High-efficiency leakage detection system for low-low-temperature economizer

Abstract

The invention provides an efficient detection system for leakage of a low-low-temperature economizer, and relates to the technical field of economizer leakage early warning, and the system comprises a region division module which is used for dividing into monitoring regions, and each monitoring region is internally provided with an ultrasonic sensor, a humidity sensor and a pressure sensor; the ultrasonic detection module is used for acquiring an ultrasonic signal and generating an ultrasonic evaluation result; the humidity detection module is used for acquiring a humidity value of the flue gas and generating a humidity evaluation result; the pressure detection module is used for detecting the pressure value of the pipeline and generating a pressure evaluation result; the comprehensive evaluation module is used for generating a comprehensive evaluation result based on the ultrasonic evaluation result, the humidity evaluation result and the pressure evaluation result; and the automatic response module is used for automatically executing a response scheme according to the comprehensive evaluation result. The accuracy of the system is improved through multi-source data fusion, and when a monitoring system detects leakage, alarm is triggered automatically, so that loss caused by leakage is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of economizer leakage early warning, and in particular to a low-temperature economizer leakage high-efficiency detection system. Background Art

[0002] Thermal power plants consume 50% of my country's total coal production, and their exhaust heat loss is the largest of all heat losses in power plant boilers, generally 5% to 8%. The exhaust temperature of boilers in my country's current thermal power units is generally maintained at around 125 to 150°C. High exhaust temperature increases the flue gas volume, reduces the dust collection area of ​​the electrostatic precipitator, increases the dust specific resistance, and reduces the efficiency of the electrostatic precipitator; for wet desulfurization systems, high exhaust temperature will lead to increased water consumption in the desulfurization system. Therefore, it is necessary to reduce the flue gas temperature before the electrostatic precipitator, improve the dust removal efficiency, reduce the water consumption of the desulfurization system, and reduce the coal consumption of the unit.

[0003] Low-temperature economizer is the main technology for utilizing flue gas waste heat at present. It installs a low-temperature economizer in the tail flue between the air preheater and the electrostatic precipitator of the power station boiler to reduce the flue gas temperature to about 90°C, which can reduce the flue gas temperature, improve the dust removal efficiency, reduce the water consumption of the desulfurization system, and reduce the coal consumption for power generation by 1.5 to 2.5g / kWh.

[0004] If the low-temperature economizer leaks but the fault is not corrected in time, water vapor will enter the dust collector, causing the dust removal device of the dust collector to be blocked; the leakage will cause the heating surface to be blocked and hardened, greatly increasing the difficulty of cleaning and the workload of maintenance; at the same time, it will also cause the flue gas temperature at the low-temperature economizer outlet to rise, the efficiency of the electrostatic precipitator to decrease, and the risk of excessive dust at the total exhaust port to increase. Summary of the invention

[0005] The present invention provides a low-temperature economizer leakage efficient detection system, which is used to solve the defect in the prior art that if the low-temperature economizer leakage is not promptly eliminated, the overall operation of the unit will be affected.

[0006] In one aspect, the present invention provides a low-temperature economizer leakage efficient detection system, comprising:

[0007] The area division module is used to divide the working area of ​​the low-temperature economizer into several monitoring areas, an ultrasonic sensor is arranged in each monitoring area, and a humidity sensor and a pressure sensor are arranged at the junction of the monitoring areas;

[0008] Ultrasonic detection module, used to obtain ultrasonic signals from the low-temperature economizer working area and generate ultrasonic evaluation results;

[0009] The humidity detection module is used to obtain the humidity value of the flue gas inside the low-temperature economizer and generate a humidity evaluation result;

[0010] The pressure detection module is used to obtain the pressure value of the internal pipeline of the low-temperature economizer and generate the pressure evaluation result;

[0011] A comprehensive evaluation module, used for generating a comprehensive evaluation result based on an ultrasonic evaluation result, a humidity evaluation result and a pressure evaluation result;

[0012] The automatic response module is used to automatically execute the response plan based on the comprehensive evaluation results.

[0013] Preferably, the ultrasonic evaluation result includes the area to which the leak point belongs and the size of the leak point, and the ultrasonic detection module includes:

[0014] An acoustic wave conversion unit, used for performing Fourier transformation on the ultrasonic signal to obtain ultrasonic frequency characteristics;

[0015] A noise frequency acquisition unit, used to periodically acquire the frequency characteristics of the environmental noise corresponding to each ultrasonic sensor;

[0016] A feature processing unit, used to remove noise from the ultrasonic frequency feature based on the frequency feature of the ambient noise to obtain a judgment frequency feature;

[0017] The feature matching unit is used to match the judged frequency feature with the frequency feature-leakage situation comparison table to obtain the monitoring point position, leakage point distance and leakage point size, determine the leakage point position based on the monitoring point position and leakage point distance, and combine the leakage point position and leakage point size to generate an ultrasonic evaluation result.

[0018] Preferably, the noise frequency acquisition unit includes:

[0019] The acoustic wave signal acquisition subunit acquires the environmental acoustic wave signal under the condition that no leakage exists after manual inspection;

[0020] The signal conversion subunit is used to perform Fourier transformation on the ambient sound wave signal to obtain the frequency characteristics of the ambient noise.

[0021] Preferably, the humidity assessment result includes the number of the monitoring area where the leakage exists, and the humidity detection module includes:

[0022] A humidity evaluation value calculation unit, used for calculating a humidity detection evaluation value;

[0023] Among them, P i is the humidity detection evaluation value of the i-th monitoring area; S i2 is the actual detection value of the humidity sensor at the end point of the i-th monitoring area; S i1 is the actual detection value of the humidity sensor at the starting point of the i-th monitoring area; S zis the actual detection value of the humidity sensor at the outlet of the low-temperature economizer; S1 is the actual detection value of the humidity sensor at the inlet of the low-temperature economizer; N is the total number of monitoring areas;

[0024] The humidity assessment result output unit is used to output the humidity assessment result according to the humidity detection assessment value. When the humidity detection assessment value of the monitoring area of ​​the humidity sensor in the i-th monitoring area is greater than the preset first judgment threshold, it is output that there is a leak in the i-th monitoring area.

[0025] Preferably, the pressure assessment result includes the number of the monitoring area where the leakage exists, and the pressure detection module includes:

[0026] A historical data recording unit, used to record the historical pressure sensor detection values ​​of each monitoring area;

[0027] A historical data sampling unit, used for randomly selecting a number of groups of historical pressure sensor detection values ​​of the monitoring area from the historical pressure sensor detection values ​​of the monitoring area as comparison data groups;

[0028] A pressure evaluation value calculation unit, used to calculate a pressure detection evaluation value;

[0029] Among them, E i is the pressure detection evaluation value of the ith monitoring area; α and β are the importance weighting coefficients of historical data and actual pressure difference, respectively; R i1 is the detection value of the pressure sensor at the outlet of the i-th monitoring area; R1 is the detection value of the pressure sensor at the inlet of the low-temperature economizer; M is the total number of comparison data groups; R ik is the detection value of the pressure sensor at the outlet of the ith monitoring area in the kth comparison data group; R 1k is the detection value of the pressure sensor at the inlet of the low-temperature economizer in the kth group of comparison data; R i2 is the detection value of the pressure sensor at the inlet of the i-th monitoring area; R0 is the preset maximum allowable pressure difference between adjacent monitoring points; || is the absolute value symbol;

[0030] The pressure assessment result output unit is used to output the pressure assessment result according to the pressure detection assessment value. When the pressure detection assessment value of the i-th monitoring area is greater than a preset second judgment threshold, it is output that there is a leak in the i-th monitoring area.

[0031] Preferably, the comprehensive assessment module includes:

[0032] A hidden danger area determination unit, used for determining all monitoring areas with leakage in the humidity assessment results, the pressure assessment results and the ultrasonic assessment results as hidden danger areas;

[0033] A hidden danger assessment parameter calculation unit, used to calculate hidden danger assessment parameters for each hidden danger area;

[0034] Among them, P j is the hidden danger assessment parameter of the jth hidden danger area; U j is the average leakage severity level of the jth potential hazard area; D j is the size of the leakage point in the ultrasonic assessment result of the jth potential hazard area; D0 is the classification basis of the leakage point diameter; v is the flue gas flow rate inside the low-temperature economizer; S j2 is the actual detection value of the humidity sensor at the end point of the jth hidden danger area; S j1 is the actual detection value of the humidity sensor at the starting point of the jth hidden danger area; C d is the flow coefficient; R j1 is the detection value of the pressure sensor at the exit of the jth hidden danger area; R j2 is the detection value of the pressure sensor at the inlet of the jth potential hazard area; ρ is the density of steam; μ is the calculation coefficient of reliability; e is the natural base; ln is the logarithmic function with e as the base; is the rounding symbol;

[0035] A grading unit, used for generating a hazard level for each hazard area based on a hazard assessment parameter of each hazard area;

[0036] Among them, G j is the hazard level of the jth hazard area; P0 is the classification basis of the hazard level;

[0037] The comprehensive assessment result generating unit is used to generate a comprehensive assessment result, which includes a potential hazard area and a corresponding potential hazard level.

[0038] Preferably, the automatic response module includes:

[0039] The alarm unit is used to alarm all potential danger areas according to the comprehensive assessment results and output the comprehensive assessment results;

[0040] The processing unit is used to automatically execute a processing plan corresponding to the hidden danger level according to the rating of each hidden danger area.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] By fusing and analyzing data from multiple sources, the accuracy and reliability of leak detection are improved. Multi-source data fusion can improve the robustness and accuracy of the system. When the monitoring system detects a leak, it automatically triggers an alarm and starts the isolation procedure. It can quickly respond to leaks and reduce losses caused by leaks. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0047] Example 1

[0048] The embodiment of the present invention provides a low-temperature economizer leakage efficient detection system, comprising:

[0049] The area division module is used to divide the working area of ​​the low-temperature economizer into several monitoring areas, an ultrasonic sensor is arranged in each monitoring area, and a humidity sensor and a pressure sensor are arranged at the junction of the monitoring areas;

[0050] Ultrasonic detection module, used to obtain ultrasonic signals from the low-temperature economizer working area and generate ultrasonic evaluation results;

[0051] The humidity detection module is used to obtain the humidity value of the flue gas inside the low-temperature economizer and generate a humidity evaluation result;

[0052] The pressure detection module is used to obtain the pressure value of the internal pipeline of the low-temperature economizer and generate the pressure evaluation result;

[0053] A comprehensive evaluation module, used for generating a comprehensive evaluation result based on an ultrasonic evaluation result, a humidity evaluation result and a pressure evaluation result;

[0054] The automatic response module is used to automatically execute the response plan based on the comprehensive evaluation results.

[0055] The beneficial effects of the above technical solution are:

[0056] By judging whether there is a leak based on ultrasound, flue gas humidity and the pressure of the internal pipeline of the low-temperature economizer, and by fusing and analyzing data from multiple sources, the accuracy and reliability of leak detection are improved. Multi-source data fusion can improve the robustness and accuracy of the system.

[0057] When the monitoring system detects a leak, it automatically triggers an alarm and starts the isolation procedure, which enables quick response to leaks and reduces losses caused by leaks.

[0058] Example 2

[0059] Based on Example 1, the ultrasonic evaluation result includes the area to which the leak point belongs and the size of the leak point, and the ultrasonic detection module includes:

[0060] An acoustic wave conversion unit, used for performing Fourier transformation on the ultrasonic signal to obtain ultrasonic frequency characteristics;

[0061] A noise frequency acquisition unit, used to periodically acquire the frequency characteristics of the environmental noise corresponding to each ultrasonic sensor;

[0062] A feature processing unit, used to remove noise from the ultrasonic frequency feature based on the frequency feature of the ambient noise to obtain a judgment frequency feature;

[0063] The feature matching unit is used to match the judged frequency feature with the frequency feature-leakage situation comparison table to obtain the monitoring point position, leakage point distance and leakage point size, determine the leakage point position based on the monitoring point position and leakage point distance, and combine the leakage point position and leakage point size to generate an ultrasonic evaluation result.

[0064] Preferably, the noise frequency acquisition unit includes:

[0065] The acoustic wave signal acquisition subunit acquires the environmental acoustic wave signal under the condition that no leakage exists after manual inspection;

[0066] The signal conversion subunit is used to perform Fourier transformation on the ambient sound wave signal to obtain the frequency characteristics of the ambient noise.

[0067] In this embodiment, the frequency characteristic-leakage condition comparison table is an information table of the comparison relationship between the leakage point distance, the leakage point size and the frequency characteristic obtained according to experiments.

[0068] In this embodiment, the leakage point distance is the straight-line distance from the leakage point to the monitoring point.

[0069] In this embodiment, the leakage point size is the diameter of the leakage point.

[0070] The beneficial effects of the above technical solution are:

[0071] By acquiring the ultrasonic frequency characteristics and the frequency characteristics of the ambient noise at the corresponding ultrasonic sensor, the noise part in the ultrasonic frequency characteristics is denoised, thereby reducing the interference of the ambient noise on the detection results and improving the accuracy of the detection results.

[0072] Example 3

[0073] Based on any one of Embodiments 1-2, the humidity assessment result includes the number of the monitoring area where the leakage exists, and the humidity detection module includes:

[0074] A humidity evaluation value calculation unit, used for calculating a humidity detection evaluation value;

[0075] Among them, P i is the humidity detection evaluation value of the i-th monitoring area; S i2 is the actual detection value of the humidity sensor at the end point of the i-th monitoring area; S i1 is the actual detection value of the humidity sensor at the starting point of the i-th monitoring area; S z is the actual detection value of the humidity sensor at the outlet of the low-temperature economizer; S1 is the actual detection value of the humidity sensor at the inlet of the low-temperature economizer; N is the total number of monitoring areas;

[0076] The humidity assessment result output unit is used to output the humidity assessment result according to the humidity detection assessment value. When the humidity detection assessment value of the monitoring area of ​​the humidity sensor in the i-th monitoring area is greater than the preset first judgment threshold, it is output that there is a leak in the i-th monitoring area.

[0077] The beneficial effects of the above technical solution are:

[0078] By S i2 -S i1 Calculate the difference in the detection results of the humidity sensors at the entrance and exit of the monitoring area, and then use The calculated humidity change of the flue gas during the whole process of passing through the low-temperature economizer is obtained by calculating S i2 -S i1 and The difference reflects the degree of deviation between the humidity change values ​​of the two humidity sensors at the inlet and outlet of the monitoring area and the average humidity change value. When the deviation is too high, it is judged that there is a leak in the monitoring area, which improves the accuracy of judging whether there is a leak in the monitoring area based on the change of smoke humidity value.

[0079] Example 4

[0080] Based on any one of embodiments 1-3, the pressure assessment result includes the number of the monitoring area where the leakage exists, the pressure assessment result includes the number of the monitoring area where the leakage exists, and the pressure detection module includes:

[0081] A historical data recording unit, used to record the historical pressure sensor detection values ​​of each monitoring area;

[0082] A historical data sampling unit, used for randomly selecting a number of groups of historical pressure sensor detection values ​​of the monitoring area from the historical pressure sensor detection values ​​of the monitoring area as comparison data groups;

[0083] A pressure evaluation value calculation unit, used to calculate a pressure detection evaluation value;

[0084] Among them, E i is the pressure detection evaluation value of the ith monitoring area; α and β are the importance weighting coefficients of historical data and actual pressure difference, respectively; R i1 is the detection value of the pressure sensor at the outlet of the i-th monitoring area; R1 is the detection value of the pressure sensor at the inlet of the low-temperature economizer; M is the total number of comparison data groups; R ik is the detection value of the pressure sensor at the outlet of the ith monitoring area in the kth comparison data group; R 1k is the detection value of the pressure sensor at the inlet of the low-temperature economizer in the kth group of comparison data; R i2 is the detection value of the pressure sensor at the inlet of the i-th monitoring area; R0 is the preset maximum allowable pressure difference between adjacent monitoring points; || is the absolute value symbol;

[0085] The pressure assessment result output unit is used to output the pressure assessment result according to the pressure detection assessment value. When the pressure detection assessment value of the i-th monitoring area is greater than a preset second judgment threshold, it is output that there is a leak in the i-th monitoring area.

[0086] The beneficial effects of the above technical solution are:

[0087] pass The ratio of the pressure sensor detection value at the outlet of the ith monitoring area relative to the pressure change value at the inlet of the low-temperature economizer and the pressure at the pressure sensor at the outlet of the ith monitoring area relative to the pressure change value at the inlet of the low-temperature economizer in the historical data is calculated to determine whether the pressure change value deviates from the historical data, and then It is calculated whether the pressure change value of the i-th monitoring area exceeds the preset maximum allowable pressure difference. By comprehensively considering the degree of deviation between the pressure change and the historical data and whether the actual pressure change exceeds the maximum allowable pressure difference, the accuracy of judging whether there is a leak based on the pressure change is improved.

[0088] Example 5

[0089] Based on any one of embodiments 1-4, the comprehensive evaluation module includes:

[0090] A hidden danger area determination unit, used for determining all monitoring areas with leakage in the humidity assessment results, the pressure assessment results and the ultrasonic assessment results as hidden danger areas;

[0091] A hidden danger assessment parameter calculation unit, used to calculate hidden danger assessment parameters for each hidden danger area;

[0092]

[0093] Among them, P j is the hidden danger assessment parameter of the jth hidden danger area; U j is the average leakage severity level of the jth potential hazard area; D j is the size of the leakage point in the ultrasonic assessment result of the jth potential hazard area; D0 is the classification basis of the leakage point diameter; v is the flue gas flow rate inside the low-temperature economizer; S j2 is the actual detection value of the humidity sensor at the end point of the jth hidden danger area; S j1 is the actual detection value of the humidity sensor at the starting point of the jth hidden danger area; C d is the flow coefficient; R j1 is the detection value of the pressure sensor at the exit of the jth hidden danger area; R j2 is the detection value of the pressure sensor at the inlet of the jth potential hazard area; ρ is the density of steam; μ is the calculation coefficient of reliability; e is the natural base; ln is the logarithmic function with e as the base; is the rounding symbol;

[0094] A grading unit, used for generating a hazard level for each hazard area based on a hazard assessment parameter of each hazard area;

[0095] Among them, G jis the hazard level of the jth hazard area; P0 is the classification basis of the hazard level;

[0096] The comprehensive assessment result generating unit is used to generate a comprehensive assessment result, which includes a potential hazard area and a corresponding potential hazard level.

[0097] Preferably, the automatic response module includes:

[0098] The alarm unit is used to alarm all potential danger areas according to the comprehensive assessment results and output the comprehensive assessment results;

[0099] The processing unit is used to automatically execute a processing plan corresponding to the hidden danger level according to the rating of each hidden danger area.

[0100] In this embodiment, the flow coefficient is determined based on the shape of the leakage port. In this embodiment, it is considered that the shape of the leakage port is circular.

[0101] In this embodiment, the treatment plan includes: increasing the feed water flow rate, reducing the boiler load, emergency shutdown, maintaining the drum water level and removing steam and flue gas.

[0102] The beneficial effects of the above technical solution are:

[0103] By determining the hidden danger assessment parameters of each hidden danger location based on data from multiple sources (reflecting the authenticity of the leakage, that is, the probability of leakage actually occurring at the location), the accuracy and reliability of leak detection are improved. The robustness and accuracy of the system can be improved by fusing multi-source data.

[0104] By respectively obtaining the estimated values ​​of the leakage point size under different data sources based on ultrasound, flue gas humidity and pipeline pressure, and then reflecting the severity of the leakage by grading, the average leakage severity value is obtained by calculating the mean, and by respectively judging the difference between the estimated values ​​of the leakage point size under different data sources based on ultrasound, flue gas humidity and pipeline pressure and the average leakage severity value, the correction parameters for the reliability of the detection results of each data source are obtained, and then the average leakage severity value is corrected to obtain the hidden danger assessment parameters for the hidden danger area, which improves the accuracy of the hidden danger assessment parameters, avoids the misjudgment of the final result caused by the misjudgment of some data sources, and improves the robustness and accuracy of the system.

[0105] By generating corresponding hidden danger levels based on the hidden danger assessment parameters of each hidden danger area, an intuitive data basis can be provided for selecting different treatment plans according to different hidden danger levels, thereby realizing automatic relevant treatment according to the severity of the hidden danger, ensuring a rapid response to leakage incidents, and reducing the losses caused by leakage.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-temperature economizer leakage high-efficiency detection system, characterized in that: include: The area division module is used to divide the working area of ​​the low-temperature economizer into several monitoring areas, an ultrasonic sensor is arranged in each monitoring area, and a humidity sensor and a pressure sensor are arranged at the junction of the monitoring areas; Ultrasonic detection module, used to obtain ultrasonic signals from the low-temperature economizer working area and generate ultrasonic evaluation results; The humidity detection module is used to obtain the humidity value of the flue gas inside the low-temperature economizer and generate a humidity evaluation result; The pressure detection module is used to obtain the pressure value of the internal pipeline of the low-temperature economizer and generate the pressure evaluation result; A comprehensive evaluation module, used for generating a comprehensive evaluation result based on an ultrasonic evaluation result, a humidity evaluation result and a pressure evaluation result; The automatic response module is used to automatically execute the response plan based on the comprehensive evaluation results.

2. A low-temperature economizer leakage high-efficiency detection system according to claim 1, characterized in that: The ultrasonic assessment results include the area to which the leak point belongs and the size of the leak point. The ultrasonic detection module includes: An acoustic wave conversion unit, used for performing Fourier transformation on the ultrasonic signal to obtain ultrasonic frequency characteristics; A noise frequency acquisition unit, used to periodically acquire the frequency characteristics of the environmental noise corresponding to each ultrasonic sensor; A feature processing unit, used to remove noise from the ultrasonic frequency feature based on the frequency feature of the ambient noise to obtain a judgment frequency feature; The feature matching unit is used to match the judged frequency feature with the frequency feature-leakage situation comparison table to obtain the monitoring point position, leakage point distance and leakage point size, determine the leakage point position based on the monitoring point position and leakage point distance, and combine the leakage point position and leakage point size to generate an ultrasonic evaluation result.

3. A low-temperature economizer leakage high-efficiency detection system according to claim 2, characterized in that: The noise frequency acquisition unit includes: The acoustic wave signal acquisition subunit acquires the environmental acoustic wave signal under the condition that no leakage exists after manual inspection; The signal conversion subunit is used to perform Fourier transformation on the ambient sound wave signal to obtain the frequency characteristics of the ambient noise.

4. A low-temperature economizer leakage high-efficiency detection system according to claim 1, characterized in that: The humidity assessment results include the ID of the monitored area where the leak exists. The humidity detection module includes: A humidity evaluation value calculation unit, used for calculating a humidity detection evaluation value; Among them, P i is the humidity detection evaluation value of the i-th monitoring area; S i2 is the actual detection value of the humidity sensor at the end point of the i-th monitoring area; S i1 is the actual detection value of the humidity sensor at the starting point of the i-th monitoring area; S z is the actual detection value of the humidity sensor at the outlet of the low-temperature economizer; S1 is the actual detection value of the humidity sensor at the inlet of the low-temperature economizer; N is the total number of monitoring areas; The humidity assessment result output unit is used to output the humidity assessment result according to the humidity detection assessment value. When the humidity detection assessment value of the monitoring area of ​​the humidity sensor in the i-th monitoring area is greater than the preset first judgment threshold, it is output that there is a leak in the i-th monitoring area.

5. The low-temperature economizer leakage high-efficiency detection system according to claim 1 is characterized in that: The pressure assessment results include the number of the monitoring area where the leak exists. The pressure detection module includes: A historical data recording unit, used to record the historical pressure sensor detection values ​​of each monitoring area; A historical data sampling unit, used for randomly selecting a number of groups of historical pressure sensor detection values ​​of the monitoring area from the historical pressure sensor detection values ​​of the monitoring area as comparison data groups; A pressure evaluation value calculation unit, used to calculate a pressure detection evaluation value; Among them, E i is the pressure detection evaluation value of the ith monitoring area; α and β are the importance weighting coefficients of historical data and actual pressure difference, respectively; R i1 is the detection value of the pressure sensor at the outlet of the i-th monitoring area; R1 is the detection value of the pressure sensor at the inlet of the low-temperature economizer; M is the total number of comparison data groups; R ik is the detection value of the pressure sensor at the outlet of the ith monitoring area in the kth comparison data group; R 1k is the detection value of the pressure sensor at the inlet of the low-temperature economizer in the kth group of comparison data; R i2 is the detection value of the pressure sensor at the inlet of the i-th monitoring area; R0 is the preset maximum allowable pressure difference between adjacent monitoring points; || is the absolute value symbol; The pressure assessment result output unit is used to output the pressure assessment result according to the pressure detection assessment value. When the pressure detection assessment value of the i-th monitoring area is greater than a preset second judgment threshold, it is output that there is a leak in the i-th monitoring area.

6. A low-temperature economizer leakage high-efficiency detection system according to claim 1, characterized in that: The comprehensive assessment modules include: A hidden danger area determination unit, used for determining all monitoring areas with leakage in the humidity assessment results, the pressure assessment results and the ultrasonic assessment results as hidden danger areas; A hidden danger assessment parameter calculation unit, used to calculate hidden danger assessment parameters for each hidden danger area; Among them, P j is the hidden danger assessment parameter of the jth hidden danger area; U j is the average leakage severity level of the jth potential hazard area; D j is the size of the leakage point in the ultrasonic assessment result of the jth potential hazard area; D0 is the classification basis of the leakage point diameter; v is the flue gas flow rate inside the low-temperature economizer; S j2 is the actual detection value of the humidity sensor at the end point of the jth hidden danger area; S j1 is the actual detection value of the humidity sensor at the starting point of the jth hidden danger area; C d is the flow coefficient; R j1 is the detection value of the pressure sensor at the exit of the jth hidden danger area; R j2 is the detection value of the pressure sensor at the inlet of the jth potential hazard area; ρ is the density of steam; μ is the calculation coefficient of reliability; e is the natural base; ln is the logarithmic function with e as the base; is the rounding symbol; A grading unit, used for generating a hazard level for each hazard area based on a hazard assessment parameter of each hazard area; Among them, G j is the hazard level of the jth hazard area; P0 is the classification basis of the hazard level; The comprehensive assessment result generating unit is used to generate a comprehensive assessment result, which includes a potential hazard area and a corresponding potential hazard level.

7. A low-temperature economizer leakage high-efficiency detection system according to claim 6, characterized in that: The automatic response module includes: The alarm unit is used to alarm all potential danger areas according to the comprehensive assessment results and output the comprehensive assessment results; The processing unit is used to automatically execute a processing plan corresponding to the hidden danger level according to the rating of each hidden danger area.

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