JP3559672B2 - Operation control device for thermal power plant - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a thermal power plant operation control device that controls the operation of a thermal power plant, and more particularly to a thermal power plant operation control device that, when a process state quantity or plant equipment is abnormal, treats the abnormality.
[0002]
[Prior art]
As a prior art, Japanese Patent Application Laid-Open No. 4-105526 discloses a hydroelectric power plant that stops only a display function part during a remote operation (unmanned operation) and registers the details of the failure, the cause of the failure, and the location to be checked. An on-site supervisory control panel is disclosed.
[0003]
Japanese Patent Application Laid-Open No. 59-149501 discloses that a plant control computer of a control station in a plant or a plant control computer of an external control station in a remote place is automatically set when the plant becomes abnormal when the plant is unmanned. On the other hand, an external control center switching interface device for transmitting a signal for simultaneously stopping the plant when a plant control computer of the external control center is abnormal is disclosed.
[0004]
[Problems to be solved by the invention]
At present, in a thermal power plant, operators are stationed for 24 hours to monitor the operation state of the plant. However, at midnight or the like, although the working conditions are severe for the operator, the demand for the electric energy is low, and the operating state of the power plant can be afforded. Therefore, it is desired to make the thermal power plant unmanned at midnight or the like.
[0005]
However, compared to a hydroelectric power plant, a thermal power plant has a complicated power generation system, has many failure factors, and has an alarm factor corresponding to more than 1000 points. Also, thermal power plants have many serious failure factors that can cause the power plant to be destroyed. Therefore, it is difficult to unmanned thermal power plants using the above-described conventional technology.
[0006]
An object of the present invention is to provide a thermal power plant operation control apparatus capable of performing plant operation control with increased safety when an abnormality of plant equipment is detected when there is no operator monitoring the operation state of the plant in the power plant. Is to provide.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the thermal power plant operation control device of the present invention detects a state quantity related to plant operation, and detects the detected state quantity and a preset threshold value of the state quantity. In comparison, in a thermal power plant operation control device that detects an abnormality of the state quantity, an operator who monitors the plant operation state has a manned operation mode set when manned and an unmanned operation mode set when manned. The threshold value in the manned operation mode, which is a value smaller than the set value at the time of rated operation, may cause damage to plant equipment if the state quantity continues to decrease, and indicates a value that requires some action, It has a threshold value in the operation mode, and the threshold value in the unmanned operation mode is set to be larger than the threshold value in the manned operation mode .
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a thermal power plant operation control device of the present invention will be described with reference to the drawings.
[0013]
FIG. 1 shows a mechanical system diagram of a single-shaft combined cycle power plant according to the present invention. In FIG. 1, 1 is a plant, 2 is air, 3 is fuel, 4 is steam, 5 is water supply, 6 is a compressor for compressing the air 2, 7 is an IGV (inlet) for adjusting the flow rate of air supplied to the compressor. Guide vanes), 8 is a combustor that mixes fuel 3 and air to generate combustion gas, 9 is a gas turbine that is rotated by the combustion gas, and 10 is a heater that heats feed water 5 using gas turbine exhaust gas as a heat source to generate steam 4. The generated waste heat recovery boiler, 11 is a steam turbine rotated by steam 4, 12 is a rotor, 13 is a generator for converting rotational energy into electric energy, 14 is a condenser for condensing steam and condensing water, and 15 is a condenser. A feed pump for increasing the pressure of condensed water, 16 a control device for controlling the operation of the plant 1 and monitoring the operating state of the plant 1, 17 a computer, 18 a computer room in which the control device 16 and the computer 17 are installed, 19 Is the plant A central operation room (hereinafter, referred to as “medium operation”) in which an operator (monitoring person) resides, and 20 is a state quantity related to the operation of the plant (a process state quantity, a state quantity indicating an abnormality of plant equipment, and the like). An operator console for displaying on the CRT, 21 a printer for outputting information on the operation state of the plant 1 on paper or the like, 22 a speaker, 23 a switch for switching the operation mode of the plant 1, 24 a signal for transmitting and outputting signals outside the power plant 1 shows a transmitting / receiving device for receiving. The process state quantities include, for example, boiler feedwater flow rate / pressure, steam flow rate / pressure / temperature, gas turbine exhaust gas temperature / pressure, exhaust gas NOx concentration, air flow rate / pressure, fuel flow rate, and the like.
[0014]
In the operator console 20, a command relating to the operation of the plant 1 from an operator who monitors the operation state of the plant 1, for example, an operation mode dedicated to manned operation (hereinafter referred to as “maned mode”) or an operation mode dedicated to unmanned operation ( Hereinafter, the operation mode selection command of “unattended mode”), a command to stop the device, a command to change the set value of the process state quantity, and the like are received. Here, the switching of the operation mode between the manned mode and the unmanned mode by the switch 23 is performed in principle depending on whether or not the operator is staying in the power plant (such as inside the operation). That is, when the operator stays in the power plant and can monitor the operation state of the plant 1, the manned mode is selected. On the other hand, when the operator cannot stay in the power plant and cannot monitor the operation state of the plant 1, the operator selects the unmanned mode.
[0015]
Hereinafter, the operation control operation of each of the manned mode and the unmanned mode in the thermal power plant will be described.
[0016]
(1) Boiler feedwater pressure A boiler feedwater pressure is detected by a pressure transmitter provided in a feedwater pipe of the low exhaust heat recovery boiler 10.
[0017]
The controller 16 inputs the detected boiler feedwater pressure signal, compares the boiler feedwater pressure signal with a preset value of the boiler feedwater pressure, and adjusts the feedwater flow to the exhaust heat recovery boiler 10. The control valve is controlled, and the boiler feedwater pressure signal is compared with a preset threshold value to detect an abnormality in the boiler feedwater pressure.
(1-a) When the boiler feedwater pressure is equal to or lower than the threshold value A (for example, 25 kg / cm ² ), the manned mode control device 16 outputs a signal indicating the abnormal rank A to the computer 17. Here, the threshold value A indicates a value smaller than the set value of the feedwater pressure during the rated operation, although the operation of the plant can be continued. Then, the computer 17 operates the speaker 22 to notify the operator of the abnormality. The computer 17 also displays data on the abnormality of the boiler feedwater pressure, the current value of the boiler feedwater pressure, and pre-stored data on the boiler feedwater pressure (such as a trend graph showing a change in the feedwater pressure from the past to the present) on the operator console. Output to the CRT on 20 and the printer 21.
[0018]
When the boiler feedwater pressure is equal to or smaller than threshold value B (for example, 20 kg / cm ² ) smaller than threshold value A, control device 16 outputs a signal indicating abnormal rank B to computer 17 and the standby unit. . As a result, the standby machine starts. Here, the threshold value B is a value that requires some action because plant equipment such as the exhaust heat recovery boiler 10 and the steam turbine 11 does not cause damage, but if the plant equipment continues to decrease as it is, the plant equipment may be damaged. Show. Then, the computer 17 performs the same operation as described above.
[0019]
When the boiler feedwater pressure is equal to or smaller than threshold value C (for example, 15 kg / cm ² ) smaller than threshold value B, control device 16 outputs a signal indicating abnormality rank C to computer 17. Here, the threshold value C is a value that causes damage to the plant equipment, for example, a value that causes the exhaust heat recovery boiler 10 to be cooked empty and burnt. Further, the control device 16 shuts off water supply to the exhaust heat recovery boiler 10, supply of the fuel 3 to the combustor 8, supply of the steam 4 to the steam turbine 11, and the like. Hereinafter, it is referred to as “trip operation”. The computer 17 outputs the fact that the trip operation has been performed to the CRT on the operator console 20 together with the same operation as described above.
[0020]
(1-b) The unmanned mode control device 16 sets the threshold value D (for example, 20 kg / cm ² ) of the value at which the boiler feed pressure is smaller than the set value (what kg / cm ² ) of the feed pressure during rated operation. In the following cases, a signal indicating the abnormal rank D is output to the central power supply command station (hereinafter, referred to as “medium power supply”) that commands the required load of the plant to the computer 17, the spare unit, and the power plant. As a result, the standby machine starts. The computer 17 outputs to the transmission / reception device 24 the abnormality of the boiler feed water pressure, the current value of the boiler feed water pressure, data on the boiler feed water pressure stored in advance, and the like. The transmission / reception device 24 transmits to the portable transmitter / receiver carried by the caller who is outside the power plant, the abnormality of the boiler feed water pressure, the current value of the boiler feed water pressure, data on the boiler feed water stored in advance in the boiler feed pressure, and the like. . Thus, the caller confirms the abnormal state of the plant. By setting D> B, the safety is further increased. In addition, a telephone line or ISDN may be used for the exchange between the computer 17 and the outside of the power plant.
[0021]
When the boiler feedwater pressure is equal to or lower than the threshold value C, the controller 16 outputs a signal indicating the abnormal rank C to the computer 17 and the middle supply, and performs a trip operation. The computer 17 outputs to the transmitting / receiving device 24 that the trip operation has been performed. The transmission / reception device 24 transmits the fact that the trip operation has been performed to the portable transmission / reception device carried by the caller outside the power plant.
[0022]
Then, the computer 17 arranges the data relating to the boiler feedwater pressure having an abnormality in a trend graph or the like and stores it. Then, when the operation mode is switched from the unmanned mode to the manned mode by the switch 23, data relating to the boiler feedwater pressure in which an abnormality has occurred during the unmanned mode is output to the CRT and the printer 21 on the operator console 20.
[0023]
(2) GT Exhaust Gas Temperature The exhaust gas temperature of the gas turbine 9 is detected by a temperature transmitter provided near the exhaust gas outlet of the high gas turbine 9. On the other hand, at a pressure transmitter provided near the outlet of the compressor 6 (the inlet of the combustor), the pressure of air (air supplied to the combustor) compressed by the compressor (hereinafter referred to as “compressed air pressure”). )). The control device 16 receives the detected exhaust gas temperature signal and the detected compressed air pressure signal, and controls the fuel flow control valve for controlling the flow rate of the fuel 3 supplied to the combustor 8 and the opening of the IGV 7. . The control device 16 calculates a theoretical value of the exhaust gas temperature based on the compressed air pressure signal, and further multiplies the theoretical value of the exhaust gas temperature by a safety coefficient to calculate an exhaust gas temperature curve. Then, the detected exhaust gas temperature signal is compared with the calculated exhaust gas temperature curve to detect an abnormality in the exhaust gas temperature.
[0024]
(2-a) When the exhaust gas temperature exceeds the exhaust gas temperature curve FGE obtained by multiplying the theoretical value of the exhaust gas temperature by the safety coefficient E, the manned mode control device 16 outputs a signal indicating the abnormal rank E to the computer 17. I do. Then, the computer 17 operates the speaker 22 to notify the operator of the abnormality. On the other hand, the computer 17 displays, on the operator console 20, an abnormality in the exhaust gas temperature, a current value of the exhaust gas temperature, and data on the exhaust gas temperature stored in advance (such as a trend graph showing a change in the exhaust gas temperature from the past to the present). Output to CRT and printer 21.
[0025]
Thereby, the operator performs a predetermined process, and when the exhaust gas temperature becomes equal to or lower than FGE, the computer 17 stops the operation of the speaker 22. That is, the notification is reset.
[0026]
When the exhaust gas temperature exceeds the exhaust gas temperature curve FGF obtained by multiplying the theoretical value of the exhaust gas temperature by the safety coefficient F (F> E), the control device 16 outputs a signal indicating the abnormal rank F to the computer 17. At the same time, a trip operation is performed. Here, the safety coefficient F is a value that causes damage to the equipment, and indicates, for example, a value that induces burnout of the combustor 8 and gas turbine blades. The computer 17 outputs the fact that the trip operation has been performed to the CRT on the operator console 20 together with the same operation as described above.
[0027]
(2-b) The unmanned mode control device 16 sets the abnormal rank G when the exhaust gas temperature exceeds the exhaust gas temperature curve FGG obtained by multiplying the theoretical value of the exhaust gas temperature by the safety coefficient G (E ≦ G <F). The output signal is output to the computer 17 and the middle supply. Further, the control device 16 controls the opening of the fuel flow control valve in the closing direction to reduce the load on the plant to a predetermined load. Hereinafter, this is referred to as “load runback”.
[0028]
When the exhaust gas temperature exceeds the FGF, the control device 16 outputs a signal indicating the abnormal rank F to the computer 17 and the middle supply, and performs a trip operation. Further, the computer 17 outputs to the transmitting / receiving device 24 that the trip operation has been performed.
[0029]
Then, the computer 17 sorts and stores the data on the temperature of the exhaust gas having an abnormality in a trend graph or the like. Then, when the operation mode is switched from the unmanned mode to the manned mode by the switch 23, data on the exhaust gas temperature in which an abnormality has occurred during the unmanned mode is output to the CRT on the operator console 20 and the printer 21.
[0030]
(3) Rotor bearing oil pressure The rotor bearing oil pressure is detected by three pressure transmitters provided in the bearing portion of the low rotor 12.
[0031]
The control device 16 compares the detected three rotor bearing oil pressure signals with a preset threshold value of the rotor bearing oil pressure to detect an abnormality of the rotor bearing oil pressure.
[0032]
(3-a) When one of the three rotor bearing hydraulic pressure signals is lower than the threshold value H, the manned mode control device 16 outputs a signal indicating the abnormal rank H to the computer 17. Then, the computer 17 operates the speaker 22 to notify the operator of the abnormality.
[0033]
When two of the three rotor bearing hydraulic signals are lower than the threshold value I (I <H), the control device 16 outputs a signal indicating the abnormal rank I to the computer 17 and performs a trip operation. . Here, the threshold value I is a value that causes damage to the device, for example, a value that induces damage to the metal of the bearing portion, vibration of the turbine, and the like. The computer 17 outputs the fact that the trip operation has been performed to the CRT on the operator console 20 together with the same operation as described above.
[0034]
(3-b) When two of the three rotor bearing oil pressure signals are lower than the threshold value J (J ≧ I), the unmanned mode control device 16 outputs a signal indicating the abnormal rank J to the computer 17, and Output, and perform a trip operation. Then, the computer 17 outputs to the transmitting / receiving device 24 that the trip operation has been performed.
[0035]
Then, the computer 17 sorts and stores data on the abnormal rotor bearing oil pressure in a trend graph or the like. Then, when the operation mode is switched from the unmanned mode to the manned mode by the switch 23, data relating to the rotor bearing oil pressure in which an abnormality has occurred during the unmanned mode is output to the CRT on the operator console 20 and the printer 21.
[0036]
(4) Exhaust gas NOx concentration The NOx concentration transmitter provided near the outlet of the high heat recovery steam generator 10 detects the NOx concentration of the exhaust gas discharged from the heat recovery steam generator 10.
[0037]
The control device 16 compares the detected NOx concentration with a preset NOx concentration threshold to detect an abnormality in the exhaust gas NOx concentration.
[0038]
(4-a) When the exhaust gas NOx concentration is higher than the threshold value K, the manned mode control device 16 outputs a signal indicating the abnormal rank K to the computer. Then, the computer 17 operates the speaker 22 to notify the operator of the abnormality.
[0039]
(4-b) When the exhaust gas NOx concentration is higher than the threshold value L (L ≦ K), the unmanned mode control device 16 cuts off the required load command from the middle supply and holds the load. As a result, a load change that becomes a disturbance for the NOx concentration control is suppressed. If the exhaust gas NOx concentration is higher than the threshold value L even after a predetermined time has elapsed from the load hold, the injection amount of ammonia for adjusting the exhaust gas NOx concentration is changed to reduce the exhaust gas NOx concentration to the threshold value L or less. Control.
[0040]
Then, the computer 17 organizes and stores the data on the concentration of the abnormal exhaust gas NOx in a trend graph or the like. Then, when the operation mode is switched from the unmanned mode to the manned mode by the switch 23, data regarding the exhaust gas NOx concentration in which an abnormality has occurred during the unmanned mode is output to the CRT and the printer 21 on the operator console 20.
[0041]
When the state quantities related to the operation of a plurality of plants become abnormal during the unattended mode, the computer 17 sorts and stores them by abnormality factor or system, and stores the data by the switch 23. When the mode is switched from the unattended mode to the attended mode , the data is output to the CRT on the operator console 20 and the printer 21. In addition, even when the control device 16 or the computer 17 is abnormal, the control device 16 or the computer 17 copes with the problem and keeps the plant safe.
[0042]
According to the above-described embodiment of the present invention, the control device 16 and the computer 17 monitor the operation state of the plant 1 and perform an appropriate measure against the abnormality of the plant 1 so that the operation state of the plant is stored in the power plant. Even if there is no operator to monitor, the effect of safely operating the plant can be achieved.
[0043]
【The invention's effect】
According to the thermal power plant operation control device of the present invention, when an abnormality of plant equipment is detected when there is no operator monitoring the operation state of the plant in the power plant, plant operation control with increased safety can be performed. It has the effect of being able to do it .
[Brief description of the drawings]
FIG. 1 is a mechanical system diagram of a single-shaft combined cycle power plant according to the present invention.
DESCRIPTION OF SYMBOLS 1 ... Plant, 2 ... Air, 3 ... Fuel, 4 ... Steam, 5 ... Water supply, 6 ... Compressor, 7 ... IGV, 8 ... Combustor, 9 ... Gas turbine, 10 ... Exhaust heat recovery boiler, 11 ... Steam turbine , 12 ... rotor, 13 ... generator, 14 ... condenser, 15 ... water supply pump, 16 ... control device, 17 ... computer, 18 ... computer room, 19 ... central operation room, 20 ... operator console, 21 ... printer, 22: speaker, 23: switch, 24: transmitting / receiving device.

Claims (1)

A thermal power plant operation control device that detects a state quantity related to plant operation, compares the detected state quantity with a preset threshold value of the state quantity, and detects an abnormality of the state quantity. ,
It has a manned operation mode that is set when the operator who monitors the plant operation state is manned and an unmanned operation mode that is set when unmanned, and is a value smaller than the set value at the time of rated operation, and the state quantity continues to decrease as it is And a threshold value in the manned operation mode, which indicates a value that may lead to damage to plant equipment and requires some action, and a threshold value in the unattended operation mode. A thermal power plant operation control device, which is set to be larger than a threshold value in the manned operation mode .

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