KR100799435B1 - Apparatus for stabilizing of a digital electric hydraulic controller of the cogeneration system - Google Patents

Abstract

An apparatus for stabilizing a DEHC(Digital Electric Hydraulic Controller) of a cogeneration system is provided to stabilize the DEHC system by preventing the delay of output rising of a generator and a turbine trip. An apparatus for stabilizing a digital electric hydraulic controller of a cogeneration system is configured by moving and installing a power supply terminal(CB-30) of a maintenance tool(200) to a power supply unit(100) configured by supplying a power from a commercial power system and power terminals(CB-10,CB-20) of an uninterruptible power supply system so as to stably supply the power to a governor unit(110) and a CPU(Central Processing Unit)(120), a power input/output unit(160) and an operation/test panel unit(170), and a signal conditional unit(150). The power may be supplied from the power terminal of the uninterruptible power supply system of the maintenance tool and the power terminal of the commercial power system to the power terminal of the maintenance tool for monitoring an operation state of the digital electric hydraulic controller and for performing the maintenance of the digital electric hydraulic controller.

Description

Apparatus for stabilizing of a digital electric hydraulic controller of the cogeneration system}

1 is a schematic diagram of a DEHC system generally used in a cogeneration plant

2 is a schematic configuration diagram of a conventional DEHC system

3 is a graph illustrating the opening degree of steam control valves MSV, GV-L, GV-R, and ICV of a turbine controlled by a conventional DEHC system.

4 is a flowchart of an artificial setting operation for the entire series of pulse signals according to manual switching of a control system in a conventional DEHC system.

Figure 5 is a block diagram illustrating a power stage connection state of the maintenance tool in the stabilization device of the DEHC system according to an embodiment of the present invention

FIG. 6 is a circuit diagram illustrating a loop in which a feedback signal of a control oil pressure transmitter of each steam control valve is input to a distributed control system (DCS) in a stabilization apparatus of a DEHC system according to another embodiment of the present invention.

7 is a steam control valve switching control circuit diagram for stabilization of a DEHC system according to another embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

10 boiler 20 turbine

100: redundant power supply unit 110: governor unit

120: CPU 130: torque motor

140: E / H converter 180: current / voltage (I / V) converter

190: pressure transmitter 300: distributed control system

301 loop 310: field control relay

320: integrated control unit

The present invention relates to a digital electric hydraulic control (hereinafter referred to as 'DEHC') system of a cogeneration plant, and more particularly, to stabilize the system of the DEHC facility to increase the productivity by operating the power plant stable Relates to a device.

In general, the DEHC system used in the cogeneration plant, as shown in Figure 1, is produced in the boiler 10, a plurality of steam control valves installed for regulating the high-temperature, high-pressure steam flow rate supplied to the turbine 20, namely Controls the opening and closing operation of the main steam shut-off valve (MSV), left and right main steam control valves (GV-L, GV-R) and reheat steam control valve (ICV), and controls the generator output and turbine speed (3600 Rpm) It is a system.

Figure 2 is a schematic configuration diagram of a conventional DEHC system, the main steam shut-off valve (MSV), the left and right main steam control valves (GV-L, GV-R), the steam control valve of the turbine, reheat steam control valve (ICV) ) Control oil pressure, condenser vacuum, generator output, turbine speed, steam pressure and the like received the field signal and converts the signal to the CPU unit, and the control signals calculated from the CPU unit torque motor 130 of each steam control valve The governor 110 and the on-site signals converted from the governor 110 are converted into a steam control valve opening / closing control signal for controlling the generator output and turbine speed 3600 [Rpm]. The CPU unit 120 converts and supplies it to the governor unit, and the valve control signals calculated by the CPU unit are received through the governor unit 110 and transmitted to the E / H converter 140 of each steam control valve. Torque motor 130 of each steam control valve, and said each increase E / H converter (140) of each steam control valve that controls the amount of control oil drain of each steam control valve (MSV, GV-L, GV-R, ICV) by a signal transmitted from the torque motor of the pre-control valve. It is configured to include).

Referring to the valve control operation performed in the DEHC system of FIG. 2, the main steam shutoff valve (MSV), the left and right main steam control valves (GV-L, GV-R) and the reheat steam control valve (ICV), which are the steam control valves of the turbine, are shown. Field signals such as control oil pressure, condenser vacuum, generator output, turbine speed, steam pressure, etc. are converted into signals from the insulation board of the governor 110 and the analog input (AI) board of the CPU 120 These signals are converted into a steam control valve opening and closing control signal for generator output and turbine speed 3600 [Rpm] control by calculation on the CPU board, and then through the analog output (AO) board of the CPU unit 120. Again, by the MRSV (Maintenance Regulation Signal Voltage) module of the governor unit 110 is transmitted to the torque motor 130 of each steam control valve to adjust the amount of control oil drain (Erain) of the E / H converter (140) It is possible to control the opening and closing operation of the steam control valve of the By controlling the steam flow rate of the high temperature and high pressure supplied to the turbine, it is possible to control the generator output and the turbine speed (3600Rpm).

FIG. 3 is a graph showing the opening degree of steam control valves MSV, GV-L, GV-R, and ICV of a turbine controlled by a conventional DEHC system. FIG. GV-L, GV-R, ICV) opening and closing operation is as follows.

First, when the turbine is initially reset, the reheat steam shutoff valves RSV-L and RSV-R are quickly opened and the main steam steam control valves GV-L and GV-R are gradually opened as shown in FIG. . After the main steam control valve (GV-L, GV-R) is completely open, the turbine is started, when the turbine is started to prevent thermal deformation due to thermal stress of the turbine casing (casing) Steam is supplied to the entire turbine casing through the main steam control valve (GV) by the main injection method.

After the turbine is started by this operation, when the speed reaches 3600 [Rpm], the system feeds in for parallel operation with the KEPCO system. When the initial load warm-up is completed after the system feeds in, it is completely open. The main steam control valves (GV-L and GV-R) were closed, and the main steam shutoff valves (MSV-L and MSV-R) were opened to switch to the load control and main steam control valve (GV) control modes. The generator output can be controlled by the steam control valve GV and the reheat steam control valve ICV.

However, in the conventional DEHC system as described above, the power of the maintenance tool 200 provided for monitoring and maintaining the operation state of the DEHC system is supplied solely by the power of an uninterruptable power supply, and the DEHC system Since the signal is only interfaced internally, when the power supply of the uninterruptible power supply occurs in such a situation or when the input power of the uninterruptible power supply is cut off for maintenance, the power supplied to the maintenance tool 200 is also included. The use of the maintenance tool 200 is blocked so that the use of the maintenance tool 200 becomes impossible. Therefore, when an abnormality occurs in the control system of the DEHC system, the identification thereof becomes impossible, and thus, an emergency action time is delayed.

In addition, the opening and closing control of the steam control valve for the generator output control during normal operation is controlled by the maintenance regulation signal voltage module by the feedback signal of the control oil pressure signal value supplied to the E / H converter. The signal value is fed back and compared with the calculated value in the CPU of the DEHC system with respect to the current generator output set value, and the signal corresponding to the deviation amount is passed through the E / H converter again to the steam control valve (MSV, GV-L, GV-R). , ICV).

However, the feedback signal of the control oil pressure signal value of the steam control valves (MSV, GV-L, GV-R, ICV) required for these calculations is only interfaced internally within the DEHC system. In the current operating situation where various control systems are operated by means of the control system, it is not possible to monitor the on-site control status of the steam control valve in the central operating room.In case of an abnormality of the control oil feedback pressure transmitter of the on-site steam control valve, Even if equipment trouble occurs due to the sudden opening and closing of the steam control valve due to the impossibility of calculating the required value of the steam control valve, the DCS does not have the steam control valve control oil feedback pressure transmitter monitoring signal. There was a problem such as being.

On the other hand, if the DEHC system switches to the main steam control valve (GV) control mode for generator output control from the control of the steam control valve and the speed control mode for controlling the turbine speed to 3600 [Rpm] DEDE system The main steam shut-off valve (MSV) switching bias value and the main steam control valve (GV) switching bias value generated through the calculation in the CPU of the main steam shut-off valve (MSV) are completely opened and the main steam control valve (GV) Is closed for initial load control.

However, if the CPU of the DEHC system goes down and then returns to normal during the valve switching, the control system of the DEHC system does not recognize the control status from the turbine reset to the turbine start and the system feed-in for parallel operation with the KEPCO system. It is impossible to proceed with the control of the furnace, and it is impossible to increase the generator output.In addition, when the CPU of the DEHC system is down, the turbine is tripped when the CPU is reset by the artificial reset or automatic reset of the CPU of the DEHC system. Phenomenon occurs. In order to solve this problem, the control system of the DEHC system is manually switched and an artificial setting operation of the entire series of pulse signals up to the current control stage in the CPU of the DEHC system, that is, as shown in the flowchart of FIG. 4, is performed. Manual Switching → Network (NT) Table Call → NT Table Manual Switching → Parameter Calling → Manual Parameter Switching → Set Signal Value '1' → Check Control System Operation Status → Automatic Parameter Switching → DEHC Control System Operation Status Confirmation → NT table call → NT table automatic switching → DEHC CPU automatic switching → DEHC control system operation status check → DEHC control system reset reset → DEHC normal return

However, since the above operation is directly linked to the turbine trip when the operation after the misoperation and the control state of the DEHC system is not confirmed, the burden of facility trouble occurs at the time of operation, and thus, the manual operation work is carefully considered during operation. After each step of operation, the operation of the DEHC system and the signal interface state after checking the operation of the next step has a problem that takes a lot of time.

The present invention is to solve the problems of the prior art, the present invention can be used at any time by the constant power supply to the maintenance tool regardless of the power supply on the uninterruptible power supply side It is an object of the present invention to provide a stabilization device of a DEHC system.

 Another object of the present invention is to monitor the feedback oil pressure control and operation status of the steam control valve in the field in the distributed control system by using the control oil feedback pressure signal value of the steam control valve which is interfaced internally in the DEHC system. And to provide a stabilization device of the DEHC system that can achieve stabilization in early response to equipment troubles and the like.

It is still another object of the present invention, even if the CPU of the DEHC facility returns to normal after the main steam shutoff valve (MSV) and the main steam control valve (GV) are switched, the next step without the need for artificial setting of the software inside the control system of the DEHC system. It is to provide a stabilization device for the DEHC system that enables the control of the furnace to solve the problems of DEHC system operation by preventing the generator output rise delay and turbine trip.

A feature of the present invention for achieving the above object is to maintain a redundant power supply unit configured to be supplied with a dual power supply of the commercial power supply and the uninterruptible power supply for the stable supply of power to the governor part and the CPU input / output part of the DEHC system Stabilization of the DEHC system by releasing and configuring the power supply terminal of the maintenance tool, so that commercial power can be supplied to the maintenance tool power supply even when the uninterruptible power supply is turned off. Device.

Another feature of the present invention for achieving the above object, the feedback signal for the control oil pressure signal value supplied from the E / H converter to the steam control valve for the generator output control relay field control of the distributed control system (DCS) A signal flow for constructing a loop to be negatively input and drawing a signal flow for each group of pressure transmitters for each feedback signal of the control oil pressure signal value of the steam control valve in the integrated control unit of the distributed control system (DCS). By constructing the monitoring screen, the pressure control status of the feedback oil of the steam control valve can be displayed on the signal flow monitoring screen for each group only by inputting the tag number of the pressure transmitter in the distributed control system. It is a stabilization device of the DEHC system that allows to monitor the condition.

In the DEHC system of the present invention, the DEHC system is configured in the integrated control unit of the distributed control system (DCS) by configuring an operation trend display screen for displaying a trend of data recording the installation operation trend of the steam control valve feedback oil pressure transmitter signal. Control oil feedback to steam control valves in the DEHC system stabilizes the early warning and response of abnormality in the pressure transmitter to prevent equipment troubles.

Another feature of the present invention for achieving the above object, the first station control circuit to the setting signal for exporting the bias calculation value calculation signal for actually operating the main steam shutoff valve (MSV) and the main steam control valve (GV) By inserting the main steam shutoff valve (MSV) fully open signal of the switch with the valve changer signal, the CPU of the DEHC facility returns normally after the main steam shutoff valve (MSV) and the main steam control valve (GV) are switched. Even if the main steam shut-off valve (MSV) is fully opened, the main steam control valve (GV) switching bias signal is calculated by the 'off' delay timer, and the main steam control valve (GV) is closed to control the main steam for generator output control. It is possible to switch to the valve (GV) control mode so that the control proceeds to the next stage without the need for artificial setting of the software inside the control system of the DEHC system. It is a stabilization device of DEHC system that solves the chronic problems of DEHC system operation by preventing delay and turbine trip.

The objects, features and advantages of the present invention will be more readily understood by reference to the accompanying drawings and the following detailed description.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration of the preferred embodiment of the stabilizing device of the DEHC system according to the present invention and the resulting effects thereof.

5 is a block diagram illustrating a power terminal connection state of the maintenance tool in the stabilization apparatus of the DEHC system according to an embodiment of the present invention, the governor unit 110 and the CPU unit 120 of the DEHC system, and In order to supply stable power to the power input / output unit 160, the driving / test panel unit 170, the signal condition unit 150, and the like, each power terminal of the commercial power supply and the uninterruptible power supply unit (CB-10, A preferred embodiment of the system stabilization apparatus configured by moving the power stage CB-30 of the maintenance tool 200 to the redundant power supply unit 100 configured to be redundantly supplied from the CB-20) is illustrated.

In the DEHC system, in order to supply stable power to each block and module, each power is redundantly supplied from the power supply terminals CB-10 and CB-20 of the commercial power supply and the uninterruptible power supply (UPS). As the power stage (CB-30) of 200 is moved to the redundant power supply unit 100 side of the redundant DEHC system, the power of the maintenance tool 200 can be supplied from both the uninterruptible power supply and the commercial power supply. Will be.

Thus, the power stage (CB-10) of the uninterruptible power supply (UPS), as well as the power stage of the commercial power supply, are connected to the power stage (CB-30) of the maintenance tool 200 for monitoring and maintaining the operation state of the DEHC system. (CB-20) is also redundant, so that power supply can be made, so if an abnormality occurs in the power supply terminal of the uninterruptible power supply, or if the power supply terminal (CB-10) of the uninterruptible power supply is arbitrarily disconnected for maintenance, commercial power supply Since the maintenance tool 200 can be used normally by the power supplied from the power supply terminal (CB-20) of the system, even if the signal of the pressure transmitter is interfaced only inside the DEHC system, When the equipment problem occurs according to the signal of the pressure transmitter can be confirmed, the normal follow-up action can be made.

FIG. 6 is a circuit configuration diagram in which a loop is formed so that a feedback signal of a control oil pressure transmitter of each steam control valve can be input to a distributed control system (DCS) in a stabilization apparatus of a DEHC system according to another embodiment of the present invention. , The feedback signal of the pressure transmitter 190 to the control oil pressure signal value supplied from the E / H converter (see FIG. 2) to each steam control valve for generator output control is relayed to the field control of the distributed control system 300. A loop 301 is formed between the pressure transmitter 190 and the field control relay 310 of the distributed control system 300 to be input to the unit 310, and the integrated control unit of the distributed control system 300 ( 320 is designed to display and display a group signal flow monitoring screen that can draw the signal flow of the pressure transmitter for each group for each feedback signal of the control oil pressure signal value of each steam control valve.

During normal operation, the valve opening and closing operation for the generator output control in the DEHC system of the cogeneration plant, the control oil pressure signal value supplied from the E / H converter 140 to each steam control valve is the pressure transmitter 190 and the current / voltage It is fed back to the MRSV module of the governor unit 110 through the (I / V) converter 180, and compared with the calculated value of the CPU unit 120 of the DEHC system with respect to the output set value of the current generator, by the amount of the deviation. Signal is again outputted to each steam control valve via the E / H converter (140). Accordingly, in the DEHC system according to the present invention, the loop 301 leading to the field signal relay 310 of the distributed control system 300 is connected to the rear end of the pressure transmitter of each steam control valve which is only interfaced inside the DEHC system as described above. Formed, the control oil feedback pressure signal through the pressure transmitter through the analog output line (AO-018, AO-019, AO-020, AO-021) of the DEHC system field control relay of the distributed control system 300 And the transmitter signals PX-4211, PX-4212, PX-4213, and PX-4214 for the control oil feedback pressure of the respective steam control valves. The signal flow monitoring screen for each group designed in the integrated control unit 320 may be displayed. In this case, when only the tag number of the pressure transmitter for each group is input in the distributed control system 300, the pressure control state of the feedback oil of each steam control valve can be displayed on the signal flow monitoring screen for each group, so that the site of each steam control valve can be displayed. Operation status can be monitored.

In addition, the integrated control unit 320 of the distributed control system 300 by designing a driving trend display screen to display the trend of the data recording the operating trend of the steam control valve feedback oil pressure transmitter signal, through the driving trend display screen It is possible to monitor and respond early to the abnormality of the control oil feedback pressure transmitter for each steam control valve of the DEHC system, thereby preventing equipment troubles.

7 is a steam control valve switching control circuit diagram for stabilizing a DEHC system according to another embodiment of the present invention, the valve switching control implemented in the distributed control system to control the switching operation of each steam control valve of the DEHC system An example of a circuit is shown.

First, when the valve switching is performed to switch the main steam shut-off valve (MSV) for controlling the turbine speed to 3600 [Rpm] and the main steam control valve control mode for generator output control in the turbine speed control mode, The main steam shut-off valve (MSV) is completely opened by the main steam shut-off valve (MSV) switching bias signal and the main steam control valve (GV) switching bias signal generated by the operation of the CPU of the system, and the main steam control valve (GV) Is closed for initial load control. In the distributed control system according to the present invention, as shown in FIG. 7, the main steam shutoff valve fully open signal at the time of switching the valve, that is, the full open signal of the left main steam shutoff valve MSV-L (MSV-LF / O). ) And the full open signal (MSV-RF / O) of the right main steam shutoff valve (MSV-R) are calculated by the logical AND condition, and the main steam shutoff valve MSV of the first station control circuit STAT01 is calculated. The fully open signal of MSV-F / O is obtained. The first station control circuit is connected to a signal setting gate 120-1 (S (R) 041) for outputting a bias calculation value calculation signal for actually operating the main steam shutoff valve MSV and the main steam control valve GV. By inserting the fully open signal (MSV-F / O) of the main steam shutoff valve (MSV) in the logical OR (OR) condition, the DEHC system can be switched on during the switching of the main steam shutoff valve (MSV) and the main steam control valve (GV). If the main steam shut-off valve MSV is fully open even after the CPU is down, the main steam is controlled by the main steam control valve GV switching bias gate 120-3 by the 'OFF' delay timer 120-2. The valve (GV) switching bias signal is calculated to close the main steam control valve (GV), so that it is possible to switch to the main steam control valve (GV) control mode for generator output control, so that the artificial software of the control system of the DEHC system is artificial. Control to the next step without setting Proceeds can be solved to solve the chronic problems of DEHC system operation by preventing generator output rise delay and turbine tripping.

According to the present invention, since the power supply on the uninterruptible power supply side and the commercial power supply are redundantly supplied to the maintenance tool, the maintenance tool can be used at all times regardless of facility inspection and power supply when a power failure occurs. In addition, the control oil feedback pressure signal value of the steam control valve, which is interfaced internally in the DEHC system, can be monitored in the distributed control system for early response to abnormal signs and equipment troubles, and to control the main steam shutoff valve (MSV) and main steam. Even if the CPU of the DEHC facility returns to normal after the valve (GV) is switched, control proceeds to the next step without the need for artificial setting of the software inside the control system of the DEHC system, thereby preventing the generator output rising delay and the turbine tripping. It is possible to achieve stabilization of the DEHC system, and so on.

Claims (4)

In the DEHC system having a redundant power supply unit configured to provide a redundant power supply of the commercial power supply and the uninterruptible power supply for stable supply of power to the governor part and the CPU input / output part of the DEHC system, The power stage of the maintenance tool is moved to the redundant power supply unit, so that the commercial power is supplied to the power stage of the maintenance tool even when the power supply of the uninterruptible power supply is cut off. System stabilization of the installation. The loop is configured so that the feedback signal for the control oil pressure signal value supplied from the E / H converter to the steam control valve for generator output can be input to the field control relay of the distributed control system (DCS), and the distributed control system ( In the integrated control unit of the DCS), a signal flow monitoring screen for drawing the signal flow for each group of the pressure transmitters for each of the feedback signals of the control oil pressure signal value of the steam control valve is configured, and the tag of the pressure transmitter in the distributed control system is constructed. The system for stabilizing cogeneration power digital electric hydraulic control equipment, characterized in that the pressure control state of the feedback oil of the steam control valve can be displayed on the signal flow monitoring screen for each group only by inputting a number. The method of claim 2, An operating trend display screen is displayed on the integrated control unit of the distributed control system DCS to display the trend of data recording the operating condition of the steam control valve feedback oil pressure transmitter signal. A system stabilization apparatus for a cogeneration power digital electric hydraulic control system, characterized in that it is configured to monitor and respond to abnormal signs of a feedback pressure transmitter early. The valve switching unit converts the main steam shut-off valve (MSV) of the first station control circuit to the set signal for exporting the bias calculation value that actually operates the main steam shut-off valve (MSV) and the main steam control valve (GV). Inserted under the condition of OR of the signal,  If the main steam shut-off valve (MSV) is fully opened even after the CPU of the DEHC facility is down and returned normally during the switching of the main steam shut-off valve (MSV) and the main steam control valve (GV), the main steam control valve is controlled by an 'off' delay timer. (GV) The switching bias signal is calculated and the main steam control valve (GV) is closed to switch to the main steam control valve (GV) control mode for generator output control. System stabilization of the installation.

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