Visual monitoring and early warning system and method for oxidizer content in edl device inlet water

Abstract

The application discloses an EDI device water inlet oxidant content visual monitoring and early warning system and method, which comprises an EDI water inlet pipe, the outlet of the EDI water inlet pipe is divided into two routes, one route is connected with a water supply tank, the water supply tank is connected with an EDI membrane block, the other route is connected with a primary resin detection column, the primary resin detection column is connected with a secondary resin detection column, the secondary resin detection column is connected with the water supply tank, a water cap and a grating sensor are arranged in the primary resin detection column, the grating sensor is connected with a PLC control unit, the primary resin detection column is filled with variable color resin and an image automatic identification device. The variable color resin is used as an indicator, the performance of the variable color resin is basically consistent with the performance of the ion exchange resin in the EDI device, the relative value of the oxidant content can be directly judged according to the color change of the indicator, the EDI device operation can be timely alarmed when the oxidant content exceeds the set standard, the operation personnel can be facilitated to manage, and the application also has the characteristics of low cost and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of water treatment, and particularly relates to an EDI device water inlet oxidant content visual monitoring and early warning system. BACKGROUND

[0002] EDI devices are core equipment of desalination systems in thermal power plants. Since ion exchange resins and ion exchange membranes inside the EDI devices are prone to oxidation, the oxidant content in the water inlet needs to be limited. Generally, the oxidant content in the water inlet is required to be less than 0.02 mg / L. If the oxidant content exceeds this value, irreversible damage will be caused to the resins and membranes inside the EDI device, and even the entire device will be scrapped. In addition, most EDI devices in thermal power plants are imported products, which are high in cost and need to be shipped to professional factories for maintenance, with a long maintenance cycle, which seriously affects the safe operation of the thermal power plant. Therefore, real-time monitoring of the oxidant content in the water inlet of the EDI device can provide early warning and automatic control protection for the EDI device, and timely discovery of the problem of excessive oxidant content in the pre-treatment can be of great significance to reducing the maintenance rate of the EDI membrane block and improving the economic benefit of the system.

[0003] At present, the monitoring of the oxidant content in the water inlet of the EDI device of the desalination system in the thermal power plant generally only sets a residual chlorine instrument or an ORP table on the water inlet pipeline, which cannot directly reflect the oxidation degree of the resins or the membranes, and the monitoring instruments are mostly imported equipment, which are expensive, have a long supply cycle, are difficult to maintain and have poor economic efficiency. In addition, the probe of the residual chlorine instrument and the ORP table is attached to a sensitive coating layer, which measures by absorbing electrons in water. After absorbing the electrons, the sensitivity of the coating layer is reduced, affecting the measurement accuracy. Such a probe is greatly affected by the pH value of water during the measurement process, especially in weak acid aqueous solution. According to the feedback from the actual application, the probe of the desalination system in the thermal power plant generally needs to be replaced after 6 months, which is high in maintenance cost. In addition, it often takes more than 3 months from ordering to putting into operation, which brings hidden dangers to the safe operation of the desalination system and is not conducive to the safe operation and management of the thermal power plant.

[0004] Moreover, the prior art has problems of large monitoring error of the residual chlorine instrument and the ORP table of the desalination system, poor intuitiveness and high maintenance cost.

[0005] Therefore, it is urgent to develop a new type of oxidant monitoring system and equipment which is low in cost and intuitive. SUMMARY

[0006] The purpose of this invention is to propose a visual monitoring and early warning system and method for the oxidant content in the feed water of an EDI device. The system uses a color-changing resin as an indicator, and its performance is basically consistent with that of the ion exchange resin inside the EDI device. The relative value of the oxidant content can be intuitively judged based on the color change of the indicator (the color after oxidation). When the oxidant content exceeds the set standard, it can provide an alarm function for the operation of the EDI device in a timely manner, which is convenient for operators to manage. It also has the characteristics of low cost.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] The EDI unit feed water oxidant content visualization monitoring and early warning system includes an EDI feed water pipe, a primary resin detection column, a secondary resin detection column, a feed water tank, an EDI membrane module, and a PLC control unit.

[0009] The EDI inlet pipe has two outlets: one is connected to the water supply tank, which is connected to the EDI membrane module; the other is connected to the primary resin detection column, which is connected to the secondary resin detection column, which is connected to the water supply tank. The primary resin detection column is equipped with a water cap and a grating sensor, which is connected to the PLC control unit.

[0010] The primary resin detection column is filled with color-changing resin and an automatic image recognition device.

[0011] Furthermore, an automatic image recognition device is placed near the interface between the color-changing resin and water.

[0012] Furthermore, a water distribution device is installed at the top of the primary resin detection column, and a water cap is installed at the bottom.

[0013] Furthermore, the primary resin detection column is provided with an inlet at the top and an outlet at the bottom.

[0014] Furthermore, the bottom of the secondary resin detection column is provided with an inlet connected to the outlet of the primary resin detection column, and the upper part of the secondary resin detection column is provided with an outlet.

[0015] Furthermore, a sampling pump is installed between the outlet of the EDI inlet pipe and the primary resin detection column.

[0016] Furthermore, the water supply tank is connected to the water supply pump, and the water supply pump outlet is divided into two paths: one path is connected to the EDI membrane module via the EDI inlet pneumatic valve, and the other path is connected to the recycling unit via the EDI bypass pneumatic valve; the water supply pump, the EDI inlet pneumatic valve, and the EDI bypass pneumatic valve are all connected to the PLC control unit.

[0017] Furthermore, the sampling pump is a peristaltic pump.

[0018] A visualization monitoring and early warning method based on the above system is characterized in that the influent enters the first-stage resin detection column, comes into contact with the color-changing resin inside the first-stage resin detection column, and then enters the second-stage resin detection column; the effluent enters the EDI membrane block through the water supply tank.

[0019] When the oxidant content in the influent is below 0.05 mg / L, the color-changing resin is oxidized and broken down. The broken color-changing resin enters the secondary resin detection column, where it is intercepted by the water cap and accumulates continuously. When the broken resin accumulates to a certain thickness, it touches the grating sensor, which then sends a signal to the PLC control unit. The PLC control unit then sends a signal to the alarm, which then issues an alarm signal.

[0020] When the oxidant content in the influent is greater than or equal to 0.05-0.1 mg / L, the automatic image recognition device collects the color of the color-changing resin and sends the color to the PLC control unit. The PLC control unit compares the received color with the initial color of the color-changing resin. If the difference is greater than 30%, the PLC control unit sends a signal to the alarm, and the alarm sounds.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] This invention installs a bypass sampling device on the water inlet pipe of the water supply tank. The color-changing resin filled in the primary resin detection column can display different colors according to the different contents of oxidant in the inlet water. The color is collected by a visual image automatic recognition device and sent to the PLC control unit. The PLC control unit automatically compares the image recognized during operation with the initial image. When the difference exceeds the set value, the alarm is triggered and can automatically shut off the EDI inlet pneumatic valve to prevent damage to the resin and ion exchange membrane in the EDI membrane block.

[0023] This invention incorporates a secondary resin detection column for enhanced early warning. When the oxidant content in the influent is below 0.05 mg / L, continuous oxidation of the color-changing resin in the primary resin detection column leads to resin breakage. At this point, the image contrast difference in the PLC control unit may not reach the set value. The broken resin from the primary column enters the secondary resin detection column. When the accumulated broken resin reaches a certain height, the photoelectric sensor in the secondary column sends a signal to the PLC control unit, which in turn sends a signal to the alarm, triggering an alarm and shutting off the EDI inlet pneumatic valve to protect the EDI membrane. This invention features a built-in PLC control system capable of outputting and receiving control signals, facilitating integration with existing electrostatic desalination systems. The system also includes an automatic control system and a wireless terminal output, allowing operators to monitor and manage the system via mobile phone. Normally, the system requires no maintenance and operates automatically with the electrostatic desalination system. System maintenance is simple; after resin oxidation, the oxidized resin is output from the corresponding interface, and new resin is added. Due to the small amount of resin required, the replacement cost is significantly lower than replacing the residual chlorine meter and ORP electrode, resulting in excellent economic efficiency. This invention allows for convenient and timely determination of the oxidant content in the influent, while also enabling automatic control and wireless terminal output, facilitating fully automated management, reducing maintenance costs, and improving the operational economy of the electrostatic desalination unit. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a visual monitoring and early warning system for the content of oxidant in the feed water of an EDI device according to the present invention.

[0025] In the diagram, 1-sampling pump, 2-automatic image recognition unit, 3-color-changing resin, 4-primary resin detection column, 5-secondary resin detection column, 6-water supply tank, 7-water supply pump, 8-EDI inlet pneumatic valve, 9-EDI bypass pneumatic valve, 10-EDI module. Detailed Implementation

[0026] The system will now be described in further detail with reference to the accompanying drawings.

[0027] See Figure 1 The present invention discloses a visualization monitoring and early warning system for the oxidant content in the feed water of an EDI device, which mainly includes an EDI feed water pipe, a sampling pump 1, an automatic image recognition device 2, a color-changing resin 3, a primary resin detection column 4, a secondary resin detection column 5, a water supply tank 6, a water supply pump 7, an EDI feed water pneumatic valve 8, an EDI bypass pneumatic valve 9, an EDI membrane block 10, and a matching PLC control unit.

[0028] The primary resin detection column 4 is filled with color-changing resin 3. A water distribution device is installed at the top of the column, and a stainless steel water cap (water distribution device) is installed at the bottom. An automatic image recognition device 2 (such as a high-definition camera) is installed near the interface between the color-changing resin 3 and water to monitor the color of the filled color-changing resin 3 in real time. An inlet connected to the water distribution device is located on the upper part of the outer surface of the primary resin detection column 4, and an outlet is located on the lower part of the outer surface.

[0029] The bottom of the secondary resin detection column 5 is provided with an inlet connected to the outlet of the primary resin detection column 4. The upper part of the secondary resin detection column 5 is provided with an outlet. An inverted stainless steel water cap is provided inside the primary resin detection column 5. Two sets of grating sensors are provided at different heights below the stainless steel water cap.

[0030] The EDI inlet pipe has two outlets. One outlet is connected to the water supply tank 6, which in turn is connected to the water supply pump 7. The outlet of the water supply pump 7 also has two outlets. One outlet connects to the EDI membrane module 10 via the EDI inlet pneumatic valve 8, while the other outlet connects to the recycling unit via the EDI bypass pneumatic valve 9. The other outlet of the EDI inlet pipe is connected to the sampling pump 1, which in turn connects to the inlet of the primary resin detection column 4. The outlet of the primary resin detection column 4 connects to the bottom inlet of the secondary resin detection column 5, and the outlet of the secondary resin detection column 5 connects to the inlet pipe of the water supply tank 6.

[0031] Sampling pump 1 is a peristaltic pump.

[0032] The water pump 7, the grating sensor, the EDI inlet pneumatic valve 8, and the EDI bypass pneumatic valve 9 are all connected to the PLC control unit.

[0033] The working process of this invention is as follows: When the EDI device is started, the EDI water inlet pneumatic door 8 is opened, the water supply pump 7 is started, and the sampling pump 1 is started in an interlock to perform sampling. After sampling, the water inlet of the sampling pump 1 enters the interior of the primary resin detection column 4 through the water distribution device at the top of the primary resin detection column 4. After fully contacting the color-changing resin 3 inside the primary resin detection column 4, the water flows out from the outlet at the bottom of the primary resin detection column 4 and enters the secondary resin detection column 5 through the bottom inlet of the secondary resin detection column 5. The water is discharged through the upper outlet pipe and then enters the water supply tank 6.

[0034] During system operation, when the oxidant concentration in the EDI influent exceeds a certain value, the upper resin of the primary resin detection column 4 will be rapidly oxidized and discolored, and the resin morphology will also change.

[0035] When the oxidant content in the influent is below 0.05 mg / L, the color change of the color-changing resin 3 is small, but the color-changing resin 3 is still subject to oxidation and breakage. At this time, the broken color-changing resin 3 enters the secondary resin detection column 5, is intercepted by the stainless steel water cap at the top of the secondary resin detection column 5 and continues to accumulate. If the broken resin accumulates to a certain thickness and touches the grating sensor, the grating is blocked. The grating sensor and the PLC control unit send a signal to the PLC control unit to the alarm. The alarm issues an alarm signal to remind the operator to check and automatically cuts off the power to protect the EDI device.

[0036] When the oxidant content is in the range of 0.05-0.1 mg / L, the color-changing resin 3 will display a light red color. At this time, the automatic image recognition device will automatically compare it with the initially set color. If the difference is greater than the set value (the set value in this invention is 30%), a signal will be sent to the PLC control unit. The PLC control unit will send a signal to the alarm, the alarm will sound, and the power supply to the EDI device will be automatically cut off. At the same time, the EDI bypass pneumatic door 9 will open and the EDI water inlet pneumatic door 8 will close, and the water containing the oxidant content will flow back to the pretreatment system.

[0037] When the oxidant content in the influent exceeds 0.1 mg / L, the color of the color-changing resin 3 after oxidation turns to color B (deep red). The automatic image recognition device collects the color of the color-changing resin 3 and sends the color to the PLC control unit. The PLC control unit compares the received color with the initial color of the color-changing resin 3 (the initial color is the color of the color-changing resin 3 when it has not been oxidized). If the difference is greater than the set value (the set value in this invention is 30%), the PLC control unit sends a signal to the alarm, and the alarm sounds.

[0038] Based on application feedback, the replacement cycle for residual chlorine meters and ORP meter probes is six months, with each replacement costing between 8,000 and 12,000 yuan. In contrast, the cost of replacing the ion exchange resin in the system of this invention is around 5,000 yuan, which is much lower than the price of residual chlorine meters and ORP meter probes, making it more economical.

[0039] The system of this invention can provide visual monitoring images through an automatic image recognition device, featuring high accuracy in comparison and analysis, ease of observation, high degree of automation, and low operation and maintenance costs. Furthermore, this system is designed as a complete unit with a control system, enabling direct interface with existing EDI devices, and can be widely applied in new construction or technical upgrade projects of electrostatic desalination systems.

[0040] The above description is merely an example of the implementation steps of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An EDI device water inlet oxidant content visual monitoring and early warning method, characterized in that, The method adopts an EDI device water inlet oxidant content visual monitoring and early warning system, the system comprising an EDI water inlet pipe, a first resin detection column (4), a second resin detection column (5), a feed water tank (6), an EDI membrane block (10), and a PLC control unit; The outlet of the EDI water inlet pipe is divided into two routes, one of which is connected to the feed water tank (6), and the other of which is connected to the first resin detection column (4), the first resin detection column (4) is connected to the second resin detection column (5), and the second resin detection column (5) is connected to the feed water tank (6); the second resin detection column (5) is internally provided with a water cap and a grating sensor, and the grating sensor is connected to the PLC control unit; the upper part of the second resin detection column (5) is provided with a water outlet, and an inverted stainless steel water cap is arranged inside the upper part of the second resin detection column (5), and two sets of grating sensors are arranged at different heights below the stainless steel water cap. The first resin detection column (4) is internally filled with a color-changeable resin (3). An image automatic recognition device (2) is arranged near the interface between the color-changeable resin (3) and water. The feed water tank (6) is connected to a feed water pump (7), the outlet of the feed water pump (7) is divided into two routes, one of which is connected to the EDI membrane block (10) through an EDI water inlet pneumatic door (8), and the other of which is connected to a recovery treatment unit through an EDI bypass pneumatic door (9); the feed water pump (7), the EDI water inlet pneumatic door (8), and the EDI bypass pneumatic door (9) are all connected to the PLC control unit. The method comprises: the water inlet enters the first resin detection column (4) and contacts the color-changeable resin (3) in the first resin detection column (4), and then enters the second resin detection column (5); the water outlet enters the EDI membrane block (10) through the feed water tank (6). When the oxidant content of the water inlet is less than 0.05 mg / L, the color-changeable resin (3) is oxidized and broken, the broken color-changeable resin (3) enters the second resin detection column (5), is intercepted by the water cap in the second resin detection column (5), and continuously accumulates; when the accumulated broken resin reaches a certain thickness and touches the grating sensor, the grating sensor sends a signal to the PLC control unit, the PLC control unit sends a signal to an alarm, and the alarm sends an alarm signal. When the oxidant content of the water inlet is greater than or equal to 0.05-0.1 mg / L, the image automatic recognition device collects the color of the color-changeable resin (3) and sends the color to the PLC control unit, the PLC control unit compares the received color with the initial color of the color-changeable resin (3), and if the difference is greater than a set value, the PLC control unit sends a signal to the alarm, and the alarm alarms.

2. The EDI device water inlet oxidant content visualized monitoring and early warning method according to claim 1, characterized in that, The top of the first resin detection column (4) is provided with a water distribution device, and the bottom is provided with a water cap.

3. The EDI device oxidant content visualization monitoring and early warning method of claim 1, wherein, The top of the first resin detection column (4) is provided with a water inlet, and the bottom is provided with a water outlet.

4. The EDI device water inlet oxidant content visualized monitoring and early warning method according to claim 3, characterized in that, The bottom of the second resin detection column (5) is provided with a water inlet connected to the water outlet of the first resin detection column (4).

5. The EDI device oxidant content visualization monitoring and early warning method of claim 3, wherein, A sampling pump (1) is arranged between the outlet of the EDI water inlet pipe and the first resin detection column (4).

6. The EDI device water-inlet oxidant content visualized monitoring and early warning method according to claim 1, characterized in that, The sampling pump (1) is a peristaltic pump.

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