Monitoring method for dust accumulation state of power generation device

Abstract

The present invention discloses a method for monitoring the dust accumulation state of a power generation device. The method sets a current time zone and a benchmark time zone, collects normal operating data of the power generation device in the current time zone, and records vibration data in the current time zone that exceeds a certain vibration threshold of the current power generation device; collects the active power generation and stator blade opening of the power generation device in the benchmark time zone to form a benchmark time zone data set; calculates the average stator blade opening and average generator active power at each time point in the set; calculates health and performance change data at each time point in the current time zone, including the percentage change in stator blade opening and the percentage change in power generation efficiency; calculates the proportion of vibration records, the percentage change in stator blade opening, and the percentage change in active power; and decides whether to perform dust cleaning operations based on the calculation results. The method provides a quantitative evaluation value for the health and performance degradation of a running power generation device caused by dust accumulation, providing a reliable basis for dust removal operations.

Description

Technical Field

[0001] The present invention relates to the technical field of equipment monitoring, and in particular to a method for monitoring the dust accumulation state of a power generation device. Background Art

[0002] Internal ash accumulation in blast furnace gas residual pressure turbines (TRTs) can lead to decreased health and performance. With continued operation, ash accumulation continues to grow, negatively impacting TRT health and performance. Currently, there's no convenient, direct way to assess the degradation of TRT health and performance caused by ash accumulation. Factors other than ash accumulation, such as gas flow and temperature at the TRT inlet, can also contribute to these degradations. Therefore, most TRTs rely on periodic shutdowns and cover cleaning to remove ash. To remove TRT ash accumulation, some TRTs are currently equipped with online ash cleaning devices. These devices are activated periodically based on experience or intuition, based on power generation and TRT shaft radial vibration measurements. However, due to a lack of effective guidance on when to initiate online cleaning, online cleaning is often not initiated promptly or is performed too frequently. Failure to initiate online cleaning promptly can lead to excessive ash accumulation early on, making subsequent cleaning more difficult and ineffective. Excessive online cleaning, however, can shorten the lifespan of TRTs due to the negative impact of cleaning chemicals on the metal inner wall of the TRT.

[0003] Chinese patent document CN201696105U discloses a TRT turbine stator dust accumulation monitoring device, which includes an inlet flow detection device, a stator blade differential pressure detection device, a stator blade angle detection device, an industrial control machine, and an alarm device. The industrial control machine analyzes the data transmitted by the inlet flow detection device, the stator blade differential pressure detection device, and the stator blade angle detection device with the relationship between the stator blade differential pressure, the stator blade angle, and the gas flow rate under clean conditions to decide whether to alarm for stator dust accumulation. This device is not simple and convenient to implement, and a special detection device needs to be installed for the TRT. At the same time, the assessment of the impact of dust accumulation is not comprehensive, and only the stator blade dust accumulation is evaluated. In actual situations, dust accumulation will not only cause changes in the relationship between the stator blade differential pressure, the stator blade angle, and the gas flow rate, but will also increase the risk of high vibration of the TRT main shaft and reduce the power generation efficiency of the turbine. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for monitoring the dust accumulation status of a power generation device. This method overcomes the defects of traditional TRT dust removal, adopts conventional measurement and recording data of the power generation device, and provides a quantitative evaluation value for the health and performance degradation of the operating power generation device caused by dust accumulation. The method can be applied to any power generation device, eliminates the influence of factors such as the aging of the power generation device itself, and does not require a complicated parameter adjustment process, providing a reliable basis for dust removal operations.

[0005] To solve the above technical problems, the method for monitoring the dust accumulation state of a power generation device of the present invention comprises the following steps:

[0006] Step 1: Set the current time zone and the benchmark time zone for the operation of the power generation device, and the benchmark time zone is earlier than the current time zone by a certain time interval;

[0007] Step 2: Collect normal operating data of the power generation device in the current time zone, including inlet gas flow, inlet gas temperature, inlet gas pressure, outlet gas pressure, stator blade opening, generator active power, and main shaft radial vibration displacement measurement values, and record vibration data in the current time zone that exceeds the vibration alarm threshold of the current power generation device;

[0008] Step 3: In the benchmark time zone, based on the normal operating condition data of the power generation device collected in the current time zone, the generator active power and stator blade opening of the power generation device under similar operating conditions in the benchmark time zone and the current time zone are collected to form a benchmark time zone data set;

[0009] Step 4: Calculate the average stator blade opening and average generator active power at each time point in the benchmark time zone data set;

[0010] Step 5: Calculate the health and performance change data at time point A within the current time zone, including:

[0011]

[0012] Where D is the percentage change of the stator blade opening, and η is the percentage change of the power generation efficiency;

[0013] Step 6: Calculate the percentage of vibration records exceeding the vibration alarm threshold of the power generation device in the entire current time zone, calculate the percentage change of the average stator blade opening at all time points in the current time zone relative to the average stator blade opening of the benchmark time zone data set, and calculate the percentage change of the average generator active power at all time points in the current time zone relative to the average generator active power of the benchmark time zone data set;

[0014] Step 7. Based on the calculated data in step 6 as three independent indicators, decide whether the power generation device needs to be cleaned, among which: the proportion of vibration records exceeding the alarm threshold represents safety. The higher the value, the worse the equipment safety. The judgment threshold of this indicator is set according to the on-site safety factor requirements. If the judgment threshold of this indicator is exceeded, the equipment safety is at risk and cleaning is recommended; the percentage change of active power represents economic benefits. If it is a positive value, it means that the power generation efficiency has increased and no cleaning is required. If it is a negative value, it means that the power generation efficiency has decreased and the economic benefits have decreased. According to the economic benefit goal, when the negative value is lower than the set threshold, cleaning is recommended; the percentage change of the stator opening represents the control reliability of the power generation device. If it is a positive value, it means that the control reliability has decreased. According to the expectation of reliability or safety, the threshold of this indicator is set. When the percentage change of the stator opening is greater than the threshold, cleaning is recommended.

[0015] Furthermore, the time interval between the benchmark time zone and the current time zone is 30 to 60 days.

[0016] Furthermore, the duration of the current time zone is 3 to 4 days, and the duration of the benchmark time zone is from the time when the power generation device was last uncovered and cleaned to 30 days before the current time zone.

[0017] Furthermore, the similar operating state of the power generation device in the benchmark time zone and the current time zone means that the inlet gas flow, inlet gas temperature, and inlet gas pressure of the power generation device are similar.

[0018] The method for monitoring the dust accumulation status of a power generation device of the present invention adopts the above-mentioned technical solution, namely, the method sets the current time zone and the benchmark time zone of the power generation device operation, collects the normal operating condition data of the power generation device in the current time zone, records the vibration data in the current time zone that exceeds the vibration alarm threshold of the current power generation device; collects the generator active power and stator blade opening of the power generation device in the benchmark time zone to form a benchmark time zone data set; calculates the average stator blade opening and average generator active power at each time point in the benchmark time zone data set; calculates the health and performance change data at time point A in the current time zone, including the percentage change in stator blade opening and the percentage change in power generation efficiency; calculates the vibration record ratio, the percentage change in stator blade opening, and the percentage change in generator active power; and decides whether the power generation device needs to be cleaned based on the calculation results. This method overcomes the shortcomings of traditional power generation device dust removal, uses the normal measurement and record data of the power generation device to provide a quantitative assessment value of the health and performance degradation of the operating power generation device caused by dust accumulation, and is applicable to any power generation device, eliminating the influence of factors such as the aging of the power generation device itself, without the need for complex parameter adjustment processes, and provides a reliable basis for dust removal operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0020] Figure 1 Flow chart of calculation of the change of stator blade opening and generator active power at each time point in this method;

[0021] Figure 2 This is a flowchart for the calculation of the three independent indicators in this method. DETAILED DESCRIPTION

[0022] like Figure 1 and Figure 2 As shown, the method for monitoring the dust accumulation state of a power generation device of the present invention includes the following steps:

[0023] Step 1: Set the current time zone and the benchmark time zone for the operation of the power generation device, and the benchmark time zone is earlier than the current time zone by a certain time interval;

[0024] Step 2: Collect normal operating data of the power generation device in the current time zone, including inlet gas flow, inlet gas temperature, inlet gas pressure, outlet gas pressure, stator blade opening, generator active power, and main shaft radial vibration displacement measurement values, and record vibration data in the current time zone that exceeds the vibration alarm threshold of the current power generation device. The alarm threshold can be determined based on the safety factor requirement. If the safety factor requirement is high, the threshold is set low, but this may lead to frequent alarms. If the safety factor requirement is low, the threshold can be set high, which will reduce the alarm frequency.

[0025] Step 3: In the benchmark time zone, based on the normal operating condition data of the power generation device collected in the current time zone, the generator active power and stator blade opening of the power generation device under similar operating conditions in the benchmark time zone and the current time zone are collected to form a benchmark time zone data set;

[0026] Step 4: Calculate the average stator blade opening and average generator active power at each time point in the benchmark time zone data set;

[0027] Step 5: Calculate the health and performance change data at time point A within the current time zone, including:

[0028]

[0029] Where D is the percentage change of the stator blade opening, and η is the percentage change of the power generation efficiency;

[0030] Step 6: Calculate the percentage of vibration records exceeding the vibration alarm threshold of the power generation device in the entire current time zone, calculate the percentage change of the average stator blade opening at all time points in the current time zone relative to the average stator blade opening of the benchmark time zone data set, and calculate the percentage change of the average generator active power at all time points in the current time zone relative to the average generator active power of the benchmark time zone data set;

[0031] Step 7. Based on the calculated data in step 6 as three independent indicators, decide whether the power generation device needs to be cleaned, among which: the proportion of vibration records exceeding the alarm threshold represents safety. The higher the value, the worse the equipment safety. The judgment threshold of this indicator is set according to the on-site safety factor requirements. If the judgment threshold of this indicator is exceeded, the equipment safety is at risk and cleaning is recommended; the percentage change of active power represents economic benefits. If it is a positive value, it means that the power generation efficiency has increased and no cleaning is required. If it is a negative value, it means that the power generation efficiency has decreased and the economic benefits have decreased. According to the economic benefit goal, when the negative value is lower than the set threshold, cleaning is recommended; the percentage change of the stator opening represents the control reliability of the power generation device. If it is a positive value, it means that the control reliability has decreased. According to the expectation of reliability or safety, the threshold of this indicator is set. When the percentage change of the stator opening is greater than the threshold, cleaning is recommended.

[0032] Preferably, the time interval between the benchmark time zone and the current time zone is 30 to 60 days.

[0033] Preferably, the duration of the current time zone is 3 to 7 days, and the duration of the benchmark time zone is from the time when the power generation device was last uncovered and cleaned to 30 days before the current time zone.

[0034] Preferably, the similar operating state of the power generation device in the benchmark time zone and the current time zone refers to that the inlet gas flow, inlet gas temperature, and inlet gas pressure of the power generation device are similar.

[0035] To facilitate the assessment of the degree of health and performance degradation of a power generation unit due to dust accumulation, this method uses existing conventional data of the power generation unit as analysis input, including the gas flow rate at the inlet of the power generation unit, the gas temperature at the inlet of the power generation unit, the gas pressure at the inlet of the power generation unit, the gas pressure at the outlet of the power generation unit, the opening of the stator blades of the power generation unit, the active power of the generator, and the radial vibration displacement measurement values of the main shaft of the power generation unit.

[0036] Without adding new measurement data, calculate the percentage of vibration records exceeding a certain threshold (such as 1 / 2 of the current TRT vibration alarm value) within a short period of time within the current time zone (for example, 3 days, 7 days, etc.) at the current time point; collect the generator active power and stator opening records at time points with similar operating conditions (inlet gas flow, inlet gas temperature, inlet gas pressure) in the benchmark time zone to calculate the percentage of generator active power decrease and stator opening increase caused by dust accumulation at each time point in the current time zone. Then, calculate the average percentage of generator active power decrease and the average percentage of stator opening increase at each time point in the current time zone.

[0037] The three independent indicators used to determine whether the power generation device needs to be cleaned are the proportion of the above-threshold vibration records, the average percentage of the decrease in the generator active power in the current time period (the percentage of the decrease in the power generation efficiency of the power generation device), and the average percentage of the increase in the stator blade opening in the current time period.

[0038] This method, without the need for specialized detection equipment and relying solely on routine generator unit measurement data, provides a quantitative assessment of the health and performance degradation of an operating TRT due to dust accumulation. This includes safety (the risk of vibration exceeding the automatic shutdown threshold), economic efficiency (the percentage decrease in generator unit efficiency), and control reliability (the percentage increase in stator blade opening due to dust accumulation). Furthermore, since the performance degradation is calculated as a percentage using only the target generator unit's recent operating data, without fixed measurement parameter thresholds, this method is adaptable to any generator unit, eliminates the impact of factors such as generator unit aging, and eliminates the need for complex parameter adjustments.

[0039] This method provides a comprehensive assessment of the dust accumulation status within a generator unit during normal operation, without shutting down the unit or removing the cover. It also indicates the appropriate time to activate the online dust cleaning system. This method is adaptive, adapting to any generator unit, eliminating the need for parameter adjustments or model retraining after switching targets, making it easy to apply. Furthermore, it assesses the dust accumulation status of both the rotor and stator blades of the generator unit, eliminating the need for specialized monitoring equipment. The calculations require only a few common monitoring data points from the generator unit, making deployment simple.

Claims

1. A method for monitoring the dust accumulation state of a power generation device, characterized in that This method comprises the following steps: Step 1: Set the current time zone and the benchmark time zone for the operation of the power generation device, and the benchmark time zone is earlier than the current time zone by a certain time interval; Step 2: Collect normal operating data of the power generation device in the current time zone, including inlet gas flow, inlet gas temperature, inlet gas pressure, outlet gas pressure, stator blade opening, generator active power, and main shaft radial vibration displacement measurement values, and record vibration data in the current time zone that exceeds the vibration alarm threshold of the current power generation device; Step 3: In the benchmark time zone, based on the normal operating condition data of the power generation device collected in the current time zone, the generator active power and stator blade opening of the power generation device under similar operating conditions in the benchmark time zone and the current time zone are collected to form a benchmark time zone data set; Step 4: Calculate the average stator blade opening and average generator active power at each time point in the benchmark time zone data set; Step 5: Calculate the health and performance change data at time point A within the current time zone, including: Where D is the percentage change of the stator blade opening, and η is the percentage change of the power generation efficiency; Step 6: Calculate the percentage of vibration records exceeding the vibration alarm threshold of the power generation device in the entire current time zone, calculate the percentage change of the average stator blade opening at all time points in the current time zone relative to the average stator blade opening of the benchmark time zone data set, and calculate the percentage change of the average generator active power at all time points in the current time zone relative to the average generator active power of the benchmark time zone data set; Step 7. Based on the calculated data in step 6 as three independent indicators, decide whether the power generation device needs to be cleaned, among which: the proportion of vibration records exceeding the alarm threshold represents safety. The higher the value, the worse the equipment safety. The judgment threshold of this indicator is set according to the on-site safety factor requirements. If the judgment threshold of this indicator is exceeded, the equipment safety is at risk and cleaning is recommended; the percentage change of active power represents economic benefits. If it is a positive value, it means that the power generation efficiency has increased and no cleaning is required. If it is a negative value, it means that the power generation efficiency has decreased and the economic benefits have decreased. According to the economic benefit goal, when the negative value is lower than the set threshold, cleaning is recommended; the percentage change of the stator opening represents the control reliability of the power generation device. If it is a positive value, it means that the control reliability has decreased. According to the expectation of reliability or safety, the threshold of this indicator is set. When the percentage change of the stator opening is greater than the threshold, cleaning is recommended.

2. The method for monitoring the dust accumulation state of a power generation device according to claim 1, characterized in that: The time interval between the benchmark time zone and the current time zone is 30 to 60 days.

3. The method for monitoring the dust accumulation state of a power generation device according to claim 1 or 2, characterized in that: The duration of the current time zone is 3 to 4 days, and the duration of the benchmark time zone is from the time when the power generation device was last uncovered and cleaned to 30 days before the current time zone.

4. The method for monitoring the dust accumulation state of a power generation device according to claim 3, characterized in that: The similar operating conditions of the power generation device in the benchmark time zone and the current time zone refer to that the inlet gas flow, inlet gas temperature, and inlet gas pressure of the power generation device are similar.

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