CN110131129B

CN110131129B - Novel structure cryopump

Info

Publication number: CN110131129B
Application number: CN201910366443.5A
Authority: CN
Inventors: 张建明; 姬广存
Original assignee: Yingjia Power Technology Wuxi Co ltd
Current assignee: Yingjia Power Technology Wuxi Co ltd
Priority date: 2019-05-05
Filing date: 2019-05-05
Publication date: 2024-08-16
Anticipated expiration: 2039-05-05
Also published as: CN110131129A

Abstract

The invention belongs to the technical field of fuel supply of internal combustion engines, and particularly relates to a novel-structure cryopump. This novel structure cryopump, including cold junction area, gaseous state cooling zone and hot junction area, be equipped with gaseous state cooling zone between cold junction area and the hot junction area, the cold junction area includes the cold junction pump body and separates the cover in vacuum, is equipped with the cold junction piston in the cold junction pump body, and cold junction piston tip design is the annular open form, installs cold junction connecting rod head in the piston open ring groove, the hot junction area includes the hot junction piston, and the hot junction piston is installed in the hot junction pump body, sets up pressure relief device on the hot junction piston, and the hot junction pump body sets up displacement sensor, be equipped with the high-pressure air pipe on the gaseous state cooling zone. The beneficial effects are as follows: the liquefied natural gas in the low-temperature tank can be pumped out completely, so that the endurance mileage of the vehicle is increased; the structure is simple and effective; the reliability is improved; the processing manufacturability is good, and the mass production is convenient.

Description

Novel structure cryopump

Technical Field

The invention belongs to the technical field of fuel supply of internal combustion engines, and particularly relates to a novel-structure cryopump.

Background

In the current market, in internal combustion engine vehicles using natural gas as fuel, the way natural gas is carried on the vehicle is classified into two types, compressed Natural Gas (CNG) and Liquefied Natural Gas (LNG). Compressed Natural Gas (CNG) is a high pressure gaseous natural gas, typically one volume of compressed natural gas is converted to 200 standard volumes of natural gas. Liquefied Natural Gas (LNG) is liquid natural gas, typically one volume of LNG is converted to 600 standard volumes of natural gas. CNG vehicles have insufficient continuous running capability and are suitable for small-sized vehicles such as taxis and the like. Compared with CNG vehicles, the continuous running capability of the LNG vehicles is greatly increased, and medium-heavy trucks also have enough space to store equipment.

In most of the present LNG vehicles, liquefied natural gas in a low-temperature tank flows out of the low-temperature tank under the action of gravity of the liquefied natural gas, and the liquefied natural gas is gasified by a gasifier and then led to an internal combustion engine to burn and do work. After the liquefied natural gas in the low-temperature tank is used to a certain extent, the residual less liquefied natural gas (about 25 percent) cannot smoothly flow out of the low-temperature tank through self gravity, and the liquefied natural gas can be continuously used only after sufficient liquefied natural gas is timely supplemented, so that the continuous running capability of a vehicle is influenced, the waste of storage space is caused, and the additional burden is added to the vehicle.

A direct in-cylinder injection technology capable of realizing dual fuel injection adopts a compression ignition mode, so that the combustion efficiency can be effectively improved. According to the dual-fuel direct injection technology, a small amount of diesel oil is injected into a combustion chamber, after compression ignition, the temperature in the combustion chamber of an internal combustion engine is raised, and then compressed natural gas injected later is ignited to perform combustion work. The technology can improve the combustion efficiency to more than 42%, can greatly reduce the PM value and the emission of NOx, and is a cleaner and more economical fuel injection system of the internal combustion engine. The dual fuel injection system requires the use of high pressure natural gas with stable pressure during operation. The liquefied natural gas flowing out of the low-temperature tank through self gravity has smaller pressure after being gasified by the gasifier, and can not provide high-pressure natural gas for the dual-fuel internal combustion engine at fixed time and fixed quantity.

Among cryopump structures currently existing in the market, there are mainly centrifugal cryopumps and reciprocating piston cryopumps. The liquefied gas pressure pumped by the centrifugal cryogenic pump is relatively low, the distance between the driving device and the cryogenic liquefied gas is very short, more heat is transferred to the cryogenic liquefied gas, and the liquefied gas is gasified. The existing reciprocating piston type cryopump has more defects: the connecting rod of the low-temperature pump is longer, and two ends of the low-temperature pump are connected with the piston through a thread structure, so that clamping stagnation and even clamping can be easily caused during movement; the interior of the low-temperature pump is sealed by a conical surface or a plane, and the sealing surface is easy to leak; the driving end is directly connected with the cold end through a common metal piece, so that heat leakage is serious; the gasifier needs to be communicated with engine cooling liquid during heat exchange, and after the gasifier is used for a period of time, scale can be generated in the gasifier, so that the gasifier cannot be cleaned and maintained; when the piston moves, the displacement cannot be accurately monitored, so that the piston is in impact failure and the like.

In view of the foregoing, there is a need to develop a novel and complete cryogenic pump with a novel structure, which can pump the liquefied natural gas in the cryogenic tank at regular time and at regular quantity, so as to convey the high-pressure natural gas to the internal combustion engine at regular time and at regular quantity, ensure the safe and reliable operation of the cryogenic pump, and meet the demands of market and social development.

Disclosure of Invention

The invention provides a novel structure cryopump for overcoming the defects of the prior art.

The invention is realized by the following technical scheme:

The utility model provides a novel structure cryopump, includes cold junction region, gaseous cooling zone and hot junction region, be equipped with gaseous cooling zone between cold junction region and the hot junction region. The cold end area comprises a cold end pump body, a cold end piston, a cold end connecting rod and the like, the cold end piston is arranged in the cold end pump body, the end part of the cold end piston is designed into an annular groove opening form, the head of the cold end connecting rod is installed in an annular groove of the piston opening, the head of the cold end pump body is provided with a corrugated pipe, a filter, a ball seat, a liquid through valve and a first steel ball, the first steel ball is installed in a channel between the conical surface of the ball seat and the conical surface of the liquid through valve, a one-way valve body and an air outlet joint are arranged on the cold end pump body, a second steel ball is fixed with the one-way valve body, a high-pressure air pipe is installed on the air outlet joint through a fastening nut, the other end of the cold end pump body is connected with a cold end flange through a fastening bolt, a balance cavity is arranged between the cold end flange and the cold end pump body, the balance cavity is respectively communicated with the second containing cavity and the LNG tank cavity, the cold end flange is provided with a sealing piece and a cold end bearing bush, the cold end bearing plays a supporting role on the cold end connecting rod, the outer end of the cold end flange is sealed with a vacuum isolation cover through the sealing piece, the connecting cover is connected with the cold end flange and is fastened through a fastening nut, a supercharging air pipe, the supercharging air pipe is arranged on the vacuum isolation cavity and the LNG tank cavity is respectively communicated with the air cavity. The hot end region comprises a hot end piston, the hot end piston is arranged in a hot end pump body and forms a third containing cavity and a fourth containing cavity, the end part of the hot end piston is designed into an annular groove opening mode, the head of a hot end connecting rod is arranged in an annular groove of the piston opening, a supporting ring and a sealing piece are arranged between the hot end piston and the hot end pump body, a pressure relief device is arranged on the hot end piston, and the hot end pump body is provided with a displacement sensor. The gas cooling area is provided with a high-pressure air pipe, the high-pressure air pipe is wound in the gas cooling area to form a gas cooling cavity, and the heat-insulating connecting rod connects the cold end connecting rod with the hot end connecting rod.

Further, the pressure relief device comprises a first pressure relief valve core, a second pressure relief valve core and a pressure relief spring, the first pressure relief valve core and the second pressure relief valve core are pressed on the sealing conical surface by the spring force of the pressure relief spring, the end faces of the pressure relief valve cores are higher than the end faces of the hot end pistons, when the hot end pistons move towards the displacement sensor, the hot end piston faces are close to the wall of the hot end pump body, the first pressure relief valve core is contacted with the wall of the hole first, the first pressure relief valve core is separated from the sealing conical surface, the third containing cavity is communicated with the fourth containing cavity through the first pressure relief hole, the hydraulic pressure of the third containing cavity and the hydraulic pressure of the fourth containing cavity are balanced, the hot end pistons are prevented from being in violent collision with the wall of the hot end pump body, and when the hot end pistons move towards the hot end bearing bush direction, the second pressure relief valve core is in the same working principle, and the hot end pistons are prevented from being in violent collision with the wall of the hole.

Further, a first hydraulic oil channel and a second hydraulic oil channel are arranged in the hot end pump body, the first hydraulic oil channel is communicated with the third containing cavity, the second hydraulic oil channel is communicated with the fourth containing cavity, and the first hydraulic oil channel and the second hydraulic oil channel are connected with the reversing valve through pipelines.

Further, in the hot end region, the hot end pump body and the hot end flange are fixedly connected through fastening bolts, the hot end flange is provided with the hot end bearing bush and the sealing piece, the supporting ring and the sealing piece are provided with the checking port, and whether the sealing piece fails or not can be detected through the checking port so as to be convenient for maintenance of the low-temperature pump. And an engine cooling liquid inlet, an engine cooling liquid outlet and a temperature sensor are arranged on the hot end flange, and the temperature sensor can transmit a temperature signal of the engine cooling liquid outlet. The hot end flange is provided with a connector, a high-pressure air pipe and a pressure sensor, the connector and the hot end flange form a three-way cavity, and the pressure sensor can transmit pressure signals of compressed natural gas in the three-way cavity. The hot end pump body is provided with a booster component, the booster valve core is pressed on the sealing conical surface through a booster spring, and when the booster valve core is opened by the air pressure, the three-way cavity is communicated with the booster cavity through the three-way air cavity and the air hole.

Further, a gasifier component is arranged in the hot end area and is fixed with the hot end flange, a heat exchange cavity is formed between a gasifier outer shell and a gasifier inner shell of the gasifier component, the heat exchange cavity is communicated with an engine cooling liquid inlet, the gasifier inner shell surrounds to form a liquid return cavity, the liquid return cavity is communicated with an engine cooling liquid outlet, and the heat exchange cavity is communicated with the liquid return cavity through a liquid through hole. One end of the gasifier is provided with a drain plug, after the gasifier is used for a set time, scale in the heat exchange cavity can be cleaned through the drain plug, a heat insulation plate is arranged at the position, located at the waterproof plug, in the connecting cover, of the gasifier, the high-pressure air pipes are arranged in a crossed spiral mode in the heat exchange cavity, and natural gas in the high-pressure air pipes is led to the tee cavity after heat exchange.

Further, the connecting cover is provided with a vent hole, and the pressurizing cavity is communicated with the gas cooling cavity through the vent hole.

The beneficial effects of the invention are as follows: the LNG tank without the low-temperature pump structure can pump all the liquefied natural gas in the low-temperature tank, so that the continuous voyage mileage of the vehicle is increased; the liquefied natural gas in the low-temperature tank can be pumped to the gasifier at fixed time and fixed quantity through the control of the system structure, so that a gas source is provided for the injector to inject high-pressure natural gas; the function of the gasifier is integrated, the structure is simple and compact, and the high-pressure air pipe is fully contacted with the cooling liquid through the structural design, so that heat exchange is performed, and the gasification efficiency of the liquefied gas is improved; the booster structure is designed through the branch of the compressed natural gas, so that the pressure in the low-temperature tank is balanced, a booster system is not required to be additionally designed for the low-temperature tank, and the structure is simple and effective; the piston and the connecting rod have larger degree of freedom in installation, and no clamping stagnation or clamping death occurs; the pressure relief device is arranged on the hot end piston to prevent the piston from being impacted with the pump body violently, so that the reliability is improved; the supporting ring structure is designed on the piston to guide and assist in sealing the piston, so that the manufacturability of piston processing is improved; the displacement sensor is arranged at the hot end region, and the displacement and the speed of the hot end piston can be effectively controlled through the control unit and the reversing valve, so that the accurate work of the low-temperature pump is ensured; the drain plug is arranged on the gasifier, so that the gasifier is convenient to maintain; the connecting rod is designed in a segmented mode, and the heat-insulating connecting rod can effectively avoid excessive heat transfer to the cold end area; the gas cooling cavity is designed by utilizing the high-pressure gas pipe to cool the pressurized gas, so that the pressurized gas is prevented from transferring excessive heat to the LNG tank cavity; the single steel ball is used for controlling the inlet and outlet of liquefied gas, so that the method is simple and effective; an inspection port is arranged to effectively detect leakage of fluid, so that maintenance of a system is facilitated; the balance cavity is arranged, so that the second containing cavity is directly communicated with the LNG tank cavity, the pressure is convenient to accurately control when the piston moves, and gasified gas can be led into the LNG tank cavity when the liquefied gas is partially gasified, so that the partial formation of excessive pressure is avoided; the whole structure has the advantages of simple and compact design, effective sealing, good reliability, good processing manufacturability and convenience for mass production.

Drawings

The invention is further described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a cryopump assembly of the present invention;

FIG. 2 is a diagram of the cold end area of the cryopump of the present invention;

FIG. 3 is a block diagram of the gaseous cooling zone of the cryopump of the present invention;

FIG. 4 is a diagram of the hot end region of the cryopump of the present invention;

FIG. 5 is a schematic diagram of a modified structure of a piston relief valve of the cryopump of the present invention;

FIG. 6 is a schematic diagram of a modified structure of the cryopump gasifier according to the present invention;

FIG. 7 is a schematic diagram of a modified structure of the connection mode of the piston and the connecting rod of the cryopump of the present invention;

FIG. 8 is a schematic diagram of a seal mode modification structure of the cryopump of the present invention;

FIG. 9 is a schematic view of a joint connection mode structure of the present invention;

fig. 10 is a schematic diagram of a modified structure of the connecting rod of the present invention.

In the figure, 001 cold end area, 002 gaseous cooling area, 003 hot end area, 01 cold end pump body, 02 cold end piston, 03 cold end flange, 04 corrugated pipe, 05 filter, 06 ball seat, 07 fastening nut, 08 first steel ball, 09 liquid-passing valve, 10 supporting ring, 11 sealing element, 12 air outlet joint, 13 high-pressure air pipe, 14 second steel ball, 15 check valve body, 16 check valve spring, 17 fastening nut, 18 cold end connecting rod, 20 cold end bearing bush, 21 pressurizing air pipe, 22 vacuum isolation cover, 23 connecting cover, 24 fastening nut, 25 fastening bolt, 27 first containing cavity, 28 second containing cavity, 29 balance cavity, 30 second liquid outlet hole, 31 first liquid outlet hole, 32 heat insulation connecting rod, 33 hot end connecting rod, 34 gas cooling cavity, 35 heat insulation board, 36 water outlet plug, 37 gasifier outer shell, 38 gasifier inner shell, 40 joint, 41 vent hole, 42 liquid-passing hole, 43 heat exchange cavity, 44 back fluid chamber, 47 engine coolant inlet, 48 engine coolant outlet, 49 temperature sensor, 50 inspection port, 52 hot end bearing, 53 three-way chamber, 54 joint, 55 high pressure air pipe, 56 hot end flange, 57 three-way air chamber, 58 air vent, 59 pressure increasing valve core, 60 pressure increasing spring, 62 first pressure relief hole, 63 second pressure relief valve core, 64 pressure relief spring, 65 first pressure relief valve core, 66 hot end piston, 67 second pressure relief hole, 68 hot end pump body, 69 third holding chamber, 70 fourth holding chamber, 71 hydraulic oil second channel, 72 hydraulic oil first channel, 73 displacement sensor, 76 reversing valve, 77 pressure increasing chamber, 78 pressure sensor, 79 spring seat, 80 first valve core, 81 second valve core, 82 pressure relief valve spring, 83 first arrow, 84 second arrow, 85 valve body inner circle face, 86 valve body mouth circle face, 87 valve body auxiliary groove.

Detailed Description

Figures 1-4 illustrate an embodiment of the present invention. The invention relates to a novel structure cryopump, which comprises a cold end region 001, a gaseous cooling region 002 and a hot end region 003, wherein the gaseous cooling region 002 is arranged between the cold end region 001 and the hot end region 003, the cold end region 001 comprises a cold end pump body 01, a cold end piston 02, a cold end connecting rod 18 and the like, the cold end piston 02 is arranged in the cold end pump body 01, the end part of the cold end piston 02 is designed into an annular groove opening form, the head part of the cold end connecting rod 18 is arranged in an annular groove of the piston, the head part of the cold end pump body 01 is provided with a corrugated pipe 04, a filter 05, a ball seat 06, a liquid through valve 09 and a first steel ball 08, the first steel ball 08 is arranged in a channel between the conical surface of the ball seat 06 and the conical surface of the liquid through valve 09, the cold end pump body 01 is provided with a one-way valve body 15 and a gas outlet joint 12, a second steel ball 14 is fixed with the one-way valve body 15, a high-pressure gas pipe 13 is arranged on the gas outlet joint 12 through a fastening nut 17, in the cold end region 001, the other end of the cold end pump body 01 is connected with the cold end flange 03 through a fastening bolt 25, a balance cavity 29 is arranged between the cold end flange 03 and the cold end pump body 01, the balance cavity 29 is respectively communicated with a second containing cavity 28 and an LNG tank cavity, a sealing piece 11 and a cold end bearing bush 20 are arranged on the cold end flange 03, the cold end bearing bush 20 supports a cold end connecting rod 18, the outer end of the cold end flange 03 is sealed with a vacuum separation cover 22 through the sealing piece 11, the connecting cover 23 is connected with the cold end flange 03 and fastened through a fastening nut 07, a pressurizing air pipe 21 is arranged on the vacuum separation cover 22, two ends of the pressurizing air pipe 21 are respectively communicated with a gas cooling cavity 34 and the LNG tank cavity, the hot end area 003 comprises a hot end piston 66, the hot end piston 66 is arranged in the hot end pump body 68 and forms a third containing cavity 69 and a fourth containing cavity 70, the end of the hot end piston 66 is designed into an annular groove opening form, the head of the hot end connecting rod 33 is arranged in an annular groove, the support ring 10 and the sealing element 11 are arranged between the hot end piston 66 and the hot end pump body 68, the pressure relief device is arranged on the hot end piston 66, the displacement sensor 73 is arranged on the hot end pump body 68, the high-pressure air pipe 13 is arranged on the gaseous cooling area 002, the high-pressure air pipe 13 is wound on the gaseous cooling area 002 to form the gas cooling cavity 34, and the heat insulation connecting rod 32 connects the cold end connecting rod 18 and the hot end connecting rod 33.

Further, the pressure relief device comprises a first pressure relief valve core 65, a second pressure relief valve core 63 and a pressure relief spring 64, the spring force of the pressure relief spring 64 presses the first pressure relief valve core 65 and the second pressure relief valve core 63 on the sealing conical surface, the end surfaces of the pressure relief valve cores are higher than the end surface of the hot end piston 66, when the hot end piston 66 moves towards the displacement sensor 73, the end surface of the hot end piston 66 is close to the wall of the hot end pump body 68, the first pressure relief valve core 65 is contacted with the wall of the hole first, the first pressure relief valve core 65 is separated from the sealing conical surface, the third containing cavity 69 is communicated with the fourth containing cavity 70 through the first pressure relief hole 62, the hydraulic pressure of the third containing cavity 69 and the hydraulic pressure of the fourth containing cavity 70 are balanced, the hot end piston 66 and the wall of the hot end pump body 68 are prevented from being collided violently, and when the hot end piston 66 moves towards the direction of the hot end 52, the second pressure relief valve core 63 is prevented from collision violently with the wall of the hot end piston 66 according to the same working principle.

Further, a first hydraulic oil channel 72 and a second hydraulic oil channel 71 are disposed in the hot end pump body 68, the first hydraulic oil channel 72 is communicated with the third cavity 69, the second hydraulic oil channel 71 is communicated with the fourth cavity 70, and the first hydraulic oil channel 72 and the second hydraulic oil channel 71 are connected with the reversing valve 76 through pipelines.

Further, in the hot end region 003, the hot end pump body 68 is fixedly connected with the hot end flange 56 through the fastening bolt 25, the hot end flange 56 is provided with the hot end bearing bush 52 and the sealing member 11, the supporting ring 10 and the sealing member 11, the checking opening 50 is arranged between the hot end bearing bush 52 and the supporting ring 10, whether the sealing member 11 fails or not can be detected through the checking opening 50 so as to carry out maintenance of the cryopump, the hot end flange 56 is provided with the engine cooling liquid inlet 47, the engine cooling liquid outlet 48, the temperature sensor 49 can transmit temperature signals of the engine cooling liquid outlet 48, the hot end flange 56 is provided with the joint 40, the high-pressure air pipe 13 and the pressure sensor 78, the joint 40 and the hot end flange 56 form a three-way cavity 53, the pressure sensor 78 can transmit pressure signals of compressed natural gas in the three-way cavity 53, the hot end pump body 68 is provided with the booster valve core 59 is pressed on the sealing conical surface through the booster spring 60, and when the booster valve core 59 is opened under the pressure, the three-way cavity 57 and the air vent 58 are communicated with the booster cavity 77.

Further, a gasifier component is arranged in the hot end region 003 and is fixed with the hot end flange 56, a heat exchange cavity 43 is formed between a gasifier outer shell 37 and a gasifier inner shell 38 of the gasifier component, the heat exchange cavity 43 is communicated with an engine cooling liquid inlet 47, the gasifier inner shell 38 surrounds and forms a liquid return cavity 44, the liquid return cavity 44 is communicated with an engine cooling liquid outlet 48, the heat exchange cavity 43 is communicated with the liquid return cavity 44 through a liquid through hole 42, a drain plug 36 is arranged at one end of the gasifier, after the gasifier is used for a set time, scale in the heat exchange cavity 43 can be cleaned through the drain plug 36, a heat insulation plate 35 is arranged in the connecting cover 23 at the position of the water plug, the high-pressure gas pipe 13 is arranged in a cross spiral shape in the heat exchange cavity 43, and natural gas in the high-pressure gas pipe 13 is led to the three-way cavity 53 after heat exchange.

Further, the connecting cover 23 is provided with a vent 41, and the pressurizing chamber 77 communicates with the gas cooling chamber 34 through the vent 41.

According to the novel-structure cryogenic pump, the fourth containing cavity 70 is filled with high-pressure hydraulic oil, the third containing cavity 69 is filled with low-pressure hydraulic oil, and the hot end piston 66 moves towards the direction of the first arrow 83 under the action of hydraulic pressure. Simultaneously, hot side piston 66 drives hot side connecting rod 33, thermally insulated connecting rod 32, and cold side connecting rod 18 in the direction of first arrow 83. The cold end connecting rod 18 drives the cold end piston 02 to move towards the direction of a first arrow 83, the volume of the first containing cavity 27 is gradually increased, and the pressure in the first containing cavity 27 is gradually reduced. At this time, the check valve body 15 and the second steel ball 14 press fitting are in a closed state by the check valve spring 16. The first steel ball 08 is separated from the conical surface of the ball seat 06 under the action of hydraulic pressure in the LNG tank cavity, and liquefied gas in the LNG tank cavity enters the first containing cavity 27 through the hole on the liquid through valve 09. The second chamber 28 communicates with the LNG tank chamber through the balance chamber 29 so that the pressure in the second chamber 28 is equal to that in the LNG tank chamber.

When the hot end piston 66 approaches the hole wall of the hot end pump body 68, the displacement sensor 73 transmits a displacement signal to the control unit, the control unit controls the reversing valve 76 to switch the direction of hydraulic oil, the third chamber 69 is filled with high-pressure hydraulic oil, the fourth chamber 70 is filled with low-pressure hydraulic oil, and the hot end piston 66 moves towards the direction of a second arrow 84 under the action of hydraulic pressure. Simultaneously, hot side piston 66 drives hot side connecting rod 33, thermally insulated connecting rod 32, and cold side connecting rod 18 in the direction of second arrow 84.

At this time, the cold end connecting rod 18 drives the cold end piston 02 to move in the direction of the second arrow 84, the volume of the first cavity 27 of the cold end piston 02 is compressed, and the pressure in the first cavity 27 gradually increases. Under the action of hydraulic pressure in the first containing cavity 27, the first steel ball 08 moves towards the ball seat 06 and is finally pressed on the sealing conical surface of the ball seat 06. The hydraulic pressure in the first cavity 27 is transferred to the second steel ball 14 through the first liquid outlet hole 31, and as the pressure in the first cavity 27 increases, the hydraulic pressure overcomes the spring force of the check valve spring 16, the second steel ball 14 opens, and the liquefied gas flows to the high-pressure gas pipe 13 through the second liquid outlet hole 30. The liquefied gas in the high-pressure gas pipe 13 flows through the gas cooling chamber 34, and cools the gas cooling chamber 34.

In the invention, the high-temperature cooling liquid after the engine circulation enters the heat exchange cavity 43 through the engine cooling liquid inlet 47, and the high-pressure air pipes 13 are arranged in the heat exchange cavity 43 in a crossed spiral mode, so that the cooling liquid flows along a curve in the heat exchange cavity 43 and fully exchanges heat with the high-pressure air pipes 13. The coolant flows out of the engine coolant outlet 48 through the coolant passage hole 42, the coolant return chamber 44. After entering the heat exchange chamber 43 in the high pressure gas pipe 13, the liquefied gas is gasified into compressed natural gas by the hot gas, flows to the three-way chamber 53, and flows out through the high pressure gas pipe 55.

As the pressure in the LNG tank cavity gradually decreases due to consumption of liquefied gas in the LNG tank cavity, the LNG tank needs to be pressurized by a pressurizer. In the invention, the pressure in the LNG tank cavity is lower, the pressure in the pressurizing cavity 77 is lower at the same time, under the action of the air pressure, the pressurizing valve core 59 overcomes the spring force of the pressurizing spring 60 to be separated from the sealing conical surface, the pressurizing device is opened, compressed natural gas flows to the pressurizing cavity 77 through the air hole 58, flows to the gas cooling cavity 34 through the air hole 41 and then flows to the LNG tank cavity through the pressurizing air pipe 21, and the pressurizing function of the pressurizing device on the LNG tank cavity is completed.

In the invention, a hot end piston pressure relief valve modified structure exists, and the hot end piston pressure relief valve modified structure is shown in fig. 5. In the modified structure, a spring seat 79, a first valve core 80, a second valve core 81, a pressure release valve spring 82 and the like are arranged, when the piston approaches to the hole wall, the first valve core 80 or the second valve core 81 contacts with the hole wall first, the valve core breaks away from the sealing surface, the third containing cavity 69 is communicated with the fourth containing cavity 70, and the piston is prevented from being in violent collision with the hole wall.

In the present invention, there is a variation of the gasifier, see fig. 6. Inside the gasifier, a spiral labyrinth structure is provided to allow the high-pressure gas pipe 13 to be in full contact with the coolant in the heat exchange chamber 43 for heat exchange, and this structure also serves as a fixing for the high-pressure gas pipe 13. The spiral labyrinth structure can be designed to be fixed with the gasifier inner shell 38 and fixed with the gasifier outer shell 37 according to the processing conditions.

In the invention, when the piston is connected with the connecting rod, various connection modification modes exist, and the connection modification modes comprise steel ball universal joint installation, piston pin installation, thread installation, bolt installation, check ring installation and the like, as shown in figure 7.

In the invention, various sealing mode modified structures exist for each sealing surface, and the sealing mode modified structures comprise spherical surface sealing, conical surface sealing, plane type sealing, sealing element sealing, engineering plastic sealing, even element gap sealing and the like, as shown in fig. 8.

In the present invention, there is a universal joint connection, see fig. 9. In this connection mode, the valve body auxiliary groove 88 is provided on the check valve body 15, the inner circular surface 85 of the valve body in the check valve body 15 is larger than the diameter of the second steel ball 14, the circular surface 86 of the valve body opening is smaller than the diameter of the second steel ball 14, and the second steel ball 14 overcomes the tension of the valve body 15 opening and is pressed into the inner circular surface 85 of the valve body. After assembly, the second steel ball 14 can freely move in the one-way valve body 15 and is not easy to fall off. The universal joint connection mode can be applied to the assembly of the one-way valve body and the steel ball, the assembly of the piston and the steel ball and other applicable structures.

In the present invention, the cryopump connecting rod has a modified structure, see fig. 10, and the cold end connecting rod 18, the heat insulation connecting rod 32 and the hot end connecting rod 33 can be combined into one connecting rod according to the situation, and the connecting rod is directly connected with the hot end piston 66 and the cold end piston 02.

The present invention is not limited to the above embodiments, and any person who makes the technical solution with the same or similar to the present invention in the light of the present invention should be known to fall within the scope of the present invention.

The technology, shape, and construction parts of the present invention, which are not described in detail, are known in the art.

Claims

1. The utility model provides a novel structure cryopump, including cold end district, gaseous state cooling zone and hot end district, its characterized in that, be equipped with gaseous state cooling zone between cold end district and the hot end district, the cold end district includes the cold end pump body, the cold end piston, cold end connecting rod etc. is equipped with the cold end piston in the cold end pump body, cold end piston tip design is the annular opening form, install cold end connecting rod head in the piston annular opening, cold end pump body head sets up the bellows, the filter, the ball seat, lead to liquid valve and first steel ball, first steel ball is installed in the passageway between ball seat conical surface and the lead to liquid valve conical surface, set up check valve body and outlet connection on the cold end pump body, the second steel ball is fixed with the check valve body, the high-pressure gas pipe passes through fastening nut to be installed on outlet connection, in the cold end district, the cold end other end passes through fastening bolt and cold end flange connection, set up the balance chamber between cold end flange and the cold end pump body, the balance cavity is respectively communicated with the second cavity and the LNG tank cavity, the cold end flange is provided with a sealing piece and a cold end bearing bush, the cold end bearing bush supports the cold end connecting rod, the outer end of the cold end flange is sealed with the vacuum separation cover through the sealing piece, the connecting cover is connected with the cold end flange and is fastened through a fastening nut, the vacuum separation cover is provided with a pressurizing air pipe, the pressurizing air pipe end is respectively communicated with the gas cooling cavity and the LNG tank cavity, the hot end area comprises a hot end piston, the hot end piston is arranged in a hot end pump body and forms a third cavity and a fourth cavity, the end part of the hot end piston is designed into an annular groove opening form, the head of the hot end connecting rod is arranged in an annular groove of the piston opening, a supporting ring and the sealing piece are arranged between the hot end piston and the hot end pump body, a pressure relief device is arranged on the hot end piston, the hot end pump body is provided with a displacement sensor, the gaseous cooling area is provided with a high-pressure air pipe, the high-pressure air pipe is wound in the gaseous cooling area to form a gaseous cooling cavity, and the heat-insulating connecting rod connects the cold end connecting rod and the hot end connecting rod;

The fourth containing cavity is communicated with high-pressure hydraulic oil, the third containing cavity is communicated with low-pressure hydraulic oil, and the hot end piston moves towards the direction of a first arrow under the action of hydraulic pressure; simultaneously, the hot end piston drives the hot end connecting rod, the heat insulation connecting rod and the cold end connecting rod to move towards the direction of a first arrow;

the cold end connecting rod drives the cold end piston to move towards the direction of a first arrow, the volume of the first containing cavity is gradually increased, and the pressure in the first containing cavity is gradually reduced; at the moment, under the action of a one-way valve spring, the one-way valve body and the pressure fitting of the second steel ball are in a closed state;

The first steel ball is separated from the conical surface of the ball seat under the action of hydraulic pressure in the LNG tank cavity, and liquefied gas in the LNG tank cavity enters the first containing cavity through a hole on the liquid passing valve; the second containing cavity is communicated with the LNG tank cavity through the balance cavity, and the pressure in the second containing cavity is equal to that in the LNG tank cavity.

2.A cryopump of novel construction according to claim 1, wherein: the pressure relief device comprises a first pressure relief valve core, a second pressure relief valve core and a pressure relief spring, wherein the first pressure relief valve core and the second pressure relief valve core are pressed on the sealing conical surface by the spring force of the pressure relief spring, the end faces of the pressure relief valve cores are higher than the end faces of the hot end pistons, when the hot end pistons move towards the displacement sensor, the first pressure relief valve core is contacted with the hole wall firstly when the hot end piston end faces are close to the hole wall of the hot end pump body, the first pressure relief valve core is separated from the sealing conical surface, the third containing cavity is communicated with the fourth containing cavity through the first pressure relief hole, the hydraulic pressure of the third containing cavity and the hydraulic pressure of the fourth containing cavity are balanced, the hot end pistons are prevented from being in violent collision with the hole wall of the hot end pump body, and when the hot end pistons move towards the hot end bearing bush direction, the second pressure relief valve core is in accordance with the same working principle, and the violent collision between the hot end pistons and the hole wall is prevented.

3. A cryopump of novel construction according to claim 1, wherein: the hot end pump body is internally provided with a hydraulic oil first channel and a hydraulic oil second channel, the hydraulic oil first channel is communicated with the third containing cavity, the hydraulic oil second channel is communicated with the fourth containing cavity, and the hydraulic oil first channel and the hydraulic oil second channel are connected with the reversing valve through pipelines.

4. A cryopump of novel construction according to claim 1, wherein: in the hot end region, a hot end pump body and a hot end flange are fixedly connected through a fastening bolt, a hot end bearing bush and a sealing piece are arranged on the hot end flange, a checking port is arranged between the hot end bearing bush and the supporting ring, whether the sealing piece fails or not can be detected through the checking port so as to carry out maintenance of the low-temperature pump, an engine cooling liquid inlet, an engine cooling liquid outlet and a temperature sensor are arranged on the hot end flange, the temperature sensor can transmit temperature signals of the engine cooling liquid outlet, a connector, a high-pressure air pipe and a pressure sensor are arranged on the hot end flange, the connector and the hot end flange form a three-way cavity, the pressure sensor can transmit pressure signals of compressed natural gas in the three-way cavity, a booster component is arranged on the pump body, a booster valve core is pressed on a sealing conical surface through a booster spring, and when the pressure of the booster valve core is opened by the pressure of the air, the three-way cavity is communicated with the booster cavity through the three-way cavity and an air hole.

5. A cryopump of novel construction according to claim 1, wherein: the gasifier is characterized in that a gasifier component is arranged in the hot end region and is fixed with the hot end flange, a heat exchange cavity is formed between a gasifier outer shell and a gasifier inner shell of the gasifier component, the heat exchange cavity is communicated with an engine cooling liquid inlet, a liquid return cavity is formed by surrounding the gasifier inner shell and is communicated with an engine cooling liquid outlet, the heat exchange cavity is communicated with the liquid return cavity through a liquid through hole, a drain plug is arranged at one end of the gasifier, after the gasifier is used for a set time, scale in the heat exchange cavity can be cleaned through the drain plug, a heat insulation plate is arranged at the position of the water plug in a connecting cover, a high-pressure air pipe is arranged in the heat exchange cavity in a cross spiral shape, and natural gas in the high-pressure air pipe is led to the three-way cavity after heat exchange.

6. A cryopump of novel construction according to claim 1, wherein: the connecting cover is provided with a vent hole, and the pressurizing cavity is communicated with the gas cooling cavity through the vent hole.