JP2017203621A - Method for monitoring and operating carbon-containing fuel heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine a failure of a carbon-containing fuel heat exchanger in an early state.SOLUTION: A method for monitoring a carbon-containing fuel heat exchanger includes: a step of calculating a Mahalanobis distance based on a matrix constituted of state quantities of a plurality of positions in a primary side flow direction of a heat exchanger of a carbon-containing fuel heat exchanger, as the elements therefor; and a step of determining whether there is failure at a heat transfer surface of the heat exchanger by the Mahalanobis distance.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for monitoring and operating a carbon-containing fuel heat exchanger.

  In various plants such as a gas turbine power plant, a nuclear power plant, or a chemical plant, in order to monitor whether or not the plant is normally operated, plant state quantities such as temperature and pressure are acquired and monitored. That is, the state quantities of multiple monitoring items to be monitored are measured at predetermined time intervals, the average and distribution of the state quantities for each monitoring item are calculated and normalized, and the correlation between the state quantities of each monitoring item And the Mahalanobis distance is calculated. When the Mahalanobis distance exceeds a preset threshold value, it is determined that there is a sign of abnormality in the plant. Patent Document 1 discloses a plant operation state monitoring method using such a Mahalanobis distance.

  Patent Document 2 discloses a technique for suppressing foreign matter from adhering to a heat transfer tube of a heat exchanger of a coal gasification combined power generation system. In the carbon-containing fuel heat exchanger such as the heat exchanger of the coal gasification combined power generation system shown in Patent Document 2, soot may adhere to the heat transfer surface of the heat exchanger depending on the type of gas. If such an abnormality of the carbon-containing fuel heat exchanger is not detected at an early stage, the attached soot will sinter and become difficult to remove. Therefore, it is preferable to monitor the abnormality of the carbon-containing fuel heat exchanger and discover the abnormality at an early stage.

JP 2010-181188 A JP 2001-254086 A

Patent Document 1 discloses a technique for appropriately monitoring the plant operation state by calculating the Mahalanobis distance based on state quantities at a plurality of locations along the circumferential direction of the rotating shaft of the gas turbine. On the other hand, Patent Document 1 does not disclose a configuration for detecting an abnormality of the carbon-containing fuel heat exchanger at an early stage.
An object of the present invention is to provide a method for monitoring and operating a carbon-containing fuel heat exchanger that can detect an abnormality of the carbon-containing fuel heat exchanger at an early stage.

The first aspect includes a process of calculating a Mahalanobis distance based on a matrix having state quantities at a plurality of positions in a primary flow direction of a heat exchanger of a carbon-containing fuel heat exchanger as elements, and the Mahalanobis distance. And a process for determining whether or not there is an abnormality in the heat transfer surface of the heat exchanger, and a method for monitoring a carbon-containing fuel heat exchanger.
In addition, the second aspect further includes a process of acquiring state quantities of the plurality of positions, and a process of comparing each Mahalanobis distance calculated in the process of calculating the Mahalanobis distance with a threshold value, and the Mahalanobis. In the process of calculating the distance, the Mahalanobis distance is calculated for each of the plurality of positions using the state quantities of the plurality of positions acquired in the process of acquiring the state quantity, and the heat transfer surface of the heat exchanger In the step of determining whether or not there is an abnormality, the carbon-containing fuel heat according to the first aspect is used to determine whether or not there is an abnormality in the heat transfer surface of the heat exchanger based on a comparison result between each Mahalanobis distance and the threshold value. This is a monitoring method for the exchanger.

  In addition, in the third aspect, in the calculation process of the Mahalanobis distance, in addition to the temperatures at a plurality of positions in the flow direction on the primary side, the differential pressure at the inlet / outlet on the primary side, the flow rate on the primary side, 1st aspect or 2nd aspect which calculates the said Mahalanobis distance based on the matrix which uses at least any one of the several temperature of the flow direction of the secondary side of the said heat exchanger, or the flow volume of a secondary side as an element The monitoring method of the carbon containing fuel heat exchanger as described in 1 above.

  Further, the fourth aspect is configured such that when the carbon-containing fuel heat exchanger monitoring method according to any one of the first to third aspects determines that the heat transfer surface is abnormal, It is the operating method of the carbon containing fuel heat exchanger which has the process of changing the operating condition of the removal apparatus with which the exchanger was equipped.

  According to the above aspect, by calculating the Mahalanobis distance based on the state quantities at a plurality of positions in the flow direction on the primary side, it is detected that the efficiency of heat exchange is reduced due to partial blockage of the heat transfer surface. be able to. Thereby, abnormality of a carbon containing fuel heat exchanger can be determined at an early stage.

It is a schematic diagram which shows the structural example of the abnormality monitoring apparatus which concerns on 1st Embodiment. It is a schematic diagram for demonstrating the process part of FIG. 1 concretely. It is a conceptual diagram which shows the concept of Mahalanobis distance. It is a flowchart which shows the procedure of the monitoring and the operating method of the carbon containing fuel heat exchanger which concerns on this embodiment. It is a schematic diagram for demonstrating specifically the process part which concerns on 2nd Embodiment.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. It should be noted that the present invention is not limited by the modes for carrying out the invention (hereinafter referred to as embodiments). In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range.

FIG. 1 is a schematic diagram illustrating a configuration example of an abnormality monitoring apparatus according to the present embodiment. The abnormality monitoring device 10 monitors the operating state of the carbon-containing fuel heat exchanger 1 to determine whether or not the carbon-containing fuel heat exchanger 1 is operating normally.
The state quantity for monitoring the carbon-containing fuel heat exchanger 1 is, for example, temperatures at a plurality of positions in the flow direction G on the primary side of the heat exchanger 2 (inlet temperature and outlet temperature of the heat exchanger 2). Etc.) There are differential pressure at the inlet / outlet in the flow direction G on the primary side, a flow rate on the primary side, a plurality of temperatures in the flow direction W on the secondary side, a flow rate of the heat exchange medium in the heat transfer tube 4, and the like. In addition, the primary side of the heat exchanger 2 shows a high temperature side. That is, in this embodiment, the primary side of the heat exchanger 2 indicates the side through which the fuel flows. On the other hand, the secondary side of the heat exchanger 2 indicates the low temperature side. That is, in this embodiment, the secondary side of the heat exchanger 2 indicates the side on which the heat exchange medium flows. These state quantities are indicated as monitoring target data.

  A carbon-containing fuel heat exchanger 1 to be monitored includes a heat exchanger 2, a fuel flow path 3, a heat transfer tube 4, and a removal device 5. The fuel is supplied into the heat exchanger 2 through the fuel flow path 3. Examples of the fuel include fuel gas and powder fuel. A heat transfer tube 4 passes through the heat exchanger 2, and thereby a heat transfer surface 6 is formed. Heat exchange is performed between the fuel flowing from the fuel flow path 3 to the heat exchanger 2 and the heat exchange medium flowing through the heat transfer pipe 4 on the heat transfer surface 6. Examples of the heat exchange medium include water. Moreover, the degassing device 5 removes soot due to carbon contained in the fuel attached to the heat transfer surface 6 constituted by the heat transfer tubes 4. As the removal device 5, a vibration-type removal device that vibrates the heat transfer surface 6, a hard ball dropping type removal device that drops a hard ball on the heat transfer surface 6, and a compressed gas (nitrogen, steam, etc.) on the heat transfer surface 6. An injection-type degaussing device (for example, a suit blower) that injects the gas can be used.

  The abnormality monitoring device 10 monitors the state of the carbon-containing fuel heat exchanger 1. In the present embodiment, the abnormality monitoring device 10 monitors the state of one carbon-containing fuel heat exchanger 1, but may monitor the operating state of a plurality of carbon-containing fuel heat exchangers 1. The abnormality monitoring device 10 is, for example, a computer, and includes an input / output unit (I / O) 11, a processing unit 12, and a storage unit 13. The abnormality monitoring apparatus 10 may be configured using a so-called personal computer, or may be configured by combining a CPU (Central Processing Unit) and a memory.

  The processing unit 12 receives the state quantity of the carbon-containing fuel heat exchanger 1 from various state quantity detection means (sensors) attached to the carbon-containing fuel heat exchanger 1 via the input / output unit 11. The various state quantity detection means periodically acquire corresponding state quantities at predetermined time intervals from the start of activation, and input them to the processing unit 12 via the input / output unit 11.

  The monitoring target data group indicating the state quantity of the carbon-containing fuel heat exchanger 1 is sent to the processing unit 12 of the abnormality monitoring device 10 in the form of an electrical signal. The processing unit 12 is constituted by, for example, a CPU, and sequentially reads and interprets an instruction sequence called a program (computer program) existing on the storage unit 13, and moves or processes data according to the result.

  Note that the processing unit 12 may be realized by dedicated hardware. Further, the computer program for realizing the function of the processing unit 12 is recorded on a non-transitory recording medium that can be read by the computer, and the computer program recorded on the recording medium is read into the computer system and executed. The processing procedure of the monitoring / driving method according to the embodiment may be executed. Here, the “computer system” includes an OS and hardware such as peripheral devices.

  In addition, “a computer-readable non-temporary recording medium” refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, or a recording device such as a hard disk built in a computer system. Say. Further, the “computer-readable recording medium” refers to a computer program that is dynamically used for a short time, such as a communication line when a computer program is transmitted via a communication line such as the Internet or a telephone line. What is held, and what holds a computer program for a certain period of time, such as a volatile memory inside a computer system as a server or a client in that case, are included. Further, the computer program may be for realizing a part of the above-described functions, and even if the functions described above can be realized in combination with a computer program already recorded in the computer system. Good.

  The method for monitoring and operating the carbon-containing fuel heat exchanger 1 according to the present embodiment can be realized by executing a computer program prepared in advance on a computer such as a personal computer or a workstation. This computer program can be distributed via a communication line such as the Internet. The computer program is recorded on a computer-readable recording medium such as a hard disk, a flexible disk (FD), a CD-ROM, an MO, and a DVD, and is executed by being read from the recording medium by the computer. May be.

  In the processing unit 12, as shown in FIG. 2, based on the monitoring target data acquisition process A for acquiring the monitoring target data indicating the state quantity of the carbon-containing fuel heat exchanger 1 and the acquired monitoring target data, the Mahalanobis distance A Mahalanobis distance calculation process B for calculating A, a comparison process C for comparing the calculated Mahalanobis distance with a threshold value, an abnormality determination process D for determining presence / absence of an abnormality based on a comparison result between the Mahalanobis distance and the threshold value, and an abnormality determination result Based on this, processing such as an operation condition change process E for changing the operation condition of the dehuller 5 is performed in each arithmetic unit.

  The concept of Mahalanobis distance is shown in FIG. In FIG. 3, as an example, the horizontal axis represents the difference between the inlet temperature and the outlet temperature in the primary flow direction G of the heat exchanger 2, and the vertical axis represents a certain point in the secondary flow direction W of the heat exchanger 2. 2 shows the correlation between the two parameters taken at the temperature. That is, when soot accumulates on the heat transfer surface 6, the efficiency of heat exchange between the fuel and the heat exchange medium decreases, and the temperature at a certain point on the secondary side of the heat exchanger 2 decreases. Although each measurement data varies depending on the atmospheric conditions and operating conditions, the temperature difference between the inlet and outlet on the primary side of the heat exchanger 2 and the temperature at a certain point on the secondary side of the heat exchanger 2 are different. There is a correlation between them and it falls within a specific range. A unit space serving as a reference is created using these as reference data. In each of the other state quantities, the correlation can be obtained like the temperature difference on the primary side and the temperature on the secondary side. Then, whether the data to be determined is normal or abnormal is determined based on the Mahalanobis distance for the unit space.

The above-described Mahalanobis unit space can be obtained by the following items that are predetermined in the present embodiment.
(1) Based on the monitoring target data indicating the state quantity of the carbon-containing fuel heat exchanger 1 in the past period from the time when the state of the carbon-containing fuel heat exchanger 1 is evaluated to the past before the predetermined period, Calculate the Mahalanobis unit space.
(2) Based on the monitoring target data indicating the state quantity at the time of evaluating the state of the carbon-containing fuel heat exchanger 1, the state of the future carbon-containing fuel heat exchanger 1 is predicted, and Mahalanobis is based on the predicted value. The unit space of is calculated.
(3) Based on the monitoring target data indicating the state quantity at the time of evaluating the state of the carbon-containing fuel heat exchanger 1 and the control target set value set when the carbon-containing fuel heat exchanger 1 is started up, future carbon The state of the contained fuel heat exchanger 1 is predicted, and the Mahalanobis unit space is calculated based on the predicted value.

  In addition, when determining whether the carbon containing fuel heat exchanger 1 is normal using Mahalanobis distance, multidimensional data is converted into one-dimensional data using Mahalanobis distance. Then, the difference between the unit space and the signal space (data to be compared with the unit space, for example, the state quantity when the state of the carbon-containing fuel heat exchanger 1 is evaluated) is evaluated by the Mahalanobis distance. In the present embodiment, the Mahalanobis distance of the signal space is obtained using a matrix created from the unit space. As a result, data anomalies can be expressed.

  A control panel 14 serving as output means is connected to the input / output unit 11 of the abnormality monitoring apparatus 10. The control panel 14 is provided with a display 14D which is a display means and an input means 14C for inputting a command to the abnormality monitoring device 10. The storage unit 13 of the abnormality monitoring device 10 includes, for example, a volatile memory such as a RAM (Random Access Memory), a nonvolatile memory such as a ROM (Read Only Memory), a hard disk device, a magneto-optical disk device, The read-only storage medium such as a CD-ROM or a combination thereof is configured. The storage unit 13 stores a computer program, data, and the like for realizing the monitoring / operating method of the carbon-containing fuel heat exchanger 1 according to the present embodiment. The processing unit 12 uses these computer programs and data to realize the monitoring and operation method of the carbon-containing fuel heat exchanger 1 according to the present embodiment, and to control the operation of the carbon-containing fuel heat exchanger 1. Or The storage unit 13 may be provided outside the abnormality monitoring device 10 so that the abnormality monitoring device 10 can access the storage unit 13 via a communication line.

Here, a calculation formula for calculating a general Mahalanobis distance D will be described.
First, the total number of a plurality of state quantities representing the state of the carbon-containing fuel heat exchanger 1 is u, each state quantity is assigned to a variable X, and u state quantities are defined by variables X1 to Xu (u is An integer of 2 or more). Next, in the operation state of the reference carbon-containing fuel heat exchanger 1, a total of v (two or more) state quantities (indicated by monitoring target data) of the variables X1 to Xu are collected.

  The average value Mi and the standard deviation σi (the degree of variation of the reference data) of each of the variables X1 to Xu are obtained by the formulas (1) and (2). Note that i is the number of items (the number of state quantities, an integer), which is a value corresponding to the variables X1 to Xu set to 1 to u. j takes any value (integer) from 1 to v, meaning that the number of each state quantity is v. For example, when 60 state quantities are acquired, v = 60. Here, the standard deviation is the square root of the expected value of the difference between the state quantity and its average value squared.

  Next, the standardization of converting the original variables X1 to Xu into x1 to xu by the following formula (3) using the above-described average value Mi and standard deviation σi which are state quantities that are calculated and indicate characteristics. Do. That is, the state quantity of the carbon-containing fuel heat exchanger 1 is converted into a random variable having an average of 0 and a standard deviation of 1. In the following mathematical formula (3), j takes any value (integer) from 1 to v, meaning that the number of each state quantity is v.

  Next, in order to analyze the data with the variables standardized to mean 0 and variance 1, the correlation between the variables X1 to Xu, that is, the covariance matrix (correlation matrix) R indicating the relationship between the variables, and the covariance An inverse matrix R-1 of the matrix (correlation matrix) is defined by the following mathematical formula (4). In the following mathematical formula (4), k is the number of items (the number of state quantities), which is u here. Further, i and p indicate values in the respective state quantities, and take values of 1 to u here.

  After such a calculation process, the Mahalanobis distance D, which is a state quantity indicating a feature, is obtained based on the following formula (5). In Equation (5), j takes any value (integer) from 1 to v, meaning that the number of each state quantity is v. Further, k is the number of items (the number of state quantities), which is u here. Further, a11 to akk are coefficients of the inverse matrix R-1 of the covariance matrix R shown in the above-described equation (4).

  The Mahalanobis distance D is reference data, that is, the average value of the Mahalanobis distance D in the unit space is 1, and is approximately 3 or less when the state quantity of the carbon-containing fuel heat exchanger 1 is normal. However, when the state quantity of the carbon-containing fuel heat exchanger 1 becomes abnormal, the value of the Mahalanobis distance D increases. As described above, the Mahalanobis distance D has a property that the value increases according to the degree of abnormality of the state quantity of the carbon-containing fuel heat exchanger 1 (the degree of separation from the unit space).

The above formulas (1) to (5) are calculation formulas for calculating a general Mahalanobis distance D. In the present embodiment, at least the heat exchanger 2 is used as a parameter for calculating the Mahalanobis distance D. The temperature at a plurality of positions in the flow direction G on the primary side is used.
When soot accumulates on the heat transfer surface 6 of the heat exchanger 2, the efficiency of heat exchange on the heat transfer surface 6 decreases. For this reason, the temperature of the fuel is unlikely to decrease on the primary side of the heat exchanger 2. At this time, when the temperature difference between the inlet and outlet on the primary side of the heat exchanger 2 at the normal time and the temperature difference between the inlet and outlet on the primary side of the heat exchanger 2 at the time of abnormality are compared, the temperature at the time of abnormality becomes smaller. Therefore, by detecting the Mahalanobis distance D based on the temperatures at a plurality of positions in the flow direction G of the heat transfer surface 6, it is detected that the efficiency of heat exchange is reduced due to partial blockage of the heat transfer surface 6. Can do. The state in which the efficiency of heat exchange decreases due to accumulation of soot on the heat transfer surface 6 increases the differential pressure at the inlet / outlet on the primary side of the heat exchanger 2 (notably at the end of the closing of the heat transfer surface 6). Occurs before). Therefore, according to the monitoring / operating method of the carbon-containing fuel heat exchanger 1 according to the present embodiment, the abnormality of the carbon-containing fuel heat exchanger 1 is detected before the increase in the differential pressure at the inlet / outlet on the primary side becomes significant. It can be determined.

  Next, the procedure of the monitoring / operation method of the carbon-containing fuel heat exchanger 1 according to the present embodiment will be described. The monitoring / operation method of the carbon-containing fuel heat exchanger 1 according to the present embodiment is realized by the processing unit 12 of the abnormality monitoring apparatus 10 illustrated in FIG.

FIG. 4 is a flowchart showing the procedure of the method for monitoring and operating the carbon-containing fuel heat exchanger according to the present embodiment.
In step S1, first, monitoring target data indicating a state quantity is obtained from the carbon-containing fuel heat exchanger 1 in the current state quantity obtaining period. The state quantity is periodically acquired from various sensors attached to the carbon-containing fuel heat exchanger 1 at predetermined time intervals, and stored in the storage unit 13 of the abnormality monitoring device 10, for example.

  In step S2, the Mahalanobis distance is calculated for each state quantity stored in the storage unit 13 according to the above formula.

  In step S3, it is determined whether or not the Mahalanobis distance exceeds the threshold value by comparing the preset threshold value with the Mahalanobis distance obtained in the previous step S2. After that, based on the determination result in step S3, when the Mahalanobis distance exceeds YES, it is determined as “abnormal” (step S4). When the Mahalanobis distance does not exceed the threshold, NO. It determines with "normal" (step S5).

  If it is determined that the carbon-containing fuel heat exchanger 1 is abnormal based on the Mahalanobis distance, the abnormality monitoring device 10 changes the operating conditions of the de-airing device 5 in step S6. As a result, the abnormality monitoring device 10 can remove the soot before the clogging occurs in the carbon-containing fuel heat exchanger 1 and the clogging is caused by the removal device 5. Examples of a method for changing the operating conditions of the removal device 5 include increasing the frequency of use. As a change in operation conditions, when increasing the frequency of use, after changing the operation conditions of the removal device 5, if it is determined in step S 4 that the carbon-containing fuel heat exchanger 1 is normal, the operation conditions are changed. It is preferable to return.

  As described above, the Mahalanobis distance increases as the distance from the unit space increases, depending on the degree of abnormality. The Mahalanobis distance D is approximately 3 or less when the reference data, that is, the average value of the unit space is 1, and the state quantity of the carbon-containing fuel heat exchanger 1 is normal. Therefore, for example, the threshold value can be appropriately set to a value larger than the maximum value of the unit space. In addition, the threshold value is preferably set to a set value that takes into consideration the unique characteristics of the carbon-containing fuel heat exchanger 1, manufacturing variations of the carbon-containing fuel heat exchanger 1, and the like.

As described above in detail, according to the monitoring / operating method of the carbon-containing fuel heat exchanger 1 shown in the present embodiment, the Mahalanobis distance is calculated at least in the flow direction G on the primary side of the heat exchanger 2. Use temperatures at multiple locations.
When soot accumulates on the heat transfer surface 6 of the heat exchanger 2, the efficiency of heat exchange on the heat transfer surface 6 decreases. For this reason, the temperature of the fuel is unlikely to decrease on the heat transfer surface 6 of the heat exchanger 2. At this time, the difference between the temperature of the heat transfer surface 6 of the heat exchanger 2 in the normal state and the temperature of the heat transfer surface 6 of the heat exchanger 2 in the abnormal state is lower in the flow direction G than in the flow direction G. Becomes larger. Therefore, by calculating the Mahalanobis distance D based on the temperatures at a plurality of positions in the flow direction G on the primary side, it can be detected that the efficiency of heat exchange is reduced due to partial blockage of the heat transfer surface 6. it can. The state in which the efficiency of heat exchange decreases due to accumulation of soot on the heat transfer surface 6 increases the differential pressure at the inlet / outlet on the primary side of the heat exchanger 2 and the heat transfer surface 6 becomes clogged. Occurs before. Therefore, according to the monitoring / operating method of the carbon-containing fuel heat exchanger 1 according to the present embodiment, the abnormality of the carbon-containing fuel heat exchanger 1 is detected before the increase in the differential pressure at the inlet / outlet on the primary side becomes significant. It can be determined.

  Moreover, according to the monitoring and operation method of the carbon-containing fuel heat exchanger 1 shown in the present embodiment, in addition to the temperatures at a plurality of positions in the flow direction G on the primary side of the heat exchanger 2, the primary side The Mahalanobis distance is calculated using the differential pressure at the inlet and outlet in the flow direction G, the flow rate on the primary side, the plurality of temperatures in the flow direction W on the secondary side, and the flow rate of the heat exchange medium in the heat transfer tube 4. Thereby, the abnormality of the carbon-containing fuel heat exchanger 1 can be determined with high accuracy. In this embodiment, the inlet / outlet differential pressure in the primary flow direction G, the primary flow rate, the multiple temperatures in the secondary flow direction W, and the heat exchange medium flow rate in the heat transfer tubes 4 Although the case where the Mahalanobis distance is calculated using the above has been described, the present invention is not limited to this. For example, in another embodiment, in addition to the temperature at a plurality of positions in the primary flow direction G of the heat exchanger 2, the inlet / outlet differential pressure in the primary flow direction G, the primary flow rate, The Mahalanobis distance may be calculated using at least one of a plurality of temperatures in the flow direction W on the secondary side and the flow rate of the heat exchange medium in the heat transfer tube 4.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIG. The monitoring and operating method of the carbon-containing fuel heat exchanger 1 shown in the second embodiment is different from the first embodiment in that the Mahalanobis distance is set for each of the plurality of ranges in the flow direction G on the primary side. It is in the point to calculate.
That is, as shown in FIG. 5, instead of the Mahalanobis distance calculation process B for calculating the Mahalanobis distance shown in the first embodiment, a plurality of Mahalanobis distances are obtained in a plurality of Mahalanobis distance calculation processes indicated by reference symbol B ′. . Further, instead of the comparison process C in which the calculated Mahalanobis distance is compared with the threshold value shown in the first embodiment, each Mahalanobis distance is compared with the threshold value in a plurality of comparison processes indicated by reference symbol C ′.

  Specifically, in the processing unit 20, as shown in FIG. 5, the monitoring target data acquisition process A for acquiring monitoring target data indicating the state quantity of the carbon-containing fuel heat exchanger 1 and the acquired monitoring target data Based on the Mahalanobis distance calculation process B ′ for calculating the Mahalanobis distance for each of a plurality of ranges in the flow direction G on the primary side, the comparison process C ′ for comparing each calculated Mahalanobis distance with a threshold value, and the Mahalanobis distance Processing such as an abnormality determination process D for determining the presence / absence of an abnormality based on a comparison result with a threshold and an operation condition change process E for changing the operation condition of the removal device 5 based on the abnormality determination result are performed in each arithmetic unit. Do it. Thereby, in the abnormality determination process D, it can be determined at which position in the flow direction G on the primary side of the heat exchanger 2 an abnormality has occurred. Thereby, the operation condition changing process E can change the operation condition so that the removal device 5 is operated intensively at a portion of the heat exchanger 2 where an abnormality has occurred.

  And also in the monitoring and operation method of the carbon-containing fuel heat exchanger 1 shown in the second embodiment, at least a plurality of positions in the flow direction G on the primary side of the heat exchanger 2 as in the first embodiment. Is used. Therefore, according to the monitoring / operating method of the carbon-containing fuel heat exchanger 1 according to the present embodiment, the abnormality of the carbon-containing fuel heat exchanger 1 is detected before the increase in the differential pressure at the inlet / outlet on the primary side becomes significant. It can be determined.

  Moreover, according to the monitoring and operation method of the carbon-containing fuel heat exchanger 1 shown in the present embodiment, the temperatures at a plurality of positions in the flow direction G on the primary side of the heat exchanger 2 are the same as in the first embodiment. In addition, the differential pressure at the inlet and outlet in the primary flow direction G, the primary flow rate, the multiple temperatures in the secondary flow direction W, and the heat exchange medium flow rate in the heat transfer tube 4 are used. To calculate the Mahalanobis distance. Thereby, the abnormality monitoring apparatus 10 can determine the abnormality of the carbon-containing fuel heat exchanger 1 with high accuracy.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

DESCRIPTION OF SYMBOLS 1 Carbon-containing fuel heat exchanger 2 Heat exchanger 12 Processing part 20 Processing part

Claims (4)

Calculating a Mahalanobis distance based on a matrix having state quantities at a plurality of positions in the flow direction on the primary side of the heat exchanger of the carbon-containing fuel heat exchanger,
The process of determining the presence or absence of an abnormality in the heat transfer surface of the heat exchanger according to the Mahalanobis distance;
A method for monitoring a carbon-containing fuel heat exchanger. Obtaining a state quantity of the plurality of positions;
A step of comparing each Mahalanobis distance calculated in the step of calculating the Mahalanobis distance with a threshold;
Further comprising
In the process of calculating the Mahalanobis distance,
The Mahalanobis distance is calculated for each of the plurality of positions using the state quantities of the plurality of positions acquired in the process of acquiring the state quantity,
In the process of determining whether there is an abnormality in the heat transfer surface of the heat exchanger,
The presence / absence of abnormality of the heat transfer surface of the heat exchanger is determined based on a comparison result between each Mahalanobis distance and the threshold value.
The method for monitoring a carbon-containing fuel heat exchanger according to claim 1. In the calculation process of the Mahalanobis distance, in addition to the temperatures at a plurality of positions in the flow direction on the primary side, the differential pressure at the inlet / outlet on the primary side, the flow rate on the primary side, the secondary side of the heat exchanger 3. The carbon-containing fuel heat exchanger according to claim 1, wherein the Mahalanobis distance is calculated on the basis of a matrix having at least one of a plurality of temperatures in the flow direction or a flow rate on the secondary side as an element. Monitoring method. The removal apparatus with which the said heat exchanger was equipped when it determined with the monitoring method of the carbon containing fuel heat exchanger of any one of Claims 1-3 having abnormality in the said heat-transfer surface A method for operating a carbon-containing fuel heat exchanger having a process of changing the operating conditions.

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