LNG Continuous Fuel Supply Device and Supply Method Applied to Ships

Abstract

The present invention relates to an LNG continuous fuel supply device and supply method applied to ships, belonging to the technical field of ship equipment. It includes a number of fuel tanks for storing LNG, a gas supply module and a control module. One end of the gas supply module is provided with a number of branches and is connected to the number of fuel tanks in one-to-one correspondence, and the other end is the main trunk connected to the power mechanism of the ship. The gas supply module is also provided with an alarm, a number of sub-monitoring units and a total monitoring unit that are electrically connected to the control module. The total monitoring unit is used to detect the main trunk flow rate and main trunk pressure, and a number of sub-monitoring units are used to detect the natural gas concentration at a number of branches. The control module adjusts the main trunk correction coefficient L and the branch correction coefficient N according to A, and corrects the main trunk flow rate, main trunk pressure and natural gas concentration according to L and N and compares them with the threshold ranges respectively; it saves space while taking into account the gas supply of multiple fuel tanks and safety.

Description

Technical Field

[0001] The present invention belongs to the technical field of ship equipment, and particularly relates to an LNG continuous fuel supply device and a supply method applied to ships. Background Art

[0002] LNG, namely liquefied natural gas, is usually a liquid formed by cooling a gaseous mixture of hydrocarbon gases naturally stored in strata to -163°C. Since its combustion products contain fewer sulfur-containing substances than those of traditional fuels and have a high calorific value per unit volume, technical solutions using LNG as a fuel supply have gradually been implemented in various transportation fields at home and abroad, such as the field of marine ships.

[0003] Since, in accordance with relevant safety regulations, the area within a certain range around the gas supply system on a ship is a hazardous area, only a few explosion-proof devices can be placed in the hazardous area. At the same time, the space inside a ship is usually limited. The traditional layout method of the fuel tank and the gas supply device of the LNG fuel supply device is that the two are respectively arranged on the hull structure through supports, which occupies a large area of the hull structure and cannot utilize the suspended space, making it unfavorable for the further spread of the LNG fuel supply device on the ship. For this reason, Chinese Patent CN109000148B discloses a marine LNG fuel supply system, which includes a fuel tank for storing LNG and a gas supply unit arranged at one end of the fuel tank for supplying gas outward, and further includes an enclosure device, a strengthening device and at least two supports; the supports are arranged at intervals along the axis direction of the fuel tank at the bottom of the fuel tank to support the fuel tank; the enclosure device covers the outside of the gas supply unit and supports the gas supply unit; the enclosure device is fixedly connected to the fuel tank and extends outwardly suspended from one end of the fuel tank; the strengthening device is arranged at the bottom of the enclosure device and extends to the bottom of the fuel tank and is fixedly connected to the adjacent support; the bottom surface of the strengthening device is higher than the bottom surface of the support. The fuel tank, the enclosure device and the support are connected into an integral structure through the strengthening device, having good strength and stiffness. The enclosure device is arranged in a suspended manner, reducing the cost of the hull foundation when arranged on the ship and meeting the layout requirements of a ship with a compact space; however, since a ship, especially a ship with a compact layout, sometimes stores LNG in several adjacent fuel tanks, and the above-mentioned solution can only take into account the solution of one fuel tank corresponding to one gas supply unit. When there are multiple fuel tanks, multiple gas supply devices are required, which occupies a large space and cannot use one gas supply unit to dock multiple gas supply tanks while taking into account the suspended arrangement of the gas supply device. At the same time, a ship needs to dock frequently to complete operations such as loading, unloading, and refueling. When parked, the LNG in the fuel tank is in a long-term static state and will form two liquid layers. When the external temperature is introduced, it will cause a rollover phenomenon, resulting in a sharp increase in the LNG evaporation rate and the pressure in the tank. If not handled in time, it will cause the container to rupture. The above-mentioned solution fails to consider such safety problems. For this reason, an LNG continuous fuel supply device and supply method for ships that takes into account the suspended arrangement while meeting the simultaneous gas outlet of multiple fuel tanks and the safety in fuel supply are needed. Summary of the Invention

[0004] To solve the above problems existing in the prior art, the present invention provides an LNG continuous fuel supply device and supply method for ships, which has the characteristics of taking into account the suspended arrangement while meeting the simultaneous gas outlet of multiple fuel tanks and the safety in fuel supply.

[0005] The object of the present invention can be achieved by the following technical solutions:

[0006] An LNG continuous fuel supply device for ships, comprising a number of fuel tanks for storing LNG and a gas supply module. The gas supply module includes a gas supply assembly. One end of the gas supply assembly is provided with a number of branches and is connected to the number of fuel tanks in one-to-one correspondence, and the other end is the main trunk and is connected to the power mechanism of the ship.

[0007] As a preferred technical solution of the present invention, the gas supply module is further provided with a control module, an alarm, a number of sub-monitoring units and a total monitoring unit electrically connected to the control module. The number of sub-monitoring units are respectively arranged at a number of branches of the gas supply assembly, and the total monitoring unit is arranged at the main trunk of the gas supply assembly. The total monitoring unit is used to detect the main trunk flow data a and the main trunk pressure data b of the gas supply assembly, and the number of sub-monitoring units are used to detect the natural gas concentration data c at a number of branches of the gas supply assembly n 。

[0008] As a preferred technical solution of the present invention, the control module is used to control the number A of fuel tanks connected to the gas supply assembly. The control module adjusts the main trunk correction coefficient L and the branch correction coefficient N according to A. The control module judges whether La obtained by multiplying the main trunk correction coefficient L by the main trunk flow data a is within the flow threshold range; at the same time, it also judges whether Lb obtained by multiplying the main trunk correction coefficient L by the main trunk pressure data b is within the pressure threshold range; if any judgment result is negative, the control module commands the alarm to sound an alarm.

[0009] As a preferred technical solution of the present invention, the control module judges the branch correction coefficient N and the natural gas concentration data c at a number of branches n and multiplies them respectively to obtain Nc n whether it exceeds the warning critical threshold; if any value exceeds the warning critical threshold, the control module commands the alarm to sound an alarm.

[0010] As a preferred technical solution of the present invention, any one of the fuel tanks includes a number of supports arranged on its outer surface, and the fuel tank is connected to the hull through the supports.

[0011] As a preferred technical solution of the present invention, the gas supply module further includes a shield. The shield is arranged between a number of fuel tanks and is hermetically connected to the number of fuel tanks to form a sealed space, and the gas supply assembly is located in the sealed space.

[0012] As a preferred technical solution of the present invention, any one of the fuel tanks is provided with a static treatment module. The static treatment module includes a pressure gauge and a stirrer. The pressure gauge is arranged in the corresponding fuel tank, and the pressure gauge and the stirrer are respectively electrically connected to the control module. The control module controls the start and stop of the stirrer according to the pressure gauge data.

[0013] As a preferred technical solution of the present invention, each of the fuel tanks is connected to a buffer chamber. The control module is electrically connected to the buffer chamber and controls the connection and disconnection between the buffer chamber and the corresponding fuel tank. Each of the fuel tanks is connected to the corresponding buffer chamber through a pressure relief valve.

[0014] As a preferred technical solution of the present invention, several of the buffer chambers are connected to each other through electromagnetic valves. The electromagnetic valves are electrically connected to the control module, and the control module opens or closes the electromagnetic valves according to the data of the pressure gauge.

[0015] As a preferred technical solution of the present invention, it further includes an emergency disposal module. The emergency disposal module includes several nozzles and several rotating seats. The several rotating seats are arranged on the gas supply device, and the several nozzles are respectively arranged on the several rotating seats in one-to-one correspondence. The control module is electrically connected to the several nozzles respectively, and the control module controls the working state of the several nozzles and the rotation direction of the rotating seats according to the sub-monitoring unit.

[0016] As a preferred technical solution of the present invention, the support is provided with a lifting lug.

[0017] As a preferred technical solution of the present invention, a collection hole is provided at the bottom of the gas supply module, and a receiving box is correspondingly provided below the collection hole. The receiving box is communicated with the collection hole.

[0018] The present invention also provides an LNG continuous fuel supply method applied to a ship, including the following steps:

[0019] Step 1: The control module connects A fuel tanks to the gas supply assembly according to the gas supply demand, so that the LNG in the connected fuel tanks is branched into the main trunk through the gas supply assembly and introduced into the power system of the ship's hull;

[0020] Step 2: The total monitoring unit is used to obtain the main trunk flow data a and the main trunk pressure data b, and upload them to the control module;

[0021] Step 3: The sub-monitoring unit is used to obtain the natural gas concentration data c at several branch points n， and upload it to the control module;

[0022] Step 4: The control module adjusts the main trunk correction coefficient L and the branch correction coefficient N according to the number A of fuel tanks;

[0023] Step 5: Judge whether La obtained by multiplying the main trunk correction coefficient L by the main trunk flow data a is within the flow threshold range; judge whether Lb obtained by multiplying the main trunk correction coefficient L by the main trunk pressure data b is within the pressure threshold range; if any one of the judgment results is negative, the control module instructs the alarm to sound an alarm; if both judgment results are positive, then proceed to the next step;

[0024] Step Six: Determine whether the product of the branch correction coefficient N and the natural gas concentration data c at several branch points n multiplied separately to obtain Nc n exceeds the warning critical threshold; if any value exceeds the warning critical threshold, the control module commands the alarm to sound

[0025] The beneficial effects of the present invention are as follows:

[0026] By setting multiple fuel tanks and making the shields of the corresponding gas supply units of the fuel tanks extend outwards and intersect from the corresponding fuel tanks by multiple branch pipes, the space formed below the gas supply module can be used to lay pipelines, personnel passages or serve as a dangerous buffer space, taking into account the layout flexibility and space saving while enabling the three fuel tanks to supply fuel to the ship in sequence or simultaneously according to the ship's power requirements;

[0027] By introducing coefficients L and N during the data collection process, and assigning different values to L and N according to the different numbers A of fuel tanks, and correcting the data uploaded by the total monitoring device and the gas concentration detector through L and N, the control module can make corresponding adjustments to the algorithm for whether the data exceeds the threshold when multiple fuel tanks adopt different fuel supply schemes;

[0028] By setting a stirrer, calculating the static time of the fuel tank by the control module and starting the stirrer regularly according to the static time, and at the same time setting a pressure gauge in each fuel tank and enabling the control module to calculate the air pressure change rate through the data of the front and rear pressure gauges, the occurrence of the tumbling phenomenon is reduced, and timely warning of the tumbling phenomenon is achieved when it occurs;

[0029] By connecting each fuel tank to a buffer chamber through a pressure relief valve, connecting the buffer chambers corresponding to several fuel tanks to each other through solenoid valves and corresponding pipe fittings, and enabling the control module to control the solenoid valves according to the pressure relief pressure gauge data in each buffer chamber, the number of connections between the buffer chambers of the fuel tank with the tumbling phenomenon can be changed according to the actual situation, delaying the gas in the fuel tank from reaching the design pressure upper limit of the fuel tank and causing damage to the fuel tank, extending the time left for the operator to handle the tumbling phenomenon, and further improving the safety of the fuel supply device;

[0030] By setting a nozzle and a rotating seat, and enabling the control module to control the rotating seat according to the polar coordinates formed by the gas detector, when there are leakage points in different directions caused by multiple fuel tanks, the water curtain can specifically isolate the leaked natural gas and the fire source according to the position of the leakage point, avoiding waste of water resources and further improving safety. Description of the Drawings

[0031] For the convenience of those skilled in the art to understand, the present invention will be further described below in conjunction with the drawings.

[0032] Figure 1 is the overall structural schematic diagram of the present invention;

[0033] Figure 2 is the structural schematic diagram of the fuel tank of the present invention;

[0034] Figure 3 is the sectional structural schematic diagram of the fuel tank of the present invention;

[0035] Figure 4 is the structural schematic diagram of the gas supply module of the present invention;

[0036] Figure 5 is the perspective structural schematic diagram of the gas supply module of the present invention;

[0037] Figure 6 is the structural schematic diagram of the gas supply unit of the present invention;

[0038] Figure 7 is the structural schematic diagram of the emergency disposal module of the present invention;

[0039] Figure 8 is the gas circuit diagram of the present invention;

[0040] Figure 9 is the control loop block diagram of the control module of the present invention;

[0041] Figure 10 is the process schematic diagram of the fuel supply method of the present invention.

[0042] Description of main component symbols:

[0043] In the figure: 1. Fuel tank; 11. Support; 12. Bracket; 13. Agitator; 2. Gas supply module; 21. Gas supply unit; 211. Heat exchanger; 212. Buffer tank; 22. Buffer chamber; 221. Solenoid valve; 23. Protective cover; 24. Main gas supply pipe; 3. Emergency disposal module; 31. Rotary seat; 32. Sprinkler head; 4. Control module; 41. Gas concentration detector; 42. Main monitoring unit. Detailed implementation manners

[0044] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following, in combination with the accompanying drawings and preferred embodiments, details the specific implementation manners, structures, features and their effects of the present invention as follows.

[0045] Please refer to Figure 1-10, an LNG continuous fuel supply device for ships, including a storage tank and a gas supply module 2, the gas supply module 2 is arranged on one side of the storage tank, and the gas supply module 2 includes a gas supply component, the gas supply component includes a gas supply unit 21, the inlet of the gas supply unit 21 is connected to the storage tank, and the outlet is connected to the ship's power unit. In this embodiment, the gas supply unit 21 is sequentially provided with a heat exchanger 211 and a buffer tank 212 and corresponding pipes and valves for connection from the inlet to the outlet. When gas supply is needed, liquefied LNG is introduced from the fuel tank 1 into the heat exchanger 211 and heated to become gas fuel. The gas fuel flows into the buffer tank 212 for buffering, and then flows into the ship's engine through the outlet, completing the supply of LNG to the ship through the fuel supply device.

[0046] In the above scheme, there is only one storage tank and one gas supply device, but due to layout and other reasons, some ships need to store LNG in several smaller fuel tanks 1. Therefore, in the present invention, there are several fuel tanks 1, and the gas supply module 2 includes several gas supply components. The gas supply component includes several gas supply units 21 corresponding to the number of fuel tanks 1. The several gas supply units 21 constitute branches of the gas supply component. The gas outlet ends of the buffer tanks 212 of the several gas supply units 21 converge at a main gas supply pipe 24. The main gas supply pipe 2 4 constitutes the backbone of the air supply assembly. The air supply units 21 and the main air supply pipe 24 enable the plurality of fuel tanks 1 to be connected in parallel, and the branches where the plurality of fuel tanks 1 are located intersect in the main air supply pipe 24. In this embodiment, there are three fuel tanks 1. When in use, the three fuel tanks 1 sequentially flow the fuel therein through the heat exchanger 211 and the buffer tank 212 into the main air supply pipe 24. Alternatively, when the ship needs to increase the speed or output power, the three fuel tanks 1 simultaneously flow the fuel into the main air supply pipe 24 through their respective air supply units 21.

[0047] During the process of supplying gas to the above structure, it is possible that the gasification rate of LNG in the fuel tank 1 is too fast, resulting in excessive outlet pressure and causing a rupture of a certain structure in the gas transmission path, or the gasification rate is too slow, resulting in insufficient pressure of the fuel output and causing the gas to flow back along the gas transmission path. These situations will all lead to potential safety hazards. To monitor the gas outlet situation of the fuel tank 1 in a timely manner, a control module 4 and an alarm are provided in the gas supply module 2. The alarm is electrically connected to the control module 4 and is controlled by the control module 4. A sub-monitoring unit is provided at the connection between several fuel tanks 1 and the gas supply unit 21, and a total monitoring unit 42 is provided in the gas supply module 2. The control module 4 is responsible for controlling whether each fuel tank 1 is connected to the corresponding gas supply unit 21 and collecting the data of the sub-monitoring unit and the total monitoring unit 42. Both the sub-monitoring unit and the total monitoring unit 42 include a flow meter and a pressure gauge. The flow meter and pressure gauge of the sub-monitoring unit are set at the branch of the gas supply component, that is, at the connection between several gas supply units 21 and the fuel tank 1, and the flow meter and pressure gauge of the total monitoring unit 42 are set on the main trunk formed by the main gas supply pipe 24. The control module 4 is a control circuit. The sub-monitoring unit and the total monitoring unit 42 upload the collected data to the control module 4 at a frequency of once per second. At the same time, the control module 4 is controlled by the operator to determine whether three fuel tanks 1 supply fuel to the ship. During the process of the fuel supply device supplying fuel to the ship, the control module 4 collects the real-time flow rate of the gas outlet of the corresponding fuel tank 1 and the hydraulic data in the pipeline, and compares the data with the pre-input threshold range. When the data is greater than the upper limit of the threshold range, the control module 4 controls the alarm to emit a sound and light signal and transmits the warning signal corresponding to the too-fast output to the operator's control terminal. When the data is less than the lower limit of the threshold range, a warning signal corresponding to the too-slow output is issued. At the same time, by reading the data of the sub-monitoring unit corresponding to the fuel tank 1 in the closed state, it can also be known whether the outlet valve of the current fuel tank 1 effectively seals the fuel tank 1. By setting the sub-monitoring unit and the total monitoring unit 42, the safety monitoring of the fuel supply device is completed during the process of supplying fuel by multiple fuel tanks 1.

[0048] Meanwhile, since the LNG at both ends of the pipeline is extremely easy to vaporize, it causes uneven pressure on the pipeline, which easily leads to leakage of natural gas from both ends of the pipeline. When natural gas mixes with air to form a mixed gas, and the explosion limit of the natural gas mixed gas is 5-15%, major accidents are extremely likely to occur without monitoring. Therefore, each sub-monitoring unit further includes a gas concentration detector 41 electrically connected to the control module 4. In this embodiment, the gas concentration detector 41 is a hydrocarbon gas concentration detector 41. A number of hydrocarbon gas concentration detectors 41 are arranged at the corresponding branch points, that is, outside the pipeline at the connection between the corresponding gas supply unit 21 and the fuel tank 1, and the gas concentration is monitored in real time and the data cn is uploaded to the control module 4 and compared with the warning critical threshold. In this embodiment, the warning critical threshold includes two values of 3% and 5%. When one of the uploaded concentration data of a number of gas concentration detectors 41 is greater than or equal to 3%, the control module 4 sends a leakage warning signal to the operator's control terminal. When two of them are greater than or equal to 5%, the control module 4 controls the alarm to emit corresponding sound and light signals for leakage, and sends an explosion warning signal to the operator's control terminal. By setting the gas concentration detector 41 electrically connected to the controller, the operator can be reminded in time when the leaked natural gas mixes with air to approach or reach the explosion limit, reducing the possibility of major accidents.

[0049] During the process of supplying fuel by the above structure, sometimes a scheme of supplying gas to the ship in sequence by several fuel tanks 1 according to demand is adopted, and sometimes a scheme of supplying gas to the ship simultaneously by several fuel tanks 1 is adopted. When several fuel tanks 1 supply gas to the ship simultaneously, since the flow rate in the main supply pipe 24 increases, the probability that the data collected by the total detection module is higher than the preset threshold will increase, and it is easy to accidentally trigger an alarm during normal fuel supply. At the same time, since several fuel tanks 1 supply gas to the outside through the gas supply unit 21 simultaneously, the natural gas leakage points will also increase accordingly. At this time, more natural gas will mix more fully with air on a larger scale, and the probability of an accident will increase. Therefore, when different fuel supply schemes are adopted, the control module 4 needs to make corresponding adjustments to the algorithm for whether the data exceeds the threshold. For this purpose, when the control module 4 receives the data transmitted by the sub-monitoring module and the total monitoring module, before judgment, it first calculates the data by introducing a correction coefficient according to the current gas supply scheme. Among them, the flow rate and pressure data of the main supply pipe 24 are recorded as a and b, the number of fuel tanks 1 opened according to the operator's instruction is recorded as A, the correction coefficient for the flow rate and pressure data of the main gas supply component, that is, the main supply pipe 24, is recorded as L, the data of the gas concentration detectors 41 corresponding to the three fuel tanks 1 are c1, c2 and c3, the correction coefficient for the data of the gas concentration detectors 41 of the branch is N, and the number of fuel tanks 1 in gas supply is A. When A = 1, L = 1 and N = 1. When A = 2, L = 0.67 and N = 1.1. When A = 3, L = 0.5 and N = 1.25. During the process of supplying fuel, when the control module 4 receives the flow rate data, pressure data and natural gas concentration data uploaded by the total monitoring device, it first takes the corresponding values of L and N according to the value of A, compares the flow rate correction value a×L with the pre-input flow rate threshold, compares the pressure correction value b×L with the pre-input pressure threshold, and compares the correction values of the three gas concentration data of the three gas concentration detectors 41 with 3% or 5%. When one of the values of a×L or b×L is greater than or less than the threshold range, the control module 4 sends the corresponding signal of too large or too small flow rate to the operator's control terminal and controls the alarm to emit the corresponding sound and light signal. When one of the values of c1×N, c2×N or c3×N is greater than or equal to 3%, the control module 4 sends the leakage warning signal to the operator's control terminal. When two values are greater than or equal to 5%, the control module 4 controls the alarm to emit the sound and light signal corresponding to leakage and sends the explosion warning signal to the operator's control terminal. By introducing the coefficients L and N, and assigning different values to L and N according to the different number A of fuel tanks 1 connected, and correcting the data uploaded by the total monitoring device and the gas concentration detectors 41 through L and N, the control module 4 completes the corresponding adjustment of the algorithm for whether the data exceeds the threshold when different fuel supply schemes are adopted.

[0050] To protect the gas supply unit 21 during the above gas supply process and prevent gas leakage from the gas supply unit 21, the gas supply module 2 further includes a shield 23. A number of gas supply units 21 are all arranged within the shield 23. The shield 23 is a multi-pass tubular structure. The number of branch pipes of the multi-pass pipe is the same as the number of fuel tanks 1. Each branch pipe is correspondingly connected to one fuel tank 1. Each branch pipe is fixed by welding near the area where the side wall or bottom surface of the corresponding fuel tank 1 is provided with an air outlet. The shape of the multi-pass pipe is arranged in coordination with the layout of multiple fuel tanks 1. The same number of gas supply units 21 as the number of fuel tanks 1 are arranged in the multi-pass pipe. At the same time, the shield 23 is a hollow cylindrical shape. The shield 23 is fixed by welding near the area where the side wall of the fuel tank 1 is provided with an air outlet. In this embodiment, the shield 23 is integrally in the shape of a tee pipe. At the same time, three gas supply units 21 are correspondingly provided in the shield 23. The three gas supply units 21 are all arranged in the three branch paths of the shield 23 connected to the fuel tank 1 corresponding to the gas supply unit 21. During use, the welded joint between the shield 23 and the outer surface of the fuel tank 1 prevents the leaked gas in the gas supply unit 21 from leaking out and prevents an external object from hitting the gas supply unit 21 and causing leakage.

[0051] When the above structure is in use, the fuel tank 1 and the gas supply device need to be arranged on the fixed structure of the hull, such as the deck or the bracket 12, respectively, through the support 11, which occupies a relatively large area or space of the hull structure and cannot save the floor area or space by means of suspension. To solve this problem, a number of fuel tanks 1 and the hull fixed structure are all connected through the bracket 12. At the same time, the multi-pass pipe-shaped shield 23 together with the gas supply unit 21 inside it is suspended above the hull fixed structure. One end of the support 11 is connected to the outer surface of the fuel tank 1 above and the fixed structure of the ship below. In this embodiment, the fuel tank 1 is integrally cylindrical. After the fuel tank 1 is fixed by the support 11, the bottom surface of the shield 23 is higher than the bottom surface of the support 11. Each fuel tank 1 corresponds to two supports 11. One end of the support 11 connected to the fuel tank 1 is a circular groove matching the interface of the fuel tank 1 shell. The outer shell of the fuel tank is connected to the circular groove. During use, the support 11 is arranged on the ship bracket 12 and provides a fixed support for the fuel tank 1. The shield 23 containing the gas supply module 2 is fixed on one side of the fuel tank and is in a suspended state. At this time, the entire continuous fuel supply device only contacts the ship hull through the support points of the fuel tank 1 supports 11, occupying a relatively small area of the hull structure. The layout scheme is more flexible and can better meet the full utilization of the compact internal space of the ship. When the fuel tank 1 is arranged at a high place, compared with the scheme of also fixing the gas supply device to the ship fixed structure, there is no need to arrange a special support structure in the space below the shield 23. The space formed below the suspended gas supply module 2 can be used to arrange pipelines, personnel passages or serve as a dangerous buffer space. While taking into account the layout flexibility and space saving, the three fuel tanks 1 supply fuel to the ship in sequence or simultaneously according to the ship's power demand, saving the occupancy of the ship space by the fuel continuous supply device and its dangerous area.

[0052] In actual use, ships often need to dock to complete operations such as loading and unloading goods or refueling. When at berth, fuel is not required from the fuel tank 1 to the power system. At this time, the LNG in the fuel tank 1 is in a long-term static state. The static LNG will form two liquid-phase layers with different densities in the fuel tank 1. When external temperature is introduced, it will cause the two liquid-phase layers to quickly flip up and down and mix, that is, the roll phenomenon occurs. At this time, the evaporation rate of LNG is 10 to 50 times the normal evaporation rate, causing the pressure in the fuel tank 1 to surge sharply. If not handled in time, it is easy to cause the fuel tank 1 to rupture. To reduce the occurrence of such situations, a static treatment module is provided in each fuel tank 1. The static treatment module includes a stirrer 13. In this embodiment, the stirrer 13 is two sets of annular rods arranged at the bottom of the fuel tank 1 and a motor for driving the annular rods. At the same time, the stirrer 13 is electrically connected to the control module 4. When in use, after adjusting the fuel supply plan, the control module 4 calculates the time elapsed since the last disconnection for each fuel tank 1 that is disconnected from the gas supply unit 21. When the time of a certain fuel tank 1 is greater than the static time threshold, the control module 4 starts the stirrer 13 in the corresponding fuel tank 1 for 10 seconds. After 10 seconds, the stirrer 13 is stopped and the time count is reset. When the time is greater than the threshold again, the above actions are repeated. By setting the stirrer 13 and calculating the static time of the fuel tank 1 by the control module 4 and starting the stirrer 13 regularly according to the static time, the occurrence of the roll phenomenon is reduced.

[0053] In the above scheme process, sometimes the stirring device cannot completely avoid the occurrence of the roll phenomenon. To timely remind the operator when it occurs to facilitate the operator to make a treatment and reduce the consequences of the accident, each static treatment module further includes a pressure gauge. The pressure gauge is arranged inside the tank and is connected to the control module 4 and uploads the pressure inside the corresponding fuel tank 1 to the control module 4 at a frequency of once per second. The control module 4 takes the pressure value uploaded most recently in a certain fuel tank 1 as d0, and the pressure value uploaded in the previous second as d1. The value of d0 - d1 is denoted as k, which is used as the air pressure change rate inside the fuel tank 1. After receiving the two pressure values, the control module 4 calculates the value of k. When the value of k exceeds the preset air pressure change rate threshold, the control module 4 determines that the roll phenomenon has occurred, controls the alarm to emit the corresponding sound and light signals for the roll phenomenon, and sends the roll phenomenon warning signal to the operator's control terminal. By setting a pressure gauge in each fuel tank 1 and enabling the control module 4 to calculate the air pressure change rate through the pressure gauge data before and after, the timely warning of the roll phenomenon is completed.

[0054] When the rolling phenomenon occurs, after the operator is alarmed, for various reasons, the operator may not be able to handle the rolling phenomenon in time. To delay the damage to the fuel tank 1 caused by the rolling phenomenon and extend the time for the operator to handle the rolling phenomenon, each fuel tank 1 is connected to a buffer chamber 22. The buffer chamber 22 is connected to the fuel tank 1 through a pressure relief valve. In this embodiment, each buffer chamber 22 is arranged in the space near the fuel tank 1 in the shield 23 of the gas supply module 2. The threshold pressure of the pressure relief valve is 0.7~0.75 MPa, and the upper limit of the design pressure of the buffer chamber 22 is 1.6 MPa. When the rolling phenomenon occurs in a certain fuel tank 1, the air pressure in the fuel tank 1 rises rapidly. When the air pressure rises to the threshold pressure, the natural gas flushes open the pressure relief valve and enters the buffer chamber 22. By connecting each fuel tank 1 to a buffer chamber 22 through a pressure relief valve, the gas in the fuel tank 1 is delayed from reaching the upper limit of the design pressure of the fuel tank 1, which may cause damage to the fuel tank 1, leaving the operator with a longer time to handle the rolling phenomenon, further improving the safety of the fuel supply device.

[0055] During the pressure relief and containment process of the fuel tank 1 that experiences tumbling in the above-mentioned buffer chamber 22, since the volume of a single buffer chamber 22 is limited, it is possible for the gas generated by the tumbling phenomenon to fill the buffer chamber 22. At this time, the newly evaporated gas cannot further enter the buffer chamber 22, resulting in a continuous increase in air pressure. To further delay the damage to the fuel tank 1 caused by the tumbling phenomenon and further extend the time left for the operator to handle the tumbling phenomenon, several buffer chambers 22 corresponding to several fuel tanks 1 are interconnected with each other through solenoid valves 221 and corresponding pipe fittings. In this embodiment, three buffer chambers 22 are interconnected with each other through three solenoid valves 221 and corresponding pipe fittings. The control module 4 compares the data uploaded by the pressure gauges in the fuel tank 1 during this process. During the pressure relief process of a single buffer chamber 22 for the tumbling phenomenon, when the data in the pressure gauge of the fuel tank 1 experiencing the tumbling phenomenon does not drop below the threshold within 10 seconds after the solenoid valve 221 is opened, it means that the air pressure in the fuel tank 1 is still too high after the single buffer chamber 22 is opened and cannot meet the pressure relief and containment function. The control module 4 opens the solenoid valve 221 connected to the buffer chamber 22 corresponding to the pressure gauge with a pressure relief value exceeding the threshold. At this time, the gas reaching the threshold in the single buffer chamber 22 flows along the solenoid valve 221 and the corresponding pipe fittings into another solenoid valve 221. When the data in the pressure gauge of the fuel tank 1 experiencing the tumbling phenomenon does not drop below the threshold within 10 seconds after two solenoid valves 221 are opened, it means that enabling two buffer chambers 22 cannot meet the pressure relief and containment function. The control module 4 opens the remaining two solenoid valves 221. At this time, the gas reaching the threshold in the two buffer chambers 22 flows into the third buffer chamber 22. By interconnecting several buffer chambers 22 corresponding to several fuel tanks 1 with each other through solenoid valves 221 and corresponding pipe fittings, and enabling the control module 4 to control the solenoid valves 221 according to the pressure gauge data of each buffer chamber 22 for pressure relief, the number of buffer chambers 22 connected to the fuel tank 1 experiencing the tumbling phenomenon can be changed according to the actual situation, further delaying the damage to the fuel tank 1 caused by the tumbling phenomenon and extending the time left for the operator to handle the tumbling phenomenon.

[0056] Although the agitator 13 and multiple interconnected buffer chambers 22 are provided, there is still a large-scale leakage of LNG in the fuel tank 1 due to rolling phenomenon or other factors in the end. When leakage occurs, spraying a water curtain on the leaked LNG is the most effective and economical means in the current technical means. By spraying a water curtain on the leaked LNG, the LNG vapor cloud can be isolated from possible ignition sources, preventing the explosion of the LNG vapor cloud that reaches the explosion threshold after reaching the explosion limit. For this reason, the present fuel supply device further includes an emergency disposal module 3. The emergency disposal module 3 includes a plurality of rotating seats 31 and a plurality of nozzles 32. The plurality of nozzles 32 are arranged on the gas supply device and can cover multiple fuel tanks 1. The plurality of nozzles 32 are all electrically connected to the control module 4 and are opened or closed under the control of the control module 4. The plurality of nozzles 32 are all arranged on the gas supply device through the rotating seats 31. The control module 4 is electrically connected to the rotating seats 31 and controls the rotation direction of the rotating seats 31 according to the data of the gas controller. In this embodiment, the six rotating seats 31 corresponding to the six nozzles 32 are respectively driven by six servo motors, and the six servo motors are respectively electrically connected to the control module 4. When the electric rotating seat 31 is horizontally arranged, the nozzle 32 thereon forms an angle of 45° with the line perpendicular to the ground and can rotate 360° in the horizontal direction. At this time, the nozzle 32 faces obliquely upward. At the same time, the universal joint is connected to the control module 4. The six rotating seats 31 have the same height from the ground, and the initial orientations of the six nozzles 32 are the same. The control module 4 takes the geometric center point of the six nozzles 32 as the pole, and takes the plane parallel to the ground containing this origin as the coordinate plane. The line connecting the projection of one gas concentration detector 41 on the coordinate plane and the pole is the polar axis. The pole, the polar axis and the coordinate plane form a reference polar coordinate. At the same time, the control module 4 pre-enters the angles of the projections of the remaining two gas concentration detectors 41 on the coordinate plane relative to the gas supply device and the orientation angles corresponding to the initial orientations of the nozzles 32 in this plane. When the comparison result of the control module 4 shows that one of the values of c1×N, c2×N or c3×N is greater than or equal to 3%, the control module 4 calculates the angle difference between the gas concentration detector 41 corresponding to the detected leakage risk in c1, c2 or c3 and the orientation angle of the initial orientation of the nozzle 32, and drives the servo motors to rotate uniformly. The control module 4 knows the rotation angle of the servo motor through the number of pulse signals fed back by the servo motor. When the rotation angle is consistent with the angle difference, the control module 4 turns off the servo motor and starts the nozzle 32. At this time, the six nozzles 32 uniformly spray a water curtain towards the area where the leakage risk is detected. By arranging the rotating seats 31 on the nozzles 32 and enabling the control module 4 to control the rotating seats 31 according to the gas detector, compared with spraying the water curtain upward alone, the targeting of the water curtain coverage is stronger, avoiding waste of water resources and further improving safety.

[0057] By setting up a static treatment module, several buffer chambers 22 connected by solenoid valves 221, and an emergency disposal module 3, and enabling the control module 4 to adjust the opening and closing of the solenoid valves 221 according to the pressure gauge in the fuel tank 1, the occurrence of tumbling phenomena is reduced during static state, the probability of gas bursting the fuel supply device and causing leakage is decreased when the tumbling phenomenon occurs, and the mixing degree of natural gas and air is reduced when leakage occurs, thus completing multi-layer prevention of accidents.

[0058] In actual use, sometimes it is necessary to disassemble and assemble the fuel tank 1 or the entire fuel supply device as a whole. To facilitate the fixing of the fuel tank 1 or the entire fuel supply device by the hoisting device, each bracket 12 is provided with a lifting lug. In this embodiment, the lifting lug is an annular structure fixedly connected to the bracket 12. During use, the hoisting device can fix the hook on the annular lifting lug, which facilitates the fixing of the hoisting device.

[0059] Due to the properties of LNG, it is extremely easy to evaporate at both ends of the pipeline. Therefore, the risk of rupture is relatively high in the space where LNG pipelines are relatively dense. And since multiple gas supply units 21 are integrated in the gas supply module 2, resulting in a large number of LNG pipelines and a high leakage risk. To avoid such situations, a collection hole is provided at the bottom of the gas supply module 2, and a receiving box is correspondingly provided below the collection hole. The receiving box is communicated with the collection hole. When a leakage occurs in the gas supply unit 21 within the protective cover 23, the low-temperature LNG liquid flows into the collection hole at the bottom of the gas supply module 2, and then flows into the receiving box below the collection hole. By setting up the receiving box and the collection hole, centralized disposal of the LNG liquid can be completed when a small amount of LNG leaks, avoiding further potential safety hazards caused by its volatilization in the open space.

[0060] Please refer to Figure 10 a continuous LNG supply method applied to ships, including the above fuel process device and the following steps:

[0061] Step 1: The control module 4 connects A fuel tanks 1 to the gas supply assembly according to the gas supply demand, so that the LNG in the connected fuel tanks 1 converges into the main pipeline through the branches of the gas supply assembly and is introduced into the power system of the ship's hull;

[0062] Step 2: The total monitoring unit 42 is used to obtain the main pipeline flow rate data a and the main pipeline pressure data b, and upload them to the control module 4;

[0063] Step 3: The sub-monitoring unit is used to obtain the natural gas concentration data cn at several branch points and upload them to the control module 4;

[0064] Step 4: The control module 4 adjusts the main pipeline correction coefficient L and the branch correction coefficient N according to the number A of fuel tanks 1;

[0065] Step 5: Determine whether La, obtained by multiplying the trunk correction coefficient L by the trunk flow data a, is within the flow threshold range; determine whether Lb, obtained by multiplying the trunk correction coefficient L by the trunk pressure data b, is within the pressure threshold range; if either judgment result is negative, the control module 4 instructs the alarm to sound an alarm; if both judgment results are positive, proceed to the next step;

[0066] Step 6: Determine whether Ncn, obtained by multiplying the branch correction coefficient N by the natural gas concentration data cn at several branches, exceeds the warning critical threshold; if any value exceeds the warning critical threshold, the control module 4 instructs the alarm to sound an alarm.

[0067] The working principle and use process of the present invention:

[0068] During gas supply, the operator determines the gas supply plan through the control terminal. The control module 4 controls the three fuel tanks 1 according to the gas supply plan to sequentially flow the fuel therein through the branches, namely the heat exchanger 211 and the buffer tank 212, and then merge into the main trunk, namely the main gas supply pipe 24. Alternatively, the three fuel tanks 1 are simultaneously connected to the main gas supply pipe 24 through their corresponding gas supply units 21. During this process, the fuel tanks 1 are fixed to the support 12 of the ship through the support 11, and the gas supply module 2 is suspended. The space formed below the suspended gas supply module 2 can be used to lay pipelines, personnel passages, or serve as a dangerous buffer space.

[0069] During the above process, the control module 4 collects the real-time flow rate and hydraulic pressure data in the pipeline when the corresponding fuel tank 1 is discharged, and compares the data with the pre-input threshold range. When the data is greater than or less than the upper limit of the threshold range, the control module 4 controls the alarm to emit an audible and visual signal and transmits a warning signal corresponding to too fast output or too slow output to the operator's control terminal. At the same time, by reading the data of the sub-monitoring unit corresponding to the fuel tank 1 in the closed state, it can also be determined whether the outlet valve of the current fuel tank 1 is effectively sealing the fuel tank 1;

[0070] During the process of fuel supply, the flow rate and pressure data of the main pipeline, i.e., the main gas supply pipe 24, are denoted as a and b, the number of fuel tanks 1 opened according to the operator's instruction is denoted as A, the correction coefficient for the flow rate and pressure data of the main pipeline is denoted as L, the data of the three gas concentration detectors 41 are c1, c2, and c3, the correction coefficient for the data of the gas concentration detectors 41 near the branch is N, and the number of fuel tanks 1 in the gas supply is A. When A = 1, L = 1 and N = 1; when A = 2, L = 0.67 and N = 1.1; when A = 3, L = 0.5 and N = 1.25. When the control module 4 receives the flow rate data, pressure data, and natural gas concentration data uploaded by the total monitoring device, it first takes the corresponding L value and N value according to the value of A, compares the flow rate correction value a×L with the pre-input flow rate threshold, compares the pressure correction value b×L with the pre-input pressure threshold, and compares the correction values of the three gas concentration data of the three gas concentration detectors 41 with 3% or 5%. When one of the values of a×L or b×L is greater than or less than the threshold range, the control module 4 sends the corresponding signal of too large or too small flow rate to the operator's control terminal and controls the alarm to emit the corresponding sound and light signals. When one of the values of c1×N, c2×N, or c3×N is greater than or equal to 3%, the control module 4 sends the leakage warning signal to the operator's control terminal. When two values are greater than or equal to 5%, the control module 4 controls the alarm to emit the sound and light signals corresponding to the leakage and sends the explosion warning signal to the operator's control terminal.

[0071] When static, after the control module 4 adjusts the fuel supply plan, it calculates the time elapsed since the last cut-off for each fuel tank 1 that is disconnected from the gas supply unit 21. When the time of a certain fuel tank 1 is greater than the static time threshold, the control module 4 starts the stirrer 13 in the corresponding fuel tank 1 for 10 seconds. After 10 seconds, the stirrer 13 is stopped and the time count is reset. When the time is greater than the threshold again, the above actions are repeated; meanwhile, the pressure gauge in each fuel tank 1 is connected to the control module 4 and uploads the pressure in the corresponding fuel tank 1 to the control module 4 at a frequency of once per second. The control module 4 takes the pressure value d0 uploaded most recently in a certain fuel tank 1 and the pressure value d1 uploaded in the previous second. The value of d0 - d1 is denoted as k, which is used as the gas pressure change rate in the fuel tank 1. The control module 4 calculates the value of k after receiving the two pressure values. When the value of k exceeds the pre-set gas pressure change rate threshold, the control module 4 determines that a tumbling phenomenon has occurred, controls the alarm to emit the sound and light signals corresponding to the tumbling phenomenon, and sends the tumbling phenomenon warning signal to the operator's control terminal.

[0072] When the tumbling phenomenon occurs, the natural gas in the corresponding fuel tank 1 opens the corresponding pressure relief valve and enters the buffer chamber 22. When the pressure relief pressure gauge data of a single buffer chamber 22 is compared and judged to exceed the threshold by the control module 4, the control module 4 opens the solenoid valve 221 connected to the buffer chamber 22 corresponding to the pressure relief pressure gauge that exceeds the threshold. At this time, the gas that reaches the threshold in the single buffer chamber 22 flows along the solenoid valve 221 and the corresponding pipe into the other solenoid valve 221. When the comparison result of the two pressure relief pressure gauge data exceeds the threshold, it means that activating two buffer chambers 22 cannot meet the pressure relief containment function. The control module 4 opens the remaining two solenoid valves 221. At this time, the gas that reaches the threshold in the two buffer chambers 22 flows into the third buffer chamber 22.

[0073] When the comparison result of the control module 4 shows that one of the values of c1×N, c2×N or c3×N is greater than or equal to 3%, the control module 4 calculates the angle difference between the orientation angle of the gas concentration detector 41 corresponding to the leakage risk detected in c1, c2 or c3 and the initial orientation of the nozzle 32, and drives the servo motor to rotate uniformly. The control module 4 obtains the rotation angle of the servo motor through the number of pulse signals fed back by the servo motor. When the rotation angle is consistent with the angle difference, the control module 4 turns off the servo motor and starts the nozzle 32. At this time, the six nozzles 32 uniformly spray water curtains toward the area where the leakage risk is detected.

[0074] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An LNG continuous fuel supply device applied to a ship, characterized in that: It includes a number of fuel tanks for storing LNG and a gas supply module. The gas supply module includes a gas supply component. One end of the gas supply component is provided with a number of branches and is connected to the number of fuel tanks one by one, and the other end is the main trunk and is connected to the power mechanism of the ship. The gas supply module is further provided with a control module, an alarm, a plurality of sub-monitoring units and a main monitoring unit which are electrically connected to the control module. The plurality of sub-monitoring units are respectively arranged at a plurality of branches of the gas supply assembly, and the main monitoring unit is arranged at the main trunk of the gas supply assembly. The main monitoring unit is used for detecting the main trunk flow data a and the main trunk pressure data b of the gas supply assembly, and the plurality of sub-monitoring units are used for detecting the natural gas concentration data c at a plurality of branches of the gas supply assembly n ; The control module is used to control the number A of fuel tanks connected to the gas supply component. The control module adjusts the main trunk correction coefficient L and the branch correction coefficient N according to A. The control module judges whether La obtained by multiplying the main trunk correction coefficient L by the main trunk flow data a is within the flow threshold range; at the same time, it also judges whether Lb obtained by multiplying the main trunk correction coefficient L by the main trunk pressure data b is within the pressure threshold range; if any judgment result is negative, the control module instructs the alarm to give an alarm. The control module determines whether the product of the branch correction coefficient N and the natural gas concentration data c at several branch points n multiplied separately to obtain Nc n exceeds the warning critical threshold; if any value exceeds the warning critical threshold, the control module instructs the alarm to give an alarm; Any one of the fuel tanks includes a number of supports provided on its outer surface. The fuel tank is connected to the hull through the supports.

2. The LNG continuous fuel supply device for a ship according to claim 1, wherein: The gas supply module further includes a shield. The shield is arranged between the number of fuel tanks and is hermetically connected to the number of fuel tanks to form a sealed space. The gas supply component is located in the sealed space.

3. The LNG continuous fuel supply device applied to a ship according to claim 1, wherein: Any one of the fuel tanks is provided with a static treatment module. The static treatment module includes a pressure gauge and a stirrer. The pressure gauge is arranged in the corresponding fuel tank. The pressure gauge and the stirrer are respectively electrically connected to the control module. The control module controls the start and stop of the stirrer according to the pressure gauge data.

4. The LNG continuous fuel supply device for a ship according to claim 3, characterized in that: Any one of the fuel tanks is connected to a buffer chamber. The control module is electrically connected to the buffer chamber and controls the on-off between the buffer chamber and the corresponding fuel tank. Any one of the fuel tanks is connected to the corresponding buffer chamber through a pressure relief valve.

5. The LNG continuous fuel supply device for a ship according to claim 4, characterized in that: The number of buffer chambers are connected to each other through solenoid valves. The solenoid valves are electrically connected to the control module. The control module opens or closes the solenoid valves according to the pressure gauge data.

6. The LNG continuous fuel supply device for a ship according to claim 1, characterized in that: It further includes an emergency disposal module. The emergency disposal module includes a number of spray heads and a number of rotating seats. The number of rotating seats are arranged on the gas supply device. The number of spray heads are arranged on the number of rotating seats one by one. The control module is respectively electrically connected to the number of spray heads. The control module controls the working state of the number of spray heads and the rotation direction of the rotating seats according to the sub-monitoring unit.

7. The LNG continuous fuel supply device for a ship according to claim 1, wherein: The support is provided with a lifting lug.

8. The LNG continuous fuel supply device for a ship according to claim 1, characterized in that: The bottom of the gas supply module is provided with a collection hole. A receiving box is correspondingly arranged below the collection hole. The receiving box is communicated with the collection hole.

9. A continuous LNG fuel supply method applied to ships, characterized in that: It includes the continuous fuel supply device according to any one of claims 1 to 8, and further includes the following steps: Step 1: The control module connects the fuel tanks with the number A to the gas supply component according to the gas supply demand, so that the LNG in the connected fuel tanks converges into the main trunk through the branches of the gas supply component and is introduced into the power system of the hull. Step 2: The total monitoring unit is used to obtain the main trunk flow data a and the main trunk pressure data b and upload them to the control module. Step 3: The sub-monitoring unit is used to obtain the natural gas concentration data c at several branch points n， and upload it to the control module; Step 4: The control module adjusts the main trunk correction coefficient L and the branch correction coefficient N according to the number A of fuel tanks. Step 5: Determine whether La obtained by multiplying the backbone correction coefficient L by the backbone flow rate data a is within the flow threshold range; determine whether Lb obtained by multiplying the backbone correction coefficient L by the backbone pressure data b is within the pressure threshold range; if the judgment result of any one item is negative, the control module instructs the alarm to sound an alarm; if the judgment results of both items are positive, then proceed to the next step; Step Six: Determine whether the product of the branch correction coefficient N and the natural gas concentration data c at several branch points n multiplied separately to obtain Nc n exceeds the warning critical threshold; if any value exceeds the warning critical threshold, the control module commands the alarm to give an alarm.

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