the first outlet 211 and the second inlet 311, the monitoring components installed on the pipeline between the second outlet 312 and the third inlet 411, and the monitoring components installed on the pipeline between the third outlet 412 and the second heat exchange inlet 710; Step S200: Compare the dissolved oxygen and dissolved carbon dioxide detection values ​​of each monitoring component with the preset dissolved oxygen and dissolved carbon dioxide thresholds, respectively, and compare the temperature detection values ​​of each monitoring component with the preset water temperature range, in order to determine whether there are conditions where dissolved oxygen and / or dissolved carbon dioxide exceed the standard or the water temperature deviates from the preset water temperature range at each monitoring location. Step S300: When the comparison and judgment step determines that at least one monitoring location has excessive dissolved oxygen and / or dissolved carbon dioxide and / or water temperature deviates from the preset water temperature range, the control unit, based on the correspondence between the corresponding monitoring location and each degassing mechanism and the first heat exchange mechanism 1 and the second heat exchange mechanism 7, adjusts the vacuum degree of the vacuum equipment corresponding to at least two degassing mechanisms and / or adjusts the opening of the first flow regulating actuator and the second flow regulating actuator, thereby ensuring that the dissolved oxygen content and dissolved carbon dioxide content of the pure water entering the second heat exchange mechanism 7 from the third outlet 412 meet the preset indicators, while controlling the water temperature of the pure water flowing out from the second heat exchange outlet 720 within the preset water temperature range.

[0074] Specifically, the linkage adjustment in step S300 includes: Step S310 When the monitoring component installed on the pipeline between the first heat exchange outlet 120 and the first inlet 220 detects that the dissolved oxygen and / or dissolved carbon dioxide in the pure water in the corresponding pipeline is higher than the first preset threshold, the control unit enhances the degassing intensity of the first degassing mechanism 2 by increasing the vacuum degree of the first vacuum device corresponding to the first degassing mechanism 2 and / or increasing the opening of the first flow rate regulating actuator. Step S320 When the monitoring component installed on the pipeline between the first outlet 211 and the second inlet 311 and / or the monitoring component installed on the pipeline between the second outlet 312 and the third inlet 411 detects that the dissolved oxygen and / or dissolved carbon dioxide in the pure water in the corresponding pipeline is higher than the corresponding preset threshold, the control unit enhances the degassing intensity of the second degassing mechanism 3 and / or the third degassing mechanism 4 by increasing the vacuum degree of the second vacuum pumping device and / or the third vacuum pumping device corresponding to the second degassing mechanism 3 and / or the third degassing mechanism 4 respectively. Step S330: When the monitoring component installed on the pipeline between the third outlet 412 and the second heat exchange inlet 710 detects that the dissolved oxygen and dissolved carbon dioxide of the pure water in the corresponding pipeline both meet the preset indicators and the water temperature is higher than the upper limit of the preset water temperature range, the control unit reduces the vacuum degree of at least one vacuum pump and / or increases the opening of the second flow regulation actuator to reduce the overall degassing intensity and / or increase the heat exchange intensity in the second heat exchange mechanism 7, so that the water temperature of the pure water flowing out of the second heat exchange outlet 720 returns to the preset water temperature range.

[0075] Specifically: In step S100, in the electronic-grade ultrapure water preparation system, multiple monitoring components are arranged on different pipelines of the system. These monitoring components collect real-time information on dissolved oxygen, dissolved carbon dioxide content, and temperature of the fluid within the pipelines. The monitoring components include a dissolved oxygen sensor 8, a carbon dioxide sensor 9, and a temperature sensor 10. Specifically, these sensors, located on the pipelines between the first heat exchange outlet 120 and the first inlet 220, between the first outlet 211 and the second inlet 311, between the second outlet 312 and the third inlet 411, and between the third outlet 412 and the second heat exchange inlet 710, respectively output real-time data on dissolved oxygen concentration, carbon dioxide concentration, and water temperature. This data provides key parameters for subsequent control.

[0076] In step S200, the collected data needs to be compared with pre-set standards. The dissolved oxygen and dissolved carbon dioxide concentrations at each monitoring point are compared with preset thresholds to determine if they exceed the limits. Simultaneously, the temperature data is also compared with a preset water temperature range. The core purpose of this step is to assess the water quality status at each node and confirm whether any abnormalities have occurred, such as excessive dissolved oxygen, high carbon dioxide levels, or water temperature deviations from the preset range. This step provides a basis for adjustments in subsequent steps by comparing the input data with preset values.

[0077] In step S300, based on the data comparison results from step S200, the control unit performs coordinated adjustments when it determines that at least one monitoring location is abnormal. The control unit adjusts the operating status of relevant degassing equipment and flow regulating devices to ensure coordinated operation between all components.

[0078] In step S310, when the content of dissolved oxygen and / or dissolved carbon dioxide in the pipe between the first heat exchange outlet 120 and the first inlet 220 exceeds a preset threshold, the control unit enhances the degassing intensity of the first degassing mechanism 2 by adjusting the vacuum level of the vacuum pump of the first degassing mechanism 2 or the opening degree of the first flow regulation actuator. Through this adjustment, the system can accelerate the removal of dissolved gases, thereby improving the purity of the water, while avoiding negative impacts on subsequent processes due to excessively high dissolved gas content.

[0079] In step S320, if the dissolved oxygen or dissolved carbon dioxide content in the pipeline between the first outlet 211 and the second inlet 311, or between the second outlet 312 and the third inlet 411, exceeds a preset threshold, the control unit will adjust the second and third degassing devices in a coordinated manner. Specifically, the control unit will increase the vacuum level of the vacuum equipment corresponding to the second and third degassing devices, further enhancing the degassing intensity of the second degassing mechanism 3 and the third degassing mechanism 4. This process can effectively remove more dissolved gases in the middle of the system, ensuring that the final water quality meets high standards.

[0080] In step S330, when the concentrations of dissolved oxygen and dissolved carbon dioxide in the pipeline between the third outlet 412 and the second heat exchange inlet 710 meet the preset targets, but the water temperature is higher than the upper limit of the preset water temperature range, the control unit will adjust the system. This is done by reducing the vacuum level of at least one vacuum pump and / or increasing the opening of the second flow regulating actuator to reduce the intensity of the degassing process, or by increasing the heat exchange intensity in the second heat exchange mechanism 7, thereby lowering the water temperature back to the preset range. This adjustment ensures that the entire system can efficiently degas while maintaining a stable water temperature, preventing excessively high water temperatures from affecting the quality of the final product.

[0081] It should be noted that in an electronic-grade ultrapure water preparation system, the monitoring components play a crucial role in real-time acquisition and transmission of critical water quality and temperature data, including dissolved oxygen concentration, dissolved carbon dioxide concentration, and water temperature. These parameters directly affect water purity and the stable operation of the system. Therefore, based on this real-time data, the control system can dynamically adjust the parameters of different degassing mechanisms and flow regulation devices to achieve optimized degassing effects and stable water temperature control. The specific principles are as follows: Dissolved Oxygen and Dissolved Carbon Dioxide Monitoring: Dissolved oxygen and dissolved carbon dioxide are key factors affecting the quality of ultrapure water. The monitoring component measures the concentrations of dissolved oxygen and dissolved carbon dioxide in the water using dissolved oxygen sensor 8 and carbon dioxide sensor 9, respectively, and transmits the data to the control unit. When the sensors detect that dissolved oxygen or dissolved carbon dioxide exceeds a preset threshold, the system considers the gas content in the water to be too high and requires further degassing to meet the standard requirements.

[0082] Temperature Monitoring: Temperature sensor 10 is used to monitor water temperature in real time. Because temperature changes can affect deaeration efficiency and water quality stability, the control system adjusts the operating status of the deaeration equipment based on the deviation of the water temperature from the set range. If the temperature is too high, it may affect the performance of the deaeration membrane or cause over-deaeration, leading to energy waste or the risk of excessively low dissolved oxygen / carbon dioxide levels. The system adjusts the flow rate or vacuum level to ensure that the water temperature is maintained within an appropriate range.

[0083] Relationship between Vacuum and Flow Regulation: First Deaeration Mechanism 2 (Vacuum and Flow Regulation): When the concentration of dissolved oxygen or dissolved carbon dioxide is detected to be too high, the control unit increases the vacuum of the first deaeration mechanism 2 to accelerate gas removal. Simultaneously, if the water flow rate is low or the dissolved gas removal efficiency is low, the control system will also increase the opening of the first flow regulation actuator to increase the water flow rate, ensuring sufficient flow velocity through the deaeration membrane and improving deaeration efficiency. Second Deaeration Mechanism 3: If the system detects that the water quality (such as dissolved oxygen and dissolved carbon dioxide) in the previous stage still exceeds the standard, the control unit will enhance the deaeration intensity of the second deaeration mechanism 3, specifically by increasing its vacuum to further remove dissolved gases from the water. Third Deaeration Mechanism 4: When the dissolved oxygen and carbon dioxide concentrations meet the requirements, but the water temperature is too high, the vacuum of the third deaeration mechanism 4 will be adjusted according to the actual situation, reducing excessive vacuum to prevent over-deaeration. At the same time, the flow rate is increased by increasing the opening of the second flow regulation actuator to improve heat exchange efficiency and ensure that the water temperature is controlled within the ideal range.

[0084] When dissolved oxygen or dissolved carbon dioxide exceeds the standard, the control unit not only adjusts the vacuum level, but also regulates the flow rate to ensure that the water can pass through each degassing unit at an appropriate flow rate, thereby improving the gas removal efficiency.

[0085] When the system detects excessively high water temperature, it reduces the vacuum level of at least one degassing device to prevent over-degassing and increases heat exchange efficiency by adjusting the flow rate, thereby restoring the water temperature to the set range. This coordinated regulation ensures the system maintains balance during operation, effectively removing dissolved gases while controlling water temperature and energy consumption.

[0086] The control unit provides real-time feedback based on monitoring data. When the dissolved oxygen and dissolved carbon dioxide levels are too high, it enhances the gas removal process by adjusting the vacuum level. When the water temperature is too high, it lowers the water temperature by increasing the flow rate, adjusting the actuator opening, or adjusting the heat exchange system to prevent excessively high water temperatures from affecting equipment performance.

[0087] This control method uses a sophisticated feedback control mechanism to dynamically adjust the degassing and heat exchange processes based on monitoring data, ensuring that parameters such as dissolved oxygen, dissolved carbon dioxide, and temperature in the pure water are always kept within the set range, thereby improving the system's operating efficiency and stability.

[0088] This control method precisely adjusts the operating status of each degassing stage, enabling the system to respond quickly to changes in water quality and temperature fluctuations. By coordinating the adjustment of each degassing device and flow regulation unit, this method solves the problems of excessive dissolved oxygen and dissolved carbon dioxide, and unstable water temperature that may occur in traditional systems. Through real-time monitoring and adaptive control, this method ensures stable operation of the system under dynamically fluctuating conditions, providing a highly efficient and low-energy-consumption solution for the preparation of electronic-grade ultrapure water. These innovative control strategies enable the degassing system to operate efficiently and stably in high-salinity areas or other complex water quality environments, overcoming the shortcomings of traditional systems.

Claims

1. An electronic grade ultra-pure water production system, characterized by, Comprise: The first heat exchange mechanism comprises a first heat exchange channel, a first heat exchange medium channel, and a first flow regulating actuating mechanism connected with the first heat exchange medium channel. The first heat exchange channel is sequentially provided with a first heat exchange inlet and a first heat exchange outlet. The first heat exchange medium channel is sequentially provided with a first heat exchange medium inlet and a first heat exchange medium outlet, and is communicated with the cooling water outlet of at least one vacuum pump, so that the cooling waste water discharged by the vacuum pump is used as the first heat exchange medium to exchange heat with the pure water to be degassed in the first heat exchange channel, and the pure water flowing out of the first heat exchange outlet reaches a first preset temperature; A plurality of degassing mechanisms of the first degassing mechanism, the second degassing mechanism and the third degassing mechanism are sequentially connected in series. Each degassing mechanism comprises a degassing cavity for pure water to flow through, an inlet and an outlet communicated with the degassing cavity, and a vacuum pumping device connected with the degassing cavity and the outlet. The pure water entering each degassing cavity flows in a negative pressure environment and is degassed. The inlet and the outlet of the first degassing mechanism are respectively a first inlet and a first outlet. The inlet and the outlet of the second degassing mechanism are respectively a second inlet and a second outlet. The inlet and the outlet of the third degassing mechanism are respectively a third inlet and a third outlet. The first inlet is communicated with the first heat exchange outlet. The first outlet is communicated with the second inlet. The second outlet is communicated with the third inlet. The second heat exchange mechanism comprises a second heat exchange channel, a second heat exchange medium channel, and a second flow regulating actuating mechanism connected with the second heat exchange medium channel. The second heat exchange channel is sequentially provided with a second heat exchange inlet and a second heat exchange outlet. The second heat exchange inlet is communicated with the third outlet. The second heat exchange medium channel is sequentially provided with a second heat exchange medium inlet and a second heat exchange medium outlet, and is used for introducing cooling water to exchange heat between the pure water in the second heat exchange channel and the cooling water, so that the pure water flowing out of the second heat exchange outlet reaches a second preset temperature. The monitoring mechanism comprises a plurality of detection assemblies. Each detection assembly is arranged at a pipeline between the first heat exchange outlet and the first inlet, a pipeline between the first outlet and the second inlet, a pipeline between the second outlet and the third inlet, and a pipeline between the third outlet and the second heat exchange inlet. Each monitoring assembly comprises at least a dissolved oxygen sensor, a carbon dioxide sensor and a temperature sensor, which are used to detect the dissolved oxygen content, the dissolved carbon dioxide content and the temperature of the pure water in the corresponding pipeline. The control unit is electrically connected with each monitoring assembly, the vacuum pumping device corresponding to each degassing mechanism, and the first flow regulating actuating mechanism and the second flow regulating actuating mechanism. The control unit is configured to adjust the vacuum degree of at least two vacuum pumping devices and / or the flow of pure water in the first heat exchange mechanism and the second heat exchange mechanism according to the detection results of each monitoring assembly, so that the pure water flowing out of the second heat exchange outlet meets the preset dissolved oxygen and dissolved carbon dioxide indicators while keeping the water temperature within a preset range.

2. The electronic grade ultra-pure water production system according to claim 1, wherein, The plurality of degassing mechanisms only comprise the first degassing mechanism, the second degassing mechanism and the third degassing mechanism connected in series.

3. The electronic grade ultra-pure water preparation system according to claim 2, wherein: The first degassing mechanism, the second degassing mechanism and the third degassing mechanism each comprise: a degassing pipe, an inner cavity of which constitutes a degassing cavity, and an inlet and an outlet are arranged on a pipe wall of the degassing pipe; a water inlet pipe arranged in the degassing pipe, one end of the water inlet pipe is in fluid communication with a water inlet area in the degassing pipe corresponding to the inlet, the other end of the water inlet pipe is closed, and at least one water outlet is arranged on the pipe wall near the side corresponding to the inlet, so that the pure water entering the degassing pipe through the inlet enters the water inlet pipe through the water inlet area and then flows into the corresponding degassing cavity through the water outlet, and an annular flow area is formed around the water inlet pipe in the degassing cavity; a degassing assembly arranged in the degassing pipe and arranged circumferentially around the water inlet pipe, the degassing assembly comprises a plurality of hollow fiber membrane bundles and fixing members and gas extraction end covers arranged at both ends of the degassing pipe, one end of each hollow fiber membrane bundle is fixedly arranged on the fixing member, and the other end is in communication with a gas extraction cavity arranged in the gas extraction end cover, a gas extraction port is arranged on the surface of the gas extraction end cover and in communication with the gas extraction cavity, and the gas extraction port is in communication with the corresponding vacuum extraction equipment, so that the pure water flowing through the degassing cavity is subjected to transmembrane mass transfer degassing between the outside of the hollow fiber membrane bundle and the negative pressure gas in the gas extraction cavity; wherein the outlet is arranged at the degassing pipe near the gas extraction end cover, and is used for discharging the pure water after degassing in the corresponding degassing cavity.

4. The electronic grade ultra-pure water preparation system according to claim 3, characterized in that: the electronic grade ultra-pure water preparation system further comprises a first external pipe and a second external pipe; the first degassing mechanism comprises a first degassing pipe, a first water inlet pipe, a first degassing assembly, a first gas extraction end cover and a first vacuum extraction equipment: an inner cavity of the first degassing pipe constitutes a first degassing cavity, a first inlet is in communication with the first degassing cavity through the first water inlet pipe arranged in the first degassing pipe, one end of the first water inlet pipe is in communication with the first inlet, the other end is closed, and at least one first water outlet is arranged on the pipe wall near the side corresponding to the first inlet, so that the pure water entering the first water inlet pipe through the first inlet flows into the first degassing cavity through the first water outlet; the first degassing assembly comprises a plurality of first hollow fiber membrane bundles arranged circumferentially around the first water inlet pipe and first fixing members and first gas extraction end covers arranged at both ends of the first degassing pipe, a first gas extraction cavity is arranged in the first gas extraction end cover, one end of each first hollow fiber membrane bundle is fixedly arranged on the first fixing member, and the other end is in communication with the first gas extraction cavity in the first gas extraction end cover, a first gas extraction port is arranged on the surface of the first gas extraction end cover and in communication with the first gas extraction cavity, the first gas extraction port is in communication with the first vacuum extraction equipment, and a first outlet is arranged on the pipe wall of the first degassing pipe near the first gas extraction end cover, and is used for discharging the pure water after degassing in the first degassing cavity. The second degassing mechanism comprises a second degassing pipe, a second water inlet pipe, a second degassing assembly, a second air extraction end cover and a second vacuum extraction device. The inner cavity of the second degassing pipe constitutes a second degassing cavity. One end of the second degassing pipe is sealingly connected to the side of the first air extraction end cover of the first degassing mechanism, away from the first degassing pipe, to seal the one end of the second degassing pipe. A second inlet is provided on the side wall of the second degassing pipe close to the sealed end. The second inlet is in communication with the first outlet through the first external pipe, so that the pure water after degassing by the first degassing mechanism is introduced into the second degassing pipe. The second degassing pipe forms a relatively closed second water inlet space in the region of the second inlet. A second communication port is provided on one side of the second water inlet space. The second water inlet pipe is arranged in the second degassing pipe and is in butt joint with the second communication port. One end of the second water inlet pipe is in communication with the second communication port, and the other end is closed. At least one second water outlet is provided on the side wall of the second water inlet pipe close to the second communication port, so that the pure water in the second water inlet space flows into the second degassing cavity through the second communication port, the second water inlet pipe and the second water outlet. The second degassing assembly comprises a plurality of second hollow fiber membrane bundles arranged circumferentially around the second water inlet pipe, and a second fixing member and a second air extraction end cover arranged at two ends of the second degassing pipe. The second air extraction end cover has a second air extraction cavity in the interior. One end of each second hollow fiber membrane bundle is fixedly connected to the second fixing member, and the other end is in communication with the second air extraction cavity in the second air extraction end cover. The surface of the second air extraction end cover is provided with a second air extraction port in communication with the second air extraction cavity. The second air extraction port is in communication with the second vacuum extraction device. A second outlet is provided on the side wall of the second degassing pipe close to the second air extraction end cover, for discharging the pure water after degassing by the second degassing cavity. The third degassing mechanism comprises a third degassing pipe, a third water inlet pipe, a third degassing assembly, a third air extraction end cover and a third vacuum extraction device. The inner cavity of the third degassing pipe forms a third degassing cavity. One end of the third degassing pipe is sealingly connected to the second air extraction end cover of the second degassing mechanism, away from the side of the second degassing pipe, so as to close one end of the third degassing pipe. A third inlet is arranged on the side wall of the third degassing pipe close to the sealing end. The third inlet is communicated with the second outlet through a second external pipe, so that the pure water after degassing by the second degassing mechanism is introduced into the third degassing pipe. A relatively closed third water inlet space is formed in the third degassing pipe at the region of the third inlet. A third communication port is arranged on one side of the third water inlet space. The third water inlet pipe is arranged in the third degassing pipe and is butted to the third communication port. One end of the third water inlet pipe is communicated with the third communication port, and the other end is closed. At least one third water outlet port is arranged on the side wall of the third water inlet pipe close to the third communication port, so that the pure water in the third water inlet space flows into the third degassing cavity through the third communication port and then through the third water outlet port.

5. The electronic grade ultra-pure water production system according to claim 4, characterized in that: The control unit is configured to: when the monitoring assembly arranged on the pipeline between the first heat exchange outlet and the first inlet detects that the dissolved oxygen and / or the dissolved carbon dioxide in the corresponding pipeline is higher than the first preset threshold value, increase the vacuum degree of the first vacuum extraction device and / or increase the opening degree of the first flow regulating actuator; when the monitoring assembly arranged on the pipeline between the first outlet and the second inlet and / or the monitoring assembly arranged on the pipeline between the second outlet and the third inlet detects that the dissolved oxygen and / or the dissolved carbon dioxide in the corresponding pipeline is higher than the corresponding preset threshold value, increase the vacuum degree of the corresponding second vacuum extraction device and / or third vacuum extraction device; when the monitoring assembly arranged on the pipeline between the third outlet and the second heat exchange inlet detects that the dissolved oxygen and the dissolved carbon dioxide in the corresponding pipeline both meet the preset index and the water temperature is higher than the upper limit of the outlet water temperature preset range, decrease the vacuum degree of at least one vacuum extraction device and / or increase the opening degree of the second flow regulating actuator.

6. The electronic grade ultra-pure water preparation system according to claim 4 or 5, characterized in that, The first, second and third degassing pipes are respectively provided with first, second and third turbulence-enhancing flow channel members, the first turbulence-enhancing flow channel member is arranged between the first water outlet and the first outlet in the first degassing pipe, the second turbulence-enhancing flow channel member is arranged between the second water outlet and the second outlet in the second degassing pipe, and the third turbulence-enhancing flow channel member is arranged between the third water outlet and the third outlet in the third degassing pipe; The first turbulence-enhancing flow channel member, the outer wall of the first water inlet pipe and the inner wall of the first degassing pipe jointly form a first turbulence flow channel extending in the axial direction of the first degassing pipe and curved in the circumferential direction, the second turbulence-enhancing flow channel member, the outer wall of the second water inlet pipe and the inner wall of the second degassing pipe jointly form a second turbulence flow channel extending in the axial direction of the second degassing pipe and curved in the circumferential direction, and the third turbulence-enhancing flow channel member, the outer wall of the third water inlet pipe and the inner wall of the third degassing pipe jointly form a third turbulence flow channel extending in the axial direction of the third degassing pipe and curved in the circumferential direction.

7. The electronic grade ultra-pure water preparation system according to claim 6, wherein, The first, second and third turbulence-enhancing flow channel members are respectively first, second and third helical flow guide vanes; The first helical flow guide vane extends helically in the axial direction of the first water inlet pipe, the inner helical edge of the first helical flow guide vane is attached to and sealed with the outer wall of the first water inlet pipe, and the outer helical edge is attached to and sealed with the inner wall of the first degassing pipe, so as to form a first helical channel between the outer wall of the first water inlet pipe, the first helical flow guide vane and the inner wall of the first degassing pipe; The second and third helical flow guide vanes extend helically in the axial direction of the second and third water inlet pipes, respectively, and are attached to and sealed with the outer walls of the second and third water inlet pipes and the inner walls of the second and third degassing pipes, respectively, so as to form a second helical channel between the outer wall of the second water inlet pipe, the second helical flow guide vane and the inner wall of the second degassing pipe, and a third helical channel between the outer wall of the third water inlet pipe, the third helical flow guide vane and the inner wall of the third degassing pipe; The first, second and third helical flow guide vanes are respectively provided with a plurality of through holes in the thickness direction, and the first, second and third hollow fiber membrane bundles respectively pass through the through holes of the corresponding helical flow guide vanes and extend in the corresponding helical channels.

8. The electronic grade ultra-pure water preparation system according to claim 1, wherein, The first heat exchange mechanism and / or the second heat exchange mechanism are plate heat exchangers or double-pipe heat exchangers.

9. A control method of an electronic grade ultra-pure water production system, characterized by, The electronic-grade ultra-pure water preparation system according to claim 4 or 5 or 7 comprises the following steps: Collecting the dissolved oxygen detection values, the dissolved carbon dioxide detection values and the temperature detection values output by the monitoring components arranged on the pipelines between the first heat exchange outlet and the first inlet, between the first outlet and the second inlet, between the second outlet and the third inlet, and between the third outlet and the second heat exchange inlet; The electronic-grade ultra-pure water preparation system according to claim 4 or 5 or 7 comprises the following steps: Collecting the dissolved oxygen detection values, the dissolved carbon dioxide detection values and the temperature detection values output by the monitoring components arranged on the pipelines between the first heat exchange outlet and the first inlet, between the first outlet and the second inlet, between the second outlet and the third inlet, and between the third outlet and the second heat exchange inlet; The dissolved oxygen detection value and the dissolved carbon dioxide detection value of each monitoring component are compared with the preset dissolved oxygen threshold value and the dissolved carbon dioxide threshold value respectively, and the temperature detection value of each monitoring component is compared with the preset water temperature preset range, to determine whether the dissolved oxygen and / or dissolved carbon dioxide exceeds the standard and / or the water temperature deviates from the water temperature preset range at each monitoring position; When the comparison and determination step determines that the dissolved oxygen and / or dissolved carbon dioxide exceeds the standard and / or the water temperature deviates from the water temperature preset range at at least one monitoring position, the control unit adjusts the vacuum degree of the vacuum equipment corresponding to at least two degassing mechanisms and / or adjusts the opening degree of the first flow adjusting execution mechanism and the second flow adjusting execution mechanism according to the corresponding relationship between the corresponding monitoring position and the degassing mechanism and the first heat exchange mechanism and the second heat exchange mechanism, so that the dissolved oxygen content and the dissolved carbon dioxide content of the pure water entering the second heat exchange mechanism from the third outlet meet the preset index, and the water temperature of the pure water flowing out of the second heat exchange outlet is controlled within the water temperature preset range.

10. The control method of the electronic grade super pure water producing system according to claim 9, wherein, The linkage adjustment step specifically includes: When the monitoring component arranged on the pipeline between the first heat exchange outlet and the first inlet detects that the dissolved oxygen and / or dissolved carbon dioxide of the pure water in the corresponding pipeline is higher than the first preset threshold value, the control unit increases the vacuum degree of the first vacuum equipment corresponding to the first degassing mechanism and / or increases the opening degree of the first flow adjusting execution mechanism, to enhance the degassing intensity of the first degassing mechanism; When the monitoring component arranged on the pipeline between the first outlet and the second inlet and / or the monitoring component arranged on the pipeline between the second outlet and the third inlet detects that the dissolved oxygen and / or dissolved carbon dioxide of the pure water in the corresponding pipeline is higher than the corresponding preset threshold value, the control unit increases the vacuum degree of the second vacuum equipment corresponding to the second degassing mechanism and / or the third vacuum equipment corresponding to the third degassing mechanism, to respectively enhance the degassing intensity of the second degassing mechanism and / or the third degassing mechanism; When the monitoring component arranged on the pipeline between the third outlet and the second heat exchange inlet detects that the dissolved oxygen and the dissolved carbon dioxide of the pure water in the corresponding pipeline both meet the preset index and the water temperature is higher than the upper limit of the water temperature preset range, the control unit reduces the vacuum degree of at least one vacuum equipment and / or increases the opening degree of the second flow adjusting execution mechanism, to reduce the overall degassing intensity and / or increase the heat exchange intensity in the second heat exchange mechanism, so that the water temperature of the pure water flowing out of the second heat exchange outlet returns to the water temperature preset range.

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