Heat Pump Unit

Abstract

The present invention comprises: a heat pump (10) that is provided with an internal heat absorption part (12) for receiving heat and an internal heat dissipation part (13) for releasing heat, and transfers heat between the internal heat absorption part (12) and the internal heat dissipation part (13) using magnetic particle dispersion liquid (11) that circulates between the internal heat absorption part (12) and the internal heat dissipation part (13); an external heat absorption part (23) where a secondary working fluid (21) receives heat from a heating fluid (2); an external heat dissipation part (24) where the secondary working fluid (21) releases heat to a heat-receiving fluid (3); and a circulation path (20) where the secondary working fluid (21) circulates, and receives heat from the heating fluid (2) at the external heat absorption part (23), and then receives the heat released from the internal heat dissipation part (13), and then releases heat to the heat-receiving fluid (3) at the external heat dissipation part (24), and then releases heat to the magnetic particle dispersion liquid (11) at the internal heat absorption part (12), and then receives heat again from the heating fluid (2) at the external heat absorption part (23).

Description

[Technical field]

[0001] The present invention relates to a heat pump unit that uses a heat pump that transfers heat by utilizing a magnetic field. [Background technology]

[0002] Conventionally, heat pumps have been used as a means for transferring heat from a low-temperature part to a high-temperature part. A heat pump receives heat from a low-temperature part, raises the temperature of the heat, and supplies it to a high-temperature part, thereby obtaining high-temperature thermal energy from low-temperature thermal energy.

[0003] As such heat pumps, mechanical heat pumps using a compressor have been commercialized, but in heat pumps using a compressor, noise caused by the compressor and the complicated maintenance are recognized as problems and risks.

[0004] Here, a heat pump that transfers heat by utilizing a magnetic field is disclosed in, for example, Patent Document 1. The heat pump disclosed in Patent Document 1 is a device in which particulate magnetic solids are packed inside, and heat exchange is performed between the magnetic solids and a liquid working fluid that flows in a packed bed packed with the magnetic solids while a magnetic field is applied or reduced to the magnetic solids. Therefore, compared to heat pumps that use a compressor, no noise caused by the compressor is generated, and maintenance is easy. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2019-509461 Summary of the Invention [Problem to be solved by the invention]

[0006] In the heat exchange between the magnetic material and the working fluid described above, the amount of heat exchanged is Q, the overall heat transfer coefficient due to the state of the heat transfer surface is U, the heat transfer area is A, and the temperature difference between the heat transfer surfaces is Δt. Q = U A Δt It is expressed as follows. Therefore, in order to obtain a large amount of heat Q, at least one of the heat transfer area A and the temperature difference Δt between the heat transfer surfaces must be increased. In order to increase the heat transfer area A, it is necessary to increase the volumetric surface area by reducing the size of the magnetic particles. However, in a heat pump such as the one disclosed in Patent Document 1, which performs heat exchange between the magnetic particles filled inside the device and a liquid working fluid, if the size of the magnetic particles is reduced, the pressure loss when the liquid working fluid flows through the packed bed increases. Then, the work input to move the working fluid increases, and the efficiency of the heat pump decreases. Therefore, in order to obtain good efficiency, it is necessary to use magnetic particles of a relatively large size. As a result, the area (heat transfer area A) where the solid magnetic material and the liquid working fluid come into contact is limited.

[0007] On the other hand, it is possible to increase the temperature difference Δt between the heat transfer surfaces in order to obtain a large amount of heat Q. However, in a heat pump, if the temperature difference Δt between the heat transfer surfaces is large, it becomes necessary to increase or decrease the temperature of the working fluid by an amount equal to the temperature difference, which reduces the thermal efficiency.

[0008] Therefore, the applicant has devised a technology that improves the efficiency of heat exchange between the magnetic particles and the solvent of the main working fluid by making the main working fluid circulating between the heat absorption part that receives heat from the outside and the heat dissipation part that dissipates heat to the outside a fluid in which magnetic particles are dispersed in a solvent, and that can transfer heat with high efficiency by utilizing a magnetic field. In this technology, heat pumps are arranged in multiple stages so that the heat released by the heat dissipation part of the heat pump in the previous stage is received by the heat absorption part of the heat pump in the subsequent stage, and a heat transfer auxiliary part is arranged between each of the heat pumps arranged in multiple stages, which receives the heat released by the heat dissipation part of the heat pump in the previous stage with a secondary working fluid and gives the heat of the secondary working fluid to the heat absorption part of the heat pump in the subsequent stage. This makes it possible to transfer heat with a larger temperature difference.

[0009] The above-mentioned main working fluid may be any dispersion form as long as the magnetic particles are dispersed in a solvent. That is, the main working fluid may be a colloidal fluid or a suspension. In the following description, the colloidal fluid and the suspension are collectively referred to as a magnetic particle dispersion.

[0010] As described above, in a configuration in which a heat transfer assistant section is disposed between each of the heat pumps arranged in a plurality of stages, which receives the heat emitted by the heat dissipation section of the heat pump in the preceding stage with a secondary working fluid and provides the heat of the secondary working fluid to the heat absorption section of the heat pump in the succeeding stage, the temperature change obtained by the heat transfer per stage is determined by the temperature change of the magnetic particle dispersion liquid due to the magnetocaloric effect when a magnetic field is applied or reduced. In this case, the temperature change of the magnetic particle dispersion liquid due to the magnetocaloric effect when a magnetic field is applied or reduced is generally about 2°C to 4°C. Therefore, when transferring heat with a large temperature difference, many heat pumps and heat transfer assistant sections are required. In addition, the number of pumps for circulating the main working fluid and the secondary working fluid is also required accordingly. For example, if the external heat-providing fluid is -30°C, the external heat-receiving fluid is 30°C, and the temperature change of the magnetic particle dispersion liquid due to the magnetocaloric effect when a magnetic field is applied or reduced per stage is 2°C, the number of stages required is 30, and 60 pumps are required.

[0011] Therefore, the applicant conducted further research into improving the efficiency of heat transfer in a technology for transferring heat between an external heat-donating fluid and an external heat-receiving fluid by using the exchange of heat between a main working fluid and an auxiliary working fluid.

[0012] The present invention aims to provide a heat pump unit that can further improve the efficiency of heat transfer in a technology for transferring heat between an external heat-donating fluid and an external heat-receiving fluid by using the exchange of heat between a main working fluid and a secondary working fluid. [Means for solving the problem]

[0013] In order to achieve the above object, the present invention provides A heat pump unit that uses a magnetic particle dispersion liquid in which magnetic particles are dispersed in a solvent as a main working fluid and transfers heat between an external heat providing fluid and an external heat receiving fluid, a heat pump including an internal heat absorption section that receives heat and an internal heat dissipation section that dissipates heat, and transferring heat between the internal heat absorption section and the heat dissipation section by applying and reducing a magnetic field to the main working fluid circulating between the internal heat absorption section and the internal heat dissipation section; an external heat sink where the secondary working fluid receives heat from the external heat-donating fluid; an external heat dissipation section where the secondary working fluid dissipates heat to the external heat receiving fluid; The secondary working fluid circulates between the external heat absorption section, the heat pump, and the external heat dissipation section, and after the secondary working fluid receives heat from the external heat-donating fluid at the external heat absorption section, the secondary working fluid receives heat released from the main working fluid at the internal heat dissipation section of the heat pump, then the secondary working fluid releases heat to the external heat-receiving fluid at the external heat dissipation section, then the secondary working fluid releases heat to the main working fluid at the internal heat absorption section of the heat pump, and then the secondary working fluid receives heat again from the external heat-donating fluid at the external heat absorption section.

[0014] In the present invention configured as described above, the auxiliary working fluid circulating through the circulation path between the external heat absorption unit, the heat pump, and the external heat radiation unit receives heat from the external heat-donating fluid at the external heat absorption unit, receives heat released from the main working fluid at the internal heat radiation unit of the heat pump, then releases heat to the external heat-receiving fluid at the external heat radiation unit, then releases heat to the main working fluid at the internal heat absorption unit of the heat pump, and then receives heat again from the external heat-donating fluid at the external heat absorption unit. As a result, the temperature difference at which the heat pump unit can pump up thermal energy, i.e., the temperature difference that can be set for the temperature conditions of the external heat-donating fluid and the external heat-receiving fluid, depends on the temperature change in the heat exchange between the main working fluid and the auxiliary working fluid. Here, the temperature change in the heat exchange between the main working fluid and the auxiliary working fluid is generally larger than the temperature change of the magnetic particle dispersion due to the magnetocaloric effect when a magnetic field is applied or reduced. Therefore, thermal energy can be transferred with a large temperature difference between the external heat-providing fluid and the external heat-receiving fluid, and the efficiency of heat transfer between the external heat-providing fluid and the external heat-receiving fluid is further improved.

[0015] In addition, in a heat pump arranged in multiple stages between the external heat absorption part and the external heat dissipation part in the flow direction of the secondary working fluid in the circulation path, the number of stages required can be reduced because thermal energy can be transferred with a large temperature difference in one stage.

[0016] Furthermore, if the source of the magnetic field is a permanent magnet, the magnetic field is generated without the need for a power source or the like.

[0017] Furthermore, if the magnetic material constituting the main working fluid in each of the multi-stage heat pumps is individually selected according to the temperature of the heat absorbed in the internal heat absorption section of the heat pump and released in the internal heat dissipation section, the overall thermal efficiency can be further improved.

[0018] Furthermore, in a region where the secondary working fluid exchanges heat with the main working fluid, if the secondary working fluid flows in the same flow path as the main working fluid, and one of the main working fluid and the secondary working fluid flowing in the same flow path is hydrophilic and the other is hydrophobic, the heat transfer resistance between the main working fluid and the secondary working fluid is reduced, making it possible to perform heat exchange more efficiently, while also making it possible to easily separate the main working fluid and the secondary working fluid after heat exchange between them. Effect of the Invention

[0019] According to the present invention, the secondary working fluid circulating through the circulation path between the external heat absorption unit, the heat pump, and the external heat radiation unit receives heat from the external heat-donating fluid at the external heat absorption unit, receives heat released from the main working fluid at the internal heat radiation unit of the heat pump, then releases heat to the external heat-receiving fluid at the external heat radiation unit, then releases heat to the main working fluid at the internal heat absorption unit of the heat pump, and then receives heat again from the external heat-donating fluid at the external heat absorption unit. This makes it possible for the heat pump unit to pump up thermal energy, i.e., the temperature difference between the external heat-donating fluid and the external heat-receiving fluid, to depend on the temperature change in the heat exchange between the main working fluid and the secondary working fluid. This makes it possible to transfer thermal energy with a large temperature difference between the external heat-donating fluid and the external heat-receiving fluid, and further improves the efficiency of heat transfer in a technology for transferring heat between the external heat-donating fluid and the external heat-receiving fluid by transferring heat between the main working fluid and the secondary working fluid.

[0020] In addition, in a heat pump arranged in multiple stages between the external heat absorption part and the external heat dissipation part in the flow direction of the secondary working fluid in the circulation path, the number of stages required can be reduced because thermal energy can be transferred with a large temperature difference in one stage.

[0021] Furthermore, in the case where the source of the magnetic field is a permanent magnet, the magnetic field can be generated without requiring a power source or the like.

[0022] Furthermore, in a multi-stage heat pump in which the magnetic material constituting the main working fluid in the heat pump is individually selected according to the temperature of the heat absorbed in the internal heat absorption section and released in the internal heat dissipation section of the heat pump, the overall thermal efficiency can be further improved.

[0023] In addition, in a region where the secondary working fluid exchanges heat with the main working fluid, the secondary working fluid flows in the same flow path as the main working fluid, and when the main working fluid and the secondary working fluid flowing in the same flow path are such that one of them is hydrophilic and the other is hydrophobic, the heat transfer resistance between the main working fluid and the secondary working fluid is reduced, making it possible to perform heat exchange more efficiently, while the main working fluid and the secondary working fluid can be easily separated after heat exchange between them. [Brief description of the drawings]

[0024] [Figure 1] 1 is a diagram showing an embodiment of a heat pump unit of the present invention; [Diagram 2] 2 is a diagram showing the characteristics of adiabatic temperature change with respect to the temperature of a magnetic particle dispersion liquid flowing in a flow path of the heat pump shown in FIG. 1. [Diagram 3] 2 is a cross-sectional view showing flow paths of an internal heat absorbing section and an internal heat radiating section through which a magnetic particle dispersion liquid flowing through a flow path of a heat pump and a secondary working fluid circulating through a circulation path flow in the heat pump unit shown in FIG. 1. [Figure 4] FIG. 2 is a diagram showing an example of the configuration of a heat pump unit that transfers thermal energy with a larger temperature difference based on the configuration shown in FIG. 1. [Diagram 5] 5 is a diagram for explaining a method of selecting a magnetic material constituting a magnetic particle dispersion liquid flowing through a flow path of a heat pump constituting the heat pump unit shown in FIG. 4. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0026] FIG. 1 is a diagram showing an embodiment of a heat pump unit of the present invention.

[0027] 1, the heat pump unit in this embodiment receives heat from a heat-donating fluid 2 and releases heat to a heat-receiving fluid 3, thereby transferring heat between the heat-donating fluid 2 and the heat-receiving fluid 3. The heat pump unit in this embodiment has a heat pump 10, an external heat absorption section 23, an external heat dissipation section 24, and a circulation path 20.

[0028] The heat pump 10 is provided with an internal heat absorption section 12, a temperature increasing section 14, an internal heat dissipation section 13, a temperature decreasing section 15, and a pump 16 on a flow path through which a magnetic particle dispersion liquid 11, which is the main working fluid, flows.

[0029] The internal heat absorption section 12 is provided in the vicinity of the circulation path 20. In the internal heat absorption section 12, the magnetic particle dispersion liquid 11 receives heat from the auxiliary working fluid 21 introduced from the circulation path 20.

[0030] The temperature increasing section 14 is provided downstream of the internal heat absorption section 12 in the flow direction of the magnetic particle dispersion liquid 11. The temperature increasing section 14 increases the temperature of the magnetic particle dispersion liquid 11 by applying a magnetic field 17 to the magnetic particle dispersion liquid 11 that has received heat at the internal heat absorption section 12.

[0031] The internal heat dissipation section 13 is provided close to the circulation path 20 and downstream of the temperature increasing section 14 in the flow direction of the magnetic particle dispersion liquid 11. In the internal heat dissipation section 13, the magnetic particle dispersion liquid 11 dissipates heat to the auxiliary working fluid 21 introduced from the circulation path 20.

[0032] The temperature reducing section 15 is provided downstream of the internal heat dissipation section 13 in the flow direction of the magnetic particle dispersion liquid 11. The temperature reducing section 15 reduces the temperature of the magnetic particle dispersion liquid 11 by removing or reducing the magnetic field 17 applied to the magnetic particle dispersion liquid 11 from which heat has been dissipated in the internal heat dissipation section 13.

[0033] The pump 16 is provided between the internal heat absorption section 12 and the temperature increasing section 14 in the flow path of the magnetic particle dispersion liquid 11. The pump 16 circulates the magnetic particle dispersion liquid 11 within the flow path. Note that the installation position of the pump 16 is not limited to between the internal heat absorption section 12 and the temperature increasing section 14, as long as the magnetic particle dispersion liquid 11 can be circulated within the flow path.

[0034] The external heat absorption section 23 is provided downstream of the internal heat absorption section 12 and upstream of the internal heat dissipation section 13 in the flow direction of the auxiliary working fluid 21. In the external heat absorption section 23, the auxiliary working fluid 21 introduced from the circulation path 20 receives heat from the heat donor fluid 2.

[0035] The external heat radiating section 24 is provided downstream of the internal heat radiating section 13 and upstream of the internal heat absorbing section 12 in the flow direction of the auxiliary working fluid 21. In the external heat radiating section 24, the auxiliary working fluid 21 introduced from the circulation path 20 radiates heat to the heat receiving fluid 3.

[0036] The circulation path 20 is provided so that the auxiliary working fluid 21 circulates between the external heat absorption section 23, the heat pump 10, and the external heat radiation section 24. The circulation path 20 is provided with a pump 22 for circulating the auxiliary working fluid 21.

[0037] The operation of the heat pump unit 1 shown in FIG. 1 will be described below.

[0038] FIG. 2 is a diagram showing the characteristics of adiabatic temperature change with respect to the temperature of the magnetic particle dispersion liquid 11 flowing in the flow path of the heat pump 10 shown in FIG.

[0039] In the heat pump unit 1 shown in FIG. 1, first, the secondary working fluid 21 receives heat from the heat donor fluid 2 in the external heat absorption section 23, and then the secondary working fluid 21 circulates through the circulation path 20 by the action of the pump 22 and is supplied to the internal heat dissipation section 13 of the heat pump 10.

[0040] Meanwhile, in the heat pump 10, a magnetic field 17 is applied to the magnetic particle dispersion 11 in an adiabatic environment in the temperature increasing section 14. This changes the magnetic moment of the magnetic particles contained in the magnetic particle dispersion 11, and the characteristic point in Fig. 2 moves from point A to point B. In this case, the change in magnetic moment in an adiabatic environment causes the temperature of the magnetic particle dispersion 11 to rise.

[0041] The magnetic particle dispersion 11, whose temperature has been increased in the temperature increasing section 14, flows through the flow path by the action of the pump 16 and is supplied to the internal heat dissipation section 13. In the internal heat dissipation section 13, a magnetic field 17 is continuously applied to the magnetic particle dispersion 11 that has passed through the temperature increasing section 14. Then, the auxiliary working fluid 21 introduced from the circulation path 20 receives heat from the magnetic particle dispersion 11. Then, the temperature of the magnetic particle dispersion 11 decreases with the heat dissipation, and the characteristic point in FIG. 2 moves from point B to point C. Here, the auxiliary working fluid 21 circulating through the circulation path 20 receives the heat released from the magnetic particle dispersion 11, i.e., the heat due to the temperature change from point B to point C in FIG. 2. Therefore, under appropriate flow rate conditions, the temperature difference between the sub working fluid 21 before the internal heat dissipation section 13 receives the heat released from the magnetic particle dispersion liquid 11 and after the internal heat dissipation section 13 receives the heat released from the magnetic particle dispersion liquid 11 is equal to the temperature change ΔT HEX It is possible to make it so that Cut.

[0042] The magnetic particle dispersion 11, which has dissipated heat to the secondary working fluid 21 in the internal heat dissipation section 13, flows through the flow path by the action of the pump 16 and is supplied to the temperature lowering section 15. In the temperature lowering section 15, the magnetic field 17 applied to the magnetic particle dispersion 11 that has passed through the internal heat dissipation section 13 is reduced. Then, the magnetic moment of the magnetic particles 11b changes, and the characteristic point in FIG. 2 moves from point C to point D. In this case, the temperature of the magnetic particle dispersion 11 decreases due to the change in the magnetic moment in an adiabatic environment. As a result, the temperature of the magnetic particle dispersion 11 that passes through the temperature lowering section 15 and is supplied to the internal heat absorption section 12 becomes lower than the temperature of the magnetic particle dispersion 11 that passes through the internal heat absorption section 12 and is supplied to the temperature raising section 14.

[0043] On the other hand, the auxiliary working fluid 21, which has received the heat released from the magnetic particle dispersion 11 at the internal heat dissipation section 13, circulates through the circulation path 20 by the action of the pump 22, is supplied to the external heat dissipation section 24, and releases the heat to the heat receiving fluid 3. At this time, the temperature of the heat released from the auxiliary working fluid 21 to the heat receiving fluid 3 is, as described above, a temperature change ΔT of the magnetic particle dispersion 11 in the heat exchange between the magnetic particle dispersion 11 and the auxiliary working fluid 21, relative to the temperature before the auxiliary working fluid 21 received the heat released from the magnetic particle dispersion 11 at the internal heat dissipation section 13. HEX It has become expensive by The temperature change ΔT of the magnetic particle dispersion liquid 11 during the heat exchange between the magnetic particle dispersion liquid 11 and the secondary working fluid 21 HEX The temperature difference that can be used as a function of the applied or reduced magnetic field is generally The temperature change ΔT of the magnetic particle dispersion 11 due to the magnetocaloric effect when MH Therefore, thermal energy can be transferred between the heat-donating fluid 2 and the heat-receiving fluid 3 with a large temperature difference, and the efficiency of the transfer of heat between the heat-donating fluid 2 and the heat-receiving fluid 3 can be further improved.

[0044] The secondary working fluid 21, which has released heat to the heat-receiving fluid 3, circulates through the circulation path 20 by the action of the pump 22, and is supplied to the internal heat absorption section 12 of the heat pump 10. The magnetic particle dispersion 11, whose temperature has been reduced in the temperature reducing section 15, flows through the flow path by the action of the pump 16 and is supplied to the internal heat absorption section 12. In the internal heat absorption section 12, heat is released from the secondary working fluid 21 to the magnetic particle dispersion 11 in a state where no magnetic field is applied to the magnetic particle dispersion 11. This causes the temperature of the magnetic particle dispersion 11 to rise, and the characteristic point in FIG. 2 moves from point D to point A.

[0045] The auxiliary working fluid 21 that has released heat to the magnetic particle dispersion liquid 11 at the internal heat absorption section 12 circulates through the circulation path 20 by the action of the pump 22 and is supplied again to the external heat absorption section 23, where it receives heat from the heat-donating fluid 2.

[0046] Incidentally, possible sources of the magnetic field 17 include permanent magnets and electromagnets. However, in the heat pump unit 1 shown in FIG. 1, it is preferable to use a permanent magnet since a permanent magnet does not require a power source, etc.

[0047] Thus, in this embodiment, the auxiliary working fluid 21 circulating through the circulation path 20 between the external heat absorption section 23, the heat pump 10, and the external heat dissipation section 24 receives heat from the heat-donating fluid 2 at the external heat absorption section 23, then receives heat dissipated from the magnetic particle dispersion 11 at the internal heat dissipation section 13 of the heat pump 10, then dissipates heat to the heat-receiving fluid 3 at the external heat dissipation section 24, then dissipates heat to the magnetic particle dispersion 11 at the internal heat absorption section 12 of the heat pump 10, and then receives heat again from the heat-donating fluid 2 at the external heat absorption section 23. As a result, the temperature difference that can realize the pumping of thermal energy as a heat pump unit, i.e., the temperature difference between the external heat-donating fluid and the external heat-receiving fluid, is set to the temperature change ΔT of the magnetic particle dispersion 11 in the heat exchange between the magnetic particle dispersion 11 and the auxiliary working fluid 21. HEX As a result, the heat supply fluid 2 and the heat receiving fluid 3 It is possible to transfer thermal energy with a large temperature difference between them, and it is possible to improve the efficiency of heat transfer in a technology for transferring heat between the heat-donating fluid 2 and the heat-receiving fluid 3 by using the exchange of heat between the magnetic particle dispersion liquid 11 and the secondary working fluid 21.

[0048] In the heat pump unit 1 having the configuration shown in FIG. 1, the temperature change ΔT HEX The larger the value, the more Thermal energy can be transferred between the heat-donating fluid 2 and the heat-receiving fluid 3 with a large temperature difference. That is, the temperature change ΔT of the magnetic particle dispersion due to the magnetocaloric effect when a magnetic field is applied or reduced is MH It is preferable to make as small as possible.

[0049] The required amount of heat transfer Q for the heat pump unit 1 is calculated by dividing the specific heat of the secondary working fluid 21 by c s , where the flow rate of the auxiliary working fluid 21 is F, Q = ΔT MH ×c s ×F That is, in order to obtain a predetermined amount of heat transfer Q, the flow rate F of the secondary working fluid 21 is increased as much as possible to obtain ΔT MH Therefore, by maximizing the flow rate F of the secondary working fluid 21, heat can be transferred between the heat donor fluid 2 and the heat receiving fluid 3 more efficiently.

[0050] In the heat pump unit 1 shown in FIG. 1, in which the magnetic particle dispersion 11 receives heat released by the magnetic particle dispersion 11 at the internal heat dissipation section 13 and the magnetic particle dispersion 11 receives heat released by the magnetic particle dispersion 11 at the internal heat absorption section 12, heat is transferred between the magnetic particle dispersion 11 flowing through the flow passage of the heat pump 10 and the magnetic particle dispersion 21 circulating through the circulation path 20. In this case, if the magnetic particle dispersion 11 and the magnetic particle dispersion 21 are not in direct contact with each other and heat is transferred through the wall of the flow passage through which they flow, a loss occurs in the transfer of heat through the wall of the flow passage. Therefore, the magnetic particle dispersion 11 must be heated or cooled by an extra amount corresponding to the temperature difference caused by the loss. The greater this temperature difference, the lower the efficiency of heat exchange as a heat pump unit. On the other hand, in order to transfer heat between the magnetic particle dispersion 11 and the magnetic particle dispersion 21 through the wall of the flow passage without lowering the efficiency of heat exchange, the material of the wall of the flow passage must be expensive. That is, if heat is transferred without contacting the magnetic particle dispersion liquid 11 and the secondary working fluid 21, difficulties arise in terms of heat exchange efficiency and economy.

[0051] Hereinafter, a configuration will be described that does not impair economy and does not reduce the efficiency of heat exchange when transferring heat between the magnetic particle dispersion liquid 11 flowing through the flow path of the heat pump 10 and the secondary working fluid 21 circulating through the circulation path 20 as shown in FIG. 1.

[0052] FIG. 3 is a cross-sectional view showing the flow paths of the internal heat absorption section 12 and the internal heat dissipation section 13, through which the magnetic particle dispersion liquid 11 flowing through the flow path of the heat pump 10 and the auxiliary working fluid 21 circulating through the circulation path 20 flow in the heat pump unit 1 shown in FIG.

[0053] 3, in a region where heat is exchanged between the magnetic particle dispersion liquid 11 and the secondary working fluid 21, the magnetic particle dispersion liquid 11 and the secondary working fluid 21 flow through the same flow path 50. In this case, if the solvent of the magnetic particle dispersion liquid 11 is hydrophilic, a hydrophobic fluid is adopted as the secondary working fluid 21, and if the solvent of the magnetic particle dispersion liquid 11 is hydrophobic, a hydrophilic fluid is adopted as the secondary working fluid 21. In other words, one of the magnetic particle dispersion liquid 11 and the secondary working fluid 21 is hydrophilic and the other is hydrophobic.

[0054] Also, for example, in a flow path having a square cross section, one of two pairs of opposing wall surfaces 51, 52 is subjected to at least one of processing to generate a magnetic field and processing to make it compatible with the magnetic particle dispersion solvent, and the other pair of wall surfaces 52 is processed to make it compatible with the secondary working fluid 21. When the magnetic particle dispersion 11 and the secondary working fluid 21 are flowed in the flow path 50 processed in this way with a magnetic field generated in the direction in which the wall surfaces 51 face each other, as shown in Fig. 3, the magnetic particle dispersion 11 and the secondary working fluid 21 flow along the wall surfaces 51, 52 in a separated state due to the effects of both the magnetic force due to the magnetic field and the surface tension of the fluid. In order to make the magnetic particle dispersion 11 and the secondary working fluid 21 flow along the wall surfaces 51, 52 in a separated state, it is necessary to make the flow path small enough so that the magnetic force due to the magnetic field and the surface tension of the fluid are dominant over other forces.

[0055] Since the magnetic particle dispersion liquid 11 and the secondary working fluid 21 are in a separated state within the flow path, the magnetic particle dispersion liquid 11 and the secondary working fluid 21 can then be removed from the wall surfaces 51, 52, which have a high affinity for each other, and after heat exchange between the magnetic particle dispersion liquid 11 and the secondary working fluid 21, they can be easily separated and removed.

[0056] In this way, by configuring the magnetic particle dispersion liquid 11 and the sub working fluid 21 so that one of them has hydrophilicity and the other has hydrophobicity, the magnetic particle dispersion liquid 11 and the sub working fluid 21 can be directly contacted in one flow path 50 to perform heat exchange. This reduces the heat transfer resistance between the magnetic particle dispersion liquid 11 and the sub working fluid 21, and allows efficient heat exchange with a temperature difference as close to "0" as possible. In addition, by configuring the magnetic particle dispersion liquid 11 and the sub working fluid 21 so that one of them has hydrophilicity and the other has hydrophobicity, the magnetic particle dispersion liquid 11 and the sub working fluid 21 can be easily separated and taken out after heat exchange between them. And, by performing heat exchange between the magnetic particle dispersion liquid 11 and the sub working fluid 21 as described above, a configuration can be realized in which the loss associated with the temperature difference required for heat exchange between the magnetic particle dispersion liquid 11 and the sub working fluid 21 is reduced as much as possible.

[0057] A configuration for transferring thermal energy with an even larger temperature difference in a heat pump unit based on the above-mentioned configuration will be described below.

[0058] FIG. 4 is a diagram showing an example of the configuration of a heat pump unit that transfers thermal energy with a larger temperature difference based on the configuration shown in FIG.

[0059] As shown in FIG. 4, this configuration example is a heat pump unit 101 that differs from that shown in FIG. 1 in that multiple stages of heat pumps 10-1 to 10-n are arranged between an external heat absorption section 23 and an external heat dissipation section 24 in the flow direction of the auxiliary working fluid 21 circulating through the circulation path 20.

[0060] In the heat pump unit 101 shown in Fig. 4, the auxiliary working fluid 21 circulating through the circulation path 20 receives heat from the heat-donating fluid 2 at the external heat absorption section 23, and then receives heat released from the magnetic particle dispersion 11 at the internal heat dissipation sections 13 of the heat pumps 10-1 to 10-n, thereby increasing in temperature. For example, when the auxiliary working fluid 21 receives heat of -30°C from the heat-donating fluid 2, a temperature change ΔT HEX is 6℃. In this case, the auxiliary working fluid 21 circulating through the circulation path 20 receives heat from the heat donor fluid 2 at −30° C. at the external heat absorption section 23 to reach −28° C., and then first receives heat emitted from the magnetic particle dispersion liquid 11 at the internal heat dissipation section 13 of the heat pump 10-1 to rise in temperature by 6° C. to −22° C. Next, the internal heat dissipation section 13 of the heat pump 10-2 receives heat emitted from the magnetic particle dispersion liquid 11 to rise in temperature by 6° C. to −16° C. In this way, the internal heat dissipation section 13 of the heat pump 10-n finally receives heat emitted from the magnetic particle dispersion liquid 11 to reach (−28+6×n)° C. Then, this heat of (−28+6×n)° C. is released from the auxiliary working fluid 21 to the heat receiving fluid 3 at the external heat dissipation section 24.

[0061] After heat is released from the secondary working fluid 21 to the heat receiving fluid 3 at the external heat release section 24, the secondary working fluid 21 drops in temperature by 6°C each time by releasing heat to the magnetic particle dispersion liquid 11 at the internal heat absorption sections 12 of each of the heat pumps 10-n to 10-1, and then receives heat again from the heat donor fluid 2 at the external heat absorption section 23.

[0062] In this case, if the heat-donating fluid 2 is −30° C. and the heat-receiving fluid 3 is 30° C., the number of stages required is 60÷6=10 stages. Therefore, the number of pumps required is 11, which is the number of heat pumps (10) plus one circulation path 20. That is, in the heat pump unit 101 shown in FIG. 4, (Number of stages required for heat pump N s ) = (Temperature difference between heat-providing fluid 2 and heat-receiving fluid 3) / (Magnetic material Temperature change ΔT during heat exchange between the particle dispersion 11 and the secondary working fluid 21 HEX ) (Number of pumps required N p ) = (temperature difference between heat-providing fluid 2 and heat-receiving fluid 3) / (magnetic particle Temperature change ΔT during heat exchange between the primary dispersion liquid 11 and the secondary working fluid 21 HEX )+1 It becomes.

[0063] Regarding the magnetocaloric effect, the extent to which heat is released or absorbed in a given temperature range is specific to the type of magnetic material constituting the magnetic particle dispersion liquid 11, and in the case of an alloy, the extent of heat release or absorption varies in a complex manner depending on the composition. Therefore, in a heat pump using the magnetocaloric effect, the appropriate magnetic material generally differs depending on the temperature level to be applied.

[0064] Therefore, it is conceivable that the magnetic material constituting the magnetic particle dispersion liquid 11 flowing through the flow path of the heat pumps 10-1 to 10-n constituting the heat pump unit 101 shown in Figure 4 can be individually selected from magnetic materials with large heat dissipation / absorption due to the magnetocaloric effect, depending on the temperature of the heat received by the internal heat absorption section 12 of the heat pumps 10-1 to 10-n and released by the internal heat dissipation section 13.

[0065] FIG. 5 is a diagram for explaining a method of selecting a magnetic material constituting the magnetic particle dispersion liquid 11 flowing through the flow paths of the heat pumps 10-1 to 10-n constituting the heat pump unit 101 shown in FIG.

[0066] In the heat pump unit 101 shown in Fig. 4, as described above, heat is transferred between the heat-donating fluid 2 and the heat-receiving fluid 3 by sequentially exchanging heat between the magnetic particle dispersion liquid 11 flowing through the flow paths of the multiple stages of heat pumps 10-1 to 10-n and the secondary working fluid 21 circulating through the circulation path 20. Therefore, as described above, the flow rate F of the secondary working fluid 21 is made as large as possible to reduce ΔT MH After setting ΔT, as shown in FIG. 5, in the characteristics of the adiabatic temperature change with respect to the temperature of the magnetic particle dispersion 11 flowing through the flow passages of the heat pumps 10-1 to 10-n in the multiple stages, the end point on the low temperature side is the end point on the high temperature side of the magnetic particle dispersion 11 flowing through the flow passage of the heat pump in the previous stage, and the end point on the high temperature side is the end point on the low temperature side of the magnetic particle dispersion 11 flowing through the flow passage of the heat pump in the subsequent stage. HEX and magnetic particles flowing through the flow passages of each stage of the heat pump. A magnetic material for forming the child dispersion liquid 11 is selected. Specifically, in the magnetic particle dispersion liquid 11 flowing through the flow path of the first stage heat pump, ΔTMH Under the above, the temperature of the heat-providing fluid 2 after cooling is set as the low-temperature end point. HEX The evaluation criterion is to maximize the magnetic Select the material from the second stage onwards. HEX The high temperature end point of ΔT as the end point HEX The magnetic material is selected based on the evaluation criterion of maximizing the Repeat, ΔT HEX The stage where the end point on the high temperature side is equal to or higher than the temperature of the heat receiving fluid 3 before heating is the final stage. As shown in Figure 5, ΔT MH By making ΔT as small as possible, HEX Enlarge As a result, the heat pump unit can be configured with a smaller number of stages.

[0067] In this way, if the magnetic material constituting the magnetic particle dispersion 11 in each of the multi-stage heat pumps is individually selected according to the temperature of the heat received by the internal heat absorption section 12 of the heat pump and released by the internal heat dissipation section 13, the overall thermal efficiency can be improved. [Explanation of symbols]

[0068] 1 Heat pump unit 2 Heating fluid 3 Heat receiving fluid 10,10-1~10-n Heat pump 11 Magnetic particle dispersion liquid 12 Internal heat sink 13 Internal heat dissipation section 14 Heating section 15 Cooling section 16,22 Pump 17 Magnetic field 20 Circulation route 21 Auxiliary working fluid 23 External heat sink 24 External heat dissipation section 50 Flow Path 51,52 Wall

Claims

1. A heat pump unit that uses a magnetic particle dispersion liquid in which magnetic particles are dispersed in a solvent as a main working fluid and transfers heat between an external heat providing fluid and an external heat receiving fluid, a heat pump including an internal heat absorption section that receives heat and an internal heat dissipation section that dissipates heat, and transferring heat between the internal heat absorption section and the internal heat dissipation section by applying and reducing a magnetic field to the main working fluid circulating between the internal heat absorption section and the internal heat dissipation section; an external heat sink in which the secondary working fluid receives heat from the external heat-donating fluid; an external heat dissipation section where the secondary working fluid dissipates heat to the external heat receiving fluid; a circulation path in which the secondary working fluid circulates between the external heat absorption section, the heat pump, and the external heat dissipation section, the secondary working fluid receives heat from the external heat providing fluid at the external heat absorption section, and then the secondary working fluid receives heat released from the main working fluid at the internal heat dissipation section of the heat pump, the secondary working fluid then releases heat to the external heat receiving fluid at the external heat dissipation section, the secondary working fluid then releases heat to the main working fluid at the internal heat absorption section of the heat pump, and then the secondary working fluid receives heat again from the external heat providing fluid at the external heat absorption section.

2. 2. The heat pump unit according to claim 1, a heat pump unit, the heat pumps being arranged in a plurality of stages between the external heat absorption section and the external heat dissipation section in a flow direction of the secondary working fluid in the circulation path;

3. The heat pump unit according to claim 2, A heat pump unit in which each of the multiple stages of the heat pump is individually selected based on the temperature of heat absorbed in an internal heat absorption section of the heat pump and released in an internal heat dissipation section of the heat pump, in accordance with a magnetic material constituting the main working fluid in the heat pump.

4. The heat pump unit according to any one of claims 1 to 3, A heat pump unit, wherein the source of the magnetic field is a permanent magnet.

5. The heat pump unit according to any one of claims 1 to 4, The secondary working fluid flows through the same flow path as the main working fluid in a region where heat is exchanged between the secondary working fluid and the main working fluid, A heat pump unit, wherein one of the main working fluid and the auxiliary working fluid flowing through the same flow path is hydrophilic and the other is hydrophobic.

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