A power plant heat supply return water comprehensive monitoring system and method

Abstract

The application discloses a power plant heat supply return water comprehensive monitoring system and method, wherein a heat supply return water pipeline is connected with an inlet of a constant temperature device; an outlet of the constant temperature device is divided into two paths, one of which is connected with an inlet of a conductivity electrode through a conductivity meter sampling valve, and the other is connected with a first opening of a three-way electromagnetic valve; a second opening of the three-way electromagnetic valve is connected with a trench; a third opening of the three-way electromagnetic valve is divided into two paths, one of which is connected with an inlet of a hydrogen type cation exchange device through a hydrogen conductivity meter sampling valve, and the other is connected with an online chemical instrument through an online chemical instrument sampling valve; the system and method can more accurately measure hydrogen conductivity and conductivity, and prolong the service life of the cation exchange resin.

Description

Technical Field

[0001] This invention belongs to the field of power plant heating return water quality monitoring technology, and relates to a comprehensive monitoring system and method for power plant heating return water. Background Technology

[0002] To promote the rapid development of energy conservation and emission reduction in coal-fired power generating units, an increasing number of power plants are using heating to reduce unit energy consumption and improve unit efficiency. With the increase in heating supply, more and more heating units are beginning to recover steam to reduce water waste and heat loss. Depending on water quality, the heating return water can be used to replenish deaerators, condensers, and water treatment systems. To maximize the cascade utilization of heating return water, real-time monitoring of its quality is crucial. Conductivity and hydrogen conductivity are two of the most important water quality monitoring indicators. Conductivity reflects the overall level of ion content in water. Hydrogen conductivity is measured after the water sample has been treated with a cation exchange resin to replace cations with hydrogen ions, reflecting the overall level of anions in the water. In addition, hardness, iron content, sodium ions, chloride ions, silica, and TOCi content are also important indicators for monitoring the quality of heating return water.

[0003] However, due to pollution, corrosion, and leaks in heating pipelines, as well as unstable return water from heat users, the return water quality fluctuates significantly, resulting in extremely poor operation of on-site online monitoring instruments and considerable limitations in the control methods. The main problems are as follows:

[0004] 1) The return water temperature for heating is high, reaching 50–90℃. The optimal operating temperature for online chemical instruments is generally 25℃. Excessively high water temperatures can cause significant measurement errors. Furthermore, the performance of ion exchange resins decreases significantly at high temperatures, thus affecting the measurement of hydrogen conductivity.

[0005] 2) The cation exchange resin used for hydrogen conductivity measurement fails quickly. When the water quality suddenly deteriorates, the cation exchange resin used for hydrogen conductivity measurement fails rapidly, greatly reducing its service life. Frequent resin replacement greatly increases the workload of on-site maintenance. There will also be a certain measurement vacuum period during the replacement process, which is not conducive to continuous measurement of water samples.

[0006] 3) The decision on where to recycle heating return water is made by on-site personnel judging the water quality. This method is highly dependent on on-site personnel, has significant limitations, and lacks intelligent features. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a comprehensive monitoring system and method for power plant heating return water. This system and method can accurately measure hydrogen conductivity and electrical conductivity, while extending the service life of cation exchange resin.

[0008] To achieve the above objectives, this invention discloses a comprehensive monitoring system for power plant heating return water, including a heating return water pipeline, a constant temperature device, a conductivity meter inlet valve, a conductivity electrode, a three-way solenoid valve, a hydrogen conductivity meter inlet valve, a hydrogen-type cation exchange device, a trench, a hydrogen conductivity electrode, an online chemical instrument inlet valve, an online chemical instrument, and a control system.

[0009] The heating return water pipe is connected to the inlet of the thermostatic device. The outlet of the thermostatic device is divided into two paths. One path is connected to the inlet of the conductivity electrode via the conductivity meter injection valve. The other path is connected to the first opening of the three-way solenoid valve. The second opening of the three-way solenoid valve is connected to the trench. The third opening of the three-way solenoid valve is divided into two paths. One path is connected to the inlet of the hydrogen cation exchange device via the hydrogen conductivity meter injection valve. The outlet of the hydrogen cation exchange device is connected to the inlet of the hydrogen conductivity electrode. The other path is connected to the online chemical instrument via the online chemical instrument injection valve.

[0010] The conductivity electrode is connected to the conductivity transmitter, the hydrogen conductivity electrode is connected to the hydrogen conductivity transmitter, the output of the conductivity transmitter, the output of the hydrogen conductivity transmitter and the output of the online chemical instrument are connected to the input of the control system, and the output of the control system is connected to the control of the constant temperature device and the control of the three-way solenoid valve.

[0011] The heating return water pipeline is connected to the inlet of the thermostat via an inlet valve and a filter.

[0012] The outlet of the conductivity electrode is connected to the trench via the first drainage pipe.

[0013] The second opening of the three-way solenoid valve is connected to the trench via the second drain pipe.

[0014] The outlet of the hydrogen conductivity electrode is connected to the trench via a third drainage pipe.

[0015] The online chemical instrument is one or a combination of several of the following: hardness analyzer, total iron analyzer, hydrogen conductivity meter, pH meter, sodium meter, silicon meter, chloride ion analyzer, TOC analyzer, TOCi analyzer, and COD analyzer.

[0016] This invention discloses a method for comprehensive monitoring of heat return water in power plants, comprising the following steps:

[0017] The temperature of the heating return water sample is adjusted to a preset range by a constant temperature device. The water from the constant temperature device enters the conductivity electrode after passing through the conductivity meter inlet valve. The conductivity and temperature information of the heating return water sample are measured by the conductivity electrode and then sent to the control system by the conductivity transmitter.

[0018] When the measured conductivity and temperature are both within the corresponding preset range, the three-way solenoid valve is controlled to send the water output from the thermostat to the hydrogen cation exchanger and the online chemical instrument. The hydrogen cation exchanger replaces all impurity cations with hydrogen ions and then sends them to the hydrogen conductivity electrode. The hydrogen conductivity and temperature information in the heating return water sample are measured by the hydrogen conductivity electrode and sent to the control system via the hydrogen conductivity transmitter. At the same time, the parameters of the heating return water sample are measured by the online chemical instrument and sent to the control system.

[0019] When the conductivity or temperature measured by the conductivity electrode is not within the corresponding preset range, the three-way solenoid valve is controlled to discharge the water output by the thermostat into the drain.

[0020] Also includes:

[0021] The control system compares the parameters and hydrogen conductivity of the heating return water sample measured by the online chemical instrument with their corresponding set values ​​to determine whether the parameters and hydrogen conductivity of the heating return water sample are qualified. If the parameters and hydrogen conductivity of the heating return water sample are qualified, the system displays the message "Recycling recommended"; otherwise, the system displays the message "Recycling not recommended".

[0022] Also includes:

[0023] When the temperature measured by the conductivity electrode is outside its corresponding preset range, the control system controls the constant temperature device to make the temperature measured by the conductivity electrode within its corresponding preset range.

[0024] The present invention has the following beneficial effects:

[0025] In specific operation, the integrated monitoring system and method for power plant heating return water described in this invention measures the conductivity and temperature of the heating return water sample using a conductivity electrode. When the measured conductivity and temperature are both within the corresponding preset range, the water output from the thermostat is sent to the hydrogen-type cation exchange device and the online chemical instrument to accurately measure the hydrogen conductivity and conductivity. In addition, when the conductivity or temperature measured by the conductivity electrode is not within the corresponding preset range, the three-way solenoid valve is controlled to drain the water output from the thermostat to the ditch to avoid affecting subsequent instruments and extend the service life of the cation exchange resin. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the present invention;

[0027] Figure 2 This is a flowchart of the present invention.

[0028] Among them, 1 is the injection valve, 2 is the filter, 3 is the thermostat, 4 is the conductivity meter injection valve, 5 is the conductivity electrode, 6 is the conductivity transmitter, 7 is the three-way solenoid valve, 8 is the hydrogen conductivity meter injection valve, 9 is the hydrogen-type cation exchange device, 10 is the hydrogen conductivity electrode, 11 is the hydrogen conductivity transmitter, 12 is the online chemical instrument injection valve, 13 is the online chemical instrument, and 14 is the control system. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, not all embodiments, and are not intended to limit the scope of the present invention. Furthermore, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion regarding the concepts disclosed in the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should fall within the scope of protection of the present invention.

[0030] The accompanying drawings show structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not drawn to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0031] refer to Figure 1 The integrated monitoring system for power plant heating return water described in this invention includes a sampling valve 1, a filter 2, a constant temperature device 3, a conductivity meter sampling valve 4, a conductivity electrode 5, a conductivity transmitter 6, a three-way solenoid valve 7, a hydrogen conductivity meter sampling valve 8, a hydrogen-type cation exchange device 9, a hydrogen conductivity electrode 10, a hydrogen conductivity transmitter 11, other online chemical instrument sampling valves 12, online chemical instruments 13, and a control system 14.

[0032] The heating return water pipeline is connected to the inlet of filter 2 via sampling valve 1, and the outlet of filter 2 is connected to the inlet of thermostatic device 3. The outlet of thermostatic device 3 is divided into two paths. One path is connected to the inlet of conductivity electrode 5 via conductivity meter sampling valve 4, and the outlet of conductivity electrode 5 is connected to the trench via the first drain pipe. The other path is connected to the first opening of three-way solenoid valve 7. The second opening of three-way solenoid valve 7 is connected to the trench via the second drain pipe. The third opening of three-way solenoid valve 7 is divided into two paths. One path is connected to the inlet of hydrogen cation exchange device 9 via hydrogen conductivity meter sampling valve 8, and the outlet of hydrogen cation exchange device 9 is connected to the inlet of hydrogen conductivity electrode 10. The outlet of hydrogen conductivity electrode 10 is connected to the trench via the third drain pipe. The other path is connected to online chemical instrument 13 via online chemical instrument sampling valve 12.

[0033] The conductivity electrode 5 is connected to the conductivity transmitter 6, the hydrogen conductivity electrode 10 is connected to the hydrogen conductivity transmitter 11, the output terminal of the conductivity transmitter 6, the output terminal of the hydrogen conductivity transmitter 11 and the output terminal of the online chemical instrument 13 are connected to the input terminal of the control system 14, and the output terminal of the control system 14 is connected to the control terminal of the constant temperature device 3 and the control terminal of the three-way solenoid valve 7.

[0034] The online chemical instrument 13 is one or a combination of several of the following: hardness analyzer, total iron analyzer, hydrogen conductivity meter, pH meter, sodium meter, silicon meter, chloride ion analyzer, TOC analyzer, TOCi analyzer, and COD analyzer.

[0035] refer to Figure 2 The integrated monitoring method for power plant heating return water according to the present invention includes the following steps:

[0036] The heating return water sample is filtered through filter 2 after passing through the sampling valve 1 to reduce the impact of impurities in the water on the accuracy of subsequent measurements and service life. The water temperature is then adjusted to the preset range by the thermostat 3. The water outlet of the thermostat 3 enters the conductivity electrode 5 after passing through the conductivity meter sampling valve 4. The conductivity and temperature information of the heating return water sample are measured by the conductivity electrode 5 and then sent to the control system 14 by the conductivity transmitter 6.

[0037] When the measured conductivity and temperature are both within the corresponding preset range, the three-way solenoid valve 7 is controlled to send the water output from the thermostat 3 into the hydrogen cation exchange device 9 and the online chemical instrument 13 respectively. After the impurity cations are completely replaced by hydrogen ions by the hydrogen cation exchange device 9, the water is sent to the hydrogen conductivity electrode 10. The hydrogen conductivity and temperature information in the heating return water sample are measured by the hydrogen conductivity electrode 10 and sent to the control system 14 via the hydrogen conductivity transmitter 11. At the same time, the parameters of the heating return water sample are measured by the online chemical instrument 13 and sent to the control system 14.

[0038] The control system 14 compares the parameters and hydrogen conductivity of the heating return water sample measured by the online chemical instrument 13 with their corresponding set values ​​to determine whether the parameters and hydrogen conductivity of the heating return water sample are qualified. If the parameters and hydrogen conductivity of the heating return water sample are qualified, the system displays the message "Recycling recommended"; otherwise, the system displays the message "Recycling not recommended".

[0039] When the conductivity or temperature measured by the conductivity electrode 5 is not within the corresponding preset range, the three-way solenoid valve 7 is controlled to drain the water output from the thermostat 3 into the ditch, and a "not recommended for recycling" message is displayed to protect the subsequent online chemical instrument 13.

[0040] When the temperature measured by the conductivity electrode 5 is not within its corresponding preset range, the control system 14 controls the constant temperature device 3 so that the temperature measured by the conductivity electrode 5 is within its corresponding preset range.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A power plant heat supply return water comprehensive monitoring system, characterized in that, It includes a heating return water pipeline, a constant temperature device (3), a conductivity meter injection valve (4), a conductivity electrode (5), a three-way solenoid valve (7), a hydrogen conductivity meter injection valve (8), a hydrogen-type cation exchange device (9), a trench, a hydrogen conductivity electrode (10), an online chemical instrument injection valve (12), an online chemical instrument (13), and a control system (14); The heating return water pipe is connected to the inlet of the thermostat (3). The outlet of the thermostat (3) is divided into two paths. One path is connected to the inlet of the conductivity electrode (5) via the conductivity meter injection valve (4). The other path is connected to the first opening of the three-way solenoid valve (7). The second opening of the three-way solenoid valve (7) is connected to the trench. The third opening of the three-way solenoid valve (7) is divided into two paths. One path is connected to the inlet of the hydrogen cation exchange device (9) via the hydrogen conductivity meter injection valve (8). The outlet of the hydrogen cation exchange device (9) is connected to the inlet of the hydrogen conductivity electrode (10). The other path is connected to the online chemical instrument (13) via the online chemical instrument injection valve (12). The conductivity electrode (5) is connected to the conductivity transmitter (6), the hydrogen conductivity electrode (10) is connected to the hydrogen conductivity transmitter (11), the output end of the conductivity transmitter (6), the output end of the hydrogen conductivity transmitter (11) and the output end of the online chemical instrument (13) are connected to the input end of the control system (14), and the output end of the control system (14) is connected to the control end of the constant temperature device (3) and the control end of the three-way solenoid valve (7).

2. The power plant heat supply return water comprehensive monitoring system according to claim 1, characterized in that, The heating return water pipeline is connected to the inlet of the thermostat (3) through the inlet valve (1) and the filter (2).

3. The power plant heat supply return water comprehensive monitoring system according to claim 1, characterized in that, The outlet of the conductivity electrode (5) is connected to the ditch through the first drainage pipe.

4. The power plant heat supply return water comprehensive monitoring system according to claim 1, characterized in that, The second opening of the three-way solenoid valve (7) is connected to the ditch through the second drain pipe.

5. The power plant heat supply return water comprehensive monitoring system according to claim 1, characterized in that, The outlet of the hydrogen conductivity electrode (10) is connected to the ditch through the third drainage pipe.

6. The integrated monitoring system for power plant heating return water according to claim 1, characterized in that, The online chemical instrument (13) is one or a combination of several of the following: hardness analyzer, total iron analyzer, hydrogen conductivity meter, pH meter, sodium meter, silicon meter, chloride ion analyzer, TOC analyzer, TOCi analyzer and COD analyzer.

7. A method for comprehensive monitoring of heat return water in power plants, characterized in that, The integrated monitoring system for power plant heating return water as described in claim 1 includes the following steps: The temperature of the heating return water sample is adjusted to the preset range by the constant temperature device (3). The water outlet of the constant temperature device (3) enters the conductivity electrode (5) after passing through the conductivity meter sampling valve (4). The conductivity and temperature information of the heating return water sample are measured by the conductivity electrode (5) and then sent to the control system (14) by the conductivity transmitter (6). When the measured conductivity and temperature are both within the corresponding preset range, the three-way solenoid valve (7) is controlled to send the water output from the constant temperature device (3) into the hydrogen cation exchange device (9) and the online chemical instrument (13). The impurity cations are completely replaced by hydrogen ions by the hydrogen cation exchange device (9) and then sent into the hydrogen conductivity electrode (10). The hydrogen conductivity and temperature information in the heating return water sample are measured by the hydrogen conductivity electrode (10) and sent to the control system (14) via the hydrogen conductivity transmitter (11). At the same time, the parameters of the heating return water sample are measured by the online chemical instrument (13) and sent to the control system (14). When the conductivity or temperature measured by the conductivity electrode (5) is not within the corresponding preset range, the three-way solenoid valve (7) is controlled to discharge the water output by the thermostat (3) into the ditch.

8. The method for comprehensive monitoring of power plant heating return water according to claim 7, characterized in that, Also includes: The control system (14) compares the parameters of the heating return water sample measured by the online chemical instrument (13) and the measured hydrogen conductivity with their corresponding set values ​​to determine whether the parameters of the heating return water sample and the measured hydrogen conductivity are qualified. When the parameters of the heating return water sample and the measured hydrogen conductivity are both qualified, the system displays the prompt "Recycling recommended"; otherwise, the system displays the prompt "Recycling not recommended".

9. The method for comprehensive monitoring of power plant heating return water according to claim 7, characterized in that, Also includes: When the temperature measured by the conductivity electrode (5) is not within its corresponding preset range, the control system (14) controls the constant temperature device (3) so that the temperature measured by the conductivity electrode (5) is within its corresponding preset range.

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