DE102013016645B3 - System for energy transmission from ship to submarine vehicle i.e. torpedo, has optical fiber for transmitting energy from platform to another platform, where transmitted energy is partially used for driving heat engine of latter platform - Google Patents

Abstract

The system (1) has a platform (12a) i.e. ship, and another platform (12b) moved relative to the former platform. The former platform is designed for providing and/or generating energy, and an optical fiber (18) is arranged between the platforms. The optical fiber is designed for optical transmission of energy from the former platform to the latter platform, where the optically transmitted energy is partially used for driving a heat engine of the latter platform. The optical fiber is provided for connecting the platforms, where the heat engine is designed with a closed process gas guide.

Description

The present invention relates to drive technology. In particular, the present invention relates to a structure for power supply or energy transfer from a first platform to a second platform. In particular, the present invention relates to the transmission of energy to an underwater vehicle, in particular unmanned, also: torpedo, for its operation, in particular for its drive, wherein the energy transfer from a base station, for. B. a carrier to said underwater vehicle by means of an optical waveguide (LWL) guided, optical radiation energy.

The state of the art in the field of laser sources, in particular in the field of electrically pumped semiconductor lasers ("diode laser"), the solid-state laser sources ("fiber") and the associated optics allow optical power in the range of many kilowatts, up to 100 kW and more, with high efficiency, electrical or optical of 25% or more, to produce, handle and focus. It corresponds to the prior art that such semiconductor or solid-state laser sources highest power and efficiency, preferably in the near infrared range, d. H. at wavelengths of about 800 nm to about 1.5 microns, work.

Furthermore, the state of the art in the field of optical waveguides (optical fiber) or optical fibers, in particular by the development of optical waveguides with low attenuation, on the one hand reliably transmit large amounts of data in the duplex method over many kilometers ("optical telecommunications"). On the other hand, high optical radiation powers in the multi-kW range may be transmitted from an optical source to a remote location. Applications of such high-power optical fibers are z. As in the field of fiber-guided material processing equipment, with conventional transmission paths are in the range of a few meters. The limiting factor for these transmission paths, apart from the application requirement, lies in the range of the beam properties due to mode mixing, dispersion and nonlinear optical effects, which is negative for the intended application.

It is conceivable optical radiation power in the high multi-kW range over long distances, z. B. several miles to transfer. When so-called "laser drilling" when drilling in the rock, z. As in the oil and gas prospecting, the radiation of a laser used to strongly heat auszubohrendes rock and thereby reduce its mechanical strength to facilitate the subsequent conveying by means of a drill string. The radiation of the laser is guided via an optical fiber to the head of a drill pipe and used there.

Already in the past there have been attempts to use the principle of energy transfer by means of generated by high-power laser and transmitted in the free jet radiation power for drive purposes. This principle, referred to as "laser propulsion", is based on generating a recoil on the object to be driven by means of ablation or by plasma formation on an auxiliary medium, which reactively drives the object in the sequence. Another variant of such energy transfer is based on the attempt, the optical radiation energy of a directed to an aircraft in the free space laser beam by means of photovoltaic elements, eg. As solar cells, first in electrical energy and then implement by means of electric motor drives in buoyancy or propulsion, and possibly to feed existing auxiliary equipment with it. Such a method is for example in US 6,364,253 B1 described.

Since the aforementioned laser sources operate preferably in the near infrared range, such a free jet transmission also prevents water or underwater. On the one hand, the intrinsic absorption of the water for such wavelengths is already too high, on the other hand, there would be considerable wastage due to suspended matter contained in natural water.

DE 10 2009 058 879 A1 describes an electrical energy storage system of an electric or hybrid vehicle. The energy storage system has a plurality of electrical components, which are designed to transmit data signals such as sensor measured values over a transmission path. The transmission path may comprise an optical fiber and an electrical conductor, wherein the data signals are transmitted via the optical fiber and electrical power via the electrical conductor.

US 2012/0256005 A1 describes a connecting cable for an electrical and optical connection of two devices, between which electrical energy or data signals can be transmitted via the connecting cable.

DE 10 2011 115 657 A1 describes a marine datacenter that is placed underwater to use the cooling power or thermal conductivity of the surrounding water to cool components of the data center. The data center receives its power from a hydroelectric power station installed in the data center environment. The data transmission to or from the data center takes place via an optical data line.

DE 41 23 489 C2 describes a device for conducted data and energy transmission by means of light energy via an optical waveguide. The optical waveguide connects a sensor unit to a data processing device. The sensor unit has an optical-electrical energy converter, which supplies a transducer of the sensor unit with electrical energy.

DE 10 2007 043 888 A1 describes a device for supplying power to a consumer via a utility network. A consumer acceptance point can be connected to the supply-side control of the power supply of the consumer via a communication transmission unit with a power supply unit. This connection is a common data communication connection and may include a fiber optic cable.

According to the invention, a system is provided which, in particular for driving a platform, transfers energy using an optical fiber and thus provides the platform for the use of the energy.

Accordingly, a system according to the independent claims is indicated. Preferred embodiments will be apparent from the dependent claims.

According to an exemplary embodiment of the present invention, there is shown a system comprising a first platform and a second platform, the first platform configured to provide and / or generate energy, wherein an optical fiber is provided between the first platform and the second platform wherein the optical fiber is configured to transfer the energy from the first platform to the second platform, and wherein the transmitted energy is at least partially used to drive the second platform.

Performing underwater activities, especially at great depths and over long periods of time, is a challenge, an inconvenience due to the physical constraints involved and also a great danger to humans, despite the progress made in the construction of submersibles the activity itself is associated with other risks, eg. As in mine laying or clearing, in the exploration and recovery of dangerous substances, to the extreme of a torpedo, which has the task to spend a warhead to a target and to destroy itself in the course of the mission itself. There are unmanned underwater vehicles, which can perform such tasks partially autonomous, partly remotely controlled by a base station or a carrier, but in any case without crew.

Such unmanned underwater vehicles (UUV) are known today in several forms. To explore, d. H. the main purpose of such a vehicle is the detection of the situation / environment, which wg. poor visibility, poor situation and the like is not possible from a distance. Furthermore, UUVs can be used for manipulation, i. H. the main purpose of such a vehicle is to perform a practical operation (eg welding, cutting, salvaging, clearing, moving) which requires a physical presence at the place of performance. Also, torpedoes represent a special expression of UUVs, whereby mixed forms of the mentioned forms are conceivable.

The mission time of such an unmanned underwater vehicle for a mission, as it is remotely controlled from a carrier, is no longer limited by the stamina of a crew (including the resources required to maintain it). Rather, the amount of resources reserved for its operation, even in this vehicle, is the limiting factor. An essential such resource is the amount of energy available for driving or supplying auxiliary systems (eg, sensors). The possible duration of use could thus be extended considerably, possibly even to continuous operation, if such a vehicle from outside, z. B. from a carrier used to control, is supplied with energy.

Depending on the type of underwater vehicle affects the limited duration of use in different ways, z. Limited range (often in conjunction with maximum speed limitation, limited time spent in a designated location / area or limited search distance or limitation on the possible search profile) Exhaustion of existing, eg electrical energy storage and return to the carrier at the end of such a mission a certain period of time is required to prepare this, for example, by charging or exchange of energy storage for the next use Systems severely restricted.

Irrespective of the question of the limited duration of use, it should also be noted that especially electrochemical energy stores have a considerable need for space and mass, which at a given total mass and / or predetermined installation space is considerable Restrictions on the possible payload. A storage of electrical energy may basically z. B. by flywheel storage, electrochemical batteries or high capacity capacitors ("supercaps"). Achievable are gravimetric storage densities of 100 Wh / kg (corresponding to 360 kJ / kg) up to 500-1000 Wh / kg (corresponding to 1800-3600 kJ / kg), compared to a gravimetric energy density of typically 40 MJ / kg on direct chemical storage ("fuels") based drives.

Despite extensive automation of such unmanned underwater vehicles through advances in sensor technology, signal processing, and algorithm-based decision making, a large number of tasks still exist or can not be dispensed with in human judgment. Since a crew who can take on such a task on the unmanned vehicle of the nature of the thing is not present, this can only be done by operators who z. B. on the carrier, but in any case at other locations, be adopted. In order to allow such operators to make decisions and to influence what is happening, it is necessary to exchange data between the underwater vehicle and the control unit for controlling it. These are typically sensor data collected at the vehicle location / vehicle to provide operators with a condition and attitude assessment, as well as control data to allow operators to control the future behavior of that vehicle, which in the simplest case in a steering, d. H. an influence on the direction of movement in the room exists.

For the data exchange different, each with specific advantages and disadvantages associated technologies are known, for. B. (water) propagating in the water (ultra) sound, (laser) light, electromagnetic waves (very large wavelength), transmitted through lines electrical signals ("wire-steered") or optical signals ("fiber-steered"). However, these approaches are usually detectable, disturbing / prone to failure, have a limited range, a limited to very low data rate and require, depending on the technology, very large / long antennas. Here, the data exchange via optical fibers has proven in many cases as a useful compromise, so that both torpedoes and UUVs are equipped for exploration or manipulation with such data transmission systems.

A typical torpedo has a diameter of about 50 cm. At a typical speed of 90 km / h, corresponding to 25 m / s, this results in a dynamic displacement of about 5 m ³ / s. Even if only 1%, ie 50 l / s, is branched off as a partial flow and used for cooling or dissipation of the lost heat, this results in a cooling capacity of 200 kW / K. Even power losses of more than 100 kW thus only lead to a warming of the cooling water flow of less than one degree Celsius. The lower temperature level of a heat engine may thus be assumed as constant and the water temperature (4-10 ° C) accordingly.

In underwater vehicles used for exploration, the speeds are significantly lower, and accordingly, the resulting volume flows and cooling capacities. However, the drive powers to be used for this purpose are also significantly reduced, so that overall no less unfavorable picture results.

In underwater vehicles, it may occur when the consumption of an existing energy supply also changes the mass of the vehicle, so that the buoyancy balance is out of balance. This can be the case, for example, when the media of a stored as compressed gas storage or as chemical fuel power reserve are discharged during operation to the outside, either because in this way the heat loss of a heat engine is completely or partially dissipated, or because it, z. B. for reasons of space, is impossible, the resulting at the outlet of a prime mover media, eg. As exhaust gases, carry on the present pressure level on board the vehicle until the end of the mission on. For underwater vehicles, which use their energy from an electrical energy storage, eg. As battery, refer, the problem is not usually given as well as in vehicles, which use their energy through a supply line from the outside, eg. B. from a base station like.

Regardless of the type of execution of the actual laser-active medium as a rod, slab, fiber or disk laser of a laser source, such a system may be so-called diode-pumped lasers, usually solid-state lasers, whereby liquid, gas or metal vapor lasers are also realized to be like). Ie. the conversion of the primary energy in the form of electrical energy into radiation energy for the optical excitation of the laser-active medium takes place by means of a (large) number of semiconductor lasers or diode lasers. A direct use of the radiation emitted by the semiconductor laser radiation comes into consideration. Here, the efficiency for the conversion of electrical energy into radiation energy for optical excitation on the one hand and for the conversion of this radiation energy to the optical Excitation in the optical output power of the laser system on the other hand due to physical laws below one. In practice, efficiencies of about 50% are achieved for both processes, so that the overall efficiency, often referred to as socket efficiency, of the conversion of electrical energy to radiant energy of a laser is in the range of 25-50%, depending on the type of implementation. Optionally, there are also optical losses in the transmission of radiation energy, as well as electrical losses in lines and in electronic circuits usually used for the controlled control of semiconductor lasers and for energy conversion.

On the side of the underwater vehicle, the transmitted optical radiation energy is first in one for the application, for. B. convert the drive suitable form of energy, z. B. in mechanical energy. For this purpose, several methods are considered. Thus, a conversion of the optical radiation energy by means of photovoltaic cells may be provided in electrical energy to then convert them by means of an electric motor drive into mechanical energy. The optical radiation power, which occur in the application for the use of solar energy, amount to about 1 kW / m ² , achieved by means of multi-layer cell structures optically-electrically achieved thereby substantially 40%. Also conceivable are so-called concentrating solar cells, which by means of an optical concentrator, the radiation power over the natural radiation density by a factor, for. B. to 500 ×, increase to get along with less of the expensive substrate material. This results in power densities of 50 W / cm ² substrate area.

In the application of photovoltaic cells for the conversion of radiant energy into electrical energy for high power applications, there is a limit to the currents that occur. The generated voltage of individual cells is regularly in the range of less than 1 V. Even in the series connection of several such cells, eg. B. 100, results in a total potential of only a few tens of volts, z. B. 50 V. For services of many kilowatts, z. B. 10 kW, currents of several hundred amperes, z. B. 200 A, which is an at least unusual operating state for photovoltaic cells.

For the provision of high mechanical performances with limited mass and limited installation space, so-called heat engines may be used. Such heat engines put their name according to heat energy into mechanical energy, the heat energy usually comes from combustion processes. Heat engines, even for mobile operation, are conceivable in a wide range of power classes from just a few watts to many megawatts. Since the vast majority of today known and in use heat engines are operated with chemical energy sources of fossil origin under combustion with the ambient air, this involves so-called internal heat engines with internal combustion, gasoline engine, diesel engine, jet turbine, etc. This is the chemical energy , the fuel, reacted within the heat engine with the ambient air to the reaction, the heat of combustion released leads to a temperature increase, pressure and / or increase in volume of the combustion gas, which is relaxed in a subsequent step and doing work. The expanded combustion gases are then discharged into the environment mostly as exhaust gas.

According to use find so-called external heat engines with external combustion. The best known heat engine of such a type is designed as a cyclic (piston) engines Stirling engine. But are also known non-cyclic turbine engines, z. B. Brayton or Ericsson turbine. All of these is common that the process gas of the heat engine is not part of the combustion process, ie that a heat supply, eg. B. from a combustion process, this process gas "from outside" takes place. Here, the process gas can be performed in a closed circuit after a regeneration or cooling following the work.

However, it is not absolutely necessary that in such external heat engines the heat supplied comes from a combustion process, even if that is often the case. According to the invention it is now proposed to make the power supply of an underwater vehicle so that the energy, eg. B. in the form of electrical energy, generated or provided on a support or a first platform, where it is converted by means of a laser into optical radiation energy, transmitted via an optical waveguide to the underwater vehicle and converted there into usable energy.

In order to optimize the overall efficiency, it is advantageous to use one or a multiplicity of semiconductor lasers in the laser used for the generation of the optical radiation energy, insofar as it is possible on account of the required power and the brilliance necessary for the coupling into the optical waveguide , Also, it may be in the laser used for the original generation of the optical radiation energy to a solid state laser, z. B. fiber laser, act, which then in particular to increase the brilliance of used for pumping semiconductor laser is used.

In the case of an underwater vehicle as a second platform, the associated carrier or the first platform may regularly be another vessel or ship or a platform anchored or anchored on land. It is also conceivable that the carrier is a flying platform or another underwater vehicle.

The system may continue to be carried out so that the underwater vehicle in an interruption of data and / or energy transfer automatically, immediately or after a predetermined waiting time, in a certain mode, while z. B. emerges, sinks to the bottom or remains in the last depth.

There are various possibilities for making use of the optical energy in the form of energy transmitted via the optical waveguide for the operation of a drive system or other auxiliary devices. On the one hand, the direct conversion of the light into electrical energy by means of photovoltaic, photothermovoltaic elements and subsequent use of electrical energy is possible. It is also conceivable for the operation of a drive system with high power to operate this by means of a heat engine, wherein the heat required for the operation of this machine comes from almost lossless conversion of transmitted via the optical fiber, optical energy into heat. The heat engine is advantageously a heat engine with closed process gas guidance. Depending on the type of process gas, it may make sense to deliver it to the environment after work performance. This is especially the case when it is water vapor, which can be generated from the water naturally surrounding an underwater vehicle by supplying heat and can be discharged without problems and without Tarierprobleme to the environment again, possibly after previous condensation.

In such a system, it is necessary to couple the optical energy as efficiently and with high power density in the process gas, which can be done for example in the following ways. For example, absorption of the radiation energy may take place in a radiation trap ("absorber"), whereby it is heated and, as a heat exchanger, in turn delivers this heat to the process gas; Here, the process gas can be performed both on the active, irradiated, as well as on the passive, separated by the absorber wall of the radiation side of the radiation trap. The efficiency is essentially limited by the degree of absorption, the thermal conductivity and the temperature resistance of the absorber. Alternatively, absorption of the radiant energy may occur directly in the process gas or in a precursor for this, e.g. B. its condensate or a dispersion of absorbent particles in it, take place. This may presuppose a corresponding absorption of the radiation with the corresponding wavelength in the process medium. Also conceivable is the absorption of the radiation energy in a plasma formed in the process gas, for. B. by means of optical arc, with mixed forms of these embodiments are conceivable.

For the regulation of the depth of an underwater vehicle over larger areas or periods, it may be necessary to change its mean density, so that there is a buoyancy or downforce compared to the mean density of the surrounding water. This is conventionally achieved by flooding or lashing ballast tanks, which in turn can be achieved by pumping and / or blowing with a medium of significantly lower density, e.g. B. a gas can be done under elevated pressure, such medium is often lost in a renewed flooding. Advantageous for the invention described herein is a purging with water vapor, which may be generated from the surrounding water due to the practically unlimited amount of energy from the transmission through the first platform. Also, a photoinduced cleavage of the water may be conceivable. It must for this purpose k an auxiliary medium, for. B. compressed air, be carried.

The proposed solution is characterized in particular by the fact that it allows a radius of use of an underwater vehicle of several kilometers with almost unlimited duration of use. Next results from the proposed solution increased reliability and operational readiness of the overall system, since by the substantial waiver of (electro) chemical energy storage in the underwater vehicle both its shelf life is improved and account for some inherently error-prone components. Finally, it is not irrelevant that in particular such electrochemical energy storage with high gravimetric energy density a significant hazard, z. As by spontaneous implementation or damage, so that ultimately can be realized a security gain.

Hereinafter, reference will be made to embodiments of the invention with reference to the accompanying drawings. Show it:

1 a schematic structure of a system according to the present invention.

1 shows a system according to the invention 1 consisting of a first platform 12a , exemplified as a ship, and a second platform 12b exemplified as an underwater vehicle. The underwater vehicle may be returning or not returning, z. As a torpedo or the like may be formed. Also conceivable, but not explicitly shown, is the design of the first platform 12a as an onshore or anchored platform, as a flying platform or even as an underwater vehicle, e.g. B. a submarine, the second platform 12b may also be designed as a ship or flying platform.

The first platform 12a and the second platform 12b are using an optical fiber 18 connected on the one hand on the first platform 12a generated energy to the second platform 12b may and may continue to provide data communication between the first and second platforms. The energy provided may be in / from the second platform 12b be used to drive, propulsion and lift or output to realize.

Since the optical fiber may be formed comparatively thin, z. B. with a core in the 100 micron range with a total dimension in the range of 300 microns, a comparatively long length of the optical fiber is conceivable in the range of several kilometers, z. 2 km, 3 km, 4 km or even 5 km and more. In particular, a length in the range of up to 5 km, in particular up to 4 km or up to 3 km may be sufficient for a comparatively large operating radius. In the case of non-returning second platforms 12b may the length be significantly longer, z. B. 10 km, 20 km or more.

In addition, it should be noted that "having" or "comprising" does not exclude other elements or steps, and that "a" or "an" does not exclude a plurality. It should also be appreciated that features or steps described with reference to any of the above embodiments may also be used in combination with other features or steps of other embodiments described above. Reference signs in the claims are not to be considered as limiting.

LIST OF REFERENCE NUMBERS

1

system

12a, b

first, second platform

18

optical fiber

Claims (11)

System ( 1 ), comprising a first platform ( 12a ); and a second platform ( 12b ), which relative to the first platform ( 12a ) is movable; the first platform ( 12a ) is arranged for the provision and / or generation of energy; wherein an optical fiber ( 18 ) between the first platform ( 12a ) and the second platform ( 12b ) is provided; the optical fiber ( 18 ) is arranged for optical transmission of energy from the first platform ( 12a ) to the second platform ( 12b ); and wherein the optically transmitted energy is at least partially for driving the second platform ( 12b ) is used. System according to the preceding claim, wherein the energy for realizing the drive is used to operate a heat engine, a closed-cycle heat engine, an external combustion engine with external combustion, a Stirling engine, a Brayton turbine, an Ericsson turbine or for direct conversion into electrical energy by means of photovoltaic, photothermovoltaic elements. A system according to the preceding claim, wherein the transmitted optical energy is coupled into the process gas by absorbing the radiant energy in a radiation trap which, as a heat exchanger, transfers the heat to a process gas, in particular wherein the process gas is on the active, irradiated side or on the passive side of the process gas Radiation trap is performed; by absorption of the radiation energy directly in the process gas, in a precursor of the process gas, a dispersion of absorbent particles and / or in a plasma formed in the process gas. System according to one of claims 2 or 3, wherein the process gas is deliverable to the working environment to the environment. System according to one of the preceding claims, wherein the optical fiber ( 18 ) is further adapted to transfer data between the first platform ( 12a ) and the second platform ( 12b ), in particular unidirectional or bidirectional. System according to one of the preceding claims, wherein the energy on the first platform ( 12a ) is generated by means of a laser element, in particular one or a plurality of semiconductor laser elements, a solid-state laser, a fiber laser, in particular additionally provided for increasing the brilliance of the semiconductor laser elements used. System according to one of the preceding claims, the first platform ( 12a ) is formed as a platform from the group consisting of ship, onshore or anchored platform, flying platform or underwater vehicle; and / or wherein the second platform ( 12b ) is formed as a platform from the group consisting of ship, flying platform or underwater vehicle. System according to one of claims 1 to 6, wherein the system ( 1 ) is designed such that the second platform ( 12b ) is designed as an underwater vehicle and automatically, immediately or after a predetermined waiting time, in a certain mode, in particular pauses, in particular pauses, sinks to the bottom or remains at the last depth in an interruption of the data and / or energy transfer. System according to one of the preceding claims, wherein a buoyancy or downforce of the second platform ( 12b ) is adjustable, in particular a buoyancy by Lenzen at least one ballast tank with a medium of lower density than the surrounding medium is adjustable, further in particular a purging with water vapor. System according to one of the preceding claims, wherein the heat engine has a water cooling, wherein the water in particular the environment of the second platform ( 12b ) is taken. System ( 1 ) according to one of the preceding claims, wherein the optical fiber ( 18 ) a length in the range of up to 8 km, in particular up to 7 km, further in particular up to 6 km, further in particular up to 5 km, more particularly up to 4 km, more particularly up to 4 km, further in particular up to 3 km, more particularly up to 2 km, more particularly up to 1 km.

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