Heat exchanger performance monitoring system and heat exchanger performance monitoring method

Abstract

To accurately evaluate performance of a heat exchanger even when there is an unmeasured process value.SOLUTION: A heat exchanger performance monitoring system 100 for monitoring performance of a heat exchanger includes an energy calculating section 4 for correcting design information to a value according to a state of an actual plant on the basis of information (maintenance construction history information) stored in a database (maintenance database 2) and calculating a pressure loss amount, an unmeasured value estimating section 5 for estimating an unmeasured value in reference information used for calculating the performance of the heat exchanger on the basis of the pressure loss amount calculated by the energy calculating section, and a performance calculating section 6 for calculating the performance of the heat exchanger on the basis of the reference information including the unmeasured value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a heat exchanger performance monitoring system and a heat exchanger performance monitoring method. [Background technology]

[0002] As a technique for monitoring the performance of a heat exchanger, Patent Document 1 describes an evaluation method, evaluation device, and evaluation program for an air-conditioning heat exchanger core. This Patent Document 1 describes a "performance evaluation method for an air-conditioning heat exchanger core, which comprises a plurality of fins arranged in parallel at predetermined intervals and tubes joined so as to be in contact with the plurality of fins, and which performs heat exchange between a medium in the tubes and the fins by circulating moist air between the plurality of fins and the tubes, and which calculates the pressure loss and average heat transfer coefficient when the moist air flows along the fins of the air-conditioning heat exchanger core, and assumes that the temperature distribution of the fins has a uniform average temperature, and calculates the temperature distribution of the fins from the fin efficiency, the fin root temperature, and the outside air temperature, and assumes that the heat transfer between the medium and the tubes has a turbulent heat transfer coefficient relationship, and calculates the pressure loss and average heat transfer coefficient when the moist air flows along the fins of the air-conditioning heat exchanger core. The document states that this is a performance evaluation method for an air-conditioning heat exchanger core, characterized in that: the fin is divided into a plurality of sections along the direction of the humid air flow, the temperature of the humid air is determined for each divided section by a differential method, the tube is regarded as a single straight pipe and divided into the same number of sections as the divided sections of the humid air, the temperature of the medium is determined for each divided section of the tube, and the relational expression: humid air speed x total fin area x inlet / outlet humid air temperature difference x specific heat = {(amount of medium x specific heat x inlet / outlet water temperature difference) + latent heat when water in the humid air condenses on the surfaces of the fins and tubes} is assumed to hold, and the amount of the medium is determined by solving this relational expression, and further the air outlet temperature and water outlet temperature are determined.

[0003] Furthermore, as a technology for monitoring the performance of a heat exchanger, a plant control device, a plant monitoring device, and a control program are described in Patent Document 2. Patent Document 2 states, "A plant control device comprising: heat source generating means for generating cold or hot heat and providing a portion of this heat to a thermal load; and heat storage means for transporting a portion of the generated heat using a medium or the like, storing this heat, and providing this heat to the thermal load; a correction means for correcting a process signal measured in the plant; an estimation means for outputting an estimation signal based on the corrected process signal from the correction means and the process signal measured in the plant; and a control means for outputting an operation signal based on the estimation signal from the estimation means and the process signal measured in the plant to perform control." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-196130 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-130433 Summary of the Invention [Problem to be solved by the invention]

[0005] When evaluating the performance of a heat exchanger, process values ​​such as flow rate and pressure used in performance calculations may not be measured. In such cases, the unmeasured process values ​​are estimated based on design information and other measurement data, and the heat exchanger's performance is evaluated using the unmeasured process values. However, conventional heat exchanger performance monitoring technologies estimate the unmeasured process values ​​based on design information that deviates from the actual plant's state when there is a discrepancy between the design information and the actual plant state where the heat exchanger is used. This results in an inability to properly estimate the unmeasured process values ​​and an inaccurate evaluation of the heat exchanger's performance. Discrepancies between the design information and the actual plant state can occur for a variety of reasons, including when the actual plant was constructed in a state different from the design information, when the actual plant state has changed from its initial state due to aging, or when maintenance work has been performed.

[0006] The present invention has been made to solve the above-mentioned problems, and a main object of the present invention is to provide a heat exchanger performance monitoring system and a heat exchanger performance monitoring method that can accurately evaluate the performance of a heat exchanger even if there are unmeasured process values. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the present invention provides a heat exchanger performance monitoring system comprising: an energy calculation unit that calculates a pressure loss amount by correcting design information to a value that conforms to the state of an actual plant based on information stored in a database; an unmeasured value estimation unit that estimates an unmeasured value in reference information used to calculate the performance of the heat exchanger based on the pressure loss amount calculated by the energy calculation unit; and a performance calculation unit that calculates the performance of the heat exchanger based on the reference information including the unmeasured value. Other means will be described later. [Effects of the Invention]

[0008] According to the present invention, the performance of a heat exchanger can be evaluated with high accuracy even if there are unmeasured process values. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram of a heat exchanger performance monitoring system according to an embodiment. [Figure 2] 10 is a flowchart illustrating the operation of an energy calculation unit of the heat exchanger performance monitoring system according to the embodiment. [Figure 3] 4 is a flowchart illustrating an operation of an unmeasured value estimation unit of the heat exchanger performance monitoring system according to the embodiment. [Figure 4] 4 is a flowchart showing the operation of a performance calculation unit of the heat exchanger performance monitoring system according to the embodiment. [Figure 5] 1 is a diagram illustrating the effect of a heat exchanger performance monitoring system according to an embodiment. [Figure 6] 1 is an explanatory diagram illustrating a case where a heat exchanger performance monitoring system according to an embodiment is used to monitor the performance of a gland steam generator (heat exchanger) in a nuclear power plant. [Figure 7] 10 is a flowchart showing the operation of an energy calculation unit when the heat exchanger performance monitoring system according to the embodiment is used to monitor the performance of a gland steam generator (heat exchanger) in a nuclear power plant. [Figure 8] 4 is a flowchart showing the operation of an unmeasured value estimation unit when the heat exchanger performance monitoring system according to the embodiment is used to monitor the performance of a gland steam generator (heat exchanger) in a nuclear power plant. [Figure 9] 4 is a flowchart showing the operation of a performance calculation unit when the heat exchanger performance monitoring system according to the embodiment is used to monitor the performance of a gland steam generator (heat exchanger) in a nuclear power plant. [Figure 10] 1 is an explanatory diagram of the effect when the heat exchanger performance monitoring system according to the embodiment is used to monitor the performance of a gland steam generator (heat exchanger) in a nuclear power plant. [Figure 11] 10 is a flowchart showing another operation of the energy calculation unit when the heat exchanger performance monitoring system according to the embodiment is used to monitor the performance of a gland steam generator (heat exchanger) in a nuclear power plant. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail with reference to the drawings. Note that each drawing is merely a schematic illustration to allow a sufficient understanding of the present invention. Therefore, the present invention is not limited to the illustrated examples. Furthermore, in each drawing, common or similar components are given the same reference numerals, and redundant explanations thereof will be omitted.

[0011] <Configuration of heat exchanger performance monitoring system> The heat exchanger performance monitoring system 100 according to this embodiment is a system that accurately evaluates the performance of heat exchangers installed in nuclear power plants, thermal power plants, chemical plants, etc., even when there is a discrepancy between the design information and the actual plant state due to the influence of maintenance work, etc.

[0012] The configuration of a heat exchanger performance monitoring system 100 according to this embodiment will be described below with reference to Fig. 1. Fig. 1 is a block diagram of the heat exchanger performance monitoring system 100 according to this embodiment.

[0013] As shown in FIG. 1, the heat exchanger performance monitoring system 100 includes an operation database 1 (hereinafter, "database" may be referred to as "DB"), a maintenance database 2, a design database 3, an energy calculation unit 4, an unmeasured value estimation unit 5, a performance calculation unit 6, and a display unit 7.

[0014] The operation database 1 is a database that stores process values ​​measured by instruments installed in the plant and used to calculate the performance of heat exchangers. The process values ​​include, for example, information on flow rate, pressure, temperature, etc. The process values ​​are constantly measured in real time and stored in the operation database 1 one by one.

[0015] The maintenance database 2 is a database that stores maintenance execution history information, which includes information such as the date and time when maintenance was performed, the location where maintenance was performed, the type of maintenance, and the state after the maintenance was performed.

[0016] The design database 3 is a database that stores design information (including structural information) of the piping and equipment of the plant. The design information includes information such as the inner diameter and length of the piping, the pipe friction coefficient, etc. The structural information includes information such as the connection and branching of the piping.

[0017] The energy calculation unit 4 is a calculation means for calculating the energy of each plant device. The energy calculation unit 4 can calculate the energy of each plant device taking into account the state of the actual plant, which may differ from the design information due to the influence of maintenance work, etc. The unmeasured value estimation unit 5 is a calculation means for estimating an unmeasured value based on the law of conservation of energy.

[0018] The performance calculation unit 6 is a calculation means for evaluating (calculating) the performance of the heat exchanger using the measured process values ​​and the estimated process values. The display unit 7 is a component that displays the calculation results of the performance of the heat exchanger.

[0019] <Operation of the heat exchanger performance monitoring system> A major feature of the heat exchanger performance monitoring system 100 according to this embodiment is that the energy calculation unit 4 corrects the design information to a value that conforms to the state of the actual plant based on the information stored in the database (in this embodiment, the maintenance work history information stored in the maintenance database 2), and calculates the amount of pressure loss (see FIG. 2).

[0020] The operation of the heat exchanger performance monitoring system 100 will be described below with reference to Figures 2 to 4. Figures 2 to 4 are flowcharts showing the operation of the energy calculation unit 4, the operation of the unmeasured value estimation unit 5, and the operation of the performance calculation unit 6, respectively. Here, the description will be made assuming a case where the state of the actual plant differs from the design information due to the influence of maintenance work. However, factors other than maintenance work that may cause the state of the actual plant to differ from the design information include when the actual plant was constructed in a state different from the design information, or when the state of the actual plant has changed from the state it was in when it was first constructed due to deterioration over time.

[0021] 2, first, the heat exchanger performance monitoring system 100 calculates the energy of each piece of plant equipment in consideration of changes in the state inside the piping due to maintenance work in the energy calculation unit 4. At this time, the energy calculation unit 4 first acquires maintenance work history information such as the location where maintenance work was performed, the type of maintenance, and the details of the maintenance work from the maintenance database 2 (step S105).

[0022] Next, the energy calculation unit 4 acquires the design information from the design database 3 (step S110).

[0023] Next, based on the maintenance work history information, the energy calculation unit 4 estimates the values ​​of the items that have changed due to changes in the condition of the inside of the piping after the maintenance work, which has changed due to the effects of the maintenance work, and if there is a difference from the design information, corrects the design information (step S115).

[0024] Next, the energy calculation unit 4 acquires reference information such as process values ​​measured by each meter from the operation database 1 (step S120).

[0025] Next, the energy calculation unit 4 calculates the velocity head (flow velocity head), pressure head, position head, and pressure loss amount for each piece of plant equipment based on the design information acquired from the design database 3 in step S110, the design information corrected in step S115, and reference information such as process values ​​acquired in step S120 (step S125). At this time, the design information corrected in step S115 has been corrected taking into account changes in the conditions inside the piping due to maintenance work, and therefore the pressure loss amount calculated in step S125 also takes into account the effects of maintenance work.

[0026] 3, after step S125 shown in Fig. 2, the heat exchanger performance monitoring system 100 estimates unmeasured process values ​​to be used in heat exchanger performance calculations in the unmeasured value estimation unit 5. At this time, first, the unmeasured value estimation unit 5 acquires piping connection and branch information from the design database 3 (step S205).

[0027] Next, the unmeasured value estimation unit 5 acquires the velocity head (flow velocity head), pressure head, position head, and pressure loss amount for each plant device from the energy calculation unit 4 (step S210).

[0028] Next, the unmeasured value estimation unit 5 formulates the law of conservation of energy using the velocity head, pressure head, position head, and pressure loss amount based on the branch connection information of the pipes (step S215).

[0029] Next, the unmeasured value estimation unit 5 solves the law of conservation of energy and estimates the unmeasured process values ​​to be used in the performance calculation of the heat exchanger (step S220).

[0030] 4, after step S220 shown in Fig. 3, the heat exchanger performance monitoring system 100 calculates the performance of the heat exchanger in the performance calculation unit 6. At that time, first, the performance calculation unit 6 acquires reference information such as process values ​​measured by each instrument from the operation database 1 (step S305). That is, the performance calculation unit 6 acquires from the operation database 1 those process values ​​that have already been measured and are to be used in calculating the performance of the heat exchanger.

[0031] Next, the performance calculation unit 6 acquires the estimated unmeasured process value from the unmeasured value estimation unit 5 (step S310).

[0032] Next, the performance calculation unit 6 creates a performance model for calculating the performance of the heat exchanger (step S315). As performance indicators, the heat exchange amount [W], which indicates the amount of thermal energy transferred in the heat exchanger, and the temperature efficiency, which indicates how much the temperatures of the high-temperature fluid and the low-temperature fluid can be changed, can be set.

[0033] Next, the performance calculation unit 6 inputs the measured process values ​​(measured values) and the estimated unmeasured process values ​​(estimated values) into the performance model of the heat exchanger created in step S315, and calculates (estimates) the performance of the heat exchanger (step S320).

[0034] Thereafter, the heat exchanger performance monitoring system 100 displays the heat exchanger performance calculated (estimated) in the performance calculation unit 6 on the display unit 7. Note that the heat exchanger performance monitoring system 100 may also be configured to calculate the heat exchanger performance for each operating state in the performance calculation unit 6 and display the calculated (estimated) heat exchanger performance for each operating state on the display unit 7.

[0035] Even if there is a discrepancy between the design information and the state of the actual plant in which the heat exchanger is used, this heat exchanger performance monitoring system 100 corrects the design information to values ​​that conform to the state of the actual plant and evaluates (calculates) the performance of the heat exchanger. In other words, the heat exchanger performance monitoring system 100 corrects the design information used to estimate unmeasured process values ​​to values ​​that conform to the state of the actual plant, the state of which has changed due to maintenance work, and evaluates (calculates) the performance of the heat exchanger. This heat exchanger performance monitoring system 100 can accurately evaluate the performance of a heat exchanger even if there are unmeasured process values.

[0036] FIG. 5 is an explanatory diagram of the effect of the heat exchanger performance monitoring system 100. FIG. 5 shows the change in heat exchange rate over time, with line 50 representing the change in heat exchange rate when maintenance is not considered and line 51 representing the change in heat exchange rate when maintenance is considered. The heat exchanger performance monitoring system 100 can display the graph image shown in FIG. 5 on the display unit 7. Line 51 when maintenance is considered evaluates the heat exchanger performance more accurately than line 50 when maintenance is not considered. In the example shown in FIG. 5, line 50 when maintenance is not considered is below the target value 52 of the heat exchange rate during rated power operation at the current time 53. Therefore, by looking at line 50 when maintenance is not considered, the plant maintenance personnel determine that heat exchanger maintenance is necessary. On the other hand, line 51 when maintenance is considered is above the target value 52 of the heat exchange rate during rated power operation at the current time 53. Therefore, by looking at the line 51 for the case where maintenance work is considered, a plant maintenance person can determine that heat exchanger maintenance is not required. In other words, even if the line 50 for the case where maintenance work is not considered leads to an erroneous determination that heat exchanger maintenance is required, the plant maintenance person can determine that heat exchanger maintenance is not required based on the line 50 for the case where maintenance work is not considered. Therefore, the heat exchanger performance monitoring system 100 according to this embodiment can accurately evaluate the performance of the heat exchanger and appropriately determine when heat exchanger maintenance is required.

[0037] Furthermore, the heat exchanger performance monitoring system 100 according to this embodiment is capable of estimating unmeasured process values ​​in the unmeasured value estimation unit 5, and therefore the performance of the heat exchanger can be monitored without installing a new instrument for measuring the process values.

[0038] Furthermore, in existing plants in the prior art, some process values ​​could not be measured because instruments were not installed, making it impossible to monitor the performance of heat exchangers. However, the heat exchanger performance monitoring system 100 of this embodiment makes it possible to monitor the performance of heat exchangers.

[0039] <Application example of heat exchanger performance monitoring system> 6, an application example in which the heat exchanger performance monitoring system 100 is used to monitor the performance of a gland steam generator 8, which is one of the heat exchangers installed in a nuclear power plant 200, will be described. FIG. 6 is an explanatory diagram of the case in which the heat exchanger performance monitoring system 100 is used to monitor the performance of a gland steam generator 8 (heat exchanger) in a nuclear power plant 200.

[0040] In the example shown in FIG. 6, the nuclear power plant 200 includes three pieces of plant equipment: a gland steam generator 8 (heat exchanger), a high-pressure turbine 9, and a feedwater heater 10.

[0041] Main steam flows into the gland steam generator 8 (heat exchanger) from the high-pressure turbine 9. After passing through the gland steam generator 8, the main steam flows into the feedwater heater 10. The gland steam generator 8 is equipped with a gland steam generator flow meter 11. The high-pressure turbine 9 is equipped with a high-pressure turbine pressure gauge 12 and a high-pressure turbine flow meter 13. The feedwater heater 10 is equipped with a feedwater heater pressure gauge 14 and a feedwater heater flow meter 15. Here, in order to calculate the performance of the gland steam generator 8, which is a heat exchanger, we will explain how to estimate the pressure of the gland steam generator 8, which is not equipped with any instruments and whose process values ​​are not measured, taking maintenance work into consideration.

[0042] In the nuclear power plant 200, pipes and other components are coated with paint that has functions such as radiation resistance, decontamination properties, and hot water resistance. The nuclear power plant 200 also uses seawater as cooling water. The inner surfaces of the pipes that circulate this seawater to the coolers of each piece of equipment are lined with a polymer material such as rubber or polyethylene (PE) to prevent corrosion from the seawater.

[0043] Here, we will explain the case where the maintenance database 2 stores coating maintenance work history information, and the energy calculation unit 4 estimates the pipe inner diameter after maintenance work based on the maintenance work history information. In this case, the maintenance database 2 should store at least the work date and time, the work piping, and the coating thickness as the coating maintenance work history information.

[0044] However, the maintenance database 2 may store lining maintenance work history information, and the energy calculation unit 4 may estimate the pipe inner diameter after maintenance work based on the maintenance work history information. In this case, the maintenance database 2 may store at least the work date and time, the installed piping, and the lining coating thickness as the lining maintenance work history information.

[0045] 7 to 9, the operation of the heat exchanger performance monitoring system 100 when applied to a gland steam generator 8 (heat exchanger) of a nuclear power plant 200 will be described. FIGS. 7 to 9 are flowcharts showing the operation of the energy calculation unit 4, the operation of the unmeasured value estimation unit 5, and the operation of the performance calculation unit 6 when the heat exchanger performance monitoring system 100 is used to monitor the performance of the gland steam generator 8 (heat exchanger) of a nuclear power plant 200, respectively. Here, an example of operation will be described in which the pipe inner diameter after maintenance work differs from the design information and the pipe inner diameter after maintenance work is treated as the value of an item that has changed in accordance with the change in the state of the inside of the pipe after maintenance work. Here, the description will be made assuming that the pipe connecting the gland steam generator 8 (heat exchanger) and the feedwater heater 10 in FIG. 6 has been increased in diameter by a coating thickness Δd from the design information by applying the coating or lining described above.

[0046] 7, first, in the heat exchanger performance monitoring system 100, the energy calculation unit 4 calculates the energy of each piece of plant equipment, taking into account changes in the state inside the piping due to maintenance work. At this time, first, the energy calculation unit 4 acquires maintenance work history information, such as the location where maintenance work was performed, the type of maintenance, and the details of the maintenance work, from the maintenance database 2 (step S605).

[0047] Next, the energy calculation unit 4 acquires, as design information, the pipe inner diameter d, the pipe length L, the pipe height h, and the pipe friction coefficient λ of the pipe at the time of design from the design database 3 (step S610).

[0048] Next, the energy calculation unit 4 estimates the pipe inner diameter da after the maintenance work that has changed due to the influence of the maintenance work, based on the maintenance work history information and the pipe inner diameter d at the time of design, and corrects the design information if there is a difference from the design information (step S615). In this embodiment, in order to take into account the change in the pipe inner diameter due to the lining work, the energy calculation unit 4 corrects the pipe inner diameter d at the time of design using the coating thickness Δd according to the following equation (1).

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[0049] Next, the energy calculation unit 4 acquires reference information such as process values ​​measured by each meter from the operation database 1 (step S620). In this embodiment, the flow rate G2 measured by the gland steam generator flow meter 11, the pressure p1 measured by the high-pressure turbine pressure meter 12, the flow rate G1 measured by the high-pressure turbine flow meter 13, the pressure p3 measured by the feedwater heater pressure meter 14, and the flow rate G3 measured by the feedwater heater flow meter 15 are acquired.

[0050] Next, the energy calculation unit 4 calculates the velocity head (flow velocity head), pressure head, position head, and pressure loss amount for each plant device using the design information (pipe length L, pipe height h, pipe friction coefficient λ) acquired from the design database 3 in step S610, the pipe inner diameter da after maintenance work corrected in step S615, and reference information such as process values ​​acquired from the operation database 1 in step S620 (step S625). At this time, the pipe inner diameter da after maintenance work, which is the design information corrected in step S615, is corrected taking into account the influence of the maintenance work on the pipe inner diameter, so the pressure loss amount calculated in step S625 also takes into account the influence of the maintenance work. In this embodiment, the energy calculation unit 4 calculates the velocity head H v1 , pressure head H p1 , position head H z1 , velocity head H of gland steam generator 8 (heat exchanger) v2 , position head H z2 , pressure loss ΔH 12 , the velocity head H of the feedwater heater 10 v3 , pressure head H p3 , position head H z3 , pressure loss ΔH 23 Each head and pressure loss can be calculated using the following formulas (2) to (5). Note that "ρ" in formula (3) represents the "fluid density" and "g" represents the "gravitational acceleration" (same below).

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[0051] Here, the pressure head H in the gland steam generator 8 (heat exchanger) p2 is not calculated because the pressure p2 of the gland steam generator 8 has not been measured. This is because the unmeasured value estimation unit 5 determines the energy of the gland steam generator 8, and thereby the pressure p2 of the gland steam generator 8 is estimated.

[0052] 7, in the heat exchanger performance monitoring system 100, the unmeasured value estimation unit 5 estimates unmeasured process values ​​to be used in calculating the performance of the heat exchanger. At that time, first, the unmeasured value estimation unit 5 acquires piping connection and branching information from the design database 3 (step S705). In this embodiment, the unmeasured value estimation unit 5 acquires information on the presence of a piping that flows from the high-pressure turbine 9 to the gland steam generator 8 and a piping that flows from the gland steam generator 8 to the feedwater heater 10.

[0053] Next, the unmeasured value estimation unit 5 acquires the velocity head (flow velocity head), pressure head, position head, and pressure loss amount of each plant device from the energy calculation unit 4 (step S710). In this embodiment, the unmeasured value estimation unit 5 acquires the velocity head H v1 , pressure head H p1 , position head H z1 , velocity head H of gland steam generator 8 (heat exchanger) v2 , position head H z2 , pressure loss ΔH 12 , the velocity head H of the feedwater heater 10 v3 , pressure head H p3 , position head H z3 , pressure loss ΔH 23 Get.

[0054] Next, the unmeasured value estimation unit 5 formulates the law of conservation of energy based on the branch connection information of the pipes (step S715). The law of conservation of energy is formulated by calculating the energy of each plant device using the velocity head, pressure head, position head, and pressure loss. In this embodiment, the unmeasured value estimation unit 5 calculates the energy E1 of the high-pressure turbine, the energy E2 of the gland steam generator, and the energy E3 of the feedwater heater according to the following equations (6) to (8).

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[0055] Next, the unmeasured value estimation unit 5 formulates the laws of conservation of energy in the following equations (9) to (11) using the energies in the equations (6) to (8).

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[0056] Next, the unmeasured value estimation unit 5 incorporates the law of conservation of energy formulated in step S715 into the constraints of data reconciliation (step S720). Data reconciliation is a technique for estimating the best value of a variable using the weighted least squares method. Data reconciliation is described in detail, for example, in "Module: Introduction to Data Reconciliation Program for North American Mobility in Higher Education Introducing Process Integration for Environmental Control in Engineering Curricula" (URL: https: / / vdocuments.net / module-introduction-to-data-reconciliation.html?page=1) (hereinafter referred to as "Reference 1"). While Reference 1 formulates the law of conservation of mass, in this embodiment, the law of conservation of energy is formulated and incorporated into the constraints of data reconciliation, thereby deriving Equations (16) and (17) described below.

[0057] In data reconciliation, the objective function of the weighted least squares method is shown as the following equation (12). Note that in the following equation (12), "J" represents the objective function, "y" represents the variable for the measured value, "y with the symbol ^ above it" represents the true value of the measured value, "z" represents the variable for the unmeasured value, and "z with the symbol ^ above it" represents the true value of the unmeasured value (same below). Also, "T" represents the top and bottom of the matrix, and "V" represents the variance-covariance matrix (same below).

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[0058] When solving the weighted least squares method, constraints are imposed as shown in the following equation (13), and the variables that minimize the value of equation (12) under the constraints are solved. Here, y is a measured variable, z is an unmeasured variable, and A y , A z are incidence matrices for satisfying the constraints of the law of conservation of energy. Here, the constraints of the law of conservation of energy are expressed by equations (9), (10), and (11), and the following equation (13) represents the incidence matrix for satisfying the constraints of the law of conservation of energy.

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[0059] In this embodiment, the unmeasured value estimation unit 5 defines the law of conservation of energy in equations (9) and (10) as constraints, and estimates (calculates) the energy E2 of the gland steam generator so as to satisfy the constraints. y and z in equation (13) are as shown in the following equations (14) and (15). Here, y and z in the following equations (14) and (15) can be substituted into equation (13).

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[0060] The incidence matrices for satisfying the constraints of the law of conservation of energy are given by the following equations (16) and (17).

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[0061] As described above, "V" in equation (12) represents the variance-covariance matrix. The diagonal components of the variance-covariance matrix V incorporate the uncertainties of the measurement values. In this embodiment, V1 and V3, which are combinations of the uncertainties of the measurement values ​​of the high-pressure turbine 9 and the feedwater heater 10 shown in FIG. 6, are incorporated into the diagonal components, as shown in equation (18) below.

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[0062] 9, after step S725 shown in Fig. 8, the heat exchanger performance monitoring system 100 calculates the performance of the heat exchanger (gland steam generator 8) in the performance calculation unit 6. At that time, first, the performance calculation unit 6 acquires reference information such as process values ​​measured by each instrument from the operation database 1 (step S805). That is, the performance calculation unit 6 acquires from the operation database 1 those process values ​​that have already been measured and are to be used in the performance calculation of the heat exchanger.

[0063] Next, the performance calculation unit 6 acquires the estimated unmeasured process value from the unmeasured value estimation unit 5 (step S810).

[0064] Next, the performance calculation unit 6 creates a performance model for calculating the performance of the heat exchanger (step S815). In this embodiment, the performance calculation unit 6 calculates the heat exchange amount Q as a performance index for the gland steam generator 8, which is a heat exchanger. The heat exchange amount Q is defined as shown in the following equation (20). "K" is the overall heat transfer coefficient [W / m 2 K] and "ΔT lm " represents the logarithmic mean temperature difference [K], and "A" represents the heat transfer area [m 2 ]. The overall heat transfer coefficient K and the logarithmic mean temperature difference ΔT lm is selected based on an empirical formula or theoretical formula appropriate for the type of heat exchanger.

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[0065] Next, the performance calculation unit 6 inputs the measured process values ​​(measured values) and the estimated unmeasured process values ​​(estimated values) into the performance model of the heat exchanger created in step S815, and calculates (estimates) the performance of the heat exchanger (step S820).

[0066] Thereafter, the heat exchanger performance monitoring system 100 displays the performance of the heat exchanger calculated (estimated) by the performance calculation unit 6 on the display unit 7.

[0067] FIG. 10 is an explanatory diagram of the effect of using the heat exchanger performance monitoring system 100 to monitor the performance of the gland steam generator 8 (heat exchanger) of a nuclear power plant 200. FIG. 10 shows the change in the heat exchange rate when maintenance work is considered as line 61, and the change in performance of the gland steam generator 8 (heat exchanger) during rated power operation over time. The heat exchanger performance monitoring system 100 can display the graph image shown in FIG. 10 on the display unit 7. In the example shown in FIG. 10, the line 61 when maintenance work is considered exceeds the target value 62 of the heat exchange rate during rated power operation at the current time 63. Therefore, by looking at the line 61 when maintenance work is considered, a plant maintenance worker can determine that maintenance of the heat exchanger is not necessary. In this way, the heat exchanger performance monitoring system 100 displays the heat exchange rate of the gland steam generator 8 (heat exchanger) during rated power operation on the display unit 7. This allows real-time performance monitoring of the gland steam generator 8 (heat exchanger) during any operating state. Therefore, the performance of the heat exchanger can be evaluated with high accuracy, and the timing for maintenance of the heat exchanger can be properly determined.

[0068] <Another example> 7 to 9 are operation examples in which the inner diameter of the pipe after maintenance work differs from the design information, and the inner diameter of the pipe after maintenance work is treated as the value of an item that has changed due to a change in the condition of the inside of the pipe after maintenance work. In contrast, here, as another operation example, an operation example will be described in which the surface roughness of the inner wall of the pipe after maintenance work differs from the design information, and the surface roughness of the inner wall of the pipe after maintenance work is treated as the value of an item that has changed due to a change in the condition of the inside of the pipe after maintenance work. In addition, here, it will be described that the pipe friction coefficient of the plant has also changed from the initial state because the surface roughness of the inner wall of the pipe after maintenance work differs from the design information.

[0069] 7 to 9, this other operation example differs in that the energy calculation unit 4 executes the processes of steps S610a, S615a, and S625a shown in Fig. 11 instead of the processes of steps S610, S615, and S625 shown in Fig. 7. Fig. 11 is a flowchart showing another operation of the energy calculation unit 4 when the heat exchanger performance monitoring system 100 is used for performance monitoring of the gland steam generator 8 (heat exchanger) of the nuclear power plant 200. Note that the operations of the unmeasured value estimation unit 5 and the performance calculation unit 6 other than the energy calculation unit 4 are the same as those in the operation examples shown in Figs. 8 and 9.

[0070] Here, we will explain the case where the maintenance database 2 stores the maintenance work history information of the coating, and the energy calculation unit 4 estimates the surface roughness of the inner wall of the pipe and the pipe friction coefficient after the maintenance work based on the maintenance work history information. In this case, the maintenance database 2 should store at least the work date and time, the applied pipe, and the coating thickness as the maintenance work history information of the coating.

[0071] However, the maintenance database 2 may store lining maintenance work history information, and the energy calculation unit 4 may estimate the surface roughness of the pipe inner wall and the pipe friction coefficient after maintenance work based on the maintenance work history information. In this case, the maintenance database 2 may store at least the work date and time, the installed piping, and the lining coating thickness as the lining maintenance work history information.

[0072] As shown in FIG. 11, in step S610a, the energy calculation unit 4 acquires, from the design database 3, the design information, including the pipe inner diameter d, pipe length L, pipe height h, pipe surface roughness R, and pipe friction coefficient λ of the pipe.

[0073] Next, in step S615a, the energy calculation unit 4 estimates the surface roughness Ra and pipe friction coefficient λa of the pipe after maintenance work that have changed due to the effects of maintenance, based on the design information, the maintenance work history information, and the surface roughness R of the pipe at the time of design and the pipe friction coefficient λ, and corrects the design information if there is a difference from the design information. Regarding this operation, the energy calculation unit 4 first estimates the surface roughness Ra of the pipe after maintenance work, based on the design information, the maintenance work history information, and the surface roughness R of the pipe at the time of design, and corrects the surface roughness R of the pipe in the design information to the surface roughness Ra of the pipe after maintenance work. When the surface roughness R of the pipe in the design information changes to the surface roughness Ra of the pipe after maintenance work, the pipe friction coefficient λ at the time of design changes to the pipe friction coefficient λa after maintenance work. The pipe friction coefficient λa after maintenance work is calculated from the surface roughness Ra of the pipe after maintenance work, the design information, and the pipe friction coefficient λ at the time of design. Therefore, next, the energy calculation unit 4 estimates the pipe friction coefficient λa after maintenance work based on the estimated surface roughness Ra of the piping after maintenance work, the design information, and the pipe friction coefficient λ at the time of design, and corrects the pipe friction coefficient λ in the design information to the pipe friction coefficient λa after maintenance work.

[0074] After that, in step S625a, the energy calculation unit 4 calculates the velocity head (flow velocity head), pressure head, position head, and pressure loss amount for each plant equipment using the design information (pipe inner diameter d at the time of design, pipe length L, pipe height h, pipe surface roughness R, and pipe friction coefficient λ of the pipe) acquired from the design database 3 in step S610a, the surface roughness Ra and pipe friction coefficient λa of the pipe after maintenance work corrected in step S615a, and reference information such as process values ​​acquired from the operation database 1 in step S620.

[0075] <Main features of the heat exchanger performance monitoring system> (1) As shown in FIG. 1, the heat exchanger performance monitoring system 100 according to this embodiment includes an energy calculation unit 4, an unmeasured value estimation unit 5, and a performance calculation unit 6. The energy calculation unit 4 corrects design information to a value that conforms to the state of the actual plant based on information stored in a database (in this embodiment, maintenance work history information stored in a maintenance database 2), and calculates the amount of pressure loss. The unmeasured value estimation unit 5 estimates unmeasured values ​​in reference information used to calculate the performance of the heat exchanger (gland steam generator 8), based on the energy calculation unit 4 and the amount of pressure loss calculated by the energy calculation unit 4. The performance calculation unit 6 calculates the performance of the heat exchanger (gland steam generator 8) based on the reference information including the unmeasured values.

[0076] The heat exchanger performance monitoring system 100 according to this embodiment estimates unmeasured values ​​(unmeasured process values) based on design information corrected to values ​​that correspond to the actual plant conditions. This allows the unmeasured values ​​(unmeasured process values) to be appropriately estimated. Therefore, even if there are unmeasured process values, the performance of the heat exchanger can be evaluated with high accuracy.

[0077] (2) As shown in FIG. 7, the energy calculation unit 4 may be configured to estimate the value of an item that has changed due to a change in the condition of the inside of the pipe caused by maintenance, based on the maintenance work history information stored in the maintenance database 2, and correct the design information to the value of that item.

[0078] The heat exchanger performance monitoring system 100 according to this embodiment corrects the design information to reflect the values ​​of items that have changed in accordance with changes in the state of the inside of the piping due to maintenance. This allows the performance of the heat exchanger to be evaluated accurately even after maintenance work, even if there are unmeasured process values.

[0079] (3) As shown in FIG. 7, the energy calculation unit 4 may be configured to estimate the inner diameter of the pipe after maintenance work as the value of an item that has changed in accordance with a change in the state of the inside of the pipe due to maintenance.

[0080] The heat exchanger performance monitoring system 100 according to this embodiment can accurately evaluate the performance of a heat exchanger even if the pipe inner diameter after maintenance work is used as an unmeasured process value.

[0081] (4) When the maintenance database 2 stores the maintenance work history information of the coating, as shown in FIG. 7, the energy calculation unit 4 may be configured to estimate the inner diameter of the pipe after the maintenance work based on the maintenance work history information.

[0082] The heat exchanger performance monitoring system 100 according to this embodiment can estimate the pipe inner diameter after maintenance work as an unmeasured process value after maintenance work for coating.

[0083] (5) The maintenance database 2 may store at least the date and time of application, the applied pipe, and the thickness of the coating as the maintenance application history information of the coating.

[0084] The heat exchanger performance monitoring system 100 according to this embodiment can estimate the inner diameter of the pipe after maintenance work using information such as the date and time of work, the pipe to be worked, and the thickness of the coating, which is stored in the maintenance database 2 as maintenance work history information for the coating.

[0085] (6) When the maintenance database 2 stores the maintenance work history information of the lining, as shown in FIG. 7, the energy calculation unit 4 may be configured to estimate the inner diameter of the pipe after the maintenance work based on the maintenance work history information.

[0086] The heat exchanger performance monitoring system 100 according to this embodiment can estimate the pipe inner diameter after maintenance work as an unmeasured process value after maintenance work on the lining.

[0087] (7) The maintenance database 2 may store at least the date and time of construction, the pipe to be constructed, and the thickness of the lining coating as lining maintenance construction history information.

[0088] The heat exchanger performance monitoring system 100 according to this embodiment can estimate the inner diameter of the pipe after maintenance work using information such as the work date and time, the work piping, and the lining coating thickness stored in the maintenance database 2 as lining maintenance work history information.

[0089] (8) As shown in FIG. 11, the energy calculation unit 4 may be configured to estimate the surface roughness of the inner wall of the pipe and the pipe friction coefficient after maintenance work as values ​​of items that have changed due to changes in the condition of the inside of the pipe caused by maintenance.

[0090] The heat exchanger performance monitoring system 100 according to this embodiment can accurately evaluate the performance of a heat exchanger even if the surface roughness of the inner wall of the pipe and the pipe friction coefficient after maintenance work are unmeasured process values.

[0091] (9) When the maintenance database 2 stores the maintenance work history information of the coating, as shown in FIG. 11, the energy calculation unit 4 may be configured to estimate the surface roughness and the pipe friction coefficient of the inner wall of the pipe after the maintenance work based on the maintenance work history information.

[0092] The heat exchanger performance monitoring system 100 according to this embodiment can estimate the surface roughness of the inner wall of the pipe and the pipe friction coefficient after the maintenance work, which are unmeasured process values, after the maintenance work for coating.

[0093] (10) The maintenance database 2 may store at least the date and time of application, the applied piping, and the pipe friction coefficient of the coated wall surface as the coating maintenance application history information.

[0094] The heat exchanger performance monitoring system 100 according to this embodiment can estimate the surface roughness and pipe friction coefficient of the inner wall of the pipe after maintenance work, using information such as the date and time of work, the pipe to be worked on, and the thickness of the coating, which is stored in the maintenance database 2 as maintenance work history information for the coating.

[0095] (11) In the case where the maintenance database 2 stores the maintenance work history information of the lining, as shown in FIG. 11, the energy calculation unit 4 may be configured to estimate the surface roughness of the inner wall of the pipe and the pipe friction coefficient after the maintenance work based on the maintenance work history information.

[0096] The heat exchanger performance monitoring system 100 according to this embodiment can estimate the surface roughness of the inner wall of the pipe and the pipe friction coefficient after the maintenance work as unmeasured process values ​​after the maintenance work on the lining.

[0097] (12) The maintenance database 2 may store at least the date and time of construction, the pipe where the lining is constructed, and the coefficient of pipe friction on the wall surface where the lining is constructed, as the lining maintenance construction history information.

[0098] The heat exchanger performance monitoring system 100 according to this embodiment can estimate the surface roughness and pipe friction coefficient of the inner wall of the pipe after maintenance work, using information such as the date and time of work, the pipe to be worked, and the thickness of the lining coating, which is stored in the maintenance database 2 as lining maintenance work history information.

[0099] (13) As shown in FIGS. 2 to 4, the heat exchanger performance monitoring method according to this embodiment includes an energy calculation step (step S125 in FIG. 2), an unmeasured value estimation step (step S220 in FIG. 3), and a performance calculation step (step S320 in FIG. 4). The energy calculation step (step S125 in FIG. 2) is a step of correcting design information to a value that conforms to the state of the actual plant based on information stored in a database (in this embodiment, maintenance work history information stored in the maintenance database 2) to calculate the amount of pressure loss. The unmeasured value estimation step (step S220 in FIG. 3) is a step of estimating an unmeasured value in reference information used to calculate the performance of the heat exchanger (gland steam generator 8) based on the amount of pressure loss calculated in the energy calculation step. The performance calculation step (step S320 in FIG. 4) is a step of calculating the performance of the heat exchanger (gland steam generator 8) based on reference information including the unmeasured value.

[0100] The heat exchanger performance monitoring method according to this embodiment estimates unmeasured values ​​(unmeasured process values) based on design information corrected to values ​​that correspond to the actual plant state. This allows the unmeasured values ​​(unmeasured process values) to be appropriately estimated. Therefore, even if there are unmeasured process values, the performance of the heat exchanger can be evaluated with high accuracy.

[0101] The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of the embodiments with other configurations, and it is also possible to add other configurations to the configuration of the embodiments. Furthermore, it is possible to add, delete, or replace part of each configuration with other configurations.

[0102] Furthermore, the present invention can be applied not only to heat exchangers installed in plants, but also to performance monitoring of heat exchangers installed in air conditioners and heat exchangers installed in refrigeration cycles. [Explanation of symbols]

[0103] 1. Driving database 2 Maintenance Database (Database) 3 Design Database 4 Energy calculation section 5 Unmeasured value estimation section 6 Performance calculation section 7 Display section 8. Grand steam generator (heat exchanger) 9. High-pressure turbine 10 Feed water heater 11 Gland Steam Generator Flow Meter 12 High pressure turbine pressure gauge 13 High-pressure turbine flow meter 14 Feedwater heater pressure gauge 15 Feed water heater flow meter 100 Heat Exchanger Performance Monitoring System 200 Nuclear Power Plant d Piping inner diameter (design information) da: Pipe inner diameter (value based on actual plant conditions) R Surface roughness (design information) Ra Surface roughness (value based on actual plant conditions) λ Pipe friction coefficient (design information) λa: Pipe friction coefficient (value based on actual plant conditions)

Claims

1. an energy calculation unit that corrects design information to a value that conforms to the state of an actual plant based on information stored in a database and calculates the amount of pressure loss; an unmeasured value estimation unit that estimates an unmeasured value in reference information used in calculating the performance of the heat exchanger based on the pressure loss calculated by the energy calculation unit; a performance calculation unit that calculates the performance of the heat exchanger based on the reference information including the unmeasured value. A heat exchanger performance monitoring system comprising:

2. 2. The heat exchanger performance monitoring system according to claim 1, The energy calculation unit estimates the value of an item that has changed due to a change in the state of the inside of the piping caused by maintenance, based on the maintenance work history information stored in the maintenance database, and corrects the design information to the value of the item. A heat exchanger performance monitoring system comprising:

3. 3. The heat exchanger performance monitoring system according to claim 2, The energy calculation unit estimates the inner diameter of the pipe after the maintenance work as the value of the item that has changed in accordance with the change in the state of the inside of the pipe due to the maintenance work. A heat exchanger performance monitoring system comprising:

4. 4. The heat exchanger performance monitoring system according to claim 3, the maintenance database stores coating maintenance application history information; The energy calculation unit estimates the pipe inner diameter after the maintenance work based on the maintenance work history information. A heat exchanger performance monitoring system comprising:

5. 5. The heat exchanger performance monitoring system according to claim 4, The maintenance database stores at least the date and time of application, the applied pipe, and the thickness of the coating as maintenance application history information of the coating. A heat exchanger performance monitoring system comprising:

6. 4. The heat exchanger performance monitoring system according to claim 3, The maintenance database stores lining maintenance construction history information, The energy calculation unit estimates the pipe inner diameter after the maintenance work based on the maintenance work history information. A heat exchanger performance monitoring system comprising:

7. 7. The heat exchanger performance monitoring system according to claim 6, The maintenance database stores at least the date and time of construction, the pipe to be constructed, and the thickness of the lining coating as lining maintenance construction history information. A heat exchanger performance monitoring system comprising:

8. 3. The heat exchanger performance monitoring system according to claim 2, The energy calculation unit estimates the surface roughness of the inner wall of the pipe after the maintenance work as a value of an item that has changed in accordance with a change in the state of the inside of the pipe due to the maintenance work. A heat exchanger performance monitoring system comprising:

9. 9. The heat exchanger performance monitoring system according to claim 8, the maintenance database stores coating maintenance application history information; The energy calculation unit estimates the surface roughness of the inner wall of the pipe after the maintenance work based on the maintenance work history information. A heat exchanger performance monitoring system comprising:

10. 10. The heat exchanger performance monitoring system according to claim 9, The maintenance database stores at least the date and time of application, the applied piping, and the pipe friction coefficient of the coated wall surface as coating maintenance application history information. A heat exchanger performance monitoring system comprising:

11. 9. The heat exchanger performance monitoring system according to claim 8, The maintenance database stores lining maintenance construction history information, The energy calculation unit estimates the surface roughness of the inner wall of the pipe after the maintenance work based on the maintenance work history information. A heat exchanger performance monitoring system comprising:

12. 12. The heat exchanger performance monitoring system according to claim 11, The maintenance database stores at least the construction date and time, the construction piping, and the pipe friction coefficient of the lining construction wall surface as lining maintenance construction history information. A heat exchanger performance monitoring system comprising:

13. an energy calculation step of correcting the design information to a value that conforms to the state of the actual plant based on the information stored in the database and calculating the amount of pressure loss; an unmeasured value estimating step of estimating an unmeasured value in reference information used for calculating the performance of the heat exchanger based on the pressure loss calculated in the energy calculating step; a performance calculation step of calculating the performance of the heat exchanger based on the reference information including the unmeasured value. A method for monitoring heat exchanger performance.

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