System for online monitoring of dissolved oxygen and pH of deaerator

Abstract

The utility model discloses a system for online monitoring of dissolved oxygen and pH of a deaerator, and belongs to the technical field of boiler water quality monitoring and control. According to the technical scheme, the system for monitoring the dissolved oxygen and the pH on line through the deaerator comprises an ammonia water preparation tank, the deaerator, a deoxidant preparation tank, a sampling cooler and a controller; the ammonia water preparation tank is connected with a stronger ammonia water feeding pipeline and a desalted water inlet pipeline I from a pipe network; the deaerator is connected with a deoxygenated steam inlet pipeline, a deoxygenated water inlet pipeline and a deoxygenated water outlet pipeline, and the deoxygenated water outlet pipeline is connected with a boiler water supply pipeline through a pipeline; the deoxygenated water outlet pipeline is further connected with a sampling cooler through a pipeline, a shell pass of the sampling cooler is provided with a circulating water feeding pipeline and a circulating water return pipeline, a tube pass outlet of the sampling cooler is connected with a detection pipeline, and a dissolved oxygen online analyzer and an online pH meter are arranged on the detection pipeline. According to the utility model, the dissolved oxygen and the pH value of the effluent of the deaerator can be rapidly detected in real time, and the safety and the economical efficiency of boiler operation are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of boiler water quality monitoring and control, and particularly relates to a system for on-line monitoring of dissolved oxygen and pH in a deaerator. Background Technique

[0002] The management of boiler water quality is the cornerstone to ensure the efficient and safe operation of the boiler system. Among them, the dissolved oxygen content and pH value in boiler water, as two crucial water quality parameters, are directly related to the corrosion rate, precipitate formation, energy efficiency and overall operation safety of the boiler. However, for a long time, the monitoring and control methods of these key indicators mainly rely on traditional manual sampling and laboratory analysis methods. This process is not only time-consuming and laborious, but also has significant hysteresis, making it difficult to reflect water quality changes in a timely manner, which brings great challenges to the precise regulation of the boiler. Dissolved oxygen is a key factor affecting the corrosion rate of boiler water, and its content directly determines the corrosion rate of the inner wall and pipeline materials of the boiler. Excessive dissolved oxygen content will accelerate the corrosion process, shorten the service life of the boiler and its auxiliary equipment, increase maintenance costs, and even may cause safety accidents. Therefore, the real-time monitoring and effective control of dissolved oxygen become an important part of boiler water quality management. On the other hand, pH value, as an indicator to measure the acidity and alkalinity of water, is also crucial for the stability of boiler water quality. An appropriate pH value range can effectively inhibit corrosion reactions and prevent the formation of precipitates, thus ensuring the smooth operation of the boiler system. However, deviations in pH value, whether too low or too high, may cause different types of corrosion problems and affect the performance and life of the boiler.

[0003] Chinese utility model patent CN207181110U discloses a sampling device for dissolved oxygen in boiler water, which includes a sampling sealing cylinder, a sampling bottle, a sampling tube, a water inlet pipe, a burette and a water vapor evacuation pipe. The bottom of the sampling sealing cylinder is provided with a water inlet pipe, the top of the sampling sealing cylinder is provided with a water vapor evacuation pipe, two sampling bottles are arranged inside the sampling sealing cylinder, the upper end of the sampling bottle is the bottle mouth, the burette is fixed on the sampling sealing cylinder above the bottle mouth of the sampling bottle, one end of the sampling tube extends from the upper part inside the sampling bottle to the bottom inside the sampling bottle, and the other end of the sampling tube passes out from the side of the sampling sealing cylinder. It can avoid the influence of oxygen in the air on the sample and ensure the accuracy of the detection result, but it has a certain hysteresis and cannot achieve real-time and rapid detection. Therefore, accurately and quickly monitor and adjust the pH value of boiler water to improve the safety and economy of boiler operation. Content of the Utility Model

[0004] The utility model provides a system for on-line monitoring of dissolved oxygen and pH in a deaerator, which can detect the dissolved oxygen and pH of the deaerator effluent in real time and quickly, and carry out control and adjustment in a timely manner, thus improving the safety and economy of boiler operation.

[0005] The technical solution of the present utility model is as follows:

[0006] A system for on-line monitoring of dissolved oxygen and pH in a deaerator, comprising an ammonia water preparation tank, a deaerator, a deoxidizer preparation tank, a sampling cooler and a controller; the ammonia water preparation tank is communicated with the deaerated water outlet pipeline through an ammonia water dosing pipeline; the ammonia water preparation tank is connected with a concentrated ammonia water feed pipeline and a first demineralized water inlet pipeline from the pipe network; the deoxidizer preparation tank is communicated with the deaerated water outlet pipeline through a deoxidizer dosing pipeline; the deoxidizer preparation tank is connected with a deoxidizer feed pipeline and a second demineralized water inlet pipeline from the pipe network; the deaerator is connected with a deaeration steam inlet pipeline, a deaeration inlet pipeline and a deaerated water outlet pipeline, and the deaerated water outlet pipeline is connected with the boiler feed water pipeline through a pipeline; the deaerated water outlet pipeline is also connected with a sampling cooler through a pipeline, the sampling cooler is provided with an exhaust port and a blowdown port, the shell side of the sampling cooler is provided with a circulating water supply pipeline and a circulating water return pipeline, the tube side outlet of the sampling cooler is connected with a detection pipeline, a dissolved oxygen on-line analyzer and an on-line pH meter are arranged on the detection pipeline, both the dissolved oxygen on-line analyzer and the on-line pH meter are electrically connected with the controller, a temperature sensor is arranged on the detection pipeline, and the temperature sensor is electrically connected with the controller; a manual valve is arranged on the circulating water supply pipeline, a temperature control valve is arranged on the circulating water return pipeline, and the temperature control valve is electrically connected with the controller.

[0007] Preferably, an ammonia water dosing metering pump is arranged on the ammonia water dosing pipeline, a deoxidizer dosing metering pump is arranged on the deoxidizer dosing pipeline, and both the ammonia water dosing metering pump and the deoxidizer dosing metering pump are electrically connected with the controller.

[0008] Preferably, a boiler feed water pump is arranged on the boiler feed water pipeline, and the boiler feed water pump is electrically connected with the controller.

[0009] Preferably, the water discharged from the circulating water return pipeline and the detection pipeline jointly flows into an external circulating water return pipe network.

[0010] Preferably, a manual sampling port is also arranged on the detection pipeline.

[0011] Preferably, check valves are arranged on both the deoxidizer feed pipeline and the concentrated ammonia water feed pipeline.

[0012] Compared with the prior art, the present utility model has the following beneficial effects:

[0013] 1. By integrating a dissolved oxygen on-line analyzer and an on-line pH meter, the present utility model can monitor the dissolved oxygen content and pH value in the deaerator outlet water in real time and accurately, ensuring that the water quality parameters meet the requirements of boiler feed water. The timeliness and accuracy of monitoring are greatly improved, which helps to timely discover and adjust water quality problems and ensure the safe and stable operation of the boiler system; the setting of the manual sampling port also facilitates the regular calibration of the accuracy of the on-line analyzer and other necessary detections.

[0014] 2. The ammonia water dosing metering pump and the deoxidizer dosing metering pump are both electrically connected to the controller, realizing the automatic adjustment of the dosing amount. According to the real-time feedback of the dissolved oxygen and pH value, the controller can intelligently adjust the dosing amount to achieve the best deoxidation effect and pH value control, reduce manual intervention, improve operation efficiency, and at the same time reduce the waste of chemical agents and environmental pollution.

[0015] 3. By precisely controlling the water quality of the deaerator outlet, the dissolved oxygen content in the water is effectively reduced, and the oxygen corrosion inside the boiler is reduced, thereby improving the heat transfer efficiency and service life of the boiler. At the same time, the stable pH value also helps to prevent scaling and corrosion inside the boiler, further ensuring the safe operation of the boiler.

[0016] 4. Through automatic control and precise adjustment, the overuse of chemical agents is reduced, the difficulty and cost of wastewater treatment are reduced, meeting the requirements of modern industry for energy conservation, emission reduction and environmental protection. In addition, by improving the operation efficiency of the boiler, the energy consumption and carbon emissions are also indirectly reduced.

[0017] 5. The design of the sampling cooler and the application of the circulating water system effectively ensure the temperature stability of the water sample during the sampling process and improve the accuracy of the detection results. At the same time, components such as control valves and check valves set in the system also enhance the stability and reliability of the system, reducing the downtime caused by equipment failures. Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of the present utility model.

[0019] In the figure, 1. ammonia water preparation tank; 2. deaerator; 3. deoxidizer preparation tank; 4. sampling cooler; 5. ammonia water dosing pipeline; 6. concentrated ammonia water feed pipeline; 7. desalted water inlet pipeline one from the pipe network; 8. deoxidizer dosing pipeline; 9. deoxidizer feed pipeline; 10. desalted water inlet pipeline two from the pipe network; 11. deoxidation steam inlet pipeline; 12. deoxidized water outlet pipeline; 13. exhaust port; 14. blowdown port; 15. circulating water supply pipeline; 16. circulating water return pipeline; 17. detection pipeline; 18. dissolved oxygen on-line analyzer; 19. on-line pH meter; 20. temperature sensor; 21. ammonia water dosing metering pump; 22. deoxidizer dosing metering pump; 23. external circulating water return pipe network; 24. manual sampling port; 25. deoxidation inlet pipeline; 26. boiler feed water pipeline. Detailed Embodiment

[0020] To enable those skilled in the art to better understand the technical solutions in the present utility model, the following will clearly and completely describe the technical solutions in the embodiments of the present utility model in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0021] Embodiment 1

[0022] As Figure 1 shown, this embodiment provides a system for on-line monitoring of dissolved oxygen and pH in a deaerator, including an ammonia water preparation tank 1, a deaerator 2, a deoxidizer preparation tank 3, a sampling cooler 4 and a controller;

[0023] The ammonia water preparation tank 1 is communicated with the deaerated water outlet pipeline 12 through an ammonia water dosing pipeline 5; the ammonia water preparation tank 1 is connected with a concentrated ammonia water feed pipeline 6 and a demineralized water inlet pipeline 7 from the pipe network; the deoxidizer preparation tank 3 is communicated with the deaerated water outlet pipeline 12 through a deoxidizer dosing pipeline 8; the deoxidizer preparation tank 3 is connected with a deoxidizer feed pipeline 9 and a demineralized water inlet pipeline 10 from the pipe network; an ammonia water dosing metering pump 21 is arranged on the ammonia water dosing pipeline 5, a deoxidizer dosing metering pump 22 is arranged on the deoxidizer dosing pipeline 8, and both the ammonia water dosing metering pump 21 and the deoxidizer dosing metering pump 22 are electrically connected to the controller.

[0024] The deaerator 2 is connected with a deaeration steam inlet pipeline 11, a deaeration water inlet pipeline 25 and a deaerated water outlet pipeline 12. The deaerated water outlet pipeline 12 is connected to the boiler feed water pipeline 26 through a pipeline. A boiler feed water pump is arranged on the boiler feed water pipeline 26, and the boiler feed water pump is electrically connected to the controller; The deaerated water outlet pipeline 12 is also connected to a sampling cooler 4 through a pipeline. The sampling cooler 4 is provided with an exhaust port 13 and a blowdown port 14. A circulating water supply pipeline 15 and a circulating water return pipeline 16 are arranged in the shell side of the sampling cooler 4. The tube side outlet of the sampling cooler 4 is connected to a detection pipeline 17. A dissolved oxygen on-line analyzer 18 and an on-line pH meter 19 are arranged on the detection pipeline 17. Both the dissolved oxygen on-line analyzer 18 and the on-line pH meter 19 are electrically connected to the controller. The dissolved oxygen on-line analyzer 18 is of the model CM42-OJA001EAZ00 produced by Endress+Hauser company, and the on-line pH meter 19 is of the model 1066-P-AN-60 produced by Emerson company. A temperature sensor 20 is arranged on the detection pipeline 17, and the temperature sensor 20 is electrically connected to the controller; A manual valve is arranged on the circulating water supply pipeline 15, and a temperature control valve is arranged on the circulating water return pipeline 16. The temperature control valve is electrically connected to the controller. The temperature control valve and the temperature sensor 20 arranged at the tube side outlet of the sampling cooler form a control loop. The water discharged from the circulating water return pipeline 16 and the detection pipeline 17 jointly flow into the external circulating water return pipe network 23; A manual sampling port 24 is also arranged on the detection pipeline 17; Check valves are arranged on both the deoxidizer feed pipeline 9 and the concentrated ammonia water feed pipeline 6.

[0025] Working process:

[0026] Open the control valves of the concentrated ammonia feed pipeline 6 and the demineralized water inlet pipeline 7 from the pipe network, and prepare an ammonia water solution with a certain concentration in the ammonia water preparation tank 1; open the control valves of the deoxidizer feed pipeline 9 and the second demineralized water inlet pipeline 10 from the pipe network, and prepare an appropriate amount of deoxidizer solution in the deoxidizer preparation tank 3. Open the deoxidizing steam inlet pipeline 11 and the deoxidizing water inlet pipeline 25, and start the deaerator 2; when the pH detection fails to meet the standard, start the ammonia water dosing metering pump 21, and add the prepared ammonia water into the deoxidized water outlet pipeline 12 through the ammonia water dosing pipeline 5; when the dissolved oxygen detection fails to meet the standard, start the deoxidizer dosing metering pump 22, and add the prepared deoxidizer into the deoxidized water outlet pipeline 12 through the deoxidizer dosing pipeline 8. Adjust the frequency conversion of the ammonia water dosing metering pump 21 and the deoxidizer dosing metering pump 22 to ensure the addition amounts of ammonia water and deoxidizer, so as to maintain the best treatment effect in the deaerator; the deoxidized water flows out through the deoxidized water outlet pipeline 12, and part of the water flows through the sampling cooler 4; in the sampling cooler 4, adjust the cooling water flow through the circulating water supply pipeline 15 and the circulating water return pipeline 16 to keep the temperature of the sampled water appropriate; monitor the dissolved oxygen and pH value of the deoxidized water in real time through the dissolved oxygen on-line analyzer 18 and the on-line pH meter 19, and transmit the data to the controller. The temperature sensor 20 monitors the temperature of the sampled water and transmits the data to the controller. The controller automatically adjusts the dosing amounts of the ammonia water dosing metering pump 21 and the deoxidizer dosing metering pump 22 and the control valve of the circulating water return pipeline 16 according to the monitored dissolved oxygen, pH value and temperature data to maintain the efficiency of the deaerator; if necessary, the operator can regularly take samples through the manual sampling port 24 for laboratory analysis to further adjust the system parameters. The deoxidized water is supplied to the boiler through the boiler feed water pipeline 26; the water discharged from the circulating water return pipeline 16 and the detection pipeline 17 is jointly discharged into the external circulating water return pipe network 23, ensure that the check valves on the ammonia water dosing pipeline 5 and the deoxidizer dosing pipeline 8 work properly to prevent the deoxidized water from flowing back into the dosing pipeline.

[0027] Although the present invention has been described in detail by referring to the accompanying drawings and in combination with the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, those of ordinary skill in the art can make various equivalent modifications or substitutions to the embodiments of the present invention, and all such modifications or substitutions should be within the scope covered by the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An online monitoring system for dissolved oxygen and pH in a deaerator, characterized in that, It includes an ammonia water preparation tank (1), a deaerator (2), a deoxidizer preparation tank (3), a sampling cooler (4) and a controller; The ammonia water preparation tank (1) is connected to the deaerated water outlet pipeline (12) through an ammonia water dosing pipeline (5); the ammonia water preparation tank (1) is connected with a concentrated ammonia water feed pipeline (6) and a desalted water inlet pipeline one (7) from the pipe network; The deoxidizer preparation tank (3) is connected to the deaerated water outlet pipeline (12) through a deoxidizer dosing pipeline (8); the deoxidizer preparation tank (3) is connected with a deoxidizer feed pipeline (9) and a desalted water inlet pipeline two (10) from the pipe network; The deaerator (2) is connected with a deaeration steam inlet pipeline (11), a deaeration inlet pipeline (25) and a deaerated water outlet pipeline (12), and the deaerated water outlet pipeline (12) is connected to the boiler feed water pipeline (26) through a pipeline; the deaerated water outlet pipeline (12) is also connected to a sampling cooler (4) through a pipeline. The sampling cooler (4) is provided with an exhaust port (13) and a blowdown port (14). A circulating water supply pipeline (15) and a circulating water return pipeline (16) are arranged on the shell side of the sampling cooler (4). The tube side outlet of the sampling cooler (4) is connected with a detection pipeline (17). A dissolved oxygen on-line analyzer (18) and an on-line pH meter (19) are arranged on the detection pipeline (17). Both the dissolved oxygen on-line analyzer (18) and the on-line pH meter (19) are electrically connected to the controller. A temperature sensor (20) is arranged on the detection pipeline (17), and the temperature sensor (20) is electrically connected to the controller; a manual valve is arranged on the circulating water supply pipeline (15), and a temperature control valve is arranged on the circulating water return pipeline (16), and the temperature control valve is electrically connected to the controller.

2. The online monitoring system for dissolved oxygen and pH of the deaerator according to claim 1, characterized in that, An ammonia water dosing metering pump (21) is arranged on the ammonia water dosing pipeline (5), and a deoxidizer dosing metering pump (22) is arranged on the deoxidizer dosing pipeline (8). Both the ammonia water dosing metering pump (21) and the deoxidizer dosing metering pump (22) are electrically connected to the controller.

3. The deaerator online monitoring system for dissolved oxygen and pH as described in claim 1, characterized in that, A boiler feed water pump is arranged on the boiler feed water pipeline (26), and the boiler feed water pump is electrically connected to the controller.

4. The system for on-line monitoring of dissolved oxygen and pH in a deaerator according to claim 1, characterized in that, The water discharged from the circulating water return pipeline (16) and the detection pipeline (17) jointly flows into an external circulating water return pipe network (23).

5. The system for on-line monitoring of dissolved oxygen and pH in a deaerator according to claim 1, characterized in that, A manual sampling port (24) is also arranged on the detection pipeline (17).

6. The system for on-line monitoring of dissolved oxygen and pH in a deaerator as claimed in claim 1, wherein, One-way valves are arranged on both the deoxidizer feed pipeline (9) and the concentrated ammonia water feed pipeline (6).

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