Heating device for a marine LNG gas supply system

Abstract

The utility model discloses a kind of heating devices of marine LNG gas supply system, including liquid tank, air supply component, air supply pipe group and heat exchange tube, the air supply pipe group includes air supply pipe and return air pipe, the air supply component and the air supply pipe are communicated, for providing cold air to the air supply pipe, the heat exchange tube is configured to be able to and the exhaust pipe of marine engine carries out heat exchange, one end of the heat exchange tube and the air supply pipe are communicated, another end of the heat exchange tube and the return air pipe are communicated, the return air pipe can and the liquid tank carry out heat exchange. The above heating device can use exhaust heat of exhaust pipe to heat LNG, can improve energy utilization, and can avoid the technical defects caused by single electric heating scheme in prior art to a large extent.

Description

Technical Field

[0001] This utility model relates to the field of LNG heating technology, specifically to a heating device for a marine LNG supply system. Background Technology

[0002] Liquefied natural gas (LNG) is typically stored in liquid form in tanks at a temperature of approximately -164°C, while the LNG used in ship main engines is gaseous and has a temperature between 0°C and 60°C. Therefore, heating devices are required to vaporize the LNG and bring it to a suitable temperature for use by the main engine.

[0003] In a typical design, the heating device is an electric heater, powered by a ship's generator. In large vessels such as LNG-powered container ships and tankers, the hourly vaporization rate of LNG can reach hundreds of cubic meters, resulting in a very high demand for electricity. However, the rated power of ship generators is generally limited and insufficient to meet these requirements. Adding a separate generator would increase construction costs and space requirements, contradicting the current design principle of "lightweight power systems." Furthermore, electric heating elements (such as heating rods and resistance wires) are constantly exposed to a humid environment, making them prone to damage and requiring frequent replacements and inspections, resulting in a relatively large maintenance workload.

[0004] Therefore, how to provide a solution to overcome or alleviate the above-mentioned defects remains a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] The purpose of this invention is to provide a heating device for a marine LNG supply system. This heating device can utilize the waste heat of the exhaust gas from the exhaust pipe to heat the LNG, thereby improving energy efficiency and largely avoiding the technical defects of the single electric heating scheme in the prior art.

[0006] To solve the above-mentioned technical problems, this utility model provides a heating device for a marine LNG supply system, including a liquid tank, an air supply component, an air supply pipe assembly, and a heat exchange pipe. The air supply pipe assembly includes an air supply pipe and a return air pipe. The air supply component is connected to the air supply pipe and is used to supply cold air to the air supply pipe. The heat exchange pipe is configured to exchange heat with the exhaust pipe of the ship's engine. One end of the heat exchange pipe is connected to the air supply pipe, and the other end of the heat exchange pipe is connected to the return air pipe. The return air pipe is capable of exchanging heat with the liquid tank.

[0007] In practical use, the heating device provided in this embodiment of the invention can supply cold air to the air supply pipe via the air supply component. The cold air can be transported to the heat exchange pipe through the air supply pipe, where it can be heated using the heat from the exhaust pipe to form hot air. Then, the hot air can enter the return air pipe, which extends into the liquid tank to exchange heat with the heat exchange medium inside the tank, thereby heating the heat exchange medium. Subsequently, the heat exchange medium can be used to heat LNG to meet the ship's requirements for using gaseous LNG.

[0008] As can be seen, this embodiment of the invention mainly utilizes the waste heat from the exhaust gas in the ship's engine exhaust pipe to heat LNG, which can achieve relatively efficient waste heat utilization, thereby improving energy efficiency and reducing equipment operating costs. Simultaneously, it can also reduce the exhaust temperature of the ship's engine, reducing thermal stress and wear on high-temperature components such as the exhaust pipe, which helps extend service life and maintenance / replacement cycles, further reducing equipment operating costs.

[0009] Compared to existing technologies that rely solely on electric heating, this invention utilizes waste heat from exhaust gases, which reduces generator fuel consumption and operating costs. Furthermore, it minimizes wear and tear on electric heating elements, reducing maintenance workload and costs. Additionally, because this invention relies less on the ship's electrical grid, even grid failures will not significantly impact LNG vaporization, reducing downtime risks and ensuring continuous and stable LNG supply, thus enhancing ship operational stability.

[0010] In some embodiments, the return air duct is inserted into the supply air duct, and there is an air passage gap between the supply air duct and the return air duct.

[0011] In some embodiments, the air supply component is a variable frequency fan.

[0012] In some embodiments, the heating device further includes a heat storage and heat exchange box, and the return air duct passes through the heat storage and heat exchange box.

[0013] In some embodiments, the heat storage and heat exchange box is at least one of a molten salt heat exchanger, a thermal oil heat exchanger, a steam heat exchanger, a liquid metal heat exchanger, a phase change energy storage heat exchanger, and an air heat exchanger.

[0014] In some embodiments, the heat storage and heat exchange box and the liquid tank are connected in series, and the heat storage and heat exchange box is located upstream of the liquid tank along the flow direction of hot air in the return air duct.

[0015] In some embodiments, the return air duct includes a main air duct and a bypass air duct. One end of the bypass air duct is connected to the main air duct, and the other end of the bypass air duct extends into the liquid tank or is also connected to the main air duct. The bypass air duct passes through the heat storage and heat exchange box.

[0016] In some embodiments, at least a portion of the heat exchange tube is a heat exchange coil, and the heat exchange coil is fitted onto the exhaust pipe.

[0017] In some embodiments, the heating device further includes a temperature detection component for detecting the temperature of the heat exchange medium in the liquid tank.

[0018] In some embodiments, the heating device further includes an electric heater for heating the heat exchange medium in the liquid tank. Attached Figure Description

[0019] Figure 1 A connection structure diagram of the heating device, deck, fuel tank, and exhaust pipe of the marine LNG supply system provided in this embodiment of the utility model;

[0020] Figure 2 A simplified heat exchange process diagram of the heating device for the marine LNG supply system provided in this embodiment of the utility model;

[0021] Figure 3 This is a connection structure diagram of a liquid tank, return air duct, and heat storage and exchange box.

[0022] Figure 4 This is an alternative connection structure diagram for the liquid tank, return air duct, and heat storage and heat exchange box.

[0023] The annotations in the attached figures are explained as follows:

[0024] 100 decks;

[0025] 200 fuel tank container;

[0026] 300 Heating device; 310 Liquid tank; 320 Air supply components; 330 Air supply duct assembly; 331 Supply air duct; 332 Return air duct; 332A Main air duct; 332B Bypass ventilation duct; 340 Heat exchange tube; 350 Heat storage and heat exchange box;

[0027] 400 exhaust pipe. Detailed Implementation

[0028] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation", "connection" and "linking" should be interpreted broadly. For example, "linking" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0030] The directional terms mentioned in the embodiments of this utility model, such as "inner" and "outer", are only for reference to the direction of the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of this utility model, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this utility model.

[0031] In the description of embodiments of this utility model, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0032] Please refer to Figures 1-4 , Figure 1 A connection structure diagram of the heating device, deck, fuel tank, and exhaust pipe of the marine LNG supply system provided in this embodiment of the utility model; Figure 2 A simplified heat exchange process diagram of the heating device for the marine LNG supply system provided in this embodiment of the utility model; Figure 3 This is a connection structure diagram of a liquid tank, return air duct, and heat storage and exchange box. Figure 4 This is an alternative connection structure diagram for the liquid tank, return air duct, and heat storage and heat exchange box.

[0033] This utility model provides a heating device 300 that can be applied to ships, specifically for heating the LNG supply system in ships. It can achieve a stable transition of LNG from liquid to gaseous state and ensure the temperature of gaseous LNG to meet the ship's usage requirements.

[0034] like Figure 1As shown, the LNG supply system may include a fuel tank 200, which may be installed on the deck 100 of the ship. The heating device 300 may also be installed on the deck 100, and may be at least partially installed on the top of the fuel tank 200 to make full use of the top space of the fuel tank 200. Of course, the fuel tank 200 and the heating device 300 may also be installed in other locations on the ship, which is not limited here.

[0035] The heating device 300 includes a liquid tank 310, an air supply component 320, an air supply duct assembly 330, and a heat exchange tube 340.

[0036] The liquid tank 310 is filled with a heat exchange medium, such as water, for exchanging heat with the LNG in the fuel tank 200. For example, the fuel tank 200 may be connected to a process pipeline for discharging LNG, and this process pipeline may extend into the liquid tank 310 to achieve heat exchange between the LNG and the heat exchange medium.

[0037] Air supply unit 320 is used to provide cool air. Combined with... Figure 1 Both the liquid tank 310 and the air supply component 320 can be installed on the top of the fuel tank 200.

[0038] The air supply duct assembly 330 includes an air supply duct 331 and a return air duct 332. An air supply component 320 is connected to the air supply duct 331 and is used to supply cool air to the air supply duct 331. A heat exchange tube 340 is configured to exchange heat with the exhaust pipe 400 of the ship's engine. One end of the heat exchange tube 340 is connected to the air supply duct 331, and the other end is connected to the return air duct 332. The return air duct 332 is capable of exchanging heat with the liquid tank 310.

[0039] In practical applications, the air supply unit 320 can supply cold air to the air supply duct 331. The cold air can then be transported from the air supply duct 331 to the heat exchange duct 340, where it can be heated by the heat from the exhaust pipe 400 to form hot air. The hot air then enters the return air duct 332, which extends into the liquid tank 310 to exchange heat with the heat exchange medium within the tank, thus heating the heat exchange medium. This heat exchange medium can then be used to heat the LNG to meet the ship's requirements for using gaseous LNG.

[0040] As can be seen, this embodiment of the invention mainly utilizes the waste heat from the exhaust gas in the ship engine exhaust pipe 400 to heat the LNG, which can achieve relatively efficient waste heat utilization, thereby improving energy efficiency and reducing equipment operating costs. Simultaneously, it can also reduce the exhaust temperature of the ship engine, reducing thermal stress and wear on high-temperature components such as the exhaust pipe 400, which helps extend service life and maintenance / replacement cycles, further reducing equipment operating costs.

[0041] Compared to existing technologies that rely solely on electric heating, this invention utilizes waste heat from exhaust gases, which reduces generator fuel consumption and operating costs. Furthermore, it minimizes wear and tear on electric heating elements, reducing maintenance workload and costs. Additionally, because this invention relies less on the ship's electrical grid, even grid failures will not significantly impact LNG vaporization, reducing downtime risks and ensuring continuous and stable LNG supply, thus enhancing ship operational stability.

[0042] In some implementations, the air supply component 320 can be a variable frequency fan.

[0043] The variable frequency fan can directly draw in air to provide cool air, and supply this cool air to the air duct 331 for use. In actual operation, the variable frequency fan can also adjust its output power as needed, thereby adjusting the flow rate of the cool air to meet the heating requirements of the heat exchange medium under different conditions.

[0044] It is understood that in some other implementations of this utility model, the air supply component 320 may also adopt other structural forms, such as an ion wind device. In short, as long as the air supply component 320 can provide cold air to the air supply pipe 331, it is acceptable.

[0045] In some implementations, the heating device 300 may also include a temperature detection component (not shown in the figure), which is used to detect the temperature of the heat exchange medium in the liquid tank 310. The air supply component 320 can adjust the cold air flow rate according to the temperature measured by the temperature detection component, so as to more accurately meet the heating requirements of the heat exchange medium.

[0046] Here, the embodiments of this utility model do not limit the specific type of the temperature detection component described above. In practical applications, those skilled in the art can select according to specific needs, as long as it can meet the requirements of use. For example, the temperature detection component described above can be a thermocouple, a resistance temperature detector (RTD), a thermistor, etc.

[0047] In some implementations, at least a portion of the heat exchange tube 340 may be a heat exchange coil.

[0048] like Figure 1 As shown, the heat exchange coil can be fitted onto the exhaust pipe 400, which can increase the heat exchange area between the heat exchange tube 340 and the exhaust pipe 400, thereby improving the heat exchange efficiency between the heat exchange tube 340 and the exhaust pipe 400.

[0049] It is understood that in some other implementations of this utility model, the heat exchange tube 340 can also adopt other structural forms, as long as they can meet the requirements of use. For example, the heat exchange tube 340 can also be a straight tube. In this case, the heat exchange tube 340 can be directly inserted and assembled into the exhaust pipe 400. In this way, the cold air entering the heat exchange tube 340 can directly contact the exhaust pipe 400 to exchange heat directly with the exhaust pipe 400, and the heat exchange efficiency can also be relatively high.

[0050] In some implementations, the return air duct 332 can be inserted into the supply air duct 331, that is, the return air duct 332 and the supply air duct 331 can be combined to form a sleeve-shaped air supply duct group 330. There can be an air passage gap between the supply air duct 331 and the return air duct 332 to allow cold air to pass through, while hot air can flow in the return air duct 332.

[0051] With this configuration, the supply air duct 331 can be located outside the return air duct 332, achieving isolation between the return air duct 332 and the external environment. This prevents people or objects in the external environment from directly contacting the return air duct 332 and causing burns, thus ensuring the safe operation of the equipment. The cold air in the air gap can also be preheated through contact with the return air duct 332, which helps to increase the temperature of the cold air. At the same time, the supply air duct 331 and the cold air inside it can also insulate the return air duct 332, reducing excessive heat loss from the hot air inside the return air duct 332 and ensuring the heating effect of the return air duct 332 on the heat exchange medium in the liquid tank 310.

[0052] Furthermore, by inserting the return air duct 332 into the supply air duct 331, the return air duct 332 and the supply air duct 331 can be combined to form an integrated air supply duct assembly 330. During installation, the return air duct 332 and the supply air duct 331 can be installed simultaneously in one go, resulting in relatively high installation efficiency. It also reduces the space required for installation.

[0053] It is understood that in some other implementations of this utility model, the return air duct 332 and the supply air duct 331 can also adopt other layouts, as long as they can meet the usage requirements. For example, the return air duct 332 and the supply air duct 331 can also be independent of each other. In this case, in order to improve the heat preservation effect of the return air duct 332, a heat preservation structure can also be set on the duct wall of the return air duct 332 to reduce the heat loss of the hot air in the return air duct 332.

[0054] In some implementations, the heating device 300 may also include a heat storage and heat exchange box 350, and a return air duct 332 may be inserted into the heat storage and heat exchange box 350 to facilitate heat exchange within the heat storage and heat exchange box 350.

[0055] The heat storage and heat exchange box 350 can be used for both heat storage and heat release. When the temperature of the hot air in the return air duct 332 is too high, the heat storage and heat exchange box 350 can absorb the heat from the hot air in the return air duct 332 to store the excess heat. When the temperature of the hot air in the return air duct 332 is relatively low, the heat storage and heat exchange box 350 can heat the hot air in the return air duct 332 to increase its temperature.

[0056] In other words, by setting up the heat storage and heat exchange box 350, the temperature of the hot air in the return air duct 332 can be better controlled, so as to better meet the heating requirements of the return air duct 332 for the heat exchange medium in the liquid tank 310.

[0057] Here, the present invention does not limit the specific type of the heat storage and heat exchange box 350. In practical applications, those skilled in the art can select according to specific needs, as long as it can meet the requirements of use. For example, the heat storage and heat exchange box 350 can be at least one of molten salt heat exchanger, thermal oil heat exchanger, steam heat exchanger, liquid metal heat exchanger, phase change energy storage heat exchanger, and air heat exchanger.

[0058] In some implementations, such as Figure 3 As shown, the heat storage heat exchange box 350 and the liquid tank 310 can be connected in series. Along the flow direction of hot air in the return air duct 332, the heat storage heat exchange box 350 can be located upstream of the liquid tank 310.

[0059] In this implementation, all hot air flows along the same path in the return air duct 332, and all of them need to pass through the heat storage and heat exchange box 350 for heat exchange before entering the liquid tank 310 for heat exchange.

[0060] In some implementations, such as Figure 4 As shown, the return air duct 332 may also include a main air duct 332A and a bypass air duct 332B. Both ends of the bypass air duct 332B can be connected to the main air duct 332A. The bypass air duct 332B can pass through the heat storage and heat exchange box 350, while the main air duct 332A can bypass the heat storage and heat exchange box 350.

[0061] In this implementation, the hot air in the return air duct 332 can be divided into two parts. One part can flow through the bypass air duct 332B to the heat storage and heat exchange box 350 for heat exchange, and then converge into the main air duct 332A. The other part can flow directly through the main air duct 332A to the liquid tank 310.

[0062] It is understood that in some other implementations of this utility model, one end of the bypass ventilation path 332B can be connected to the main ventilation path 332A, while the other end can be directly connected to the liquid tank 310. That is, the bypass ventilation path 332B does not need to merge with the main ventilation path 332A, which is also feasible.

[0063] In some implementations, the heating device 300 may also include an electric heater (not shown) for heating the liquid tank 310.

[0064] With this configuration, when the heat of the exhaust gas in the exhaust pipe 400 is relatively insufficient during the initial stage of ship startup or in low-temperature environments, an electric heater can be used for auxiliary heating to meet the heating requirements of the heat exchange medium in the liquid tank 310, thereby improving the versatility of the heating device 300 provided in this embodiment of the present invention in dealing with different working conditions.

[0065] As can be seen, the electric heater in this embodiment of the present invention is an auxiliary heating component, used only when the heat of the exhaust gas in the exhaust pipe 400 is relatively insufficient. Therefore, its usage frequency is relatively low, and correspondingly, its power demand and the possibility of damage to the electric heating element are relatively low, and it will not place an excessive burden on the operation and maintenance of the equipment. In other words, although this embodiment of the present invention is equipped with the aforementioned electric heater, it operates in a "waste heat priority, electric heating supplement" mode. The technical defects existing in the current electric heating technology are not obvious in this embodiment of the present invention.

[0066] To better understand this solution, this utility model embodiment can also be illustrated with a specific example to illustrate the operation of the heating device 300 provided by this utility model embodiment. In this example, the electric heater is not installed or is not used.

[0067] like Figure 2As shown, the air supply unit 320 can directly draw cold air from the atmosphere. The temperature of the cold air is the ambient temperature, for example, 20℃-25℃. The cold air can be delivered to the heat exchange pipe 340 through the air supply pipe 331, and exchange heat with the exhaust gas pipe 400. The exhaust gas temperature in the exhaust gas pipe 400 can be, for example, between 300℃-350℃. Afterward, the cold air can be converted into hot air. The hot air can enter the heat storage heat exchange box 350 through the return air pipe 332 for heat exchange. The hot air can also exchange heat with the cold air in the air supply pipe 331 to control the temperature of the hot air. For example, the temperature of the hot air entering the liquid tank 310 can be controlled at 100℃. Then, the hot air can exchange heat with the heat exchange medium in the liquid tank 310 to control the temperature of the heat exchange medium in the liquid tank 310 at 100℃. Finally, the LNG in the process pipeline can be heated through the heat exchange medium.

[0068] It can be seen that the heating device 300 provided in this embodiment of the present invention can effectively recover and utilize the heat of the exhaust gas in the exhaust pipe 400, and can effectively meet the heating requirements for LNG.

[0069] The above are merely preferred embodiments of this utility model. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model.

Claims

1. A heating device for a marine LNG supply system, characterized in that, The system includes a liquid tank (310), an air supply component (320), an air supply duct assembly (330), and a heat exchange tube (340). The air supply duct assembly (330) includes an air supply duct (331) and a return air duct (332). The air supply component (320) is connected to the air supply duct (331) and is used to supply cold air to the air supply duct (331). The heat exchange tube (340) is configured to exchange heat with the exhaust pipe (400) of the ship's engine. One end of the heat exchange tube (340) is connected to the air supply duct (331), and the other end of the heat exchange tube (340) is connected to the return air duct (332). The return air duct (332) is capable of exchanging heat with the liquid tank (310).

2. The heating device for the marine LNG supply system according to claim 1, characterized in that, The return air duct (332) is inserted into the supply air duct (331), and there is an air passage gap between the supply air duct (331) and the return air duct (332).

3. The heating device for the marine LNG supply system according to claim 1, characterized in that, The air supply component (320) is a variable frequency fan.

4. The heating device for a marine LNG supply system according to any one of claims 1-3, characterized in that, The heating device (300) also includes a heat storage and heat exchange box (350), and the return air duct (332) passes through the heat storage and heat exchange box (350).

5. The heating device for the marine LNG supply system according to claim 4, characterized in that, The heat storage and heat exchange box (350) is at least one of the following: molten salt heat exchanger, thermal oil heat exchanger, steam heat exchanger, liquid metal heat exchanger, phase change energy storage heat exchanger, and air heat exchanger.

6. The heating device for the marine LNG supply system according to claim 4, characterized in that, The heat storage heat exchange box (350) and the liquid tank (310) are connected in series. Along the flow direction of hot air in the return air duct (332), the heat storage heat exchange box (350) is located upstream of the liquid tank (310).

7. The heating device for the marine LNG supply system according to claim 4, characterized in that, The return air duct (332) includes a main air duct (332A) and a bypass air duct (332B). One end of the bypass air duct (332B) is connected to the main air duct (332A), and the other end of the bypass air duct (332B) extends into the liquid tank (310) or is also connected to the main air duct (332A). The bypass air duct (332B) is inserted through the heat storage heat exchange box (350).

8. The heating device for a marine LNG supply system according to any one of claims 1-3, characterized in that, At least a portion of the heat exchange tube (340) is a heat exchange coil, and the heat exchange coil is fitted onto the exhaust pipe (400).

9. The heating device for a marine LNG supply system according to any one of claims 1-3, characterized in that, The heating device (300) also includes a temperature detection component, which is used to detect the temperature of the heat exchange medium in the liquid tank (310).

10. The heating device for a marine LNG supply system according to any one of claims 1-3, characterized in that, The heating device (300) further includes an electric heater for heating the heat exchange medium in the liquid tank (310).

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