541 results about "LNG storage tank" patented technology

The invention discloses a welding detection method and application thereof in welding monitoring of an LNG (liquefied natural gas) storage tank. According to the scheme, 3D point cloud data, surface image data and cross-sectional image data acquired from a welding seam by combining a 3D laser scanner, an industrial camera and an ultrasonic phased array probe are subjected to multi-modal data fusion; the fusion data is input into a trained defect recognition model, so that the weld joint can have a more perfect data source in quality detection classification, and a reliable data basis is provided for weld joint detection; besides, according to the scheme, a welding seam model based on digital twinning is constructed on the basis of fusion data, in this way, when the welding seam has defects caused by abnormal welding, the welding seam model constructed by the digital twinning model can be used for positioning the defects and outputting local welding seam model data with the defects, and meanwhile, by combining a detection result, the defect detection accuracy is improved. And more visual and reliable detection feedback can be provided for background management personnel.

The invention discloses an LNG storage tank BOG liquefaction recovery system and a control method thereof.The system comprises an LNG storage tank, an LNG buffer tank, an LNG pump and a refrigerating machine, the LNG pump is installed in the LNG buffer tank, when BOG in the LNG storage tank needs to be recovered, BOG conveyed by the LNG storage tank is cooled and liquefied through the refrigerating machine and then returns to the LNG storage tank, recovery of BOG gas in the LNG storage tank is achieved, and in the BOG recovery process, the BOG is recovered through the refrigerating machine. And when the supercooling degree of the LNG storage tank needs to be maintained, the LNG conveyed by the LNG storage tank is cooled through the refrigerating machine, the cooled LNG returns into the LNG storage tank, and after the cooled LNG is mixed with the LNG in the LNG storage tank, the temperature of the LNG in the LNG storage tank is reduced, so that the supercooling degree of the LNG storage tank is maintained. The whole system is simple in structure, BOG in the LNG storage tank can be liquefied and recycled, and the supercooling degree of the LNG storage tank can be maintained.

The invention relates to a Cr-Mo-containing 5.5 Ni steel plate for an LNG (Liquefied Natural Gas) storage tank and a manufacturing method of the Cr-Mo-containing 5.5 Ni steel plate. The steel plate comprises the following chemical components in percentage by mass: 0.03-0.05% of C; 0.15% to 0.30% of Si; mn: 1.20% to 1.30%; p: < = 0.005%; s: < = 0.002%; al: greater than or equal to 0.020%; the content of Ni is 5.00 to 6.00 percent; 0.30% to 0.50% of Cr and Mo; h < = 1 ppm; 0.10% or less of As + Sb + Bi + Sn + Pb; and the balance of Fe and inevitable impurities. The invention relates to a 5.5 Ni steel plate for an LNG (Liquefied Natural Gas) storage tank, in particular to a steel plate for a pressure vessel with the thickness of 5-50mm and the temperature of minus 196 DEG C. A converter is used for production, and the delivery-state mechanical properties and process properties of the obtained steel plate meet the following requirements: the tensile strength Rm of transverse and longitudinal samples of the steel plate is 690-820 MPa, the yield strength Rel is greater than or equal to 590 MPa, and the elongation A is greater than or equal to 21%; at the temperature of-196 DEG C, the impact absorption energy KV8 of the transverse and longitudinal impact sample is greater than or equal to 100J; the sample is bent at normal temperature under the condition that D is equal to 2a and b is equal to 2a, the bending angle is 180 degrees, and no crack exists.

The invention discloses a storage tank pressurization control method and system based on LNG gas station fuzzy self-adaptive PID control, and aims to solve the technical problems that a traditional pressurization control method of an LNG storage tank is low in control precision, poor in stability and rapid in equipment abrasion. According to the control method, dynamic compensation for the target pressure is introduced, so that the system can aim at a more accurate control target in the initial stage, the steady-state control deviation is reduced, and the control precision is improved. And static pressure head change disturbance caused by liquid level change is overcome through dynamic compensation, the adjusting burden of the controller is reduced, the controller can focus on processing other dynamic disturbance, and therefore the control process is more stable, and overshoot is smaller. Through the design of a dynamic compensation mechanism and a special fuzzy rule base, the system can automatically adapt to various complex working conditions, and fast, stable and overshoot-free pressure control is always kept. Therefore, frequent and large-amplitude action and surge phenomena of the valve are avoided, and the energy consumption of an executing mechanism is reduced.

The utility model discloses a BOG liquefaction recovery device of an LNG storage tank. The LNG storage tank is provided with a gas phase opening and a liquid phase opening, and the gas phase opening is formed in the top of the LNG storage tank; the BOG liquefaction recovery device comprises a refrigerating machine, an LNG buffer tank and an LNG pump, the LNG pump is installed in the LNG buffer tank, a liquid phase inlet is formed in the bottom of the LNG buffer tank, the refrigerating machine is provided with a gas phase inlet and a liquid phase outlet, a gas phase opening of the LNG storage tank is connected with the gas phase inlet of the refrigerating machine through a first gas phase pipeline, a first valve is installed on the first gas phase pipeline, and a second valve is installed on the second gas phase pipeline. A liquid phase outlet of the refrigerating machine is connected with a liquid phase inlet of the LNG buffer tank through a first liquid phase pipeline, a second valve is installed on the first liquid phase pipeline, a liquid outlet of the LNG pump is connected with a liquid phase opening of the LNG storage tank through a second liquid phase pipeline, and a third valve is installed on the second liquid phase pipeline. The BOG in the LNG storage tank can be liquefied and recycled, and therefore emission of the BOG in the LNG storage tank is effectively reduced.

The invention provides a ship LNG fuel supply and tail gas carbon dioxide capture system. The ship LNG fuel supply and tail gas carbon dioxide capture system comprises an LNG storage tank, a CO2 separation device, a CO2 compressor, an ejector, an LNG vaporization heater, a mixed gas heat exchanger, a flash tank, a liquid CO2 storage tank, a flue gas heat exchanger and an engine. According to the system, LNG cold energy and engine tail gas heat energy can be effectively utilized, and the energy consumption of the system is reduced.

The BOG reliquefaction system of the LNG storage tank comprises the LNG storage tank and a heat exchanger arranged side by side with the LNG storage tank, and a first conveying pipe for outputting to the heat exchanger is arranged at the top end of the LNG storage tank; the rewarming heat exchange piece is arranged on one side of the heat exchanger to adjust the BOG temperature, and the rewarming heat exchange piece communicates with the interior of the heat exchanger; the BOG compressor is arranged at the lower end of the rewarming heat exchange piece so as to pressurize BOG; by arranging the heat exchanger, the rewarming heat exchange piece, the BOG compressor, the refrigerant assembly and the pressure adjusting assembly, the pressure in the LNG storage tank can be adjusted conveniently, the storage safety is guaranteed, gas and liquid phase refrigerants are separated in the gas-liquid separator and used for different purposes respectively, and therefore the system energy utilization rate is increased, the pressure of the gas phase space at the top of the LNG storage tank is controlled by arranging the pressure adjusting assembly, and the system energy utilization rate is increased. And the pressure difference is reduced through a throttling valve and other devices, and pressure balance and safe operation of the system in the BOG reliquefaction process are ensured.

The invention discloses a pump booster type LNG cold energy utilization system and a control method thereof, the LNG cold energy utilization system comprises an LNG storage tank, a cooler, a gas supply mechanism and a booster pump, the cooler comprises a cooling shell, a first heat dissipation pipe and a second heat dissipation pipe, and the first heat dissipation pipe and the second heat dissipation pipe are arranged in the cooling shell; the gas supply mechanism comprises a vaporizer and a buffer tank, and a third heat dissipation pipe and a fourth heat dissipation pipe are arranged in the vaporizer. The system has the beneficial effects that by arranging the booster pump, the system can effectively suck LNG gas in the buffer tank into the LNG storage tank, so that the pressure in the LNG storage tank is increased, and the pressure in the LNG storage tank can be kept stable when a vehicle runs; meanwhile, according to the system, cold energy is provided for the refrigeration air conditioner through a second heat dissipation pipe in the cooler, recycling of LNG cold energy is achieved, and the energy utilization efficiency of the whole system is improved.

The invention discloses an LNG storage tank supercooling degree maintaining system and a control method thereof. The LNG storage tank supercooling degree maintaining system comprises an LNG storage tank, an LNG pump pool, an LNG pump and a refrigerating machine, and the LNG pump is installed in the LNG pump pool; a liquid phase outlet and a bottom liquid inlet are formed in the bottom of the LNG storage tank, a top liquid inlet is formed in the top of the LNG storage tank, a liquid phase inlet is formed in the bottom of the LNG pump pool, when the system works, LNG in the LNG storage tank is conveyed to the refrigerating machine through the LNG pump to be cooled, the cooled LNG returns to the bottom liquid inlet of the LNG storage tank to reduce the temperature of the LNG in the LNG storage tank, and therefore the supercooling degree of the LNG storage tank is maintained; or returning to a top liquid inlet of the LNG storage tank to reduce the temperature of part of BOG in the LNG storage tank and liquefy the part of BOG to ensure that the LNG storage tank is not overpressure. The LNG storage tank can be cooled and depressurized, so that the supercooling degree of the LNG storage tank is maintained within the LNG inlet liquid supercooling degree range required by the operation of the immersed pump of the LNG station, and cavitation caused by insufficient supercooling degree of sucked LNG of the immersed pump is effectively avoided.

The utility model relates to a coupling energy supply system based on LNG and a fuel cell, a gas supply unit comprises an LNG storage tank and an LNG vaporizer which are connected through an LNG pipeline, the LNG vaporizer is connected with a downstream gas pipeline through a gas supply pipeline, a power generation unit comprises a cooling heat exchanger and the fuel cell, a cooling loop is arranged between the secondary side of the cooling heat exchanger and the fuel cell, and the fuel cell is connected with the cooling loop. A primary side inlet of the cooling heat exchanger is connected with the LNG storage tank through a BOG pipeline, a primary side outlet of the cooling heat exchanger is connected with a gas inlet of the fuel cell through a fuel pipeline, electric energy generated by the fuel cell is merged into a user electric power internal network, and the system has the advantages of being good in stability and high in safety.

The utility model provides an efficient depressurization device for an LNG storage tank, and relates to the technical field of LNG storage tanks, the efficient depressurization device for the LNG storage tank comprises a tank body, a supporting structure is arranged below the tank body, the tank body extends in the horizontal direction, pressure gauges are arranged at the two ends of the tank body respectively, a connecting pipe is fixedly arranged above the tank body, and the upper end of the connecting pipe is connected with a depressurization pipe; the upper end of the condensation pipe is connected with an input pipe, and the lower end of the condensation pipe is connected with an output pipe; a connecting pipe is arranged in the connecting pipe, a pressure reducing pipe is arranged in the connecting pipe, a through pipe is arranged below the pressure reducing pipe, the through pipe is inserted into the connecting pipe to connect the pressure reducing pipe and the connecting pipe, a control valve is arranged in the connecting pipe, and a sealing ring is arranged between the control valve and the through pipe. Pollution caused by interaction of gas and air in the storage tank is avoided, and by arranging a positioning column and a dismounting assembly, the depressurization pipe is convenient to dismount.

The utility model relates to the field of natural gas dehydration, and discloses a natural gas cold energy dehumidification system which comprises a dehumidification structure and a water storage buffer tank, a flow meter is arranged on a gas inlet pipe of a high-pressure natural gas pipeline, the dehumidification structure comprises a dehumidification box body communicated with the high-pressure natural gas pipeline, and a heat exchange pipeline is arranged in the dehumidification box body. Low-temperature flash steam circulates in the heat exchange pipeline, a flow control valve used for controlling the flow of the low-temperature flash steam is arranged on the heat exchange pipeline, the bottom of the dehumidification box communicates with a water storage buffer tank through a pipeline, and a drainage valve is arranged at the bottom of the water storage buffer tank. Natural gas in the high-pressure natural gas conveying pipeline is cooled through low-temperature flash steam guided out of the LNG storage tank, so that water vapor mixed in the natural gas is liquefied when meeting cold, collected condensate water is discharged in time, the dehumidification system can continuously and automatically work, the water vapor content in the natural gas is reduced, and the energy consumption is reduced. The dehumidification device has the advantages of simple structure, low cost and excellent dehumidification effect.

The utility model discloses a device for detecting the temperature of an inner tank of an LNG (Liquefied Natural Gas) storage tank in all directions, which relates to the technical field of LNG storage tank temperature detection and comprises a temperature sensing optical cable laid on the inner tank of the LNG storage tank and connected with a distributed optical fiber temperature detection system. The temperature sensing optical cable comprises an outer wall optical cable laid on the outer wall of the inner tank of the LNG storage tank and a bottom optical cable arranged at the bottom of the inner tank of the LNG storage tank. The temperature of the inner tank of the LNG storage tank is detected through the distributed optical fiber temperature detection system, 360-degree temperature detection is carried out on the outer wall of the inner tank of the LNG storage tank through the outer wall optical cable, temperature detection is carried out on the bottom of the inner tank through the bottom optical cable, the temperature monitoring range of the inner tank of the LNG storage tank is widened, and all-dimensional temperature detection on the inner tank of the LNG storage tank is completed. Only one optical cable inlet hole and one optical cable outlet hole need to be formed in the tank top, the laying requirement of the temperature sensing optical cable can be met, the number of holes formed in the tank top is reduced, and the risk is reduced.

The invention discloses an LNG anti-tumbling prediction method and device based on a GA-BP neural network algorithm, and the method comprises the steps: carrying out the simulation based on an LNG storage tank two-dimensional model, obtaining the size, diameter, initial density difference and critical density difference corresponding to the layering height of different storage tanks, and constructing a tumbling process data set; establishing an LNG storage tank rolling prediction model based on a GA-BP neural network algorithm, and training the LNG storage tank rolling prediction model by adopting the training set; the optimized and trained LNG storage tank rolling prediction model is adopted for rolling prediction, and the critical density difference is calculated according to the input values of the storage tank volume, diameter, initial density difference and layering height so as to judge whether the LNG storage tank is about to roll or not. The method can be used for predicting the critical density difference of the LNG storage tank so as to ensure safe operation of the LNG storage tank.

The invention discloses a gas cylinder heating and pressurizing and LNG cold energy utilization system and a control method thereof.The system comprises an LNG storage tank, a cooler, a gas supply mechanism and a booster pump, the cooler comprises a cooling shell, a first cooling pipe and a second cooling pipe, and the first cooling pipe and the second cooling pipe are arranged in the cooling shell; the gas supply mechanism comprises a vaporizer and a buffer tank, and a third heat dissipation pipe, a fourth heat dissipation pipe and a fifth heat dissipation pipe are arranged in the vaporizer. The system has the beneficial effects that by arranging the heat exchange channel and the booster pump, the temperature of low-temperature LNG in the LNG storage tank can be effectively increased, and then the gasification process of the low-temperature LNG is accelerated. The pressure in the LNG storage tank is always kept at the LNG saturation pressure, so that the pressure in the LNG storage tank can be always kept stable even if a vehicle runs; and meanwhile, the system provides cold energy for the refrigeration air conditioner through the second heat dissipation pipe in the cooler, cold energy recycling is achieved, and the energy utilization efficiency of the whole system is improved.

The utility model belongs to the technical field of liquefied natural gas storage equipment, and discloses an LNG storage tank supporting frame which comprises a base and an LNG storage tank body, the LNG storage tank body is arranged in a groove of the base, the top end of the base is fixedly connected with a fixing block, a sliding rod is slidably connected in a sliding groove of the fixing block, an abutting ring is fixedly arranged on the outer side of the sliding rod in a sleeved mode, and the abutting ring is fixedly connected with the LNG storage tank body. A first spring is arranged on the left side of the abutting ring in an abutting mode, a sliding ring is arranged at the other end of the first spring in an abutting mode, the sliding ring slides on the outer side of the sliding rod, a connecting disc is fixedly connected to the left side of the sliding rod, a shock pad is arranged on the left side of the connecting disc in an abutting mode, and the outer side of the LNG storage tank body is attached to the interior of the shock pad. The problems that an LNG storage tank body is poor in stability, potential safety hazards exist, due to the lack of a fixing mechanism, the LNG storage tank body is prone to inclining and being damaged, fuel leakage is further caused, and finally the serious consequence that the environment is polluted is caused are solved, and even serious safety accidents are possibly caused are solved.

The invention discloses a vehicle-mounted mobile device capable of being remotely controlled and recycling and emptying natural gas by using liquid nitrogen cold energy. The system comprises a liquid nitrogen storage tank, a centrifugal pump, a throttle valve, a plate-fin heat exchanger, a temperature controller and an LNG storage tank, carrying out liquefaction treatment on the vented natural gas by adopting low-temperature liquid nitrogen; liquid nitrogen stored in the liquid nitrogen storage tank is pressurized by the pump and enters the heat exchanger to exchange heat with recycled natural gas, the liquid nitrogen is discharged into air after losing cold energy, and the liquefied natural gas enters the LNG storage tank through the throttling valve to be temporarily stored and then can be injected into an LNG pipeline or directly sold. The process is simple, an expansion machine is not needed, the equipment investment cost is low, the size is small, and vehicle-mounted movement can be achieved; remote dynamic control can be realized, and workers do not need to stay beside the device for a long time; the pressure range of the recovered and vented natural gas comprises but is not limited to 0.2-4 MPa, the liquefaction efficiency is stable, and the minimum liquefaction rate is 98.2%; the device is suitable for gas compression stations and gas transmission stations which are small in emptying amount, large in gas pressure fluctuation range, scattered in gas source distribution, high in methane content and free of operations such as light hydrocarbon removal.

A liquefied natural gas (LNG) production facility includes gravity-based structures (GBSs) with process lines for liquefying natural gas. A GBS contains: tanks for each component of a mixed refrigerant, wherein a GBS process line includes a fractionating apparatus for mixed refrigerant component production from a broad fraction of light hydrocarbons; a stabilized gas condensate (SGC) storage tank; and a berth for offloading LNG and SGC into tankers. Each GBS contains an LNG storage tank. One tank per mixed refrigerant component from each GBS is connected by pipe to systems for preparing and compressing all process line refrigerants, thus forming a common component feed system. The SGC storage tank is connected by pipes to condensate-stabilizing apparatus for all process lines, thus forming a common system for storing and offloading SGC. The LNG storage tanks are interconnected by pipes, forming a common system for storing and offloading LNG.

The invention discloses an oversize LNG storage tank mixed medium precooling dynamic regulation and control system and method, and relates to the technical field of LNG storage tank precooling, and the system comprises a precooling medium supply module for providing two or more precooling media; the pre-cooling spraying distribution pipe network is arranged at the top of the inner tank of the LNG storage tank and is used for uniformly spraying a pre-cooling medium into the storage tank; the pre-cooling process control module is used for sequentially controlling the switching, proportioning and conveying rate of liquid nitrogen and LNG according to a preset stage; the thermal stress control and temperature difference balance subsystem is used for monitoring and adjusting the temperature difference of each area in the storage tank; the boil-off gas recovery module is used for collecting and treating natural gas boil-off gas caused by temperature drop in the pre-cooling process; the pre-cooling pre-safety control unit is used for executing air tightness detection, replacement, drying and cold brittleness pre-judgment operation before pre-cooling; a liquid nitrogen and LNG mixed medium pre-cooling scheme is adopted, and more efficient temperature reduction speed and uniformity can be achieved.

The invention relates to the technical field of LNG filling, and discloses an LNG storage tank pressure control system and method based on a fuzzy control algorithm, the system comprises an LNG storage tank, an LNG pump pool and an LNG immersed pump, the LNG immersed pump is arranged in the LNG pump pool, the LNG storage tank is connected with the LNG immersed pump, a liquid level sensor and pressure sensors are arranged on the LNG storage tank, and the pressure sensors are arranged at an inlet and an outlet of the LNG pump pool. The problem that in the prior art, the unloading efficiency is difficult to improve under the condition that liquid adding is not affected is solved.

The invention discloses a joint for connecting an LNG (Liquefied Natural Gas) storage tank and a side wall elevator, the joint for connecting the LNG storage tank and the side wall elevator comprises a storage tank wall embedded part and a first lug plate, the first lug plate is connected to the storage tank wall embedded part, and the two sides of the first lug plate are respectively connected with a first stiffening cover plate and a second stiffening cover plate; the end of the first stiffening cover plate and the end of the second stiffening cover plate are connected with a storage tank wall embedded part. The first lug plate is hinged to the second lug plate, a first stiffening rib, a second stiffening rib and a third stiffening rib are arranged on the second lug plate at intervals, the second lug plate is fixedly connected with a lug plate end plate, the lug plate end plate is arranged on the elevator frame steel beam, and an end plate stiffening rib is connected between the elevator frame steel beam and the lug plate end plate. The joint for connecting the LNG storage tank and the side wall elevator has the beneficial effects of being high in strength and structure stability, pin shaft connection has the rotating performance, accumulated energy caused by the settlement difference of the storage tank and an elevator foundation can be absorbed, and the overall structure is prevented from being collapsed and damaged.

The invention discloses a hydrogen liquefaction, liquid hydrogen storage and transportation and LNG receiving station integrated design system and method based on cold energy utilization, and belongs to the technical field of hydrogen liquefaction treatment systems. The system comprises an LNG receiving station, a hydrogen liquefaction treatment system and a liquid hydrogen storage and transportation system. The LNG receiving station comprises an LNG storage tank and a BOG condensation unit, and the BOG condensation unit condenses NG generated in the LNG storage tank into LNG through low-temperature hydrogen generated by the liquid hydrogen storage and transportation system. The hydrogen liquefaction treatment system precools hydrogen through LNG gasification cold energy in the LNG receiving station and the nitrogen refrigeration cycle system, and the nitrogen refrigeration cycle system cools nitrogen through the LNG gasification cold energy. According to the system and method, a large amount of LNG gasification cold energy in the LNG receiving station is fully utilized to achieve hydrogen liquefaction, meanwhile, low-temperature hydrogen generated in the liquid hydrogen storage and transportation system is fully utilized to achieve NG condensation, and therefore LNG and hydrogen energy industry chain optimization matching is achieved, and the investment and operation cost of the LNG receiving station, hydrogen liquefaction and liquid hydrogen storage and transportation factories is reduced.

A gear transmission and rotation amplification type device for reducing sloshing is arranged inside and located above a body of an LNG storage tank. The device includes a combination disc, a wheel set, an outer sleeve, an overhanging fan blade, ball screws, springs and a sloshing plate. The combination disc is connected with the sloshing plate below through the springs. The combination disc is fixed above an inner wall surface of the body of the LNG storage tank, while the sloshing plate is fitted but not fixedly connected with the inner wall surface of the body of the LNG storage tank. The wheel set, the outer sleeve, the overhanging fan blade and the ball screws are arranged between the combination disc and the sloshing plate and located below the liquid level in the LNG storage tank.

The invention relates to a high-Ni alloy flux-cored wire for 9% Ni steel welding, which is prepared by coating a flux core with a nickel-based steel strip, and the flux core comprises the following components in percentage by weight: 18.0-30.0% of metal nickel powder, 5.0-8.0% of metal chromium powder, 5.0-9.0% of metal molybdenum powder, 1-2% of metal tungsten powder, 20.0-30.0% of rutile, 1.0-3.0% of quartz, 2.0-5.0% of albite, 1.0-3.0% of potassium feldspar, 0.5-3.0% of mica, 1.0-4.0% of cryolite, 0.2-0.8% of self-made raw material and the balance of reduced iron powder and inevitable impurities. The flux-cored wire belongs to a hastelloy system and is particularly suitable for welding of horizontal position welding and vertical position welding of the marine LNG storage tank, the mechanical performance of cladding metal of the flux-cored wire can reach 50 J or above at the low-temperature impact of-196 DEG C, the tensile strength is larger than 700 MPa, and the flux-cored wire is excellent in crack resistance and comprehensive performance.

In order to solve the traceability problem of the LNG filling machine calibrating device, the utility model discloses a mass real flow calibration system for the LNG filling machine calibrating device, which is used for calibrating the LNG filling machine calibrating device. The system comprises an LNG filling machine, an LNG filling machine calibrating device and an LNG storage tank which are connected in sequence, and the LNG filling machine calibrating device comprises a calibrating mass flow meter used for detecting the accumulated mass flow value in a pipeline; a high-precision mass sensor is installed in the LNG storage tank and used for detecting the accumulated mass flow value of the LNG storage tank. By recording the accumulated mass flow value output by the calibration mass flowmeter and the accumulated mass flow value output by the high-precision mass sensor within the same time and comparing the accumulated mass flow value with the accumulated mass flow value, the error of the LNG filling machine calibration device can be determined.

The utility model relates to the technical field of liquefied natural gas (LNG) receiving stations, in particular to a system for mutually utilizing liquid nitrogen cold energy and boil-off gas (BOG) heat energy, which comprises a BOG direct output system, a BOG recondensation system and a liquid nitrogen system, the BOG direct output system comprises an LNG storage tank, the LNG storage tank is sequentially connected with a first BOG compressor and a first heat exchanger for providing a cold source by the liquid nitrogen system through a BOG pipeline, and the first heat exchanger is connected with a second BOG compressor through a BOG pipeline. The BOG outlet end of the first heat exchanger is communicated with a natural gas pipe network; the BOG recondensation system comprises a second BOG compressor, a second heat exchanger, a recondenser, a high-pressure pump and a first gasifier which are sequentially connected with the LNG storage tank through a BOG pipeline, the liquid nitrogen system provides a cold source through the second heat exchanger, the recondenser, the high-pressure pump and the first gasifier, and the outlet end of the first gasifier is communicated with a natural gas pipe network; and the in-tank low-pressure pump is connected with the re-condenser through a low-pressure output pipeline. The system is safe and reliable, energy stored by media of the system is mutually utilized, electricity charge is saved, noise is reduced, efficiency is improved, and compared with the prior art, the system has obvious advantages.

The present invention provides a gear-driven rotational amplification type anti-sloshing apparatus. The gear-driven rotational amplification type anti-sloshing apparatus is disposed within a tank body of an LNG storage tank and positioned at an upper portion thereof, and comprises: a composite disc, a wheel set, an outer sleeve, an outward-extending fan blade, a ball screw, a spring, and a slosh baffle plate; the composite disc is connected to the slosh baffle plate below the composite disc by means of the spring, the composite disc being fixed to an upper portion of an inner wall surface of the tank body of the LNG storage tank, the slosh baffle plate abutting the inner wall surface of the tank body of the LNG storage tank without being fixedly connected thereto, and the wheel set, the outer sleeve, the outward-extending fan blades, and the ball screw being arranged between the composite disc and the slosh baffle plate, and all being located below a liquid level in the LNG storage tank. When an earthquake occurs, the anti-sloshing apparatus of the present invention utilizes the rotational amplification effect thereof to efficiently dissipate energy, thereby reducing the impact of the earthquake on the structure of large LNG storage tanks, and improving the safety of said LNG storage tank structure.

The utility model provides an LNG (Liquefied Natural Gas) storage tank, which relates to the technical field of LNG storage, and comprises a tank body with a cavity and a heat conducting piece, and the heat conducting piece is arranged in the cavity so as to passively and automatically conduct heat of a high-temperature layer in the cavity to a low-temperature layer. The problems that extra heat is introduced to LNG in a storage tank and the effect of a heat insulation system is affected due to intervention of a stirring system in the prior art are solved, the stirring system is complex in structure, and the system is efficient, reliable, free of moving parts and energy loss and low in cost. The problem that LNG in the storage tank rolls over is thoroughly solved, the problems that equipment is inevitable to age and difficult to maintain due to the fact that the stirring system is in a starting state for a long time or in the repeated starting and stopping process are solved, in addition, the LNG in the storage tank operated and maintained through the system is more stable, the quality of the LNG is easier to maintain, and aging is reduced.

The utility model relates to a liquefied natural gas storage tank precooling mixed gas separation device in the technical field of gas separation. The liquefied natural gas storage tank precooling mixed gas separation device comprises a gas-liquid conveying system, a hydrate generation system, a cooling heat exchange system, a hydrate decomposition system, a separation and collection system and a data monitoring and collection system. The nano-bubble generator and the folded tubular reactor work cooperatively, nano-bubbles can be kept stable in a liquid carrier for a long time, high suction capacity and high generation efficiency can be guaranteed, natural gas and nitrogen mixed gas generated in the precooling process of the LNG storage tank is recycled at high efficiency and low cost, energy input is reduced, cost is reduced, and the production efficiency is improved. The resource waste is reduced, and the environmental pollution is reduced.

The invention discloses a manufacturing method of an LNG storage tank, the manufacturing method is used for manufacturing the LNG storage tank, the manufactured LNG storage tank comprises an inner lining layer and a shell layer, the outer side of the inner lining layer is coaxially sleeved with the shell layer, horn-shaped first through openings are formed in the axis positions of the two ends of the inner lining layer, and straight-barrel-shaped second through openings are formed in the axis positions of the two ends of the shell layer. According to the detachable and maintainable LNG storage tank, the shell layer and the lining layer which are separated are arranged and assembled with the mounting end and the reinforcing layer to form the detachable and maintainable LNG storage tank, and the problem that a gap exists between the lining and the shell layer, so that a combined structure is not firm is solved; the machining precision is improved in cooperation with welding equipment, the effect of facilitating assembly and later maintenance is achieved, the maintenance cost is greatly reduced, a protection structure is formed by a protection rod, an installation nut, a short shaft ring buckle and a cable piece, the structural connection strength of the shell layer is enhanced, the protection effect is provided, and the safety is greatly improved.