CN113446753A

CN113446753A - Room-temperature magnetic refrigeration device and refrigeration method of coupling gravity heat pipe

Info

Publication number: CN113446753A
Application number: CN202110711664.9A
Authority: CN
Inventors: 巫江虹; 张尧康
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 2021-06-25
Filing date: 2021-06-25
Publication date: 2021-09-28
Anticipated expiration: 2041-06-25
Also published as: CN113446753B

Abstract

The invention discloses a room temperature magnetic refrigeration device and a refrigeration method of a coupling gravity assisted heat pipe, wherein the device comprises a gravity assisted heat pipe body, an internal heat exchange plate, a magnetic thermal material, a blocking filter screen, a fluid working medium and a magnet set; the interior of the gravity heat pipe body is divided into a plurality of areas by a plurality of internal heat exchange plates, the bottom end is a cold end for refrigerating a load, and the top end is a hot end for releasing heat to the environment; the invention widens the temperature span by alternately adding and demagnetizing odd-numbered stage and even-numbered stage magnetocaloric materials or gradually demagnetizing magnetocaloric materials from the hot end to the cold end, obtains low temperature and realizes refrigeration. The magnetic refrigeration device directly places the magnetic thermal material in the gravity heat pipe, and improves the heat exchange efficiency of the magnetic thermal material and the fluid working medium through the phase change of the fluid working medium, and improves the working frequency and the refrigerating capacity of the magnetic refrigeration device; the use of valve components and fluid pumps is reduced by utilizing the one-way heat transfer characteristic of the gravity heat pipe, the pipeline structure is simplified, and the reliability is improved; and multistage magnetic refrigeration is adopted, so that the operating temperature span is widened.

Description

Room-temperature magnetic refrigeration device and refrigeration method of coupling gravity heat pipe

Technical Field

The invention relates to the technical field of magnetic refrigeration, in particular to a room-temperature magnetic refrigeration device and a room-temperature magnetic refrigeration method of a coupling gravity heat pipe.

Background

The room temperature magnetic refrigeration uses Magnetocaloric Effect (MCE) of Magnetocaloric Material (MCM) in a room temperature region to realize refrigeration. Compared with the vapor compression refrigeration technology, the room temperature magnetic refrigeration does not need to use Hydrofluorocarbon (HFCs) refrigerants which aggravate the greenhouse effect, the cycle efficiency can reach 60 percent of Carnot cycle, and the room temperature magnetic refrigeration system has the advantages of environmental protection, energy conservation, high efficiency, low noise, safety, reliability and the like. Therefore, room temperature magnetic refrigeration technology is recognized as one of the most potential new refrigeration technologies to replace vapor compression refrigeration.

In recent years, with the development of room-temperature magnetic refrigeration technology, a plurality of room-temperature magnetic refrigeration models have been developed. Most prototypes are constructed based on the principle of Active Magnetic Regenerator (AMR).

However, the prototype based on AMR has a key technical difficulty in implementation, namely low operating frequency. One important reason for the low operating frequency of prototype machines is the limited convective heat transfer rate between the heat transfer fluid and the MCM. Therefore, the strengthening of the heat transfer between the heat exchange fluid and the MCM has important significance for improving the working frequency of a prototype.

Phase change heat transfer is a typical enhanced heat exchange method and is mature and applied in the field of heat pipes. Considering the coupling of the magnetic refrigeration technology and the heat pipe technology, chinese patent 201710412043.4 discloses a method for processing a heat pipe assembly with a magnetic refrigeration function. Firstly, the MCM is embedded into the liquid absorption core, and then the composite core is assembled on the heat pipe body, so that the structure is complex, and the processing difficulty is high; secondly, valve components are arranged on two sides of the magneto-caloric effect pipe section, and the functions of magnetizing, releasing heat, demagnetizing and refrigerating are realized through frequent switching of the valves, so that the requirements on control are high; finally, the maximum temperature span that can be achieved by the present invention is limited to the adiabatic temperature change of the MCM and cannot meet certain application requirements. Therefore, how to design a magnetic refrigeration device which has high heat transfer efficiency, simple structure, easy processing, large temperature span and high refrigeration capacity is a key technical problem to be solved by the invention.

Disclosure of Invention

The invention aims to overcome the defects and shortcomings of the prior art and provides a room-temperature magnetic refrigeration device and a room-temperature magnetic refrigeration method coupled with a gravity heat pipe. According to the invention, the magnetocaloric material is directly placed in the gravity heat pipe, and the heat exchange efficiency of the magnetocaloric material and the working medium is improved through the phase change of the fluid working medium in the heat pipe, so that the working frequency is improved; meanwhile, due to the one-way heat transfer characteristic of the gravity heat pipe, a valve component is not needed for heat insulation, so that the structure is simplified; and on the basis, multistage magnetic refrigeration is adopted, so that the operating temperature span is widened.

The invention is realized by the following technical scheme:

a room temperature magnetic refrigeration device of a primary coupling gravity heat pipe comprises a gravity heat pipe body 1, an internal heat exchange plate 2, a magnetic thermal material 3, a separation filter screen 4, a fluid working medium and a magnet group 5,

the central line of the gravity heat pipe body 1 is arranged along the vertical direction, and the interior of the gravity heat pipe body is divided into an upper area and a lower area by the internal heat exchange plate 2, namely a heavy load gravity heat pipe area 6 and a magnetic heat gravity heat pipe area 7;

the bottom of the heavy load gravity heat pipe area 6 is a cold end 9, and the top of the magnetic heat gravity heat pipe area 7 is a hot end 10;

the magnetocaloric material 3 is filled in the upper part of the inner heat exchange plate 2 of the magnetocaloric gravity heat pipe area 7 to form a magnetocaloric material area 8, and the Curie temperature of the magnetocaloric material 3 is matched with the working temperature of the magnetocaloric gravity heat pipe area 7;

the blocking filter screen 4 is positioned at the upper part of the magnetocaloric material 3, the periphery of the blocking filter screen is combined with the inner wall of the gravity heat pipe body 1, and the mesh number of the blocking filter screen is smaller than the particle size of the magnetocaloric material 3; the blocking filter screen 4 provides a flow channel for the fluid working medium and prevents the magnetocaloric material 3 from moving along with the flow of the fluid working medium;

and the fluid working medium is filled in the vacuumized heavy load force heat pipe area 6 and the magnetic heat gravity heat pipe area 7.

The magnet set 5 is located outside the gravity heat pipe body 1 and corresponds to the magnetocaloric material region 8.

The gravity heat pipe body 1 is made of copper or stainless steel pipe, and the cross section of the gravity heat pipe body is circular or rectangular.

The material of the inner heat exchange plate 2 is the same as that of the gravity heat pipe body 1, and the shape of the inner heat exchange plate is a flat plate structure or a rectangular raised fin-shaped expanded surface structure.

The magneto-thermal material 3 is granular Gd, Gd-based alloy or La-Fe-Si alloy.

The separation filter screen 4 is a woven wire mesh made of copper materials or stainless steel materials.

The fluid working medium is water or methanol; the magnet group 5 is a permanent magnet or an electromagnetic field.

The operation method of the room temperature magnetic refrigeration device of the primary coupling gravity heat pipe comprises the following steps:

the magnetocaloric material 3 is magnetized by the magnet group 5, the temperature rises, the load gravity heat pipe area 6 stops running, the fluid working medium in the magnetocaloric gravity heat pipe area 7 absorbs the heat of the magnetocaloric material 3 and evaporates, the steam rapidly diffuses to the hot end 10, the hot end 10 is condensed into liquid by the environment, the liquid flows back to the magnetocaloric material area 8 under the action of gravity, the fluid working medium circulates repeatedly according to the above, the heat after the magnetocaloric material 3 is magnetized is rapidly transferred to the environment, and the temperature of the magnetocaloric material 3 is reduced to the environment temperature; then, the magnet group 5 is removed, the magnetocaloric material 3 is demagnetized, the temperature is reduced, the magnetocaloric gravity heat pipe area 7 stops working, the fluid working medium in the load gravity heat pipe area 6 absorbs the load heat of the cold end 9 and evaporates, the steam rapidly diffuses to the inner heat exchange plate 2 at the upper end, the demagnetized low-temperature magnetocaloric material 3 in the inner heat exchange plate 2 is condensed to liquid, the liquid flows back to the cold end 9 under the action of gravity, the fluid working medium is circulated repeatedly in sequence, and cold energy is continuously output to the cold end; the above process is repeated to realize continuous refrigeration.

A room temperature magnetic refrigeration device of a multi-stage (two-stage) coupling gravity heat pipe comprises a gravity heat pipe body 1, a primary internal heat exchange plate 201, a secondary internal heat exchange plate 202, a primary magnetocaloric material 301, a secondary magnetocaloric material 302, a primary blocking filter screen 401, a secondary blocking filter screen 402, a fluid working medium, a primary magnet group 501 and a secondary magnet group 502;

the center line of the gravity heat pipe body 1 is arranged along the vertical direction, and the interior of the gravity heat pipe body is divided into an upper area, a middle area and a lower area by a primary internal heat exchange plate 201 and a secondary internal heat exchange plate 202 which are sequentially arranged at intervals, namely a load gravity heat pipe area 6, a primary magneto-thermal gravity heat pipe area 701 and a secondary magneto-thermal gravity heat pipe area 702;

the bottom of the load bearing gravity heat pipe area 6 is a cold end 9, and the top of the secondary magneto-thermal gravity heat pipe area 702 is a hot end 10;

the primary magnetocaloric material 301 is filled in the upper part of the primary internal heat exchange plate 201 to form a primary magnetocaloric material area 801; the Curie temperature of the primary magnetocaloric material 301 is matched with the working temperature of the primary magnetocaloric thermal-gravity heat pipe zone 701; the matching means that the two temperatures are the same or the temperature difference is plus or minus 1-2 ℃.

The secondary magnetocaloric material 302 is filled in the upper portion of the secondary internal heat exchange plate 202 to form a secondary magnetocaloric material region 802; the curie temperature of the secondary magnetocaloric material 302 matches the operating temperature of the secondary magnetocaloric thermal pipe region 702; the matching means that the two temperatures are the same or the temperature difference is plus or minus 1-2 ℃.

The primary blocking filter screen 401 and the secondary blocking filter screen 402 are respectively positioned at the upper parts of the primary magnetocaloric material 301 and the secondary magnetocaloric material 302, the peripheries of the primary blocking filter screen 401 and the secondary blocking filter screen 402 are combined with the inner wall of the gravity heat pipe body 1, and the mesh number of the primary blocking filter screen 401 and the mesh number of the secondary blocking filter screen 402 are respectively smaller than the particle size of the primary magnetocaloric material 301 and the particle size of the secondary magnetocaloric material 302; the first-stage blocking filter screen 401 and the second-stage blocking filter screen 402 are fluid working media, provide a flow channel and prevent the magnetocaloric material from moving along with the flow of the fluid working media;

the fluid working medium is filled in the load bearing pressure heat pipe area 6, the primary magnetocaloric pressure heat pipe area 701 and the secondary magnetocaloric pressure heat pipe area 702 after being vacuumized;

the primary magnetic set 501 and the secondary magnetic set 502 are respectively located outside the gravity heat pipe body 1, and respectively correspond to the primary magnetocaloric material region 801 and the secondary magnetocaloric material region 802.

The gravity heat pipe body 1 is made of copper or stainless steel pipes, and the cross section of the gravity heat pipe body is circular or rectangular.

The material of the first-stage internal heat exchange plate 201 and the material of the second-stage internal heat exchange plate 202 are the same as the material of the gravity heat pipe body 1, and the shapes of the first-stage internal heat exchange plate and the second-stage internal heat exchange plate are flat plate structures or rectangular raised fin-shaped extended surface structures.

The primary magnetocaloric material 301 and the secondary magnetocaloric material 302 are granular Gd, Gd-based alloy, or La-Fe-Si alloy.

The first-stage blocking filter screen 401 and the second-stage blocking filter screen 402 are copper or stainless steel woven wire meshes. The fluid working medium is water or methanol.

The primary magnet set 501 and the secondary magnet set 502 are permanent magnets or electromagnetic fields.

An operation method of a room temperature magnetic refrigeration device of a multistage coupling gravity heat pipe comprises the following operation modes:

the first operation mode is as follows:

the primary magnetocaloric material 301 is magnetized to raise the temperature, the secondary magnetocaloric material 302 is demagnetized to lower the temperature, the load thermodynamic heat pipe area 6 and the secondary magnetocaloric heat pipe area 702 stop running, a fluid working medium in the primary magnetocaloric heat pipe area 701 absorbs the heat of the primary magnetocaloric material 301 to evaporate, the steam is rapidly diffused to the secondary internal heat exchange plate 202, the low-temperature secondary magnetocaloric material 302 condenses into liquid on the secondary internal heat exchange plate 202, the liquid returns to the primary magnetocaloric material area 801 under the action of gravity, the fluid working medium is circulated repeatedly in turn, the heat generated after the primary magnetocaloric material 301 is magnetized is rapidly transferred to the demagnetized low-temperature secondary magnetocaloric material 302, and the temperature of the primary magnetocaloric material 301 is lowered;

then, the primary magnetocaloric material 301 is demagnetized at the temperature to further lower the temperature, so as to widen the temperature span, the secondary magnetocaloric material 302 is magnetized and heated, the primary magnetocaloric heat pipe area 701 stops working, the fluid working mediums in the load thermodynamic heat pipe area 6 and the secondary magnetocaloric heat pipe area 702 absorb the load heat of the cold end 9 and the heat of the secondary magnetocaloric material 302 respectively to evaporate, the vapor is rapidly diffused to the primary internal heat exchange plate 201 and the hot end 10 respectively and is condensed to liquid by the low-temperature primary magnetocaloric material 301 and the environment respectively, the liquid respectively returns to the cold end 9 and the secondary magnetocaloric material area 802 under the action of gravity, and the fluid working mediums are sequentially and repeatedly circulated and continuously output cold energy to the cold end; the process is repeatedly operated, and continuous refrigeration is realized;

and a second operation mode:

the primary magnetocaloric material 301 is magnetized to raise the temperature, the negative thermodynamic heat pipe area 6 and the secondary magnetocaloric heat pipe area 702 stop operating, a fluid working medium in the primary magnetocaloric heat pipe area 701 absorbs the heat of the primary magnetocaloric material 301 to evaporate, the steam is rapidly diffused to the secondary internal heat exchange plate 202, the secondary magnetocaloric material 302 condenses the liquid on the secondary internal heat exchange plate 202, the liquid returns to the primary magnetocaloric material area 801 under the action of gravity, and the fluid working medium circulates repeatedly in turn to rapidly transfer the heat of the primary magnetocaloric material 301 to the secondary magnetocaloric material 302;

then, the secondary magnetocaloric material 302 is magnetized to raise the temperature, the load thermodynamic heat pipe area 6 and the primary magnetocaloric heat pipe area 701 stop operating, the fluid working medium in the secondary magnetocaloric heat pipe area 702 absorbs the heat of the secondary magnetocaloric material 302 to evaporate, the vapor rapidly diffuses to the hot end 10, the vapor is condensed into liquid by the environment at the hot end 10, the liquid flows back to the secondary magnetocaloric material area 802 under the action of gravity, and the fluid working medium circulates repeatedly in turn to rapidly transfer the heat of the secondary magnetocaloric material 302 to the environment;

then, the secondary magnetocaloric material 302 is demagnetized and cooled, the primary magnetocaloric material 301 is still in the magnetic field, the temperature of the primary magnetocaloric material 301 is kept unchanged but higher than the temperature of the demagnetized secondary magnetocaloric material 302, the load thermodynamic heat pipe area 6 and the secondary magnetocaloric heat pipe area 702 stop operating, the fluid working medium in the primary magnetocaloric heat pipe area 701 absorbs the heat of the primary magnetocaloric material 301 to evaporate, the vapor rapidly diffuses to the secondary internal heat exchange plate 202, the demagnetized low-temperature secondary magnetocaloric material 302 condenses to liquid in the secondary internal heat exchange plate 202, the liquid returns to the primary magnetocaloric material area 801 under the action of gravity, the fluid working medium sequentially and repeatedly circulates, the heat of the primary magnetocaloric material 301 is further rapidly transferred to the demagnetized and cooled secondary magnetocaloric material 302, and the temperature of the primary magnetocaloric material 301 is further reduced;

then, the primary magnetocaloric material 301 is demagnetized and cooled at the temperature to obtain a lower temperature, so as to widen the temperature span, at this time, the primary magnetocaloric heat pipe area 701 and the secondary magnetocaloric heat pipe area 702 stop running, the fluid working medium in the load thermodynamic heat pipe area 6 absorbs the load heat of the cold end 9 and evaporates, the vapor rapidly diffuses to the primary internal heat exchange plate 201, the low-temperature primary magnetocaloric material 301 after the primary internal heat exchange plate 201 is demagnetized condenses to liquid, the liquid returns to the cold end 9 under the action of gravity, the fluid working medium sequentially circulates repeatedly, and cold energy is continuously output to the cold end; the above process is repeated to realize continuous refrigeration.

Compared with the prior art, the invention has the following advantages and effects:

according to the invention, the magnetocaloric material is directly placed in the gravity heat pipe, and the heat exchange efficiency of the magnetocaloric material and the working medium is improved through the phase change of the fluid working medium in the heat pipe, so that the working frequency is improved, and the refrigerating capacity of the magnetic refrigerating device is finally improved; meanwhile, the use of a valve component and a fluid pump is reduced by utilizing the one-way heat transfer characteristic of the gravity heat pipe, so that the pipeline structure is simplified, and the reliability is improved;

on the basis of a single-stage gravity heat pipe, the invention derives multi-stage magnetic refrigeration, thereby greatly widening the operating temperature span. Of course, the number of the stages can be three, four or more according to the requirement of practical application.

Drawings

Fig. 1 is a schematic structural diagram of a primary room-temperature magnetic refrigerator according to the present invention.

Fig. 2 is an operation principle diagram of the one-stage room temperature magnetic refrigerator of the present invention.

Fig. 3 is a schematic structural diagram of the two-stage room temperature magnetic refrigerator of the present invention.

Fig. 4 is a first operation schematic diagram of the two-stage room temperature magnetic refrigerator of the present invention.

Fig. 5 is a second operation principle diagram of the two-stage room temperature magnetic refrigerator of the present invention.

Fig. 6 is a partial structural schematic view of an inner heat exchange plate according to the present invention.

Detailed Description

The present invention will be described in further detail with reference to specific examples.

Example 1:

as shown in fig. 1, the invention discloses a room temperature magnetic refrigeration device of a primary coupling gravity heat pipe, which comprises a gravity heat pipe body 1, an internal heat exchange plate 2, a magnetocaloric material 3, a blocking filter screen 4, a fluid working medium and a magnet group 5.

Particularly, gravity heat pipe body 1's central line place along vertical direction, its inside is separated into two regions by inside heat transfer board 2, from up being under load power heat pipe area 6 and the hot gravity heat pipe of magnetic heat district 7 in proper order down along vertical direction.

Specifically, the bottom of the heavy load gravity heat pipe area 6 is a cold end 9, and the top of the magnetocaloric gravity heat pipe area 7 is a hot end 10.

Specifically, the shape of the periphery of the inner heat exchange plate 2 is the same as the shape of the inner section of the gravity heat pipe body 1, and the periphery of the inner heat exchange plate is welded with the inner wall of the gravity heat pipe body 1.

Specifically, the magnetocaloric material 3 is filled in the upper portion of the inner heat exchange plate 2 of the magnetocaloric gravity heat pipe area 7 to form the magnetocaloric material area 8, and the curie temperature of the magnetocaloric material 3 matches the operating temperature of the magnetocaloric gravity heat pipe area 7. The matching means that the two temperatures are the same or the temperature difference is plus or minus 1-2 ℃.

Specifically, the blocking filter screen 4 is located on the upper portion of the magnetocaloric material 3, the periphery of the blocking filter screen is combined with the inner wall of the gravity heat pipe body 1, the mesh number of the blocking filter screen is smaller than the particle size of the magnetocaloric material 3, a flow channel is provided for the fluid working medium, and the magnetocaloric material 3 is prevented from moving along with the flow of the fluid working medium.

Specifically, the fluid working medium is filled in the vacuumized heavy load force heat pipe area 6 and the magnetocaloric gravity heat pipe area 7.

Specifically, the magnet assembly 5 is located outside the gravity heat pipe body 1 and corresponds to the magnetocaloric material region 8.

Preferably, the gravity heat pipe body 1 is a metal pipe material such as copper, stainless steel and the like, and the cross section of the pipe material is circular, rectangular and the like; the material of the internal heat exchange plate 2 is the same as that of the gravity heat pipe body 1, and the shape of the internal heat exchange plate is a flat plate structure or a rectangular raised fin-shaped expanded surface structure as shown in fig. 6; the magnetocaloric material 3 is granular Gd, Gd-based alloy, La-Fe-Si alloy, and the like; the separation filter screen 4 is a woven wire mesh made of copper or stainless steel; the fluid working medium is water, methanol and the like; the magnet group 5 is a permanent magnet or an electromagnetic field. The magnet assembly 5 is generally a C-shaped, ring-shaped or concentric nested Halbach magnet.

The refrigeration method of the room temperature magnetic refrigeration device of the primary coupling gravity heat pipe is shown in figure 2, and the refrigeration operation process is as follows:

the magnetocaloric material 3 is magnetized by the magnet group 5, the temperature rises (5-8 ℃ relative to the ambient temperature), the negative pressure heat pipe area 6 stops running, the fluid working medium in the magnetocaloric gravity heat pipe area 7 absorbs the heat of the magnetocaloric material 3 and evaporates, the steam rapidly diffuses to the hot end 10, the hot end 10 is condensed into liquid by the environment, the liquid reflows to the magnetocaloric material area 8 under the action of gravity, the fluid working medium circulates repeatedly according to the cycle, the heat after the magnetocaloric material 3 is magnetized is rapidly transferred to the environment, and the temperature of the magnetocaloric material 3 is reduced to the ambient temperature; then, the magnet group 5 is removed, the magnetocaloric material 3 is demagnetized, the temperature is reduced (5-8 ℃ lower than the ambient temperature), the magnetocaloric gravity heat pipe area 7 stops working, the fluid working medium in the load gravity heat pipe area 6 absorbs the load heat of the cold end 9 and evaporates, the steam is rapidly diffused to the inner heat exchange plate 2 at the upper end, the low-temperature (5-8 ℃ lower than the ambient temperature) magnetocaloric material 3 after the inner heat exchange plate 2 is demagnetized is condensed to liquid, the liquid flows back to the cold end 9 under the action of gravity, the fluid working medium is sequentially and repeatedly circulated, and cold energy is continuously output to the cold end; the above process is repeated to realize continuous refrigeration.

Example 2:

as shown in fig. 3, a multi-stage (two-stage in this embodiment) room temperature magnetic refrigeration device coupled with a gravity heat pipe includes a gravity heat pipe body 1, a first-stage internal heat exchange plate 201, a second-stage internal heat exchange plate 202, a first-stage magnetocaloric material 301, a second-stage magnetocaloric material 302, a first-stage blocking filter screen 401, a second-stage blocking filter screen 402, a fluid working medium, a first-stage magnet set 501, and a second-stage magnet set 502.

Specifically, the central line of gravity heat pipe body 1 place along vertical direction, its inside is separated into three region by inside heat transfer board 201 of one-level and the inside heat transfer board 202 of second grade, follow vertical direction from up be in proper order under the control of the heavy load power heat pipe area 6, one-level magnetism heat pipe area 701, second grade magnetism heat pipe area 702 under the control of the heavy load power heat pipe.

Specifically, the bottom of the heavy load heating pipe area 6 is a cold end 9, and the top of the secondary magnetocaloric heating pipe area 702 is a hot end 10.

Particularly, inside heat transfer board 201 of one-level and the inside heat transfer board 202 of second grade from up placing in proper order the interval down in gravity heat pipe body 1 along vertical direction, its all around shape is the same with the interior cross-sectional shape of gravity heat pipe body 1 to all around with the welding of the 1 inner wall of gravity heat pipe body together.

Specifically, the primary magnetocaloric material 301 is filled in the upper portion of the primary inner heat exchange plate 201 to form a primary magnetocaloric material region 801, and the curie temperature of the primary magnetocaloric material 301 matches the operating temperature of the primary magnetocaloric thermal tube region 701. The matching means that the two temperatures are the same or the temperature difference is plus or minus 1-2 ℃.

Specifically, the secondary magnetocaloric material 302 is filled in the upper portion of the secondary inner heat exchange plate 202 to form a secondary magnetocaloric material region 802, and the curie temperature of the secondary magnetocaloric material 302 matches the operating temperature of the secondary magnetocaloric thermal pipe region 702. The matching means that the two temperatures are the same or the temperature difference is plus or minus 1-2 ℃.

Specifically, the primary blocking filter screen 401 and the secondary blocking filter screen 402 are respectively located on the upper portions of the primary magnetocaloric material 301 and the secondary magnetocaloric material 302, and are peripherally combined with the inner wall of the gravity heat pipe body 1, and the mesh number of the primary blocking filter screen 401 and the mesh number of the secondary blocking filter screen 402 are respectively smaller than the particle size of the primary magnetocaloric material 301 and the particle size of the secondary magnetocaloric material 302, so that a flow channel is provided for the fluid working medium, and the magnetocaloric material is prevented from moving along with the flow of the fluid working medium.

Specifically, the fluid working medium is filled in the load bearing heat pipe area 6, the first-stage magnetocaloric heat pipe area 701 and the second-stage magnetocaloric heat pipe area 702 after being vacuumized.

Specifically, the primary magnet set 501 and the secondary magnet set 502 are respectively located outside the gravity heat pipe body 1, and respectively correspond to the primary magnetocaloric material region 801 and the secondary magnetocaloric material region 802.

Preferably, the gravity heat pipe body 1 is a metal pipe material such as copper, stainless steel and the like, and the cross section of the pipe material is circular, rectangular and the like; the materials of the primary internal heat exchange plate 201 and the secondary internal heat exchange plate 202 are the same as those of the gravity heat pipe body 1, and the shapes of the primary internal heat exchange plate and the secondary internal heat exchange plate are flat plate structures or rectangular raised fin-shaped extended surface structures as shown in fig. 6; the primary magnetocaloric material 301 and the secondary magnetocaloric material 302 are granular Gd, Gd-based alloy, La-Fe-Si alloy, and the like; the first-stage blocking filter screen 401 and the second-stage blocking filter screen 402 are woven wire screens made of copper materials or stainless steel materials; the fluid working medium is water, methanol and the like; the primary magnet set 501 and the secondary magnet set 502 are permanent magnets or electromagnetic fields.

The refrigeration method of the room temperature magnetic refrigeration device of the multistage coupling gravity heat pipe is shown in fig. 4 and 5, and the refrigeration operation process mainly comprises the following two modes:

operation mode 1:

as shown in fig. 4, the primary magnetocaloric material 301 is magnetized to raise the temperature (which is 5 to 8 ℃ higher than the ambient temperature), the secondary magnetocaloric material 302 is demagnetized to lower the temperature (which is 5 to 8 ℃ lower than the ambient temperature), the negative load heating zone 6 and the secondary magnetocaloric heating zone 702 stop operating, the fluid working medium in the primary magnetocaloric heating zone 701 absorbs the heat of the primary magnetocaloric material 301 to evaporate, the vapor rapidly diffuses to the secondary internal heat exchange plate 202, the secondary magnetocaloric material 302 with low temperature (5-8 ℃ lower than the ambient temperature) is condensed into liquid in the secondary internal heat exchange plate 202, the liquid flows back to the primary magnetocaloric material area 801 under the action of gravity, the fluid working medium circulates repeatedly, heat generated after the primary magnetocaloric material 301 is magnetized is quickly transferred to the low-temperature secondary magnetocaloric material 302 after demagnetization, and the temperature of the primary magnetocaloric material 301 is reduced (3-6 ℃ lower than the ambient temperature);

then, the primary magnetocaloric material 301 is demagnetized at the temperature, so that the temperature is further reduced (which is 8-12 ℃ lower than the ambient temperature), so that the temperature span is widened, the secondary magnetocaloric material 302 is magnetized and heated (which is 2-5 ℃ higher than the ambient temperature), the primary magnetocaloric heat pipe area 701 stops working, fluid working mediums in the load heat pipe area 6 and the secondary magnetocaloric heat pipe area 702 absorb the load heat of the cold end 9 and the heat of the secondary magnetocaloric material 302 respectively to evaporate, the vapor is rapidly diffused to the primary internal heat exchange plate 201 and the hot end 10 respectively and are condensed to liquid by the primary magnetocaloric material 301 and the ambient at low temperature (which is 8-12 ℃ lower than the ambient temperature), the liquid respectively reflows to the cold end 9 and the secondary magnetocaloric material area 802 under the action of gravity, and the fluid working mediums circulate repeatedly in sequence and output cold energy to the cold end; the process is repeatedly operated, and continuous refrigeration is realized;

operation mode 2:

as shown in fig. 5, the primary magnetocaloric material 301 is magnetized to raise the temperature (which is 5 to 8 ℃ higher than the ambient temperature), the negative load thermodynamic heat pipe area 6 and the secondary magnetocaloric heat pipe area 702 stop operating, the fluid working medium in the primary magnetocaloric heat pipe area 701 absorbs the heat of the primary magnetocaloric material 301 to evaporate, the vapor rapidly diffuses to the secondary internal heat exchange plate 202, the secondary magnetocaloric material 302 condenses into liquid in the secondary internal heat exchange plate 202, the liquid returns to the primary magnetocaloric material area 801 under the action of gravity, and the fluid working medium circulates repeatedly in this way to rapidly transfer the heat of the primary magnetocaloric material 301 to the secondary magnetocaloric material 302;

then, the secondary magnetocaloric material 302 is magnetized to raise the temperature (which is raised by 8-12 ℃ relative to the ambient temperature), the negative pressure thermal tube area 6 and the primary magnetocaloric thermal tube area 701 stop running, the fluid working medium in the secondary magnetocaloric thermal tube area 702 absorbs the heat of the secondary magnetocaloric material 302 to evaporate, the vapor rapidly diffuses to the hot end 10, the vapor is condensed into liquid by the ambient at the hot end 10, the liquid reflows to the secondary magnetocaloric material area 802 under the action of gravity, and the fluid working medium circulates repeatedly in turn to rapidly transfer the heat of the secondary magnetocaloric material 302 to the ambient;

then, the secondary magnetocaloric material 302 is demagnetized and cooled (which is 5 to 8 ℃ lower than the ambient temperature), the primary magnetocaloric material 301 is still in the magnetic field, the temperature of the primary magnetocaloric material 301 is kept constant but higher than the temperature of the demagnetized secondary magnetocaloric material 302, the load thermodynamic heat pipe area 6 and the secondary magnetocaloric heat pipe area 702 stop operating, the fluid working medium in the primary magnetocaloric heat pipe area 701 absorbs the heat of the primary magnetocaloric material 301 to evaporate, the vapor rapidly diffuses to the secondary internal heat exchange plate 202, the secondary magnetocaloric material 302 condenses to liquid at the low temperature (which is 5 to 8 ℃ lower than the ambient temperature) of the demagnetized secondary internal heat exchange plate 202, the liquid returns to the primary magnetocaloric material area 801 under the action of gravity, the fluid working medium sequentially and repeatedly circulates, and further the heat of the primary magnetocaloric material 301 is rapidly transferred to the demagnetized secondary magnetocaloric material 302, the temperature of the primary magnetocaloric material 301 is further reduced (which means that the temperature is 3-6 ℃ lower than the ambient temperature);

then, the primary magnetocaloric material 301 is demagnetized and cooled at the temperature to obtain a lower temperature (which is 8-12 ℃ lower than the ambient temperature) so as to widen the temperature span, at the moment, the primary magnetocaloric thermal tube area 701 and the secondary magnetocaloric thermal tube area 702 stop running, the fluid working medium in the load thermal tube area 6 absorbs the load heat of the cold end 9 and evaporates, the steam quickly diffuses to the primary internal heat exchange plate 201, the primary magnetocaloric material 301 is condensed to liquid at the low temperature (which is 8-12 ℃ lower than the ambient temperature) after the primary internal heat exchange plate 201 is demagnetized, the liquid flows back to the cold end 9 under the action of gravity, the fluid working medium circulates repeatedly in sequence, and cold energy is continuously output to the cold end; the above process is repeated to realize continuous refrigeration.

As described above, the interior of the gravity heat pipe body of the present invention is divided into a plurality of regions by a plurality of internal heat exchange plates (three, four or more in practical application), the bottom end is a cold end for refrigerating to a load, and the top end is a hot end for releasing heat to the environment; the temperature span is widened by alternately demagnetizing one or more magnetocaloric materials or gradually demagnetizing the magnetocaloric materials from the hot end to the cold end, so that low temperature is obtained, and refrigeration is realized.

According to the invention, the magnetocaloric material is directly placed in the gravity heat pipe, and the heat exchange efficiency of the magnetocaloric material and the fluid working medium is improved and the working frequency and the refrigerating capacity of the magnetic refrigerating device are improved through the phase change of the fluid working medium; the use of valve components and fluid pumps is reduced by utilizing the one-way heat transfer characteristic of the gravity heat pipe, the pipeline structure is simplified, and the reliability is improved; and multistage magnetic refrigeration is adopted, so that the operating temperature span is widened.

The embodiments of the present invention are not limited to the above-described embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and they are included in the scope of the present invention.

Claims

1. The utility model provides a room temperature magnetism refrigerating plant of one-level coupling gravity heat pipe which characterized in that: comprises a gravity heat pipe body (1), an internal heat exchange plate (2), a magnetocaloric material (3), a blocking filter screen (4), a fluid working medium and a magnet group (5),

the central line of the gravity heat pipe body (1) is arranged along the vertical direction, and the interior of the gravity heat pipe body is divided into an upper area and a lower area by an internal heat exchange plate (2), namely a heavy-load gravity heat pipe area (6) and a magnetic-heat gravity heat pipe area (7);

the bottom of the heavy load gravity heat pipe area (6) is a cold end (9), and the top of the magneto-thermal gravity heat pipe area (7) is a hot end (10);

the magnetocaloric material (3) is filled at the upper part of the internal heat exchange plate (2) of the magnetocaloric thermal tube area (7) to form a magnetocaloric material area (8), and the Curie temperature of the magnetocaloric material (3) is matched with the working temperature of the magnetocaloric thermal tube area (7);

the blocking filter screen (4) is positioned at the upper part of the magnetocaloric material (3), the periphery of the blocking filter screen is combined with the inner wall of the gravity heat pipe body (1), and the mesh number of the blocking filter screen is smaller than the particle size of the magnetocaloric material (3); the blocking filter screen (4) provides a flow channel for the fluid working medium and prevents the magnetocaloric material (3) from moving along with the flow of the fluid working medium;

the fluid working medium is filled in the load bearing force heat pipe area (6) and the magneto-thermal gravity heat pipe area (7) after being vacuumized;

the magnet group (5) is positioned outside the gravity heat pipe body (1) and corresponds to the position of the magnetocaloric material area (8).

2. The room temperature magnetic refrigeration device of the primary coupling gravity heat pipe of claim 1, wherein: the gravity heat pipe body (1) is made of copper or stainless steel pipes, and the cross section of the gravity heat pipe body is circular or rectangular.

3. The room temperature magnetic refrigeration device of the primary coupling gravity heat pipe of claim 2, wherein: the material of the inner heat exchange plate (2) is the same as that of the gravity heat pipe body (1), and the shape of the inner heat exchange plate is a flat plate structure or a rectangular raised fin-shaped expanded surface structure.

4. A room temperature magnetic refrigeration device of a primary coupling gravity heat pipe according to claim 3, wherein: the magneto-thermal material (3) is granular Gd, Gd-based alloy or La-Fe-Si alloy.

5. The room temperature magnetic refrigeration device of the primary coupling gravity heat pipe of claim 4, wherein: the separation filter screen (4) is a woven wire mesh made of copper materials or stainless steel materials.

6. The room temperature magnetic refrigeration device of the primary coupling gravity heat pipe of claim 5, wherein: the fluid working medium is water or methanol; the magnet group (5) is a permanent magnet or an electromagnetic field.

7. An operation method of a room temperature magnetic refrigeration device of a primary coupling gravity heat pipe according to any one of claims 1 to 6, characterized by comprising the following steps:

the magnetic heating material (3) is magnetized by the magnet group (5), the temperature is raised, the load bearing thermal tube area (6) stops running, a fluid working medium in the magnetic heating thermal tube area (7) absorbs the heat of the magnetic heating material (3) to evaporate, steam is diffused to the hot end (10), the steam is condensed into liquid by the environment at the hot end (10), the liquid flows back to the magnetic heating material area (8) under the action of gravity, the fluid working medium is circulated repeatedly according to the above, the heat after the magnetic heating material (3) is magnetized is transferred to the environment, and the temperature of the magnetic heating material (3) is lowered; then, the magnet group (5) is removed, the magnetocaloric material (3) is demagnetized, the temperature is further reduced, the magnetocaloric thermal tube region (7) stops working, the fluid working medium in the load thermodynamic thermal tube region (6) absorbs the load heat of the cold end (9) and evaporates, the steam is diffused to the inner heat exchange plate (2) at the upper end, the demagnetized low-temperature magnetocaloric material (3) in the inner heat exchange plate (2) is condensed to liquid, the liquid flows back to the cold end (9) under the action of gravity, the fluid working medium is sequentially and repeatedly circulated, and cold energy is continuously output to the cold end; the above process is repeated to realize continuous refrigeration.

8. The utility model provides a room temperature magnetism refrigerating plant of multistage coupling gravity heat pipe which characterized in that: the gravity heat pipe comprises a gravity heat pipe body (1), a primary internal heat exchange plate (201), a secondary internal heat exchange plate (202), a primary magnetocaloric material (301), a secondary magnetocaloric material (302), a primary blocking filter screen (401), a secondary blocking filter screen (402), a fluid working medium, a primary magnet group (501) and a secondary magnet group (502);

the center line of the gravity heat pipe body (1) is arranged along the vertical direction, and the interior of the gravity heat pipe body is divided into an upper area, a middle area and a lower area by a primary internal heat exchange plate (201) and a secondary internal heat exchange plate (202) which are sequentially arranged at intervals, namely a load gravity heat pipe area (6), a primary magneto-thermal gravity heat pipe area (701) and a secondary magneto-thermal gravity heat pipe area (702);

the bottom of the heavy load thermodynamic heat pipe area (6) is a cold end (9), and the top of the secondary magnetocaloric thermodynamic heat pipe area (702) is a hot end (10);

the primary magnetocaloric material (301) is filled in the upper part of the primary internal heat exchange plate (201) to form a primary magnetocaloric material area (801); the Curie temperature of the primary magnetocaloric material (301) is matched with the working temperature of the primary magnetocaloric thermal-thermal thermodynamic pipe region (701);

the secondary magnetocaloric material (302) is filled at the upper part of the secondary internal heat exchange plate (202) to form a secondary magnetocaloric material area (802); the Curie temperature of the secondary magnetocaloric material (302) is matched with the working temperature of the secondary magnetocaloric thermal pipe region (702);

the primary blocking filter screen (401) and the secondary blocking filter screen (402) are respectively positioned at the upper parts of the primary magnetocaloric material (301) and the secondary magnetocaloric material (302), the peripheries of the primary blocking filter screen and the secondary blocking filter screen are combined with the inner wall of the gravity heat pipe body (1), and the mesh number of the primary blocking filter screen (401) and the mesh number of the secondary blocking filter screen (402) are respectively smaller than the particle size of the primary magnetocaloric material (301) and the particle size of the secondary magnetocaloric material (302); the first-stage blocking filter screen (401) and the second-stage blocking filter screen (402) are fluid working media, provide a flow channel and prevent the magnetocaloric material from moving along with the flow of the fluid working media;

the fluid working medium is filled in the load bearing gravity heat pipe area (6), the primary magnetocaloric heat pipe area (701) and the secondary magnetocaloric heat pipe area (702) after being vacuumized;

the primary magnet set (501) and the secondary magnet set (502) are respectively located outside the gravity heat pipe body (1) and respectively correspond to the primary magnetocaloric material region (801) and the secondary magnetocaloric material region (802).

9. The room temperature magnetic refrigeration device of the multistage coupling gravity heat pipe of claim 8, wherein: the gravity heat pipe body (1) is made of copper or stainless steel pipe materials, and the cross section of the gravity heat pipe body is circular or rectangular;

the material of the first-stage internal heat exchange plate (201) and the material of the second-stage internal heat exchange plate (202) are the same as that of the gravity heat pipe body (1), and the shape of the first-stage internal heat exchange plate is a flat plate structure or a rectangular raised fin-shaped expanded surface structure.

10. The operation method of the room temperature magnetic refrigeration device of the multistage coupling gravity heat pipe as claimed in claim 8, characterized by the following operation modes:

the first operation mode is as follows:

the primary magnetocaloric material (301) is magnetized to raise the temperature, the secondary magnetocaloric material (302) is demagnetized to lower the temperature, the load heating pipe area (6) and the secondary magnetocaloric heating pipe area (702) stop running, a fluid working medium in the primary magnetocaloric heating pipe area (701) absorbs the heat of the primary magnetocaloric material (301) to evaporate, steam diffuses to the secondary internal heat exchange plate (202), the secondary magnetocaloric material (302) at a low temperature condenses the secondary magnetocaloric material (202) into liquid, the liquid returns to the primary magnetocaloric material area (801) under the action of gravity, the fluid working medium circulates repeatedly according to the above steps, the heat generated after the magnetization of the primary magnetocaloric material (301) is quickly transferred to the demagnetized secondary magnetocaloric material (302), and the temperature of the primary magnetocaloric material (301) is reduced;

then, the primary magnetocaloric material (301) is demagnetized at the temperature to further reduce the temperature, so that the temperature span is widened, the secondary magnetocaloric material (302) is magnetized and heated, the primary magnetocaloric thermal tube area (701) stops working, fluid working media in the load magnetocaloric thermal tube area (6) and the secondary magnetocaloric thermal tube area (702) respectively absorb the load heat of the cold end (9) and the heat of the secondary magnetocaloric material (302) to evaporate, the steam is respectively and rapidly diffused to the primary internal heat exchange plate (201) and the hot end (10) and respectively condensed to liquid by the low-temperature primary magnetocaloric material (301) and the environment, the liquid respectively returns to the cold end (9) and the secondary magnetocaloric material area (802) under the action of gravity, the fluid working media sequentially and repeatedly circulate, and cold energy is continuously output to the cold end; the process is repeatedly operated, and continuous refrigeration is realized;

and a second operation mode:

the primary magnetocaloric material (301) is magnetized to raise the temperature, the load thermodynamic heat pipe area (6) and the secondary magnetocaloric heat pipe area (702) stop running, a fluid working medium in the primary magnetocaloric heat pipe area (701) absorbs the heat of the primary magnetocaloric material (301) to evaporate, steam diffuses to the secondary internal heat exchange plate (202), the secondary magnetocaloric material (302) condenses into liquid in the secondary internal heat exchange plate (202), the liquid returns to the primary magnetocaloric material area (801) under the action of gravity, and the fluid working medium circulates repeatedly in turn to quickly transfer the heat of the primary magnetocaloric material (301) to the secondary magnetocaloric material (302);

then, the secondary magnetocaloric material (302) is magnetized to raise the temperature, the load thermodynamic heat pipe area (6) and the primary magnetocaloric heat pipe area (701) stop running, a fluid working medium in the secondary magnetocaloric heat pipe area (702) absorbs the heat of the secondary magnetocaloric material (302) to evaporate, the steam is rapidly diffused to the hot end (10), the steam is condensed into liquid in the hot end (10), the liquid flows back to the secondary magnetocaloric material area (802) under the action of gravity, the fluid working medium circulates repeatedly according to the above steps, and the heat of the secondary magnetocaloric material (302) is rapidly transferred to the environment;

then, the secondary magnetocaloric material (302) is demagnetized and cooled, the primary magnetocaloric material (301) is still in the magnetic field, the temperature is kept unchanged but is higher than the temperature of the demagnetized secondary magnetocaloric material (302), the load heating pipe area (6) and the secondary magnetocaloric heating pipe area (702) stop running, the fluid working medium in the primary magnetocaloric heating pipe area (701) absorbs the heat of the primary magnetocaloric material (301) to evaporate, the steam rapidly diffuses to the secondary internal heat exchange plate (202), the demagnetized low-temperature secondary magnetocaloric material (302) in the secondary internal heat exchange plate (202) is condensed into liquid, the liquid flows back to the primary magnetocaloric material area (801) under the action of gravity, the fluid working medium circulates repeatedly in sequence, heat of the primary magnetocaloric material (301) is further transferred to the demagnetized and cooled secondary magnetocaloric material (302), and the temperature of the primary magnetocaloric material (301) is further reduced;

then, the primary magnetocaloric material (301) is demagnetized and cooled at the temperature to obtain a lower temperature, so that the temperature span is widened, at the moment, the primary magnetocaloric heat pipe area (701) and the secondary magnetocaloric heat pipe area (702) stop running, fluid working media in the load bearing thermodynamic heat pipe area (6) absorb the load heat of the cold end (9) and evaporate, steam rapidly diffuses to the primary internal heat exchange plate (201), the demagnetized primary magnetocaloric material (301) in the primary internal heat exchange plate (201) condenses to liquid, the liquid returns to the cold end (9) under the action of gravity, the fluid working media sequentially and repeatedly circulate, and cold energy is continuously output to the cold end; the above process is repeated to realize continuous refrigeration.