A system and method for online measurement of sodium ions in cation bed water

Abstract

A system and method for measuring sodium ions in cation bed water online, comprising an online alkalizer preparation device, a water supply module, a reagent module, a water sample pH value monitoring module, a sodium ion concentration measurement module and a data processing unit; the water supply module, the reagent module and the water sample pH value monitoring module are all connected to the online alkalizer preparation device, and the water effluent from the water sample pH value monitoring module enters the sodium ion concentration measurement module; the online alkalizer preparation device, the water sample pH value monitoring module and the sodium ion concentration measurement module are all connected to the data processing unit. The water sample to be tested enters the online alkalizer preparation device to generate OH online. ‑ To adjust the pH of the water sample to be tested, after the pH value of the water sample reaches the requirement, the water sample enters the electrode cup, the sodium ion electrode measures the sodium ion concentration in the water online, and outputs the measurement signal to the data processing unit for data processing and display. This method has a good alkalinization effect on the cation bed water, and can greatly improve the measurement accuracy and sensitivity of sodium ions in the water sample to be tested.

Description

Technical Field

[0001] The invention belongs to the technical field of water sample monitoring in power stations and relates to an online measurement system and method for sodium ions in effluent from a cation bed. Background Art

[0002] The treatment of boiler feed water system generally adopts cation bed-anion bed-mixed bed for fine desalination, and the outlet of cation bed needs to monitor the sodium ion content of the outlet water online to judge the water quality and failure end point. In the process of online sodium ion measurement, the pH value of water generally needs to be adjusted to above 10.5 to avoid the influence of H+ on sodium ion measurement. Since ammonia has been added to water vapor samples such as boiler feed water and steam to adjust the pH value of water samples to above 9.0, alkalization generally uses isopropylamine online to adjust the pH of water samples to above 10.5; but the cation bed outlet water is generally acidic, and sometimes the pH value is even lower than 3.0. At this time, if isopropylamine is used for online alkalization, not only the dosage of reagents is large, but also the alkalization effect is not good, which seriously affects the measurement results of sodium ions in water. Summary of the invention

[0003] The purpose of the present invention is to provide a system and method for measuring sodium ions in cation bed effluent online, so as to solve the problem that the online alkalization with isopropylamine not only requires a large amount of reagent, but also has a poor alkalization effect, which seriously affects the measurement result of sodium ions in water.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] An online sodium ion measurement system for cation bed outlet water comprises an online alkalizer preparation device, a water supply module, a reagent module, a water sample pH value monitoring module, a sodium ion concentration measurement module and a data processing unit; the water supply module, the reagent module and the water sample pH value monitoring module are all connected to the online alkalizer preparation device, and the water sample enters the sodium ion concentration measurement module after passing through the pH value monitoring module; the online alkalizer preparation device, the water sample pH value monitoring module and the sodium ion concentration measurement module are all connected to the data processing unit.

[0006] Furthermore, the online alkalizer preparation device includes a cathode, an anode and an intermediate packing chamber, the packing chamber is filled with an ammonia type cation exchange resin, and the packing chamber and the cathode and anode chambers are isolated by cation exchange membranes; the cathode of the online alkalizer preparation device is connected to a data processing unit.

[0007] Furthermore, the reagent module includes a reagent bottle and a first solenoid valve; the outlet of the reagent bottle is connected to the filler chamber of the online alkalizer preparation device through the first solenoid valve and then connected to the anode of the online alkalizer preparation device; dilute ammonia water is placed in the reagent bottle; the first solenoid valve is connected to the data processing unit.

[0008] Furthermore, the water supply module includes a water sample, an injection pump and a multi-way valve; one end of the multi-way valve is connected to different water samples, and the other end is connected to the cathode of the online alkalizer preparation device through the injection pump; the injection pump and the multi-way valve are both connected to the data processing unit.

[0009] Furthermore, the water sample pH value monitoring module includes a composite pH electrode and an overflow cup; the overflow cup is connected to the cathode of the online alkalizer preparation device, and the composite pH electrode is arranged in the overflow cup; the composite pH electrode is connected to the data processing unit.

[0010] Furthermore, the sodium ion concentration measurement module includes a second solenoid valve, a sodium ion electrode, a reference electrode and an electrode cup; the overflow cup is connected to the electrode cup through the second solenoid valve, the sodium ion electrode and the reference electrode are arranged in the electrode cup, and the second solenoid valve, the sodium ion electrode and the reference electrode are all connected to the data processing unit.

[0011] Furthermore, the electrode cup is connected to the discharge port through a sewage pump, and the sewage pump is connected to the data processing unit.

[0012] Furthermore, a method for online measurement of sodium ions in effluent from a cation bed comprises the following steps:

[0013] 1) The data processing unit controls the multi-way valve and selects a certain water sample to enter the measurement system through the channel in the multi-way valve;

[0014] 2) The water sample enters the cathode of the online alkalizer preparation device through the sampling pump and then enters the overflow cup. At this time, the system is flushed and the current of the online alkalizer preparation device is zero;

[0015] 3) After the overflow cup overflows, open the second solenoid valve switch, and the water sample enters the electrode cup and is discharged through the sewage pump. Repeat steps 1)-3) to flush the measurement system twice;

[0016] 4) During the water sample measurement phase, the water sample enters the measurement system through the multi-way valve and the sample injection pump, and at the same time, the data processing unit controls the current of the online alkalizer preparation device to be Ix, and the first solenoid valve is in an open state;

[0017] 5) The water sample to be tested enters the cathode of the online alkalizer preparation device, and the pH of the water sample to be tested is adjusted to about 11 through the OH generated at the cathode. After the pH value measured by the composite pH electrode reaches the standard, the sample injection pump is turned off;

[0018] 6) The water sample to be tested with the pH adjusted in the overflow cup enters the electrode cup through the second solenoid valve, where the sodium ion electrode and the reference electrode measure the sodium ion concentration and output the measurement signal to the data processing unit for data processing and display.

[0019] Furthermore, the specific operation of step 5) is:

[0020] A current Ix within 1000 mA is applied to the cathode and anode of the online alkalizer preparation device, and the first solenoid valve is opened;

[0021] The water sample enters the online alkalizer preparation device, and the dilute ammonia water placed in the reagent bottle passes through the packing chamber of the online alkalizer preparation device and is discharged through the anode. At this time, the anode electrolysis produces O2 and H + , H + Enter the resin packing room of the online alkalizer preparation device through the cation exchange membrane, and exchange with the ammonia type cation exchange resin in it. The exchanged NH4 + The H2 and OH produced by cathode electrolysis enter the cathode of the online alkalizer preparation device through the cation exchange membrane. - With NH4 + Combined with ammonia water, it is added to the water sample to adjust the pH value of the water sample;

[0022] A composite pH electrode is placed in the overflow cup to monitor the pH signal. When the pH reaches 11±0.2, the sample pump is turned off and the water sample is placed in the electrode cup for measurement. If the pH is low, the concentration of NH4OH produced by electrolysis is adjusted by adjusting the constant current Ix applied to the cathode and anode of the online alkalizer preparation device to increase the pH of the water sample to be measured until the measurement requirements are met.

[0023] After the pH value of the water sample to be tested reaches the standard, the current applied to the cathode and anode of the online alkalizer preparation device becomes zero, and the first solenoid valve is closed.

[0024] Furthermore, the concentration of the dilute ammonia water placed in the reagent bottle is not greater than 1 mol / L, so that the pump and valve are not corroded by alkali; after the dilute ammonia water in the reagent bottle passes through the packing chamber of the online alkalizer preparation device, the ammonia type cation exchange resin therein always maintains the ammonia type, and the ammonium radical enters the cathode under the action of electromigration and reacts with the OH generated by the cathode electrolysis. - Ammonia is formed to adjust the pH.

[0025] Compared with the prior art, the present invention has the following technical effects:

[0026] In the specific operation of the cation bed effluent sodium ion online measurement system and method described in the present invention, a multi-way valve can be selected to connect multiple water samples, and the samples are switched at regular intervals to realize the switching measurement of the multiple water samples. For example, originally two online sodium meters were required, but now one online sodium meter can be equipped, and the switching measurement of the two water samples is performed by using a two-way valve; the amount of water sample required for measurement is small, and the amount of alkalizing agent used is greatly reduced; the method of the present invention can be used to quickly alkalize the acidic water sample online to a pH value of more than 10.5, and the alkalization speed is fast and the effect is good, thereby greatly improving the measurement precision and accuracy of the sodium ions. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the present invention.

[0028] Among them, 1 is a multi-way valve, 2 is a sample injection pump, 3 is an online alkalizing agent preparation device, 4 is a solenoid valve, 5 is a reagent bottle, 6 is an overflow cup, 7 is a composite pH electrode, 8 is a solenoid valve, 9 is a sodium ion electrode, 10 is a reference electrode, 11 is an electrode cup, 12 is a data processing unit, and 13 is a sewage pump. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only an embodiment of a part of the present invention, not all embodiments, and is not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concepts disclosed in the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

[0030] The accompanying drawings show schematic diagrams of structures according to embodiments disclosed in the present invention. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0031] The invention discloses an online measurement system and method for sodium ions in cation bed effluent, comprising a multi-way valve, a sample injection pump, an online alkalizer preparation device, a solenoid valve, a reagent bottle, an overflow cup, a composite pH electrode, a solenoid valve, a sodium ion electrode, a reference electrode, an electrode cup, a data processing unit and a sewage pump; the water sample to be tested enters the online alkalizer preparation device to generate OH- online to adjust the pH of the water sample to be tested, and after the pH value of the water sample is measured to meet the requirement, the water sample enters the electrode cup, and the sodium ion electrode measures the sodium ion concentration in the water online, and outputs the measurement signal to the data processing unit for data processing and display. The method has a good alkalization effect on the effluent of the cation bed, and can greatly improve the measurement accuracy and sensitivity of sodium ions in the water sample to be tested.

[0032] refer to Figure 1The present invention discloses an online measurement system for sodium ions in cation bed water, comprising a multi-way valve 1, a sample injection pump 2, an online alkalizer preparation device 3, a first solenoid valve 4, a reagent bottle 5, an overflow cup 6, a composite pH electrode 7, a second solenoid valve 8, a sodium ion electrode 9, a reference electrode 10, an electrode cup 11, a data processing unit 12 and a sewage pump 13. After the water sample passes through the multi-way valve 1 and the sample injection pump 2 and enters the cathode inlet of the online alkalizer preparation device, it enters the overflow cup 6 and is monitored by the composite pH electrode 7 for the pH value of the water sample. After the pH value of the water sample reaches the set value, the sample water in the overflow cup 6 enters the electrode cup 11 through the second solenoid valve 8, and after the sodium ion concentration of the water sample is measured by the sodium ion electrode 9 and the reference electrode 10 in the electrode cup 11, it is discharged from the sewage pump 13.

[0033] It also includes a data processing unit 12, and the electrical signals of the multi-way valve 1, the sample injection pump 2, the online alkalizer preparation device 3, the first solenoid valve 4, the composite pH electrode 7, the second solenoid valve 8, the sodium ion electrode 9, the reference electrode 10, and the sewage pump 13 are all connected to the data processing unit 12.

[0034] The online alkalizer preparation device 3 includes a cathode, an anode and an intermediate packing chamber, the packing chamber is filled with an ammonia type cation exchange resin, and the packing chamber and the cathode and anode chambers are isolated by cation exchange membranes; a reagent bottle 5, in which dilute ammonia water is placed and discharged through the anode after passing through the packing chamber of the online alkalizer preparation device 3.

[0035] The data processing unit 12 switches different water samples into the measurement system through the multi-way valve 1; the data processing unit 12 can control the flow rate of the sample injection pump 2, adjust the current signal of the online alkalizer preparation device 3 through the signal of the composite pH electrode 7; output the sodium ion concentration measured by the sodium ion electrode 9 and the reference electrode 10; and control the switching time of the first solenoid valve 4, the second solenoid valve 8 and the sewage pump 13.

[0036] The method for online measurement of sodium ions in effluent from a cation bed of the present invention comprises the following steps:

[0037] The data processing unit 12 controls the multi-way valve 1, and selects a certain water sample to enter the measurement system through a certain channel in the multi-way valve 1;

[0038] 2 The water sample enters the cathode of the online alkalizer preparation device 3 through the sample injection pump 2 and then enters the overflow cup 6. At this time, the system is flushed and the current of the online alkalizer preparation device 3 is zero.

[0039] 3 After the overflow cup 6 overflows, the second electromagnetic valve 8 is opened, and the water sample enters the electrode cup 11 and is discharged through the sewage pump 13. Repeat steps 1-3 to flush the measurement system twice.

[0040] 4 Water sample measurement stage, the water sample enters the measurement system through the multi-way valve 1 and the sample pump 2, and at the same time the data processing unit 12 controls the current of the online alkalizing agent preparation device 3 to be Ix, and the first solenoid valve 4 is in the open state.

[0041] 5 The water sample to be tested enters the cathode of the online alkalizer preparation device 3, and the pH of the water sample to be tested is adjusted to about 11 through the OH- generated at the cathode. After the pH value measured by the composite pH electrode 7 reaches the standard, the sample injection pump 2 is turned off.

[0042] The water sample to be tested with the pH adjusted in the overflow cup 6 enters the electrode cup 11 through the second solenoid valve 8, wherein the sodium ion electrode 9 and the reference electrode 10 measure the sodium ion concentration and output the measurement signal to the data processing unit 12 for data processing and display.

[0043] The specific operations of step 5 are:

[0044] 7 The cathode and anode of the online alkalizing agent preparation device 3 are applied with a current Ix within 1000 mA, and the first solenoid valve 4 is opened;

[0045] 8 The water sample enters the online alkalizer preparation device 3, and the dilute ammonia water placed in the reagent bottle 5 passes through the packing chamber of the online alkalizer preparation device 3 and is discharged through the anode. At this time, the anode electrolysis produces O2 and H+, and H+ enters the resin packing chamber of the online alkalizer preparation device 3 through the cation exchange membrane, and is exchanged with the ammonia type cation exchange resin therein. The exchanged NH4+ enters the cathode of the online alkalizer preparation device 3 through the cation exchange membrane, and the H2 and OH- produced by the cathode electrolysis combine with NH4+ to form ammonia water and are added to the water sample to adjust the pH value of the water sample;

[0046] A composite pH electrode 7 is placed in the overflow cup 6 to monitor the pH signal. After the pH reaches 11±0.2, the sample pump 2 is turned off and the water sample is placed in the electrode cup 11 for measurement. If the pH is low, the concentration of NH4OH produced by electrolysis is adjusted by adjusting the size of the constant current Ix applied to the cathode and anode of the online alkalizer preparation device 3 to increase the pH of the water sample to be tested until the measurement requirements are met.

[0047] 10 After the pH value of the water sample to be tested reaches the standard, the current applied to the cathode and anode of the online alkalizer preparation device 3 becomes zero, and the first solenoid valve 4 is closed.

[0048] The specific operations of step 8 are:

[0049] 11 After the packing chamber of the online alkalizer preparation device (3), the ammonia-type cation exchange resin therein is always kept in the ammonia type, and the ammonium radical enters the cathode under the action of electromigration and reacts with the OH generated by the cathode electrolysis. - Ammonia is formed to adjust the pH.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. An online measurement system for sodium ions in cation bed water, characterized in that: It comprises an online alkalizer preparation device (3), a water supply module, a reagent module, a water sample pH value monitoring module, a sodium ion concentration measurement module and a data processing unit (12); the water supply module, the reagent module and the water sample pH value monitoring module are all connected to the online alkalizer preparation device (3), and the sodium ion concentration measurement module is connected to the water sample pH value monitoring module; the online alkalizer preparation device (3), the water sample pH value monitoring module and the sodium ion concentration measurement module are all connected to the data processing unit (12); The online alkalizer preparation device (3) comprises a cathode, an anode and an intermediate packing chamber, wherein the packing chamber is filled with an ammonia-type cation exchange resin, and the packing chamber and the cathode and anode chambers are isolated by cation exchange membranes; the cathode of the online alkalizer preparation device (3) is connected to a data processing unit (12); The reagent module comprises a reagent bottle (5) and a first solenoid valve (4); the outlet of the reagent bottle (5) is connected to the packing chamber of the online alkalizer preparation device (3) through the first solenoid valve (4) and then connected to the anode of the online alkalizer preparation device (3); dilute ammonia water is placed in the reagent bottle (5), and the concentration of the dilute ammonia water is not greater than 1 mol / L; the first solenoid valve (4) is connected to a data processing unit (12).

2. The online measurement system for sodium ions in effluent from a cation bed according to claim 1, characterized in that: The water supply module comprises a water sample, a sample injection pump (2) and a multi-way valve (1); one end of the multi-way valve (1) is connected to different water samples respectively, and the other end is connected to the cathode of the online alkalizing agent preparation device (3) through the sample injection pump (2); the sample injection pump (2) and the multi-way valve (1) are both connected to a data processing unit (12).

3. A cation bed water sodium ion online measurement system according to claim 2, characterized in that: The water sample pH value monitoring module comprises a composite pH electrode (7) and an overflow cup (6); the overflow cup (6) is connected to the cathode of the online alkalizer preparation device (3), and the composite pH electrode (7) is arranged in the overflow cup (6); the composite pH electrode (7) is connected to a data processing unit (12).

4. A cation bed water sodium ion online measurement system according to claim 3, characterized in that: The sodium ion concentration measurement module comprises a second solenoid valve (8), a sodium ion electrode (9), a reference electrode (10) and an electrode cup (11); the water sample in the overflow cup (6) flows into the electrode cup (11) through the second solenoid valve (8); the sodium ion electrode (9) and the reference electrode (10) are arranged in the electrode cup (11); and the second solenoid valve (8), the sodium ion electrode (9) and the reference electrode (10) are all connected to a data processing unit (12).

5. The online measurement system for sodium ions in effluent from a cation bed according to claim 4, characterized in that: The electrode cup (11) is connected to the discharge port via a sewage pump (13), and the sewage pump (13) is connected to the data processing unit (12).

6. A method for online measurement of sodium ions in effluent from a cation bed, characterized in that: The online measurement system for sodium ions in effluent from a cation bed according to claim 5 comprises the following steps: 1) The data processing unit (12) controls the multi-way valve (1) to select a certain water sample to enter the measurement system through a channel in the multi-way valve (1); 2) The water sample enters the cathode of the online alkalizer preparation device (3) through the sample injection pump (2) and then enters the overflow cup (6). At this time, the system is flushed and the current of the online alkalizer preparation device (3) is zero; 3) After the water sample overflows from the overflow cup (6), the second solenoid valve (8) is opened, and the water sample enters the electrode cup (11) and is discharged through the sewage pump (13). Steps 1) to 3) are repeated to flush the measurement system twice; 4) During the water sample measurement phase, the water sample enters the measurement system through the multi-way valve (1) and the sample feed pump (2), and at the same time, the data processing unit (12) controls the current of the online alkalizing agent preparation device (3) to be Ix, and the first solenoid valve (4) is in an open state; 5) The water sample to be tested enters the cathode of the online alkalizer preparation device (3), and the OH generated at the cathode - Adjust the pH value of the water sample to be tested to about 11, and turn off the sample injection pump (2) after the pH value measured by the composite pH electrode (7) reaches the standard; 6) The water sample to be tested, the pH of which is adjusted in the overflow cup (6), enters the electrode cup (11) through the second solenoid valve (8), wherein the sodium ion electrode (9) and the reference electrode (10) measure the sodium ion concentration and output the measurement signal to the data processing unit (12) for data processing and display.

7. The method for online measurement of sodium ions in effluent from a cation bed according to claim 6, characterized in that: The specific operations of step 5) are: The cathode and anode of the online alkalizing agent preparation device (3) are applied with a current Ix within 1000 mA, and the first solenoid valve (4) is opened; The water sample enters the online alkalizer preparation device (3), and the dilute ammonia water placed in the reagent bottle (5) passes through the packing chamber of the online alkalizer preparation device (3) and is discharged through the anode. At this time, the anode electrolysis produces O2 and H + , H + The NH4 + The H2 and OH produced by cathode electrolysis are then transported to the cathode of the online alkalizer preparation device (3) through the cation exchange membrane. - With NH4 + Combined with ammonia water, it is added to the water sample to adjust the pH value of the water sample; A composite pH electrode (7) is placed in the overflow cup (6) to monitor the pH signal. When the pH reaches 11±0.2, the sample pump (2) is turned off and the water sample is placed in the electrode cup (11) for measurement. If the pH is too low, the concentration of NH4OH generated by electrolysis is adjusted by adjusting the magnitude of the constant current Ix applied to the cathode and anode of the online alkalizer preparation device (3) to increase the pH of the water sample to be measured until the measurement requirement is met. After the pH value of the water sample to be tested reaches the standard, the current applied to the cathode and anode of the online alkalizer preparation device (3) becomes zero, and the first solenoid valve (4) is closed.

8. The method for online measurement of sodium ions in effluent from a cation bed according to claim 7, characterized in that: The concentration of the dilute ammonia water placed in the reagent bottle (5) is not greater than 1 mol / L, so that the pump and valve are not corroded by alkali; after the dilute ammonia water in the reagent bottle (5) passes through the packing chamber of the online alkalizer preparation device (3), the ammonia type cation exchange resin therein always maintains the ammonia type, and the ammonium radical enters the cathode under the action of electromigration and reacts with the OH generated by electrolysis at the cathode. - Ammonia is formed to adjust the pH.

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