RU2354898C2 - Method for adjustment of magnetocaloric refrigerator operation parametres in laboratory conditions and device for its realisation - Google Patents

Abstract

FIELD: heating. ^ SUBSTANCE: inventions are related to refrigerating equipment. Method for adjustment of magnetocaloric refrigerator operation parametres in laboratory conditions is based on superposition of magnetic field on magnetocaloric working medium, coolant pumping for its contact with working medium, organisation of heated coolant heat-exchange with environment, drain of cooled coolant into cooling chamber of refrigerator, regulation and control of refrigerator operation parametres. Working medium used is set of single-type replaceable capsules with magnetocaloric effect, which are combined in single unit. Contact of replaceable capsules is arranged along their entire surface with coolant. Optimisation of refrigerator operation is carried out by means of variation of magnetic field intensity value, coolant pumping rate, rate of replaceable capsules passage through zone of magnetic field, intensity of coolant heat transfer into environment. When minimum value of temperature is achieved in refrigerator cooling chamber, refrigerator operation parametre values that provided maximum refrigerating capacity are fixed. ^ EFFECT: realisation of method for adjustment of magnetocaloric refrigerator operation parametres in laboratory conditions. ^ 12 cl, 13 dwg

Description

The invention relates to refrigeration, in particular to methods and devices for working out in the laboratory the operating parameters of refrigerators operating on the basis of the magnetocaloric effect.

Intensive research is currently underway in the field of creating refrigeration units based on the magnetocaloric effect (FEM). Created materials possessing FEM require careful and large-scale laboratory tests in order to incorporate the results into newly developed refrigerated structures.

Well-known from patent sources [1, 2, 3] bench installations and methods used solve particular problems and cannot be used for the integrated development of refrigerated structures and optimization of their parameters.

Known magnetic refrigerator [4], containing a housing with a rotating wheel, which is rigidly mounted on a shaft and made of a working substance with a magnetocaloric effect (FEM), in the form of coaxial rings mounted on each other with radial channels for the passage of warm and cold coolant flows and divided into segments by impermeable heat-insulating partitions, a magnet covering a part of the wheel, a gas distribution device for supplying and discharging the coolant located in the central part of the housing, and load heat exchanger, made in the form of a refrigerator body, rigidly connected with the wheel placed in it with the possibility of rotation together with the latter, while a gap was made between the body and the outer surface of the wheel for the passage of a cold coolant stream.

Despite the good operational characteristics, this design was developed for the use of porous materials with FEM, which does not allow the use of other materials with FEM without significant alteration of the design of the refrigerator, to study their effect on the structural elements of newly created refrigerators, and to optimize the parameters of refrigerated trucks.

Known magnetocaloric refrigerator operating on the basis of the magnetocaloric effect [5], containing a housing filled with liquid or gaseous heat carrier, magnetocaloric elements having channels for the passage of the coolant, heat transfer, load heat exchanger, magnetic system and two reciprocating mechanisms for driving magnetocaloric elements and a magnet. The disadvantages of the specified device:

low efficiency

- a relatively small resource of work,

- large dimensions and mass resulting from the use of two reciprocating drive mechanisms,

- the impossibility of its use as a laboratory setup for research and development of the working parameters of newly designed magnetocaloric refrigerators.

Also known is a magnetocaloric refrigerator [6] for producing low temperatures, comprising a housing inside which a rotor with channels is placed, a coolant system consisting of a coolant flow inducer, a load heat exchanger, inlet and outlet pipes, a magnetic system comprising at least three sections and a ring of superconducting material is installed on the outer surface of the rotor, and the rotor is made of material with FEM. Despite the obvious advantages compared with the known designs, the technical solution described above has a significant drawback: the refrigerator for its stable operation must contain at least three sections of the magnetic system, which complicates the design, and the failure of one of the sections leads to unstable operation of the refrigerator as a whole. In addition, without significant alterations, it is very difficult to use it for experimental testing of newly created refrigerators.

Despite these shortcomings, the design described in patent RU 2029203 [6], can be taken as a prototype.

The task to which the proposed technical solutions are directed is to create a design suitable for working out in laboratory conditions the working parameters of magnetocaloric refrigerators, and on its basis to implement a development method that consists in conducting experiments that allow to study the influence of numerous factors and design decisions on the efficiency of refrigerators , and changing them comprehensively, to optimize the parameters of the refrigerated trucks and to achieve the perfection of their design.

The invented invention consists in the fact that a method for working out in laboratory conditions the operation parameters of magnetocaloric refrigerators, based on the application of a magnetic field on the magnetocaloric working fluid, pumping the coolant for its contact with the working fluid, organizing heat transfer of the heated coolant with the environment, removing the cooled coolant to the cooling chamber refrigerator, regulation and control of the parameters of the refrigerator, characterized in that as a working fluid use a set of od of detachable removable capsules with a magnetocaloric effect, combined into one unit, organize contact of the replaceable capsules along their entire surface with the coolant, while the refrigerator is optimized by changing the magnitude of the magnetic field, the pumping rate of the coolant, the speed of the replaceable capsules through the magnetic field, intensity heat transfer of the coolant to the external environment, and when the minimum temperature is reached, the values of the parameter are fixed in the refrigerator cooling chamber s operation of the refrigerator, to ensure maximum cooling performance.

Also, the claimed invention lies in the fact that the device for testing in laboratory conditions the parameters of magnetocaloric refrigerators, containing a magnetic system, a rotor with a removable cover, provided with channels for the passage of coolant, a working fluid made of a material with a magnetocaloric effect, a rotor drive, a coolant system with a pump and its a drive, a heat receiver located in the cooling chamber, and a heat transmitter, the blocks for adjusting and monitoring the parameters of the refrigerator, differs in that the working fluid completed in the form of a set of the same type of replaceable capsules with a magnetocaloric effect, mounted in the cells washed in the coolant and separated from each other in the rotor body, and the rotor axis is fixed and provided with channels for supplying and removing the coolant and two sealing belts that prevent the coolant from flowing along the stationary plane of interaction axis and rotor, while the rotor is kinematically connected with the drive, the heat sink is made in the form of a removable rim sealed on the rotor with an external and internal axis shaving and a cavity for pumping, and the pump and rotor drives are adjustable.

The replaceable rim mounted on the rotor can be made of a material with a high coefficient of thermal conductivity, for example, copper or aluminum alloy.

The external fins of the replaceable rim of the heat transfer can be made in the form of multi-stage multi-section vanes mounted at an angle to the plane of rotation of the rotor.

The cell shapes in the rotor body for mounting interchangeable capsules can be made similar to the outer contours of interchangeable capsules.

Replaceable capsules can be made in the form of a package of horizontal or vertical plates of material with a magnetocaloric effect installed with a gap.

Replaceable capsules can be made of a material with a magnetocaloric effect in the form of a finned monolith.

Replaceable capsules can be made of a material with a magnetocaloric effect in the form of a monolith with through channels for the passage of coolant.

Replaceable capsules can be made of a porous material that is permeable to a coolant with a magnetocaloric effect.

Replaceable capsules can be made of a material with a magnetocaloric effect in the form of balls or granules placed in a mesh housing.

The fixed axis of the rotor can be provided with two grooves located between the two seal belts.

The units for controlling and controlling the parameters of the refrigerator can be made in the form of a combined control and parameter control panel containing a rotor speed controller with the same replaceable capsules installed in it, a coolant flow rate regulator and devices for controlling the rotor speed, coolant flow rate, magnetic field strength, temperature in the refrigerator cooling chamber and the ambient temperature.

Thus, the technical result is achieved by using a set of the same replaceable capsules with the magnetocaloric effect combined in one block (rotor) as the working fluid, arrange the contact of the replaceable capsules along their entire surface with the coolant, and the refrigerator operation is optimized by changing the intensity value magnetic field, coolant pumping speed, replaceable capsule passage speed through the magnetic field zone, heat transfer rate of the coolant to the external environment, and when available zhenii minimum temperature in the cooling chamber of the refrigerator are fixed values of operating parameters of the refrigerator to ensure maximum refrigerating capacity.

The proposed method is implemented in a device containing a magnetic system, a rotor with a removable cover, provided with channels for the passage of the coolant, a working fluid made of a material with a magnetocaloric effect, a rotor drive, a coolant system with a pump and its drive, a heat receiver located in the refrigerator cooling chamber, and a heat transmitter , blocks of adjustment and control of the parameters of the refrigerator. In this case, the working fluid is made in the form of a set of replaceable capsules of the same type, mounted in the cells washed in the rotor body and separated from each other, the rotor axis is fixed and provided with channels for supplying and discharging the coolant and two sealing belts that exclude the flow of the coolant along the stationary plane of interaction axis and rotor, and the rotor is kinematically connected with the drive, the heat sink is made in the form of a removable rim hermetically mounted on the rotor with external and internal fins and a cavity th for pumping coolant. The pump and rotor drives are adjustable.

Patented method and device allow to carry out the development of refrigerated structures in laboratory conditions, to investigate a wide range of working fluids from materials with FEM, including newly created ones, to optimize the parameters of refrigerated trucks being developed.

The invention is illustrated graphic materials, where

figure 1 shows a block diagram of a device;

figure 2 shows the remote element I in figure 1;

figure 3 shows a section aa in figure 2 is a transverse section of the rotor;

figure 4 presents a view of B in figure 3 - the external ribbing of the rim of the rotor;

figure 5 shows a view in figure 3 is a variant of the external fins of the rim of the rotor;

in Fig.6 shows a section aa in Fig.1 - an embodiment of the fixed axis of the rotor with two grooves for the passage of the coolant simultaneously through several adjacent rotor cells;

in Fig.7 shows a view of G in Fig.6 - view of the groove in the fixed axis for the passage of the coolant, made between two zones of seals;

on Fig shows a replaceable capsule, made in the form of a package of horizontal plates of material with FEM, installed with a gap for the passage of coolant;

figure 9 presents a replaceable capsule in the form of a package of vertically mounted plates of material with FEM.

figure 10 shows a replaceable capsule in the form of a finned monolith from a material with FEM;

11 shows a replaceable capsule of material with FEM in the form of a monolith with through channels for the passage of coolant;

on Fig presents a replaceable capsule made of a porous material with FEM;

13 shows a replaceable capsule made in the form of a mesh body with balls or granules made of material with FEM placed therein.

A device for working out in laboratory conditions the operation parameters of magnetocaloric refrigerators (Figs. 1, 2) comprises a cooling chamber 1, a magnetic system 2, a rotor 3 with a removable cover 4. In the body of the rotor 3 there are recesses in the form of cells 5 separated from each other, in which the same type of interchangeable capsules 6 (Figs. 1, 2, 3, 6) of material 7 having a magnetocaloric effect are installed. The device is equipped with a coolant system 8 with a pump 9, a heat sink 10, a heat sink 11, a compensation tank 12 with a cover 13, pipelines 14 and 15 supplying and discharging the coolant, respectively. The rotor 3 and the cover 4 are made of magnetically permeable material, such as organic glass. Cells 5 in the body of the rotor 3 (Figs. 3, 6) are separated from each other and provided with radial channels 16 and 17 for passage of the coolant. Replaceable capsules of the same type 6 (not all are shown in FIGS. 1, 2, 3, 6) have the form of segments, cylinders, polyhedral bars, etc. and are installed in the cells with a gap for the passage of the coolant that washes each capsule 6. Replaceable capsules 6 can be made in the form of packets of horizontal (Fig. 8) or vertical (Fig. 9) plates 18 and 19 installed with a gap, respectively, of material with FEM , finned monoliths (Fig. 10), monoliths with through channels 20 for the passage of the coolant (Fig. 11), monoliths of porous, heat-permeable material with FEM (Fig. 12) or mesh cases, inside which are placed balls or granules of material with FEM (Fig.13). The heat sink 11 (Figure 2) is made in the form of a replaceable rim 21 hermetically mounted on the rotor 3 with external and internal fins 22 and 23, respectively. The replaceable rim 21 is made of a material having high thermal conductivity, such as copper or aluminum alloy. Inside the interchangeable rim 21, a cavity 24 is contacted with the coolant 24. The external ribbing 22 of the interchangeable rim 21 is a cylinder with annular ribs 25 (FIG. 4). The external fins of the replaceable rim 21 for increasing heat transfer can also be made in the form of well-developed surfaces, for example, multi-stage multi-section vanes 33 (Figure 5), mounted at an angle to the plane of rotation of the rotor 3. Kinematically connected with an adjustable drive (not shown in Figure 2 ) the rotor 3 is mounted on a fixed axis 26 (Figs. 2, 3, 6, 7) made of a material with a low coefficient of friction, for example fluoroplastic, and equipped with inlet and outlet channels 27 and 28, respectively, and seal belts 29 and 30 (Ф g.2, 7), excluding the flow of the coolant along the plane of interaction 31 (Figure 2) of the fixed axis 26 and the rotor 3. For simultaneous passage of the coolant through several channels 17 (in the rotor 3), the slots 32 are made in the fixed axis 26 (Figure 6 , 7) located between the two belts of the seals 29 and 30 (Fig.2, 7). This technical solution allows simultaneous contact of the coolant with several interchangeable capsules 6 located in adjacent cells 5, both at the entrance of the coolant into the rotor 3, and at the exit from it. To change the speed of rotation of the rotor 3 and the flow rate of the coolant, the device is equipped with adjustable drives 34 and 35 (Figure 1), respectively. To control the operating parameters, the patented device is equipped with a flow sensor 36 of the coolant, a temperature sensor 37 in the cooling chamber, an ambient temperature sensor 38, a temperature meter 39. For the convenience of testing, the adjustment and control units of the refrigerator operation parameters are made in the form of a combined control and parameter control panel 40 .

The patented method is carried out in the above device as follows. In cells 5 (with the cover 4 removed), replaceable capsules 6 of the same type (in shape and material) are installed with the selected material 7 having a magnetocaloric effect (Figs. 8, 9, 10, 11, 12, 13). The removable cover 4 is hermetically fixed to the rotor 3. A removable rim 21 with the selected option of the external fins 22 is also installed on the rotor 3 (Figs. 4, 5). The compensation tank 12 is filled with coolant and the adjustable drives 34 and 35 of the rotor 3 and pump 9 are activated, respectively (Figure 1). The pump 9 pumps the coolant (FIGS. 2, 3, 6) through the compensation tank 12, the supply pipe 14, the supply channel 27, channel 17 (the channels 17 in the rotor 3, depending on their position relative to the magnetic system 2, are input or output for the coolant) cell 5.

Washing the replaceable capsule 6, the coolant through the channel 16 enters the cavity 24 of the finned rim 21 of the heat sink 11. The heated replaceable capsules 6 in the area of the strong magnetic field created by the magnetic system 2, transfer their heat through the coolant to the rim 21, equipped with external and internal fins 22 and 23 Then, the coolant moves in the inner cavity 24 of the rim 21, transferring heat to the external environment (see arrows shown in Figs. 3 and 6), and enters through channels 16 (their functions, similar to channels 17, also depend on the position of the rotor 3) into cells 5 , g e it is cooled, as interchangeable capsules 6 with material 7, leaving the zone of a strong magnetic field, are demagnetized and cooled as a result of the magnetocaloric effect. The cooled fluid through the channels 17, 28 and the discharge pipe 15 enters the cooling chamber 1, where the cooling capacity is realized. Further, the cycle is repeated many times. During testing, the remote control 40 sets the operating modes of the adjustable drives 35 and 34, which allow you to change the flow rate of the coolant in the system 8 and the rotational speed of the rotor 3, which determines the time spent by the capsules 6 with magnetocaloric materials 7 in the magnetic field created by the magnetic system 2. The magnetic field strength, if it is created by the electromagnet of the magnetic system 2, is controlled from the remote control 40. In the case of the use of permanent magnets, the magnetic field is discretely changed by setting a constant x magnets with fixed parameters. The refrigerator operation parameters are optimized by replacing a set of one replaceable capsule 6 with another (with different materials with FEM and forms of their implementation), selecting the designs of the replaceable rim 21 of the heat transfer device 11, changing the flow rate of the coolant and the magnetic field strength, as well as the rotor speed 3. When when the minimum temperature is reached in the freezer 1 of the investigated refrigerator, the values of the parameters ensuring the maximum cooling capacity are recorded.

Patented method and device allow laboratory tests of working parameters of refrigerators under development, to investigate the effect of used structural elements on cooling capacity, and through the use of a rotor with the same replaceable capsules installed in it, with a material having a magnetocaloric effect, to achieve the optimal ratio of operating parameters and accepted design decisions.

Information sources

1. Patent of Russia RU 2027929, cl. F16J 15/00. Test bench for magnetic fluids, publ. 1995.

2. Patent of Russia RU 2269077, cl. F25B 25/02. Test bench for an absorption compressor refrigerator, publ. 2006.

3. Patent of Russia RU 2105938, cl. F25B 25/02. Test bench for the absorption compressor unit, publ. 1998.

4. A.S. 1668829, class F25B 21/00. Rotary magnetic refrigerator.

5. Patent US 4392356, cl. 62-3. Magnetocaloric refrigerator, publ. 1984.

6. Patent of Russia RU 2029203, cl. F25B 21/00. Magnetocaloric refrigerator, publ. 1995.

7. Patent of Russia RU 2252375, cl. F25B 21/00. Magnetic heat engine, publ. 2005.

8. Patent of Russia RU 2079802, cl. F25B 21/00. Refrigerator, publ. 1997.

9. Patent of Russia RU 2040740, cl. F25B 21/00. Magnetocaloric refrigerator, publ. 1995.

10. A.S. 1726930, class F25B 21/00. Magnetocaloric refrigerator, publ. 1992.

11. A.S. 1719815, class F25B 21/00. Cryostatization system, publ. 1992.

12. A.S. 1629706, cl. F25B 21/00. Magnetocaloric refrigerator, publ. 1991.

13. A.S. 1590881, cl. F25B 21/00. Magnetocaloric refrigerator, publ. 1990.

14. A.S. 1451490, class F25B 21/00. Magnetocaloric refrigerator, publ. 1989.

15. Patent US 6668560, CL F25B 21/00. Rotary magnetocaloric refrigerator, publ. 2003.

16. Patent US 6446441, CL F25B 21/00. Magnetocaloric refrigerator, publ. 2002.

17. Patent US 4727721, cl. F25B 21/02. The device of the magnetocaloric refrigerator, publ. 1988.

18. US Patent 4,532,770, cl. F25B 21/02. Magnetocaloric refrigerator, publ. 1985.

19. Patent US 4107935, CL F25B 21/02. High-temperature refrigerator, publ. 1978.

20. Japan patent 60-259870, cl. F25B 21/00. Magnetocaloric refrigerator, publ. 1985.

Claims (12)

1. The method of working out in laboratory conditions the operating parameters of magnetocaloric refrigerators, based on the application of a magnetic field on the magnetocaloric working fluid, pumping the coolant for its contact with the working fluid, organizing the heat exchange of the heated coolant with the environment, the removal of the cooled coolant in the refrigerator cooling chamber, regulation and control parameters of the refrigerator, characterized in that as a working fluid use a set of the same type of interchangeable capsules with magnetocaloric The combined effect in one unit makes contact of the replaceable capsules on their entire surface with the coolant, while the refrigerator is optimized by changing the magnitude of the magnetic field, the pumping rate of the coolant, the speed of the replaceable capsules through the magnetic field, the heat transfer rate of the coolant to the external medium, and when the minimum temperature is reached in the cooling chamber of the refrigerator, the values of the parameters of the refrigerator, which ensure the maximum cooling capacity. 2. A device for working out in laboratory conditions the parameters of magnetocaloric refrigerators, containing a magnetic system, a rotor with a removable cover, equipped with channels for the passage of coolant, a working fluid made of a material with a magnetocaloric effect, a rotor drive, a coolant system with a pump and its drive, a heat sink located in the cooling chamber, and the heat transmitter, adjustment and control units for the parameters of the refrigerator, characterized in that the working fluid is made in the form of a set of replaceable capsules of the same type with a magnetocaloric effect, mounted in the cells washed in the coolant and separated from each other in the rotor body, and the rotor axis is fixed and provided with channels for supplying and discharging the coolant and two sealing belts that prevent the coolant from flowing along the plane of interaction of the fixed axis and the rotor, while the rotor kinematically connected with the drive, the heat sink is made in the form of a removable rim hermetically mounted on the rotor with external and internal fins and a cavity for pumping, and the pump drives and the rotor are adjustable. 3. The device according to claim 2, characterized in that the interchangeable rim mounted on the rotor is made of a material with a high coefficient of thermal conductivity, for example, copper or aluminum alloy. 4. The device according to claim 2 or 3, characterized in that the external ribbing of the replaceable rim of the heat sink is made in the form of multi-stage multi-section vanes mounted at an angle to the plane of rotation of the rotor. 5. The device according to claim 2, characterized in that the cell shapes in the rotor body for mounting interchangeable capsules are made similar to the outer contours of interchangeable capsules. 6. The device according to claim 2, characterized in that the replaceable capsules are made in the form of a package of horizontal or vertical plates installed with a gap of material with a magnetocaloric effect. 7. The device according to claim 2, characterized in that the replaceable capsules are made of a material with a magnetocaloric effect in the form of a finned monolith. 8. The device according to claim 2, characterized in that the replaceable capsules are made of a material with a magnetocaloric effect in the form of a monolith with through channels for the passage of coolant. 9. The device according to claim 2, characterized in that the replaceable capsules are made of porous material permeable to a heat transfer medium with a magnetocaloric effect. 10. The device according to claim 2, characterized in that the replaceable capsules are made of a material with a magnetocaloric effect in the form of balls or granules placed in a mesh housing. 11. The device according to claim 2, characterized in that the fixed axis of the rotor is provided with two grooves located between the two seal belts. 12. The device according to claim 2, characterized in that the adjustment and control units of the refrigerator operation parameters are made in the form of a combined control and parameter control panel comprising a rotor speed controller with replaceable capsules of the same type installed therein, a coolant flow rate controller and revolutions control devices rotor, coolant flow rate, magnetic field strength, temperature in the refrigerator cooling chamber and ambient temperature.

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