Method for protection shutdown of large hydroelectric station cylindrical valve sliding to emergency position

Abstract

The application discloses a protection shutdown method for large hydroelectric station cylindrical valve sliding to an accident position, wherein, condition one sets an alarm value of 95%, also sets an action value of 50%, and judges whether a displacement channel of the cylindrical valve is faulty; condition two and three set a situation that there is no opening cylindrical valve flow or closing cylindrical valve flow starting command, so as to avoid triggering a shutdown flow in a normal opening and closing process of the cylindrical valve; condition six adds a unit state, so as to further avoid a misoperation of the shutdown flow. The application sets a delay constant value of a type II mechanical accident shutdown triggered by the cylindrical valve sliding to the accident position, prevents a misoperation of the shutdown flow caused by signal shaking output, and improves the reliability of the shutdown protection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic turbine, in particular to a protection shutdown method for large hydropower station cylindrical valve sliding to accident position. BACKGROUND

[0002] The hydraulic turbine cylindrical valve is a new type of water inlet control valve, which is often used in high water head hydropower stations. It is arranged between the movable guide vane and the fixed guide ring of the hydro-generator unit, and only stays in the full open or full closed position, and is not used for flow regulation. When the unit is out of control or the water guide mechanism fails to close, the movable water can close the cylindrical valve to stop; after the guide vane is closed in normal shutdown, the static water can close the cylindrical valve.

[0003] According to the action characteristics and functions of the cylindrical valve: under normal circumstances, the cylindrical valve is a full open / full closed two-position device without intermediate position state. At the same time, after the cylindrical valve is fully opened, the lower cavity of the servomotor continues to supply pressure to keep it in the fully open position, so there is no possibility of sliding down, and therefore no sliding down lifting logic is designed. At present, only the function of remotely manually closing the cylindrical valve in emergency is designed, and there is no alarm signal after the cylindrical valve slides down in accident, and no accident shutdown is triggered. The operation personnel deal with the fault through the emergency disposal plan. Once the cylindrical valve slides down abnormally, the generator unit still runs, and the guide vane needs to be opened greatly to meet the requirement of stable output, which may cause abnormal output of the hydro-generator unit, increase mechanical vibration, and may cause permanent damage to the mechanical structure, and in severe cases, may cause the accident to expand, which seriously endangers the safe and stable operation of the hydropower station. According to the relevant provisions of the "Water Turbine Generator Unit Automation Component (Device) and Its System Basic Technical Conditions" and the "Hydroelectric Power Plant Automation Design Technical Specification", when the cylindrical valve slides down to the accident position, an alarm signal should be sent and the shutdown process should be triggered. SUMMARY

[0004] The purpose of the present application is to provide a protection shutdown method for large hydropower station cylindrical valve sliding to accident position to solve the above problems. The present application increases the protection logic of the cylindrical valve sliding to the accident position in the unit LCU (local control unit) program based on the computer monitoring system, so as to realize the alarm signal and the shutdown process when the cylindrical valve abnormally slides to the accident position.

[0005] The present application realizes the above-mentioned purpose through the following technical scheme:

[0006] A protection shutdown method for large hydropower station cylindrical valve sliding to accident position, when the following six conditions are met at the same time, the cylindrical valve slides to the accident position alarm signal action, at this time, if the cylindrical valve sliding to the accident position shutdown protection soft pressure plate has been put into, the delay of 5 seconds will trigger the second type of mechanical accident shutdown;

[0007] Condition one: the cylindrical valve slides to 50% full opening degree, triggered by the following four criteria: the cylindrical valve displacement analog quantity < 50% full opening degree, the cylindrical valve slides to 95% full opening degree (alarm value) and the cylindrical valve slides to 50% full opening degree (action value) are output to the monitoring system LCU through the switch quantity; when the above analog quantity and switch quantity are satisfied and the cylindrical valve displacement channel is not faulty, the condition one is satisfied;

[0008] Condition two: there is no closing cylindrical valve process starting command; when the remote closing cylindrical valve order or the emergency manual cylindrical valve order is any one command 1, the SR trigger S end input is 1; at this time, the cylindrical valve full closing state is 0 and the cylindrical valve displacement < 3% full opening degree is 0, and the remote opening cylindrical valve order is 0, the SR trigger R end input is 0, and the SR trigger output is 1, and the inverse will not report the cylindrical valve sliding to the accident position signal;

[0009] Condition three: there is no opening cylindrical valve process starting command; when the remote opening cylindrical valve order is 1, the SR trigger S end input is 1; at this time, the cylindrical valve full opening state is 0 and the cylindrical valve displacement > 97% full opening degree is 0, or the remote closing cylindrical valve order is 0, or the emergency manual cylindrical valve order is 0, the SR trigger R end input is 0, and the SR trigger output is 1, and the inverse will not report the cylindrical valve sliding to the accident position signal;

[0010] Condition four and condition five limit that the cylindrical valve sliding to the accident position signal can be output only when the cylindrical valve is not in the full opening state and the cylindrical valve is not in the full closing state;

[0011] Condition six adds the speed lock, that is, when the unit speed is not less than 10% rated speed, the cylindrical valve sliding to the accident position signal can be reported.

[0012] A further scheme is that the cylindrical valve displacement analog quantity < 50% full opening degree is an average value obtained by comprehensive calculation according to six relay displacements, so that the influence of single relay jump and fault is avoided, and the actual opening degree of the cylindrical valve is reflected.

[0013] A further scheme is that the condition two and the condition three limit that the cylindrical valve sliding to the accident position signal can be reported only when the unit has no closing or opening cylindrical valve process starting command; the alarm signal is prevented from being output when the cylindrical valve normally rises or falls during the unit start-stop process, and the stop process is triggered.

[0014] A further scheme is that when the six conditions are satisfied at the same time, the cylindrical valve sliding accident position stop protection soft pad is set at the same time, so as to improve the protection action reliability.

[0015] The beneficial effects of the present application are that:

[0016] The present application has clear and complete logic: in condition one, the cylindrical valve slides to 50% full opening degree, 95% alarm value and 50% action value are set, and whether the displacement channel of the cylindrical valve is faulty is judged; conditions two and three set the situation that the start command of the flow process without opening the cylindrical valve or closing the cylindrical valve, to avoid triggering the shutdown process in the normal opening and closing process of the cylindrical valve; condition six adds the unit state, to further avoid the misoperation of the shutdown process.

[0017] In the present application, the cylindrical valve sliding accident position shutdown protection soft pressure plate is set, and the user can flexibly control the function of triggering the shutdown process when the cylindrical valve slides to the accident position in the computer monitoring system. When the unit is in the running or shutdown standby state, the cylindrical valve sliding accident position shutdown protection soft pressure plate remains to be put into operation, so that the cylindrical valve sliding accident position shutdown protection function is always in the put-in state; when the unit is in the shutdown state for defect elimination or maintenance, the cylindrical valve sliding accident position shutdown protection soft pressure plate can be taken out to prevent protection misoperation; it can also be used for simulating the continuous sliding of the cylindrical valve to 50% to check whether the LCU of the unit correctly receives the alarm signal.

[0018] In the present application, the cylindrical valve sliding accident position shutdown protection soft pressure plate is set in the computer monitoring system, and the user can flexibly control the function of triggering the shutdown process when the cylindrical valve slides to the accident position.

[0019] In the present application, the cylindrical valve sliding accident position triggers the second type of mechanical accident shutdown delay constant value, to prevent the misoperation of the shutdown process caused by signal jitter output and improve the reliability of shutdown protection. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creating laborious work.

[0021] Figure 1 The present application is a cylindrical valve sliding to an accident position action protection logic diagram.

[0022] Condition one: the cylindrical valve slides to 50% full opening degree: 1-the displacement simulation of the cylindrical valve is less than 50% full opening degree; 2-the displacement channel of the cylindrical valve is not faulty; 3-the cylindrical valve slides to 95% full opening degree (on-off quantity, alarm value); 4-the cylindrical valve slides to 50% full opening degree (on-off quantity, action value).

[0023] Condition two: no shutdown cylindrical valve flow process start command: 5-remote cylindrical valve closing order; 6-emergency manual cylindrical valve closing order; 7-cylindrical valve full closing state; 8-cylindrical valve displacement <3% full opening degree; 9-remote cylindrical valve opening order.

[0024] Condition three: no open cylinder valve flow process start command: 10-remote open cylinder valve order; 11-cylinder valve full open state; 12-cylinder valve displacement> 97% full open degree; 13-remote close cylinder valve order; 14-emergency manual cylinder valve order.

[0025] Condition four: 15-cylinder valve is not in full open state.

[0026] Condition five: 16-cylinder valve is not in full closed state.

[0027] Condition six: 17-unit speed is not less than 10% rated speed.

[0028] When the six conditions are met at the same time, the cylinder valve slides to the accident position to alarm signal action, at this time, if the cylinder valve sliding accident position shutdown protection soft pressure plate has been put into, delay 5 seconds will trigger the second type of mechanical accident shutdown. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the present application more clear, the technical scheme of the present application will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

[0030] In any embodiment, as shown in Figure 1 A protection shutdown method for cylinder valve sliding to accident position of large hydropower station of the present application, when the following six conditions are met at the same time, the cylinder valve slides to the accident position to alarm signal action, at this time, if the cylinder valve sliding accident position shutdown protection soft pressure plate has been put into, delay 5 seconds will trigger the second type of mechanical accident shutdown;

[0031] Condition one: cylinder valve slides to 50% full open degree, triggered by the following four criteria: cylinder valve displacement analog quantity<50% full open degree 1, cylinder valve slides to 95% full open degree (alarm value) 3, cylinder valve slides to 50% full open degree (action value) 4 output to monitoring system LCU through switch quantity; when the above analog quantity, switch quantity are all satisfied and cylinder valve displacement channel is not fault 2, then condition one is satisfied;

[0032] Condition two: no close cylinder valve flow process start command: when remote close cylinder valve order 5 or emergency manual cylinder valve order 6 is any one command is 1, SR trigger S end input is 1; at this time, cylinder valve full closed state 7 is 0 and cylinder valve displacement<3% full open 8 degree is 0, and remote open cylinder valve order 9 is 0, SR trigger R end input is 0, SR trigger output is 1, after taking the inverse, cylinder valve sliding to accident position signal will not be reported;

[0033] Condition three: no opening cylinder valve flow process start command: when the remote opening cylinder valve order 10 is 1, the SR trigger S end input is 1; at this time, the cylinder valve full opening state 11 is 0 and the cylinder valve displacement > 97% full opening opening degree 12 is 0, or the remote closing cylinder valve order 13 is 0, or the emergency manual cylinder valve order 14 is 0, the SR trigger R end input is 0, the SR trigger output is 1, and the inverse will not report the cylinder valve sliding to the accident position signal;

[0034] Condition four and condition five limit the cylinder valve to output the cylinder valve sliding to the accident position signal when the cylinder valve is not in the full opening state 15 and the cylinder valve is not in the full closing state 16;

[0035] Condition six adds speed lock, that is, when the unit speed is not less than 10% of the rated speed 17, the cylinder valve sliding to the accident position signal can be reported;

[0036] The cylinder valve displacement analog quantity < 50% full opening opening degree is an average value obtained by comprehensive calculation according to 6 servo actuators, which avoids the influence of single servo actuator jump and fault, and reflects the actual opening degree of the cylinder valve.

[0037] The condition two and condition three limit the cylinder valve sliding to the accident position signal to be reported when the unit has no closing or opening cylinder valve flow process start command; prevent the cylinder valve from outputting alarm signal and triggering shutdown process when the cylinder valve normally rises or falls during unit start and stop.

[0038] When the six conditions are met, the cylinder valve sliding accident position shutdown protection soft pad is set at the same time, so as to improve the protection action reliability.

[0039] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims. In addition, it should be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction, in order to avoid unnecessary repetition, the present application does not further describe various possible combination manners. In addition, various different embodiments of the present application can also be combined arbitrarily, as long as it does not violate the idea of the present application, it should also be considered as disclosed by the present application.

Claims

1. A protective shutdown method for a large hydropower station when a cylindrical valve slides down to an accident position, characterized in that: When the following six conditions are met at the same time, the cylinder valve slides down to the emergency position and the alarm signal is activated. At this time, if the cylinder valve slides down to the emergency position and the shutdown protection soft pressure plate is engaged, a delay of 5 seconds will trigger a Class II mechanical emergency shutdown; Condition 1: The cylindrical valve slides down to 50% of its full opening, which is triggered by the following four criteria: the cylindrical valve displacement analog value is less than 50% of its full opening, the cylindrical valve slides down to 95% of its full opening, and the cylindrical valve slides down to 50% of its full opening is output to the monitoring system LCU via a switch value. When the above analog values ​​and switch values ​​are all met and there is no fault in the cylindrical valve displacement channel, condition 1 is met. Condition 2: No command to start the process of closing the cylindrical valve: When either the remote command to close the cylindrical valve or the emergency manual command to lower the cylindrical valve is 1, the S-terminal input of the SR trigger is 1. At this time, the fully closed state of the cylindrical valve is 0 and the cylindrical valve displacement is <3%, the fully open position is 0, and the remote command to open the cylindrical valve is 0. The R-terminal input of the SR trigger is 0, and the output of the SR trigger is 1. After inversion, the signal that the cylindrical valve has fallen to the emergency position will not be reported. Condition 3: No command to start the process of opening the cylindrical valve: When the remote command to open the cylindrical valve is 1, the S-terminal input of the SR trigger is 1; at this time, the fully open state of the cylindrical valve is 0 and the cylindrical valve displacement is greater than 97% of the fully open position, or the remote command to close the cylindrical valve is 0, or the emergency manual cylindrical valve lowering command is 0, the R-terminal input of the SR trigger is 0, and the output of the SR trigger is 1. After the inversion, the cylindrical valve sliding to the emergency position signal will not be reported; Conditions 4 and 5 stipulate that the signal indicating that the cylindrical valve has fallen to the emergency position can be output only when the cylindrical valve is not in the fully open state or the cylindrical valve is not in the fully closed state; Condition six adds speed lock, that is, the cylindrical valve slides down to the accident position signal only when the unit speed is not less than 10% of the rated speed.

2. A protective shutdown method for a large hydropower station when a cylindrical valve slides down to an emergency position as claimed in claim 1, characterized in that: The displacement analog value of the cylindrical valve <50% full opening is an average value obtained by comprehensive calculation based on the displacements of 6 servomotors, avoiding the influence of jumps and failures of a single servomotor and reflecting the actual opening of the cylindrical valve.

3. A protective shutdown method for a large hydropower station when a cylindrical valve slides down to an emergency position as claimed in claim 1, characterized in that: The second and third conditions stipulate that when there is no start command for closing or opening the cylindrical valve process of the unit, the cylindrical valve slides down to the accident position signal to be reported; to prevent the output of the alarm signal when the cylindrical valve is normally lifted or dropped during the start-up and shutdown process of the unit, thereby triggering the shutdown process.

4. A protective shutdown method for a large hydropower station when a cylindrical valve slides down to an emergency position as claimed in claim 1, characterized in that: When all six conditions are met, a soft pressure plate for the cylindrical valve to be shut down at the emergency position is set to improve the reliability of the protection action.

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