System and method for multi-parameter cooperative monitoring and positioning of urea hydrolyzer heating pipe corrosion

Abstract

The invention discloses a system and a method for multi-parameter cooperative monitoring and positioning of corrosion of heating pipes of urea hydrolyzers, a first liquid level meter and a first temperature monitoring device are arranged in a shell side of a first urea hydrolyzer, and a second liquid level meter and a second temperature monitoring device are arranged in a shell side of a second urea hydrolyzer; a first steam pipeline in the first urea hydrolyzer is internally provided with a first hydrogen conductometer, a second hydrogen conductometer, a third hydrogen conductometer, a fourth hydrogen conductometer, a fifth hydrogen conductometer, a sixth hydrogen conductometer and a seventh hydrogen conductometer; a first hydrogen conductivity meter of the standby urea hydrolyzer, a second hydrogen conductivity meter of the standby urea hydrolyzer, a third hydrogen conductivity meter of the standby urea hydrolyzer, a fourth hydrogen conductivity meter of the standby urea hydrolyzer and a fifth hydrogen conductivity meter of the standby urea hydrolyzer are arranged in a second steam pipeline in the second urea hydrolyzer; according to the system and the method, the corrosion condition of the steam pipeline in the urea hydrolysis process can be monitored.

Description

Technical Field

[0001] The invention belongs to the technical field of urea hydrolysis and industrial corrosion, and relates to a system and method for multi-parameter coordinated monitoring and positioning of corrosion of a urea hydrolyzer heating tube. Background Art

[0002] Urea hydrolysis to produce ammonia is a key link in the flue gas denitrification of coal-fired power plants. Urea is decomposed into ammonia and carbon dioxide through high-temperature and high-pressure steam. During this process, the steam pipes are exposed to high temperature (150-250), high pressure (1.5-3.0MPa) and corrosive media (such as ammonium carbamate, ammonia, CO2, etc.) for a long time, causing serious corrosion of the pipe materials (such as carbon steel or stainless steel). Corrosion not only shortens equipment life but may also cause leaks, shutdowns, and even safety accidents, affecting production stability and economy. Existing corrosion monitoring methods mainly include offline detection (such as ultrasonic thickness measurement and visual inspection), but offline detection requires shutdown and cannot monitor the dynamic corrosion process in real time, and is prone to missing sudden localized corrosion. In addition, using online electrochemical technology (such as polarization resistance), the sensor stability is poor under high temperature and high pressure environments, and the multiphase flow state of the medium will also interfere with measurement accuracy. Indirect monitoring (such as pH and temperature) cannot directly reflect the corrosion rate, and the data lag makes it difficult to provide timely warnings. In recent years, methods have emerged to monitor the corrosion of urea hydrolyzers using corrosion prediction models. However, because this method relies on historical data, it is not adaptable to complex operating conditions such as raw material fluctuations and start-stop operations.

[0003] Based on the above problems, it is now necessary to design a system for monitoring the corrosion of steam pipes during the urea hydrolysis process, which can be used to timely and efficiently monitor the corrosion situation during the urea hydrolysis process and accurately locate the corrosion leak point, provide technical support for the anti-corrosion work of the urea hydrolysis device, and at the same time provide guarantee for the safe operation of the denitrification system. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a system and method for multi-parameter coordinated monitoring and positioning of urea hydrolyzer heating pipe corrosion, which can monitor the corrosion of steam pipes during urea hydrolysis.

[0005] To achieve the above object, the present invention discloses a system for multi-parameter coordinated monitoring and positioning of urea hydrolyzer heating tube corrosion, comprising a first urea hydrolyzer and a second urea hydrolyzer connected in parallel;

[0006] A first liquid level gauge and a first temperature monitoring device are provided in the shell side of the first urea hydrolyzer, a second liquid level gauge and a second temperature monitoring device are provided in the shell side of the second urea hydrolyzer, a first hydrogen conductivity meter, a second hydrogen conductivity meter, a third hydrogen conductivity meter, a fourth hydrogen conductivity meter, a fifth hydrogen conductivity meter, a sixth hydrogen conductivity meter and a seventh hydrogen conductivity meter are provided in the first steam pipe of the first urea hydrolyzer; a first hydrogen conductivity meter, a second hydrogen conductivity meter, a third hydrogen conductivity meter, a fourth hydrogen conductivity meter, a fifth hydrogen conductivity meter, a sixth hydrogen conductivity meter and a seventh hydrogen conductivity meter of a standby urea hydrolyzer are provided in the second steam pipe of the second urea hydrolyzer; a ninth hydrogen conductivity meter is provided at the outlet of the first steam pipe, and an eighth hydrogen conductivity meter of a standby urea hydrolyzer is provided at the outlet of the second steam pipe.

[0007] The system for multi-parameter coordinated monitoring and positioning of urea hydrolyzer heating tube corrosion according to the present invention is further improved in that:

[0008] Furthermore, an eighth hydrogen conductivity meter is provided at the inlet of the water collection tank.

[0009] Furthermore, it also includes a heating steam input pipeline, a drain tank, a water collection tank, a urea dissolution tank, a urea solution storage tank and a denitrification system;

[0010] The heating steam input pipeline is connected to the inlet of the first steam pipeline and the inlet of the second steam pipeline in the second urea hydrolyzer, the outlet of the first steam pipeline and the outlet of the second steam pipeline are connected to the inlet of the drain tank, the bottom outlet of the drain tank is connected to the sump, the water outlet of the drain tank is connected to the inlet of the urea dissolution tank, the outlet of the urea dissolution tank is connected to the inlet of the urea solution storage tank, the outlet of the urea solution storage tank is connected to the urea solution inlet of the second urea hydrolyzer and the urea solution inlet of the first urea hydrolyzer, and the ammonia outlet at the top of the first urea hydrolyzer and the ammonia outlet at the top of the second urea hydrolyzer are connected to the inlet of the denitrification system.

[0011] Furthermore, the heating steam input pipeline is connected to the inlet of the first steam pipeline in the first urea hydrolyzer through the tenth valve, the heating steam input pipeline is connected to the inlet of the second steam pipeline in the second urea hydrolysis reactor through the seventh valve, and the outlet of the first steam pipeline and the outlet of the second steam pipeline are connected through the pipeline and then connected to the inlet of the drain tank through the eighth valve and the third delivery pump.

[0012] Furthermore, the bottom outlet of the drain tank is connected to the water collection tank through the sixth valve and the fourth delivery pump.

[0013] Furthermore, the water outlet of the drain tank is connected to the inlet of the urea dissolution tank via the third valve and the first delivery pump, the outlet of the urea dissolution tank is connected to the inlet of the urea solution storage tank via the fourth valve and the second delivery pump, the outlet of the urea solution storage tank is connected to the urea solution inlet of the second urea hydrolyzer via the second valve, and the outlet of the urea solution storage tank is connected to the urea solution inlet of the first urea hydrolyzer via the fifth valve, the third delivery pump and the first valve.

[0014] Furthermore, the ammonia outlet at the top of the first urea hydrolyzer is connected to the denitration system via a ninth valve, and the ammonia outlet at the top of the second urea hydrolyzer is connected to the inlet of the denitration system via an eleventh valve.

[0015] Furthermore, a first pressure reducing valve is provided at the pressure reducing port on the top of the first urea hydrolyzer, and a second pressure reducing valve is provided at the pressure reducing port on the top of the second urea hydrolyzer.

[0016] Furthermore, a first pressure gauge is provided at the ammonia outlet at the top of the first urea hydrolyzer; a second pressure gauge is provided at the ammonia outlet at the top of the second urea hydrolyzer.

[0017] The present invention discloses a method for multi-parameter coordinated monitoring and positioning of urea hydrolyzer heating tube corrosion, comprising the following steps:

[0018] The first urea hydrolyzer and the second urea hydrolyzer adopt a one-for-one operation mode;

[0019] Determine whether a leak occurs in the first steam pipe and the location of the leak based on data measured by the first hydrogen conductivity meter, the second hydrogen conductivity meter, the third hydrogen conductivity meter, the fourth hydrogen conductivity meter, the fifth hydrogen conductivity meter, the sixth hydrogen conductivity meter, the seventh hydrogen conductivity meter, the first liquid level gauge, the first temperature monitoring device, and the ninth hydrogen conductivity meter;

[0020] Whether the second steam pipeline is leaking and the leakage location are determined based on the data measured by the first hydrogen conductivity meter of the spare urea hydrolyzer, the second hydrogen conductivity meter of the spare urea hydrolyzer, the third hydrogen conductivity meter of the spare urea hydrolyzer, the fourth hydrogen conductivity meter of the spare urea hydrolyzer, the fifth hydrogen conductivity meter of the spare urea hydrolyzer, the sixth hydrogen conductivity meter of the spare urea hydrolyzer, the seventh hydrogen conductivity meter of the spare urea hydrolyzer, the eighth hydrogen conductivity meter of the spare urea hydrolyzer, the second liquid level gauge and the second temperature monitoring device.

[0021] The present invention has the following beneficial effects:

[0022] The system and method for multi-parameter coordinated monitoring and localization of urea hydrolyzer heating tube corrosion, described herein, can timely and efficiently monitor corrosion during the urea hydrolysis process by detecting hydrogen conductivity at different locations in the steam pipeline, accurately locating corrosion leaks, and providing technical support for corrosion prevention in the urea hydrolysis unit while ensuring the safe operation of the denitrification system. Furthermore, this system can reduce or even eliminate the frequent manual monitoring required to monitor corrosion during the urea hydrolysis process, or the frequent downtime caused by traditional offline corrosion testing. This further saves manpower, energy, and drug consumption, and reduces the difficulty of operating and regulating the denitrification system in thermal power plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0024] Figure 1 It is a structural schematic diagram of the present invention.

[0025] Among them, 1-1 is the first urea hydrolyzer, 1-2 is the second urea hydrolyzer, 2-1 is the first pressure reducing valve, 2-2 is the second pressure reducing valve, 3-1 is the first pressure gauge, 3-2 is the second pressure gauge, 4 is the connecting pipe, 5 is the denitrification system, 6 is the early warning system, 7 is the control feedback system, 8-1 is the first steam pipe, 8-2 is the second steam pipe, 9-1 is the first hydrogen conductivity meter, 9-2 is the second hydrogen conductivity meter, 9-3 is the third hydrogen conductivity meter, 9-4 is the fourth hydrogen conductivity meter, 9-5 is the fifth hydrogen conductivity meter, 9-6 is the fifth hydrogen conductivity meter, 9-7 is the seventh hydrogen conductivity meter, 9-8 is the ninth hydrogen conductivity meter, 10-1 is the first hydrogen conductivity meter of the spare urea hydrolyzer, 10-2 is the second hydrogen conductivity meter of the spare urea hydrolyzer, 10-3 is the third hydrogen conductivity meter of the spare urea hydrolyzer, 10-4 is the fourth hydrogen conductivity meter of the spare urea hydrolyzer, 10-5 is the fifth hydrogen conductivity meter of the spare urea hydrolyzer, 10 -6 is the sixth hydrogen conductivity meter of the spare urea hydrolyzer, 10-7 is the seventh hydrogen conductivity meter of the spare urea hydrolyzer, 10-8 is the eighth hydrogen conductivity meter of the spare urea hydrolyzer, 10-9 is the eighth hydrogen conductivity meter, 11-1 is the first valve, 11-2 is the second valve, 11-3 is the third valve, 11-4 is the fourth valve, 11-5 is the fifth valve, 11-6 is the sixth valve, 11-7 is the seventh valve, 11-8 is the eighth valve, 11-9 is The ninth valve, 11-10 is the tenth valve, 12 is the drain tank, 13 is the water collection tank, 14 is the urea dissolution tank, 15 is the urea solution storage tank, 16 is the data connection line, 17-1 is the first liquid level gauge, 17-2 is the second liquid level gauge, 18-1 is the first temperature monitoring device, 18-2 is the second temperature monitoring device, 19-1 is the first delivery pump, 19-2 is the second delivery pump, 19-3 is the third delivery pump, and 19-4 is the fourth delivery pump. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0027] In the description of the present invention, it is to be understood that the terms “include” and “comprise” indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0028] It should also be understood that the terms used in the present specification are only for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0029] It should be further understood that the term "and / or" as used in the present specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the present invention generally indicates that the associated objects are in an "or" relationship.

[0030] It should be understood that although the terms "first," "second," and "third" may be used to describe preset ranges in embodiments of the present invention, these preset ranges should not be limited to these terms. These terms are merely used to distinguish one preset range from another. For example, without departing from the scope of embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0031] The word "if," as used herein, may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to the determination" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)," depending on the context.

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] The accompanying drawings illustrate various schematic diagrams of structures according to embodiments disclosed herein. These figures are not drawn to scale; for clarity, some details are exaggerated and some details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0034] refer to Figure 1 The system for multi-parameter coordinated monitoring and positioning of urea hydrolyzer heating pipe corrosion of the present invention includes a heating steam input pipeline, a first urea hydrolyzer 1-1, a second urea hydrolyzer 1-2, a first pressure reducing valve 2-1, a second pressure reducing valve 2-2, a first pressure gauge 3-1, a second pressure gauge 3-2, a connecting pipeline 4, a denitrification system 5, an early warning system 6, a control feedback system 7, a first steam pipeline 8-1, a second steam pipeline 8-2, a first hydrogen conductivity meter 9-1, a second hydrogen conductivity meter 9-2, a third hydrogen conductivity meter 9-3, a fourth hydrogen conductivity meter 9-4, a fifth hydrogen conductivity meter 9-5, a fifth hydrogen conductivity meter 9-5, a seventh hydrogen conductivity meter 9-7, a ninth hydrogen conductivity meter 9-8, a first hydrogen conductivity meter 10-1 for a standby urea hydrolyzer, a second hydrogen conductivity meter 10-2 for a standby urea hydrolyzer, a third hydrogen conductivity meter 10-3 for a standby urea hydrolyzer, and a fourth hydrogen conductivity meter 10-4 for a standby urea hydrolyzer. The fifth hydrogen conductivity meter 10-5 of the spare urea hydrolyzer, the sixth hydrogen conductivity meter 10-6 of the spare urea hydrolyzer, the seventh hydrogen conductivity meter 10-7 of the spare urea hydrolyzer, the eighth hydrogen conductivity meter 10-8 of the spare urea hydrolyzer, the eighth hydrogen conductivity meter 10-9, the first valve 11-1, the second valve 11-2, the third valve 11-3, the fourth valve 11-4, the fifth valve 11-5, the sixth valve 11-6, the seventh valve 11-7, the eighth valve Valve 11-8, ninth valve 11-9, tenth valve 11-10, drain tank 12, sump 13, urea dissolution tank 14, urea solution storage tank 15, data connection line 16, first liquid level gauge 17-1, second liquid level gauge 17-2, first temperature monitoring device 18-1, second temperature monitoring device 18-2, first delivery pump 19-1, second delivery pump 19-2, third delivery pump 19-3, and fourth delivery pump 19-4;

[0035] The heating steam input pipeline is connected to the inlet of the first steam pipeline 8-1 in the first urea hydrolyzer 1-1 through the tenth valve 11-10, and the heating steam input pipeline is connected to the inlet of the second steam pipeline 8-2 in the second urea hydrolyzer 1-2 through the seventh valve 11-7. The outlet of the first steam pipeline 8-1 and the outlet of the second steam pipeline 8-2 are connected through a pipeline and then connected to the inlet of the drain tank 12 through the eighth valve 11-8 and the third delivery pump 19-3. The bottom outlet of the drain tank 12 is connected to the water collecting tank 13 through the sixth valve 11-6 and the fourth delivery pump 19-4. The water outlet of the drain tank 12 is connected to the urea dissolution tank through the third valve 11-3 and the first delivery pump 19-1. The outlet of the urea solution storage tank 15 is connected to the urea solution inlet of the second urea hydrolyzer 1-2 through the second valve 11-2. The outlet of the urea solution storage tank 15 is connected to the urea solution inlet of the first urea hydrolyzer 1-1 through the fifth valve 11-5, the third delivery pump 19-3 and the first valve 11-1. The ammonia outlet at the top of the first urea hydrolyzer 1-1 is connected to the denitration system 5 through the ninth valve 11-9. The ammonia outlet at the top of the second urea hydrolyzer 1-2 is connected to the inlet of the denitration system 5 through the eleventh valve.

[0036] A first pressure reducing valve 2-1 is provided at the pressure reducing port on the top of the first urea hydrolyzer 1-1, a second pressure reducing valve 2-2 is provided at the pressure reducing port on the top of the second urea hydrolyzer 1-2, a first liquid level gauge 17-1 and a first temperature monitoring device 18-1 are provided in the shell side of the first urea hydrolyzer 1-1, a second liquid level gauge 17-2 and a second temperature monitoring device 18-2 are provided in the shell side of the second urea hydrolyzer 1-2, a first hydrogen conductivity meter 9-1, a second hydrogen conductivity meter 9-2, a third hydrogen conductivity meter 9-3, a fourth hydrogen conductivity meter 9-4, a fifth hydrogen conductivity meter 9-5, a sixth hydrogen conductivity meter 9-6 and a seventh hydrogen conductivity meter 9-7 are provided in the first steam pipe 8-1; a second The steam pipe 8-2 is provided with a first hydrogen conductivity meter 10-1 of the standby urea hydrolyzer, a second hydrogen conductivity meter 10-2 of the standby urea hydrolyzer, a third hydrogen conductivity meter 10-3 of the standby urea hydrolyzer, a fourth hydrogen conductivity meter 10-4 of the standby urea hydrolyzer, a fifth hydrogen conductivity meter 10-5 of the standby urea hydrolyzer, a sixth hydrogen conductivity meter 10-6 of the standby urea hydrolyzer, and a seventh hydrogen conductivity meter 10-7 of the standby urea hydrolyzer; a ninth hydrogen conductivity meter 9-8 is provided at the outlet of the first steam pipe 8-1; an eighth hydrogen conductivity meter 10-8 of the standby urea hydrolyzer is provided at the outlet of the second steam pipe 8-2; and an eighth hydrogen conductivity meter 10-9 is provided at the inlet of the water collecting tank 13.

[0037] A first pressure gauge 3-1 is provided at the ammonia outlet at the top of the first urea hydrolyzer 1-1; a second pressure gauge 3-2 is provided at the ammonia outlet at the top of the second urea hydrolyzer 1-2.

[0038] The control feedback system 7 is connected to the first pressure reducing valve 2-1, the second pressure reducing valve 2-2, the first pressure gauge 3-1, the second pressure gauge 3-2, the early warning system 6, the first hydrogen conductivity meter 9-1, the second hydrogen conductivity meter 9-2, the third hydrogen conductivity meter 9-3, the fourth hydrogen conductivity meter 9-4, the fifth hydrogen conductivity meter 9-5, the sixth hydrogen conductivity meter 9-6, the seventh hydrogen conductivity meter 9-7, the ninth hydrogen conductivity meter 9-8, the first hydrogen conductivity meter 10-1 of the standby urea hydrolyzer, the second hydrogen conductivity meter 10-2 of the standby urea hydrolyzer, the third hydrogen conductivity meter 10-3 of the standby urea hydrolyzer, the fourth hydrogen conductivity meter 10-4 of the standby urea hydrolyzer, the fifth hydrogen conductivity meter 10-5 of the standby urea hydrolyzer, the sixth hydrogen conductivity meter 9-6, the seventh hydrogen conductivity meter 9-7, the ninth hydrogen conductivity meter 9-8, the first hydrogen conductivity meter 10-1 of the standby urea hydrolyzer, the second hydrogen conductivity meter 10-2 of the standby urea hydrolyzer, the third hydrogen conductivity meter 10-3 of the standby urea hydrolyzer, the fourth hydrogen conductivity meter 10-4 of the standby urea hydrolyzer, the fifth hydrogen conductivity meter 10-5 of the standby urea hydrolyzer, the sixth hydrogen conductivity meter 9-6, the seventh hydrogen conductivity meter The sixth hydrogen conductivity meter 10-6, the seventh hydrogen conductivity meter 10-7 of the spare urea hydrolyzer, the seventh hydrogen conductivity meter 10-7 of the spare urea hydrolyzer, the eighth hydrogen conductivity meter 10-9, the first valve 11-1, the second valve 11-2, the third valve 11-3, the fourth valve 11-4, the fifth valve 11-5, the sixth valve 11-6, the seventh valve 11-7, the eighth valve 11-8, the ninth valve 11-9, the tenth valve 11-10, the first liquid level gauge 17-1, the second liquid level gauge 17-2, the first temperature monitoring device 18-1, the second temperature monitoring device 18-2, the first delivery pump 19-1, the second delivery pump 19-2, the third delivery pump 19-3 and the fourth delivery pump 19-4 are connected.

[0039] The method for multi-parameter coordinated monitoring and positioning of urea hydrolyzer heating tube corrosion according to the present invention comprises the following steps:

[0040] At the beginning of the denitration process, the tenth valve 11-10 is opened to maintain the bottom temperature of the first urea hydrolyzer 1-1 above 80°C to prevent the urea solution from crystallizing. Subsequently, the first valve 11-1 and the fifth valve 11-5 are opened by controlling the feedback system 7 to maintain the pressure and temperature of the first urea hydrolyzer 1-1 and prevent the first urea hydrolyzer 1-1 from overheating and overpressure. During the operation, the first hydrogen conductivity meter 9-1, the second hydrogen conductivity meter 9-2, the third hydrogen conductivity meter 9-3, the fourth hydrogen conductivity meter 9-4, and the fourth hydrogen conductivity meter 9-5 are evenly distributed and installed on the first steam pipe 8-1. The hydrogen conductivity meter 9-4, the fifth hydrogen conductivity meter 9-5, the sixth hydrogen conductivity meter 9-6 and the seventh hydrogen conductivity meter 9-7 monitor the steam hydrogen conductivity in real time and feed the monitoring data back to the control feedback system 7. The steam hydrogen conductivity of the urea hydrolysis process is generally less than 0.3 μS / cm (25°C). The first hydrogen conductivity meter 9-1, the second hydrogen conductivity meter 9-2, the third hydrogen conductivity meter 9-3, the fourth hydrogen conductivity meter 9-4, the fifth hydrogen conductivity meter 9-5, the sixth hydrogen conductivity meter 9-6 and the seventh hydrogen conductivity meter 9-7 are used to monitor the steam water quality of different steam pipeline sections.When the hydrogen conductivity of steam rises to 0.05-0.1μS / cm, it can be determined as a slight leak or sampling contamination and measurement error; when the hydrogen conductivity of steam rises to 0.1-0.3μS / cm, it can be determined as a moderate leak (such as local corrosion or valve leakage); when the hydrogen conductivity of steam is greater than 0.3μS / cm, it can be determined as a serious leak (pipeline rupture or perforation). In addition to monitoring the hydrogen conductivity of steam during operation, the pressure and liquid level of the first urea hydrolyzer 1-1 are also monitored. During the hydrolysis process, the temperature, pressure, and liquid level of the first urea hydrolyzer 1-1 are monitored. For example, when the data detected by multiple parameters such as the first hydrogen conductivity meter 9-1, the second hydrogen conductivity meter 9-2, the third hydrogen conductivity meter 9-3, the fourth hydrogen conductivity meter 9-4, the fifth hydrogen conductivity meter 9-5, the sixth hydrogen conductivity meter 9-6 and the seventh hydrogen conductivity meter 9-7 are consistent, it is considered that the first urea hydrolyzer 1-1 is operating normally; when the data detected by multiple parameters such as the first hydrogen conductivity meter 9-1, the second hydrogen conductivity meter 9-2, the third hydrogen conductivity meter 9-3, the fourth hydrogen conductivity meter 9-4, the fifth hydrogen conductivity meter 9-5, the sixth hydrogen conductivity meter 9-6 and the seventh hydrogen conductivity meter 9-7 fluctuate, The difference is greater than 0.1 μS / cm. At the same time, the monitored pressure value and temperature exceed the standard, and a comprehensive judgment is made as to whether minor corrosion or severe corrosion occurs. For example, when the hydrogen conductivity values at different positions of the first steam pipe 8-1 fluctuate greatly for more than 10 minutes, it is determined that "corrosion occurs". At the same time, the corrosion leakage position is accurately located according to the measured value of hydrogen conductivity. The control feedback system 7 is preset with a steam hydrogen conductivity value of 0.3 μS / cm. For example, when the first hydrogen conductivity meter 9-1 and the subsequently set hydrogen conductivity meters (the second hydrogen conductivity meter 9-2, the third hydrogen conductivity meter 9-3, the fourth hydrogen conductivity meter 9-4) If the monitoring data of more than two instruments (such as the first hydrogen conductivity meter 9-4) show abnormal data (fluctuations exceeding 0.1 μS / cm) compared to the set values, the corrosion location will be located in the pipeline section before the first hydrogen conductivity meter 9-1. If the monitoring data of more than two instruments (such as the fifth hydrogen conductivity meter 9-5 and subsequent hydrogen conductivity meters (such as the sixth hydrogen conductivity meter 9-6, the seventh hydrogen conductivity meter 9-7, and the third hydrogen conductivity meter) show abnormal data (fluctuations exceeding 0.1 μS / cm) compared to the set values, the corrosion location will be located in the pipeline section after the fourth hydrogen conductivity meter 9-4 and before the fifth hydrogen conductivity meter 9-5. In addition, the control feedback system 7 will automatically interlock with the early warning system 6 to issue an alarm, which will be immediately fed back to the control feedback system 7. The control feedback system 7 will automatically adjust and open the seventh valve 11-7 and the second valve 11-2, activating the second urea hydrolyzer 1-2. The activation process of the urea hydrolyzer is basically the same as that of the first urea hydrolyzer 1-1.After the second urea hydrolyzer 1-2 can supply product gas normally and does not affect the subsequent flue gas denitrification, the ninth valve 11-9 is slowly closed. At the same time, the tenth valve 11-10 is closed, and the first valve 11-1 and the fifth valve 11-5 are closed to stop the urea solution feed. The system switch is completed, and the first urea hydrolyzer 1-1 enters the maintenance stage. If the steam hydrogen conductivity data are tested normally, the drain is monitored again after heat exchange to confirm the hydrogen conductivity and then enters the drain tank 12. The drain in the drain tank 12 is used to dissolve urea, and the excess drain is finally discharged into the sump 13 and enters other systems.

[0041] It should be noted that the present invention utilizes a control feedback system 7 throughout the entire process, controlling the opening and closing of various valves and delivery pumps. This allows for timely and efficient monitoring of corrosion during the urea hydrolysis process, accurately locating corrosion leaks, and providing technical support for corrosion prevention efforts in the urea hydrolysis unit while ensuring the safe operation of the denitrification system 5. Furthermore, this system can reduce or even eliminate the frequent manual monitoring required to monitor corrosion during the urea hydrolysis process, or the frequent downtime associated with traditional offline corrosion testing. This further saves manpower, energy, and pharmaceutical consumption, and reduces the difficulty of operating and regulating the denitrification system 5 in a thermal power plant.

[0042] Those skilled in the art will readily identify other embodiments of the present invention after considering the specification and disclosure of the invention. This application is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.

[0043] It should be understood that the present invention is not limited to the exact construction described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

[0044] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A system for multi-parameter coordinated monitoring and positioning of urea hydrolyzer heating tube corrosion, characterized in that: It comprises a first urea hydrolyzer (1-1) and a second urea hydrolyzer (1-2) connected in parallel; A first liquid level gauge (17-1) and a first temperature monitoring device (18-1) are provided in the shell side of the first urea hydrolyzer (1-1); a second liquid level gauge (17-2) and a second temperature monitoring device (18-2) are provided in the shell side of the second urea hydrolyzer (1-2); a first hydrogen conductivity meter (9-1), a second hydrogen conductivity meter (9-2), a third hydrogen conductivity meter (9-3), a fourth hydrogen conductivity meter (9-4), a fifth hydrogen conductivity meter (9-5), a sixth hydrogen conductivity meter (9-6) and a seventh hydrogen conductivity meter (9-7) are provided in the first steam pipe (8-1) in the first urea hydrolyzer (1-1); and a second steam pipe (8-1) in the second urea hydrolyzer (1-2) is provided. A first hydrogen conductivity meter (10-1) of a standby urea hydrolyzer, a second hydrogen conductivity meter (10-2) of a standby urea hydrolyzer, a third hydrogen conductivity meter (10-3) of a standby urea hydrolyzer, a fourth hydrogen conductivity meter (10-4) of a standby urea hydrolyzer, a fifth hydrogen conductivity meter (10-5) of a standby urea hydrolyzer, a sixth hydrogen conductivity meter (10-6) of a standby urea hydrolyzer, and a seventh hydrogen conductivity meter (10-7) of a standby urea hydrolyzer are provided in the pipeline (8-2); a ninth hydrogen conductivity meter (9-8) of a standby urea hydrolyzer is provided at the outlet of the first steam pipeline (8-1), and an eighth hydrogen conductivity meter (10-8) of a standby urea hydrolyzer is provided at the outlet of the second steam pipeline (8-2).

2. The system for multi-parameter coordinated monitoring and positioning of urea hydrolyzer heating tube corrosion according to claim 1, characterized in that: An eighth hydrogen conductivity meter (10-9) is provided at the inlet of the water collecting tank (13).

3. The system for multi-parameter coordinated monitoring and positioning of urea hydrolyzer heating tube corrosion according to claim 1 is characterized in that: It also includes a heating steam input pipe, a drain tank (12), a water collecting tank (13), a urea dissolving tank (14), a urea solution storage tank (15) and a denitrification system (5); The heating steam input pipeline is connected to the inlet of the first steam pipeline (8-1) and the inlet of the second steam pipeline (8-2) in the second urea hydrolyzer (1-2); the outlet of the first steam pipeline (8-1) and the outlet of the second steam pipeline (8-2) are connected to the inlet of the drain tank (12); the bottom outlet of the drain tank (12) is connected to the water collecting tank (13); the water outlet of the drain tank (12) is connected to the inlet of the urea dissolving tank (14); the outlet of the urea dissolving tank (14) is connected to the inlet of the urea solution storage tank (15); the outlet of the urea solution storage tank (15) is connected to the urea solution inlet of the second urea hydrolyzer (1-2) and the urea solution inlet of the first urea hydrolyzer (1-1); and the ammonia outlet at the top of the first urea hydrolyzer (1-1) and the ammonia outlet at the top of the second urea hydrolyzer (1-2) are connected to the inlet of the denitration system (5).

4. The system for multi-parameter coordinated monitoring and positioning of urea hydrolyzer heating tube corrosion according to claim 3 is characterized in that: The heating steam input pipeline is connected to the inlet of the first steam pipeline (8-1) in the first urea hydrolyzer (1-1) through the tenth valve (11-10), and the heating steam input pipeline is connected to the inlet of the second steam pipeline (8-2) in the second urea hydrolysis reactor through the seventh valve (11-7). The outlet of the first steam pipeline (8-1) and the outlet of the second steam pipeline (8-2) are connected through a pipeline and then connected to the inlet of the drain tank (12) through the eighth valve (11-8) and the third delivery pump (19-3).

5. The system for multi-parameter coordinated monitoring and positioning of urea hydrolyzer heating tube corrosion according to claim 3 is characterized in that: The bottom outlet of the drain tank (12) is connected to the water collecting tank (13) through the sixth valve (11-6) and the fourth delivery pump (19-4).

6. The system for multi-parameter coordinated monitoring and positioning of urea hydrolyzer heating tube corrosion according to claim 3 is characterized in that: The water outlet of the drain tank (12) is connected to the inlet of the urea dissolving tank (14) via the third valve (11-3) and the first delivery pump (19-1); the outlet of the urea dissolving tank (14) is connected to the inlet of the urea solution storage tank (15) via the fourth valve (11-4) and the second delivery pump (19-2); the outlet of the urea solution storage tank (15) is connected to the urea solution inlet of the second urea hydrolyzer (1-2) via the second valve (11-2); and the outlet of the urea solution storage tank (15) is connected to the urea solution inlet of the first urea hydrolyzer (1-1) via the fifth valve (11-5), the third delivery pump (19-3) and the first valve (11-1).

7. The system for multi-parameter coordinated monitoring and positioning of urea hydrolyzer heating tube corrosion according to claim 3 is characterized in that: The ammonia outlet at the top of the first urea hydrolyzer (1-1) is connected to the denitration system (5) via a ninth valve (11-9), and the ammonia outlet at the top of the second urea hydrolyzer (1-2) is connected to the inlet of the denitration system (5) via an eleventh valve.

8. The system for multi-parameter coordinated monitoring and positioning of urea hydrolyzer heating tube corrosion according to claim 3 is characterized in that: A first pressure reducing valve (2-1) is provided at the pressure reducing port on the top of the first urea hydrolyzer (1-1), and a second pressure reducing valve (2-2) is provided at the pressure reducing port on the top of the second urea hydrolyzer (1-2).

9. The system for multi-parameter coordinated monitoring and positioning of urea hydrolyzer heating tube corrosion according to claim 3, characterized in that: A first pressure gauge (3-1) is provided at the ammonia outlet at the top of the first urea hydrolyzer (1-1); and a second pressure gauge (3-2) is provided at the ammonia outlet at the top of the second urea hydrolyzer (1-2).

10. A method for multi-parameter coordinated monitoring and positioning of urea hydrolyzer heating tube corrosion, characterized in that: The system for multi-parameter coordinated monitoring and positioning of urea hydrolyzer heating tube corrosion according to claim 1 comprises the following steps: The first urea hydrolyzer (1-1) and the second urea hydrolyzer (1-2) adopt an operation mode of one in standby and one in use; Determining whether a leak occurs in the first steam pipe (8-1) and the location of the leak based on data measured by the first hydrogen conductivity meter (9-1), the second hydrogen conductivity meter (9-2), the third hydrogen conductivity meter (9-3), the fourth hydrogen conductivity meter (9-4), the fifth hydrogen conductivity meter (9-5), the sixth hydrogen conductivity meter (9-6), the seventh hydrogen conductivity meter (9-7), the first liquid level meter (17-1), the first temperature monitoring device (18-1) and the ninth hydrogen conductivity meter (9-8); Whether a second steam pipe (8-2) is leaking and the location of the leak are determined based on data measured by a first hydrogen conductivity meter (10-1) of a standby urea hydrolyzer, a second hydrogen conductivity meter (10-2) of a standby urea hydrolyzer, a third hydrogen conductivity meter (10-3) of a standby urea hydrolyzer, a fourth hydrogen conductivity meter (10-4) of a standby urea hydrolyzer, a fifth hydrogen conductivity meter (10-5) of a standby urea hydrolyzer, a sixth hydrogen conductivity meter (10-6) of a standby urea hydrolyzer, a seventh hydrogen conductivity meter (10-7) of a standby urea hydrolyzer, an eighth hydrogen conductivity meter (10-8) of a standby urea hydrolyzer, a second liquid level meter (17-2) and a second temperature monitoring device (18-2).

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