Ventilation system

System for emergency ventilation of an underwater environment (dry); the system includes a supply device to supply air; a capsule to be immersed in water to a depth of at least 60 meters; a duct to fluidically connect the power device to the capsule; a duct in order to fluidically connect the capsule to the underwater environment; a duct to fluidically connect the underwater environment to the capsule; a compressor to discharge the gas, arriving in the capsule from the underwater environment, in water at a depth of at least 60 meters.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

The present application is a U.S. national stage application under 35 U.S.C. § 371 of PCT Application No. KT/IB2016/056773, filed Nov. 10, 2016. The disclosure of the aforementioned priority application is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to a system for emergency ventilation of an underwater environment, a method for the emergency ventilation of an underwater environment and a capsule for the emergency ventilation of an underwater environment.

This invention also relates to the use of the system and/or the capsule for an emergency recovery intervention of underwater environment.

Context of the Invention

In the deep diving systems sector, when it is necessary to recover a damaged underwater environment (for example a submarine and/or a welding habitat), a rescue vessel (or a platform) is usually used equipped with a large compressed air storage system. The underwater environment is connected to two ducts, one is for transferring the pressurized air from this storage system to the underwater environment, and the other to bring the exhaust air back to the surface. The air that is pushed must be with high pressure, since it has to reach the underwater environment and come back to surface (to facilitate this air movement, there are some pumps at the end of the second duct).

The recovery activities as described above, have certain disadvantages including: the necessity to have huge and expensive devices to direct the pressurized air and (most of all) to recovery and allow air to escape in surface; and a relevant pressure increase inside the underwater environment with some health risks for the operators inside the underwater environment and the necessity to keep them in a decompression chamber in way to reduce embolism risks, once they are recovered.

The aim of the present invention is to provide an emergency ventilation system of an underwater environment, a method for the emergency ventilation of an underwater environment and a capsule for the emergency ventilation of an underwater environment and a use of the system and/or of the capsule for an emergency recovery, which make it possible to overcome, at least partially, the inconvenience of this type of activity and is at the same time cost-effective and easy to realize.

SUMMARY

According to the present invention, an emergency ventilation system for an underwater environment, a method for the emergency ventilation of an underwater environment, a capsule for the emergency ventilation of an underwater environment and a use of the system and/or the capsule for an emergency recovery is provided, as recited in the independent claims below, and, preferably, in any one of the claims depending directly or indirectly on the aforementioned independent claims.

DETAILED DESCRIPTION

InFIG. 1, 1indicates a system for the emergency ventilation of an underwater environment2(dry) as a whole. According to some non-limiting examples, the underwater environment2is a submarine and/or a welding habitat.

The system1comprises a supply device3for providing a gas containing oxygen, in particular air; a capsule4adapted to be immersed in water (in particular, to a depth of at least 60 meters—below the surface5); a duct6to fluidically connect the power supply device3to the capsule4so that the capsule4uploads the gas coming from the supply device3.

Advantageously but not necessarily, the capsule4is adapted to be immersed in water to a depth of at least 100 meters (below the surface5of water).

The system1comprises also a duct7to fluidically connect the capsule4to the underwater environment2so as to allow the passage of gas from the capsule4to the underwater environment2itself; a duct8to fluidically connect the underwater environment2to the capsule4so that it allows the passage of the gas from the underwater environment2to the capsule4; and one compressor9for the exhaust of the gas arrived inside the capsule4through the duct8from the underwater environment2into the water at a depth of at least 60 meters (under the surface5of the water itself). In particular, the compressor9is adapted to unload the gas inside water at a depth of at least 100 meters (under the surface5of the water itself). The compressor9is fluidically connected to duct8.

In particular, the capsule4includes the compressor9.

More precisely, the duct6is extended from the supplying device3to the capsule4; the duct7and8protrude from capsule4and are arranged to bond at the underwater environment2.

Advantageously but not necessarily, the supplying device3is suitable to be (and during the use is) placed outside of the water in an environment substantially dry.

According to some not limiting embodiments, the supplying device3is designed to supply gas to the capsule4at a pressure that is higher than atmospheric pressure (for example, at a pressure up to 3 bar).

Advantageously but not necessarily, the system1(more precisely, the capsule4) comprises an adjustment device10to adjust the pressure of the gas that is supplied to the underwater environment2. More particularly, the adjustment device10is designed to adjust the pressure of the gas inside the duct7, so that the gas reaches the underwater environment2at a pressure that is lower than a first given pressure (in some cases of 3 bar absolute—corresponding to 305Pa). More precisely, the adjustment device10is suitable to adjust the pressure of the gas inside the duct7, so that the gas reaches the underwater environment2at a pressure that is lower than a first given pressure of 2 bar—corresponding to 205 Pa.

In particular, higher-pressure levels, up to 6 bar, may be necessary to maintain the ventilation flow whenever pressure increases take place due to failures inside the underwater environment2.

According to some embodiments, the adjustment device10comprises (is) a valve (in some cases a ball valve) and/or a membrane mechanism. Due to the adjustment device10the risk of excessive pressure increase inside the underwater environment2is reduced. Advantageously but not necessarily, the system1(more precisely, the capsule4) comprises a control unit11.

In some cases, the control unit11is designed to adjust the operation of at least one between the supplying device3and compressor9(and/or the heat exchanger9′), so as to keep the concentration of the carbon dioxide (and/or other specific gases) and/or oxygen (and/or the temperature) (and/or the ventilation) inside the underwater environment2within a given interval (to allow the air inside the underwater environment2to be breathable for the operators located inside it).

For example, where an oxygen concentration which may be considered too low is detected, the control unit11will operate the supplying device3and the compressor9in such a way to increase the air flow (coming from the surface) through the capsule4.

In some cases, the system1comprises a sensor12for the detection of the carbon dioxide and/or oxygen concentration inside the gas coming from the underwater environment2(particularly, through the duct8).

In addition, or alternatively, the system1comprises a connection13for a detection system, which is arranged in the underwater environment2and is designed to detect the concentration of carbon dioxide (and/or of other specific gases) and/or oxygen (and/or temperature) in the underwater environment2itself. In particular, the control unit11is connected to the sensor12and/or to the connection13and is adapted to adjust the actuation of at least one of the power supply device3and the compressor9(and/or the heat exchanger9′) according to what is detected by the sensor12and/or by the detection system (of the underwater environment2), respectively.

Advantageously but not necessarily, the system1(in particular, the capsule4) includes a heat exchanger9in order to heat the gases to be fed in the underwater environment2through the duct7. In particular, the heat exchanger9′ is connected to the compressor9so that the heat produced by the compressor9itself can be used.

According to some non-limiting embodiments, the system1(in particular, the capsule4) comprises an adjusting device14to allow the passage of gas from the underwater environment2to the compressor9through the duct8when the pressure in the duct8is higher than a reference pressure (in particular, 1 bar absolute, more particularly, not more than 1 bar in addition to the original pressure of the underwater environment2). More precisely, the adjusting device14comprises (is) a valve (in some cases a ball valve) and/or a diaphragm mechanism. Thanks to the adjusting device14it reduces the risk that the pressure inside the underwater environment2decreases excessively.

According to some non-limiting embodiments, the system1(in particular, the capsule4) comprises a tank15for fluidically connecting the duct8and the compressor9. In particular, the duct8goes from the reservoir15to the underwater environment2.

More precisely, the tank15fluidically connects (is located between) the adjusting device14and the compressor9.

Advantageously but not necessarily, the control unit11is adapted to activate the compressor9so as to maintain the pressure inside the tank15in a given range, in particular compatible with the performance of the compressor9(more specifically, from 1 bar to 2 bar absolute). In particular, the capsule4comprises a pressure sensor16for measuring the pressure inside the tank15. More particularly, the control unit11activates the compressor9as a function what is detected by the pressure sensor16.

In some cases (such as the one illustrated inFIG. 2), a valve (ball valve) is located between the sensor16and the tank15.

Typically but not necessarily, the system1includes a vessel or a platform17, on which the power supply device3is located. In particular, the power supply device3comprises a pump (and a tank/gas storage) which enables the gas (air) to be pushed from above the water surface5to the capsule4.

According to some non-limiting embodiments, the system1also includes an electrical connection18for supplying electrical energy to the capsule4(and its components) from outside (in particular, from the platform17). More precisely, the electrical connection18is adapted to supply the control unit11, the compressor9and the sensors12and16.

Advantageously but not necessarily, the system1also comprises a link19to allow the transfer of information between the boat or platform17and the control unit11.

According to some non-limiting embodiments, the system1comprises a ballast20, which, in particular, maintains the capsule4at the required depth (maintaining its own stability in water).

Advantageously but not necessarily, system1includes an auxiliary umbilical cable21, which is adapted to bear the weight of the capsule4(and possibly also the ballast20) in the air and the related dynamic loads during the launching. In particular, the electrical connection18, the link19and in the duct6are part of or connected to (inserted into) the umbilical cable21. More particularly, the umbilical cable21connects the vessel or platform17to the capsule4.

According to some non-limiting embodiments, the system1also includes a launch and recovery unit22, which is suitable for moving (for example, bring it in water and/or lift it) the capsule4by acting on the umbilical cable21.

According to some non-limiting embodiments, the capsule4includes an exhaust outlet23, adapted to allow the exit of the gas (exhausted) in the water from the capsule4. The compressor9is designed to convey the gas through the exhaust outlet23.

Advantageously but not necessarily, a one-way valve24(to prevent water coming from the exhaust outlet23reaches the compressor9) is located between the exhaust outlet23and the compressor9. According to some non-limiting embodiments, the capsule4comprises a filter25also, which is located between the duct8(more specifically, the adjusting device10; even more precisely, the tank15) and the compressor9. The filter25helps to improve the mechanical protection of the compressor9.

According to some non-limiting embodiments, the capsule4also comprises a vacuum breaker valve26, which is located downstream of the underwater environment2in order to avoid creating an excessive depression in the underwater environment2itself. In particular, the vacuum breaker valve26is located between the duct8and the compressor9.

Advantageously but not necessarily, a one-way valve27which allows the passage of gas only from the duct6to the capsule4and not vice versa is also provided. More precisely, the one-way valve27is placed between the duct6and the adjusting device10.

In particular, the capsule4comprises a casing28(typically of metal), which is resistant to the external pressure at high depth and encloses the various further components of the capsule4, for example: the adjustment devices10and14, the unit control11, the sensors12and16and the tank15(and, possibly, the one-way valves24and27, the vacuum breaker valve26and the filter25).

According to some embodiments not illustrated and not limitative, the capsule4can be composed of two or more separate groups each one provided with its own casing28.

In some cases, in order to improve maintenance activities, a vent29is also provided to allow the correct emptying of the tank15. In particular, a valve (ball valve) is located between the tank15and the vent29.

In operation, after the launch from the surface, the capsule4reaches the depth required (in particular, a depth similar to the underwater environment depth2where it operates).

At this point, the capsule4(more precisely, the ducts7and8—and potentially the connection13) is connected to the underwater environment2, for example by means of a ROV, through an underwater environment2emergency connection30.

At this point, the power supply device3and the compressor9are actuated to allow the supply of gas (fresh air) from above the surface5to the capsule4and from the capsule4to the underwater environment2, and the gas (exhaust air) from the underwater environment2to the compressor9and from the compressor9to the water (through the exhaust outlet23).

Please note that the system1in accordance with the present invention has considerable advantages over known systems. Among these, we emphasize that the system1according to the present invention is relatively simple and cost-effective (especially because it does not require any equipment to transfer and vent the exhaust air to the surface) and less harmful and dangerous for the health of the operators present in the underwater environment2(you can keep relatively low pressures within the underwater environment2).

In particular, in accordance with an additional aspect of this invention, a method for the emergency ventilation of an underwater environment2(dry) is provided with a system as described above, and comprising: a first supplying step, during which the gas is fed from the supply device3to the capsule4immersed in water at a pressure higher than the atmospheric pressure; a second supplying step, during which the gas is conveyed from the capsule4immersed in water to the underwater environment2through the duct7; a recovery step, which is at least partly subsequent to the second supplying step and during which the gas is brought from the underwater environment2to the capsule4immersed in the water through the duct8; and a draining step, which is at least partially after the recovery step and during which the gas coming from the underwater environment2and arriving to the capsule4, which is immersed in the water, is discharged into the water.

Advantageously but not necessarily, during the first and the second supplying steps, the recovery step and the draining step, the capsule4is maintained immersed in water at a distance of at most 40 meters from the underwater environment2.

Typically, the underwater environment2is at a depth of 60 (in particular, from 100) to 700 meters (from the surface5).

According to some non-limiting embodiments, during the supply step, the gas pressure coming from the supply device3is maintained within a given range in the area of the capsule4, in particular proportional to the depth of intervention (more particularly between 2 bar absolute and a higher value due to the increase in pressure that makes it possible to overcome the pressure losses of the flow line, according to the depth of intervention—70 bar absolute for example).

According to some non-limiting embodiments, the method also comprises a pressure regulation step, during which, in the area of the capsule4, the gas pressure (from the capsule4itself) towards the underwater environment2is maintained (flow rate) within a given range.

In particular, during the regulation step, the gas pressure (coming from the supplying device3) is reduced.

According to some non-limiting embodiments (in other words), during the second supply step, the gas is conveyed from the capsule4, which is immersed in water, to the underwater environment2at a pressure within the given range.

In particular, the pressure of the gas conveyed from the capsule4to the underwater environment2during the second supply step is less than the pressure of the gas supplied to the capsule4during the first supply step.

In particular, the given range is from 1 bar absolute to 3 bar absolute (more particularly, to 2 bar).

In particular, in accordance with further aspect of this invention, a capsule4as described above is provided.

In accordance with a further aspect of this invention, a use of the system1and/or of the capsule4for a emergency recovery intervention of an underwater environment2is provided (such an underwater environment2is as described above). In particular, the use provides to follow a method as described above.