Device and method for creating or expanding a borehole in the ground

Abstract

In a device and a method for creating or widening a borehole in the ground (18), in particular for directional horizontal drilling, at least one electrically operated drive unit (116 to 124) is supplied with electrical energy by means of at least one power electronics unit (126 to 134). At least part of the electrical energy required to supply the drive unit (116 to 124) is provided by a rechargeable battery (52). The drive unit (116 to 124), the power electronics unit (126 to 134) and / or the battery (52) are electrical components of the drilling device (12). At least one electrical component (116 to 134, 52) of the drilling device (52) is actively cooled by means of a cooling unit (56) comprising at least one cooling unit with a heat pump.

Description

[0001] The invention relates to a device and a method for creating or expanding a borehole in the ground, and to a method for operating such a device. At least one electrically operated drive unit is used to drive the drilling device. The drilling device is, in particular, a horizontal drilling device, through which a bore can be carried out using a controllable horizontal drilling method (horizontal directional drilling).

[0002] Known horizontal drilling rigs for creating earth bores have hydraulic drives powered by diesel- or gasoline-powered hydraulic units. To avoid pollutant emissions from these diesel- or gasoline-powered hydraulic units, it is known to use electrically powered hydraulic units that are supplied with the required electrical energy via a public power grid or a battery pack. Such a drilling rig is disclosed in particular in document DE 10 2018 113 274 A1. This document further discloses electric drive units for directly driving a drilling and / or reaming tool connected to the drilling rig via a rod assembly, wherein the electrical energy required for the electric drive unit is provided by a battery pack.

[0003] At least with powerful electrically driven drilling devices, the problem arises that electrical components of the drilling device become too hot and must be protected from thermal overload.

[0004] The object of the invention is to provide a device and a method for creating or expanding a borehole in the ground, through which the electrical components can be operated safely and in an energy-saving manner.

[0005] This object is achieved by a device having the features of claim 1 and by a method having the features of the independent method claim. Advantageous further developments are specified in the dependent claims.

[0006] The device with the features of claim 1 ensures that at least one electrical component of the device can be efficiently cooled. The use of at least one cooling unit with a heat pump for cooling the electrical component results in energy-efficient cooling, which reduces the energy consumption of the entire device and allows the cooled electrical components to operate safely and at high performance. Preferably, the heat pump is operated in reverse and thus functions as a compressor cooling unit.

[0007] It is advantageous if the cooling unit includes a cooling circuit with a coolant for actively cooling the electrical components. This enables simple and efficient cooling. In particular, the cooling circuit can also be used to easily and efficiently cool multiple electrical components of the drilling device.

[0008] It is particularly advantageous if the cooling unit actively cools the battery and / or the electric motor and / or if the power electronics unit comprises at least one inverter and the cooling unit actively cools the inverter.

[0009] It is also advantageous if the cooling unit alternatively or additionally cools other electrical components of the drilling device, in particular a DC-DC converter, charging electronics for charging the battery, and a power supply unit for converting the mains voltage of a public power grid into DC voltage for supplying at least one electrical component of the drilling device. This allows the electrical components of the device to be cooled simply and efficiently, and the cooled electrical components to be operated safely and at high performance. The cooling unit can also cool a machine operator's cabin of the device.

[0010] It is also advantageous if the cooling device for dissipating heat comprises a liquid / air heat exchanger and / or a liquid / liquid heat exchanger. The liquid / liquid heat exchanger can be designed to transfer heat to a drilling fluid, such as bentonite, used in the drilling process.

[0011] It is particularly advantageous if the cooling device can be operated in a first operating mode to cool the electrical component, and if the cooling device can be operated in a second operating mode to heat the electrical component. This allows the electrical components to be heated as well if necessary. In particular, the battery should not fall below a preset minimum temperature for charging and / or power delivery.

[0012] Furthermore, it is advantageous if the drive unit has a first electric motor for rotary driving a drill rod of the drilling device and at least one second electric motor for a feed drive for advancing the drill rod. In particular, the drive unit can have at least two, preferably three, electric motors for the feed drive. Furthermore, the device can have an electric drive unit for driving a drilling fluid pump and an electric drive unit for a mixing station for producing the drilling fluid. These electric drive units are preferably direct electric drives, i.e. electric motors, in particular permanent magnet synchronous motors (PMSM), for directly generating the drive movement of the respective component, i.e. without the interposition of a hydraulic pump and hydraulic drives. This achieves a high degree of efficiency.All drives of the device required to create or expand the borehole are therefore direct electric drives.

[0013] Furthermore, the drive unit can comprise at least one electric drive of an electro-hydraulic unit. The electro-hydraulic unit preferably comprises at least one hydraulic pump for supplying hydraulic drives.

[0014] With the aid of this electro-hydraulic unit, in particular linear hydraulic actuators, such as hydraulic cylinders, can be driven, in particular for clamping drill rods of the drill string of the drilling device, for adjusting the inclination of a drilling ramp of the drilling device, for removing drill rods from a rod magazine and / or for depositing them in the rod magazine.

[0015] Although the drive of the hydraulic drives by an electro-hydraulic unit is not as efficient as when using direct electric drives, the hydraulic drives mentioned are not used permanently and cannot currently be replaced cost-effectively by direct electric drives.

[0016] Alternatively or additionally, the electro-hydraulic unit can be used to drive a chassis of the drilling rig. This is cost-effective, at least if the drilling rig has an electro-hydraulic unit for other hydraulic drives. However, the chassis can also be driven directly by at least one electric motor.

[0017] The electro-hydraulic unit can then be deactivated during drilling operation of the device.

[0018] Drive units for driving ground anchors to anchor the device in the ground can be driven either by the same electro-hydraulic unit or by direct electric motors.

[0019] The method with the features of the independent method claim has the same advantages as the claimed device. In particular, the method can be further developed with the features of the dependent claims directed to the device and the aforementioned developments.

[0020] Embodiments of the invention are explained in more detail below with reference to the figures, in which: Figure 1A shows a schematic representation of a drilling rig for the controlled drilling of a pilot bore according to a first embodiment, with which a through hole is created in the ground, which can subsequently be expanded using an expansion tool; Figure 1B shows an enlarged section of the drilling rig according to Figure 1A, wherein the drill head for producing the pilot hole is shown; Figure 1C a schematic representation of a drilling rig for expanding the with the drilling rig according to Figure 1A created pilot hole using an expansion tool; Figure 1: An enlarged section of the drilling rig after Figure 1C , showing the expansion tool for expanding the pilot bore; Figure 2 shows a block diagram with electrical components to be cooled of a horizontal drilling device of the drilling rig.

[0021] In Figure 1Aa drilling rig 10 for the controlled drilling of a pilot borehole according to a first embodiment is shown. The drilling rig 10 operates according to a horizontal drilling method, which is also referred to as horizontal directional drilling (HDD). In the present exemplary embodiment, a horizontal drilling rig available under the trade name TERRA-JET is used for this purpose. Such a horizontal drilling rig is known, for example, from the document DE 101 15 233 A1. In the HDD method, a rod assembly 14 composed of several rod sections 13 is inserted into the ground 18 in the direction of arrow P0 with the aid of a horizontal drilling device 12 at a starting point 16 with a drill head 20 arranged on the end of the rod assembly 14 remote from the horizontal drilling device 12. The entire horizontal drilling device 12 can be moved via a chassis 54 of the horizontal drilling device 12.

[0022] The horizontal drilling device 12 has a pump 42 that draws drilling fluid 46 from a drilling fluid container 40 via a hose 48 and pumps it at high pressure into the hollow rod 14. The drilling fluid 46 exits the drill head 20 at high pressure. The high pressure and the hard metal teeth of the drill head 20 cut a borehole into the ground 18. Water with bentonite or polymers can be used as the drilling fluid 46. Such drilling fluids 46 stabilize the bore channel 15, reduce the friction between the drill rod 14 and the ground 18, and also reduce the friction between a pipe 26 to be pulled into the bore channel and the ground 18. A control unit 50 of the horizontal drilling device 12, in particular a programmable logic control unit (PLC), controls the pump 42 to pump the drilling fluid 46 through the rod 14.The pump 42 can be controlled by the control unit 50 in particular such that the volume flow of the flushing fluid 46 conveyed by the pump 42 and thus emerging at the drilling or expanding head 20, 24 can be controlled.

[0023] The drive units for driving the pump 42, for rotating the rod assembly 14 about its longitudinal axis, and for moving the rod assembly 14 along its longitudinal axis are electric motors for direct drive, i.e., without the interposition of a hydraulic pump and hydraulic motors. However, the electric motor or motors can include at least one gear stage. The electric motors are permanent magnet synchronous motors (PMSM). In other embodiments, the electric motors are other electric motors, in particular DC motors or asynchronous motors.

[0024] A battery 52 for providing at least part of the electrical energy required by the electric motors is integrated into the horizontal drilling device 12. The battery 52 is rechargeable and is also referred to as a battery pack. In the present embodiment, the battery 52 is permanently integrated into the horizontal drilling device 12. In other embodiments, the battery 52 can also be designed as a removable battery, i.e., the battery 52 can be exchanged for another, preferably charged, battery 52.

[0025] The electric motors of the horizontal drilling device 12 are each controlled by a power electronics unit, in particular an inverter, using the control unit 50 of the horizontal drilling device 12. In addition to the electric motors, the inverters required to control the electric motors, the battery 52, a charging circuit for charging the battery 52, and at least one power supply for generating the required DC voltage for charging the battery 52 and / or for powering the electric motors when the power supply is supplied via a power grid, in particular via a public power grid, are also electrical components of the horizontal drilling device 12.

[0026] At least some of the electrical components have a relatively high power loss, so that they must be cooled during drilling operation and / or during continuous drilling operation of the horizontal drilling device 12. At least for some electrical components, air cooling is very complex and inefficient. In the horizontal drilling device 12, at least some of the electrical components are therefore actively cooled by a cooling unit 56, wherein the cooling takes place via a liquid circuit with a coolant. The cooling unit 56 comprises a cooling unit with a heat pump having a liquid / air heat exchanger for dissipating the heat to the environment. In other embodiments, a liquid / liquid heat exchanger for dissipating heat to the flushing liquid 40 is provided alternatively or additionally.

[0027] The structure and further function of the electrical components of the horizontal drilling device 12 is described in conjunction with Figure 2 explained in more detail below.

[0028] The drill head 20 is asymmetrically flattened at its front end and is continuously rotated by means of the rod assembly 14 to create a straight borehole. For a desired lateral, upward, or downward movement, the drill head 20 is stopped in a position suitable for this desired movement and is not rotated any further, so that, due to the asymmetrically flattened shape of the front end of the drill head 20, a corresponding deflection movement of the drill head 20 occurs in the ground 18. Figure 1B A detailed view of the end of the rod 14 remote from the horizontal drilling device 12 is shown, together with the drill head 20. An electronic probe is arranged in the drill head 20, which can be precisely located from the earth's surface at any time using an appropriate locating device, so that the position of the drill head 20 in the ground 18 can be precisely determined at any time.

[0029] The path of movement of the drill head 20 and thus the course of the drill channel 15 of the pilot bore is simply controlled by controlled stopping of the rotation of the drill head 20 via the rod 14, so that the control surface of the drill head 20 is brought into a position required for the desired movement.

[0030] After reaching the target point 22, which is provided for example in a target pit, the drill head 20 is replaced by an expander head 24, which expands the previously created pilot bore when the rod 14 is withdrawn and at the same time pulls in a HDPE pipe 26, as shown in the Figures 1C and 1D HDPE pipes are made of high-density polyethylene, which is a high-density thermoplastic. In other embodiments, pipes 26 made of other materials, particularly metal, can also be used.

[0031] Figure 1Dshows an enlarged section of the Figure 1C shown drilling rig 10. In this section, the end of the rod 14 removed from the horizontal drilling device 12, the expander head 24 and the pipe 26 which has already been partially pulled into the ground 18 are shown.

[0032] Figure 2 shows a block diagram with the electrical components to be cooled of the horizontal drilling device 12 of the drilling rig 10. The electrical switching and control components of the electric drive system 110 of the horizontal drilling device 12 are arranged in a housing 100, preferably in a control cabinet, of the horizontal drilling device 12. The battery 52, the cooling unit 56, the electric motors 116 to 124 to be controlled, and a connection to the public power grid 112 are arranged outside the housing 100.

[0033] The switching and control components of the electric drive system 110 include a power supply 140, which is connected to the public power grid 112 via a main switch 136 and a choke 138. The public power grid 112 supplies the electric drive system 110 with electrical energy to charge the battery 52 and provide the power required for the electric motors 116 to 124. During normal drilling operation, the electric motors 116 to 124 are powered simultaneously by the battery 52 and the public power grid 112, thereby keeping the connected load of the public power grid 112 relatively low. For example, the TERRA-JET DJ 60e model without a 52 battery requires a connected load of 2x 200 kW / 2 connections 3x400V AC 128A, and with the support of a 52 battery with, for example, 60 kWh, only a connected load of 100 kW / 1 connection 3x400V AC, 64 A is required.The connection to the public power grid 112 can be established via a construction site power distribution board. During work breaks, for example, when adding or removing rod sections 15, the battery 52 can then be recharged at any time. Alternatively or additionally, the battery 52 can be fully charged after work, e.g., overnight. The power supply unit 140 provides a main distribution board 142 with DC voltage to supply the electric motors 116 to 124 and to charge the battery 52 via a DC / DC converter 144, as well as to supply other components, such as the DC / DC converter 146 for supplying other components of the horizontal drilling device 12 and the cooling unit 56. The DC / DC converter 144 includes a charging circuit for charging the battery 52.The electric motors 116 to 124 are connected to the main distributor 142 via inverters 126 to 134, which are controlled by a control unit 148 of the electric drive system 110 to activate and control the electric motors 116 to 134.

[0034] The control unit 148 is further connected to the central control unit 50 of the horizontal drilling device 12 for controlling the drilling process and for moving the horizontal drilling device 12 using the chassis 54. Furthermore, the control unit 148 controls the DC / DC converter 146, the main switch 136, the power supply 140, and the central distribution 142.

[0035] The cooling unit 56 comprises a cooling unit with a heat pump, which is designed such that an evaporator of the heat pump circuit cools the cooling liquid of a cooling liquid circuit for cooling electrical components of the electric drive system 110. The cooling liquid circuit is in Figure 2represented by dashed lines. The coolant circuit comprises a supply line 150 and a return line 152, with the coolant flow preferably being controlled or regulated depending on the temperature for each electrical component to be cooled. The flow can be adjusted, in particular, via appropriate valves.

[0036] In the present embodiment, the battery 52, the power supply 140, the inverters 126 to 134, the DC / DC converter 144, and the DC / DC converter 146 are actively cooled using the cooling fluid. In other embodiments, at least one electric motor 116 to 124 can also be cooled. In other embodiments, fewer electrical components can also be actively cooled using the cooling fluid.

[0037] The cooling unit 56 can be operated in a first mode to cool electrical components and in a second mode to heat the electrical components. In particular, the battery 52 can be heated in cold outside temperatures to increase charging efficiency and / or to improve the power output and capacity of the battery 52.

[0038] In other embodiments, a battery, preferably a battery container with rechargeable batteries, can be used instead of or in addition to the public power grid 112. The batteries are preferably arranged in a so-called 20-foot storage and shipping container, which allows for easy transport to and from a construction site. The battery capacity of the batteries arranged in the battery container is preferably sufficient to supply the drilling device for at least one working day. List of reference symbols

[0039] 10 Drilling rig 12 Horizontal drilling device 13 Rod section 14 Rods 15 Drill channel 16 Starting point 18 Soil 20 Drill head 22 Target point 24 Expanding head 26 HDPE pipe 40 Flushing fluid tank 42 Pump 46 Flushing fluid 48 Hose 50 Control unit 52 Battery 54 Chassis 56 Cooling unit 100 Control components for electric drives 110 Electric drive system 112 Public power grid 116 Electric rotary drive rods 118 Electric drive hydraulics 120 to 124 Electric feed drive rods 126 to 134 Inverter electric drive 136 Main switch 138 Choke 140 Power supply unit 142 Main distribution board 144 DC / DC converter with charging circuit 146 DC / DC converter other consumers 148Control unit electric drive system 150Forward 152Return P0Direction arrow

Claims

1. A device for creating or expanding an earth borehole in the ground, in particular for direction-guided horizontal drilling, comprising at least one electrically operated drive unit (116 to 124), at least one power electronics unit (126 to 134) designed to supply the drive unit (116 to 124) with electrical energy, a rechargeable battery (52) for providing at least part of the electrical energy required to supply the drive unit (116 to 124), the drive unit (116 to 124), the power electronics unit (126 to 134) and / or the battery (52) being electrical components of the drilling device (12), and at least one cooling unit (56) designed to actively cool at least one electrical component (116 to 134, 52) of the drilling device (12), the cooling unit (56) comprising at least one cooling unit with a heat pump.

2. Device according to claim 1, characterized in thatthe cooling unit (56) comprises a cooling circuit with a cooling liquid for actively cooling the electrical component (116 to 134, 52).

3. Device according to one of the preceding claims, characterized in that the cooling unit (56) actively cools the battery (52).

4. Device according to one of the preceding claims, characterized in that the cooling unit (56) actively cools the electric motor (116 to 124).

5. Device according to one of the preceding claims, characterized in that the power electronics unit comprises at least one inverter (126 to 134), and that the cooling unit (56) cools the inverter (126 to 134).

6. Device according to one of the preceding claims, characterized in thatthe cooling unit (56) cools further electrical components of the drilling device (12), in particular a DC-DC converter (144, 146), charging electronics (144) for charging the battery (52), a power supply unit (140) for converting the mains voltage of a public energy supply network (112) into DC voltage for supplying at least one electrical component (116 to 134, 52, 56) of the drilling device (12).

7. Device according to one of the preceding claims, characterized in that the cooling unit (56) cools a machine operator's cab.

8. Device according to one of the preceding claims, characterized in that the cooling device (56) for dissipating heat comprises a liquid / air heat exchanger and / or a liquid / liquid heat exchanger, wherein the liquid / liquid heat exchanger is preferably designed such that it transfers heat to a flushing liquid (46) used in creating the bore.

9. Device according to one of the preceding claims, characterized in that the cooling device (56) is operable in a first operating mode for cooling the electrical component (116 to 134, 52), and that the cooling device (56) is operable in a second operating mode for heating the electrical component (116 to 134, 52).

10. Device according to one of the preceding claims, characterized in that the drive unit has a first electric motor (116) for a rotary drive of a drill rod (14) of the drilling device (12) and at least one second electric motor (120 to 126) for a feed drive for feeding the drill rod (14).

11. Device according to one of the preceding claims, characterized in that the drive unit has at least two, preferably three, electric motors (120 to 126) for the feed drive of the drill rod (14).

12. Device according to one of the preceding claims, characterized in thatthe drive unit comprises at least one electric drive (118) of a chassis (54) of the drilling device (12), wherein the electric drive (118) preferably comprises a hydraulic pump for supplying hydraulic drives of the chassis (54).

13. A method for operating a device for creating or expanding an earth borehole in the ground, in particular for direction-guided horizontal drilling, in which at least one electrically operated drive unit (116 to 124) is supplied with electrical energy by means of at least one power electronics unit (126 to 134), in which at least part of the electrical energy required to supply the drive unit (116 to 124) is provided by a rechargeable battery (52), wherein the drive unit (116 to 124), the power electronics unit (126 to 134) and / or the battery (52) are electrical components of the drilling device (12), in which at least one electrical component of the drilling device (116 to 134, 52) is actively cooled by means of a cooling unit (56) comprising at least one cooling unit with a heat pump.

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