Method and control system for monitoring the process of circulating solid materials in a circulating fluidized bed reactor.

Abstract

The invention relates to a method for monitoring a solid material circulation process in a circulating fluidized bed reactor, which at least comprises the steps of: selecting process variables of the solid material circulation process in the return path of the solid material and selecting performance indicators of the process from among the selected process variables for each performance indicator of the process; creating a multivariate model for each performance indicator using historical data of the process variables and the performance indicators; applying the current measured values of the process variables to the multivariate model to determine the modeled values of the performance indicators; comparing the modeled values of each performance indicator with the measured values of each performance indicator to check for the presence of anomalies between the modeled values and the measured values. As a result of this method, problems that may occur in the circulation of solid materials can be effectively predicted, so that corrective measures can be taken early enough to keep the process operable. The invention also relates to a control system for monitoring the solid material circulation process in a circulating fluidized bed reactor.

Description

[Technical Field]

[0001]

[01] The present invention relates to a method for monitoring the process of circulating solid materials in a circulating fluidized bed reactor as described in the preamble of claim 1.

[0002]

[02] The present invention relates to a control system for monitoring the process of circulating solid materials in a circulating fluidized bed reactor as described in the preamble of the second independent claim. [Background technology]

[0003]

[03] In a circulating fluidized bed reactor, fine solid material is utilized in the process by fluidizing the solid material to such an extent that a substantial portion of the material is drawn from the reaction chamber into at least one solid material separator, and from the solid material separator, a portion of the solid material separated from the gas can be circulated to a fluidized bed heat exchanger and then back to the combustion chamber. Such a CFB reactor is well applicable to generating electricity by the combustion of fuel within the CFB reactor for the generation of steam, in which case the CFB reactor is usually referred to as a CFB boiler. Similarly, CFB reactors are also known to be used to produce product gases such as gaseous fuels, in which case the reaction takes place within the CFB reactor. When producing gaseous fuel from solid fuel, the CFB reactor is usually referred to as a CFB gasifier.

[0004]

[04] Difficult fuels can cause particle aggregation in the fluidized bed material, which can further lead to more serious sintering of the solid material, and ultimately to blockage in the solid return system and reactor shutdown if corrective procedures are not initiated in time. For example, due to continuously fluctuating fuel quality, it may be impossible for the operator to recognize sintering by following conventional basic operating routines.

[0005]

[05] U.S. Patent No. 8,292,977 discloses a system for controlling the circulation rate of particles in a circulating fluidized bed furnace, in which particles are circulated between a fluidized bed combustion furnace for heating the particles and a fluidized bed gasifier for gasifying the raw materials through heating the raw materials with the heated high-temperature particles. The control is based on measuring the pressure in the fluidized bed gasifier and controlling the exhaust rate from the fluidized bed gasifier.

[0006]

[06] Japanese Patent No. 4254004 discloses control of fluidization rate based on estimation of external circulating solids in a circulating fluidized bed boiler. This estimation is based on measuring the temperature and pressure in the reactor and external fluidized bed superheater heat exchanger, as well as the outlet steam temperature and the amount of superheat prevention water.

[0007]

[07] Japanese Patent No. 4443481 relates to a system for diagnosing blockage of a fluid medium, comprising a plurality of differential pressure gauges for measuring differential pressure at predetermined locations in a fluid medium circulation path and a plurality of thermometers for measuring temperature at predetermined locations in a fluid medium circulation path, and provides a determination result display means that displays the fact that the fluid medium is blocked and the location where the fluid medium is blocked when the determination means determines that the fluid medium is blocked.

[0008]

[08] Even if circulating fluidized bed (CFB) reactors have advantages over other combustion technologies, the problem of solid material aggregation in CFB technology in particular is a concern as it can lead to unscheduled plant shutdowns.

[0009]

[09] The object of the present invention is to provide a method for monitoring and controlling the monitoring of a solid material circulation process in a circulating fluidized bed reactor, which can avoid or at least minimize unintended shutdowns. [Overview of the project]

[0010]

[0010] Objects of the present invention can be achieved substantially as disclosed in the independent claim and in other claims describing further details of different embodiments of the present invention.

[0011]

[0011] According to the present invention, a method for monitoring the process of circulation of a solid material in a circulating fluidized bed reactor, wherein the reactor comprises a reaction chamber, at least one solid material separator, and a return path between at least one solid material separator and the reaction chamber, and in this method, the process of circulation of the solid material comprises arranging the solid material to be drawn in by a gas flow in the reaction chamber and further drawn from the reaction chamber to at least one solid material separator, and sending the solid material from the solid material separator to the reaction chamber via the return path. The method comprises at least the following steps: a. Select process variables for the solid material circulation process in the return path, and select performance indicators for the solid material circulation process from the selected process variables for each performance indicator of the solid material circulation process. b. A step of creating a multivariate model for each performance indicator using historical data of process variables and performance indicators for the circulation process of solid materials. c. A step of determining the modeled values ​​of performance indicators by applying the currently measured values ​​of process variables to a multivariate model. d. A step of comparing the modeled value of each performance indicator with the measured value of each performance indicator and checking for the presence of anomalies between the modeled value and the measured value.

[0012]

[0012] When a modeled value of a performance indicator is determined by using online value process variables and the modeled value of that performance indicator is compared with the online value of each performance indicator, the method provides the effect that potential problems such as floor quality issues and / or the risk of floor material sintering and / or the risk of potential floor material blockage in the circulation of solid materials can be effectively foreseen so that corrective actions can be taken quickly enough to keep the process operational.

[0013]

[0013] According to a preferred embodiment of the present invention, the method comprises combustion of fuel in a circulating fluidized bed reactor, i.e., in a circulating fluidized bed boiler. Thus, according to a preferred embodiment of the present invention, the reaction chamber is a combustion chamber.

[0014]

[0014] According to another aspect of the present invention, the method comprises producing a gaseous fuel by converting a combustible substance into a gaseous fuel in a circulating fluidized bed reactor, i.e., a circulating fluidized bed gasifier.

[0015]

[0015] According to one aspect of the present invention, the method may, in combination with any other step of the method, include indicating to the operator possible corrective measures to be taken to control the situation in a manner that reduces the tendency of the solid material to aggregate, the corrective measures including at least one of the following: • Modifying the fuel mixture by reducing the proportion of fuels that are prone to forming aggregates. - To increase the coagulation temperature of the floor by introducing additives such as clay (e.g., kaolin) or by increasing the amount of such additives, and / or • Reduce the load on the reactor, and / or first reduce the load and then increase the load, thereby also reducing the tendency to aggregate. • Increase the supply of supplemental materials such as sand to the reaction chamber or fluidized bed heat exchanger. • Remove aggregates from the reaction chamber by discharging bottom ash from the reaction chamber or by increasing the rate of bottom ash discharge. • Removal of solid material from the return path, which also makes it possible to remove aggregated floor material.

[0016]

[0016] According to one aspect of the present invention, the comparison between the modeled value of the performance indicator in step d above and the measured value of each performance indicator may be based on at least one of the following: the difference, the absolute value of the difference, or the ratio.

[0017]

[0017] According to one aspect of the present invention, the process of circulating a solid material comprises sending the solid material directly from a separator through a loop seal to a reaction chamber, at least i. Pressure difference of the loop seal in the return path, ii. The temperature within the loop seal in the return path of the solid material circulation is selected as an indicator of the performance of the solid material circulation process.

[0018]

[0018] This embodiment relates to one embodiment of the present invention, in which the CFB reactor is equipped with a loop seal in the return path, and a selected performance indicator provides an efficient method for monitoring the process of solid material circulation.

[0019]

[0019] According to one aspect of the present invention, the process of circulating a solid material comprises sending the solid material directly from a separator through a return path to a reaction chamber, at least i. Pressure difference in the return path and, ii. The temperature in the return path of the solid material circulation is selected as an indicator of the performance of the solid material circulation process.

[0020]

[0020] This embodiment relates to one embodiment of the present invention in which the return path of the CFB reactor does not have a loop seal, or the solid material is led from a position upstream of the loop seal to the reaction chamber.

[0021]

[0021] According to one aspect of the present invention, the process of circulating a solid material comprises sending the solid material from a separator through a fluidized bed heat exchanger to a reaction chamber, at least i. Pressure difference of the loop seal in the return path, ii. Temperature in the loop seal in the return path of the solid material circulation, iii. Pressure difference in a fluidized bed heat exchanger, iv. Temperature of solid material downstream of the heat exchange unit of a fluidized bed heat exchanger and However, it is selected as a performance indicator for the solid material recycling process.

[0022]

[0022] This embodiment relates to one embodiment of the present invention in which the selected performance indicator covers a CFB reactor comprising a loop seal and a fluidized bed heat exchanger in the return path. The selected performance indicator provides an efficient method for monitoring the process of solid material circulation at several key locations in the process.

[0023]

[0023] According to one aspect of the present invention, the temperature of the solid material downstream of the fluidized bed heat exchange unit is measured at the bottom of the fluidized bed heat exchanger. According to another aspect of the present invention, the temperature of the solid in the fluidized bed heat exchanger is measured at the bottom of the fluidized bed above the fluidizing nozzle. Generally, the term “downstream of the heat exchange unit” can be understood as downstream or below the heat exchange tubes of the unit that extend into the fluidized bed heat exchanger. In other words, the temperature of the solid material downstream of the fluidized bed heat exchange unit can be measured below the heat exchange unit of the fluidized bed heat exchanger. To put it another way, the temperature of the solid material downstream of the fluidized bed heat exchange unit can be measured below the heat exchange tubes of the fluidized bed heat exchanger and above the fluidizing nozzle. The fluidized bed heat exchange unit may be selected as needed and may be, for example, an evaporator, a superheater, or a reheater.

[0024]

[0024] According to one aspect of the present invention, the process of circulating a solid material comprises sending the solid material directly from a separator through a loop seal to a reaction chamber, and at least, i. Pressure difference of the loop seal in the return path, ii. The temperature within the loop seal in the return path of the solid material circulation is selected as a performance indicator of the solid material circulation process. i. The process variables of the performance indicator, the pressure difference of the loop seal in the return path, include the total reaction gas flow rate supplied into the reactor, the product gas temperature upstream of the loop seal, and the floor temperature inside the reaction chamber. ii. The process variables for the performance indicator of temperature within the loop seal in the circulation of solid materials include the total reaction gas flow rate supplied into the reactor, the temperature of the product gas upstream of the loop seal, and the floor temperature within the reaction chamber.

[0025]

[0025] According to one aspect of the present invention, in the case of a circulating fluidized bed boiler, the generated gas can be called flue gas containing the products of the combustion reaction.

[0026]

[0026] According to one embodiment, in the case of a circulating fluidized bed gasifier, when carbonaceous fuels such as biofuels or waste-derived fuels are gasified, the main components are carbon monoxide (CO), hydrogen (H2), and hydrocarbons (C). x H y Air and / or oxygen and vapor may be supplied to the reaction chamber to generate a product gas comprising the following characteristics. The product gas of a circulating fluidized bed gasifier may be called synthesis gas.

[0027]

[0027] According to one aspect of the present invention, the process of circulating a solid material comprises sending the solid material directly from a separator through a loop seal to a reaction chamber, and at least, i. Pressure difference of the loop seal in the return path, ii. The temperature within the loop seal in the return path of the solid material circulation is selected as a performance indicator of the solid material circulation process. i. The process variables of the performance indicator, the pressure difference of the loop seal in the return path, include the total combustion gas flow rate supplied into the reactor, the flue gas temperature upstream of the loop seal, and the floor temperature inside the reaction chamber. ii. The process variables for the performance indicator of temperature within the loop seal in the circulation of solid materials include the total combustion gas flow rate supplied into the reactor, the temperature of the flue gas upstream of the loop seal, and the floor temperature within the reaction chamber.

[0028]

[0028] According to one aspect of the present invention, the reaction gas is air. According to one aspect of the present invention, the reaction gas is air or a mixture of air and recirculated flue gas. According to one aspect of the present invention, the reaction gas is pure oxygen. According to one aspect of the present invention, the reaction gas is a mixture of oxygen and recirculated product gas. According to one aspect of the present invention, in the case of a circulating fluidized bed boiler, the reaction gas can be called the combustion gas.

[0029]

[0029] According to one aspect of the present invention, the method comprises fuel gasification in a CFB reactor, and the process of circulating solid material comprises sending the solid material directly from a separator through a loop seal to the reaction chamber, at least, i. Pressure difference of the loop seal in the return path, ii. The temperature within the loop seal in the return path of the solid material circulation is selected as a performance indicator of the solid material circulation process. i. The process variables of the performance indicator, the pressure difference of the loop seal in the return path, include the total gas flow rate supplied into the reactor, the product gas temperature upstream of the loop seal, and the floor temperature inside the reaction chamber. ii. The process variables of the performance indicator of temperature in the loop seal in the circulation of solid materials include the total gas flow rate supplied into the reactor, the temperature of the product gas upstream of the loop seal, and the bed temperature in the reaction chamber. According to one embodiment, the circulating fluidized bed reactor is a circulating fluidized bed gasifier, and the fluidizing gas comprises at least one of the following: an inert gas, steam, oxygen, or a mixture thereof.

[0030]

[0030] According to one aspect of the present invention, the process of circulating a solid material comprises sending the solid material from a separator through a fluidized bed heat exchanger to a reaction chamber, at least i. Pressure difference of the loop seal in the return path, ii. Temperature in the loop seal in the return path of the solid material circulation, iii. Pressure difference in a fluidized bed heat exchanger, iv. Temperature of solid material downstream of fluidized bed heat exchange unit and However, it was selected as a process performance indicator in the steps of the solid material recycling process, i. The process variables of the performance indicator, the pressure difference of the loop seal in the return path, include the total reaction gas flow rate supplied into the reactor, the temperature of the product gas upstream of the loop seal, and the floor temperature in the reaction chamber. ii. The process variables for the performance indicator of temperature within the loop seal in the circulation of solid materials include the total reaction gas flow rate supplied into the reactor, the temperature of the product gas upstream of the loop seal, and the floor temperature within the reaction chamber. iii. The process variables of the performance indicator of the fluidized bed heat exchanger, namely the pressure difference, include the total reaction gas flow rate supplied into the reactor, the temperature in the loop seal in the return path of the solid material circulation, the pressure difference in the loop seal, the gas flow rate to the fluidized bed heat exchanger, and the bed temperature in the reaction chamber. iv. The process variables for the performance indicator of fluidized bed heat exchanger temperature include the total reaction gas flow rate supplied into the reactor, the temperature in the loop seal, the pressure difference in the loop seal, the gas flow rate to the fluidized bed heat exchanger, and the bed temperature in the reaction chamber.

[0031]

[0031] According to one aspect of the present invention, the total reaction gas flow rate is the total flow rate of gas into the reaction chamber of the CFB reactor.

[0032]

[0032] According to one embodiment of the method, which comprises combustion of fuel in the presence of air, the total reaction gas flow rate is the total flow rate of air into the reaction chamber of the CFB reactor.

[0033]

[0033] According to one embodiment of the method, which comprises combustion of fuel in the presence of air, the total airflow rate is the flow rate of the primary airflow supplied into the reaction chamber.

[0034]

[0034] According to one embodiment of the method, which comprises combustion of fuel in the presence of air, the total airflow rate is the flow rate comprising a primary airflow and a secondary airflow supplied into the reaction chamber.

[0035]

[0035] According to one embodiment of the method, which comprises combustion of fuel in the presence of air, the total airflow rate comprises a primary airflow, a secondary airflow, and a tertiary airflow supplied into the reaction chamber.

[0036]

[0036] According to one embodiment of the method, which comprises the combustion of fuel in the presence of air, the total airflow rate is the flow rate comprising the primary airflow and secondary airflow supplied into the reaction chamber and the air supplied into the fluidized bed heat exchanger.

[0037]

[0037] According to one embodiment of the method, which comprises combustion of fuel in the presence of air, the total airflow is the total flow rate of air into the reaction chamber and into the fluidized bed heat exchanger.

[0038]

[0038] According to one embodiment of the method, which comprises combustion of fuel in the presence of air, the total airflow rate comprises a primary airflow and a secondary airflow supplied into the reaction chamber and the fluidized bed heat exchanger and into the loop seal.

[0039]

[0039] According to one embodiment of the method, which comprises combustion of fuel in the presence of air, the total airflow is the total flow of air into the reaction chamber, the fluidized bed heat exchanger, and the loop seal.

[0040]

[0040] According to one aspect of the present invention, the process of circulating a solid material comprises sending the solid material from a separator through a fluidized bed heat exchanger to a reaction chamber, at least i. Pressure difference of the loop seal in the return path, ii. Temperature in the loop seal in the return path of the solid material circulation, iii. Pressure difference in a fluidized bed heat exchanger, iv. Temperature of solid material downstream of fluidized bed heat exchange unit and However, it was selected as a process performance indicator in the steps of the solid material recycling process, i. The process variables of the performance indicator, the pressure difference of the loop seal in the return path, include the total combustion gas flow rate supplied into the reactor, the temperature of the product gas upstream of the loop seal, and the floor temperature in the reaction chamber. ii. The process variables for the performance indicator of temperature within the loop seal in the circulation of solid materials include the total combustion gas flow rate supplied into the reactor, the temperature of the product gas upstream of the loop seal, and the floor temperature within the reaction chamber. iii. The process variables of the performance indicator of the fluidized bed heat exchanger, namely the pressure difference, include the total combustion gas flow rate supplied into the reactor, the temperature in the loop seal in the return path of the solid material circulation, the pressure difference in the loop seal, the combustion gas flow rate to the fluidized bed heat exchanger, and the bed temperature in the reaction chamber. iv. The process variables for the performance indicator of fluidized bed heat exchanger temperature include the total combustion gas flow rate supplied into the reactor, the temperature in the loop seal, the pressure difference in the loop seal, the combustion gas flow rate to the fluidized bed heat exchanger, and the bed temperature in the reaction chamber.

[0041]

[0041] According to one aspect of the present invention, the total combustion gas flow rate is the total flow rate of combustion gas into the reaction chamber of the CFB reactor.

[0042]

[0042] According to one aspect of the present invention, the total combustion gas flow rate is the flow rate comprising the primary combustion gas flow supplied into the reaction chamber.

[0043]

[0043] According to one preferred embodiment of the present invention, the total combustion gas flow rate is a flow rate comprising a primary combustion gas flow and a secondary combustion gas flow supplied into the reaction chamber.

[0044]

[0044] According to another preferred aspect of the present invention, the total combustion gas flow rate is a flow rate comprising a primary combustion gas flow, a secondary combustion gas flow, and a tertiary combustion gas flow supplied into the reaction chamber.

[0045]

[0045] According to one aspect of the present invention, the combustion gas is air and recirculated product gas. According to one aspect of the present invention, the combustion gas is oxygen and recirculated product gas. According to one aspect of the present invention, the combustion gas is primary air and recirculated product gas. According to one aspect of the present invention, the combustion gas is oxygen and recirculated product gas.

[0046]

[0046] According to one aspect of the present invention, the floor temperature is the average floor temperature in the reaction chamber, which is calculated from at least two measurement points in the reaction chamber, at least one of which is at the grid level of the chamber.

[0047]

[0047] According to one aspect of the present invention, creating a multivariate model is • Measure the value of a predetermined process variable, store the measured value along with a timestamp, and thereby form historical data for the process variable. • Measure the values ​​of performance metrics, store the measured values ​​along with timestamps, and thereby form historical data of performance metrics. • Selection of valid historical data using a predetermined data filter, It is equipped with.

[0048]

[0048] According to one aspect of the present invention, creating a multivariate model is • Measure the value of a predetermined process variable, store the measured value along with a timestamp, and thereby form historical data for the process variable. • Measure the values ​​of performance metrics, store the measured values ​​along with timestamps, and thereby form historical data of performance metrics. • Select valid historical data using a predetermined data filter, • Updating the multivariate model, It is equipped with.

[0049]

[0049] According to one aspect of the present invention, the data filter is configured to accept data older than a preset quarantine time. Advantageously, this prevents the model from being taught potential abnormal operating values, for example, due to the initiation of solid material aggregation within a loop seal. In other words, data relevant to the problem is not used in model training.

[0050]

[0050] According to one aspect of the present invention, the data filter is configured to approve data older than two weeks.

[0051]

[0051] According to one aspect of the present invention, the data filter is configured to approve data that is no older than two months.

[0052]

[0052] According to one aspect of the present invention, the data filter is configured to filter out any data from shutdown status and / or any abnormal operation from the historical data based on predetermined limits of the input variable or external information of abnormal operation.

[0053] According to one aspect of the present invention, the method comprises at least the following steps. a. Selecting process variables of the process of the circulation of the solid material in the return path, and selecting performance indicators of the process of the circulation of the solid material from among the selected process variables for each performance indicator of the process of the circulation of the solid material; b. Creating a multivariate model for each performance indicator using historical data of the process variables and performance indicators of the process of the circulation of the solid material; The multivariate model is a multivariate linear regression having measured observed values of each of the first number (N) of process variables and different process variables of the process of the circulation of the solid material of the second number (P). y i =b0+b1x i,1 +b2x i,2 +...b P x i,P +ε i where i = 1, 2,... N, the method being to read historical data of y = performance indicator and x i,1 ,x i,2 ,...,x i,p which are process variables, to solve for the constants b0 and factors b1, b2,... b i ,x i,1 ,x i,2 ,...,x i,p and to perform fitting by minimizing the sum of the squares of the vertical deviations from each data point to the line that best fits the historical data. c. Determining a modeled value of the performance indicator by applying the currently measured values of the process variables to the multivariate model; P and d. Comparing the modeled value of each performance indicator with the respective measured value of each performance indicator and examining for the presence of an anomaly between the modeled value and the measured value.

[0054] ​​

[0054] According to one aspect of the present invention, the method comprises at least the following steps: a. Select process variables for the solid material circulation process in the return path, and select performance indicators for the solid material circulation process from the selected process variables for each performance indicator of the solid material circulation process. b. A step of creating a multivariate model for each performance indicator using historical data of process variables and performance indicators for the circulation process of solid materials. The multivariate model is a multivariate linear regression with a first number (N) of measured observations of each process variable and a second number (P) of different process variables of the solid material cycle process, as follows: y i =b0+b1x i,1 +b2x i,2 +...b P x i,P +ε i However, i = 1, 2, ..., N The method is y = performance index and x i,1 ,x i,2 ,...,x i,p y is a process variable, i ,x i,1 ,x i,2 ,...,x i,p To read the historical data, constant b0 and factors b1, b2, ... b P Solving the problem, The system includes performing fitting by minimizing the sum of the squares of the vertical deviations from each data point to the line that best fits the historical data. Here, the steps for creating a multivariate model include measuring the values ​​of predetermined process variables, storing the measured values ​​along with timestamps to form historical data for the process variables, measuring the values ​​of performance indicators, storing the measured values ​​along with timestamps to form historical data for the performance indicators, selecting valid historical data using predetermined data filters, and updating the multivariate model. c. A step of determining the modeled values ​​of performance indicators by applying the currently measured values ​​of process variables to a multivariate model. d. A step of comparing the modeled value of each performance indicator with the measured value of each performance indicator and checking for the presence of anomalies between the modeled value and the measured value.

[0055]

[0055] According to one aspect of the present invention, the measured observed value N of the first number is at least 10 times the different process variables of the second number P.

[0056]

[0056] According to one aspect of the present invention, the multivariate mode is updated after a certain predetermined time interval has elapsed or after a period triggered by a trigger input.

[0057]

[0057] According to one aspect of the present invention, the risk index for each performance indicator is calculated using information on the presence of anomalies.

[0058]

[0058] According to one aspect of the present invention, the risk index for each performance indicator is calculated using anomalies between the modeled value and the measured value.

[0059]

[0059] According to one aspect of the present invention, the reactor comprises at least a first return path, a first solid material separator and a reaction chamber, and a second return path between a second solid material separator and a reaction chamber, wherein a method relating to the process of circulating solid material in the first return path and a method relating to the process of circulating solid material in the second return path are performed separately with respect to the return paths.

[0060]

[0060] A control system for monitoring the process of circulation of solid material in a circulating fluidized bed reactor between the reaction chamber and at least one solid material separator, and to the reaction chamber via a return path with a loop seal, and a control system for controlling the process of circulation of solid material, wherein the control system is • Access to the source history data of the process metrics for the circulation of solid materials in the return path and the process variables of each performance metric. • Multivariate models for each performance indicator, When executed in the data processing unit, Using historical data of predetermined process variables and performance indicators for a solid material circulation process, the program updates the multivariate model for each performance indicator, providing executable instructions that result in a calibrated multivariate model. A performance modeling unit equipped with, • Input for receiving measurement data of process variables and performance indicators for the circulation of solid materials, When executed in the data processing unit, By applying the currently measured values ​​of process variables to a calibrated multivariate model, the modeled values ​​of performance metrics are determined. An executable instruction that compares the modeled value of each performance indicator with the measured value of the respective performance indicator, and checks for the existence of anomalies between the modeled value and the measured value. A performance diagnostic module equipped with, It is equipped with.

[0061]

[0061] According to one aspect of the present invention, the control system comprises measuring sensors for at least the following process variables: a pressure sensor for measuring the pressure drop in the loop seal, a generated gas temperature sensor, and means for determining the total air flow rate to the reactor and the floor temperature in the reaction chamber of the reactor.

[0062]

[0062] According to one aspect of the present invention, a circulation of solid material in a circulating fluidized bed reactor between a reaction chamber and at least one solid material separator, and to the reaction chamber via a fluidized bed heat exchanger in a return path, wherein the control system comprises measuring sensors for at least the following process variables: a pressure sensor for measuring the pressure drop in a loop seal, a product gas temperature sensor upstream of the loop seal, a temperature sensor in the loop seal, a pressure sensor for measuring the pressure drop in the fluidized bed heat exchanger, a temperature sensor for measuring the temperature of solid material downstream of the fluidized bed heat exchange unit in the fluidized bed heat exchanger, and means for determining the total air flow rate to the reactor and the bed temperature in the reaction chamber of the reactor.

[0063]

[0063] This provides the effect that problems that may occur in the circulation of solid materials can be effectively foreseen. Detected anomalies act as precursors to problems in the process of the circulation of solid materials, such as a tendency to sinter.

[0064]

[0064] By avoiding unnecessary shutdowns, the availability of the CFB reactor is improved and operating costs are reduced.

[0065]

[0065] Thus, by monitoring the measured and modeled values, the onset of solid material sintering can be detected, and timely measures can be taken to correct the process or at least prevent the sintering from deteriorating. In CFB boiler applications, this can help avoid the shutdown of the combustion boiler system due to solid material sintering, as well as costly repairs. Advantageously, anomalies detected in the solid material circulation provide information about the floor quality, preferably information about whether sintering is occurring in the solid material. Or, in other words, it becomes possible to receive information about problems related to the solid circulation that, if no corrective action is taken, may tend to lead to shutdown. Thus, reactor availability may be improved and / or operating costs may be reduced. The method is performed in a local reactor control system or remotely, preferably in a process intelligence system, preferably automatically.

[0066]

[0066] A multivariate model may be an artificial intelligence tool. According to one embodiment of the present invention, a multivariate model may be a neural network.

[0067]

[0067] Preferably, when an anomaly is detected, the model calibration is not performed for a predetermined period of time (i.e., the calibration is skipped). Additionally or alternatively, boiler / reactor shutdowns, abnormal operation, and / or abnormal conditions are preferably filtered out or omitted from the calibration data. This approach can help avoid circulation quality issues that may contaminate the calibration. This approach can be fine-tuned so that when a localized temperature anomaly that meets a given threshold is detected, the calibration is not performed for a predetermined period of time. Then, only conditions that are sufficiently severe to generate a sufficiently large anomaly signal can be selected so that the calibration is skipped for a predetermined period of time.

[0068]

[0068] According to one aspect of the present invention, the estimation of the risk index of the performance indicator in the method is evaluated as follows. • Current data on key performance indicators (KPIs) for the circulation of solid materials will be measured. Based on the reactor's current operating data, at least one of the following can be calculated: i) Average of performance metrics ii) Standard deviation of the measured performance indicators iii) The difference between the highest measured performance metric value and the lowest measured performance metric value. iv) The difference between the average performance index and the measured performance index. Prepare the risk index for the performance indicator KPI using the calculation results from i), ii), iii), and / or iv).

[0069]

[0069] The calculation results of i), ii), iii), and / or iv) are compared with corresponding predetermined limits in order to obtain the mean, standard deviation, the difference between the maximum KPI value and the minimum KPI value, and / or the risk index of the difference between the mean KPI value and the measured KPI value.

[0070]

[0070] KPIs from average KPIs k In calculating the deviation for k=1,...,K, the mean is the KPI. k Includes all KPI metrics except for the specified measurement.

[0071]

[0071] Preferably, in the method, v) KPI k Modeled values ​​for k=1,...K are also calculated, and the residuals between the measured values ​​of the performance indicator and the modeled values ​​of the performance indicator are also calculated. The results of step v) are also, favorably, used to prepare a risk index, which is preferably by which the residuals are compared to a corresponding predetermined limit in order to obtain a sintered risk index of the KPI residuals.

[0072]

[0072] According to one aspect of the present invention, in the method, the risk index of the performance indicator is measured by the current data of the performance indicator (KPI) of the circulation of solid materials, v) KPI kModeled values ​​for k=1,...K are calculated and evaluated so that the residuals between the measured values ​​of the performance indicator and the modeled values ​​of the performance indicator are calculated. The results of step v) are also, favorably, used to prepare a risk index, which is preferably by which the residuals are compared to a corresponding predetermined limit in order to obtain a sintered risk index of the KPI residuals.

[0073]

[0073] The final risk index can then be, for example, the maximum value of the above risk index. In this way, the prediction accuracy of the floor sintering index can be further improved.

[0074]

[0074] Advantageously, according to one aspect of the present invention, it is possible to pinpoint the most important locations where the greatest risk of blockage or sintering occurs. This would be particularly advantageous when there are multiple separator and return path assemblies.

[0075]

[0075] In this regard, the term floor temperature refers to a number that is a typical expression of floor temperature, such as the mean floor temperature. Floor temperature can be calculated using different methods, such as the arithmetic mean, pruned mean, or midrange, to name just a few examples. The calculation may involve a desired amount of data at one or more locations within the CFB reactor.

[0076]

[0076] The exemplary embodiments of the present invention presented in this patent application should not be construed as limiting the applicability of the appended claims. The verb “comprise” is used in this patent application as an open limitation that does not exclude the existence of features not enumerated. The features enumerated in the dependent claims can be freely combined with each other unless otherwise explicitly stated. Novel features that are considered to be characteristics of the present invention are specifically described in the appended claims. [Brief explanation of the drawing]

[0077]

[0077] The present invention will be described below with reference to the attached illustrative schematic diagrams.

[0078] [Figure 1] A circulating fluidized bed reactor according to one embodiment of the present invention is shown in the figure. [Figure 2] A control system according to one embodiment of the present invention is illustrated. [Figure 3] A circulating fluidized bed reactor according to another embodiment of the present invention is shown. [Figure 4] The results obtained by the method according to the present invention are illustrated. [Figure 5] A circulating fluidized bed reactor according to another embodiment of the present invention is shown. [Modes for carrying out the invention]

[0079]

[0078] In the following description of the figures, the figures generally relate to examples of methods for combustion of fuel in air within a CFB reactor. The CFB reactors and embodiments thereof described in the figures are equally applicable to producing synthesis gas by carrying out a gasification process within the reactor, although some minor structural modifications may be required. Correspondingly, the CFB reactors and embodiments thereof described may be used to carry out a so-called oxygen combustion process, which means combustion using an oxygen-enriched gas that may contain air and / or recirculated product gas. Figure 1 schematically shows a circulating fluidized bed reactor 10, specifically a circulating fluidized bed boiler 10 configured to produce superheated steam by means of known methods. For brevity, the circulating fluidized bed boiler will be referred to as a CFB boiler. The CFB boiler 10 comprises a combustion chamber 12, at least one solid material separator 14, and a solid material return channel 16. Generally, the route through which the separated solid material returns from the separator to the combustion chamber is called the return path 15. The combustion chamber 12 has a tubular wall, a so-called finned tubular wall, with fins welded between the tubes. The wall tubes are connected to the water-steam circuit (not shown) of the boiler system. The solid material separator 14 is preferably cooled and also has a tubular wall, similar to the combustion chamber 12. The combustion chamber 12 includes a wind box 18, which is configured to supply a fluidizing gas, typically air, through a nozzle in a grid 20 at the bottom of the combustion chamber 12. The air introduced through the grid acts as the fluidizing gas and is the primary combustion air. Secondary air may be supplied into the combustion chamber 12 at a higher level through one or more air inlets 21. As previously mentioned, the fluidizing gas and combustion gas are usually air, but may also include a circulating product gas and / or oxygen or a mixture thereof. Generally, it should be understood that the term product gas can be understood as the gas leaving the separator 14 being the product gas of the reaction in the reaction chamber. For example, if the method involves the gasification of a fuel material, the resulting gas is a combustible gas, a so-called synthesis gas, and if the method involves the combustion of a fuel in a reaction chamber and the generation of steam by the heat released, the resulting gas may be called flue gas.In some practical applications, such as so-called oxygen combustion, a portion of the flue gas may be recirculated into the reaction chamber as a fluidized gas, and can therefore be referred to as recirculated gas.

[0080]

[0079] The wind box 18, and other air inlets, are connected to the air source 24. This is an example of an air-operated CFB boiler. There is at least one inlet 22 for fuel connected to the combustion chamber 12. The operation of the CFB boiler involves the process of circulating solid material, which may in this context also be referred to as floor material. The floor material may consist of sand, limestone, and / or clay, which may particularly contain kaolin, and also unburned fuel. Due to the floor material in the boiler, the CFB boiler has a high heat transfer coefficient and a substantially uniform temperature distribution, as well as a fairly low and stable combustion temperature. The combustion of fuel in the circulating fluidized bed results in heating, evaporation of water in the water-steam circuit, and superheating of steam, which can be used in methods known to the extent that, for example, the generation of electricity in a steam turbine generator. The steam cycle will not be described in more detail here.

[0081]

[0080] A characteristic feature of a CFB boiler is that, during its operation, the process of circulating solid material is maintained through a route formed by the combustion chamber, separator, and solid return path. Combustion of fuel in a CFB results in high-efficiency combustion of various solid fuels with low emissions, even when burning fuels with completely different calorific values ​​simultaneously. Due to fluidization, as shown by the arrows in Figure 1, inside the combustion chamber 12, there is an internal movement of solid material, mostly upward in the middle of the chamber, and a downward flow of solid near the walls. The generated gas and solid material are flowed from the combustion chamber 12 to a solid material separator 14, the inlet of which is connected to the combustion chamber by a connector duct 26. The solid material separator 14, which is preferably a cooled cyclone separator, has a first outlet 28 for the generated gas and a second outlet 30 for the separated solid material 32. The first outlet 28 of the separator is actually connected to a back pass 40. The backpass comprises several heat exchanges, which may include an air preheater 46, an economizer 44, and a superheater and reheater 42. The actual amounts of different heat transfer surfaces in each of these components may be selected differently for each CFB boiler, for example, depending on the actual requirements.

[0082]

[0081] The solid material transported to the separator 14 by the generated gas is separated from the gas as indicated by the arrows in the figure. A second outlet 30, which may also be called a particle outlet, is connected to the bottom of the combustion chamber 12 by a return path 15 for returning the separated solid material back to the combustion chamber 12. The return path 15 is provided with a so-called loop seal 32, which prevents backflow from the combustion chamber 12 to the particle outlet and allows for the controlled supply of the separated solid material back to the combustion chamber 12. The loop seal may also be called a gas seal. The operation of the loop seal is controlled by fluidized air which can be controlledly supplied through the air inlet 23. Thus, the circulation of the solid material comprises a flow of solid material from the combustion chamber 12 to the solid material separator 14, and from the solid material separator 14 back to the combustion chamber 12 via the return path 15 and the loop seal 32. The process of solid material circulation is maintained and controlled while the CFB boiler is operating. The general direction of solid material movement is sometimes used to refer to its position within a CFB boiler, and that direction will become clear in the description above.

[0083]

[0082] In a CFB boiler, the solid material circulation can be divided into two categories: the internal circulation material flow, which refers to the solid material circulating inside the combustion chamber (12), schematically shown in Figure 1 by an inverted U-shaped arrow and described above; and the external circulation material flow, which refers to the solid material circulating outside the combustion chamber, i.e., within the particle separator and loop seal and return path 15 (in Figure 1). The external circulation material flow may also involve the processing of solid material in a fluidized bed heat exchanger, as shown in Figure 3. Advantageously, according to one aspect of the present invention, the solid material in the return path may be referred to in other terms as the solid material in the external circulation of the CFB boiler.

[0084]

[0083] To monitor the process of circulating solid materials, the CFB boiler 10 is equipped with multiple sensors for obtaining online data of performance indicators and process variables. The online data becomes historical data when stored after the moment of measurement. To carry out the method according to the present invention, the CFB boiler is equipped with at least the following sensors and measurement points: • A first pressure sensor 101 is located upstream of the loop seal 32 but downstream of the solid material separator, i.e., between the loop seal and the solid material separator 14. • A second pressure sensor 102 is located downstream of the loop seal 32, between the loop seal 32 and the combustion chamber 12. The purpose of the first and second pressure sensors is to determine the pressure difference provided by the loop seal 32. • A first temperature sensor 100 is located inside the loop seal 32. • A second temperature sensor 103 is located upstream of the loop seal 32. Figure 1 shows that the second temperature sensor 103 is located at the first outlet 28 of the solid separator 14, which also represents the temperature of the solid material upstream of the loop seal 32 in the sense of Figure 1. • First airflow sensor 105 for measuring the primary airflow rate through grid 20 of the CFB boiler • Second airflow sensor 106 for measuring secondary airflow The purpose of the first and second air flow sensors is to determine the total air flow rate supplied into the CFB boiler. Several third temperature sensors 104 connected to the combustion chamber 12 are positioned to determine the floor temperature inside the combustion chamber 12.

[0085]

[0084] In addition, as shown in Figure 1, there may be an airflow sensor 109 for measuring the airflow to the loop seal, which may optionally be included in the total airflow. A temperature sensor downstream of the second outlet 30 of the separator 14 provides a measurement value representing the temperature of the solid material.

[0086]

[0085] The CFB boiler further comprises a control system 48 for passing numerical calculations related to the control of the CFB boiler and, in particular, the monitoring of the process of solid material circulation in the CFB boiler. Figure 1 should be understood to be an illustrative description of the process of solid material circulation through a particular type of return path, and an illustration of the process of solid material circulation through one return path. If the CFB boiler has two or more return paths, as is often the case in practice, the present invention is applicable separately to each of the return paths. Advantageously, the CFB boiler may have solid material separators 14 and corresponding return paths 15 on either side of the combustion chamber 12 (not shown).

[0087]

[0086] Figure 2 shows a general illustration of a method and control system 48 in which a control system can monitor the process of solid material circulation in the CFB reactor 10 so that indications of conditions related to the circulation of solid material that could lead to reactor shutdown can be observed early enough to take corrective action and reactor shutdown can be avoided.

[0088]

[0087] The control system 48 is involved in executing a method for monitoring the process of circulating solid material in the circulating fluidized bed boiler 10. The control system comprises one or more computers and executable instructions, i.e., computer programs that, when executed in the control system 48, carry out the method in the circulating fluidized bed boiler 10. The method is a. Select performance indicators for the solid material circulation process and process variables for each performance indicator of the solid material circulation process. b. Calibrating multivariate models for each performance indicator using historical data of process variables and performance indicators for the circulation process of solid materials. c. Determining the modeled values ​​of performance indicators by applying the currently measured values ​​of process variables to a multivariate model. d. Compare the modeled values ​​of each performance indicator with the measured values ​​of each performance indicator and check for any anomalies between the modeled values ​​and the measured values. It is equipped with.

[0089]

[0088] The control system includes a performance modeling unit 400. The modeling unit 400, when executed in the control system 48, includes executable instructions that use predetermined process variables and historical data of performance indicators of the solid material circulation process to calibrate a multivariate model of each performance indicator, resulting in a calibrated multivariate model.

[0090]

[0089] The performance modeling unit 400 has or includes access to a) performance indicators of the process of circulating solid material obtained from the CFB boiler and b) historical data sources 401 for each performance indicator. The historical data is stored in a data medium used as the source 401 for the historical data and is obtained by measuring the values ​​101, 102, 103, ... 109 (see Figure 1) of predetermined process variables over a period of time, storing the measured values ​​along with timestamps, thereby forming historical data for the process variables. Acquiring historical data involves measuring the values ​​of each performance indicator, storing the measured values ​​along with timestamps, thereby forming historical data for the performance indicators. The control system 48 includes a data filter unit 406 configured to filter out invalid process data, so the historical data includes data that has undergone a filtering process using predetermined data filters. Thus, the historical data is data that describes the normal operating conditions of the CFB boiler 10.

[0091]

[0090] Advantageously, the filtering process 406 may have the following conditions or rules: First, a quarantine time is set for the measured data so that only data older than a predetermined quarantine time is approved. The quarantine time varies depending on the case. In some practical applications, the quarantine time may be as short as 3 to 7 days. However, the quarantine time is preferably 7 to 14 days, more preferably at least 2 weeks. In addition, it is preferable to filter out data that may be too old and no longer usable, and therefore a given data filter is configured to approve data that is not older than a predetermined time, advantageously not older than 2 months. The filter unit is also configured to filter out any data from stop situations and / or data originating from any abnormal operating conditions from the historical data, for example, based on predetermined limits of input variables, or external information that makes the data unusable, or data of abnormal operation.

[0092]

[0091] In this way, the model is based on historical data representing normal operating conditions. For example, the historical data related to the CFB boiler shown in Figure 1 includes process variables and performance indicators: • The pressure value (sensor 101) located upstream of the loop seal 32 but downstream of the solid material separator, i.e., between the loop seal and the solid material separator 14. • Pressure value downstream of the loop seal 32, between the loop seal 32 and the combustion chamber 12 (sensor 102) Alternatively, the pressure difference across the loop seal 32 (combination of sensors 101 and 102) • Temperature upstream of loop seal 32 (sensor 103) • Total air flow rate supplied to the CFB boiler (sensors 105, 106) • Total floor temperature inside the combustion chamber 12 (sensor 104) It contains data.

[0093]

[0092] The performance index represents a factor that describes the state of the solid material circulation process. In the embodiment shown in Figure 1, the performance index is advantageously, i. Pressure difference of the loop seal in the return path, and ii. Temperature within the loop seal in the return path of solid material circulation That is the case.

[0094]

[0093] The data in the historical data source 401 is used as input to a modeling unit 400 configured to prepare and / or calibrate separately assigned multivariate models for each performance indicator, in this case two performance indicators. Thus, the performance modeling unit 400 provides a multivariate model for each performance indicator. Calibration can be repeated at predetermined intervals or periodically. This helps keep the model in a realistic state, reflecting changes that may occur due to the normal use of the CFB boiler, as well as changes in fuel quality and environmental conditions (changes in temperature, ambient humidity, ambient pressure) that may cause changes in operating parameters over time. Calibration can be stopped if an anomaly is detected in the process. This ensures that any ongoing problems in the floor material circulation do not contaminate the calibration and the model.

[0095]

[0094] The model can be constructed by the modeling unit 400 using multivariate linear regression. In principle, the model's coefficients are estimated using the model's past input values ​​(i.e., historical data of measurements). The model is then used to estimate the dominant situation by utilizing the current online data and the estimated coefficients.

[0096]

[0095] For example, in linear regression, the response variable is expected to be a linear combination of process variables. By fitting a linear equation to historical data, multiple linear regression can be used to model the relationship between multiple process variables and performance indicators.

[0097]

[0096] In the embodiment shown in Figure 1, the multivariate model of the loop seal temperature having an observed value of N is defined as follows. y i =b0+b1x i,1 +b2x i,2 +b3x i,3 +ε i however, y represents the performance index value as the loop seal temperature. x i,1 This is the i-th value of the temperature (sensor 103) upstream of the loop seal 32, x i,2 This is the i-th value of the total air flow rate supplied into the CFB boiler (sensors 105, 106), x i,3 This is the i-th value of the floor temperature (sensor 104) inside the combustion chamber 12. b0 is a constant, and b1...b3 are coefficients specific to the unknown KPI that should be estimated. ε i This includes the experimental error of the model.

[0098]

[0097] In the embodiment shown in Figure 1, the multivariate model of the loop seal pressure difference having an observed value of N is defined as follows. y i =b0+b1x i,1 +b2x i,2 +b3x i,3 +ε i however, y represents the value of the performance indicator. x i,1 This is the i-th value of the temperature (sensor 103) upstream of the loop seal 32, x i,2 This is the i-th value of the total air flow rate supplied into the CFB boiler (sensors 105, 106), x i,3 This is the i-th value of the floor temperature (sensor 104) inside the combustion chamber 12. b0 is a constant, and b1...b3 are coefficients specific to the unknown KPI that should be estimated. ε iThis includes the experimental error of the model. Fitting is performed by minimizing the sum of the squares of the vertical deviations from each data point to the line that best fits the observed data, which is the optimal coefficient value obtained by minimizing the sum of the squared errors.

[0099]

[0098] The modeling unit 400 provides the necessary coefficients for a model based on executable historical data, which are used to model performance indicators by applying online data of process variables to the model. While the control system 48 and the CFB boiler 10 are operating, historical data containing data on process variables and performance indicators is continuously read and stored in the historical data source 401. The modeling unit 400 is configured to update or calibrate the model, i.e., the coefficients of the model, in order to learn the latest conditions of the normal operation of the solid material circulation process.

[0100]

[0099] The control system 48 is also provided with a performance diagnostic module 404. The performance diagnostic module is configured to receive current online data from the CFB boiler of performance indicators via the current data source 402, and newly calibrated models of process variables and performance indicators from the modeling unit 400. The performance diagnostic module 404 has instructions for determining the modeled values ​​of the performance indicators by applying the currently measured values ​​of the process variables to the calibrated multivariate models. In addition, the performance diagnostic module 404 is configured to compare the modeled value of each performance indicator with the respective measured value of the performance indicator and to check for the presence of anomalies between the modeled value and the measured value. Based on the results of the comparison, one or more predetermined actions may be taken and generated as a diagnostic output 408.

[0101]

[0100] The presence of anomalies and the need for corrective action can be recognized by estimating the risk index for each KPI. The performance diagnostic module 404 may also have instructions for performing a method for estimating the risk index of performance indicators, which perform the following actions: • Current data on key performance indicators (KPIs) for the circulation of solid materials will be measured. Based on current boiler data, at least one of the following: i) The average of the performance indicators is calculated. ii) The standard deviation of the measured performance indicators is calculated. iii) The difference between the highest measured performance metric value and the lowest measured performance metric value is calculated. iv) The difference between the average performance indicator (KPI) and the measured performance indicator is calculated. Using the calculation results of i), ii), iii), and / or iv), prepare a risk index for the performance indicator KPI. The calculation results of i), ii), iii), and / or iv) are compared to corresponding predetermined limits to obtain the risk index for the mean, standard deviation, the difference between the maximum KPI and the minimum KPI, and the difference between the mean KPI and the measured KPI. In calculating the deviation of KPIk from the mean KPI, the mean includes all KPI measurements except for the measured KPIk.

[0102]

[0101] Preferably, in the method, further or alternatively, v) KPI k Modeled values ​​for k=1,...K are calculated, and the residuals between the measured values ​​of the performance indicator and the modeled values ​​of the performance indicator are calculated. The results of step v) are also, favorably, used to prepare a risk index, which is preferably by which the residuals are compared to a corresponding predetermined limit in order to obtain a sintered risk index of the KPI residuals.

[0103]

[0102] Then, the final risk index may be, for example, the maximum value of the above risk index. In this way, the prediction accuracy of the floor sintering index can be further improved.

[0104]

[0103] The inventors have observed that this provides an indication of the conditions in the process of circulating solid materials in a circulating fluidized bed boiler that could lead to a boiler shutdown unless corrective measures are taken quickly enough to avoid the need to shut down the boiler.

[0105]

[0104] Optionally, the control system includes a model history coefficient storage device 410 in which each calibrated model is stored. The performance diagnostic module 404 may also include a model evaluation function to check newly created models, and if it is found that the newly created model is incomplete, a model from the model history coefficient storage device 410 is used until a complete new model can be provided.

[0106]

[0105] Figure 3 schematically shows a circulating fluidized bed boiler 10 in which a fluidized bed heat exchanger 50 is provided in one of the return paths 15 (only one is shown for clarity). The return paths 15 shown in Figure 3 may be considered to be within the same CFB boiler disclosed in Figure 1, that is, a CFB boiler may be provided with several return paths 15, and preferably two or more of these return paths 15 are provided with fluidized bed heat exchangers 50. Figure 3 also refers to a real-world application in which a CFB boiler has several return paths 15, all of which are provided with fluidized bed heat exchangers 50. The method according to the present invention is performed separately for all of the return paths 15.

[0107]

[0106] The fluidized bed heat exchanger 50 is located in the return path 15 downstream of the loop seal 32 in the return channel 16. The solid material flows into the fluidized bed heat exchanger 50 through the loop seal 32, where a bubbling bed of the solid material is formed by introducing fluidizing air into the fluidized bed heat exchanger 50 through the grid 52 at its bottom. The fluidized bed heat exchanger 50 is provided with a lifting chamber 54, each having an inlet 54 for transport air. The lifting chamber transports the solid material back to the combustion chamber 12 via the return duct 55 from the fluidized bed heat exchanger 50.

[0108]

[0107] The fluidized bed heat exchanger 50 is provided with one or more heat exchange units 58, which are preferably connected to a steam cycle, for example. The heat exchange units may be evaporators, steam superheaters, and / or steam reheaters. The heat exchange units have one or more heat transfer surfaces, such as bundles of tubes, inside the bubbling bed of solid material formed within the fluidized bed heat exchanger 50.

[0109]

[0108] In the CFB boiler, the solid material transported to the separator 14 by the generated gas is separated from the gas as indicated by the arrows in the figure. A second outlet 30 of the separator 14, which may also be called the particle outlet, is connected to the bottom of the combustion chamber 12 by a return path 15 for returning the separated solid material back to the combustion chamber 12. The return path 15 is provided with a so-called loop seal 32, which prevents backflow from the combustion chamber 12 to the particle outlet and allows the separated solid material to be supplied forward in a controllable manner within the return path 15. The operation of the loop seal is controlled by fluidized air which can be supplied in a controllable manner through the air inlet 23. Thus, the circulation of the solid material comprises a flow of solid material from the combustion chamber 12 to the solid material separator 14, from the solid material separator 14 to the fluidized bed heat exchanger 50 via the return channel 16, and from the fluidized bed heat exchanger 50 back to the combustion chamber 12. While the fluidized bed heat exchanger 50 is operating, heat is transferred from the solid material to the steam flowing through the heat exchange unit 58, which cools the solid material before it is introduced back into the combustion chamber 12.

[0110]

[0109] To monitor the process of circulating solid materials, the CFB boiler 10 according to the embodiment of Figure 3 is equipped with multiple sensors for obtaining online data of performance indicators and process variables. The online data becomes historical data when stored after the moment of measurement. To carry out the method according to the present invention, the CFB boiler is equipped with at least the following sensors and measurement points: • A first pressure sensor 101 is located upstream of the loop seal 32 but downstream of the solid material separator, i.e., between the loop seal and the solid material separator 14. • A second pressure sensor 102 is located downstream of the loop seal 32, between the loop seal 32 and the fluidized bed heat exchanger 50. The purpose of the first and second pressure sensors is to determine the pressure difference provided by the loop seal 32. • A first temperature sensor 100 is located inside the loop seal 32. • A second temperature sensor 103 is located upstream of the loop seal 32. Figure 2 shows that the second temperature sensor 103 is located at the first outlet 28 of the solid separator 14, which also represents the temperature of the solid material upstream of the loop seal 32 in the sense of Figure 2. • First airflow sensor 105 for measuring the primary airflow rate through grid 20 of the CFB boiler • Second airflow sensor 106 for measuring secondary airflow The purpose of the first and second air flow sensors is to determine the total air flow rate supplied into the CFB boiler. Several third temperature sensors 104 are connected to the combustion chamber 12 and are positioned to determine the floor temperature inside the combustion chamber 12. • A third airflow sensor 108 for measuring the airflow rate supplied to the fluidized bed heat exchanger 50. • A third pressure sensor 110 located upstream of the heat exchange unit 58 within the fluidized bed heat exchanger 50. • A fourth pressure sensor 112 located downstream of the heat exchange unit 58 within the fluidized bed heat exchanger 50. • A third temperature sensor 114 located downstream of the heat exchange unit 58 within the fluidized bed heat exchanger 50.

[0111]

[0110] The control system 48 shown in Figure 2 is applicable to the CFB boiler 10 shown in Figure 3 with necessary modifications relating to performance indicators and process variable data. The actual precise locations of the sensors can be determined on a case-by-case basis. For example, the third temperature sensor may be placed between the lifting chamber 54 and the combustion chamber 12, for the temperature at that particular location represents the temperature of the solid material downstream of the heat exchange unit 58. Similarly, the temperature sensor 103 at the outlet 28 of the separator 14 may be positioned differently, as long as it represents the temperature of the solid material upstream of the loop seal 32.

[0112]

[0111] When applied to the CFB boiler shown in Figure 3, the control system 48 is involved in executing a method for monitoring the process of circulating solid material in the circulating fluidized bed boiler 10. The control system comprises one or more computers and executable instructions, i.e., computer programs that, when executed in the control system 48, carry out the method in the circulating fluidized bed boiler 10. The method is a. Select performance indicators for the solid material circulation process and process variables for each performance indicator of the solid material circulation process. b. Calibrating multivariate models for each performance indicator using historical data of process variables and performance indicators for the circulation process of solid materials. c. Determining the modeled values ​​of performance indicators by applying the current measured values ​​of process variables to a multivariate model; d. Comparing the modeled values ​​of each performance indicator with their respective measured values ​​to check for any anomalies between the modeled and measured values. It is equipped with.

[0113]

[0112] The control system includes a performance modeling unit 400. The modeling unit 400, when executed in the control system 48, includes executable instructions that use predetermined process variables and historical data of performance indicators of the solid material circulation process to calibrate a multivariate model of each performance indicator, resulting in a calibrated multivariate model.

[0114]

[0113] The performance modeling unit 400 has or includes access to a) performance indicators of the process of circulating solid materials obtained from the CFB boiler and b) historical data of process variables for each performance indicator, such as data transfer communication with a source 401. The historical data is stored in a data medium used as the source 401 of the historical data and is obtained by measuring the values ​​101, 102, 103, ... 114 (see Figure 3) of predetermined process variables over a period of time, storing the measured values ​​along with timestamps, thereby forming historical data of the process variables. Acquiring historical data involves measuring the values ​​of each performance indicator, storing the measured values ​​along with timestamps, thereby forming historical data of the performance indicators. The control system 48 includes a data filter unit 406 configured to filter out invalid process data, so that the historical data includes data that has undergone a filtering process using predetermined data filters. Thus, the historical data is data that describes the normal operating conditions of the CFB boiler 10. The filter unit will be described in more detail in connection with the description of Figure 2.

[0115]

[0114] The historical data related to the CFB boiler shown in Figure 3 includes process variables and performance indicators: • The pressure value (sensor 101) located upstream of the loop seal 32 but downstream of the solid material separator, i.e., between the loop seal and the solid material separator 14. • Pressure value downstream of the loop seal 32, between the loop seal 32 and the fluidized bed heat exchanger 50 (sensor 102) Alternatively, the pressure difference across the loop seal 32 (combination of sensors 101 and 102) • Temperature inside the loop seal 32 (sensor 100) • Temperature upstream of the loop seal 32 (sensor 103) • Pressure value upstream of the heat exchange unit 58 in the fluidized bed heat exchanger 50 (sensor 110) • Pressure value downstream of the heat exchange unit 58 in the fluidized bed heat exchanger 50 (sensor 110) • Temperature downstream of the heat exchange unit 58 in the fluidized bed heat exchanger 50 (sensor 114) • Total air flow rate supplied into the fluidized bed heat exchanger 50 (sensor 108) • Total air flow rate supplied to the CFB boiler (sensors 105, 106) • Floor temperature inside the combustion chamber 12 (sensor 104) It contains data.

[0116]

[0115] The performance index represents a factor that describes the process of circulating solid materials and the state of the fluidized bed heat exchanger. In the embodiment shown in Figure 3, the performance index is advantageously, i. Pressure difference of the loop seal in the return path, and ii. Temperature in the loop seal during the circulation of solid materials, iii. Pressure difference in a fluidized bed heat exchanger, iv. Temperature of solid material downstream of the fluidized bed heat exchange unit That is the case.

[0117]

[0116] The data in the historical data source 401 is used as input to a modeling unit 400 configured to prepare and / or calibrate separately assigned multivariate models for each performance indicator, in this case two performance indicators. Thus, the performance modeling unit 400 provides a multivariate model for each performance indicator. Calibration can be repeated at predetermined intervals or periodically. This helps keep the model in a realistic state, reflecting changes that may be caused by the normal use of the CFB boiler, as well as changes in fuel quality and environmental conditions (changes in temperature, ambient humidity, ambient pressure) that may cause changes in operating parameters over time. Calibration can be stopped if an anomaly is detected in the process. This ensures that problems that are just beginning to occur in the floor material circulation do not contaminate the calibration and the model.

[0118]

[0117] The model can be constructed using multivariate linear regression by the modeling unit 400. In principle, the model's coefficients are estimated using the model's past input values ​​(i.e., historical measurement data). The model is then used to estimate the dominant situation by utilizing the current online data and the estimated coefficients.

[0119]

[0118] For example, in linear regression, the response variable is expected to be a linear combination of process variables. By fitting the linear equation to historical data, multiple linear regression can be used to model the relationship between multiple process variables and performance indicators.

[0120]

[0119] In the embodiment shown in Figure 3, the multivariate model of the temperature of the solid material downstream of the fluidized bed heat exchange unit (hereinafter referred to as FBHX) having an observed value of N is defined as follows. y i =b0+b1x i,1 +b2x i,2 +b3x i,3 +b4x i,4 +b5x i,5 +ε i however, y represents the value of the performance indicator. x i,1 This is the i-th value of the pressure difference across the loop seal 32 (sensors 110, 112), x i,2 This is the i-th value of the temperature (sensor 100) inside the loop seal 32, x i,3 This is the i-th value of the total air flow rate supplied into the CFB boiler (sensors 105, 106), x i,4 This is the i-th value of the floor temperature (sensor 104) inside the combustion chamber 12. x i,5 This is the i-th value of the airflow rate (sensor 108) supplied to the chamber of the fluidized bed heat exchanger 50. b0 is a constant, and b1...b5 are coefficients specific to the unknown KPI that should be estimated. ε represents the experimental error of the model.

[0121]

[0120] In the embodiment shown in Figure 3, the multivariate model of the pressure difference across a fluidized bed heat exchanger having an observed value of N is defined as follows: y i =b0+b1x i,1 +b2x i,2 +b3x i,3 +b4x i,4 +b5x i,5 +ε i however, y represents the value of the performance indicator. x i,1 This is the i-th value of the pressure difference across the loop seal 32 (sensors 110, 112), x i,2 This is the i-th value of the temperature (sensor 100) inside the loop seal 32, x i,3 This is the i-th value of the total air flow rate supplied into the CFB boiler (sensors 105, 106), x i,4 This is the i-th value of the floor temperature (sensor 104) inside the combustion chamber 12. x i,5This is the i-th value of the airflow rate (sensor 108) supplied to the chamber of the fluidized bed heat exchanger 50. b0 is a constant, and b1...b5 are coefficients specific to the unknown KPI that should be estimated. ε represents the experimental error of the model. Fitting is performed by minimizing the sum of the squares of the vertical deviations from each data point to the line that best fits the observed data, which is the optimal coefficient value obtained by minimizing the sum of the squared errors.

[0122]

[0121] The modeling unit 400 provides the necessary coefficients for a model based on executable historical data, which are used to model performance indicators by applying online data of process variables to the model. While the control system 48 and the CFB boiler 10 are operating, historical data containing data on process variables and performance indicators is continuously read and stored in the historical data source 401. The modeling unit 400 is configured to update or calibrate the model, i.e., the coefficients of the model, in order to learn the latest conditions of the normal operation of the solid material circulation process.

[0123]

[0122] The control system 48 is also provided with a performance diagnostic module 404, which is also applicable to CFB boilers equipped with one or more fluidized bed heat exchangers. Therefore, the description or performance diagnostic module related to Figure 2 is also applicable to the embodiment shown in Figure 3.

[0124]

[0123] Figure 4 illustrates the results obtained by the method of monitoring the process of circulating solid material in a circulating fluidized bed boiler according to Figure 3. Figure 4 discloses the online measurement results provided by a third temperature sensor 114. The third temperature sensor is located below the heat exchange unit 58 in the fluidized bed heat exchanger, near the chamber grid, and thus curve M114 shows the temperature of the solid material downstream of the fluidized bed heat exchange unit, which is the temperature of performance index iv. Another curve P114 shown in Figure 4 shows the modeled value of the performance index when the current measured value of the process variable is applied to a multivariate model of the KPI. The horizontal axis represents time, with zero being the actual time of boiler shutdown. As seen in the graph, after the modeled value of the model shows a deviation from the measured value for several hours, the process becomes too disrupted to recover, and no corrective action will be able to prevent the shutdown. As is clear from this example, the model indicates the impending problem more than 30 hours before the shutdown becomes irreversible. Undesirable conditions can be observed well in advance, within a sufficiently long timeframe (shaded area), and at an appropriate pace, before the actual problem occurs.

[0125]

[0124] Figure 5 schematically shows a circulating fluidized bed boiler 10, which has a fluidized bed heat exchanger 50 and a bypass route 56 that connects the solid material return path 15 to the combustion chamber 12 at a location between the loop seal 32 and the fluidized bed heat exchanger 50, on one of the return paths 15 (only one is shown for clarity). Thus, the bypass route 56 is configured to controllably send 0-100% of the solid material flow in the return path 15 directly to the combustion chamber, while sending the portion that may be re-mined to the fluidized bed heat exchanger 50. In this way, the process of circulating the solid material has two modes: a first mode (bypass mode) in which the method is applied to the circulation of solid material from the loop seal 32 directly to the combustion chamber 12 of the CFB boiler (when there is a flow of solid material through the bypass route), and a second mode in which the method is applied to the circulation of solid material from the loop seal 32 to the combustion chamber 12 of the CFB boiler via the fluidized bed heat exchanger 50 (when there is a flow of solid material through the fluidized bed heat exchanger 50). Therefore, the embodiment shown in Figure 5 can be understood as a combination of the embodiments shown in Figures 1 and 3 in a single solid material return path 15, with respect to applying the method according to the present invention.

[0126]

[0125] Furthermore, the return path 15 shown in Figure 5 may be considered to be within the same CFB boiler disclosed in Figure 1 or 3, that is, the CFB boiler may be provided with several return paths 15 with different configurations, and it should be understood that two or more of these return paths 15 are preferably provided with fluidized bed heat exchangers 50. Figure 5 also refers to a real-world application in which the CFB boiler has several return paths 15, and all or some of them are provided with fluidized bed heat exchangers 50 having bypass paths 55. The method according to the present invention is performed separately for all of the return paths 15.

[0127]

[0126] In addition to or instead of having a bypass path 56, Figure 5 discloses a solid material discharge path 56' connected to a solid material return path 15 at a location between the loop seal 32 and the fluidized bed heat exchanger 50. The location of the discharge path 56' or the extraction point of the material therefrom may be other than those shown herein, if desired. The solid material discharge path 56' makes it possible to remove 0-100% of the solid material flow from the solid material circulation process. The removed portion of the material can later be returned to the reactor 10, either as is or after any desired treatment of the solid material has been performed.

[0128]

[0127] The control system 48 shown in Figure 2 can be applied to the CFB boiler 10 shown in Figure 5 with necessary modifications relating to the performance indicators and process variable data.

[0129]

[0128] An exemplary embodiment of the calculation of residual-based KPIs and risk indices when a circulating fluidized bed boiler 10 is provided with a fluidized bed heat exchanger 50 in one of its return paths 15. The following steps are taken. - A step of creating a KPI model based on the pressure difference and temperature in the loop seal, and the pressure difference and temperature in the fluidized bed heat exchange chamber. • A step to compare the modeled value of the KPI with the measured value at the current point in time (t). For example, the KPI for the modeled loop seal temperature can be calculated as follows: KPI loop seal temp.modelled (t):=y t =b0+b1x t,1 +b2x t,2 +b3x t,3 +ε t However, b0 is a constant specific to the previously solved KPI, and b0...b3 are known coefficients specific to the previously solved KPI. x t,1 This is the t-th value of the temperature upstream of the loop seal 32 (sensor 103), x t,2is the t-th value of the total air flow rate supplied into the CFB boiler (sensors 105, 106), x t,3 is the t-th value of the bed temperature in the combustion chamber 12 (sensor 104). · Residual (KPI k,res (t), where k = 1 to K (K = number of KPIs), is obtained by calculating the deviation between the model output and the measured value for comparison. (For example, the modeled temperature - the measured temperature in the loop seal, i.e., KPI loop seal temp.res (t)=KPI loop seal temp.modelled (t)-KPI loop seal temp.meas (t))

[0130]

[0129] The residual limits for each KPI type are shown schematically in the following table.

[0131]

Table 1

[0132] However, A, B, C, and D represent predetermined limit values. · Calculate the risk index for each KPI as follows. r k = 100×(|KPI k,res (t)-(l up,k + l lo,k ) / 2|) / ((l up,k - l lo,k ) / 2) However, |.| is the absolute value, and k = 1 to K (K = number of KPIs). · Calculate the overall risk index RI as follows. RI = max(r <00:00097>) However, r k = individual risk, and k = 1 to K (K = number of KPIs).

[0133]

[0130] As an example, the residual of the temperature in the loop seal is such that KPI loop seal temp,res (t)=KPI loop seal temp,modelled (t)-KPI loop seal temp,meas (t)=B upLet's assume that this is the case. Next, we obtain the loop seal temperature risk index using the above formula. r loop seal temp =100×(|B up -( B up +B lo ) / 2|) / ((B up -B lo ) / 2) B up =B and B lo If = -B, then r loop seal temp = 100, and therefore, the calculation of the overall risk index using the above formula is RI = max(r k ) = 100.

[0134]

[0131] If there is no fluidized bed heat exchange chamber, proceed as in the example above, but omit the values ​​(KPIs) related to the fluidized bed heat exchange chamber.

[0135]

[0132] According to one aspect of the present invention, the overall risk index can be calculated using at least one of the following formulas: Maximum RI = max(r k ), average RI=mean(r k ), weighted average RI=Wmean(r k ), or median RI = median(r k ).

[0136]

[0133] According to a preferred embodiment of the present invention, the risk index of each KPI is limited to having a maximum value of 100 and a minimum value of 0, i.e., r k =[0,...,100]. Therefore, KPI k The absolute value of is the lower bound (l lo,k ) or upper limit (l up,k If it is greater than the absolute value of ), k = 100. Generally speaking, KPIs k is interval [l lo,k ,l up,k If it does not belong to ], r k = 100. 100 × (|KPI k (t)-(l up,k +l lo,k ) / 2|) / ((l up,k -llo,k If ) / 2)>100 then r k = 100, otherwise r k =100×(|KPI k (t)-(l up,k +l lo,k ) / 2|) / ((l up,k -l lo,k It is also possible to have a condition written as ) / 2).

[0137]

[0134] In the example above, the table shows that the absolute limit values ​​can be equal, but the upper and lower limits can be defined differently, just as the absolute values ​​of the upper and lower limits differ for the corresponding KPIs. However, l lo,k <l up,k It is important to note that this is the case.

[0138]

[0135] The above examples are given for clarification purposes only and are not intended to limit the scope of the claimed invention. Furthermore, instead of residuals, other mathematical comparisons, such as the ratio between corresponding values, can be calculated.

[0139]

[0136] In this specification, the present invention has been described as an example relating to what is considered to be the most preferred embodiment at present, but it will be obvious to those skilled in the art that, with technological advancements, the basic concept of the present invention can be implemented in many ways. Details mentioned in relation to any of the above embodiments may be used in relation to other embodiments when such combinations are technically feasible.

[0140] Parts list Circulating fluidized bed boiler 10 Combustion chamber 12 solid material separator 14 Solid material return path 15 Solid material return channel 16 Window Box 18 Grid 20 Air inlet 21 Loop seal fluidization air inlet 23 Air source 24 fuel inlet 22 Duct 26 Exit 1, 28 Exit 2 30 Loop Seal 32 Back pass 40 Superheater and optional reheater 42 Economizer 44 Air preheater 46 Control system 48 Fluidized bed heat exchanger 50 Grid 52 of fluidized bed heat exchanger, lifting chamber 54 Return duct 55 Bypass Route 56 Heat exchange unit 58 First temperature sensor 100 First pressure sensor 101 Second pressure sensor 102 Second temperature sensor 103 Third temperature sensor 104 First airflow sensor 105 Second airflow sensor 106 Third airflow sensor 108 Fourth airflow sensor 109 Third pressure sensor 110 Fourth pressure sensor 112 Third temperature sensor 114 Performance modeling unit 400 Historical data source 401 Current data source 402 Performance diagnostic module 404 Data filter unit 406 Diagnostic output 408 Model history coefficient storage 410

Claims

1. A method for monitoring the circulation process of solid materials in a circulating fluidized bed reactor (10), The reactor (10) comprises a reaction chamber (12), at least one solid material separator (14), and a return path (15) between the at least one solid material separator (14) and the reaction chamber (12). In this method, the process of circulating the solid material comprises: arranging the solid material such that it is drawn from the reaction chamber (12) to the at least one solid material separator (14) by a gas flow; separating the solid material from the gas flow within the at least one solid material separator (14); and sending the separated solid material from the solid material separator (14) to the reaction chamber (12) via the return path (15), The above method involves at least the following steps: a) Selecting process variables for the solid material circulation process within the return path (15), and selecting performance indicators for the solid material circulation process from among the selected process variables, b) A step of creating a multivariate model for each performance indicator using the process variables and historical data of the solid material circulation process and the performance indicators. c) A step of determining the modeled value of the performance indicator by applying the currently measured values ​​of the process variables to the multivariate model, d) A step of comparing the modeled value of each performance indicator with the measured value of each performance indicator and checking for the existence of anomalies between the modeled value and the measured value. A method characterized by comprising:

2. The process of circulating the solid material comprises sending the solid material directly from the solid material separator (14) to the reaction chamber (12) via a loop seal, at least, i. The pressure difference of the loop seal (32) in the return path (15), ii. The temperature inside the loop seal (32) in the return path (15) of the circulation of the solid material, The method according to claim 1, characterized in that it is selected as the performance indicator of the process in step a).

3. The process of circulating the solid material comprises sending the solid material from the solid material separator (14) to the reaction chamber (12) via the fluidized bed heat exchanger (50), at least, i. The pressure difference of the loop seal in the return path (15) and ii. The temperature inside the loop seal (32) in the return path of the circulation of the solid material, iii. The pressure difference of the fluidized bed heat exchanger (50) and iv. The temperature of the solid material downstream of the fluidized bed heat exchange unit (58) of the fluidized bed heat exchanger (50), The method according to claim 1, characterized in that it is selected as the performance indicator of the process in step a).

4. i. The process variables of the performance indicator, namely the pressure difference of the loop seal in the return path (15), include the total flow rate of reaction gas supplied into the reactor (10), the temperature of the product gas upstream of the loop seal (32), and the floor temperature in the reaction chamber (12). ii. The method according to claim 2, wherein the process variables of the performance indicator, namely the temperature inside the loop seal (32) in the return path (15) of the circulation of the solid material, include the total flow rate of reaction gas supplied into the reactor (10), the temperature of the product gas upstream of the loop seal (32), and the floor temperature inside the reaction chamber (12).

5. i. The process variables of the performance indicator, namely the pressure difference of the loop seal in the return path (15), include the total flow rate of reaction gas supplied into the reactor (10), the temperature of the product gas upstream of the loop seal (32), and the floor temperature in the reaction chamber (12). ii. The process variables of the performance indicator, namely the temperature inside the loop seal (32) in the return path (15) of the circulation of the solid material, include the total flow rate of reaction gas supplied into the reactor (10), the temperature of the product gas upstream of the loop seal (32), and the floor temperature inside the reaction chamber (12). iii. The process variables of the performance indicator, the pressure difference of the fluidized bed heat exchanger, include the total reaction gas flow rate supplied into the reactor (10), the temperature in the loop seal (32) in the return path (15) of the circulation of the solid material, the pressure difference of the loop seal (32), the gas flow rate to the fluidized bed heat exchanger (50), and the bed temperature in the reaction chamber (12). iv. The method according to claim 3, characterized in that the process variables of the performance indicator, the temperature of the fluidized bed heat exchanger, include the total flow rate of reaction gas supplied into the reactor (10), the temperature inside the loop seal (32) in the return path (15), the pressure difference of the loop seal, the gas flow rate to the fluidized bed heat exchanger (50), and the bed temperature inside the reaction chamber (12).

6. The method according to claim 4, characterized in that the total reaction gas flow rate is the total flow rate of gas into the reaction chamber (12).

7. The method according to claim 5, characterized in that the total reaction gas flow rate is the total flow rate of gas into the reaction chamber (12).

8. The method according to claim 4, characterized in that the floor temperature is the average floor temperature in the reaction chamber (12), calculated from at least two measurement points in the reaction chamber (12), at least one of which is at the grid level of the reaction chamber (12).

9. The method according to claim 5, characterized in that the floor temperature is the average floor temperature in the reaction chamber (12), calculated from at least two measurement points in the reaction chamber (12), at least one of which is at the grid level of the reaction chamber (12).

10. Creating the aforementioned multivariate model is The process involves measuring the value of a predetermined process variable, storing the measured value of the predetermined process variable along with a timestamp, thereby forming historical data for the process variable. The process involves measuring the value of a performance indicator, storing the measured value of the performance indicator along with a timestamp, and thereby forming historical data of the performance indicator. Select valid historical data using a predetermined data filter, The method according to claim 1, characterized by comprising:

11. The method according to claim 10, characterized in that the data filter is configured to approve data older than a preset isolation time.

12. The method according to claim 11, characterized in that the data filter is configured to approve data older than two weeks.

13. The method according to claim 10, characterized in that the data filter is configured to approve data that is no older than two months.

14. The method according to claim 10, wherein the data filter is configured to filter out any data from shutdown status and / or any abnormal operation from historical data based on predetermined limits or external information of abnormal operation of an input variable.

15. The multivariate model is a multivariate linear regression having measured observed values ​​for each of a first number (N) of process variables and a second number (P) of different process variables of the solid material circulation process, as follows: y i =b 0 +b 1 x i,1 +b 2 x i,2 +...b P x i,P +ε i However, i = 1, 2, ... N, The method is, y = performance indicator and x i,1 , x i,2 , . . ,xi,P are process variables, y i ,xi,1,xi,2,..., xi,P, and the historical data to be read, constant b 0 and factor b 1 , b 2 , . . . b P Solving the problem, The fitting process is performed by minimizing the sum of the squares of the vertical deviations from each data point to the line that best fits the historical data, The method according to claim 1, characterized by comprising:

16. The method according to claim 15, characterized in that the first number (N) is at least 10 times the second number (P).

17. The method according to claim 1, characterized in that the multivariate model is updated after a certain predetermined time interval has elapsed or after a period triggered by a trigger input.

18. The method according to claim 1, characterized in that the risk index for each performance indicator is calculated using the information on the presence of the anomaly.

19. The method according to claim 18, characterized in that the risk index for each performance indicator is calculated from a comparison between the modeled value and the respective measured value.

20. When the reactor (10) includes at least a first return path (15) between the first solid material separator (14) and the reaction chamber (12), and a second return path (15) between the second solid material separator (14) and the reaction chamber (12), The method according to any one of claims 1 to 19, characterized in that performing the method relating to the process of circulating the solid material in the first return path (15) and performing the method relating to the process of circulating the solid material in the second return path (15) are separate actions.

21. A control system (48) for monitoring the process of circulation of solid material in a circulating fluidized bed reactor (10) between the reaction chamber (12) and at least one solid material separator (14), and to the reaction chamber (12) via a return path (15) with a loop seal, The system includes a performance modeling unit (400) and a performance diagnostic module (404), The performance modeling unit (400) is, Access to the source history data (401) of the performance indicators of the solid material circulation process in the return path (15) and the process variables of each performance indicator, Multivariate models for each performance indicator, When executed in the control system, the system updates the multivariate model for each performance indicator using predetermined process variables of the solid material circulation process and historical data of the performance indicators, and provides executable instructions that result in a calibrated multivariate model. It has, The performance diagnostic module (404) is An input for receiving measurement data of process variables and performance indicators for the circulation process of the solid material, An executable instruction, when executed in the control system, determines the modeled value of the performance indicator by applying the current measured value of the process variable to the calibrated multivariate model, compares the modeled value of each performance indicator with the measured value of each performance indicator, and checks for the presence of anomalies between the modeled value and the measured value. A control system characterized by having the following features.

22. A control system for monitoring the process of circulating solid material in a circulating fluidized bed reactor (10) according to claim 21, comprising at least: pressure sensors (101, 102) for measuring the pressure drop in the loop seal; a product gas temperature sensor (103) downstream of the solid material separator (14); and means for determining the total gas flow rate to the reactor (10) and the bed temperature in the reaction chamber (12) of the reactor (10).

23. A control system for monitoring the process of circulation of solid material in a circulating fluidized bed reactor (10) according to claim 21, further comprising: a fluidized bed heat exchanger (50) in the return path (15), and at least: pressure sensors (101, 102) for measuring the pressure drop in the loop seal; a temperature sensor (103) in the loop seal (32); a generated gas temperature sensor (103) downstream of the solid material separator (14); pressure sensors (110, 112) for measuring the pressure drop in the fluidized bed heat exchanger; a temperature sensor (114) for measuring the temperature of solid material downstream of the heat exchange unit (58) in the fluidized bed heat exchanger (50); and means for determining the total gas flow rate to the reactor (10) and the bed temperature in the reaction chamber (12) of the reactor (10).

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