EP3504435B1 - Hydrostatic system and pumping station for an oil or gas pipeline - Google Patents

Description

Hydrostatic system and pumping station for an oil or gas pipeline The invention relates generally to a hydrostatic system according to the preamble of claim 1 and in particular to a pumping station for an oil or gas pipeline with such a hydrostatic system, the hydrostatic system for starting up an internal combustion engine of the pump station is used.

In pumping stations for oil or gas pipelines, also called compressor stations, internal combustion engines, for example large gas engines, are used which drive one or more feed pumps for conveying the medium - oil or gas - through the pipeline. Such gas engines have, for example, an output of 1800 to 11000 hp and a starting torque of, for example, 32000 Nm at 4000 hp. The starting speed can then be, for example, 65 rpm and should be reached within 30 seconds.

The medium conveyed through the pipeline, in particular gas, is conventionally used to start the internal combustion engine. This is no longer desirable for environmental reasons.

Alternative starting devices for internal combustion engines are in RU 2 035 614 C1 and ES 1 072 269 U disclosed. DE 102014215567 discloses closest prior art.

The use of a hydrostatic system, in particular for starting a corresponding internal combustion engine, but also generally independently of this application, for example generally for driving a hydraulic motor or for supplying a consumer with a pressurized hydraulic medium, has the disadvantage that the regulation of the power consumption of the hydraulic motor or the Pressure for the consumer conventionally through variably adjustable Throttling orifices take place, which is associated with dissipation and reduced efficiency. Furthermore, it is known to provide a hydraulic motor instead of such a throttle orifice, which likewise brings about the desired pressure reduction, but at the same time converts the pressure into mechanical drive power, which in turn can then be converted into electrical energy in a connected electrical generator. This arrangement makes it easy to regulate the power consumed by the hydraulic motor and thus the pressure drop across the hydraulic motor. The disadvantage of this solution, however, is that, on the one hand, the hydraulic energy is converted into electrical energy and is therefore no longer directly available in the hydraulic system and, on the other hand, electrical control must be provided, which is associated with additional outlay.

The disadvantage that hydraulic energy is converted into electrical energy and is therefore no longer available in the hydrostatic system without conversion is particularly serious if a hydraulic accumulator is provided as the pressure source for the hydrostatic system, since more energy is extracted from it than for Drive of the hydraulic motor or for pressurizing the consumer is necessary. This disadvantage is particularly serious when the hydrostatic system is used to start up the comparatively large internal combustion engine in the pumping station of an oil or gas pipeline, because starting up is associated with particularly high energy consumption due to the performance data mentioned.

The present invention is based on the object of specifying a hydrostatic system which avoids the disadvantages mentioned and enables efficient control of the hydraulic pressure for a consumer and / or the drive power of a hydraulic motor, for example for an internal combustion engine in particular in the pumping station or compressor station of an oil or gas pipeline.

The object of the invention is achieved by a hydrostatic system with the features of the independent claims. Advantageous and particularly expedient refinements of the invention and a pumping station for an oil or gas pipeline are specified in the dependent claims.

The solution according to the invention makes it possible to achieve a pressure reduction in the hydrostatic system by using an additional hydraulic motor which drives a hydraulic pump which in turn conveys hydraulic medium to the pressure side of the consumer and / or the first hydraulic motor, so that the volume flow of the hydraulic medium through the first hydraulic motor and / or the consumer is increased and the energy contained in this hydraulic medium flow conveyed by means of the hydraulic pump remains in the hydrostatic system as hydraulic energy. With the solution according to the invention, a higher efficiency than with a variably adjustable throttle diaphragm can be achieved and undesirable forces and / or torques, which can lead to strong accelerations and can have a dangerous effect, are avoided due to the precise controllability.

According to an alternative embodiment, the hydraulic pump is used to supply the first hydraulic motor and / or the consumer with pressurized hydraulic medium.

In detail, according to one embodiment, a hydrostatic system according to the invention has a hydraulic pressure source, as well as a first hydraulic motor that has an output shaft that forms a mechanical power output of the hydrostatic system, and / or at least one consumer that is pressurized with pressurized hydraulic medium from the pressure source.

The first hydraulic motor is used to drive it and / or at least one consumer is connected to the pressure source with a pressure line to pressurize it.

According to the invention, a hydraulic motor-pump unit is provided, comprising an additional hydraulic motor (in addition to the first hydraulic motor and / or in addition to the at least one consumer) and a hydraulic pump, which are in a drive connection with one another, such that the hydraulic pump from the additional hydraulic motor is drivable.

The additional hydraulic motor is connected to drive it in series with the first hydraulic motor and / or the at least one consumer at the pressure source and the hydraulic pump has a pressure side with which it is connected to the pressure line. The hydraulic pump thus conveys pressurized hydraulic medium, in particular from a hydraulic pressure source such as a tank, into the pressure line, which is why this hydraulic medium is in turn available for the first hydraulic motor and / or the at least one consumer.

According to an alternative embodiment of the invention, it is not necessary to apply the pressurized hydraulic medium directly from the pressure source to the first hydraulic motor and / or the consumer, but rather the hydraulic motor of the hydraulic motor-pump unit which drives the hydraulic pump is used to drive it a pressure line is connected to the pressure source and the first hydraulic motor is connected to drive it and / or the consumer is connected to its pressurization with hydraulic medium on a pressure side of the hydraulic pump.

A hydraulic reservoir, in particular in the form of a hydraulic tank or hydraulic sump, is preferably provided, from which the hydraulic pressure source is fed by means of at least one charge pump. The charge pump can do this be operated to work directly as a hydraulic pressure source, which provides the pressurized hydraulic medium without intermediate storage. Particularly preferably, however, the hydraulic pressure source has at least one pressure accumulator, to which the charge pump is connected with a charge pump pressure side for feeding hydraulic medium into the pressure accumulator.

Various options are available for driving the charge pump. However, an electric motor is preferably provided for driving the charge pump.

The hydraulic pump preferably has a suction side which is connected to the hydraulic supply by means of a suction line. Thus, in one embodiment with a pressure accumulator, the pressure accumulator and the motor-pump unit can be supplied from the same hydraulic supply.

According to one embodiment of the invention, the hydraulic pressure source has a multiplicity of pressure accumulators. Such pressure accumulators can be filled simultaneously or in succession by means of the at least one charge pump. Such pressure accumulators can also be emptied simultaneously or in succession to supply the first hydraulic motor and / or the at least one consumer with pressurized hydraulic medium.

According to one embodiment of the invention, a variably adjustable throttle valve is provided in the pressure line for regulating the pressure in the pressure line on the input side or output side of the first hydraulic motor and / or on the input side or output side of the at least one consumer. In the alternative embodiment of the invention, a variably adjustable throttle valve for regulating the pressure in the pressure line can be used on the input or output side of the additional hydraulic motor can be provided. In this case in particular, the additional hydraulic motor and the hydraulic pump for driving the hydraulic pump can be rigidly coupled to one another. Due to the motor-pump unit, the adjustable throttle valve can be made smaller than conventional and thus generate less dissipation energy.

The drive connection between the additional hydraulic motor and the hydraulic pump is preferably made purely mechanically, in particular by the rigid coupling mentioned, which can be produced, for example, by a shaft which carries the impellers of the additional hydraulic motor and the hydraulic pump or is connected to them in a rotationally rigid manner.

In order to be able to make the adjustable throttle valve in the pressure line even smaller or to save it entirely, at least one of the two units - the additional hydraulic motor and / or the hydraulic pump - can be designed as an adjustable unit - variable motor and / or variable pump - that is, with variably adjustable delivery volume per revolution, in particular with variably adjustable stroke volume, in the embodiment of the corresponding unit as a reciprocating piston machine.

According to one embodiment of the invention, a transmission gear with a variably adjustable speed ratio is provided in the drive connection between the additional hydraulic motor and the hydraulic clutch. The speed of the hydraulic pump is thus decoupled from the speed of the additional hydraulic motor, so that by regulating the speed it is possible to regulate the power consumption of the motor-pump unit. Here too, the throttle valve provided in the pressure line can be made smaller and can only be used for controls outside the control range of the speed control, or can even be saved entirely.

If both the additional hydraulic motor and the hydraulic pump are adjustable, the throttle valve can generally be dispensed with completely, and the entire control range can be covered solely by the variable adjustment of the delivery volume per revolution of both units.

In addition to the first hydraulic motor and the additional hydraulic motor, at least one further hydraulic motor and / or at least one consumer is preferably provided, in which the hydraulic medium is expanded or consumed, these units also being connected or connectable to the pressure line.

According to one embodiment of the invention, an electric generator or an electric motor generator for energy storage or reversible energy storage is connected to the hydraulic motor-pump unit. The generator or the electric motor generator correspondingly converts drive power into electrical energy, so that this can be stored in an electrical energy store or can be used for another electrical unit. If a motor generator is provided, electrical energy can accordingly be converted into drive power from the energy store in order to drive the hydraulic motor-pump unit, that is to say the additional hydraulic motor and / or the hydraulic pump.

According to an embodiment of the invention, the additional hydraulic motor can be operated as a hydraulic pump with or without reversing the direction of flow of the hydraulic medium flowing through it. The drive can take place, for example, by the electric motor generator mentioned or by the fact that the hydraulic pump can also be switched over so that it can be operated by a motor.

If the hydraulic pump can be operated by a motor, it can also be used to dissipate pressure energy from the hydrostatic system.

If the additional hydraulic motor can be operated as a hydraulic pump, the differential pressure on the first hydraulic motor and / or on the at least one consumer can thereby be increased. By means of a suitable switching device, the additional hydraulic motor can also be used in pump operation to reduce the differential pressure. In general, the additional hydraulic motor in pump operation can also be used to supply a subsystem of the hydrostatic system with a higher pressure of the hydraulic medium, so that a corresponding high-pressure pump can be dispensed with.

A pump station according to the invention for an oil or gas pipeline has at least one feed pump in order to convey the oil or gas through the pipeline. Furthermore, at least one internal combustion engine is provided for driving the at least one feed pump.

The internal combustion engine is connected to a hydrostatic system according to the invention, which is then designed as a drive system with a first hydraulic motor, the internal combustion engine being in driving connection with the first hydraulic motor or being switchable in such a way when it starts up. Accordingly, the internal combustion engine is switched or switchable into a drive connection with the output shaft of the first hydraulic motor. Alternatively, the internal combustion engine can also be acted upon as a consumer with pressurized hydraulic medium from the hydraulic pump.

The invention will be described below using exemplary embodiments and the figures as examples.

Figur 1

eine erste Ausführungsform der Erfindung mit einem von einem ersten Hydraulikmotor antreibbaren Verbrennungsmotor;

Figur 2

eine alternative Ausgestaltung der Erfindung mit einem mittels der Hydraulikpumpe der Motor-Pumpen-Einheit mit druckbeaufschlagtem Hydraulikmedium versorgten Verbraucher.

Show it:

Figure 1

a first embodiment of the invention with an internal combustion engine drivable by a first hydraulic motor;

Figure 2

an alternative embodiment of the invention with a consumer supplied by the hydraulic pump of the motor-pump unit with pressurized hydraulic medium.

In the Figure 1 shows a hydrostatic system according to the invention, which is used to drive an internal combustion engine, in particular a pumping station for an oil or gas pipeline. However, the invention is not limited to this.

In the Figure 1 the internal combustion engine is numbered 1, the feed pumps of the gas pipeline 4 shown by way of example with 2 and 3. The illustration of the pump station 5 is very schematic.

The hydrostatic system for starting the internal combustion engine 1 has a hydraulic motor 10 which can be coupled to the internal combustion engine 1 via a clutch 6. In addition or instead of the clutch 6, one or more gear ratios and / or at least one gear can also be provided.

The hydraulic motor 10 is fed from a hydraulic pressure source 11. In the exemplary embodiment shown, the pressure source 11 comprises a pressure accumulator 12, here in the form of a accumulator with a gas tensioning device. A further gas-filled, in particular nitrogen-filled, gas store 13 is preferably connected to the pressure store 12 and is connected to the gas side of the pressure store 12 or can be switched into such a flow-conducting connection. So that the gas spring of the Pressure accumulator are increased and the maximum possible hydraulic medium supply in the pressure accumulator 12 increases with a constant pressure level, in particular with a constant preload pressure of the gas spring and with a constant maximum accumulator pressure. The gas reservoir 13 has, for example, the same volume as the pressure reservoir 12.

In the Figure 1 is indicated schematically that in addition to the first hydraulic motor 10 at least one consumer 14 could be provided in the hydraulic system, which is fed with hydraulic medium from the pressure source 11. Such a consumer 14 is, for example, a working cylinder, a hydraulic motor, a pump or the like. The invention can also be used in a hydrostatic system in which only a corresponding consumer 14 is provided without the first hydraulic motor 10.

The pressure source 11 can be filled with hydraulic medium by means of a charge pump 15. The charge pump 15 is driven, for example, by an electric motor 16 and conveys hydraulic medium from the hydraulic reservoir 17.

To control the first hydraulic motor 10, in particular to start the internal combustion engine 1 with minimal energy consumption from the hydraulic pressure source 11, a hydraulic motor-pump unit 18 is provided, which has an additional hydraulic motor 19 and a hydraulic pump 20, the hydraulic pump 20 from additional hydraulic motor 19 is driven.

The additional hydraulic motor 19 can, as indicated schematically, be designed as a constant motor or as an adjusting motor. Accordingly, the hydraulic pump 20 can be designed as a constant pump or a variable displacement pump. The hydraulic pump 20 can in particular have a fixed speed ratio be connected purely mechanically to the additional hydraulic motor 19, in particular rotating at the same speed. Alternatively, a transmission gear 21 with a variable speed ratio can be provided in the drive connection between the additional hydraulic motor 19 and the hydraulic pump 20.

The additional hydraulic motor 19 is connected in series with the first hydraulic motor 10 and / or the at least one consumer 14 at the hydraulic pressure source 11.

By operating the motor-pump unit 18, the pressure provided by the hydraulic pressure source 11 is reduced, so that the first hydraulic motor 10 provides a correspondingly lower drive power on its output shaft 25, which forms the power output of the hydrostatic system. At the same time, the volume flow through the first hydraulic motor 10 is increased by driving the hydraulic pump 20, so that sensitive control can be achieved and energy can only be withdrawn from the hydrostatic system to a desired extent.

If required, the hydraulic motor-pump unit 18 can have an electrical generator or a motor generator 22 in order to dissipate further energy from the hydraulic circuit by charging the electrical store 23. If a motor generator 22 is provided, this energy can later be fed back into the system by driving the hydraulic pump 20 and / or the additional hydraulic motor 19.

If the additional hydraulic motor 19 can be operated as a pump which feeds into the hydraulic reservoir 17, the differential pressure across the first hydraulic motor 10 or the at least one consumer 14 is increased. Furthermore, it is possible that in this case the additional hydraulic motor 19 has an increased pressure for another subsystem or a other consumers. For this drive of the additional hydraulic motor 19, the motor generator 22 can be used and / or the hydraulic pump 20 if it can be operated by a motor.

If the control capacity of the motor-pump unit 18 is not sufficient to ensure the desired reduction in drive power of the first hydraulic motor 10 to a sufficient extent and thereby to minimize the consumption of hydraulic medium from the pressure source 11, the pressure line 26, which is the pressure source 11 connects to the consumer 14 and / or the first hydraulic motor 10, an adjustable throttle valve 24 can be provided in order to throttle the hydraulic medium flow from the pressure source 11 either more or less. In principle, such a throttle valve 24 could also be provided in the flow direction of the hydraulic medium behind the consumer 14 and / or the first hydraulic motor 10 in order to accumulate the pressure downstream and thereby reduce the pressure difference across the consumer 14 and / or the first hydraulic motor 10.

In the Figure 2 An alternative embodiment of the invention is shown, the same reference numerals being used for corresponding components. In the design according to the Figure 2 the pressure accumulator 12 is also filled by means of the charge pump 15, but here via a check valve 31. However, this is not mandatory.

Even with the design according to the Figure 2 A hydraulic motor-pump unit 18 is provided, the additional hydraulic motor 19 being connected to the pressure line 26 and thus to the pressure source 11 for driving it. In contrast, the hydraulic pump 20 of the hydraulic motor-pump unit 18 is used to supply the hydraulic medium or pressure to the consumer 14. The hydraulic pump 20 also delivers from the hydraulic medium supply 17 to the consumer 14. Thus, the consumer 14 is not in series with the additional one Hydraulic motor 19 connected to the pressure line 26, but the pressure source 11 serves only indirectly for pressurized hydraulic medium supply to the consumer 14. As in the Figure 2 is indicated by the dashed lines, instead of the consumer 14 or in addition to the consumer 14, a first hydraulic motor 10 could also be provided here, which is supplied with hydraulic medium from the hydraulic pump 20. The first hydraulic motor 10 can be switched on and off, for example, via a valve 30 shown here by way of example, in particular in the form of a switching valve or directional valve.

For example, a sensor 33 is provided which, together with a control device 34, determines the speed of the hydraulic motor-pump unit 18 and thus indirectly the current hydraulic medium consumption of the consumer 14 or the speed of the first hydraulic motor 10 and / or an assembly driven by the latter. The same can of course also apply to the configuration according to the Figure 1 be applied. In the design according to the Figure 2 could also be analogous to the design of the first hydraulic motor 10 Figure 1 or a similar design, an internal combustion engine can be driven or accelerated, for example a pump station for an oil or gas pipeline.

Claims (17)

1. Hydrostatic system

   1.1 having a hydraulic pressure source (11);

   1.2 having a first hydraulic motor (10) which has an output shaft (25) which forms a mechanical power output of the hydrostatic system, and/or having at least one consumer (14) which is loaded with pressurized hydraulic medium from the pressure source (11),

   1.3 the first hydraulic motor (10) being connected, in order to drive it, and/or the at least one consumer (14) being connected, in order to pressurize it, by way of a pressure line (26) to the pressure source (11);
   characterized in that

   1.4 a hydraulic motor/pump unit (18) is provided, comprising an additional hydraulic motor (19) and a hydraulic pump (20) which are drive-connected to one another, in such a way that the hydraulic pump (20) can be driven by the additional hydraulic motor (19),

   1.5 the additional hydraulic motor (19) being connected, in order to drive it, in series with the first hydraulic motor (10) and/or the at least one consumer (14) to the pressure source (11), and

   1.6 the hydraulic pump (20) having a pressure side, by way of which it is connected to the pressure line (26).
2. Hydrostatic system

   2.1 having a hydraulic pressure source (11);

   2.2 having at least one first hydraulic motor (10) and/or consumer (14) which can be loaded with pressurized hydraulic medium;
   characterized in that

   2.3 a hydraulic motor/pump unit (18) is provided, comprising an additional hydraulic motor (19) and a hydraulic pump (20) which are drive-connected to one another, in such a way that the hydraulic pump (20) can be driven by the additional hydraulic motor (19),

   2.4 the additional hydraulic motor (19) being connected, in order to drive it, by way of a pressure line (26) to the pressure source (11), and

   2.5 the first hydraulic motor (10) being connected, in order to drive it, and/or the consumer (14) being connected, in order to pressurize it with hydraulic medium, to a pressure side of the hydraulic pump (20).
3. Hydrostatic system according to either of Claims 1 and 2, characterized in that a hydraulic supply (17) is provided, in particular in the form of a hydraulic tank or hydraulic sump, from which hydraulic supply (17) the hydraulic pressure source (11) is fed by means of at least one charge pump (15).
4. Hydrostatic system according to Claim 3, characterized in that the hydraulic pressure source (11) comprises at least one pressure accumulator (12), to which the charge pump (15) is connected by way of a charge pump pressure side for feeding hydraulic medium into the pressure accumulator (12).
5. Hydrostatic system according to either of Claims 3 and 4, characterized in that the hydraulic pressure source (11) comprises at least one pressure accumulator (12) and a gas tank (13) which is connected to the pressure accumulator (12) and is connected to a gas side of the pressure accumulator (12) in a flow-conducting manner or can be switched into a connection of this type.
6. Hydrostatic system according to one of Claims 3 to 5, characterized in that the hydraulic pump (20) has a suction side which is connected to the hydraulic supply (17) by means of a suction line.
7. Hydrostatic system according to one of Claims 4 to 6, characterized in that the hydraulic pressure source (11) comprises a multiplicity of pressure accumulators (12).
8. Hydrostatic system according to one of Claims 1 to 7, characterized in that a variably adjustable throttle valve (24) is provided in the pressure line (26) for regulating the pressure in the pressure line on the input side or on the output side of the first hydraulic motor (10), the additional hydraulic motor (19) and/or at least one consumer (14).
9. Hydrostatic system according to one of Claims 1 to 8, characterized in that the drive connection between the additional hydraulic motor (19) and the hydraulic pump (20) is of purely mechanical configuration.
10. Hydrostatic system according to one of Claims 1 to 9, characterized in that the drive connection between the additional hydraulic motor (19) and the hydraulic pump (20) is established by way of a rigid coupling, in particular with a shaft which carries impellers of the additional hydraulic motor (19) and the hydraulic pump (20) and/or is connected in a torsionally rigid manner to them.
11. Hydrostatic system according to one of Claims 1 to 10, characterized in that the additional hydraulic motor (19) is configured as a variable displacement motor and/or the hydraulic pump (20) is configured as a variable displacement pump with a variably adjustable delivery volume per revolution, in particular a variably adjustable swept volume.
12. Hydrostatic system according to one of Claims 1 to 9, characterized in that a transmission mechanism (21) with a variable rotational speed ratio is provided in the drive connection between the additional hydraulic motor (19) and the hydraulic pump (20).
13. Hydrostatic system according to one of Claims 1 to 12, characterized in that an electric generator or an electric motor generator (22) is connected to the hydraulic motor/pump unit (18) for energy storage, reversible energy storage and/or the provision of electric energy.
14. Hydrostatic system according to one of Claims 1 to 13, characterized in that the additional hydraulic motor (19) can be operated as a hydraulic pump with or without a flow direction reversal of the hydraulic medium.
15. Hydrostatic system according to one of Claims 1 to 14, characterized in that the hydraulic pump (20) can be operated by motor.
16. Hydrostatic system according to one of Claims 3 to 15, characterized in that the additional hydraulic motor (19) is connected to the hydraulic supply (17), in order to convey hydraulic medium from the pressure line (26) into said hydraulic supply (17).
17. Pumping station (5) for an oil or gas pipeline (4)

    17.1 having at least one delivery pump (2, 3), in order to convey the oil or gas through the pipeline (4);

    17.2 having at least one internal combustion engine (1) for driving the at least one delivery pump (2, 3) ;
    characterized in that

    17.3 the internal combustion engine (1) is connected to a hydrostatic system according to one of Claims 1 to 16, the internal combustion engine (1) being drive-connected to the first hydraulic motor (10), in order to start the former, or it being possible for said internal combustion engine (1) to be switched into a drive connection of this type, or the internal combustion engine (1), as a consumer (14), being loaded with pressurized hydraulic medium from the hydraulic pump (20).

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