JP2011002189A - Refrigerating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily perform a demounting work of an electromagnetic induction coil in a refrigerating device including an electromagnetic induction heating unit.SOLUTION: A return pipe 3F has a curved pipe part 3F2 curved between its inlet and outlet. Further the return pipe 3F has a straight pipe part 3F1 extending from an inlet of the curved pipe part 3F2, and a straight pipe part 3F1 extending from an outlet of the curved pipe part 3F2. On the other hand, the electromagnetic induction heating unit 6A has the electromagnetic induction coil 68 for heating the straight pipe parts 3F1, 3F3 by electromagnetic induction. The electromagnetic induction heating coil 68 is wound around the straight pipe parts 3F1, 3F3. The electromagnetic induction coil 68 is mounted separatably from the return pipe 3F by being pulled out from the side of the curved pipe part 3F2.

Description

  The present invention relates to a refrigeration apparatus that transfers heat by circulating a refrigerant, and particularly relates to a refrigeration apparatus that heats a circulating refrigerant by electromagnetic induction heating.

  The refrigeration apparatus includes a radiator that releases heat of the refrigerant in the refrigeration cycle, a heater that gives heat to the refrigerant, and the like. In a general vapor compression refrigeration cycle, for example, a refrigerant obtains heat by exchanging heat with indoor air in a heater provided indoors for cooling, and is provided outdoors for heating. In the heater, heat is exchanged with outdoor air to obtain heat.

  By the way, in Patent Document 1 (Japanese Patent Application Laid-Open No. 11-2111195), the refrigerant obtains heat by a petroleum refrigerant heater provided separately from a heater of a vapor compression refrigeration cycle that obtains heat from indoor or outdoor air. A system has been proposed. In this petroleum refrigerant heater, oil is burned and the refrigerant flowing in the petroleum refrigerant heater is heated. When a heating unit such as a petroleum refrigerant heater or a gas burner that receives energy supply other than the thermal energy of air in the atmosphere is used, restrictions such as indoor and outdoor temperature can be imposed when the refrigerant requires heat. It is possible to heat the refrigerant without receiving it. Further, as the heating unit, an electromagnetic induction heating system that receives supply of electrical energy can be adopted for heating the refrigerant. Thus, in a heating unit that receives an energy supply other than the thermal energy of the atmosphere, rapid heating is facilitated by increasing the amount of energy input.

  When a heating unit that heats by the electromagnetic induction heating method as described above is employed in a refrigeration apparatus, the refrigerant flowing in the pipe (refrigerant piping) must be heated. For example, Patent Document 2 (Japanese Patent Laid-Open No. 8-326997) The member heated by the electromagnetic induction heating must be heated in contact with the refrigerant to be heated as described in the above. When the refrigerant is heated, normally, the refrigerant pipe is heated because it is the inner surface of the refrigerant pipe that is in thermal contact with the refrigerant. Therefore, as described in the cited document 2, the electromagnetic induction coil of the electromagnetic induction heating unit is spirally wound around the refrigerant pipe.

  Since the electromagnetic induction coil is spirally wound around the refrigerant pipe, if you try to remove the electromagnetic induction coil of the electromagnetic induction heating unit from the refrigerant pipe for maintenance or other purposes, the braided refrigerant pipe It is necessary to remove the wax and disassemble the refrigerant piping. If such work is required during maintenance, the cost for maintaining the refrigeration apparatus will also increase.

  The subject of this invention is enabling it to perform the removal operation | work of an electromagnetic induction coil easily in a freezing apparatus provided with an electromagnetic induction heating unit.

A refrigeration apparatus according to a first aspect of the present invention includes a member that makes thermal contact with a refrigerant that flows through a predetermined refrigerant flow path, and an electromagnetic induction heating unit that heats the member. The predetermined refrigerant flow path has an inlet and an outlet for the refrigerant, and a curved portion that is curved between the inlet and the outlet, a first extending portion that extends from the inlet of the curved portion, and a second extending portion that extends from the outlet of the curved portion have. The member is disposed so as to transfer heat to the refrigerant passing through at least the first extending portion and the second extending portion. The electromagnetic induction heating unit has an electromagnetic induction coil that is wound around a member and heats the member by electromagnetic induction. The electromagnetic induction coil is attached so as to be separated from the predetermined refrigerant flow path by being pulled out from the curved portion .

  According to the present invention, the electromagnetic induction coil can be pulled out along the direction in which the first extending portion and the second extending portion extend to be separated from the predetermined refrigerant flow path. Can work. Thereby, it is possible to omit the work conventionally required for removing or attaching the electromagnetic induction coil from the continuous predetermined refrigerant flow path, that is, the work of disassembling the refrigerant pipes constituting the predetermined refrigerant flow path, Assembly of the electromagnetic induction heating unit at the time of manufacture and attachment / detachment of the electromagnetic induction coil at the time of maintenance become easy.

  The refrigeration apparatus according to the second invention is the refrigeration apparatus according to the first invention, wherein the member is a member to be heated provided separately from the refrigerant pipe and / or the refrigerant pipe.

  According to the present invention, when the refrigerant pipe itself is the member to be heated, it is not necessary to provide the member to be heated separately from the refrigerant pipe, so that the refrigeration apparatus can be easily designed in a compact manner. Further, since the refrigerant pipe itself is a member to be heated, the loss of heat transfer is reduced and the heating efficiency is improved. On the other hand, when a member to be heated provided separately from the refrigerant pipe is heated by electromagnetic induction, specifications such as corrosion resistance necessary for the refrigerant pipe, etc. are relaxed. Therefore, it is easy to improve performance related to electromagnetic induction heating such as heating efficiency.

A refrigeration apparatus according to a third aspect of the present invention is the refrigeration apparatus of the first aspect, wherein the member includes a cylindrical magnetic body around which an electromagnetic induction coil is wound. This magnetic body is attached so as to be separated from the predetermined refrigerant flow path by being pulled out from the curved portion together with the electromagnetic induction coil.

  According to the present invention, since the magnetic body is pulled out simultaneously with the electromagnetic induction coil, the maintenance work can be further facilitated.

  A refrigeration apparatus according to a fourth aspect of the present invention is the refrigeration apparatus according to any one of the first to third aspects of the present invention, wherein the member is disposed so as to transmit heat to the refrigerant passing through the curved portion.

According to the present invention, since the refrigerant is heated in the curved portion in addition to the first extending portion and the second extending portion, the region for heating the refrigerant can be expanded and the heating time of the refrigerant can be increased. Becomes easier.

  The refrigeration apparatus according to a fifth aspect of the present invention is the refrigeration apparatus according to any one of the first to fourth aspects of the present invention, wherein there are a plurality of electromagnetic induction coils and covers both the first extension part and the second extension part. And at least the inside of the region sandwiched between the first extending portion and the second extending portion.

  According to the present invention, when electromagnetic induction heating units housed in a space having the same volume are compared, the electromagnetic induction coil is disposed in a region sandwiched between the first extending portion and the second extending portion, thereby Since the density at which the induction coils are arranged increases, the electromagnetic induction heating unit can be made compact.

  The refrigeration apparatus according to a sixth aspect of the present invention is the refrigeration apparatus according to any one of the first to fifth aspects of the present invention, wherein the predetermined refrigerant flow path has a curved portion disposed below the second extending portion.

According to the present invention, the density of the liquid layer of the refrigerant is higher than that of the gas layer, and since the refrigerant flows upward from the first extending portion through the curved portion to the second extending portion, the liquid layer easily collects below. Since the thermal conductivity of the liquid layer accumulated underneath is high, the liquid layer is heated in the first extending portion and the heating efficiency is improved. Similarly, when the refrigerant flows upward from the second extending portion, the heating efficiency is also improved in the second extending portion.

  A refrigeration apparatus according to a seventh aspect is the refrigeration apparatus according to any one of the first to sixth aspects, wherein the predetermined refrigerant flow path includes a contact portion that is in thermal contact with the member, and the contact portion is a refrigerant It is arranged to be in thermal contact with the liquid layer.

  According to the present invention, since the contact portion that is in thermal contact with the member heated by electromagnetic induction heating is in thermal contact with the liquid layer of the refrigerant, the liquid layer of the refrigerant having high thermal conductivity can be efficiently heated. Can do.

  In the refrigeration apparatus according to the first invention, the electromagnetic induction coil is easily separated from the predetermined refrigerant flow path for maintenance and attached after the maintenance, so that maintainability is improved, so that the manufacturing cost and the cost for maintenance are improved. Can be reduced.

  In the refrigeration apparatus according to the second invention, the design of a high-performance refrigeration apparatus is facilitated.

  In the refrigeration apparatus according to the third aspect of the invention, the maintenance work can be performed more easily, and the apparatus can be easily maintained.

  In the refrigeration apparatus according to the fourth aspect of the invention, it is easy to heat the refrigerant, and it is easy to design the apparatus in a compact manner.

  In the refrigeration apparatus according to the fifth aspect of the invention, an apparatus having the same heating performance can be reduced in size.

  In the refrigeration apparatus according to the sixth aspect of the invention, it is easy to improve the heating efficiency and reduce the ratio of the liquid refrigerant after heating. Thereby, it becomes easy to prevent problems, such as a liquid back | bag, for example.

In the refrigeration apparatus according to the seventh aspect of the invention, the heating efficiency can be improved.

Schematic which shows the refrigerant circuit which comprises the freezing apparatus of 1st Embodiment. The perspective view for demonstrating the concept which concerns on an example of an electromagnetic induction heating unit. The perspective view which shows an example of the external appearance of an electromagnetic induction heating unit. Sectional drawing of the electromagnetic induction heating unit of FIG. The conceptual diagram which shows the electric power supply to an electromagnetic induction heating unit. The block diagram for demonstrating the structure of the control part of a refrigerant circuit. The conceptual diagram which shows the electromagnetic induction heating unit periphery of the freezing apparatus of 2nd Embodiment. The conceptual diagram which shows the electromagnetic induction heating unit periphery of the freezing apparatus of 3rd Embodiment. The conceptual diagram which shows the electromagnetic induction heating unit periphery of the freezing apparatus of 4th Embodiment. The conceptual diagram which shows the electromagnetic induction heating unit periphery of the freezing apparatus of 4th Embodiment. The conceptual diagram which shows the electromagnetic induction heating unit periphery of the freezing apparatus of 5th Embodiment. The conceptual diagram which shows the electromagnetic induction heating unit periphery of the modification of 2nd Embodiment. (A) The conceptual diagram which shows the electromagnetic induction heating unit periphery of the modification of 2nd Embodiment. (B) 13 a perspective view showing another example of mating members 102 of (a). The conceptual diagram which shows the modification electromagnetic induction heating unit periphery of 5th Embodiment. The conceptual diagram which shows the modification electromagnetic induction heating unit periphery of 1st Embodiment.

[First Embodiment]
[Outline of air conditioner]
The outline of the configuration of the air-conditioning apparatus according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a refrigerant circuit diagram showing a refrigerant circuit 10 of the air conditioner 1. The air conditioner 1 includes a refrigerant circuit 10 in which an outdoor unit 2 and an indoor unit 4 are connected by a refrigerant pipe, and the heat energy supplied from the outdoor unit 2 of the heat source side device is used for the utilization side device. Air conditioning of the space where the indoor unit 4 is arranged is performed.

The air conditioner 1 includes a compressor 21, a four-way switching valve 22, an outdoor heat exchanger 23, an outdoor electric expansion valve 24, an accumulator 25, an outdoor fan 26, a hot gas bypass valve 27, which are accommodated in the outdoor unit 2. Various devices such as the capillary tube 28 and the electromagnetic induction heating unit 6 </ b> A , the indoor heat exchanger 41 and the indoor fan 42 housed in the indoor unit 4 are provided.

  The compressor 21 is rotationally driven by a compressor motor (not shown). Electric power is supplied to the compressor motor from a commercial power supply via an inverter. In that case, it converts into alternating current of a desired frequency from a commercial power source with an inverter. The compressor 21 is configured such that the rotational speed of the compressor motor is changed by changing the frequency of the alternating current to be supplied, whereby the discharge amount of the compressor 21 is changed.

  In the air conditioner 1 of FIG. 1, in order to connect the various devices described above, the discharge pipe 3A, the indoor side gas pipe 3B, the indoor side liquid pipe 3C, the outdoor side liquid pipe 3D, the outdoor side gas pipe 3E, and the return pipe The refrigerant circuit 10 includes 3F, a suction pipe 3G, and a hot gas bypass circuit 3H. Among these pipes through which the refrigerant passes, the indoor side gas pipe 3B and the outdoor side gas pipe 3E pass a large amount of gas refrigerant in the gas state, but the refrigerant passing therethrough is not limited to the gas refrigerant. Further, the indoor liquid pipe 3C and the outdoor liquid pipe 3D pass a lot of liquid refrigerant in the liquid state, but the refrigerant passing therethrough is not limited to the liquid refrigerant.

  Connection of each device of the refrigerant circuit 10 using the above-described piping will be described. The discharge pipe 3 </ b> A connects the discharge port of the compressor 21 and the first port of the four-way switching valve 22. The indoor side gas pipe 3 </ b> B connects the second port of the four-way switching valve 22 and one end of the indoor heat exchanger 41. The indoor side liquid pipe 3 </ b> C connects the other end of the indoor heat exchanger 41 and one end of the outdoor electric expansion valve 24. The outdoor liquid pipe 3D connects the other end of the outdoor electric expansion valve 24 and one end of the outdoor heat exchanger 23. The outdoor gas pipe 3E connects the other end of the outdoor heat exchanger 23 and the third port of the four-way switching valve 22. The return pipe 3F connects the fourth port of the four-way switching valve 22 and the inlet of the accumulator 25. The suction pipe 3G connects the outlet of the accumulator 25 and the suction port of the compressor 21. The hot gas bypass circuit 3H connects a branch point A1 provided in the middle of the discharge pipe 3A and a branch point D1 provided in the middle of the outdoor liquid pipe 3D. In the hot gas bypass circuit 3H, a hot gas bypass valve 27 for switching between a state where the refrigerant is allowed to pass and a state where the refrigerant is not allowed is disposed in the middle of the hot gas bypass circuit 3H.

The return pipe 3F includes a straight pipe part 3F1, a U-shaped curved pipe part 3F2 following the straight pipe part 3F1, and a straight pipe part 3F3 following the curved pipe part 3F2. An electromagnetic induction heating unit 6A is attached to the straight pipe portions 3F1 and 3F3. Further, a return pipe temperature sensor 39 is attached to the straight pipe portion 3F3 on the downstream side of the electromagnetic induction heating unit 6A .

The air conditioner 1 can switch between a cooling operation cycle and a heating operation cycle by the four-way switching valve 22. In FIG. 1, the connection state when performing the heating operation is indicated by a solid line, and the connection state when performing the cooling operation is indicated by a dotted line. That is, during the heating operation, the refrigerant passes between the second port and the second port of the four-way switching valve 22 and between the third port and the fourth port, and the indoor heat exchanger 41 serves as a refrigerant cooler (condenser). The outdoor heat exchanger 23 functions as a refrigerant heater (evaporator). On the other hand, during the cooling operation, the refrigerant passes between the first port and the third port of the four-way switching valve 22 and between the second port and the fourth port, and the outdoor heat exchanger 23 is a refrigerant cooler (condenser). The indoor heat exchanger 41 functions as a refrigerant heater (evaporator).
The air conditioner 1 includes a control unit 11 for performing the control. The control unit 11 includes an outdoor control unit 12 and an indoor control unit 13 connected by a communication line 11a. The outdoor control unit 12 controls devices disposed in the outdoor unit 2, and the indoor control unit 13 Controls the equipment arranged in the machine 4. A control system including the control unit 11 will be described later.

[Configuration of electromagnetic induction heating unit]
FIG. 2 is a conceptual diagram for explaining the configuration of the electromagnetic induction heating unit. FIG. 2 shows the configuration of the electromagnetic induction heating unit 6A and the return pipe 3F around it. Magnetic bodies Co1 and Co2 are attached to the outer periphery of the straight pipe portions 3F1 and 3F3 of the return pipe 3F. The straight pipe portions 3F1 and 3F3 of the return pipe 3F to which the electromagnetic induction heating unit 6A is attached are made of, for example, copper pipes, and the magnetic bodies Co1 and Co2 are made of SUS (Stainless Used Steel) pipes. ing. That is, it has a double tube structure in which a copper tube is expanded and combined in a SUS tube. The magnetic SUS tube is formed of, for example, ferritic stainless steel or martensitic stainless steel.

The electromagnetic induction coil 68 of the electromagnetic induction heating unit 6A is wound around the two straight pipe portions 3F1 and 3F3 and disposed so as to cover the portions of the magnetic bodies Co1 and Co2 from the outside in the radial direction. In the magnetic bodies Co1 and Co2, magnetic flux concentrates in the electromagnetic induction heating, so that an eddy current is generated so as to wrap the magnetic flux passing through the magnetic bodies Co1 and Co2, and the magnetic bodies Co1 and Co2 generate heat. Since there are no members through which current flows outside the magnetic bodies Co1 and Co2, the magnetic bodies Co1 and Co2 are heated members. Here, the member to be heated refers to a member that is directly heated by a current flowing by electromagnetic induction. At this time, the heating amount P (W) is given by P = RI ² by the eddy current I (A) and the resistance values R (Ω) of the magnetic bodies Co1 and Co2 themselves. The electric power necessary for this is supplied from the high frequency power source So to the electromagnetic induction coil 68.

  As can be seen from FIG. 2, since the return pipe 3F has a U-shaped curved pipe part 3F2, the electromagnetic induction coil 68 can be inserted and removed in the direction of the arrow Dir. Therefore, when the electromagnetic induction coil 68 of the electromagnetic induction heating unit 6A is assembled to the air conditioner 1 or removed during maintenance, the brazed portion is removed and the return pipe 3F is not disassembled, and the continuous refrigerant pipe is used. It can be separated from a certain return pipe 3F.

  Here, the configuration of the electromagnetic induction heating unit 6A will be described more specifically in order to make it easier to perceive the improvement effect of the installation and maintenance work of the electromagnetic induction heating unit 6A. FIG. 3 is a perspective view showing the appearance of the electromagnetic induction heating unit, and FIG. 4 is a cross-sectional view showing the configuration of the electromagnetic induction heating unit.

  The electromagnetic induction heating unit 6A includes a first hexagon nut 61, a second hexagon nut 66, a first bobbin lid 63, a second bobbin lid 64, a bobbin main body 65, a first ferrite case 71, a second ferrite case 72, and a third ferrite. A case 73, a fourth ferrite case 74, a first ferrite 98, a second ferrite 99, an electromagnetic induction coil 68, a shielding cover 75, a thermistor (not shown) and a fuse (not shown) are provided. The first hexagon nut 61 is made of resin, and fixes the electromagnetic induction heating unit 6A to the straight pipe portions 3F1 and 3F3 in the vicinity of the upper end of the electromagnetic induction heating unit 6A. The second hexagon nut 66 is made of resin, and fixes the electromagnetic induction heating unit 6A to the straight pipe portions 3F1 and 3F3 in the vicinity of the lower end of the electromagnetic induction heating unit 6A.

  The first bobbin lid 63 is made of resin and is one of members that determine the relative positions of the straight pipe portions 3F1 and 3F3 and the electromagnetic induction coil 68 in the electromagnetic induction heating unit 6A, and is located above the electromagnetic induction heating unit 6A. The magnetic bodies Co1 and Co2 which are SUS tubes are covered from the periphery. The second bobbin lid 64 is made of resin and has the same shape as the first bobbin lid 63, and covers the magnetic bodies Co1 and Co2 that are SUS tubes from the periphery below the electromagnetic induction heating unit 6A.

  The first bobbin lid 63 is a tubular portion for piping for fixing the straight pipe portions 3F1, 3F3 and the electromagnetic induction heating unit 6A in cooperation with the first hexagon nut 61 while penetrating the straight pipe portions 3F1, 3F3. 63c. The first bobbin lid 63 has a substantially T-shaped hook-shaped portion 63a formed inwardly from the outer peripheral portion in order to hold the coil first portion 68b and the coil second portion 68c while passing therethrough. Yes. The first bobbin lid 63 has a plurality of heat radiation openings 63b penetrating in the vertical direction in order to release heat accumulated between the bobbin main body 65 and the magnetic bodies Co1 and Co2 to the outside.

  First to fourth ferrite cases 71 to 74 are screwed to the first bobbin lid 63 with screws 69. A thermistor and a fuse can be inserted from the first bobbin lid 63. The thermistor is attached so as to be in direct contact with the outer surfaces of the magnetic bodies Co1 and Co2, and exhibits a resistance value according to the temperature of the outer surfaces of the magnetic bodies Co1 and Co2. The fuse is attached so as to be in direct contact with the outer surfaces of the magnetic bodies Co1 and Co2, and when the surface temperature of the magnetic bodies Co1 and Co2 exceeds a predetermined value, the conduction is interrupted to stop electromagnetic induction heating.

  On the lower surface side of the first bobbin lid 63, a bobbin cylinder upper portion 63g that fits the bobbin main body 65 by being located inside the upper end cylindrical portion of the bobbin main body 65 extends downward. The bobbin cylinder upper portion 63g is formed to extend in a penetrating direction from a portion along the outer edge of each opening so as not to close a penetrating state of a necessary opening such as the heat radiation opening 63b described above.

  Note that the opening and shape of the first bobbin lid 63 are the same for the second bobbin lid 64, and each member number of the 63rd series in the first bobbin lid 63 is the same as that of the 64th series in the second bobbin lid 64. It shows corresponding to each member number, and the description is omitted.

  As shown in FIG. 3, the bobbin main body 65 has a cylindrical portion 65 a around which the electromagnetic induction coil 68 is wound. The bobbin main body 65 has a first winding stop 65s formed to protrude in the radial direction at a portion slightly lowered from the upper end, and a second winding formed to protrude in the radial direction at a portion slightly raised from the lower end. And a stop portion 65t. The first winding stop 65s has a coil holding groove (not shown) formed inward in the radial direction so as to sandwich the first coil portion 68b, and a recess in the radial direction in order to sandwich the second coil portion 68c. It has a formed coil holding groove (not shown). Inside the bobbin main body 65, a space is formed between the magnetic bodies Co1 and Co2.

  A coil winding portion 68a (see FIG. 4) of the electromagnetic induction coil 68 is spirally wound on the outside of the bobbin main body 65 with the straight tube portion 3F1 extending in the axial direction. The coil first portion 68b extends to one end side of the electromagnetic induction coil 68 with respect to the coil winding portion 68a, and the coil second portion 68c extends to the other end side opposite to the one end side of the electromagnetic induction coil 68. .

  The coil first portion 68b and the coil second portion 68c are connected to the control printed board 18 as shown in FIG. The control printed circuit board 18 is supplied from a high frequency power source having a frequency of about several tens of kHz and an output of about several kW, for example. The electromagnetic induction coil 68 is supplied with a high-frequency current from the control printed circuit board 18. The control printed circuit board 18 is controlled by the control unit 11.

  The first ferrite case 71, the second ferrite case 72, the third ferrite case 73, and the fourth ferrite case 74 are arranged at positions that cover the four outer sides in a plan view and along the direction in which the magnetic bodies Co1 and Co2 extend. The first bobbin lid 63 and the second bobbin lid 64 are sandwiched in the extending direction of the magnetic bodies Co1 and Co2. The first ferrite case 71 has a portion for accommodating the first ferrite 98 and the second ferrite 99. The second ferrite case 72, the third ferrite case 73, and the fourth ferrite case 74 are the same as the first ferrite case 71.

The electromagnetic induction coil 68 is located inside the first to fourth ferrite cases 71 to 74. The first ferrite 98 of the first to fourth ferrite cases 71 to 74 forms a path of magnetic flux by ferrite that is a material having high magnetic permeability, and when a current is passed through the electromagnetic induction coil 68, the magnetic substance The magnetic flux passing through Co1 and Co2 and the outside of the electromagnetic induction coil 68 is concentrated. In particular, the first ferrite 98 is accommodated in the accommodating portions of the first to fourth ferrite cases 71 to 74 near the upper end and the lower end of the electromagnetic induction heating unit 6. The second ferrite 99 is also the same as the first ferrite 98 except for the arrangement position and shape, and is arranged at a position near the outside of the bobbin main body 65 in the accommodating portion of the first to fourth ferrite cases 71 to 74. . In the electromagnetic induction heating unit 6A, since the first ferrite 98 and the second ferrite 99 are provided outside the electromagnetic induction coil 68, most of the magnetic flux that flows around the outside of the electromagnetic induction coil 68 flows . Has been able to.

  When the electromagnetic induction coil 68 is supplied with a high-frequency current from the control printed circuit board 18, a magnetic flux is generated at the coil winding portion 68a. Specifically, most of the magnetic flux passes through the magnetic bodies Co1 and Co2 which are ferromagnetic materials inside the coil winding portion 68a, and most of the magnetic flux passes through the first magnetic material Co1 and Co2 which are ferromagnetic materials. It passes through the ferrite 98, the second ferrite 99 and the shielding cover 75. The magnetic flux that leaves the magnetic bodies Co1 and Co2, passes through the first ferrite 98, the second ferrite 99, and the shielding cover 75 and returns to the magnetic bodies Co1 and Co2 again. The magnetic bodies Co1 and Co2, the first ferrite 98, and the shielding cover 75 Passes through close air. For example, when viewed in a cross section including the first ferrite case 71 and the third ferrite case 73 as shown in FIG. 3, the magnetic flux that has spread out from the magnetic bodies Co1 and Co2 to the left and right crosses the air first. The first ferrite 98 on the lid 63 side enters, passes from the first ferrite 98 through the second ferrite 99, and exits from the first ferrite 98 on the second bobbin lid 64 side into the air. Most of the magnetic flux emitted from the first ferrite 98 on the second bobbin lid 64 side into the air again passes through the magnetic bodies Co1 and Co2 toward the first bobbin lid 63. The magnetic flux closed so that it may become substantially elliptical shape in the plane of FIG. 3 arises. Due to the magnetic flux generated in this way, currents (eddy currents) due to electromagnetic induction are generated in the magnetic bodies Co1 and Co2, and a large amount of heat is generated near the surfaces of the magnetic bodies Co1 and Co2, and the magnetic body Co1 having high thermal conductivity. , Co2 transfers heat to the refrigerant flowing in the copper tube 3Fb1.

  The shielding cover 75 is disposed on the outermost peripheral portion of the electromagnetic induction heating unit 6A, and collects magnetic flux that cannot be drawn only by the first ferrite 98 and the second ferrite 99. As shown in FIG. 2, the shielding cover 75 is fixed by being screwed to the first ferrite case 71 via screws 70a, 70b, 70c, and 70d. Thereby, in the electromagnetic induction heating unit 6A, almost no leakage magnetic flux is generated outside the shielding cover 75, and the influence of magnetism on the surroundings can be prevented.

[Control system]
FIG. 5 is a block diagram for explaining the outline of the configuration of the control system. The outdoor control unit 12 and the indoor control unit 13 of the control unit 11 are connected by a communication line 11a (see FIG. 1) and transmit / receive data to / from each other. The outdoor control unit 12 and the indoor control unit 13 receive the detection results of various sensors, and the devices that configure the outdoor unit 2 and the indoor unit 4 according to the state of the air conditioner 1 and the surrounding conditions and setting conditions. In order to output various commands, a microcomputer (not shown) and a memory (not shown) are incorporated.

  The outdoor control unit 12 of the control unit 11 includes a suction side pressure sensor 31, a discharge side pressure sensor 32, a suction side temperature sensor 33, a discharge side temperature sensor 34, a heat exchange temperature sensor 35, a liquid side temperature sensor 36, and an outdoor temperature sensor. Various sensors such as 37 and the return pipe temperature sensor 39 are connected, and the detection result of each sensor is input.

  The suction side pressure sensor 31 detects the pressure of the refrigerant on the suction side of the compressor 21. The discharge side pressure sensor 32 detects the pressure of the refrigerant on the discharge side of the compressor 21. The suction side temperature sensor 33 detects the temperature of the refrigerant on the suction side of the compressor 21. The discharge side temperature sensor 34 detects the temperature of the refrigerant on the discharge side of the compressor 21. The heat exchanger temperature sensor 35 detects the temperature of the refrigerant flowing in the outdoor heat exchanger 23. The liquid side temperature sensor 36 is located between the outdoor heat exchanger 23 and the outdoor electric expansion valve 24 and detects the temperature of the refrigerant on the liquid side of the outdoor heat exchanger 23. The outdoor temperature sensor 37 is provided on the inlet side of the unit of the outdoor unit 2 and detects the temperature of the outside air that has flowed into the unit. The return pipe temperature sensor 39 is provided on the downstream side of the electromagnetic induction heating unit 6A of the straight pipe portion 3F3, and detects the temperature of the refrigerant in the straight pipe portion 3F3.

The outdoor control unit 12 is connected to devices such as the control printed circuit board 18, the compressor 21, the four-way switching valve 22, the outdoor electric expansion valve 24, and the outdoor fan 26, or control terminals for the devices. Various devices operate under the control of the outdoor control unit 12.

A signal instructing the output of the electromagnetic induction heating unit 6A is given from the outdoor control unit 12 to the control printed circuit board 18, and is supplied from the control printed circuit board 18 to the electromagnetic induction coil 68 in accordance with an instruction from the outdoor control unit 12. The high frequency current increases or decreases. Thereby, the eddy current generated in the magnetic bodies Co1 and Co2 is increased and decreased, and the heating amount of the refrigerant flowing through the straight pipe portions 3F1 and 3F3 is controlled. At this time, it is not necessary to make the length of the section heated by the electromagnetic induction heating unit 6A in the straight pipe portions 3F1 and 3F3 the same. For example, since the refrigerant passing through the downstream straight pipe portion 3F1 is less likely to be heated because the ratio of the gas refrigerant is increased, the heating section of the electromagnetic induction heating unit 6A can be set longer.

  The outdoor control unit 12 is provided with an inverter circuit (not shown), and the rotational speeds of the compressor 21 and the outdoor fan 26 are controlled by the output frequency of the inverter circuit. The four-way switching valve 22 has a drive unit, and the outdoor control unit 12 is connected to the drive unit of the four-way switching valve 22 when switching the connection of the four-way switching valve 22 in switching between heating operation and cooling operation. To output a switching command. Further, the outdoor control unit 12 outputs a control signal instructing the opening degree in order to adjust the opening degree of the outdoor electric expansion valve 24.

  A liquid side temperature sensor 43, a gas side temperature sensor 44, and a room temperature sensor 45 are connected to the indoor control unit 13, and the detection results of each sensor are input. The liquid side temperature sensor 43 is provided on the other end side of the indoor heat exchanger 41 and detects the temperature of the refrigerant on the liquid side of the indoor heat exchanger 41. The gas side temperature sensor 44 is provided on one end side of the indoor heat exchanger 41 and detects the temperature of the refrigerant on the gas side of the indoor heat exchanger 41. The indoor temperature sensor 45 is provided on the inlet side of the unit of the indoor unit 4 and detects the temperature of the indoor air flowing into the unit.

  The indoor control unit 13 is connected with an indoor fan 42, a wind direction adjusting mechanism 46, a display unit 47, and the like, and various devices of the indoor unit 4 operate under the control of the indoor control unit 13. The indoor control unit 13 is provided with an inverter circuit (not shown), and the rotation speed of the indoor fan 42 is controlled by the frequency of the output of the inverter circuit. Since the air direction adjusting mechanism 46 adjusts the direction of the wind blown into the room by changing the angle of a louver (not shown) provided in the indoor unit 4, the indoor control unit 13 controls the angle and operation of the louver. Output a signal. The indoor control unit 13 outputs a signal instructing display to the display unit 47 to perform various displays. For example, the state of the electromagnetic induction heating unit 6A can be displayed on the display unit 47.

[Overview of refrigerant circuit operation]
(Heating operation)
During the heating operation, the four-way switching valve 22 is in the state indicated by the solid line in FIG. That is, the refrigerant discharged from the discharge side of the compressor 21 sequentially passes through the four-way switching valve 22, the indoor heat exchanger 41, the outdoor electric expansion valve 24, the outdoor heat exchanger 23, the four-way switching valve 22, and the accumulator 25. Around, it is sucked from the suction side of the compressor 21. At this time, the refrigerant passing through the return pipe 3F is heated by the electromagnetic induction heating unit 6A in the straight pipe portions 3F1 and 3F3. The refrigerant circulating through the refrigerant circuit 10 is, for example, carbon dioxide, HFC, HCFC, or the like.

  First, the high-temperature and high-pressure gas refrigerant compressed by the compressor 21 is sent to the indoor heat exchanger 41 via the four-way switching valve 22. At this time, the pressure of the refrigerant sucked by the suction side pressure sensor 31 is detected on the suction side of the compressor 21, and the pressure of the refrigerant discharged by the discharge side pressure sensor 32 is detected on the discharge side. At the same time, the temperature of the refrigerant sucked by the suction side temperature sensor 33 is detected on the suction side of the compressor 21, and the temperature of the refrigerant discharged by the discharge side temperature sensor 34 is detected on the discharge side.

  In order to perform efficient heating, the rotation speed of the compressor 21 is obtained, for example, by calculating the difference between the set temperature by the remote controller and the room temperature as a heating load, or the temperature of the refrigerant discharged from the compressor 21 and the room heat exchange. The heating load is obtained by using the temperature of the refrigerant in the vessel 41 and the like, and is controlled according to the heating load. In order to prevent failure of the air conditioner 1 and the like, based on the detection results of the suction side pressure sensor 31 and the discharge side pressure sensor 32, the pressure of the refrigerant sucked into the compressor 21 is higher than a predetermined low pressure, and the compressor The pressure of the refrigerant discharged from 21 is controlled to fall within a range lower than a predetermined high pressure. When the pressure exceeds the predetermined high pressure, the rotation speed of the compressor 21 is decreased and the discharge pressure of the compressor 21 is decreased. For the same reason, the temperature of the refrigerant discharged from the compressor 21 is monitored by the discharge side temperature sensor 34 so as not to be higher than a predetermined high temperature. Since the temperature and pressure must be sufficiently managed as described above, it is efficient that the above-described pressure and temperature can be easily controlled by heating with high accuracy and stability by the electromagnetic induction heating unit 6A. This has a positive effect on the prevention of heating and failure of the air conditioner 1. In particular, at the start of operation, since the temperature rise mainly due to the heating amount of the electromagnetic induction heating unit 6A, the electromagnetic induction heating unit 6A is used which has a fast response speed, is stable, and can control the heating amount with high accuracy. And is advantageous.

  Before entering the indoor heat exchanger 41, the gas side temperature sensor 44 detects the inlet temperature of the high-temperature and high-pressure gas refrigerant discharged from the compressor 21. And the heat exchange between a refrigerant | coolant and room air is performed in the indoor heat exchanger 41, and a refrigerant | coolant is cooled. For example, when the refrigerant is HFC or the like, the state changes from a gas refrigerant to a gas-liquid two-phase state or a liquid refrigerant. At this time, the indoor heat exchanger 41 functions as a condenser, and the state of heat exchange of the refrigerant in the indoor heat exchanger 41 is changed by controlling the rotation speed of the indoor fan 42. The temperature of the refrigerant leaving the indoor heat exchanger 41 is detected by the liquid side temperature sensor 43.

  The refrigerant leaving the indoor heat exchanger 41 is decompressed by the outdoor electric expansion valve 24. The opening degree of the outdoor electric expansion valve 24 is adjusted according to the heating load, and the opening degree of the outdoor electric expansion valve 24 is adjusted so that the decompressed refrigerant has a predetermined degree of superheat. The degree of superheat of the refrigerant is, for example, a difference between the temperature of the refrigerant in the outdoor heat exchanger 23 detected by the heat exchange temperature sensor 35 and the temperature of the refrigerant sucked into the compressor 21 detected by the suction side temperature sensor 33. Based on.

  The refrigerant that has been decompressed by the outdoor electric expansion valve 24 and is in a gas-liquid two-phase state is sent to the outdoor heat exchanger 23. In the outdoor heat exchanger 23, the refrigerant is heated by heat exchange with the outdoor air to become a gas refrigerant. At this time, the outdoor heat exchanger 23 functions as an evaporator, and an outdoor air flow is generated by the outdoor fan 26 to promote heat exchange between the outdoor air and the refrigerant. Are controlled so that heat exchange can be performed so that the COP becomes high.

  In the outdoor heat exchanger 23, frost formation may occur when the evaporation temperature of the refrigerant becomes 0 ° C. or less. Therefore, the inflow refrigerant temperature of the outdoor heat exchanger 23 detected by the liquid side temperature sensor 36 and the outdoor temperature sensor 37 The presence or absence of frost formation is determined based on the outside temperature. If there is frost, the efficiency of heat exchange is reduced, leading to an increase in power consumption and a decrease in comfort. Therefore, when there is frost, a defrosting operation is performed.

  The gas refrigerant evaporated in the outdoor heat exchanger 23 is sent to the accumulator 25 via the four-way switching valve 22. In the return pipe 3F before the accumulator 25 enters, the refrigerant sequentially passes through the straight pipe part 3F1, the curved pipe part 3F2, and the straight pipe part 3F3. The refrigerant heated by the electromagnetic induction heating unit 6A in the straight pipe portion 3F1 is stirred by the curved pipe portion 3F2 because the density of the gas refrigerant is small and the density of the liquid refrigerant is high, and further, the refrigerant is heated by the electromagnetic induction heating unit 6A in the straight pipe portion 3F3. Heated. Therefore, it is possible to avoid the concentration of the gas refrigerant in the portion of the straight pipe portion 3F3 that receives heat transfer from the inner surface of the pipe, and it is possible to prevent the heating efficiency in the straight pipe portion 3F3 from being significantly reduced compared to the straight pipe portion 3F1. it can. The temperature of the refrigerant after being heated by the electromagnetic induction heating unit 6A is detected by a return pipe temperature sensor 39. The control of the heating amount in the electromagnetic induction heating unit 6A is feedback-controlled by the output of the electromagnetic induction heating unit 6A so that the temperature detected by the return pipe temperature sensor 39 becomes the target temperature. For example, the control unit 11 stores in advance the optimum combination of heating amounts of the electromagnetic induction heating unit 6A for the refrigerant circulation amount, the detection temperature of the return pipe temperature sensor 39, and the target temperature, thereby reducing energy consumption. Heating can be performed.

  The refrigerant flowing through the return pipe 3F and flowing into the accumulator 25 is gas-liquid separated in the accumulator 25, so that the liquid refrigerant does not return to the compressor 21. Thereby, liquid compression occurs in the compressor 21 and the compressor 21 is prevented from malfunctioning.

(Cooling operation)
During the cooling operation, the four-way switching valve 22 is in the state indicated by the dotted line in FIG. That is, the refrigerant discharged from the discharge side of the compressor 21 sequentially passes through the four-way switching valve 22, the outdoor heat exchanger 23, the outdoor electric expansion valve 24, the indoor heat exchanger 41, the four-way switching valve 22, and the accumulator 25. Around, it is sucked from the suction side of the compressor 21.

  In the case of cooling operation, the outdoor heat exchanger 23 functions as a condenser, and the indoor heat exchanger 41 functions as an evaporator. As described above, in the cooling operation, the functions of the outdoor heat exchanger 23 and the indoor heat exchanger 41 are switched with respect to the heating operation.

  First, the high-temperature and high-pressure gas refrigerant compressed by the compressor 21 is sent to the outdoor heat exchanger 23 via the four-way switching valve 22. At this time, the pressure of the refrigerant sucked by the suction side pressure sensor 31 is detected on the suction side of the compressor 21, and the pressure of the refrigerant discharged by the discharge side pressure sensor 32 is detected on the discharge side. At the same time, the temperature of the refrigerant sucked by the suction side temperature sensor 33 is detected on the suction side of the compressor 21, and the temperature of the refrigerant discharged by the discharge side temperature sensor 34 is detected on the discharge side.

  For example, the difference between the set temperature by the remote controller or the like and the room temperature is obtained as the cooling load, or the cooling load is obtained by using the temperature of the refrigerant discharged from the compressor 21 and the temperature of the refrigerant in the outdoor heat exchanger 23. The rotational speed of the compressor 21 is controlled according to the cooling load. Moreover, in order to prevent the failure of the air conditioner 1, the pressure and temperature of the refrigerant discharged from the compressor 21 are limited as in the heating operation.

  In the outdoor heat exchanger 23, heat exchange between the refrigerant and the outdoor air is performed to cool the refrigerant. For example, when the refrigerant is HFC, the state changes from a gas refrigerant to a gas-liquid two-phase state or a liquid refrigerant. At this time, the temperature of the refrigerant flowing inside the outdoor heat exchanger 23 is detected by the heat exchange temperature sensor 35. Further, by controlling the rotation speed of the outdoor fan 26, the state of heat exchange of the refrigerant in the outdoor heat exchanger 23 changes. Then, the temperature of the refrigerant sent from the outdoor heat exchanger 23 to the outdoor electric expansion valve 24 is detected by the liquid side temperature sensor 36.

  The refrigerant sent from the outdoor heat exchanger 23 is decompressed by the outdoor electric expansion valve 24. At this time, the opening degree of the outdoor electric expansion valve 24 is adjusted according to the cooling load, and the opening degree of the outdoor electric expansion valve 24 is adjusted so that the decompressed refrigerant has a predetermined degree of superheat. The degree of superheat of the refrigerant is, for example, a difference between the temperature of the refrigerant in the outdoor heat exchanger 23 detected by the heat exchange temperature sensor 35 and the temperature of the refrigerant sucked into the compressor 21 detected by the suction side temperature sensor 33. Based on.

  The refrigerant that has been decompressed by the outdoor electric expansion valve 24 and is in a gas-liquid two-phase state is sent to the indoor heat exchanger 41. In the indoor heat exchanger 41, the refrigerant is heated by heat exchange with room air to become a gas refrigerant. Indoor air flow is generated by the indoor fan 42 to promote heat exchange between the indoor air and the refrigerant.

  The gas refrigerant evaporated in the indoor heat exchanger 41 is sent to the accumulator 25 via the four-way switching valve 22. And, in the return pipe 3F before the accumulator 25 enters, the electromagnetic induction heating unit 6A is heated in the same manner as in the heating operation. The refrigerant flowing through the return pipe 3F and flowing into the accumulator 25 is gas-liquid separated in the accumulator 25, so that the liquid refrigerant does not return to the compressor 21. Thereby, liquid compression occurs in the compressor 21 and the compressor 21 is prevented from malfunctioning.

  In cooling, since operation is performed to release heat to the outside, it is not necessary to supply heat for air conditioning from the electromagnetic induction heating unit 6. However, there is a scene where accurate and stable heating is required in order to prevent liquid back and ensure the amount of refrigerant circulation for the purpose of preventing failure of the air conditioner 1.

(Defrosting operation)
During the heating operation, when the outside air temperature decreases, the outdoor heat exchanger 23 may be frosted. When the outdoor heat exchanger 23 is frosted, the efficiency of heat exchange in the outdoor heat exchanger 23 is reduced, so that a defrosting operation is necessary. Therefore, during the heating operation, for example, when the temperature of the outdoor heat exchanger 23 is detected by the heat exchange temperature sensor 35 and it is determined that the detected temperature is equal to or lower than the predetermined temperature and frost formation occurs, Switch from heating operation to defrosting operation.

  In a refrigeration apparatus that does not have a heating unit, for example, the outdoor heat exchanger 23 functions as a condenser, and high-temperature and high-pressure gas refrigerant is supplied from the compressor 21 to the outdoor heat exchanger 23 to heat the outdoor heat exchanger 23. To defrost. Similarly, when the heating unit is provided, the four-way switching valve 22 is switched so that the outdoor heat exchanger 23 functions as a condenser, and the indoor heat exchanger 41 uses the electromagnetic induction heating unit 6A as a supplement. The outdoor heat exchanger 23 that is a condenser can be heated while suppressing the heat exchange capability between the air and the refrigerant.

  When defrosting is performed using the electromagnetic induction heating unit 6A as an auxiliary, the refrigerant is supplied by the dotted line connection of the four-way switching valve 22 as in the cooling operation. The high-temperature and high-pressure gas refrigerant discharged from the compressor 21 enters the outdoor heat exchanger 23 and is cooled by exchanging heat with frost attached to the outdoor heat exchanger 23. The refrigerant depressurized by the outdoor electric expansion valve 24 enters the indoor heat exchanger 41. However, in the defrosting operation performed during the heating operation, it is preferable not to cool the room, so the amount of heat exchange in the indoor heat exchanger 41 is small. Thus, the opening degree of the outdoor electric expansion valve 24 and the rotational speed of the compressor 21 are adjusted, and the rotational speed of the indoor fan 42 is also lowered. The amount of heating in the electromagnetic induction heating unit 6A is increased by the amount that the amount of heat exchange in the indoor heat exchanger 41 is lower than that in the cooling operation so as to have a predetermined degree of superheat on the suction side of the compressor 21. At this time, since the electromagnetic induction heating unit 6A heats the refrigerant divided into the return pipe 3F, defrosting during heating operation in which the controllability and responsiveness of the heating amount are high and the outdoor heat exchanger 23 functions as a condenser. It can cope with driving sufficiently.

  Further, when the heating capacity of the electromagnetic induction heating unit 6A is sufficiently large, the outdoor heat exchanger 23 can be defrosted while performing the heating operation. In the case of the defrosting operation while heating, the four-way switching valve 22 is switched to the solid line. Also, the hot gas bypass valve 27 is opened to open the hot gas bypass circuit 3H, and the outdoor electric expansion valve 24 is throttled so that the refrigerant returned from the indoor heat exchanger 41 and the high-temperature and high-pressure discharged from the compressor 21 A mixed refrigerant with a gas refrigerant is supplied to the outdoor heat exchanger 23. Thereby, the frost attached to the outdoor heat exchanger 23 can be melted. On the other hand, the indoor unit 4 is heated by the high-temperature and high-pressure gas refrigerant branched at the branch point A1 and flowing into the indoor heat exchanger 41, as in the normal heating operation.

  At this time, since the outdoor heat exchanger 23 does not function as an evaporator, the amount of heat consumed by the outdoor heat exchanger 23 and the indoor heat exchanger 41 is supplied from the electromagnetic induction heating unit 6A. Also at this time, the heating amount of the electromagnetic induction heating unit 6A is adjusted so that the return pipe temperature sensor 39 has a predetermined temperature.

[Second Embodiment]
The air conditioner according to the second embodiment of the present invention also has substantially the same configuration as that of the air conditioner 1 of the first embodiment shown in FIG. The difference between the air conditioner of the second embodiment and the air conditioner of the first embodiment is the configuration of the electromagnetic induction heating unit.

  FIG. 7 is a conceptual diagram for explaining the configuration of the electromagnetic induction heating unit 6B of the second embodiment. The return pipe 3F shown in FIG. 7 has the same configuration as the return pipe 3F shown in FIG. And also in 2nd Embodiment, the electromagnetic induction heating unit 6B is provided in the return piping 3F similarly to 1st Embodiment. However, in the first embodiment, the two straight pipe portions 3F1 and 3F3 of the return pipe 3F are provided with two magnetic bodies Co1 and Co2, whereas in the second embodiment, the two straight pipe portions 3F1 and 3F3 are provided. However, only one magnetic body Co3 is provided.

  The electromagnetic induction coil 68 and the magnetic body Co3 of the electromagnetic induction heating unit 6B are connected to the arrow Dir1 with respect to the entire portion composed of the two straight pipe portions 3F1 and 3F3 and the U-shaped curved pipe portion 3F2 in the return pipe 3F. It is mounted so that it can be inserted and removed in the direction of. Therefore, the magnetic body Co3 includes a substantially elliptic opening CA in plan view. In the electromagnetic induction heating unit 6B of FIG. 7, since the magnetic body Co3 is heated, the magnetic body Co3 is provided so as to be in thermal contact with the two straight pipe portions 3F1 and 3F3 of the return pipe 3F. In order to increase the effect of heat conduction, it is preferable that the contact area between the magnetic body Co3 and the straight pipe portions 3F1 and 3F3 is large. Therefore, the opening CA is formed and arranged so as to circumscribe the straight pipe portions 3F1 and 3F3. ing. In order to increase the efficiency of heat conduction, ceramic or metal having high heat conductivity may be fitted into the opening CA of the magnetic body Co1.

  Thus, since the electromagnetic induction coil 68 of the electromagnetic induction heating unit 6B can be detachably attached to the return pipe 3F, maintenance can be easily performed. Further, since the magnetic body Co1 can be inserted and removed together with the electromagnetic induction coil 68, the maintenance is further facilitated.

  The electromagnetic induction heating unit 6B is supplied with electric power from the high frequency power source So. Regarding the temperature of the refrigerant heated by the electromagnetic induction heating unit 6B, when the detection result by the return pipe temperature sensor 39 is below the target temperature range or above the target temperature range with respect to the target temperature range, the output of the high frequency power source So The controller 11 controls the same as in the first embodiment. In the electromagnetic induction heating unit 6B of the second embodiment, since the two straight pipe portions 3F1 and 3F3 are heated by one unit, the heating amount is adjusted for each of the straight pipe portions 3F1 and 3F3 as in the first embodiment. I can't. However, since one electromagnetic induction heating unit 6B can be omitted, the cost can be reduced. In addition, the heating amount of the two straight pipe portions 3F1 and 3F3 can be made different by changing the contact area with the magnetic body Co3 for each of the straight pipe portions 3F1 and 3F3.

The refrigerant flowing through the return pipe 3F flows from the left and flows through the straight pipe portion 3F1 downward from the inlet of the straight pipe portion 3F1 as indicated by an arrow Fl. Then, it makes a U-turn suddenly at the bending tube portion 3F2 and flows upward. When the flow direction changes in the curved pipe portion 3F2, the refrigerant is agitated due to the density difference between the gas refrigerant and the liquid refrigerant. Thereby, it can suppress that the ratio of the liquid refrigerant which contacts the pipe inner surface of straight pipe part 3F3 reduces , and can prevent that the efficiency of heat transfer falls in straight pipe part 3F3 rather than straight pipe part 3F1.

[Third Embodiment]
The air conditioner according to the third embodiment of the present invention also has substantially the same configuration as that of the air conditioner 1 of the first embodiment shown in FIG. 1 except for the periphery of the electromagnetic induction heating unit. First, the air conditioner of 3rd Embodiment differs from the air conditioner of 1st Embodiment in the structure of an electromagnetic induction heating unit, and the air conditioner of 3rd Embodiment is the air conditioner of 2nd Embodiment. The same electromagnetic induction heating unit 6B is used. The difference between the third embodiment and the first embodiment is the shape of the return pipe 3F.

  FIG. 8 is a conceptual diagram showing the electromagnetic induction heating unit 6B of the third embodiment and its peripheral structure. In FIG. 8, the upper part of the figure coincides with the upper part of the air conditioner. That is, the return pipe 3F in FIG. 8 includes straight pipe portions 3F4 and 3F6 arranged horizontally, and a U-shaped curved pipe portion 3F5 that connects two straight pipe portions 3F4 and 3F6 arranged vertically. Have.

  The electromagnetic induction heating unit 6B can be inserted / removed in the direction (horizontal direction) of the arrow Dir2 with respect to the entire portion composed of the two straight pipe portions 3F4, 3F6 and the U-shaped curved pipe portion 3F5 in the return pipe 3F. It is attached to. Therefore, the electromagnetic induction heating unit 6B includes a magnetic body Co3 having a substantially elliptic opening CA in plan view and an electromagnetic induction coil 68 wound around the magnetic body Co3, and supplies power from the high-frequency power source So. The points received and the effects thereof are also as described in the second embodiment.

  In the electromagnetic induction heating unit 6B of FIG. 8, since the magnetic body Co3 is heated, the magnetic body Co3 is provided so as to be in thermal contact with the two straight pipe portions 3F4 and 3F6 of the return pipe 3F. This is the same as in the second embodiment. In order to increase the effect of heat conduction, it is preferable that the contact area between the magnetic body Co3 and the straight pipe portions 3F4 and 3F6 is large. Therefore, the magnetic body Co3 is formed and attached so as to circumscribe the straight pipe portions 3F4 and 3F6. ing.

  As indicated by an arrow Fl, the refrigerant flowing through the return pipe 3F flows from the top to the bottom toward the inlet of the straight pipe portion 3F4, and changes the flow direction in the horizontal direction at the straight pipe portion 3F4. Then, the refrigerant flows upward from the straight tube portion 3F4 toward the curved tube portion 3F5. At this time, in the straight pipe portion 3F4, the liquid layer (liquid refrigerant) is formed below, and the heated gas layer (gas refrigerant) forms a flow that flows upward. The refrigerant gasified by being brought into thermal contact with the inner surface of the straight pipe portion 3F4 and being heated is agitated with the liquid refrigerant in the curved pipe portion 3F5, so that it is thermally applied to the inner surface of the straight pipe portion 3F6. It is possible to prevent a large amount of gas refrigerant from being unevenly distributed in the portion in contact with the pipe, and to prevent the heating efficiency in the straight pipe portion 3F6 from being significantly reduced as compared to the straight pipe portion 3F4.

[Fourth Embodiment]
The air conditioner according to the fourth embodiment of the present invention also has substantially the same configuration as that of the air conditioner 1 of the first embodiment shown in FIG. The difference between the air conditioner of the fourth embodiment and the air conditioner of the first embodiment is the configuration of the electromagnetic induction heating unit.

  9 and 10 are conceptual diagrams for explaining the configuration of the electromagnetic induction heating unit 6C and the return pipe 3F of the fourth embodiment. The return pipe 3F shown in FIGS. 9 and 10 is the same pipe as the pipe shown in FIG. And also in 4th Embodiment, 6C of electromagnetic induction heating units are provided in the return piping 3F similarly to 1st Embodiment. The electromagnetic induction heating unit 6 </ b> C of the fourth embodiment is a further modification of the electromagnetic induction heating unit 6 </ b> B of the second embodiment. Therefore, the electromagnetic induction heating unit 6C includes an electromagnetic induction coil 68C1, a magnetic body Co4, and a high frequency power source So1 corresponding to the electromagnetic induction coil 68, the magnetic body Co3, and the high frequency power source So of the electromagnetic induction heating unit 6B.

  The electromagnetic induction heating unit 6C of the fourth embodiment further includes a fitting member 100, a magnetic body Co5 attached in the cavity 100a of the fitting member 100, and an electromagnetic induction coil 68C2 wound around the magnetic body Co5. And a high-frequency power source So2. Since the magnetic body Co4 is inserted from the curved pipe portion 3F2 of the return pipe 3F, the fitting member 100 is inserted into the opening CA1 of the magnetic body Co4 from the side opposite to the direction in which the magnetic body Co4 is inserted. The fitting member 100 is in contact with the inner peripheral surface of the magnetic body Co4 and the outer peripheral surfaces of the straight pipe portions 3F1 and 3F3 while being inserted into the magnetic body Co4. The fitting member 100 has a high thermal conductivity and transfers heat generated by the magnetic body Co4 to the straight pipe portions 3F1 and 3F3. The fitting member 100 also contributes to fixing the magnetic body Co4 and the straight pipe portions 3F1 and 3F3. In order to concentrate the magnetic flux on the magnetic bodies Co4 and Co5, the fitting member 100 is formed of a non-magnetic body, and for example, a ceramic such as aluminum nitride can be used so as not to flow a current due to electromagnetic induction.

  As shown in FIG. 10, the magnetic body Co5 is in contact with the cavity 100a of the fitting member 100, and heat is transmitted from the magnetic body Co5 that generates heat by the alternating magnetic field generated by the electromagnetic induction coil 68C2. The straight pipe portions 3F1 and 3F3 are further heated by the heat transmitted from the magnetic body Co5 to the fitting member 100. Therefore, compared with the electromagnetic induction heating unit 6B of the second embodiment using only the magnetic body Co3, the heating amount can be increased by the amount of the magnetic body Co5. In particular, the portions where the two straight pipe portions 3F1 and 3F3 are opposed to each other are close to the magnetic body Co5, and thus are efficiently heated by the magnetic body Co5. Note that the electromagnetic induction coil 68C2 becomes an obstacle in order for the magnetic body Co5 to contact the inner peripheral surface of the cavity 100a. Therefore, for example, a thread groove can be cut in the inner peripheral surface of the cavity 100a of the fitting member 100, and the electromagnetic induction coil 68C2 can be accommodated in the spiral thread groove. In this case, the crest portion between the screw grooves on the inner peripheral surface of the cavity 100a contacts the magnetic body Co5. This is an example, and the electromagnetic induction coil 68C2 and the magnetic body Co5 are arranged between the two straight pipe portions 3F1 and 3F3, and the two straight pipe portions 3F1 by electromagnetic induction heating using them. , 3F3 may be heated and is not limited to this structure.

  Regarding the temperature of the refrigerant heated by the electromagnetic induction heating unit 6C, when the detection result by the return pipe temperature sensor 39 is below the target temperature range or above the target temperature range with respect to the target temperature range, the high frequency power sources So1, So2 Is controlled by the control unit 11. In the second embodiment, the amount of heating of the two straight pipe portions 3F1 and 3F3 can be made different by changing the contact areas with the magnetic bodies Co4 and Co5 for the straight pipe portions 3F1 and 3F3. It is the same. Further, the refrigerant flowing through the return pipe 3F is agitated by the curved pipe portion 3F2, as in the second embodiment. Furthermore, the return pipe 3F can be arranged so that the straight pipe portion is horizontal as in the third embodiment, and the effect when the return pipe 3F is formed in this way is the same as in the third embodiment.

[Fifth Embodiment]
The air conditioner according to the fifth embodiment of the present invention also has substantially the same configuration as that of the air conditioner 1 of the first embodiment shown in FIG. 1 except for the periphery of the electromagnetic induction heating unit. Basically, in the fifth embodiment, as shown in FIG. 11, an electromagnetic induction heating unit 6D different from the second embodiment is used. The electromagnetic induction heating unit 6B of the second embodiment conducts heat from the inner peripheral surface of the magnetic body Co3 to the straight pipe portions 3F1 and 3F3, whereas in the electromagnetic induction heating unit 6D, a return pipe is connected from the outer peripheral surface of the magnetic body Co6. Heat is conducted to 3F. Therefore, the return pipe 3F has an introduction pipe part 3F7, a spiral pipe part 3F8 wound around the outer peripheral surface of the magnetic body Co6, and a lead-out pipe part 3F9 returning along the inner peripheral surface of the magnetic body Co6. . In this case, the spiral tube portion 3F8 can insulate adjacent ones to heat the magnetic body Co6. Further, not only the magnetic material Co6 but also the spiral tube portion 3F8 may generate eddy current so that the spiral tube portion 3F8 generates heat.

  Also in the fifth embodiment, the electromagnetic induction coil 68 is configured to be detachable from the spiral tube portion 3F8 which is a curved tube portion. Therefore, as in the above embodiments, the refrigeration apparatus can be easily assembled and maintained.

<Modification>
(A)
In the first to fifth embodiments, the case has been described in which the electromagnetic induction heating units 6A, 6B, 6C, and 6D are provided in the return pipe 3F, and the refrigerant is heated by electromagnetic induction in the return pipe 3F. The place to be heated by induction is not limited to the place where the return pipe 3F of the refrigeration circuit is located, and may be another place. In the case of heating by electromagnetic induction at another location, a curved tube portion or a straight tube portion for attaching the electromagnetic induction heating unit is provided at that location.

(B)
In the first to sixth embodiments, the return pipe 3F is provided with the electromagnetic induction heating units 6A, 6B, 6C, 6D, and the return pipe 3F heats the refrigerant by electromagnetic induction to control the electromagnetic induction heating. For this reason, the case where the return pipe temperature sensor 39 is used has been described. However, the electromagnetic induction heating units 6A, 6B, 6C, and 6D can be controlled based on the detection results of other sensors. In particular, when the electromagnetic induction heating units 6A, 6B, 6C, 6D are provided at locations other than the return pipe 3F, it is preferable to use a sensor near the provided location.

(C)
In the first embodiment, the case where the refrigerant passing through the straight pipe portions 3F1 and 3F3 is heated by the electromagnetic induction heating unit 6A has been described. However, the refrigerant passing through the curved pipe portion 3F2 is further heated by the electromagnetic induction heating unit 6A. You may comprise as follows. For this purpose, for example, as shown in FIG. 12, the formation regions of the magnetic bodies Co1 and Co2 are extended to the bending tube portion 3F2. A region indicated by hatching in FIG. 12 is an extended portion. Since the magnetic bodies Co1 and Co2 generate heat by electromagnetic induction heating, the refrigerant can be heated also in the bending tube portion 3F2.

(D)
In the second embodiment, the magnetic body Co3 is integrated. However, as shown in FIG. 13A, the magnetic body can be assembled. A part of the magnetic bodies Co7 and Co8 is formed on the outer ring member 101, and the remaining part of the magnetic bodies Co7 and Co8 is formed on the fitting member 102. Then, by fitting the fitting member 102 into the outer ring member 101, magnetic bodies Co7 and Co8 that are in close contact with the periphery of the straight pipe portions 3F1 and 3F3 are completed. For example, in the outer ring member 101 and the fitting member 102, ferrite is used for the material of the part that will become the cylindrical magnetic bodies Co7 and Co8 when completed, and thermal conductivity such as zirconia is used for the material of the other part. A low material can be used. Accordingly, heat can be generated near the straight pipe portions 3F1 and 3F3 to efficiently heat the straight pipe portions 3F1 and 3F3. In order to prevent the resistance value of the divided portions from increasing, a metal having a lower resistance value than that of the magnetic materials Co7 and Co8 may be plated on the end surfaces of the joints of the magnetic materials Co7 and Co8.

(E)
In each of the above-described embodiments, the case where the magnetic body has one cylindrical or columnar shape with respect to one tube portion has been described. However, heating can be performed by a plurality of discrete members. FIG. 13B shows the fitting member 104, but a thin columnar magnetic body 105 is arranged around the straight pipe portions 3F1 and 3F3. Even if it is discrete, since the eddy current is generated on the outer peripheral surface of each magnetic body 105 by changing the magnetic flux density in the magnetic body 105, the straight pipe portions 3F1 and 3F3 can be heated.

(F)
In the fifth embodiment, the example in which the pipe 3F is spirally wound around the outer peripheral surface of the cylindrical magnetic body Co6 has been shown. However, as shown in FIG. 14, on the outer peripheral surface of the columnar magnetic body Co9, The magnetic material Co9 may be wound while being folded back in the axial direction. With such a winding method, the curved tube portions 3F11 and 3F12 are connected to both ends of the plurality of straight tube portions 3F10. Even in the case of such an electromagnetic induction heating unit 6E, the electromagnetic induction coil 68 can be pulled out from the bending tube portion 3F11. In the case of such a configuration, the refrigerant is also heated in the curved tube portions 3F11 and 3F12.

(G)
For example, in the first embodiment, the case where the bending tube portion 3F2 is simply bent has been described. However, the straight tube portions 3F13a, 3F13b, 3F15a, 3F15b and the bending tube portions 3F14a, 3F14b of the electromagnetic induction heating unit 6F in FIG. In this way, it can be bent into a plurality of branches. By branching into a plurality of pipes, it becomes easier to bend the pipe, and it becomes difficult for cracks or the like to enter the pipe during manufacturing. When branching in this way, in order to prevent the occurrence of pressure loss, for example, the cross-sectional area of one straight pipe portion 3F1 of the first embodiment and the two straight pipe portions 3F13a and 3F13b of this modification example. It is preferable to make the sum of the cross-sectional areas the same. When the cross-sectional areas are made the same in this way, the sum of the areas of the inner peripheral surfaces of the straight pipe portions 3F13a and 3F13b becomes larger than the area of the inner peripheral surface of the straight pipe portion 3F1, and heat is applied to the refrigerant. It turns out that branching is more advantageous for transmission.

<Features>
(1)
The electromagnetic induction heating units 6A to 6F of the air conditioner 1 (refrigeration apparatus) include straight pipe portions 3F1, 3F4, 3F6, 3F10, 3F13a, 3F13b, 3F15a, 3F15b, curved pipe portions 3F2, 3F11, 3F12 and a helical tube portion 3F8. (Member in thermal contact with the refrigerant) is heated. Heating by the electromagnetic induction heating units 6A to 6F includes direct heating to the straight pipe portions 3F1, 3F4, 3F6, 3F10, 3F13a, 3F13b, 3F15a, 3F15b, the curved pipe portions 3F2, 3F11, 3F12 and the helical tube portion 3F8, and Indirect heating performed through the magnetic bodies Co1 to Co9 is included. Here, the member is a concept including magnetic bodies Co1 to Co9.

  These members constitute a part of the return pipe 3F (predetermined refrigerant flow path), and thus a part of the continuous refrigerant flow path to constitute a part of the refrigerant circuit 10. For example, in the bending tube portion 3F2, the boundary with the straight tube portion 3F1 is an inlet of the bending tube portion 3F2, and the boundary with the straight tube portion 3F3 is an outlet of the bending tube portion 3F2. Here, the boundary is the end of the straight pipe portions 3F1 and 3F3 and is where the pipe starts to bend. Although the electromagnetic induction coils 68 and 68C1 of the electromagnetic induction heating units 6A to 6F are wound around a member that forms part of such a continuous refrigerant flow path, the curved pipe portions 3F2, 3F5, and 3F10 are wound. Or it can isolate | separate from the direction of the helical tube part 3F8 which is 1 type of a curved tube part. Thereby, the assembly | attachment to the air conditioning apparatus 1 of the electromagnetic induction heating units 6A-6F and the attachment / detachment work at the time of a maintenance become easy. In the electromagnetic induction heating units 6B, 6C, and 6E, the magnetic bodies Co3, Co4, Co7, and Co8 can be pulled out together with the electromagnetic induction coils 68 and 68C1. This further facilitates maintenance work and assembly of the air conditioner 1.

  For example, the electromagnetic induction heating unit 6B of the second embodiment is a straight pipe that is a member that is in thermal contact with the refrigerant passing through the straight pipe portion 3F1 (first extending portion) and the straight pipe portion 3F3 (second extending portion). The part 3F1 and the straight pipe part 3F3 are indirectly heated through the magnetic body Co3. In this case, if the magnetic body Co1 is removed and the straight pipe portions 3F1 and 3F3 are made of a magnetic material, the straight pipe portions 3F1 and 3F3 become members that are directly heated by the electromagnetic induction heating unit. Here, the case where the first extending portion and the second extending portion are straight pipe portions is shown, and it is preferable that the first extending portion and the second extending portion extend linearly in terms of performance, cost, and handling, but they are not necessarily linear. It is not an essential requirement to extend.

  As shown in FIG. 12, the electromagnetic pipe is configured to continue to receive heat from the inner peripheral surface of the refrigerant pipe (the straight pipe portion 3F1.3F3 and the curved pipe portion 3F2) as long as possible in the shortest refrigerant flow section. The induction heating unit 6B can be made compact.

(2)
The return pipe 3F can be arbitrarily arranged up and down, left and right. However, when the curved pipe portions 3F2 and 3F5 are arranged below the straight pipe portions 3F3 and 3F6 (second extending portions), the liquid layer of the refrigerant is a gas. Since it tends to accumulate below the layer, the liquid layer accumulated below can be heated, so that the heating efficiency is good.

  For example, in the case as shown in FIG. 8, a high-density liquid layer (liquid refrigerant flow) is formed in the lower part of the straight pipe portion 3F4, and a gas layer (flow to the gas refrigerant) is easily formed above. ing. Therefore, the heat can be efficiently transferred to the refrigerant by arranging the magnetic body Co3 that generates heat by electromagnetic induction heating so as to contact the lower portion (contact portion) of the straight pipe portion 3F4. For example, in the case shown in FIG. 1, since the return pipe 3F flows from the horizontal state to the vertical straight pipe portion 3F1, a high-density liquid layer is formed in the lower part of the horizontal pipe, and the liquid The layer flows downward along the wall surface of the vertical straight pipe portion 3F1. Therefore, heat can be efficiently transferred to the refrigerant by arranging the magnetic body Co1 that generates heat by electromagnetic induction heating so as to contact the lower portion (contact portion) of the straight pipe portion 3F1.

2 Outdoor unit 4 Indoor unit 6A, 6B, 6C, 6D, 6E, 6F Electromagnetic induction heating unit 10 Refrigerant circuit 11 Control unit 21 Compressor 3F Return pipe 3F1, 3F4, 3F7, 3F13a, 3F13b Straight pipe part (first extension part) )
3F3, 3F6, 3F9, 3F10, 3F15a, 3F15b Straight pipe part (second extending part)
3F2, 3F5, 3F11, 3F12, 3F14a, 3F14b Curved tube section (curved section)
3F8 spiral tube (curved)
101 Outer ring member Co1-Co9 Magnetic body 68, 68C1, 68C2 Electromagnetic induction coil

JP-A-11-2111195 JP-A-8-326997

Claims (7)

Members (3F1, 3F3, 3F4, 3F6, 3F8, 3F9, 3F10, 3F11, 3F12, 3F13a, 3F13b, 3F15a, 3F15b) that are in thermal contact with the refrigerant flowing through the predetermined refrigerant flow path (3F);
An electromagnetic induction heating unit (6A, 6B, 6C, 6D) for heating the member;
The predetermined refrigerant flow path has a refrigerant inlet and an outlet, and a curved portion (3F2, 3F5, 3F8, 3F11, 3F14a, 3F14b) in which a portion between the inlet and the outlet is curved, A first extending portion (3F1, 3F4, 3F7, 3F10, 3F13a, 3F13b) extending from the inlet and a second extending portion (3F3, 3F6, 3F9, 3F12, 3F15a, 3F15b) extending from the outlet of the curved portion;
The member is arranged to transmit heat to a refrigerant passing through at least the first extending portion and the second extending portion,
The electromagnetic induction heating unit has an electromagnetic induction coil (68, 68C1, 68C2) wound around the member and for electromagnetically heating the member.
The refrigeration apparatus, wherein the electromagnetic induction coil is attached so as to be separated from the predetermined refrigerant flow path by being extracted from the curved portion.   The refrigeration apparatus according to claim 1, wherein the member is a member to be heated provided separately from the refrigerant pipe and / or the refrigerant pipe.   The member includes a cylindrical magnetic body (Co3, Co4) around which the electromagnetic induction coil is wound, and is attached to the electromagnetic induction coil so as to be separated from the predetermined refrigerant flow path by being pulled out from the curved portion. The refrigeration apparatus according to claim 1, wherein   The refrigeration apparatus according to any one of claims 1 to 3, wherein the member is disposed so as to transmit heat to a refrigerant passing through the curved portion.   The electromagnetic induction coils (68C1, 68C2) are plural, and are sandwiched between the outside of the region covering both the first extending portion and the second extending portion, and the first extending portion and the second extending portion. The refrigeration apparatus according to any one of claims 1 to 4, wherein the refrigeration apparatus is disposed at least inside the area.   The refrigeration according to any one of claims 1 to 5, wherein the predetermined refrigerant flow path is disposed such that the curved portion (3F2, 3F5) is below the second extending portion (3F3, 3F6). apparatus. The predetermined refrigerant flow path includes contact portions (3F1, 3F4, 3F13a, 3F13b) that are in thermal contact with the member,
The refrigeration apparatus according to claim 1, wherein the contact portion is disposed so as to be in thermal contact with the liquid layer of the refrigerant.

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