CN114542427A - Zero suction pressure head cryogenic liquid pump - Google Patents
Zero suction pressure head cryogenic liquid pump Download PDFInfo
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- CN114542427A CN114542427A CN202210440750.5A CN202210440750A CN114542427A CN 114542427 A CN114542427 A CN 114542427A CN 202210440750 A CN202210440750 A CN 202210440750A CN 114542427 A CN114542427 A CN 114542427A
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B37/00—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00
- F04B37/10—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for special use
- F04B37/18—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for special use for specific elastic fluids
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B25/00—Multi-stage pumps
- F04B25/005—Multi-stage pumps with two cylinders
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B39/00—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00
- F04B39/0005—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00 adaptations of pistons
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B39/00—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00
- F04B39/10—Adaptations or arrangements of distribution members
- F04B39/102—Adaptations or arrangements of distribution members the members being disc valves
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B9/00—Piston machines or pumps characterised by the driving or driven means to or from their working members
- F04B9/08—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid
- F04B9/10—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid
- F04B9/109—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid having plural pumping chambers
- F04B9/1095—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being liquid having plural pumping chambers having two or more pumping chambers in series
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C13/00—Details of vessels or of the filling or discharging of vessels
- F17C13/005—Details of vessels or of the filling or discharging of vessels for medium-size and small storage vessels not under pressure
- F17C13/006—Details of vessels or of the filling or discharging of vessels for medium-size and small storage vessels not under pressure for Dewar vessels or cryostats
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C13/00—Details of vessels or of the filling or discharging of vessels
- F17C13/06—Closures, e.g. cap, breakable member
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C3/00—Vessels not under pressure
- F17C3/02—Vessels not under pressure with provision for thermal insulation
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C3/00—Vessels not under pressure
- F17C3/02—Vessels not under pressure with provision for thermal insulation
- F17C3/08—Vessels not under pressure with provision for thermal insulation by vacuum spaces, e.g. Dewar flask
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B21/00—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant
- G01B21/02—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring length, width, or thickness
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2221/00—Handled fluid, in particular type of fluid
- F17C2221/01—Pure fluids
- F17C2221/011—Oxygen
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2221/00—Handled fluid, in particular type of fluid
- F17C2221/01—Pure fluids
- F17C2221/012—Hydrogen
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2221/00—Handled fluid, in particular type of fluid
- F17C2221/03—Mixtures
- F17C2221/032—Hydrocarbons
- F17C2221/033—Methane, e.g. natural gas, CNG, LNG, GNL, GNC, PLNG
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
- F17C2227/00—Transfer of fluids, i.e. method or means for transferring the fluid; Heat exchange with the fluid
- F17C2227/01—Propulsion of the fluid
- F17C2227/0128—Propulsion of the fluid with pumps or compressors
- F17C2227/0135—Pumps
- F17C2227/0142—Pumps with specified pump type, e.g. piston or impulsive type
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/32—Hydrogen storage
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- General Physics & Mathematics (AREA)
- Reciprocating Pumps (AREA)
Abstract
The invention discloses a zero-suction pressure head low-temperature liquid pump which comprises a displacement sensing mechanism, a double-acting hydraulic cylinder and a supercharging mechanism, wherein the displacement sensing mechanism is fixedly connected with a piston arranged in the double-acting hydraulic cylinder through a hollow connecting rod; the lower part of the double-acting hydraulic cylinder is fixedly arranged on the low-temperature liquid storage tank and is isolated from low-temperature liquid in the low-temperature liquid storage tank through a heat insulation isolation cylinder; the supercharging mechanism is hermetically and fixedly connected to the lower end of the heat insulation isolation cylinder and is fixedly connected with a piston rod in the double-acting hydraulic cylinder through a piston head arranged in the supercharging mechanism; a liquid outlet arranged on the supercharging mechanism is connected with a liquid outlet arranged on the low-temperature liquid storage tank through a liquid discharge pipeline; the invention ensures that the suction pressure head is always kept in a zero pressure state by arranging the supercharging mechanism, thereby ensuring the long-term effective use of piston sealing in an ultralow temperature working environment; through setting up displacement sensing mechanism, can the position of accurate control piston, and then the discharge flow of accurate control cryogenic liquids to greatly reduced the probability that the piston hit the jar.
Description
Technical Field
The invention relates to the technical field of cryogenic liquid pumps, in particular to a cryogenic liquid pump with a zero suction pressure head.
Background
In the petroleum, air separation and chemical industry, low-temperature liquid pumps are often adopted in the transportation process of low-temperature liquid such as liquid hydrogen, liquid oxygen, liquefied natural gas and the like, and can convey and pressurize the low-temperature liquid;
the reciprocating low-temp liquid pump is similar to reciprocating compressor in working principle, and is a positive-displacement compression machine, and its piston (plunger) can be reciprocated in working cavity of hydraulic cylinder to make the volume of working cavity produce periodic change so as to implement the whole process of liquid-suction, compression and liquid-discharge.
However, in the prior art, there are two problems with the use of reciprocating cryogenic liquid pumps:
firstly, according to the principle that a reciprocating type cryogenic liquid pump sucks cryogenic liquid, in order to keep the pump sucking the sent liquid normally, the required suction pressure head is generally a net positive suction pressure head (NPSH), namely when the volume of a pump cylinder is increased by the movement of a piston, the pressure is reduced, when the pressure of the liquid in an inlet pipe is larger than the pressure in the pump cylinder, a suction valve is opened, and the liquid flows into the pump cylinder; however, in the process, as the working environment of the cryogenic liquid pump is generally between-253 ℃ and-180 ℃, the piston sealing is often a severe test for sucking cryogenic liquid by the reciprocating motion of the piston;
secondly, in a common compound cryogenic liquid pump, no matter a normal temperature power part adopts a crank link mechanism directly driven by a motor or a remote drive, the precision of the discharge flow of cryogenic liquid is not high, and the problem of cylinder collision is often caused by incapability of controlling the stroke when the remote drive is adopted.
In view of the above, it is desirable to provide a cryogenic liquid pump with zero suction head and high accuracy.
Disclosure of Invention
Aiming at the problems, the invention provides a low-temperature liquid pump with zero suction pressure head, which adopts the following technical scheme:
a zero suction pressure head low-temperature liquid pump comprises a displacement sensing mechanism, a double-acting hydraulic cylinder and a supercharging mechanism, wherein the displacement sensing mechanism is fixedly connected with a piston arranged in the double-acting hydraulic cylinder through a hollow connecting rod; the lower part of the double-acting hydraulic cylinder is fixedly arranged on the low-temperature liquid storage tank and is isolated from low-temperature liquid in the low-temperature liquid storage tank through a heat insulation isolation cylinder; the supercharging mechanism is hermetically and fixedly connected to the lower end of the heat insulation isolation cylinder and is fixedly connected with a piston rod in the double-acting hydraulic cylinder through a piston head arranged in the supercharging mechanism; the liquid outlet that the last liquid outlet that sets up of booster mechanism passes through the leakage fluid dram that sets up on drain line and the low temperature liquid storage pot and is connected for discharge low temperature liquid.
Further, the displacement sensing mechanism further includes: the displacement sensor is fixed on the mounting frame, and the displacement detection rod is inserted into the mounting frame; the magnetic ring and the hollow connecting rod are both slidably sleeved on the displacement detection rod, and the lower end of the magnetic ring is fixedly connected with the upper end of the hollow connecting rod; the mounting rack is fixedly mounted at the upper end of the double-acting hydraulic cylinder.
Further, the double acting hydraulic cylinder further comprises: the upper end of the cylinder body I is fixedly installed with the mounting frame; the upper end and the lower end of the piston are respectively fixedly connected with the hollow connecting rod and the piston rod.
Furthermore, the piston is at least provided with an anti-collision pressure relief valve, the anti-collision pressure relief valve comprises a valve cavity arranged on the piston and a floating valve body arranged in the valve cavity in a floating mode, and the length of the floating valve body is larger than the height of the piston.
Furthermore, the floating valve body is provided with a sealing surface matched with the valve cavity, a pressure relief groove and a push rod for protecting the piston and the cylinder body.
Further, the booster mechanism still includes: the second cylinder body is fixedly connected with the lower end of the heat insulation isolation cylinder in a sealing way; the piston rod penetrates through the second cylinder body in a sliding mode and is fixedly connected with the piston head; the lower end of the cylinder body II is provided with a low-temperature liquid inlet and a low-temperature liquid outlet; a cylinder body III is fixedly arranged at the lower end of the cylinder body II; the middle lower part of the cylinder body III is provided with an open type piston cavity, and the upper part of the cylinder body III is at least provided with a suction channel communicated with the piston cavity; the suction channel is communicated with a low-temperature liquid inlet at the lower end of the cylinder body II; the check valve plate is arranged between each suction passage and the low-temperature liquid inlet and used for ensuring that the low-temperature liquid flows into the second cylinder body from the open piston cavity of the third cylinder body in a one-way mode.
Furthermore, a pressurizing piston is arranged in an open piston cavity of the cylinder III and is fixedly connected with the piston head through a pull rod which penetrates through the cylinder III in a sliding manner; primary liquid inlets are uniformly distributed on the pressurizing piston; the valve plate is characterized in that a limiting block used for limiting the position of the valve plate is arranged on the pull rod, and a valve plate (409) used for sealing the primary liquid inlet when the pressurizing piston moves upwards along with the pull rod is arranged on the limiting block.
Further, the part of the piston rod, which is positioned in the heat insulation isolation cylinder, is provided with a transmission mechanism for reducing heat transfer loss generated when the piston rod moves up and down.
Further, the transmission mechanism comprises a special-shaped rack, a gear assembly, a second bevel gear, a lead screw, a push-pull rod and a sliding block; the upper end of the special-shaped rack is fixedly connected with the piston rod; the gear assembly is formed by fixedly connecting a straight gear and a bevel gear together with the axis and is rotatably connected to the inner wall of the heat insulation isolation cylinder, and the straight gear is meshed with the special-shaped rack; the screw rod is rotatably arranged in the heat insulation isolation cylinder through a support frame and a bearing and is positioned on the same axis with the piston rod; a heat insulation sealing ring is arranged between the upper end of the screw rod and the heat insulation isolation cylinder; the screw rod is fixedly connected with a second bevel gear coaxially, and the second bevel gear is meshed with the first bevel gear; the sliding block is matched with the lead screw and ascends and descends along with the positive and negative rotation of the lead screw under the guiding action of the heat insulation isolation cylinder; a hollow push-pull rod is arranged outside the lead screw and is fixedly connected with the lower end of the sliding block; the lower end of the push-pull rod is fixedly connected with a piston rod positioned in the supercharging mechanism.
Further, the low temperature liquid storage tank still includes: the tank comprises a tank body, a sealing cover and a heat insulation isolation cylinder supporting frame, wherein the top of the tank body is hermetically connected with the sealing cover; the upper end of the sealing cover is fixedly connected with the double-acting hydraulic cylinder, a through hole is formed in the center of the sealing cover, and the heat-insulating isolation cylinder is fixedly arranged in the through hole and supported and reinforced by a heat-insulating isolation cylinder supporting frame arranged at the bottom of the sealing cover; the tank body is provided with a liquid inlet, an air return port and a vacuumizing connector, and the sealing cover is provided with a vent and a sewage outlet.
Due to the adoption of the technical scheme, the invention has the following advantages:
1. according to the invention, by arranging the pressurization mechanism, the low-temperature liquid firstly enters the cylinder body III through the pressurization piston and the valve plate under the condition of no negative pressure, and then enters the cylinder body II through the suction channel under the condition of sealing the primary liquid inlet, so that the suction pressure head is always kept in a zero-pressure state, the problem that the piston seal cannot be effectively used for a long time under the ultralow-temperature working environment when the suction pressure head of the conventional reciprocating type low-temperature liquid pump is a net positive suction pressure head (NPSH) is solved, and the working efficiency and the service life of the low-temperature liquid pump are effectively ensured.
2. According to the invention, the displacement sensing mechanism is arranged on the double-acting hydraulic cylinder, so that the position of the piston can be accurately controlled under the condition of being matched with an external electric control device, the discharge flow of the low-temperature liquid can be accurately controlled, and the probability of the piston hitting the cylinder is greatly reduced.
3. According to the invention, the anti-collision pressure relief valve is arranged on the piston of the double-acting hydraulic cylinder, so that the problem that the piston hits the cylinder can be further avoided when the displacement sensing mechanism fails or the set displacement parameter is not accurate.
4. According to the invention, the part of the piston rod, which is positioned in the heat insulation isolation cylinder, is set as the transmission mechanism, so that the piston rod connected with the piston head is always positioned in the pressurization mechanism in the up-and-down movement process, the problem that the piston rod absorbs external heat to cause large evaporation of low-temperature liquid in the conventional reciprocating type low-temperature liquid pump because the piston rod frequently enters and exits between the normal-temperature power component and the cold-end pump head is avoided, and the environmental pollution and the storage cost are effectively reduced.
Drawings
Fig. 1 is a schematic view of the overall structure of embodiment 1 of the present invention.
Fig. 2 is a schematic structural diagram of the displacement sensing mechanism of the present invention.
Fig. 3 is a schematic structural view of a double-acting hydraulic cylinder of the present invention.
Fig. 4 is a schematic view of the structure of the piston in the double acting hydraulic cylinder of the present invention.
Fig. 5-6 are schematic structural diagrams of the anti-collision pressure relief valve of the invention.
FIG. 7 is a schematic view of a cryogenic liquid storage tank according to the present invention.
Fig. 8 is a schematic view of the pressurizing mechanism of the present invention.
Fig. 9 is a schematic structural diagram of a cryogenic liquid temporary storage tank according to the present invention.
Fig. 10 is a schematic view of the overall structure of embodiment 2 of the present invention.
Fig. 11 is a partially enlarged view of a portion a of fig. 10 according to the present invention.
Fig. 12, 16 and 17 are schematic views of the assembly structure of the transmission mechanism of the invention.
Fig. 13 is a partially enlarged view of the portion B in fig. 12 according to the present invention.
Fig. 14 is a partially enlarged view of the structure at C in fig. 12 according to the present invention.
Fig. 15 is a schematic structural view of the transmission mechanism of the present invention.
Reference numerals: 1-a displacement sensing mechanism; 2-double acting hydraulic cylinder; 3-a low-temperature liquid storage tank; 4-a supercharging mechanism; 5-a transmission mechanism; 101-a displacement sensor; 102-a mounting frame; 103-a magnetic ring; 104-hollow connecting rod; 105-a displacement detection rod; 201-cylinder one; 202-a piston; 203-a piston rod; 204-a thermally insulating barrier cylinder; 301-tank body; 302-a sealing cover; 303-heat insulation isolation cylinder support frame; 304-a liquid inlet; 305-a return air port; 306-a vent; 307-a liquid discharge port; 308-a sewage draining outlet; 401-cylinder two; 402-a piston head; 403-a suction channel; 404-check valve plate; 405-a liquid outlet; 406-a drain line; 407-a pull rod; 408-cylinder III; 409-a valve plate; 410-a booster piston; 411-cryogenic liquid inlet; 412-open piston cavity; 413-a limiting block; 501-special-shaped racks; 502-a gear assembly; 5021, a straight gear; 5022, a first bevel gear; 503-bevel gear two; 504-lead screw; 505-a push-pull rod; 506-a slide block; 2021-anti-collision relief valve; 2021 a-floating valve body; 2021 b-sealing face; 2021 c-pressure relief groove; 2021 d-push rod; 3011-evacuation interface; 4101-primary liquid inlet.
Detailed Description
The technical scheme of the invention is further specifically described by the following embodiments and the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in many ways other than those described herein, and it will be apparent to those of ordinary skill in the art that similar modifications can be made without departing from the spirit of the invention, and it is therefore intended that the invention not be limited to the specific embodiments disclosed below.
In the description of the present invention, it should be noted that the terms "upper", "lower", "in", "out", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships conventionally arranged when products of the present invention are used, and are only used for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements referred to must have specific orientations, be constructed in specific orientations, and operated, and thus, should not be construed as limiting the present invention.
Example 1:
as shown in fig. 1-3 and 8-9, a zero suction head cryogenic liquid pump comprises a displacement sensing mechanism 1, a double-acting hydraulic cylinder 2 and a supercharging mechanism 4, wherein the displacement sensing mechanism 1 is fixedly connected with a piston 202 arranged in the double-acting hydraulic cylinder 2 through a hollow connecting rod 104; the lower part of the double-acting hydraulic cylinder 2 is fixedly arranged on the low-temperature liquid storage tank 3 and is isolated from the low-temperature liquid in the low-temperature liquid storage tank 3 through a heat insulation isolation cylinder 204; the supercharging mechanism 4 is hermetically and fixedly connected to the lower end of the heat insulation isolation cylinder 204 and is fixedly connected with a piston rod 203 inside the double-acting hydraulic cylinder 2 through a piston head 402 arranged inside; the liquid outlet 405 arranged on the pressurization mechanism 4 is connected with the liquid outlet 307 arranged on the low-temperature liquid storage tank 3 through a liquid outlet pipeline 406, and is used for discharging the low-temperature liquid.
Specifically, as a preferable aspect of the present embodiment, the displacement sensing mechanism 1 further includes: the displacement sensor 101 is fixed on the mounting frame 102, and the displacement detection rod 105 is inserted into the mounting frame 102; the magnetic ring 103 and the hollow connecting rod 104 are both slidably sleeved on the displacement detection rod 105, and the lower end of the magnetic ring 103 is fixedly connected with the upper end of the hollow connecting rod 104; the mounting frame 102 is fixedly arranged at the upper end of the double-acting hydraulic cylinder 2; the double-acting hydraulic cylinder 2 further comprises: the piston 202 is slidably arranged in the cylinder body I201, and the upper end of the cylinder body I201 is fixedly arranged with the mounting frame 102; the upper end and the lower end of the piston 202 are respectively fixedly connected with the hollow connecting rod 104 and the piston rod 203; the upper end and the lower end of the first cylinder body 201 are provided with an oil inlet and an oil outlet.
When the piston 202 moves up and down under the action of hydraulic oil, the hollow connecting rod 104 and the magnetic ring 103 are driven to move up and down along the displacement detection rod 105, the displacement sensor 101 converts mechanical displacement into resistance or voltage which is linear or in any function relation with the mechanical displacement through a potentiometer element and feeds the resistance or voltage back to an external electric control device in real time, and the electric control device accurately controls the displacement of the piston 202 according to real-time data fed back by the displacement sensor 101 so as to accurately control the discharge flow of the low-temperature liquid; besides, the arrangement of the displacement sensing mechanism 1 greatly avoids the problem that the piston hits the cylinder.
Meanwhile, in order to further avoid the problem that the piston hits the cylinder, as shown in fig. 4-6, three anti-collision pressure relief valves 2021 are uniformly distributed and arranged on the piston 202 in a penetrating manner, each anti-collision pressure relief valve 2021 comprises a valve cavity arranged on the piston 202 and a floating valve body 2021a float-mounted in the valve cavity, and the length of the floating valve body 2021a is greater than the height of the piston 202; the floating valve body 2021a is provided with a sealing surface 2021b matched with the valve cavity, a pressure relief groove 2021c and a push rod 2021d for protecting the piston 202 and the cylinder body I201;
in the working process, when hydraulic oil enters the cylinder body I201 from one end and pushes the piston 202 to move towards the other end in the cylinder body I201, due to the large pressure in the oil inlet direction, the hydraulic oil pushes the piston 202 to move in the cylinder body I201 and discharges the hydraulic oil at the other end out of the cylinder body I201, and also pushes the floating valve body 2021a to move towards the piston 202 in the valve cavity on the piston 202, so that the sealing surface 2021b of the floating valve body 2021a is attached and sealed with the valve cavity, and at the moment, the push rod 2021d on the floating valve body 2021a protrudes out of the piston 202, when the piston 202 moves to be collided with the cylinder body I201, because the push rod 2021d protrudes out of the piston 202, the push rod 2021d collides with the cylinder body I201 first, after collision, the floating valve body 2021a is subjected to a force which is greater than the oil inlet direction, so that the floating valve body 2021a moves reversely in the valve cavity, and at the moment, the floating valve body 2021a sealing surface 2021b is separated from the valve cavity, therefore, the hydraulic oil can enter the other end of the piston 202 from the relief groove 2021c, thereby preventing the piston from hitting the cylinder.
Specifically, as a preferable aspect of the present embodiment, the pressurization mechanism 4 further includes: the second cylinder 401, the suction channel 403, the check valve plate 404, the pull rod 407, the third cylinder 408 and the pressurizing piston 410 are fixedly connected with the lower end of the heat-insulating isolation cylinder 204 in a sealing manner; the piston rod 203 slides through the second cylinder 401 and is fixedly connected with the piston head 402; the lower end of the cylinder body II 401 is provided with a low-temperature liquid inlet 411 and a liquid outlet 405; a cylinder body III 408 is fixedly arranged at the lower end of the cylinder body II 401; the middle lower part of the cylinder body III 408 is provided with an open type piston cavity 412, and the upper part is uniformly provided with four suction channels 403 communicated with the open type piston cavity 412; the suction channel 403 is communicated with a low-temperature liquid inlet 411 at the lower end of the second cylinder 401; a check valve plate 404 is disposed between each suction passage 403 and the cryogenic liquid inlet port for ensuring that the cryogenic liquid flows unidirectionally from the open-type piston chamber 412 of the cylinder block three 408 into the cylinder block two 401; a pressurizing piston 410 is arranged in an open piston cavity 412 of the cylinder body III 408 and is fixedly connected with the piston head 402 through a pull rod 407 which penetrates through the cylinder body III 408 in a sliding manner; primary liquid inlets 4101 are uniformly distributed on the pressurizing piston 410; a limiting block 413 for limiting the position of the valve plate 409 is arranged on the pull rod 407, and the valve plate 409 is arranged on the limiting block 413 in a floating or sliding manner and used for sealing the primary liquid inlet 4101 when the pressurizing piston 410 moves upwards along with the pull rod 407; wherein, pressure boost piston 410 can play limiting displacement to the lower extreme of valve plate 409, and the upper end of valve plate 409 is spacing through the stopper that sets up on pull rod 407.
In the working process of the pressurization mechanism 4, under the action of hydraulic oil, the piston 202 drives the piston rod 203 to reciprocate, the piston rod 203 drives the piston head 402 to perform lifting reciprocating motion, when the piston head 402 performs lifting motion, the pull rod 407 connected with the piston head is driven to perform lifting motion simultaneously, the pull rod 407 drives the pressurization piston 410 which is arranged in the cylinder body III 408 and connected with the pull rod 407 to move, and meanwhile, as the pull rod 407 performs lifting motion, the valve plate 409 slidably mounted on the pull rod 407 is driven to fall down to seal the primary liquid inlet 4101; after the primary liquid inlet 4101 is closed, the low-temperature liquid is temporarily stored in an open piston cavity 412 of the cylinder body three 408 and cannot flow back through the primary liquid inlet 4101, the pressurizing piston 410 and the valve plate 409 push the low-temperature liquid to enter a suction channel 403 of the cylinder body three 408 under the driving of the pull rod 407, and the low-temperature liquid pushes a check valve plate 404 above the suction channel 403 in the cylinder body three 408 to enter a cylinder body two 401 through a low-temperature liquid inlet 411 along with the pushing of the pressurizing piston 410 and the valve plate 409 on the low-temperature liquid;
when the piston head 402 descends, pushing force is applied to the low-temperature liquid to push the low-temperature liquid to enter a liquid outlet 405 arranged on the cylinder II 401, and the low-temperature liquid is discharged through a liquid discharge pipeline 406 and a liquid discharge port 307 on the low-temperature liquid storage tank 3; meanwhile, in the process of pushing the low-temperature liquid by pushing the piston head 402 down to push the low-temperature liquid, the low-temperature liquid pushes the check valve plate 404 to block the low-temperature liquid suction passage 403, so that the low-temperature liquid cannot flow back into the cylinder block III 408 through the suction passage 403;
in addition, in the descending process of the piston head 402, the pull rod 407 is driven to descend, the pull rod 407 drives the pressurizing piston 410 and the valve plate 409 to descend and reset, and the low-temperature liquid enters the secondary liquid inlet 4101 to push the valve plate 409 away and enter the cylinder body III 408; and then repeating the above operation circularly, and suspending the operation of the cryogenic liquid pump after finishing the discharge amount of the cryogenic liquid.
In the working process of the supercharging mechanism 4, the low-temperature liquid firstly enters the cylinder body III 408 through the supercharging piston 410 and the valve plate 409 under the condition of no negative pressure, and then enters the cylinder body II 401 through the suction channel 403 under the condition of sealing the primary liquid inlet 4101, so that the suction pressure head is always kept in a zero-pressure state, the problem that the piston seal cannot be effectively used for a long time under the ultralow-temperature working environment when the suction pressure head of the low-temperature liquid pump is a net positive suction pressure head (NPSH) is solved, and the working efficiency and the service life of the low-temperature liquid pump are effectively ensured.
Specifically, as a preferable scheme of this embodiment, as shown in fig. 7, the low-temperature liquid storage tank 3 further includes: the tank body 301, the sealing cover 302 and the heat insulation isolation cylinder supporting frame 303, wherein the top of the tank body 301 is hermetically connected with the sealing cover 302; the upper end of the sealing cover 302 is fixedly connected with the double-acting hydraulic cylinder 2 through a bolt, a through hole is formed in the center of the sealing cover, and the heat-insulating isolation cylinder 204 is fixedly arranged in the through hole and supported and reinforced through a heat-insulating isolation cylinder supporting frame 303 arranged at the bottom of the sealing cover 302; the lower end and the upper end of the side surface of the tank body 301 are respectively provided with a liquid inlet 304 and an air return port 305, and the side surface is vacuumized through a vacuumizing interface 3011 arranged on the side surface; the sealing cover 302 is provided with a vent 306 and a sewage outlet 308.
Example 2:
as shown in fig. 10 to 17, the present embodiment is different from embodiment 1 in that: the portion of the piston rod 203 located in the heat insulating cylinder 204 is provided as a transmission mechanism 5 for reducing heat transfer loss generated when the piston rod 203 moves up and down.
Specifically, as a preferable solution of the present embodiment, the transmission mechanism 5 includes a special-shaped rack 501, a gear assembly 502, a bevel gear set 503, a lead screw 504, a push-pull rod 505 and a slider 506; the upper end of the special-shaped rack 501 is fixedly connected with the piston rod 203; the gear assembly 502 is formed by coaxially and fixedly connecting a straight gear 5021 and a bevel gear one 5022, is rotatably connected to the inner wall of the heat insulation isolation cylinder 204, and the straight gear 5021 is meshed with the special-shaped rack 501; the screw rod 504 is rotatably arranged in the heat insulation isolation cylinder 204 through a support frame and a bearing and is positioned on the same axis with the piston rod 203; a heat insulation sealing ring is arranged between the upper end of the screw rod 504 and the heat insulation isolation cylinder 204; the screw rod 504 is coaxially and fixedly connected with a second bevel gear 503, and the second bevel gear 503 is meshed with a first bevel gear 5022; the sliding block 506 is matched with the lead screw 504, the heat insulation isolation cylinder 204 and the sliding block 506 are both square, and the sliding block 506 ascends and descends along with the positive and negative rotation of the lead screw 504 under the guiding effect of the heat insulation isolation cylinder 204; a hollow push-pull rod 505 is arranged outside the lead screw 504 and is fixedly connected with the lower end of the sliding block 506; the lower end of the push-pull rod 505 is fixedly connected with a piston rod 203 positioned in the supercharging mechanism 4;
in the working process of the transmission mechanism 5, the piston rod 203 drives the special-shaped rack 501 to move up and down, so that the straight gear 5021 in the gear assembly 502 is driven to rotate forwards and backwards, and the first bevel gear 5022 rotates synchronously with the straight gear 5021; the second bevel gear 503 is driven by the first bevel gear 5022 to drive the screw rod 504 to rotate positively and negatively; the sliding block 506 drives the push-pull rod 505 to ascend and descend along with the positive and negative rotation of the lead screw 504 under the guiding action of the heat insulation isolation cylinder 204, and further drives the piston rod 203 in the pressurization mechanism 4 to ascend and descend, so that the transmission action of the transmission mechanism 5 is completed; due to the arrangement of the transmission mechanism 5, the section of the piston rod 203 connected with the piston head 402 is always positioned in the pressurizing mechanism 4 in the up-and-down movement process, so that the problem that the piston rod absorbs external heat to cause evaporation of a large amount of low-temperature liquid in a conventional reciprocating type low-temperature liquid pump because the piston rod frequently enters and exits between a normal-temperature power component and a cold-end pump head is solved, and the environmental pollution and the storage cost are effectively reduced.
Claims (10)
1. A zero suction head low-temperature liquid pump is characterized by comprising a displacement sensing mechanism (1), a double-acting hydraulic cylinder (2) and a supercharging mechanism (4), wherein the displacement sensing mechanism (1) is fixedly connected with a piston (202) arranged in the double-acting hydraulic cylinder (2) through a hollow connecting rod (104); the lower part of the double-acting hydraulic cylinder (2) is fixedly arranged on the low-temperature liquid storage tank (3) and is isolated from low-temperature liquid in the low-temperature liquid storage tank (3) through a heat insulation isolation cylinder (204); the supercharging mechanism (4) is fixedly connected to the lower end of the heat insulation isolation cylinder (204) in a sealing manner and is fixedly connected with a piston rod (203) in the double-acting hydraulic cylinder (2) through a piston head (402) arranged in the supercharging mechanism; and a liquid outlet (405) arranged on the pressurization mechanism (4) is connected with a liquid outlet (307) arranged on the low-temperature liquid storage tank (3) through a liquid drainage pipeline (406) and is used for discharging the low-temperature liquid.
2. A zero suction head cryogenic liquid pump according to claim 1, wherein the displacement sensing mechanism (1) further comprises: the displacement sensor (101) is fixed on the mounting frame (102), and the displacement detection rod (105) is inserted into the mounting frame (102) through the displacement sensor (101); the magnetic ring (103) and the hollow connecting rod (104) are both slidably sleeved on the displacement detection rod (105), and the lower end of the magnetic ring (103) is fixedly connected with the upper end of the hollow connecting rod (104); the mounting rack (102) is fixedly arranged at the upper end of the double-acting hydraulic cylinder (2).
3. A zero suction head cryogenic liquid pump according to claim 2, characterized in that the double acting hydraulic cylinder (2) further comprises: the piston type cylinder assembly comprises a cylinder body I (201) and a piston (202) arranged in the cylinder body I (201), wherein the upper end of the cylinder body I (201) is fixedly arranged with a mounting frame (102); the upper end and the lower end of the piston (202) are respectively fixedly connected with the hollow connecting rod (104) and the piston rod (203).
4. The zero suction head cryogenic liquid pump of claim 3, characterized in that at least one anti-collision pressure relief valve (2021) is arranged on a piston (202) installed in the cylinder body I (201) in a penetrating manner, the anti-collision pressure relief valve (2021) comprises a valve cavity arranged on the piston and a floating valve body (2021 a) installed in the valve cavity in a floating manner, and the length of the floating valve body (2021 a) is greater than the height of the piston (202).
5. The zero suction head cryogenic liquid pump of claim 4, characterized in that the floating valve body (2021 a) is provided with a sealing surface (2021 b) which is matched with the valve cavity, a pressure relief groove (2021 c) and a push rod (2021 d) which is used for protecting the piston (202) and the cylinder body I (201).
6. A zero suction head cryogenic liquid pump according to claim 1, characterized in that the pressurization mechanism (4) further comprises: the cylinder II (401) is fixedly connected with the lower end of the heat insulation isolation cylinder (204) in a sealing manner; the piston rod (203) penetrates through the second cylinder body (401) in a sliding mode and is fixedly connected with the piston head (402); the lower end of the second cylinder body (401) is provided with a low-temperature liquid inlet (411) and a liquid outlet (405); a cylinder body III (408) is fixedly arranged at the lower end of the cylinder body II (401); the middle lower part of the cylinder body III (408) is an open type piston cavity (412), and the upper part of the cylinder body III is at least provided with an intake channel (403) communicated with the open type piston cavity (412); the suction channel (403) is communicated with a low-temperature liquid inlet (411) at the lower end of the second cylinder body (401), and the check valve plate (404) is arranged between each suction channel (403) and the low-temperature liquid inlet (411) and used for ensuring that the low-temperature liquid flows into the second cylinder body (401) from an open piston cavity (412) of the third cylinder body (408) in a one-way mode.
7. The zero suction head cryogenic liquid pump of claim 6, wherein a booster piston (410) is arranged in an open piston cavity (412) of the cylinder block three (408), and is fixedly connected with the piston head (402) through a pull rod (407) which penetrates through the cylinder block three (408) in a sliding manner; primary liquid inlets (4101) are uniformly distributed on the pressurizing piston (410); the device is characterized in that a limiting block (413) used for limiting the position of the valve plate (409) is arranged on the pull rod (407), and the valve plate (409) is arranged on the limiting block (413) and used for sealing the primary liquid inlet (4101) when the pressurizing piston (410) moves upwards along with the pull rod (407).
8. A zero suction head cryogenic liquid pump according to claim 2, characterized in that the part of the piston rod (203) inside the thermally insulated isolation cylinder (204) is provided as a transmission (5) for reducing heat transfer losses when the piston rod (203) moves up and down.
9. The zero suction head cryogenic liquid pump of claim 8, wherein the transmission mechanism (5) comprises a shaped rack (501), a gear assembly (502), a bevel gear two (503), a lead screw (504), a push-pull rod (505), and a slider (506); the upper end of the special-shaped rack (501) is fixedly connected with the piston rod (203); the gear assembly (502) is formed by fixedly connecting a straight gear (5021) and a bevel gear I (5022) with the same axis, and is rotatably connected to the inner wall of the heat insulation isolation cylinder (204), and the straight gear (5021) is meshed with the special-shaped rack (501); the lead screw (504) is rotatably arranged in the heat insulation isolation cylinder (204) through a support frame and a bearing and is positioned on the same axis with the piston rod (203); a heat insulation sealing ring is arranged between the upper end of the lead screw (504) and the heat insulation isolation cylinder (204); the screw rod (504) is coaxially and fixedly connected with a second bevel gear (503), and the second bevel gear (503) is meshed with the first bevel gear (5022); the sliding block (506) is matched with the lead screw (504) and ascends and descends along with the positive and negative rotation of the lead screw (504) under the guiding action of the heat insulation isolation cylinder (204); a hollow push-pull rod (505) is arranged outside the lead screw (504) and is fixedly connected with the lower end of the sliding block (506); the lower end of the push-pull rod (505) is fixedly connected with a piston rod (203) positioned in the supercharging mechanism (4).
10. A zero suction head cryogenic liquid pump according to any of claims 1-8, characterized in that the cryogenic liquid storage tank (3) further comprises: the insulation tank comprises a tank body (301), a sealing cover (302) and a heat insulation isolation cylinder supporting frame (303), wherein the top of the tank body (301) is hermetically connected with the sealing cover (302); the upper end of the sealing cover (302) is fixedly connected with the double-acting hydraulic cylinder (2), a through hole is formed in the center of the sealing cover, and the heat-insulating isolation cylinder (204) is fixedly arranged in the through hole and supported and reinforced by a heat-insulating isolation cylinder supporting frame (303) arranged at the bottom of the sealing cover (302); the tank body (301) is provided with a liquid inlet (304), an air return port (305) and a vacuumizing interface (3011), and the sealing cover (302) is provided with an emptying port (306) and a sewage outlet (308).
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| CN202210440750.5A CN114542427B (en) | 2022-04-26 | 2022-04-26 | Zero suction pressure head cryogenic liquid pump |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202210440750.5A CN114542427B (en) | 2022-04-26 | 2022-04-26 | Zero suction pressure head cryogenic liquid pump |
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| CN114542427B CN114542427B (en) | 2022-08-05 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116085349A (en) * | 2023-03-08 | 2023-05-09 | 仪征天华活塞环有限公司 | High-temperature-resistant high-pressure-resistant piston sealing element |
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| CN212535971U (en) * | 2020-07-21 | 2021-02-12 | 湖州三井低温设备有限公司 | Hydraulic drive low-temperature reciprocating pump capable of reducing influence of low temperature on sealing position of piston rod |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN116085349A (en) * | 2023-03-08 | 2023-05-09 | 仪征天华活塞环有限公司 | High-temperature-resistant high-pressure-resistant piston sealing element |
| CN116085349B (en) * | 2023-03-08 | 2023-10-13 | 仪征天华活塞环有限公司 | High-temperature-resistant high-pressure-resistant piston sealing element |
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| CN114542427B (en) | 2022-08-05 |
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