CN220707829U - Cold energy conduction device - Google Patents

Abstract

The utility model discloses a cold quantity conduction device which comprises a connecting pipeline arranged between a pressure control container and a liquid nitrogen circulating pipeline, wherein the connecting pipeline comprises a cold guide pipeline, a copper rod is arranged in the cold guide pipeline, one end of the copper rod stretches into the cold guide pipeline, the other end of the copper rod stretches into the pressure control container, and the copper rod is used for reducing the heat difference between circulating nitrogen in the liquid nitrogen circulating pipeline and saturated liquid nitrogen in the pressure control container. According to the utility model, one end of the copper bar extends into the cold guide pipeline, and the other end extends into the pressure control container, so that redundant cold in the first connecting pipeline is transmitted to the first pressure control container through the copper bar, saturated liquid nitrogen in the first connecting pipeline is cooled, the supercooling degree is improved, the heat difference between circulating nitrogen in the first connecting pipeline and saturated liquid nitrogen in the pressure control container is reduced, the heat balance of the circulating nitrogen and the saturated liquid nitrogen in the pressure control container is ensured, and the vaporization of the liquid nitrogen in the pressure control container caused by heat leakage is prevented.

Description

Cold energy conduction device

Technical Field

The utility model relates to the technical field of superconducting cable cooling, in particular to a cold energy conduction device.

Background

The high-temperature superconducting technology is taken as a leading edge leading technology with strategic significance, and has wide application prospect in the fields of urban power grid transformation, magnetic suspension traffic, large scientific devices and the like along with rapid development of urbanization and industrialization. In particular, the high-temperature superconductive power transmission is praised as a revolution in the power industry of the century, is the electrical technology with the most potential in the 21 st century, has the advantages of low loss, large capacity, small volume, no pollution and the like, and is hopeful to obtain engineering application and popularization in urban power grid reconstruction, narrow corridor main power grid, occasions requiring special and conventional technology difficult to solve. High temperature superconducting cables are rapidly approaching commercial reality, and many cable demonstration projects are showing the feasibility of this technology worldwide. One common feature of these projects is that the high temperature superconducting cable is cooled with subcooled circulating liquid nitrogen. Typically, the circulating liquid nitrogen is at a temperature in the range of 68-75K, which does not allow boiling under the power of the cable to avoid potential electrical problems and uneven cooling.

The refrigeration of the high-temperature superconducting cable is divided into open refrigeration and closed refrigeration; open refrigeration, which is the use of large amounts of liquid nitrogen, is supplied to a cold box operating at reduced pressure and under evacuation to cool the circulating liquid nitrogen. The open refrigeration has the main advantages of relatively simple design, large liquid nitrogen consumption and high reliability. Closed refrigeration is to use a mechanical refrigerator to maintain the supercooled liquid nitrogen operating temperature. Compared with open refrigeration, the closed refrigeration has the main advantages of lower operation cost and capability of avoiding daily liquid nitrogen filling by using a relatively large liquid nitrogen storage tank.

The patent document with the prior patent publication number of CN112542271A discloses a liquid nitrogen cooling circulation system which is applied to cooling of a superconducting cable and comprises a control device, a cooling circulation pipeline, an evacuating refrigeration device and a liquid nitrogen supplementing device; the evacuating and refrigerating device comprises a supercooled liquid nitrogen Dewar, refrigerating equipment and a heat exchanger; the supercooled liquid nitrogen dewar is internally stored with supercooled liquid nitrogen, and the heat exchanger is arranged in the supercooled liquid nitrogen dewar; the control device controls the refrigeration equipment to refrigerate the supercooled liquid nitrogen in the supercooled liquid nitrogen Dewar in an evacuating and depressurizing mode, the heat exchanger is connected with the cooling circulation pipeline, and the supercooled liquid nitrogen in the supercooled liquid nitrogen Dewar is used for cooling the circulating liquid nitrogen in the cooling circulation pipeline; the nitrogen problem generated by liquid nitrogen evaporation in the process of treating circulating liquid nitrogen heat exchange is solved, and refrigeration can be realized without a refrigeration unit with relatively high cost; therefore, the manufacturing cost and the maintenance cost of the liquid nitrogen cooling circulation system are reduced while the nitrogen generated by liquid nitrogen evaporation in the process of treating and circulating liquid nitrogen heat exchange are solved.

The liquid nitrogen cooling circulation system is used for cooling the inlet wire of the superconducting cable through a cooling circulation pipeline, a pressure control container is usually arranged on the circulation pipeline and used for controlling the pressure in the circulation pipeline, saturated liquid nitrogen is usually obtained from a liquid nitrogen supplementing device, if the heat leakage of the saturated liquid nitrogen in the pressure control container is larger than the cold input, the saturated liquid nitrogen is vaporized, the pressure in the pressure control container is increased by vaporization, the pressure in the pressure control container is required to be continuously discharged, the vaporized nitrogen is discharged by pressure relief, the consumption of the liquid nitrogen is increased, and the production cost is increased.

Disclosure of Invention

The utility model aims to solve the technical problem of how to prevent vaporization of liquid nitrogen in a pressure control container caused by heat leakage.

The utility model solves the technical problems by the following technical means: the utility model provides a cold energy conduction device, includes the connecting line of locating between accuse pressure vessel and the liquid nitrogen circulation pipeline, the connecting line includes leads cold pipeline, be equipped with the bar copper in the cold pipeline of leading, bar copper one end stretches into in leading cold pipeline, the other end stretches into accuse pressure vessel, the bar copper is used for reducing the heat difference between the saturated state liquid nitrogen in the circulating nitrogen gas in the liquid nitrogen circulation pipeline and the accuse pressure vessel.

Through the setting of bar copper, make its one end stretch into in the cold pipeline of leading, the other end stretches into in the accuse pressure container for with the redundant cold volume in the first connecting pipeline pass through the bar copper and transmit to first accuse pressure container, cool off the saturated liquid nitrogen in it, improve the supercooling degree, reduce the heat difference between the saturated liquid nitrogen in the circulating nitrogen in the first connecting pipeline and the accuse pressure container, guarantee its heat balance, prevented that the heat leak from causing the liquid nitrogen vaporization in the accuse pressure container.

Three sets of cold sources of the Stirling refrigerator, the reverse Brayton refrigerator and the evacuating and decompressing system are arranged to provide cold for the refrigerating system, the three sets of cold sources are mutually independent and are mutually backup, on-line switching operation and on-line maintenance can be realized, the running reliability of the cold sources of the system is improved, meanwhile, the cost is saved to the greatest extent, two sets of pump boxes are used for providing circulating power for the refrigerating system, the two sets of pump boxes are connected in parallel and are mutually backup, on-line switching operation and on-line maintenance can be realized, and liquid nitrogen pumps are independently arranged in independent pump boxes at the same time, so that the maintenance is convenient.

As an optimal technical scheme, the copper rod is detachably connected in the cold guide pipeline.

As the preferable technical scheme, female head of socket joint is fixedly connected with in accuse pressure container top, female head top of socket joint is equipped with the male head of socket joint, female head of socket joint and the male head sliding fit of socket joint, female head of socket joint, the male head top of socket joint all are equipped with the ring flange, female head of socket joint, male head of socket joint can be connected at female head top of socket joint through the flange joint to through bolted connection fastening, bar copper fixed connection is in the male head bottom of socket joint.

As the preferable technical scheme, the pressure control container comprises a first pressure control container cylinder body, the first pressure control container cylinder body comprises a first pressure control container inner cylinder body and a first pressure control container outer cylinder body which are coaxially fixed, the first pressure control container inner cylinder body is fixedly connected in the first pressure control container outer cylinder body, and the socket joint female head is fixedly connected at the top of the first pressure control container outer cylinder body.

As the preferable technical scheme, the pressure control container further comprises a heat exchange rod fixing pipe and a heat exchange rod, wherein the bottom of the socket male head is fixedly connected with the heat exchange rod through the heat exchange rod fixing pipe, and the bottom of the heat exchange rod is fixedly connected with the copper rod.

As an optimal technical scheme, the bottom of the heat exchange rod is in threaded connection with the copper rod.

As the preferable technical scheme, the connecting pipeline further comprises a liquid supplementing pipeline, one end of the liquid supplementing pipeline is connected with the inner cylinder of the first pressure control container, and the other end of the liquid supplementing pipeline is connected with the liquid nitrogen circulating pipeline.

As the preferable technical scheme, a first filter screen of the pressure control container and a second filter screen of the pressure control container are arranged in the inner cylinder of the first pressure control container, the first filter screen of the pressure control container is wrapped on the outer side of the copper rod and is communicated with the cold guide pipeline, and the second filter screen of the pressure control container is arranged on the outer side of the inlet of the fluid infusion pipeline.

The utility model has the advantages that:

(1) According to the utility model, one end of the copper bar extends into the cold guide pipeline, and the other end extends into the pressure control container, so that redundant cold in the first connecting pipeline is transmitted to the first pressure control container through the copper bar, saturated liquid nitrogen in the first connecting pipeline is cooled, the supercooling degree is improved, the heat difference between circulating nitrogen in the first connecting pipeline and saturated liquid nitrogen in the pressure control container is reduced, the heat balance of the circulating nitrogen and the saturated liquid nitrogen in the pressure control container is ensured, and the vaporization of the liquid nitrogen in the pressure control container caused by heat leakage is prevented.

(2) According to the utility model, the resistance caused by the additionally arranged copper bars is balanced through the arrangement of the liquid supplementing pipeline, and meanwhile, the copper bars and the heat exchange bars are detachably connected, so that the copper bars with different sizes can be conveniently replaced, and the copper bars can be conveniently replaced during debugging through the arrangement of the socket male head and the socket female head.

Drawings

FIG. 1 is a schematic diagram of a system structure according to an embodiment of the present utility model;

FIG. 2 is a schematic diagram of an overall structure according to an embodiment of the present utility model;

FIG. 3 is a schematic diagram of a first pump case according to an embodiment of the present utility model;

fig. 4 is a schematic structural diagram of a first pressure control container according to an embodiment of the present utility model;

FIG. 5 is a schematic view of a socket male assembly according to an embodiment of the present utility model;

FIG. 6 is a schematic view of a female socket assembly according to an embodiment of the present utility model;

fig. 7 is a schematic structural diagram of a first pressure control container according to an embodiment of the present utility model;

fig. 8 is a schematic structural diagram of a second filter screen of the pressure control container according to an embodiment of the present utility model;

fig. 9 is a schematic diagram of a first filter screen of a pressure control container according to an embodiment of the present utility model;

reference numerals: 1. an air compressor; 2. a one-way valve; 3. a valve air source storage tank; 4. a first pressure reducing valve; 5. a second pressure reducing valve; 6. an air temperature type vaporizer; 7. a first manual shut-off valve; 8. a pipe filter; 9. a second manual shut-off valve; 10. a liquid nitrogen storage tank; 11. a first pneumatic shut-off valve; 12. a second pneumatic shut-off valve; 13. a third pneumatic shut-off valve; 14. a fourth pneumatic shut-off valve; 15. a first pipe filter; 151. a filter tube; 152. a filter screen; 16. a fluid replacement container; 17. a first pump tank; 171. a socket female assembly; 1711. the first socket joint female head pipe body; 1712. the second socket joint female head pipe body; 1713. a socket joint female connecting pipe; 1714. a socket female flange; 172. a socket male assembly; 1721. a socket joint male pipe body; 1722. a socket male compression ring; 18. a fifth pneumatic shut-off valve; 19. a sixth pneumatic shut-off valve; 20. a first pressure control vessel; 201. a copper bar; 202. a heat exchange rod; 203. a heat exchange rod fixing tube; 204. a first filter screen of the pressure control container; 205. a second filter screen of the pressure control container; 206. a first pressure control vessel cylinder; 2061. a first pressure control container outer cylinder; 2062. a first pressure control container inner cylinder; 21. a Stirling refrigerator; 22. a seventh pneumatic shut-off valve; 23. an eighth pneumatic shut-off valve; 24. a first air temperature vaporizer; 25. a ninth pneumatic shut-off valve; 26. a tenth pneumatic shut-off valve; 27. an eleventh pneumatic shut-off valve; 28. a first evacuation pump; 29. a second evacuation pump; 30. a twelfth pneumatic shut-off valve; 31. a second air temperature type vaporizer; 32. a cold box; 33. a supercooling heat exchanger; 34. a thirteenth pneumatic shut-off valve; 35. a fourteenth pneumatic shut-off valve; 36. a fifteenth pneumatic shut-off valve; 37. an inverse brayton refrigerator; 38. a sixteenth pneumatic stop valve; 39. a first terminal thermostat; 40. seventeenth pneumatic shutoff valve; 41. a superconducting cable thermostat; 42. an eighteenth pneumatic shut-off valve; 43. a first flowmeter; 44. a first liquid nitrogen pump; 45. nineteenth pneumatic shutoff valve; 46. a twentieth pneumatic stop valve; 47. a second pressure control vessel; 48. a second flowmeter; 49. a second liquid nitrogen pump; 50. a second pipe filter; 51. a second terminal thermostat; 52. a second pump tank; 53. a twenty-first pneumatic shut-off valve; 54. a twenty-second pneumatic shut-off valve; 55. a twenty-third pneumatic shut-off valve; 56. pressure-controlled air-supplementing buffer tank.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions in the embodiments of the present utility model will be clearly and completely described in the following in conjunction with the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

Referring to fig. 1 and 2, a supercooled liquid nitrogen circulation system with a cold energy conduction device comprises a superconducting cable assembly and a liquid nitrogen circulation assembly, wherein an output end and an input end of the liquid nitrogen circulation assembly are respectively connected with an input end and an output end of the superconducting cable assembly and form a closed liquid nitrogen circulation loop, the superconducting cable assembly comprises a first terminal thermostat 39, a superconducting cable thermostat 41 and a second terminal thermostat 51 which are arranged along the liquid nitrogen circulation direction, and the liquid nitrogen circulation assembly is used for providing cold energy for the superconducting cable assembly; the temperature-returning liquid nitrogen (< 77K) flowing out of the second terminal thermostat 51 is pressurized by a liquid nitrogen pump in the pump box 17, enters a supercooling heat exchanger 33 in the cold box 32 to obtain cold 70K supercooled liquid nitrogen (the cold source is an inverse Brayton refrigerator 37 or a Stirling refrigerator 21 or an evacuating and depressurizing system), then flows into a first terminal thermostat 39 of the high-temperature superconducting cable, cools the superconducting cable, finally returns to the liquid nitrogen pump, and starts a new cycle;

the liquid nitrogen circulation assembly comprises a cold box 32, two groups of pump boxes, a cold source assembly, a pressure control system, a liquid nitrogen storage tank 10, a liquid supplementing container 16, an air compressor 1 and a pressure control and air supplementing buffer tank 56, wherein the output end of the superconducting cable assembly is connected with the input end of the cold box 32 through a first connecting pipe, the output end of the cold box 32 is connected with the input end of the superconducting cable assembly through a second connecting pipe, namely a first terminal thermostat 39, the two groups of pump boxes are connected in parallel on the first connecting pipe, an insulating section is arranged on the first connecting pipe, the insulating section can meet the condition that liquid nitrogen is communicated on the first connecting pipe and can play an insulating role, the insulating section is positioned at the downstream of the second terminal thermostat 51, and because all the connecting pipes are metal pipes and are prevented from being conducted, a liquid nitrogen pump and a pressure control container is arranged in the pump box, the liquid nitrogen pump is connected on the first connecting pipe and provides power for circulation, the pressure control container is connected with the first connecting pipe, and is used for controlling the working pressure of circulation, and buffering the volume change in the liquid nitrogen expansion process, the cold source assembly comprises a liquid nitrogen compressor 21, an evacuation device 37, a Stirling compressor and a Stirling compressor 37, a Stirling compressor 32 can be saturated and a cold medium can be evacuated independently, namely, and the cold medium can be cooled and the cold source assembly is in the state 32.

The three cold sources of the reverse brayton refrigerator 37, the Stirling refrigerator 21 and the evacuating and depressurizing system are adopted, the three cold sources are mutually backed up, the on-line switching and the on-line maintenance and repair can be carried out at will, a liquid nitrogen circulating power source liquid nitrogen pump is arranged in an independent pump box, the system adopts two sets of pump boxes to mutually backup, the pump boxes can realize the on-line switching and the on-line maintenance, the system pressure control adopts three pressure control modes of liquid supplementing pressure control, air supplementing pressure control and heating pressure control, the pressure control modes are mutually independent and mutually backup, an automatic valve of the system is a pneumatic valve, a valve air source is from the liquid nitrogen storage tank 10 or the air compressor 1, one of the two is used for one, and the reliability of the air source is ensured.

Referring to fig. 1, the pressure control system comprises an air supplementing pressure control pipeline, a liquid supplementing pressure control pipeline and a heating pressure control assembly, wherein the air output port and the liquid output port of the liquid nitrogen storage tank 10 are respectively connected with the pressure control container through the air supplementing pressure control pipeline and the liquid supplementing pressure control pipeline, the heating pressure control assembly comprises a heater arranged in the pressure control container, and the air supplementing pressure control pipeline and the liquid supplementing pressure control pipeline are respectively provided with a control valve which is a pneumatic stop valve.

Referring to fig. 1, the two sets of pump boxes comprise a first pump box 17 and a second pump box 52, the first pump box 17 and the second pump box 52 have the same structure, a first pressure control container 20, a first pipeline filter 15, a first liquid nitrogen pump 44 and a first flowmeter 43 are arranged in the first pump box 17, a second pressure control container 47, a second pipeline filter 50, a second liquid nitrogen pump 49 and a second flowmeter 48 are arranged in the second pump box 52, the first pump box 17 and the second pump box 52 are connected in parallel on a first connecting pipeline, a first pneumatic stop valve 11 and an eighteenth pneumatic stop valve 42 are respectively arranged at the upstream and downstream of the first pump box 17 and the first connecting pipeline, a twenty-first pneumatic stop valve 53 and a twenty-second pneumatic stop valve 46 are respectively arranged at the upstream and downstream of the second pump box 52 and heaters are respectively arranged in the first pressure control container 20 and the second pressure control container 47.

Referring to fig. 3, 4, 5 and 6, the first pipe filter 15 and the second pipe filter 50 are both detachable structures, and the original pipe filters are directly welded on the pipes, i.e. the first connecting pipe in the embodiment, but are inconvenient to overhaul, once a problem occurs, only the metal pipe can be broken and disassembled, so that the overhaul is unchanged;

in this embodiment, taking a socket structure on the first pipe filter 15 as an example, the top of the first pump case 17 is fixedly connected with a socket head assembly 171, one end of the first connecting pipeline, which is connected with the socket head assembly 171, is fixedly connected with a socket head assembly 172, the bottom of the socket head assembly 172 is fixedly connected with the first pipe filter 15, wherein the socket head assembly 172 comprises a socket head pipe 1721 and a socket head press ring 1722, the socket head press ring 1722 is fixedly connected with the top of the socket head pipe 1721, the socket head assembly 171 comprises a first socket head pipe 1711, a second socket head pipe 1712, a socket head connecting pipe 1713 and a socket head flange 1714, the second socket head pipe 1712 is coaxially fixed in the first socket head pipe 1711, the first socket head pipe 1711 is fixedly connected with the first pump case 17, the second socket head pipe 1712 is in sliding fit with the socket head pipe 1721, the bottom of the second socket joint female pipe body 1712 is fixedly connected with a socket joint female pipe 1713, the socket joint female pipe 1713 is a part of a first connecting pipe, the top of the first socket joint female pipe body 1711 is fixedly connected with a socket joint female flange 1714, the inner diameter of the second socket joint female pipe body 1712 is slightly larger than the outer diameter of the socket joint male pipe body 1721, a threaded interface is formed at the bottom of the socket joint male pipe body 1721 and is in threaded connection with the first pipeline filter 15, the first pipeline filter 15 comprises a filter pipe 151 and a filter screen 152, a plurality of groups of circular through holes are formed in the circumference of the filter pipe 151, each group of through holes comprise a plurality of through holes which are distributed along the circumference of the filter pipe 151 at equal angles, the groups of through holes are distributed along the axial direction of the through holes at equal intervals, the purpose of the side surface opening is to ensure the overcurrent area, no resistance is caused to the circulating system, a gap is reserved between the socket joint female pipe 1713 and the filter pipe 151, the filter screen 152 is fixedly arranged in the gap, a closed cavity structure, namely a compact steel wire mesh, is formed between the filter screen 152 and the socket joint female connecting pipe 1713, so that the filter screen 152 can play a role in filtering and can be fixed at the bottom of the second socket joint female pipe 1712;

nitrogen gas enters the female socket joint body 1721 from the first connecting pipeline, enters the filter tube 151, is filtered by dense steel wire gauze from the through holes on the side surface of the filter tube, enters a closed cavity structure formed between the filter screen 152 and the female socket joint 1713, and enters the subsequent first connecting pipeline.

Referring to fig. 1, the pressure control container is connected to the first connection pipe, that is, the first pressure control container 20 and the second pressure control container 47 are both connected to the first connection pipe, in this embodiment, the first pressure control container 20 is connected to the first connection pipe through a cold guide pipe, a copper rod 201 is disposed in the cold guide pipe, and is used for transferring the redundant cold in the first connection pipe to the first pressure control container 20 through the copper rod 201, cooling the first connection pipe, reducing the heat difference between the circulating nitrogen in the first connection pipe and the saturated liquid nitrogen in the pressure control container, ensuring the heat balance of the first connection pipe (that is, the saturated liquid nitrogen leakage in the pressure control container is greater than the cold input), if there is heat leakage (that is, the saturated liquid nitrogen leakage in the pressure control container is greater than the cold input), then the liquid nitrogen will be vaporized, the vaporization will increase the pressure in the pressure of the pressure control container, then the sixth pneumatic stop valve 19 needs to be opened, ensuring the pressure stability, so that the cold liquid nitrogen input into the pressure control container and the pressure control container can not reach the balance through the copper rod 201, but the optimal heat leakage rate can not be ensured by the copper rod is not be fixed in the two-dimensional ways, and the pressure control pipe 201 can not reach the optimal heat-conducting and the two-up rate can not reach the first connection pipe, and the optimal heat-up ratio can not reach the pressure control pipe, and the two-up-down rate can not reach the effect, and the direct-flow control pipe 201 is ensured, and the optimal, and the heat-up rate can reach the direct-down effect, and the pressure-flow through the pressure control pipe, and the pressure control pipe can be directly reaches the pressure-down.

Referring to fig. 7, 8 and 9, the first pressure control vessel 20 includes a first pressure control vessel cylinder 206, a first filter screen 204 of the pressure control vessel, a second filter screen 205 of the pressure control vessel, a heat exchange rod fixing tube 203, and a heat exchange rod 202, the first pressure control vessel cylinder 206 includes a first pressure control vessel outer cylinder 2061 and a first pressure control vessel inner cylinder 2062 which are coaxially fixed, a socket head 2063 is fixedly connected to the first pressure control vessel outer cylinder 2061, a socket male 2064 is detachably and fixedly connected to the socket head 2063, the socket head 2063 and the socket male 2064 are in the same principle as the socket male assembly 172 and the socket female assembly 171, and are both in sliding fit and are connected through flange bolts, the socket head 2063 is fixedly connected to the top of the first pressure control vessel outer cylinder 2061, the socket male 2064 is clamped on the socket head 2063, the socket male 2064 is detachably fixed with two flange plates of the socket head 2063 through bolts, the bottom of the spigot-and-socket joint male head 2064 is fixedly connected with the copper rod 201 through the heat exchange rod fixing tube 203 and the heat exchange rod 202, wherein the heat exchange rod fixing tube 203 is fixedly connected with the heat exchange rod 202, the bottom of the heat exchange rod 202 is in threaded connection with the copper rod 201, the copper rod 201 is convenient to replace, the pressure control container first filter screen 204 is fixed in the first pressure control container inner cylinder 2062 and is positioned outside the heat exchange rod fixing tube 203 and the heat exchange rod 202, the pressure control container second filter screen 205 is fixedly connected with the inner wall of the bottom of the first pressure control container inner cylinder 2062, the pressure control container first filter screen 204 and the pressure control container second filter screen 205 can both prevent impurities from entering the circulating pipeline, thus the first pressure control container 20 is communicated with the first connecting pipeline through the fluid supplementing pipeline, the first pressure control container 20 is also communicated with the first connecting pipeline through the cold guide pipeline, the vertical side wall of the cold guide pipeline is provided with an input port of the first connecting pipeline, the first connecting pipeline is connected with one end of the cold guide pipeline and one end of the fluid supplementing pipeline in a tee joint mode.

Referring to fig. 1, the input end of the air supply pressure control pipeline is further connected with the output end of the air compressor 1, the air supply pressure control pipeline is provided with a pressure control air supply buffer tank 56, the air supply pressure control pipeline comprises a first branch, a second branch and a main pipeline, the liquid nitrogen storage tank 10 is connected with the main pipeline through the first branch, the air compressor 1 is connected with the main pipeline through the second branch, the first branch is sequentially provided with a first manual stop valve 7 and an air temperature type carburetor 6, the second branch is sequentially provided with a one-way valve 2, a valve air source storage tank 3 and a first pressure reducing valve 4, the valve air source storage tank 3 is used for supplying air to all the pneumatic valves, the main pipeline is provided with a second pressure reducing valve 5, the first pressure control container 20 and the second pressure control container 47 in the first pump box 17 and the second pump box 52 are respectively connected with an exhaust pipeline, the main pipeline is provided with a sixth pneumatic stop valve 19, the main pipeline is sequentially connected with the first pressure control container 20 through the first air supply pipeline, the main pipeline is sequentially provided with a second air supply pipeline and a third air stop valve 13, and the third air supply stop valve 13 is respectively arranged on the main pipeline and the second air supply container 52.

Referring to fig. 1, the input end of the fluid-supplementing pressure control pipeline is connected with a liquid nitrogen storage tank 10, two output ends of the fluid-supplementing pressure control pipeline are respectively connected with a first pressure control container 20 and a second pressure control container 47, a second manual stop valve 9, a pipeline filter 8, a second pneumatic stop valve 12 and a twenty-second pneumatic stop valve 54 are arranged on the fluid-supplementing pressure control pipeline, the fluid-supplementing pressure control pipeline is connected with the first pressure control container 20 through a first fluid-supplementing pipeline, the fluid-supplementing pressure control pipeline is connected with the second pressure control container 47 through a second fluid-supplementing pipeline, wherein the second pneumatic stop valve 12 and the twenty-second pneumatic stop valve 54 are respectively provided with a controllable fluid-supplementing pressure control pipeline which is communicated with the first pressure control container 20 and the second pressure control container 47, the other output end of the fluid-supplementing pressure control pipeline is connected with a fluid-supplementing container 16, the fluid-supplementing container 16 is connected with a cold box 32 through a fluid-supplementing output pipeline for supplementing liquid nitrogen for the cold box 32, a fourth pneumatic stop valve 14 is arranged on the fluid-supplementing pressure control pipeline, and a fifth pneumatic stop valve 18 is arranged on the fluid-supplementing output pipeline;

through the arrangement of the liquid supplementing container 16, the liquid supplementing container 16 is a normal pressure liquid nitrogen Dewar with an exhaust port communicated with the atmosphere, high pressure liquid nitrogen in the liquid nitrogen storage tank 10 is changed into 77.2K normal pressure liquid nitrogen after entering the liquid supplementing container 16, and the liquid supplementing container 16 supplements liquid nitrogen into the negative pressure cold box 32, so that the temperature fluctuation of the cold box 32 in the liquid supplementing process is reduced, and the temperature stability of the circulating liquid nitrogen of the system is ensured.

Referring to fig. 1, a cold box 32 is a double-layer vacuum heat-insulating container, a supercooling heat exchanger 33 is arranged in the cold box 32, two ends of the supercooling heat exchanger 33 are respectively connected with a first connecting pipeline and a second connecting pipeline, the supercooling heat exchanger 33 is positioned below the liquid level of a cooling medium in the cold box 32, so that the supercooling heat exchanger 33 is soaked in negative-pressure liquid nitrogen, the temperature of the negative-pressure liquid nitrogen is consistent with that of the negative-pressure liquid nitrogen, high-pressure liquid nitrogen circulated by the system exchanges heat with the negative-pressure liquid nitrogen through the supercooling heat exchanger 33 to obtain cold energy, so that the liquid nitrogen entering a superconducting cable is guaranteed to be in a supercooled state, the cold box 32 is a double-layer vacuum heat-insulating container, negative-pressure saturated liquid nitrogen is stored therein, the cold energy of the negative-pressure liquid nitrogen is obtained from an inverse brayton refrigerator 37 or a stirling refrigerator 21 or an evacuation pressure reducing pump first evacuation pump 28 or a second evacuation pump 29.

Referring to fig. 1, the first pump tank 17 adopts a single-layer structure, adopts vacuum multi-layer heat insulation and heat preservation, the first liquid nitrogen pump 44 and the second liquid nitrogen pump 49 both provide circulating power for supercooled liquid nitrogen, the circulating flow is regulated through a frequency converter, the first pressure control container 20 and the second pressure control container 47 are both used for controlling the working pressure of circulating liquid nitrogen, and meanwhile, the first pressure control container 20 and the second pressure control container 47 are also used as buffer containers of a circulating system so as to buffer the volume change in the expansion and contraction process of liquid nitrogen, the system fluid infusion and the pressure control are both realized through the pressure control containers, the bottoms of the first pressure control container 20 and the second pressure control container 47 are communicated with the circulating liquid nitrogen through pipelines, so that the pressure transmission is carried out, and the system working pressure control has three modes:

(1) Air supplementing and pressure controlling: when the pressure is lower than the lower limit of the set value, the third pneumatic stop valve 13 is opened, the pressure control and air supplementing buffer tank 56 supplements air to the pressure control container (the first pressure control container 20 or the second pressure control container 47), when the target pressure is reached, air intake is stopped, when the pressure is higher than the upper limit of the set value, the sixth pneumatic stop valve 19 is opened to exhaust, after the pressure reaches the set value, the air source of the pressure control and air supplementing buffer tank 56 comes from the gas phase space of the liquid nitrogen storage tank 10, after passing through the air temperature type vaporizer 6, the air source is changed into normal-temperature nitrogen, after being depressurized through the second pressure reducing valve 5, the normal-temperature nitrogen enters the pressure control and air supplementing buffer tank 56;

(2) Supplementing liquid and controlling pressure: when the pressure is lower than the lower limit of the set value, the second pneumatic stop valve 12 is opened, the liquid nitrogen storage tank 10 supplements liquid to the pressure control container, when the target pressure is reached, liquid feeding is stopped, when the pressure is higher than the upper limit of the set value, the sixth pneumatic stop valve 19 of the pressure control container is opened, and after the set value is reached, the second pneumatic stop valve 12 (used for supplementing liquid) is closed, and when the second pneumatic stop valve 12 is just opened, gas-liquid two-phase flow is coming in, so that the aim of pressurization can be achieved;

(3) Heating and controlling pressure: when the pressure is lower than the lower limit of the set value, a heater arranged in the pressure control container is turned on, when the target pressure is reached, heating is stopped, and when the pressure is higher than the upper limit of the set value, a first pneumatic stop valve (for exhausting) 19 of the pressure control container is opened, and after the set value is reached, the first pneumatic stop valve is closed.

The pressure control modes can be selected by self and mutually independent and backed up, the pressure control process is automatically controlled by a program, personnel is not required to watch, the top of the pressure control container is provided with a liquid supplementing port, liquid nitrogen is required to be provided by the liquid nitrogen storage tank 10, the pressure control container is provided with a liquid level meter, the liquid level of the pressure control container can be monitored in real time, when the liquid level is lower than the lower limit of a set value, the third pneumatic stop valve 13 is opened to supplement liquid to the system, when the liquid level is higher than the upper limit of the set value, the liquid supplementing valve is closed, the liquid supplementing is stopped, the impeller of the liquid nitrogen pump is protected from being damaged by solid particles, a pipeline filter is arranged at the upstream of the liquid nitrogen pump, the liquid nitrogen pump is provided with a first flowmeter 43, the flow of the system can be monitored in real time, the rotation frequency of the pump can be controlled through a frequency converter so as to regulate the liquid nitrogen circulation flow, the inlet and outlet temperature difference of a superconducting cable can be regulated, the liquid nitrogen pump is a moving part, regular maintenance is required, the liquid nitrogen pump and the pressure control container is placed in a pump box, and the system is provided with a redundancy design for 2 sets of pumps, the first pump box 17 and a second pump box 52 are arranged, a backup pump box is ready, and a cold state is switched to a working state.

When the refrigerating system is in operation, the saturated liquid nitrogen in the cold box 32 is about 68K, the saturated pressure is about 17kPa, at the moment, the saturated liquid nitrogen in the liquid nitrogen storage tank 10 is about 0.8MPa, the temperature is higher, in order to prevent the impact on the liquid nitrogen temperature of the cold box 32 when the liquid is replenished to the cold box 32, the cold box 32 is provided with a normal pressure liquid replenishing container 16, the high-pressure liquid nitrogen in the liquid nitrogen storage tank 10 enters the liquid replenishing container 16 and is changed into normal pressure liquid nitrogen, the liquid replenishing container 16 always keeps liquid nitrogen with a certain liquid level corresponding to the liquid nitrogen temperature of 77.2K, and when the liquid replenishing is needed by the cold box 32, the fifth pneumatic stop valve 18 is opened, and the liquid replenishing is carried out to the cold box 32 by utilizing the gravity and the pressure difference.

Referring to fig. 1, a stirling cooler 21 is connected to a cold box 32 through a stirling cooler input line and a stirling cooler output line, the stirling cooler input line and the stirling cooler output line are respectively provided with a seventh pneumatic stop valve 22 and an eighth pneumatic stop valve 23, the first connecting line is connected to the cold box 32 through the cold box input line, the cold box input line is provided with a seventeenth pneumatic stop valve 40, the cold box 32 is connected to a second connecting line through the cold box output line, the cold box output line is provided with a thirteenth pneumatic stop valve 34, the first connecting line and the second connecting line are also connected through an intermediate connecting line, the intermediate connecting line is sequentially provided with a sixteenth pneumatic stop valve 38, an inverse brayton cooler 37 and a fifteenth pneumatic stop valve 36, the intermediate connecting line is arranged so that the whole circulation system does not need to pass through the cold box 32, the cold energy can be directly supplied through the inverse brayton refrigerator 37 and through the inverse brayton refrigerator 37, wherein the cold energy input pipeline of the cold energy storage system is further connected with the middle connecting pipeline through the third connecting pipeline, one end of the third connecting pipeline connected with the cold energy input pipeline is positioned at the downstream of the seventeenth pneumatic stop valve 40, one end of the third connecting pipeline connected with the middle connecting pipeline is positioned at the upstream of the fifteenth pneumatic stop valve 36 and at the downstream of the inverse brayton refrigerator 37, the fourteenth pneumatic stop valve 35 is arranged on the third connecting pipeline, the cold energy can be supplied to the cold energy storage system 32 through the inverse brayton refrigerator 37 through the arrangement of the third connecting pipeline, the cold energy storage system has the advantages that the cold energy storage system 32 is used as a cold energy storage device, the cold energy of the cold energy storage system 32 can be maintained for a certain time even if a turbine breaks down, and the whole operation of the system is ensured, the end of the third connecting line connected to the intermediate connecting line is located upstream of the fifteenth pneumatic shut-off valve 36.

Referring to fig. 1, the evacuation pressure reducing system includes two groups of parallel evacuation pressure reducing pipelines with the same structure, namely a first evacuation pressure reducing pipeline and a second evacuation pressure reducing pipeline, wherein the first evacuation pressure reducing pipeline is sequentially provided with a first air temperature type vaporizer 24, an eleventh pneumatic stop valve 27 and a first evacuation pump 28, the second evacuation pressure reducing pipeline is sequentially provided with a second air temperature type vaporizer 31, a twelfth pneumatic stop valve 30 and a second evacuation pump 29, a first maintenance pipeline is further connected between the first air temperature type vaporizer 24 and the eleventh pneumatic stop valve 27, a ninth pneumatic stop valve 25 is arranged on the first maintenance pipeline, a second maintenance pipeline is further connected between the second air temperature type vaporizer 31 and the twelfth pneumatic stop valve 30, and a tenth pneumatic stop valve 26 is arranged on the second maintenance pipeline.

The maintenance period of the inverse brayton refrigerator 37 is long, the temperature control is stable, liquid nitrogen is not consumed in the working process, the inverse brayton refrigerator can be disconnected from the cold box 32, when maintenance is needed, the fifteenth pneumatic stop valve 36 and the sixteenth pneumatic stop valve 38 can be closed, and when other cold sources need maintenance, the operation of the system can be ensured by using the refrigerator; the Stirling refrigerator 21 is connected with the cold box 32 through the Stirling refrigerator input pipeline and the Stirling refrigerator output pipeline, cold nitrogen enters the Stirling refrigerator 21 to cool and return to the cold box 32, the vapor pressure of the cold box 32 is continuously reduced to provide cold for the cold box 32, liquid nitrogen in the cold box 32 is not consumed in operation, and when maintenance is needed, the seventh pneumatic stop valve 22 and the eighth pneumatic stop valve 23 are closed, so that the cold nitrogen can be disconnected from a refrigerating system; the evacuation decompression system is connected with the cold box 32 through the first evacuation decompression pipeline and the second evacuation decompression pipeline, when the evacuation decompression system is started, taking the first evacuation decompression pipeline as an example, the evaporated nitrogen is heated to normal temperature through a pipeline by the first air temperature type vaporizer 24 and is then pumped out to the atmosphere by the first evacuation pump 28, the liquid nitrogen provides cold energy for the residual liquid nitrogen in the cold box 32 in the evaporation process, the evacuation decompression system adopts a redundant design, 1 is used for 1 equipment, the mode needs to pump out the nitrogen, so the liquid nitrogen consumption is larger, but the evacuation decompression system has the advantages of simple structure, low cost, high cooling speed and the like, and when maintenance is needed, the valve ninth pneumatic stop valve 25, the tenth pneumatic stop valve 26, the eleventh pneumatic stop valve 27 and the twelfth pneumatic stop valve 30 can be closed, and the evacuation pump is disconnected from the system.

In this embodiment, all the pneumatic stop valves (i.e., the first pneumatic stop valve 11 to the twenty-third pneumatic stop valve 55) are pneumatic valves, and the pneumatic valves need 4-6bar air sources for operation, so as to ensure stable and reliable air sources, and two air sources of nitrogen and air are adopted, and one is used. The nitrogen source comes from a gas valve for the liquid nitrogen storage tank 10, the nitrogen is heated to room temperature through the air temperature type vaporizer 6, the nitrogen is decompressed through the first decompression valve 4 and then enters the gas source storage tank 3 to be provided for each valve, the air source comes from the air compressor 1, enters the valve gas source storage tank 3 through the one-way valve 2 to be provided for each valve, the nitrogen source is dry and sufficient, the nitrogen source is preferentially used, and the aim can be achieved by adjusting the gas outlet pressure of the first decompression valve 4 to be larger than the starting pressure of the air compressor 1.

The above embodiments are only for illustrating the technical solution of the present utility model, and are not limiting; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present utility model.

Claims (8)

1. The utility model provides a cold quantity conduction device, its characterized in that, including locating the connecting line between accuse pressure container and the liquid nitrogen circulation pipeline, the connecting line is including leading cold pipeline, it is equipped with the bar copper to lead in the cold pipeline, bar copper one end stretches into in leading cold pipeline, the other end stretches into accuse pressure container, the bar copper is used for reducing the heat difference between the saturated state liquid nitrogen in the circulating nitrogen gas in the liquid nitrogen circulation pipeline and the accuse pressure container.

2. A cold energy transfer apparatus according to claim 1 wherein the copper rod is removably connected within the cold guide line.

3. The cold energy conduction device according to claim 2, wherein the top of the pressure control container is fixedly connected with a socket female head, the top of the socket female head is provided with a socket male head, the socket female head is in sliding fit with the socket male head, the tops of the socket female head and the socket male head are respectively provided with a flange plate, the socket female head and the socket male head can be connected to the top of the socket female head through flange clamping and are fastened through bolt connection, and the copper bar is fixedly connected to the bottom of the socket male head.

4. A cold energy conduction device according to claim 3 wherein the pressure control vessel comprises a first pressure control vessel cylinder comprising a first pressure control vessel inner cylinder and a first pressure control vessel outer cylinder coaxially fixed, the first pressure control vessel inner cylinder being fixedly connected within the first pressure control vessel outer cylinder, the socket head being fixedly connected at the top of the first pressure control vessel outer cylinder.

5. The cold energy conduction device according to claim 4, wherein the pressure control container further comprises a heat exchange rod fixing tube and a heat exchange rod, the bottom of the socket male head is fixedly connected with the heat exchange rod through the heat exchange rod fixing tube, and the bottom of the heat exchange rod is fixedly connected with the copper rod.

6. The cold energy conduction device according to claim 5, wherein the bottom of the heat exchange rod is in threaded connection with the copper rod.

7. The cold energy transfer apparatus of claim 4 wherein the connecting line further comprises a fluid replacement line having one end connected to the cylinder in the first pressure control vessel and the other end connected to the liquid nitrogen circulation line.

8. The cold energy conduction device according to claim 7, wherein the first pressure control container inner cylinder is internally provided with a first pressure control container filter screen and a second pressure control container filter screen, the first pressure control container filter screen is wrapped on the outer side of the copper bar and is communicated with the cold conducting pipeline, and the second pressure control container filter screen is arranged on the outer side of the fluid supplementing pipeline inlet.