Air supply device for a marine vessel, marine vessel comprising the air supply device, and method of supplying air to an air lubrication device

Abstract

An air supply device (100) for a ship is described. The air supply device includes a first turbocharger (130) having a first compressor (131) and a first turbine (132), the first turbine (132) being capable of being driven by exhaust gas supplied from one or more engines (120). The first compressor (131) is coupled to the first turbine (132) via a transmission (133) configured to change the speed of the first compressor (131). Furthermore, the air supply device includes an air lubrication system (140) for reducing ship drag. The first compressor (131) is connected to the air lubrication system (140) to supply air to the air lubrication system (140).

Description

Technical Field

[0001] Embodiments of this disclosure relate to an air supply device for air-lubricated ships to reduce water friction resistance. Furthermore, embodiments of this disclosure relate to a method for supplying air to the air lubrication system of a ship. Background Technology

[0002] Typically, during a ship's voyage at sea, the submerged surface of its hull experiences frictional resistance from the water. This is especially true for large ships, such as cargo ships, where a significant portion of the ship's hull resistance is caused by frictional resistance resulting from the relative flow of water outside the hull at the bottom.

[0003] To reduce the frictional resistance of a ship's hull, air lubrication can be used, specifically by discharging air around the ship's hull. This reduction in frictional resistance significantly improves fuel economy and thus represents an effective means of reducing carbon dioxide emissions from ships.

[0004] In the prior art, various systems and methods exist for generating bubbles for hull lubrication. For example, for the generation of bubbles for hull lubrication, the prior art teaches the direct use of exhaust gas from the driving engine or the use of a separate electric compressor or blower. However, known systems for hull lubrication have some drawbacks, such as limitations in energy consumption and efficiency.

[0005] Therefore, in view of the above, there is a need for improved air supply equipment for ships and improved methods for supplying air to the air lubrication system of ships, which at least partially overcome the problems of the prior art. Summary of the Invention

[0006] In view of the foregoing, an air supply device for a ship and a method for supplying air to an air lubrication system of a ship are provided according to the independent claim. Other aspects, advantages, and features will become apparent from the dependent claims, the description, and the drawings.

[0007] According to one aspect of this disclosure, an air supply device for a ship is provided. The air supply device includes a first turbocharger having a first compressor and a first turbine, the first turbine being driveable by exhaust gas supplied by one or more engines. The first compressor is coupled to the first turbine via a transmission configured to change the speed of the first compressor. Furthermore, the air supply device includes an air lubrication device for reducing ship drag. The first compressor is connected to the air lubrication device to supply air to the air lubrication device.

[0008] Therefore, the air supply equipment disclosed herein is an improvement over conventional equipment used in air-lubricated ships. In particular, embodiments of the air supply equipment described herein are improved in terms of energy efficiency. More specifically, by providing an air supply equipment with a first turbocharger, the amount of air supplied to the air lubrication device can be controlled by using a transmission having a gearbox that couples a first turbine to a first compressor to supply air to the air lubrication device. More specifically, the first turbocharger, particularly the first compressor, is used to compress low-pressure air, which is then fed to the air lubrication device to generate bubbles under the ship's hull to reduce the ship's water-hull friction. Less friction on the ship's hull results in an overall reduction in the ship's energy consumption. Therefore, by increasing the speed of the first compressor relative to the speed of the first turbine, for example by using a transmission, the amount of air supplied to the air lubrication device can be increased, resulting in an increase in the bubbles generated under the ship's hull. Thus, a greater reduction in the ship's water-hull friction can be achieved compared to the prior art. Therefore, the overall reduction in ship energy use can be achieved, resulting in fuel savings and thus lower overall operating costs.

[0009] Therefore, according to another aspect of this disclosure, a vessel is provided that includes an air supply device according to any of the embodiments described herein.

[0010] According to another aspect of this disclosure, a method for supplying air to an air supply system of a ship is provided. The method includes driving a first turbocharger by using exhaust gas from one or more engines. Furthermore, the method includes changing the speed of the first compressor of the first turbocharger by using a transmission coupled to a first turbine of the first turbocharger and coupled to a first compressor of the first turbocharger. Additionally, the method includes supplying air from the first compressor of the first turbocharger to an air lubrication system.

[0011] Therefore, it should be understood that embodiments of this disclosure provide an air supply device, a ship including the air supply device, and a method for supplying air to the ship's air lubrication system, which improves energy efficiency and reduces operating costs. Attached Figure Description

[0012] To provide a more detailed understanding of the features of this disclosure, the brief summary of this disclosure has been described in more detail with reference to embodiments. The accompanying drawings are related to embodiments of this disclosure and are described below:

[0013] Figure 1 A schematic diagram of a gas supply device according to an embodiment described herein is shown;

[0014] Figures 2 to 8 A schematic diagram of a gas supply device according to other embodiments described herein is shown;

[0015] Figure 9a A flowchart illustrating a method for supplying air to an air lubrication system of a ship according to embodiments described herein is shown; and

[0016] Figure 9b and Figure 9c A flowchart illustrating a method for supplying air to an air lubrication system of a ship according to other embodiments described herein is shown. Detailed Implementation

[0017] Reference will now be made in detail to various embodiments, one or more examples of which are illustrated in each of the accompanying drawings. Each example is provided for illustration only and is not intended to be limiting. For example, features shown or described as part of one embodiment may be used in any other embodiment or in combination with any other embodiment to produce yet another embodiment. This disclosure is intended to include such modifications and variations.

[0018] In the following description of the accompanying drawings, the same reference numerals refer to the same or similar components. Generally, only differences with respect to various embodiments are described. Unless otherwise stated, the description of a part or aspect in one embodiment may also apply to the corresponding part or aspect in another embodiment.

[0019] Exemplary Reference Figure 1 This document describes an air supply device 100 according to the present disclosure. According to an embodiment that may be combined with other embodiments described herein, the air supply device 100 includes a first turbocharger 130 having a first compressor 131 and a first turbine 132. The first turbine 132 is capable of being driven by exhaust gas supplied by one or more engines 120. In this regard, it should be noted that "capable of being driven by exhaust gas" can be understood as providing exhaust gas for driving. Therefore, the first turbine 132 may be connected to one or more engines 120, for example, via one or more pipes, such that one or more engines 120 can supply exhaust gas to the first turbine 132. One or more engines 120 may be turbocharged. Therefore, it should be understood that exhaust gas supplied to the first turbine 132 from one or more engines 120 can already be expanded in one or more turbochargers of one or more engines 120. The first compressor 131 is coupled to the first turbine 132 via a transmission 133 configured to change the speed of the first compressor 131. In particular, the transmission 133 can be configured to change the speed of the first compressor 131. For example, the transmission 133 can be configured to increase the speed of the first compressor 131 relative to the speed of the first turbine 132. Furthermore, or alternatively, the transmission 133 can be configured to decrease the speed of the first compressor 131 relative to the speed of the first turbine 132. Additionally, as... Figure 1 As exemplarily shown, the air supply equipment 100 includes an air lubrication device 140 for reducing ship drag. A first compressor 131 is specifically connected to the air lubrication device 140 via a second air supply conduit 17 to supply air to the air lubrication device 140.

[0020] Therefore, an improved air supply device with enhanced efficiency is advantageously provided. In particular, the advantage of providing a first turbocharger with the transmission described herein is that the speed of the first compressor used to supply air to the air lubrication device can be changed, and thus the amount of air supplied to the air lubrication device can be adjusted. For example, by increasing the speed of the first compressor using the transmission, the amount of air supplied to the air lubrication device can be increased. Therefore, by decreasing the speed of the first compressor using the transmission, the amount of air supplied to the air lubrication device can be decreased. Thus, the amount of air supplied to the air lubrication device can be controlled as needed.

[0021] For example, by increasing the speed of the first compressor relative to the first turbine using a gearbox located between the first compressor and the first turbine, the efficiency of the first compressor used to supply air to the air lubrication system can be improved. Therefore, the effectiveness of the air lubrication system can be improved, resulting in more air bubbles generated beneath the ship's hull and thus a greater reduction in water-hull friction. As a result, the overall energy consumption of the ship can be reduced, leading to fuel savings and lower overall operating costs.

[0022] According to embodiments that can be combined with other embodiments described herein, transmission 133 may be a mechanical transmission, an electric transmission, a pneumatic transmission, or a hydraulic transmission. According to examples that can be combined with other embodiments described herein, transmission 133 includes a generator and an electric motor.

[0023] It should be understood that the transmissions described herein, such as the first transmission 133 and / or the second transmission 136 described below, can be configured to be variable. In other words, the first transmission 133 and / or the second transmission 136 can have variable gear ratios. Therefore, the transmissions described herein can be configured to provide variable gear ratios. Consequently, the speeds of the first compressor 131 and / or the second compressor 135 can be advantageously regulated and controlled during ship operation, i.e., during the operation of one or more engines 120, particularly independently of the speeds of the connected turbines (e.g., the first turbine 132 and / or the second turbine 134 described herein).

[0024] Exemplary Reference Figure 2According to embodiments that can be combined with other embodiments described herein, the gas supply device 100 further includes a second turbine 134 parallel to the first turbine 132. For example... Figure 2 As exemplarily shown, the first turbine 132 and the second turbine 134 can be coupled to the first compressor 131 via the transmission 133.

[0025] Exemplary Reference Figure 3 According to embodiments that can be combined with other embodiments described herein, the gas supply device further includes a second turbocharger 137 having a second compressor 135 and a second turbine 134. The second turbine 134 can be driven by exhaust gas supplied by one or more engines 120. Therefore, the second turbine 134 can be connected to one or more engines 120, for example, via one or more pipes, such that one or more engines 120 can supply exhaust gas to the second turbine 134. Furthermore, or alternatively, the second turbine 134 can be driven by exhaust gas supplied by a first turbine 132. Therefore, the second turbine 134 can be connected to the first turbine 132, for example, via one or more pipes, such that the first turbine 132 can supply exhaust gas to the second turbine 134. Figure 3 As exemplarily shown, the second compressor 135 is specifically connected to the air lubrication device 140 via a third air supply pipe 19 to supply air to the air lubrication device 140.

[0026] According to another alternative implementation that can be combined with other embodiments described herein, the second turbine 134 can be driven by compressed air supplied to the second turbine 134 from the first air supply conduit 16, such as Figures 5 to 8 As exemplarily shown. Therefore, it should be understood that an air supply duct (not explicitly shown in the figures) from the third compressor 111 to the second turbine 134 can be provided. Similarly, according to another example that can be combined with other embodiments described herein, the first turbine 132 can be supplied from the first air supply duct 16 (as shown in the figures). Figures 5 to 8 The compressed air supplied to the first turbine 2 (as shown) drives the turbine. Therefore, it should be understood that an air supply duct (not explicitly shown in the figures) from the third compressor 111 to the first turbine 132 can be provided.

[0027] like Figure 3 As exemplarily shown, the second compressor 135 is typically coupled to the second turbine 134 via another transmission 136. The other transmission 136 is configured to change the speed of the second compressor 135.

[0028] Specifically, another transmission 136 can be configured to change the speed of the second compressor 135. For example, the other transmission 136 can be configured to increase the speed of the second compressor 135 relative to the speed of the second turbine 134. Alternatively, the other transmission 136 can be configured to decrease the speed of the second compressor 135 relative to the speed of the second turbine 134.

[0029] According to embodiments that can be combined with other embodiments described herein, another transmission 136 may be a mechanical transmission, an electric transmission, a pneumatic transmission, or a hydraulic transmission. According to examples that can be combined with other embodiments described herein, another transmission 136 includes a generator and an electric motor.

[0030] Exemplary Reference Figures 4 to 8 According to embodiments that can be combined with other embodiments described herein, the gas supply device further includes a third turbocharger 110 having a third compressor 111 and a third turbine 112. For example, the third turbocharger 110 may be one or more turbochargers for boosting one or more engines 120. In this regard, it should be noted that the third turbocharger 110 shown in the figures may represent one or more turbochargers. Therefore, it should be understood that one or more engines 120 may be boosted or unboosted (i.e., not boosted). Figure 4 As exemplarily shown, the third turbine 112 is connected to the exhaust gas receiver 122 of one or more engines 120 via a first exhaust gas duct 11. Therefore, it should be understood that the turbocharger of the air supply device according to the embodiments described herein, particularly the first turbocharger 130, is typically a separate turbocharger not used for boosting the engine. In other words, the first turbocharger 130 may be a secondary turbine-compressor pair provided in addition to the turbocharger used for boosting the engine. Specifically, according to embodiments that can be combined with other embodiments described herein, no mechanical force is transmitted from the engine's turbocharger main turbine (e.g., the third turbine 112) to the air supply device.

[0031] According to embodiments that can be combined with other embodiments described herein, the first exhaust gas duct 11 may be connected to a flow controller 160 for controlling the flow rate of exhaust gas supplied from the exhaust gas receiver 122 to the third turbine 112, such as... Figure 8 As exemplified. In particular, the flow controller 160 may be disposed in the first bypass duct 13 that bypasses the third turbine 112.

[0032] Exemplary Reference Figure 8According to an embodiment that can be combined with other embodiments described herein, the first turbine 132 can be connected to the third turbine 112 via a second exhaust gas conduit 12. The second exhaust gas conduit 12 can be connected to a bypass valve 170 to control the exhaust gas flow rate supplied from the third turbine 112 to the first turbine 132. In particular, the bypass valve 170 can be disposed in a second bypass conduit 14 that bypasses the first turbine 132.

[0033] like Figures 4 to 8 As exemplarily shown, according to an embodiment that can be combined with other embodiments described herein, the third compressor can be connected to the air receiver 121 of one or more engines 120 via the first air supply conduit 16. Specifically, as... Figure 8 As exemplarily shown, the first air supply conduit 16 includes a booster air cooler 150.

[0034] Exemplary Reference Figure 8 According to embodiments that can be combined with other embodiments described herein, another flow controller 161 may be disposed downstream of the first turbine 132 of the first turbocharger. The conduit where the other flow controller 161 is disposed may be connected to the exhaust gas discharge conduit 15 via an exhaust gas connection 20. The exhaust gas discharge conduit 15 may be part of an exhaust system. The exhaust system may include exhaust gas aftertreatment equipment and / or a muffler before the exhaust gases are released into the environment. In this regard, it should be noted that exhaust gas aftertreatment equipment and / or a muffler may also be disposed in other embodiments described herein.

[0035] Therefore, according to Figures 1 to 8 It is understood that, according to another aspect of this disclosure, a vessel 200 is provided that includes an air supply device according to any embodiment described herein. Therefore, a vessel with a more energy-efficient system for reducing water-hull friction can be provided, thereby reducing overall operating costs.

[0036] Exemplary Reference Figure 9a The flowchart shown illustrates a method 300 for supplying air to an air lubrication system of a ship according to this disclosure.

[0037] According to embodiments that can be combined with other embodiments described herein, method 300 includes driving (by) using exhaust gas from one or more engines 120. Figure 9a (Box 310 in the text indicates) the first turbocharger 130. Furthermore, the method includes altering (by using a transmission 133 coupled to a first turbine 132 coupled to the first compressor 131 of the first turbocharger 130) the... Figure 9a(Box 320 in the text indicates) the speed of the first compressor 131 of the first turbocharger 130. Furthermore, the method includes supplying air from the first compressor 131 of the first turbocharger 130 to the air lubrication device 140 (by...) Figure 9a The box 330 in the text represents air.

[0038] Specifically, change (by) Figure 9a , Figure 9b and Figure 9c (Box 320 indicates) The speed of the first compressor 131 can include changing the speed of the first compressor 131. For example, changing the speed of the first compressor 131 by using the transmission 133 can include increasing the speed of the first compressor 131 relative to the speed of the first turbine 132. Alternatively, changing the speed of the first compressor 131 by using the transmission 133 can include decreasing the speed of the first compressor 131 relative to the speed of the first turbine 132.

[0039] Exemplary Reference Figure 9b According to embodiments that can be combined with other embodiments described herein, changes (from...) Figure 9b Box 320 in the figure indicates) The speed of the first compressor 131 includes the use of (by Figure 9b Box 321 in the diagram indicates a second turbine 134 parallel to the first turbine 132. The first turbine 132 and the second turbine 134 are coupled to the first compressor 131 via a transmission 133.

[0040] According to embodiments that can be combined with other embodiments described herein, method 300 further includes controlling (by controlling the rotational speed of the first turbocharger 130) Figure 9b (Box 335 in the figure indicates) the amount of air supplied to the air lubrication device 140. The rotational speed of the first turbocharger 130 can be controlled by controlling the exhaust gas flow rate supplied to the third turbine 112 of the third turbocharger 110, which is connected to the exhaust gas receiver 122 of one or more engines 120. The exhaust gas flow rate supplied to the third turbine 112 of the third turbocharger 110 can be controlled by using (by...) Figure 9b The box 336 in the image represents the flow controller 160, which controls the flow. Figure 7 and Figure 8 As exemplified. Specifically, the flow controller 160 may be disposed in the first bypass duct 13 that bypasses the third turbine 112, such as... Figure 7 and Figure 8 As shown in the example. Furthermore, or alternatively, control (by...) Figure 9b The amount of air supplied to the air lubrication device 140 (represented by box 335 in the figure) may include the amount of air supplied by (by...) Figure 9b(Box 337 in the image indicates) Bypass valve 170 controls the exhaust gas flow supplied to the first turbine 132 to control the speed of the first turbocharger 130, such as... Figure 7 and Figure 8 As exemplified. Specifically, bypass valve 170 may be disposed in a second bypass conduit 14 that bypasses the first turbine 132. Furthermore, or alternatively, control (by...) Figure 9b The amount of air supplied to the air lubrication device 140 (represented by box 335 in 9b) may include controlling the rotational speed of the first turbocharger 130 by using another flow controller 161 (represented by box 338 in 9b) located downstream of the first turbine 132 of the first turbocharger, as referenced Figure 8 As exemplified.

[0041] Exemplary Reference Figure 9c According to embodiments that may be combined with other embodiments described herein, method 300 further includes driving (by using exhaust gas from one or more engines) Figure 9c (Box 340 in the text indicates) the second turbocharger 137. Additionally, or alternatively, the drive (by...) Figure 9c (Box 340 indicates) The second turbocharger 137 can be operated using exhaust gas from the first turbine 132. The second turbocharger 137 has a second compressor 135 coupled to the second turbine 134 via another transmission 136. The other transmission 136 is configured to change the speed of the second compressor 135. Furthermore, as... Figure 9c The exemplary method 300 includes changing (by using another transmission 136) Figure 9c (Box 350 in the text indicates) the speed of the second compressor 135. Furthermore, the method 300 includes supplying air from the second compressor 135 of the second turbocharger 137 to the air lubrication device 140 (by...) Figure 9c The 360-degree box in the image represents air.

[0042] Therefore, in view of the foregoing, it should be understood that the embodiments described herein advantageously provide an improved air lubrication device, for which the amount of air supplied to the air lubrication device can be controlled and adjusted. In particular, as described herein, the effectiveness of the air lubrication device can be improved compared to the prior art by employing a transmission for increasing the speed of the compressor used to supply air to the air lubrication device. Therefore, an increase in the number of bubbles generated below the hull of the ship can be achieved, and thus a greater reduction in water-hull friction can be achieved, resulting in a reduction in overall operating costs. Furthermore, compared to the prior art, the embodiments described herein have the advantage that the residual energy of the turbine of the engine's turbocharger can be used to operate the air supply equipment. Therefore, the embodiments described herein provide improved energy efficiency compared to the prior art. Moreover, the embodiments described herein advantageously provide the possibility of compensating for so-called mismatch between the compressor and turbine by using a separate turbocharger with a transmission that couples the turbine and compressor to generate bubbles for hull lubrication.

[0043] While the foregoing is directed at the embodiments, other and additional embodiments may be devised without departing from the basic scope defined by the appended claims.

[0044] Explanation of reference numerals in the attached figures

[0045] 1. Exhaust gas supplied from one or more engines

[0046] 11 First Exhaust Gas Pipeline

[0047] 12 Second Exhaust Gas Pipeline

[0048] 13 First bypass pipe

[0049] 14 Second bypass pipe

[0050] 15. Exhaust gas discharge pipe

[0051] 16 First Gas Supply Pipeline

[0052] 17 Second gas supply pipeline

[0053] 18. Intake

[0054] 19 Third gas supply pipeline

[0055] 20 Exhaust gas connection parts

[0056] 100 Gas supply equipment

[0057] 110 Third Turbocharger

[0058] 111 Third Compressor

[0059] 112 Third Turbine

[0060] 113 axis

[0061] 120 may include one or more engines with one or more turbochargers.

[0062] 121 Air Receiver

[0063] 122 Exhaust Gas Receiver

[0064] 130 First Turbocharger

[0065] 131 First Compressor

[0066] 132 First Turbine

[0067] 133 transmission

[0068] 134 Second Turbine

[0069] 135 Second Compressor

[0070] 136 Another transmission

[0071] 137 Second Turbocharger

[0072] 140 Air lubrication device

[0073] 150 Boost Air Cooler

[0074] 160 Flow Controller

[0075] 161 Another flow controller

[0076] 170 bypass valve

[0077] 200 ships

[0078] 300 Method for supplying air to an air lubrication device

[0079] Blocks 310, 320, 321, 330, 335, 336, 337, 338, 340, 350, and 360 represent the method steps of the method for supplying air to an air lubrication device described in this disclosure.

Claims

1. An air supply device (100) for a ship (200), comprising: - A first turbocharger (130) having a first compressor (131) and a first turbine (132), the first turbine (132) being driven by exhaust gas supplied from one or more engines (120), the first compressor (131) being coupled to the first turbine (132) via a transmission (133) configured to increase or decrease the speed of the first compressor (131) relative to the speed of the first turbine (132), wherein the transmission (133) is disposed between the first compressor (131) and the first turbine (132), and the transmission (133) is configured to regulate the speed of the first compressor (131) independently of the speed of the first turbine (132); - An air lubrication device (140) for reducing ship drag, wherein a first compressor (131) is connected to the air lubrication device (140) to supply air to the air lubrication device (140); and A second turbocharger (137) having a second compressor (135) and a second turbine (134), the second turbine (134) being driven by at least one of exhaust gas supplied from one or more engines (120) and exhaust gas supplied from a first turbine (132), the second compressor (135) being coupled to the second turbine (134) via another transmission (136) configured to change the speed of the second compressor (135), and the other transmission (136) being configured to regulate the speed of the second compressor (135) independently of the speed of the second turbine (134), and the second compressor (135) being connected to an air lubrication device (140) to supply air to the air lubrication device (140); as well as A third turbocharger (110) having a third compressor (111) and a third turbine (112), the third turbine (112) being connected via a first exhaust pipe (11) to an exhaust gas receiver (122) of one or more engines (120), the first exhaust gas pipe (11) being connected to a flow controller (160) for controlling the amount of exhaust gas supplied from the exhaust gas receiver (122) to the third turbine (112). The first turbine (132) is connected to the third turbine (112) via the second exhaust pipe (12), and the second exhaust pipe (12) is connected to a bypass valve (170) for controlling the exhaust gas flow from the third turbine (112) to the first turbine (132).

2. The gas supply device (100) according to claim 1, wherein the transmission (133) is a mechanical transmission, an electric transmission, a pneumatic transmission or a hydraulic transmission.

3. The gas supply device (100) according to claim 1 further includes a second turbine (134) parallel to the first turbine (132), the first turbine (132) and the second turbine (134) being coupled to the first compressor (131) via a transmission (133).

4. The gas supply device (100) according to any one of claims 1 to 3, wherein the transmission (133) comprises a generator and an electric motor.

5. The gas supply device (100) according to claim 1, wherein the other transmission (136) is a mechanical transmission, an electric transmission, a pneumatic transmission or a hydraulic transmission.

6. The gas supply device (100) according to claim 1, wherein the flow controller (160) is disposed in a first bypass pipe (13) that bypasses the third turbine (112).

7. The gas supply device (100) according to claim 1, wherein the bypass valve (170) is disposed in a second bypass pipe (14) that bypasses the first turbine (132).

8. In the air supply device (100) according to claim 1, the third compressor (111) is connected to the air receiver (121) of the one or more engines (120) via the first air supply pipe (16).

9. The gas supply device (100) according to claim 8, wherein the first gas supply pipe (16) includes a booster air cooler (150).

10. The gas supply device (100) according to any one of claims 1 to 3, wherein the first turbocharger (130) is a secondary turbine-compressor pair provided in addition to the turbochargers for pressurizing the one or more engines (120).

11. A vessel (200) comprising an air supply device (100) according to any one of claims 1 to 10.

12. A method (300) for supplying air to an air lubrication system (140) of a ship, the method comprising: - The first turbocharger (130) is driven (310) by using exhaust gas from one or more engines (120). - The speed of the first compressor (131) of the first turbocharger (130) is changed (320) by using a transmission (133) coupled to the first compressor (131) of the first turbocharger (130) and coupled to the first turbine (132), wherein the transmission (133) is configured to increase or decrease the speed of the first compressor (131) relative to the speed of the first turbine (132), and the transmission (133) is disposed between the first compressor (131) and the first turbine (132); as well as - Air (330) is supplied from the first compressor (131) of the first turbocharger (130) to the air lubrication device (140). The method further includes: - A second turbocharger (137) is driven (340) by using exhaust gas from one or more engines and exhaust gas from a first turbine (132), the second turbocharger (137) having a second compressor (135) coupled to a second turbine (134) by another transmission (136) configured to change the speed of the second compressor (135). - By using the other transmission (136) to change the speed of the second compressor (135) (350), and - Air (360) is supplied from the second compressor (135) of the second turbocharger (137) to the air lubrication device (140). The method further includes controlling (335) the amount of air supplied to the air lubrication device (140) by controlling the rotational speed of the first turbocharger (130), wherein the rotational speed of the first turbocharger (130) is controlled by controlling the exhaust gas flow rate of the third turbine (112) supplied to the third turbocharger (110) by using a flow controller (160), the third turbine (112) being connected to the exhaust gas receiver (122) of the one or more engines (120). The method further includes controlling the amount of air supplied to the air lubrication device (140) by controlling the rotational speed of the first turbocharger (130), wherein the rotational speed of the first turbocharger (130) is controlled by controlling the exhaust gas flow rate supplied to the first turbine (132) by using a bypass valve (170) (337), the bypass valve (170) being disposed in a second bypass pipe (14) bypassing the first turbine (132).

13. The method (300) of claim 12, wherein changing the speed of the first compressor (131) (320) comprises using a second turbine (134) (321) parallel to the first turbine (132); the first turbine (132) and the second turbine (134) are coupled to the first compressor (131) via a transmission (133).

14. The method (300) according to claim 12, wherein the flow controller (160) is disposed in a first bypass pipe (13) that bypasses the third turbine (112).

Images