JPS62102306A - Automatic plant starting and stopping device - Google Patents

Abstract

PURPOSE:To easily decide the factor of delay by modeling the mutual relation with the completion condition of auxiliary equipment operation which is started and stopped before auxiliary equipment operation and computing the model. CONSTITUTION:A thermal power plant consists of a boiler, a steam turbine, etc., and is equipped with a controller and a computer for control so as to start and stop the plant. The automatic starting and stopping device for this plant stores the operation contents of the computer in a control logic table 21 by object auxiliary equipments and when a process state inputted by process input fetch processing 22 changes, a control logic number is specified to start control logic arithmetic processing 23. Further, the mutual relation between operation timing condition and a main event is modeled and stored in the table 21, and its object model number is specified to start model arithmetic processing 25. When a check period is detected with the arithmetic result, operation timing condition monitor processing 26 is started and when there is an unsatisfied condition item found by the checking, that is displayed on a display device, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an automatic start/stop device for a plant, and more particularly to an abnormality diagnosis technique for detecting and analyzing traffic congestion caused by automation and notifying an operator of the problem.

[Background of the invention]

As a method for monitoring the progress of automation related to plant automatic start/stop devices, for example, Thermal Power and Nuclear Power Development No. 324 P, 4
1 to P, 52 As discussed in the document entitled "Automation of Intermediate Load Thermal Power Plant of Unit 1 of Aioi Power Plant", the relevant break points of congestion, auxiliary equipment operation names, etc., and the corresponding control logic numbers are displayed on a CRT. There is a known method in which the control logic chart is displayed on a display device, the operator looks at it, calls up a control logic chart on a cathode ray tube display device, and checks the color print for the presence or absence of an input signal to identify the cause of the traffic jam.

This method is useful when the control logic number is known in advance, but it tends to require the operator to call up the control logic chart every time a traffic jam occurs. It is necessary to decipher it and identify the causes of traffic congestion. Furthermore, when the control logic number is unknown, the control logic chart cannot be called up, and searching for the cause of traffic congestion requires the rich experience and advanced judgment of a skilled operator.

[Purpose of the invention]

An object of the present invention is to solve the above-mentioned drawbacks by predicting a control port sick that starts execution due to a certain event in a plant, monitoring the presence or absence of an input signal of the control logic, and displaying the contents on a cathode ray tube when the input signal is not established. An object of the present invention is to provide an automatic plant start/stop device having an abnormality diagnosis panel function that automatically outputs output to a display device or printer.

[Summary of the invention]

FIG. 1 shows an example of the configuration of an automation system for a thermal power plant as an example of an automatic plant start/stop device.

The thermal power plant includes a pump 1, a flow rate regulating valve 2, a boiler 3, a main steam pipe 4, a steam turbine 5, and the like. In order to start and stop the plant, the plant's temperature, pressure, flow rate, auxiliary machine status, etc. are measured and input as individual signals to the control device 8 and control computer 6. Based on the obtained input, the control device 8 determines the control amount necessary for controlling the plant, and also records changes in the process amount using an instrument that displays the state amount of the plant in an analog manner, that is, an indicator, and changes in the process amount over time. A control signal is output to a monitoring operation panel 9 made up of instruments, such as recorders, and an operation panel 7 made up of displays and operating instruments capable of monitoring and controlling the plant. Similarly, signals are exchanged with the control computer 6.

The control computer 6 inputs plant data and data from the control device 8, comprehensively judges the plant state, and outputs operation commands to various control devices. Further, the contents operated by the control computer are displayed and printed on a cathode ray tube display device and a printer IO installed on the operation panel 7, and are useful for the operator's operation monitoring. By operating these organically, the plant can be automatically started and stopped in a safe and reliable manner.

The contents of the operation controlled by the control computer 6 are described in a control logic diagram, and the computer control proceeds by calculating and executing the described contents.

FIG. 2 shows an example of a control logic diagram, and FIG. 3 shows an arithmetic processing flow of the control logic in the control computer. Input signals for the control logic diagram include operation timing conditions that define the conditions for starting calculation processing of the control logic for operating the auxiliary equipment, pre-operation conditions that define the necessary conditions for safely operating the auxiliary equipment, and operation command output. There are three types of operation completion conditions that define the necessary conditions for monitoring whether the auxiliary equipment has operated normally.

Even if any of these input signals is out of order, the automatic start and stop of the plant will result in a traffic jam, and the operator will have to perform an operation to remove the cause of the traffic jam.

In conventional plant automatic start/stop systems, the third method is used to notify the operator of the cause of control congestion.
As shown in the figure, after the operation timing condition is satisfied, the pre-operation condition is checked, the cause of the failure of the condition is outputted as a message, and the operation completion condition is checked after the operation command is output.
A common method was to output a message indicating the cause of the failure of the condition.

However, both the pre-operation condition and the operation completion condition are checked only when the operation timing condition is satisfied. No notice will be given. Therefore, investigation of the causes of congestion when the operation timing conditions are not met relies entirely on the operator's experience and intuition.

The present invention focuses on the fact that all operation timing conditions input to the control logic are derived from other events in the plant and are established, and the completion of an auxiliary equipment operation that is started and stopped before the corresponding auxiliary equipment operation. By modeling the correlation with the conditions and calculating the model, the operation timing of the corresponding auxiliary equipment operation is determined, the presence or absence of the input signal is monitored, the cause of failure is restored, and the CRT display is performed. The goal is to be achieved by displaying and printing on devices and printers.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 4 is a block diagram showing an embodiment of the present invention applied to an automatic plant start/stop device, and FIG.
It is an explanatory diagram for explaining the operation.

In the plant automatic start/stop system, the operations controlled by the control computer are specified in the control logic diagram for each target auxiliary equipment.
It is stored in the control logic table 21. When the plant state input in the process input acquisition process 22 changes and an event occurs, the control logic calculation process 23 is activated by specifying the control logic number for the auxiliary equipment operation. In the control logic calculation process 23, the control logic is extracted from the control logic table 21, and as shown in the processing flow shown in FIG. Outputs operation commands. Check the operation completion condition after a certain period of time after outputting the operation command. If there is an item that is not satisfied in the pre-operation information or operation completion conditions, the content is displayed and printed as a traffic jam message on the display device or printer. In the control logic arithmetic processing 23, when the operation timing condition is not satisfied, subsequent processing is ignored and the next event is waited for.

On the other hand, the mutual relationship between the operation timing condition and the main event is modeled and stored in the model table 24. When the plant state captured in the process input capture process 22 changes and a major event corresponding to the input of the model table occurs, the target model number is specified and the model calculation process 25
is started. The model calculation process 25 takes out the model from the model table 24 and calculates the contents described in the model. When it is detected that it is time to check the operation timing condition based on the calculation result, specify the control logic number and
The operation timing condition monitoring process 26 is activated. The operation timing monitoring process 26 extracts the relevant control logic from the control logic table 21, checks the input signal of the operation timing condition, and if there is an item that does not satisfy, displays and prints the content on a cathode ray tube display device or printer and displays it for the operator. let them know.

In Fig. 5, starting the two demineralization towers operates when the condenser vacuum level is H3 or higher (event E,), and opening the valve after the deaerator sitting control valve operates when the condenser vacuum level is higher than H2 (event E,). This is a timing condition. Events E2 and E are both derived from the condenser vacuum breaker valve being fully closed (7 events E), which is established in relation to the condenser vacuum raising operation, and the timing of the occurrence of the event is determined by the condenser vacuum raising characteristics. is determined.

Therefore, by calculating the condenser vacuum rise characteristics with a model using the fully closed condenser vacuum breaker valve (event E,) as input, the time t until the condenser vacuum level reaches H8 is found, and E is established. By checking the operating timing conditions for starting the two demineralization towers later, it is possible to detect the cause of congestion, such as a delay in the rise of vacuum in the demineralizer.

Similarly, by finding the time t until the condenser vacuum level reaches H2 and checking the operation timing conditions for opening the deaerator water level control valve after t after EI is established, the condenser It is possible to detect the cause of traffic jams such as vacuum lift operation. By displaying and printing out the traffic congestion factors detected in this way on a cathode ray tube display or printer, it is possible to quickly notify the operator of the progressing traffic jam.

FIG. 6 is a diagram showing an example of description of a model table related to model calculation processing. The model table consists of a model index, model specifications, and constant specifications. The model index stores the input signal V5 RE t of the model and the model specification pointer P+ in order of model number. The model specification stores the type of arithmetic expression of the model, parameters, constants or constant indexes, and control logic numbers to be checked for the arithmetic results of the model.

Here, the types of arithmetic expressions include constant arithmetic, polygonal line approximation function arithmetic, and polynomial function arithmetic. In the case of constant calculation, the operation timing conditions of the control logic are checked after a predetermined period of time. In the case of polygonal function calculations and polynomial function calculations, the function calculation is executed using constant specification data indicated by the constant index based on the value of the input signal indicated by the parameter, and the relevant control is executed after the determined time has elapsed. This is to check the logic operation timing conditions.

FIG. 7 is a diagram showing another embodiment of the present invention.

It has become common for recent automatic plant start-stop devices to be equipped with a schedule calculation function for calculating individual operation schedules in detail in order to strengthen the management of plant start-stop times. Therefore, instead of the above-mentioned model calculation, the operator constant time determined by schedule calculation is monitored, and when the scheduled time arrives, the control logic of the relevant operation is extracted and the operation timing condition is checked, and the input signal of the operation timing condition is If there is a failure, the cause is displayed or printed on a cathode ray tube display or printer to notify the operator.

FIG. 7 is a diagram showing the concept of schedule calculation. 7th
In the figure, the times required for operations A, B, C, and DXE are each expressed as 1 mm, t11%, tC%, tD%, and jK. Event E. - The required time t for El is the operation A, B
, C is determined to be the longer one of the time required for operation AXD, t,==t,-)-t=-1-tc, and the time required for operation AXD, t,=jA-)-t, +tD. Here, t indicates the delay time from the occurrence of the event E to the start of the operation Tn.

The operation timing condition check timing for each operation is event E for operation B. After establishment 1. After that, event E occurs for operation C, and after tII, event E occurs for operation E. After t4 after the event is established, the operation is determined as event E, t after the event is established, and so on.

〔Effect of the invention〕

According to the present invention, it is possible to eliminate the drawback of progress congestion without warning, which was a blind spot of conventional automatic plant start/stop devices, and has the following effects: (1) The control logic is specified by model calculation. 1. Determine when to check the operation timing conditions, determine whether there is an input signal,
Since the operator is notified, it is easy to determine the cause of traffic congestion.

(2) Since the causes of congestion are clearly shown, the operator does not need to investigate the causes of congestion, and can investigate the immediate cause and perform recovery operations.

(3) Monitoring of the automatic start and stop of the plant can be performed without the need for experienced and skilled operators.

(4) Because of the investigation into the causes of traffic jams, there is no longer a large delay in plant start-up and stop times, and plant start-up and stop can be reliably carried out in accordance with a predetermined schedule.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of an automation system for a thermal power plant according to an embodiment of the present invention, Figure 2 is a diagram of computer pricing logic in a control computer, and Figure 3 is arithmetic processing of control logic in a control computer. Flowchart
Figure 5 is an explanatory diagram of the operation of a plant automatic start/stop device equipped with an abnormality diagnosis function based on model calculations, Figure 6 is a model table display diagram related to model calculation processing, and Figure 7 is a four-position block diagram. is an explanatory diagram showing the concept of schedule calculation. DESCRIPTION OF SYMBOLS 1... Pump, 2... Flow rate adjustment valve, 3... Boiler, 4... Main steam pipe, 5... Steam turbine, 6...
Control computer, 7... Operation panel, 8... Control device, 9
... Monitoring operation panel, 10... Printer, 21... Control logic.

Claims (1)

[Claims] 1. In a device that controls the start and stop of a plant using a control computer equipped with a cathode ray tube display and printer, a certain event in the plant is input so that it can be detected even if any input signal of the control logic goes out of order. What is claimed is: 1. An automatic plant start/stop device comprising: a model calculation unit that predicts when a corresponding control logic should operate;