EP2381740A1 - Electromagnetic induction heating unit and air conditioning device - Google Patents

Electromagnetic induction heating unit and air conditioning device Download PDF

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Publication number
EP2381740A1
EP2381740A1 EP09837460A EP09837460A EP2381740A1 EP 2381740 A1 EP2381740 A1 EP 2381740A1 EP 09837460 A EP09837460 A EP 09837460A EP 09837460 A EP09837460 A EP 09837460A EP 2381740 A1 EP2381740 A1 EP 2381740A1
Authority
EP
European Patent Office
Prior art keywords
electromagnetic induction
induction heating
magnetic
heating unit
refrigerant
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP09837460A
Other languages
German (de)
French (fr)
Inventor
Toshie Okada
Hidehiro Ishii
Masahiro Wakashima
Satoshi Asada
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Daikin Industries Ltd
Original Assignee
Daikin Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Daikin Industries Ltd filed Critical Daikin Industries Ltd
Publication of EP2381740A1 publication Critical patent/EP2381740A1/en
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B13/00—Compression machines, plants or systems, with reversible cycle
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/10—Induction heating apparatus, other than furnaces, for specific applications
    • H05B6/105—Induction heating apparatus, other than furnaces, for specific applications using a susceptor
    • H05B6/108—Induction heating apparatus, other than furnaces, for specific applications using a susceptor for heating a fluid
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/01—Heaters

Definitions

  • the present invention relates to an electromagnetic induction heating unit and an air conditioner.
  • a refrigeration cycle is provided with a radiator, which releases the heat from a refrigerant, a heater, which imparts heat to the refrigerant, and the like.
  • the refrigerant that circulates through the refrigeration cycle obtains heat by, for example, exchanging heat with indoor air during a cooling operation cycle, exchanging heat with outdoor air during a heating operation cycle, and the like.
  • Patent Document 1 i.e., Japanese Unexamined Patent Application Publication No. H08-210720
  • a system has been proposed wherein the refrigerant obtains heat not only from indoor air and outdoor air as discussed above but also by means of a refrigerant heating apparatus separately provided.
  • this refrigerant heating apparatus heat is imparted to the refrigerant, which flows through the interior of a heat exchanger, by heating the heat exchanger with a burner.
  • this air conditioner adopts a refrigerant heating apparatus, it is possible to heat the refrigerant when the refrigerant requires heat without being constrained by, for example, the indoor or outdoor air temperature.
  • an electromagnetic induction coil can be wound around a refrigerant piping, which contains a magnetic material, and thereby, owing to the magnetic flux induced by the flow of electric current to the electromagnetic induction heating coil, the refrigerant piping can generate heat. Furthermore, the refrigerant can be heated using the heat generated in that refrigerant piping.
  • the present invention considers the points discussed above, and it is an object of the present invention to provide an electromagnetic induction heating unit and an air conditioner that, even if a magnetic field is generated by an electromagnetic induction heating unit when performing electromagnetic induction heating, the amount of the magnetic field that leaks to the portions outside of the refrigerant piping can be kept small.
  • An electromagnetic induction heating unit is an electromagnetic induction heating unit that heats a refrigerant piping or a material that thermally contacts a refrigerant that flows through the refrigerant piping, or both, and comprises: a coil, an external member, and a magnetic part.
  • the coil is disposed in the vicinity of the refrigerant piping.
  • the external member is disposed around the refrigerant piping and includes a magnetic body.
  • the magnetic part is disposed on the outer side of the coil, which is the opposite side of the inner side, namely, the refrigerant piping side, of the coil, and on the inner side of the external member and contains a magnetic material whose magnetic permeability is higher than that of the external member.
  • heating performed using the electromagnetic induction heating unit includes at least: the case wherein a heat generating member that thermally contacts the refrigerant piping is heated through electromagnetic induction; the case wherein a heat generating member that thermally contacts the refrigerant flowing through the refrigerant piping is heated through electromagnetic induction; and the case wherein a heat generating member that constitutes at least part of the refrigerant piping is heated through electromagnetic induction.
  • the magnetic field that arises in portions outside of the refrigerant piping can be made to efficiently pass through the magnetic body; consequently, the strength of the magnetic field in outside of the magnetic part caused by the leakage can be kept lower than the strength of the magnetic field in the magnetic part.
  • An electromagnetic induction heating unit is the electromagnetic induction heating unit according to the first aspect of the invention, wherein the coil is wound around at least part of the refrigerant piping.
  • part of the magnetic flux that arises owing to the flow of electric current to the coil can be aligned with the directions in which the refrigerant piping extends. Consequently, if the longitudinal directions of the magnetic body included in the refrigerant piping and the axial directions of the refrigerant piping are substantially the same, then the heating efficiency of the electromagnetic induction can be improved.
  • An electromagnetic induction heating unit is the electromagnetic induction heating unit according to the first or second aspects of the invention, wherein at least part of the magnetic part extends to at least one side selected from the group consisting of: one side of the coil in directions in which the refrigerant piping extends; and another side, which is the opposite side of the one side with respect to the coil.
  • the magnetic flux that arises owing to the supply of electric power to the coil and that would leak out to the opposite side of the refrigerant piping can be captured by the magnetic part prior to being conducted to the external member. Consequently, the magnetic part can hinder a greater amount of the magnetic field leakage than the external member can. Thereby, not only the leakage of the magnetic field to the outer side of the magnetic part but also the leakage of the magnetic field to the outer side of the external member can be much more effectively reduced by virtue of the external member capturing the magnetic field that leaks to the outer side of the magnetic part.
  • An electromagnetic induction heating unit is the electromagnetic induction heating unit according to any one aspect of the first through third aspects of the invention, wherein at least part of the magnetic part extends to the inner side of the coil, which is the outer side of the refrigerant piping when viewed from the axial directions of the refrigerant piping.
  • the strength of the magnetic field generated by the coil can be kept lower than a strength that would leak to the portions outside of the magnetic part and thereby the magnetic field can be made to pass through the magnetic part more efficiently.
  • An electromagnetic induction heating unit is the electromagnetic induction heating unit according to any one aspect of the first through fourth aspects of the invention, wherein the magnetic part comprises a plurality of magnetic components disposed such that the magnetic components contact one another.
  • the magnetic part is not made as an integral member that conforms to a target shape; rather, the magnetic part can be made as a combination of multiple components that conform to the target shape. Furthermore, because these magnetic components are disposed in a state wherein they contact one another, any decline in the magnetic permeability at the portions at which the magnetic components contact one another can be reduced.
  • An electromagnetic induction heating unit is the electromagnetic induction heating unit according to any one aspect of the first through fifth aspects of the invention, wherein the magnetic part contains a material that is a good conductor.
  • the Joule heat generated by the electrical resistance can be reduced because the magnetic part contains a material that is a good conductor.
  • An electromagnetic induction heating unit is the electromagnetic induction heating unit according to any one aspect of the first through sixth aspects of the invention, wherein the magnetic part contains ferrite.
  • the magnetic flux can be made to actively pass through the magnetic part, which contains ferrite, and thereby the magnetic field that leaks to the outer side of the magnetic part can be reduced.
  • An air conditioner according to all eighth aspect of the invention is an air conditioner that comprises: an electromagnetic induction heating unit according to any one aspect of the first through seventh aspects; and a refrigeration cycle that includes a portion wherethrough a refrigerant flows to the refrigerant piping.
  • the impact on the surroundings of the electromagnetic induction heating unit can be reduced.
  • the strength of the magnetic field in outside of the magnetic part caused by the leakage can be kept lower than the strength of the magnetic field in the magnetic part.
  • the heating efficiency of the electromagnetic induction can be improved.
  • the leakage of the magnetic field to the outer side of the magnetic part can be much more effectively reduced by virtue of the external member capturing the magnetic field that leaks to the outer side of the magnetic part.
  • the magnetic field can be made to pass through the magnetic part more efficiently.
  • any decline in the magnetic permeability at the portions at which the magnetic components contact one another can be reduced.
  • the magnetic field that leaks to the outer side of the magnetic part can be reduced.
  • the impact on the surroundings of the electromagnetic induction heating unit can be reduced.
  • FIG. 1 is a refrigerant circuit diagram that shows a refrigerant circuit 10 of the air conditioner 1 .
  • the air conditioner 1 is an apparatus wherein an outdoor unit 2, which serves as a heat source side apparatus, and an indoor unit 4, which serves as a utilization side apparatus, are connected by a refrigerant piping, and the space wherein the utilization side apparatus is disposed is air conditioned; furthermore, the air conditioner 1 comprises a compressor 21, a four-way switching valve 22, an outdoor heat exchanger 23, an outdoor motor operated expansion valve 24, an accumulator 25, outdoor fans 26, an indoor heat exchanger 41, an indoor fan 42, a hot gas bypass valve 27, a capillary tube 28, the electromagnetic induction heating unit 6, and the like.
  • the compressor 21, the four-way switching valve 22, the outdoor heat exchanger 23, the outdoor motor operated expansion valve 24, the accumulator 25, the outdoor fans 26, the hot gas bypass valve 27, the capillary tube 28, and the electromagnetic induction heating unit 6 are housed inside the outdoor unit 2.
  • the indoor heat exchanger 41 and the indoor fan 42 are housed inside the indoor unit 4.
  • the refrigerant circuit 10 comprises a discharge pipe A, an indoor side gas pipe B, an indoor side liquid pipe C, an outdoor side liquid pipe D, an outdoor side gas pipe E, an accumulator pipe F, a suction pipe G, a hot gas bypass circuit H, branched piping K, and union piping J.
  • the refrigerant that passes through the indoor side gas pipe B and the outdoor side gas pipe E is mostly in the gas state, but the refrigerant passing through is not limited to the gas state.
  • the refrigerant that passes through the indoor side liquid pipe C and the outdoor side liquid pipe D is mostly in the liquid state, but the refrigerant passing through is not limited to the liquid state.
  • the discharge pipe A connects the compressor 21 and the four-way switching valve 22.
  • a discharge temperature sensor 29d which detects the temperature of the refrigerant passing through, is provided to the discharge pipe A. Furthermore, an electric power supply part 21e supplies electric power to the compressor 21. The amount of electric power the electric power supply part 21e supplies is detected by a compressor electric power detection unit 29f.
  • the indoor side gas pipe B connects the four-way switching valve 22 and the indoor heat exchanger 41.
  • a pressure sensor 29a which detects the pressure of the refrigerant passing through, is provided along the indoor side gas pipe B.
  • the indoor side liquid pipe C connects the indoor heat exchanger 41 and the outdoor motor operated expansion valve 24.
  • the outdoor side liquid pipe D connects the outdoor motor operated expansion valve 24 and the outdoor heat exchanger 23.
  • the outdoor side gas pipe E connects the outdoor heat exchanger 23 and the four-way switching valve 22.
  • the accumulator pipe F connects the four-way switching valve 22 and the accumulator 25 and, in the state wherein it is installed in the outdoor unit 2, extends in the vertical directions.
  • the electromagnetic induction heating unit 6 is mounted to part of the accumulator pipe F.
  • At least a heat generating portion of the accumulator pipe F, which is enveloped by a coil 68 (discussed below), comprises a magnetic pipe F2 provided such that it envelops a copper pipe F1, wherein the refrigerant flows (refer to FIG. 11 ).
  • the magnetic pipe F2 is made of steel use stainless (SUS) 430.
  • SUS 430 is a ferromagnetic material; when placed in a magnetic field, eddy currents arise, which generate heat by the action of Joule heat induced by the material's own electrical resistance.
  • the portion of the piping that constitutes the refrigerant circuit 10 and that is outside of the magnetic pipe F2 comprises copper pipes.
  • the material property of the pipe that envelops the copper pipe is not limited to SUS 430, and can be, for example: one type of conductor selected from the group consisting of iron, copper, aluminum, chrome, and nickel; an alloy containing at least two or more types of metal selected from the same group; and the like.
  • examples of SUS include ferritic steel, martensitic steel, or a combination thereof.
  • the accumulator pipe F herein requires a larger amount of electric power; however, instead of a magnetic body and a material that contains a magnetic body, it may contain a material that can be induction heated. Furthermore, for example, the magnetic material may constitute all of the accumulator pipe F, only an inner side surface of the accumulator pipe F, or be simply included in the material that constitutes the accumulator pipe F.
  • the accumulator pipe F can generate heat by electromagnetic induction, and thereby the refrigerant that is suctioned into the compressor 21 via the accumulator 25 can be heated.
  • the heating capacity of the air conditioner 1 can be improved.
  • the electromagnetic induction heating unit 6 can perform quick heating, thereby supplementing the capacity shortfall during startup.
  • the four-way switching valve 22 switches to the cooling operation state and the defrosting operation, which eliminates frost that adheres to the outdoor heat exchanger 23 and the like, is performed, then the compressor 21 can compress the quickly heated refrigerant by virtue of the electromagnetic induction heating unit 6 quickly heating the accumulator pipe F.
  • the temperature of the hot gas discharged from the compressor 21 can be quickly raised. Thereby, the time needed for the defrosting operation to perform defrosting can be shortened. Thereby, even if it is necessary to perform the defrosting operation when appropriate during heating operation, it is possible to return to the heating operation as quickly as possible and thereby to improve user comfort.
  • the suction pipe G connects the accumulator 25 and the inlet side of the compressor 21.
  • the hot gas bypass circuit H connects a branching point A1, which is provided along the discharge pipe A, and a branching point D1, which is provided along the outdoor side liquid pipe D.
  • the capillary tube 28, which lowers the pressure of the refrigerant passing through, is provided along the hot gas bypass circuit H between the hot gas bypass valve 27 and the branching point D1.
  • the capillary tube 28 can hinder a rise in the pressure of the refrigerant in the outdoor side liquid pipe D by supplying hot gas, which has passed through the hot gas bypass circuit H, to the outdoor side liquid pipe D.
  • the branched piping K constitutes part of the outdoor heat exchanger 23 and is the refrigerant piping that, to increase the effective surface area for exchanging heat, extends from a gas side inlet/outlet 23e of the outdoor heat exchanger 23 and branches into multiple pipes at a branching and merging point 23k (discussed below).
  • the branched piping K comprises a first branch pipe K1, a second branch pipe K2, and a third branch pipe K3, each of which independently extend from the branching and merging point 23k to a merging and branching point 23j ; furthermore, the branched pipes K1, K2, K3 merge at the merging and branching point 23j .
  • the branched piping K branches at the merging and branching point 23j and extends therefrom.
  • the union piping J constitutes part of the outdoor heat exchanger 23 and is a piping that extends from the merging and branching point 23j to a liquid side inlet/outlet 23d of the outdoor heat exchanger 23.
  • the union piping J can, during cooling operation, make uniform the degree of supercooling of the refrigerant flowing out of the outdoor heat exchanger 23 and, during heating operation, defrost any ice that adheres to the vicinity of the lower end of the outdoor heat exchanger 23.
  • the union piping J has a cross sectional area that is substantially three times that of each of the branched pipes K1, K2, K3, and therefore the amount of refrigerant passing through is substantially three times that of each of the branched pipes K1, K2, K3.
  • the four-way switching valve 22 is capable of switching between a cooling operation cycle and a heating operation cycle.
  • solid lines indicate the connection state wherein heating operation is performed
  • dotted lines indicate the connection state wherein cooling operation is performed.
  • the indoor heat exchanger 41 functions as a cooler of the refrigerant
  • the outdoor heat exchanger 23 functions as a heater of the refrigerant.
  • the outdoor heat exchanger 23 functions as a cooler of the refrigerant
  • the indoor heat exchanger 41 functions as a heater of the refrigerant.
  • the outdoor heat exchanger 23 comprises the gas side inlet/outlet 23e, the liquid side inlet/outlet 23d, the branching and merging point 23k, the merging and branching point 23j, the branched piping K, the union piping J, and heat exchanging fins 23z.
  • the gas side inlet/outlet 23e is positioned at an end part on the outdoor side gas pipe E side of the outdoor heat exchanger 23 and connects to the outdoor side gas pipe E.
  • the liquid side inlet/outlet 23d is positioned at an end part on the outdoor side liquid pipe D side of the outdoor heat exchanger 23 and connects to the outdoor side liquid pipe D.
  • the branching and merging point 23k branches the piping that extends from the gas side inlet/outlet 23e and can branch or merge the refrigerant in accordance with the direction in which the refrigerant is flowing.
  • multiple pipes extend from the branched portions at the branching and merging point 23k.
  • the merging and branching point 23j merges the branched piping K and can merge or branch the refrigerant in accordance with the direction in which the refrigerant is flowing.
  • the union piping J extends from the merging and branching point 23j to the liquid side inlet/outlet 23d.
  • the heat exchanging fins 23z are plate shaped aluminum fins arrayed in the plate thickness directions and disposed at prescribed intervals.
  • Both the branched piping K and the union piping J are to be inserted through the heat exchanging fins 23z, which they have in common.
  • the branched piping K and the union piping J are disposed such that they are inserted through, at different portions of, each of the heat exchanging fins 23z, which they have in common, in the plate thickness directions.
  • An outdoor air temperature sensor 29b which detects the outdoor air temperature, is provided to the outdoor heat exchanger 23 on the leeward side in the direction of the airflow of the outdoor fans 26.
  • an outdoor heat exchanger temperature sensor 29c which detects the temperature of the refrigerant flowing through the branched piping K, is provided to the outdoor heat exchanger 23.
  • An indoor temperature sensor 43 which detects the indoor temperature, is provided inside the indoor unit 4.
  • the indoor heat exchanger 41 is provided with an indoor heat exchanger temperature sensor 44, which detects the temperature of the refrigerant on the indoor side liquid pipe C, along which the outdoor motor operated expansion valve 24 is connected, side of the indoor heat exchanger 41.
  • a control unit 11 is constituted by the connection of an outdoor control unit 12, which controls equipment disposed inside the outdoor unit 2, and an indoor control unit 13, which controls equipment disposed inside the indoor unit 4, via a communications wire 11a.
  • the control unit 11 performs various control functions with respect to the air conditioner 1.
  • a timer 95 which counts in order to measure the time elapsed when various control functions are performed, is provided to the outdoor control unit 12.
  • a controller 90 which accepts the input of settings from the user, is connected to the control unit 11.
  • FIG. 2 is an external oblique view of the front surface side of the outdoor unit 2.
  • FIG. 3 is an oblique view that shows the positional relationship between the outdoor heat exchanger 23 and the outdoor fans 26.
  • FIG. 4 is an oblique view of the rear surface side of the outdoor heat exchanger 23.
  • the outer surface of the outdoor unit 2 is a substantially rectangular parallelepipedic outdoor unit casing that comprises a top plate 2a, a bottom plate 2b, a front panel 2c, a left side surface panel 2d, a right side surface panel 2f, and a rear surface panel 2e.
  • the outdoor unit 2 is partitioned by a partition plate 2h into a fan chamber, which is on the left side surface panel 2d side and wherein the outdoor heat exchanger 23, the outdoor fans 26, and the like are disposed, and a machine chamber, which is on the right side surface panel 2f side and wherein the compressor 21 , the electromagnetic induction heating unit 6, and the like are disposed.
  • the outdoor unit 2 comprises outdoor unit support platform 2g, which are fixed to the bottom plate 2b by screwing and constitute the lowest end parts of the outdoor unit 2 on the right and left sides.
  • the electromagnetic induction heating unit 6 is disposed at an upper position of the machine chamber in the vicinity of the left side surface panel 2d and the top plate 2a.
  • a plurality of the heat exchanging fins 23z of the outdoor heat exchanger 23 discussed above is arrayed in the plate thickness directions, which are substantially oriented in the horizontal directions.
  • the union piping J is disposed by inserting it through the heat exchanging fins 23z of the outdoor heat exchanger 23 in the thickness directions at the lowermost portion of the heat exchanging fins 23z.
  • the hot gas bypass circuit H is disposed such that it runs along below the outdoor fans 26 and the outdoor heat exchanger 23.
  • FIG. 5 is a general, front, oblique view that shows the internal structure of the machine chamber of the outdoor unit 2.
  • FIG. 6 is an oblique view that shows the internal structure of the machine chamber of the outdoor unit 2.
  • FIG. 7 is an oblique view that shows the layout of the outdoor heat exchanger 23 and the bottom plate 2b in relation to each other.
  • FIG. 8 is a top plan view that shows the layout of the electromagnetic induction heating unit 6.
  • the partition plate 2h of the outdoor unit 2 partitions, from the front to the back and from the upper end to the lower end, the fan chamber, wherein the outdoor heat exchanger 23, the outdoor fans 26, and the like are disposed, and the machine chamber, wherein the electromagnetic induction heating unit 6, the compressor 21, the accumulator 25, and the like are disposed.
  • the compressor 21 and the accumulator 25 are disposed in a lower space of the machine chamber of the outdoor unit 2.
  • the electromagnetic induction heating unit 6, the four-way switching valve 22, and the outdoor control unit 12 are disposed in an upper space of the machine chamber of the outdoor unit 2, above the compressor 21, the accumulator 25, and the like.
  • the compressor 21, the four-way switching valve 22, the outdoor heat exchanger 23, the outdoor motor operated expansion valve 24, the accumulator 25, the hot gas bypass valve 27, the capillary tube 28, and the electromagnetic induction heating unit 6, which are disposed in the machine chamber and are the functional elements that constitute the outdoor unit 2, are corrected via the discharge pipe A, the indoor side gas pipe B, the outdoor side liquid pipe D, the outdoor side gas pipe E, the accumulator pipe F, the hot gas bypass circuit H, and the like such that the refrigerant circuit 10 shown in FIG. 1 performs a refrigeration cycle.
  • the hot gas bypass circuit H comprises nine linked portions, namely, a first bypass portion H1 through a ninth bypass portion H9; furthermore, when the refrigerant flows to the hot gas bypass circuit H, it flows in order from the first bypass portion H1 to the ninth bypass portion H9.
  • the electromagnetic induction heating unit 6 is disposed such that it covers the magnetic pipe F2, which is the heat generating portion of the accumulator pipe F, from the outer side in the radial directions and causes the magnetic pipe F2 to generate heat by electromagnetic induction heating.
  • the heat generating portion of the accumulator pipe F has a double pipe structure that comprises the copper pipe F1 on the inner side and the magnetic pipe F2 on the outer side.
  • the first hex nut 61 and the second hex nut 66 are made of resin, and the electromagnetic induction heating unit 6 and the accumulator pipe F are stably fixed using a C ring (not shown).
  • the first bobbin cover 63 and the second bobbin cover 64 are made of resin and cover the accumulator pipe F from the outer side in the radial directions at the upper end position and the lower end position, respectively.
  • the first bobbin cover 63 and the second bobbin cover 64 each have four screw holes for screws 69, which are for screwing the first through fourth ferrite cases 71-74 (discussed below) to the first bobbin cover 63 and the second bobbin cover 64 using screws 69.
  • control unit 11 receives a notification from the fuse 15 that the temperature detected exceeds a prescribed limit, then the control unit 11 performs control such that the supply of electric power to the coil 68 is stopped, thereby avoiding thermal damage to the equipment.
  • the bobbin main body 65 is made of resin, and the coil 68 is wound around the bobbin main body 65.
  • the coil 68 is wound helically around the outer side of the bobbin main body 65 , the directions in which the accumulator pipe F extends being the axial directions.
  • the coil 68 is connected to a control printed circuit board 18 (not shown), and receives the supply of a high frequency electric current.
  • the output of the control printed circuit board 18 is controlled by the control unit 11. As shown in FIG.
  • the first ferrite case 71 is inserted into the first bobbin cover 63 and the second bobbin cover 64 from the directions in which the accumulator pipe F extends and is fixed by the screws 69.
  • the first ferrite case 71 through the fourth ferrite case 74 each house first ferrite parts 98 and second ferrite parts 99, which are made of ferrite-a raw material that has high magnetic permeability. As shown in the magnetic flux explanatory diagram of FIG.
  • the shielding cover 75 is disposed at the outermost circumferential portion of the electromagnetic induction heating unit 6 and collects the magnetic flux that cannot be completely gathered by the first ferrite parts 98 and the second ferrite parts 99 alone. Thereby, virtually none of the magnetic flux leaks to the outer side of the shielding cover 75: furthermore, the location at which the magnetic flux is generated can be determined independently.
  • FIG. 14 is a schematic oblique view of the first ferrite case 71, wherein the first ferrite parts 98 and the second ferrite parts 99 are housed and fixed.
  • FIG. 15 shows the structure of the vicinity of the screw part on the upper side of the first ferrite case 71.
  • FIG. 16 shows the structure of the vicinity of the screw part on the lower side of the first ferrite case 71.
  • the first through fourth ferrite cases 71-74 all have the same shape.
  • the first ferrite case 71 is made of resin and has a function wherein the first bobbin cover 63 and the second bobbin cover 64 are inserted from the directions in which the accumulator pipe F extends and are thereby fixed and a function wherein the first ferrite parts 98 and the second ferrite parts 99 are housed and held.
  • the first ferrite case 71 comprises a bottom surface part 71j, side surface parts 71h , a first cover screw part 71a , a first cover screw hole 71b, a second cover screw part 71f, a second cover screw hole 71g, shielding cover screw parts 71c, and shielding cover screw holes 71d.
  • the bottom surface part 71j constitutes the bottom surface of the first ferrite case 71 .
  • the first ferrite parts 98 and the second ferrite parts 99 are bonded to the bottom surface part 71j.
  • the bottom surface part 71j In the state wherein it is fixed to the electromagnetic induction heating unit 6, the bottom surface part 71j is provided at a position at which its surface is oriented in the radial directions, its longitudinal directions being the directions in which the accumulator pipe F extends.
  • the bottom surface part 71j is mounted to one of four symmetrically provided substantially linear sides of the outer edges of the first bobbin cover 63 and the second bobbin cover 64 in the radial directions.
  • the rear surface side of the bottom surface part 71j and the substantially linear sides of both the first bobbin cover 63 and the second bobbin cover 64 are fixed in the state wherein they have been brought into contact.
  • the first ferrite case 71 has a structure that restrains movement in the circumferential directions.
  • the side surface parts 71h have surfaces that extend from both sides of the bottom surface part 71j in directions orthogonal to the longitudinal directions thereof and in the direction leading away from the bottom surface part 71j.
  • the first cover screw part 71a is provided for screwing the first ferrite case 71 and the first bobbin cover 63 together and is provided at a position displaced from a virtual space that extends in the radial directions and is interposed by the two side surface parts 71h.
  • the first ferrite parts 98 can be disposed as far as the vicinity of the magnetic pipe F2, which makes it possible to reduce leakage of the magnetic force.
  • the second cover screw part 71f is provided for screwing the first ferrite case 71 and the second bobbin cover 64 together and is provided, on the opposite side of the first cover screw part 71a, at a position displaced from the virtual space that extends in the radial directions and is interposed by the two side surface parts 71h.
  • the first ferrite parts 98 can be disposed as far as the vicinity of the magnetic pipe F2 , which makes it possible to reduce leakage of the magnetic force.
  • first cover screw part 71a and the second cover screw part 71f are disposed on opposite sides of the virtual space that extends in the radial directions and is interposed by the two side surface parts 71h , the first cover screw part 71a and the second cover screw part 71f serve not only to reduce leakage of the magnetic force but also to more rigidly fix the first ferrite case 71 to the first bobbin cover 63 and the second bobbin cover 64.
  • the second cover screw hole 71g is used for screwing the first ferrite case 71 and the second bobbin cover 64 to one another, thereby fixing them. Specifically, as in the first cover screw hole 71b discussed above, the second cover screw hole 71g of the first ferrite case 71 and a screw hole (not shown) for the screw 69 of the second bobbin cover 64 are screwed together by the metal screw 69 and are thereby fixed.
  • the shielding cover screw parts 71c are provided at two upper locations and two lower locations and are formed such that they protrude toward the outer side, which is the opposite of the inner side wherein the side surface parts 71h face one another.
  • the shielding cover screw holes 71d are openings that are provided to each of the shielding cover screw parts 71c and, in the state wherein the shielding cover 75 is mounted as shown in FIG. 9 , the shielding cover 75 is screwed by screws. Thereby, the first ferrite case 71 and the shielding cover 75 are fixed. Furthermore, the shielding cover screw parts 71c and the shielding cover screw holes 71d are also provided for each of the second through fourth ferrite cases 72-74; however, in actuality, the shielding cover 75 is fixed by just two opposing ferrite cases of the first through forth ferrite cases 71-74; in the present embodiment, the two opposing ferrite cases are the first ferrite case 71 and the third ferrite case 73.
  • first ferrite parts 98 and the second ferrite parts 99 housed in each of the ferrite cases 71-74 are disposed such that their surface portions contact one another.
  • the two different shapes of the ferrite parts 98, 99 combine to conduct the magnetic field.
  • a ferrite part that is integrally formed in a U shape is not used; rather, ferrite parts of the same shape are combined, which makes it possible to lower cost.
  • the first ferrite parts 98 and the second ferrite parts 99 housed in each of the ferrite cases 71-74 are disposed such that their surface portions contact one another.
  • the shielding cover 75 is a substantially octagonal piece of sheet metal that contains a magnetic material and that in a plan view follows along the shape of the outer edge of the first through fourth ferrite cases 71-74 when they are mounted to the first bobbin cover 63 and the second bobbin cover 64.
  • the shielding cover 75 comprises an overlapped portion 75d, wherein one end 75a and an other end 75b in the circumferential directions overlap in the plate thickness directions.
  • a surface in the vicinity of the one end 75a and a surface in the vicinity of the other end 75b are welded-from above to below in the directions in which the accumulator pipe F extends-in the state wherein the two surfaces are in contact with one another.
  • the shielding cover 75 which constitutes the outer side of the electromagnetic induction heating unit 6, and to maintain a low temperature as a provision against the risk of the user touching the shielding cover 75.
  • FIG. 10 which shows the state wherein the shielding cover 75 is not mounted
  • FIG. 9 which shows the state wherein the shielding cover 75 is mounted
  • the shielding cover 75 envelops the coil 68 such that a finger and the like of the user is denied access to the coil 68.
  • the user can be effectively prevented from accessing the coil 68 because both ends of the coil 68 in the directions in which the accumulator pipe F extends are disposed between both ends of the shielding cover 75.
  • the shielding cover 75 has screw holes 75x, 75y in the vicinity of the upper end in the longitudinal directions. As shown in FIG. 9 , when the shielding cover 75 is fixed to the first ferrite case 71 , these screw holes 75x, 75y function as holes wherethrough screws 70a, 70b pass.
  • FIG. 19 is a cross sectional view that shows an aspect wherein the magnetic flux tends to be conducted to the ferrite parts 98 , 99 more than to the shielding cover 75.
  • the magnetic permeability of the ferrite parts 98, 99 is higher than that of the shielding cover 75, which comprises a piece of sheet metal; furthermore, the ferrite parts 98, 99 are disposed such that they extend in the radial directions at the upper end and the lower end of the coil 68 and such that they straddle the coil 68 when viewed from the directions in which the accumulator pipe F extends. Consequently, the magnetic flux that would leak out tends to be conducted to the ferrite parts 98, 99 more than to the shielding cover 75, the magnetic flux generated by the coil 68 is collected by the ferrite parts 98, 99 before it is collected by the shielding cover 75, and therefore virtually all of that magnetic flux can be conducted to the ferrite parts 98 , 99. Furthermore, it is possible to lighten the burden of the shielding cover 75 to prevent magnetic flux leakage, and thereby the magnetic field that leaks out of the electromagnetic induction heating unit 6 can be significantly more reduced.
  • the first ferrite case 71 is formed from a resin, even if the shielding cover 75 is screwed to the first ferrite case 71 using the metal screws 70a, 70b, the first ferrite parts 98 and the second ferrite parts 99 do not directly contact the shielding cover 75.
  • the first ferrite parts 98 and the second ferrite parts 99 do not contact the shielding cover 75, there is naturally no local point of contact between the first ferrite parts 98 and the second ferrite parts 99 on one side and the shielding cover 75 on the other side.
  • the shielding cover 75 covers from the outer side in the radial directions at a position other than a gap portion of the shielding cover 75
  • the shielding cover 75 which contains the magnetic body
  • the first ferrite parts 98 and the second ferrite parts 99 which are housed in the second through fourth ferrite cases 72-74
  • the portion of the shielding cover 75 positioned near the right side surface panel 2f of the outdoor unit 2 in a plan view is disposed such that it is secured against and plane parallel with the right side surface panel 2f.
  • the magnetic flux conducted to the shielding cover 75 is prevented from, for example, being further conducted to the right side surface panel 2f or causing the local generation of heat by the generation of eddy currents at local points of contact between the right side surface panel 2f and the shielding cover 75.
  • the ferrite parts 98, 99 which contain a magnetic material of a higher magnetic permeability than that of the shielding cover 75, are disposed on the outer side of the coil 68 and such that they extend nearer to the coil 68 than the shielding cover 75 does. Consequently, the magnetic field that arises in portions outside of the accumulator pipe F tends to pass through the ferrite parts 98, 99 more than through the shielding cover 75. Consequently, the ferrite parts 98, 99 can efficiently capture the magnetic flux that would leak out to portions outside of the accumulator pipe F .
  • the magnetic field that arises in portions outside of the accumulator pipe F can be made to efficiently pass through the ferrite parts 98, 99; furthermore, any magnetic flux not collected by the ferrite parts 98, 99 is collected by the shielding cover 75. Consequently, the magnetic flux that leaks out to portions outside of the electromagnetic induction heating unit 6 can be reduced.
  • the material used to conduct the magnetic flux may be a good conductor that is not as magnetic as ferrite. In such a case, it is possible to reduce the Joule heat generated by electrical resistance when the magnetic field has been conducted.
  • a refrigerant piping other than the accumulator pipe F may be provided.
  • a magnetic body of, for example, the magnetic pipe F2 is provided to a portion of the refrigerant piping whereto the electromagnetic induction heating unit 6 is provided.
  • the accumulator pipe F is configured as a double pipe, namely, as the copper pipe F1 and the magnetic pipe F2.
  • a member to be heated F2a and two stoppers F1a, F1b may be disposed inside the accumulator pipe F, the refrigerant piping to be heated, or the like.
  • the member to be heated F2a contains a magnetic material and generates heat by the electromagnetic induction heating of the abovementioned embodiment.
  • the stoppers F1a, F1b continuously permit the passage of the refrigerant but do not permit the passage of the member to be heated F2a.
  • the member to be heated F2a does not move even when the refrigerant flows. Consequently, the target heating position of the accumulator pipe F and the like can be heated.
  • the heat transfer efficiency can be improved because the member to be heated F2a and the refrigerant directly contact one another.
  • the position of the member to be heated F2a explained in the abovementioned other embodiment (C) may be prescribed with respect to the piping.
  • bent portions FW may be provided to the copper pipe F1 at two locations, and the member to be heated F2a may be disposed on the inner side of the copper pipe F1 between the two bent portions FW. In so doing, too, the movement of the member to be heated F2a can be hindered while the refrigerant is made to pass through.
  • coils 168 which are wound around bobbin main bodies 165 , are disposed at the circumference of-without being wound around-the accumulator pipe F.
  • each of the bobbin main bodies 165 is disposed such that its axial directions are substantially perpendicular to the axial directions of the accumulator pipe F.
  • the two pairs of the bobbin main bodies 165 and coils 168 are disposed such that they sandwich the accumulator pipe F.
  • a first bobbin cover 163 and a second bobbin cover 164 may be disposed in a state wherein they are mated to the bobbin main bodies 165.
  • the first bobbin cover 163 and the second bobbin cover 164 may be interposed by a first ferrite case 171 and a second ferrite case 172, and thereby fixed.
  • FIG. 24 presents an exemplary case wherein two ferrite cases are disposed such that they sandwich the accumulator pipe F; however, as in the abovementioned embodiment, ferrite cases may be disposed in four directions.
  • the ferrite parts may be housed therein.
  • the shielding cover 175 may be provided such that it covers the outermost circumferential portion of the electromagnetic induction heating unit 6 fixed in this manner.
  • the present invention also includes combination embodiments obtained by, where appropriate, combining the abovementioned embodiments with portions other than those included in the embodiments discussed above within a range that a person skilled in the art could effect based on the scope of the invention described above.
  • Using the present invention is particularly effective in an electromagnetic induction heating unit and an air conditioner wherein, even if a refrigerant piping is heated by electromagnetic induction, it is possible to hinder the leakage of the magnetic field to the periphery while hindering the local generation of heat, and thereby the refrigerant can be heated using electromagnetic induction.
  • Patent Document 1

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Electromagnetism (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • General Induction Heating (AREA)
  • Compression-Type Refrigeration Machines With Reversible Cycles (AREA)

Abstract

The present invention solves the problem of how to provide an electromagnetic induction heating unit and an air conditioner that, even if a magnetic field is generated by an electromagnetic induction heating unit when performing electromagnetic induction heating, the amount of the magnetic field that leaks to the portions outside of the refrigerant piping can be kept small. An electromagnetic induction heating unit (6) heats a refrigerant piping (F) through electromagnetic induction heating, and comprises: a coil (68), a shielding cover (75), and a ferrite part (98, 99). The coil (68) is disposed in the vicinity of the refrigerant piping (F). The shielding cover (75) is disposed around the refrigerant piping (F) and includes a magnetic body. The ferrite part (98, 99) is disposed on the outer side of the coil (68), which is the opposite side of the inner side, namely, the refrigerant piping (F) side, of the coil (68), and on the inner side of the shielding cover (75) and contains a magnetic material whose magnetic permeability is higher than that of the shielding cover (75). Both end parts of the shielding cover (75) in the directions in which the refrigerant piping (F) extends are positioned on the inner side of both end parts of the ferrite part (98, 99).

Description

    TECHNICAL FIELD
  • The present invention relates to an electromagnetic induction heating unit and an air conditioner.
    • BACKGROUND WART
  • A refrigeration cycle is provided with a radiator, which releases the heat from a refrigerant, a heater, which imparts heat to the refrigerant, and the like. The refrigerant that circulates through the refrigeration cycle obtains heat by, for example, exchanging heat with indoor air during a cooling operation cycle, exchanging heat with outdoor air during a heating operation cycle, and the like.
  • According to the refrigeration cycle of an air conditioner recited in Patent Document 1 (i.e., Japanese Unexamined Patent Application Publication No. H08-210720 ) indicated below, a system has been proposed wherein the refrigerant obtains heat not only from indoor air and outdoor air as discussed above but also by means of a refrigerant heating apparatus separately provided. In this refrigerant heating apparatus, heat is imparted to the refrigerant, which flows through the interior of a heat exchanger, by heating the heat exchanger with a burner. Thus, because this air conditioner adopts a refrigerant heating apparatus, it is possible to heat the refrigerant when the refrigerant requires heat without being constrained by, for example, the indoor or outdoor air temperature.
    • SUMMARY OF THE INVENTION <Technical Problem>
  • Instead of heating with a system that uses the fire of a burner and the like, it is also possible to adopt an electrical electromagnetic induction heating system as the refrigerant heating apparatus discussed above. For example, an electromagnetic induction coil can be wound around a refrigerant piping, which contains a magnetic material, and thereby, owing to the magnetic flux induced by the flow of electric current to the electromagnetic induction heating coil, the refrigerant piping can generate heat. Furthermore, the refrigerant can be heated using the heat generated in that refrigerant piping.
  • However, if the heating of the refrigerant piping by electromagnetic induction generates a magnetic field, then that magnetic field will arise not only inside the refrigerant piping but also in portions outside of that piping.
  • In response, it is conceivable to dispose, around the refrigerant piping, a member that has a material that tends to capture magnetic flux; however, even in such a case, it is sometimes difficult to sufficiently hinder the leakage of the magnetic field.
  • The present invention considers the points discussed above, and it is an object of the present invention to provide an electromagnetic induction heating unit and an air conditioner that, even if a magnetic field is generated by an electromagnetic induction heating unit when performing electromagnetic induction heating, the amount of the magnetic field that leaks to the portions outside of the refrigerant piping can be kept small.
    • <Solution to Problem>
  • An electromagnetic induction heating unit according to a first aspect of the invention is an electromagnetic induction heating unit that heats a refrigerant piping or a material that thermally contacts a refrigerant that flows through the refrigerant piping, or both, and comprises: a coil, an external member, and a magnetic part. The coil is disposed in the vicinity of the refrigerant piping. The external member is disposed around the refrigerant piping and includes a magnetic body. The magnetic part is disposed on the outer side of the coil, which is the opposite side of the inner side, namely, the refrigerant piping side, of the coil, and on the inner side of the external member and contains a magnetic material whose magnetic permeability is higher than that of the external member. Both end parts of the external member in the directions in which the refrigerant piping extends are positioned on the inner side of both end parts of the magnetic part. Furthermore, heating performed using the electromagnetic induction heating unit herein includes at least: the case wherein a heat generating member that thermally contacts the refrigerant piping is heated through electromagnetic induction; the case wherein a heat generating member that thermally contacts the refrigerant flowing through the refrigerant piping is heated through electromagnetic induction; and the case wherein a heat generating member that constitutes at least part of the refrigerant piping is heated through electromagnetic induction.
  • There are cases wherein, when electromagnetic induction heating is performed, not only does a magnetic field arise in the target magnetic body, which is meant to generate heat, but also in the periphery thereof.
  • In contrast, in the present electromagnetic induction heating unit, the magnetic part, which contains a magnetic material of a higher magnetic permeability than that of the external member, is disposed on the outer side of the coil; consequently, the magnetic field that arises in portions outside of the refrigerant piping tends to pass through the magnetic part more than through the external member. Furthermore, because both end parts of the external member in the directions in which the refrigerant piping extends are positioned on the inner side of both end parts of the magnetic body, the magnetic flux that would leak out to portions outside of the refrigerant piping can be much more effectively captured than the external member can. Thereby, when electromagnetic induction heating is performed, the magnetic field that arises in portions outside of the refrigerant piping can be made to efficiently pass through the magnetic body; consequently, the strength of the magnetic field in outside of the magnetic part caused by the leakage can be kept lower than the strength of the magnetic field in the magnetic part.
  • An electromagnetic induction heating unit according to a second aspect of the invention is the electromagnetic induction heating unit according to the first aspect of the invention, wherein the coil is wound around at least part of the refrigerant piping.
  • In the present electromagnetic induction heating unit, part of the magnetic flux that arises owing to the flow of electric current to the coil can be aligned with the directions in which the refrigerant piping extends. Consequently, if the longitudinal directions of the magnetic body included in the refrigerant piping and the axial directions of the refrigerant piping are substantially the same, then the heating efficiency of the electromagnetic induction can be improved.
  • An electromagnetic induction heating unit according to a third aspect of the invention is the electromagnetic induction heating unit according to the first or second aspects of the invention, wherein at least part of the magnetic part extends to at least one side selected from the group consisting of: one side of the coil in directions in which the refrigerant piping extends; and another side, which is the opposite side of the one side with respect to the coil.
  • In the present electromagnetic induction heating unit, the magnetic flux that arises owing to the supply of electric power to the coil and that would leak out to the opposite side of the refrigerant piping can be captured by the magnetic part prior to being conducted to the external member. Consequently, the magnetic part can hinder a greater amount of the magnetic field leakage than the external member can. Thereby, not only the leakage of the magnetic field to the outer side of the magnetic part but also the leakage of the magnetic field to the outer side of the external member can be much more effectively reduced by virtue of the external member capturing the magnetic field that leaks to the outer side of the magnetic part.
  • An electromagnetic induction heating unit according to a fourth aspect of the invention is the electromagnetic induction heating unit according to any one aspect of the first through third aspects of the invention, wherein at least part of the magnetic part extends to the inner side of the coil, which is the outer side of the refrigerant piping when viewed from the axial directions of the refrigerant piping.
  • In the present electromagnetic induction heating unit, the strength of the magnetic field generated by the coil can be kept lower than a strength that would leak to the portions outside of the magnetic part and thereby the magnetic field can be made to pass through the magnetic part more efficiently.
  • An electromagnetic induction heating unit according to a fifth aspect of the invention is the electromagnetic induction heating unit according to any one aspect of the first through fourth aspects of the invention, wherein the magnetic part comprises a plurality of magnetic components disposed such that the magnetic components contact one another.
  • In the present electromagnetic induction heating unit, the magnetic part is not made as an integral member that conforms to a target shape; rather, the magnetic part can be made as a combination of multiple components that conform to the target shape. Furthermore, because these magnetic components are disposed in a state wherein they contact one another, any decline in the magnetic permeability at the portions at which the magnetic components contact one another can be reduced.
  • An electromagnetic induction heating unit according to a sixth aspect of the invention is the electromagnetic induction heating unit according to any one aspect of the first through fifth aspects of the invention, wherein the magnetic part contains a material that is a good conductor.
  • In the present electromagnetic induction heating unit, even if the magnetic flux is made to pass through the magnetic part for the purpose of reducing the number of lines of magnetic force on the outer side of the magnetic part, the Joule heat generated by the electrical resistance can be reduced because the magnetic part contains a material that is a good conductor.
  • An electromagnetic induction heating unit according to a seventh aspect of the invention is the electromagnetic induction heating unit according to any one aspect of the first through sixth aspects of the invention, wherein the magnetic part contains ferrite.
  • In the present electromagnetic induction heating unit, the magnetic flux can be made to actively pass through the magnetic part, which contains ferrite, and thereby the magnetic field that leaks to the outer side of the magnetic part can be reduced.
  • An air conditioner according to all eighth aspect of the invention is an air conditioner that comprises: an electromagnetic induction heating unit according to any one aspect of the first through seventh aspects; and a refrigeration cycle that includes a portion wherethrough a refrigerant flows to the refrigerant piping.
  • In the present air conditioner, even if electromagnetic induction heating is performed, the impact on the surroundings of the electromagnetic induction heating unit can be reduced.
    • <Advantageous Effects of Invention>
  • In the electromagnetic induction heating unit according to the first aspect of the invention, the strength of the magnetic field in outside of the magnetic part caused by the leakage can be kept lower than the strength of the magnetic field in the magnetic part.
  • Tin the electromagnetic induction heating unit according to the second aspect of the invention, the heating efficiency of the electromagnetic induction can be improved.
  • In the electromagnetic induction heating unit according to the third aspect of the invention, not only the leakage of the magnetic field to the outer side of the magnetic part but also the leakage of the magnetic field to the outer side of the external member can be much more effectively reduced by virtue of the external member capturing the magnetic field that leaks to the outer side of the magnetic part.
  • In the electromagnetic induction heating unit according to the fourth aspect of the invention, the magnetic field can be made to pass through the magnetic part more efficiently.
  • In the electromagnetic induction heating unit according to the fifth aspect of the invention, any decline in the magnetic permeability at the portions at which the magnetic components contact one another can be reduced.
  • In the electromagnetic induction heating unit according to the sixth aspect of the invention, the Joule heat generated by the electrical resistance can be reduced.
  • In the electromagnetic induction heating unit according to the seventh aspect of the invention, the magnetic field that leaks to the outer side of the magnetic part can be reduced.
  • In the air conditioner according to the eighth aspect of the invention, even if electromagnetic induction heating is performed, the impact on the surroundings of the electromagnetic induction heating unit can be reduced.
    • BRIEF DESCRIPTION OF THE DRAWING
    • FIG. 1 is a refrigerant circuit diagram of an air conditioner according to one embodiment of the present invention.
    • FIG. 2 is an external oblique view that includes a front surface side of an outdoor unit.
    • FIG. 3 is an oblique view of the internal layout and configuration of the outdoor unit.
    • FIG. 4 is an external oblique view that includes a rear surface side of the internal layout and configuration of the outdoor unit.
    • FIG. 5 is a general, front, oblique view that shows the internal structure of a machine chamber of the outdoor unit.
    • FIG. 6 is an oblique view that shows the internal structure of the machine chamber of the outdoor unit.
    • FIG. 7 is an oblique view of a bottom plate and an outdoor heat exchanger of the outdoor unit.
    • FIG. 8 is a top plan view of the layout of an electromagnetic induction heating unit.
    • FIG. 9 is a schematic oblique view of the electromagnetic induction heating unit mounted to an accumulator pipe.
    • FIG. 10 is an external oblique view of the state wherein a shielding cover has been removed from the electromagnetic induction heating unit.
    • FIG. 11 is a cross sectional view of the electromagnetic induction heating unit mounted to the accumulator pipe.
    • FIG. 12 is a view that shows the state wherein a thermistor and a fuse are mounted.
    • FIG. 13 is an explanatory diagram of the state wherein magnetic flux arises around the electromagnetic induction heating unit.
    • FIG. 14 is a schematic oblique view of a first ferrite case.
    • FIG. 15 is a view of the vicinity of a screw part on the upper side of the first ferrite case.
    • FIG. 16 is a view of the vicinity of a screw part on the lower side of the first ferrite case.
    • FIG. 17 is a top plan view of the shielding cover.
    • FIG. 18 is a front view of the shielding cover.
    • FIG. 19 is a view that shows an aspect wherein ferrite parts tend to conduct magnetic flux more than the shielding cover does.
    • FIG. 20 is an explanatory diagram of a refrigerant piping according to another embodiment (C).
    • FIG. 21 is an explanatory diagram of the refrigerant piping according to another embodiment (D).
    • FIG. 22 is a view that shows an example of the layout of a coil and the refrigerant piping according to another embodiment (E).
    • FIG. 23 is a view that shows an example of the layout of bobbin covers according to another embodiment (E).
    • FIG. 24 is a view that shows an example of the layout of ferrite cases according to another embodiment (E).
    DESCRIPTION OF EMBODIMENTS
  • An exemplary case of an air conditioner 1, which comprises an electromagnetic induction heating unit 6 according to one embodiment of the present invention, will now be explained, referencing the drawings.
    • <1-1> Air Conditioner 1
  • FIG. 1 . is a refrigerant circuit diagram that shows a refrigerant circuit 10 of the air conditioner 1.
  • The air conditioner 1 is an apparatus wherein an outdoor unit 2, which serves as a heat source side apparatus, and an indoor unit 4, which serves as a utilization side apparatus, are connected by a refrigerant piping, and the space wherein the utilization side apparatus is disposed is air conditioned; furthermore, the air conditioner 1 comprises a compressor 21, a four-way switching valve 22, an outdoor heat exchanger 23, an outdoor motor operated expansion valve 24, an accumulator 25, outdoor fans 26, an indoor heat exchanger 41, an indoor fan 42, a hot gas bypass valve 27, a capillary tube 28, the electromagnetic induction heating unit 6, and the like.
  • The compressor 21, the four-way switching valve 22, the outdoor heat exchanger 23, the outdoor motor operated expansion valve 24, the accumulator 25, the outdoor fans 26, the hot gas bypass valve 27, the capillary tube 28, and the electromagnetic induction heating unit 6 are housed inside the outdoor unit 2. The indoor heat exchanger 41 and the indoor fan 42 are housed inside the indoor unit 4.
  • The refrigerant circuit 10 comprises a discharge pipe A, an indoor side gas pipe B, an indoor side liquid pipe C, an outdoor side liquid pipe D, an outdoor side gas pipe E, an accumulator pipe F, a suction pipe G, a hot gas bypass circuit H, branched piping K, and union piping J. The refrigerant that passes through the indoor side gas pipe B and the outdoor side gas pipe E is mostly in the gas state, but the refrigerant passing through is not limited to the gas state. The refrigerant that passes through the indoor side liquid pipe C and the outdoor side liquid pipe D is mostly in the liquid state, but the refrigerant passing through is not limited to the liquid state.
  • The discharge pipe A connects the compressor 21 and the four-way switching valve 22. A discharge temperature sensor 29d, which detects the temperature of the refrigerant passing through, is provided to the discharge pipe A. Furthermore, an electric power supply part 21e supplies electric power to the compressor 21. The amount of electric power the electric power supply part 21e supplies is detected by a compressor electric power detection unit 29f.
  • The indoor side gas pipe B connects the four-way switching valve 22 and the indoor heat exchanger 41. A pressure sensor 29a, which detects the pressure of the refrigerant passing through, is provided along the indoor side gas pipe B.
  • The indoor side liquid pipe C connects the indoor heat exchanger 41 and the outdoor motor operated expansion valve 24.
  • The outdoor side liquid pipe D connects the outdoor motor operated expansion valve 24 and the outdoor heat exchanger 23.
  • The outdoor side gas pipe E connects the outdoor heat exchanger 23 and the four-way switching valve 22.
  • The accumulator pipe F connects the four-way switching valve 22 and the accumulator 25 and, in the state wherein it is installed in the outdoor unit 2, extends in the vertical directions. The electromagnetic induction heating unit 6 is mounted to part of the accumulator pipe F. At least a heat generating portion of the accumulator pipe F, which is enveloped by a coil 68 (discussed below), comprises a magnetic pipe F2 provided such that it envelops a copper pipe F1, wherein the refrigerant flows (refer to FIG. 11 ). The magnetic pipe F2 is made of steel use stainless (SUS) 430. SUS 430 is a ferromagnetic material; when placed in a magnetic field, eddy currents arise, which generate heat by the action of Joule heat induced by the material's own electrical resistance. The portion of the piping that constitutes the refrigerant circuit 10 and that is outside of the magnetic pipe F2 comprises copper pipes. Furthermore, the material property of the pipe that envelops the copper pipe is not limited to SUS 430, and can be, for example: one type of conductor selected from the group consisting of iron, copper, aluminum, chrome, and nickel; an alloy containing at least two or more types of metal selected from the same group; and the like. In addition, examples of SUS include ferritic steel, martensitic steel, or a combination thereof. Furthermore, it is preferable to use a material that is a ferromagnetic, has a comparatively high electrical resistance, and has a higher Curie temperature than that of the working temperature range. Furthermore, the accumulator pipe F herein requires a larger amount of electric power; however, instead of a magnetic body and a material that contains a magnetic body, it may contain a material that can be induction heated. Furthermore, for example, the magnetic material may constitute all of the accumulator pipe F, only an inner side surface of the accumulator pipe F, or be simply included in the material that constitutes the accumulator pipe F. By performing electromagnetic induction heating in this manner, the accumulator pipe F can generate heat by electromagnetic induction, and thereby the refrigerant that is suctioned into the compressor 21 via the accumulator 25 can be heated. Thereby, the heating capacity of the air conditioner 1 can be improved. In addition, for example, even if the compressor 21 is not sufficiently heated when heating operation is started up, the electromagnetic induction heating unit 6 can perform quick heating, thereby supplementing the capacity shortfall during startup. Furthermore, if the four-way switching valve 22 switches to the cooling operation state and the defrosting operation, which eliminates frost that adheres to the outdoor heat exchanger 23 and the like, is performed, then the compressor 21 can compress the quickly heated refrigerant by virtue of the electromagnetic induction heating unit 6 quickly heating the accumulator pipe F. Consequently, the temperature of the hot gas discharged from the compressor 21 can be quickly raised. Thereby, the time needed for the defrosting operation to perform defrosting can be shortened. Thereby, even if it is necessary to perform the defrosting operation when appropriate during heating operation, it is possible to return to the heating operation as quickly as possible and thereby to improve user comfort.
  • The suction pipe G connects the accumulator 25 and the inlet side of the compressor 21.
  • The hot gas bypass circuit H connects a branching point A1, which is provided along the discharge pipe A, and a branching point D1, which is provided along the outdoor side liquid pipe D. The hot gas bypass valve 27, which is capable of switching between the state in which the refrigerant is permitted to pass through and the state in which it isn't, is disposed along the hot gas bypass circuit H. Furthermore, the capillary tube 28, which lowers the pressure of the refrigerant passing through, is provided along the hot gas bypass circuit H between the hot gas bypass valve 27 and the branching point D1. Because the pressure of the refrigerant can approach that of the refrigerant after the pressure has been decreased by the outdoor motor operated expansion valve 24 during heating operation, the capillary tube 28 can hinder a rise in the pressure of the refrigerant in the outdoor side liquid pipe D by supplying hot gas, which has passed through the hot gas bypass circuit H, to the outdoor side liquid pipe D.
  • The branched piping K constitutes part of the outdoor heat exchanger 23 and is the refrigerant piping that, to increase the effective surface area for exchanging heat, extends from a gas side inlet/outlet 23e of the outdoor heat exchanger 23 and branches into multiple pipes at a branching and merging point 23k (discussed below). The branched piping K comprises a first branch pipe K1, a second branch pipe K2, and a third branch pipe K3, each of which independently extend from the branching and merging point 23k to a merging and branching point 23j; furthermore, the branched pipes K1, K2, K3 merge at the merging and branching point 23j. Furthermore, viewed from the union piping J side, the branched piping K branches at the merging and branching point 23j and extends therefrom.
  • The union piping J constitutes part of the outdoor heat exchanger 23 and is a piping that extends from the merging and branching point 23j to a liquid side inlet/outlet 23d of the outdoor heat exchanger 23. The union piping J can, during cooling operation, make uniform the degree of supercooling of the refrigerant flowing out of the outdoor heat exchanger 23 and, during heating operation, defrost any ice that adheres to the vicinity of the lower end of the outdoor heat exchanger 23. The union piping J has a cross sectional area that is substantially three times that of each of the branched pipes K1, K2, K3, and therefore the amount of refrigerant passing through is substantially three times that of each of the branched pipes K1, K2, K3.
  • The four-way switching valve 22 is capable of switching between a cooling operation cycle and a heating operation cycle. In FIG. 1 , solid lines indicate the connection state wherein heating operation is performed, and dotted lines indicate the connection state wherein cooling operation is performed. During heating operation, the indoor heat exchanger 41 functions as a cooler of the refrigerant, and the outdoor heat exchanger 23 functions as a heater of the refrigerant. During cooling operation, the outdoor heat exchanger 23 functions as a cooler of the refrigerant, and the indoor heat exchanger 41 functions as a heater of the refrigerant.
  • The outdoor heat exchanger 23 comprises the gas side inlet/outlet 23e, the liquid side inlet/outlet 23d, the branching and merging point 23k, the merging and branching point 23j, the branched piping K, the union piping J, and heat exchanging fins 23z. The gas side inlet/outlet 23e is positioned at an end part on the outdoor side gas pipe E side of the outdoor heat exchanger 23 and connects to the outdoor side gas pipe E. The liquid side inlet/outlet 23d is positioned at an end part on the outdoor side liquid pipe D side of the outdoor heat exchanger 23 and connects to the outdoor side liquid pipe D. The branching and merging point 23k branches the piping that extends from the gas side inlet/outlet 23e and can branch or merge the refrigerant in accordance with the direction in which the refrigerant is flowing. In the branched piping K, multiple pipes extend from the branched portions at the branching and merging point 23k. The merging and branching point 23j merges the branched piping K and can merge or branch the refrigerant in accordance with the direction in which the refrigerant is flowing. The union piping J extends from the merging and branching point 23j to the liquid side inlet/outlet 23d. The heat exchanging fins 23z are plate shaped aluminum fins arrayed in the plate thickness directions and disposed at prescribed intervals. Both the branched piping K and the union piping J are to be inserted through the heat exchanging fins 23z, which they have in common. Specifically, the branched piping K and the union piping J are disposed such that they are inserted through, at different portions of, each of the heat exchanging fins 23z, which they have in common, in the plate thickness directions. An outdoor air temperature sensor 29b, which detects the outdoor air temperature, is provided to the outdoor heat exchanger 23 on the leeward side in the direction of the airflow of the outdoor fans 26. In addition, an outdoor heat exchanger temperature sensor 29c, which detects the temperature of the refrigerant flowing through the branched piping K, is provided to the outdoor heat exchanger 23.
  • An indoor temperature sensor 43, which detects the indoor temperature, is provided inside the indoor unit 4. In addition, the indoor heat exchanger 41 is provided with an indoor heat exchanger temperature sensor 44, which detects the temperature of the refrigerant on the indoor side liquid pipe C, along which the outdoor motor operated expansion valve 24 is connected, side of the indoor heat exchanger 41.
  • A control unit 11 is constituted by the connection of an outdoor control unit 12, which controls equipment disposed inside the outdoor unit 2, and an indoor control unit 13, which controls equipment disposed inside the indoor unit 4, via a communications wire 11a. The control unit 11 performs various control functions with respect to the air conditioner 1.
  • In addition, a timer 95, which counts in order to measure the time elapsed when various control functions are performed, is provided to the outdoor control unit 12.
  • Furthermore, a controller 90, which accepts the input of settings from the user, is connected to the control unit 11.
    • <1-2> Outdoor Unit 2
  • FIG. 2 is an external oblique view of the front surface side of the outdoor unit 2. FIG. 3 is an oblique view that shows the positional relationship between the outdoor heat exchanger 23 and the outdoor fans 26. FIG. 4 is an oblique view of the rear surface side of the outdoor heat exchanger 23.
  • The outer surface of the outdoor unit 2 is a substantially rectangular parallelepipedic outdoor unit casing that comprises a top plate 2a, a bottom plate 2b, a front panel 2c, a left side surface panel 2d, a right side surface panel 2f, and a rear surface panel 2e.
  • The outdoor unit 2 is partitioned by a partition plate 2h into a fan chamber, which is on the left side surface panel 2d side and wherein the outdoor heat exchanger 23, the outdoor fans 26, and the like are disposed, and a machine chamber, which is on the right side surface panel 2f side and wherein the compressor 21, the electromagnetic induction heating unit 6, and the like are disposed. In addition, the outdoor unit 2 comprises outdoor unit support platform 2g, which are fixed to the bottom plate 2b by screwing and constitute the lowest end parts of the outdoor unit 2 on the right and left sides. Furthermore, the electromagnetic induction heating unit 6 is disposed at an upper position of the machine chamber in the vicinity of the left side surface panel 2d and the top plate 2a. Here, a plurality of the heat exchanging fins 23z of the outdoor heat exchanger 23 discussed above is arrayed in the plate thickness directions, which are substantially oriented in the horizontal directions. The union piping J is disposed by inserting it through the heat exchanging fins 23z of the outdoor heat exchanger 23 in the thickness directions at the lowermost portion of the heat exchanging fins 23z. The hot gas bypass circuit H is disposed such that it runs along below the outdoor fans 26 and the outdoor heat exchanger 23.
  • FIG. 5 is a general, front, oblique view that shows the internal structure of the machine chamber of the outdoor unit 2. FIG. 6 is an oblique view that shows the internal structure of the machine chamber of the outdoor unit 2. FIG. 7 is an oblique view that shows the layout of the outdoor heat exchanger 23 and the bottom plate 2b in relation to each other. FIG. 8 is a top plan view that shows the layout of the electromagnetic induction heating unit 6.
  • The partition plate 2h of the outdoor unit 2 partitions, from the front to the back and from the upper end to the lower end, the fan chamber, wherein the outdoor heat exchanger 23, the outdoor fans 26, and the like are disposed, and the machine chamber, wherein the electromagnetic induction heating unit 6, the compressor 21, the accumulator 25, and the like are disposed. The compressor 21 and the accumulator 25 are disposed in a lower space of the machine chamber of the outdoor unit 2. Furthermore, the electromagnetic induction heating unit 6, the four-way switching valve 22, and the outdoor control unit 12 are disposed in an upper space of the machine chamber of the outdoor unit 2, above the compressor 21, the accumulator 25, and the like. The compressor 21, the four-way switching valve 22, the outdoor heat exchanger 23, the outdoor motor operated expansion valve 24, the accumulator 25, the hot gas bypass valve 27, the capillary tube 28, and the electromagnetic induction heating unit 6, which are disposed in the machine chamber and are the functional elements that constitute the outdoor unit 2, are corrected via the discharge pipe A, the indoor side gas pipe B, the outdoor side liquid pipe D, the outdoor side gas pipe E, the accumulator pipe F, the hot gas bypass circuit H, and the like such that the refrigerant circuit 10 shown in FIG. 1 performs a refrigeration cycle. Here, as discussed below, the hot gas bypass circuit H comprises nine linked portions, namely, a first bypass portion H1 through a ninth bypass portion H9; furthermore, when the refrigerant flows to the hot gas bypass circuit H, it flows in order from the first bypass portion H1 to the ninth bypass portion H9.
    • <1-3> Electromagnetic Induction Heating Unit 6
  • FIG. 9 is a schematic oblique view of the electromagnetic induction heating unit 6 mounted to the accumulator pipe F. FIG. 10 is an external oblique view that shows the state wherein a shielding cover 75 has been removed from the electromagnetic induction heating unit 6. FIG. 11 is a cross sectional view of the electromagnetic induction heating unit 6 mounted to the accumulator pipe F.
  • The electromagnetic induction heating unit 6 is disposed such that it covers the magnetic pipe F2, which is the heat generating portion of the accumulator pipe F, from the outer side in the radial directions and causes the magnetic pipe F2 to generate heat by electromagnetic induction heating. The heat generating portion of the accumulator pipe F has a double pipe structure that comprises the copper pipe F1 on the inner side and the magnetic pipe F2 on the outer side.
  • The electromagnetic induction heating unit 6 comprises a first hex nut 61, a second hex nut 66, a first bobbin cover 63, a second bobbin cover 64, a bobbin main body 65, a first ferrite case 71, a second ferrite case 72, a third ferrite case 73, a fourth ferrite case 74, first ferrite parts 98, second ferrite parts 99, the coil 68, the shielding cover 75, a thermistor 14, a fuse 15, and the like.
  • The first hex nut 61 and the second hex nut 66 are made of resin, and the electromagnetic induction heating unit 6 and the accumulator pipe F are stably fixed using a C ring (not shown). The first bobbin cover 63 and the second bobbin cover 64 are made of resin and cover the accumulator pipe F from the outer side in the radial directions at the upper end position and the lower end position, respectively. The first bobbin cover 63 and the second bobbin cover 64 each have four screw holes for screws 69, which are for screwing the first through fourth ferrite cases 71-74 (discussed below) to the first bobbin cover 63 and the second bobbin cover 64 using screws 69. Furthermore, the second bobbin cover 64 has an electromagnetic induction thermistor insertion opening 64f, which is for inserting the thermistor 14 into the second bobbin cover 64 in order to mount the thermistor 14 to the outer surface of the magnetic pipe F2. In addition, the second bobbin cover 64 has a fuse insertion opening 64e, which is for inserting the fuse 15 shown in FIG. 13 into the second bobbin cover 64 in order to mount the fuse 15 to the outer surface of the magnetic pipe F2. The thermistor 14 converts the temperature detected to a signal and transmits such to the control unit 11. The fuse 15 converts the detection result to a signal and transmits such to the control unit 11. If the control unit 11 receives a notification from the fuse 15 that the temperature detected exceeds a prescribed limit, then the control unit 11 performs control such that the supply of electric power to the coil 68 is stopped, thereby avoiding thermal damage to the equipment. The bobbin main body 65 is made of resin, and the coil 68 is wound around the bobbin main body 65. The coil 68 is wound helically around the outer side of the bobbin main body 65, the directions in which the accumulator pipe F extends being the axial directions. The coil 68 is connected to a control printed circuit board 18 (not shown), and receives the supply of a high frequency electric current. The output of the control printed circuit board 18 is controlled by the control unit 11. As shown in FIG. 12 , the thermistor 14 and the fuse 15 are mounted in the state wherein the bobbin main body 65 and the second bobbin cover 64 are mated. Here, in the state wherein the thermistor 14 is mounted, satisfactory pressure contact between the thermistor 14 and the outer surface of the magnetic pipe F2 is maintained by a leaf spring 16, which presses the thermistor 14 inward in the radial directions of the magnetic pipe F2. In addition, in the state wherein the fuse 15 is mounted, too, satisfactory contact pressure between the fuse 15 and the outer surface of the magnetic pipe F2 is likewise maintained by a leaf spring 17, which presses the fuse 15 inward in the radial directions of the magnetic pipe F2. Thus, because tight contact is satisfactorily maintained between the thermistor 14 and the outer surface of the accumulator pipe F as well as between the fuse 15 and the outer surface of the accumulator pipe F, responsiveness is improved and sudden changes in temperature owing to electromagnetic induction heating can be detected promptly. The first ferrite case 71 is inserted into the first bobbin cover 63 and the second bobbin cover 64 from the directions in which the accumulator pipe F extends and is fixed by the screws 69. The first ferrite case 71 through the fourth ferrite case 74 each house first ferrite parts 98 and second ferrite parts 99, which are made of ferrite-a raw material that has high magnetic permeability. As shown in the magnetic flux explanatory diagram of FIG. 13 , by capturing the magnetic field generated by the coil 68 and thereby forming a path for the magnetic flux, the first ferrite parts 98 and the second ferrite parts 99 tend not to externally leak the magnetic field. The shielding cover 75 is disposed at the outermost circumferential portion of the electromagnetic induction heating unit 6 and collects the magnetic flux that cannot be completely gathered by the first ferrite parts 98 and the second ferrite parts 99 alone. Thereby, virtually none of the magnetic flux leaks to the outer side of the shielding cover 75: furthermore, the location at which the magnetic flux is generated can be determined independently.
    • (Ferrite Cases and Ferrite Parts)
  • The details of the ferrite cases will now be explained.
  • FIG. 14 is a schematic oblique view of the first ferrite case 71, wherein the first ferrite parts 98 and the second ferrite parts 99 are housed and fixed. FIG. 15 shows the structure of the vicinity of the screw part on the upper side of the first ferrite case 71. FIG. 16 shows the structure of the vicinity of the screw part on the lower side of the first ferrite case 71. Furthermore, the first through fourth ferrite cases 71-74 all have the same shape.
  • The first ferrite case 71 is made of resin and has a function wherein the first bobbin cover 63 and the second bobbin cover 64 are inserted from the directions in which the accumulator pipe F extends and are thereby fixed and a function wherein the first ferrite parts 98 and the second ferrite parts 99 are housed and held.
  • The first ferrite case 71 comprises a bottom surface part 71j, side surface parts 71h, a first cover screw part 71a, a first cover screw hole 71b, a second cover screw part 71f, a second cover screw hole 71g, shielding cover screw parts 71c, and shielding cover screw holes 71d.
  • The bottom surface part 71j constitutes the bottom surface of the first ferrite case 71. As discussed below, the first ferrite parts 98 and the second ferrite parts 99 are bonded to the bottom surface part 71j. In the state wherein it is fixed to the electromagnetic induction heating unit 6, the bottom surface part 71j is provided at a position at which its surface is oriented in the radial directions, its longitudinal directions being the directions in which the accumulator pipe F extends. The bottom surface part 71j is mounted to one of four symmetrically provided substantially linear sides of the outer edges of the first bobbin cover 63 and the second bobbin cover 64 in the radial directions. Thereby, the rear surface side of the bottom surface part 71j and the substantially linear sides of both the first bobbin cover 63 and the second bobbin cover 64 are fixed in the state wherein they have been brought into contact. Thereby, the first ferrite case 71 has a structure that restrains movement in the circumferential directions.
  • The side surface parts 71h have surfaces that extend from both sides of the bottom surface part 71j in directions orthogonal to the longitudinal directions thereof and in the direction leading away from the bottom surface part 71j.
  • The first cover screw part 71a is provided for screwing the first ferrite case 71 and the first bobbin cover 63 together and is provided at a position displaced from a virtual space that extends in the radial directions and is interposed by the two side surface parts 71h. Thereby, the first ferrite parts 98 can be disposed as far as the vicinity of the magnetic pipe F2, which makes it possible to reduce leakage of the magnetic force.
  • The second cover screw part 71f is provided for screwing the first ferrite case 71 and the second bobbin cover 64 together and is provided, on the opposite side of the first cover screw part 71a, at a position displaced from the virtual space that extends in the radial directions and is interposed by the two side surface parts 71h. Thereby, the first ferrite parts 98 can be disposed as far as the vicinity of the magnetic pipe F2, which makes it possible to reduce leakage of the magnetic force. Furthermore, because the first cover screw part 71a and the second cover screw part 71f are disposed on opposite sides of the virtual space that extends in the radial directions and is interposed by the two side surface parts 71h, the first cover screw part 71a and the second cover screw part 71f serve not only to reduce leakage of the magnetic force but also to more rigidly fix the first ferrite case 71 to the first bobbin cover 63 and the second bobbin cover 64.
  • The second cover screw hole 71g is used for screwing the first ferrite case 71 and the second bobbin cover 64 to one another, thereby fixing them. Specifically, as in the first cover screw hole 71b discussed above, the second cover screw hole 71g of the first ferrite case 71 and a screw hole (not shown) for the screw 69 of the second bobbin cover 64 are screwed together by the metal screw 69 and are thereby fixed.
  • The shielding cover screw parts 71c are provided at two upper locations and two lower locations and are formed such that they protrude toward the outer side, which is the opposite of the inner side wherein the side surface parts 71h face one another.
  • The shielding cover screw holes 71d are openings that are provided to each of the shielding cover screw parts 71c and, in the state wherein the shielding cover 75 is mounted as shown in FIG. 9 , the shielding cover 75 is screwed by screws. Thereby, the first ferrite case 71 and the shielding cover 75 are fixed. Furthermore, the shielding cover screw parts 71c and the shielding cover screw holes 71d are also provided for each of the second through fourth ferrite cases 72-74; however, in actuality, the shielding cover 75 is fixed by just two opposing ferrite cases of the first through forth ferrite cases 71-74; in the present embodiment, the two opposing ferrite cases are the first ferrite case 71 and the third ferrite case 73.
  • Furthermore, the first ferrite parts 98 and the second ferrite parts 99 housed in each of the ferrite cases 71-74 are disposed such that their surface portions contact one another.
  • In addition, the two different shapes of the ferrite parts 98, 99, namely, the shape of the first ferrite parts 98 and the shape of the second ferrite parts 99, combine to conduct the magnetic field. A ferrite part that is integrally formed in a U shape is not used; rather, ferrite parts of the same shape are combined, which makes it possible to lower cost. Furthermore, the first ferrite parts 98 and the second ferrite parts 99 housed in each of the ferrite cases 71-74 are disposed such that their surface portions contact one another.
    • (Shielding Cover)
  • The details of the shielding cover 75 will now be explained.
  • As shown in the top cross sectional view of FIG. 17 , the shielding cover 75 is a substantially octagonal piece of sheet metal that contains a magnetic material and that in a plan view follows along the shape of the outer edge of the first through fourth ferrite cases 71-74 when they are mounted to the first bobbin cover 63 and the second bobbin cover 64.
  • As shown in the top plan view of FIG. 17 , the shielding cover 75 comprises an overlapped portion 75d, wherein one end 75a and an other end 75b in the circumferential directions overlap in the plate thickness directions. In the overlapped portion 75d, a surface in the vicinity of the one end 75a and a surface in the vicinity of the other end 75b are welded-from above to below in the directions in which the accumulator pipe F extends-in the state wherein the two surfaces are in contact with one another. Thereby, even if a magnetic field is generated by the electromagnetic induction heating unit 6 and the leakage magnetic flux is drawn in by the shielding cover 75, it is possible to prevent the local generation of eddy currents because at no place do the parts of the shielding cover 75 contact one another locally. Thereby, it is possible to reduce the heat generated by the shielding cover 75, which constitutes the outer side of the electromagnetic induction heating unit 6, and to maintain a low temperature as a provision against the risk of the user touching the shielding cover 75. In addition, as can be understood by comparing FIG. 10 , which shows the state wherein the shielding cover 75 is not mounted, and FIG. 9 , which shows the state wherein the shielding cover 75 is mounted, the shielding cover 75 envelops the coil 68 such that a finger and the like of the user is denied access to the coil 68. Furthermore, here, the user can be effectively prevented from accessing the coil 68 because both ends of the coil 68 in the directions in which the accumulator pipe F extends are disposed between both ends of the shielding cover 75.
  • In addition, as shown in FIG. 18 , the shielding cover 75 has screw holes 75x, 75y in the vicinity of the upper end in the longitudinal directions. As shown in FIG. 9 , when the shielding cover 75 is fixed to the first ferrite case 71, these screw holes 75x, 75y function as holes wherethrough screws 70a, 70b pass.
  • FIG. 19 is a cross sectional view that shows an aspect wherein the magnetic flux tends to be conducted to the ferrite parts 98, 99 more than to the shielding cover 75.
  • The magnetic permeability of the ferrite parts 98, 99 is higher than that of the shielding cover 75, which comprises a piece of sheet metal; furthermore, the ferrite parts 98, 99 are disposed such that they extend in the radial directions at the upper end and the lower end of the coil 68 and such that they straddle the coil 68 when viewed from the directions in which the accumulator pipe F extends. Consequently, the magnetic flux that would leak out tends to be conducted to the ferrite parts 98, 99 more than to the shielding cover 75, the magnetic flux generated by the coil 68 is collected by the ferrite parts 98, 99 before it is collected by the shielding cover 75, and therefore virtually all of that magnetic flux can be conducted to the ferrite parts 98, 99. Furthermore, it is possible to lighten the burden of the shielding cover 75 to prevent magnetic flux leakage, and thereby the magnetic field that leaks out of the electromagnetic induction heating unit 6 can be significantly more reduced.
  • In addition, because the first ferrite case 71 is formed from a resin, even if the shielding cover 75 is screwed to the first ferrite case 71 using the metal screws 70a, 70b, the first ferrite parts 98 and the second ferrite parts 99 do not directly contact the shielding cover 75. Thus, because a structure is adopted wherein the first ferrite parts 98 and the second ferrite parts 99 do not contact the shielding cover 75, there is naturally no local point of contact between the first ferrite parts 98 and the second ferrite parts 99 on one side and the shielding cover 75 on the other side. Consequently, even if an electric current flows to the coil 68 owing to electromagnetic induction, the concentration of magnetic flux that would result from the presence of a point of contact between the first ferrite parts 98 and the second ferrite parts 99 on one side and the shielding cover 75 on the other side tends not to occur. Thereby, it is possible to hinder the occurrence of a rise in the temperature in some portion owing to the concentration of magnetic flux.
  • In addition, with regard to the ferrite parts 98, 99 of the second through fourth ferrite cases 72-74 that the shielding cover 75 covers from the outer side in the radial directions at a position other than a gap portion of the shielding cover 75, the shielding cover 75, which contains the magnetic body, and the first ferrite parts 98 and the second ferrite parts 99, which are housed in the second through fourth ferrite cases 72-74, can have a double structure that hinders leakage of magnetic flux. Thereby, it is possible to more effectively hinder the leakage of magnetic flux.
  • Furthermore, as shown in FIG. 8 , the portion of the shielding cover 75 positioned near the right side surface panel 2f of the outdoor unit 2 in a plan view is disposed such that it is secured against and plane parallel with the right side surface panel 2f. Thereby, the magnetic flux conducted to the shielding cover 75 is prevented from, for example, being further conducted to the right side surface panel 2f or causing the local generation of heat by the generation of eddy currents at local points of contact between the right side surface panel 2f and the shielding cover 75.
    • <Features of the Air Conditioned 1 of the Present Embodiment>
  • There are cases wherein, when electromagnetic induction heating is performed, not only does a magnetic field arise in the target magnetic body, which is meant to generate heat, but also in the periphery thereof.
  • In contrast, in the electromagnetic induction heating unit 6 of the air conditioner 1, the ferrite parts 98, 99, which contain a magnetic material of a higher magnetic permeability than that of the shielding cover 75, are disposed on the outer side of the coil 68 and such that they extend nearer to the coil 68 than the shielding cover 75 does. Consequently, the magnetic field that arises in portions outside of the accumulator pipe F tends to pass through the ferrite parts 98, 99 more than through the shielding cover 75. Consequently, the ferrite parts 98, 99 can efficiently capture the magnetic flux that would leak out to portions outside of the accumulator pipe F. Thereby, when electromagnetic induction heating is performed, the magnetic field that arises in portions outside of the accumulator pipe F can be made to efficiently pass through the ferrite parts 98, 99; furthermore, any magnetic flux not collected by the ferrite parts 98, 99 is collected by the shielding cover 75. Consequently, the magnetic flux that leaks out to portions outside of the electromagnetic induction heating unit 6 can be reduced.
    • <Other Embodiment>
  • The above text explained an embodiment of the present invention based on the drawings, but the specific constitution is not limited to these embodiments, and it is understood that variations and modifications may be effected without departing from the spirit and scope of the invention.
    • (A)
  • The above embodiment explained an exemplary case wherein the ferrite parts 98, 99 conduct the magnetic flux.
  • However, the present invention is not limited thereto.
  • For example, the material used to conduct the magnetic flux may be a good conductor that is not as magnetic as ferrite. In such a case, it is possible to reduce the Joule heat generated by electrical resistance when the magnetic field has been conducted.
    • (B)
  • The embodiment explained a case wherein the electromagnetic induction heating unit 6 is mounted to the accumulator pipe F of the refrigerant circuit 10.
  • However, the present invention is not limited thereto.
  • For example, a refrigerant piping other than the accumulator pipe F may be provided. In such a case, a magnetic body of, for example, the magnetic pipe F2 is provided to a portion of the refrigerant piping whereto the electromagnetic induction heating unit 6 is provided.
    • (C)
  • The embodiment explained an exemplary case wherein the accumulator pipe F is configured as a double pipe, namely, as the copper pipe F1 and the magnetic pipe F2.
  • However, the present invention is not limited thereto.
  • As shown in FIG. 20 , for example, a member to be heated F2a and two stoppers F1a, F1b may be disposed inside the accumulator pipe F, the refrigerant piping to be heated, or the like. Here, the member to be heated F2a contains a magnetic material and generates heat by the electromagnetic induction heating of the abovementioned embodiment. At two locations on the inner side of the copper pipe F1, the stoppers F1a, F1b continuously permit the passage of the refrigerant but do not permit the passage of the member to be heated F2a. Thereby, the member to be heated F2a does not move even when the refrigerant flows. Consequently, the target heating position of the accumulator pipe F and the like can be heated. Furthermore, the heat transfer efficiency can be improved because the member to be heated F2a and the refrigerant directly contact one another.
    • (D)
  • Instead of using the stoppers F1a, the position of the member to be heated F2a explained in the abovementioned other embodiment (C) may be prescribed with respect to the piping.
  • As shown in FIG. 21 , for example, bent portions FW may be provided to the copper pipe F1 at two locations, and the member to be heated F2a may be disposed on the inner side of the copper pipe F1 between the two bent portions FW. In so doing, too, the movement of the member to be heated F2a can be hindered while the refrigerant is made to pass through.
    • (E)
  • The abovementioned embodiment explained a case wherein the coil 68 is helically wound around the accumulator pipe F.
  • However, the present invention is not limited thereto.
  • For example, as shown in FIG. 22 , coils 168, which are wound around bobbin main bodies 165, are disposed at the circumference of-without being wound around-the accumulator pipe F. Here, each of the bobbin main bodies 165 is disposed such that its axial directions are substantially perpendicular to the axial directions of the accumulator pipe F. In addition, the two pairs of the bobbin main bodies 165 and coils 168 are disposed such that they sandwich the accumulator pipe F.
  • In this case, for example, as shown in FIG. 23 , a first bobbin cover 163 and a second bobbin cover 164, wherethrough the accumulator pipe F is inserted, may be disposed in a state wherein they are mated to the bobbin main bodies 165.
  • Furthermore, as shown in FIG. 24 , the first bobbin cover 163 and the second bobbin cover 164 may be interposed by a first ferrite case 171 and a second ferrite case 172, and thereby fixed. FIG. 24 presents an exemplary case wherein two ferrite cases are disposed such that they sandwich the accumulator pipe F; however, as in the abovementioned embodiment, ferrite cases may be disposed in four directions. In addition, as in the abovementioned embodiment, the ferrite parts may be housed therein.
  • Furthermore, the shielding cover 175 may be provided such that it covers the outermost circumferential portion of the electromagnetic induction heating unit 6 fixed in this manner.
    • <Miscellaneous>
  • The above text explained embodiments of the present invention based on the drawings, but the specific constitution is not limited to these embodiments. For example, the present invention also includes combination embodiments obtained by, where appropriate, combining the abovementioned embodiments with portions other than those included in the embodiments discussed above within a range that a person skilled in the art could effect based on the scope of the invention described above.
    • INDUSTRIAL APPLICABILITY
  • Using the present invention is particularly effective in an electromagnetic induction heating unit and an air conditioner wherein, even if a refrigerant piping is heated by electromagnetic induction, it is possible to hinder the leakage of the magnetic field to the periphery while hindering the local generation of heat, and thereby the refrigerant can be heated using electromagnetic induction.
    • REFERENCE SIGNS LIST
    • 1
    Air conditioner
    6
    Electromagnetic induction heating unit
    10
    Refrigerant circuit
    14
    Thermistor
    15
    Fuse
    21
    Compressor
    22
    Four-way switching valve
    23
    Outdoor heat exchanger
    24
    Motor operated expansion valve
    25
    Accumulator
    41
    Indoor heat exchanger
    65
    Bobbin main body
    68
    Coil
    71-74
    First through fourth ferrite cases
    75
    Shielding cover
    98, 99
    First ferrite part, second ferrite part
    F
    Accumulator pipe, refrigerant piping
    CITATION LIST PATENT LITERATURE Patent Document 1
  • Japanese Unexamined Patent Application Publication No. H08-210720

Claims (8)

  1. An electromagnetic induction heating unit (6) that heats a refrigerant piping (F) or a material that thermally contacts a refrigerant that flows through the refrigerant piping (F), or both, comprising:
    a coil (68), which is disposed in the vicinity of the refrigerant piping (F);
    an external member (75), which is disposed around the refrigerant piping (F) and
    includes a magnetic body; and
    a magnetic part (98, 99) that is disposed on the outer side of the coil (68), which is the opposite side of the inner side, namely, the refrigerant piping (F) side, of the coil (68),
    and on the inner side of the external member (75, 175) and that contains a magnetic
    material whose magnetic permeability is higher than that of the external member; wherein,
    both end parts of the external member (75) in the directions in which the refrigerant piping (F) extends are positioned on the inner side of both end parts of the magnetic part (98, 99).
  2. An electromagnetic induction heating unit (6) according to claim 1, wherein
    the coil (68) is wound around at least part of the refrigerant piping (F).
  3. An electromagnetic induction heating unit (6) according to claim 1 or claim 2, wherein
    at least part of the magnetic part (98, 99) extends to at least one side selected from the group consisting of: one side of the coil (68) in directions in which the refrigerant piping (F) extends; and another side, which is the opposite side of the one side with respect to the coil (68).
  4. An electromagnetic induction heating unit (6) according to any one claim of claim 1 through claim 3, wherein
    at least part of the magnetic part (98, 99) extends to the inner side of the coil (68), which is the outer side of the refrigerant piping (F) when viewed from the axial directions of the refrigerant piping.
  5. An electromagnetic induction heating unit (6) according to any one claim of claim 1 through claim 4, wherein
    the magnetic part (98, 99) comprises a plurality of magnetic components (98, 99) disposed such that the magnetic components (98, 99) contact one another.
  6. An electromagnetic induction heating unit (6) according to any one claim of claim 1 through claim 5, wherein
    the magnetic part (98, 99) contains a material that is a good conductor.
  7. An electromagnetic induction heating unit (6) according to any one claim of claim 1 through claim 6, wherein
    the magnetic part (98, 99) contains ferrite.
  8. An air conditioner (1), comprising:
    an electromagnetic induction heating unit (6) according to any one claim of claim 1 through claim 7; and
    a refrigeration cycle (10) that includes a portion wherethrough a refrigerant flows to the refrigerant piping (F).
EP09837460A 2009-01-07 2009-12-25 Electromagnetic induction heating unit and air conditioning device Withdrawn EP2381740A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2009001931 2009-01-07
PCT/JP2009/007240 WO2010079570A1 (en) 2009-01-07 2009-12-25 Electromagnetic induction heating unit and air conditioning device

Publications (1)

Publication Number Publication Date
EP2381740A1 true EP2381740A1 (en) 2011-10-26

Family

ID=42316348

Family Applications (1)

Application Number Title Priority Date Filing Date
EP09837460A Withdrawn EP2381740A1 (en) 2009-01-07 2009-12-25 Electromagnetic induction heating unit and air conditioning device

Country Status (4)

Country Link
EP (1) EP2381740A1 (en)
JP (1) JP5267572B2 (en)
CN (1) CN102227951A (en)
WO (1) WO2010079570A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2988973A1 (en) * 2012-03-27 2013-10-04 Jean Serge Yves Herskovits Device for producing heat by electromagnetic induction in e.g. electric household appliance, has armature, where shape of part composing armature allows circulation of flux, and armature parts are manufactured out of magnetisable materials
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Publication number Priority date Publication date Assignee Title
FR2988973A1 (en) * 2012-03-27 2013-10-04 Jean Serge Yves Herskovits Device for producing heat by electromagnetic induction in e.g. electric household appliance, has armature, where shape of part composing armature allows circulation of flux, and armature parts are manufactured out of magnetisable materials
US10914503B2 (en) 2018-02-01 2021-02-09 Johnson Controls Technology Company Coil heating systems for heat pump systems

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WO2010079570A1 (en) 2010-07-15
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CN102227951A (en) 2011-10-26

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