Natural gas supply apparatus and ship

Abstract

A natural gas supply apparatus and a ship. The natural gas supply apparatus comprises a storage tank, a first pump, a buffer tank, a compressor, and a condenser. The first pump is connected between the storage tank and a first tank inlet of the buffer tank. The compressor is connected between a gas outlet of the storage tank and a first condenser inlet of the condenser. A first condenser outlet of the condenser is communicated with a second tank inlet of the buffer tank. A second condenser inlet of the condenser is communicated with a first tank outlet of the buffer tank. A second condenser outlet of the condenser is configured to be communicated with a gas consuming device.

Description

Natural gas supply facilities and ships

[0001] This application claims priority to Chinese patent application No. CN 202411906403.2, filed on December 20, 2024, entitled "Gas Supply Unit and Vessel Coupled with BOG Reliquefaction", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the marine sector, and more specifically to natural gas supply units and vessels coupled with BOG reliquefaction. Background Technology

[0003] Due to increasingly stringent emission requirements, liquefied natural gas (LNG), as a clean energy source, will gradually replace traditional diesel fuel as marine fuel. LNG-powered ships using LNG need to be equipped with corresponding LNG supply systems to meet fuel supply demands. Under normal operating conditions, LNG is stored as a cryogenic fuel in storage tanks. Due to the temperature difference between LNG and the ambient temperature, LNG absorbs heat from the outside and vaporizes, producing flash gas (BOG), which causes the pressure inside the storage tank to gradually increase. Currently, BOG is pressurized by a compressor and then liquefied by exchanging heat with a refrigerant (non-LNG). This necessitates a refrigerant supply system, making the ship structure complex when using LNG supply systems. Summary of the Invention

[0004] The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed embodiments section. This summary section is not intended to limit the key features and essential technical features of the claimed technical solutions, nor is it intended to determine the scope of protection of the claimed technical solutions.

[0005] To at least partially solve the above-mentioned technical problems, this application provides a natural gas supply device coupled with BOG reliquefaction, the natural gas supply device comprising:

[0006] Storage tank, used to store liquefied natural gas, with a gas outlet at the top;

[0007] The first pump, whose inlet is connected to the lower space of the storage tank, is used to extract liquefied natural gas from the storage tank.

[0008] The buffer tank has its first inlet connected to the first outlet of the first pump.

[0009] The compressor, with its inlet connected to the gas outlet, is used to extract flash vapor from the storage chamber; and

[0010] The condenser has a first condensing inlet connected to the compressor outlet, a first condensing outlet connected to the first condensing inlet connected to the second tank inlet of the buffer tank, a second condensing inlet connected to the first tank outlet of the buffer tank, and a second condensing outlet connected to the second condensing inlet of the condenser for connection to gas-consuming equipment.

[0011] Thus, the first pump is used to extract LNG from the storage tank. The LNG is fed into the condenser via the buffer tank and the second condensation inlet. The compressor is used to extract BOG from the storage tank and deliver it to the condenser via the first condensation inlet. BOG and LNG exchange heat in the condenser to liquefy the BOG. ​​The liquefied BOG is delivered to the buffer tank via the first condensation outlet to mix with the LNG in the buffer tank to form mixed LNG. The second condensation outlet is used to output the LNG after heat exchange.

[0012] According to the natural gas supply device of this application, the cold energy of mixed LNG is used to cool BOG in a condenser to liquefy the BOG. ​​The liquefied BOG is then transported to a buffer tank to mix with LNG drawn from a storage tank to form mixed LNG. The mixed LNG is then transported to a condenser to release its cold energy, and the cooled mixed LNG is supplied to the gas-consuming equipment. In this way, the cold energy of LNG can be effectively utilized, and the mixed LNG formed by mixing liquefied BOG and LNG can be transported to the gas-consuming equipment. This can effectively utilize natural gas, reduce the environmental pollution caused by BOG, eliminate the need for a separate refrigerant supply device to liquefy BOG, and simplify the ship structure using the natural gas supply device. In addition, the process of directly cooling BOG with mixed LNG to liquefy it is simple and has low processing costs.

[0013] Optionally, the natural gas supply unit also includes a second pump, the second pump inlet of which is connected to the outlet of the first tank, and the second pump outlet of which is connected to the second condensate inlet. Thus, the second pump is used to deliver the mixed LNG to the second condensate inlet.

[0014] Optionally, the natural gas supply unit also includes a natural gas vaporizer, the vaporization inlet of which is connected to a second condensation outlet, and the vaporization outlet of which is connected to a gas-consuming device. The natural gas vaporizer is used to vaporize LNG.

[0015] Optionally, the natural gas supply unit also includes a pressure sensor and a controller. The controller is electrically connected to the pressure sensor, which is connected to the storage compartment to sense the pressure signal in the upper space of the first internal space of the storage compartment. The controller senses the pressure signal through the pressure sensor.

[0016] When the air pressure signal indicates a pressure value lower than the preset air pressure value, the controller controls the compressor to stop working, and / or

[0017] When the air pressure signal indicates an air pressure value greater than or equal to a preset air pressure value, the controller controls the compressor to work.

[0018] Optionally, the natural gas supply unit further includes a first flow sensor, which is installed on the pipeline between the compressor and the first condensate inlet to sense a first flow signal from the compressor output. The controller is electrically connected to the first flow sensor, and the controller senses the first flow signal through the first flow sensor.

[0019] When the air pressure value represented by the air pressure signal is greater than or equal to the preset air pressure value, the controller controls the speed of the compressor motor according to the air pressure signal and the first flow signal, thereby controlling the flow rate output by the compressor.

[0020] Optionally, the natural gas supply unit also includes a second flow sensor and a controller electrically connected to each other. The second flow sensor is disposed on the pipeline between the second pump outlet and the second condensate inlet, and is used to sense a second flow signal from the output of the second pump.

[0021] The controller senses the second flow signal through the second flow sensor. Based on the second flow signal and the current natural gas flow required by the gas-consuming equipment, the controller controls the speed of the second pump, and thus controls the output flow of the second pump to meet the current natural gas flow required by the gas-consuming equipment.

[0022] Optionally, the natural gas supply unit also includes:

[0023] The first valve has its inlet connected to the outlet of the second tank of the buffer tank, and its outlet connected to the first internal space of the storage compartment.

[0024] A liquid level sensor is used to sense the liquid level signal inside a buffer tank; and

[0025] The controller is electrically connected to the first valve and the liquid level sensor. When the liquid level signal indicates that the liquid level in the buffer tank is greater than or equal to a preset liquid level value, the controller controls the first valve to open so that the liquid in the buffer tank can be diverted to the storage compartment.

[0026] Optionally, the natural gas supply unit also includes:

[0027] The second valve has its inlet connected to the outlet of the third tank of the buffer tank, and its outlet connected to the outlet of the first condensate tank; and

[0028] The third pump has its inlet connected to the first condenser outlet and its outlet connected to the second tank inlet.

[0029] Optionally, the inner wall of the buffer tank protrudes inward to form a buffering protrusion, which is spiral or corrugated.

[0030] Optionally, the natural gas supply unit also includes an agitator, which is rotatably mounted inside a buffer tank.

[0031] This application also provides a vessel that includes the aforementioned BOG reliquefaction coupled natural gas supply unit.

[0032] According to this application, the vessel includes the aforementioned BOG reliquefaction coupled with a natural gas supply unit. In a condenser, the cold energy of mixed LNG is used to cool the BOG, thereby liquefying it. The liquefied BOG is then transported to a buffer tank to mix with LNG drawn from a storage tank to form mixed LNG. The mixed LNG is then transported to a condenser to release its cold energy, and the cooled mixed LNG is supplied to gas-consuming equipment. This effectively utilizes the cold energy of LNG and transports the mixed LNG formed by mixing liquefied BOG and LNG to gas-consuming equipment, effectively utilizing natural gas and reducing BOG pollution to the environment. There is no need to install a separate refrigerant supply unit to liquefy the BOG, and the vessel structure using the natural gas supply unit is simple. Furthermore, directly cooling the BOG with mixed LNG to liquefy it results in a simple process flow and low processing costs. Attached Figure Description

[0033] To make the advantages of this application more readily apparent, the application briefly described above will be described in more detail with reference to the specific embodiments shown in the accompanying drawings. It is to be understood that these drawings depict only typical embodiments of this application and should not be considered as limiting its scope of protection. The application is described and explained with additional features and details through the drawings.

[0034] Figure 1 is a schematic diagram of a natural gas supply unit coupled with BOG reliquefaction according to a preferred embodiment of this application; and

[0035] Figure 2 is a partially enlarged schematic diagram of point A of the BOG reliquefaction coupled natural gas supply unit in Figure 1;

[0036] Figure 3 is a simplified structural diagram of a ship according to a specific embodiment of this application.

[0037] Explanation of reference numerals: 110: Storage chamber; 111: Gas section; 112: Liquid section; 113: Gas outlet; 120: First pump; 121: First pump inlet; 122: First pump outlet; 130: Buffer tank; 131: First tank inlet; 132: Second tank inlet; 133: First tank outlet; 134: Second tank outlet; 135: Third tank outlet; 140: Compressor; 141: Compressor inlet; 142: Compressor outlet; 150: Condenser; 151: First condenser inlet; 152: First condenser outlet; 153: Second condenser inlet; 154: Second condenser outlet; 160: Second pump; 161: Second pump inlet 162: Second pump outlet 170: Natural gas vaporizer 171: Vaporization inlet 172: Vaporization outlet 180: First flow sensor 181: Second flow sensor 182: Pressure sensor 183: Third pump 184: Third pump inlet 185: Third pump outlet 186: Agitator 190: First valve 193: Liquid level sensor 194: Gas-using equipment 195: Second valve 196: First valve inlet 197: First valve outlet 198: Second valve inlet 199: Second valve outlet 200: Natural gas supply unit 300: Ship Detailed Implementation

[0038] In the following description, numerous specific details are set forth to provide a more thorough understanding of this application. However, it will be apparent to those skilled in the art that embodiments of this application may be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described to avoid confusion with embodiments of this application.

[0039] The preferred embodiments of this application will now be described with reference to the accompanying drawings. It should be noted that the terms "upper," "lower," and similar expressions used herein are for illustrative purposes only and are not intended to be limiting.

[0040] In this document, ordinal numbers such as “first” and “second” used in this application are merely identifiers and do not have any other meaning, such as a specific order.

[0041] To fully understand the embodiments of this application, a detailed structure will be presented in the following description. Obviously, the implementation of the embodiments of this application is not limited to the specific details familiar to those skilled in the art. Preferred embodiments of this application are described in detail below; however, other embodiments may be available in addition to these detailed descriptions.

[0042] This embodiment provides a natural gas supply device coupled with BOG reliquefaction (hereinafter referred to as the natural gas supply device). This natural gas supply device can be used in ships. As shown in FIG1, the ship's storage tank 110 is used to store LNG. LNG forms gaseous BOG in the storage tank 110. Thus, the first internal space of the storage tank 110 includes a gas section 111 and a liquid section 112. The gas section 111 is located above the liquid section 112. That is, the gas section 111 is the upper space of the storage tank 110, and the liquid section 112 is the lower space of the storage tank 110. BOG accumulates in the gas section 111, and LNG accumulates in the liquid section 112. This natural gas supply device can utilize the cold energy of LNG to cool the BOG, thereby liquefying the BOG into liquefied natural gas, and then supply natural gas to the ship.

[0043] Referring to Figures 1 and 2, the natural gas supply unit 200 includes a storage chamber 110. The first internal space of the storage chamber 110 is used to store natural gas. LNG fills the liquid section 112 in the lower part of the first internal space. BOG fills the gas section 111 in the upper part of the first internal space. The upper end of the storage chamber 110 has a gas outlet 113 communicating with the gas section 111. BOG covers the gas outlet 113.

[0044] The natural gas supply unit 200 also includes a first pump 120. The first pump 120 has a first pump inlet 121 and a first pump outlet 122. The first pump inlet 121 is connected to a liquid section 112. LNG covers the first pump inlet 121.

[0045] The natural gas supply unit 200 also includes a buffer tank 130 and pipelines. The buffer tank 130 has a main body. The main body has a second internal space, a first tank inlet 131, a second tank inlet 132, a first tank outlet 133, and a second tank outlet 134. The first tank inlet 131, the second tank inlet 132, the first tank outlet 133, and the second tank outlet 134 are all connected to the second internal space. The first tank inlet 131 is connected via a pipeline to the first pump outlet 122 of the first pump 120. Thus, the first pump 120 can draw LNG from the storage tank 110 and deliver the LNG to the buffer tank 130.

[0046] The natural gas supply unit 200 also includes a compressor 140. The compressor 140 has a compressor inlet 141 and a compressor outlet 142. The compressor inlet 141 is connected via a pipe to the gas outlet 113 of the storage silo 110.

[0047] As shown in Figure 1, the natural gas supply unit 200 also includes a condenser 150. The condenser 150 has a first condensation inlet 151, a first condensation outlet 152, a second condensation inlet 153, and a second condensation outlet 154. The first condensation inlet 151 and the first condensation outlet 152 are connected. The second condensation inlet 153 and the second condensation outlet 154 are connected.

[0048] The first condensate inlet 151 is connected to the compressor outlet 142 of the compressor 140 via a pipe. The first condensate outlet 152 is connected to the second tank inlet 132 of the buffer tank 130 via a pipe. The second condensate inlet 153 is connected to the first tank outlet 133. The second condensate outlet 154 is used to connect to the gas supply equipment 194.

[0049] Please refer to Figure 1. BOG enters compressor 140. Compressor 140 processes the BOG to increase its temperature and pressure, and then delivers the BOG to the first condenser inlet 151 of condenser 150 to enter condenser 150.

[0050] The first pump 120 is capable of drawing LNG from the storage tank 110 and delivering the LNG to the second internal space of the buffer tank 130.

[0051] The mixed LNG (described later) flowing from the first tank outlet 133 is conveyed to the second condenser inlet 153 to enter the condenser 150. The mixed LNG and BOG exchange heat within the condenser 150 to liquefy the BOG. ​​The liquefied BOG is then conveyed from the first condenser outlet 152 to the second tank inlet 132, thus entering the second internal space. At this point, the liquefied BOG and LNG drawn from the first pump 120 mix and exchange heat within the second internal space to form mixed LNG. The mixed LNG is then conveyed to the second condenser inlet 153 to enter the condenser 150.

[0052] In this way, the LNG extracted from the storage tank 110 exchanges heat with the liquefied BOG in the buffer tank 130, and the mixed LNG exchanges heat with the gaseous BOG again in the condenser 150, resulting in high LNG cold energy utilization.

[0053] The mixed LNG after heat exchange with BOG is discharged from condenser 150 via second condenser outlet 154 and then transported to gas-using equipment 194.

[0054] In this embodiment, the cold energy of mixed LNG is used to cool the BOG in the condenser 150 to liquefy it. The liquefied BOG is then transported to the buffer tank 130 to mix with LNG drawn from the storage tank 110 to form mixed LNG. The mixed LNG is then transported to the condenser 150 to release its cold energy. The mixed LNG after releasing its cold energy is supplied to the gas-using equipment 194. In this way, the cold energy of LNG can be effectively utilized, and the mixed LNG formed by mixing liquefied BOG and LNG can be transported to the gas-using equipment 194 to effectively utilize natural gas, reduce the environmental pollution caused by BOG, and eliminate the need for a separate refrigerant supply device to liquefy BOG. ​​The ship structure using the natural gas supply device 200 is simple. In addition, the process of directly cooling BOG with mixed LNG to liquefy it is simple and has low processing costs.

[0055] As shown in Figure 1, the natural gas supply unit 200 also includes a second pump 160. The second pump 160 has a second pump inlet 161 and a second pump outlet 162. The second pump inlet 161 is connected via a pipeline to the first tank outlet 133. The second pump outlet 162 is connected via a pipeline to the second condenser inlet 153. Thus, the second pump 160 is used to deliver mixed LNG to the second condenser inlet 153, enabling rapid supply of mixed LNG to the condenser 150.

[0056] Optionally, the second pump 160 pressurizes the liquefied natural gas to 200 barg to 380 barg (e.g., 302 barg) and delivers it to the second condenser inlet 153. This increases the pressure of the mixed LNG supplied to the condenser 150.

[0057] Optionally, the LNG output from the second pump 160 has a temperature range of -135°C to -145°C, for example -139.1°C. Therefore, the mixed LNG can more effectively cool the BOG.

[0058] As shown in Figure 1, the natural gas supply unit 200 also includes a natural gas vaporizer 170. The natural gas vaporizer 170 has a vaporization inlet 171 and a vaporization outlet 172. The vaporization inlet 171 is connected via a pipeline to a second condensation outlet 154. The vaporization outlet 172 is used to connect via a pipeline to a gas-using device 194. Thus, the LNG output from the condenser 150 is transported to the natural gas vaporizer 170. The natural gas vaporizer 170 processes the LNG to vaporize it. The temperature of the vaporized natural gas ranges from 30°C to 50°C, for example, 40°C. The pressure of the vaporized natural gas ranges from 250 barg to 350 barg (for example, 300 barg, indicating high-pressure natural gas). Therefore, gaseous natural gas can be supplied to the gas-using device 194 so that the gas-using device 194 can burn the natural gas as completely as possible.

[0059] The gas vaporizer 170 outputs gaseous natural gas at a flow rate ranging from 2400 kg / h to 2500 kg / h. For example, the flow rate of gaseous natural gas is 2440 kg / h. Therefore, the gas-using equipment 194 can burn the natural gas as completely as possible.

[0060] Alternatively, the natural gas vaporizer 170 can be an electric heater or a heat exchanger for other heat media.

[0061] As shown in Figure 1, the natural gas supply unit 200 also includes flow sensors and a controller (not shown). The flow sensors include a first flow sensor 180 for sensing a first flow signal and a second flow sensor 181 for sensing a second flow signal. The first flow sensor 180 is installed in the pipeline between the compressor 140 and the first condensate inlet 151, so that the first flow signal is the flow signal output by the compressor 140. The second flow sensor 181 is installed in the pipeline between the second pump outlet 162 and the second condensate inlet 153, so that the second flow signal is the flow signal output by the second pump 160. Therefore, the flow rate of the BOG output by the compressor 140 and the flow rate of the mixed LNG input to the second condensate inlet 153 can be monitored in real time. The first flow signal represents the flow rate of the BOG output by the compressor 140. The second flow signal represents the flow rate of the mixed LNG input to the second condensate inlet 153.

[0062] The controller is electrically connected to the first flow sensor 180, the second flow sensor 181, the first pump 120, the second pump 160, the first valve 190 (described later), the second valve 195 (described later), and the compressor 140, thereby controlling the operation of the first pump 120, the second pump 160, the first valve 190 (described later), the second valve 195 (described later), and the compressor 140. The operation of the first pump 120, the second pump 160, the compressor 140, and the first valve 190 (described later) can be remotely controlled via the controller.

[0063] The natural gas supply unit 200 also includes a pressure sensor 182. The pressure sensor 182 is electrically connected to a controller. The pressure sensor 182 is connected to the storage compartment 110 to sense the pressure signal of gaseous BOG in the gas section 111 at the upper part of the first internal space of the storage compartment 110. The pressure sensor 182 is, for example, disposed in the upper space of the storage compartment 110.

[0064] Furthermore, the controller acquires a first flow signal via the first flow sensor 180. The controller acquires a pressure signal via the pressure sensor 182. The controller controls the operation of the compressor 140 based on the first flow signal and the pressure signal.

[0065] Specifically, when the air pressure value indicated by the air pressure signal is less than the preset air pressure value, the controller controls the compressor 140 to stop working.

[0066] When the air pressure value indicated by the air pressure signal is greater than or equal to the preset air pressure value, the controller controls the compressor 140 to work.

[0067] During the operation of compressor 140, the BOG (Boiled Gas) in storage compartment 110 gradually decreases. When the pressure value indicated by the pressure signal is lower than the preset pressure value, it means that the BOG in storage compartment 110 is less than the preset amount. At this time, in order to save energy consumed by compressor 140, compressor 140 can be controlled to stop working.

[0068] When the air pressure signal indicates an air pressure value greater than or equal to a preset air pressure value, it means that the BOG in storage chamber 110 is greater than or equal to a preset amount. If the air pressure in storage chamber 110 continues to increase, it may damage storage chamber 110. At this time, the compressor 140 is controlled to work to liquefy the BOG, thereby reducing the air pressure in storage chamber 110.

[0069] Furthermore, when the pressure value represented by the pressure signal is greater than or equal to the preset pressure value, the controller controls the speed of the motor of the compressor 140 according to the pressure signal and the first flow signal, thereby controlling the flow rate output by the compressor 140.

[0070] When the air pressure value indicated by the air pressure signal is greater than or equal to the preset air pressure value, the controller controls the speed of the compressor 140 motor in real time according to the air pressure signal and the first flow signal, thereby controlling the output flow of the compressor 140 and realizing closed-loop control. For example, when the air pressure value indicated by the air pressure signal is large, the output flow of the compressor 140 increases (the sensed flow of the first flow sensor 180 increases), and when the air pressure value indicated by the air pressure signal decreases, the output flow of the compressor 140 decreases (the sensed flow of the first flow sensor 180 decreases), thus preventing the air pressure in the storage chamber 110 from being too high and reducing the energy consumed by the compressor 140.

[0071] Optionally, the controller acquires a second flow signal via a second flow sensor 181. Based on the second flow signal and the current required natural gas flow rate of the gas-consuming device 194, the controller controls the rotational speed of the second pump 160, thereby controlling the output flow rate of the second pump 160 to meet the current required natural gas flow rate of the gas-consuming device 194, thus achieving closed-loop control and real-time control of the rotational speed of the second pump 160. The required natural gas flow rate of the gas-consuming device 194 can be determined in other ways, such as through pre-experimental operating data.

[0072] Optionally, when the controller stops the compressor 140, the third pump 183 (described later) also stops operating, and LNG is supplied to the condenser 150 only through the second pump 160, and then gaseous natural gas is supplied to the gas-consuming equipment 194. During this process, the LNG can be heated by the natural gas vaporizer 170 to vaporize the LNG.

[0073] Optionally, when the compressor 140 is working, the controller controls the speed of the motor of the compressor 140, the speed of the second pump 160, and the heating efficiency of the natural gas vaporizer 170 based on the first flow signal, the second flow signal, and the current required natural gas flow of the gas-consuming device 194, so as to meet the current required natural gas flow of the gas-consuming device 194.

[0074] Thus, when the first flow signal indicates that the output flow of compressor 140 is low or compressor 140 is not working, and the heat from the BOG is insufficient to raise the temperature of the LNG output from the second pump 160 to the preset temperature, the LNG can be heated by the natural gas vaporizer 170 so that the output flow of the natural gas vaporizer 170 can meet the current natural gas flow requirement of the gas-consuming device 194. When the LNG temperature is at the preset temperature, the output flow of the natural gas vaporizer 170 can meet the current natural gas flow requirement of the gas-consuming device 194.

[0075] When the flow rate output by compressor 140 is large, and the heat from BOG can raise the temperature of LNG output by second pump 160 to the preset temperature, LNG can be vaporized directly without heating it through natural gas vaporizer 170.

[0076] Optionally, both the motor driving the compressor 140 and the motor driving the second pump 160 can be variable frequency motors for easy control.

[0077] As shown in Figure 1, the natural gas supply unit 200 also includes valves. The valves include a first valve 190.

[0078] The valve has an inlet and an outlet. The valve has an open state that connects the inlet and outlet, and a closed state that cuts off the connection between the inlet and outlet. The inlet 196 of the first valve 190 is connected via a pipe to the outlet 134 of the second tank. The outlet 197 of the first valve 190 is connected via a pipe to the first internal space of the storage compartment 110.

[0079] The natural gas supply unit 200 also includes a level sensor 193. The level sensor 193 is connected to or located within the second internal space of the buffer tank 130 to sense the level signal within the buffer tank 130. The level signal indicates the level of the liquid in the second internal space.

[0080] The controller is electrically connected to the first valve 190 and the level sensor 193. The controller monitors the level signal via the level sensor 193. When the level signal indicates that the level in the buffer tank 130 is greater than or equal to a preset level value, the controller controls the first valve 190 to open, diverting the liquid (liquefied natural gas) in the buffer tank 130 to the storage compartment 110. This prevents the level in the buffer tank 130 from becoming too high, which would result in high pressure within the buffer tank 130 and make it difficult for the first pump 120 to deliver LNG to the second internal space. Furthermore, it prevents damage to the buffer tank 130 due to an excessively high level.

[0081] Further, as shown in Figure 2, the buffer tank 130 also has a third tank outlet 135. The valve of the natural gas supply unit 200 also includes a second valve 195. The valve inlet 198 of the second valve 195 is connected to the third tank outlet 135 via a pipeline. The natural gas supply unit 200 also includes a third pump 183. The third pump 183 has a third pump outlet 185 and a third pump inlet 184. The third pump outlet 185 is connected to the second tank inlet 132 via a pipeline. The third pump inlet 184 is connected to the valve outlet 199 of the second valve 195 and the first condensate outlet 152 via a pipeline.

[0082] When the second valve 195 is open, the liquid in the buffer tank 130 can flow through the second valve 195 and mix with the liquid BOG discharged through the first condenser outlet 152. Then, the third pump 183 delivers the liquid in the pipe connecting the third pump inlet 184 and the first condenser outlet 152 to the buffer tank 130 for mixing with the liquid in the buffer tank 130. Thus, the mixing of BOG and LNG in the pipe connecting the third pump inlet 184 and the first condenser outlet 152, and in the buffer tank 130, ensures thorough mixing of BOG and LNG, improving the heat exchange efficiency of BOG and LNG in the buffer tank 130.

[0083] In addition, the mixture of BOG and LNG (mixed LNG) circulates in the loop formed by the third pump 183, the buffer tank 130 and the second valve 195, which can more thoroughly mix BOG and LNG.

[0084] Optionally, the inner wall of the buffer tank 130 body protrudes inward (towards the interior of the body, for example, towards the middle region of the second internal space) to form a mitigation protrusion (not shown). The mitigation protrusion can block the flow of liquid entering the buffer tank 130, thereby causing the liquid to form a vortex in the buffer tank 130, which can more fully mix BOG and LNG and improve the heat exchange effect of BOG and LNG in the buffer tank 130.

[0085] Furthermore, the raised structure is made into a spiral or corrugated shape. This allows for more thorough mixing of BOG and LNG, improving the heat exchange efficiency of BOG and LNG within the buffer tank 130.

[0086] Optionally, the natural gas supply unit 200 also includes a stirrer 186. The stirrer 186 is rotatably disposed within the buffer tank 130. The stirrer 186 can be connected to the wall of the buffer tank 130. In this way, by rotating the stirrer 186, the liquid within the buffer tank 130 can be stirred, allowing for more thorough mixing of BOG and LNG, thereby improving the heat exchange efficiency of BOG and LNG within the buffer tank 130.

[0087] Optionally, the first pump 120 is located inside the storage compartment 110. Thus, the natural gas supply unit 200 has a compact structure.

[0088] Optionally, the first pump 120 pressurizes the LNG to 6 barg to 20 barg (e.g., 8 barg) and then delivers it to the first tank inlet 131.

[0089] Optionally, the temperature range of the LNG output by the first pump 120 is -155°C to -165°C. For example, -162.9°C.

[0090] Optionally, compressor 140 pressurizes BOG to 7 barg to 20 barg (e.g., 10 barg) and then delivers it to the first condenser inlet 151.

[0091] Optionally, the temperature range of the BOG output by the compressor 140 is -55°C to -60°C. For example, -58.3°C.

[0092] Optionally, the condenser 150 outputs LNG at a pressure ranging from 295 barg to 305 barg (e.g., 301 barg) through the second condensation outlet 154, and then delivers it to the first condensation inlet 151.

[0093] Optionally, the LNG output from the condenser 150 through the second condensation outlet 154 has a temperature range of -55°C to -65°C, for example -61.39°C.

[0094] Optionally, the pressure of the mixed LNG output from the buffer tank 130 through the first tank outlet 133 ranges from 5 barg to 10 barg (e.g., 8 barg), and is then delivered to the first condensation inlet 151.

[0095] Optionally, the temperature range of the mixed LNG output from the buffer tank 130 through the first tank outlet 133 is -145°C to -155°C. For example, -148.3°C.

[0096] The pressure of the BOG supplied to compressor inlet 141 ranges from 1 barg to 4 barg (e.g., 3 barg). The temperature of the BOG supplied to compressor inlet 141 ranges from -115°C to -125°C (e.g., -120°C). The flow rate of the BOG supplied to compressor inlet 141 ranges from 1050 kg / h to 1070 kg / h (e.g., 1064 kg / h).

[0097] The pressure of the LNG delivered to the first pump inlet ranges from 4 barg to 7 barg (e.g., 5 barg). The temperature of the LNG delivered to the first pump inlet ranges from -160°C to -170°C (e.g., -163°C). The flow rate of the LNG delivered to the first pump inlet ranges from 1360 kg / h to 1380 kg / h (e.g., 1376 kg / h).

[0098] The natural gas supply unit 200 can achieve BOG liquefaction through heat exchange in the condenser 150. The natural gas supply unit 200 has few parts and a simple structure.

[0099] This application also provides a vessel. In a specific embodiment, the vessel 300 includes the aforementioned natural gas supply unit 200 and gas-consuming equipment 194. The gas-consuming equipment 194 may be a high-pressure main engine. The natural gas supply unit 200 supplies natural gas to the gas-consuming equipment 194.

[0100] In this embodiment, the vessel 300 includes the aforementioned natural gas supply device 200. In the condenser 150, the cold energy of mixed LNG is used to cool the BOG, thereby liquefying the BOG. ​​The liquefied BOG is then transported to the buffer tank 130 to mix with LNG drawn from the storage tank 110 to form mixed LNG. The mixed LNG is then transported to the condenser 150 to release its cold energy. The mixed LNG after releasing its cold energy is then supplied to the gas-using equipment 194. In this way, the cold energy of LNG can be effectively utilized, and the mixed LNG formed by mixing liquefied BOG and LNG can be transported to the gas-using equipment 194, which can effectively utilize natural gas, reduce the environmental pollution caused by BOG, and eliminate the need for a separate device to supply refrigerant for BOG liquefaction. The vessel 300 using the natural gas supply device 200 has a simple structure. In addition, the process of directly cooling the BOG with mixed LNG to liquefy it is simple and has low processing costs.

[0101] This application has been described through the above embodiments. However, it should be understood that the above embodiments are for illustrative purposes only and are not intended to limit this application to the scope of the described embodiments. Furthermore, those skilled in the art will understand that this application is not limited to the above embodiments, and many more variations and modifications can be made based on the teachings of this application, all of which fall within the scope of protection claimed in this application. The scope of protection of this application is defined by the appended claims and their equivalents.

[0102] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for descriptive purposes only and is not intended to limit the scope of this application. Terms such as “component” as used herein may refer to a single part or a combination of multiple parts. Terms such as “installation” or “installation” as used herein may refer to a component being directly attached to another component or a component being attached to another component via an intermediary. A feature described in one embodiment herein may be applied, alone or in combination with other features, to another embodiment, unless that feature is not applicable in that other embodiment or is otherwise stated.

Claims

1. A natural gas supply device (200), characterized by, The natural gas supply device (200) comprises: a storage tank (110) for storing liquefied natural gas, the upper end of the storage tank (110) having a gas outlet (113); a first pump (120), a first pump inlet (121) of the first pump (120) being in communication with a lower space (112) of the storage tank (110) for pumping out liquefied natural gas from the storage tank (110); a buffer tank (130), a first tank inlet (131) of the buffer tank (130) being in communication with a first pump outlet (122) of the first pump (120); a compressor (140), a compressor inlet (141) of the compressor (140) being in communication with the gas outlet (113) for pumping out flash vapor from the storage tank (110); and a condenser (150), a first condenser inlet (151) of the condenser (150) being in communication with a compressor outlet (142) of the compressor (140), a first condenser outlet (152) of the condenser (150) in communication with the first condenser inlet (151) being in communication with a second tank inlet (132) of the buffer tank (130), a second condenser inlet (153) of the condenser (150) being in communication with a first tank outlet (133) of the buffer tank, and a second condenser outlet (154) of the condenser (150) in communication with the second condenser inlet (153) being for being in communication with a gas using device (194).

2. The natural gas supply device (200) according to claim 1, characterized in that The natural gas supply device (200) further comprises a second pump (160), a second pump inlet (161) of the second pump (160) being in communication with the first tank outlet (133), and a second pump outlet (162) of the second pump (160) being in communication with the second condenser inlet (153).

3. The natural gas supply device (200) according to claim 1 or 2, characterized in that The natural gas supply device (200) further comprises a natural gas vaporizer (170), a vaporization inlet (171) of the natural gas vaporizer (170) being in communication with the second condenser outlet (154), and a vaporization outlet (172) of the natural gas vaporizer (170) being for being in communication with the gas using device (194), the natural gas vaporizer (170) being for vaporizing liquefied natural gas.

4. The natural gas supply arrangement (200) according to any one of claims 1 to 3, characterized in that The natural gas supply device (200) further comprises a gas pressure sensor (182) and a controller, the controller being electrically connected to the gas pressure sensor (182), the gas pressure sensor being for sensing a gas pressure signal in an upper space of a first internal space of the storage tank (110), wherein when the gas pressure value indicated by the gas pressure signal is less than a preset gas pressure value, the controller controls the compressor (140) to stop working, and / or when the gas pressure value indicated by the gas pressure signal is greater than or equal to the preset gas pressure value, the controller controls the compressor (140) to work.

5. The natural gas supply device (200) according to claim 4, characterized in that The natural gas supply unit (200) further includes a first flow sensor (180), which is disposed on the pipeline between the compressor (140) and the first condensate inlet (151) for sensing a first flow signal output by the compressor (140). The controller is electrically connected to the first flow sensor (180). When the air pressure value represented by the air pressure signal is greater than or equal to the preset air pressure value, the controller controls the speed of the motor of the compressor (140) according to the air pressure signal and the first flow signal, thereby controlling the flow output of the compressor (140).

6. The natural gas supply device (200) according to claim 2, characterized in that The natural gas supply unit (200) also includes a second flow sensor (181) and a controller electrically connected to each other. The second flow sensor (181) is installed on the pipeline between the second pump outlet (162) and the second condensate inlet (153) for sensing the second flow signal output by the second pump (160). The controller controls the rotational speed of the second pump (160) based on the second flow signal and the current required natural gas flow of the gas-using device (194).

7. The natural gas supply arrangement (200) according to any one of claims 1 to 6, characterized in that The natural gas supply unit (200) also includes: A first valve (190) has its valve inlet (196) connected to the second tank outlet (134) of the buffer tank (130), and its valve outlet (197) connected to the first internal space of the storage compartment (110). A liquid level sensor (193) for sensing the liquid level signal within the buffer tank (130); and The controller is electrically connected to the first valve (190) and the liquid level sensor (193). When the liquid level signal indicates that the liquid level in the buffer tank (130) is greater than or equal to a preset liquid level value, the controller controls the first valve to open so as to guide the liquid in the buffer tank (130) to the storage chamber (110).

8. The natural gas supply device (200) according to any one of claims 1 to 7, characterized in that The natural gas supply unit (200) also includes: The second valve (195) has its inlet (198) connected to the third outlet (135) of the buffer tank (130), and its outlet (199) connected to the first condensate outlet (152); and The third pump (183) has its third pump inlet (184) connected to the first condensate outlet (152) and its third pump outlet (185) connected to the second tank inlet (132).

9. The natural gas supply arrangement (200) according to any one of claims 1 to 8, characterized in that The inner wall of the buffer tank (130) protrudes inward to form a buffering protrusion, which is spiral or corrugated.

10. The natural gas supply device (200) according to any one of claims 1 to 9, characterized in that The natural gas supply device (200) also includes a stirrer (186), which is rotatably disposed within the buffer tank (130).

11. A vessel (300) characterized in that The vessel (300) includes a natural gas supply unit (200) according to any one of claims 1 to 10.

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