Air supply system for a hull of a ship and ship comprising said air supply system

Abstract

A gas supply system (100) for supplying air to the exterior of a hull of a marine vessel is disclosed. The gas supply system (100) comprises a plurality of air discharge units, ADUs (20), for releasing a flow of compressed air to the exterior of the hull below the waterline of the marine vessel, wherein the plurality of ADUs (20) are arranged around a longitudinal centerline (202) of the hull of the marine vessel. The gas supply system (100) comprises a first flow path (11A) for providing the flow of compressed air from an engine to the ADUs (20). The gas supply system (100) comprises one or more pressure control devices (30) arranged in the first flow path (11A) for feeding the flow of compressed air to the ADUs (20) at a pressure greater than a discharge pressure at the ADUs (20). Each pressure control device (30) comprises an inlet (34) for receiving an inlet air flow, a first outlet (35A) and a second outlet (35B) for feeding the air flow to a subset (20AB, 20BA; 20CD, 20DC) of the plurality of ADUs. The first outlet (35A) is connected to a first subset (20AB; 20CD) of ADUs arranged on a first side of the longitudinal centerline (202) of the hull (201) of the marine vessel (200) and the second outlet (35B) is connected to a second subset (20BA; 20DC) of ADUs arranged on an opposite second side of the longitudinal centerline (202) of the hull of the marine vessel. The one or more pressure control devices (30) are configured to compensate for a discharge pressure difference between the first subset (20AB; 20CD) of ADUs and the second subset (20BA; 20DC) of ADUs.

Description

[0001] This disclosure relates to the field of ship propulsion. This disclosure relates to an air supply system for supplying air to the exterior of a ship's hull and a ship including said air supply system. Background Technology

[0002] The resistance a ship experiences while navigating water consists of several components, with frictional resistance being the most significant. Injecting airflow into the turbulent boundary layer surrounding the ship's hull can reduce this frictional resistance. The turbulent boundary layer lies between still water and moving water near the ship's hull.

[0003] Air lubrication of the hull can significantly reduce frictional losses. Depending on the type of propulsion used, the ship's efficiency can be significantly improved. The efficiency gain depends on speed, hull shape, ship draft, and / or the distribution and amount of air to the ship's waterline. The ship's draft is the vertical distance from the bottom of the keel to the waterline, while the waterline is the total area of ​​the ship's outer surface in contact with the surrounding water.

[0004] The improvement in overall net efficiency depends on the power required to pressurize the airflow needed to reduce friction. Therefore, net propulsion efficiency depends on the power required to facilitate airflow and the given discharge pressure at the air outlet in the hull. The discharge pressure corresponds to the water pressure acting on the air outlet port from around the ship.

[0005] When a ship rolls in the water, such as when the ship rotates along its longitudinal centerline and is not level, the discharge pressure may vary at each air outlet port due to changes in the water level acting on it. Air outlet ports that are submerged deeper in the water during rolling experience higher discharge pressures because more water needs to be discharged from them, while those that are rising in the water experience lower discharge pressures because less water needs to be discharged. This can result in uneven or interrupted air discharge from certain air outlet ports. Summary of the Invention

[0006] Therefore, there is a need for an air supply system for supplying air to the outside of a ship's hull, which would mitigate, alleviate, or resolve existing deficiencies and provide a more efficient air supply system.

[0007] The pressure of the air supplied to the air outlet ports should be controlled to ensure that the airflow to the air outlet ports is not interrupted when the discharge pressure at one or more air outlet ports increases. Known solutions for controlling the pressure of the airflow to the air outlet ports are complex, costly, and require significant processing power to operate; therefore, a simpler solution is needed to control the airflow to avoid problems such as uneven or interrupted air discharge.

[0008] An air supply system for supplying air to the exterior of a ship's hull is disclosed. The air supply system includes a plurality of air exhaust units (ADUs) for releasing a flow of compressed air below the waterline of the ship to the exterior of the hull. The plurality of ADUs are configured to be arranged around the longitudinal centerline of the ship's hull. The air supply system includes a first flow path for supplying the compressed air flow from an engine to the ADUs. The air supply system includes one or more pressure control devices arranged in the first flow path for supplying the compressed air flow to the ADUs at a pressure greater than the exhaust pressure at the ADU. Each pressure control device includes an inlet for receiving the inlet air flow, a first outlet, and a second outlet for supplying the air flow to a subset of the plurality of ADUs. The first outlet is connected to a first subset of ADUs arranged on a first side of the longitudinal centerline of the ship's hull, and the second outlet is connected to a second subset of ADUs arranged on a opposite second side of the longitudinal centerline of the ship's hull. The one or more pressure control devices are configured to compensate for the exhaust pressure difference between the first subset of ADUs and the second subset of ADUs.

[0009] One advantage of the air supply system disclosed herein is that it provides a uniform distribution of compressed air across the ship's hull (such as on the ship's beams), which are the widest parts of the ship from one side to the other. By supplying compressed air flows to ADUs located on opposite sides of the hull from different outlets of the same pressure control device, the compressed air flows to the ADUs will be equal; however, the pressure of the compressed air flows may vary depending on the discharge pressure at the ADU, for example, due to the ship's angle of inclination. One advantage is that the air supply system provided herein ensures constant flow control of the air to the ADUs without requiring throttle valves or other valves to control the compressed air flow to the ADUs. Therefore, the air supply system provides a passive solution for controlling the distribution of air to the ADUs during ship roll.

[0010] A vessel is disclosed, the vessel comprising a hull, an engine, and an air supply system according to the present disclosure.

[0011] One advantage of this disclosure is that the vessel including the air supply system will have a uniform distribution of compressed air on the hull (such as on the beams). By supplying compressed air flows to ADUs arranged on opposite sides of the hull from different outlets of the same pressure control device, the compressed air flows to the ADUs will be equal; however, the pressure of the compressed air flows may vary depending on the discharge pressure at the ADU, for example, due to the ship's angle of inclination. One advantage is that the air supply system provided herein ensures constant flow control of the air to the ADUs without requiring throttle valves or other valves to control the compressed air flow. Therefore, the vessel according to this disclosure provides a passive solution for controlling the distribution of air to the ADUs during ship roll. Attached Figure Description

[0012] The above and other features and advantages of this disclosure will be readily apparent to those skilled in the art from the following detailed description of exemplary embodiments with reference to the accompanying drawings, in which:

[0013] Figure 1 The diagram illustrates a known gas supply system.

[0014] Figure 2 The diagram illustrates an exemplary gas supply system according to this disclosure.

[0015] Figure 3 The diagram illustrates an exemplary gas supply system according to this disclosure.

[0016] Figure 4 The illustrations in this disclosure pertain to the control of an exemplary air supply system for a horizontal vessel.

[0017] Figure 5 The illustrations in this disclosure depict control of an exemplary gas supply system for a rolling vessel. Detailed Implementation

[0018] Various exemplary embodiments and details are described below with reference to the accompanying drawings, where applicable. It should be noted that the drawings may be drawn to scale or not, and in all drawings, elements with similar structure or function are indicated by the same reference numerals. It should also be noted that the drawings are intended only to facilitate the description of embodiments. The drawings are not intended as an exhaustive description of this disclosure or a limitation on the scope of this disclosure. Furthermore, the illustrated embodiments need not possess all the aspects or advantages shown. Aspects or advantages described in connection with a particular embodiment are not necessarily limited to that embodiment and can be practiced in any other embodiment, even if not so shown or explicitly described.

[0019] For clarity, the accompanying drawings are schematic and simplified, and only details that aid in understanding this disclosure are shown, while other details are omitted. Throughout, the same reference numerals are used for the same or corresponding parts.

[0020] During ship rolling, such as when the ship rotates about its longitudinal centerline, the discharge pressure at the ADU may vary with the ADU, depending on the depth of the ADU immersed in the water surrounding the ship. The depth of the ADU in the water during ship rolling may depend on the distance of the ADU from the ship's longitudinal centerline. When the ship rolls about its longitudinal centerline, an ADU positioned further away from the ship's longitudinal centerline will be immersed deeper or rise higher. If the ship rolls along its longitudinal centerline, an ADU positioned on the port diffuser may experience increased discharge pressure when the ship heels to port (such as when the port side is closer to the water). Discharge pressure can include a static component P and a dynamic component dP. Therefore, the discharge pressure of an ADU positioned on the port side (PS) can be P + dP(PS). However, the pressure of an ADU positioned on the starboard side (SB) at the same distance from the axis of rotation (such as the ship's longitudinal centerline) can be P + dP(SB). When the ADU is positioned at the same distance from the ship's longitudinal centerline, dP(SB) = -dP(PS). Therefore, the amount by which the dynamic pressure decreases on the starboard side is the same as the amount by which the dynamic pressure increases on the port side. The same phenomenon occurs when the ship rolls to the other side during a roll cycle. The static component P of the discharge pressure includes the hydrostatic pressure P (draft) at the ADU when there is no inclining (e.g., when the ship is level), and the pressure loss P (loss) in the air supply system upstream of the ADU. The dynamic component of the pressure is caused by the ship's movement (e.g., rolling). When the ship is moving at a high inclining angle in high waves, the dynamic component of the pressure will be higher than when the ship is moving at a low inclining angle in low waves.

[0021] This document discloses an air supply system for supplying air to the exterior of a ship's hull. The air supply system includes a plurality of air intake units (ADUs) for discharging a flow of compressed air below the waterline of the ship to the exterior of the hull. The plurality of ADUs are configured to be arranged around the longitudinal centerline of the ship's hull, such as symmetrically or at least substantially symmetrically, such that the compressed air is uniformly distributed along the hull of the ship. The air supply system includes a first flow path for providing the compressed air flow to the ADUs. The air supply system includes one or more pressure control devices arranged in the first flow path for supplying the compressed air flow to the ADUs at a pressure greater than the discharge pressure at the ADU. Each pressure control device includes an inlet for receiving the inlet air flow and a plurality of outlets, such as a first outlet and a second outlet, for supplying the compressed air flow to a subset of the plurality of ADUs (such as to a respective subset of ADUs). The first outlet is connected to a first subset of ADUs arranged on a first side (such as the port side) of the longitudinal centerline of the ship's hull. The second outlet is connected to a second subset of ADUs located on a second side (such as the starboard side) opposite the longitudinal centerline of the hull of the vessel.

[0022] In one or more exemplary air supply systems, the one or more pressure control devices may be fixed volumetric displacement pressure control devices. The pressure control device may be arranged in the first flow path to supply the compressed air flow to the ADU at a fixed volumetric displacement and a pressure greater than the discharge pressure at the ADU. The advantage of having a fixed volumetric displacement pressure control device is that the pressure control device will always supply a fixed flow rate of compressed air to the first outlet and the second outlet, regardless of the pressure of the flow to each of the first outlet and / or the second outlet. If the discharge pressure of the compressed air flow acting on the pressure control device increases, the pressure control device will ensure a fixed flow rate by generating a compressed air flow with increased pressure.

[0023] In one or more exemplary air supply systems, the inlet airflow can be ambient air, such as air at atmospheric pressure. Ambient air can be supplied to a first pressure control device and a second pressure control device, where the air can be compressed to a pressure greater than the discharge pressure at the ADU. The compressed air is then supplied to the ADU via a first outlet and a second outlet of the first and second pressure control devices. The advantage of using ambient air as the inlet airflow is that the air supply system is easy to implement in ships and can be used as a separate system for controlling the compressed air flow to the ADU. Furthermore, using ambient air reduces the requirement to cool the air before supplying it to the first flow path. Therefore, the risk of corrosion of the air supply system due to condensation of the air supplied to the system is reduced.

[0024] In one or more exemplary air supply systems, the inlet air flow may be a compressed scavenging air flow from the ship's engine. The advantage of using scavenging air as the inlet air flow is that the inlet air flow is already compressed, thereby reducing the compression ratio required for pressure control devices to provide a compressed air flow with a pressure higher than the discharge pressure at the ADU. Therefore, simpler and more cost-effective pressure control devices, such as blowers or compressors, can be used.

[0025] In some exemplary gas supply systems disclosed herein, the pressure control device may include more than two outlets, such as three, four, five, or even more outlets, for supplying compressed air flow to a subset of the plurality of ADUs, such as to a specific subset of ADUs. In some exemplary gas supply systems disclosed herein, the one or more pressure control devices may include as many outlets as the number of ADUs included in the gas supply system divided by the number of pressure control devices. Therefore, individual control of the flow to each ADU can be provided. For example, if the gas supply system includes one pressure control device and ten ADUs, the pressure control device may include up to ten outlet ports for individually supplying each ADU. If the gas supply system includes more than one pressure control device, each pressure control device may include, for example, five outlets for individually supplying a subset of ADUs when the ADUs are evenly distributed among the pressure control devices. However, in one or more exemplary gas supply systems, the ADUs may also be unevenly distributed, such that a first pressure control device supplies compressed air to, for example, four of the ten ADUs, while a second pressure control device supplies compressed air to the remaining six of the ten ADUs. In this example scenario, the first pressure control unit may include up to four outlets connected to individual ADUs, while the second pressure control unit may include up to six outlets connected to individual ADUs. However, the number of outlet ports on the pressure control unit may also be less than the number of ADUs supplied by the pressure control unit, since one outlet can supply compressed air to multiple ADUs. By supplying compressed air to more than one ADU from the same outlet, the cost and complexity of the air supply system can be reduced.

[0026] In some exemplary gas supply systems described herein, the first subset of ADUs may be arranged at the same distance from the longitudinal centerline of the vessel as the second subset of ADUs. Therefore, the first and second outlets of the one or more pressure control devices may be connected to corresponding subsets of ADUs arranged at equidistant from the longitudinal centerline of the vessel's hull but on opposite sides. By arranging the first subset of ADUs at the same distance from the longitudinal centerline of the vessel as the second subset of ADUs, the dynamic pressures (such as pressure changes) at the first and second sets of ADUs will cancel each other out during the vessel's rolling. This dynamic pressure cancellation means that when the vessel rolls about its longitudinal centerline, the amount by which the dynamic pressure at the first subset of ADUs increases is the same as the amount by which the dynamic pressure at the second subset of ADUs decreases, and vice versa. Therefore, the pressure increase at the first outlet of the pressure control device will be equal to the pressure decrease at the second outlet of the pressure control device, and vice versa.

[0027] In some exemplary air supply systems described herein, each pressure control device may include a drive unit and one or more booster units for supplying compressed air to the first outlet and / or the second outlet of the pressure control device. In some exemplary air supply systems described herein, the pressure control device may include multiple booster units, such as a first booster unit for supplying compressed air to the first outlet and a second booster unit for supplying compressed air to the second outlet. The first booster unit and the second booster unit may be driven by the same drive unit, such that the booster units are driven synchronously and provide the same airflow. When the ship rolls about its longitudinal centerline, causing a change in dynamic pressure at the ADU, the pressure that must be provided by each of the multiple booster units depends on the dynamic portion of the discharge pressure at the corresponding outlet of the booster unit. If the pressure control device includes a first booster unit and a second booster unit, and the first booster unit and the second booster unit are connected to corresponding ADUs arranged at equal distances on opposite sides of the longitudinal centerline of the ship, then when the ship rolls, the first booster unit and the second booster unit will experience opposite dynamic discharge pressures. Experiencing opposite dynamic discharge pressures means that the increase in discharge pressure experienced by the first booster unit is the same as the decrease in discharge pressure experienced by the second booster unit, and vice versa. To ensure a constant volumetric flow rate to the ADU, the first booster unit must therefore increase the pressure of the compressed air stream to overcome the increased discharge pressure. Simultaneously, the second booster unit can decrease the pressure of the compressed air stream to overcome the decreased discharge pressure. The increased power demand experienced by the drive unit to increase the pressure at the first booster unit thus corresponds to the decreased power demand from the second booster unit, and the changes in power demand from the first and second booster units thus cancel each other out. Accordingly, the discharge pressure difference between ADUs located on opposite sides of the ship's longitudinal centerline can be compensated, while the power demand experienced by the drive unit of the pressure control device remains unchanged. In some exemplary air supply systems disclosed herein, a booster unit can supply compressed air to all outlets of the pressure control device, such as the first and second outlets. The compressed air streams supplied to these multiple outlets (such as the first and second outlets) can therefore be the same. Multiple booster units, such as the first booster unit and / or the second booster unit, can be blowers or compressors, such as fixed-displacement blowers or compressors. In some exemplary gas supply systems, the first booster unit and / or the second booster unit can be one or more Roots blowers or reciprocating compressors.A blower can be a simpler pressure boosting device than a compressor, but it can operate at a lower pressure ratio than a compressor, such as a ratio of 1.1 to 1.2 compared to a compressor's ratio of greater than 1.2, depending on the compressor's configuration. A Roots blower includes two rotating blades configured to mesh with each other during rotation. Each rotating blade is arranged on a separate shaft, wherein the separate shafts are connected to each other via gears, such that the shafts can be synchronously driven by a single drive unit. According to this disclosure, each of the rotating blades can be considered a pressure boosting unit. Therefore, a Roots compressor can be considered to include a drive unit and a first pressure boosting unit and a second pressure boosting unit.

[0028] In one or more exemplary pressure control devices, the first and second booster units may be driven by the drive unit via a common shaft or via a gear system. However, in one or more exemplary air supply systems, the first and second booster units may also be separately driven booster units that are synchronously controlled to provide the same flow. The drive unit may be an electric motor. By synchronously operating one or more booster units, such as by connecting the booster units to the same drive unit via a common shaft, the one or more booster units will provide the same volume of flow at both outlets of the pressure control device, assuming the booster units are of the same shape and size. Therefore, the flow through the multiple outlets may be identical, but the pressure of the compressed air flow may differ and may depend on the discharge pressure at the ADU. The discharge pressure may depend on the ship's roll, such as the angle of inclination. When the discharge pressure of one or more of the ADUs located on the port side increases, the pressure required to provide a fixed volume flow rate at the first booster unit increases. This will increase the power demand on the drive unit from the first booster unit. However, since the discharge pressure at the starboard ADU will decrease by the same amount simultaneously (e.g., concurrently), the power demand on the drive unit from the second booster unit will also decrease. Therefore, the drive unit will not experience any net change in power demand from the first and second booster units, or at least not any significant net change. Consequently, the one or more pressure control devices will passively adapt to the pressure at the first and second outlets (e.g., at the first and second booster units).

[0029] In one or more exemplary air supply systems disclosed herein, the air supply system may include one or more turbochargers. Each turbocharger includes a turbine driven by an exhaust flow from a ship's engine. The turbine may include a turbine housing and a turbine impeller rotatably arranged within the turbine housing. The turbine impeller may be forced to rotate by an exhaust flow through the turbine housing. The exhaust flow may be received from an exhaust receiver of the engine. The exhaust receiver may receive exhaust gas generated during combustion from the engine. Each turbocharger also includes a compressor for supplying a compressed scavenging air flow to the engine via the first flow path, such as to a scavenging air receiver for the engine. The compressor may include a compressor housing and a compressor impeller rotatably arranged within the compressor housing, the compressor impeller also being referred to as a pump impeller. The compressor impeller may be rigidly connected to the turbine impeller such that the turbine impeller drives the compressor impeller. The compressor receives air and then compresses the air by the rotation of the compressor impeller. The compressed air from the compressor of the turbocharger (the compressed air may also be referred to as scavenging air) may then be supplied to the engine, such as to a scavenging air receiver for the engine via a scavenging air flow path. The scavenging air flow path may include an air cooler for cooling compressed air from the compressors of each turbocharger, a water mist trap for removing moisture from the compressed air stream, and / or a check valve for preventing air from flowing from the scavenging air receiver into the scavenging air flow path. The water mist trap may be positioned downstream of the air cooler. The check valve may be positioned downstream of the water mist trap. In one or more exemplary air supply systems, the first flow path may be connected to the scavenging air flow path for extracting the scavenging air stream. The first flow path may be connected between the air cooler and the water mist trap. The advantage of extracting scavenging air downstream of the air cooler is that the extracted scavenging air is cooled. Cooling the air reduces the risk of corrosion in the air supply system, thereby reducing the maintenance required by the system. Cooling the air also allows for a higher density flow, thereby improving the system's energy efficiency. Extracting scavenging air upstream of the water mist trap prevents contaminated gases from the combustion process from leaking into the first flow path. Therefore, only uncontaminated (e.g., clean) air is supplied to the exterior of the ship's hull, which reduces the environmental impact of the air supply system. In some exemplary air supply systems, the first flow path can be connected downstream of the water mist collector to the scavenging air flow path. Therefore, condensation generated by cooling the scavenging air can be removed from the scavenging air before it is supplied to the pressure control device in the first flow path. This reduces the risk of damage to the pressure control device caused by residual condensation.When the first flow path connects to the scavenging air path downstream of the water mist collector, the scavenging air path may include a check valve disposed downstream of the connection point between the first flow path and the scavenging air path to prevent contaminant gases from the combustion process from leaking from the scavenging air receiver into the first flow path. The air supply system may include a switching valve disposed in the first flow path for opening and / or closing the first flow path to allow or prevent airflow (such as scavenging air) through the first flow path.

[0030] In some exemplary gas supply systems, the pressure control device and / or booster unit may include a drain or deflector for discharging condensate from the pressure control device and / or booster unit. This reduces the risk of malfunction of the pressure control device and / or booster unit due to moisture.

[0031] The pressure of the scavenging airflow can vary depending on the engine load. Under low load, the exhaust flow rate may be low, causing the turbine of the turbocharger driven by the exhaust flow to rotate at a low revolutions per minute (rpm). Therefore, the turbocharger compressor will rotate at the same rpm and will not provide its maximum compression performance. Under low engine load, the scavenging pressure may therefore be lower than the discharge pressure at the ADU. Therefore, scavenging air can be supplied to one or more pressure control devices, where the pressure of the scavenging airflow is increased, for example, to a pressure greater than the discharge pressure at the ADU. The scavenging airflow with a pressure greater than the discharge pressure at the ADU is then supplied to the ADU, where it is discharged to the outside of the ship's hull. The advantage of using scavenging airflow as the inlet airflow is that the inlet airflow has already been compressed, for example, pre-compressed, by one or more turbochargers. Therefore, the pressure control devices must perform less compression work compared to one or more exemplary air supply systems where the inlet airflow is ambient air. When the inlet airflow has been pre-compressed, a blower or compressor with a lower compression ratio can be used as a booster unit because the compression work that must be performed by the pressure control device is lower.

[0032] When the pressure of the compressed air flow upstream of the pressure control device exceeds the discharge pressure at the ADU, such as under higher engine loads where the scavenging air pressure is greater than the discharge pressure, the first booster unit and / or the second booster unit can be configured to reduce the flow rate through the first flow path. Reducing the flow rate through the first flow path ensures sufficient compressed air flow, such as scavenging air, to the engine. If the compressed air flow rate through the first flow path is too high, causing most of the air to flow to the ADU without passing through the engine combustion chamber, the ship's engine may overheat. By reducing the flow rate through the first flow path, it can be ensured that the engine receives the air required for cooling and combustion of fuel in the combustion chamber. The first booster unit and / or the second booster unit can rotate, for example, like a windmill, in the air flow through the first flow path. Therefore, the first booster unit and / or the second booster unit can act as a limiter in the first flow path. The pressure control device can be controlled to allow a target flow rate through the first flow path, such as by increasing the pressure when the air flow received by the pressure control device is below the target flow rate or by limiting the air flow when the air flow received by the pressure control device is above the target flow rate. The flow rate through the pressure control device can be controlled based on the engine load and / or the maximum permissible bypass flow rate under the given engine load.

[0033] In some exemplary air supply systems described herein, the drive unit can be configured to be driven by the first booster unit and / or the second booster unit when the pressure of the compressed air flow upstream of the pressure control device exceeds the discharge pressure at the ADU, and to remove energy from the air flow. When the drive unit is an electric motor, the electric motor can be configured to be driven by the first booster unit and / or the second booster unit when the pressure of the compressed air flow upstream of the pressure control device exceeds the discharge pressure at the ADU, and to act as an electrical energy generator. The generated electrical energy can be supplied to the ship's electrical system or to an energy storage device. When the pressure and / or flow rate of the compressed air must be increased, the generated electrical energy can be used to drive the pressure control unit.

[0034] In one or more exemplary gas supply systems, the gas supply system may include two or more turbochargers. The gas supply system may also include one or more shut-off valves for connecting or disconnecting gas flow to the turbine side of at least one of the two or more turbochargers and / or from the compressor side of at least one of the two or more turbochargers. By cutting off the exhaust flow to the turbine side of at least one of the turbochargers by closing the shut-off valves, a larger exhaust flow can be provided to the remaining turbochargers, thereby increasing the compression capacity of the turbochargers, which will increase the pressure generated by the active turbocharger.

[0035] In one or more exemplary air supply systems, engine efficiency can be improved by increasing the pressure of the airflow in the main flow path from one or more turbochargers to the engine using turbocharger throttling (TCCO). If, for example, multiple turbochargers, such as two or more, are used to feed air into the engine, one of the multiple turbochargers can be disconnected, for example, by disconnecting at least one of the multiple turbochargers from the exhaust inlet of the turbocharger's turbine and / or from the compressed air outlet of the turbocharger's compressor. This will allow all air, such as all exhaust air supplied to the engine and / or all ambient air, to flow through one or more of the multiple turbochargers, which may also be referred to as one or more active turbochargers. Since the available exhaust flow must drive a smaller number of turbochargers, the exhaust flow to each active turbocharger (such as the turbocharger that has not yet been disconnected) will increase. Increased exhaust pressure to one or more active turbochargers causes these turbochargers to rotate faster, which in turn increases the pressure of the compressed air from the compressor side of these turbochargers through the main flow path. The higher exhaust pressure to one or more active turbochargers improves turbocharger efficiency compared to a scenario where all turbochargers are active, and therefore allows for higher air pressure to flow through the main flow path to the engine. The scenario where all turbochargers are active may also be referred to herein as normal operation or normal operating condition.

[0036] In one or more exemplary air supply systems, the air supply system may include a flow control device arranged in the first flow path for controlling the flow rate through the first flow path. The flow control device may be a fixed orifice allowing a fixed flow through the first flow path, or a variable orifice, such as a control valve, allowing a variable air flow through the first flow path. The flow control device may be controlled based on engine load and / or the maximum permissible bypass flow rate under the given engine load.

[0037] In one or more exemplary gas supply systems, the gas supply system may include one or more check valves arranged in the first flow path between the one or more pressure control devices and the ADU, for preventing seawater from entering the first flow path through the ADU.

[0038] When a ship rolls, such as when the ship is positioned at an angle to the water, the discharge pressure may vary with the ADU, depending on the relative distance between the ADU and the ship's centerline. An ADU located on the opposite side of the ship's roll (such as the ADU on the starboard side when the ship rolls to port, and vice versa) will be submerged less deeply in the water than the ADU on the port side.

[0039] Therefore, the water pressure acting on the ADU on the starboard side will be lower than that acting on the port side. Each pair of ADUs equidistant from the longitudinal centerline (e.g., arranged at equal distances) on both sides of the vessel (e.g., on the port and starboard sides) will experience equal positive / negative pressure increments. A pressure increment means a change in pressure. For pairs of ADUs arranged at different distances from the longitudinal centerline, such as further inward or outward laterally from the centerline, the actual pressure increments will differ. The one or more pressure control devices can supply a fixed volumetric flow rate of air to each of the plurality of ADUs; however, the pressure supplied by connecting to the outlet of the ADU located on the port side of the vessel will be higher than the pressure supplied by a second outlet connected to the starboard ADU. If the vessel will supply lower pressure to the ADUs at a constant flow rate, the second pressure control device connected to the ADU will be installed closer to the centerline because the pressure difference between the port and starboard ADUs will be less than the pressure difference of ADUs installed further away from the centerline (e.g., in a laterally position further away from the vessel's centerline), and therefore will experience less vertical movement than the ADU. Therefore, the pressure difference caused by the difference in water level on both sides of the longitudinal centerline will also be smaller.

[0040] The distribution of air to ADUs, depending on the discharge pressure at the ADU (such as depending on the ship's inclination angle), can be controlled using the air supply system disclosed herein without the need for control valves (such as throttle valves) to control the airflow to different ADUs.

[0041] Although the exemplary air supply system disclosed herein is described as compensating for the discharge pressure difference between ADUs arranged on opposite sides of the longitudinal centerline of a vessel, the air supply system can also be configured to compensate for the pressure difference at ADUs arranged on opposite sides of the lateral centerline of the vessel's hull. Therefore, the air supply system can compensate for the discharge pressure difference at ADUs caused by the vessel's trim and / or pitch. A first outlet of the pressure control device can be connected to a first subset of ADUs arranged on a first side of the lateral centerline of the vessel's hull. A second outlet can be connected to a second subset of ADUs arranged on a opposite second side of the lateral centerline of the vessel's hull. By connecting the ADUs arranged on the first side of the vessel to the first outlet of one or more pressure control devices and connecting the ADUs arranged on the second side of the vessel to the second outlet of one or more pressure control devices, one or more pressure control devices are configured to compensate for the discharge pressure difference between the first subset of ADUs and the second subset of ADUs.

[0042] A vessel is also disclosed, comprising a hull and an air supply system according to any of the examples provided herein. The vessel may also include an engine for propelling the vessel, such as a main engine.

[0043] Figure 1 The illustration shows an example of a known solution for controlling the air supply system during a ship's roll. During a ship's roll, such as when the ship rotates around its longitudinal centerline, the discharge pressure at the ADU may vary with the ADU, depending on the depth of the ADU immersed in the water surrounding the ship. If the ship rolls along its longitudinal centerline, the ADU located on the port diffuser may experience increased discharge pressure as the ship heels to port (such as when the port side is closer to the water). To compensate for the varying pressure at ADU 20 during a ship's roll, known solutions typically use separate control valves, such as throttle valves, to individually control the flow to each ADU 20. The control valves can be controlled by an air release control unit based on the ship's heel, the air flow to the ADU 20, and / or pressure sensors located at each ADU. The air release control unit can set a static pressure setpoint for airflow control based on the ship's heel and speed, and a dynamic setpoint based on the ship's heel, roll period, and speed. For all ADU 20s, the static pressure can be constant, while the dynamic setpoint can vary with the ship's roll. Figure 1 In the scenario shown, the ship rolls to its starboard side. (As...) Figure 1As can be seen, the discharge pressure at the starboard ADU 20 increases, while the discharge pressure at the port ADU decreases until the discharge pressure reaches the static pressure setpoint. To ensure flow to all ADUs 20, individual control valves can be operated to individually increase the pressure of the airflow to ADU 20, thereby increasing the pressure of the airflow to the starboard ADU until said pressure overcomes the discharge pressure, while the pressure at the port ADU can decrease. This system is therefore very complex and requires a large amount of information from sensors (such as tilt sensors, flow sensors, speed sensors, pressure sensors, and / or draft pressure sensors) to continuously adapt the pressure to the ship's current operating conditions. Therefore, known systems use active valve control to ensure equal airflow across the hull (such as the ship's beams). The ship's beams are the widest parts of the ship from one side to the other.

[0044] Figure 2 The illustration shows an exemplary air supply system 100 for supplying air to the exterior of a ship's hull according to this disclosure. The air supply system 100 includes a plurality of air intake units (ADUs) 20 for releasing a flow of compressed air below the ship's waterline to the exterior of the hull. The ADUs 20 may be openings in the ship's hull through which air can escape to the exterior of the hull. The plurality of ADUs 20 are configured to be arranged around a longitudinal centerline 202 of the ship's hull. The ADUs 20 may be arranged symmetrically around the longitudinal centerline of the ship, or at least substantially symmetrically. A substantially symmetrical arrangement around the longitudinal centerline means that the positions of the ADUs on the ship's hull may differ slightly between a first side and a second side (such as the port and starboard sides of the ship). The plurality of ADUs are arranged to provide equal flow rates on the ship's hull (such as on the ship's beams). The air supply system includes a first flow path 11A for providing a flow of compressed air to the ADUs 20. Figure 2The exemplary air supply system 100 shown also includes two pressure control devices 30, such as a first pressure control device 30A and a second pressure control device 30B, arranged in a first flow path 11A for supplying compressed air to ADU 20 at a pressure greater than the discharge pressure at ADU 20. Each pressure control device 30 includes an inlet 34 for receiving inlet air flow, a first outlet 35A for supplying air flow to a subset 20AB or 20CD of the plurality of ADU 20, and a second outlet 35B for supplying air flow to a subset 20BA or 20DC of the plurality of ADU 20. The pressure control devices 30 can be configured to control the pressure and / or flow rate of air passing through the pressure control device 30, such as increasing and / or decreasing the pressure and / or flow rate of the air. The pressure control device 30 can be a fixed volumetric displacement pressure control device. The pressure control device 30 can be configured to provide a fixed volumetric flow rate at a given speed of the pressure control device 30. The first outlet 35A of the first pressure control device 30A is connected to a first ADU subset 20AB located on a first side (such as the port side) of the longitudinal centerline 202 of the hull 201 of the vessel 200. The second outlet 35B of the first pressure control device 30A is connected to a second ADU subset 20BA located on the opposite second side (such as the starboard side) of the longitudinal centerline 202 of the hull of the vessel 200. The first outlet 35A of the second pressure control device 30B is connected to a third ADU subset 20CD located on the first side of the longitudinal centerline 202 of the hull 201 of the vessel 200. The third ADU subset 20CD may be positioned closer to the centerline of the hull than the first ADU subset 20AB. The second outlet 35B of the second pressure control device 30B is connected to a fourth ADU subset 20DC located on the opposite second side of the longitudinal centerline 202 of the hull of the vessel. The first ADU subset 20AB can be arranged at the same distance from the longitudinal centerline 202 of the ship as the second ADU subset 20BA, such that the first outlet 35A and the second outlet 35B are connected to the corresponding ADU subsets 20AB and 20BA, which are arranged equidistant from the longitudinal centerline 202 but on opposite sides of the longitudinal centerline 202. Accordingly, the third ADU subset 20CD can be arranged at the same distance from the longitudinal centerline 202 of the ship as the fourth ADU subset 20DC. In other words, ADUs 20AB and 20BA, and 20CD and 20DC, can be mirror images of the longitudinal centerline 202. Therefore, the first outlet 35A and the second outlet 35B of the first pressure control device 30A and the second pressure control device 30B are configured to provide compressed air flow to the corresponding ADU subsets 20AB, 20BA; 20CD, 20DC on opposite sides of the centerline 202 of the ship's hull.

[0045] exist Figure 2In the exemplary air supply system 100 shown, each pressure control device 30; 30A, 30B includes a drive unit 31, a first booster unit 32A for supplying compressed air to a first outlet 35A, and / or a second booster unit 32B for supplying compressed air to a second outlet 35B. The first booster unit 32A and the second booster unit 32B may be driven synchronously, such as by the same drive unit 31. The drive unit 31 may be an electric motor. The first booster unit 32A and / or the second booster unit 32B may be, for example, a blower or compressor, such as a fixed-volume displacement blower or compressor. The fixed-volume displacement blower is configured to provide a predetermined airflow at a predetermined speed (such as revolutions per minute (rpm) of the booster device). In some exemplary air supply systems 100, the first booster unit 32A and / or the second booster unit 32B may be one or more Roots blowers. The Roots blower includes two rotating blades configured to mesh with each other during rotation. Each rotating blade is arranged on a separate shaft, wherein the separate shafts are connected to each other via gears, such that the shafts can be synchronously driven by a single drive unit. According to this disclosure, each of the rotating blades can be considered as a booster unit 32. Therefore, the Roots compressor can be considered to include a drive unit 31, a first booster unit 32A, and a second booster unit 32B. Figure 2 In the exemplary pressure control devices 30; 30A, 30B shown, the first booster unit 32A and the second booster unit 32B are driven by the drive unit 31 via a common shaft 33.

[0046] Although the ADU subsets are preferably arranged symmetrically in pairs, the distances from outlets 35A and 35B to their respective ADU subsets may not be the same. Typically, the pressure control units 30 are not symmetrically positioned, or the air pipes to one side of the hull may extend along paths of varying lengths. This will mean different flow rates and / or pressure losses in the supply from one or more pressure control units 30 to subsets 20AB and 20BA or 20CD and 20DC. These differences can be compensated for by a first booster unit 32A and a second booster unit 32B having different capacities or efficiencies in size and shape, such that the booster unit 32 connected to the supply line with higher losses has a higher capacity or efficiency, resulting in the symmetrically arranged ADU subsets being supplied with the same flow rate when booster units 32A and 32B are driven via a common shaft 33.

[0047] In one or more exemplary air supply systems 100, the inlet airflow may be ambient air, such as air at atmospheric pressure. The ambient air is then supplied to a first pressure control device 30A and a second pressure control device 30B, where the air can be compressed to a pressure greater than the discharge pressure at ADU 20; 20AB, 20BA; 20CD, 20DC. The compressed air is then supplied to ADU 20; 20AB, 20BA; 20CD, 20DC via a first opening 35A and a second opening 35B of the first pressure control device 30A and the second pressure control device 30B.

[0048] Figure 3 The illustrations depict gas supply systems based on some examples from this article. Figure 3 In the air supply system 100 shown, the inlet air flow is a compressed scavenging air flow from the ship's engine. Figure 3 The exemplary air supply system 100 shown includes one or more turbochargers 10. Each turbocharger 10 includes components supplied by an engine from a ship (…). Figure 3 A turbine 10A is driven by an exhaust flow (not shown). The turbine may include a turbine housing and a turbine impeller rotatably arranged within the turbine housing. The turbine impeller may be forced to rotate by an exhaust flow through the turbine housing. The exhaust flow may be received from an exhaust receiver of the engine. The exhaust receiver may receive exhaust gas generated during combustion from the engine. Each turbocharger 10 also includes a compressor 10B for supplying a compressed scavenging air flow to the engine via a first flow path 11A, such as to a scavenging air receiver of the engine. The compressor may include a compressor housing and a compressor impeller rotatably arranged within the compressor housing, the compressor impeller also being referred to as a pump impeller. The compressor impeller may be rigidly connected to the turbine impeller such that the turbine impeller drives the compressor impeller. The compressor receives air and then compresses the air by the rotation of the compressor impeller. The compressed air from the compressor of the turbocharger (the compressed air may also be referred to as scavenging air) may then be supplied to the engine, such as to a scavenging air receiver of the engine via the scavenging air flow path 11.

[0049] The scavenging air flow path 11 may include an air cooler 16 for cooling the compressed air from the compressor of each turbocharger 10, a water mist trap 18 for removing moisture from the compressed air flow, and / or a check valve 19 for preventing air from flowing from the scavenging air receiver into the scavenging air flow path 11. The water mist trap 18 may be arranged downstream of the air cooler 16. The check valve 19 may be arranged downstream of the water mist trap 18. Figure 3In the exemplary air supply system shown, a first flow path 11A is connected to a scavenging air flow 11 to extract the scavenging air flow. The first flow path 11A can be connected between the air cooler 16 and the water mist collector 18 to the scavenging air flow path 11. The advantage of extracting the scavenging air downstream of the air cooler is that the extracted scavenging air is cooled. Cooling the air reduces the risk of corrosion in the air supply system, thereby reducing the maintenance required by the system. Cooling the air also allows for a higher density flow, thereby improving the system's energy efficiency. Extracting the scavenging air upstream of the water mist collector 18 prevents contaminated gases from the combustion process from leaking into the first flow path 11A. Therefore, only uncontaminated (e.g., clean) air is supplied to the exterior of the vessel's hull, which reduces the environmental impact of the air supply system. The air supply system 100 may include a switching valve 13 arranged in the first flow path 11A for opening and / or closing the first flow path 11A to allow or block airflow (such as scavenging air) through the first flow path 11A.

[0050] The pressure of the compressed air stream can depend on the engine load. Under low load, the exhaust flow rate may be low, which will cause the turbine of the turbocharger driven by the exhaust flow to rotate at a low revolutions per minute (rpm). Therefore, the compressor will rotate at the same rpm and will not provide its maximum compression performance. Under low engine load, the scavenging pressure may therefore be lower than the discharge pressure at ADU 20. Therefore, scavenging air can be supplied to one or more pressure control devices 30, in which the pressure of the scavenging air stream is increased, for example, increased, to a pressure greater than the discharge pressure at ADU 20. The scavenging air stream with a pressure greater than the discharge pressure at ADU 20 is then supplied to ADU 20, where it is discharged to the outside of the ship's hull. The advantage of using the scavenging air stream as the inlet air stream is that the inlet air stream has already been compressed, for example, pre-compressed, by one or more turbochargers 10. Therefore, with Figure 1 Compared to the exemplary system disclosed in which the inlet airflow is ambient air, the pressure control device 30 must perform less compression work.

[0051] When the pressure of the compressed air flow upstream of the pressure control device 30 exceeds the discharge pressure at ADU 20, such as under higher engine loads where the scavenging air pressure is greater than the discharge pressure, the first booster unit 32A and / or the second booster unit 32B can be configured to reduce the flow rate through the first flow path 11A. When the booster unit is a fixed displacement (such as a fixed flow rate) unit (such as a blower or compressor), the flow rate through the booster unit is set based on the booster unit's rpm. Therefore, if the inlet flow rate to the booster unit is higher than the fixed displacement at the current rpm of the booster units 32A, 32B, the flow rate will be reduced to the fixed displacement of the booster units 32A, 32B. The first booster unit 32A and / or the second booster unit 32B can, for example, rotate like a windmill in the airflow through the first flow path 11A. Therefore, the first booster unit 32A and / or the second booster unit 32B can act as a limiter in the first flow path 11A.

[0052] In one or more exemplary gas supply systems 100, the gas supply system may further include one or more shut-off valves 17 for connecting or disconnecting gas flow to the turbine side of at least one of two or more turbochargers 10 and / or from the compressor side of at least one of two or more turbochargers 10. Figure 3 The exemplary air supply system shown includes two turbochargers 10, one of which includes a shut-off valve 17. However, the air supply system may include more than two turbochargers 10, such as three, four, five, or six turbochargers 10, wherein at least a subset of the turbochargers 10 are provided with shut-off valves 17. Shut-off valves 17 may be configured to be fully open or fully closed, or may be configured to be gradually controlled between an open and closed position. Sub-flow path 11A may be connected to the respective main flow path 11 of each of the one or more turbochargers 10. The air supply system may also include an exhaust bypass (EGB) valve 15. In the event of an overspeed risk at the turbocharger 10, the EGB valve may be opened to release some exhaust flow, which will reduce the amount of exhaust driving the turbocharger 10. Therefore, the speed of the turbocharger 10 can be reduced. The one or more turbochargers 10 are generally configured to provide the maximum permissible scavenging air pressure to the engine. The maximum permissible scavenging air pressure can be determined based on the engine pressure ratio and the pressure rise during combustion. A maximum scavenging pressure can be selected such that the provided scavenging pressure does not overload the engine. However, when a bypass, such as a sub-flow path, is added or opened, causing the sub-airflow to be drawn from the main flow path 11, the scavenging air pressure decreases as the flow rate in the bypass increases. This is because the amount of air circulating through the engine and supplied to one or more turbochargers is reduced, thus reducing energy.

[0053] In some exemplary air supply systems 100 described herein, drive unit 31 may be configured to be driven by first booster unit 32A and / or second booster unit 32B and remove energy from the airflow when the pressure of the compressed air flow upstream of pressure control device 30 exceeds the discharge pressure at ADU 20. When drive unit 31 is an electric motor, the electric motor may be configured to be driven by first booster unit 32A and / or second booster unit 32B and act as an energy generator when the pressure of the compressed air flow upstream of pressure control device 30 exceeds the discharge pressure at ADU 20. The generated electrical energy may be supplied to the ship's electrical system or to an energy storage device. The first and second booster units may include flow reduction devices for limiting the flow rate through the first flow path 11A. The flow reduction device may serve as a brake on the air supply system, thereby causing control and limitation of the flow rate through the first flow path. The flow reduction device may, for example, be a resistor that generates resistance in the electrical system and / or a variable frequency drive (VFD) for controlling the electric motor. Reducing the flow rate can be used to ensure that a sufficient amount of compressed air is available at the ship's engine.

[0054] In one or more exemplary gas supply systems 100, the gas supply system 100 may include a flow control device 12 disposed in a first flow path 11A for controlling the flow through the first flow path 11A. The flow control device 12 may be a fixed orifice allowing a fixed flow through the first flow path 11A, or a variable orifice allowing a variable air flow through the first flow path 11A, such as a control valve.

[0055] In one or more exemplary gas supply systems 100, the gas supply system 100 may include one or more check valves 14 arranged in a first flow path 11A between one or more pressure control devices 30 and ADU 20 to prevent seawater from entering the first flow path 11A through ADU 20.

[0056] Figure 4 An exemplary air supply system 100 according to this disclosure is shown when the vessel is in a stable state (such as when the vessel is level in the water). When the vessel is level in the water, the discharge pressure in all ADUs can be the same. Therefore, one or more pressure control devices 30 can supply air at the same pressure and a fixed volumetric flow rate to each of the plurality of ADUs 20 via outlets 32A, 32B, as indicated by the diagonals of the ADUs 20.

[0057] Figure 5An exemplary air supply system 100 according to this disclosure is shown when the vessel rolls (e.g., when the vessel rotates about its longitudinal centerline and is positioned at an angle to the water surface). When the vessel rolls, the discharge pressure may vary with ADUs 20AB, 20BA; 20CD, 20DC. The discharge pressure may vary depending on the depth of ADUs 20AB, 20BA; 20CD, 20DC immersed in the water surrounding the vessel. ADUs 20AB, 20BA; 20CD, 20DC located on the opposite side of the vessel's roll (e.g., the starboard side when the vessel rolls to port) will be immersed to a lower depth than ADUs on the opposite side (e.g., on the port side of the vessel). The discharge pressure at ADU 20 may include a static portion P and a dynamic portion dP. Therefore, the discharge pressure of ADUs 20AB; 20CD located on the port side (PS) may be P + dP(PS). For a relative ADU 20BA; 20DC positioned at the same distance from the axis of rotation (such as the longitudinal centerline of the ship) on the starboard side (SB) of the ship, the pressure can be P + dP(SB). In this case, where ADU 20AB and ADU 20BA or ADU 20CD and ADU 20DC are positioned at the same distance from the longitudinal centerline of the ship, the dynamic pressure on the port side may increase by the same amount as the dynamic pressure on the starboard side, such that dP(SB) = -dP(PS). The two ADUs (such as the port ADU 20AB and the starboard 20BA) will jointly experience a constant power requirement equivalent to pressure P. Therefore, the pressure difference can be balanced by the work done by one or more pressurization units 32 of one or more pressure control devices 30 (such as a first pressurization unit 32A connected to ADU 20AB; 20CD and a second pressurization unit 32B connected to ADU 20BA; 20DC), which are connected by a common shaft 33. Therefore, the discharge pressure (such as water pressure) acting on ADD 20BA; 20DC on the starboard side will be lower than the water pressure acting on ADD 20AB; 20CD on the port side. One or more pressure control devices 30 can supply a fixed volumetric flow rate of air to each of the multiple ADD 20; 20AB, 20BA; 20CD, 20DC; however, the pressure supplied by the outlet 32A connected to the port side ADD 20AB; 20CD will be higher than the pressure supplied by the second outlet 32B connected to the starboard side ADD 20BA; 20DC to each of the multiple ADD 20AB; 20CD. When the discharge pressure of one or more of the ADD 20AB; 20CD on the port side increases, the pressure required to supply a fixed volumetric flow rate at the first pressurization unit 32A increases. This will increase the power demand on the drive unit 31 from the first pressurization unit 32A.However, since the exhaust pressure at starboard ADD 20BA; 20DC will decrease by the same amount, the power demand on drive unit 31 from the second booster unit 32B will also decrease. Therefore, the drive unit will not experience any net change in power demand from the first booster unit 32A and the second booster unit 32B, or at least not any significant net change. Consequently, one or more pressure control devices 30 will passively adapt to the pressure at the first outlet 35A and the second outlet 35B (e.g., at the first booster unit 32A and the second booster unit 32B). Higher pressures are indicated by the thicker lines of the patterns in ADD 20AB; 20CD. If the vessel provides lower pressure to the ADD at a constant flow rate, the second pressure control device 30B connected to ADD 20CD; 20DC is installed closer to the centerline 202 because the pressure difference between the port ADD 20CD and the starboard ADD 20DC will be smaller than that of ADDs 20AB and 20BA installed further away from the centerline 202 (such as in a transverse position further away from the vessel's centerline 202), and therefore will experience less vertical movement than ADDs 20AB and 20BA. Consequently, the pressure difference caused by the difference in water levels acting on both sides of the longitudinal centerline will also be smaller.

[0058] It should be noted that, Figures 2 to 5 The features mentioned in the embodiments described herein are not limited to these specific embodiments. Therefore, the description relates to the gas supply system and the components included therein, and concerns... Figure 2 Any features mentioned regarding the use of ambient air supply systems also apply to the use of ambient air supply systems. Figures 3 to 5 The described air supply system uses scavenging air. Therefore, it relates to and concerns the air supply system and the components included therein. Figures 3 to 5 Any features mentioned regarding the use of scavenging air supply systems (such as controlling the pressure of the airflow to the ADD) also apply to the information regarding... Figure 2 The described air supply system uses ambient air.

[0059] It should also be noted that, when referred to herein, a vertical axis refers to an imaginary line extending vertically through the ship and through its center of gravity; a transverse or lateral axis is an imaginary line extending horizontally through the ship and through its center of gravity; and a longitudinal axis is an imaginary line extending horizontally through the length of the ship, through its center of gravity, and parallel to the waterline. Similarly, when referred to herein, a vertical plane refers to an imaginary plane extending vertically through the width of the ship; a transverse or lateral plane is an imaginary plane extending horizontally through the ship; and a longitudinal plane is an imaginary plane extending vertically through its length.

[0060] The following clauses set forth implementation schemes (gas supply systems and vessels) of the products according to this disclosure:

[0061] Clause 1. An air supply system (100) for supplying air to the exterior of a ship's hull, said air supply system (100) comprising:

[0062] - Multiple air emission units (ADDs) (20; 20AB, 20BA), said multiple ADUs for releasing compressed air flow below the waterline of the vessel to the outside of the hull, said multiple ADDs (20; 20AB, 20BA) being configured to be arranged symmetrically around the longitudinal centerline (202) of the hull of the vessel.

[0063] -A first flow path (11A) for providing the compressed air flow to the ADD (20),

[0064] - One or more pressure control devices (30), arranged in the first flow path (11A), for supplying the compressed air flow to the ADD (20) at a pressure greater than the discharge pressure at the ADD (20; 20AB, 20BA), wherein each pressure control device (30) includes an inlet (34) for receiving the inlet air flow, a first outlet (35A) and a second outlet (35B) for supplying the air flow to a subset (20; 20AB, 20BA) of the plurality of ADDs, wherein the first outlet... The outlet (35A) is connected to a first ADD subset (20AB) arranged on a first side of the longitudinal centerline (202) of the hull (201) of the vessel (200), and the second outlet (35B) is connected to a second ADD subset (20BA) arranged on a opposite second side of the longitudinal centerline (202) of the hull of the vessel, wherein one or more pressure control devices (30) are configured to compensate for the discharge pressure difference between the first ADD subset (20AB; 20CD) and the second ADD subset (20BA; 20DC).

[0065] Clause 2. The gas supply system (100) according to Clause 1, wherein the first ADU subset (20AB) is arranged at the same distance from the longitudinal centerline (202) of the vessel as the second ADU subset (20BA).

[0066] Clause 3. The air supply system (100) according to any one of the preceding clauses, wherein each pressure control device (30) includes a drive unit (31), a first booster unit (32A) for supplying compressed air to the first outlet and / or a second booster unit (32B) for supplying compressed air to the second outlet, wherein the first booster unit (32A) and the second booster unit (32B) are driven by the same drive unit (31).

[0067] Clause 4. The gas supply system (100) according to Clause 3, wherein the first booster unit (32A) and / or the second booster unit (32B) is a blower or a compressor.

[0068] Clause 5. The gas supply system (100) according to Clause 3 or 4, wherein the first booster unit (32A) and the second booster unit (32B) are fixed displacement blowers or compressors.

[0069] Clause 6. The gas supply system (100) according to any one of Clauses 3 to 5, wherein the drive unit (31) is an electric motor.

[0070] Clause 7. An air supply system (100) according to any one of Clauses 3 to 6, wherein when the pressure of the compressed air flow upstream of the pressure control device (30) exceeds the discharge pressure at the ADU (20), the first pressure boosting unit (32A) and / or the second boosting unit (32B) are configured to reduce the flow rate through the first flow path (11A).

[0071] Clause 8. An air supply system (100) according to any one of Clauses 3 to 7, wherein when the pressure of the compressed air flow upstream of the booster (30) exceeds the discharge pressure at the ADU (20), the drive unit (31) is configured to be driven by the first booster unit (32A) and / or the second booster unit (32B) and to remove energy from the air flow.

[0072] Clause 9. An air supply system (100) according to any one of Clauses 3 to 8, wherein the drive unit (31) is an electric motor, and the electric motor (31) is configured to be driven by the first booster unit (32A) and / or the second booster unit (32B) and to act as an electrical energy generator when the pressure of the compressed air flow upstream of the booster (30) exceeds the discharge pressure at the ADU (20).

[0073] Clause 10. The gas supply system (100) according to any one of the preceding clauses, wherein the inlet airflow is ambient air.

[0074] Clause 11. An air supply system (100) according to any one of Clauses 1 to 10, wherein the inlet air flow is a compressed scavenging air flow from the engine of the vessel.

[0075] Clause 12. The air supply system (100) according to Clause 11, wherein the air supply system (100) includes one or more turbochargers (10), each turbocharger (10) including a turbine (10A) driven by an exhaust flow from the engine and a compressor (10B) for supplying the compressed scavenging air flow to the first flow path (11A).

[0076] Clause 13. A gas supply system (100) according to any one of the preceding clauses, wherein the gas supply system (100) includes a switching valve (13) arranged in the first flow path (11A) for opening and / or closing the first flow path (11A).

[0077] Clause 14. The gas supply system (100) according to any one of the preceding clauses, wherein the gas supply system (100) includes a flow control device (12) arranged in the first flow path (11A) for controlling the flow rate through the first flow path (11A).

[0078] Clause 15. The gas supply system (100) according to any one of the preceding clauses, wherein the gas supply system (100) includes one or more check valves (14) arranged in the first flow path (11A) between the one or more pressure control devices (30) and the plurality of ADUs (20) for preventing seawater from entering the first flow path (11A) through the plurality of ADUs (20).

[0079] Clause 16. The air supply system (100) according to any one of the preceding claims, wherein the one or more pressure control devices (30) are fixed volume displacement pressure control devices that supply a fixed volume flow rate of air to each of the plurality of ADUs (20).

[0080] Clause 17. A vessel (200) comprising a hull (201), an engine, and an air supply system (100) according to any one of the preceding clauses.

[0081] The use of terms such as "first," "second," "third," and "fourth," "first-level," "second-level," and "third-level," etc., does not imply any particular order, but is included to identify individual elements. Furthermore, the use of terms such as "first," "second," "third," and "fourth," "first-level," "second-level," and "third-level," etc., does not indicate any order or importance, but is used to distinguish one element from another. Note that the use of the terms "first," "second," "third," and "fourth," "first-level," "second-level," and "third-level," etc., here and elsewhere, is solely for labelling purposes and is not intended to indicate any particular spatial or temporal order. Moreover, the labeling of a first element does not imply the existence of a second element, and vice versa.

[0082] It should be noted that the word "includes" does not necessarily exclude the existence of other elements or steps besides those listed.

[0083] It should be noted that the words "one" or "a kind" preceding an element do not preclude the existence of multiple such elements.

[0084] Although features have been shown and described, it should be understood that they are not intended to limit the claimed disclosure, and it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the scope of the claimed disclosure. Accordingly, the specification and drawings are to be considered illustrative rather than restrictive. The claimed disclosure is intended to cover all alternatives, modifications, and equivalents.

Claims

1. An air supply system (100) for supplying air to the exterior of a ship's hull, the air supply system (100) comprising: - A plurality of air discharge units (20) for releasing compressed air flow below the waterline of the vessel to the outside of the hull, wherein the plurality of air discharge units (20) are configured to be arranged around the longitudinal centerline (202) of the hull of the vessel. - A first flow path (11A) for providing the compressed air flow to the air discharge unit (20), - One or more pressure control devices (30), arranged in the first flow path (11A), for supplying the compressed air flow to the air discharge unit (20) at a pressure greater than the discharge pressure at the air discharge unit (20), wherein each pressure control device (30) includes an inlet (34) for receiving the inlet air flow, a first outlet (35A) and a second outlet (35B) for supplying the air flow to a subset of the plurality of air discharge units, wherein the first outlet (35A) is connected to the vessel (200) arranged in the first flow path (11A) for receiving the inlet air flow, a first outlet (35A) and a second outlet (35B) for supplying the air flow to a subset of the plurality of air discharge units, wherein the first outlet (35A) is connected to the vessel (200) for receiving the inlet air flow. A first air exhaust unit subset (20AB; 20CD) on a first side of the longitudinal centerline (202) of the hull (201) of the vessel, and a second outlet (35B) connected to a second air exhaust unit subset (20BA; 20DC) on a opposite second side of the longitudinal centerline (202) of the hull of the vessel, wherein one or more pressure control devices (30) are configured to compensate for the exhaust pressure difference between the first air exhaust unit subset (20AB; 20CD) and the second air exhaust unit subset (20BA; 20DC); The air supply system is configured to control a fixed flow rate of air to the air discharge unit without requiring a throttle valve to control the compressed air flow to the air discharge unit.

2. The air supply system (100) according to claim 1, wherein the first air emission unit subset (20AB; 20CD) is arranged at the same distance from the longitudinal centerline (202) of the vessel as the second air emission unit subset (20BA; 20DC) is arranged at the same distance from the longitudinal centerline (202) of the vessel.

3. The air supply system (100) according to claim 1, wherein each pressure control device (30) includes a drive unit (31), a first booster unit (32A) for supplying compressed air to the first outlet and / or a second booster unit (32B) for supplying compressed air to the second outlet, wherein the first booster unit (32A) and the second booster unit (32B) are driven by the same drive unit (31).

4. The gas supply system (100) according to claim 3, wherein the first booster unit (32A) and / or the second booster unit (32B) is a blower or a compressor.

5. The gas supply system (100) according to claim 3, wherein the first booster unit (32A) and the second booster unit (32B) are fixed volume displacement blowers or compressors.

6. The gas supply system (100) according to claim 3, wherein the drive unit (31) is an electric motor.

7. The air supply system (100) according to claim 3, wherein when the pressure of the compressed air flow upstream of the pressure control device (30) exceeds the discharge pressure at the air discharge unit (20), the first booster unit (32A) and / or the second booster unit (32B) are configured to reduce the flow rate through the first flow path (11A).

8. The air supply system (100) according to claim 3, wherein when the pressure of the compressed air flow upstream of the pressure control device (30) exceeds the discharge pressure at the air discharge unit (20), the drive unit (31) is configured to be driven by the first booster unit (32A) and / or the second booster unit (32B) and to remove energy from the air flow.

9. The air supply system (100) according to claim 3, wherein the drive unit (31) is an electric motor, and the electric motor is configured to be driven by the first booster unit (32A) and / or the second booster unit (32B) and to act as an energy generator when the pressure of the compressed air flow upstream of the pressure control device (30) exceeds the discharge pressure at the air discharge unit (20).

10. The air supply system (100) according to any one of claims 1-9, wherein the inlet airflow is ambient air.

11. The air supply system (100) according to any one of claims 1-9, wherein the inlet air flow is a compressed scavenging air flow from the engine of the ship.

12. The air supply system (100) according to claim 11, wherein the air supply system (100) includes one or more turbochargers (10), each turbocharger (10) including a turbine (10A) driven by an exhaust flow from the engine and a compressor (10B) for supplying the compressed scavenging air flow to the first flow path (11A).

13. The gas supply system (100) according to any one of claims 1-9, wherein the gas supply system (100) includes a switching valve (13) arranged in the first flow path (11A) for opening and / or closing the first flow path (11A).

14. The gas supply system (100) according to any one of claims 1-9, wherein the gas supply system (100) includes a flow control device (12) arranged in the first flow path (11A) for controlling the flow rate through the first flow path (11A).

15. The gas supply system (100) according to any one of claims 1-9, wherein the gas supply system (100) includes one or more check valves (14) arranged in the first flow path (11A) between the one or more pressure control devices (30) and the plurality of air discharge units (20) for preventing seawater from entering the first flow path (11A) through the plurality of air discharge units (20).

16. The air supply system (100) according to any one of claims 1-9, wherein the one or more pressure control devices (30) are fixed volume displacement pressure control devices that supply a fixed volume flow rate of air to each of the plurality of air discharge units (20).

17. A vessel (200) comprising a hull (201), an engine, and an air supply system (100) according to any one of claims 1-16.

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