Anti-corrosion drainage system for high-pressure heater of supercritical unit
By using ammonia and oxygen-adding devices to form an iron oxide film in the hydrophobic system of high-pressure heater, the problem of accelerated corrosion of the flow is solved, the service life of the system is extended and the reliable protection of the system is achieved.
Patent Information
- Application Number
- CN202420866939.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-25
- Publication Date
- 2025-01-07
- Estimated Expiration
- 2034-04-25
AI Technical Summary
High-pressure heaters are prone to accelerated flow corrosion in strong reduction environments. The existing oxygenation method cannot effectively solve the corrosion problem of hydrophobic systems, especially in local areas such as pipeline elbows and valves.
The combination of ammonia and oxygen-adding devices is used to form a dense iron oxide film in the hydrophobic system of the high-pressure heater. The pH value and dissolved oxygen content of the hydrophobic are accurately controlled through the pH instrument and the dissolved oxygen instrument to form a protective film. , slow down corrosion.
It effectively slows down accelerated flow corrosion, extends the service life of the high-pressure heater hydrophobic system, and realizes reliable protection of the system through the coordination of circulation pipelines and metering pumps.
Smart Images
Figure CN222316955U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of anti-corrosion of a drain system, and more specifically to an anti-corrosion drain system for a high-pressure heater of a supercritical unit. Background Art
[0002] At present, with the improvement of unit parameters, the phenomenon of accelerated flow corrosion of units is becoming more and more serious. Flow accelerated corrosion is a type of corrosion caused by the influence of liquid flow, and often occurs in local areas, especially turbulent areas under strong reducing environments, such as pipe elbows, tees, and reducers; the drain system is the most complex and cumbersome system, in which there are many pipe elbows and valves. When the local water flow conditions deteriorate, if there is no dense oxide film in the drain pipe to resist corrosion, it is easy to cause flow accelerated corrosion. The water side of the high-pressure heater is seriously deposited, and the deposition rate of the boiler water-cooled wall is relatively high. At present, most units use oxygenation to alleviate accelerated flow corrosion, but the corrosion of the high-pressure drain cannot be solved.
[0003] Therefore, there is an urgent need for an anti-corrosion drain system for a supercritical unit high-pressure heater. Utility Model Content
[0004] The technical problem to be solved by the utility model is to provide a corrosion-resistant drain system for a high-pressure heater of a supercritical unit to solve the problems in the background technology.
[0005] In order to solve the above technical problems, the technical solutions adopted by the present utility model are as follows.
[0006] A supercritical unit high-pressure heater anti-corrosion drain system comprises a high-pressure heater, wherein the high-pressure heater drain is connected to an ammonia adding device; the high-pressure heater drain is connected to an oxygen adding device; the high-pressure heater is sequentially connected to an economizer, a water-cooled wall, a superheater, a high-pressure cylinder, and a reheater, and the high-pressure cylinder is connected to the high-pressure heater; the reheater is sequentially connected to an intermediate-pressure cylinder, a low-pressure cylinder, a condenser, a low-pressure heater, and a deaerator, and the deaerator is connected to the high-pressure heater; the intermediate-pressure cylinder is connected to a pipeline between the high-pressure heater and the deaerator, and a circulation pipeline is connected between the deaerator and the high-pressure heater; an online pH meter and an online dissolved oxygen meter are installed on the pipeline between the high-pressure heater and the economizer.
[0007] To further optimize the technical solution, a circulation valve is provided on the circulation pipeline.
[0008] To further optimize the technical solution, the ammonia adding device is equipped with an ammonia adding metering pump.
[0009] To further optimize the technical solution, the oxygenation device is equipped with an oxygenation metering pump.
[0010] Due to the adoption of the above technical scheme, the technical progress achieved by the utility model is as follows.
[0011] The utility model provides a supercritical unit high-pressure heater anti-corrosion drain system, which uses precise ammonia and oxygen addition to increase the pH value and dissolved oxygen of the high-pressure heater drain, and forms a dense ferric oxide film on the inner wall of the high-pressure heater drain pipe to slow down the accelerated flow corrosion phenomenon. The utility model realizes reliable protection of the high-pressure heater drain system through a combination of multiple devices, and prolongs the service life of the system. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 It is a schematic diagram of the structure of the utility model;
[0013] Among them: 1. Ammonia addition device, 2. Oxygen addition device, 3. pH online instrument, 4. Dissolved oxygen online instrument, 5. Ammonia addition metering pump, 6. Oxygen addition metering pump, 7. Deaerator, 8. High-pressure heater, 9. Low-pressure heater, 10. Condenser, 11. Low-pressure cylinder, 12. Medium-pressure cylinder, 13. High-pressure cylinder, 14. Reheater, 15. Superheater, 16. Water-cooled wall, 17. Economizer. DETAILED DESCRIPTION
[0014] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0015] A supercritical unit high pressure heater anti-corrosion drain system, combined with Figure 1 As shown, it includes an ammonia adding device 1, an oxygen adding device 2, a pH online meter 3, a dissolved oxygen online meter 4, an ammonia adding metering pump 5, an oxygen adding metering pump 6, a deaerator 7, a high-pressure heater 8, a low-pressure heater 9, a condenser 10, a low-pressure cylinder 11, a medium-pressure cylinder 12, a high-pressure cylinder 13, a reheater 14, a superheater 15, a water-cooled wall 16, and an economizer 17.
[0016] The high-pressure heater 8 is connected to an ammonia adding device 1, which is used to add ammonia water to the high-pressure heater 8; the ammonia adding device 1 is equipped with an ammonia adding metering pump 5 to control the amount of ammonia added.
[0017] The high-pressure heater 8 is connected to an oxygenating device 2 to add oxygen to the high-pressure heater 8; the oxygenating device 2 is equipped with an oxygen metering pump 6 to control the amount of oxygen added.
[0018] A pH online meter 3 is installed on the pipeline between the high-pressure heater 8 and the economizer 17 to detect the pH value in the boiler feed water so as to adjust the amount of ammonia added to the drain of the high-pressure heater 8. A dissolved oxygen online meter 4 is installed on the pipeline between the high-pressure heater 8 and the economizer 17 to detect the dissolved oxygen in the boiler feed water so as to adjust the amount of oxygen added to the drain of the high-pressure heater 8. Increasing the pH value and dissolved oxygen content of the drain can form a dense ferric oxide film on the inner wall of the drain pipe.
[0019] The high-pressure heater is sequentially connected to the economizer 17, the water wall 16, the superheater 15, the high-pressure cylinder 13, and the reheater 14, and the high-pressure cylinder 13 is connected to the high-pressure heater. The reheater 14 is sequentially connected to the medium-pressure cylinder 12, the low-pressure cylinder 11, the condenser 10, the low-pressure heater 9, and the deaerator 7, and the deaerator 7 is connected to the high-pressure heater 8.
[0020] The medium-pressure cylinder 12 is connected to a pipeline between the high-pressure heater 8 and the deaerator 7 , and a circulation pipeline is connected between the deaerator 7 and the high-pressure heater 8 , and a circulation valve is provided on the circulation pipeline.
[0021] When the utility model is actually used, the ammonia metering pump 5 and the oxygen metering pump 6 are used to inject ammonia and oxygen into the high-pressure heater 8 to increase the pH value and dissolved oxygen content of the hydrophobicity. The pH online meter 3 and the dissolved oxygen online meter 4 of the water supply system are used to detect the pH value and dissolved oxygen of the water supply, and the ammonia metering pump 5 and the oxygen metering pump 6 are adjusted. The pH value in the water supply is between 9.2-9.6, and the dissolved oxygen in the water supply is between 10-20ug / L. A dense ferric oxide film is formed on the inner wall of the hydrophobic pipe to slow down the accelerated flow corrosion phenomenon. The deaerator 7 deoxygenation door is closed to reduce heat loss. The pH value between 9.2-9.6 increases the pH value of the hydrophobicity of the high-pressure heater 8, allowing iron to enter the passivation zone, and the amount of oxygen added can be reduced accordingly; the lower dissolved oxygen can be consumed in the water supply system, avoiding the appearance of oxide scale on the steam pipe.
Claims
1. A supercritical unit high pressure heater anti-corrosion drain system, characterized by: The invention comprises a high-pressure heater (8), wherein the high-pressure heater (8) is connected to an ammonia adding device (1) through a drain; the high-pressure heater (8) is connected to an oxygen adding device (2) through a drain; the high-pressure heater is connected to an economizer (17), a water-cooled wall (16), a superheater (15), a high-pressure cylinder (13), and a reheater (14) in sequence, and the high-pressure cylinder (13) is connected to a high-pressure water heater; the reheater (14) is connected to an intermediate-pressure cylinder (12), a low-pressure cylinder (11), a condenser (10), a low-pressure heater (9), and a deaerator (7) in sequence, and the deaerator (7) is connected to the high-pressure heater (8); the intermediate-pressure cylinder (12) is connected to a pipeline between the high-pressure heater (8) and the deaerator (7), and a circulation pipeline is connected between the deaerator (7) and the high-pressure heater (8); and a pH online meter (3) and a dissolved oxygen online meter (4) are installed on the pipeline between the high-pressure heater (8) and the economizer (17).
2. The anti-corrosion drain system for a supercritical unit high-pressure heater according to claim 1, characterized in that: The circulation pipeline is provided with a circulation valve.
3. The anti-corrosion drain system for a supercritical unit high-pressure heater according to claim 1, characterized in that: The ammonia adding device (1) is equipped with an ammonia adding metering pump (5).
4. The anti-corrosion drain system for a supercritical unit high-pressure heater according to claim 3, characterized in that: The oxygenation device (2) is equipped with an oxygenation metering pump (6).