A thermal power plant high temperature and high pressure steam oxidation online experimental system and method

Abstract

The present invention discloses an online experimental system and method for high-temperature and high-pressure steam oxidation in a thermal power plant. The system is provided with a steam introduction module, an experimental module and a steam recovery module. The steam introduction module introduces the high-temperature and high-pressure steam actually operated by the thermal power plant generator set from the hot re-drainage pipeline. After passing through the experimental pipeline, the steam enters the steam recovery module and finally enters the heating pipeline for recovery, which has little impact on the efficiency of the generator set. The system can use the high-temperature and high-pressure steam actually operated by the thermal power plant generator set to conduct high-temperature and high-pressure steam oxidation experiments on metal materials to be studied. The experimental parameters of the system are the same as the actual service parameters of the metal materials, and can be controlled and adjusted within a certain range. The experimental data has high accuracy, analyzability and comparability, which reduces the adverse effects caused by the difference between the experimental parameters in the laboratory of the scientific research institution and the actual service environment parameters of the metal materials.

Description

Technical Field

[0001] The invention belongs to the field of steam oxidation of metal materials in thermal power plants, and relates to an online experimental system and method for high-temperature and high-pressure steam oxidation in thermal power plants. Background Art

[0002] During the operation of the power plant generator set, the overheated (re)heated gas pipeline and other components are in service for a long time in a high temperature and high pressure steam environment, which is prone to oxidation corrosion. Universities, research institutes and other scientific research institutions around the world have conducted long-term research on the high temperature and high pressure oxidation corrosion resistance of metal materials, but most of the research is carried out under laboratory conditions. Many experimental parameters (such as pressure, water supply conditions, etc.) are different from the actual operating parameters of the power plant. There are certain deviations in the experimental determination and research of the high temperature and high pressure oxidation corrosion resistance of metal materials.

[0003] On the other hand, some researchers have proposed to test the service performance of pipes and pipe welds on site in power plants. For example, the invention application document with the publication number CN 112304779A discloses an online experimental device for the service performance of high-temperature and high-pressure pipes for power plants. It is mentioned that the device adopts a header parallel connection mode, which has certain disadvantages: 1. The parallel experimental pipeline of the device diverts the steam of the header. The reference documents "Numerical Simulation of Pressure Distribution and Flow Distribution of Three-Way Header Superheater" and "The Influence of Velocity Distribution of Boiler Distribution Header on Flow Distribution" point out that the steam flow, velocity and pressure of the header parallel pipeline are uneven and unstable. Although the device has added parameter measurement points on the diversion pipeline, the steam parameters in the diversion pipeline are uncontrollable and always in an uneven and unstable state, resulting in low accuracy, comparability and analyzability of the experimental data. 2. The device states that each shunt pipe is equipped with flow, flow rate, pressure and other measuring equipment. Since the steam parameters of each shunt pipe are uneven, it is easy to cause the steam parameters in the shunt pipe to be too high or too low. If the steam parameters of a shunt pipe are too high and exceed the protection value, the entire experimental device will be abnormally shut down. 3. The patent states that "the high-temperature and high-pressure steam in the power plant in service will be led out through the pipeline", but research has found that if the high-temperature and high-pressure steam in the power plant is directly led out through the pipeline, it is extremely dangerous and not conducive to the stable operation of the boiler unit. 4. The patent describes that "the steam passes through the experimental device and then flows into the power plant operation system for power generation or heating, energy saving and environmental protection". If the steam flows into the power generation system, the steam needs to be heated again, which is costly and reduces the efficiency of the unit; and the impurities in the steam enter the power plant system, which is easy to damage the core components such as the turbine. 5. According to the patent, it cannot achieve the purpose of adjusting the temperature, pressure and flow rate in the experimental tube sample. In summary, the above patent intends to use the steam environment of a power plant to conduct experiments, but the degree of feasibility is not high, and the controllability and stability of the experimental parameters are poor, and the analyzability, comparability and accuracy of the experimental data are low. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide an online experimental system and method for high-temperature and high-pressure steam oxidation in a thermal power plant, so as to solve the problems that the experimental parameters in the laboratory in the prior art are inconsistent with the actual operating parameters of the power plant, resulting in certain deviations in the research on the high-temperature and high-pressure oxidation corrosion resistance of metal materials; and the experimental device described in the prior art is difficult to implement, the controllability and stability of the experimental parameters are poor, and the analyzability, comparability and accuracy of the experimental data are low.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A high-temperature and high-pressure steam oxidation online experimental system for a thermal power plant comprises a steam introduction module, an experimental module and a steam recovery module; the input end of the steam introduction module is connected to a hot re-drain pipe, and the output end is connected to the input end of the experimental module; the output end of the experimental module is connected to the input end of the steam recovery module, and the output end of the steam recovery module is connected to a heating pipeline;

[0007] The experimental module includes an experimental pipeline, the steam input end of the experimental pipeline is connected to the steam introduction module, and the output end of the experimental pipeline is connected to the steam recovery module; the experimental pipeline includes M straight segments and N curved segments, the M straight segments are parallel to each other, and every two adjacent straight segments are connected through a curved segment, the curved segment is an arc segment, and the straight segments are connected in series;

[0008] The inlet and outlet ends of the experimental pipeline are both provided with a thermometer, a pressure gauge, a flow meter and a flow rate meter, and the thermometer, pressure gauge, flow meter and flow rate meter are all connected to the laboratory control system;

[0009] The experimental control system is also connected to an inlet electric valve and an outlet electric valve. The inlet electric valve is arranged in the steam introduction module, and the outlet electric valve is arranged in the steam recovery module.

[0010] A further improvement of the present invention is:

[0011] Preferably, the steam introduction module includes a tee, one input end of the tee is connected to the hot re-drainage pipe, the output end of the tee is connected to the inlet electric valve, the inlet electric valve is connected to the steam pipeline, and the steam pipeline is connected to the experimental pipeline.

[0012] Preferably, an inlet manual valve is provided between the three-way valve and the inlet electric valve.

[0013] Preferably, an electromagnetic induction heating device is provided on the steam pipeline.

[0014] Preferably, the experimental module is arranged in a laboratory, and a real-time monitoring system is arranged in the laboratory.

[0015] Preferably, the material of the experimental pipe is T91, TP347H, TP347HFG, Super304H or HR3C, the outer diameter of the experimental pipe is 30-50 mm, and the wall thickness is 5-12 mm.

[0016] Preferably, the inlet of the experimental pipeline is provided with an inlet thermometer, an inlet pressure gauge, an inlet flow meter and an inlet flow rate meter, and the outlet of the experimental pipeline is provided with an outlet thermometer, an outlet pressure gauge, an outlet flow meter and an outlet flow rate meter.

[0017] Preferably, the steam recovery module includes a steam cooling system and a recovery device, and the steam cooling system includes a cooling device; the cooling device is composed of three coolers connected in series, the cooling water inlet pipeline of the cooling device is connected to the closed cooling water system of the power plant, and the cooling water outlet pipeline of the cooling device is connected to the closed cooling water system of the power plant; the steam recovery input pipe of the cooling device is connected to the outlet end of the experimental pipeline, and the steam recovery output pipe of the cooling device is connected to the heating pipeline.

[0018] Preferably, the steam recovery output pipe is connected to the heating pipe through a reinforced pipe seat; the outlet electric valve is arranged on the steam recovery output pipe, and an outlet manual valve is arranged on the steam recovery output pipe between the outlet electric valve and the heating pipe.

[0019] An online experimental method for high temperature and high pressure steam oxidation in a power plant of any of the above experimental systems, the specific process is:

[0020] (1) Opening the inlet electric valve and the outlet electric valve, introducing steam into the experimental pipeline, and the steam enters the steam recovery module after passing through the experimental pipeline; after reaching the first set time, closing the inlet electric valve and the outlet electric valve, and performing a sampling operation; the sampling operation is to cut a tube sample of a set length, and at the same time introduce a replacement tube sample to replace the cut tube sample, and the replacement tube sample is welded to the experimental pipeline;

[0021] (2) After sampling is completed, open the inlet electric valve and the outlet electric valve to continue to introduce steam, and repeat the steps until all sampling times of the set time are completed;

[0022] (3) After all samples are inlaid, ground and polished, they are characterized and analyzed to obtain the high temperature and high pressure oxidation corrosion resistance of the materials used in the experimental pipeline.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The invention discloses an online experimental system for high-temperature and high-pressure steam oxidation in a thermal power plant. The system is provided with a steam introduction module, an experimental module and a steam recovery module. The steam introduction module introduces the high-temperature and high-pressure steam actually operated by the thermal power plant generator set from the hot re-drainage pipeline. After passing through the experimental pipeline, the steam enters the steam recovery module and finally enters the heating pipeline for recovery. The experimental pipeline of the series structure used in the system makes the steam flow and parameters in the experimental pipeline stable. The steam input end of the system is connected to the hot re-drainage pipeline. The steam pressure introduced is about one-third of the superheated steam, which is less dangerous. The final steam is input to the heating pipeline, which maximizes the use of the steam flow and reduces the impact of steam extraction on the efficiency of the generator set. The system can use the high-temperature and high-pressure steam actually operated by the thermal power plant generator set to conduct high-temperature and high-pressure steam oxidation experiments on the metal materials to be studied. The experimental parameters of the system are the same as the actual service parameters of the metal materials and can be controlled and adjusted within a certain range, reducing the adverse effects caused by the difference between the experimental parameters in the laboratory of the scientific research institution and the actual service environment parameters of the metal materials.

[0025] Furthermore, in the steam introduction module, steam is introduced from the hot re-drain pipe into the experimental pipeline through a tee, so that high-temperature and high-pressure steam is led out of the pipeline, which is less dangerous and has little impact on the operation of the boiler unit.

[0026] Furthermore, an inlet manual valve is provided before the inlet electric valve to enhance the safety of the experimental process.

[0027] Furthermore, an electromagnetic induction heating device is provided on the steam pipeline to adjust the temperature and pressure of the introduced steam.

[0028] Furthermore, a real-time monitoring system is installed in the laboratory to facilitate experimenters to monitor the experimental conditions from outside.

[0029] Furthermore, the pipe material of the experimental pipeline can be selected according to the needs to fully simulate the experimental process.

[0030] Furthermore, detection instruments are provided at the inlet and outlet of the experimental pipeline to detect the inlet and outlet parameters of the steam.

[0031] Furthermore, the steam is cooled before recovery so that it meets the recovery requirements.

[0032] The present invention also discloses an experimental method based on the above system. In addition to taking out the experimental tube, the method can continuously perform oxidation experiments on the entire pipeline. The system can use the high-temperature and high-pressure steam actually operated by the thermal power plant generator set to perform high-temperature and high-pressure steam oxidation experiments on the metal materials to be studied. The experimental parameters of the system are the same as the actual service parameters of the metal materials and can be controlled and adjusted within a certain range, reducing the adverse effects caused by the difference between the experimental parameters in the laboratory of the scientific research institution and the actual service environment parameters of the metal materials. The analyzability, comparability and accuracy of the experimental data are greatly improved, making the determination and research of the high-temperature and high-pressure oxidation corrosion resistance of metal materials more accurate. The experimental system has been actually applied in power plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a structural diagram of a steam introduction module of the present invention;

[0034] Figure 2 It is the structure diagram of the experimental module of the present invention;

[0035] Figure 3 It is a structural diagram of the steam recovery module of the present invention;

[0036] Among them: 1-steam pipeline, 2-inlet thermometer, 3-inlet pressure gauge, 4-inlet flowmeter, 5-inlet flowmeter, 6-experimental pipeline, 7-cooling device, 8-cooling water inlet pipeline, 9-cooling water outlet pipeline, 10-experimental pipeline bracket, 11-cooler bracket, 12-outlet thermometer, 13-outlet pressure gauge, 14-outlet flowmeter, 15-outlet flowmeter; 16-tee; 17-hot drain pipe; 18-inlet manual valve; 19-inlet electric valve; 20-electromagnetic induction heating device; 21-outlet electric valve; 22-outlet manual valve; 23-reinforced pipe seat; 24-heating pipeline; 25-steam recovery input pipe; 26-steam recovery output pipe; 27-cooler; 6-1-straight section; 6-2-bend section. DETAILED DESCRIPTION

[0037] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0038] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention; the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance; in addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] The present invention discloses an online experimental system for high-temperature and high-pressure steam oxidation in a thermal power plant and a method for using the same. The system comprises a steam introduction module, an experimental module and a steam recovery module. The steam introduction module comprises a tee, a manual valve, an electric valve, an electromagnetic induction heating device, a steam pipeline and a pipeline support and hanger; the experimental module comprises a laboratory, a test bench control system, a laboratory temperature control system, a laboratory real-time monitoring system, an experimental pipeline, an experimental pipeline support, a thermometer, a pressure gauge, a flow meter, a flow meter and an emergency protection system; the steam recovery module comprises a reinforced pipe seat, a manual valve, an electric valve, a steam cooling system, a thermometer, a pressure gauge, a flow meter and a flow meter.

[0040] The system can use the high-temperature and high-pressure steam actually operated by the power plant generator set to conduct high-temperature and high-pressure steam oxidation experiments on the metal materials to be studied. The experimental parameters of the system are the same as the actual service parameters of the metal materials and can be controlled and adjusted within a certain range, reducing the adverse effects caused by the difference between the experimental parameters in the laboratory of the scientific research institution and the actual service environment parameters of the metal materials. The analyzability, comparability and accuracy of the experimental data are greatly improved, making the determination and research of the high-temperature and high-pressure oxidation corrosion resistance of metal materials more accurate.

[0041] The present invention discloses a high-temperature and high-pressure steam oxidation online experimental system for a thermal power plant and a method for using the same. The entire experimental system includes a steam introduction module, an experimental module, and a steam recovery module;

[0042] See also Figure 1 The steam introduction module disclosed in the present invention comprises a three-way valve 16, a manual valve 18, an electric valve 19, an electromagnetic induction heating device 20, a steam pipeline 1 and a pipeline support and hanger;

[0043] One input end of the tee 16 is connected to the hot re-drain pipe 17, and the other input end is connected to the original pipeline of the power plant. One end of the tee 16 is connected to the hot re-input pipe, so that high-temperature and high-pressure steam can be drawn out from the pipeline, which is less dangerous and has little impact on the operation of the boiler unit. The output end of the tee 16 is connected to the steam pipeline 1. Specifically, the material and size of the hot re-input pipe 17 are selected according to the actual situation on site, and the material is generally T91 or 12Cr1MoV.

[0044] An inlet manual valve 18 and an inlet electric valve 19 are arranged upstream of the steam pipeline 1. More specifically, one end of the inlet manual valve 18 is connected to the output end of the steam pipeline 1, and the other end is connected to the inlet electric valve 19. One end of the inlet electric valve 19 is connected to the inlet manual valve 18, and the other end is connected to the steam pipeline 1. The inlet manual valve 18 and the tee 16, the inlet manual valve 18 and the inlet electric valve 19, and the inlet electric valve 19 and the steam pipeline 1 are all welded. The material and size of the valve are selected according to the actual situation on site, and the material is generally T91 or 12Cr1MoV.

[0045] The material of the steam pipeline 1 is welded to the electric valve 18, and the size is selected according to the actual situation on site. The material is generally T91 or 12Cr1MoV, and the size is generally 38*5.

[0046] The electromagnetic induction heating device 20 is arranged on the steam pipeline 1 and welded behind the manual and electric valves. It is used to adjust the temperature and pressure of the introduced steam and has signal input and output functions. The signal input and output ends are both connected to the computer and the test bench control system of the emergency protection system. Its specifications and models can be selected according to the actual situation on site.

[0047] The material and size of the pipeline support and hanger are selected according to the actual situation on site, and carbon steel is generally used as the material; it is located after the electric valve and connected to the steam pipeline 1 by suspension. More specifically, the steam pipeline 1 is installed on the pipeline support and hanger, and the pipeline support and hanger provides support for the steam pipeline 1, thereby reducing the weight borne by the steam pipeline 1.

[0048] The experimental module includes a laboratory table control system, a laboratory temperature control system, a laboratory real-time monitoring system, an experimental pipeline 6, an experimental pipeline support 10, an inlet thermometer 2, an inlet pressure gauge 3, an inlet flow meter 4, an inlet flow meter 5 and an emergency protection system; the entire experimental module is arranged inside the laboratory.

[0049] The laboratory should be fireproof, heat-insulated, waterproof, well-ventilated, equipped with emergency exits and first aid facilities and with an area of ​​no less than 12m 2 , the laboratory can be built inside or outside the building.

[0050] The experimental bench control system is used to monitor and control the temperature, pressure, flow rate, flow velocity and other parameters of the steam pipeline in real time, and can remotely control the electric valves of the steam introduction module and the steam recovery module, and is arranged in the laboratory.

[0051] The emergency protection system can remotely control the electric valve 19 of the steam introduction module and the electric valve of the steam recovery module;

[0052] The laboratory temperature control system includes a temperature measuring device and a temperature regulator, wherein the temperature measuring device is arranged in the laboratory and the temperature regulator is arranged on the laboratory wall;

[0053] The laboratory real-time monitoring system includes a monitor, a signal transmission device, a video receiver and memory, and a video display. The monitor is arranged on the wall inside the laboratory, and the video receiver and memory, and the video display can be remotely arranged in the power plant operation control room;

[0054] The inlet end of the experimental pipeline 6 is connected by welding to the outlet end of the steam pipeline 1 in the steam introduction module. The experimental pipelines are connected by welding. The material and size are selected according to the actual situation on site. The material is generally T91, TP347H, TP347HFG, Super304H, HR3C. The size is generally 30-50mm in outer diameter and 5-12mm in wall thickness. The experimental pipeline 6 is arranged in a circuitous manner from top to bottom along the horizontal direction, that is, the experimental pipeline 6 includes a straight section 6-1 and a curved section 6-2. Several straight sections 6-1 are parallel to each other, and each adjacent two straight sections 6-1 are connected by a curved section 6-2, so that the experimental pipeline 6 is in series between the steam pipeline 1 and the subsequent cooling device. The series connection can avoid the problem of uneven and unstable steam parameters in the shunt pipeline caused by the parallel connection of the headers, which may easily lead to unplanned shutdown of the experimental system.

[0055] See also Figure 2 Each straight line segment 6-1 is connected to the laboratory pipe support 10, so that the entire experimental pipe 6 can be supported by the laboratory pipe support 10. The experimental pipe support 10 adopts a clamp type to fix the straight line segment 6-1 of the experimental pipe 6. The material and size are selected according to the actual situation on site. The material is generally T91, TP347H, and Super304H.

[0056] See also Figure 2 An inlet thermometer 2, an inlet pressure gauge 3, an inlet flow meter 4 and an inlet flow meter 5 are arranged at the input end of the experimental pipeline 6, and an outlet thermometer 12, an outlet pressure gauge 13, an outlet flow meter 14 and an outlet flow meter 15 are arranged at the outlet end of the experimental pipeline 6.

[0057] The emergency protection system includes a signal acquisition unit and a signal output unit, both of which are arranged in a computer; the signal acquisition unit is mainly connected to the above-mentioned thermometer, flowmeter, flowmeter, and pressure gauge, and is used to input the collected temperature, flow rate, flow rate, and pressure of the steam outlet and inlet of the experimental pipeline 6 into the computer; the signal output unit is mainly connected to the electric valve, and is used to output control instructions to the electric valves at the inlet and outlet of the experimental device to control the switching of the electric valves.

[0058] The steam recovery module includes a steam cooling system and a recovery device, wherein the steam cooling system includes an outlet thermometer 12, an outlet pressure gauge 13, an outlet flow meter 14, an outlet flow meter 15, and a cooling device 7, and the recovery device includes an outlet electric valve 21, an outlet manual valve 22, and a reinforced pipe seat 11;

[0059] The outlet thermometer 12, outlet pressure gauge 13, outlet flow meter 14 and outlet flow meter 15 are all welded to the steam pipeline at the outlet of the experimental pipeline 6 at one time;

[0060] The steam cooling system includes a cooling water inlet pipeline 8, a cooling device 7, a cooling water outlet pipeline 9, a cooler bracket 11, a steam recovery input pipe 25 and a steam recovery output pipe 26; the cooler inlet pipeline 8, the cooler outlet pipeline 9 and the cooling device 7 are generally made of T91 or TP347H material, and the cooler bracket 11 is generally made of T91 material. Preferably, the cooling device 7 is composed of three groups of coolers 27 connected in series. A cooler 27 at one end is connected to the cooling water inlet pipeline 8 as the cooling water inlet end of the entire cooling device 7, and the cooler 27 at this end is also connected to the outlet end of the experimental pipeline 6 through the steam recovery inlet pipe 25, as the steam inlet end of the entire cooling device 7. The cooler 27 at the other end is connected to the cooling water outlet pipeline 9 as the cooling water drainage end of the entire cooling device 7, and the cooler 27 at this end is also connected to the heating pipeline 24 through the steam recovery output pipe 26. The cooling water inlet pipeline 8 and the cooling water outlet pipeline 9 are both connected to the closed cold water system.

[0061] See also Figure 3The steam recovery output pipe 26 is connected to the heating pipe 24 through the reinforced pipe seat 9, and an outlet electric valve 21 and an outlet manual valve 22 are arranged on the steam recovery output pipe 26. More specifically, the reinforced pipe seat 11 is welded to the industrial heating pipe 24, and the other end of the reinforced pipe seat 9 is welded to the outlet electric valve 21, and the outlet electric valve 21 is welded to the outlet manual valve 22. The other end of the outlet manual valve 22 is connected to the steam recovery output pipe 26. The material and size of the valve are selected according to the actual situation on site, and the material is generally 20G. By allowing the steam to enter the industrial gas supply pipeline through the experimental pipeline 6, the influence of steam extraction on the efficiency of the unit can be minimized. If it enters the power generation equipment, the steam needs to be heated secondary, which is costly, and the impurities in the steam are easy to have adverse effects on the turbine.

[0062] The above device is used during the operation of the thermal power unit. The specific oxidation test method is: according to the set interval time, at each time point, cutting sampling is carried out. Specifically, at each time point, the steam outlet stop valve is closed, and the pipe is cut to take samples. The length of the pipe sample to be cut must avoid the heat affected zone of the weld. The length of the pipe sample to be cut is tentatively set to 100mm each time. Then, a replacement pipe section is introduced to replace the cut sample for welding, and after the weld is tested to be qualified, the steam outlet stop valve is opened to continue the oxidation process.

[0063] Preferably, the time nodes are 25h, 49h, 100h, 224h, 500h, 1000h, 2500h, 5000h, and 10000h.

[0064] (1) During the operation of power plant units, the system is operated under the premise of ensuring safety;

[0065] (2) Turn on the real-time monitoring system in the laboratory and start the laboratory temperature control system to make the temperature in the laboratory at the set temperature value;

[0066] (3) After the unit is running stably, open the inlet manual valve 18 in the steam introduction module;

[0067] (4) After the personnel have safely evacuated, open the inlet electric valve 19 in the steam introduction module;

[0068] (5) Steam enters the experimental module through the steam introduction module, and observes whether the various instrument parameters such as temperature, pressure, flow rate, and flow velocity are normal. If there is any abnormality, immediately close the inlet electric valve 19 in the steam introduction module through the experimental bench control system, and then close the inlet manual valve 17 in the steam introduction module. If there is no abnormality, wait for 10 minutes to stabilize, and then open the manual valve of the steam recovery module;

[0069] (6) After the personnel have safely evacuated and there is no abnormality in the steam introduction module and the experimental module, open the outlet electric valve 21 of the steam recovery module;

[0070] (7) The experimental system enters the operating state, and the emergency protection system is turned on. When an abnormality occurs, the emergency protection system will be activated, and the electric valves of the steam introduction module and the steam recovery module will be immediately closed, and an alarm will be issued. After receiving the alarm, the on-duty personnel will immediately close the manual valves of the steam introduction module and the steam recovery module, and shut down the experimental system. The on-duty personnel must report the abnormal situation to the person in charge of the experimental system;

[0071] (8) When the experimental time reaches the designed time node, the experimental system is shut down;

[0072] (9) Close the electric valve of the steam outlet module through the test bench control system;

[0073] (10) Close the electric valve of the steam recovery module through the test bench control system;

[0074] (11) Close the manual valves of the steam outlet and recovery modules one after another.

[0075] All the samples finally taken out are sorted according to the time nodes, and all the samples are inlaid, ground and polished, and the cross-sectional microstructure and element distribution of the oxide layer of the sample section are analyzed using SEM (scanning electron microscope), EPMA (electron probe), XRD (X-Ray analysis), metallographic microscope and other equipment to analyze the material oxidation thermodynamic behavior and finally analyze the material's resistance to high temperature and high pressure oxidation corrosion.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A thermal power plant high temperature and high pressure steam oxidation online experimental system, characterized in that: It comprises a steam introduction module, an experimental module and a steam recovery module; the input end of the steam introduction module is connected to a hot re-drain pipe (17), and the output end is connected to the input end of the experimental module; the output end of the experimental module is connected to the input end of the steam recovery module, and the output end of the steam recovery module is connected to a heating pipeline (24); The experimental module comprises an experimental pipeline (6), the steam input end of the experimental pipeline (6) is connected to the steam introduction module, and the output end of the experimental pipeline (6) is connected to the steam recovery module; the experimental pipeline (6) comprises M straight segments (6-1) and N curved segments (6-2), the M straight segments (6-1) are parallel to each other, and every two adjacent straight segments (6-1) are connected through a curved segment (6-2), the curved segment (6-2) is an arc segment, and the straight segments (6-1) are connected in series; The inlet and outlet ends of the experimental pipeline (6) are both provided with a thermometer, a pressure gauge, a flow meter and a flow rate meter, and the thermometer, pressure gauge, flow meter and flow rate meter are all connected to the laboratory control system; The experimental control system is also connected to an inlet electric valve (19) and an outlet electric valve (21), wherein the inlet electric valve (19) is arranged in the steam introduction module, and the outlet electric valve (21) is arranged in the steam recovery module; The steam introduction module comprises a tee (16), one input end of the tee (16) is connected to a hot re-drain pipe (17), the output end of the tee (16) is connected to an inlet electric valve (19), the inlet electric valve (19) is connected to a steam pipeline (1), and the steam pipeline (1) is connected to an experimental pipeline (6).

2. The online experimental system for high temperature and high pressure steam oxidation in a thermal power plant according to claim 1, characterized in that: An inlet manual valve (18) is arranged between the three-way valve (16) and the inlet electric valve (19).

3. The online experimental system for high temperature and high pressure steam oxidation in a thermal power plant according to claim 1, characterized in that: The steam pipeline (1) is provided with an electromagnetic induction heating device (20).

4. The online experimental system for high temperature and high pressure steam oxidation in a thermal power plant according to claim 1, characterized in that: The experimental module is arranged in a laboratory, and a real-time monitoring system is arranged in the laboratory.

5. The online experimental system for high temperature and high pressure steam oxidation in a thermal power plant according to claim 1, characterized in that: The material of the experimental pipe (6) is T91, TP347H, TP347HFG, Super304H or HR3C. The outer diameter of the experimental pipe (6) is 30 to 50 mm, and the wall thickness is 5 to 12 mm.

6. The online experimental system for high temperature and high pressure steam oxidation in a thermal power plant according to claim 1, characterized in that: The inlet of the experimental pipeline (6) is provided with an inlet thermometer (2), an inlet pressure gauge (3), an inlet flow meter (4) and an inlet flow rate meter (5), and the outlet of the experimental pipeline (6) is provided with an outlet thermometer (12), an outlet pressure gauge (13), an outlet flow meter (14) and an outlet flow rate meter (15).

7. The online experimental system for high temperature and high pressure steam oxidation in a thermal power plant according to claim 1, characterized in that: The steam recovery module comprises a steam cooling system and a recovery device, wherein the steam cooling system comprises a cooling device (7); the cooling device (7) is composed of three coolers (27) connected in series, the cooling water inlet pipeline (8) of the cooling device (7) is connected to the closed cooling water system of the power plant, and the cooling water outlet pipeline (9) of the cooling device (7) is connected to the closed cooling water system of the power plant; the steam recovery input pipe (25) of the cooling device (7) is connected to the outlet end of the experimental pipeline (6), and the steam recovery output pipe (26) of the cooling device (7) is connected to the heating pipeline (24).

8. The on-line experimental system for high temperature and high pressure steam oxidation in a thermal power plant according to claim 7, characterized in that: The steam recovery output pipe (26) is connected to the heating pipe (24) via a reinforced pipe seat (11); an outlet electric valve (21) is arranged on the steam recovery output pipe (26); and an outlet manual valve (22) is arranged on the steam recovery output pipe (26) between the outlet electric valve (21) and the heating pipe (24).

9. An online experimental method for high temperature and high pressure steam oxidation in a power plant based on the experimental system of any one of claims 1 to 8, characterized in that: The specific process is: (1) opening the inlet electric valve (19) and the outlet electric valve (21), introducing steam into the experimental pipeline (6), and the steam enters the steam recovery module after passing through the experimental pipeline (6); after reaching a first set time, closing the inlet electric valve (19) and the outlet electric valve (21), and performing a sampling operation; the sampling operation is to cut a tube sample of a set length, and at the same time introduce a replacement tube sample to replace the cut tube sample, and the replacement tube sample and the experimental pipeline (6) are welded and connected; (2) After the sampling is completed, the inlet electric valve (19) and the outlet electric valve (21) are opened to continue to introduce steam, and step (1) is repeated until all the sampling times of the set time are completed; (3) After all samples are inlaid, ground and polished, the samples are characterized and analyzed to obtain the high temperature and high pressure oxidation corrosion resistance of the materials used in the experimental pipeline (6).

Images