A double pressure maintaining control system and method for a slurry shield tunneling machine

Abstract

The application provides a double pressure maintaining control system and method for a slurry shield tunneling machine, which comprises two control loops; each control loop comprises a pressure maintaining control unit, an air inlet valve and an air outlet valve; the pressure maintaining control unit is connected to and controls the air inlet valve and the air outlet valve in the corresponding control loop, and the air inlet valve and the air outlet valve are communicated with an air cushion bin; the pressure set value of the air cushion bin is adjusted by the pressure maintaining control unit of any control loop, the air inlet valve and the air outlet valve of the corresponding control loop perform air inlet and air outlet on the air cushion bin, and the pressure maintaining control unit of the other control loop is adjusted to the same pressure set value. When the pressure set value of the pressure maintaining control unit of any control loop is set, the pressure value of the other control loop changes accordingly, so that when a fault occurs in one of the loops, the pressure value of the other loop does not need to be set, and the other loop can be quickly switched to continue working, thereby realizing the stability of the tunnel face.

Description

TECHNICAL FIELD

[0001] The application relates to a shield machine, in particular to a pressure maintaining system of a shield machine. BACKGROUND

[0002] With the wide application of the slurry pressure balance shield machine and the complexity of the construction stratum, the control requirement of the pressure maintaining system is higher and higher, and how to quickly adjust the air cushion cabin pressure to balance the face pressure is crucial. In the traditional design, two sets of the same pressure maintaining systems are independent of each other, one set is in operation and the other set is in standby. Although the set pressure can be remotely adjusted, when a fault such as the air inlet and outlet valve of one set of system is suddenly stuck, the pipeline is burst, and the components are damaged occurs in the tunneling process, only adjusting the set pressure cannot meet the changing use condition on site. The construction personnel needs to enter the machine to close the system in operation, start the standby system, and adjust the set pressure to the required working pressure, so that the system can be recovered. In this process, the air cushion cabin and face pressure cannot be adjusted, and if the operation is improper, the risk of ground penetration and settlement will be caused. SUMMARY

[0003] The application aims to provide a slurry shield machine double pressure maintaining control system and method which can quickly switch the operation of two pressure maintaining systems.

[0004] Technical scheme: a slurry shield machine double pressure maintaining control system comprises two control loops.

[0005] Each control loop comprises a pressure maintaining control unit, an air inlet valve and an air outlet valve; the pressure maintaining control unit is connected to and controls the air inlet valve and the air outlet valve in the corresponding control loop, and the air inlet valve and the air outlet valve are communicated with the air cushion cabin.

[0006] The pressure maintaining control unit of any control loop adjusts the air cushion cabin pressure set value, the air inlet valve and the air outlet valve of the corresponding control loop carry out air inlet and outlet on the air cushion cabin, and the pressure maintaining control unit of the other control loop is adjusted to the same pressure set value.

[0007] Further, the two pressure maintaining control units comprise a shared PLC module, a pneumatic stepping motor and a PI controller of each pressure maintaining control unit, the PLC module receives the air cushion cabin pressure set value of any pressure maintaining control unit, controls the action of the pneumatic stepping motor of the corresponding pressure maintaining control unit, and connects and controls the action of the air inlet valve or the air outlet valve through the PI controller.

[0008] Further, each control loop further comprises a pressure sensor connected to the air cushion cabin, and the pressure sensor is connected to the PI controller.

[0009] Further, the PI controller is connected to the PLC module through a piezoelectric conversion module, and the PLC module is further connected to a man-machine interaction display unit.

[0010] Further, the PI controller of each pressure maintaining control unit is connected with the air inlet valve and the air outlet valve through a control valve, and switches the two control loops by opening and closing the control valve.

[0011] Further, a pneumatic valve is arranged on the pipeline connecting the air cushion chamber of the air outlet valve, and the pneumatic valve is connected with the PLC module.

[0012] A double pressure maintaining control method of a slurry shield tunneling machine, when pressure boosting is needed, the pressure value is set by the pressure maintaining control unit of any control loop, the pressure maintaining control unit of the loop controls the air inlet valve to intake air, and the pressure maintaining control unit of the other control loop is adjusted to the same pressure setting value; when pressure reduction is needed, the pressure setting value is set by the pressure maintaining control unit of any control loop, the pressure maintaining control unit of the loop controls the air outlet valve to exhaust air, and the pressure maintaining control unit of the other control loop is adjusted to the same pressure setting value.

[0013] Further, the PLC module receives the pressure setting value of any pressure maintaining control unit, controls the pneumatic stepping motor corresponding to the pressure maintaining control unit to act, and transmits the pressure setting value to the PI controller; the actual pressure value of the air cushion chamber in the corresponding control loop is detected by the pressure sensor and transmitted to the PI controller at the same time, the PI controller compares the pressure setting value and the actual pressure value, and controls the air inlet valve or the air outlet valve in the control loop to intake air or exhaust air; in addition, the PLC module transmits the pressure setting value in the control loop to the pressure maintaining control unit of the other control loop, and adjusts the pressure setting value of the pressure maintaining control unit to the same value.

[0014] Further, the PI controller transmits the pressure setting value and the actual pressure value to the piezoelectric conversion module, the piezoelectric conversion module converts the pressure setting value and the actual pressure value into an electric signal and sends the electric signal to the PLC module, and the PLC module transmits the electric signal to the man-machine interactive display interface for display.

[0015] Further, when any control loop fails, the control valve is switched to the other control loop without failure to boost and reduce pressure.

[0016] Beneficial effects: 1. When the pressure setting value is set by the pressure maintaining control unit of any control loop, the pressure setting value of the other control loop changes accordingly, so when one of the loops fails, the other loop can be quickly switched to continue working, without the need to reset the pressure value of the standby loop, thereby realizing the stability of the working face;

[0017] 2. The present application can realize the mutual switching work of the operator in the driver's room through the switching control of the two control loops, shorten the response time, and reduce the influence of the pressure fluctuation of the working face on the stratum;

[0018] 3. The application also proposes to set a pneumatic valve on the exhaust pipeline, and the pneumatic valve is controlled by the pressure maintaining control unit, and when the slurry level of the air cushion cabin is full, the pneumatic valve is closed to ensure the stability of the pressure of the working face. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a schematic diagram of the double pressure maintaining control system of the application;

[0020] Figure 2 It is a control flow chart of the double pressure maintaining control system of the application;

[0021] Figure 3 It is an electrical schematic diagram of pressure setting;

[0022] Figure 4 It is an electrical schematic diagram of pressure display;

[0023] Figure 5 It is an electrical schematic diagram of the switching of the first pressure maintaining control unit LOOP1 and the second pressure maintaining control unit LOOP2;

[0024] Figure 6 It is an electrical schematic diagram of pressure detection;

[0025] Figure 7 It is a working principle diagram of the pneumatic valve. DETAILED DESCRIPTION

[0026] A double pressure maintaining control system of a slurry shield tunneling machine, as shown in the figure, comprises a first control loop and a second control loop; Figure 1

[0027] The first control loop comprises a first pressure maintaining control unit LOOP1, a first air inlet valve 101, a first air outlet valve 102, a first pressure sensor 103, a first pneumatic valve 104, a first air supply pressure sensor 105, a first air supply flow meter 106, a first pressure reducing valve 107, a first silencer 108, a first pneumatic triplex 109 and a first pneumatic duplex 110. The first air inlet valve 101, the first air outlet valve 102 and the first pressure sensor 103 are all connected to the first pressure maintaining control unit LOOP1.

[0028] ​The first control loop is communicated with the air cushion bin 1. The first air inlet valve 101, the first air supply pressure sensor 105, the first air supply flow meter 106 and the first pressure reducing valve 107 are sequentially arranged on the air inlet pipeline of the first control loop. The first air supply pressure sensor 105 is used for detecting the air supply pressure of the first control loop. The first air supply flow meter 106 is used for detecting the air inlet flow. The first pressure reducing valve 107 is installed on the air supply pipeline and is used for adjusting the pressure of the air supply pipeline. The first pneumatic three-way joint 109 and the first pneumatic two-way joint 110 connected with the first pressure maintaining control unit LOOP1 are further arranged on the air inlet pipeline. The control air source is generally low in pressure and clean. The first pneumatic three-way joint 109 and the first pneumatic two-way joint 110 play the roles of reducing pressure and filtering the air source.

[0029] The first pneumatic valve 104 and the first air outlet valve 102 are arranged on the air outlet pipeline of the first control loop communicated with the air cushion bin 1. The first silencer 108 is arranged on the first air outlet valve 102 and is used for eliminating the noise generated by the air outlet.

[0030] The first pressure sensor 103 arranged in the first control loop of the air cushion bin 1 is used for detecting the actual pressure of the air cushion bin 1.

[0031] The second control loop comprises a second pressure maintaining control unit LOOP2, a second air inlet valve 201, a second air outlet valve 202, a second pressure sensor 203, a second pneumatic valve 204, a second air supply pressure sensor 205, a second air supply flow meter 206, a second pressure reducing valve 207, a second silencer 208, a second pneumatic three-way joint 209 and a second pneumatic two-way joint 210. The connection mode is the same as that of the first control loop.

[0032] The first pressure maintaining control unit LOOP1 and the second pressure maintaining control unit LOOP2 have a common PLC module. The PLC module of the embodiment is selected from a Mitsubishi PLC master module and a Mitsubishi PLC slave module. The man-machine interactive display unit is selected from a Proface man-machine interface. In addition, each pressure maintaining control unit further integrates a DC 24V power supply, a pneumatic stepping motor, a PI controller, a piezoelectric conversion module and a reversing valve. Figure 2As shown, the pneumatic stepper motor and the PI controller in the first control loop are the first pneumatic stepper motor and the first PI controller, and the pneumatic stepper motor and the PI controller in the second control loop are the second pneumatic stepper motor and the second PI controller. When the pressure is increased or decreased in any control loop, on the one hand, the pressure of the air cushion bin is set through the man-machine interaction display unit, the man-machine interaction display unit transmits the pressure set value to the PLC module, the PLC module controls the action of the pneumatic stepper motor of the control loop, and sends the air pressure signal to the PI controller of the control loop; on the other hand, the pressure sensor of the control loop detects the actual pressure value of the air cushion bin 1 and transmits it to the PI controller. The PI controller compares the pressure set value and the actual pressure value, when the pressure set value is less than the actual pressure value, the PI controller controls the exhaust valve of the control loop to act; when the pressure set value is greater than the actual pressure value, the PI controller controls the intake valve of the control loop to act. In addition, the PI controller transmits the air pressure signals of the actual pressure value and the pressure set value to the PLC module through the piezoelectric conversion module to convert them into electric signals, and the PLC module transmits them to the man-machine interaction display unit to display the pressure set value and the actual value. Combined with Figure 4 When the first pressure maintaining control unit LOOP1 controls the increase and decrease of the pressure set value, the piezoelectric conversion modules 4B1 and 4B3 respectively convert the pressure set value and the actual pressure value of the first pressure maintaining control unit LOOP1 into current signals and transmit them to the PLC module, and the PLC module transmits them to the man-machine interaction display unit. When the second pressure maintaining control unit LOOP2 controls the increase and decrease of the pressure set value, the piezoelectric conversion modules 4B2 and 4B4 respectively convert the pressure set value and the actual pressure value of the second pressure maintaining control unit LOOP2 into current signals and transmit them to the PLC module, and the PLC module transmits them to the man-machine interaction display unit.

[0033] As Figure 3As shown, when the pressure set value of the first pressure maintaining control unit LOOP1 is increased, the PLC point Y50 is output, the relay 2K4 is powered on, the relay 2K4 normally open contact is closed, the electromagnetic valve 2Y5 is powered on, the first pneumatic stepper motor is controlled to act, and the first intake valve 101 is opened through the first PI controller to allow the air cushion bin 1 to intake air. When the pressure set value of the first pressure maintaining control unit LOOP1 is decreased, the PLC point Y51 is output, the relay 2K5 is powered on, the relay 2K5 normally open contact is closed, the electromagnetic valve 2Y6 is powered on, the first pneumatic stepper motor is controlled to act, and the air source is connected to the first exhaust valve 102 through the first PI controller to exhaust. Similarly, the second pressure maintaining control unit LOOP2 can also be used to increase and decrease the pressure set value. When the pressure set value is increased, the PLC point Y52 is output, the relay 3K2 is powered on, the relay 3K2 normally open contact is closed, the electromagnetic valve 3Y2 is powered on, the second pneumatic stepper motor is controlled to act, and the second intake valve 201 is opened through the second PI controller to allow the air cushion bin 1 to intake air. When the pressure set value is decreased, the PLC point Y53 is output, the relay 3K3 is powered on, the relay 3K3 normally open contact is closed, the electromagnetic valve 3Y3 is powered on, the second pneumatic stepper motor is controlled to act, and the air source is connected to the second exhaust valve 202 through the second PI controller to exhaust.

[0034] The pressure of the air cushion bin 1 is adjusted by the first pressure maintaining control unit LOOP1 or the second pressure maintaining control unit LOOP2. The intake valve and the exhaust valve of the unit allow the air cushion bin 1 to intake and exhaust air. The pressure set value of the pressure maintaining control unit of the other control loop is adjusted to the corresponding pressure value.

[0035] For example, when the first pressure maintaining control unit LOOP1 is used, the PLC module receives the pressure set value of the unit set in the human-computer interaction display unit, sends a control signal to control the first pneumatic stepper motor to act, and controls the first intake valve or the first exhaust valve to act through the judgment of the first PI controller. At the same time, the PLC module compares the current pressure set values of the first pressure maintaining control unit LOOP1 and the second pressure maintaining control unit LOOP2, and if there is a difference, the PLC module sends a control signal to adjust the loop2 system pressure set value, and the loop2 system only performs the set value following action without valve action.

[0036] Specifically, when the first pressure maintaining control unit LOOP1 set value increases or decreases, the PLC module compares the pressure set value of the second pressure maintaining control unit LOOP2 with the first pressure maintaining control unit LOOP1, and if LOOP2 is less than the pressure set value of LOOP1, the PLC module outputs a signal for increasing the pressure set value of LOOP2, the PLC point Y52 outputs, the relay 3K2 is powered on, the normally open contact of the relay 3K2 is closed, the electromagnetic valve 3Y2 is powered on, the second pneumatic stepper motor is controlled to act, the gas source enters the second PI controller, the adjusted pressure set value of LOOP2 is transmitted to the man-machine interactive display unit through the piezoelectric conversion module 4B2, so as to be consistent with the pressure set value of LOOP1, but the intake valve and the exhaust valve are not controlled; at the same time, the gas pressure signal is converted into a current signal by the piezoelectric conversion module 4B2, and transmitted to the PLC module and compared with the set value of LOOP1 again, if LOOP2 is greater than the set value of LOOP1, the PLC point Y53 outputs, the relay 3K3 is powered on, the normally open contact of the relay 3K3 is closed, the electromagnetic valve 3Y3 is powered on, the second pneumatic stepper motor is controlled to act, the gas source enters the second PI controller, the adjusted pressure set value of LOOP2 is transmitted to the man-machine interactive display unit through the piezoelectric conversion module 4B2, so as to be consistent with the pressure set value of LOOP1, but the intake valve and the exhaust valve are not controlled; at the same time, the gas pressure signal is converted into a current signal by the piezoelectric conversion module 4B2, and transmitted to the PLC module and compared with the set value of LOOP1 again, and the cycle is repeated until the set value of LOOP2 is equal to the set value of LOOP1 or within the error range.

[0037] When the pressure value of the second pressure maintaining control unit LOOP2 is set, the set value of LOOP1 will also be adjusted following the set value of LOOP2, and the same applies.

[0038] The switching electrical principle of the first pressure maintaining control unit LOOP1 and the second pressure maintaining control unit LOOP2 can be realized by using a two-position four-way reversing valve, which corresponds to the intake and exhaust valves of the two pressure maintaining control units. When one of the pressure maintaining control units is used for intake or exhaust, the two channels in the two-position four-way reversing valve corresponding to the intake and exhaust valves in the unit are opened, and the intake and exhaust valve channels corresponding to the other pressure maintaining control unit are closed. When a fault occurs, the two-position four-way reversing valve opens the intake and exhaust valve channels corresponding to the non-fault unit, and switches the system to work. As shown in Figure 5 Figure 2 ​, shield machine normal tunneling, so when using LOOP1 set and adjust the pressure value, while, LOOP2 pressure set value follow-up adjustment, until the pressure set value and LOOP1 system pressure set value is the same or within the error range; if LOOP1 at this time has a fault, PLC point Y55 output, relay 2K3 get electricity, relay 2K3 normally open contact closure, LOOP2 system reversing valve 2Y4 get electricity, will keep the system switched to LOOP2 system work, maintain the stability of the working face; switch LOOP1 system work, the principle is the same, do not repeat here.

[0039] The gas supply pressure detection electrical principle of the pressure maintaining control unit is shown in Figure 6 , in combination with Figure 3 , the first gas supply pressure sensor 105 is installed on the gas supply pipeline to detect the gas source pressure. If the LOOP1 system gas source pressure is low at this time, the pressure value measured by the first gas supply pressure sensor 105 is converted into a current signal and sent to the PLC module, and compared with the pressure alarm value set in the PLC module. If it is lower than the pressure alarm value set in the PLC module, the PLC module outputs an alarm, and the alarm device alarms and buzzes. At the same time, the human-computer interaction display unit displays the low gas supply pressure alarm lamp in red. The operator can mute the alarm through the mute button. This function is only used for muting and reducing noise. After the low pressure alarm is eliminated, the low gas supply pressure alarm lamp returns to black. When the LOOP2 system gas source pressure is low, the alarm mute principle is the same, and will not be repeated here.

[0040] The exhaust valve principle of the pressure maintaining control unit is shown in Figure 7 . In the construction of the shield machine, if the gas cushion bin 1 is full of mud liquid level, the pressure maintaining control unit loses control, the first pneumatic valve 104 and the second pneumatic valve 204 can be manually closed. The PLC module point Y4E, Y4F outputs, relay 20K1, 20K5 gets electricity, relay 20K1, 20K5 normally open contact closure, 20Y2, 20Y5 coil corresponding to the first pneumatic valve 104 and the second pneumatic valve 204 gets electricity, controls the pneumatic valve to close, and the valve closed signal XD, XF is fed back to the PLC module, preventing mud from being sprayed into the shield machine shield, while ensuring the stability of the working face pressure. If the first pneumatic valve 104 and the second pneumatic valve 204 need to be opened, the valve opening signal XC, XE is fed back to the PLC module.

Claims

1. A dual-pressure-maintaining control system for a slurry shield tunneling machine, characterized in that: Two control circuits are included; each control circuit includes a pressure maintaining control unit, an air inlet valve and an air outlet valve; the pressure maintaining control unit is connected to and controls the air inlet valve and the air outlet valve in the corresponding control circuit, and the air inlet valve and the air outlet valve are communicated with the air cushion bin; the pressure maintaining control unit of any control circuit adjusts the pressure set value of the air cushion bin, and the air inlet valve and the air outlet valve of the corresponding control circuit perform air inlet and air outlet on the air cushion bin, and the pressure maintaining control unit of the other control circuit adjusts to the same pressure set value, The two pressure maintaining control units include a shared PLC module, a pneumatic stepping motor and a PI controller of each pressure maintaining control unit, the PLC module receives the pressure set value of any pressure maintaining control unit, controls the action of the pneumatic stepping motor of the corresponding pressure maintaining control unit, and connects and controls the action of the air inlet valve or the air outlet valve through the PI controller, The PI controller of each pressure maintaining control unit is connected to the air inlet valve and the air outlet valve through a control valve, and realizes the switching of the two control circuits by opening and closing the control valve.

2. The slurry shield machine double pressure-keeping control system according to claim 1, characterized in that: Each control circuit further includes a pressure sensor connected to the air cushion bin, and the pressure sensor is connected to the PI controller.

3. The slurry shield machine double pressure-keeping control system according to claim 1 or 2, characterized in that: The PI controller is connected to the PLC module through a piezoelectric conversion module, and the PLC module is further connected to a man-machine interaction display unit.

4. The slurry shield machine double pressure control system of claim 1, wherein: The pipeline through which the air outlet valve communicates with the air cushion bin is provided with a pneumatic valve, and the pneumatic valve is connected to the PLC module.

5. A method for twin pressure control of a slurry shield tunneling machine, characterized in that: If pressure boosting is needed, the pressure value is set by the pressure maintaining control unit of any control circuit, the pressure maintaining control unit of this circuit controls the air inlet valve to perform air inlet, and the pressure maintaining control unit of the other control circuit adjusts to the same pressure set value; if pressure reduction is needed, the pressure set value is set by the pressure maintaining control unit of any control circuit, the pressure maintaining control unit of this circuit controls the air outlet valve to perform air outlet, and the pressure maintaining control unit of the other control circuit adjusts to the same pressure set value, The two pressure maintaining control units include a shared PLC module, a pneumatic stepping motor and a PI controller of each pressure maintaining control unit, the PLC module receives the pressure set value of any pressure maintaining control unit, controls the action of the pneumatic stepping motor of the corresponding pressure maintaining control unit, and transmits the pressure set value to the PI controller; the actual pressure value of the air cushion bin is detected by the pressure sensor in the corresponding control circuit and is transmitted to the PI controller at the same time, the PI controller compares the pressure set value and the actual pressure value, and controls the air inlet valve or the air outlet valve in this control circuit to perform air inlet or air outlet; in addition, the PLC module transmits the pressure set value in this control circuit to the pressure maintaining control unit of the other control circuit, and adjusts the pressure set value of the other control circuit to the same value.

6. The slurry shield double pressure control method according to claim 5, wherein: The PI controller transmits the pressure set value and the actual pressure value to the piezoelectric conversion module, the piezoelectric conversion module converts the signal into an electric signal and sends it to the PLC module, and the PLC module transmits it to the man-machine interaction display interface for display.

7. The slurry shield double pressure control method according to claim 5, wherein: If any control circuit fails, the control valve is switched to the other control circuit without failure to perform pressure boosting and pressure reduction operations.

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