Diagnostic system and diagnostic method for coal-fired condensing steam type generator set

Abstract

The invention belongs to the technical field of generator set diagnosis, and particularly relates to a coal-fired condensing type generator set diagnosis system and method. Voltage data values of a main power supply and a coal-fired condensing type generator set are collected at time nodes of a period; obtaining a main power state signal and a coal power state signal according to the voltage data values of the plurality of time nodes; based on the main electricity normal signal and the coal electricity abnormal signal, the rotating speed and the voltage of the coal-fired condensing steam generator set in use are analyzed, and a coal electricity rotating speed normal signal and a coal electricity rotating speed abnormal signal are obtained; according to the coal-electricity rotating speed abnormal signal, dynamically analyzing the rotating speed in a plurality of time nodes to obtain a coal-electricity protection signal and a coal-electricity regulation and control signal; based on the coal electricity regulation and control signal, the use state of the filter of the coal-fired condensed steam type generator set is recognized, voltage regulation of the coal-fired condensed steam type generator set is completed, the operation efficiency of the coal-fired condensed steam type generator set is improved, and stable power supply of an electric power system is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of generator set diagnosis, and in particular to a diagnosis system and a diagnosis method for a coal-fired condensing generator set. Background Art

[0002] In modern society, the stability and reliability of power supply are crucial to all walks of life, especially in important places such as chemical, metallurgical, and petroleum industries where key equipment requires continuous and stable power supply. Once power is interrupted, it may bring huge economic losses and social impacts. Therefore, these places usually need to be equipped with backup power or emergency power to ensure that they can quickly and smoothly switch to backup power during power grid failure or maintenance to maintain the normal operation of key equipment. Coal-fired condensing steam generator sets have become the first choice for backup power supply in these places due to their high reliability, easy maintenance, and strong adaptability.

[0003] In the use of existing coal-fired condensing steam generator set power supply non-inductive access technology, when the main power supply voltage is actually close to or begins to deviate from the normal range (i.e., close to the maximum or minimum voltage value), but has not yet reached the switching threshold, the system cannot respond immediately. This lag may result in continued reliance on unstable main power supply even when the quality of the main power supply has obviously declined, increasing the risk of equipment damage or data loss.

[0004] To this end, the present invention provides a diagnostic system and method for a coal-fired condensing generator set. Summary of the invention

[0005] In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a diagnostic method for a coal-fired condensing steam generator set according to the present invention comprises the following steps:

[0007] A preset cycle is used to obtain several time nodes within the cycle, and voltage data values ​​of the main power supply and the coal-fired condensing steam generator set are collected at the time nodes of the cycle, and the main power state signal and the coal power state signal are obtained according to the voltage data values ​​of the several time nodes;

[0008] The main power status signal is divided into main power abnormal signal and main power normal signal;

[0009] The coal power status signal is divided into coal power normal signal and coal power abnormal signal;

[0010] Based on the normal signal of the main power and the abnormal signal of the coal-fired power, the speed and voltage of the coal-fired condensing steam generator set are analyzed during use, and the normal signal of the coal-fired power speed and the abnormal signal of the coal-fired power speed are obtained;

[0011] According to the abnormal speed signal of coal-fired power, the speed within several time nodes is dynamically analyzed to obtain the coal-fired power protection signal and coal-fired power regulation signal;

[0012] Based on the coal-fired power control signal, the use status of the filter of the coal-fired condensing steam generator set is identified to obtain the filter's inlet pressure influence signal and non-inlet pressure influence signal. According to the filter's inlet pressure influence signal, the voltage of the coal-fired condensing steam generator set is regulated to maintain a balance with the voltage of the main power supply.

[0013] As a further solution of the present invention: the identification process of the main power status signal is:

[0014] Processing the voltage data values ​​of the main power supply at multiple time nodes within a cycle to obtain the main voltage average value of the main power supply within the cycle;

[0015] The voltage data value of each time node is calculated by difference with the main voltage mean value and the absolute value is taken to obtain the main voltage deviation value;

[0016] A plane coordinate system is established, with time as the X-axis and the main voltage deviation value as the Y-axis. The main voltage deviation value corresponding to each time node is constructed in chronological order as a time-main voltage deviation value curve;

[0017] Draw a straight line parallel to the X-axis with the maximum limit value and the minimum limit value of the preset main voltage deviation range;

[0018] The voltage within a unit time when the deviation value curve is between the maximum limit value and the minimum limit value of the main voltage deviation interval is recorded as the main power normal voltage, and a main power normal signal is obtained;

[0019] The voltage per unit time when the deviation value curve is outside the maximum limit value and the minimum limit value of the main voltage deviation interval is recorded as the main power abnormal voltage, and the main power abnormal signal is obtained.

[0020] As a further solution of the present invention: the recognition process of the coal power status signal is:

[0021] The voltage data values ​​of the coal-fired condensing steam generator set at multiple time nodes in a cycle are processed to obtain the average value of the coal voltage of the main power supply in the cycle;

[0022] The voltage data value at each time node is calculated by difference with the coal voltage mean value and the absolute value is taken to obtain the coal voltage deviation value;

[0023] A plane coordinate system is established, with time as the X-axis and the coal voltage deviation value as the Y-axis, and the coal voltage deviation value corresponding to each time node is constructed in chronological order as a time-coal voltage deviation value curve;

[0024] Draw a straight line parallel to the X-axis with the maximum limit value and the minimum limit value of the preset coal voltage deviation range;

[0025] The voltage within a unit time when the deviation value curve is between the maximum limit value and the minimum limit value of the coal voltage deviation interval is recorded as the normal voltage of coal power generation, and a normal signal of coal power generation is obtained;

[0026] The voltage per unit time when the deviation value curve is outside the maximum limit value and the minimum limit value of the coal voltage deviation interval is recorded as the coal-fired power abnormal voltage, and the coal-fired power abnormal signal is obtained.

[0027] As a further solution of the present invention: obtaining the rated speed of the generator at the standard frequency, denoted as Np;

[0028] Get the actual speed of the generator when the coal-fired condensing steam generator set is running at each time node, recorded as Nm;

[0029] The ratio of the rated speed value Np to the actual speed value Nm at each time node is calculated, and the speed deviation value is recorded as Nqm;

[0030] The speed deviation value of each time node is recorded as Nqm and compared with the preset speed deviation threshold interval. When the speed deviation value Nqm is within the preset speed deviation threshold interval, the time node is recorded as a positive time node. When the speed deviation value Nqm is outside the preset speed deviation threshold interval, the time node is recorded as a reverse time node.

[0031] Obtain the number of reverse time nodes, calculate the ratio of the number of reverse time nodes to the total number of time nodes, and obtain the reverse node ratio;

[0032] The speed deviation values ​​Nqm of all time nodes in the cycle are integrated to obtain a speed deviation value group;

[0033] The speed deviation value group is processed according to the variance calculation formula to obtain the speed deviation variance value;

[0034] The speed deviation variance value is calculated by multiplying the reverse node ratio with the speed deviation variance value;

[0035] Compare the speed deviation abnormal value with the speed deviation abnormal threshold value;

[0036] If the speed deviation abnormal value is greater than or equal to the speed deviation abnormal threshold, it means that the speed of the generator is abnormal when the coal-fired condensing steam generator set is running, and a coal-fired power speed abnormal signal is obtained;

[0037] If the speed deviation abnormal value is less than the speed deviation abnormal threshold, it means that the speed of the generator is normal when the coal-fired condensing steam generator set is running, and a normal coal-fired power speed signal is obtained.

[0038] As a further solution of the present invention: based on the abnormal coal power speed signal, the filter is divided into a number of identical filter areas;

[0039] At each time point, the steam flow rate of each filter zone is collected by a flow meter and recorded as the steam flow value Q;

[0040] Obtain the flow rate of the filter to obtain the pressure difference on both sides of the filter, recorded as ΔP;

[0041] The filter resistance value S at each time node is obtained by calculating the ratio of the filter pressure difference ΔP to the steam flow value Q at each time node.

[0042] As a further solution of the present invention: by formula Calculate the speed n at each time node and record it as a positive speed value, where R is the torque;

[0043] The positive speed value is multiplied by the interference coefficient to obtain the theoretical speed value of the generator at the time node;

[0044] The difference between the theoretical speed value and the actual speed value at each time node is calculated to obtain the theoretical speed deviation value at each time node;

[0045] When the deviation value of the transfer is within the preset difference range, a pressure influence signal is generated;

[0046] When the transfer deviation value is not within the preset difference range, a non-advance pressure influence signal is generated.

[0047] As a further solution of the present invention: the process of obtaining the interference coefficient is:

[0048] At each time point, the intake air temperature and ambient temperature of the coal-fired condensing steam generator set are collected, and the intake air temperature is recorded as T a , the ambient temperature is recorded as T b ;

[0049] At each time point, the intake pressure and ambient atmospheric pressure of the coal-fired condensing steam generator set are collected, and the intake pressure is P a , the ambient atmospheric pressure is P b ;

[0050] That is, through the formula The interference coefficient f is calculated; where k1 and k2 are preset proportional coefficients, η z is the turbocharger intake efficiency, S z The degree of filter clogging.

[0051] As a further solution of the present invention: the process of obtaining the filter blockage degree is:

[0052] Based on the filter resistance value S at each time node, the filter blockage degree at each time node is identified;

[0053] That is, through the formula Calculate the filter blockage degree S at each time node z ;

[0054] Among them, α is the preset proportional coefficient, and α is greater than zero, and is a constant known from historical experimental data, S o It is the resistance value when the filter is not clogged at all.

[0055] As a further solution of the present invention: Based on the input pressure influence signal, the transfer deviation value of each time node is arranged to obtain the transfer deviation interval, which is recorded as By converting the deviation interval The maximum and minimum values ​​of are added to the theoretical speed value to obtain the standard speed range of the coal-fired condensing steam generator set, that is,

[0056] The speed of the generator of the coal-fired condensing steam generator set is controlled within the standard speed range, and the voltage is adjusted to achieve a balance with the voltage of the main power supply.

[0057] As a further solution of the present invention: a diagnostic system for a coal-fired condensing steam generator set, comprising a voltage data acquisition module, a real-time speed data acquisition module, a speed data analysis acquisition module, a filter data acquisition module and a speed control module;

[0058] A preset cycle is used to obtain several time nodes within the cycle. The voltage data acquisition module is used to collect voltage data values ​​of the main power supply and the coal-fired condensing steam generator set at the time nodes of the cycle, and obtain the main power state signal and the coal power state signal according to the voltage data values ​​of several time nodes;

[0059] The main power status signal is divided into main power abnormal signal and main power normal signal;

[0060] The coal power status signal is divided into coal power normal signal and coal power abnormal signal;

[0061] The real-time speed data acquisition module analyzes the speed and voltage of the coal-fired condensing steam generator set when in use based on the main power normal signal and the coal power abnormal signal, and obtains the coal power speed normal signal and the coal power speed abnormal signal;

[0062] The speed data analysis and acquisition module dynamically analyzes the speed within several time nodes according to the abnormal speed signal of coal-fired power generation, and obtains the coal-fired power protection signal and coal-fired power regulation signal;

[0063] The filter data acquisition module identifies the use status of the filter of the coal-fired condensing steam generator set based on the coal-fired power control signal, and obtains the filter's pressure-affected signal and non-pressure-affected signal;

[0064] The speed control module completes the voltage regulation of the coal-fired condensing steam generator set according to the filter's inlet pressure influence signal, and keeps the voltage balanced with the main power supply.

[0065] The beneficial effects of the present invention are as follows:

[0066] 1. A diagnostic system and method for a coal-fired condensing steam generator set described in the present invention generates a normal coal-fired power speed signal. At this time, the speed deviation value of the coal-fired condensing steam generator set in operation fluctuates within the rated speed range, indicating that the speed of the coal-fired condensing steam generator set is normal at this time node, and the frequencies of the coal-fired condensing steam generator set and the main power supply are both within the preset fluctuation range and can continue to work. When the speed deviation value is outside the preset speed deviation threshold range, an abnormal coal-fired power speed signal is generated. At this time, the speed of the coal-fired condensing steam generator set at this time node is abnormal, and the generator speed needs to be controlled. By analyzing the speed deviation, the abnormal fluctuation of the speed is obtained in advance, so as to achieve the effect of early analysis and then early regulation.

[0067] 2. The diagnostic system and method for a coal-fired condensing steam generator set described in the present invention effectively monitor and analyze the relationship between the abnormal generator speed and the degree of filter blockage by acquiring the positive speed adjustment interval and the specific acquisition and analysis process, thereby realizing the evaluation and analysis of the degree of filter blockage. At the same time, by calculating the deviation between the theoretical speed and the actual speed, the theoretical speed deviation interval is obtained, and it is quickly identified whether the speed abnormality is mainly affected by the degree of filter blockage, and the pressure influence signal is issued in time. Then, the speed of the coal-fired condensing steam generator set is regulated so that the actual speed value can reach the value within the positive speed adjustment interval, thereby improving the operating efficiency of the coal-fired condensing steam generator set, reducing the risk of failure due to filter blockage, and ensuring the stable power supply of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] The present invention will be further described below in conjunction with the accompanying drawings.

[0069] Figure 1 is a flow chart of a method for diagnosing a coal-fired condensing generator set according to an embodiment of the present invention;

[0070] Figure 2 The present invention is a flow chart of coal-fired power rotation speed identification in a method for diagnosing a coal-fired condensing steam generator set in an embodiment of the present invention. DETAILED DESCRIPTION

[0071] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0072] Example 1

[0073] See also Figure 1 As shown, the present invention is a diagnostic method for a coal-fired condensing steam generator set, comprising the following steps:

[0074] A preset cycle is divided into a number of time nodes, voltage data values ​​of the main power supply and the coal-fired condensing steam generator set are collected at the time nodes of the cycle, and a main power state signal and a coal power state signal are obtained according to the voltage data values ​​at the number of time nodes;

[0075] The main power status signal is divided into main power abnormal signal and main power normal signal;

[0076] The coal power status signal is divided into coal power normal signal and coal power abnormal signal;

[0077] Based on the normal signal of the main power and the abnormal signal of the coal-fired power, the speed and voltage of the coal-fired condensing steam generator set are analyzed during use, and the normal signal of the coal-fired power speed and the abnormal signal of the coal-fired power speed are obtained;

[0078] According to the abnormal speed signal of coal-fired power, the speed within several time nodes is dynamically analyzed to obtain the coal-fired power protection signal and coal-fired power regulation signal;

[0079] Based on the coal-electricity control signal, the use status of the filter of the coal-fired condensing steam generator set is identified to obtain the pressure-influencing signal and non-pressure-influencing signal of the filter. The voltage of the coal-fired condensing steam generator set is regulated according to the pressure-influencing signal of the filter to keep the voltage balanced with the main power supply.

[0080] Among them, dividing the period into several time nodes is based on the length of time.

[0081] Example 2

[0082] Acquire voltage data of the main power supply within a cycle and generate a main power status signal;

[0083] Based on the voltage data of the main power supply in the cycle, the cycle is divided into several time nodes, and the voltage data value Vi of each time node is obtained;

[0084] According to the average value formula Calculate the main voltage mean Where N is the number of measurements;

[0085] Then, the voltage data value Vi at each time node and the average voltage value are calculated. Calculate the difference and take the absolute value to get the main voltage deviation value, which is recorded as Vo;

[0086] In the plane coordinate system, with several time nodes in the main power supply unit time as the X-axis and the voltage deviation value Vo as the Y-axis, a time-main voltage deviation value curve is established;

[0087] A straight line parallel to the X-axis is drawn with the maximum limit value and the minimum limit value of the preset main voltage deviation range. The preset voltage deviation range is known from historical experience.

[0088] When the voltage deviation value is between the maximum limit value and the minimum limit value of the preset voltage deviation interval, it means that the voltage of the main power supply within the unit time is normal, which is recorded as a main power normal signal;

[0089] On the contrary, when the voltage deviation value Vo is outside the maximum limit value and the minimum limit value of the preset voltage deviation interval, it means that the voltage of the main power supply per unit time at this time is abnormal, and a main power abnormality signal is generated;

[0090] It should be noted that the main power normal signal of the main power supply within a unit time at this time may be affected by other factors, resulting in the voltage deviation value Vo being outside the maximum limit value and the minimum limit value of the preset voltage deviation range;

[0091] At the same time, because the existing coal-fired condensing steam generator set and the main power supply are switched only when the main power supply exceeds the maximum or minimum voltage, but the main power supply will have a certain fluctuation range in the process of reaching the maximum voltage or decreasing to the minimum voltage, so it can be predicted in advance;

[0092] Obtain the voltage data of the coal-fired condensing steam generator set within a unit time and generate a coal power status signal;

[0093] Based on the voltage data value of the coal-fired condensing steam generator set in unit time, the unit time is divided into several time nodes, the voltage data value of the coal-fired condensing steam generator set at each time node is obtained, and the voltage data value of the coal-fired condensing steam generator set at each time node is processed according to the average value formula to calculate the coal voltage mean;

[0094] Then, the difference between the voltage data value at each time node of the coal-fired condensing steam generator set and the average value of the coal voltage is calculated, and the absolute value is taken to obtain the coal voltage deviation value;

[0095] In the plane coordinate system, a time-coal voltage deviation value curve is established with a number of time nodes in a unit time of the coal-fired condensing steam generator set as the X-axis and the coal voltage deviation value as the Y-axis;

[0096] A straight line parallel to the X-axis is drawn with the maximum limit value and the minimum limit value of the preset coal voltage deviation range, and the preset coal voltage deviation range is known from historical experience;

[0097] When the coal voltage deviation value is between the maximum limit value and the minimum limit value of the preset coal voltage deviation range, it means that the voltage of the coal-fired condensing steam generator set in the unit time is normal, and a coal power normal signal is generated;

[0098] On the contrary, when the coal voltage deviation value is outside the maximum limit value and the minimum limit value of the preset coal voltage deviation range, it indicates that the voltage of the coal-fired condensing steam generator set per unit time is abnormal, and a coal power abnormality signal is generated.

[0099] Example 3

[0100] Based on the coal power normal signal and the main power normal signal in the above embodiment, it can be known that the power supply inductive access system of the coal-fired condensing steam generator set is in a normal state, and can switch back and forth between the main power supply and the coal-fired condensing steam generator set inductively, so as to realize the rapid and inductive access of the coal-fired condensing steam generator set without power outage of the main power supply;

[0101] Based on the coal-fired power abnormal signal in the above embodiment, the generator speed of the coal-fired condensing steam generator set is taken as the analysis object;

[0102] Get the rated speed of the generator at the standard frequency through the formula The calculated rated speed value is recorded as Np;

[0103] Based on Example 1, the actual speed of the generator when the coal-fired condensing steam generator set is running is obtained through a tachometer or other measuring equipment at each time node, which is recorded as the actual speed value Nm;

[0104] The speed deviation value is calculated by calculating the ratio of the rated speed value Np to the actual speed value Nm at each time node and recorded as Nqm;

[0105] The speed deviation value of each time node is recorded as Nqm and compared with the preset speed deviation threshold interval. When the speed deviation value Nqm is within the preset speed deviation threshold interval, the time node is recorded as a positive time node. When the speed deviation value Nqm is outside the preset speed deviation threshold interval, the time node is recorded as a reverse time node.

[0106] Obtain the number of reverse time nodes, calculate the ratio of the number of reverse time nodes to the total number of time nodes, and obtain the reverse node ratio;

[0107] The speed deviation values ​​Nqm of all time nodes in the cycle are integrated to obtain a speed deviation value group;

[0108] The speed deviation value group is processed according to the variance calculation formula to obtain the speed deviation variance value;

[0109] The speed deviation variance value is obtained by multiplying the reverse node ratio and the speed deviation variance value;

[0110] like Figure 2 As shown, the speed deviation abnormal value is compared with the speed deviation abnormal threshold value;

[0111] If the speed deviation abnormal value is greater than or equal to the speed deviation abnormal threshold, it means that the speed of the generator is abnormal when the coal-fired condensing steam generator set is running, and a coal-fired power speed abnormal signal is obtained;

[0112] If the speed deviation abnormal value is less than the speed deviation abnormal threshold, it means that the speed of the generator is normal when the coal-fired condensing steam generator set is running, and a normal coal-fired power speed signal is obtained;

[0113] It should be noted that when a normal coal-fired power speed signal is generated, the speed deviation value of the coal-fired condensing steam generator set in operation fluctuates within the rated speed range, indicating that the speed of the coal-fired condensing steam generator set is normal, and the frequencies of the coal-fired condensing steam generator set and the main power supply are within the preset fluctuation range and can continue to work. When the speed deviation value Nqm is outside the preset speed deviation threshold range and an abnormal coal-fired power speed signal is generated, the speed of the coal-fired condensing steam generator set is abnormal and the motor speed needs to be controlled.

[0114] Example 4

[0115] The filter is an important component of the generator set, used to filter particles and impurities in the air entering the engine. If the filter is blocked or damaged, it will affect the air flow, and then affect the engine's air intake, which will cause abnormal generator speed of coal-fired condensing generator sets;

[0116] Based on the abnormal coal power speed signal obtained in the above embodiment, the filter blockage degree is analyzed;

[0117] Divide the filter into several equal filter zones;

[0118] When dividing the filter area, it is necessary to ensure that the area, flow rate and filter element specifications of each filter area are evenly distributed to ensure the stability and consistency of the filtering effect;

[0119] At each time point, the steam flow rate of each filter zone is collected by a flow meter and recorded as the steam flow value Q;

[0120] It should be noted that the steam flow value at the current time node is equal to the difference between the measured steam flow value and the steam flow value at the previous time node, because the steam flow value measured by the flow meter is calculated from the time the filter starts working;

[0121] The velocity of air passing through the filter is then measured by a flow meter, and the pressure difference on both sides of the filter is calculated according to the Bernoulli formula, which is recorded as ΔP.

[0122] Calculate the ratio of the filter pressure difference ΔP to the steam flow value Q at each time node to obtain the filter resistance value S at each time node;

[0123] It is common knowledge that the resistance value of the filter can be regarded as a measure of the resistance value encountered by the fluid when passing through the filter. This resistance value is directly related to the degree of blockage of the filter. The higher the degree of blockage, the more obstacles the fluid encounters when passing through the filter, and therefore the greater the resistance value.

[0124] Then the filter blockage degree at each time node is obtained Among them, α is a constant known from historical experimental data;

[0125] Where S o It is the resistance value when the filter is completely unblocked;

[0126] The temperature sensor is used to measure the inlet temperature of the coal-fired condensing steam generator set at each time point, which is T a , the ambient temperature is T b ;

[0127] The intake pressure of the coal-fired condensing steam generator set at each time node is measured by the intake pressure sensor as P a , the ambient atmospheric pressure is P b ;

[0128] The power at each time node is obtained through the power meter and recorded as O;

[0129] Using the formula Calculate the speed at each time node and record it as a positive speed value n; where R is the torque;

[0130] According to the formula, the theoretical speed value is equal to the interference coefficient multiplied by the positive speed value, where f is the interference coefficient. The interference coefficient at each time node can be calculated using the specific formula:

[0131]

[0132] k1 and k2 are preset proportional coefficients, and η z is the turbocharger intake efficiency;

[0133] The interference coefficient of each time node is multiplied by the positive speed value to obtain the theoretical speed value of each time node, and the theoretical speed deviation value of each time node is obtained by performing a difference calculation between the theoretical speed value of each time node and the actual speed value measured by the tachometer;

[0134] When the speed deviation value is within the preset difference range, it can be known that the actual speed value at this time node is mainly affected by the blockage degree of the filter, and the pressure influence signal is generated;

[0135] On the contrary, when the rotation speed deviation value is not within the preset difference range, it can be known that the actual rotation speed value is not mainly affected by the blockage degree of the filter, and a non-inlet pressure influence signal is generated;

[0136] Based on the obtained pressure impact signal, the transfer deviation value of each time node is arranged to obtain the transfer deviation interval, which is recorded as By converting the deviation interval The maximum and minimum values ​​of the theoretical speed are added to obtain the standard speed range of the coal-fired condensing steam generator set. During the operation of the coal-fired condensing steam generator set, the speed of the generator of the coal-fired condensing steam generator set is regulated according to the standard speed range to achieve stable operation of the coal-fired condensing steam generator set;

[0137] Therefore, when using a coal-fired condensing steam generator set, if the rational speed deviation value is not within the preset difference range, it can be seen that the actual speed value is not mainly affected by the degree of filter blockage. At this time, the coal-fired condensing steam generator needs to be checked, repaired and maintained. When the rational speed deviation value is within the preset difference range, it can be seen that the actual speed value at this time node is mainly affected by the degree of filter blockage. At this time, the speed of the coal-fired condensing steam generator is regulated so that the actual speed value can reach the value within the positive speed adjustment range, and then the voltage is adjusted to restore the voltage to normal and keep it balanced with the voltage of the main power supply.

[0138] Example 5

[0139] A diagnostic system for a coal-fired condensing steam generator set, comprising a voltage data acquisition module, a real-time speed data acquisition module, a speed data analysis acquisition module, a filter data acquisition module and a speed control module;

[0140] A preset cycle is used to obtain several time nodes within the cycle. The voltage data acquisition module is used to collect voltage data values ​​of the main power supply and the coal-fired condensing steam generator set at the time nodes of the cycle, and obtain the main power state signal and the coal power state signal according to the voltage data values ​​of several time nodes;

[0141] The main power status signal is divided into main power abnormal signal and main power normal signal;

[0142] The coal power status signal is divided into coal power normal signal and coal power abnormal signal;

[0143] The real-time speed data acquisition module analyzes the speed and voltage of the coal-fired condensing steam generator set when in use based on the main power normal signal and the coal power abnormal signal, and obtains the coal power speed normal signal and the coal power speed abnormal signal;

[0144] The speed data analysis and acquisition module dynamically analyzes the speed within several time nodes according to the abnormal speed signal of coal-fired power generation, and obtains the coal-fired power protection signal and coal-fired power regulation signal;

[0145] The filter data acquisition module identifies the use status of the filter of the coal-fired condensing steam generator set based on the coal-fired power control signal, and obtains the filter's pressure-affected signal and non-pressure-affected signal;

[0146] The speed control module completes the voltage regulation of the coal-fired condensing steam generator set according to the filter's inlet pressure influence signal, and keeps the voltage balanced with the main power supply.

[0147] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for diagnosing a coal-fired condensing generator set, characterized in that: The following steps are involved: A preset cycle is divided into a number of time nodes, voltage data values ​​of the main power supply and the coal-fired condensing steam generator set are collected at the time nodes of the cycle, and a main power state signal and a coal power state signal are obtained according to the voltage data values ​​at the number of time nodes; The main power status signal is divided into main power abnormal signal and main power normal signal; The coal power status signal is divided into coal power normal signal and coal power abnormal signal; Based on the normal signal of the main power and the abnormal signal of the coal-fired power, the speed and voltage of the coal-fired condensing steam generator set are analyzed during use, and the normal signal of the coal-fired power speed and the abnormal signal of the coal-fired power speed are obtained; According to the abnormal speed signal of coal-fired power, the speed within several time nodes is dynamically analyzed to obtain the coal-fired power protection signal and coal-fired power regulation signal; Based on the coal-fired power control signal, the use status of the filter of the coal-fired condensing steam generator set is identified to obtain the filter's inlet pressure influence signal and non-inlet pressure influence signal. According to the filter's inlet pressure influence signal, the voltage of the coal-fired condensing steam generator set is regulated to maintain a balance with the voltage of the main power supply.

2. A method for diagnosing a coal-fired condensing generator set according to claim 1, characterized in that: The identification process of the main power status signal is as follows: Processing the voltage data values ​​of the main power supply at multiple time nodes within a cycle to obtain the main voltage average value of the main power supply within the cycle; The voltage data value of each time node is calculated by difference with the main voltage mean value and the absolute value is taken to obtain the main voltage deviation value; A plane coordinate system is established, with time as the X-axis and the main voltage deviation value as the Y-axis. The main voltage deviation value corresponding to each time node is constructed in chronological order as a time-main voltage deviation value curve; Draw a straight line parallel to the X-axis with the maximum limit value and the minimum limit value of the preset main voltage deviation range; The voltage within a unit time when the deviation value curve is between the maximum limit value and the minimum limit value of the main voltage deviation interval is recorded as the main power normal voltage, and a main power normal signal is obtained; The voltage per unit time when the deviation value curve is outside the maximum limit value and the minimum limit value of the main voltage deviation interval is recorded as the main power abnormal voltage, and the main power abnormal signal is obtained.

3. A method for diagnosing a coal-fired condensing generator set according to claim 1, characterized in that: The recognition process of the coal power status signal is as follows: The voltage data values ​​of the coal-fired condensing steam generator set at multiple time nodes in a cycle are processed to obtain the average value of the coal voltage of the main power supply in the cycle; The voltage data value at each time node is calculated by difference with the coal voltage mean value and the absolute value is taken to obtain the coal voltage deviation value; A plane coordinate system is established, with time as the X-axis and the coal voltage deviation value as the Y-axis, and the coal voltage deviation value corresponding to each time node is constructed in chronological order as a time-coal voltage deviation value curve; Draw a straight line parallel to the X-axis with the maximum limit value and the minimum limit value of the preset coal voltage deviation range; The voltage within a unit time when the deviation value curve is between the maximum limit value and the minimum limit value of the coal voltage deviation interval is recorded as the normal voltage of coal power generation, and a normal signal of coal power generation is obtained; The voltage per unit time when the deviation value curve is outside the maximum limit value and the minimum limit value of the coal voltage deviation interval is recorded as the coal power abnormal voltage, and the coal power abnormal signal is obtained.

4. A method for diagnosing a coal-fired condensing generator set according to claim 1, characterized in that: Get the rated speed of the generator at the standard frequency, recorded as Np; Get the actual speed of the generator when the coal-fired condensing steam generator set is running at each time node, recorded as Nm; The ratio of the rated speed value Np to the actual speed value Nm at each time node is calculated, and the speed deviation value is recorded as Nqm; The speed deviation value of each time node is recorded as Nqm and compared with the preset speed deviation threshold interval. When the speed deviation value Nqm is within the preset speed deviation threshold interval, the time node is recorded as a positive time node. When the speed deviation value Nqm is outside the preset speed deviation threshold interval, the time node is recorded as a reverse time node. Obtain the number of reverse time nodes, calculate the ratio of the number of reverse time nodes to the total number of time nodes, and obtain the reverse node ratio; The speed deviation values ​​Nqm of all time nodes in the cycle are integrated to obtain a speed deviation value group; The speed deviation value group is processed according to the variance calculation formula to obtain the speed deviation variance value; The speed deviation variance value is obtained by multiplying the reverse node ratio and the speed deviation variance value; Compare the speed deviation abnormal value with the speed deviation abnormal threshold value; If the speed deviation abnormal value is greater than or equal to the speed deviation abnormal threshold, it means that the speed of the generator is abnormal when the coal-fired condensing steam generator set is running, and a coal-fired power speed abnormal signal is obtained; If the speed deviation abnormal value is less than the speed deviation abnormal threshold, it means that the speed of the generator is normal when the coal-fired condensing steam generator set is running, and a normal coal-fired power speed signal is obtained.

5. A method for diagnosing a coal-fired condensing generator set according to claim 4, characterized in that: Based on the abnormal signal of coal power speed, the filter is divided into several identical filter areas; At each time point, the steam flow rate of each filter zone is collected by a flow meter and recorded as the steam flow value Q; Obtain the flow rate of the filter to obtain the pressure difference on both sides of the filter, recorded as ΔP; The filter resistance value S at each time node is obtained by calculating the ratio of the filter pressure difference ΔP to the steam flow value Q at each time node.

6. A method for diagnosing a coal-fired condensing generator set according to claim 5, characterized in that: By formula Calculate the speed n at each time node and record it as a positive speed value, where R is the torque; The positive speed value is multiplied by the interference coefficient to obtain the theoretical speed value of the generator at the time node; The difference between the theoretical speed value and the actual speed value at each time node is calculated to obtain the theoretical speed deviation value at each time node; When the deviation value of the transfer is within the preset difference range, a pressure influence signal is generated; When the transfer deviation value is not within the preset difference range, a non-advance pressure influence signal is generated.

7. A method for diagnosing a coal-fired condensing generator set according to claim 6, characterized in that: The process of obtaining the interference coefficient is: At each time point, the intake air temperature and ambient temperature of the coal-fired condensing steam generator set are collected, and the intake air temperature is recorded as T a , the ambient temperature is recorded as T b ; At each time point, the intake pressure and ambient atmospheric pressure of the coal-fired condensing steam generator set are collected, and the intake pressure is P a , the ambient atmospheric pressure is P b ; That is, through the formula The interference coefficient f is calculated; where k1 and k2 are preset proportional coefficients, η z is the turbocharger intake efficiency, S z The degree of filter clogging.

8. A diagnostic system and method for a coal-fired condensing generator set according to claim 7, characterized in that: The process of obtaining the filter blockage degree is as follows: Based on the filter resistance value S at each time node, the filter blockage degree at each time node is identified; That is, through the formula Calculate the filter blockage degree S at each time node z ; Among them, α is the preset proportional coefficient, and α is greater than zero, and is a constant known from historical experimental data, S o It is the resistance value when the filter is not clogged at all.

9. A method for diagnosing a coal-fired condensing generator set according to claim 8, characterized in that: Based on the pressure impact signal, the deviation value of the transfer at each time node is arranged to obtain the transfer deviation interval, which is recorded as [Q min ,Q max ], by converting the deviation interval [Q min ,Q max The maximum and minimum values ​​of ] are added to the theoretical speed value to obtain the standard speed range of the coal-fired condensing steam generator set, that is, [D min ,D max ]; The speed of the generator of the coal-fired condensing steam generator set is controlled within the standard speed range, and the voltage is adjusted to achieve a balance with the voltage of the main power supply.

10. A diagnostic system for a coal-fired condensing generator set, characterized in that: It includes voltage data acquisition module, real-time speed data acquisition module, speed data analysis acquisition module, filter data acquisition module and speed control module; A preset cycle is used to obtain several time nodes within the cycle. The voltage data acquisition module is used to collect voltage data values ​​of the main power supply and the coal-fired condensing steam generator set at the time nodes of the cycle, and obtain the main power state signal and the coal power state signal according to the voltage data values ​​of several time nodes; The main power status signal is divided into main power abnormal signal and main power normal signal; The coal power status signal is divided into coal power normal signal and coal power abnormal signal; The real-time speed data acquisition module analyzes the speed and voltage of the coal-fired condensing steam generator set when in use based on the main power normal signal and the coal power abnormal signal, and obtains the coal power speed normal signal and the coal power speed abnormal signal; The speed data analysis and acquisition module dynamically analyzes the speed within several time nodes according to the abnormal speed signal of coal-fired power generation, and obtains the coal-fired power protection signal and coal-fired power regulation signal; The filter data acquisition module identifies the use status of the filter of the coal-fired condensing steam generator set based on the coal-fired power control signal, and obtains the filter's pressure-affected signal and non-pressure-affected signal; The speed control module completes the voltage regulation of the coal-fired condensing steam generator set according to the filter's inlet pressure influence signal, and keeps the voltage balanced with the main power supply.

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