JP2010223456A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner capable of suppressing excessive heat generation of a member for generating heat by induction heating. <P>SOLUTION: The air conditioner 1 has a compressor 21, an outdoor heat exchanger 23, an electric expansion valve 24, and an indoor heat exchanger 41, and is provided with a coil 68 and a controller 11. The coil 68 generates a magnetic field for inductively heating an accumulator tube F. The controller 11 figures out the quantity of circulating refrigerant in a refrigeration cycle which includes the compressor 21, the indoor heat exchanger 41, the electric expansion valve 24, and the outdoor heat exchanger 23, and causes the coil 68 to generate a magnetic field when the quantity of circulating refrigerant increases. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an air conditioner.

  Conventionally, an air conditioner provided with a refrigerant heating device using an electromagnetic induction heating method has been proposed.

  For example, in the following Patent Document 1 (Japanese Patent Application Laid-Open No. 2007-255736), in order to efficiently heat the refrigerant by induction heating, control for starting induction heating in a state in which the circulation amount of the refrigerant is secured to some extent is performed. An air conditioner to perform has been proposed.

  In the technique described in Patent Document 1 (Japanese Patent Laid-Open No. 2007-255736), the circulation amount is secured from the viewpoint of efficient heating of the refrigerant, but the refrigerant is not directly induction-heated. It is heated by receiving heat transfer from the heat generating member by induction heating such as a magnetic material. For this reason, even if the circulation amount is ensured to some extent, the circulation amount necessary for performing induction heating may not be ensured.

  This invention is made | formed in view of the point mentioned above, The subject of this invention is providing the air conditioning apparatus which can suppress that the member made to heat | fever-generate by induction heating can generate | occur | produce excessively.

  An air conditioner according to a first aspect of the present invention is an air conditioner including at least a compression mechanism, a refrigerant cooler, an expansion mechanism, and a refrigerant heater, and includes a magnetic field generation unit, a circulation amount grasping unit, and a control unit. The magnetic field generation unit induction-heats a refrigerant pipe for circulating the refrigerant through the compression mechanism, the refrigerant cooler, the expansion mechanism, and the refrigerant heater and / or a member that makes thermal contact with the refrigerant flowing in the refrigerant pipe. Therefore, a magnetic field is generated. The circulation amount grasping portion grasps the refrigerant circulation amount of the refrigeration cycle including at least the compression mechanism, the refrigerant cooler, the expansion mechanism, and the refrigerant heater. The control unit performs magnetic field output control for generating a magnetic field in the magnetic field generation unit or increasing the upper limit of the generated magnetic field when the refrigerant circulation amount grasped by the circulation amount grasping unit increases.

  In this air conditioner, when the amount of refrigerant sucked by the compression mechanism is small, if the magnitude of the magnetic field generated by the magnetic field generation unit is increased to increase the degree of induction heating, the portion to be subjected to induction heating May overheat.

  On the other hand, in this air conditioner, when the refrigerant circulation amount is increased, a magnetic field is generated or the magnetic field to be generated is increased, so that it is possible to suppress excessive heating of the induction heating portion. .

  An air conditioner according to a second aspect of the present invention is the air conditioner according to the first aspect, wherein the magnetic field generator is a refrigerant and heat that flows in the suction refrigerant pipe and / or the suction refrigerant pipe on the suction side of the compression mechanism among the refrigerant pipes. A magnetic field for inductively heating a member that makes a mechanical contact is generated.

  In this air conditioner, the refrigerant immediately before being sucked into the compression mechanism is rapidly heated instead of the refrigerant flowing through the refrigerant pipe considerably away from the compression mechanism. The refrigerant flowing on the suction side of the compression mechanism has a high degree of dryness or is in an overheated state, which is obvious when compared with the case where the refrigerant in the gas-liquid two-phase state or the like flowing more upstream changes in latent heat. Temperature is likely to rise because it is easy to change heat.

  On the other hand, in this air conditioner, since the magnetic field output control is performed after the refrigerant circulation amount is increased, it is possible to prevent excessive induction heating in a state where the refrigerant circulation amount is small. Thereby, even if it is a case where the refrigerant | coolant which passes the suction | inhalation side of the compression mechanism which a temperature rise tends to produce is heated, it can suppress that an induction heating part is heated too much.

  The air conditioner according to a third aspect is the air conditioner according to the first or second aspect, wherein the circulation amount grasping unit is at least a predetermined piston displacement of the compression mechanism, a drive frequency of the compression mechanism, and Determined based on the suction refrigerant density.

  In this air conditioner, it is possible to perform magnetic field output control according to the state of the refrigerant passing through the suction side of the compression mechanism.

  An air conditioner according to a fourth aspect of the present invention is the air conditioner according to the third aspect of the present invention, further comprising a low pressure grasping part and an intake refrigerant temperature grasping part. The low pressure grasping portion grasps the pressure of the refrigerant flowing through the low pressure portion of the refrigeration cycle. The intake refrigerant temperature grasping unit grasps the intake refrigerant temperature of the compression mechanism. The circulation amount grasping unit obtains the suction refrigerant density of the compression mechanism using the pressure grasped by the low pressure grasping unit and the temperature grasped by the intake refrigerant temperature grasping unit.

  In this air conditioner, the refrigerant circulation amount can be grasped more accurately.

  An air conditioner according to a fifth aspect of the present invention is the air conditioner according to the fourth aspect of the present invention, wherein the suction refrigerant temperature grasping portion is on the suction side of the compression mechanism in the refrigeration cycle and is downstream of the portion heated by induction by the magnetic field generating portion. The state quantity of the refrigerant passing through the side is detected.

  In this air conditioner, by grasping the state quantity of the refrigerant flowing upstream of the heat generation part due to induction heating, it becomes possible to grasp a value that is not affected by induction heating.

  The air conditioner according to a sixth aspect of the present invention is the air conditioner according to the fourth aspect or the fifth aspect of the present invention, wherein the controller is in a state where the refrigerant sucked by the compression mechanism is in a wet state or in a superheat state below a predetermined superheat degree. Perform magnetic field output control.

  In this air conditioner, when the degree of superheat of the refrigerant sucked by the compression mechanism is high, there is a risk that the temperature rise in the portion that generates heat due to induction heating will become significant.

  On the other hand, in this air conditioner, induction heating is performed only when it is in an overheated state or a wet state below a predetermined degree of superheat. For this reason, even if the driving frequency of the compression mechanism is high and the refrigerant flow speed is high, the magnetic field output control is not performed unless the superheat state is lower than the predetermined superheat degree or the wet state. It becomes possible to suppress more.

  An air conditioner according to a seventh aspect is the air conditioner according to any one of the first to sixth aspects, wherein the control unit controls the magnetic field output when the refrigerant circulation amount grasped by the circulation amount grasping unit exceeds a predetermined value. I do.

  In this air conditioner, in a state where the refrigerant circulation amount exceeds a predetermined value, even if the induction heating portion is heated by performing magnetic field output control, heat generation is suppressed by a large amount of refrigerant passing through the surroundings. Thereby, excessive heat generation in the induction heating portion can be reliably suppressed.

  In the air conditioner of the first invention, it is possible to suppress the induction heating portion from being heated excessively.

  In the air conditioner according to the second aspect of the present invention, excessive heating of the induction heating portion can be suppressed even when the refrigerant passing through the suction side of the compression mechanism that is likely to increase in temperature is heated.

  In the air conditioner of the third invention, it is possible to perform magnetic field output control according to the state of the refrigerant passing through the suction side of the compression mechanism.

  In the air conditioner of the fourth aspect of the invention, the refrigerant circulation amount can be grasped more accurately.

  In the air conditioner of the fifth aspect of the invention, it becomes possible to grasp a value that is not affected by induction heating.

  In the air conditioner of the sixth aspect, excessive overheating can be further suppressed.

  In the air conditioner of the seventh aspect, excessive heat generation in the induction heating portion can be reliably suppressed.

It is a refrigerant circuit figure of the air harmony device concerning one embodiment of the present invention. It is an external appearance perspective view of an electromagnetic induction heating unit. It is an external appearance perspective view which shows the state which removed the shielding cover from the electromagnetic induction heating unit. It is an external appearance perspective view of an electromagnetic induction thermistor. It is an external perspective view of a fuse. It is a schematic sectional drawing which shows the attachment state of an electromagnetic induction thermistor and a fuse. It is a section lineblock diagram of an electromagnetic induction heating unit. It is a figure which shows the mode of the magnetic flux produced in the state which provided the shielding cover. It is a figure which shows the flowchart of wet protection induction heating control. It is a figure which shows the flowchart of abnormal overheat suppression control. It is explanatory drawing of the refrigerant | coolant piping of other embodiment (H). It is explanatory drawing of refrigerant | coolant piping of other embodiment (I). It is a figure which shows the example of arrangement | positioning with the coil and refrigerant | coolant piping of other embodiment (J). It is a figure which shows the example of arrangement | positioning of the bobbin lid of other embodiment (J). It is a figure which shows the example of arrangement | positioning of the ferrite case of other embodiment (J).

  Hereinafter, an air conditioner 1 including an electromagnetic induction heating unit 6 according to an embodiment of the present invention will be described as an example with reference to the drawings.

<First Embodiment>
<1-1> Air conditioner 1
FIG. 1 is a refrigerant circuit diagram showing a refrigerant circuit 10 of the air conditioner 1.

  The air conditioner 1 is an air conditioner in a space where a use side device is arranged by connecting an outdoor unit 2 as a heat source side device and an indoor unit 4 as a use side device by a refrigerant pipe. , Compressor 21, four-way switching valve 22, outdoor heat exchanger 23, electric expansion valve 24, accumulator 25, outdoor fan 26, indoor heat exchanger 41, indoor fan 42, hot gas bypass valve 27, capillary tube 28 and electromagnetic An induction heating unit 6 and the like are provided.

  The compressor 21, the four-way switching valve 22, the outdoor heat exchanger 23, the electric expansion valve 24, the accumulator 25, the outdoor fan 26, the hot gas bypass valve 27, the capillary tube 28, and the electromagnetic induction heating unit 6 are included in the outdoor unit 2. Contained. The indoor heat exchanger 41 and the indoor fan 42 are accommodated in the indoor unit 4.

  The refrigerant circuit 10 includes a discharge pipe A, an indoor gas pipe B, an indoor liquid pipe C, an outdoor liquid pipe D, an outdoor gas pipe E, an accumulator pipe F, a suction pipe G, and a hot gas bypass circuit H. Yes. The indoor side gas pipe B and the outdoor side gas pipe E pass a large amount of refrigerant in the gas state, but the refrigerant passing therethrough is not limited to the gas refrigerant. The indoor side liquid pipe C and the outdoor side liquid pipe D pass a large amount of liquid refrigerant, but the refrigerant passing therethrough is not limited to liquid refrigerant.

  The discharge pipe A connects the compressor 21 and the four-way switching valve 22. The discharge pipe A is provided with a discharge temperature sensor 29d for detecting the temperature of the refrigerant passing therethrough. The current supply unit 21e supplies current to the compressor 21. The power supply amount of the current supply unit 21e is detected by the compressor power detection unit 29f. The rotational speed grasping unit 29r detects the rotational speed of the piston of the compressor 21. The indoor side gas pipe B connects the four-way switching valve 22 and the indoor heat exchanger 41. In the middle of the indoor side gas pipe B, a first pressure sensor 29a for detecting the pressure of the refrigerant passing therethrough is provided. The indoor side liquid pipe C connects the indoor heat exchanger 41 and the electric expansion valve 24. The outdoor liquid pipe D connects the electric expansion valve 24 and the outdoor heat exchanger 23. The outdoor gas pipe E connects the outdoor heat exchanger 23 and the four-way switching valve 22. In the middle of the outdoor gas pipe E, a second pressure sensor 29g for detecting the pressure of the refrigerant passing therethrough is provided.

  The accumulator pipe F connects the four-way switching valve 22 and the accumulator 25, and extends in the vertical direction when the outdoor unit 2 is installed. An electromagnetic induction heating unit 6 is attached to a part of the accumulator tube F. Of the accumulator tube F, at least a heat generating portion whose periphery is covered by a coil 68, which will be described later, is constituted by a magnetic body tube F2 provided so as to cover the periphery of the copper tube F1 in which the refrigerant is flowing inside. . The magnetic tube F2 is made of SUS (Stainless Used Steel) 430. The SUS430 is a ferromagnetic material, and generates eddy currents when placed in a magnetic field, and generates heat due to Joule heat generated by its own electrical resistance. Portions other than the magnetic pipe F2 among the pipes constituting the refrigerant circuit 10 are made of copper pipes. By performing electromagnetic induction heating in this manner, the accumulator tube F can be heated by electromagnetic induction, and the refrigerant sucked into the compressor 21 via the accumulator 25 can be warmed. Thereby, the heating capability of the air conditioning apparatus 1 can be improved. Further, for example, even when the compressor 21 is not sufficiently warmed at the time of starting the heating operation, the lack of capacity at the time of starting can be compensated for by the rapid heating by the electromagnetic induction heating unit 6. Further, when the four-way switching valve 22 is switched to the cooling operation state and the defrost operation is performed to remove the frost attached to the outdoor heat exchanger 23 or the like, the electromagnetic induction heating unit 6 quickly opens the accumulator tube F. By heating, the compressor 21 can compress the rapidly heated refrigerant as a target. For this reason, the temperature of the hot gas discharged from the compressor 21 can be raised rapidly. Thereby, the time required to thaw frost by defrost operation can be shortened. Thereby, even if it is necessary to perform a defrost operation in a timely manner during the heating operation, the operation can be returned to the heating operation as soon as possible, and the user's comfort can be improved.

  The accumulator tube F is provided with a suction temperature sensor 19 that detects the temperature of the refrigerant flowing between the electromagnetic induction heating unit 6 and the four-way switching valve 22. This suction temperature sensor 19 detects the refrigerant temperature flowing downstream of the electromagnetic induction heating unit 6 before the refrigerant is warmed by induction heating of the electromagnetic induction heating unit 6 in a state where the refrigeration cycle performs heating operation. .

  The suction pipe G connects the accumulator 25 and the suction side of the compressor 21.

  The hot gas bypass circuit H connects a branch point A1 provided in the middle of the discharge pipe A and a branch point D1 provided in the middle of the outdoor liquid pipe D. The hot gas bypass circuit 27 is provided with a hot gas bypass valve 27 that can switch between a state that allows passage of refrigerant and a state that does not allow passage of the refrigerant. In the hot gas bypass circuit H, a capillary tube 28 is provided between the hot gas bypass valve 27 and the branch point D1 to reduce the pressure of refrigerant passing therethrough. Since this capillary tube 28 can be brought close to the pressure after the refrigerant pressure is lowered by the electric expansion valve 24 during heating operation, the outdoor side by supplying hot gas to the outdoor side liquid pipe D through the hot gas bypass circuit H is provided. An increase in the refrigerant pressure in the liquid pipe D can be suppressed.

  The four-way switching valve 22 can switch between a cooling operation cycle and a heating operation cycle. 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. During the heating operation, the indoor heat exchanger 41 functions as a refrigerant cooler, and the outdoor heat exchanger 23 functions as a refrigerant heater. During the cooling operation, the outdoor heat exchanger 23 functions as a refrigerant cooler, and the indoor heat exchanger 41 functions as a refrigerant heater.

  One end of the outdoor heat exchanger 23 is connected to the end of the outdoor heat exchanger 23 on the outdoor gas pipe E side, and the other end is connected to the end of the outdoor heat exchanger 23 on the outdoor liquid pipe D side. Has been. The outdoor heat exchanger 23 is provided with an outdoor heat exchange temperature sensor 29c that detects the temperature of the refrigerant flowing through the air conditioner 1. Furthermore, an outdoor temperature sensor 29b that detects outdoor air temperature is provided downstream of the outdoor heat exchanger 23 in the air flow direction.

  In the indoor unit 4, an indoor temperature sensor 43 that detects the indoor temperature is provided. In addition, the indoor heat exchanger 41 is provided with an indoor heat exchanger temperature sensor 44 that detects the refrigerant temperature on the indoor liquid pipe C side to which the electric expansion valve 24 is connected.

  The outdoor control unit 12 that controls the devices arranged in the outdoor unit 2 and the indoor control unit 13 that controls the devices arranged in the indoor unit 4 are connected by the communication line 11a, so that the control unit 11 is constituted. The control unit 11 performs various controls for the air conditioner 1.

  Further, the outdoor control unit 12 is provided with a timer 95 that counts elapsed time when performing various controls.

  Note that a controller 90 that accepts a setting input from the user is connected to the control unit 11.

<1-2> Electromagnetic induction heating unit 6
FIG. 2 shows a schematic perspective view of the electromagnetic induction heating unit 6 attached to the accumulator tube F. FIG. 3 shows an external perspective view of the electromagnetic induction heating unit 6 with the shielding cover 75 removed. FIG. 4 shows a schematic configuration diagram of the electromagnetic induction thermistor 14. FIG. 5 shows a schematic configuration diagram of the fuse 15. FIG. 6 shows a cross-sectional view of the electromagnetic induction thermistor 14 and the fuse 15 attached to the accumulator tube F. FIG. 7 shows a cross-sectional view of the electromagnetic induction heating unit 6 attached to the accumulator tube F. FIG. 8 is an explanatory diagram showing a state in which a magnetic field is generated by the coil 68.

  The electromagnetic induction heating unit 6 is disposed so as to cover the magnetic tube F2 that is a heat generating portion of the accumulator tube F from the outside in the radial direction, and causes the magnetic tube F2 to generate heat by electromagnetic induction heating. The heat generating portion of the accumulator tube F has a double tube structure having an inner copper tube F1 and an outer magnetic tube F2.

  The electromagnetic induction heating unit 6 includes a first hexagon nut 61, a second hexagon nut 66, a first bobbin lid 63, a second bobbin lid 64, a bobbin 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, a coil 68, a shielding cover 75, an electromagnetic induction thermistor 14, a fuse 15 and the like are provided.

  The first hexagon nut 61 and the second hexagon nut 66 are made of resin, and stabilize the fixed state between the electromagnetic induction heating unit 6 and the accumulator pipe F using a C-shaped ring (not shown). The first bobbin lid 63 and the second bobbin lid 64 are made of resin and cover the accumulator tube F from the radially outer side at the upper end position and the lower end position, respectively. The first bobbin lid 63 and the second bobbin lid 64 have four screw holes for the screws 69 for screwing first to fourth ferrite cases 71 to 74 described later through the screws 69. ing. Furthermore, the second bobbin lid 64 has an electromagnetic induction thermistor insertion opening 64f for inserting the electromagnetic induction thermistor 14 and attaching it to the outer surface of the magnetic tube F2. The second bobbin lid 64 has a fuse insertion opening 64e for inserting the fuse 15 and attaching it to the outer surface of the magnetic tube F2. As shown in FIG. 4, the electromagnetic induction thermistor 14 is an electromagnetic induction thermistor wiring that transmits the detection results of the electromagnetic induction thermistor detector 14a, the outer protrusion 14b, the side protrusion 14c, and the electromagnetic induction thermistor detector 14a as signals to the controller 11. 14d. The electromagnetic induction thermistor detection unit 14a has a shape that follows the curved shape of the outer surface of the accumulator tube F, and has a substantial contact area. As shown in FIG. 5, the fuse 15 includes a fuse detection unit 15a, an asymmetric shape 15b, and a fuse wiring 15d that transmits a detection result of the fuse detection unit 15a to the control unit 11 as a signal. Receiving the notification of temperature detection exceeding the predetermined limit temperature from the fuse 15, the control unit 11 performs control to stop the power supply to the coil 68 to avoid thermal damage of the device. The bobbin main body 65 is made of resin, and the coil 68 is wound around it. The coil 68 is wound spirally around the outside of the bobbin main body 65 with the direction in which the accumulator tube F extends as the axial direction. The coil 68 is connected to a control printed board 18 (not shown) and receives a high-frequency current. The output of the control printed circuit board is controlled by the control unit 11. As shown in FIG. 6, the electromagnetic induction thermistor 14 and the fuse 15 are attached in a state where the bobbin main body 65 and the second bobbin lid 64 are fitted together. Here, in the attached state of the electromagnetic induction thermistor 14, the plate spring 16 is pushed inward in the radial direction of the magnetic body tube F <b> 2, thereby maintaining a good pressure contact state with the outer surface of the magnetic body tube F <b> 2. Similarly, the attachment state of the fuse 15 is also pressed by the leaf spring 17 inward in the radial direction of the magnetic tube F2, so that a good pressure contact state with the outer surface of the magnetic tube F2 is maintained. As described above, since the electromagnetic induction thermistor 14 and the fuse 15 maintain good adhesion to the outer surface of the accumulator tube F, the responsiveness is improved and a rapid temperature change due to electromagnetic induction heating can be detected quickly. I can do it. The first ferrite case 71 is sandwiched between the first bobbin lid 63 and the second bobbin lid 64 from the direction in which the accumulator tube F extends, and is fixed by screwing with screws 69. The first ferrite case 71 to the fourth ferrite case 74 contain a first ferrite 98 and a second ferrite 99 made of ferrite, which is a material having high magnetic permeability. As shown in the sectional view of the accumulator tube F and the electromagnetic induction heating unit 6 in FIG. 7 and the magnetic flux explanatory diagram in FIG. By forming it, the magnetic field is made difficult to leak outside. The shielding cover 75 is disposed on the outermost peripheral portion of the electromagnetic induction heating unit 6 and collects magnetic flux that cannot be drawn only by the first ferrite 98 and the second ferrite 99. Almost no leakage magnetic flux is generated on the outside of the shielding cover 75, and the location where the magnetic flux is generated can be determined.

<1-3> Electromagnetic induction heating control The electromagnetic induction heating unit 6 described above is configured so that the accumulator pipe F is activated when starting the heating operation when heating the refrigeration cycle, when assisting the heating capacity, and when performing the defrost operation. Control is performed to generate heat in the magnetic tube F2.

  Here, control for suppressing the temperature of the magnetic tube F2 of the accumulator tube F from rising abnormally among the controls of the electromagnetic induction heating unit 6 at the time of assisting the heating capacity will be described as an example.

(Abnormal overheat suppression control)
The abnormal overheat suppression control is performed after the start-up control of the compressor 21 or the like is completed and in a steady control state in which the refrigerant distribution state in the refrigerant circuit 10 of the air-conditioning apparatus 1 is stabilized, such as assisting heating operation capability. When induction heating by the electromagnetic induction heating unit 6 is started for the purpose, it is control for confirming that a sufficient amount of refrigerant circulating through the accumulator pipe F is secured.

  Here, the amount of refrigerant circulating in the refrigeration cycle (the amount of refrigerant passing through the magnetic pipe F2 portion of the accumulator pipe F) is the amount of piston displacement and rotation of the compressor 21 stored in a memory (not shown) as a predetermined amount. The control unit 11 calculates by multiplying the drive rotational speed of the compressor 21 grasped by the number grasping unit 29r and the suction refrigerant density of the compressor 21. The suction refrigerant density is calculated by the control unit 11 based on the refrigerant pressure detected by the second pressure sensor 29g and the refrigerant temperature detected by the suction temperature sensor 19.

  In the steady control state, after the various controls at the time of starting the air conditioner 1 are completed and the drive frequency of the compressor 21 is maintained at the rated maximum frequency, the control unit 11 operates the electric expansion valve. The refrigerant circulation amount is changed by adjusting the opening degree of 24, and control corresponding to a change in situation such as a change in outside air temperature or a change in set temperature by the user is performed. Here, the control unit 11 operates the electric expansion valve 24 so that the degree of supercooling of the refrigerant passing between the indoor heat exchanger 41 and the electric expansion valve 24 in the refrigerant flow in the heating operation state is maintained at 5 ° C. The degree of opening is controlled. This degree of supercooling is obtained by the controller 11 calculating the difference between the saturation temperature corresponding to the detected pressure of the second pressure sensor 29g and the temperature detected by the indoor heat exchanger temperature sensor 44.

  Hereinafter, description will be made with reference to the flowchart of the abnormal humidity overheat suppression control shown in FIG.

  In step S11, the control part 11 judges whether it is in a steady control state. Here, when it is determined that the vehicle is in the steady control state, the process proceeds to step S12. In the steady control state, the output of the electromagnetic induction heating unit 6 is zero.

  In step S12, the control unit 11 determines whether or not the refrigerant circulation amount of the refrigeration cycle is equal to or greater than a predetermined abnormal overheat suppression amount. If it is less than the abnormal overheat suppression amount, step S12 is repeated. If it is equal to or greater than the abnormal overheat suppression amount, the process proceeds to step S13.

  In step S <b> 13, the control unit 11 starts induction heating of the accumulation tube F by the electromagnetic induction heating unit 6.

  In step S14, the control unit 11 waits for a predetermined time to elapse while maintaining the control state.

  In step S15, the control unit 11 again determines whether or not the refrigerant circulation amount of the refrigeration cycle is equal to or greater than a predetermined abnormal overheat suppression amount. If it is equal to or greater than the abnormal overheat suppression amount, the process returns to step S14. When it is less than the abnormal overheat suppression amount, the process proceeds to step S16.

  In step S <b> 16, the control unit 11 stops the induction heating of the accumulation tube F by the electromagnetic induction heating unit 6.

  In this way, by ensuring the refrigerant flow amount in the accumulator pipe F when induction heating by the electromagnetic induction heating unit 6 is performed, an abnormal increase in the temperature of the accumulator pipe F can be prevented.

<Characteristics of the air conditioner 1 according to the first embodiment>
In the air conditioner 1, the refrigerant circulation amount in the refrigeration cycle is ensured to be equal to or greater than the abnormal overheat suppression amount by performing the abnormal overheat suppression control before the accumulator tube F is induction heated by the electromagnetic induction heating unit 6. Is confirmed. For this reason, induction heating by the electromagnetic induction heating unit 6 is performed only in a state where the refrigerant is flowing in the refrigeration cycle at an amount equal to or greater than the abnormal overheat suppression amount. Induction heating by the unit 6 is not performed.

  For this reason, the heat supplied to the accumulation tube F by induction heating of the electromagnetic induction heating unit 6 is taken away by the circulating refrigerant, and the amount of the refrigerant is sufficiently secured, so that the temperature of the accumulation tube F is abnormal. The rise can be prevented.

<Second Embodiment>
Since the structure of the air conditioning apparatus of 2nd Embodiment is the same as that of the air conditioning apparatus 1 of 1st Embodiment mentioned above, description is abbreviate | omitted.

  In the air conditioner of the second embodiment, abnormal overheat suppression wetness protection control is performed instead of the abnormal overheat suppression control of the first embodiment.

  The abnormal overheat suppression wetness protection control is performed by the compressor 21 after the start-up control of the compressor 21 or the like is completed and when the induction heating by the electromagnetic induction heating unit 6 is performed to assist the heating capacity. When induction heating by the electromagnetic induction heating unit 6 is started so that liquid compression does not occur, this is control for confirming that the circulation amount of the refrigerant flowing through the accumulator pipe F is sufficiently secured. In the induction heating by the electromagnetic induction heating unit 6 for assisting the heating capacity here, the power supplied to the coil 68 is set to be 50% of the maximum output.

  The situation in which induction heating by the electromagnetic induction heating unit 6 is performed to assist the heating capacity is after the completion of various controls at the start of the air conditioner 1, and the drive frequency of the compressor 21 is rated. In the state maintained at the maximum frequency, the control unit 11 changes the refrigerant circulation amount by adjusting the opening degree of the electric expansion valve 24, and responds to a situation change such as a change in the outside air temperature or a change in the set temperature by the user. Control is being performed. Here, the control unit 11 operates the electric expansion valve 24 so that the degree of supercooling of the refrigerant passing between the indoor heat exchanger 41 and the electric expansion valve 24 in the refrigerant flow in the heating operation state is maintained at 5 ° C. The degree of opening is controlled. This degree of supercooling is obtained by the controller 11 calculating the difference between the saturation temperature corresponding to the detected pressure of the second pressure sensor 29g and the temperature detected by the indoor heat exchanger temperature sensor 44.

  The dryness or superheat degree of the refrigerant sucked in the compressor 21 is calculated by the controller 11 based on the difference between the saturation temperature corresponding to the pressure detected by the second pressure sensor 29g and the temperature detected by the electromagnetic induction thermistor 14.

  The dryness or superheat degree of the refrigerant discharged from the compressor 21 is calculated by the control unit 11 based on the difference between the saturation temperature corresponding to the pressure detected by the first pressure sensor 29a and the temperature detected by the discharge temperature sensor 29d.

  Hereinafter, the abnormal overheat suppression wetness protection control shown in FIG. 10 will be described.

  In step S21, the control unit 11 determines whether induction heating by the electromagnetic induction heating unit 6 is being performed. Here, when it is determined that induction heating is being performed, the process proceeds to step S22. If induction heating is not being performed, step S21 is repeated.

  In step S22, the control unit 11 determines whether or not the induction heating start condition that the superheat degree of the suction refrigerant is less than 4 ° C. and the superheat degree of the discharged refrigerant is less than 10 ° C. is satisfied. If the induction heating start condition is not satisfied, step S22 is repeated. When the induction heating start condition is satisfied, the process proceeds to step S23.

  In step S23, the control unit 11 determines whether or not the refrigerant circulation amount of the refrigeration cycle is equal to or greater than a predetermined maximum output abnormal overheat suppression amount. When it is less than the maximum output abnormal overheat suppression amount, step S23 is repeated. If it is equal to or greater than the maximum output abnormal overheat suppression amount, the process proceeds to step S24.

  In step S <b> 24, the control unit 11 increases the degree of induction heating of the accumulation tube F by the electromagnetic induction heating unit 6. That is, the force is increased by supplying the electromagnetic induction heating unit 6 to the coil 68. Here, the power supplied to the coil 68 is increased from the state of 50% of the maximum output until it reaches the maximum output.

  In step S25, the control unit 11 waits for a predetermined time to elapse while maintaining the control state.

  In step S26, the control unit 11 determines again whether or not the refrigerant circulation amount of the refrigeration cycle is equal to or greater than a predetermined maximum output abnormal overheat suppression amount. If it is equal to or greater than the maximum output abnormal overheat suppression amount, the process proceeds to step S27. If it is less than the maximum output abnormal overheat suppression amount, the process proceeds to step S28.

  In step S27, the control unit 11 determines whether or not the superheating degree of the suction refrigerant is 5 ° C. or higher, or whether the induction heating end condition that the superheating degree of the discharged refrigerant is 12 ° C. or higher is satisfied. If the induction heating end condition is not satisfied, the process returns to step S25. If the induction heating end condition is satisfied, the process proceeds to step S28.

  In step S28, the control unit 11 reduces the induction heating output of the accumulator tube F by the electromagnetic induction heating unit 6 to a state of 50% of the maximum output, which is a heating capacity assisting state.

  In this way, even when the output of induction heating by the electromagnetic induction heating unit 6 is increased, the amount of refrigerant flowing in the accumulator pipe F is ensured, thereby preventing the occurrence of liquid compression in the compressor 21 and the accumulator pipe F. An abnormal rise in temperature can be prevented.

<Characteristics of the air conditioner 1 of the second embodiment>
In the abnormal overheat suppression wetness protection control of the second embodiment, not only the characteristics of the first embodiment but also the prevention of the occurrence of liquid compression in the compressor 21 and the prevention of the abnormal rise in the temperature of the accumulator tube F can be achieved. is made of.

  In addition, when the output by the electromagnetic induction heating unit 6 is further increased while the induction heating at 50% output by the electromagnetic induction heating unit 6 for assisting the heating capacity in the second embodiment is being performed, Since the temperature detected by the electromagnetic induction thermistor 14 is rising, it is difficult to determine whether or not the refrigerant circulation amount of the target portion to be induction heated by the electromagnetic induction heating unit 6 is secured. On the other hand, in the air conditioning apparatus 1 of the second embodiment, the installation position of the suction temperature sensor 19 is on the downstream side of the induction heating target portion by the electromagnetic induction heating unit 6. For this reason, by calculating | requiring the density of the refrigerant | coolant which has flowed in the downstream of the induction heating object part by the electromagnetic induction heating unit 6 among the refrigerant | coolants circulation amount of a refrigerating cycle, it flows between the induction heating object part and the compressor 21. It is possible to grasp the amount of refrigerant flowing downstream of the induction heating target portion, not the amount of refrigerant in the state after being warmed. And the control part 11 has permitted permitting the output of the electromagnetic induction heating unit 6 to be the maximum, when this circulation amount is the amount of abnormal overheating suppression at the time of maximum output. Thereby, even if it is a case where the induction heating by the electromagnetic induction heating unit 6 is performed by the maximum output, the abnormal temperature rise of the induction heating target part can be suppressed.

<Other embodiments>
As mentioned above, although embodiment of this invention was described based on drawing, a specific structure is not restricted to these embodiment, It can change in the range which does not deviate from the summary of invention.

(A)
In the above embodiment, the case where SUS430 is used as the material of the magnetic tube F2 has been described as an example.

  However, the present invention is not limited to this. For example, a conductor such as iron, copper, aluminum, chromium, nickel, and an alloy containing at least two kinds of metals selected from these groups can be used.

  Examples of the magnetic material include three types of ferrite, martensite, and austenite, and combinations of these types, but are ferromagnetic and have a relatively high electrical resistance. A material having a Curie temperature higher than the operating temperature range is preferable.

  The accumulator tube F here requires more electric power, but does not have to include a magnetic body and a material containing the magnetic body, and contains a material to be subjected to induction heating. It may be a thing.

  For example, the magnetic material may constitute all of the accumulator pipe F, or may be formed only on the inner surface of the accumulator pipe F, and is contained in the material constituting the accumulator pipe F pipe. May exist.

(B)
In the said 2nd Embodiment, the case where the dryness or superheat degree of the suction | inhalation refrigerant | coolant of the compressor 21 was grasped | ascertained using the detected temperature of the electromagnetic induction thermistor 14 was mentioned as an example, and was demonstrated.

  However, the present invention is not limited to this.

  For example, in the electromagnetic induction thermistor 14, it is difficult to detect the temperature of the refrigerant flowing through the induction heating portion during induction heating by the electromagnetic induction heating unit 6, and a higher temperature is generated by the heat generation of the magnetic body tube F 2. It may be detected.

  In such a case, instead of the electromagnetic induction thermistor 14, the induction heating target portion is between the induction heating target portion and the suction side of the compressor 21, and the heat conduction error due to induction heating is negligible. You may further provide the sensor which detects the temperature of the accumulation pipe | tube F of the distant place. Thereby, even during induction heating, the dryness or superheat degree of the refrigerant sucked in the compressor 21 can be grasped more accurately.

(C)
The induction heating start condition and the induction heating end condition of the first embodiment and the induction heating start condition and the induction heating end condition of the second embodiment have been described by way of example with the same condition setting.

  However, the present invention is not limited to this. For example, in the abnormal overheat suppression wetness protection control of the second embodiment, the output of the electromagnetic induction heating unit 6 that is already outputting the induction heating at 50% is further increased to the maximum output. For this reason, the induction heating start condition (induction heating start condition of the second embodiment) for increasing the maximum output is such that the refrigerant sucked in the compressor 21 is wetter than the induction heating start condition of the first embodiment. You may make it a condition.

(D)
In the second embodiment, the case where the output by the electromagnetic induction heating unit 6 is increased from 50% to the maximum output when the refrigerant circulation amount of the abnormal overheat suppression amount is secured has been described as an example.

  However, the present invention is not limited to this. For example, the output of the electromagnetic induction heating unit 6 may be adjusted according to the obtained refrigerant circulation amount.

(E)
In the first and second embodiments, the case where it is determined whether or not the abnormal overheat suppression amount has been reached and whether or not the maximum output abnormal overheat suppression amount has been reached has been described as an example.

  However, the present invention is not limited to this. For example, when the output by the electromagnetic induction heating unit 6 cannot be increased because the abnormal overheat suppression amount or the maximum overheating suppression amount is not reached, control to increase the rotational frequency of the compressor 21 is performed to perform induction heating. You may make it produce the condition which can increase the capability of the induction heating by the electromagnetic induction heating unit 6 positively, without accompanying the abnormal temperature rise of an object part.

(F)
In the said 1st Embodiment, the case where stabilization of the refrigerant | coolant state of a refrigerating cycle was performed by supercooling degree constant control was mentioned as an example, and was demonstrated.

  However, the present invention is not limited to this.

  For example, the degree of change in the refrigerant distribution state in the refrigeration cycle may be controlled to be maintained for a predetermined time in a predetermined distribution state or within a predetermined distribution range. As the detection of the refrigerant distribution state, for example, the refrigerant distribution state is grasped by grasping the liquid level of the refrigerant by, for example, providing a sight glass in the condenser of the refrigeration cycle, and this distribution state is a predetermined distribution state or Stabilization control may be performed so as to be within a predetermined distribution range.

(G)
In the above embodiment, the case where the electromagnetic induction heating unit 6 is attached to the accumulator tube F in the refrigerant circuit 10 has been described.

  However, the present invention is not limited to this.

  For example, other refrigerant pipes other than the accumulator pipe F may be provided. In this case, a magnetic material such as the magnetic material tube F2 is provided in the refrigerant piping portion where the electromagnetic induction heating unit 6 is provided.

(H)
In the said embodiment, the case where the accumulation pipe F was comprised as a double pipe | tube of the copper pipe F1 and the magnetic body pipe | tube F2 was mentioned and demonstrated.

  However, the present invention is not limited to this.

  As shown in FIG. 11, for example, the magnetic member F2a and the two stoppers F1a may be disposed inside the accumulator pipe F or the refrigerant pipe to be heated. Here, the magnetic member F2a contains a magnetic material, and is a member that generates heat by electromagnetic induction heating in the above embodiment. The stopper F1a always allows passage of the refrigerant at two locations inside the copper tube F1, but does not allow passage of the magnetic member F2a. Thereby, the magnetic member F2a does not move even when the refrigerant flows. For this reason, the target heating position of the accumulator tube F or the like can be heated. Furthermore, since the magnetic member F2a that generates heat and the refrigerant are in direct contact, the heat transfer efficiency can be improved.

(I)
The magnetic member F2a described in the other embodiment (H) may be positioned with respect to the pipe without using the stopper F1a.

  As illustrated in FIG. 12, for example, the copper pipe F <b> 1 may be provided with two bent portions FW, and the magnetic member F <b> 2 a may be disposed inside the copper pipe F <b> 1 between the two bent portions FW. Even in this case, the movement of the magnetic member F2a can be suppressed while allowing the refrigerant to pass therethrough.

(J)
In the above embodiment, the case where the coil 68 is spirally wound around the accumulator tube F has been described.

  However, the present invention is not limited to this.

  For example, as shown in FIG. 13, the coil 168 wound around the bobbin main body 165 may be arranged around the accumulator tube F without being wound around the accumulator tube F. Here, the bobbin main body 165 is disposed so that the axial direction is substantially perpendicular to the axial direction of the accumulator tube F. Further, the bobbin main body 165 and the coil 168 are arranged separately in two so as to sandwich the accumulator tube F.

  In this case, for example, as shown in FIG. 14, the first bobbin lid 163 and the second bobbin lid 164 penetrating the accumulator tube F may be arranged in a state of being fitted to the bobbin main body 165. Good.

  Further, as shown in FIG. 15, the first bobbin lid 163 and the second bobbin lid 164 may be sandwiched and fixed by the first ferrite case 171 and the second ferrite case 172. In FIG. 15, the case where the two ferrite cases are arranged so as to sandwich the accumulator tube F is taken as an example, but may be arranged in four directions as in the above embodiment. Moreover, you may accommodate the ferrite similarly to the said embodiment.

<Others>
The embodiments of the present invention have been described above with some examples, but the present invention is not limited to these. For example, combined embodiments obtained by appropriately combining different portions of the above-described embodiments within the scope that can be implemented by those skilled in the art from the above description are also included in the present invention.

  If the present invention is used, it is possible to suppress excessive heat generation by a member that generates heat by induction heating, and thus it is particularly useful in an air conditioner that can heat a refrigerant by electromagnetic induction heating.

DESCRIPTION OF SYMBOLS 1 Air conditioning apparatus 11 Control part 19 Suction temperature sensor (intake refrigerant temperature grasping part)
21 Compressor (compression mechanism)
23 Outdoor heat exchanger (refrigerant heater)
24 Electric expansion valve (expansion mechanism)
29a 1st pressure sensor 29g 2nd pressure sensor (low pressure grasping part)
29r Number of revolutions grasping part (circulation amount grasping part)
41 Indoor heat exchanger (refrigerant cooler)
44 Indoor heat exchange temperature sensor (supercooling degree grasping part)
68 Coil (Magnetic field generator)
F accumulator pipe (refrigerant pipe)

JP 2007-255736 A

Claims (7)

An air conditioner (1) including at least a compression mechanism (21), a refrigerant cooler (41), an expansion mechanism (24), and a refrigerant heater (23),
Refrigerant piping (F) for circulating the refrigerant through the compression mechanism (21), the refrigerant cooler (41), the expansion mechanism (24), and the refrigerant heater (23), and / or the refrigerant piping ( F) a magnetic field generator (68) for generating a magnetic field for inductively heating a member that is in thermal contact with the refrigerant flowing through the medium;
A circulation amount grasping part (29r) for grasping a refrigerant circulation amount of a refrigeration cycle including at least the compression mechanism (21), the refrigerant cooler (41), the expansion mechanism (24), and the refrigerant heater (23);
When the refrigerant circulation amount grasped by the circulation amount grasping unit (29r) increases, the control unit (11) performs magnetic field output control for generating a magnetic field in the magnetic field generating unit (68) or increasing the upper limit of the generated magnetic field. )When,
An air conditioner (1) comprising: The magnetic field generator (68) is in thermal contact with the refrigerant flowing through the suction refrigerant pipe (F) and / or the suction refrigerant pipe (F) on the suction side of the compression mechanism (21) in the refrigerant pipe. Generating a magnetic field for inductively heating the member
The air conditioner (1) according to claim 1. The circulation amount grasping part (29r) is based on at least a predetermined piston displacement of the compression mechanism (21), a driving frequency of the compression mechanism (21), and a suction refrigerant density of the compression mechanism (21). Define
The air conditioner (1) according to claim 1 or 2. A low pressure grasping portion (29g) for grasping the pressure of the refrigerant flowing in the low pressure portion of the refrigeration cycle;
An intake refrigerant temperature grasping part (19) for grasping an intake refrigerant temperature of the compression mechanism (21);
Further comprising
The circulation amount grasping part (11) obtains the suction refrigerant density of the compression mechanism (21) using the pressure grasped by the low pressure grasping part (29g) and the temperature grasped by the suction refrigerant temperature grasping part (19). ,
The air conditioner (1) according to claim 3. The suction refrigerant temperature grasping part (19) is a refrigerant that passes on the suction side of the compression mechanism (21) in the refrigeration cycle and downstream of the part heated by induction by the magnetic field generation part (68). Detect the state quantity of the
The air conditioner (1) according to claim 4. The control unit (11) performs the magnetic field output control when the suction refrigerant of the compression mechanism (21) is in a wet state or in an overheat state of a predetermined superheat degree or less.
The air conditioner (1) according to claim 4 or 5. The control unit (11) performs the magnetic field output control when the refrigerant circulation amount grasped by the circulation amount grasping unit (29r) exceeds a predetermined value.
The air conditioner (1) according to any one of claims 1 to 6.

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