Double wall pipe ventilation system and ship

Abstract

The invention provides a double-walled pipe ventilation system and a ship, comprising an engine, a fuel system, an air intake system, a first double-walled pipe, a second double-walled pipe and a ventilation system, wherein the air intake system comprises a first ventilation inlet, a second ventilation inlet, a first salt spray filter and a second salt spray filter, wherein the first ventilation inlet is connected to the engine through the first double-walled pipe; the second ventilation inlet is connected to the engine through the second double-walled pipe; the first salt spray filter is installed on the first double-walled pipe, and the second salt spray filter is installed on the second double-walled pipe; the ventilation system is respectively connected to the first double-walled pipe and the second double-walled pipe; an ammonia detector is installed on the ventilation pipeline; a first outer pipe of the first double-walled pipe and a second outer pipe of the second double-walled pipe are connected to a fan through the ventilation pipeline; the fan forms two output branches, and the fan is connected to a ventilation mast through a first discharge pipe; the fan is connected to an absorption tower through a second discharge pipe, and a gas output end of the absorption tower is connected to the ventilation mast.

Description

Technical Field

[0001] The invention relates to the technical field of ships, and in particular to a double-walled pipe ventilation system and a ship. Background Art

[0002] To achieve the emission reduction target of the shipping industry, it is possible to improve technology, operating methods or use alternative fuels. Currently available alternative fuels such as LNG, LPG, ethane, methanol and biofuels cannot achieve zero carbon emissions. Liquefied gas ships powered by ammonia fuel can effectively reduce emissions of carbon oxides and sulfur oxides, achieving true "zero" emissions. Therefore, the shipping industry generally believes that ammonia is one of the most promising fuels on the road to decarbonization in the future.

[0003] At present, marine ammonia fuel engines are in the research and development stage. According to the requirements of various classification societies, the liquid ammonia supply system of the ammonia fuel engine needs to use a double-walled pipe system in the engine room, and ventilate the annular area between the inner and outer pipes of the double-walled pipe through a suction mechanical ventilation fan to prevent leaked ammonia from entering the engine room. The ventilation volume of the traditional single-inlet double-walled pipe ventilation system is small, and it is difficult to meet the selection requirements of the ventilation fan; in addition, the ventilation inlet of the double-walled pipe is located on the open deck, and the humid and salty marine atmosphere is used as the air source, which is easy to cause corrosion of the inner wall of the double-walled pipe, thereby increasing the hidden danger of double-walled pipe leakage. In the extreme case of double-walled pipe leakage and ventilation fan failure, the ammonia concentration entering the engine room exceeds 30ppm, which will affect the life safety of personnel. Summary of the invention

[0004] In view of the above-mentioned deficiencies, the object of the present invention is to provide a double-walled pipe ventilation system and a ship, which increase the air intake of the ventilation system, while ensuring that the air inside the double-walled pipe is dry and salt-free, and enable the double-walled pipe ventilation system to prevent ammonia from leaking into the cabin under various extreme working conditions, thereby ensuring the personal safety of cabin personnel and the safe operation of the liquid ammonia supply system.

[0005] An embodiment of the present invention provides a double-walled pipe ventilation system for a power ship, comprising:

[0006] engine;

[0007] A fuel system, the fuel system comprising a fuel valve group unit, a fuel inlet and a fuel outlet;

[0008] An air intake system, the air intake system comprising a first ventilation inlet, a second ventilation inlet, a first salt mist filter and a second salt mist filter;

[0009] A first double-walled tube and a second double-walled tube, wherein the first ventilation inlet is connected to the engine through the first double-walled tube; the second ventilation inlet is connected to the engine through the second double-walled tube; the first double-walled tube comprises a first outer tube and a first inner tube, the first ventilation inlet is connected to the first outer tube, and the fuel inlet is connected to the first inner tube; the second double-walled tube comprises a second outer tube and a second inner tube, the second outer tube is connected to the second ventilation inlet, and the fuel outlet is connected to the second inner tube; the outer wall of the first outer tube and the outer wall of the second outer tube are both provided with electric heating elements; the first double-walled tube is provided with a first stop valve at the first ventilation inlet and the second double-walled tube is provided with a first stop valve at the second ventilation inlet; the first salt spray filter is installed on the first double-walled tube to filter out the salt of the first ventilation inlet; the second salt spray filter is installed on the second double-walled tube to filter out the salt of the second ventilation inlet;

[0010] A ventilation system, the ventilation system comprising a ventilation duct, a fan, an air mast, an absorption tower and an ammonia detector, the ammonia detector being installed on the ventilation duct; the first outer pipe and the second outer pipe being connected to the fan through the ventilation duct; the fan forming two output branches, the fan being connected to the air mast through a first discharge pipe; the fan being connected to the absorption tower through a second discharge pipe, the gas output end of the absorption tower being connected to the air mast; a first pneumatic stop valve being arranged on the first discharge pipe, and a second pneumatic stop valve being arranged on the second discharge pipe; wherein at least two fans are arranged in parallel for alternating use.

[0011] Furthermore, the first salt spray filter and the second salt spray filter each include a bag-type salt spray filter and an HHS high-efficiency salt spray filter arranged in sequence, the first salt spray filter is provided with a first differential pressure transmitter, and the second salt spray filter is provided with a second differential pressure transmitter to monitor the blockage of the first salt spray filter and the second salt spray filter.

[0012] Furthermore, the outer wall of the first outer tube and the outer wall of the second outer tube are both covered with a thermal insulation layer.

[0013] Furthermore, the first double-walled tube is provided with a first temperature sensor for monitoring the internal temperature of the first double-walled tube, and the second double-walled tube is provided with a second temperature sensor for monitoring the internal temperature of the second double-walled tube.

[0014] Furthermore, the ventilation pipeline is also connected to a jet drainage chamber, and the ventilation pipeline is connected to the second exhaust pipe through the jet drainage chamber for use when the fan fails; the jet drainage chamber is also connected to a nitrogen inlet.

[0015] Furthermore, the ventilation pipeline is connected to the injection drainage chamber through a ventilation branch, and a third pneumatic stop valve is provided on the ventilation branch; the nitrogen inlet is connected to the injection drainage chamber through a nitrogen delivery pipeline, and a fourth pneumatic stop valve and a first check valve are provided on the nitrogen delivery pipeline.

[0016] Furthermore, the double-wall ventilation system also includes a fuel leakage treatment system, which includes a heat exchanger and a fuel delivery pipe, wherein the fuel input end of the heat exchanger is connected to the fuel delivery pipe, and the ammonia output end of the heat exchanger is connected to the absorption tower through a gas delivery pipe; the fuel valve group unit, the first double-walled pipe and the second double-walled pipe are all connected to the fuel delivery pipe, so that the leaked fuel enters the heat exchanger through the fuel delivery pipe for heat exchange and gasification, and then is input into the absorption tower;

[0017] The fuel delivery pipe is also provided with a fifth pneumatic valve and a second check valve.

[0018] Furthermore, the exhaust gas output end of the engine is connected to the heat exchanger to provide a heat source to the heat exchanger, and the heat exchanger is also connected to an exhaust gas outlet for exhaust gas discharge; the pipeline between the exhaust gas output end of the engine and the heat exchanger is provided with a regulating valve, and a third temperature sensor is configured on the gas delivery pipe, and the third temperature sensor is interlocked with the regulating valve.

[0019] Furthermore, a first pressure transmitter is provided on the first double-walled pipe, and a second pressure transmitter is provided on the second double-walled pipe.

[0020] Furthermore, a second stop valve is provided at the air inlet end of each fan on the ventilation pipeline, and a third check valve is provided at the air outlet end of each fan.

[0021] An embodiment of the present invention further provides a ship, comprising the above-mentioned double-walled pipe ventilation system.

[0022] The double-walled pipe ventilation system and ship provided in this embodiment have the following beneficial effects:

[0023] (1) A first double-walled tube and a second double-walled tube are provided to form two air intake pipes, thereby increasing the air intake volume and solving the problem of difficulty in selecting a conventional ventilation fan; the first salt mist filter and the second salt mist filter can filter out the salt in the sea breeze, and an electric heating element and a thermal insulation layer are provided outside the double-walled tube to ensure that the air entering the double-walled tube is dry and does not contain salt, thereby effectively preventing corrosion of the inner wall of the double-walled tube;

[0024] (2) In normal ventilation mode, the ventilation system connected to the double-walled pipe is connected to the air mast through the first pneumatic stop valve and discharged to the atmosphere. When the ammonia detector in the ventilation pipeline detects ammonia leakage, the first pneumatic stop valve is closed and the second pneumatic stop valve is opened to achieve automatic switching of the ventilation outlet; the leaked ammonia is treated in the absorption tower and then discharged, minimizing the impact of toxic ammonia on the crew;

[0025] (3) A jet drainage ventilation system is set up. In the extreme case that all fans fail mechanically at the same time, and the ammonia concentration detected by the ammonia detector exceeds 30 ppm, high-pressure nitrogen with a pressure of 80 barg passes through the jet drainage chamber to form a low-pressure area, and the gas in the double-walled pipe is quickly extracted to ensure the safe operation of the system; the jet drainage chamber is small in size, simple in structure, has no moving parts, and operates stably and reliably;

[0026] (4) When a large amount of leakage occurs in the inner tube of the double-walled tube, the leaked liquid ammonia is exchanged with the exhaust gas of the engine through the heat exchanger, and the vaporized ammonia is treated in the absorption tower and then discharged, thereby realizing waste heat recovery and reducing the volume of the waste liquid storage tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0028] Figure 1 Schematic diagram of the structure of the double-walled pipe ventilation system in an embodiment of the present invention.

[0029] Figure 2 for Figure 1 A schematic cross-sectional view of the first double-wall tube or the second double-wall tube.

[0030] Figure 3 for Figure 1 A cross-sectional schematic diagram of the first salt spray filter or the second salt spray filter. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] See also Figure 1The embodiment of the present invention provides a double-walled pipe ventilation system for a power ship, including an engine 10, a fuel system, an air intake system, a first double-walled pipe 41, a second double-walled pipe 42 and a ventilation system 50, wherein the fuel system includes a fuel valve group unit 21, a fuel inlet 22 and a fuel outlet 23. The air intake system includes a first ventilation inlet 31, a second ventilation inlet 32, a first salt mist filter 33 and a second salt mist filter 34.

[0033] The first ventilation inlet 31 is connected to the engine 10 through the first double-walled pipe 41, and the second ventilation inlet 32 ​​is connected to the engine 10 through the second double-walled pipe 42. In actual use, the first ventilation inlet 31 and the second ventilation inlet 32 ​​are located in a safe area of ​​the open deck, and a rain shelter 37 is provided on the upper part.

[0034] The first double-walled tube 41 includes a first outer tube 411 and a first inner tube 412, the first ventilation inlet 31 is connected to the first outer tube 411, and the fuel inlet 22 is connected to the first inner tube 412; the second double-walled tube 42 includes a second outer tube 421 and a second inner tube 422, the second outer tube 421 is connected to the second ventilation inlet 32, and the fuel outlet 23 is connected to the second inner tube 422. The first double-walled tube 41 is provided with a first stop valve (not shown) at the first ventilation inlet 31 and the second double-walled tube 42 is provided at the second ventilation inlet 32.

[0035] Please combine Figure 1 and Figure 2 The outer wall of the first outer tube 411 and the outer wall of the second outer tube 421 are both provided with electric heating elements 43. The number of electric heating elements 43 can be increased or decreased according to actual needs. In this embodiment, the first double-walled tube 41 has three electric heating elements 43 wound around the first outer tube 411, and the second double-walled tube 42 has three electric heating elements 43 wound around the second outer tube 421.

[0036] Specifically, the first double-walled tube 41 is provided with a first temperature sensor 45 for monitoring the internal temperature of the first double-walled tube 41, and the second double-walled tube 42 is provided with a second temperature sensor 46 for monitoring the internal temperature of the second double-walled tube 42. The first double-walled tube 41 and the second double-walled tube 42 cooperate with the temperature sensors to fix the first double-walled tube 41 and the second double-walled tube 42 at a constant temperature. Taking the first double-walled tube 41 as an example, when the first temperature sensor 45 detects that the temperature of the first double-walled tube 41 is lower than 35°C, the electric heating element 43 is turned on for heating. When the temperature reaches 45°C, the electric heating element 43 stops heating.

[0037] Specifically, the first double-walled tube 41 is provided with a first pressure transmitter 47, and the second double-walled tube 42 is provided with a second pressure transmitter 48. The first pressure transmitter 47 and the second pressure transmitter 48 can monitor the vacuum between the inner and outer tubes of the double-walled tube when testing the suction capacity of the blower 52.

[0038] The outer wall of the first outer tube 411 and the outer wall of the second outer tube 421 are both covered with a heat-insulating layer 44 , and the material used for the heat-insulating layer is polyurethane.

[0039] The double-walled pipe ventilation system is provided with a first double-walled pipe 41 and a second double-walled pipe 42, and two air intake pipes are used to intake air simultaneously, which can increase the air intake volume of the ventilation system.

[0040] The first salt mist filter 33 is installed on the first double-walled tube 41, and the first salt mist filter 33 is arranged near the first ventilation inlet 31, and is arranged at the outlet end of the first stop valve of the first ventilation inlet 31, so as to filter out the salt of the first ventilation inlet 31, and can effectively prevent the corrosion of the inner wall of the first double-walled tube 41. The second salt mist filter 34 is installed on the second double-walled tube 42, and the second salt mist filter 34 is arranged near the second ventilation inlet 32, and is arranged behind the first stop valve of the second ventilation inlet 32, so as to filter out the salt of the second ventilation inlet 32, and can effectively prevent the corrosion of the inner wall of the second double-walled tube 42.

[0041] The ventilation system 50 includes a ventilation pipeline 51, a fan 52, a ventilation mast 53, an absorption tower 54, and an ammonia detector 55. The ammonia detector 55 is installed on the ventilation pipeline 51. In actual use, the ammonia detector 55 should be connected to the sound and light alarm of the control room. When the ammonia detector 55 detects that the concentration of ammonia exceeds a threshold value (for example, 30ppm), the sound and light alarm in the control room is triggered.

[0042] The first outer tube 411 and the second outer tube 421 are connected to the fan 52 through the ventilation pipe 51, and the air outlet end of the fan 52 forms two output branches. One output branch is that the fan 52 is connected to the air mast 53 through the first exhaust pipe 521, and the other output branch is that the fan 52 is connected to the absorption tower 54 through the second exhaust pipe 522, and the gas output end of the absorption tower 54 is connected to the air mast 53.

[0043] The fan 52 is preferably a suction type mechanical explosion-proof fan, a suction type mechanical ventilation fan, which has the ventilation capacity of ventilating the annular space between the inner and outer tubes of the double-walled pipe 30 times per hour, and can also make the pressure between the inner and outer tubes of the double-walled pipe reach -2000Pa.

[0044] The first discharge pipe 521 is provided with a first pneumatic stop valve 523, and the second discharge pipe 522 is provided with a second pneumatic stop valve 524. Among them, at least two fans 52 are arranged in parallel for alternate use. The number of fans 52 can be set according to actual conditions. In this embodiment, two fans 52 are arranged, and they serve as backup for each other. When a working fan fails, the second backup fan is activated to alternate.

[0045] Specifically, the air inlet end of each fan 52 on the ventilation pipeline 51 is provided with a second stop valve 57, and the air outlet end of the fan 52 is provided with a third check valve 58. Under normal ventilation conditions, the second stop valve 57 of one of the fans 52 remains open, so that the air in the double-walled pipe is sucked into the air mast 53 for discharge.

[0046] The ventilation line 51 is also connected to the jet drainage chamber 56, and the ventilation line 51 is connected to the second discharge pipe 522 through the jet drainage chamber 56 for use when the blower 52 fails. The jet drainage chamber 56 is also connected to a nitrogen input port 561 to introduce nitrogen into the jet drainage chamber 56. Specifically, the ventilation line 51 is connected to the jet drainage chamber 56 through a ventilation branch 511, and a third pneumatic stop valve 512 is provided on the ventilation branch 511. The nitrogen input port 561 is connected to the jet drainage chamber 56 through a nitrogen delivery pipeline (not shown), and a fourth pneumatic stop valve 562 and a first check valve 563 are provided on the nitrogen delivery pipeline.

[0047] There are also the following processing modes when the following two situations occur:

[0048] (1) All fans 52 fail and the ammonia detector 55 detects that the concentration of ammonia exceeds a preset threshold value (e.g., 30 ppm), and the output branch of the fan 52 is closed, that is, the first pneumatic stop valve 523 and the second pneumatic stop valve 524 are closed, and the third pneumatic stop valve 512 and the fourth pneumatic stop valve 562 are opened at the same time. The jet drainage chamber 56 sucks nitrogen with a pressure of 80 barg into the suction chamber through the nitrogen inlet 561, forming a high-speed low-pressure zone in the suction chamber, and quickly sucks out the gas in the double-walled pipe. After being fully mixed with the high-pressure nitrogen in the mixing chamber of the jet drainage chamber 56, it enters the absorption tower 54 and is discharged into the atmosphere through the air mast 53. It is worth mentioning that when the ammonia detector 55 detects that the concentration of ammonia exceeds a preset threshold value (e.g., 300 ppm), the liquid ammonia fuel supply system stops running.

[0049] (2) When a large amount of leakage occurs in the inner tube of the double-walled tube, it is difficult for the leaked liquid ammonia to be completely vaporized in a short time. In order to deal with this situation, the double-walled ventilation system also includes a fuel leakage processing system, which includes a heat exchanger 61 and a fuel delivery pipe 62. The fuel input end of the heat exchanger 61 is connected to the fuel delivery pipe 62, and the ammonia output end of the heat exchanger 61 is connected to the absorption tower 54 through the gas delivery pipe 64 to process the ammonia, and finally discharged into the atmosphere through the air mast 53. The fuel valve group unit 21, the first double-walled tube 41 and the second double-walled tube 42 are all connected to the fuel delivery pipe 62, so that the leaked fuel enters the heat exchanger 61 through the fuel delivery pipe 62 for heat exchange and vaporization, and then is input into the absorption tower 54.

[0050] A fifth pneumatic valve 67 and a second check valve 68 are also provided at the end of the fuel delivery pipe 62 (i.e., the fuel input end close to the heat exchanger 61). When a large amount of fuel leakage occurs and the fuel leakage treatment system needs to be opened, the fuel leakage treatment system is opened through the fifth pneumatic valve 67.

[0051] The heat exchanger 61 is preferably a wound tube heat exchanger.

[0052] Specifically, the exhaust gas output end of the engine 10 is connected to the heat exchanger 61 to provide a heat source to the heat exchanger 61, and the heat exchanger 61 is also connected to an exhaust gas outlet 63 for exhaust gas after heat exchange with the heat exchanger 61. A regulating valve 65 is provided on the pipeline between the exhaust gas output end of the engine 10 and the heat exchanger, and the output amount of the exhaust gas can be adjusted by the regulating valve 65 to control the temperature of the heat exchanger 61. A third temperature sensor 66 is arranged on the gas delivery pipe 64, and the third temperature sensor 66 is interlocked with the regulating valve 65. The output temperature of the ammonia gas is monitored by the third temperature sensor 66 to adjust the opening of the regulating valve 65 to maintain temperature stability.

[0053] See also Figure 3 The first salt spray filter 33 and the second salt spray filter 34 each include a bag-type salt spray filter 35 and a HHS high-efficiency salt spray filter 36 which are sequentially arranged. The bag-type salt spray filter is used to filter salt and dust with a particle size greater than 5 μm, and the HHS high-efficiency salt spray filter is used to filter salt with a particle size less than 5 μm.

[0054] The first salt mist filter 33 is provided with a first differential pressure transmitter 331 , and the second salt mist filter 34 is provided with a second differential pressure transmitter 341 , so as to monitor the clogging conditions of the first salt mist filter 33 and the second salt mist filter 34 .

[0055] An embodiment of the present invention further provides a ship, comprising the above-mentioned double-walled pipe ventilation system.

[0056] The main working process of the double-walled pipe ventilation system provided by the embodiment of the present invention is as follows:

[0057] (1) Before the double-walled pipe ventilation system is put into operation, the suction capacity of the fan 52 is first tested: the first stop valve located at the first ventilation inlet 31 and the second ventilation inlet 32 ​​is closed, the second stop valve 57 and the first pneumatic stop valve 523 are opened, one of the fans 52 is turned on, and the vacuum degree between the inner and outer tubes of the double-walled pipe is detected by the first pressure transmitter 47 and the second pressure transmitter 48.

[0058] When the ammonia fuel supply system operates normally, liquid ammonia flows through the fuel inlet 22, passes through the fuel valve group unit 21 and the second inner tube 422, and finally enters the ammonia fuel engine 10 for injection and ignition. Part of the liquid ammonia flows back from the engine 10, and the ammonia fuel flows through the first inner tube 412 in the first double wall 41 and the fuel valve group unit 21, and flows back to the liquid ammonia supply system from the reflux liquid ammonia outlet 5.

[0059] When the double-walled pipe ventilation system operates normally, the first stop valve is opened, the second stop valve 57 and any fan 52 are opened, and the air outside the ship enters the first double-walled pipe 41 and the second double-walled pipe 42 through the first ventilation inlet 31 and the second ventilation inlet 32, and the moist and salty air passes through the first salt mist filter 33 and the second salt mist filter 34 respectively to filter the salt. The first salt mist filter 33 monitors whether the salt mist filter is blocked through the first differential pressure transmitter 331, and the second salt mist filter 34 monitors whether the salt mist filter is blocked through the second differential pressure transmitter 341. The electric heating element 43 wrapped around the outside of the double-walled pipe heats the air entering the double-walled pipe to 35-45°C, and the internal temperature of the double-walled pipe is monitored by the first temperature sensor 45 and the second temperature sensor 46 respectively. Ensure that the air entering the double-walled pipe is dry and does not contain salt to avoid corrosion inside the double-walled pipe.

[0060] (2) An ammonia detector 55 is provided on the ventilation pipeline 51 of the double-walled pipe to monitor whether there is ammonia leakage in the double-walled pipe. The fan 52 is a suction type mechanical ventilation fan. Each fan 52 has the ventilation capacity to ventilate the annular space between the inner and outer pipes of the double-walled pipe 30 times per hour, and can make the pressure between the inner and outer pipes of the double-walled pipe reach -2000Pa. Under normal ventilation conditions, the first pneumatic stop valve 523 is opened, and the air in the double-walled pipe is sucked to the ventilation mast 53 by a fan 52 for discharge. When the ammonia detector 55 detects leakage in the double-walled pipe and the ammonia concentration is 0-30ppm, the first pneumatic stop valve 523 is closed, the second pneumatic stop valve 524 is opened, and the gas in the double-walled pipe is sucked to the ammonia absorption tower 54 by the fan 52. After the ammonia is absorbed, the remaining air is discharged to the ventilation mast 53 through the upper part of the ammonia absorption tower. When one of the fans 52 fails, the second stop valve 57 corresponding to the failed fan is closed, and the second stop valve 57 of a spare fan is opened, and the spare fan 52 is turned on.

[0061] (3) When the following two working conditions occur: All fans 52 fail at the same time, and the ammonia detector 55 detects that the ammonia concentration in the ventilation pipeline 51 exceeds 30ppm, the first pneumatic stop valve 523 and the second pneumatic stop valve 524 are closed, and the third pneumatic stop valve 512 and the fourth pneumatic stop valve 562 are opened. Nitrogen with a pressure of 80barg enters the suction chamber of the injection drainage chamber 56 through the nitrogen inlet 561, forming a high-speed low-pressure area in the suction chamber, and quickly sucking out the gas in the double-walled pipe. After being fully mixed with the high-pressure nitrogen in the mixing chamber of the injection drainage chamber 56, the gas enters the absorption tower 54 and is discharged into the atmosphere through the ventilation mast 53. At the same time, when the ammonia detector 55 detects that the ammonia concentration of the double-walled pipe leakage exceeds 300ppm, the liquid ammonia supply system stops running.

[0062] (4) When a large amount of fuel leaks from the inner tube of the double-walled tube, it is difficult for the leaked liquid ammonia to be completely vaporized in a short time. At this time, the fifth pneumatic stop valve 67 is opened, and the leaked liquid ammonia enters the heat exchanger 61 through the fuel delivery pipe 62. The exhaust gas of the engine 10 using ammonia fuel enters the heat exchanger 61 through the exhaust gas output end of the engine 10 to exchange heat with the liquid ammonia fuel. The vaporized ammonia enters the absorption tower 54 for ammonia treatment. The exhaust gas after heat exchange in the heat exchanger 61 is discharged through the exhaust gas outlet 63. The third temperature sensor 66 is used to control the opening of the regulating valve 65.

[0063] The double-walled pipe ventilation system and ship provided by the embodiments of the present invention have the following beneficial effects:

[0064] (1) A first double-walled tube 41 and a second double-walled tube 42 are provided to form two air intake pipes, thereby increasing the air intake volume and solving the problem of difficulty in selecting a conventional ventilation fan; the first salt mist filter 33 and the second salt mist filter 34 can filter out the salt in the sea breeze, and an electric heating element 43 and a heat preservation layer 44 are provided on the outer wall of the outer tube of the double-walled tube to ensure that the air entering the double-walled tube is dry and does not contain salt, thereby effectively preventing corrosion of the inner wall of the double-walled tube;

[0065] (2) In normal ventilation mode, the ventilation system connected to the double-walled pipe is connected to the ventilation mast 53 through the first pneumatic stop valve 523 and discharged to the atmosphere. When the ammonia detector 55 in the ventilation pipeline detects ammonia leakage, the first pneumatic stop valve 523 is closed and the second pneumatic stop valve 524 is opened to achieve automatic switching of the ventilation outlet. The leaked ammonia is treated in the absorption tower 54 and then discharged to reduce the impact of toxic ammonia on the crew;

[0066] (3) A jet drainage ventilation system is provided. When all fans 52 have mechanical failures at the same time, and the ammonia concentration detected by the ammonia detector 55 exceeds 30 ppm, high-pressure nitrogen with a pressure of 80 barg forms a low-pressure area through the jet drainage chamber 56, and the gas in the double-walled pipe is quickly extracted to ensure the safe operation of the system. The jet drainage chamber 56 is small in size, simple in structure, has no moving parts, and operates stably and reliably.

[0067] (4) When a large amount of leakage occurs in the inner tube of the double-walled tube, the leaked liquid ammonia is heat-exchanged with the exhaust gas of the engine 10 through the heat exchanger 61, and the vaporized ammonia is treated in the absorption tower 54 and then discharged, thereby realizing waste heat recovery and reducing the volume of the waste liquid storage tank.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A double-walled pipe ventilation system for a power ship, characterized in that: include: Engine (10); A fuel system, comprising a fuel valve group unit (21), a fuel inlet (22) and a fuel outlet (23); An air intake system, the air intake system comprising a first ventilation inlet (31), a second ventilation inlet (32), a first salt mist filter (33) and a second salt mist filter (34); A first double-walled tube (41) and a second double-walled tube (42), wherein the first ventilation inlet (31) is connected to the engine (10) via the first double-walled tube (41); and the second ventilation inlet (32) is connected to the engine (10) via the second double-walled tube (42); the first double-walled tube (41) comprises a first outer tube (411) and a first inner tube (412), the first ventilation inlet (31) is connected to the first outer tube (411), and the fuel inlet (22) is connected to the first inner tube (412); the second double-walled tube (42) comprises a second outer tube (421) and a second inner tube (422), the second outer tube (421) is connected to the second ventilation inlet ( 32), the fuel outlet (23) is connected to the second inner tube (422); the outer wall of the first outer tube (411) and the outer wall of the second outer tube (421) are both provided with an electric heating element (43); the first double-walled tube (41) is provided with a first stop valve at the first ventilation inlet (31) and the second double-walled tube (42) is provided with a first stop valve at the second ventilation inlet (32); the first salt mist filter (33) is installed on the first double-walled tube (41) to filter out the salt of the first ventilation inlet (31); the second salt mist filter (34) is installed on the second double-walled tube (42) to filter out the salt of the second ventilation inlet (32); A ventilation system (50), the ventilation system (50) comprising a ventilation pipeline (51), a fan (52), a ventilation mast (53), an absorption tower (54) and an ammonia detector (55), wherein the ammonia detector (55) is installed on the ventilation pipeline (51); the first outer tube (411) and the second outer tube (421) are connected to the fan (52) through the ventilation pipeline (51); the fan (52) forms two output branches, and the fan (52) is connected to the first outer tube (411) and the second outer tube (421) through the ventilation pipeline (51); The exhaust pipe (521) is connected to the ventilation mast (53); the fan (52) is connected to the absorption tower (54) through a second exhaust pipe (522), and the gas output end of the absorption tower (54) is connected to the ventilation mast (53); the first exhaust pipe (521) is provided with a first pneumatic stop valve (523), and the second exhaust pipe (522) is provided with a second pneumatic stop valve (524); wherein, at least two fans (52) are arranged in parallel for alternate use.

2. The double-walled pipe ventilation system according to claim 1, characterized in that: The first salt mist filter (33) and the second salt mist filter (34) each include a bag-type salt mist filter (35) and an HHS high-efficiency salt mist filter (36) arranged in sequence; the first salt mist filter (33) is provided with a first differential pressure transmitter (331), and the second salt mist filter (34) is provided with a second differential pressure transmitter (341) to monitor the blockage conditions of the first salt mist filter (33) and the second salt mist filter (34).

3. The double-walled pipe ventilation system according to claim 1, characterized in that: The outer wall of the first outer tube (411) and the outer wall of the second outer tube (421) are both covered with a thermal insulation layer (44).

4. The double-walled pipe ventilation system according to claim 1, characterized in that: The first double-walled tube (41) is provided with a first temperature sensor (45) for monitoring the internal temperature of the first double-walled tube (41), and the second double-walled tube (42) is provided with a second temperature sensor (46) for monitoring the internal temperature of the second double-walled tube (42).

5. The double-walled pipe ventilation system according to claim 1, characterized in that: The ventilation pipeline (51) is also connected to a jet drainage chamber (56), and the ventilation pipeline (51) is connected to the second exhaust pipe (522) through the jet drainage chamber (56) for use when the fan (52) fails; the jet drainage chamber (56) is also connected to a nitrogen input port (561).

6. The double-walled pipe ventilation system according to claim 5, characterized in that: The ventilation pipeline (51) is connected to the jet drainage chamber (56) via a ventilation branch (511), and a third pneumatic stop valve (512) is provided on the ventilation branch (511); the nitrogen input port (561) is connected to the jet drainage chamber (56) via a nitrogen delivery pipeline, and a fourth pneumatic stop valve (562) and a first check valve (563) are provided on the nitrogen delivery pipeline.

7. The double-walled pipe ventilation system according to claim 1, characterized in that: The double-walled pipe ventilation system further comprises a fuel leakage treatment system, which comprises a heat exchanger (61) and a fuel delivery pipe (62), wherein the fuel input end of the heat exchanger (61) is connected to the fuel delivery pipe (62), and the ammonia output end of the heat exchanger (61) is connected to the absorption tower (54) via a gas delivery pipe (64); the fuel valve group unit (21), the first double-walled pipe (41) and the second double-walled pipe (42) are all connected to the fuel delivery pipe (62), so that the leaked fuel enters the heat exchanger (61) through the fuel delivery pipe (62) for heat exchange and gasification, and then is input into the absorption tower (54); The fuel delivery pipe (62) is also provided with a fifth pneumatic valve (67) and a second check valve (68).

8. The double-walled pipe ventilation system according to claim 7, characterized in that: The exhaust gas output end of the engine (10) is connected to the heat exchanger (61) to provide a heat source to the heat exchanger (61), and the heat exchanger (61) is also connected to an exhaust gas outlet (63) for exhaust gas discharge; a regulating valve (65) is provided on the pipeline between the exhaust gas output end of the engine (10) and the heat exchanger, and a third temperature sensor (66) is arranged on the gas delivery pipe (64), and the third temperature sensor (66) is interlocked with the regulating valve (65).

9. The double-walled pipe ventilation system according to claim 1, characterized in that: The first double-walled tube (41) is provided with a first pressure transmitter (47), and the second double-walled tube (42) is provided with a second pressure transmitter (48).

10. The double-walled pipe ventilation system according to claim 1, characterized in that: A second stop valve (57) is provided at the air inlet end of each fan (52) on the ventilation pipeline (51), and a third check valve (58) is provided at the air outlet end of each fan (52).

11. A ship, characterized in that: A double-walled pipe ventilation system comprising the double-walled pipe ventilation system as claimed in any one of claims 1 to 10.

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