Cold energy recycling device for LNG (Liquefied Natural Gas) factory

Abstract

The utility model discloses an LNG (Liquefied Natural Gas) factory cold energy recycling device, which comprises a BOG (Boil Off Gas) incoming pipeline, a circulating water cooler, a BOG heat exchanger inlet circulating water pipeline I, a BOG heat exchanger outlet circulating water pipeline II, a BOG heat exchanger inlet circulating water pipeline II, a BOG heat exchanger outlet circulating water pipeline II, a BOG heat exchanger outlet circulating water pipeline III, a BOG heat exchanger outlet circulating water pipeline III and a BOG heat exchanger outlet circulating water pipeline III, the outer end of the first BOG heat exchanger inlet circulating water pipeline is connected with an installation pipe in a sealed mode, the installation pipe is installed on the outer side of the BOG heater, and meanwhile the outer side of the BOG heater is connected with a circulating water cooler in a sealed mode through a second BOG heat exchanger inlet circulating water pipeline. According to the cold energy recycling device for the LNG factory, cold energy can be effectively recycled, the cold energy can be effectively recycled without additionally arranging equipment on the basis of existing equipment, and the problem that the existing equipment is insufficient in heat exchange amount in summer is solved by utilizing the cold energy of BOG; and the operation stability efficiency of the compressor in the BOG recovery process is improved through heat generated by air cooling and water cooling equipment.

Description

Technical Field

[0001] The utility model relates to the technical field of cold energy recovery, in particular to a cold energy recovery and utilization device for an LNG plant. Background Art

[0002] As an important supplement to the domestic LNG market, LNG plants play a pivotal role in the natural gas market. BOG, as a by-product of LNG plants, has the advantages of low temperature (<-150°C) and simple composition (more than 80% methane, the rest is nitrogen). BOG is usually recycled and reused. LNG plant cold energy recovery refers to the use of liquefied natural gas (LNG) The cold energy released during the gasification process is converted into other forms of energy or used in a variety of fields. During the production, storage and transportation of LNG, LNG needs to undergo a phase change process from liquid to gas, and a large amount of cold energy will be released in this process. Through specific recovery technology, this cold energy can be effectively captured and converted into electricity, heat or other forms of energy, and the application range of LNG cold energy recovery technology is wide, including but not limited to low-temperature power generation, air separation, dry ice manufacturing, light hydrocarbon separation, ultra-low temperature freezing, seawater desalination and other fields;

[0003] In the "A Cold Energy Recovery and Utilization Device for LNG Gasification Station" with the patent publication CN219160129U, a cold energy recovery box is included, an LNG injection box is plugged into the upper side of the cold energy recovery box, a liquid inlet pipe is fixedly provided on the upper side of the LNG injection box, and a liquid guide pipe A, a liquid guide pipe B, and a liquid guide pipe C are arranged on the lower side of the LNG injection box from left to right, and a deicing mechanism is provided on the outer side of the liquid guide pipe A, the liquid guide pipe B, and the liquid guide pipe C, and a heat exchanger is provided at the bottom end of the liquid guide pipe A, the liquid guide pipe B, and the liquid guide pipe C. The cold energy recovery and utilization device for the LNG gasification station has the function of storing cold energy in branches during the use of LNG, and has a deicing mechanism inside to efficiently store cold energy;

[0004] When the above-mentioned cold energy recovery and utilization device recovers cold energy, because the recovery and utilization of BOG is mostly carried out by heating BOG and then pressurizing it for recovery by using air-temperature vaporizer, water-bath vaporizer or electric heater, a large amount of BOG cold energy is wasted, which will subsequently lead to a low utilization rate of cold energy recovery, and it is not convenient for the stable recovery and utilization of the cold energy recovery and utilization device in the later stage;

[0005] Therefore, we proposed that the cold energy recovery and utilization device of the LNG plant can solve the above problems well. Utility Model Content

[0006] The utility model aims to provide a cold energy recovery and utilization device for an LNG plant, so as to solve the problem raised in the above background technology that, in the current market, BOG recovery and utilization are mostly carried out by heating BOG in an air-temperature vaporizer, a water-bath vaporizer or an electric heater and then pressurizing and recovering BOG, thereby causing a large amount of waste of BOG cold energy, which subsequently leads to a low utilization rate of cold energy recovery and inconvenience for stable recovery and utilization of the cold energy recovery and utilization device in the later stage.

[0007] To achieve the above object, the utility model provides the following technical solutions: a cold energy recovery and utilization device for an LNG plant, comprising a BOG gas pipeline, the outer end of which is sealedly connected to a BOG heater, and the outer side of the BOG heater is sealedly connected to a BOG compressor through a BOG heat exchanger outlet BOG pipeline;

[0008] It also includes: a circulating water cooler, the left side of which is sealedly connected to the BOG heat exchanger inlet circulating water pipeline 1, and the outer end of the BOG heat exchanger inlet circulating water pipeline 1 is sealedly connected to the installation pipe, and the installation pipe is installed on the outside of the BOG heater, and at the same time, the outer side of the BOG heater is sealedly connected to the circulating water cooler through the BOG heat exchanger inlet circulating water pipeline 2, and the installation pipe has grooves at both ends inside and push rods are slidably installed, and the two push rods are symmetrically arranged about the vertical center line of the installation pipe, and the outer ends of the two push rods extend through and extend to the outside of both ends of the installation pipe.

[0009] Preferably, the mounting tube is provided with positioning plates at both ends thereof, and the two positioning plates are both semicircular in shape, and the inner sides of the two positioning plates are fittedly connected to the outer wall of the BOG heat exchanger inlet circulating water pipeline 1 through anti-skid pads. The two anti-skid pads can be used to increase the friction between the mounting tube and the BOG heat exchanger inlet circulating water pipeline 1, thereby preventing the BOG heat exchanger inlet circulating water pipeline 1 from loosening and falling off due to vibration during use.

[0010] Preferably, the outer sides of the two pressing rods are connected to rotating gears through rack meshing, and the outer sides of the two rotating gears are also connected to moving rods through rack meshing, and the two moving rods are slidably installed at the two ends of the interior of the mounting tube, and the inner ends of the two moving rods are connected to positioning plates through screws, and the interiors of the two rotating gears are grooved with first torsion springs, and the two first torsion springs have the same structure, and the outer ends of the two first torsion springs are connected to the inner side wall of the mounting tube, and the two rotating gears are rotatably installed at the two ends of the interior of the mounting tube, and the positions of the two rotating gears after rotation can be elastically reset by the elastic force of the two first torsion springs themselves.

[0011] Preferably, the BOG heater has a feed pipe sealedly installed in the upper left groove, and the feed pipe is sealed and connected to two spray heads through a hose, and the bottom groove of the BOG heater is provided with a discharge pipe, and the BOG heater has spray heads rotatably installed on both sides of the top, and a drive motor is installed in the top left groove of the BOG heater, the output end of the drive motor is connected to a worm, and the worm is rotatably installed on the inner side of the top of the BOG heater, and worm wheels are meshedly connected on both sides of the worm, and both worm wheels are rotatably installed on both sides of the top of the BOG heater, and the half gears connected to the output ends of the two worm wheels can be driven to rotate while the worm rotates, and then the transmission gears meshedly connected on the outer sides of the two half gears can be driven to rotate at the same time, so that the two spray heads can be driven to swing back and forth for spraying.

[0012] Preferably, half gears are connected through the outer sides of the output ends of the two worm gears, and the outer sides of the two half gears are meshingly connected with transmission gears, and the output ends of the two transmission gears are rotationally connected to the output ends of the spray heads through second torsion springs, and the positions of the two spray heads after rotation and swinging can be elastically reset by the elastic force of the two second torsion springs themselves, so that the coolant delivered by the two spray heads can be evenly sprayed to the inner ends of the BOG heater.

[0013] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0014] (1) Cold energy can be effectively recycled and utilized. Effective recycling of cold energy can be achieved on the basis of existing equipment without adding new equipment. The cold energy of BOG can be used to solve the problem of insufficient heat exchange of existing equipment in summer. The heat generated by air cooling and water cooling equipment can be used to improve the stable operation efficiency of the compressor during BOG recovery.

[0015] (2) A mounting pipe is installed by slotting the left side of the bottom of the BOG heater, and then positioning plates are respectively slotted at both ends of the mounting pipe, and then anti-skid pads are provided on the inner sides of the two positioning plates. The two anti-skid pads can increase the friction between the BOG heater and the BOG heat exchanger inlet circulating water pipeline 1, thereby preventing the BOG heat exchanger inlet circulating water pipeline 1 from loosening and falling off during use, thereby improving the use stability of the BOG heat exchanger inlet circulating water pipeline 1;

[0016] (3) Furthermore, when it is necessary to quickly disassemble and replace the BOG heat exchanger inlet circulating water pipeline 1, the two pressing rods are manually pressed to retract and move, and the racks arranged on the outer sides of the two pressing rods will simultaneously drive the two rotating gears to rotate, and then the two rotating gears will simultaneously drive the positioning plates connected to the inner ends of the two moving rods to retract and move, and then the two positioning plates can be separated from the BOG heat exchanger inlet circulating water pipeline 1, and then the BOG heat exchanger inlet circulating water pipeline 1 can be quickly disassembled and replaced, and finally the positions of the two rotating gears after rotation can be elastically reset by using the elastic force of the two first torsion springs themselves, which is more practical and more time-saving and labor-saving;

[0017] (4) A feed pipe is installed through a slotted seal on the left outer side of the BOG heater, and then the external coolant can be connected to two spray heads through a hose seal, and spray heads are installed on both sides of the top of the BOG heater. The coolant can be sprayed into the interior of the BOG heater through the two spray heads for cooling, thereby improving the heat exchange efficiency of the BOG heater;

[0018] (5) Furthermore, a driving motor is provided in a slot inside the left side of the BOG heater, and a worm is connected to the output end of the driving motor. The driving motor can drive the worm wheels meshing on both sides of the worm to rotate while the driving motor rotates. Then, the half gears connected to the outer sides of the two worm wheel output ends can also drive the two spray heads connected to the output ends of the transmission gears to swing at the same time. Finally, the elastic force of the two second torsion springs can be used to elastically reset the positions of the two swung spray heads, thereby driving the two spray heads to evenly spray the coolant to both sides of the interior of the BOG heater, thereby improving the cooling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the process of the BOG cold energy recovery and utilization device of the utility model;

[0020] Figure 2 This is a schematic diagram of the side section structure of the installation pipe of the utility model;

[0021] Figure 3 For this utility model Figure 2 The enlarged structural diagram at A in the middle;

[0022] Figure 4 This is a schematic diagram of the partial three-dimensional structure of the installation pipe and the rotating gear of the utility model;

[0023] Figure 5 This is a schematic diagram of the main cross-sectional structure of the BOG heater of the utility model;

[0024] Figure 6 For this utility model Figure 5 The enlarged structural diagram at B in the middle;

[0025] Figure 7 It is a partial three-dimensional structural schematic diagram of the worm gear, half gear and transmission gear of the utility model.

[0026] In the figure: 1. BOG gas pipeline; 2. BOG heater; 3. BOG pipeline at BOG heat exchanger outlet; 4. BOG compressor; 5. BOG heat exchanger inlet circulating water pipeline 1; 6. BOG heat exchanger inlet circulating water pipeline 2; 7. Circulating water cooler; 8. Positioning plate; 9. Anti-skid pad; 10. Pressing rod; 11. Rotating gear; 12. Moving rod; 13. First torsion spring; 14. Feed pipe; 15. Worm; 16. Sprinkler head; 17. Worm wheel; 18. Transmission gear; 19. Second torsion spring; 20. Half gear. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] This utility provides the following technical solutions:

[0029] Embodiment 1, in order to solve the problem that the existing recovery equipment performs pressurized recovery after heating, thereby causing a large amount of waste of BOG cold energy, discloses:

[0030] The BOG gas pipeline 1 has a BOG heater 2 sealed at its outer end, and the outer side of the BOG heater 2 is sealedly connected to a BOG compressor 4 through a BOG heat exchanger outlet BOG pipeline 3;

[0031] It also includes: a circulating water cooler 7, the left side of which is sealedly connected to a BOG heat exchanger inlet circulating water pipeline 1 5, and the outer end of the BOG heat exchanger inlet circulating water pipeline 1 5 is sealedly connected to a mounting pipe, and the mounting pipe is mounted on the outside of the BOG heater 2, and at the same time, the outer side of the BOG heater 2 is sealedly connected to the circulating water cooler 7 through the BOG heat exchanger inlet circulating water pipeline 2 6, and the mounting pipe has grooves at both ends inside and a pressing rod 10 is slidably installed therethrough, and the two pressing rods 10 are symmetrically arranged about the vertical center line of the mounting pipe, and the outer ends of the two pressing rods 10 extend through and extend to the outside of both ends of the mounting pipe.

[0032] like Figure 1As shown in the figure, large equipment such as mixed refrigerant compressors, feed gas compressors, and regeneration gas compressors in LNG plants are generally equipped with air cooling or water cooling equipment according to the location of the plant. The air cooler is cooled by adding spray equipment to utilize the cold energy generated during the BOG recovery process; a new hot water exchange pipeline is added to the water cooling equipment to exchange heat with the BOG heat exchanger, thereby achieving the purpose of recovering BOG cold energy and cooling the water cooler.

[0033] Embodiment 2 is different from Embodiment 1 in that the installed BOG heat exchanger inlet circulating water pipeline 1 5 can be quickly disassembled and replaced, and the following is disclosed:

[0034] The mounting tube has positioning plates 8 at both ends thereof, and the two positioning plates 8 are semicircular in shape, and the inner sides of the two positioning plates 8 are connected to the outer wall of the BOG heat exchanger inlet circulating water pipeline 5 through anti-slip pads 9, the outer sides of the two pressing rods 10 are connected to the rotating gears 11 through rack meshing, and the outer sides of the two rotating gears 11 are also connected to the moving rods 12 through rack meshing, and the two moving rods 12 are slidably installed at the two ends of the inner part of the mounting tube, and the inner ends of the two moving rods 12 are connected to the positioning plates 8 through screws, the interiors of the two rotating gears 11 are slotted with first torsion springs 13, and the structures of the two first torsion springs 13 are the same, and the outer ends of the two first torsion springs 13 are connected to the inner wall of the mounting tube, and the two rotating gears 11 are rotatably installed at the two ends of the inner part of the mounting tube.

[0035] like Figure 1-Figure 4 As shown, when it is necessary to quickly disassemble and replace the BOG heat exchanger inlet circulating water pipeline 5, it is only necessary to manually press the two pressing rods 10 to retract and move them, and then the racks arranged on the outer sides of the two pressing rods 10 will simultaneously drive the two rotating gears 11 to rotate, and then the two rotating gears 11 will also simultaneously drive the positioning plates 8 connected to the inner ends of the two moving rods 12 to retract and move, thereby realizing the BOG heat exchanger inlet circulating water pipeline 5 to be quickly disassembled and assembled, and then the elastic force of the two first torsion springs 13 can be used to elastically reset the positions of the two rotating gears 11 after rotation, so that the two positioning plates 8 can be driven to clamp and position the outer side wall of the BOG heat exchanger inlet circulating water pipeline 5 through the anti-slip pad 9, so as to avoid the BOG heat exchanger inlet circulating water pipeline 5 from loosening and falling off due to vibration during use in the later stage, which is more practical and saves time and effort.

[0036] Embodiment 3 is different from Embodiment 2 in that the external coolant can be evenly sprayed to the two ends of the BOG heater 2 through two spray heads 16, thereby solving the problem of insufficient heat exchange capacity of the existing equipment in summer.

[0037] The BOG heater 2 has a feed pipe 14 sealedly installed in the upper left groove, and the feed pipe 14 is sealed and connected to two spray heads 16 through a hose. At the same time, the bottom groove of the BOG heater 2 is provided with a discharge pipe. The BOG heater 2 has spray heads 16 rotatably installed on both sides of the top, and a drive motor is installed in the left groove of the top of the BOG heater 2. The output end of the drive motor is connected to a worm 15, and the worm 15 is rotatably installed on the inner side of the top of the BOG heater 2, and the two sides of the worm 15 are meshedly connected with worm wheels 17, and the two worm wheels 17 are rotatably installed on both sides of the top of the BOG heater 2. The outer sides of the output ends of the two worm wheels 17 are penetrated and connected, and the outer sides of the two half gears 20 are meshed and connected with transmission gears 18, and the output ends of the two transmission gears 18 are rotatably connected to the output ends of the spray heads 16 through second torsion springs 19.

[0038] like Figure 1-Figure 7 As shown, when the BOG heater 2 is working, the external coolant is sealed and transported to the two spray heads 16 through the feed pipe 14 for spraying and cooling, and then the driving motor is started to drive the worm gears 17 meshingly connected on both sides of the worm 15 to rotate. At this time, the half gears 20 connected to the output ends of the two worm gears 17 will simultaneously drive the transmission gears 18 meshingly connected on the outer sides thereof to rotate, and then the spray heads 16 connected to the output ends of the two transmission gears 18 will reciprocate left and right through the second torsion spring 19, and then the coolant can be evenly sprayed to both sides of the interior of the BOG heater 2 through the two spray heads 16, so as to improve the heat exchange efficiency of the BOG heater 2.

[0039] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in the field. Although the present invention is described in detail with reference to the aforementioned embodiments, it is still possible for technical personnel in the field to modify the technical solutions described in the aforementioned embodiments, or to replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A cold energy recovery and utilization device for an LNG plant, comprising a BOG gas pipeline (1), the outer end of which is sealedly connected to a BOG heater (2), and the outer side of the BOG heater (2) is sealedly connected to a BOG compressor (4) through a BOG heat exchanger outlet BOG pipeline (3); It is characterized in that Also includes: A circulating water cooler (7), the left side of which is sealedly connected to the BOG heat exchanger inlet circulating water pipeline 1 (5), and the outer end of the BOG heat exchanger inlet circulating water pipeline 1 (5) is sealedly connected to a mounting pipe, and the mounting pipe is mounted on the outside of the BOG heater (2), and the outside of the BOG heater (2) is sealedly connected to the circulating water cooler (7) through the BOG heat exchanger inlet circulating water pipeline 2 (6); The mounting tube has grooves at both ends thereof through which pressing rods (10) are slidably mounted, and the two pressing rods (10) are symmetrically arranged about the vertical center line of the mounting tube, and the outer ends of the two pressing rods (10) extend through and extend to the outside of both ends of the mounting tube.

2. The cold energy recovery and utilization device of an LNG plant according to claim 1, characterized in that: The installation pipe has positioning plates (8) at both ends thereof, and the two positioning plates (8) are both semicircular in shape, and the inner sides of the two positioning plates (8) are connected to the outer side wall of the BOG heat exchanger inlet circulating water pipeline 1 (5) through anti-slip pads (9).

3. The cold energy recovery and utilization device of an LNG plant according to claim 2, characterized in that: The outer sides of the two pressing rods (10) are connected to the rotating gears (11) through rack meshing, and the outer sides of the two rotating gears (11) are also connected to the moving rods (12) through rack meshing, and the two moving rods (12) are slidably installed at the two ends of the interior of the installation tube, and the inner ends of the two moving rods (12) are connected to the positioning plates (8) through screws.

4. The cold energy recovery and utilization device of an LNG plant according to claim 3, characterized in that: The interiors of the two rotating gears (11) are both grooved with first torsion springs (13), and the two first torsion springs (13) have the same structure. The outer ends of the two first torsion springs (13) are connected to the inner side wall of the mounting tube, and the two rotating gears (11) are both rotatably mounted at both ends of the interior of the mounting tube.

5. The cold energy recovery and utilization device of an LNG plant according to claim 1, characterized in that: The BOG heater (2) has a feed pipe (14) installed in a sealed groove on the upper left side thereof, and the feed pipe (14) is sealedly connected to two spray heads (16) via a hose, and a discharge pipe is provided in a groove at the bottom of the BOG heater (2).

6. The cold energy recovery and utilization device of an LNG plant according to claim 5, characterized in that: The BOG heater (2) has a spray head (16) rotatably mounted on both sides of the top, and a driving motor is mounted in a slot on the left side of the top of the BOG heater (2), the output end of the driving motor is connected to a worm (15), and the worm (15) is rotatably mounted on the inner side of the top of the BOG heater (2), and worm wheels (17) are meshedly connected on both sides of the worm (15), and the two worm wheels (17) are rotatably mounted on both sides of the top of the BOG heater (2).

7. The cold energy recovery and utilization device of an LNG plant according to claim 6, characterized in that: The outer sides of the output ends of the two worm gears (17) are both penetrated and connected with half gears (20), and the outer sides of the two half gears (20) are both meshed and connected with transmission gears (18), and the output ends of the two transmission gears (18) are rotationally connected to the output end of the sprinkler head (16) through a second torsion spring (19).

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