Plant simulators and operator training simulators

Abstract

To improve the accuracy of prediction of simulation in an operation area different from a normal operation time.SOLUTION: A plant simulator 30 simulates the behavior of a plant comprising a circulating fluidized bed boiler that circulates fluid material discharged from a combustor through a cyclone and an external heat exchanger to the combustor. The plant simulator 30 comprises: a model storage unit 40 that stores a physical model of the plant; and an operation unit 45 that simulates the behavior of the plant by using input data and the physical model. The physical model of the plant includes a physical model related to the components of the circulating fluidized bed boiler. The operation unit 45 includes at least one of a combustor operation unit 46 that simulates a delay in combustion of fuel introduced into a combustor, a cyclone operation unit 47 that simulates an afterburning phenomenon in the cyclone, and an external heat exchange operation unit 48 that simulates a delay in heat transfer caused by the fluid material in the external heat exchanger.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a plant simulator and an operator training simulator. [Background technology]

[0002] Conventionally, simulators for operation training have been developed for use in educating and training operators in power plants such as thermal power plants, nuclear power plants, etc. For example, Patent Document 1 discloses an operation training simulator for a thermal power plant that uses a circulating fluidized bed (CFB) boiler. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5917366 Summary of the Invention [Problem to be solved by the invention]

[0004] The operator training simulator disclosed in Patent Document 1 uses a statistical model to represent plant behavior and simulates plant behavior by calculating process values ​​according to setting values ​​input by an operator. Therefore, a considerable amount of operational data is required to improve the prediction accuracy of the simulation. Therefore, while the prediction accuracy is high during normal operation when sufficient operational data is available, it is difficult to achieve sufficient prediction accuracy in operating regions where data is insufficient, such as when an abnormality occurs.

[0005] The present disclosure has been made in consideration of the above circumstances, and aims to provide a plant simulator and an operator training simulator that can improve the prediction accuracy of simulations in operating regions that differ from normal operation. [Means for solving the problem]

[0006] A first aspect of the present disclosure is a plant simulator that simulates the behavior of a plant that has a circulating fluidized bed boiler that circulates fluid material discharged from a combustor via a cyclone and an external heat exchanger back to the combustor, the plant simulator comprising: a model memory unit for storing a physical model of the plant; and a calculation unit that simulates the behavior of the plant using input data and the physical model, wherein the physical model of the plant includes a physical model related to components of the circulating fluidized bed boiler, and the calculation unit performs calculations that include at least one of a combustion delay of input fuel in the combustor, an afterburning phenomenon in the cyclone, and a heat transfer delay due to the fluid material in the external heat exchanger.

[0007] A second aspect of the present disclosure is a program for causing a computer to function as the plant simulator.

[0008] A third aspect of the present disclosure is an operation training simulator including the above-mentioned plant simulator, a trainee terminal for inputting operation variables, a control simulator for giving control command values ​​based on the operation variables to the plant simulator, and a supervisor terminal for giving changes to internal parameters of the plant simulator or the control simulator. [Effects of the Invention]

[0009] The plant simulator and the operator training simulator of the present disclosure have the advantage of being able to improve the prediction accuracy of simulations in operating regions that differ from normal operation. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram of a power plant according to an embodiment of the present disclosure. [Figure 2] FIG. 1 is a diagram illustrating an example of a hardware configuration of a plant simulator according to an embodiment of the present disclosure. [Figure 3] FIG. 2 is a functional block diagram illustrating an example of functions provided in a plant simulator according to an embodiment of the present disclosure. [Figure 4] FIG. 2 is a diagram illustrating an example of the relationship between each calculation unit that simulates the behavior of a circulating fluidized bed boiler according to an embodiment of the present disclosure and an example of input / output data. [Figure 5] FIG. 2 is a diagram showing the contents of a calculation process executed by a combustor calculation unit according to an embodiment of the present disclosure. [Figure 6] FIG. 4 is a diagram showing the contents of a calculation process executed by a cyclone calculation unit according to an embodiment of the present disclosure. [Figure 7] FIG. 10 is a diagram showing the contents of a calculation process executed by an external heat exchange calculation unit according to an embodiment of the present disclosure. [Figure 8] 1 is a diagram illustrating a schematic overall configuration of a driving training simulator according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of a plant simulator according to the present disclosure will be described with reference to the drawings. A plant simulator according to an embodiment of the present disclosure is a simulator that simulates the behavior of a power plant equipped with a circulating fluidized bed boiler (hereinafter referred to as a "CFB boiler"). Before describing the plant simulator according to this embodiment, a configuration of a power plant 1 will be briefly described below.

[0012] (Power plant configuration) Fig. 1 is a schematic configuration diagram of a power plant 1 according to an embodiment of the present disclosure. As shown in Fig. 1, the power plant 1 according to this embodiment includes a CFB boiler 2 as a boiler that generates steam. The power plant 1 further includes a steam turbine 3 that is rotationally driven by the steam generated in the CFB boiler 2, and a generator 4 that generates electricity using the driving force of the steam turbine 3. In the following description, "upper" refers to the vertically upper direction, and "lower" refers to the vertically lower direction.

[0013] The CFB boiler 2 includes, for example, a combustor 5, a cyclone 13, and an external heat exchanger 15. Furthermore, the CFB boiler 2 includes a convection heat transfer section 7 including a plurality of heat exchangers 8 and the like. The CFB boiler 2 circulates the fluidized material discharged from the combustor 5 to the combustor 5 via a cyclone 13 and an external heat exchanger 15. An example of the fluidized material is fluidized sand (for example, particles mainly composed of SiO2, such as river sand).

[0014] Furthermore, the CFB boiler 2 is equipped with a fuel supply device 6 that supplies fuel to the combustor 5. The CFB boiler 2 is capable of burning a wide range of fuels, such as coal (bituminous coal, subbituminous coal, lignite, anthracite, etc.), petroleum coke, woody biomass, paper sludge, RPF (Refuse Paper & Plastic Fuel), RDF (Refuse Derived Fuel), waste tires, dewatered sludge, municipal solid waste, etc.

[0015] 1 is an example of a fuel supply device 6 that uses coal as fuel. In this embodiment, since the internal pressure of the combustor 5 is slightly higher than atmospheric pressure, the fuel supply device 6 is provided with a rotary valve 10 and a sealing air supply device (not shown) to prevent combustion gases and the like from flowing back into the fuel supply system.

[0016] The combustor 5 fluidizes the fluidized material inside by, for example, air (gas) supplied from a nozzle provided in the furnace bottom 29, forming a fluidized bed of the fluidized material. By forming a fluidized bed in this way, the CFB boiler 2 promotes mixing of the fuel, fluidized material, and air inside the combustor 5, thereby improving combustion efficiency. During normal operation of the CFB boiler 2, air is supplied as gas from the nozzle, but an inert gas (such as nitrogen gas) may be introduced when purging the inside of the furnace during shutdown.

[0017] Furthermore, circulating particles (e.g., fluidized material and unburned fuel) ejected from the combustor 5 along with the exhaust gas are separated into combustion gas and circulating particles by a cyclone 13 provided at the outlet side of the combustor 5. The circulating particles separated and collected by the cyclone 13 are returned to the combustor 5 via a seal pot 14 and an external heat exchanger 15. In this manner, the CFB boiler 2 according to this embodiment aims to improve combustion efficiency by adopting a system for circulating fluidized material and unburned fuel. Furthermore, the temperature inside the combustor 5 can be adjusted by adjusting the branching ratio of the circulating particles sent to the external heat exchanger 15 with an ash removal valve 16. A fluid (e.g., air) for fluidizing the circulating particles is supplied to the external heat exchanger 15 from a blower 17.

[0018] The combustion gas separated in the cyclone 13 is sent to the convection heat transfer section 7. In the convection heat transfer section 7, the combustion gas exchanges heat with water and steam circulating inside a plurality of heat exchangers 8 provided in the convection heat transfer section 7. In the heat exchanger 8, steam is generated by heat exchange with the combustion gas. The generated steam is sent to the steam turbine 3 and drives the steam turbine 3 to rotate. When the steam turbine 3 is driven to rotate, the rotational force is transmitted to the generator 4, which generates electricity. Furthermore, in the convection heat transfer section 7, the combustion gas that has exchanged heat with the heat exchanger 8 passes through an air preheater 22 and a bag filter 23, and then is released into the atmosphere from a chimney (not shown).

[0019] The combustor 5 is provided with multiple nozzles (not shown) for fluidizing the fluid material within the combustor 5 and a combustion air supply unit 26 for supplying combustion air. While combustors used in pulverized combustion systems have temperatures exceeding approximately 1500°C in some areas, the combustor 5 used in the CFB boiler 2 maintains a uniform furnace temperature, controlled to, for example, 800-900°C. This allows the CFB boiler 2 to suppress the generation of thermal NOx (NOx generated depending on the combustion temperature). Additionally, by supplying limestone into the combustor 5, it is also possible to perform in-furnace desulfurization (CaCO3 → CaO + CO2, CaO + SO2 + 1 / 2O2 → CaSO4).

[0020] For example, a plurality of combustion air supply units 26 are provided. Each combustion air supply unit 26 is supplied with air from an FDF (Forced Delivery Fan) 27 and ejects a portion of the air preheated by heat exchange with the combustion gas in the air preheater 22 into the furnace as combustion air. The ejected combustion air is distributed approximately uniformly to each combustion air supply unit 26 by an air chamber 28. As a result, a uniform fluidized bed is formed in the combustor 5, and the temperature inside the furnace becomes relatively uniform.

[0021] In this way, the CFB boiler 2 exhibits characteristic behaviors that differ from those of pulverized fuel-fired boilers using entrained bed combustion, such as heat transfer by fluidized materials with relatively large heat capacities in each component, fluidized bed combustion with a relatively slow reaction rate in the combustor 5, separation of fluidized materials and combustion gas in the cyclone 13, and fluidized bed heat transfer in the external heat exchanger 15.

[0022] (Plant simulator) Next, a plant simulator 30 according to this embodiment will be described with reference to the drawings. The plant simulator 30 is a device that simulates the behavior of the power plant 1 described above.

[0023] FIG. 2 is a diagram showing an example of a hardware configuration of a plant simulator 30. As shown in FIG. 2, the plant simulator 30 is a so-called computer, and includes, for example, a CPU (Central Processing Unit: processor) 31, a main memory 32, and a secondary storage 33. The plant simulator 30 may further include an external interface 34 for connecting to external devices and a communication interface 35 for communicating with other devices via a network and transmitting and receiving information. The plant simulator 30 may also include an input unit (not shown) for providing various data such as setting values ​​and operating conditions to the plant simulator 30, and a display unit (not shown) for displaying simulation results. These units are configured to be able to exchange information with each other via, for example, a bus 36. The input unit and the display unit may also be configured to exchange information with the CPU 31 of the plant simulator 30 via the external interface 34 or the communication interface 35.

[0024] The main memory device 32 is composed of writable memory such as cache memory, RAM (Random Access Memory), etc., and is used as a working area for reading out the execution program of the CPU 31 and writing the processing data by the execution program. The secondary storage device 33 is a non-transitory computer-readable storage medium, such as a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, or a semiconductor memory.

[0025] A series of processes for realizing the various functions described below is stored in the secondary storage device 33 in the form of a program, for example, and the CPU 31 reads this program into the main storage device 32 and executes information processing and arithmetic processing to realize the various functions described below. The program may be pre-installed in the secondary storage device 33, provided in a state stored in a computer-readable storage medium, or distributed via wired or wireless communication means. Examples of computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories.

[0026] There may be multiple CPUs 31, main storage devices 32, and secondary storage devices 33. For example, the CPU 31 may be realized as a multi-core single processor in which multiple processor cores are mounted in a single processor package. Alternatively, the CPU 31 may be realized as a single-core multiprocessor in which multiple single cores, each with one processor core, are mounted in a single processor package.

[0027] Fig. 3 is a functional block diagram showing an example of functions of the plant simulator 30 according to this embodiment. As shown in Fig. 3, the plant simulator 30 includes a model storage unit 40 for storing a physical model of the power plant 1, and a calculation unit 45 for executing calculations related to the simulation.

[0028] The model storage unit 40 stores a plurality of physical models for calculating the behavior of the power plant 1. For example, the model storage unit 40 stores a physical model of each component that constitutes the power plant 1. For example, in the CFB boiler 2, physical models related to components such as the combustor 5, the cyclone 13, and the external heat exchanger 15 are stored. Each physical model is represented by a matrix such as a Jacobian, and includes internal parameters that link the input and output of each component.

[0029] The model storage unit 40 may be realized, for example, as the secondary storage unit 33 described above. Alternatively, the model storage unit 40 may be realized as an external storage device connected via the external interface 34 or the communication interface 35. For example, the model storage unit 40 may be realized as a server on the cloud. In this way, the model storage unit 40 only needs to be realized as a storage unit accessible by the calculation unit 45 described later, and there are no particular limitations on the location where the physical models are stored.

[0030] The calculation unit 45 simulates the behavior of the power plant 1 using input data (control command signals, set values, etc.) and various physical models stored in the model storage unit 40. For example, the calculation unit 45 includes a combustor calculation unit 46, a cyclone calculation unit 47, an external heat exchange calculation unit 48, etc.

[0031] 4 is a diagram showing an example of the relationship between the calculation units and input / output data that simulate the behavior of the CFB boiler 2 according to this embodiment. The physical model for the CFB boiler 2 is constructed as a physical model that can calculate mass heat balance that reproduces the unique behavior of the CFB boiler 2, such as heat transfer by fluidizing material, which is a characteristic of the CFB boiler 2, fluidized bed combustion in the combustor 5, and separation and recovery of combustion gas and fluidizing material by the cyclone 13.

[0032] As shown in Fig. 1, in the CFB boiler 2, the fuel that is input is mixed with the fluidized material, and the heat generated by combustion is supplied to the convection heat transfer section 7, while the fluidized material is recovered by the cyclone 13 and is again input into the combustor 5 from the seal pot 14 or the external heat exchanger 15. Therefore, the respective calculation sections 46 to 48 perform calculations along the flow of the combustion gas and the fluidized material. In addition, FIG. 4 mainly shows input data and output data related to the circulation of the flowable material, and some of the input data and some of the output data are not shown.

[0033] Fig. 5 is a diagram showing the contents of the calculation process executed by the combustor calculation unit 46. As shown in Fig. 5, the combustor calculation unit 46 mainly simulates the behavior of the combustion state in which fuel input into the combustor 5 is mixed with a fluid material and combusted. The combustor calculation unit 46 includes, for example, a combustion delay calculation unit 461 and an outlet state calculation unit 462.

[0034] The combustion delay calculation unit 461 simulates the combustion delay of the input fuel in the combustor 5. For example, the combustion delay calculation unit 461 acquires at least one of the fuel type, fuel flow rate, combustion gas flow rate, and information on the operating state of the fuel input device (for example, operating point, operating load, etc.) as input data, and calculates the combustion delay of the input fuel in the combustor 5 using the acquired input data and a physical model for calculating the combustion delay of the input fuel.

[0035] Examples of fuel types include coal, biomass fuel (e.g., wood pellets, PKS, wood chips, etc.), and waste fuel (e.g., scrap tires). Examples of fuel input equipment include a discharge conveyor and a charcoal feeder.

[0036] In the present embodiment, as an example, the input fuel amount, fuel calorific value, fuel moisture content, fuel properties (composition of contained components, amount of volatile matter, amount of fixed carbon, amount of ash, etc.), fluidizing material flow rate Fr_com, fluidizing material temperature Tr_fbhe, in-furnace fluid velocity, air flow rate, circulating gas flow rate Fg_r_com, fuel pulverization performance, fuel ratio, combustion gas properties, and combustor differential pressure are input as input data to the combustor calculation unit 46. Of this input data, as shown in FIG. 4, the fluidizing material flow rate Fr_com and the circulating gas flow rate Fg_r_com (see FIG. 5) are data calculated based on data fed back from the seal pot and external heat exchange calculation unit 48. That is, the following equation is established.

[0037] Fr_com=Fr_cyc2 +Fr_fbhe +Fr_supply Fg_r_com=Fg_cyc2 +Fg_cyc3

[0038] Here, Fr_cyc2 is the flow rate of fluid material returned from the seal pot 14 to the combustor 5, Fr_fbhe is the flow rate of fluid material returned from the external heat exchanger 15 to the combustor 5, and Fr_supply is the flow rate of additional fluid material. Also, Fg_cyc2 is the flow rate of combustion gas returned from the seal pot 14 to the combustor 5, and Fg_cyc3 is the flow rate of combustion gas returned from the external heat exchanger 15 to the combustor 5.

[0039] The combustion delay calculation unit 461, for example, uses all or part of the above-mentioned input data to simulate at least one of the communication delay from the output of the flow command value for fuel input until it is transmitted to the fuel input device for fuel input, the operational delay of the fuel input device, the time it takes for the input fuel to reach the combustor, and the time it takes for the input fuel to burn in the combustor.

[0040] The outlet state calculation unit 462 simulates the behavior of the outlet state of the combustor 5 using the output result of the combustion delay calculation unit 461. The outlet state calculation unit 462 simulates the behavior of, for example, the amount of heat, the combustion gas flow rate, the pressure, etc. in the combustor. At this time, the outlet state calculation unit 462 performs fitting of each internal parameter. Examples of the internal parameters include heat loss, heat absorption, and fluid material state (thickness).

[0041] The combustor calculation unit 46 outputs the combustion gas temperature Tg_com and combustion gas flow rate (excluding fluidized material) Fg_com at the combustor outlet, the fluidized material temperature Tr_com and fluidized material flow rate Fr_com, the combustion gas oxygen concentration O2_com in the furnace, the combustion gas properties, the gas pressure in the furnace of the combustor 5, the fluid velocity in the furnace of the combustor 5, etc. as output data indicating the behavior of the outlet state of the combustor 5. These output data output from the combustor calculation unit 46 are given as input data to the cyclone calculation unit 47, as shown in FIG.

[0042] Fig. 6 is a diagram showing the contents of the calculation process executed by cyclone calculation unit 47. As shown in Fig. 6, cyclone calculation unit 47 mainly simulates the behavior of heat transfer and mass transfer in cyclone 13. Cyclone calculation unit 47 includes, for example, an afterburning calculation unit 471 and a heat quantity calculation unit 472.

[0043] The afterburning calculation unit 471 simulates the afterburning phenomenon. "Afterburning" in the cyclone 13 is a phenomenon in which unburned fuel that was not completely burned in the combustor 5 burns near the inlet of the cyclone 13, which is located downstream of the combustor 5. Because "afterburning" increases the temperature of the combustion gas, the afterburning calculation unit 471 simulates the behavior of this combustion gas temperature. For example, the afterburning calculation unit 471 acquires, as input data, at least one of the combustion gas temperature and combustion gas flow rate at the combustor outlet, the fluidizing material temperature and fluidizing material flow rate at the combustor outlet, and the combustion gas oxygen concentration in the furnace, and simulates the temperature increase of the combustion gas using the acquired input data and a physical model for performing afterburning calculation.

[0044] In this embodiment, as an example, the combustion gas temperature Tg_com and combustion gas flow rate Fg_com at the combustor outlet, the fluid material temperature Tr_com and fluid material flow rate Fr_com at the combustor outlet, the combustion gas oxygen concentration O2_com in the furnace, the fuel gas properties, the furnace gas pressure in the combustor 5, the furnace fluid velocity in the combustor 5, etc. are input to the cyclone calculation unit 47 as input data.

[0045] Furthermore, the afterburning calculation unit 471 performs a calculation to separate the combustion gas and the recirculation gas using the simulation results of the temperature rise of the combustion gas due to afterburning and all or part of the above input data. By reflecting this separation and allocation in the physical model, it is possible to improve the prediction accuracy of the simulation.

[0046] The heat quantity calculation unit 472 simulates the behavior of the cyclone 13 using all or part of the output result and input data of the afterburning calculation unit 471. The heat quantity calculation unit 472 performs, for example, a heat quantity calculation in the cyclone 13, specifically, a flow rate branching calculation due to centrifugal separation. At this time, the heat quantity calculation unit 472 performs fitting of each internal parameter. Examples of the internal parameters include the flow rate of the fluidizing fluid and the gas properties at the combustor outlet.

[0047] The cyclone calculation unit 47 outputs the combustion gas temperature Tg_cyc and combustion gas flow rate Fg_cyc at the cyclone outlet, the fluid material temperature Tr_cyc and fluid material flow rate Fr_cyc at the external heat exchanger inlet, and the combustion gas oxygen concentration O2_com in the furnace as output data indicating the behavior of the cyclone.

[0048] The combustion gas flow rate Fg_cyc among the output data of the cyclone calculation unit 47 is separated into input data to a convection heat transfer calculation unit 49 that simulates the behavior of the convection heat transfer unit 7, and input data to the seal pot. Specifically, a portion of the combustion gas flow rate Fg_cyc is input to the convection heat transfer calculation unit 49 as the combustion gas flow rate Fg_hs, and the remainder of the combustion gas flow rate Fg_cyc is input to the seal pot as the combustion gas flow rate Fg_cyc1. That is, the following relational expression is established.

[0049] Fg_cyc=Fg_hs+Fg_cyc1

[0050] The convection heat transfer calculation unit 49 uses input data to simulate the behavior of the convection heat transfer unit 7. Note that simulation of the behavior of the combustion gas and the like after the convection heat transfer unit 7 and simulation of the behavior in the feedwater steam system are not calculations specific to a power plant equipped with a CFB boiler 2, so known simulation methods for power plants may be appropriately adopted. Therefore, detailed explanation of the convection heat transfer calculation unit 49 and after will be omitted.

[0051] On the other hand, input data input to the seal pot is output as is as output data. That is, in Fig. 4, for convenience of explanation and to make the data flow easier to understand, the seal pot is shown as an element of the input / output data of the calculation unit, similar to the configuration of the actual CFB boiler 2 shown in Fig. 1, but since the input data and output data for this seal pot are the same, it can be omitted.

[0052] Of the output data from the seal pot, the combustion gas flow rate Fg_cyc1 and the fluid material flow rate Fr_cyc1 are separated into the combustion gas flow rate Fg_cyc2 and the fluid material flow rate Fr_cyc2 that are input directly from the seal pot outlet to the combustor calculation unit 46, and the combustion gas flow rate Fg_cyc3 and the fluid material flow rate Fr_cyc3 that are input to the external heat exchange calculation unit 48. That is, the following relational expression holds: The fluid material flow rate Fr_cyc input to the seal pot is temporarily accumulated inside the seal pot, and is output from the seal pot as Fr_cyc1, taking into account the delay time until it flows to the combustor 5 and the external heat exchanger 15.

[0053] Fg_cyc1=Fg_cyc2 +Fg_cyc3 Fr_cyc1=Fr_cyc2 +Fr_cyc3

[0054] In addition, for the flow material temperature Tr_cyc3 and combustion gas temperature Tg_cyc3 input to the external heat exchange calculation unit 48, values ​​different from the flow material temperature Tr_cyc and combustion gas temperature Tg_cyc at the seal pot outlet are used in order to take into account the piping between the seal pot 14 and the external heat exchanger 15 and simulate the temperature drop in that piping.

[0055] From the above, the input data input from the seal pot to the combustor calculation unit 46 are the combustion gas temperature Tg_cyc, the combustion gas flow rate Fg_cyc2, the flow material temperature Tr_cyc, and the flow material flow rate Fr_cyc2. The input data input from the seal pot to the external heat exchange calculation unit 48 are the combustion gas temperature Tg_cyc3 and combustion gas flow rate Fg_cyc3, the fluid material temperature Tr_cyc3 and fluid material flow rate Fr_cyc3, and the combustion gas oxygen concentration O2_com in the furnace.

[0056] Fig. 7 is a diagram showing the contents of the calculation process executed by the external heat exchange calculation unit 48. As shown in Fig. 7, the external heat exchange calculation unit 48 mainly simulates the heat transfer behavior in the external heat exchanger 15. The external heat exchange calculation unit 48 includes, for example, a heat transfer delay calculation unit 481 and a heat transfer calculation unit 482.

[0057] The heat transfer delay calculation unit 481 acquires, as input data, for example, the temperature and flow rate of the flow material flowing into the external heat exchanger 15, and at least one of the temperature, flow rate, and pressure of the fluid, and simulates the heat transfer delay in the external heat exchanger 15 using the acquired input data and a physical model for calculating the heat transfer delay. Here, examples of the fluid include at least one of air, combustion gas, steam, feedwater, etc. In this embodiment, the fluid is steam or feedwater flowing inside the external heat exchanger 15. The heat transfer delay calculation unit 481 simulates the heat transfer delay by assuming that the delay (time component) in the amount of heat transfer and the efficiency of heat exchange change according to the values ​​of the input data described above, for example.

[0058] In this embodiment, as an example, the combustion gas temperature Tg_cyc3 and combustion gas flow rate Fg_cyc3, the fluid material temperature Tr_cyc3 and fluid material flow rate Fr_cyc3, the furnace combustion gas oxygen concentration O2_com, the fluid flow rate Ffw_in, the fluid temperature Tfw_in, and the fluid pressure Pfw_in are input to the external heat exchange calculation unit 48 as input data.

[0059] The heat transfer calculation unit 482 simulates the behavior of the external heat exchanger 15 using all or part of the output result and input data of the heat transfer delay calculation unit 481. At this time, the heat transfer calculation unit 482 performs fitting of each internal parameter. Examples of the internal parameters include the heat retained in the fluid material and the heat transfer coefficient of the external heat exchange heat transfer surface.

[0060] The external heat exchange calculation unit 48 outputs the combustion gas temperature Tg_fbhe and combustion gas flow rate Fg_cyc3, the fluidizing material temperature Tr_fbhe and fluidizing material flow rate Fr_fbhe, and the in-furnace combustion gas oxygen concentration O2_com as output data indicating the behavior of the external heat exchanger 15. Furthermore, the external heat exchange calculation unit 48 may output the heat transfer surface outlet fluid temperature Tfw_out as output data. These output data are then used as input data for the combustor calculation unit 46. Note that the fluidizing material flow rate Fr_fbhe fluctuates depending on the gas flow rate and blower flow rate relative to Fr_cyc3 input to the external heat exchange calculation unit 48.

[0061] Next, the operation of the above-mentioned plant simulator 30 will be briefly described with reference to Figures 4 to 7. First, at the start of a simulation, data such as various setting values ​​and control command values ​​required for performing the simulation are input from an input unit (not shown) provided in the plant simulator 30. When this input data is input, the calculation unit 45 of the plant simulator 30 starts simulating the power plant 1.

[0062] First, the behavior of the combustion state of the combustor is simulated by the combustor calculation unit 46. Specifically, the input fuel amount, fuel calorific value, fuel moisture content, fuel properties, fluidized material flow rate Fr_com, fluidized material temperature Tr_fbhe, in-furnace fluid velocity, air flow rate, circulating gas flow rate Fg_r_com, fuel pulverization performance, fuel ratio, combustion gas properties, and combustor differential pressure are provided as input data to the combustor calculation unit 46. The combustion delay calculation unit 461 calculates the combustion delay of the input fuel in the combustor 5 using this input data and a physical model for calculating the combustion delay.

[0063] The calculation result of the combustion delay is output to the outlet state calculation unit 462, which simulates the behavior of the outlet state of the combustor 5. As a result, the combustor calculation unit 46 outputs the combustion gas temperature Tg_com, combustion gas flow rate Fg_com, fluid material temperature Tr_com, fluid material flow rate Fr_com, in-furnace combustion gas oxygen concentration O2_com, combustion gas properties, in-furnace gas pressure, and in-furnace fluid velocity as output data.

[0064] These output data are given as input data to the cyclone calculation unit 47, which simulates the behavior of the heat quantity in the cyclone 13. Specifically, the afterburning calculation unit 471 of the cyclone calculation unit 47 simulates the temperature rise of the combustion gas using these input data and a physical model for performing afterburning calculations. Furthermore, the afterburning calculation unit 471 performs a calculation to separate the combustion gas from the circulating gas using the simulation results of the temperature rise of the combustion gas due to afterburning.

[0065] The calculation result of the afterburning calculation unit 471 is output to the heat quantity calculation unit 472. The heat quantity calculation unit 472 calculates the heat quantity in the cyclone 13 using the output result of the afterburning calculation unit 471 and the input data. As a result, the cyclone calculation unit 47 outputs the combustion gas temperature Tg_cyc, the combustion gas flow rate Fg_cyc, the fluid material temperature Tr_cyc, the fluid material flow rate Fr_cyc, and the in-furnace combustion gas oxygen concentration O2_com.

[0066] Of the output data of the cyclone calculation unit 47, the combustion gas flow rate Fg_cyc is separated into the combustion gas flow rate Fg_hs and the combustion gas flow rate Fg_cyc, and the combustion gas flow rate Fg_hs is provided as input data to the convection heat transfer calculation unit 49, and the combustion gas flow rate Fg_cyc1 is provided as input data to the seal pot.

[0067] The input data input to the seal pot is output as is, except for the flow material flow rate. Of the output data from the seal pot, the combustion gas flow rate Fg_cyc1 is separated into the combustion gas flow rate Fg_cyc2 and the combustion gas flow rate Fg_cyc3. Similarly, the flow material flow rate Fr_cyc1 is separated into the flow material flow rate Fr_cyc2 and the flow material flow rate Fr_cyc3. The combustion gas temperature Tg_cyc, the combustion gas flow rate Fg_cyc2, the flow material temperature Tr_cyc, and the flow material flow rate Fr_cyc2 are then given from the seal pot to the combustor calculation unit 46 as input data, and are used again in the calculations in the combustor calculation unit 46 described above.

[0068] The external heat exchange calculation unit 48 is also provided with input data based on the output data output from the seal pot. That is, the external heat exchange calculation unit 48 is provided with the combustion gas temperature Tg_cyc3, combustion gas flow rate Fg_cyc3, fluid material temperature Tr_cyc3, fluid material flow rate Fr_cyc3, and in-furnace combustion gas oxygen concentration O2_com as input data. The external heat exchange calculation unit 48 is also provided with the fluid flow rate Ffw_in, fluid temperature Tfw_in, and fluid pressure Pfw_in as input data. Note that, for the fluid material temperature Tr_cyc3 and the combustion gas temperature Tg_cyc3, values ​​different from the fluid material temperature Tr_cyc and the combustion gas temperature Tg_cyc at the seal pot outlet are used to simulate the temperature drop in the piping, as described above.

[0069] The heat transfer delay calculation unit 481 of the external heat exchange calculation unit 48 simulates the heat transfer delay due to the flow material using these input data and a physical model for calculating the heat transfer delay of the flow material. The calculation results of the heat transfer delay calculation unit 481 are output to the heat transfer calculation unit 482. The heat transfer calculation unit 482 simulates the heat transfer behavior in the external heat exchanger 15 using the calculation results of the heat transfer delay and the input data. As a result, the external heat exchange calculation unit 48 outputs the combustion gas temperature Tg_fbhe, combustion gas flow rate Fg_cyc3, flow material temperature Tr_fbhe, flow material flow rate Fr_fbhe, in-furnace combustion gas oxygen concentration O2_com, etc. These output data are provided as input data to the combustor calculation unit 46 and are used again for the calculations in the combustor calculation unit 46 described above.

[0070] As described above, the plant simulator 30 according to this embodiment provides the following advantageous effects. The plant simulator 30 is a simulator that simulates the behavior of the power plant 1 using a physical model, and further includes a combustion delay calculation unit 461 that simulates the combustion delay when fuel is introduced into the combustor 5, an afterburning calculation unit 471 that simulates the afterburning phenomenon in the cyclone 13, and a heat transfer delay calculation unit 481 that simulates the heat transfer delay of the fluid material in the external heat exchanger 15. This makes it possible to reproduce the plant behavior specific to the CFB boiler 2. As a result, it is possible to improve the prediction accuracy of the simulation of the power plant 1 in an operating region different from normal operation (for example, when an abnormality occurs).

[0071] The plant simulator 30 of this embodiment does not need to include all of the combustion delay calculation unit 461, the afterburning calculation unit 471, and the heat transfer delay calculation unit 481. For example, it may be configured to include at least one of these calculation units.

[0072] (Driving training simulator) Next, an operation training simulator 60, which is an application example of the plant simulator 30 according to the present embodiment, will be described with reference to the drawings. The operation training simulator 60 according to the present embodiment is a simulator used for operation training of the power plant 1. FIG. 8 is a diagram showing a schematic diagram of the overall configuration of a driving training simulator 60 according to this embodiment.

[0073] 8, the operator training simulator 60 includes the above-mentioned plant simulator 30. Furthermore, the operator training simulator 60 includes a trainee terminal 62, a control simulator 64, and a supervisor terminal 66.

[0074] The trainee terminal 62 is a terminal that is mainly operated by the trainee. The trainee operates the trainee terminal 62 to input operation amounts for operating the power plant 1. The control simulator 64 is a simulator that simulates a control device for controlling the power plant 1. The control simulator 64 provides the plant simulator 30 with a control command value based on an operation amount input from, for example, the trainee terminal 62. The control simulator 64 also acquires, for example, the control amount of the plant simulator 30 as input data, and performs feedback control to make the input data coincide with a target value. The supervisor terminal 66 is a device for changing the internal parameters of the plant simulator 30 or the control simulator 64, and is mainly operated by a supervisor who instructs trainees.

[0075] The trainee terminal 62, the control simulator 64, and the supervisor terminal 66 are all computers. Note that an example of the configuration of these devices is similar to the hardware configuration of the plant simulator 30 shown in Fig. 2, and therefore detailed description thereof will be omitted here.

[0076] Next, driving training using the driving training simulator 60 according to this embodiment will be described.

[0077] For example, setting items for causing multiple types of abnormalities are registered in the supervisor terminal 66. The supervisor selects a setting item that he / she wants the trainee to practice from among the setting items displayed on the display screen of the supervisor terminal 66. As a result, an abnormality occurrence command for causing an abnormality corresponding to the setting item selected by the supervisor is output to the control simulator 64 or the plant simulator 30. Below, a case will be described in which the supervisor selects the setting item for tube leak (internal fluid leakage from heat transfer tubes) in the superheater of the external heat exchanger 15 during rated load operation.

[0078] In this case, an abnormality occurrence command causing a tube leak in the superheater is sent from the supervisor terminal 66 to the plant simulator 30. This causes the plant simulator 30 to simulate a condition in which a tube leak occurs in the superheater. For example, in the combustion gas system illustrated in FIG. 6 , steam leaks into the furnace and expands, causing changes in the superheater outlet gas pressure and temperature. This changes the combustion gas pressure and combustion gas temperature output from the combustor calculation unit, and this affects the input data input to the convection heat transfer unit. In this case, the calculation unit 45 of the plant simulator 30 simulates the behavior in the event of an abnormality by taking into account the combustion delay of the input fuel in the combustor 5, the afterburning phenomenon in the cyclone 13, and the heat transfer delay due to the fluid material in the external heat exchanger 15. This improves the accuracy of the simulation of the plant behavior in the event of an abnormality.

[0079] When an abnormality occurs, the input data, internal parameters, and output data in each of the combustor calculation unit 46, the cyclone calculation unit 47, and the external heat exchange calculation unit 48 fluctuate, and the control amount fed back from the plant simulator 30 to the control simulator 64 changes. This changes the control command value given to the plant simulator 30 from the control simulator 64. For example, the control command value for the superheater spray, the turbine governor valve, etc. changes, and this change is reflected in the behavior of the power plant 1 in the plant simulator 30.

[0080] These changes in the various process values ​​and the control command values ​​are displayed on the display unit of the trainee terminal 62. The trainee checks the changes in the process values ​​and the control command values ​​displayed on the display unit and checks the sensor values ​​of the measuring instruments and the like simulated by the plant simulator 30 to determine whether or not an abnormality has occurred. If the trainee determines that an abnormality has occurred, he or she operates the input unit of the trainee terminal 62 to take initial response action to suppress the abnormality. For example, the trainee performs an operation that he or she considers to be correct on the trainee terminal 62 depending on the level of the abnormality (in this case, the magnitude of the fluctuations in the various process values ​​corresponding to the amount of leakage). Examples of initial response actions include shutting off fuel and adjusting the load. The supervisor provides guidance to the trainee by checking the trainee's initial response actions when an abnormality occurs.

[0081] As described above, the driving training simulator 60 according to this embodiment provides the following advantages. The plant simulator 30 is a simulator that simulates the behavior of the power plant 1 using a physical model. It is also configured to be able to reproduce parameters specific to the CFB boiler 2, such as the combustion delay when fuel is introduced into the combustor 5, the separation and recovery of combustion gas and fluidizing material by the cyclone 13, and the heat retained by the fluidizing material in the external heat exchanger 15. This makes it possible to accurately simulate the behavior of the power plant 1 in the event of an abnormality. This allows for training in the startup, shutdown, and normal operation of the power plant 1, as well as training in the event of an abnormality. This effectively improves the trainee's operating skills. Furthermore, it also helps prevent unexpected plant shutdowns and minimizes plant shutdown periods. This contributes to improving the plant's availability.

[0082] The plant simulator 30 and the operator training simulator 60 of the present disclosure have been described above using various embodiments, but the technical scope of the present disclosure is not limited to the scope described in the above embodiments. Various modifications and improvements can be made to the above embodiments without departing from the gist of the disclosure, and forms incorporating such modifications or improvements are also included in the technical scope of the present disclosure. Furthermore, the above embodiments may be combined as appropriate.

[0083] For example, input delay and output delay may be taken into account in the simulations in each of the above-described embodiments. For example, in an actual power plant 1, when a control command value or the like is set or changed from a control device or an input unit operated by an operator, a time lag occurs before each device (operational end) constituting the plant operates in response to the control command value. This time lag is caused by, for example, a communication delay or an operational delay in the operation of the operation end itself. Therefore, the input delay may be simulated by using internal parameters or the like that represent these input delays.

[0084] Similarly, when a control command value or setting is changed, the behavior of the power plant 1 changes, and until the change in behavior is detected by various sensors provided in the power plant 1, there occurs a response delay of each device, a detection delay of the sensor, a communication delay, a display delay on the display unit, etc. Therefore, the output delay may be simulated by using internal parameters that represent these response delays, etc.

[0085] The plant simulator 30 and the operator training simulator 60 described in the above-described embodiments can be understood, for example, as follows.

[0086] A plant simulator (30) according to a first aspect of the present disclosure is a plant simulator that simulates the behavior of a plant (1) having a circulating fluidized bed boiler (2) that circulates fluidized material discharged from a combustor (5) to the combustor via a cyclone (13) and an external heat exchanger (15). The plant simulator includes a model storage unit (40) for storing a physical model of the plant, and a calculation unit (45) that simulates the behavior of the plant using input data and the physical model. The physical model of the plant includes a physical model related to components of the circulating fluidized bed boiler, and the calculation unit performs calculations that include at least one of a combustion delay of input fuel in the combustor, an afterburning phenomenon in the cyclone, and a heat transfer delay caused by the fluidized material in the external heat exchanger.

[0087] The plant simulator simulates plant behavior using a physical model and further performs calculations including at least one of the combustion delay of fuel input in the combustor, the afterburning phenomenon in the cyclone, and the heat transfer delay due to the fluid material in the external heat exchanger. This makes it possible to reproduce internal parameters specific to a circulating fluidized bed boiler. As a result, it is possible to improve the prediction accuracy of plant simulations in operating regions different from normal operation (e.g., when an abnormality occurs).

[0088] In a plant simulator (30) according to a second aspect of the present disclosure, in the first aspect, the calculation unit (45) includes a combustor calculation unit (46) that simulates the behavior of the combustor, and the combustor calculation unit acquires at least one of information on a fuel type, a fuel flow rate, a combustion gas flow rate, and an operating state of a device that inputs fuel as input data, and includes a combustion delay calculation unit (461) that simulates the combustion delay of the input fuel in the combustor by using the acquired input data and a physical model for calculating the combustion delay of the input fuel.

[0089] The plant simulator can simulate the combustion behavior of a combustor by taking into account the combustion delay of fuel input into the combustor, thereby improving the accuracy of predicting the behavior of a circulating fluidized bed boiler.

[0090] In a plant simulator (30) according to a third aspect of the present disclosure, in the first or second aspect, the calculation unit (45) includes a cyclone calculation unit (47) that simulates the behavior of the cyclone, and the cyclone calculation unit acquires, as input data, at least one of the combustion gas temperature and combustion gas flow rate at an outlet of the combustor, the fluidized material temperature and fluidized material flow rate at the outlet of the combustor, and the oxygen concentration of the combustion gas in the combustor, and includes an afterburning calculation unit (471) that simulates the afterburning phenomenon by using the acquired input data and a physical model for calculating the afterburning phenomenon near the inlet of the cyclone.

[0091] The plant simulator allows for simulation of the heat transfer behavior of a cyclone taking into account the afterburning phenomenon in the cyclone, thereby improving the accuracy of prediction of the behavior in a circulating fluidized bed boiler.

[0092] A plant simulator (30) according to a fourth aspect of the present disclosure is configured in any one of the first to third aspects, wherein the calculation unit (45) includes an external heat exchange calculation unit (48) that simulates behavior of the external heat exchanger, and the external heat exchange calculation unit acquires, as input data, at least one of the temperature and flow rate of the flow material flowing into the external heat exchanger and the temperature, flow rate, and pressure of a fluid, and includes a heat transfer delay calculation unit (481) that simulates heat transfer delay in the external heat exchanger using the acquired input data and a physical model for calculating heat transfer delay in the external heat exchanger.

[0093] The plant simulator can simulate the heat transfer behavior in the external heat exchanger by taking into account the heat transfer delay in the external heat exchanger, thereby improving the accuracy of predicting the behavior in the circulating fluidized bed boiler.

[0094] A program according to a fifth aspect of the present disclosure is a program for causing a computer to function as the plant simulator according to any one of the first to fourth aspects.

[0095] An operator training simulator (60) according to a sixth aspect of the present disclosure includes the plant simulator (30) according to any one of the first to fourth aspects, a trainee terminal (62) for inputting an operation amount, a control simulator (64) for giving a control command value based on the operation amount to the plant simulator, and a supervisor terminal (66) for changing an internal parameter of the plant simulator or the control simulator.

[0096] The above-described operation training simulator includes the plant simulator according to any one of the first to fourth aspects. That is, the plant simulator is a simulator that simulates plant behavior using a physical model and is configured to be able to simulate parameters specific to a circulating fluidized bed boiler. Therefore, the operation training simulator can accurately simulate the behavior of a power plant in the event of an abnormality, achieving a level of reproduction of the actual plant that is sufficient for operational training of a circulating fluidized bed boiler. This enables training in the startup and shutdown of the power plant 1 as well as training in the event of an abnormality. This effectively improves the trainee's operational skills. Furthermore, this also leads to the prevention of unexpected plant shutdowns, minimizing plant shutdown periods and contributing to improved power generation availability. [Explanation of symbols]

[0097] 1: Power plant (plant) 2: CFB boiler (circulating fluidized bed boiler) 3: Steam turbine 4: Generator 5: Combusta 6:Fuel supply device 7: Convection heat transfer section 8: Heat exchanger 10: Rotary valve 13: Cyclone 14: Seal pot 15 :External heat exchanger 16: Ash removal valve 17: Blower 22: Air preheater 23: Bag filter 26: Combustion air supply section 28: Wind room 29: hearth bottom 30: Plant simulator 31: CPU 32: Main memory 33:Secondary storage device 34: External interface 35: Communication interface 36: Bus 40: Model memory section 45: Arithmetic section 46: Combustor calculation unit 47: Cyclone calculation unit 48: External heat exchange calculation section 49: Convection heat transfer calculation section 60: Driving training simulator 62: Trainee terminal 64: Control simulator 66: Supervisor terminal 461: Combustion delay calculation unit 462: Exit state calculation unit 471: Afterburning calculation unit 472: Calorie calculation section 481: Heat transfer delay calculation unit 482: Heat transfer calculation unit

Claims

1. A plant simulator that simulates the behavior of a plant equipped with a circulating fluidized bed boiler that circulates a fluid material discharged from a combustor via a cyclone and an external heat exchanger to the combustor, a model storage unit for storing a physical model of the plant; a calculation unit that simulates the behavior of the plant using input data and the physical model; Equipped with the physical model of the plant includes a physical model of components of the circulating fluidized bed boiler; the calculation unit performs a calculation including at least one of a combustion delay of the input fuel in the combustor, an afterburning phenomenon in the cyclone, and a heat transfer delay due to the flowable material in the external heat exchanger, The calculation unit includes at least one of a combustion delay calculation unit that simulates a combustion delay of the fuel input in the combustor, an afterburning calculation unit that simulates the afterburning phenomenon, and a heat transfer delay calculation unit that simulates a heat transfer delay in the external heat exchanger, and the combustion delay calculation unit, the afterburning calculation unit, and the heat transfer delay calculation unit perform simulations using a physical model for calculation.

2. the calculation unit includes a combustor calculation unit that simulates the behavior of the combustor, 2. The plant simulator according to claim 1, wherein the combustor calculation unit acquires, as input data, at least one of information on a fuel type, a fuel flow rate, a combustion gas flow rate, and an operating state of a device that inputs fuel, and comprises the combustion delay calculation unit that simulates the combustion delay of the input fuel in the combustor using the acquired input data and a physical model for calculating the combustion delay of the input fuel.

3. the calculation unit includes a cyclone calculation unit that simulates the behavior of the cyclone, 2. The plant simulator according to claim 1, wherein the cyclone calculation unit acquires, as input data, at least one of the combustion gas temperature and combustion gas flow rate at an outlet of the combustor, the fluidizing material temperature and fluidizing material flow rate at the outlet of the combustor, and the oxygen concentration of the combustion gas in the combustor, and simulates the afterburning phenomenon using the acquired input data and a physical model for calculating the afterburning phenomenon in the vicinity of the inlet of the cyclone.

4. the calculation unit includes an external heat exchange calculation unit that simulates the behavior of the external heat exchanger, 2. The plant simulator according to claim 1, wherein the external heat exchange calculation unit acquires, as input data, at least one of the temperature and flow rate of the flow material flowing into the external heat exchanger and the temperature, flow rate, and pressure of a fluid, and comprises the heat transfer delay calculation unit that simulates the heat transfer delay in the external heat exchanger using the acquired input data and a physical model for calculating the heat transfer delay of the external heat exchanger.

5. A program for causing a computer to function as the plant simulator according to claim 1.

6. The plant simulator according to claim 1; a trainee terminal for inputting an operation amount; a control simulator that gives a control command value based on the manipulated variable to the plant simulator; a supervisor terminal for changing internal parameters of the plant simulator or the control simulator; A driving training simulator equipped with:

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