JP7012394B1 - Turbine emergency stop control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To replace a 4-port solenoid valve constituting a 2oo3 logic circuit in an emergency stop control device adopting a 2oo3 logic circuit which operates based on a detection result of a turbine rotation speed, without stopping the emergency stop control device. Make it possible. SOLUTION: Stop valves NV1P, NV2P and NV3P which can be opened and closed between a first pipe 22P connected to a hydraulic oil supply source and ports P of three 4-port solenoid valves MV1, MV2 and MV3. The stop valves NV1T, NV2T and NV3T that can be opened and closed between the second pipe 22T connected to the oil turning unit 30 and the ports T of the three 4-port solenoid valves MV1, MV2 and MV3. I inserted it. [Selection diagram] Fig. 1

Description

The present invention relates to an emergency stop control device for a turbine used in a power generation facility or the like.

In power generation equipment using a turbine, in order to ensure safety, an emergency stop control device is provided that measures the rotation speed of the turbine with a sensor and stops the turbine when the rotation speed exceeds the upper limit. Here, the sensor that measures the rotational speed of the turbine operates in a harsh environment, and therefore may malfunction. Therefore, the rotation speed of the turbine is measured by three sensors, and when any two of the three sensors detect that the upper limit of the rotation speed is exceeded, the turbine is stopped 2oo3 (2 out of 3; 3). 2) An emergency stop control device equipped with a logic circuit is provided. It should be noted that this kind of emergency stop control device is disclosed in, for example, Patent Document 1.

European Patent Application No. 3152447

The 2oo3 logic circuit of the above-mentioned emergency stop control device is composed of a hydraulic circuit using three solenoid valves controlled to open and close by detection signals from three sensors. Here, the emergency stop control device must operate for a long period of time, and if the rotation speed of the turbine is exceeded during that period, the turbine must be reliably stopped. Therefore, in the emergency stop control device, it is necessary to frequently perform maintenance of the solenoid valve of the 2oo3 logic circuit. In the past, the operation of the emergency stop control device was stopped during the maintenance of this solenoid valve, which caused a decrease in the operating rate of the emergency stop control device and the power generation equipment using the emergency stop control device.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an emergency stop control device capable of performing maintenance of a solenoid valve of a 2oo3 logic circuit without stopping the operation.

According to the present invention, in an emergency stop control device for stopping the turbine when the rotation speed of the turbine exceeds the upper limit, the first pipe to which the hydraulic oil is supplied from the hydraulic oil supply source and the lubrication section are operated. A second pipe that supplies oil and a quick stop valve that switches from the closed state to the open state when the hydraulic oil of the hydraulic oil of the first pipe drops and stops the turbine when the open state is reached, respectively. A shut-off state that has ports P, T, A and B and blocks the passage of hydraulic fluid in both the sections between ports P and A and between ports B and T, and between ports P and A and port B. 1st to 3rd 4-port solenoid valves capable of switching between passing states through which hydraulic oil is passed in both sections between and T, and each port P is connected to the first pipe. , Each port T is connected to the second pipe, and the port A of the first 4-port solenoid valve and the port B of the second 4-port solenoid valve are connected by the first solenoid valve-to-valve pipe. The port A of the 2 4-port solenoid valve and the port B of the 3rd 4-port solenoid valve are connected by a second solenoid valve-to-valve pipe, and the port A of the 3rd 4-port solenoid valve and the 1st 4-port solenoid valve are connected. A first solenoid valve is connected between the ports B of the valves by a first solenoid valve pipe, and the shutoff state is switched to the passing state when the rotation speed of the turbine, which is measured by a separate sensor, exceeds the upper limit. A second is provided with a 2oo3 logic circuit including a third 4-port solenoid valve, and can be opened and closed between the first pipe and each port P of the first to third 4-port solenoid valves. The first to third stop valves are inserted, and the fourth to sixth stop valves that can be opened and closed between the second pipe and each port T of the first to third four-port solenoid valves are Provide an inserted emergency stop control device.

It is a circuit diagram which shows the structure of the hydraulic circuit of the emergency stop control device which is one Embodiment of this invention. It is a circuit diagram which shows the structure of the hydraulic circuit. It is a circuit diagram which shows the structure of the hydraulic circuit. It is a front view which shows the appearance of the emergency stop control device. It is a top view of the emergency stop control device. It is a perspective view which shows the layout of the pipe in the solenoid valve module of the emergency stop control device. It is a figure which shows the operation for replacement of the 4-port solenoid valve in the same embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a circuit diagram showing a configuration of a hydraulic circuit of a turbine emergency stop control device 1 according to an embodiment of the present invention. As shown in FIG. 1, the emergency stop control device 1 includes a solenoid valve module BK1, a stop valve module BK2, and a cartridge valve module BK3.

The solenoid valve module BK1 includes three 4-port solenoid valves MV1, MV2 and MV3. Each of the 4-port solenoid valves MV1, MV2 and MV3 has ports P, A, B and T. Each of these solenoid valves is switched based on the measurement result of the rotational speed of the turbine by three sensors independent of each other. For example, in the 4-port solenoid valve MV1, when the rotation speed of the turbine measured by one sensor is within the upper limit, the coil is energized and both between ports P and A and between ports B and T. When the passage of hydraulic oil in the section is blocked and the rotation speed of the turbine measured by the sensor exceeds the upper limit, the coil is de-energized and between ports P and A and between ports B and T. In both sections, the passage state is such that the passage of hydraulic oil is permitted. The same applies to the other 4-port solenoid valves MV2 and MV3, which are switched to a cutoff state or a passing state based on the measurement result of the rotation speed by another sensor. Further, the 4-port solenoid valves MV1, MV2 and MV3 have valve core position switches S1, S2 and S3, respectively. These valve core position switches S1, S2 and S3 detect the valve core positions of the 4-port solenoid valves MV1, MV2 and MV3, respectively, and confirm whether the 4-port solenoid valves MV1, MV2 and MV3 are operating normally. can do.

The port A of the 4-port solenoid valve MV1 and the port B of the 4-port solenoid valve MV2 are connected by a solenoid valve inter-valve pipe AB12. Further, the port A of the 4-port solenoid valve MV2 and the port B of the 4-port solenoid valve MV3 are connected by a solenoid valve inter-valve pipe AB23. Further, the port A of the 4-port solenoid valve MV3 and the port B of the 4-port solenoid valve MV1 are connected by a solenoid valve intervalving pipe AB31. In this way, the solenoid valve spacing pipes AB12, AB23 and AB31 connecting the four-port solenoid valves and the four-port solenoid valves MV1, MV2 and MV3 form a 2oo3 logic circuit.

The stop valve module BK2 includes stop valves NV1T to NV3T and NV1P to NV3P, which are needle type stop valves, and orifices OA and O0, respectively. The hydraulic oil supplied from the hydraulic oil supply source 20 such as a pump is given to the orifices OA and O0 via the pipe 21.

The hydraulic oil that has passed through the orifice OA from the pipe 21 is supplied to the pipe 31. The hydraulic oil of the pipe 31 is supplied to the turbine as safety oil. The turbine operates normally when the oil pressure of this safety oil is sufficiently high.

The hydraulic oil that has passed through the orifice O0 from the pipe 21 is supplied to the first pipe 22P, and the hydraulic oil of the first pipe 22P is passed through the stop valves NV1P, NV2P and NV3P, respectively, so that the 4-port solenoid valve MV1 , MV2 and MV3, respectively.

The hydraulic oil discharged from the port T of the 4-port solenoid valves MV1, MV2 and MV3 is supplied to the second pipe 22T via the stop valves NV1T, NV2T and NV3T, respectively. The hydraulic oil supplied to the second pipe 22T is sent to the oil circulation unit 30.

The cartridge valve module BK3 includes rapid stop valves NG1 and NG2, which are two-way cartridge valves, respectively. The rapid stop valves NG1 and NG2 are inserted between the second pipe 22T and the pipe 31, and the open / closed state is controlled by the states of the four-port solenoid valves MV1, MV2 and MV3.

When the rapid stop valves NG1 and NG2 are closed, the hydraulic pressure of the hydraulic oil in the pipe 31 is sufficiently high, and the turbine operates normally. On the other hand, when the rapid stop valves NG1 and NG2 are opened, the second pipe 22T connected to the oil turning unit 30 is connected to the pipe 31 by the rapid stop valves NG1 and NG2, so that the hydraulic pressure of the hydraulic oil of the pipe 31 drops. do. This causes the turbine to stop rapidly.

In the example shown in FIG. 1, since the rotational speeds of the turbines measured by the three sensors are all within the upper limit, the four-port solenoid valves MV1, MV2, and MV3 are all shut off. In this case, the space between the first pipe 22P and the second pipe 22T is cut off. Therefore, the hydraulic oil of the first pipe 22P maintains a high hydraulic pressure, and the rapid stop valves NG1 and NG2 are closed.

In the example shown in FIG. 2, the rotation speed of the turbine measured by one sensor exceeds the upper limit, the 4-port solenoid valve MV1 is in the passing state, and the other 4-port solenoid valves MV2 and MV3 are in the shutoff state. In this case, the hydraulic oil of the first pipe 22P is given to the port P of the 4-port solenoid valve MV1 via the stop valve NV1P, and is supplied to the A port of the 4-port solenoid valve MV1 via the solenoid valve inter-valve pipe AB12. The connection between ports B and T of the connected 4-port solenoid valve MV2 is cut off. Therefore, the hydraulic oil does not move between the first pipe 22P and the second pipe 22T via the 4-port solenoid valves MV1 and MV2, and the first pipe 22P and the second pipe 22T are cut off. , The rapid stop valves NG1 and NG2 are closed.

In the example shown in FIG. 3, the rotation speed measured by the two sensors exceeds the upper limit, and the 4-port solenoid valves MV1 and MV3 are in the passing state and the 4-port solenoid valve MV2 is in the shutoff state. In this case, the hydraulic oil of the first pipe 22P is given to the port P of the 4-port solenoid valve MV3 via the stop valve NV3P, and the hydraulic oil of the first pipe 22P is supplied to the port P of the 4-port solenoid valve MV3 via the solenoid valve inter-valve pipe AB31. A passing state is provided between ports B and T of the connected 4-port solenoid valve MV1. Therefore, the hydraulic oil can be transferred between the first pipe 22P and the second pipe 22T via the 4-port solenoid valves MV3 and MV1, and the first pipe 22P and the second pipe 22T are connected to each other. The hydraulic pressure of the hydraulic oil of the first pipe 22P drops. As a result, the rapid stop valves NG1 and NG2 are opened, the hydraulic pressure of the hydraulic oil of the pipe 31 is lowered, and the turbine is rapidly stopped.

As a result of investigation by the inventor of the present application, it was found that the following problems occur in the configuration shown in FIG. That is, when one of the three 4-port solenoid valves MV1, MV2 and MV3 returns from the passing state to the shutoff state, and then the other two return to the passing state, the hydraulic pressure of the hydraulic oil of the first pipe 22P and The hydraulic pressure of the hydraulic oil of the pipe 31 suddenly drops in a short time, causing shutoff (rapid stop of the turbine) due to a system error and false reporting of the error.

As a result of many experiments, we found the following as the cause of this problem. After one 4-port solenoid valve (for example, a 4-port solenoid valve MV1) returns from the passing state to the cutoff state, the port B of the 4-port solenoid valve MV1 and the port A of the adjacent 4-port solenoid valve MV3. An air cavity is formed in the solenoid valve inter-valve pipe AB31 connected to the above, and when the 4-port solenoid valve MV3 is in a passing state, the hydraulic oil in the solenoid valve inter-valve pipe AB31 fills the air cavity. By filling the air cavity with this hydraulic oil, the hydraulic pressure of the hydraulic oil of the first pipe 22P is instantaneously lowered and recovered. As a result, the rapid stop valves NG1 and NG2 open and close instantaneously, and the hydraulic pressure of the hydraulic oil of the pipe 31 drops instantaneously, causing a shutoff due to a system error and a false alarm.

As a result of many experiments and theoretical demonstrations, the duration of the abnormal pressure drop is proportional to the depth of the drop and the volume of the solenoid valve intervalving pipes AB12, AB23 and AB31 in which the air cavity is formed, and the 4-port solenoid valves MV1 and MV2. And it was found to be inversely proportional to the amount of internal leakage of MV3.

The emergency control device according to this embodiment is designed based on the results of the above experiments and theoretical proofs. In this embodiment, the design is made to minimize the volume of the solenoid valve intervalve pipes AB12, AB23 and AB31. Specifically, in the present embodiment, the solenoid valve pipes AB12, AB23 and AB31 have the same length and are shortened. Further, in the present embodiment, as the 4-port solenoid valves MV1, MV2 and MV3, those having a large internal leakage amount are adopted. Here, the internal leakage refers to the amount of leakage between ports P and A and between ports B and T of the 4-port solenoid valve in the shutoff state. This amount of leakage is related to the type of valve core of the valve. The amount of internal leakage of the electromagnetic slide valve is larger than the amount of internal leakage of the electromagnetic seat valve. Therefore, in this embodiment, the solenoid slide valve is adopted as the 4-port solenoid valves MV1, MV2 and MV3.

FIG. 4 is a front view showing the appearance of the emergency stop control device 1 according to the present embodiment. Further, FIG. 5 is a plan view of the emergency stop control device as viewed from above. As shown in these figures, the emergency stop control device 1 according to the present embodiment has a configuration in which the solenoid valve module BK1, the stop valve module BK2, and the cartridge valve module BK3 are vertically stacked in the vertical direction.

As shown in FIG. 5, the three 4-port solenoid valves MV1, MV2 and MV3 of the solenoid valve module BK1 have the same shape and size as each other, and are in the maximum close contact state in the solenoid valve module BK1. Have been placed. In the present embodiment, the 4-port solenoid valves MV1, MV2 and MV3 can be attached to and detached from the outside to the housing of the emergency stop control device 1. The solenoid valve module BK1 is provided with hydraulic sensors M1, M2 and M3 for measuring the hydraulic pressure in each of the solenoid valve intervalving pipes AB12, AB23 and AB31. By monitoring the output signals of the hydraulic sensors M1, M2 and M3, it is possible to detect the failure of the 4-port solenoid valves MV1, MV2 and MV3. Further, since the 4-port solenoid valves MV1, MV2 and MV3 have the valve core position switches S1, S2 and S3 described above, the 4-port solenoid valves MV1, MV2 and MV3 are provided by the valve core position switches S1, S2 and S3. It is possible to determine whether or not there is a failure in the.

FIG. 6 is a perspective view showing the layout of the pipe in the solenoid valve module BK1 of the emergency stop control device 1. As shown in FIG. 6, the solenoid valve intervalving pipes AB12, AB23 and AB31 are arranged in the solenoid valve module BK1 so as to form each side of an equilateral triangle. The length of the solenoid valve pipes AB12, AB23 and AB31 is the 4-port solenoid valve adjacent to the A port of the 1 4-port solenoid valve when the 4-port solenoid valves MV1, MV2 and MV3 are arranged as close as possible. Equal to the length between the valve and the B port.

The inventor of the present application has confirmed that the duration of the abnormal hydraulic pressure drop can be controlled within 50 ms by making the shapes, sizes, and layouts of the solenoid valve intervalbular pipes AB12, AB23, and AB31 as shown in FIG. Further, the inventor of the present application has set the descent width to less than 2 bar and the hydraulic pressure of the hydraulic oil of the hydraulic oil supply source 20 to 20 bar. , AB23 and AB31 were confirmed to be able to fill the air cavities. By improving the solenoid valve pipes AB12, AB23 and AB31 in this way, the safety hydraulic pressure does not suddenly drop in a short time, and the usage requirements are completely satisfied.

In order to improve the reliability of the emergency stop control device 1, it is necessary to frequently perform maintenance of the 4-port solenoid valves MV1, MV2 and MV3 constituting the 2oo3 logic circuit. Under the prior art, the emergency stop control device 1 was stopped to perform maintenance on the 4-port solenoid valves MV1, MV2 and MV3, so that the operating rate of the emergency stop control device 1 and the power generation system using the same was reduced. I was invited. Therefore, in the present embodiment, there is provided a means for enabling the replacement of the 4-port solenoid valves MV1, MV2 and MV3 while maintaining the operation of the emergency stop control device 1 without stopping the emergency stop control device 1.

As shown in FIG. 1, in the emergency stop control device 1, between the first pipe 22P and each port P of the 4-port solenoid valves MV1, MV2 and MV3, a stop valve NV1P, NV2P and a stop valve capable of opening and closing can be operated. NV3P is inserted, and stop valves NV1T, NV2T and NV3T that can be opened and closed are inserted between the second pipe 22T and each port T of the 4-port solenoid valves MV1, MV2 and MV3.

Further, as shown in FIG. 4, the housing of the emergency stop control device 1 is provided with a plug for supplying an electric signal for opening / closing operation to the stop valves NV1P to NV3P and NV1T to NV3T. In the present embodiment, an electric signal is sent from this plug to the stop valves NV1P to NV3P and NV1T to NV3T to open and close the stop valves NV1P to NV3P and NV1T to NV3T without stopping the emergency stop control device 1. It is possible to replace the 4-port solenoid valves MV1, MV2 and MV3.

FIG. 7 is a diagram showing an operation for replacing the 4-port solenoid valve in the present embodiment. When replacing the 4-port solenoid valve MV1, the stop valves NV1P, NV1T, NV2T and NV3P are closed and the stop valves NV2P and NV3T are open. In this state, the 4-port solenoid valve MV1 is forcibly shut off and does not react to the measurement result of the rotation speed by the sensor. The four-port solenoid valves MV2 and MV3 are both in the passing state only when the rotation speed measured by the two sensors associated with each exceeds the upper limit, and the first pipe 22P and the second pipe 22P and the second pipe are in the passing state. Pipe 22T is connected. In this way, the 4-port solenoid valves MV2 and MV3 function as 2oo2 (2 out of 2) logic circuits. When the replacement of the 4-port solenoid valve MV1 is completed, the stop valves NV1P, NV1T, NV2T and NV3P are switched to the open state. As a result, the operation as a 2oo3 logic circuit is restarted.

When replacing the 4-port solenoid valve MV2, the stop valves NV1P, NV2P, NV2T and NV3T are closed and the stop valves NV1T and NV3P are open. In this state, the 4-port solenoid valve MV2 is forcibly shut off and does not react to the measurement result of the rotation speed by the sensor. The four-port solenoid valves MV1 and MV3 are both in the passing state only when the rotation speed measured by the two sensors corresponding to each exceeds the upper limit, and the first pipe 22P and the second pipe 22P and the second pipe 2 Connect the pipe 22T. In this way, the 4-port solenoid valves MV1 and MV3 function as 2oo2 logic circuits. When the replacement of the 4-port solenoid valve MV2 is completed, the stop valves NV1P, NV2P, NV2T and NV3T are switched to the open state. As a result, the operation as a 2oo3 logic circuit is restarted.

When replacing the 4-port solenoid valve MV3, the stop valves NV1T, NV2P, NV3P and NV3T are closed and the stop valves NV1P and NV2T are open. In this state, the 4-port solenoid valve MV3 is forcibly shut off and does not react to the measurement result of the rotation speed by the sensor. The four-port solenoid valves MV1 and MV2 are both in the passing state only when the rotation speed measured by the two sensors corresponding to each exceeds the upper limit, and the first pipe 22P and the second pipe 22P and the second pipe 2 Connect the pipe 22T. In this way, the 4-port solenoid valves MV1 and MV2 function as 2oo2 logic circuits. When the replacement of the 4-port solenoid valve MV3 is completed, the stop valves NV1T, NV2P, NV3P and NV3T are switched to the open state. As a result, the operation as a 2oo3 logic circuit is restarted.

As described above, according to the present embodiment, the 4-port solenoid valves MV1, MV2 and MV3 can be replaced without stopping the emergency stop control device 1.

When one of the 4-port solenoid valves MV1, MV2 and MV3 (for example, the 4-port solenoid valve MV1) is replaced, the 4-port solenoid valve MV1 is energized from a long-term non-energized state (that is, a passing state). It will return to the state (that is, the cutoff state). However, in the present embodiment, the three solenoid valve intervalve pipes AB12, AB23 and AB23 are shortened by having the same length, and the solenoid slide valve is adopted as the 4-port solenoid valves MV1, MV2 and MV3. Therefore, even if the other 4-port solenoid valves MV2 and MV3 are in the passing state after returning from the passing state of the 4-port solenoid valve MV1 to the shut-off state, the hydraulic pressure of the hydraulic oil of the first pipe 22P and the pipe described above The problem that the hydraulic pressure of the hydraulic oil of 31 suddenly drops in a short time does not occur.

1 ... Emergency stop control device, BK1 ... Solenoid valve module, BK2 ... Stop valve module, BK3 ... Cartridge valve module, MV1, MV2, MV3 ... 4-port solenoid valve, NV1P to NV3P, NV1T to NV3T ... Stop valve, ..., AB12, AB23, AB31 ... Solenoid valve inter-valve pipe, 22P ... 1st pipe, 22T ... 2nd pipe, NG1, NG2 ... Rapid stop valve, 20 ... Hydraulic oil supply unit , 30 ... Oil section, 31 ... Pipe.

Claims (3)

In the emergency stop control device that stops the turbine when the rotation speed of the turbine exceeds the upper limit.
The first pipe to which the hydraulic oil is supplied from the hydraulic oil supply source,
A second pipe that supplies hydraulic oil to the oil circulation part,
A rapid stop valve that switches from the closed state to the open state when the hydraulic pressure of the hydraulic oil of the first pipe drops and stops the turbine when it becomes the open state.
A shut-off state that has ports P, T, A and B, respectively, and blocks the passage of hydraulic fluid in both the sections between ports P and A and between ports B and T, and between ports P and A and ports. 1st to 3rd 4-port solenoid valves capable of switching between passing states through which hydraulic oil is passed in both sections between B and T, and each port P is connected to the first pipe. Each port T is connected to the second pipe, and the port A of the first 4-port solenoid valve and the port B of the second 4-port solenoid valve are connected by the first solenoid valve-to-valve pipe. Port A of the second 4-port solenoid valve and port B of the third 4-port solenoid valve are connected by a second solenoid valve-to-valve pipe, and port A of the third 4-port solenoid valve and port B of the first 4 port. The ports B of the solenoid valves are connected by a first solenoid valve pipe, and when the rotational speed of the turbine measured by a separate sensor exceeds the upper limit, the shutoff state is switched to the passing state. It is equipped with a 2oo3 logic circuit consisting of 1st to 3rd 4-port solenoid valves.
A first to third stop valves capable of opening and closing operations are inserted between the first pipe and each port P of the first to third four-port solenoid valves, and the second pipe and the first stop valve are inserted. An emergency stop control device in which a fourth to sixth stop valve capable of opening and closing is inserted between each port T of the first to third four-port solenoid valves. The emergency stop control device according to claim 1, wherein the housing accommodating the first to sixth stop valves is provided with a plug that receives an electric signal for opening and closing the first to sixth stop valves from the outside. The emergency stop control device according to claim 1 or 2, wherein the first to third four-port solenoid valves can be attached to and detached from the housing of the emergency stop control device from the outside.

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