Combined heating device for preventing ice clogging and heavy gas diffusion of ventilated mast and LNG ship

Abstract

The present invention provides a combined heating device for preventing ice accumulation and heavy gas diffusion of a ventilation mast, comprising a ventilation mast with a hollow tubular structure and an LNG ventilation system discharge main pipe connected to the bottom of the ventilation mast, and the combined heating device also includes: a first water bath jacket, a second water bath jacket, an inlet heating pipeline, an ethylene glycol aqueous solution thermal expansion cabinet, a cylinder jacket hot water-ethylene glycol aqueous solution heat exchanger, an outlet heating pipeline, a boiler steam outlet pipeline, a cylinder jacket hot water outlet pipeline, an ethylene glycol aqueous solution circulation pipeline, a boiler steam inlet pipeline, a cylinder jacket hot water inlet pipeline, a first cylinder jacket hot water pipeline, a second cylinder jacket hot water pipeline, a third cylinder jacket hot water pipeline, an ethylene glycol aqueous solution inlet pipeline, an ethylene glycol aqueous solution outlet pipeline and an ethylene glycol aqueous solution discharge pipeline.

Description

Technical Field

[0001] The invention relates to the technical field of ships, and in particular to a combined heating device for preventing ice accumulation and heavy gas diffusion on a ventilated mast and an LNG ship with the device. Background Art

[0002] LNG (Liquefied Natural Gas) as a new green fuel has attracted great attention from the shipping industry. Industry experts regard LNG as a clean energy that can cope with the sulfur limit and reduce carbon emissions. In recent years, the number of LNG-powered ships and LNG transport ships has increased, and many ship owners are considering converting existing ships into LNG-powered ships.

[0003] LNG has high risks of low temperature, high pressure, flammability and explosion during storage and use. Therefore, in the process of LNG-powered ship transformation, the safety cost of LNG use accounts for more than half of the transformation cost, and the breathable mast of the LNG ship is one of the safety assurance links.

[0004] As the only way for ships to discharge exhaust gas and LNG gas, the ventilation mast needs to be designed to be cold-proof according to the requirements of classification societies to prevent ice accumulation and blockage. The ventilation mast of LNG ships may also face LNG leakage. Once LNG leaks, the ventilation system will blow the LNG gas out through the ventilation mast. However, a large amount of low-temperature gas will sink and gather because its density is greater than that of air (generally, when the temperature of LNG gas is below -80℃, its density is greater than that of air), resulting in the diffusion of heavy gas. There is a risk of explosion, and it will also cause the hull structure to become cold and brittle, causing huge losses.

[0005] According to the relevant patent "Vent Mast for Liquefied Natural Gas System" (patent number CN201620279981.2) and actual engineering experience, the current mainstream treatment methods at home and abroad are to install an air-temperature vaporizer at the entrance of the vent mast or to install a heating cable at the top of the vent mast. The air-temperature vaporizer installed at the entrance of the vent mast is easily affected by environmental factors. It cannot effectively supply heat under cold climate conditions, and thus cannot achieve the effect of cold protection. In addition, the air-temperature vaporizer occupies a large space and has high costs. Installing a heating cable on the top of the vent mast can ensure sufficient heat supply, but the vaporized gas temperature during LNG leakage can be as low as about -155°C, while the minimum operating temperature of the heating cable is about -60°C. There is no guarantee that the heating cable can work normally during LNG leakage.

[0006] The patent "A steam heating pipeline for cold protection in ice areas at the top of the breathable mast of an LNG ship" (patent number CN201710522357.X) introduces another way to protect against cold, but its heating capacity is affected by the coil structure and cannot guarantee sufficient heat supply to cope with the phenomenon of heavy gas diffusion. Summary of the invention

[0007] The purpose of the present invention is to provide a combined heating device to prevent ice accumulation and heavy gas diffusion on the ventilation mast, aiming to solve the shortcomings of the above-mentioned background technology and the problem that the ventilation mast cannot ensure sufficient heating under special conditions such as cold climate, LNG leakage and LNG ship discharging LNG due to failure, resulting in ice accumulation and heavy gas diffusion on the ventilation mast.

[0008] The present invention provides a combined heating device to prevent ice accumulation and heavy gas diffusion of a ventilation mast, comprising a ventilation mast with a hollow tubular structure and an LNG ventilation system discharge main pipe connected to the bottom of the ventilation mast, and the combined heating device also includes:

[0009] A first water bath sleeve, sleeved on the LNG ventilation system discharge main pipe;

[0010] A second water bath sleeve, disposed on the top of the air-permeable mast;

[0011] an inlet heating pipeline connected between the first water bath jacket and the second water bath jacket;

[0012] Ethylene glycol aqueous solution thermal expansion tank and cylinder jacket hot water-ethylene glycol aqueous solution heat exchanger;

[0013] an outlet heating pipeline, the upper end of which is connected to the second water bath jacket;

[0014] A boiler steam outlet pipeline is connected to the lower end of the outlet heating pipeline;

[0015] A cylinder jacket hot water outlet pipeline is connected to the lower end of the outlet heating pipeline;

[0016] An ethylene glycol aqueous solution circulation pipeline is connected between the lower end of the outlet heating pipeline and the ethylene glycol aqueous solution thermal expansion tank;

[0017] A boiler steam inlet pipeline is connected to the first water bath jacket;

[0018] Cylinder jacket hot water inlet pipe;

[0019] a first cylinder jacket hot water pipeline, connected between the cylinder jacket hot water inlet pipeline and the first water bath jacket;

[0020] a second cylinder liner hot water pipeline, connected between the cylinder liner hot water inlet pipeline and the cylinder liner hot water-ethylene glycol aqueous solution heat exchanger;

[0021] a third cylinder liner hot water pipeline, connected between the cylinder liner hot water-ethylene glycol aqueous solution heat exchanger and the cylinder liner hot water outlet pipeline;

[0022] An ethylene glycol aqueous solution inlet pipeline is connected between the ethylene glycol aqueous solution thermal expansion tank and the cylinder jacket hot water-ethylene glycol aqueous solution heat exchanger;

[0023] An ethylene glycol aqueous solution outlet pipeline is connected between the cylinder jacket hot water-ethylene glycol aqueous solution heat exchanger and the first water bath jacket;

[0024] The ethylene glycol aqueous solution discharge pipeline is connected to the ethylene glycol aqueous solution outlet pipeline.

[0025] Furthermore, a cylinder jacket hot water booster pump is provided on the first cylinder jacket hot water pipeline.

[0026] Furthermore, an ethylene glycol aqueous solution pressure pump is provided on the ethylene glycol aqueous solution inlet pipeline or the ethylene glycol aqueous solution outlet pipeline.

[0027] Furthermore, the ethylene glycol aqueous solution outlet pipeline is first collected on the first cylinder jacket hot water pipeline, and then communicated with the first water bath jacket through the first cylinder jacket hot water pipeline.

[0028] Furthermore, the ethylene glycol aqueous solution outlet pipeline is directly connected to the first water bath sleeve.

[0029] Furthermore, the combined heating device also includes a second valve arranged on the boiler steam inlet pipeline, a third valve arranged on the first cylinder jacket hot water pipeline, a fourth valve arranged on the second cylinder jacket hot water pipeline, a fifth valve arranged on the ethylene glycol aqueous solution outlet pipeline, a sixth valve arranged on the ethylene glycol aqueous solution discharge pipeline, a seventh valve arranged on the third cylinder jacket hot water pipeline, an eighth valve arranged on the ethylene glycol aqueous solution inlet pipeline, a ninth valve arranged on the cylinder jacket hot water outlet pipeline, a tenth valve arranged on the ethylene glycol aqueous solution circulation pipeline and an eleventh valve arranged on the boiler steam outlet pipeline.

[0030] Furthermore, the second water bath sleeve is installed on the top inner wall of the air-permeable mast.

[0031] Furthermore, a ventilation cap is provided on the top of the ventilation mast, a ventilation port is provided on the top of the ventilation cap, a drip tray with a funnel-shaped structure is provided inside the ventilation cap, and a discharge pipeline is connected to the bottom of the drip tray.

[0032] Furthermore, a protective net is provided inside the air vent, a circle of annular baffle is provided downwardly at the air vent, and the maximum diameter of the upper end of the drip tray is greater than the inner diameter of the air vent.

[0033] Furthermore, an insulating sleeve is laid along the outer wall of the mast of the breathable mast, the discharge pipeline, the inlet heating pipeline and the outlet heating pipeline are all wrapped in the insulating sleeve, and thermal insulation materials are provided between the pipe walls of each pipeline.

[0034] The present invention also provides an LNG ship equipped with the above-mentioned combined heating device for preventing ice clogging of the air-permeable mast and diffusing heavy gas.

[0035] The combined heating device for preventing ice accumulation and heavy gas diffusion of the ventilated mast provided by the present invention utilizes two sections of water bath sleeves to heat the exhaust gas, and its heat source comes from the steam of the ship boiler, the hot water of the cylinder jacket of the main engine, or the ethylene glycol aqueous solution in the LNG gas supply system. The heat is sufficient and stable, ensuring that the present invention can prevent cold and ice blockage of the ventilated mast under any conditions. At the same time, when the LNG gas is discharged, the low freezing point of the ethylene glycol aqueous solution can be used to prevent the heating medium from freezing.

[0036] The effects of the present invention also include that the two sections of water bath jackets can heat the LNG gas twice, and if the LNG gas sinks after being discharged, it can be heated for a third time through the water bath jacket on the top. Combined with the original height of the air mast, the damage caused by the diffusion of heavy gas of LNG is effectively prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic structural diagram of a combined heating device for preventing ice accumulation and heavy gas diffusion of a ventilation mast in a first embodiment of the present invention;

[0038] Figure 2 It is a schematic structural diagram of the top of the air-permeable mast in an embodiment of the present invention;

[0039] Figure 3 It is a schematic structural diagram of an insulating sleeve in an embodiment of the present invention;

[0040] Figure 4 This is a schematic diagram of the structure of the second water bath sleeve in an embodiment of the present invention;

[0041] Figure 5 It is a schematic structural diagram of a combined heating device for preventing ice accumulation and heavy gas diffusion on a ventilation mast in a second embodiment of the present invention. DETAILED DESCRIPTION

[0042] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0043] The terms "first", "second", "third", "fourth", "fifth" and the like (if any) in the description and claims of the present invention are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence.

[0044] First embodiment

[0045] like Figure 1 As shown, the combined heating device for preventing ice accumulation and heavy gas diffusion of the ventilation mast provided in the first embodiment of the present invention comprises a ventilation mast 5 with a hollow tubular structure and an LNG ventilation system discharge main pipe 7 connected to the bottom of the ventilation mast 5. The combined heating device also includes:

[0046] A first water bath sleeve 1 is sleeved on the LNG ventilation system discharge main pipe 7, and the first water bath sleeve 1 is used to heat the LNG gas passing through the LNG ventilation system discharge main pipe 7;

[0047] A second water bath jacket 3 is disposed on the top of the air mast 5, and is used to heat the LNG gas passing through the air mast 5;

[0048] An inlet heating pipeline 114 is connected between the first water bath jacket 1 and the second water bath jacket 3;

[0049] An ethylene glycol aqueous solution heat expansion tank 11 and a cylinder jacket hot water-ethylene glycol aqueous solution heat exchanger 10, wherein the ethylene glycol aqueous solution heat expansion tank 11 is used to temporarily store the ethylene glycol aqueous solution, and the cylinder jacket hot water-ethylene glycol aqueous solution heat exchanger 10 is used to heat the ethylene glycol aqueous solution using the cylinder jacket hot water;

[0050] An outlet heating pipeline 303, the upper end of which is connected to the second water bath jacket 3;

[0051] The boiler steam outlet pipeline 309 is connected to the lower end of the outlet heating pipeline 303 and is used to discharge the boiler steam after heating;

[0052] The cylinder jacket hot water outlet pipe 113 is connected to the lower end of the outlet heating pipe 303 and is used to discharge the heated cylinder jacket hot water;

[0053] The ethylene glycol aqueous solution circulation pipeline 17 is connected between the lower end of the outlet heating pipeline 303 and the ethylene glycol aqueous solution thermal expansion tank 11, and is used to circulate the heated ethylene glycol aqueous solution back to the ethylene glycol aqueous solution thermal expansion tank 11;

[0054] The boiler steam inlet pipeline 121 is connected to the first water bath jacket 1 and is used to transport the boiler steam into the first water bath jacket 1;

[0055] Cylinder jacket hot water inlet pipe 112;

[0056] A first cylinder jacket hot water pipeline 12 is connected between the cylinder jacket hot water inlet pipeline 112 and the first water bath jacket 1, and is used to transport the cylinder jacket hot water to the first water bath jacket 1;

[0057] The second cylinder jacket hot water pipeline 13 is connected between the cylinder jacket hot water inlet pipeline 112 and the cylinder jacket hot water-ethylene glycol aqueous solution heat exchanger 10;

[0058] The third cylinder jacket hot water pipeline 14 is connected between the cylinder jacket hot water-ethylene glycol aqueous solution heat exchanger 10 and the cylinder jacket hot water outlet pipeline 113;

[0059] The ethylene glycol aqueous solution inlet pipeline 15 is connected between the ethylene glycol aqueous solution thermal expansion tank 11 and the cylinder jacket hot water-ethylene glycol aqueous solution heat exchanger 10;

[0060] The ethylene glycol aqueous solution outlet pipeline 16 is connected between the cylinder jacket hot water-ethylene glycol aqueous solution heat exchanger 10 and the first water bath jacket 1, and is used to transport the heated ethylene glycol aqueous solution to the first water bath jacket 1;

[0061] The ethylene glycol aqueous solution discharge pipeline 122 is connected to the ethylene glycol aqueous solution outlet pipeline 16 .

[0062] Specifically, LNG gas is discharged into the atmosphere through the LNG ventilation system discharge main pipe 7 and the ventilation mast 5 in sequence, and the heating medium heats the LNG gas when passing through the first water bath jacket 1 and the second water bath jacket 3. The heating medium in the first water bath jacket 1 and the second water bath jacket 3 comes from boiler steam, cylinder jacket hot water or ethylene glycol aqueous solution of the LNG gas supply system.

[0063] Specifically, in cold weather conditions, the steam from the boiler or the hot water from the cylinder jacket can be flexibly selected to be turned on for circulating heating of the vent mast 5 according to the actual conditions of the ship. When LNG gas is discharged or LNG leaks, the steam from the boiler or the hot water from the cylinder jacket can still be used to heat the vent mast 5, but because the temperature of LNG is too low or the amount of LNG discharged / leaked is large, the water may freeze, so the heating by the steam from the boiler or the hot water from the cylinder jacket cannot be used normally. In this case, the ethylene glycol aqueous solution needs to be used to heat the vent mast 5, taking advantage of the lower freezing point of the ethylene glycol aqueous solution than that of water to prevent the low-temperature LNG gas from freezing the heating medium.

[0064] Specifically, the ethylene glycol aqueous solution is heated by the cylinder jacket hot water-ethylene glycol aqueous solution heat exchanger 10 equipped with the LNG gas supply system, and the heating medium is the main engine cylinder jacket hot water when the LNG ship is running normally, so that the patent does not need to change the basic structure of the LNG gas supply system. When LNG gas is discharged or LNG gas leaks, the cylinder jacket hot water only heats the ethylene glycol aqueous solution, and no longer heats the vent mast 5.

[0065] Specifically, the first cylinder jacket hot water pipeline 12 and the ethylene glycol aqueous solution outlet pipeline 16 are connected to the upper end of the first water bath jacket 1, and the boiler steam inlet pipeline 121 is connected to the lower end of the first water bath jacket 1; the bottom end of the inlet heating pipeline 114 is connected to the upper end of the first water bath jacket 1, the top end of the inlet heating pipeline 114 is connected to the bottom end of the second water bath jacket 3, and the top end of the outlet heating pipeline 303 is connected to the top end of the second water bath jacket 3. The ethylene glycol aqueous solution or cylinder jacket hot water enters from the upper end of the first water bath jacket 1, and the boiler steam enters from the lower end of the first water bath jacket 1. The circulating heating pipeline successively penetrates and connects the first water bath jacket 1 and the second water bath jacket 3, and adopts a bottom-in-top-out installation method on the second water bath jacket 3, and the heat transfer medium flows from the first water bath jacket 1 to the second water bath jacket 3 from bottom to top. The lengths of the first water bath jacket 1 and the second water bath jacket 3 can be set according to the conditions of the ship. The above is a connection method provided in this embodiment. Of course, other connection methods can also be used and there is no need to limit them here.

[0066] Specifically, when the cylinder liner hot water is heated, the cylinder liner hot water passes through the outlet heating pipeline 303 and flows out from the cylinder liner hot water outlet pipeline 113; when the ethylene glycol aqueous solution is heated, the ethylene glycol aqueous solution passes through the outlet heating pipeline 303 and the ethylene glycol aqueous solution circulation pipeline 16 in turn and flows back to the ethylene glycol aqueous solution thermal expansion tank 11; when the boiler steam is heated, the boiler steam passes through the outlet heating pipeline 303 and is discharged from the boiler steam outlet pipeline 309.

[0067] Furthermore, a cylinder jacket hot water booster pump 8 is provided on the first cylinder jacket hot water pipeline 12 .

[0068] Furthermore, an ethylene glycol aqueous solution pressure pump 9 is provided on the ethylene glycol aqueous solution inlet pipeline 15 or the ethylene glycol aqueous solution outlet pipeline 16 .

[0069] Furthermore, the ethylene glycol aqueous solution outlet pipeline 16 is firstly collected on the first cylinder jacket hot water pipeline 12 , and then communicated with the first water bath jacket 1 through the first cylinder jacket hot water pipeline 12 .

[0070] Furthermore, if Figure 2 As shown, a breathable cap 6 is provided on the top of the breathable mast 5 , a breathable port 306 is provided on the top of the breathable cap 6 , a funnel-shaped drip tray 304 is provided inside the breathable cap 6 , and a discharge pipeline 115 is connected to the bottom of the drip tray 304 .

[0071] Furthermore, a protective net 301 is provided inside the air vent 306 , and a circle of annular baffles 307 are provided downwardly at the air vent 306 . The maximum diameter of the upper end of the drip tray 304 is greater than the inner diameter of the air vent 306 .

[0072] Specifically, the protective net 301 can prevent foreign objects from entering the ventilation mast; the annular baffle 307 is used to divert rainwater falling into the ventilation mast 5 on rainy days. The diameter of the annular baffle 307 is the same as the inner diameter of the ventilation port 306. The maximum diameter of the upper end of the drip plate 304 is larger than the inner diameter of the ventilation port 306, so that the drip plate 304 can collect water vapor to the maximum extent and will not interfere too much with the effective discharge of gas in the ventilation mast 5; the bottom of the drip plate 304 is connected to a discharge pipeline 115, and the outlet of the discharge pipeline 115 passes through the second water bath sleeve 3 and extends out of the ventilation mast 5, and is finally connected to the downspout on the deck of the ship for discharge.

[0073] Preferably, the height of the annular baffle 307 can be set to 20-30 mm.

[0074] Further, the second water bath sleeve 3 is installed from the air mast 5 at the bottom of the air cap 6 and extends to the expansion section at the lower end of the air cap 6. The length of the second water bath sleeve 3 can be adjusted according to actual conditions. The second water bath sleeve 3 can be installed outside or inside the air mast 5. The heating efficiency is higher when installed inside. In this embodiment, the second water bath sleeve 3 is installed on the top inner wall of the air mast 5.

[0075] Preferably, if Figure 2 and Figure 4 As shown, the second water bath jacket 3 is a funnel-shaped structure as a whole, and the top positions of the drip tray 304 and the discharge pipeline 115 are both installed in the enclosed space of the second water bath jacket 3, which can prevent the condensation of steam and water in the drip tray 304 and the discharge pipeline 115.

[0076] Preferably, the first water bath jacket 1, the second water bath jacket 3, the inlet heating pipeline 114, the outlet heating pipeline 303, the discharge pipeline 115 and the drip tray 304 are all made of 316L stainless steel to cope with the low temperature impact when LNG leaks or discharges.

[0077] Furthermore, if Figure 2 and Figure 3 As shown, an insulating sleeve 4 is laid along the outer wall of the air-permeable mast 5, the discharge pipeline 115, the inlet heating pipeline 114 and the outlet heating pipeline 303 are all wrapped in the insulating sleeve 4, and thermal insulation materials 402 are provided between the pipe walls of each pipeline.

[0078] Preferably, the insulating sleeve 4 can be made of PPO (Polyphenylene Oxide) material, and the insulating sleeve 4 is fixed to the outer wall of the air-permeable mast 5 by a pipe clamp 401 .

[0079] Preferably, in order to prevent heat loss, a layer of heat-insulating material may be wrapped outside the first water bath jacket 1 and the second water bath jacket 3 .

[0080] Furthermore, a water discharge pipeline 2 is provided at the bottom of the ventilation mast 5 , and a residual drain port 120 is provided at the bottom of the first water bath sleeve 1 .

[0081] Specifically, the water discharge pipeline 2 is arranged below all the air inlet pipelines of the air mast 5 to discharge the accumulated water in the air mast 5. The residual drain port 120 is used to discharge the accumulated liquid in the pipeline when the circulation of the heating pipeline stops and the heating medium is changed from cylinder jacket hot water to boiler steam, so as to prevent the residual medium in the heating pipeline from freezing in cold weather.

[0082] Furthermore, if Figure 1 As shown, the combined heating device also includes a second valve 102 arranged on the boiler steam inlet pipeline 121, a third valve 103 arranged on the first cylinder jacket hot water pipeline 12, a fourth valve 104 arranged on the second cylinder jacket hot water pipeline 13, a fifth valve 105 arranged on the ethylene glycol aqueous solution outlet pipeline 16, a sixth valve 106 arranged on the ethylene glycol aqueous solution discharge pipeline 122, a seventh valve 107 arranged on the third cylinder jacket hot water pipeline 14, an eighth valve 108 arranged on the ethylene glycol aqueous solution inlet pipeline 15, a ninth valve 109 arranged on the cylinder jacket hot water outlet pipeline 113, a tenth valve 110 arranged on the ethylene glycol aqueous solution circulation pipeline 17 and an eleventh valve 111 arranged on the boiler steam outlet pipeline 309.

[0083] The combined heating device for preventing ice accumulation and heavy gas diffusion of the air permeable mast described above in this embodiment has the following main working procedures:

[0084] In cold climates, if boiler steam is used to heat the ventilation mast 5, the second valve 102 is opened to allow the boiler steam to enter the first water bath jacket 1 from the boiler steam inlet pipeline 121 to heat the ventilation mast 5, and the ninth valve 109 and the tenth valve 110 are kept closed, and the eleventh valve 111 is opened to allow the boiler steam or its condensed water that has completed the heating of the ventilation mast 5 to be discharged from the boiler steam outlet pipeline 309 where the eleventh valve 111 is located.

[0085] When the ship uses the cylinder jacket hot water to heat the breathable mast 5, the second valve 102, the fourth valve 104, and the fifth valve 105 remain closed, and the third valve 103 is opened to transport the cylinder jacket hot water to the first water bath jacket 1 through the cylinder jacket hot water booster pump 8; at the same time, the seventh valve 107, the tenth valve 110, and the eleventh valve 111 are kept closed, and the ninth valve 109 is opened to allow the cylinder jacket hot water that has completed the heating of the breathable mast 5 to be discharged from the cylinder jacket hot water outlet pipeline 113.

[0086] When a LNG ship fails and needs to discharge LNG gas or LNG gas leakage occurs, the fourth valve 104, the fifth valve 105, the seventh valve 107, the eighth valve 108, and the tenth valve 110 are opened, the third valve 103, the ninth valve 109, and the eleventh valve 111 are kept closed, and the sixth valve 106 is cut off to stop the delivery of ethylene glycol aqueous solution to the LNG gas supply system. The cylinder liner hot water flows in through the cylinder liner hot water inlet 117 of the cylinder liner hot water-ethylene glycol aqueous solution heat exchanger 10, and flows out from the cylinder liner hot water outlet 119 of the cylinder liner hot water-ethylene glycol aqueous solution heat exchanger 10, to heat the ethylene glycol aqueous solution, and finally discharged from the cylinder liner hot water outlet pipeline 113; the ethylene glycol aqueous solution flows out from the ethylene glycol aqueous solution thermal expansion tank 11, is pressurized and transported by the ethylene glycol aqueous solution booster pump 9, flows in from the ethylene glycol aqueous solution inlet 116 of the cylinder liner hot water-ethylene glycol aqueous solution heat exchanger 10, flows out from the ethylene glycol aqueous solution outlet 118 of the cylinder liner hot water-ethylene glycol aqueous solution heat exchanger 10, flows through the ethylene glycol aqueous solution outlet pipeline 16 where the fifth valve 105 is located, and is pressurized for the second time by the booster pump 8, thereby transporting the ethylene glycol aqueous solution to the first water bath jacket 1 and the second water bath jacket 3. The ethylene glycol aqueous solution heated by the ventilation mast 5 is transported to the ethylene glycol aqueous solution thermal expansion tank 11 through the ethylene glycol aqueous solution circulation pipeline 17 where the tenth valve 110 is located, so as to circulate the ethylene glycol aqueous solution.

[0087] When the use of ethylene glycol aqueous solution for heating the breathable mast 5 is stopped, the fifth valve 105 is closed, the sixth valve 106 is opened, the ethylene glycol aqueous solution is discharged from the ethylene glycol aqueous solution discharge pipeline 122 leading to the LNG gas supply system, and the fourth valve 104 and the seventh valve 107 are closed, thereby stopping the circulation of the cylinder liner hot water.

[0088] In special circumstances, boiler steam can also be used to heat the ethylene glycol aqueous solution.

[0089] Second embodiment

[0090] like Figure 5 As shown, the structure of the combined heating device provided in the second embodiment of the present invention is substantially the same as that of the first embodiment, except that the connection mode between the ethylene glycol aqueous solution outlet pipeline 16 and the first water bath jacket 1 is different.

[0091] Specifically, the ethylene glycol aqueous solution outlet pipeline 16 is directly connected to the first water bath jacket 1. Therefore, in this embodiment, when the ethylene glycol aqueous solution is used for heating, it is only necessary to turn on the ethylene glycol aqueous solution pressure pump 9, and there is no need to turn on the cylinder jacket hot water pressure pump 8.

[0092] The combined heating device for preventing ice accumulation and heavy gas diffusion of the ventilation mast provided by the present invention solves the problem of ice accumulation and blockage of the ventilation mast 5 due to failure to ensure sufficient heating under special conditions such as cold climate, LNG leakage and LNG discharge from LNG ships due to malfunctions. The present invention can ensure sufficient heat supply under various conditions to cope with the heavy gas diffusion phenomenon caused by LNG leakage and discharge.

[0093] The present invention uses two sections of water bath jackets to heat the exhaust gas. The heat source comes from the steam of the ship boiler, the hot water of the main engine cylinder jacket or the ethylene glycol aqueous solution in the LNG gas supply system. The heat is sufficient and stable. The water bath jacket is made of 316L stainless steel, which ensures that the invention can protect the ventilation mast 5 from cold and ice blockage under any conditions. At the same time, the two sections of water bath jackets can heat the LNG gas twice, and if the LNG gas sinks after being discharged, it can be heated for the third time through the second water bath jacket 3 on the top. Combined with the original height of the ventilation mast 5, it can effectively prevent the damage caused by the diffusion of heavy gas during LNG leakage.

[0094] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A combined heating device for preventing ice accumulation and heavy gas diffusion of a ventilation mast, comprising a ventilation mast (5) with a hollow tubular structure and an LNG ventilation system discharge main pipe (7) connected to the bottom of the ventilation mast (5), characterized in that: The combined heating device also includes: A first water bath sleeve (1) sleeved on the LNG ventilation system discharge main pipe (7); A second water bath sleeve (3) is arranged on the top of the ventilation mast (5); an inlet heating pipeline (114) connected between the first water bath jacket (1) and the second water bath jacket (3); A glycol aqueous solution heat expansion tank (11) and a cylinder jacket hot water-glycol aqueous solution heat exchanger (10); An outlet heating pipeline (303), the upper end of which is connected to the second water bath jacket (3); A boiler steam outlet pipeline (309) is connected to the lower end of the outlet heating pipeline (303); A cylinder jacket hot water outlet pipeline (113) is connected to the lower end of the outlet heating pipeline (303); An ethylene glycol aqueous solution circulation pipeline (17) is connected between the lower end of the outlet heating pipeline (303) and the ethylene glycol aqueous solution thermal expansion tank (11); A boiler steam inlet pipeline (121) is connected to the first water bath jacket (1); Cylinder jacket hot water inlet pipe (112); A first cylinder jacket hot water pipeline (12) connected between the cylinder jacket hot water inlet pipeline (112) and the first water bath jacket (1); a second cylinder jacket hot water pipeline (13), connected between the cylinder jacket hot water inlet pipeline (112) and the cylinder jacket hot water-ethylene glycol aqueous solution heat exchanger (10); a third cylinder liner hot water pipeline (14), connected between the cylinder liner hot water-ethylene glycol aqueous solution heat exchanger (10) and the cylinder liner hot water outlet pipeline (113); An ethylene glycol aqueous solution inlet pipeline (15) is connected between the ethylene glycol aqueous solution thermal expansion tank (11) and the cylinder jacket hot water-ethylene glycol aqueous solution heat exchanger (10); An ethylene glycol aqueous solution outlet pipeline (16) is connected between the cylinder jacket hot water-ethylene glycol aqueous solution heat exchanger (10) and the first water bath jacket (1); The ethylene glycol aqueous solution discharge pipeline (122) is connected to the ethylene glycol aqueous solution outlet pipeline (16).

2. The combined heating device for preventing ice clogging and heavy gas diffusion of the air permeable mast according to claim 1, characterized in that: The first cylinder jacket hot water pipeline (12) is provided with a cylinder jacket hot water booster pump (8).

3. The combined heating device for preventing ice clogging and heavy gas diffusion of the air permeable mast according to claim 1, characterized in that: An ethylene glycol aqueous solution pressure pump (9) is provided on the ethylene glycol aqueous solution inlet pipeline (15) or the ethylene glycol aqueous solution outlet pipeline (16).

4. The combined heating device for preventing ice clogging and heavy gas diffusion of the air permeable mast according to claim 1, characterized in that: The ethylene glycol aqueous solution outlet pipeline (16) is firstly connected to the first cylinder jacket hot water pipeline (12), and then connected to the first water bath jacket (1) through the first cylinder jacket hot water pipeline (12).

5. The combined heating device for preventing ice clogging and heavy gas diffusion of the air permeable mast according to claim 1, characterized in that: The ethylene glycol aqueous solution outlet pipeline (16) is directly connected to the first water bath sleeve (1).

6. The combined heating device for preventing ice clogging and heavy gas diffusion of the air permeable mast according to claim 1, characterized in that: The combined heating device further comprises a second valve (102) arranged on the boiler steam inlet pipeline (121), a third valve (103) arranged on the first cylinder jacket hot water pipeline (12), a fourth valve (104) arranged on the second cylinder jacket hot water pipeline (13), a fifth valve (105) arranged on the ethylene glycol aqueous solution outlet pipeline (16), a sixth valve (106) arranged on the ethylene glycol aqueous solution discharge pipeline (122), a seventh valve (107) arranged on the third cylinder jacket hot water pipeline (14), an eighth valve (108) arranged on the ethylene glycol aqueous solution inlet pipeline (15), a ninth valve (109) arranged on the cylinder jacket hot water outlet pipeline (113), a tenth valve (110) arranged on the ethylene glycol aqueous solution circulation pipeline (17), and an eleventh valve (111) arranged on the boiler steam outlet pipeline (309).

7. The combined heating device for preventing ice clogging and heavy gas diffusion of the air permeable mast according to claim 1, characterized in that: The second water bath sleeve (3) is installed on the top inner wall of the air-permeable mast (5).

8. The combined heating device for preventing ice clogging and heavy gas diffusion of the air permeable mast according to claim 1, characterized in that: A ventilation cap (6) is provided on the top of the ventilation mast (5), a ventilation port (306) is provided on the top of the ventilation cap (6), a drip tray (304) with a funnel-shaped structure is provided inside the ventilation cap (6), and a discharge pipeline (115) is connected to the bottom of the drip tray (304).

9. The combined heating device for preventing ice clogging and heavy gas diffusion of the air permeable mast according to claim 8, characterized in that: A protective net (301) is provided inside the air vent (306), a ring-shaped baffle (307) is provided downwardly at the air vent (306), and the maximum diameter of the upper end of the drip tray (304) is greater than the inner diameter of the air vent (306).

10. The combined heating device for preventing ice clogging and heavy gas diffusion of the air permeable mast according to claim 8, characterized in that: An insulating sleeve (4) is laid along the outer wall of the mast of the air-permeable mast (5); the discharge pipeline (115), the inlet heating pipeline (114) and the outlet heating pipeline (303) are all wrapped in the insulating sleeve (4), and thermal insulation materials (402) are provided between the pipe walls of each pipeline.

11. An LNG carrier, characterized in that: The utility model is equipped with a combined heating device for preventing ice accumulation and heavy gas diffusion of the air-permeable mast as described in any one of claims 1 to 10.

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