A method and device for evaluating the anti-corrosion effect of shutdown protection of thermal power units

Abstract

The present invention provides a method and device for evaluating the anti-corrosion effect of shutdown protection of a thermal power unit. The method and device are simple to operate and easy to implement. The method can effectively grasp the anti-corrosion condition of the water vapor system pipeline of a huge coal-fired boiler in the shutdown protection state, and judge whether the currently used shutdown protection method of the coal-fired boiler is reliable and effective. A method for evaluating the anti-corrosion effect of shutdown protection of a thermal power unit comprises: measuring the cumulative flow rate at the outlet of a condensate pump during the startup phase of the unit; measuring the mass content of iron in the water vapor related to the heating surface of the boiler during the startup phase of the unit, and calculating the average iron content in the water vapor related to the heating surface of the corresponding boiler; calculating the total iron content of the unit startup phase by a preset total iron fitting formula according to the cumulative flow rate and the average iron content; using the total iron content as an evaluation index, evaluating the anti-corrosion effect of the shutdown protection before the current startup of the unit.

Description

Technical Field

[0001] The invention belongs to the technical field of boiler corrosion protection, and in particular relates to a method and a device for evaluating the anti-corrosion effect of shutdown protection of a thermal power unit. Background Art

[0002] In recent years, with the continuous commissioning of nuclear power, hydropower, wind power and photovoltaic power generation units, thermal power units have strictly controlled their operation time and are facing longer and longer shutdown states or more and more start-up and shutdown times. Therefore, the anti-corrosion requirements for the shutdown protection of coal-fired boilers in thermal power units are becoming more and more stringent, in order to prevent a large amount of corrosion from occurring during the shutdown period, to ensure that the coal-fired boilers of the units can be started safely and reliably at any time, and to maintain long-term normal, safe and stable operation, and to avoid accidents such as pipe bursts caused by shutdown corrosion during the operation of coal-fired boilers.

[0003] At present, there are many records of the anti-corrosion methods for the decommissioning protection of coal-fired boilers in thermal power units in relevant standards, but there is no evaluation method for the anti-corrosion effect of the decommissioning protection of coal-fired boilers, which makes it impossible to evaluate the anti-corrosion effect of the decommissioning protection of coal-fired boilers, and it is impossible to grasp the anti-corrosion situation of the huge coal-fired boiler water vapor system under the decommissioning protection state, and it is impossible to characterize whether the adopted decommissioning protection method of coal-fired boilers is reliable and effective, which lays a safety hazard for the corrosion of coal-fired boilers caused by improper decommissioning protection and even pipe burst in subsequent operation. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a method and device for evaluating the anti-corrosion effect of shutdown protection of a thermal power unit. The method and device are simple to operate and easy to implement. The method and device can effectively grasp the anti-corrosion situation in the water vapor system pipeline of a huge coal-fired boiler under the shutdown protection state, and judge whether the currently used shutdown protection method of the coal-fired boiler is reliable and effective.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for evaluating the anti-corrosion effect of shutdown protection of a thermal power unit, comprising:

[0007] Measure the cumulative flow rate at the condensate pump outlet during the unit startup phase;

[0008] Measure the mass content of iron in the water vapor related to the boiler heating surface during the unit startup phase, and calculate the average value of the iron content in the water vapor related to the corresponding boiler heating surface;

[0009] According to the cumulative flow and the average iron content, the total iron content of the unit startup stage is calculated by the preset total iron fitting formula;

[0010] Taking the total iron content as the evaluation index, the anti-corrosion effect of the shutdown protection before the unit's start-up was evaluated.

[0011] Preferably, the cumulative flow rate at the outlet of the condensate pump during the startup phase of the unit is measured, including:

[0012] Measure the first cumulative flow rate of the unit from the start of stable operation of the condensate pump to the end of hot flushing;

[0013] And measure the second cumulative flow of the unit from the start of turbine run-up to the grid connection of the steam turbine generator unit.

[0014] Preferably, the iron content in the water vapor related to the boiler heating surface during the startup phase of the unit is measured, including the iron content of condensate, the iron content of feed water, the iron content of boiler water or startup separator outlet water, and the iron content of superheated steam.

[0015] Preferably, the calculating the average value of the iron content in the water vapor related to the boiler heating surface includes, within a detection period, calculating the average value of the iron content based on the iron content in the water vapor related to the boiler heating surface.

[0016] Preferably, the preset total iron content fitting formula is:

[0017] M 总铁量 =V 热态冲洗结束时 ×c 凝结水铁含量平均值 +V 热态冲洗结束时 ×c 给水铁含量平均值 +V 热态冲洗结束时 ×c 炉水或启动分离器出水铁含量平均值 +V 汽轮机冲阶段至并网时 ×c 过热蒸汽铁含量平均值 ;

[0018] Among them, M 总铁量 is the total iron content during the unit startup phase, V 热态冲洗结束时 V is the first cumulative flow rate of the unit from the start of stable operation of the condensate pump to the end of hot flushing. 汽轮机冲转阶段至并网时 It is the second cumulative flow rate of the unit from the start of turbine run-up to the grid connection of the turbine generator set.

[0019] c 凝结水铁含量平均值 is the average iron content of condensate, c 给水铁含量平均值 is the average iron content of feed water, c 炉水或启动分离器出水铁含量平均值 is the average iron content of boiler water or start-up separator outlet water, c 过热蒸汽铁含量平均值 It is the average value of superheated steam iron content.

[0020] Preferably, the method further comprises the steps of adding ammonia to condensate water and feed water during the startup phase.

[0021] An evaluation device for the anti-corrosion effect of shutdown protection of a thermal power unit, comprising:

[0022] The cumulative flow measurement module is used to measure the cumulative flow at the outlet of the condensate pump during the unit startup phase;

[0023] The iron content measurement module is used to measure the iron mass content in the water vapor related to the boiler heating surface during the unit startup phase;

[0024] A calculation unit, used for calculating the average value of the iron content in the water vapor related to the corresponding boiler heating surface;

[0025] A total iron content calculation module is used to calculate the total iron content of the unit during the startup phase according to the cumulative flow and the average iron content using a preset total iron content fitting formula;

[0026] The evaluation module is used to evaluate the anti-corrosion effect of the shutdown protection before the unit is started up, taking the total iron content as an evaluation index.

[0027] Preferably, the cumulative flow measurement module comprises:

[0028] The first stage measurement module is used to measure the first cumulative flow rate of the unit from the start of stable operation of the condensate pump to the end of hot flushing;

[0029] The second stage measurement module is used to measure the second cumulative flow of the unit from the start of turbine run-up to the grid connection of the steam turbine generator set.

[0030] Preferably, the iron content measurement module comprises:

[0031] The first measuring module is used to measure the iron content of condensate;

[0032] The second measuring module is used to measure the iron content of the feed water;

[0033] The third measuring module is used to measure the iron content of boiler water or water discharged from the start-up separator;

[0034] The fourth measuring module is used to measure the iron content of superheated steam.

[0035] Preferably, it also includes condensate water ammonia adding equipment and feed water ammonia adding equipment.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The present invention provides an evaluation method and device for the anti-corrosion effect of shutdown protection of a thermal power unit. Any shutdown protection method can be selected to protect the unit for a period of time, and then the unit can be started to evaluate the anti-corrosion protection effect thereof. The invention has a wide range of applications. The cumulative flow rate at each startup stage and the iron content of each water vapor system of the main heating surface of the coal-fired boiler are measured and the corresponding total iron content in the system is obtained by fitting calculation. The shutdown protection and anti-corrosion conditions of each water vapor system of the coal-fired boiler are very effectively characterized. The data has high accuracy, and the results are intuitive and clear. The device has a simple structure and is easy to operate. The total iron content can be used to effectively grasp the anti-corrosion conditions in the huge water vapor system pipeline of the coal-fired boiler under the shutdown protection state, and it can be judged whether the shutdown protection method of the coal-fired boiler currently used is reliable and effective, thereby avoiding the safety hazards caused by the shutdown corrosion of the coal-fired boiler.

[0038] The present invention can ensure that the pH value of the feed water is controlled within an appropriate range, that is, the conductivity is controlled within an optimal range, by adding ammonia to the condensate and the feed water at any time during the startup phase, and no fine treatment equipment is put into operation during the startup process of the unit. The provisions on the water vapor control and fine treatment equipment for the addition of drugs during the startup process can unify and standardize the prerequisites, and facilitate horizontal comparison of each coal-fired boiler shutdown protection method and the anti-corrosion effect of each coal-fired boiler shutdown protection. The change of the anti-corrosion effect of the same protection method with the shutdown time can be observed by comparison, and the endurance of its protection can be judged; the protection effects of different protection methods within the same shutdown time can also be compared, so as to select a better protection scheme, and the protection method can be further optimized, which has strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a process flow chart of the evaluation device of the present invention;

[0040] Figure 2 is a flow chart of the evaluation method of the present invention;

[0041] Figure 3 It is a flow chart of the implementation of the evaluation method of the embodiment of the present invention.

[0042] In the figure, a selection module 100, a cumulative flow measurement module 110, a first stage measurement module 111, a second stage measurement module 112, an iron content measurement module 120, a first measurement module 121, a second measurement module 122, a third measurement module 123, a fourth measurement module 124, a total iron content calculation module 130, and an evaluation module 140 are included. DETAILED DESCRIPTION

[0043] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0044] According to the detection data analysis and experimental research results of water vapor quality during the cold start-up process of thermal power units, the present invention proposes an evaluation method and device for the anti-corrosion effect of shutdown protection of thermal power units. The monitoring and control method is: the total iron content in the water vapor discharged from each heating surface of the coal-fired boiler of the thermal power unit during the startup stage is used to characterize the anti-corrosion effect of the shutdown protection of the coal-fired boiler. The lower the total iron content, the better the anti-corrosion effect of the shutdown protection of the coal-fired boiler.

[0045] Specifically, Figure 2 As shown, a method for evaluating the anti-corrosion effect of shutdown protection of a thermal power unit comprises:

[0046] Before evaluation, select any shutdown protection method to protect the unit for a preset shutdown time;

[0047] Measure the cumulative flow rate at the condensate pump outlet during the unit startup phase;

[0048] Measure the mass content of iron in the water vapor related to the boiler heating surface during the unit startup phase, and calculate the average value of the iron content in the water vapor related to the boiler heating surface;

[0049] According to the cumulative flow and the average iron content, the total iron content of the unit startup stage is calculated by the preset total iron fitting formula;

[0050] The total iron content is used as an evaluation index to evaluate the anti-corrosion effect of the shutdown protection before the unit is started. The higher the total iron content, the worse the anti-corrosion effect of the shutdown protection method.

[0051] The present invention provides an evaluation method and device for the anti-corrosion effect of shutdown protection of a thermal power unit. Any shutdown protection method can be selected to protect the unit for a period of time, and then the unit can be started to evaluate the anti-corrosion protection effect thereof. The invention has a wide range of applications. The cumulative flow rate at each startup stage and the iron content of each water vapor system of the main heating surface of the coal-fired boiler are measured and the corresponding total iron content in the system is obtained by fitting calculation. The shutdown protection and anti-corrosion conditions of each water vapor system of the coal-fired boiler are very effectively characterized. The data has high accuracy, and the results are intuitive and clear. The device has a simple structure and is easy to operate. The total iron content can be used to effectively grasp the anti-corrosion conditions in the huge water vapor system pipeline of the coal-fired boiler under the shutdown protection state, and it can be judged whether the shutdown protection method of the coal-fired boiler currently used is reliable and effective, thereby avoiding the safety hazards caused by the shutdown corrosion of the coal-fired boiler.

[0052] like Figure 3 As shown, further, the cumulative flow rate of the condensate pump outlet during the unit startup phase is measured, including:

[0053] Measure the first cumulative flow rate of the unit from the start of stable operation of the condensate pump to the end of hot flushing;

[0054] Measure the second cumulative flow of the unit from the start of turbine run-up to the grid connection of the turbine generator unit.

[0055] Specifically, the end of hot flushing is the same time as the start of turbine run-up.

[0056] Furthermore, the iron content in the steam associated with the boiler heating surface during the unit startup phase is measured, including:

[0057] Iron content in condensate, iron content in feed water, iron content in boiler water or start-up separator outlet water and iron content in superheated steam.

[0058] Furthermore, the average iron content in the water vapor related to the boiler heating surface during the unit startup phase is measured, including calculating the arithmetic mean of the iron content based on the iron content in the water vapor related to the boiler heating surface during the detection period.

[0059] In a preferred embodiment, the detection period may be 1 hour, 2 hours or 3 hours, and the detection period is determined according to actual conditions.

[0060] Specifically, it includes the average iron content in condensate, the average iron content in feed water, the average iron content in boiler water or start-up separator outlet water, and the average iron content in superheated steam.

[0061] Furthermore, the preset total iron content fitting formula is as follows:

[0062] M 总铁量 =V 热态冲洗结束时 ×c 凝结水铁含量平均值 +V 热态冲洗结束时 ×c 给水铁含量平均值 +V 热态冲洗结束时 ×c 炉水或启动分离器出水铁含量平均值 +V 汽轮机冲转阶段至并网时 ×c 过热蒸汽铁含量平均值 ;

[0063] Among them, M 总铁量 is the total iron content during the unit startup phase, V 热态冲洗结束时 V is the first cumulative flow rate of the unit from the start of stable operation of the condensate pump to the end of hot flushing. 汽轮机冲转阶段至并网时 It is the second cumulative flow rate of the unit from the start of turbine run-up to the grid connection of the turbine generator set.

[0064] c 凝结水铁含量平均值 is the average iron content of condensate, c 给水铁含量平均值 is the average iron content of feed water, c 炉水或启动分离器出水铁含量平均值 is the average iron content of boiler water or start-up separator outlet water, c 过热蒸汽铁含量平均值 It is the average value of superheated steam iron content.

[0065] Furthermore, the method also includes the steps of adding ammonia to condensate water and feed water during the startup phase.

[0066] The present invention can ensure that the pH value of the feed water is controlled within 9.5±0.1, that is, the conductivity is controlled within the range of 6.8μS / cm to 10.8μS / cm, by adding ammonia to the condensate and the feed water at any time during the startup phase, and no fine treatment equipment is put into operation during the startup process of the unit. The provisions on the water vapor control and fine treatment equipment for the addition of drugs during the startup process can unify and standardize the prerequisite conditions, facilitate horizontal comparison of each coal-fired boiler shutdown protection method and the anti-corrosion effect of each coal-fired boiler shutdown protection, and compare and observe the changes in the anti-corrosion effect of the same protection method with the shutdown time, so as to judge the endurance of its protection; the protection effects of different protection methods within the same shutdown time can also be compared, so as to select a better protection scheme, and the protection method can be further optimized, which is highly practical.

[0067] like Figure 1 As shown, a device for evaluating the anti-corrosion effect of shutdown protection of a thermal power unit comprises:

[0068] A selection module 100 is used to select any shutdown protection method to protect the unit for a preset shutdown time before evaluation;

[0069] The cumulative flow measurement module 110 is used to measure the cumulative flow at the outlet of the condensate pump during the unit startup phase;

[0070] The iron content measurement module 120 is used to measure the mass content of iron in the water vapor related to the boiler heating surface during the unit startup phase;

[0071] A calculation unit, used for calculating the average value of the iron content in the water vapor related to the corresponding boiler heating surface;

[0072] A total iron content calculation module 130 is used to calculate the total iron content of the unit during the startup phase according to the cumulative flow and the average iron content using a preset total iron content fitting formula;

[0073] The evaluation module 140 is used to evaluate the anti-corrosion effect of the shutdown protection before the unit is started up, using the total iron content as an evaluation index.

[0074] Furthermore, the cumulative flow measurement module 110 includes:

[0075] The first stage measurement module 111 is used to measure the first cumulative flow rate of the unit from the start of stable operation of the condensate pump to the end of hot flushing;

[0076] The second stage measurement module 112 is used to measure the second cumulative flow of the unit from the start of the steam turbine to the grid connection of the steam turbine generator set.

[0077] Furthermore, the iron content measurement module 120 includes:

[0078] The first measuring module 121 is used to measure the iron content of condensate;

[0079] The second measuring module 122 is used to measure the iron content of the feed water;

[0080] The third measuring module 123 is used to measure the iron content of the boiler water or the water discharged from the start-up separator;

[0081] The fourth measuring module 124 is used to measure the iron content of the superheated steam.

[0082] Furthermore, the calculation unit is also used to calculate the arithmetic mean of the iron content according to the iron content in the water vapor related to the boiler heating surface within the detection period.

[0083] Furthermore, it also includes condensate ammonia adding equipment and feed water ammonia adding equipment in operation.

[0084] The present invention specifically quantifies the evaluation of the anti-corrosion effect of the shutdown protection of the coal-fired boiler of a thermal power unit. The specific data of the total iron content finally obtained can be used to compare the anti-corrosion effects of the shutdown protection of the unit in all previous times. It can also be used to compare the anti-corrosion effects under different shutdown protection methods, and it can also be used to compare the anti-corrosion effects of shutdown protection under similar units. This is an evaluation method that can perform direct data comparison. In addition, the present invention has clearer and more specific requirements and monitoring for the supervision of water vapor quality during the startup process of the unit, which can be based on rules and regulations.

[0085] Embodiment 1:

[0086] In this embodiment 1, a certain ultra-supercritical 660MW direct current furnace is selected for shutdown protection. The shutdown protection method of the coal-fired boiler adopts the method of increasing the pH value of the feed water for protection. During a certain startup process, the evaluation method and device of the present invention are used to evaluate the anti-corrosion effect of the shutdown protection of the coal-fired boiler under different shutdown protection times, as follows:

[0087] During the startup process, the high-speed mixed bed for fine treatment of the unit is not put into operation, and the condensate ammonia adding equipment and the feed water ammonia adding equipment are put into operation to control the pH value of the feed water to be maintained between 9.5±0.1 and the conductivity to be controlled between 7.0μS / cm and 10.0μS / cm;

[0088] During the entire startup phase from cold weather flushing to unit grid connection, samples are taken every 2 hours and at important nodes such as ignition, flushing, and grid connection to test indicators such as iron content in each water vapor sample;

[0089] The cumulative flow rate of condensate is read and recorded according to the cumulative flow meter installed at the outlet of the condensate pump until the unit is connected to the grid.

[0090] During the first restart of the unit after 170 days of shutdown protection, the measurement results obtained by the evaluation method according to the present invention are as follows:

[0091] At the end of hot flushing, the cumulative flow rate at the outlet of the condensate pump is 9014t;

[0092] The average iron content of condensate water was 111.8 μg / L;

[0093] The average iron content of the feed water was 82 μg / L;

[0094] The average iron content of the effluent from the start-up separator was 102.1 μg / L;

[0095] From the turbine run-up stage to grid connection, the cumulative flow rate at the condensate pump outlet is 3765t;

[0096] The average iron content of superheated steam is 30.3 μg / L;

[0097] The total iron content calculated according to the fitting formula provided by the present invention is 2781.3 kg.

[0098] During the second restart of the unit after 8 days of shutdown protection, the measurement results obtained by the evaluation method according to the present invention are as follows:

[0099] At the end of hot flushing, the cumulative flow rate at the outlet of the condensate pump is 7514t;

[0100] The average iron content of condensate is 24 μg / L;

[0101] The average iron content of the feed water was 9.5 μg / L;

[0102] The average iron content of the effluent from the start-up separator was 12.5 μg / L;

[0103] From the turbine run-up stage to grid connection, the cumulative flow rate at the condensate pump outlet is 5327t;

[0104] The average iron content of superheated steam is 5.5 μg / L;

[0105] The total iron content calculated according to the fitting formula provided by the present invention is 375.0 kg.

[0106] According to the evaluation results, it can be observed that the corrosion amount of the unit during a long shutdown time is obviously much higher than that during a short shutdown time, which shows that the method of the present invention can more intuitively understand the anti-corrosion effect of the shutdown protection, and can also improve the shutdown protection method accordingly.

[0107] Embodiment 2:

[0108] In a certain ultra-supercritical 660MW DC furnace in my country, the coal-fired boiler was protected by nitrogen filling and increasing the pH value of feed water during the two shutdowns. During the startup process after the two shutdowns, this method was used to evaluate the anti-corrosion effect of the shutdown protection of the coal-fired boiler: during the startup process, the high-speed mixed bed for fine treatment of the unit was not put into operation, and the condensate ammonia adding equipment and the feed water ammonia adding equipment were put into operation to ensure that the pH of the feed water was controlled between 9.5±0.1 and the conductivity was controlled between 7.0μS / cm and 10.0μS / cm; from the cold weather flushing to the unit grid connection, the iron content and other indicators in each water vapor sample were sampled and tested every 2 hours and at important nodes of ignition, flushing, and grid connection, and the cumulative flow of condensate was recorded at the same time until the unit was connected to the grid.

[0109] The nitrogen filling protection method is adopted: the unit is started up about 179 days after the shutdown protection: at the end of hot flushing, the cumulative flow rate of the condensate pump outlet is 8173t, the average iron content of condensate is 86.9μg / L, the average iron content of feed water is 71.3μg / L, and the average iron content of the start-up separator outlet is 80.9μg / L; from the turbine run-up stage to the grid connection, the cumulative flow rate of the condensate pump outlet is 3019t, and the average iron content of superheated steam is 26.1μg / L. According to the fitting formula proposed in this method, the total iron content is 2033.0kg.

[0110] The protection method of increasing the pH value of feed water is adopted: the unit is started up after 170 days of shutdown protection: at the end of hot flushing, the cumulative flow rate of the condensate pump outlet is 9014t, the average iron content of condensate is 111.8μg / L, the average iron content of feed water is 82μg / L, and the average iron content of the start-up separator outlet is 102.1μg / L; from the turbine run-up stage to the grid connection, the cumulative flow rate of the condensate pump outlet is 3765t, and the average iron content of superheated steam is 30.3μg / L. According to the fitting formula proposed in this method, the total iron content is 2781.3kg.

[0111] According to the evaluation results, it can be observed that, obviously, the corrosion amount of the same unit using the nitrogen filling shutdown protection method within the same shutdown time is less than the corrosion amount of the shutdown protection method using the increased pH value of the feed water, indicating that the nitrogen filling shutdown protection method has a better anti-corrosion effect on shutdown protection. The method of the present invention can also be used to compare the anti-corrosion effects under different shutdown protection methods, so as to select a better shutdown protection method.

[0112] The above description is only a specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for evaluating the anti-corrosion effect of shutdown protection of thermal power units, characterized in that: include: Measure the cumulative flow rate at the condensate pump outlet during the unit startup phase; Measure the mass content of iron in the water vapor related to the boiler heating surface during the unit startup phase, and calculate the average value of the iron content in the water vapor related to the corresponding boiler heating surface; According to the cumulative flow and the average iron content, the total iron content of the unit startup stage is calculated by the preset total iron fitting formula; Taking the total iron content as the evaluation index, the anti-corrosion effect of the shutdown protection before the unit was started was evaluated; The cumulative flow rate at the outlet of the condensate pump during the startup phase of the unit is measured, including: Measure the first cumulative flow rate of the unit from the start of stable operation of the condensate pump to the end of hot flushing; And measure the second cumulative flow of the unit from the start of turbine run-up to the grid connection of the steam turbine generator set; The preset total iron content fitting formula is: ； Among them, M 总铁量 is the total iron content during the unit startup phase, V 热态冲洗结束时 V is the first cumulative flow rate of the unit from the start of stable operation of the condensate pump to the end of hot flushing. 汽轮机冲转阶段至并网时 It is the second cumulative flow rate of the unit from the start of turbine run-up to the grid connection of the turbine generator set. c 凝结水铁含量平均值 is the average iron content of condensate, c 给水铁含量平均值 is the average iron content of feed water, c 炉水或启动分离器出水铁含量平均值 is the average iron content of boiler water or start-up separator outlet water, c 过热蒸汽铁含量平均值 It is the average value of iron content in superheated steam.

2. The method for evaluating the anti-corrosion effect of shutdown protection of a thermal power unit according to claim 1, characterized in that: The iron content in the water vapor related to the boiler heating surface during the startup phase of the unit is measured, including the iron content of condensate, the iron content of feed water, the iron content of boiler water or startup separator outlet water, and the iron content of superheated steam.

3. The method for evaluating the anti-corrosion effect of shutdown protection of a thermal power unit according to claim 1, characterized in that: The calculating the average value of the iron content in the water vapor related to the boiler heating surface includes, within a detection period, calculating the average value of the iron content based on the iron content in the water vapor related to the boiler heating surface.

4. The method for evaluating the anti-corrosion effect of shutdown protection of a thermal power unit according to claim 1, characterized in that: The method also includes the steps of adding ammonia to condensate and feed water during the startup phase.

5. An evaluation device for the anti-corrosion effect of shutdown protection of thermal power units, characterized in that: The evaluation method according to any one of claims 1 to 4 above comprises: The cumulative flow measurement module (110) is used to measure the cumulative flow at the outlet of the condensate pump during the unit startup phase; An iron content measurement module (120) is used to measure the mass content of iron in water vapor associated with the boiler heating surface during the unit startup phase; A calculation unit, used for calculating the average value of the iron content in the water vapor related to the corresponding boiler heating surface; A total iron content calculation module (130) is used to calculate the total iron content of the unit during the startup phase according to the cumulative flow rate and the average iron content using a preset total iron content fitting formula; An evaluation module (140) is used to evaluate the anti-corrosion effect of the shutdown protection before the unit is started up using the total iron content as an evaluation index; The cumulative flow measurement module (110) comprises: A first stage measurement module (111) is used to measure the first cumulative flow rate of the unit from the start of stable operation of the condensate pump to the end of hot flushing; The second stage measurement module (112) is used to measure the second cumulative flow of the unit from the start of the steam turbine run to the grid connection of the steam turbine generator set; The preset total iron content fitting formula is: ； Among them, M 总铁量 is the total iron content during the unit startup phase, V 热态冲洗结束时 V is the first cumulative flow rate of the unit from the start of stable operation of the condensate pump to the end of hot flushing. 汽轮机冲转阶段至并网时 It is the second cumulative flow rate of the unit from the start of turbine run-up to the grid connection of the turbine generator set. c 凝结水铁含量平均值 is the average iron content of condensate, c 给水铁含量平均值 is the average iron content of feed water, c 炉水或启动分离器出水铁含量平均值 is the average iron content of boiler water or start-up separator outlet water, c 过热蒸汽铁含量平均值 It is the average value of iron content in superheated steam.

6. The device for evaluating the anti-corrosion effect of shutdown protection of a thermal power unit according to claim 5, characterized in that: The iron content measurement module (120) comprises: A first measuring module (121), used for measuring the iron content of condensate; A second measuring module (122), used for measuring the iron content of feed water; A third measuring module (123) is used to measure the iron content of boiler water or water discharged from a startup separator; The fourth measuring module (124) is used to measure the iron content of the superheated steam.

7. The device for evaluating the anti-corrosion effect of shutdown protection of a thermal power unit according to claim 5, characterized in that: It also includes condensate ammonia adding equipment and feed water ammonia adding equipment.

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