Ship drive system and its management method

Abstract

TITLE: Ship drive system and method for managing the same System (10) comprising a heat engine (11) developing exhaust gases and having a high-pressure turbocharger (13a) consisting of a high-pressure turbine (14a) and a high-pressure compressor (15a) and a low-pressure turbocharger (13b) consisting of a low-pressure turbine (14b) and a low-pressure compressor (15b) for expanding the exhaust gases in the turbine (14a, 14b) of the respective turbocharger (13a, 13b), and driving the compressor (15a, 15b) of the exhaust gas turbocharger (13a, 13b). An air lubrication system (16) with several nozzles (17) releasing air bubbles under the hull.The engine (11) is coupled to the lubrication system (16) by bypass lines (18a, 18b) to supply it via a line (18a) with the compressed charge air from the compressor (15a) and via a line (18b) with the compressed charge air from the compressor (15b). Figure 1.

Description

Title of the invention: Ship drive system and its management method FIELD OF THE INVENTION

[0001] The present invention relates to a ship drive system comprising:

[0002] - a heat engine releasing exhaust gases by the combustion of fuel, and having a high-pressure exhaust gas turbocharger consisting of a high-pressure turbine and a high-pressure compressor and a low-pressure turbocharger consisting of a low-pressure turbine and a low-pressure compressor for expanding the exhaust gas in the respective turbine of the respective exhaust gas turbocharger, and

[0003] expanding the exhaust gases in the respective turbine using the recovered energy to drive the compressor of the exhaust gas turbocharger to compress the charge air of the cylinders, and

[0004] - an air lubrication system, having several nozzles releasing air bubbles expelled under the hull to reduce the resistance of the ship.

[0005] The invention also relates to a method for managing such a ship drive system. STATE OF THE ART

[0006] The ship drive system has at least one heat engine. This heat engine has cylinders in which fuel is burned. The combustion of the fuel releases exhaust gases. The heat engine cooperates with an exhaust gas turbocharger, which allows the heat engine to cooperate with a high-pressure turbocharger and a low-pressure turbocharger. An exhaust gas turbocharger consists of a turbine and a compressor. The exhaust gases from the cylinders expand in the turbine of the exhaust gas turbocharger, and this expansion of the exhaust gases in the turbine releases energy used to drive the compressor of the exhaust gas turbocharger for compressing the charge air supplied to the cylinders. The respective heat engine may, for example, drive a generator to generate electrical energy to drive an electric propeller motor of the ship.It is also possible to drive the propeller directly with a thermal engine.

[0007] A ship drive system further has an air lubrication system that ejects air bubbles under the hull; these air bubbles reduce the resistance the friction of the ship in the water. To generate the air supplying the air lubrication system, electric compressors are typically used to supply the necessary compressed air. Driving the compressors requires a lot of energy.

[0008] Document DE 10 2020 117 399 A1 describes a ship drive system having a heat engine and an air lubrication system. Exhaust gases are taken by an exhaust valve upstream of a turbine of an exhaust gas turbocharger to be supplied to the air lubrication system and to be ejected by this system in the form of exhaust gas air bubbles under the hull.

[0009] PURPOSE OF THE INVENTION

[0010] Based on this state of the art, the present invention aims to develop a new ship training system and a method for managing it.

[0011] DISCLOSURE AND ADVANTAGES OF THE INVENTION

[0012] To this end, the invention relates to a ship drive system comprising:

[0013] - at least one heat engine,

[0014] * the heat engine having cylinders generating exhaust gases by the fuel combustion,

[0015] * the respective heat engine having at least two gas turbochargers exhaust gas, namely at least one high-pressure exhaust gas turbocharger consisting of a high-pressure turbine and a high-pressure compressor and a low-pressure turbocharger which consists of a low-pressure turbine and a low-pressure compressor cooperating to expand the exhaust gases from the cylinders in the respective turbine of the respective exhaust gas turbocharger, and

[0016] expanding the exhaust gases in the respective turbine of the respective exhaust gas turbocharger using the recovered energy to drive the respective compressor of the respective exhaust gas turbocharger to compress the charge air for the cylinders,

[0017] - an air lubrication system,

[0018] * the air lubrication system having several nozzles which release bubbles air expelled under the hull to reduce the resistance of the ship,

[0019] system characterized in that

[0020] - the thermal engine is coupled to the air lubrication system by bypass lines for supplying the air lubrication system, via a first bypass line, with the compressed supercharging air in the high pressure compressor and through a second bypass line, the compressed charge air into the low pressure compressor,

[0021] - the respective supercharging air being ejected through nozzles of the system of air lubrication in the form of supercharging air bubbles under the fairing.

[0022] The present invention relates to a drive system whose heat engine comprises at least one high-pressure exhaust gas turbocharger and one low-pressure exhaust gas turbocharger for supplying the lubrication system with charge air from the high-pressure compressor of the high-pressure turbocharger and / or the low-pressure compressor of the low-pressure turbocharger to eject it as charge air bubbles under the hull. In the ship drive system, the air lubrication system does not receive exhaust gas but charge air from the heat engine. This makes it possible to reduce the energy consumption of the air lubrication system of the state of the art, for driving the compressors. Furthermore, there is no risk of pollution of the nozzles of the air lubrication system.

[0023] Preferably, the bypass lines are each provided with a valve so that if the valve is closed, the corresponding bypass line is closed and if the respective valve is open, the respective bypass line is open to supply a portion of the charge air to the air lubrication system. This makes it possible, in a particularly advantageous and simple manner, to supply the air lubrication system from the high-pressure compressor of the high-pressure turbocharger and from the low-pressure compressor of the low-pressure turbocharger.

[0024] Preferably, the ship drive system has a control installation which opens or closes the respective valve depending on the load state of the heat engine and / or depending on the quantity of air required by the air lubrication system and / or depending on the air pressure required by the air lubrication system. Thus, on the one hand, the heat engine and on the other hand the air lubrication system of the ship drive system according to the invention will advantageously operate with high efficiency.

[0025] Depending on the load condition of the heat engine and / or the quantity required by the air lubrication system and / or depending on the air pressure required by the air lubrication system, the control system opens or closes the respective valve to open or close the corresponding bypass line. If there is no excess charge air at the heat engine or if the available excess charge air quantity or its pressure is too low to operate the air lubrication system, the compressed air supplying the air lubrication system is supplied with a compressor. additional. Preferably, the air lubrication system has a compressor to compress the air in the lubrication system. This compressor operates advantageously when the respective valve is closed or when the valve being open, the amount of charge air arriving via the bypass line is too low.

[0026] The present invention allows particularly efficient operation of the ship's drive system, namely its heat engine and its air lubrication system.

[0027] Preferably, if the load of the heat engine is below a threshold, preferably above a first threshold and below a second threshold, the charge air is taken downstream of the high-pressure compressor to supply the air lubrication system. If the load of the respective heat engine is above a threshold, preferably above a second threshold, the charge air is taken downstream of the low-pressure compressor to supply the air lubrication system. In particular, if the load of the heat engine is below the first threshold, no charge air is taken to supply it to the air lubrication system. This allows a particularly advantageous operation of the ship drive system. For a relatively low load of the respective heat engine, the charge air can be taken downstream of the high-pressure compressor.For relatively high engine loads, especially at or near maximum load, charge air is taken from downstream of the low-pressure compressor to supply the air lubrication system. In particular, for high loads, the high-pressure compressor is avoided, providing significant work that would then be lost in adapting the charge pressure to the pressure demand of the air lubrication system by throttling. Throttling losses can be effectively avoided by alternately diverting the charge air downstream of the low-pressure compressor or downstream of the high-pressure compressor. This makes it possible to operate both the engine and the air lubrication system simultaneously, and thus ultimately to operate the ship's drive system with high efficiency. Brief description of the drawings

[0028] Advantageous developments of the invention will be described below with the aid of exemplary embodiments shown in the attached drawing in which:

[0029] [Fig.l] diagram of a detail of the ship drive system.

[0030] DESCRIPTION OF AN EMBODIMENT

[0031] [Fig.l] shows a highly schematic ship drive system 10. The ship drive system 10 of [Fig.l] consists of a heat engine 11 with several cylinders 12. The fuel is burned in the cylinders 12 of the heat engine. This combustion of fuel in the cylinders 12 releases exhaust gases A which must be evacuated from the cylinders 12 feeding an exhaust gas turbocharger system 13 comprising two exhaust gas turbochargers 13a, 13b. The heat engine 11 is a gas engine, a dual-fuel engine, a diesel engine, a methanol engine, an ammonia engine or a hydrogen engine.

[0032] The exhaust gas turbocharger 13a is a high-pressure exhaust gas turbocharger comprising a high-pressure turbine 14a and a high-pressure compressor 15a. The exhaust gas turbocharger 13b is a low-pressure exhaust gas turbocharger comprising a low-pressure turbine 14b and a low-pressure compressor 15b. The exhaust gas A from the cylinders 12 of the heat engine 11 first passes into the high-pressure turbine 14a of the high-pressure exhaust gas turbocharger 13a and then into the low-pressure turbine 14b of the low-pressure exhaust gas turbocharger 13b. The turbines 14a, 14b of the exhaust gas turbochargers 13a, 13b recover kinetic energy to drive the compressor 15a, 15b of the respective exhaust gas turbocharger 13a, 13b.Thus the high-pressure turbine 14a of the exhaust gas turbocharger 13a drives the high-pressure compressor 15a; the low-pressure turbine 14b of the low-pressure exhaust gas turbocharger 13b drives the low-pressure turbocharger 15b. The compressors 15a, 15b compress the charge air L; this charge air L is first compressed in the low-pressure compressor 15b and then in the high-pressure compressor 15a.

[0033] [Fig.l] shows an air lubrication system 16 of the ship drive system 10. The air lubrication system 16 has several nozzles 17 which eject air bubbles B under the hull. This makes it possible to reduce the resistance of the ship, i.e. the friction of the ship in the water.

[0034] According to the invention, the respective heat engine 11 is coupled by the exhaust gas turbocharger system 13 to the air lubrication system 16 and this by the bypass lines 18a, 18b, shown in [Fig.l].

[0035] The air lubrication system 16 receives the compressed supercharging air, via a first bypass line 18a from the high pressure compressor 15a and via a second bypass line 18b from the low pressure compressor 15b; the supercharging air is ejected via the nozzles 17 of the air lubrication system 16 in the form of supercharging air bubbles under the fairing. Thus via the first Bypass 18a, we have charge air from the high pressure compressor 15a and by a second bypass 18b, we have charge air from the low pressure compressor 15b supplying the air lubrication system 16. The first bypass line 18a is divided according to the flow direction of the charge air L downstream of the high pressure compressor 15a and the second bypass line 18b, downstream of the low pressure compressor 15b in the direction of the air lubrication system 16.

[0036] Each of the bypass lines 18a, 18b is provided with a valve 19a, 19b. When the valve 19a of the first bypass line 18a is closed, the first bypass line 18a is then closed. When the valve 19b of the second bypass line 18b is closed, then the second bypass line 18b is also closed. If, on the other hand, the valve 19a is open, then the first bypass line 18a is open. If the second valve 19b is open, then the second bypass line 18b is open.

[0037] A portion of the charge air is taken downstream of the respective compressor 15a, 15b of the respective exhaust gas turbocharger 13a, 13b when the respective valve 19a, 19b is open, and this air passes through the open bypass line 18a, 18b to supply the air lubrication system 16.

[0038] The two bypass lines 18a, 18b thus cooperate with the common air line 22. This air line 22 integrates the valves 19a, 19b in [Fig.l]. In addition, a compressor 20 cooperates with the air line 22. If, for example, the two valves 19a, 19b and the two bypass lines 18a, 18b are closed, then the compressor 20 compresses air and supplies it to the nozzles 17 of the air lubrication system 16.

[0039] [Fig.l] further shows a control system 21 which is part of the ship drive system 10. The control system 21 allows the valves 19a, 19b to be controlled to open and close. The valves 19a, 19b are preferably controlled to open and close from the control system 21 as a function of the load state of the heat engine 11 and / or as a function of the quantity of air required by the air lubrication system 16 and / or as a function of the air pressure required by the air lubrication system 16. Furthermore, the control system 21 serves in particular to control the compressor 20.

[0040] If the load of the respective heat engine 11 is below a threshold, preferably above a first threshold and below a second threshold, the control installation 21 controls the opening of the valve 19a and the closing of the valve 19b so that the supercharging air taken downstream of the high-pressure compressor 15a arrives at the air lubrication system 16, namely if the quantity of air of supercharging available downstream of the high pressure compressor 15a is not fully used by the heat engine 11.

[0041] If the load of the heat engine 11 is greater than a threshold, preferably greater than a second threshold, i.e. if the respective heat engine 11 is operating with a relatively high load, in particular at full load or close to full load, then the control installation 21 controls the closing of the valve 19a and the opening of the valve 19b. In this case, the supercharging air is taken downstream of the low-pressure compressor 15b to be supplied to the air lubrication system 16.

[0042] The charge air sampling downstream of the low-pressure compressor 15b and downstream of the high-pressure compressor 15a is preferably carried out only if the exhaust gas turbocharger 13a, 13b, the valves 19a, 19b being closed, supplies the excess charge air quantity not used by the heat engine 11. The selective charge air sampling downstream of the low-pressure compressor 15b or downstream of the high-pressure compressor 15a makes it possible to operate the ship drive system efficiently. Thus, in particular if the heat engine 11 is operating with a relatively high load, in particular close to the maximum load, it is avoided to operate the high-pressure compressor 15a with too much compression work.Furthermore, losses due to lamination of the charge air taken downstream of the high pressure compressor 15a and which would have to be laminat to supply the air lubrication system 16 are avoided.

[0043] If at the level of the exhaust gas turbochargers 13a, 13b, in particular of their compressors 15a, 15b, there is no excess supercharging air, then the valves 19a, 19b remain closed and the air of the air lubrication system 16 is supplied exclusively by the compressor 20. This is in particular the case if the load applied to the heat engine 11 is lower than the first threshold.

[0044] If downstream of the low pressure compressor 15b or downstream of the high pressure compressor 15a the quantity of charge air taken to the air lubrication system 16 is too low, the compressor 20 supplies the sufficient quantity of air at the appropriate pressure to the air lubrication system 16.

[0045] Preferably, only one valve 19a, 19b is always opened. Thus, valve 19a is open and valve 19b is preferably closed. If, on the other hand, valve 19b is open, then valve 19a will preferably be closed. However, it is also possible to open both valves 19a, 19b simultaneously in a defined load range of the heat engine 11 and in this case, valve 19a reduces the pressure of the charge air taken downstream of the high-pressure compressor 15a, and the pressure of the charge air taken downstream of the low-pressure compressor 15b.

[0046] Particularly at full load, it is possible to supply the air lubrication system 16 only with charge air taken when the valve 19a is closed and the valve 19b is open, downstream of the low-pressure compressor 15b and supply it via the second bypass line 18b to the air lubrication system 16. In this case, the compressor 20 is left stopped or is stopped.

[0047] The invention relates to a ship drive system 10 and its management method. Depending on the load state of the respective heat engine 11 and / or depending on the quantity of air required by the air lubrication system 16 and / or depending on the air pressure required by the air lubrication system 16, the supercharging air compressed by the high-pressure compressor 15a and / or the supercharging air compressed by the low-pressure compressor 15b is ejected through the nozzles 17 of the air lubrication system 16 in the form of supercharging air bubbles under the hull of the ship.

[0048] The supercharging air can be taken at the pressure level requested by the air lubrication system 16 depending on the load state of the respective heat engine from or downstream of the high pressure compressor 15a and / or downstream of the low pressure compressor 15b to supply the air lubrication system 16.

[0049] The method for managing the ship drive system provides in particular that if the respective heat engine 11 operates with a load greater than a threshold, preferably a second threshold, the compressed supercharging air will be taken downstream of the low-pressure compressor 15 to supply the air lubrication system 16. If the load is less than a limit value, preferably less than the second limit value but greater than the first limit value, then the compressed supercharging air is taken downstream of the high-pressure compressor 15a to supply the air lubrication system 16. If the load of the heat engine 11 is less than the first threshold, the supercharging air is preferably not taken downstream of the low-pressure compressor 15b or downstream of the high-pressure compressor 15a to supply the air lubrication system 16.If the load of the heat engine 11 is lower than the first threshold, then there will be no excess charge air at the exhaust gas turbochargers 13a, 13b. But the charge air will then be supplied to the cylinders 12. But if neither downstream of the high-pressure compressor 15a nor downstream of the low-pressure compressor 15b, charge air is taken to be supplied to the air lubrication system 16 and / or if the quantity of charge air and / or its charge air pressure taken to be supplied to the air lubrication system are too low, then the air lubrication system 16 is supplied with the compressor 20 of the lubrication system 16.

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[0067] NOMENCLATURE OF MAIN COMPONENTS 10 Ship drive system 11 Heat engine 12 Cylinder 13 Exhaust gas turbocharger 13a High pressure exhaust gas turbocharger 13b Low pressure exhaust gas turbocharger 14a High pressure turbine 14b Low pressure turbine 15a High pressure compressor 15b Low pressure compressor 16 Air lubrication system 17 Nozzle 18a Exhaust gas line Bypass 18b Bypass line 19a Valve 19b Valve 20 Compressor

Claims

Claims

1. A ship drive system (10) comprising: - at least one heat engine (11), * the heat engine (11) having cylinders (12) generating exhaust gases by the combustion of fuel, * the respective heat engine (11) having at least two exhaust gas turbochargers (13a, 13b) namely at least one high-pressure exhaust gas turbocharger (13a) which consists of a high-pressure turbine (14a), a high-pressure compressor (15a) as well as a low-pressure turbocharger (13b) which consists of a low-pressure turbine (14b) and a low-pressure compressor (15b) cooperating to expand the exhaust gases from the cylinders (12) in the respective turbine (14a, 14b) of the respective exhaust gas turbocharger (13a, 13b), and the expansion of the exhaust gases in the turbine (14a, 14b) respective of the exhaust gas turbocharger (13a,13b) using the recovered energy to drive the respective compressor (15a, 15b) of the respective exhaust gas turbocharger (13a, 13b) to compress the charge air for the cylinders (12), - an air lubrication system (16), * the air lubrication system (16) having several nozzles (17) which release air bubbles expelled under the hull to reduce the resistance of the ship, characterized in that - the respective heat engine (11) is coupled to the air lubrication system (16) by bypass lines (18a, 18b) to supply the air lubrication system (16) by a first bypass line (18a) with the charge air compressed in the high-pressure compressor (15a) and by a second bypass line (18b) with the charge air compressed in the low pressure compressor (15b),- the respective charge air being ejected by nozzles (17) of the air lubrication system (16) in the form of charge air bubbles under the fairing.,

2. A ship drive system according to claim 1, characterized in that at least the heat engine (11) is a gas engine, a dual-fuel engine, a diesel engine, a methanol engine, an ammonia engine or a hydrogen engine.

3. A ship drive system according to claim 1 or 2, characterized in that the first bypass line (18a) is issued downstream of the high pressure compressor (15a) and the second bypass line (18b) is issued downstream of the low pressure compressor (15b) towards the air lubrication system (16).

4. A ship drive system according to one of claims 1 to 3, characterized in that the bypass lines (18a, 18b) have a respective valve (19a, 19b) so that if the respective valve (19a, 19b) is closed, the respective bypass line (18a, 18b) is closed, and if the valve (19a, 19b) is open, the respective bypass line (18a, 18b) is open to supply a portion of the charge air to the air lubrication system (16).

5. A ship drive system according to claim 4, characterized in that the bypass lines (18a, 18b) open into a common line (22) through which the supercharging air is supplied to the nozzles (17) of the air lubrication system (16).

6. Ship drive system according to claim 4 or 5, characterized by a control device (21) which opens or closes the respective valve (19a, 19b) depending on the load state of the respective heat engine (11) and / or depending on the quantity of air required by the air lubrication system (16) and / or depending on the air pressure required by the air lubrication system (16).

7. A ship drive system according to one of claims 1 to 6, characterized in that the air lubrication system (16) has a compressor (20) for compressing air for the air lubrication system (16).

8. Ship drive system according to one of claims 4 and 7 / , characterized in that the compressor (20) is driven if the respective valve (19a, 19b) is closed and / or the amount of charge air passing through the respective open valve (19a, 19b) of the respective bypass line (18a, 18b) is low.

9. Method for controlling a ship drive system (10) according to one of claims 1 to 8, characterized in that depending on the load state of the respective heat engine (11) and / or depending on the quantity of air required by the air lubrication system (16) and / or depending on the air pressure required by the air lubrication system (16), the charge air compressed in the high-pressure compressor (15a) and / or the charge air compressed in the low-pressure compressor (15b) is expelled through the nozzles (17) of the air lubrication system (16) in the form of charge air bubbles under the hull.

10. Method according to claim 9, characterized in that - if the load of the respective heat engine (11) is below a threshold, the charge air is taken downstream of the high pressure compressor (15a) to be supplied to the air lubrication system (16), and if the load of the respective heat engine (11) is above a threshold, the charge air is taken downstream of the low pressure compressor (15b) and supplied to the air lubrication system (16).

11. Method according to claim 9 or 10, characterized in that - if the load of the respective heat engine (11) is greater than a first threshold and less than a second threshold, the charge air is taken downstream of the high pressure compressor (15a) to be supplied to the air lubrication system (16), and - if the load of the respective heat engine (11) is greater than the second threshold, the charge air is taken downstream of the low pressure compressor (15b) to be supplied to the air lubrication system (16).

12. Method according to claim 11, characterized in that if the load of the respective heat engine (11) is lower than the first threshold, the supercharging air is taken downstream of the low pressure compressor (15b) or downstream of the high pressure compressor (15a) to be supplied to the air lubrication system (16).

13. Method according to one of claims 9 to 12, characterized in that the supercharging air is taken downstream of the high pressure compressor (15a) or downstream of the low pressure compressor (15b) to be supplied to the air lubrication system (16).

14. Method according to one of claims 9 to 13, characterized in that if neither downstream of the high pressure compressor (15a) nor downstream of the low pressure compressor (15b) is charge air taken to supply it to the air lubrication system (16) and / or if the charge air taken and supplied to the air lubrication system (16) and / or its boost pressure are too low, the air is compressed by the compressor (20) of the air lubrication system (16) to supply this air lubrication system (16).

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