Tunnel boring machine with a device for detecting the content of critical gases

Abstract

In a device for detecting the content of critical gases in a cavity, in particular in the excavation chamber of a tunnel boring machine, there is a separation module (224), by means of which solid and liquid components can be largely removed from a fluid introduced via a withdrawal line connection (203). A gas line device (236) downstream of the separation module (224) in the flow direction of the fluid guides the fluid, which still essentially only has a gaseous component, mainly through a pressure reducer (239) and a flow control valve (251) of a metering module (240), by means of which the gas to be analyzed can be supplied to a gas analysis unit (133) in a controlled manner even when high pressure is present in the cavity, the supply being advantageously assisted by a double membrane pump (245) and a pressure stabilizer (248).

Description

Technical Field

[0001] The invention relates to a tunnel boring machine. Background Art

[0002] Such a tunnel boring machine is known from document JP 2678563 B2. This type of tunnel boring machine has an installation with a withdrawal line which is fluidically connected to a cavity located behind the cutting wheel. On the side opposite the cavity, the withdrawal line is connected to a separation module, by means of which the gas to be detected can be separated from the fluid. The separated gas can be conveyed to a gas analysis unit downstream of the separation module, by means of which a warning message can be triggered, for example an alarm in the event of critical gas conditions.

[0003] A further tunnel boring machine with a device for detecting the content of critical gases is known from the document JP2004-300721A. This known device has a separation module for separating the gas to be detected from the fluid taken from the output unit and a metering module arranged downstream of the separation module for controllably applying the separated gas to a gas analysis unit. In the known device, the gas to be detected is separated by changing the pressure conditions in a gas-liquid mixture with solid components. In order to detect the content of critical, in particular explosive gases such as methane, it is provided that the gas portion separated from the mixture is transferred to the gas analysis unit.

[0004] Documents US2018 / 0171786 A1 and WO 2019 / 143362 A1 disclose a device for analyzing gas extracted from a fluid from a wellbore, wherein there is a separation module for separating the gas to be detected from the fluid and a metering module, a pressure reducer and a flow regulating valve arranged downstream of the separation module for controllably applying the separated gas to a gas analysis unit. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a tunnel boring machine of the type mentioned above, which is characterized in that even under severe and in some cases rapidly and strongly changing tunneling conditions, the content of critical gas in the cavity behind the cutting wheel, which is under relatively high pressure but is also subject to pressure fluctuations, in particular strong pressure drops, can be detected with an accuracy at least sufficient to report a danger.

[0006] The technical problem is solved according to the present invention by a tunnel boring machine, which has a device for detecting the content of critical gas in a cavity, wherein the cavity is located on the rear side of the cutting wheel, and the tunnel boring machine has an extraction pipeline, which extends between an excavation chamber serving as the cavity and the device, and the device has a separation module for separating the gas to be detected from the fluid and a gas analysis unit arranged downstream of the separation module, wherein it is provided that a metering module is arranged downstream of the separation module, the metering module is used to controllably apply the separated gas to the gas analysis unit, the metering module has a pressure reducer and a flow regulating valve arranged downstream of the pressure reducer, and there is a double diaphragm pump, which is connected downstream of the pressure reducer.

[0007] In the tunnel boring machine according to the invention, the metering module has a pressure reducer and a flow control valve arranged downstream of the pressure reducer, and a double membrane pump is provided downstream of the pressure reducer, whereby the high pressure can be reduced in a controlled manner, but the flow rate of the separated gas applied to the gas analysis unit, which is important for sufficiently reliable detection of the critical gas content, can still be regulated and maintained sufficiently accurately during the pressure drop.

[0008] In an advantageous embodiment, it is provided that the two diaphragms of the double diaphragm pump are positively coupled to one another and that they can be actuated alternately by means of pressurized control air by means of a magnetically operated switch via a control air line.

[0009] In an advantageous embodiment, the double membrane pump is connected to a first throttle valve and a second throttle valve, the openings of which can be adjusted to relatively small values, so that the air required to release the membranes for pressure relief escapes only with considerable delay into the environment.

[0010] In an advantageous embodiment, it is further provided that a pressure stabilizer is present, which is arranged between the double membrane pump and the flow control valve.

[0011] In an advantageous embodiment, it is further provided that the flow control valve is a needle valve.

[0012] In an advantageous embodiment, it is further provided that a volume flow measuring module is present, which is arranged downstream of the flow control valve.

[0013] In an advantageous design, it is further provided that a Y-shaped branch line is present downstream of the pressure reducer, the Y-shaped branch line being asymmetrical with respect to the divided volume flow, the Y-shaped branch line having a main branch arranged downstream and a bypass branch arranged downstream, and the volume flow measuring module being arranged in the main branch downstream of the Y-shaped branch line.

[0014] In an advantageous embodiment, it is further provided that a bypass filter module is arranged in the bypass.

[0015] In an advantageous embodiment, it is further provided that the flow control valve is arranged between the pressure reducer and the Y-branch.

[0016] In an advantageous embodiment, it is further provided that the flow control valve is arranged downstream of the Y-shaped branch line in the main branch.

[0017] In an advantageous embodiment, it is further provided that a main flow filter module is present in the main branch between the Y-shaped branch line and the flow control valve.

[0018] In an advantageous embodiment, it is further provided that a gas analysis unit is present, which is arranged downstream of the bypass and is provided for detecting explosive gases.

[0019] In an advantageous design, it is further provided that the double diaphragm pump is capable of resisting abrasive components in the fluid and is connected to the first throttle valve and the second throttle valve and can be supplied with pressurized control air from a control air line via the magnetically controlled switch, wherein, if necessary, the pressure of the fluid downstream of the double diaphragm pump in the flow direction can be increased to a certain overpressure via the double diaphragm pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Further advantageous embodiments and advantages of the present invention are apparent from the following description of exemplary embodiments of the present invention with reference to the attached drawings.

[0021] In the attached picture:

[0022] Figure 1 shows a greatly simplified side view of an embodiment of a tunnel boring machine according to the invention, which has an embodiment of the device according to the invention;

[0023] Figure 2 Show according to Figure 1 A perspective view of an embodiment of the device according to the invention, in which the front side accessible to an operator during operation and the gas analysis unit can be seen;

[0024] Figure 3 Show according to Figure 2 A perspective view of an embodiment of the invention, wherein the rear side facing away from the front side can be seen; and

[0025] Figure 4 A perspective view showing another embodiment of the device according to the invention is shown, in which the Figure 3 The rear side corresponds to the illustration. DETAILED DESCRIPTION

[0026] Figure 1An embodiment of a tunnel boring machine 103 according to the invention is shown in a greatly simplified side view. The tunnel boring machine 103 has a cutting wheel 106 at the front end in the direction of excavation, which can be rotated by a drive unit 109 and is equipped with excavation tools 115 adapted to the exposed geology in order to excavate material on a working face 112.

[0027] On the side of the cutting wheel 106 facing away from the working face 112, there is an excavation chamber 118 as a cavity, which can be under a pressure of several thousand hectopascals (hPa), especially in the case of an excavation method operating under pressure support. The material excavated from the working face 112 and conveyed into the excavation chamber 118 can be removed by a conveying unit 121, which is equipped with a screw conveyor, for example.

[0028] In the embodiment according to the invention, the extraction line 124 opens with one end into the excavation chamber 118 into the upper region of the excavation chamber which is mainly free of liquid and solids, and the excavation chamber is sealed with respect to the passage of the extraction line 124. The extraction line 124 is connected to a fluid treatment unit 127 with its end facing away from the excavation chamber 118. Thus, the fluid present in the extraction region in the excavation chamber 118 can be conveyed to the fluid treatment unit 127 via the extraction line 124, which fluid has liquid and solid components in addition to gas components due to the harsh excavation conditions. The fluid treatment unit 127 is connected to a gas analysis unit 133 via a measurement gas transmission line 130. Both the fluid treatment unit 127 and the gas analysis unit 133 are connected to a discharge line 136, via which the fluid extracted from the excavation chamber 118 via the extraction line 124 can be discharged with its individual components from a tunnel space 139 located behind the working face 112.

[0029] Figure 2 A perspective view showing the structure of a fluid treatment unit 127 of an embodiment of an apparatus according to the invention, in which the front side accessible to an operator during normal operation can be seen, the apparatus being typically used, for example, by means of Figure 1 In the tunnel boring machine 103 described. Figure 2 The fluid processing unit 127 is designed to have an extraction pipeline connector 203 on the inlet side. Figure 1 In Figure 2 The withdrawal line 124, which is not shown for the sake of clarity, can be connected to the withdrawal line connection in a pressure-tight manner. The withdrawal line connection 203 is connected to the input section of the fluid mixture line device 206, on which an air connection 209, a test gas connection 212, a maintenance connection 215 and a water connection 218 are also installed. A water line device 221 is connected to the water connection 218, through which water can be supplied to the fluid mixture line device 206 as required.

[0030] In the fluid mixture pipeline device 206, a separation module 224 is integrated, which is arranged downstream of the extraction pipeline connection 203 and the further connections 209, 212, 215, 218 in the flow direction of the fluid introduced through the extraction pipeline connection 203. In this embodiment, the separation module has two separators 227, 230 connected in series. The separators 227, 230 are suitably configured for continuous coarse separation and subsequent fine separation and work under the action of gravity. Solid components and liquid components carried by the fluid from the excavation chamber 118, such as small stones, sand and / or mud materials, can be removed by these separators, so that in the flow direction of the fluid, only gaseous components are basically still contained on the outlet side of the separation module 224. The separators 227, 230 are connected to the discharge pipeline device 233 in the bottom area, such as Figure 2 As shown, liquid and solid matter occurring in the separators 227 , 230 can be discharged in a controlled manner via this discharge line arrangement, expediently via a shut-off plug, if necessary.

[0031] After passing through the separation module 224 and substantially completely separating the solid and liquid components at the same time, the fluid, which is substantially still composed of gaseous components, then enters the gas line device 236, in which the pressure reducer 239 of the metering module 240 is integrated. The inlet pressure in the gas line device 236 can be reduced to an outlet pressure of typically about 1000 hPa to about 2000 hPa by means of the pressure reducer 239, with a corresponding reduction in the volume flow. A double membrane pump 245 is also integrated in the gas line device 236, which is resistant to abrasive components in the fluid, such as sand, is connected to the first throttle valve 241 and the second throttle valve 242, and can be supplied with pressurized control air from the control air line 244 via the magnetic switch 243, and the fluid pressure downstream of the double membrane pump 245 in the flow direction can be increased to a certain overpressure by means of the double membrane pump if necessary.

[0032] The double membrane pump 245 has two diaphragms forcibly coupled to each other, which are activated by a magnetically controlled switch 243 through a control air line 244 with the help of a pulse voltage when the magnetically controlled switch 243 is higher than a certain voltage signal level, and after the voltage drops below the voltage signal level, they are alternately controlled by the control air under pressure in a controlled manner through a return spring, so that a sufficiently high lifting capacity is provided under a sufficiently high cycle frequency and a suitable pressure in the control air line 244. The magnetically controlled switch is designed as a 3 / 2 two-position three-way control valve, for example, and the pulse voltage is activated by a magnetically controlled switch 243 through a control air line 244. Figure 2 A voltage pulse generator (not shown) is provided. Thus, the average short time portion in the low pressure range or low volume flow range of the diaphragm after reaching the stroke end position and for resetting is omitted.

[0033] In order to even out remaining pressure fluctuations, especially under atmospheric conditions in the excavation chamber 118, i.e. without self-feeding of fluid, the openings of the throttle valves 241, 242 are adjusted to relatively small values, so that the air required to release the diaphragms for pressure relief escapes only with considerable delay to the environment. Thus, each diaphragm, when resetting, moves into the next stroke again before reaching the initial position, and during this time the opposite diaphragm already assumes the lifting work essentially seamlessly.

[0034] Downstream of the double membrane pump 245 in the flow direction of the fluid, a pressure stabilizer 248 in the form of a compensation container with a membrane for stabilizing the pressure in the gas pipeline device 236 is first integrated in the gas pipeline device 236, and subsequently a flow control valve 251 of the metering module 240 is also integrated, and the flow control valve is advantageously designed as a needle valve for fine-tuning the flow rate. Downstream of the flow control valve 251 in the flow direction of the fluid, there is a Y-shaped branch line 254, which divides the gas pipeline device 236 into a main branch 257 and a bypass 260, the main branch having a relatively large flow rate, and the bypass having a lower flow rate than the flow rate in the main branch 257.

[0035] Arranging the flow control valve 251 upstream of the Y-shaped branch line 254 in the flow direction of the gaseous fluid has the advantage that the entire volume flow in the gas line arrangement 236 can be influenced in a targeted manner, taking into account the fluid dynamics of the components located downstream in the flow direction of the fluid. If, for example, the discharge line 136 is relatively long for operational reasons, this leads to additional pressure losses, which are correspondingly accompanied by a reduction in the volume flow. In this case, the entire volume flow can be pre-metered to a value suitable for relatively accurate measurement by the gas analysis unit 133 by means of the flow control valve 251.

[0036] In the main branch 257, a volume flow measuring module 266 is integrated after the passive check valve 263 provided for safety reasons in the flow direction of the fluid, through which the volume flow of the gaseous fluid flowing through the main branch 257 can be measured, and the volume flow has a fixed ratio with respect to the volume flow flowing in the bypass 260. A flow meter 266 is connected to the outlet side of the volume flow measuring module 266. Figure 1 The exhaust line 136 described in .

[0037] In the bypass 260 , a bypass filter module 269 is integrated, which has two bypass filters 272 , 275 connected in parallel for redundancy reasons, so as to remove residual contaminants from the fluid in the bypass 260 flowing through the gas line arrangement 236 before entering the measurement gas transmission line 130 , in order to avoid damage to the gas analysis unit 133 , which is usually relatively sensitive.

[0038] Thus, a gaseous, clean fluid that is only subject to relatively small pressure fluctuations can be fed to the gas analysis unit 133 with a relatively constant volume flow. The composition of the gaseous fluid in its gaseous components can be detected by the gas analysis unit 133 with respect to critical, especially explosive gases such as methane. For this purpose, the gas analysis unit 133 advantageously has a very precise volume flow meter with a quantity adjustment wheel coupled thereto for very precisely metering the gaseous fluid supplied to the gas sensor of the gas analysis unit 133.

[0039] The connections 203, 209, 212, 215, 218, which are accessible to the operator from the front during normal operation, can be closed and opened by means of respective stopcocks. Thus, in particular when the withdrawal line connection 203 is closed, air under pressure can flow through in both directions via the air connection 209, and water, in particular for flushing the fluid mixture line 206, can flow through in both directions via the water connection 218 together with the connected water line 221. Test gas can be passed through the test gas connection 212 for checking the functionality of the fluid treatment unit 127 and in particular the gas analysis unit 133, when the respective stopcock is opened and the other stopcocks are closed.

[0040] Figure 3 Show according to Figure 2 A perspective view of an embodiment of a fluid treatment unit 127 of FIG. 1 , wherein the rear side facing away from the front side can be seen. Figure 3 It can be seen that the gas pipeline device 236 is based on Figure 2 Parts not visible in the illustration and components integrated in the gas line arrangement. Figure 3 As can be seen in the illustration of , the gas line arrangement 236 is equipped with a shut-off valve 303, which can be used to block the front area of ​​the gas line arrangement in the flow direction of the gaseous fluid flowing in the gas line arrangement 236 from the rear area in the flow direction, for example, when a critical filling level occurs in the separation module 224. Figure 3 The arrangement of the Y-shaped branch line 254 in the form of a T-shaped piece can be clearly seen in the figure, and the T-shaped piece has a T-shaped neck on the inlet side of the bypass 260. Figure 3 It can be seen that the separators 227 , 230 are each equipped with a fill level sensor 306 , via which a warning signal can be generated so that in the case of a maximum fill level the contents of the separators 227 , 230 can be discharged via the discharge line arrangement 233 by operator intervention.

[0041] Figure 4 Another embodiment of the fluid treatment unit 127 is shown. Figure 2A perspective view showing the front side accessible to the operator during operation, wherein the Figure 2 and Figure 3 In the embodiment of the fluid treatment unit 127 described and with the aid of Figure 4 In the exemplary embodiment of the fluid treatment unit 127 described, components that correspond to one another are provided with the same reference numerals and are not explained in detail below in order to avoid repetitions.

[0042] according to Figure 4 Embodiments and basis Figure 2 and Figure 3 The difference of the embodiment of the embodiment of the invention is that the flow regulating valve 251 is integrated in the main branch 257 upstream of the volume flow measuring module 266 in the flow direction of the fluid together with the upstream main flow filter module 403 for protection, especially when arranged lower in the lower area of ​​the fluid treatment unit 127. Figure 4 In the embodiment of the present invention, the check valve 263 is not provided. Figure 4 The embodiment of the fluid processing unit 127 is distinguished in that the flow rate in the bypass 260 can be adjusted relatively accurately by adjusting the flow rate in the main branch 257 , which is required for the measurement accuracy of the gas analysis unit 133 .

[0043] according to Figure 2 and Figure 3 Embodiments and basis Figure 4 The embodiments of the present invention have in common that the pressure regulation, pressure stabilization and flow rate regulation for achieving the required functionality of the gas analysis unit 133 are achieved by the sequence of a pressure reducer 239, a double membrane pump 245, a pressure stabilizer 248 and a flow control valve 251 arranged in the flow direction of the fluid, and then branching into a main branch 257 with a larger flow rate and a bypass 260 with a smaller flow rate at a Y-shaped branch line 254 in the direction of the gas analysis unit 133. Thus, even under strongly changing ambient conditions in the excavation chamber 118, the content of critical gases in the gaseous fluid can be determined largely without delay at least to such an extent that, for example, the presence of explosive methane in safety-related concentrations can be detected reliably and relatively quickly.

Claims

1. A tunnel boring machine having a device for detecting the content of critical gases in a cavity, the cavity being located behind a cutting wheel (106), the tunnel boring machine having a withdrawal line (124) extending between an excavation chamber (118) as the cavity and the device, the device having a separation module (224) for separating the gas to be detected from a fluid and a gas analysis unit (133) arranged downstream of the separation module (224), characterized in that: A metering module (240) is provided after the separation module (224), and the metering module is used to controllably apply the separated gas to the gas analysis unit (133). The metering module (240) has a pressure reducer (239) and a flow regulating valve (251) after the pressure reducer (239), and there is a double membrane pump (245), which is connected after the pressure reducer (239).

2. The tunnel boring machine according to claim 1, characterized in that The two diaphragms of the double diaphragm pump (245) are positively coupled to one another and can be actuated alternately by a magnetically controlled switch (243) via a control air line (244) with the aid of pressurized control air.

3. The tunnel boring machine according to claim 2, characterized in that: The double membrane pump (245) is connected to a first throttle valve (241) and a second throttle valve (242), the openings of which can be adjusted to relatively small values ​​so that the air required to release the membranes for pressure relief escapes only with considerable delay into the environment.

4. The tunnel boring machine according to claim 1, characterized in that: There is a pressure stabilizer (248) which is arranged between the double membrane pump (245) and the flow regulating valve (251).

5. The tunnel boring machine according to claim 1, characterized in that: The flow regulating valve (251) is a needle valve.

6. The tunnel boring machine according to claim 1, characterized in that: A volume flow measuring module (266) is provided, which is arranged downstream of the flow regulating valve (251).

7. The tunnel boring machine according to any one of claims 1 to 6, characterized in that A Y-shaped branch line (254) is located downstream of the pressure reducer (239), the Y-shaped branch line being asymmetrical with respect to the separated volume flow, the Y-shaped branch line having a main branch (257) arranged downstream and a bypass branch (260) arranged downstream, and the volume flow measuring module (266) being arranged in the main branch (257) downstream of the Y-shaped branch line (254).

8. The tunnel boring machine according to claim 7, characterized in that A bypass filter module (269) is arranged in the bypass (260).

9. The tunnel boring machine according to claim 7, characterized in that: The flow regulating valve (251) is arranged between the pressure reducer (239) and the Y-shaped branch line (254).

10. The tunnel boring machine according to claim 7, characterized in that: The flow regulating valve (251) is arranged in the main branch (257) after the Y-shaped branch line (254).

11. The tunnel boring machine according to claim 10, characterized in that In the main branch (257), a main flow filter module (403) is present between the Y-shaped branch line (254) and the flow regulating valve (251).

12. The tunnel boring machine according to claim 7, characterized in that A gas analysis unit (133) is provided, which is arranged downstream of the bypass (260) and is provided for detecting explosive gases.

13. The tunnel boring machine according to claim 3, characterized in that The double membrane pump (245) is capable of resisting abrasive components in the fluid and is connected to the first throttle valve (241) and the second throttle valve (242) and can be supplied with pressurized control air from the control air line (244) via the magnetically controlled switch (243), wherein, when necessary, the double membrane pump (245) can increase the fluid pressure downstream of the double membrane pump (245) in the flow direction to a certain overpressure.

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