Mechanical interrupting device for quick closing of unit

Abstract

The invention relates to a mechanical interruption device for quick closing of a unit. A fly ball mechanism is mounted on a rotor of a rotating machine, a lifting hook is arranged above the fly ball mechanism, hinged to the lower end of a shell and capable of rotating after being impacted by the fly ball mechanism, and the lower end of an impact rod is connected with the lifting hook and can be jacked up by the rotating lifting hook; the upper end of the impact rod is connected with the first transmission rod through the second transmission rod, the second transmission rod is sleeved with the buffer spring, one end of the connecting rod is hinged to the first transmission rod, the other end of the connecting rod is connected with the LVDT sensor, the piston rod is arranged in the shell and located above the first transmission rod, the piston rod is sleeved with the reset spring, and the two ends of the reset spring abut against the shell and the piston rod respectively. As a pure mechanical structure, the device can be effectively used for quick closing of a unit. Compared with a traditional structure, the device has fewer external connection interfaces, the LVDT installation interface is additionally arranged, the state of the interrupting mechanism can be observed through electric signals, and the intelligent degree of the steam turbine is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of safety protection of rotating mechanical equipment, and in particular to a fast-closing mechanical tripping device for units such as steam turbines and gas turbines. Background Art

[0002] Mechanical trip devices are key to ensuring the safe operation of industrial equipment. When a mechanical system loses speed control due to control failure, sudden load changes, or abnormal power, the mechanical overspeed protection device can quickly trigger a shutdown, preventing catastrophic consequences such as rotor fracture and bearing damage caused by overspeeding.

[0003] Compared with the electronically controlled safety system, the mechanical shut-off device has the characteristics of high reliability, strong anti-interference and simple structure. It is the last line of defense to prevent equipment from speeding.

[0004] Figure 1 The structure of a traditional mechanical tripping device is described in [1]. It consists of a housing, piston rod, tension spring, hook, and flyweight mechanism. The flyweight is mounted on the rotor of a rotating machine. When the rotating machine's speed is too high, the flyweight is ejected by centrifugal force, causing the hook to rotate and the tension spring to pull the piston rod downward.

[0005] Figure 2 The interface names of traditional mechanical isolation devices are given in the table. Traditional mechanical isolation devices have three interfaces: the hydraulic oil inlet, the hydraulic oil return port, and the safety valve oil port. The hydraulic oil inlet connects to the high-pressure oil pipeline outlet, the hydraulic oil station return port connects to the high-pressure oil pipeline inlet, and the safety valve oil port connects to the safety valve, which controls the regulating valve oil motor.

[0006] Figure 3 Two working states of the traditional mechanical interrupting device are given in FIG.

[0007] When not overspeeding, the hydraulic oil inlet is connected to the hydraulic oil return port. After overspeeding, the tension spring pulls the piston rod downward, and the hydraulic oil inlet is connected to the safety device oil port, and the hydraulic oil enters the safety device, causing the unit to shut down.

[0008] Traditional mechanical interrupters are widely used in rotating machinery. Although they have the characteristics of high stability, they also have the following disadvantages:

[0009] (1) With traditional mechanical shutoff mechanisms, it is impossible to tell from the outside whether the piston rod is moving;

[0010] (2) The traditional mechanical shutoff mechanism has three interfaces, which is too many;

[0011] (3) Due to its purely mechanical structure, the traditional mechanical shut-off mechanism cannot send out an electrical signal after it is actuated and can only be determined by the valve motion state.

[0012] In the prior art, for example, the centrifugal diesel engine emergency shutdown device disclosed in patent document CN117404188A uses a mechanical structure to achieve overspeed shutdown, but relies on camshaft drive, has many components (fly hammer housing, locking rod, actuator piston, etc.), has a complex structure and is only applicable to diesel engine fuel systems, and has insufficient interface and signal feedback design; the symmetrical double fly hammer emergency shutoff device in patent document CN201074530Y is designed for TRT devices, relies on oil pressure control, has many interfaces and no electrical signal output, and is limited in applicable scenarios; the mechanical overspeed shutoff device in patent document CN208564651U is mainly used in test scenarios, requires manual adjustment, relies on a hydraulic slide valve structure, is easily affected by impurities and affects reliability, and does not solve the problems of status visualization and electrical signal feedback.

[0013] Therefore, there is an urgent need for a mechanical tripping device with a simplified structure, streamlined interfaces, status monitoring, and adaptability to a variety of units. Summary of the Invention

[0014] This invention proposes a mechanical tripping device for rapid unit shutdown, aiming to address the complex interfaces, invisible status, and lack of electrical signal feedback associated with conventional devices, while also improving structural reliability and adaptability. This device utilizes a purely mechanical structure, making it effective for rapid unit shutdown. Compared to conventional structures, this design features fewer external connections and incorporates an LVDT mounting interface, enabling monitoring of the tripping mechanism's status via electrical signals, thereby enhancing the intelligence of the steam turbine.

[0015] To achieve the above-mentioned purpose, the technical solution of the present invention is: a mechanical shut-off device for quick shutdown of a unit, comprising a housing, a piston rod, a return spring, a first transmission rod, a connecting rod, a buffer spring, a second transmission rod, an impact rod, a hook and a fly hammer mechanism. The fly hammer mechanism is installed on the rotor of the rotating machinery. The hook is arranged above the fly hammer mechanism and is hinged to the lower end of the housing. It can be rotated after being hit by the fly hammer mechanism. The lower end of the impact rod is connected to the hook and can be lifted up by the rotating hook. The upper end of the impact rod is connected to the first transmission rod through the second transmission rod. The buffer spring is sleeved on the outside of the second transmission rod. One end of the connecting rod is hinged to the first transmission rod, and the other end is connected to the LVDT sensor. The piston rod is arranged in the housing and is located above the first transmission rod. A return spring is sleeved on the outside of the piston rod, and the two ends of the return spring respectively abut the housing and the piston rod.

[0016] Furthermore, the fly hammer mechanism includes a fly hammer body, a fly hammer spring and an adjustment seat. The fly hammer body is slidably arranged in the adjustment seat. One end of the fly hammer spring is connected to the fly hammer body and the other end is fixed to the adjustment seat. Under the action of centrifugal force, the fly hammer body overcomes the elastic force of the fly hammer spring and extends outward to hit the hook.

[0017] Furthermore, a threaded hole is provided on the adjustment seat, and the preload force of the fly hammer spring can be changed by rotating the adjustment seat, thereby adjusting the action speed threshold of the fly hammer body.

[0018] Furthermore, an LVDT mounting interface is provided at one end of the connecting rod away from the first transmission rod, and the LVDT sensor is fixed through the interface and can detect the displacement of the connecting rod.

[0019] Furthermore, two ends of the buffer spring respectively abut against the limiting boss of the second transmission rod and the bottom wall of the shell, so as to buffer the upward movement impact force of the second transmission rod.

[0020] Furthermore, the hook is hinged to the inside of the shell through a pin shaft, one end of the hook is a striking part, and the other end is a driving part. After the striking part is struck by the hammer body, the driving part rotates upward to lift the impact rod.

[0021] Furthermore, an impact head is provided at the upper end of the first transmission rod, and an impact platform is provided at the lower end of the piston rod. When the first transmission rod moves upward, the impact head pushes the piston rod to move synchronously.

[0022] Furthermore, a sealing ring is provided on the piston rod for forming a sealed hydraulic cavity inside the housing to ensure the sealing of the hydraulic oil passage switching.

[0023] Furthermore, the shell is provided with two interfaces, namely the hydraulic oil inlet and the safety device oil outlet. When there is no overspeed, the hydraulic oil inlet is connected to the oil return channel in the shell. When there is overspeed, the piston rod moves to connect the hydraulic oil inlet with the safety device oil outlet.

[0024] A mechanical tripping method for rapid shutdown of a unit, using the aforementioned mechanical tripping device for rapid shutdown of a unit, comprising:

[0025] (1) When not in overspeed state, the fly hammer body remains contracted under the constraint of the fly hammer spring, the hook is in the initial position, the impact rod, the second transmission rod, and the first transmission rod are all in the low position, and the piston rod blocks the connection between the hydraulic oil inlet and the safety device oil port under the action of the return spring, and the hydraulic oil returns through the return oil channel;

[0026] (2) When the speed exceeds the design speed, the hammer body flies out under the action of centrifugal force and hits the hook. The hook rotates to lift the impact rod, which in turn drives the second transmission rod and the first transmission rod to move upward. The first transmission rod pushes the piston rod to overcome the elastic force of the return spring and move upward, so that the hydraulic oil inlet is connected to the oil outlet of the safety device. The high-pressure oil enters the safety device and triggers the unit to quickly close. At the same time, the movement of the first transmission rod drives the connecting rod to move synchronously. The LVDT sensor detects the displacement of the connecting rod and outputs an electrical signal to the control system, which provides real-time feedback on the action status of the device.

[0027] Compared with the mechanical blocking device of the prior art, the present invention has the following beneficial effects:

[0028] (1) The mechanical interrupter mechanism of the present invention can determine whether the mechanical interrupter is actuated by the LVDT connecting rod status;

[0029] (2) The mechanical shutoff mechanism of the present invention has fewer interfaces than the traditional mechanical shutoff mechanism, and the external pipeline connection is simpler;

[0030] (3) After the mechanical interrupter mechanism of the present invention is actuated, the LVDT connecting rod can send out a position signal, and the state of the interrupter can be determined on the control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the structure of a traditional mechanical interrupting device;

[0032] Figure 2 This is the interface name of the traditional mechanical interrupter device;

[0033] Figure 3 Two state diagrams of traditional mechanical interrupting device;

[0034] Among them: (a) the state when not exceeding the speed limit; (b) the state when exceeding the speed limit;

[0035] Figure 4 This is a schematic structural diagram of a shutoff device for rapid shutdown of a unit according to the present invention;

[0036] Figure 5 Two state diagrams of the shutoff device for quick shutdown of a unit according to the present invention;

[0037] Among them: (a) the state when not exceeding the speed limit; (b) the state when exceeding the speed limit.

[0038] In the figure: 1-housing, 2-piston rod, 3-return spring, 4-first transmission rod, 5-connecting rod, 6-buffer spring, 7-second transmission rod, 8-impact rod, 9-hook, 10-flying hammer mechanism, 11-hydraulic oil inlet, 12-safety device oil outlet. DETAILED DESCRIPTION

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0040] like Figure 4 As shown, an embodiment of the present invention provides a shut-off device for quick shutdown of a unit, comprising a housing 1, a piston rod 2, a return spring 3, a first transmission rod 4, a connecting rod 5, a buffer spring 6, a second transmission rod 7, an impact rod 8, a hook 9, a flying hammer mechanism 10, and an LVDT sensor.

[0041] The fly hammer mechanism 10 is installed on the rotor of the rotating machinery. The hook 9 is arranged corresponding to the fly hammer mechanism 10 and can be rotated after being hit by the fly hammer mechanism 10. The lower end of the impact rod 8 is connected to the hook 9 and can be lifted up by the rotating hook 9. The lower end of the second transmission rod 7 is connected to the upper end of the impact rod 8. The buffer spring 6 is mounted on the outside of the second transmission rod 7. The lower end of the first transmission rod 4 is connected to the upper end of the second transmission rod 7. One end of the connecting rod 5 is hinged to the first transmission rod 4 and the other end can be connected to the LVDT sensor. The piston rod 2 is arranged in the housing 1 and is located above the first transmission rod 4. The reset spring 3 is mounted on the outside of the piston rod 2 and its two ends respectively abut the housing 1 and the piston rod 2.

[0042] The flyweight mechanism 10 includes a flyweight body, a flyweight spring, and an adjustment seat. The flyweight body slides within the adjustment seat. One end of the flyweight spring is connected to the flyweight body, and the other end is fixed to the adjustment seat. The adjustment seat has a threaded hole and is threadedly connected to the rotor sleeve. Rotating the adjustment seat changes the spring preload, thereby setting the actuation speed threshold.

[0043] The hook 9 is hinged to the inner wall of the shell 1 through a pin shaft. One end of the hook 9 is a striking part and the other end is a driving part. After the striking part is struck by the hammer body, the driving part rotates upward to lift the impact rod 8.

[0044] Two ends of the buffer spring 6 respectively abut against the limiting boss of the second transmission rod 7 and the bottom wall of the housing, so as to buffer the upward movement impact force of the second transmission rod 7 .

[0045] An impact head is provided at the upper end of the first transmission rod 4, and an impact platform is provided at the lower end of the piston rod. When the first transmission rod 4 moves upward, the impact head pushes the piston rod to move synchronously.

[0046] An LVDT mounting interface is provided at one end of the connecting rod 5 away from the first transmission rod 4 , and the LVDT sensor is fixed through the interface and can detect the displacement of the connecting rod 5 .

[0047] A sealing ring is provided on the piston rod 2 to form a sealed hydraulic cavity inside the housing 1 to ensure the sealing of the hydraulic oil passage switching.

[0048] There are two interfaces on the housing 1, namely the hydraulic oil inlet 11 and the safety oil port 12. When there is no overspeed, the hydraulic oil inlet is connected to the oil return channel in the housing. Figure 5 (a); when overspeeding, the piston rod moves to connect the hydraulic oil inlet with the safety device oil port; see Figure 5 (b).

[0049] When installing the device of the present invention, the fly hammer mechanism is installed on the rotor of the rotating machinery, the mechanical shutoff structure housing is installed on the rotating machinery housing, and the remaining equipment is installed in the housing to complete the installation of the mechanical shutoff device of the present invention.

[0050] A mechanical tripping method for rapid shutdown of a unit, using the aforementioned tripping device for rapid shutdown of a unit, comprising:

[0051] When not in overspeed state, the fly hammer body remains contracted under the constraint of the fly hammer spring, the hook is in the initial position, the impact rod, the second transmission rod and the first transmission rod are all in the low position, and the piston rod blocks the connection between the hydraulic oil inlet and the safety device oil outlet under the action of the return spring, and the hydraulic oil flows back through the return oil channel.

[0052] When the speed exceeds the design speed (the speed of the unit exceeds the threshold), the hammer body flies out under the action of centrifugal force and hits the hook. The hook rotates to lift the impact rod, which drives the second transmission rod and the first transmission rod to move upward in turn. The first transmission rod pushes the piston rod to overcome the elastic force of the return spring and move upward, so that the hydraulic oil inlet is connected to the safety device oil port. The high-pressure oil enters the safety device and triggers the unit speed shutdown. Figure 3 (b); At the same time, when the first transmission rod moves, it drives the connecting rod to move synchronously. The LVDT sensor detects the displacement of the connecting rod and outputs an electrical signal to the control system, providing real-time feedback on the device's operating status.

Claims

1. A mechanical tripping device for rapid shutdown of a unit, characterized in that: It includes a shell, a piston rod, a return spring, a first transmission rod, a connecting rod, a buffer spring, a second transmission rod, an impact rod, a hook and a fly hammer mechanism. The fly hammer mechanism is installed on the rotor of the rotating machinery. The hook is arranged above the fly hammer mechanism and is hinged to the lower end of the shell. It can be rotated after being hit by the fly hammer mechanism. The lower end of the impact rod is connected to the hook and can be lifted up by the rotating hook. The upper end of the impact rod is connected to the first transmission rod through the second transmission rod. The buffer spring is sleeved on the outside of the second transmission rod. One end of the connecting rod is hinged to the first transmission rod, and the other end is connected to the LVDT sensor. The piston rod is arranged in the shell and is located above the first transmission rod. The return spring is sleeved on the outside of the piston rod, and the two ends of the return spring are respectively against the shell and the piston rod.

2. The mechanical shutoff device for rapid shutdown of a unit according to claim 1, characterized in that: The fly hammer mechanism includes a fly hammer body, a fly hammer spring and an adjustment seat. The fly hammer body is slidably arranged in the adjustment seat. One end of the fly hammer spring is connected to the fly hammer body and the other end is fixed to the adjustment seat. Under the action of centrifugal force, the fly hammer body overcomes the elastic force of the fly hammer spring and extends outward to hit the hook.

3. The mechanical shutoff device for rapid shutdown of a unit according to claim 2, characterized in that: The adjusting seat is provided with a threaded hole, and the preload force of the fly hammer spring can be changed by rotating the adjusting seat, thereby adjusting the action speed threshold of the fly hammer body.

4. The mechanical shutoff device for rapid shutdown of a unit according to claim 1, characterized in that: An LVDT mounting interface is provided at one end of the connecting rod away from the first transmission rod, and the LVDT sensor is fixed through the interface and can detect the displacement of the connecting rod.

5. The mechanical shutoff device for rapid shutdown of a unit according to claim 1, characterized in that: The two ends of the buffer spring respectively abut against the limiting boss of the second transmission rod and the bottom wall of the shell, and are used to buffer the upward movement impact force of the second transmission rod.

6. The mechanical shutoff device for rapid shutdown of a unit according to claim 1, characterized in that: The hook is hinged to the inside of the shell through a pin shaft. One end of the hook is a striking part and the other end is a driving part. After the striking part is struck by the fly hammer, the driving part rotates upward to lift the impact rod.

7. The mechanical shutoff device for rapid shutdown of a unit according to claim 1, characterized in that: The upper end of the first transmission rod is provided with an impact head, and the lower end of the piston rod is provided with an impact platform. When the first transmission rod moves upward, the impact head pushes the piston rod to move synchronously.

8. The mechanical shutoff device for rapid shutdown of a unit according to claim 1, characterized in that: The piston rod is provided with a sealing ring for forming a sealed hydraulic cavity inside the housing to ensure the sealing of the hydraulic oil passage switching.

9. The mechanical shutoff device for rapid shutdown of a unit according to claim 1, characterized in that: The housing is provided with two interfaces, namely a hydraulic oil inlet and a safety device oil outlet. When not overspeeding, the hydraulic oil inlet is connected to the oil return channel in the housing. When overspeeding, the piston rod moves to connect the hydraulic oil inlet with the safety device oil outlet.

10. A mechanical tripping method for rapid shutdown of a unit, using the mechanical tripping device for rapid shutdown of a unit according to any one of claims 1 to 9, characterized in that: include: (1) When not in overspeed state, the fly hammer body remains contracted under the constraint of the fly hammer spring, the hook is in the initial position, the impact rod, the second transmission rod, and the first transmission rod are all in the low position, and the piston rod blocks the connection between the hydraulic oil inlet and the safety device oil port under the action of the return spring, and the hydraulic oil returns through the return oil channel; (2) When the speed exceeds the design speed, the hammer body flies out under the action of centrifugal force and hits the hook. The hook rotates to lift the impact rod, which in turn drives the second transmission rod and the first transmission rod to move upward. The first transmission rod pushes the piston rod to overcome the elastic force of the return spring and move upward, so that the hydraulic oil inlet is connected to the oil outlet of the safety device. The high-pressure oil enters the safety device and triggers the unit to quickly close. At the same time, the movement of the first transmission rod drives the connecting rod to move synchronously. The LVDT sensor detects the displacement of the connecting rod and outputs an electrical signal to the control system, which provides real-time feedback on the action status of the device.

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