A pH measuring device dedicated to a generator internal cooling water system and its working method

Abstract

The invention discloses a special pH measuring device for a generator internal cooling water system and a working method thereof, comprising a flow meter, a conductivity flow cell, a hydrogen conductivity flow cell, a degassed hydrogen conductivity flow cell, a flow regulating valve, a multi-channel conductivity meter, a PLC control panel, a color-changing cation exchange column, a carbon dioxide remover and an electric regeneration cation exchanger, wherein the flow regulating valve and the flow meter are installed on a sampling pipeline led out of a water outlet pipeline of a generator internal cooling water cooler, and the flow regulating valve and the flow meter, the conductivity flow cell, the electric regeneration cation exchanger, the color-changing cation exchange column, the hydrogen conductivity flow cell, the carbon dioxide remover and the degassed hydrogen conductivity flow cell are sequentially connected according to the water flow direction; the conductivity flow cell, the hydrogen conductivity flow cell and the degassed hydrogen conductivity flow cell are respectively connected to the multi-channel conductivity meter, and the multi-channel conductivity meter is connected to the PLC control panel. The invention has a wide range of applications and can be used for a fixed cooling water system and also for a double water internal cooling system.

Description

Technical Field

[0001] The invention relates to the technical field of water quality monitoring in power plants, and in particular to a device for measuring pH of cooling water in generators. Background Art

[0002] The internal cooling water system of the generator plays a vital role in the safe operation of the generator. The internal cooling water plays a cooling and insulating role in the stator wire rods at the same time, which can effectively prevent the generator from overheating or short circuiting and causing accidents. During the operation of large steam turbine generators, the conductivity and pH value of the internal cooling water should be measured online and continuously, and the copper content and the flow rate, ammonia content and hardness of the internal cooling water should be measured regularly. According to the current chemical detection methods, online monitoring of the conductivity of the internal cooling water can be well achieved, and the copper content, ammonia content and hardness can be sampled and analyzed. However, when the pH value of the internal cooling water (pure water) is tested offline, it is greatly affected by external interference factors, so it is required to be able to monitor the pH online.

[0003] At present, the direct electrode method is mainly used for online monitoring of the pH value of the cooling water in the generator. However, the cooling water in the generator is pure water, and the static charge, liquid junction potential and temperature will have a great impact on the measurement. In addition, most pH meters are currently installed directly in pressurized pipelines, which results in the inability of the pH electrode reference solution to penetrate normally, seriously affecting the measurement accuracy; if the measured water sample is not recovered, the amount of water replenishment will be too large. These factors lead to poor accuracy in the measurement of the pH value of the cooling water in the generator. Taking corresponding measures can only reduce the impact, but cannot completely eliminate the impact. Therefore, it is difficult for the pH value measuring instrument used in power plants to accurately measure the pH value of the cooling water.

[0004] The poor accuracy of pH measurement of internal cooling water has seriously affected the normal operation of the internal cooling water system of the generator. It is often the case that the conductivity and copper content are qualified, but the pH is low. In order to ensure that the grounding resistance meets the requirements, the pH value cannot be adjusted by increasing the conductivity on site, which ultimately causes the internal cooling water quality to fail to meet the standard requirements. Fundamentally, the reason is that the pH measurement value of the internal cooling water is too small, which fails to reflect the actual water quality and misleads the normal judgment of the operator. In order to solve this problem that interferes with on-site operation, it is urgent to solve the problem of accurate measurement of the pH of the internal cooling water. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art and to provide a dedicated pH measuring device for a generator internal cooling water system that can realize online monitoring of pH and is not affected by static charge, liquid junction potential and temperature, and can ensure measurement accuracy.

[0006] The technical solution adopted by the present invention to solve the above-mentioned problem is: a special pH measuring device for a cooling water system in a generator, characterized in that it includes a flow meter, a conductivity flow cell, a hydrogen conductivity flow cell, a degassed hydrogen conductivity flow cell, a flow regulating valve, a multi-channel conductivity meter, a PLC control panel, a color-changing cation exchange column, a carbon dioxide remover and an electrically regenerated cation exchanger, wherein the flow regulating valve and the flow meter are installed on a sampling pipeline led out from a water outlet pipeline of a cooling water cooler in the generator, and the flow regulating valve and the flow meter, the conductivity flow cell, the electrically regenerated cation exchanger, the color-changing cation exchange column, the carbon dioxide remover and the electrically regenerated cation exchanger. The ion exchange column, the hydrogen conductivity flow cell, the carbon dioxide remover and the degassed hydrogen conductivity flow cell are connected in sequence according to the water flow direction, and the degassed hydrogen conductivity flow cell is connected to the internal cooling water tank; the conductivity flow cell, the hydrogen conductivity flow cell and the degassed hydrogen conductivity flow cell are respectively provided with a conductivity electrode, a hydrogen conductivity electrode and a degassed hydrogen conductivity electrode, and the conductivity flow cell, the hydrogen conductivity flow cell and the degassed hydrogen conductivity flow cell are respectively connected to a multi-channel conductivity meter through a conductivity electrode line, a hydrogen conductivity electrode line and a degassed hydrogen conductivity electrode line, and the multi-channel conductivity meter is connected to a PLC control panel.

[0007] Furthermore, the water outlet pipe of the generator internal water cooler is connected to the sampling pipe through a three-way valve.

[0008] Furthermore, the carbon dioxide remover is connected to an electric heating controller, and a cooling water inlet and a cooling water outlet are respectively provided at the top and the bottom of the carbon dioxide remover.

[0009] The working method of the dedicated pH measuring device for the internal cooling water system of the generator is characterized in that the process is as follows: the water sample flows through the flow regulating valve and then flows through the conductivity flow cell, the hydrogen conductivity flow cell and the degassed hydrogen conductivity flow cell in sequence, the multi-channel conductivity meter measures the conductivity, hydrogen conductivity and degassed hydrogen conductivity of the internal cooling water, and the measurement results are input into the PLC control panel through 4-20mA, and the pH measurement value is displayed after being processed by the PLC control panel.

[0010] Furthermore, the present invention continuously monitors the concentration of impurity anions in the internal cooling water by measuring the hydrogen conductivity and degassed hydrogen conductivity of the internal cooling water, thereby eliminating the influence of the impurity anions on the pH calculation.

[0011] Furthermore, the internal cooling water pH calculation of the present invention only requires three variables, namely conductivity, hydrogen conductivity and degassed hydrogen conductivity, and these three variables can all be accurately measured, thereby ensuring the accuracy of pH calculation.

[0012] Furthermore, the present invention realizes accurate calculation of the pH value of the inner cooling water, avoids various problems existing in directly measuring the pH value of the inner cooling water with a pH meter, and greatly improves the accuracy and reliability of the measurement of the pH value of the inner cooling water.

[0013] Furthermore, the conductivity, hydrogen conductivity and degassed hydrogen conductivity of the present invention are measured using a multi-channel conductivity meter, which requires a cell constant of 0.01 cm -1 or 0.04cm -1 Level, requires pure water, acid and ammonia temperature compensation methods, to ensure that the selected instrument is suitable for the measurement requirements of special water quality of internal cooling water.

[0014] Furthermore, in order to accurately measure the hydrogen conductivity of the internal cooling water, the present invention adopts a method of connecting an electrically regenerated cation exchange column and a color-changing cation exchange column in series, which can ensure both the measurement accuracy and the operation cycle.

[0015] Furthermore, in order to ensure that the hydrogen conductivity of the internal cooling water needs to be measured continuously, the present invention installs an electric regeneration cation exchange column in front of the color-changing cation exchange column, and the electric regeneration cation exchange column removes most of the cations in the water. The color-changing cation exchange column only serves to improve the accuracy and standby function, so the hydrogen conductivity measurement can be carried out continuously for a long time.

[0016] Compared with the prior art, the present invention has the following advantages and effects:

[0017] The pH measurement results are highly accurate. When the internal cooling water is treated by a certain process, the conductivity, hydrogen conductivity and degassed hydrogen conductivity determine the specific composition of the internal cooling water, and the corresponding pH is unique. As long as the conductivity, hydrogen conductivity and degassed hydrogen conductivity of the internal cooling water are measured, the pH of the internal cooling water can be calculated. The accuracy and reliability requirements of this calculation of pH are much higher than the measurement results using the direct electrode method.

[0018] It can run for a long time and is maintenance-free. When the pH of internal cooling water is measured by direct method, regular inspection and calibration work is required, and the electrode needs to be replaced every six months or one year. The pH measuring device of the present invention does not need calibration and maintenance after installation and commissioning, and does not need to replace the electrode. Due to the installation of the pre-electric regeneration cation exchange column, the service life of the color-changing cation exchange column can reach at least one year.

[0019] There is no sewage discharge, and the amount of water replenishment in the internal cooling water system is very small. Since the present invention only monitors the conductivity, hydrogen conductivity and degassed hydrogen conductivity during operation, the water sample after sampling and measurement can be directly returned to the internal cooling water tank, so there is basically no water loss in the entire internal cooling water system, and basically no water replenishment is required.

[0020] It has a wide range of applications and can be used in fixed cooling water systems as well as double water internal cooling systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is an installation layout diagram of a dedicated pH measuring device for a cooling water system in a generator according to an embodiment of the present invention.

[0022] Figure 2It is a structural schematic diagram of a dedicated pH measuring device for a cooling water system in a generator according to an embodiment of the present invention.

[0023] In the figure: three-way valve 1, flow meter 2, conductivity flow cell 3, hydrogen conductivity flow cell 4, degassed hydrogen conductivity flow cell 5, flow regulating valve 6, multi-channel conductivity meter 7, PLC control panel 8, conductivity electrode 9, hydrogen conductivity electrode 10, degassed hydrogen conductivity electrode 11, color-changing cation exchange column 12, carbon dioxide remover 13, electrically regenerated cation exchanger 14, conductivity electrode line 15, hydrogen conductivity electrode line 16, degassed hydrogen conductivity electrode line 17, electric heating controller 18. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and by way of examples. The following examples are intended to explain the present invention but the present invention is not limited to the following examples.

[0025] Example 1.

[0026] See also Figure 2 The dedicated pH measuring device for the cooling water system in the generator in this embodiment includes a flow meter 2, a conductivity flow cell 3, a hydrogen conductivity flow cell 4, a degassed hydrogen conductivity flow cell 5, a flow regulating valve 6, a multi-channel conductivity meter 7, a PLC control panel 8, a color-changing cation exchange column 12, a carbon dioxide remover 13 and an electric regeneration cation exchanger 14. The flow regulating valve 6 and the flow meter 2 are installed on a sampling pipeline led out from a water outlet pipe of the cooling water cooler in the generator, and the flow regulating valve 6 and the flow meter 2, the conductivity flow cell 3, the electric regeneration cation exchanger 14, the color-changing cation exchange column 12, the hydrogen conductivity The circulation cell 4, the carbon dioxide remover 13 and the degassed hydrogen conductivity circulation cell 5 are connected in sequence according to the direction of water flow, and the degassed hydrogen conductivity circulation cell 5 is connected to the internal cooling water tank; the conductivity circulation cell 3, the hydrogen conductivity circulation cell 4 and the degassed hydrogen conductivity circulation cell 5 are respectively provided with a conductivity electrode 9, a hydrogen conductivity electrode 10 and a degassed hydrogen conductivity electrode 11, and the conductivity circulation cell 3, the hydrogen conductivity circulation cell 4 and the degassed hydrogen conductivity circulation cell 5 are respectively connected to the multi-channel conductivity meter 7 through the conductivity electrode line 15, the hydrogen conductivity electrode line 16 and the degassed hydrogen conductivity electrode line 17, and the multi-channel conductivity meter 7 is connected to the PLC control panel 8.

[0027] In this embodiment, the water outlet pipe of the generator internal cooling water cooler is connected to the sampling pipe through a three-way valve 1.

[0028] In this embodiment, the carbon dioxide remover 13 is connected to an electric heating controller 18, and a cooling water inlet and a cooling water outlet are respectively provided at the top and the bottom of the carbon dioxide remover 13.

[0029] The working method of the dedicated pH measuring device for the internal cooling water system of the generator is characterized in that the process is as follows: the water sample flows through the flow regulating valve 6 and then flows through the conductivity flow cell 3, the hydrogen conductivity flow cell 4 and the degassed hydrogen conductivity flow cell 5 in sequence, the multi-channel conductivity meter 7 measures the conductivity, hydrogen conductivity and degassed hydrogen conductivity of the internal cooling water, and inputs the measurement results into the PLC control panel 8 through 4~20mA, and the pH measurement value is displayed after being processed by the PLC control panel 8.

[0030] The multi-channel conductivity meter 7 has at least 3 conductivity channels and temperature compensation function. The conductivity electrode constant required is 0.01cm -1 Level or 0.04cm -1 class.

[0031] When measuring hydrogen conductivity, the electric regeneration cation exchange column 14 and the color-changing cation exchange column 12 are connected in series to remove cations. The color-changing cation exchange column 12 is made of transparent organic glass, and the resin in the color-changing cation exchange column 12 is replaced when 3 / 4 of the resin fails.

[0032] The conductivity, hydrogen conductivity and degassed hydrogen conductivity values ​​measured by the multi-channel conductivity meter 7 are transmitted to the PLC control panel 8 as a standard signal of 4-20 mA, and the PLC control panel 8 performs data processing to finally obtain the pH value of the cooling water in the generator.

[0033] Example 2.

[0034] See also Figure 1 The dedicated pH measuring device for the generator internal cooling water system is installed at the cooler outlet of the generator internal cooling water system to ensure that the water sample temperature is not too high. The pH measuring device is connected in series with the internal cooling water sampling pipeline through a three-way valve 1, and the measured water sample is returned to the exchanger inlet or directly to the internal cooling water tank. When sampling, the water sample flow rate of the measuring pipeline will be reduced for a short time, and the impact on the measurement can be ignored.

[0035] See also Figure 2 The dedicated pH measuring device for the cooling water system in the generator consists of a three-way valve 1, a flow meter 2, a conductivity flow cell 3, a hydrogen conductivity flow cell 4, a degassed hydrogen conductivity flow cell 5, a flow regulating valve 6, a multi-channel conductivity meter 7, a PLC control panel 8, a color-changing cation exchange column 12, a carbon dioxide remover 13, an electrically regenerated cation exchanger 14 and an electric heating controller 18.

[0036] The three-way valve 1, the flow regulating valve 6, the flow meter 2, the conductivity flow cell 3, the electric regeneration cation exchanger 14, the color-changing cation exchange column 12, the hydrogen conductivity flow cell 4, the carbon dioxide remover 13 and the degassed hydrogen conductivity flow cell 5 are connected in series, and the measured water sample passes through the above devices in turn. The conductivity electrode line 15, the hydrogen conductivity electrode line 16 and the degassed hydrogen conductivity electrode line 17 are in a parallel relationship, one end of the three is connected to the conductivity flow cell 3, the hydrogen conductivity flow cell 4 and the degassed hydrogen conductivity flow cell 5 respectively, and the other end is simultaneously connected to the multi-channel conductivity meter 7, and the real-time measurement value is displayed on different channels of the multi-channel conductivity meter 7.

[0037] In order to reduce the temperature of the high-temperature water sample after the removal of carbon dioxide to the acceptable value of the multi-channel conductivity meter 7, a separate water channel is introduced as cooling water for the high-temperature water sample, and a cooling water inlet and a cooling water outlet are respectively set at the top and bottom of the carbon dioxide remover 13. The cooling water sample can be closed water or industrial water. After heat exchange, the cooling water can be directly discharged into the unit drainage tank, or it can be recycled to the closed water system or the industrial water system.

[0038] The pH of the inner cooling water is calculated by a dedicated pH calculation model. The theoretical derivation of the model is as follows: When NaOH is used as an alkalizing agent for the inner cooling water, with the continuous infiltration of CO2, the following balance exists in the inner cooling water:

[0039] [H + ]+[Na + ]=[OH - ]+2[CO3 2- ]+[HCO3 - ] (1)

[0040] When the CO2 content (CC) and pH of the internal cooling water are known, it can be known that [CO3 2- ]、[HCO3 - ] and [CO2] have the following relationship:

[0041]

[0042]

[0043] [CO2]=[CO3 2- ]+[HCO3 - ]+[H2CO3] (4)

[0044] After finishing, we can get:

[0045]

[0046]

[0047] [CO3 2-]、[HCO3 - ] and [H + ] is substituted into formula (1) to obtain [Na + ]:

[0048]

[0049] From this, the internal cooling water conductivity SC can be obtained:

[0050]

[0051] Theoretical calculations show that when the CO2 content (CC), pH and SC of the internal cooling water have a one-to-one correspondence. On the basis of the one-to-one correspondence between CC, SC and pH of the internal cooling water, combined with a large number of experiments, a special pH calculation model for the internal cooling water of the generator can be established. The model contains three characteristic input variables, namely conductivity, hydrogen conductivity and degassed hydrogen conductivity.

[0052] Compared with the direct measurement of pH value by electrode method, the measurement accuracy of conductivity, hydrogen conductivity and degassed hydrogen conductivity is high, which can ensure the accuracy of input variables. The internal cooling water pH calculation model is derived through theoretical calculation and verified by experiments. The accuracy of the calculation model can be guaranteed, so the accuracy of internal cooling water pH measurement can be ensured.

[0053] The PLC control panel 8 can receive 4-20mA current signals. The built-in program of the PLC control panel 8 can output the pH value of the cooling water in the generator according to the dedicated pH calculation model. At the same time, the panel can be connected to the DCS control system of the power plant and display the measured value in the industrial computer in the centralized control room.

[0054] The conductivity, hydrogen conductivity and degassed hydrogen conductivity values ​​measured by the multi-channel conductivity meter 7 are transmitted to the PLC control panel 8 with a standard signal of 4-20 mA. The PLC control panel 8 processes the data with a built-in pH calculation model to finally obtain the pH value of the cooling water in the generator.

[0055] The flow control valve 6 is preferably used for flow control, and the appropriate flow range is 150 mL to 250 mL. If the flow control valve 6 fails, the flow meter 2 can be used for flow control.

[0056] An automatic exhaust valve is provided inside the electrically regenerated cation exchanger 14 to prevent air from entering the electrical regeneration chamber, thereby causing measurement errors or failure to regenerate.

[0057] The color-changing cation exchange column 12 adopts a down-flow mode with an exhaust valve at the top to remove the air that may gather at the top of the color-changing cation exchange column 12. When the color-changing resin reaches 3 / 4 of the total amount of resin, the regenerated hydrogen type resin is refilled.

[0058] The water sample flows through the hydrogen conductivity flow cell 4 and then enters the carbon dioxide remover 13. The carbon dioxide remover 13 removes carbon dioxide by thermal degassing. The heating method is electric heating. The temperature is controlled by an electric heating controller 18 to ensure that the water sample reaches a boiling state but does not overheat.

[0059] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0060] Although the present invention has been disclosed as above by way of embodiments, it is not intended to limit the protection scope of the present invention. Any changes and modifications made by any technician familiar with the technology without departing from the concept and scope of the present invention should fall within the protection scope of the present invention.

Claims

1. A working method of a dedicated pH measuring device for a generator internal cooling water system, characterized in that: The dedicated pH measuring device for the generator internal cooling water system comprises a flow meter (2), a conductivity flow cell (3), a hydrogen conductivity flow cell (4), a degassed hydrogen conductivity flow cell (5), a flow regulating valve (6), a multi-channel conductivity meter (7), a PLC control panel (8), a color-changing cation exchange column (12), a carbon dioxide remover (13) and an electrically regenerated cation exchanger (14), wherein the flow regulating valve (6) and the flow meter (2) are installed on a sampling pipeline led out from a water outlet pipeline of a generator internal cooling water cooler, and the flow regulating valve (6) and the flow meter (2), the conductivity flow cell (3), the electrically regenerated cation exchanger (14), the color-changing cation exchange column (12), the hydrogen conductivity flow cell (4) , a carbon dioxide remover (13) and a degassed hydrogen conductivity flow cell (5) are connected in sequence according to the direction of water flow, and the degassed hydrogen conductivity flow cell (5) is connected to an internal cooling water tank; the conductivity flow cell (3), the hydrogen conductivity flow cell (4), and the degassed hydrogen conductivity flow cell (5) are respectively provided with a conductivity electrode (9), a hydrogen conductivity electrode (10), and a degassed hydrogen conductivity electrode (11), and the conductivity flow cell (3), the hydrogen conductivity flow cell (4), and the degassed hydrogen conductivity flow cell (5) are respectively connected to a multi-channel conductivity meter (7) through a conductivity electrode line (15), a hydrogen conductivity electrode line (16), and a degassed hydrogen conductivity electrode line (17), and the multi-channel conductivity meter (7) is connected to a PLC control panel (8); The water outlet pipe of the generator internal cooling water cooler is connected to the sampling pipe via a three-way valve (1); The carbon dioxide remover (13) is connected to an electric heating controller (18), and a cooling water inlet and a cooling water outlet are respectively provided at the top and the bottom of the carbon dioxide remover (13); The working method is as follows: after the water sample flows through the flow regulating valve (6), it flows through the conductivity flow cell (3), the hydrogen conductivity flow cell (4) and the degassed hydrogen conductivity flow cell (5) in sequence, and the multi-channel conductivity meter (7) measures the conductivity of the internal cooling water, the hydrogen conductivity and the degassed hydrogen conductivity, and inputs the measurement results into the PLC control panel (8) through 4-20 mA, and after being processed by the PLC control panel (8), the pH measurement value is displayed; A dedicated pH measuring device for the generator internal cooling water system is installed at the outlet of the cooler of the generator internal cooling water system to ensure that the water sample temperature is not too high; the pH measuring device is connected in series with the internal cooling water sampling pipeline through a three-way valve (1), and the measured water sample is returned to the exchanger inlet or directly to the internal cooling water tank; when sampling is performed, the water sample flow rate of the measuring pipeline will be reduced for a short time, and the influence on the measurement is negligible; The dedicated pH measuring device for the cooling water system in the generator is composed of a three-way valve (1), a flow meter (2), a conductivity flow cell (3), a hydrogen conductivity flow cell (4), a degassed hydrogen conductivity flow cell (5), a flow regulating valve (6), a multi-channel conductivity meter (7), a PLC control panel (8), a color-changing cation exchange column (12), a carbon dioxide remover (13), an electric regeneration cation exchanger (14) and an electric heating controller (18); The three-way valve (1), the flow regulating valve (6), the flow meter (2), the conductivity flow cell (3), the electrically regenerated cation exchanger (14), the color-changing cation exchange column (12), the hydrogen conductivity flow cell (4), the carbon dioxide remover (13) and the degassed hydrogen conductivity flow cell (5) are connected in series; the conductivity electrode line (15), the hydrogen conductivity electrode line (16) and the degassed hydrogen conductivity electrode line (17) are in a parallel relationship, one end of the three is respectively connected to the conductivity flow cell (3), the hydrogen conductivity flow cell (4) and the degassed hydrogen conductivity flow cell (5), and the other end is simultaneously connected to the multi-channel conductivity meter (7), and the real-time measurement value is displayed on different channels of the multi-channel conductivity meter (7); In order to reduce the temperature of the high-temperature water sample after the removal of carbon dioxide to an acceptable value of the multi-channel conductivity meter (7), a separate water channel is introduced as cooling water for the high-temperature water sample, and a cooling water inlet and a cooling water outlet are respectively provided at the top and bottom of the carbon dioxide remover (13); The pH of the inner cooling water is calculated by a dedicated pH calculation model. The theoretical derivation of the model is as follows: When NaOH is used as an alkalizing agent for the inner cooling water, with the continuous infiltration of CO2, the following balance exists in the inner cooling water: <h2 style=";text-align:left;direction:ltr">[H<h2 style=";text-align:left;direction:ltr"> + <h2 style=";text-align:left;direction:ltr"> ]+[Na<h2 style=";text-align:left;direction:ltr"> + <h2 style=";text-align:left;direction:ltr"> ]=[OH<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> ]+2[CO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> ]+[HCO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> ] (1) When the CO2 content (CC) and pH of the internal cooling water are known, it can be known that [CO3 2- ]、[HCO3 - ] and [CO2] have the following relationship: <h2 style=";text-align:left;direction:ltr">[CO2]=[CO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> ]+[HCO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> ]+[H2CO3] (4) After finishing, we can get: [CO3 2- ]、[HCO3 - ] and [H + ] is substituted into formula (1) to obtain [Na + ]: From this, the internal cooling water conductivity SC can be obtained: Theoretical calculations show that when the CO2 content CC, pH and SC of the internal cooling water have a one-to-one correspondence; on the basis of the one-to-one correspondence between CC, SC and pH of the internal cooling water, combined with a large number of experiments, a special pH calculation model for the internal cooling water of the generator can be established. The model contains three characteristic input variables, namely conductivity, hydrogen conductivity and degassed hydrogen conductivity. Compared with the direct measurement of pH value by electrode method, the measurement accuracy of conductivity, hydrogen conductivity and degassed hydrogen conductivity is high, which can ensure the accuracy of input variables; the internal cooling water pH calculation model is derived through theoretical calculation and verified by experiments, and the accuracy of the calculation model can be guaranteed, thus ensuring the accuracy of internal cooling water pH measurement; The conductivity, hydrogen conductivity and degassed hydrogen conductivity values ​​measured by the multi-channel conductivity meter (7) are transmitted to the PLC control panel (8) in the form of a 4-20 mA standard signal. The PLC control panel (8) processes the data using a built-in pH calculation model to ultimately obtain the pH value of the cooling water in the generator. A flow control valve (6) is used to control the flow rate, and the flow rate range is 150 mL to 250 mL; if the flow control valve (6) fails, a flow meter (2) is used to control the flow rate; An automatic exhaust valve is provided inside the electric regeneration cation exchanger (14) to prevent air from entering the electric regeneration chamber, causing measurement errors or failure of regeneration; The color-changing cation exchange column (12) adopts a top-in, bottom-out downstream mode, and an exhaust valve is provided on the top of the color-changing cation exchange column (12) to remove air that may have accumulated on the top of the color-changing cation exchange column (12); when the color-changing resin reaches 3 / 4 of the total amount of the resin, the regenerated hydrogen-type resin is refilled; The water sample flows through the hydrogen conductivity flow cell (4) and then enters the carbon dioxide remover (13). The carbon dioxide remover (13) removes carbon dioxide by means of thermal degassing. The heating method is electric heating. The temperature is controlled by an electric heating controller (18) to ensure that the water sample reaches a boiling state but does not overheat.

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