CN106052258A - Refrigerator having multiple temperature zones - Google Patents

Abstract

The invention relates to a refrigerator with multiple temperature zones. The refrigerating chamber is located in the upper half of the refrigerator box, and the freezing chamber and variable room are located in the lower half of the refrigerator; the condensing section pipeline of the gravity heat pipe at the hot end is arranged upward on the left wall of the refrigerator shell On the inner side, the pipelines of the evaporating section of the gravity heat pipe at the cold end are arranged downward on the rear wall and the left and right walls of the variable temperature chamber. The evaporation section of the gravity heat pipe at the hot end is connected to the hot end of the free-piston Stirling refrigerator through a heat-conducting copper sleeve. The free-piston Stirling refrigerator has the characteristics of wide cooling temperature range, compact structure, and high low-temperature cooling efficiency. Combined with the advantages of high heat transfer efficiency and simple structure of the gravity heat pipe, the variable temperature greenhouse can reach a temperature as low as -60°C. The new multi-temperature zone refrigerator can realize precise control of different refrigeration temperatures in the refrigerator by adjusting the operating frequency of the frequency conversion compressor and the input voltage of the free-piston Stirling refrigerator.

Description

Multi-zone refrigerator

technical field

The invention relates to a refrigerator, in particular to a multi-temperature zone refrigerator combined with compression and throttling refrigeration of a Stirling refrigerator.

Background technique

With the improvement of people's living standards, the freezing function of ordinary refrigerators (temperature higher than -18°C) is gradually unable to meet people's freezing requirements for some foods, such as some seafood that needs to be preserved better below -40°C. Taking meat as an example, when stored in an ordinary refrigerator, it should not be stored at 7°C for more than 2 days, at 0°C for no more than 5 days, and at -18°C for no more than one month. For foods that need to be stored for a long time, the lower the freezing temperature, the more it can inhibit the growth and reproduction of microorganisms and the activity of enzymes, the smaller the loss of nutrients, and the better the freshness of preservation.

Traditional household refrigerator refrigeration generally adopts a single-stage vapor compression throttling refrigeration system, which consists of four basic parts: compressor, condenser, throttling component and evaporator, and each part is connected together through pipelines to form a closed system. The system is filled with a certain amount of refrigerant, and the refrigerant refrigerates through four cycles of compression, condensation, throttling, and evaporation in the system. Refrigerators using vapor compression refrigeration have fast cooling speed, good cooling effect, and mature technology, so they have stable performance and long service life. When the refrigerator using vapor compression refrigeration is working, the compressor starts and stops intermittently under the control of the thermostat. When the temperature in the refrigerator is higher than the set temperature, the compressor starts to refrigerate, and the temperature in the cabinet drops until the temperature in the refrigerator reaches a certain critical value below the set temperature, the compressor stops working, and the temperature in the refrigerator starts to rise. When the temperature rises to another critical value higher than the set temperature, the compressor starts to work again. The above process repeats cycle. Therefore, even if the refrigerator is in a stable state, the temperature in the cabinet fluctuates periodically, which is unfavorable for the preservation of some high-grade foods such as seafood. Moreover, the single-stage vapor compression throttling refrigeration system is also difficult to achieve a refrigeration temperature below -40°C, which cannot meet the temperature requirements for some food preservation.

The Stirling refrigeration cycle consists of two isothermal processes and isovolumic processes, and its theoretical cycle efficiency is Carnot efficiency. Relatively speaking, the use of Stirling refrigeration technology under low-temperature refrigeration conditions has higher refrigeration efficiency. The Stirling refrigerator adopts a closed cycle of gas expansion refrigeration, which is formed by a valveless connection between a compression unit and an expansion unit. The use of helium as the refrigerant will not damage the ozone layer and is an extremely environmentally friendly refrigeration technology. The free-piston Stirling refrigerator has no complicated pipeline system, and the compressor and expander are integrated together, which has the advantages of less moving parts, no oil lubrication, no wear and tear, high reliability, long life, compact structure, light weight, and high refrigeration efficiency It also has high temperature control accuracy, high efficiency under full load and partial load, and the cooling capacity and cooling temperature can be controlled by adjusting the input voltage.

A heat pipe is a heat transfer element with extremely high thermal conductivity. It transfers heat through the evaporation and condensation of liquid in a fully enclosed vacuum tube, and has high thermal conductivity. The gravity heat pipe can only conduct heat in one direction, and the condensation section must be higher than the evaporation section. When working, the working liquid inside the gravity heat pipe absorbs heat and vaporizes into steam in the evaporating section, and the steam rises to the cooling section to release heat and re-condenses into a liquid, and then flows back to the evaporating section by gravity. The heat pipe used in the present invention is a two-phase closed thermosiphon (gravity heat pipe).

Contents of the invention

The purpose of the present invention is to propose a multi-temperature zone refrigerator that combines a free-piston Stirling refrigerator and a compression throttling refrigeration system to meet the requirements of different storage temperatures for food. The refrigerator can achieve a minimum cooling temperature of -60°C. Moreover, the temperature control precision is high and the reliability is good.

The technical solution of the present invention is: a multi-temperature zone refrigerator, including a refrigerator box and a refrigeration system. The refrigerator box is composed of a refrigerator room, a freezer room and a temperature-changing room. The refrigerator room is located in the upper half of the refrigerator box body. The freezing chamber and variable temperature chamber are located in the lower part of the refrigerator; the refrigeration system is composed of a compression throttling refrigeration system, a free piston Stirling refrigerator-heat pipe system, and the free piston Stirling refrigerator-heat pipe system includes a free piston Stirling refrigerator. Piston Stirling refrigerator, cold-end gravity heat pipe, hot-end gravity heat pipe, cold-conducting copper sleeve and heat-conducting copper sleeve. The pipes of the evaporating section of the end gravity heat pipe are arranged downward on the rear wall and the left and right walls of the variable temperature chamber. The condensation section of the gravity heat pipe at the cold end is connected to the cold head of the free piston Stirling refrigerator through a cold conducting copper sleeve. The evaporation section of the gravity heat pipe at the hot end is connected to the hot end of the free-piston Stirling refrigerator through a heat-conducting copper sleeve.

The cold-conducting copper sleeve is a circular copper sleeve, with a hole at one end connected to the cold head of the free-piston Stirling refrigerator, and a heat conducting Silicone grease, a circular groove is provided in the circular copper sleeve, so that the heat transfer medium R170 can flow in the circular groove to fully exchange heat; the side of the circular copper sleeve is provided with two circular grooves Connected cooling holes.

The heat-conducting copper sleeve is an annular copper sleeve, and heat-conducting silicone grease is coated between the inner surface of the annular copper sleeve and the hot end of the free-piston Stirling refrigerator, and an annular groove is arranged inside the annular copper sleeve, so that the heat transfer working medium R600a The flow in the annular groove fully exchanges heat; two small heat conduction holes communicated with the annular groove are opened on the side of the annular copper sleeve.

The cooling temperature range of the variable room is -60-10°C, and the cooling capacity of the variable room is provided by a free-piston Stirling refrigerator; the free-piston Stirling refrigerator is an integral free-piston Stirling driven by a linear motor Free-piston Stirling refrigerator uses helium as the internal working medium. The free-piston Stirling refrigerator is installed in the middle of the left side of the refrigerator. A shock absorber is fixed at the end of the free-piston Stirling refrigerator, and the block toward the back of the refrigerator cabinet.

The cold-end gravity heat pipe includes a first cold-end heat pipe and a second cold-end heat pipe, and the first cold-end heat pipe and the second cold-end heat pipe are respectively connected to the first and second cold-conducting small holes on the side of the cold-conducting copper sleeve. The cold-end gravity heat pipe pipeline is inclined downward at an angle of 15°, and the internal working fluid is R170; the hot-end gravity heat pipe includes a first hot-end heat pipe and a second hot-end heat pipe, and the first hot-end heat pipe and the second hot-end heat pipe are respectively It is connected with the first and second small heat conduction holes on the side of the heat conduction copper sleeve, the gravity heat pipe pipeline at the hot end is inclined downward by 10°, and the working fluid used inside is R600a.

Compared with existing refrigerators, the beneficial effects of the present invention are:

(1) Due to the free-piston Stirling refrigerator, the lowest cooling temperature of the refrigerator can reach -60°C, and the stroke of the compression piston can be adjusted by changing the driving voltage, thereby controlling the cooling capacity and cooling temperature. According to the requirements of different freezing temperatures, food can be classified and preserved.

(2) Due to the combination of the free-piston Stirling and the gravity heat pipe, the problem of cooling and heat dissipation of the free-piston Stirling is effectively solved, and it is closely combined with the refrigerator box, which increases the efficiency of heat transfer, and is easy to install. Occupies the internal volume of the box.

Description of drawings

Fig. 1 is the schematic diagram of the free-piston Stirling refrigerator adopted in the present invention;

Fig. 2 is the schematic diagram of the cold-end conduction copper sleeve of the free-piston Stirling refrigerator used in the present invention;

Fig. 3 is the schematic diagram of the heat-conducting copper sleeve at the hot end of the free-piston Stirling refrigerator used in the present invention;

Fig. 4 is the combined assembly schematic diagram of the free piston Stirling refrigerator adopted in the present invention, the cold conduction copper sleeve, the heat conduction copper sleeve;

Fig. 5 is a combined assembly schematic diagram of the free-piston Stirling refrigerator and the gravity heat pipe system of the present invention;

Fig. 6 is a combined assembly diagram of the compression throttling refrigeration system, the free-piston Stirling refrigerator and the gravity heat pipe system of the present invention;

Fig. 7 is a combined front view of the refrigeration system and the refrigerator box of the present invention;

Fig. 8 is a combined back view of the refrigeration system and the refrigerator box of the present invention;

Fig. 9 is a schematic diagram of the appearance of the refrigerator of the present invention;

Fig. 10 is a schematic diagram of the working principle of the multi-temperature zone refrigerator of the present invention.

detailed description

In order to better understand the technical solution of the present invention, the specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings:

As shown in FIGS. 1 to 9 , a multi-temperature zone refrigerator combining a Stirling refrigerator and compression throttling refrigeration includes a refrigerator box 700 and a refrigeration system. The refrigerator box 700 includes a refrigerator shell 706 , a display screen 707 , a refrigerator door 708 , and a heat insulating layer 705 . Casing interior space has refrigerating chamber 701, is positioned at refrigerator top half, freezer chamber 703, is positioned at the right side of refrigerator bottom half, variable chamber 702, is positioned at refrigerator bottom half left side, and each room has storage board 704. The display screen 707 is connected to the controller 800, which can not only display the temperature in each refrigeration room, but also control the operating frequency of the variable frequency compressor 608 and the input voltage of the free-piston Stirling refrigerator 100, so as to effectively control the refrigeration temperature in each room.

The refrigeration system includes a compression throttling refrigeration system 600 and a free piston Stirling refrigerator-heat pipe system 500 . Compression and throttling refrigeration system 600 includes: variable frequency compressor 608, condenser 604, dry filter 601, capillary tube 607, freezer compartment liquid collector 606, freezer compartment evaporator 605, refrigerator compartment liquid collector 603, refrigerator compartment evaporator 602 . The frequency conversion compressor 608 is located at the bottom of the refrigerator, and there is a vent at the position of the frequency conversion compressor at the back of the refrigerator, so as to discharge the heat generated by the compressor to the environment; Passed to the environment through the shell; the dry filter 601 is located at the end of the evaporator 604, connecting the evaporator 604 and the capillary 607; the other end of the capillary 607 is connected to the freezer evaporator 605, which is located on the right side of the lower half of the refrigerator side, used to provide cooling capacity for the freezer compartment 703; the freezer compartment evaporator 605 is connected to the refrigerating compartment evaporator 602, and the refrigerating compartment evaporator 602 is arranged in the upper half of the refrigerator to provide cooling capacity for the refrigerating compartment 701; the refrigerating compartment collects liquid The collector 603 and the freezer liquid collector 606 are located at the inlet ends of the refrigerating chamber evaporator 602 and the freezing chamber evaporator 605, respectively.

As shown in Figures 4 and 5, the free-piston Stirling refrigerator-heat pipe system 500 is composed of a free-piston Stirling refrigerator system 400 and a heat pipe system, and the free-piston Stirling refrigerator system 400 includes a free-piston Stirling refrigerator Machine 100, cold conduction copper sleeve 200, heat conduction copper sleeve 300. The heat pipe system includes a cold-end gravity heat pipe and a hot-end gravity heat pipe, wherein the cold-end gravity heat pipe is composed of a first cold-end heat pipe 503 and a second cold-end heat pipe 504, and the hot-end gravity heat pipe is composed of a first hot-end heat pipe 501 and a second heat pipe. end heat pipe 502. In order to make it work normally, the pipelines of the first cold-end heat pipe 503 and the second cold-end heat pipe 504 of cold conduction are inclined downward at an angle of 15°, and the pipelines of the first heat-conduction heat pipe 501 and the second heat-end heat pipe 502 of heat conduction are downward Tilted at a 10° angle. The free-piston Stirling refrigerator 100 is installed in the middle left of the refrigerator, and can be conveniently connected to the first hot end heat pipe 501 and the second hot end heat pipe 502 as well as the first cold end heat pipe 503 and the second cold end heat pipe 504 . Bolts 102 can fix the shock absorber 101 of the refrigerator on the tail of the free-piston Stirling refrigerator 100 .

The working fluid used in the first hot-end heat pipe 501 and the second hot-end heat pipe 502 is R600a, which is arranged on the half of the left side of the refrigerator, inside the refrigerator shell 706, and the lower end is respectively connected to the first and second heat-conducting copper sleeves 300. The small holes 301 and 302 are connected to dissipate heat for the hot end 103 of the free-piston Stirling refrigerator 100; the working fluid used in the first cold end heat pipe 503 and the second cold end heat pipe 504 is R170, which is folded and arranged in the variable room The inner side of 702 and the upper end are respectively connected with the first and second cooling holes 202 and 203 on the cooling copper sleeve to transfer the cold produced by the cold head 104 of the free-piston Stirling refrigerator 100 to the variable chamber 702. There are grooves inside the cold conducting copper sleeve 200 and the heat conducting copper sleeve 300 to allow the working fluid to exchange heat in the mobile phase.

As shown in Figure 2, the cooling copper sleeve 200 is a circular copper sleeve, with a hole at one end connected to the cold head 104 of the free-piston Stirling refrigerator 100, and the inner side of the circular copper sleeve is connected to the cold head 104 of the free-piston Stirling refrigerator 100. The heat-conducting silicone grease is coated between the cold heads 104, and the circular copper sleeve is provided with a circular groove 201, so that the heat transfer medium R170 flows in the circular groove 201 to fully exchange heat; the side of the circular copper sleeve is provided with Two first and second cooling guide holes 202 and 203 communicated with the annular groove 201 .

As shown in FIG. 3 , the heat-conducting copper sleeve 300 is an annular copper sleeve, and heat-conducting silicone grease is coated between the inner surface of the annular copper sleeve and the hot end 103 of the free-piston Stirling refrigerator 100, and an annular groove is arranged inside the annular copper sleeve. 303, making the heat transfer medium R600a flow in the annular groove 303 to fully exchange heat; the side of the annular copper sleeve is provided with two first and second heat conduction small holes 301 and 302 communicating with the annular groove 303 .

As shown in Figure 10, in the compression and throttling refrigeration system 600, the working medium is compressed by the frequency conversion compressor 608 and becomes a high-temperature and high-pressure gas, which flows into the condenser 604 from the outlet of the compressor 608, and condenses and releases heat in the condenser 604 to become The low-temperature and high-pressure liquid becomes a low-temperature and low-pressure liquid after being throttled by the capillary 607. It enters the freezer evaporator 605 to evaporate and absorb heat, and then continues to enter the freezer evaporator 602 to absorb heat to provide cooling for the freezer 703 and the freezer 701. After the evaporation process, the working medium becomes a low-temperature and low-pressure gas, which flows into the frequency conversion compressor 608 to complete the compression and throttling cycle process. The cold end of the free-piston Stirling refrigerator is connected to the first cold end heat pipe 503 and the second cold end heat pipe 504, and its working fluid is R170, which becomes liquid after being condensed in the cold conducting copper sleeve 200, and moves downward under the action of gravity In the evaporating section in the temperature-changing chamber 702, the gas absorbs heat and turns into a gaseous state, and then flows upwards and returns to the cold-conducting copper sleeve 200 to complete the cycle process. The free piston Stirling hot end is connected to the first hot end heat pipe 501 and the second hot end heat pipe 502, and its working fluid is R600a, which evaporates into a gas flowing upward in the heat conduction copper sleeve 300, and becomes liquid after condensing and releasing heat in the condensation section , flow back to the thermally conductive copper sleeve 300 under the action of gravity. The display screen 707 is connected to the controller 800, which can not only display the temperature of each refrigeration room, but also control the operating frequency of the frequency conversion compressor 608 and the input voltage of the free-piston Stirling refrigerator 100, so as to precisely control the refrigeration temperature of each room.

Claims (5)

1. a temperature-zone refrigerator more than, including refrigerator body (700), refrigeration system, it is characterised in that: described refrigerator body (700) Being made up of cold room (701), refrigerating chamber (703) and temperature-changing chamber (702), described cold room (701) is positioned on refrigerator body (700) Half part, described refrigerating chamber (703) and temperature-changing chamber (702) are positioned at refrigerator the latter half；Described refrigeration system is by compression throttling system Cooling system (600), free-piston Stirling cooler-hot-pipe system (500) are constituted, and described free-piston Stirling cooler- Hot-pipe system (500) includes free-piston Stirling cooler (100), cold end gravity assisted heat pipe, hot junction gravity assisted heat pipe, conduction cooling copper sheathing (200) and heat conduction copper sheathing (300), the condensation segment pipeline of described hot junction gravity assisted heat pipe is upwards arranged in outcase of refrigerator (706) left wall Inside face, described cold end gravity assisted heat pipe evaporator section pipeline is arranged in downwards temperature-changing chamber (702) inner back wall face and left and right wall, institute State the condensation segment cold head (104) by conduction cooling copper sheathing (200) with free-piston Stirling cooler (100) of cold end gravity assisted heat pipe Being connected, the evaporator section of described hot junction gravity assisted heat pipe is by heat conduction copper sheathing (300) and free-piston Stirling cooler (100) Hot junction (103) is connected.

2. according to the many temperature-zone refrigerators described in claims 1, it is characterised in that: described conduction cooling copper sheathing (200) is circular copper Set, one end perforate is connected with the cold head (104) of free-piston Stirling cooler (100), circle copper sheathing inside and free-piston Scribble heat-conducting silicone grease between the cold head (104) of sterlin refrigerator (100), be provided with toroidal cavity (201) in circular copper sheathing, make Heat-transfer working medium R170 flows abundant heat exchange at toroidal cavity (201)；Described circular copper sheathing side have two recessed with annular The conduction cooling aperture that groove (201) connects.

3. according to the many temperature-zone refrigerators described in claims 1, it is characterised in that: described heat conduction copper sheathing (300) is annular copper sheathing, Heat-conducting silicone grease, annular copper sheathing is scribbled between annular copper sheathing inner surface and the hot junction (103) of free-piston Stirling cooler (100) Inside is provided with annular groove (303), makes heat-transfer working medium R600a flow abundant heat exchange at annular groove (303)；Annular copper sheathing side Have two heat conduction apertures connected with annular groove (303).

4. according to claims 1 state many temperature-zone refrigerators, it is characterised in that: the cryogenic temperature model of described temperature-changing chamber (702) Enclosing for-60-10 DEG C, temperature-changing chamber (702) is provided cold by free-piston Stirling cooler；Described free piston stirling freezes In machine (100) is the monoblock type free-piston Stirling cooler that linear electric motors drive, free-piston Stirling cooler (100) Working medium used by portion is helium, and free-piston Stirling cooler (100) is installed on the left side central portion of refrigerator, free piston stirling Refrigeration machine (100) afterbody is fixed with snubber block (101), and snubber block (101) is towards refrigerator body backboard.

5. according to the many temperature-zone refrigerators described in any one of claim 1-4, it is characterised in that: described cold end gravity assisted heat pipe includes One cool side heat pipes (503) and the second cool side heat pipes (504), the first cool side heat pipes (503) and the second cool side heat pipes (504) respectively with The first and second conduction cooling aperture (202,203) of conduction cooling copper sheathing (200) side connects, and described cold end gravity assisted heat pipe pipeline is downward-sloping 15 ° of angles, internal working medium used is R170；Described hot junction gravity assisted heat pipe includes the first hot side heat (501) and the second hot side heat (502), the first hot side heat (501) and the second hot side heat (502) first and second leading with heat conduction copper sheathing (300) side respectively Hot aperture (301,302) connects, downward-sloping 10 ° of described hot junction gravity assisted heat pipe pipeline, and internal working medium used is R600a.