Ship propulsion system, and method for operating a ship propulsion system

Abstract

A ship propulsion system is disclosed comprising an internal combustion engine for driving a ship, wherein the internal combustion engine comprises a combustion chamber for combusting fossil fuel, a supply line for delivering a gas mixture to the combustion chamber, an electrolysis chamber for producing hydrogen gas and oxygen gas, and a vacuum pump for sucking the hydrogen gas and the oxygen gas from the electrolysis chamber. The ship propulsion system furthermore comprises a gasification tank with volatile organic compounds received therein, in particular methanol or ethanol, as well as a supply line for supplying a gas mixture to the combustion chamber, wherein the gas mixture comprises gasified organic compounds from the gasification tank and at least a part of the hydrogen gas and the oxygen gas. Furthermore a corresponding method for operation a ship propulsion system is disclosed.

Claims

1. A ship propulsion system, comprising an internal combustion engine for propelling a ship, wherein the internal combustion engine has a combustion chamber for burning a fossil fuel, an electrolysis chamber for producing hydrogen gas and oxygen gas, a turbocharger, a supply line, which is designed so that a gas mixture can be conveyed via a compressor of the turbocharger to the combustion chamber, the gas mixture including at least a part of the hydrogen gas and the oxygen gas, a vacuum pump for drawing off the hydrogen gas and the oxygen gas from the electrolysis chamber, a gasification tank with volatile organic compounds received therein, and an air supply for supplying compressed air into the gasification tank, and in addition to the turbocharger there is an air compressor for pumping air into the gasification tank, wherein the gas mixture, which is guided via the supply line and the turbo charger to the combustion chamber, also includes gasified organic compounds from the gasification tank.

2. The ship propulsion system as defined in claim 1, wherein: the vacuum pump and the gasification tank are arranged so that the hydrogen gas and the oxygen gas can be conveyed at least partially through the vacuum pump from the electrolysis chamber into the gasification tank to produce the gas mixture.

3. The ship propulsion system as defined in claim 1, wherein: the electrolysis chamber and a pipeline system are formed from the electrolysis chamber to the gasification tank so that hydrogen gas and oxygen gas can be conveyed, unseparated, as oxyhydrogen.

4. The ship propulsion system as defined in claim 2, wherein: the hydrogen gas and oxygen gas conveyed into the gasification tank are introduced via a plurality of nozzles in a lower part of the gasification tank.

5. The ship propulsion system as defined in claim 1, wherein: a storage tank is provided and connected to the gasification tank for filling the gasification tank with organic compounds.

6. The ship propulsion system as defined in claim 1 wherein: the electrolysis chamber is supplied with an electric current, through which the hydrogen gas and the oxygen gas are obtained in the electrolysis chamber, and further comprising a controller configured to control at least one of: the electric current, an introduction of water into the electrolysis chamber, or a pumping capacity of the vacuum pump, in dependence on a momentary property of an internal combustion engine operation.

7. The ship propulsion system as defined in claim 6, wherein: the controller is configured to: use a boost pressure of the internal combustion engine as a momentary property of the internal combustion engine operation in dependence on which the at least one of: the electric current, the water introduction or the pumping capacity of the vacuum pump is controlled, a boost pressure of the internal combustion engine (50), and set the electric current and the pumping capacity to be higher, the higher the boost pressure is.

8. A ship comprising: a ship propulsion system as defined in claim 1.

9. A method for operating a ship propulsion system, the method comprising: propelling a ship with an internal combustion engine by introducing a fossil fuel into a combustion chamber of the internal combustion engine, wherein, in an electrolysis chamber, hydrogen gas and oxygen gas are produced, and wherein a gas mixture is conveyed via a compressor of a turbocharger to the combustion chamber, the gas mixture including at least a part of the hydrogen gas and the oxygen gas, wherein: the hydrogen gas and the oxygen gas are drawn off from the electrolysis chamber with a vacuum pump, in a gasification tank, volatile organic compounds are gasified, an air supply for supplying compressed air into the gasification tank is provided, and with an air compressor, which is provided in addition to the turbocharger, air is pumped into the gasification tank, and the gas mixture, which is guided via the turbocharger to the combustion chamber, also includes gasified organic compounds from the gasification tank.

10. The method as defined in claim 9, wherein: in the electrolysis chamber, a reduced pressure is generated by the vacuum pump, the reduced pressure being between 200 mbar and 700 mbar.

11. The method as defined in claim 9, wherein: the vacuum pump draws off so much gas from the electrolysis chamber that, during operation of the electrolysis chamber, at most a quarter of the electrolysis chamber is filled with gas.

12. The method as defined in claim 9, wherein: an ignition timing is effected at a crankshaft angle of less than 20 before top dead centre.

13. The method as defined in claim 9 wherein: the vacuum pump is operated with maximum pumping capacity when a parameter for an engine operation reaches a predefined threshold value, and in addition the air compressor is operated, which pumps air into the gasification tank, when the parameter exceeds the predefined threshold value.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages and features of the invention will be described hereinbelow with reference to the accompanying schematic figures, wherein:

(2) FIG. 1 is a schematic representation of an embodiment of a ship propulsion system of the invention, and

(3) FIG. 2 is a schematic representation of a further embodiment of a ship propulsion system of the invention.

DETAILED DESCRIPTION OF THE INVENTION

(4) FIG. 1 shows schematically an embodiment of a ship propulsion system 100 according to the invention. It may be part of a ship according to the invention (not depicted). In addition to the ship propulsion system 100, the ship may comprise another propulsion system, for example a combustion engine for crude oil. Furthermore, the ship may comprise several ship propulsion systems 100 which may be each formed as described below.

(5) As main components, the ship propulsion system 100 comprises an electrolysis chamber 20 for producing hydrogen gas and oxygen gas, a gasification tank 30 for gasifying volatile organic compounds, and an internal combustion engine 50, which is supplied with fossil fuel as well as the produced hydrogen gas, the oxygen gas and the gaseous organic compounds.

(6) By adding this gas mixture, the combustion of diesel or another fossil fuel may take place faster and the amount of pollutants or emissions output in the exhaust gas is reduced.

(7) As a first step, water or another starting material is converted in the electrolysis chamber 20 with the help of electrical energy into hydrogen gas, oxygen gas and possibly further components.

(8) The produced hydrogen gas and the produced oxygen gas are transported via a supply system or line system 28. These two gases may in particular be provided as a mixture, i.e., oxyhydrogen. For transportation a vacuum pump 25 is provided in the supply system 28. The vacuum pump 25 produces a reduced pressure in the electrolysis chamber 20, thus sucking off the oxygen gas and the hydrogen gas.

(9) Furthermore, the reduced pressure in the electrolysis chamber 20 reduces the amount of electrolyte (which is present in the electrolysis chamber 20) that transfers from the liquid state into a gaseous state. In this way, the efficiency of the electrolysis chamber 20 can be increased.

(10) The supply system 28 supplies the oxygen gas and the hydrogen gas to the gasification tank 30. Organic compounds such as methanol and/or ethanol are provided in the gasification tank 30 and experience a surface gasification due to introduction of the hydrogen gas and the oxygen gas. To this end the hydrogen gas and the oxygen gas are introduced into the gasification tank 30 in a lower part thereof, in particular at its bottom. A gas mixture is thus formed within the gasification tank 30, comprising at least hydrogen gas, oxygen gas and gasified organic compounds, in particular methanol and/or ethanol. This gas mixture is then forwarded via a supply line 38. Instead of forwarding the oxyhydrogen through the gasification tank 30, it is alternatively also possible to direct gaseous organic compounds out of the gasification tank and only then bring it together with the oxyhydrogen.

(11) The size of the gasification tank 30 may be chosen such that a desired amount of organic compounds in transferred into the gaseous state and forms a mixture with hydrogen gas and oxygen gas, when the hydrogen gas and oxygen gas is passed through the gasification tank 30. A ship comprising the ship propulsion system of the invention shall carry larger amounts than possible with the gasification tank, and to this end a storage tank 32 may be provided. The storage tank 32 supplies organic compounds to the gasification tank 30 and is not itself supplied with produced hydrogen gas or oxygen gas. A level sensor may be provided at the gasification tank 30 with which introduction of organic compounds from the storage tank 32 into the gasification tank 30 may be controlled.

(12) The supply line 38 leads the produced gas mixture from the gasification tank 30 to a compressor 42 of a turbocharger 40. The gas mixture may be transported to the compressor 42 together with ambient air. For this merging, a corresponding line may be provided (not depicted). The gas mixture is led from the turbocharger 40 into a combustion chamber 52 of the internal combustion engine 50. In the combustion chamber 52 the gas mixture ignites and causes combustion of injected fossil fuel, for example injected diesel fuel.

(13) Exhaust gases are guided from the combustion chamber 52 via an exhaust line 54 to an exhaust turbine 44 of the turbocharger 40. A pressure of the exhaust gas is thus used by the exhaust turbine 44 to transport the gas mixture with the compressor 42 in the direction of the internal combustion engine 50. Downstream of the exhaust turbine 44, the exhaust gas reaches an optional exhaust filter 60.

(14) A supply of the gas mixture into the combustion chamber 52 shall be increased if the amount of injected/introduced fossil fuel increases. For this purpose, inter alia, the turbocharger 40 is used. The compressor 42 of the turbocharger 40 is driven by the exhaust turbine 44. The exhaust turbine 44 drives the compressor 42 with more power if an exhaust pressure at the exhaust turbine 44 increases. If only small amounts of fuel are combusted in the combustion chamber 52, it follows that the pressure at the exhaust turbine 44 is small and the compressor 42 only produces a small suction in the supply line 38. If, on the other hand, larger amounts of diesel are combusted in the combustion chamber 52, then the compressor 42 will cause a stronger suction of gas mixture from the supply line 38.

(15) Furthermore, the amount of the produced gas mixture may be controlled according to demand. To this end, controller 10 may be provided which may in particular be configured to adjust an electrical current through the electrolysis chamber 20 and may thus set the amount of hydrogen gas and oxygen gas to be produced. Furthermore, the controller 10 may control the vacuum pump 25 and may thus set the amount of hydrogen gas and oxygen gas that is transported from the electrolysis chamber 20 into the gasification tank 30. For increasing the amount of produced gas mixture, a larger electrical current and a higher pumping power of the vacuum pump 25 may be set. The amount of produced gas mixture may be set the larger, the higher the rate or amount of injected diesel into the combustion chamber 52. The boost pressure of the internal combustion engine 50 may be used as a measure for this. The controller 10 may thus be configured to increase the pumping power of the vacuum pump 25 and the electrical current in the electrolysis chamber 20 with increasing boost pressure. Pressure measuring means for this purpose may be provided. In the depicted example, pressure measuring means 12 are provided which measure an exhaust pressure upstream of the turbocharger 40. Also this exhaust pressure may be used for controlling the produced amount of gas mixture.

(16) It may be desired to supply even larger amounts of gas mixture to the turbocharger 40 or the internal combustion engine 50 as can be achieved with a maximum current through the electrolysis chamber 20 and a maximum pumping power of the vacuum pump 25. In particular for such a case, an additional air compressor 35 may be provided. The air compressor 35 pumps air, in particular ambient air, into the gasification tank 30 and thus causes an increased gasification of the organic compounds. It may be desired if a line of the air compressor 35 and the line system 28 end at the vacuum pump 25 into a common line so that air from the air compressor 35 and hydrogen gas and oxygen gas produced by the electrolysis are let via the same nozzles into the gasification tank 30. In other variants, however, it may be preferred that the air from the air compressor 35 and the produced hydrogen gas and oxygen gas reach the gasification tank 30 through separate lines.

(17) The controller 10 may also set a pumping power of the air compressor 35. It may be provided that the air compressor 35 is only operated when the electrolysis chamber 20 is supplied with a maximum current and the vacuum pump 25 operates with maximum pumping power.

(18) It may also be preferable if gas can only be introduced into the gasification tank 30 through the air compressor 35 and not through the vacuum pump 25. In this way the amount of organic compounds introduced into the internal combustion engine 50 is adjustable independent from the amount of oxyhydrogen supplied to the internal combustion engine.

(19) For cleaning exhaust filter 60 particularly efficiently, it may be supplied with oxygen gas from the electrolysis chamber 20. In the depicted embodiment, a line 62 is provided for this purpose which leads from electrolysis chamber 20 to exhaust filter 60. Depending on the example embodiment, a design of electrolysis chamber 20 may be preferred in which either oxygen gas is guided through line 62 separated from and without the hydrogen gas, or oxygen gas and hydrogen gas are together transported through line 62.

(20) By supplying the produced gas mixture to the fossil energy carrier in the combustion chamber 52, a particularly fast combustion is made possible. This allows ignition to take place very shortly before a top dead center of the piston of the internal combustion engine 50 which makes a higher efficiency possible. Furthermore, the amount of produced pollutants in the exhaust is reduced.

(21) A further embodiment of a ship propulsion system 100 according to the invention is shown schematically in FIG. 2. Components with the same reference numerals as in FIG. 1 may be built similarly and have the same effect as described with respect to FIG. 1, or vice versa.

(22) As featured components, the ship propulsion system 100 comprises again an electrolysis chamber 20, a gasification tank 30 and a turbo charger 40 as well as an internal combustion engine 50.

(23) As described with respect to FIG. 1, the electrolysis chamber 20 produces hydrogen gas and oxygen gas. Together with gaseous volatile hydrocarbons from the gasification tank 30, the hydrogen gas and oxygen gas are supplied via the turbo charger 40 to the internal combustion engine 50.

(24) A storage tank 32 is furthermore depicted which includes a supply of volatile hydrocarbons, in particular a supply of ethanol or in general other volatile organic compounds. These can be adjustably introduced into the gasification tank 30 via a line 31.

(25) Furthermore, an air supply 33 for supplying compressed air into the gasification tank 30 is shown. This air supply 33 may be important for producing larger amounts of gaseous volatile hydrocarbons in the gasification tank 30, in order to supply larger amounts of gaseous volatile hydrocarbons to the turbo charger 40 and the internal combustion engine 50. The compression of air may be achieved with the air compressor which is not shown here.

(26) Whereas compressed ambient air, i.e., a mixture of mostly nitrogen and oxygen, may be introduced into the gasification tank 30 with the air supply 33, it is also possible to provide a CO.sub.2 tank 36 from which CO.sub.2 can be supplied into the gasification tank 30, controlled with a valve 37.

(27) The electrolysis chamber 20 may connect to a condensate trap 21 or condensate accumulator 21 in which electrolyte and the produced mixture of hydrogen and oxygen may be separated.

(28) The electrolyte condensates in the condensate trap 21 and can then be pumped back into the electrolysis chamber 20 with an electrolyte circulation pump 15. The condensate trap 21 thus may advantageously protect the internal combustion engine 50 against entry of liquids. Gaseous hydrogen and oxygen gases are, in contrast, drawn out of the condensate trap 21 with the vacuum pump 25.

(29) The oxyhydrogen (that is the produced hydrogen and oxygen gases) transported with the vacuum pump 25 are transported together with hydrocarbons or other organic compounds out of the gasification tank 30 and via a line 28 to a diaphragm 39 of the turbo charger 40.

(30) Water can be directed through a water inlet 23 into the electrolysis chamber 20 where it is converted into hydrogen gas and oxygen gas. The electrolyte circulation pump 15 can also be used for transporting water from the water inlet 23 to the electrolysis chamber 20, which allows an easier and cost-efficient setup. As shown, a water line from the water inlet 23 and an electrolyte line from the condensate trap 21 may lead to a common line which in turn leads to the electrolyte circulation pump 15.

(31) The electrolysis chamber 20 which produces the easily ignitable oxyhydrogen may be arranged in an explosion-proof area 19. This explosion-proof area 19 may in particular be formed by an air-tight casing and/or may comprise galvanically separated transmitters for electrical signals. Besides the electrolysis chamber 20, also the gasification tank 30, the condensate trap 21 and the vacuum pump 25 may be arranged in this explosion-proof area 19. To avoid an undue large size of the explosion-proof area 19, the storage tank 32, in contrast, is preferably arranged outside the explosion-proof area 19. The turbo charger 40 and its diaphragm 39 are also arranged outside the explosion-proof area 19.

(32) The ship propulsion system of the invention allows to operate an internal combustion engine particularly efficiently by adding oxyhydrogen and additional volatile organic compounds. Furthermore, production of pollutants/emissions is thus reduced.