An on-line evaluation device and method for the maintenance effect of a thermal power unit during shutdown

Abstract

The present invention discloses an on-line evaluation device and method for the maintenance effect of a thermal power generating unit during shutdown. The evaluation device is arranged at the inlet of the economizer or the outlet of the condensate pump. During the cold and hot flushing stages in the startup process of the thermal power generating unit, the evaluation device is connected to the inlet of the economizer; during the impulse stage, the evaluation device is connected to the outlet of the condensate pump. The evaluation device includes a flow stabilizing device, a flow-through cell, an image capture device, and an image analysis and processing unit. The evaluation method is as follows: the water sample passes through the sampling pipe at the inlet of the economizer or the sampling pipe at the outlet of the condensate pump, the sampling valve at the inlet of the economizer or the sampling valve at the outlet of the condensate pump, and enters the flow-through cell through the flow stabilizing device and the water inlet pipe; the sampling valve at the inlet of the economizer or the sampling valve at the outlet of the condensate pump and the water outlet valve are adjusted to control that the high liquid level in the flow-through cell does not overflow; after the liquid level in the flow-through cell is stable, the morphology of the particulate matter in the water is photographed by the image capture device and transmitted to the image analysis and processing unit through the data line for statistical analysis of the particle size and quantity of the particulate matter, so as to judge the maintenance effect of the unit during shutdown.

Description

Technical Field

[0001] The present invention relates to an on-line evaluation device and method for the maintenance effect of a thermal power generating unit during shutdown, belonging to the technical field of metal corrosion and protection. Background Technique

[0002] With the construction of new energy power stations and the requirements of carbon neutrality, most domestic thermal power generating units operate in a regulated manner according to the grid dispatching instructions, resulting in frequent starts and stops and an extended shutdown period. As a result, the corrosion during the shutdown of thermal power generating units has become the main form of corrosion of the thermal equipment of the units. There are many existing shutdown protection methods for the units. Due to the improper evaluation method of the shutdown protection effect of the units, it is impossible to correctly guide the units to select and improve the shutdown protection method according to the specific shutdown conditions, prevent the corrosion of the thermal equipment of the units during shutdown, and reduce the non-stop accidents caused by pipe bursts due to shutdown corrosion during the operation of the units. At present, the shutdown protection effect of the units is mainly evaluated by visually inspecting the internal surface corrosion of some thermal equipment pipelines after the unit is shut down, as well as the water consumption during the start-up process of the unit and the iron content in the water quality at a certain stage. However, due to factors such as the absolute control of the superior dispatching instructions during the start-up process of the unit, there are many influencing factors and large randomness in the above evaluation indicators, resulting in inaccurate effect evaluation. Summary of the Invention

[0003] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide an on-line evaluation device for the maintenance effect of a thermal power generating unit during shutdown, which is simple, easy to operate, and can realize real-time on-line evaluation. Another purpose of the present invention is to provide an on-line evaluation method for the maintenance effect of a thermal power generating unit during shutdown, which can evaluate the protection effect of the shutdown maintenance method adopted by the unit during shutdown in real time, online, quickly, and intuitively, and select and improve the shutdown maintenance method for the next shutdown of the unit according to the evaluation results.

[0004] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0005] An on-line evaluation device for the maintenance effect of a thermal power generating unit during shutdown, the evaluation device is arranged at the inlet of economizer a or the outlet of condensate pump b. During the cold and hot flushing stages of the start-up process of the thermal power generating unit, the evaluation device is connected to the inlet of economizer a; during the impulse stage, the evaluation device is connected to the outlet of condensate pump b;

[0006] The evaluation device includes a flow stabilizing device 1, a flow-through cell 2, an image capture device 8, and an image analysis processor 10;

[0007] The flow stabilizing device 1 is located on the inlet pipe 3 between the sampling valve k1 at the inlet of the economizer or the sampling valve k2 at the outlet of the condensate pump and the flow-through cell 2;

[0008] The flow cell 2 is provided with a water inlet pipe 3, a water outlet pipe 4, a water outlet valve 5, a sewage pipe 6 and a sewage valve 7;

[0009] The water inlet pipe 3 is located at the upper part of the narrower side of the flow cell 2; the water outlet pipe 4 is located at the lower part of the opposite side of the side where the water inlet pipe 3 is located; the sewage pipe 6 is located at the bottom of the flow cell 2;

[0010] The image capturer 8 is located at the center of the longer side of the flow cell 2 and is perpendicular to the water inlet pipe 3 and the water outlet pipe 4;

[0011] The image capturer 8 is connected to the image analysis processor 10 through a data line 9.

[0012] The upper part of the flow cell 2 is rectangular, and the ratio of length, width and height is 3:1:2. The particulate matters in water can be self-dispersed according to their mass under the action of their own gravity, which is convenient for the image capturer 8 to take pictures and the image analysis processor 10 to perform fractal counting processing according to the size of the particulate matters.

[0013] The bottom of the flow cell 2 is conical, which is convenient for collecting and discharging the internal sediments.

[0014] The image capturer 8 has macro and wide-angle functions and can capture the whole image of the longer side of the flow cell 2.

[0015] An on-line evaluation method for the maintenance effect of a thermal power generating unit. Using the described evaluation device, during the cold state and hot state flushing stages in the start-up process of the thermal power generating unit, the evaluation device is connected to the sampling pipe c at the inlet of the economizer and the sampling valve k1 at the inlet of the economizer; during the impulse stage, the evaluation device is connected to the sampling pipe d at the outlet of the condensate pump and the sampling valve k2 at the outlet of the condensate pump; the water sample passes through the sampling pipe c at the inlet of the economizer or the sampling pipe d at the outlet of the condensate pump, the sampling valve k1 at the inlet of the economizer or the sampling valve k2 at the outlet of the condensate pump, enters the flow cell 2 through the flow stabilizing device 1 and the water inlet pipe 3; the sampling valve k1 at the inlet of the economizer or the sampling valve k2 at the outlet of the condensate pump and the water outlet valve 5 are adjusted to control that the high liquid level in the flow cell 2 does not overflow; after the liquid level in the flow cell 2 is stable, the morphology of the particulate matters in the water is captured by the image capturer 8 and transmitted to the image analysis processor 10 through the data line 9 for statistical analysis of the particle size and quantity of the particulate matters; if the number of large particle size particulate matters is greater than the number of small particle size particulate matters, and the number of large particle size particulate matters is greater than 1000 pieces / L, and at the same time the flushing time is greater than 5h, it indicates that the maintenance effect of the unit during shutdown is not good; otherwise, it indicates that the maintenance effect of the unit during shutdown is better.

[0016] The image capturer 8 can capture particulate matters with all particle sizes above the micron level.

[0017] For the analysis of the particle size of the particulate matters by the image analysis processor 10, particulate matters with a particle size of 500μm and above are large particle size particulate matters, and those with a particle size of 500μm and below are small particle size particulate matters.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] The device is simple, easy to operate, and can be evaluated online. According to different stages during the unit startup process, such as cold flushing, hot flushing, turning, grid connection, etc., it can evaluate in real time and online the maintenance effect of the anti-corrosion of each section of thermal equipment during the shutdown period by the shutdown maintenance method adopted by the unit.

[0020] This method can evaluate in real time, online, quickly and intuitively different stages during the unit startup process, such as cold flushing, hot flushing, turning, grid connection, etc., evaluate in real time and online the maintenance effect of the anti-corrosion of each section of thermal equipment during the shutdown period by the shutdown maintenance method adopted by the unit, and select and improve the shutdown maintenance method for the next shutdown of the unit according to the evaluation results. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the device of the present invention.

[0022] In the figure: a economizer; b condensate pump; c sampling pipe at the inlet of the economizer; d sampling pipe at the outlet of the condensate pump; k1 sampling valve at the inlet of the economizer; k2 sampling valve at the outlet of the condensate pump; 1 flow stabilizer; 2 flow-through cell; 3 inlet pipe; 4 outlet pipe; 5 outlet valve; 6 drain pipe; 7 drain valve; 8 image capture device; 9 data line; 10 image analysis processor. DETAILED DESCRIPTION OF THE INVENTION

[0023] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0024] As Figure 1 shown, an on-line detection device for leakage of condensate polishing packing of the present invention, the evaluation device is arranged at the inlet of the economizer a and the outlet of the condensate pump b; during the cold and hot flushing stages of the startup process of the thermal power generating unit, the evaluation device is connected to the inlet of the economizer a; during the turning stage, the evaluation device is connected to the outlet of the condensate pump b;

[0025] The evaluation device includes a flow stabilizer 1, a flow-through cell 2, an image capture device 8 and an image analysis processor 10;

[0026] The flow stabilizer 1 is located on the inlet pipe 3 between the sampling valve k1 at the inlet of the economizer or the sampling valve k2 at the outlet of the condensate pump and the flow-through cell 2;

[0027] The flow-through cell 2 is provided with an inlet pipe 3, an outlet pipe 4 and an outlet valve 5, a drain pipe 6 and a drain valve 7;

[0028] The inlet pipe 3 is located at the upper part of the narrower side of the flow-through cell 2; the outlet pipe 4 is located at the lower part of the opposite side of the side where the inlet pipe 3 is located; the drain pipe 6 is located at the bottom of the flow-through cell 2;

[0029] The image capturer 8 is located at the center of the longer side of the flow cell 2 and is perpendicular to the water inlet pipe 3 and the water outlet pipe 4;

[0030] The image capturer 8 is connected to the image analysis processor 10 through a data line 9.

[0031] The features and further improvements of the present invention are as follows:

[0032] Further, the upper part of the flow cell 2 is rectangular, and the ratio of length, width and height is 3:1:2. The particulate matters in the water can be self-dispersed according to their mass under the action of their own gravity, which is convenient for the image capturer 8 to take pictures and the image analysis processor 10 to perform fractal counting processing according to the size of the particulate matters.

[0033] Further, the bottom of the flow cell 2 is conical, which is convenient for collecting and discharging the internal sediments.

[0034] Further, the image capturer 8 has macro and wide-angle functions and can capture the entire image of the longer side of the flow cell 2.

[0035] An on-line evaluation method for the shutdown maintenance effect of a thermal power generating unit uses the above evaluation device. During the cold and hot flushing stages in the startup process of the thermal power generating unit, the evaluation device is connected to the sampling pipe c at the inlet of the economizer and the sampling valve k1 at the inlet of the economizer; during the impulse stage, the evaluation device is connected to the sampling pipe d at the outlet of the condensate pump and the sampling valve k2 at the outlet of the condensate pump; the water sample passes through the sampling pipe c at the inlet of the economizer or the sampling pipe d at the outlet of the condensate pump, and the sampling valve k1 at the inlet of the economizer or the sampling valve k2 at the outlet of the condensate pump, and enters the flow cell 2 through the flow stabilizer 1 and the water inlet pipe 3; the sampling valve k1 at the inlet of the economizer or the sampling valve k2 at the outlet of the condensate pump and the water outlet valve 5 are adjusted to control the high liquid level of the flow cell 2 from overflowing; after the liquid level of the flow cell 2 is stable, the morphology of the particulate matters in the water is captured by the image capturer 8 and transmitted to the image analysis processor 10 through the data line 9 for statistical analysis of the particle size and quantity of the particulate matters; if the number of large-particle-size particulate matters is greater than the number of small-particle-size particulate matters, and the number of large-particle-size particulate matters is greater than 1000 per liter, and the flushing time is greater than 5 hours, it indicates that the shutdown maintenance effect of the unit is not good; otherwise, it indicates that the shutdown maintenance effect of the unit is better.

[0036] The features and further improvements of the present invention are as follows:

[0037] Further, the image capturer 8 can capture particulate matters with all particle sizes above the micron level.

[0038] Further, the image analysis processor 10 can perform analysis on the particle size and quantity of the particulate matters according to the shooting results of the image capturer 8.

[0039] Further, the image analysis processor 10 analyzes the particle size of the particulate matter. Particulate matter with a particle size of 500 μm or more is large-particle-size particulate matter, and particulate matter with a particle size of 500 μm or less is small-particle-size particulate matter.

Claims

1. An online evaluation method for an online evaluation device of the shutdown maintenance effect of a thermal power generating unit. The evaluation device is arranged at the inlet of the economizer (a) or the outlet of the condensate pump (b). During the cold and hot flushing stages in the startup process of the thermal power generating unit, the evaluation device is connected to the inlet of the economizer (a); during the turning - on stage, the evaluation device is connected to the outlet of the condensate pump (b). The evaluation device includes a flow - stabilizing device (1), a flow - through cell (2), an image capture device (8), and an image analysis and processing unit (10). The flow - stabilizing device (1) is located on the inlet pipe (3) between the sampling valve (k1) at the economizer inlet or the sampling valve (k2) at the condensate pump outlet and the flow - through cell (2). The flow - through cell (2) is provided with an inlet pipe (3), an outlet pipe (4), an outlet valve (5), a blow - down pipe (6), and a blow - down valve (7). The inlet pipe (3) is located at the upper part of the narrower side of the flow - through cell (2); the outlet pipe (4) is located at the lower part of the opposite side of the side where the inlet pipe (3) is located; the blow - down pipe (6) is located at the bottom of the flow - through cell (2). The image capture device (8) is located at the center of the longer side of the flow - through cell (2) and is perpendicular to the inlet pipe (3) and the outlet pipe (4). The image capture device (8) is connected to the image analysis and processing unit (10) through a data line (9). It is characterized in that: The online evaluation method is as follows: During the cold and hot flushing stages in the startup process of the thermal power generating unit, the evaluation device is connected to the sampling pipe (c) at the economizer inlet and the sampling valve (k1) at the economizer inlet; during the turning - on stage, the evaluation device is connected to the sampling pipe (d) at the condensate pump outlet and the sampling valve (k2) at the condensate pump outlet. The water sample passes through the sampling pipe (c) at the economizer inlet or the sampling pipe (d) at the condensate pump outlet, the sampling valve (k1) at the economizer inlet or the sampling valve (k2) at the condensate pump outlet, enters the flow - through cell (2) through the flow - stabilizing device (1) and the inlet pipe (3). Adjust the sampling valve (k1) at the economizer inlet or the sampling valve (k2) at the condensate pump outlet and the outlet valve (5) to control that the high liquid level in the flow - through cell (2) does not overflow. After the liquid level in the flow - through cell (2) is stable, the morphology of the particulate matter in the water is photographed by the image capture device (8) and transmitted to the image analysis and processing unit (10) through the data line (9) for statistical analysis of the particle size and quantity of the particulate matter. If the number of large - particle - size particulate matters is greater than the number of small - particle - size particulate matters, and the number of large - particle - size particulate matters is greater than 1000 pieces / L, and at the same time the flushing time is greater than 5 h, it indicates that the shutdown maintenance effect of the unit is not good; otherwise, it indicates that the shutdown maintenance effect of the unit is better.

2. The online evaluation method for an online evaluation device of the shutdown maintenance effect of a thermal power generating unit according to claim 1, It is characterized in that: The upper part of the flow - through cell (2) is rectangular, and the ratio of length, width, and height is 3:1:

2. The particulate matter in the water can be self - dispersed according to the mass size under its own gravity, which is convenient for the image capture device (8) to take pictures and the image analysis and processing unit (10) to perform fractal counting processing according to the particle size of the particulate matter.

3. The online evaluation method for an online evaluation device of the shutdown maintenance effect of a thermal power generating unit according to claim 1, It is characterized in that: The bottom of the flow cell (2) is conical, which is convenient for collecting and discharging internal sediments.

4. The online evaluation method of an online evaluation device for the shutdown maintenance effect of a thermal power generation unit according to claim 1, characterized in that: The image capturer (8) has macro and wide-angle functions and can capture the entire image of the longer side of the flow cell (2).

5. The online evaluation method of an online evaluation device for the shutdown maintenance effect of a thermal power generation unit according to claim 1, characterized in that: The image capturer (8) can capture particles with all particle sizes above the micron level.

6. The online evaluation method of an online evaluation device for the shutdown maintenance effect of a thermal power generation unit according to claim 1, characterized in that: The image analysis processor (10) analyzes the particle size of the particles. Particles with a particle size of 500 μm or more are large-particle-size particles, and particles with a particle size of 500 μm or less are small-particle-size particles.

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