JP4826643B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner.

  As an air conditioner capable of heating operation, one having a refrigerant heating function has been proposed for the purpose of increasing the heating capacity.

  For example, in the air conditioner described in Patent Document 1 (Japanese Patent Laid-Open No. 2000-97510) shown below, the heating capacity is increased by heating the refrigerant flowing into the refrigerant heater with a gas burner.

  Here, in the air conditioner described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2000-97510), during the heating operation, the temperature of the refrigerant is excessively increased, so that the protection operation is not frequently performed. In addition, a technique for adjusting the combustion amount of the gas burner based on the detection value of the thermistor has been proposed.

  In the technique described in Patent Document 1 described above, only the frequency of the protection operation is suppressed, and no control has been proposed that pays attention to the difference in load at the time of activation and after activation.

  For example, when the air conditioner starts up, the difference between the ambient temperature and the set temperature is large, and it is desirable to quickly approach the set temperature. On the other hand, if the load at the start and after the start is different, increase the target value. There is a risk that overshoot will occur.

  In addition, when the heating method of a refrigerant | coolant is an electromagnetic induction heating method, since the heating rate is quick, the above-mentioned overshoot tends to become a problem especially.

  The present invention has been made in view of the above-described points, and an object of the present invention is to provide an air conditioner that can ensure the ability at the time of startup quickly and can keep the overshoot after startup small. There is.

  An air conditioner according to a first aspect of the invention is an air conditioner that uses a refrigeration cycle including a refrigerant mechanism and / or a member that is in thermal contact with the refrigerant flowing in the refrigerant pipe and includes a compression mechanism that circulates the refrigerant. The apparatus includes a magnetic field generation unit, a refrigerant state quantity detection unit, and a control unit. The magnetic field generation unit generates a magnetic field for induction heating of a portion to be heated by induction heating. The refrigerant state quantity detection unit detects a state quantity relating to the refrigerant flowing through the predetermined state quantity detection part that is at least a part of the refrigeration cycle. The state quantity here includes, for example, at least one of temperature and pressure. The control unit performs startup magnetic field generation control and post-startup magnetic field generation control. In start-up magnetic field generation control, the control unit starts a state in which the output from the magnetic field generation unit is set to a predetermined maximum output at the start of heating operation in the refrigeration cycle from the time when the compression mechanism is in the drive state. The process is terminated when the state quantity detected by the refrigerant state quantity detection unit reaches the first predetermined target state quantity. In the post-startup magnetic field generation control, the control unit performs a state in which the first magnetic field limit reference value lower than the predetermined maximum output is constrained as the upper limit of the output of the magnetic field generation unit after the start-up magnetic field generation control ends. Here, “when the refrigeration cycle is performing the heating operation” does not include, for example, an operation such as a defrosting operation. In addition, as the heating by the electromagnetic induction heating unit here, for example, in the case of electromagnetic induction heating of a heat generating member that is in thermal contact with the refrigerant pipe, heat generation that is in thermal contact with the refrigerant flowing in the refrigerant pipe The case where the member is heated by electromagnetic induction and the case where the heating member constituting at least a part of the refrigerant pipe is heated by electromagnetic induction are included at least.

  In this air conditioner, by performing start-up magnetic field generation control that maximizes the output of the magnetic field generation unit at start-up, the time required from the start of heating operation to the time when warm air is provided to the user is reduced. It becomes possible to shorten. In the magnetic field generation control after startup, it is possible to suppress the control overshoot caused by excessively increasing the output from the magnetic field generation unit. As a result, it is possible to suppress the control overshoot to be small while quickly starting the supply of warm air to the user.

  The air conditioner according to a second aspect of the present invention is the air conditioner according to the first aspect of the present invention, wherein the heating target portion of the induction heating includes a magnetic material.

  In this air conditioner, since the magnetic field generator generates a magnetic field for a portion containing the magnetic material, heat generation efficiency by electromagnetic induction can be efficiently performed.

  An air conditioner according to a third aspect is the air conditioner according to the first or second aspect, wherein the predetermined state quantity detection part is a part where a magnetic field is generated by the magnetic field generator.

  In this air conditioner, since it becomes possible to grasp a rapid temperature change due to electromagnetic induction heating, it becomes possible to improve control responsiveness.

  The air conditioner according to a fourth aspect of the present invention is the air conditioner according to any one of the first to third aspects of the invention, wherein the state quantity detected by the refrigerant state quantity detector is a temperature and pressure related to the refrigerant flowing through the predetermined state quantity detector. At least one of them.

  In this air conditioner, it is possible to perform detection here using various sensors used for state control of the refrigeration cycle.

  The air conditioner according to a fifth aspect of the present invention is the air conditioner according to any one of the first to fourth aspects of the invention, wherein the refrigerant state quantity detector is a temperature detector that detects the temperature related to the refrigerant flowing through the predetermined state quantity detector. . In the post-startup magnetic field generation control, the control unit performs post-startup magnetic field generation PI control for PI control of the output value or output frequency of the magnetic field generation unit so that the temperature detected by the temperature detection unit is maintained at the target maintenance temperature. The target maintenance temperature here may be the same temperature as the first predetermined target temperature.

  In this air conditioner, the temperature change due to electromagnetic induction heating is generally more rapid than the temperature change caused by the change in the state of the refrigerant passing through the predetermined state quantity detection part. Here, even when the temperature is suddenly changed by electromagnetic induction heating, the magnitude of the magnetic field generated in the magnetic field generator and / or the frequency of generating the magnetic field in the magnetic field generator is controlled by PI. It becomes possible to stabilize the temperature detected by the temperature detector at the second predetermined target temperature.

  An air conditioner according to a sixth aspect is the air conditioner according to any one of the first to fifth aspects, wherein the refrigerant state quantity detector is a temperature detector that detects a temperature related to the refrigerant flowing through the predetermined state quantity detector. . The control unit executes startup magnetic field generation control after satisfying the magnetic field level increase condition. The condition for increasing the magnetic field level is that the temperature detected by the temperature detector is changed by performing a magnetic field level change process that raises or lowers the level of the magnetic field generated by the magnetic field generator within a range lower than the predetermined maximum output. Alternatively, the temperature detection unit detects a temperature change.

  Even when electromagnetic induction heating is performed, if the temperature detection unit cannot detect a temperature change, the attachment state of the temperature detection unit may be unstable or detached.

  On the other hand, in this air conditioner, when the mounting state of the temperature detection unit is unstable or disconnected in this way, the temperature change does not occur sufficiently and the magnetic field level increase condition is satisfied. No. For this reason, since the generation of the magnetic field is limited so that the control unit has a level lower than the predetermined maximum output, and the magnetic field is not generated at a high level, the reliability of the device can be improved. . When the condition for increasing the magnetic field level is met, the heating target part of the induction heating is generating heat due to the generation of the magnetic field by the magnetic field generation part, the installation state of the temperature detection part is good, and the temperature of the heating target part of the induction heating is good. Can be recognized accurately. As a result, it is possible to suppress damage to the device due to an abnormal temperature rise due to electromagnetic induction heating, and it is possible to improve the reliability of the device.

  An air conditioner according to a seventh aspect is the air conditioner according to the sixth aspect, wherein the maximum magnetic field level output in the magnetic field level change process is a value smaller than the first magnetic field limit reference value.

  In this air conditioner, it is possible to prevent electromagnetic induction heating due to a magnetic field having a magnitude of about the first magnetic field limit reference value at a stage where it is not confirmed that the temperature detector is attached in a good state.

  An air conditioner according to an eighth aspect of the present invention is the air conditioner according to any one of the first to seventh aspects, wherein the refrigerant state quantity detector is a temperature detector that detects a temperature related to the refrigerant flowing through the predetermined state quantity detector. . The control unit executes the determination of the magnetic field level increase condition after satisfying the flow condition. The flow condition is that when the compression mechanism realizes both compression mechanism states in which the output of the compression mechanism is different between the first compression mechanism state and the second compression mechanism state whose output level is higher than the first compression mechanism state. That is, there is a change in the detected temperature of the temperature detection unit between the first compression mechanism state and the second compression mechanism state. The first compression mechanism state includes a state where the compression mechanism is stopped.

  In this air conditioner, if the flow condition is not satisfied, the refrigerant flow is insufficient, and even if the output from the magnetic field generation unit is at a level for determining the magnetic field level increase condition, There is a risk of causing an increase in temperature. On the other hand, in this air conditioner, it is possible to execute the determination of the magnetic field level increase condition while ensuring the flow of the refrigerant that passes through the predetermined state quantity detection portion, so that the magnetic field can be maintained while maintaining the reliability of the device. It is possible to determine the level increase condition.

  An air conditioner according to a ninth aspect is the air conditioner according to any one of the first to eighth aspects, wherein the refrigerant state quantity detector is a temperature detector that detects a temperature related to the refrigerant flowing through the predetermined state quantity detector. . After starting the magnetic field generation control after startup, and when the defrosting operation different from the heating operation is being performed in the refrigeration cycle, the control unit sets the upper limit of the output of the magnetic field generation unit as a predetermined maximum output and detects the temperature. Defrosting operation output control for controlling the output of the magnetic field generation unit based on the detected temperature of the unit is performed.

  In this air conditioner, the output from the magnetic field generation unit can be increased in the same manner as the startup magnetic field generation control, so that the defrosting process can be speeded up.

  An air conditioner according to a tenth aspect of the present invention is the air conditioner according to the ninth aspect of the present invention, wherein the controller detects the second predetermined target temperature at which the temperature detected by the temperature detector is lower than the first predetermined target temperature during the defrosting operation output control. The defrosting PI control is performed to perform the PI control so as to be maintained at

  In this air conditioner, during the defrosting operation, an abnormal temperature rise is less likely to occur than in the startup magnetic field generation control. Therefore, the temperature of the startup magnetic field generation control is the second predetermined target temperature. It becomes possible to reduce the overshoot at the time of defrosting operation by making it lower than 1 predetermined target temperature.

  An air conditioner according to an eleventh aspect of the present invention is the air conditioner according to any one of the first to tenth aspects of the invention, wherein the refrigerant state quantity detector is a temperature detector that detects a temperature related to the refrigerant flowing through the predetermined state quantity detector. . An elastic member that gives an elastic force to the temperature detection unit is further provided. The temperature detection unit is in pressure contact with the predetermined state quantity detection portion by the elastic force of the elastic member.

  In this air conditioner, when electromagnetic induction heating is performed, generally, a rapid temperature increase is more likely to occur than a temperature increase due to a change in the circulation state of the refrigerant in the refrigeration cycle.

  On the other hand, in this air conditioner, since the state pressed against the predetermined state quantity detection portion is maintained by the elastic member, the responsiveness of the temperature detection unit can be improved. This makes it possible to perform control with improved responsiveness.

  In the air conditioner according to the first aspect of the present invention, it is possible to suppress the control overshoot small while quickly starting the supply of warm air to the user.

  In the air conditioner of the second invention, it is possible to efficiently perform the heat generation efficiency by electromagnetic induction.

  In the air conditioner of the third aspect of the invention, it becomes possible to improve control responsiveness.

  In the air conditioner of the fourth aspect of the invention, it is possible to perform detection here using various sensors used for state control of the refrigeration cycle.

  In the air conditioner of the fifth aspect, the temperature detected by the temperature detector can be stabilized at the second predetermined target temperature.

  In the air conditioner according to the sixth aspect of the present invention, it is possible to suppress damage to the device due to an abnormal temperature rise due to electromagnetic induction heating, and it is possible to improve the reliability of the device.

  In the air conditioner according to the seventh aspect of the present invention, it is possible to prevent electromagnetic induction heating due to a magnetic field having a magnitude of the first magnetic field limit reference value at a stage where it is not confirmed that the temperature detector is properly attached. Become.

  In the air conditioner according to the eighth aspect of the present invention, it is possible to determine the condition for increasing the magnetic field level while maintaining the reliability of the device.

  In the air conditioner according to the ninth aspect of the invention, it is possible to speed up the defrosting process.

  In the air conditioner of the tenth aspect, overshoot during defrosting operation can be reduced.

  In the air conditioner of the eleventh aspect of the invention, it is possible to perform control with improved responsiveness.

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 including the front side of an outdoor unit. It is an internal arrangement configuration perspective view of an outdoor unit. It is an external appearance perspective view containing the back side of the internal arrangement structure of an outdoor unit. It is a whole front perspective view which shows the internal structure of the machine room of an outdoor unit. It is a perspective view which shows the internal structure of the machine room of an outdoor unit. It is a perspective view of a bottom plate of an outdoor unit and an outdoor heat exchanger. It is a top view in the state where the ventilation mechanism of the outdoor unit was removed. It is a top view which shows the arrangement | positioning relationship between the baseplate of an outdoor unit, and a hot gas bypass circuit. 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 time chart of electromagnetic induction heating control. It is a figure which shows the flowchart of a flow condition determination process. It is a figure which shows the flowchart of a sensor disconnection detection process. It is a figure which shows the flowchart of a rapid pressure increase process. It is a figure which shows the flowchart of a steady output process. It is a figure which shows the flowchart of a defrost process. It is a figure which shows the attachment position of the electromagnetic induction thermistor concerning other embodiment (A). It is explanatory drawing of the refrigerant | coolant piping of other embodiment (F). It is explanatory drawing of refrigerant | coolant piping of other embodiment (G). It is a figure which shows the example of arrangement | positioning with the coil and refrigerant | coolant piping of other embodiment (H). It is a figure which shows the example of arrangement | positioning of the bobbin lid of other embodiment (H). It is a figure which shows the example of arrangement | positioning of the ferrite case of other embodiment (H).

  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.

<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, outdoor 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 An electromagnetic induction heating unit 6 and the like are provided.

  The compressor 21, the four-way switching valve 22, the outdoor heat exchanger 23, the outdoor 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. Is housed in. 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, a hot gas bypass circuit H, and a branch pipe K. And a merging pipe J. 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 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 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 outdoor electric expansion valve 24.

  The outdoor liquid pipe D connects the outdoor 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.

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. (See FIG. 15). 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. In addition, the material of the pipe | tube covering the circumference | surroundings of the said copper pipe | tube is not limited to SUS430, For example, at least 2 or more types of metals chosen from conductors, such as iron, copper, aluminum, chromium, nickel, and these groups are used. It can be an alloy or the like. Examples of the magnetic material include a ferrite material , a martensite material, and a combination of these types. Examples of the magnetic material include a ferromagnetic material that has a relatively high electric resistance and is higher than the operating temperature range. However, a material having a high Curie temperature 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. 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 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 reduced by the outdoor electric expansion valve 24 during the heating operation, the chamber by the supply of hot gas to the outdoor liquid pipe D through the hot gas bypass circuit H is provided. An increase in the refrigerant pressure in the outer liquid pipe D can be suppressed.

  The branch pipe K constitutes a part of the outdoor heat exchanger 23, and a refrigerant pipe extending from the gas side inlet / outlet 23e of the outdoor heat exchanger 23 will be described later in order to increase the effective surface area for heat exchange. It is a pipe branched into a plurality of lines at a branching junction 23k. The branch pipe K includes a first branch pipe K1, a second branch pipe K2, and a third branch pipe K3 that extend independently from the branch junction point 23k to the junction branch point 23j. The pipes K1, K2, and K3 merge at the merge branch point 23j. Note that, when viewed from the merging pipe J side, the branch pipe K extends at a merging branch point 23j.

  The junction pipe J constitutes a part of the outdoor heat exchanger 23 and extends from the junction branch point 23j to the liquid side inlet / outlet 23d of the outdoor heat exchanger 23. The junction pipe J can unify the degree of supercooling of the refrigerant flowing out of the outdoor heat exchanger 23 during the cooling operation, and can defrost frosted ice near the lower end of the outdoor heat exchanger 23 during the heating operation. . The junction pipe J has a cross-sectional area that is approximately three times the cross-sectional area of each of the branch pipes K1, K2, and K3, and the amount of refrigerant passing through is approximately three times that of each of the branch pipes K1, K2, and K3. .

  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.

The outdoor heat exchanger 23 includes a gas side inlet / outlet 23e, a liquid side inlet / outlet 23d, a branch junction 23k, a junction branch point 23j, a branch pipe K, a junction pipe J, and a heat exchange fin 23z. The gas side inlet / outlet 23 e is located at the end of the outdoor heat exchanger 23 on the outdoor gas pipe E side, and is connected to the outdoor gas pipe E. The liquid side inlet / outlet 23 d is located at the end of the outdoor heat exchanger 23 on the outdoor liquid pipe D side, and is connected to the outdoor liquid pipe D. The branch junction 23k branches a pipe extending from the gas side inlet / outlet port 23e, and can branch or join the refrigerant according to the direction of the flowing refrigerant. A plurality of branch pipes K extend from each branch portion at the branch junction 23k. The junction branch point 23j joins the branch pipe K and can join or branch the refrigerant according to the direction of the flowing refrigerant. The junction pipe J extends from the junction branch point 23j to the liquid side inlet / outlet 23d. The heat exchange fins 23z are configured by arranging a plurality of plate-like aluminum fins in the thickness direction and arranged at predetermined intervals. The branch pipe K and the merge pipe J both have the heat exchange fins 23z as a common penetration target. Specifically, the branch pipe K and the junction pipe J are disposed so as to penetrate in the plate pressure direction at different portions of the common heat exchange fin 23z. This the outdoor heat exchanger 23, the air flow direction wind upper side of the outdoor fan 26, the outdoor air temperature sensor 29b for detecting the temperature of the outdoor is provided. 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 branch pipe air conditioner.

  In the indoor unit 4, an indoor temperature sensor 43 that detects the indoor temperature is provided. 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 outdoor 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> Outdoor unit 2
In FIG. 2, the external appearance perspective view of the front side of the outdoor unit 2 is shown. In FIG. 3, the perspective view about the positional relationship with the outdoor heat exchanger 23 and the outdoor fan 26 is shown. In FIG. 4, the perspective view of the back side of the outdoor heat exchanger 23 is shown.

  The outdoor unit 2 has an outer surface formed by a substantially rectangular parallelepiped outdoor unit casing that includes a top plate 2a, a bottom plate 2b, a front panel 2c, a left side panel 2d, a right side panel 2f, and a back panel 2e.

  In the outdoor unit 2, an outdoor heat exchanger 23, an outdoor fan 26, and the like are arranged, a blower room on the left side panel 2d side, a compressor 21 and an electromagnetic induction heating unit 6 are arranged, and the right side panel 2f side. The machine room is separated by a partition plate 2h. The outdoor unit 2 is fixed by being screwed to the bottom plate 2b, and has an outdoor unit support 2g that forms the lowermost end portion of the outdoor unit 2 on the right side and the left side. The electromagnetic induction heating unit 6 is disposed at an upper position in the vicinity of the left side panel 2d and the top plate 2a in the machine room. Here, the heat exchange fins 23z of the outdoor heat exchanger 23 described above are arranged side by side in the plate thickness direction so that the plate thickness direction is substantially horizontal. The joining pipe J is disposed in the lowermost portion of the heat exchange fins 23z of the outdoor heat exchanger 23 by penetrating the heat exchange fins 23z in the thickness direction. The hot gas bypass circuit H is arranged along the lower side of the outdoor fan 26 and the outdoor heat exchanger 23.

<1-3> Internal Structure of Outdoor Unit 2 FIG. 5 is an overall front perspective view showing the internal structure of the machine room of the outdoor unit 2. FIG. 6 is a perspective view showing the internal structure of the machine room of the outdoor unit 2. In FIG. 7, the perspective view about the arrangement | positioning relationship between the outdoor heat exchanger 23 and the baseplate 2b is shown.

  The partition plate 2h of the outdoor unit 2 includes a fan room in which the outdoor heat exchanger 23 and the outdoor fan 26 are arranged, a machine room in which the electromagnetic induction heating unit 6, the compressor 21, the accumulator 25, and the like are arranged, Is partitioned from the upper end to the lower end from the front to the rear. The compressor 21 and the accumulator 25 are disposed in a space below the machine room of the outdoor unit 2. The electromagnetic induction heating unit 6, the four-way switching valve 22, and the outdoor control unit 12 are disposed in a space above the machine room of the outdoor unit 2 and above the compressor 21, the accumulator 25, and the like. . A compressor 21, a four-way switching valve 22, an outdoor heat exchanger 23, an outdoor electric expansion valve 24, an accumulator 25, a hot gas bypass valve 27, a capillary, which are functional elements constituting the outdoor unit 2 and are disposed in the machine room The tube 28 and the electromagnetic induction heating unit 6 include a discharge pipe A, an indoor side gas pipe B, an outdoor side liquid pipe D, an outdoor side gas pipe E, an accumulator so as to execute the refrigeration cycle by the refrigerant circuit 10 shown in FIG. They are connected via a tube F, a hot gas bypass circuit H, and the like. Here, as will be described later, the hot gas bypass circuit H is configured by connecting nine parts of the first bypass part H1 to the ninth bypass part H9, and when the refrigerant flows into the hot gas bypass circuit H, , Flows in the direction from the first bypass portion H1 toward the ninth bypass portion H9 in order.

<1-4> Junction piping J and branch piping K
As described above, the merge pipe J shown in FIG. 7 has an area equivalent to the cross-sectional area of each of the first branch pipe K1, the second branch pipe K2, and the third branch pipe K3. In the outdoor heat exchanger 23, the heat exchange effective surface area can be increased more than the merged pipe J in the first branch pipe K1, the second branch pipe K2, and the third branch pipe K3. In addition, since a large amount of refrigerant flows in the merging pipe J in a concentrated manner as compared with the first branch pipe K1, the second branch pipe K2, and the third branch pipe K3, the outdoor heat Ice growth under the exchanger 23 can be more effectively suppressed. Here, the merging pipe J is configured by connecting the first merging pipe part J1, the second merging pipe part J2, the third merging pipe part J3, and the fourth merging pipe part J4 as shown in FIG. Has been. And the refrigerant | coolant which flowed through the branch piping K among the outdoor heat exchangers 23 is merged in the merge branch point 23j, and the flow of the refrigerant in the refrigerant circuit 10 is put together into one, and the outdoor heat exchanger 23 It arrange | positions so that the lowest end part may reciprocate once. Here, the first merging pipe portion J1 extends from the merging branch point 23j to the heat exchange fins 23z disposed at the outermost edge portion of the outdoor heat exchanger 23. The second joining pipe portion J2 extends from the end of the first joining pipe portion J1 so as to penetrate the plurality of heat exchange fins 23z. Moreover, the 4th junction piping part J4 is extended so that the several heat exchanger fin 23z may be penetrated similarly to the 2nd junction piping part J2. The third joining pipe portion J3 is a U-shaped pipe that connects the second joining pipe portion J2 and the fourth joining pipe portion J4 at the end of the outdoor heat exchanger 23. During the cooling operation, the refrigerant flow in the refrigerant circuit 10 is divided into a plurality of flows in the branch pipe K by the merge pipe J. Therefore, even if the merge branch point 23j of the refrigerant flowing through the branch pipe K is Even if the degree of supercooling in the immediately preceding portion is different for each refrigerant flowing through the individual pipes constituting the branch pipe K, the refrigerant flow can be made one in the junction pipe J, so that the supercooling at the outlet of the outdoor heat exchanger 23 The degree can be adjusted. When the defrosting operation is performed during the heating operation, the hot gas bypass valve 27 is opened, and the high-temperature refrigerant discharged from the compressor 21 is placed outside the outdoor heat exchanger 23 before the outdoor part. It can be supplied to the junction pipe J provided at the lower end of the heat exchanger 23. For this reason, ice that has formed frost in the vicinity of the lower part of the outdoor heat exchanger 23 can be effectively thawed.

<1-5> Hot gas bypass circuit H
In FIG. 8, the top view in the state which removed the ventilation mechanism of the outdoor unit 2 is shown. FIG. 9 is a plan view showing the positional relationship between the bottom plate of the outdoor unit 2 and the hot gas bypass circuit H.

  As shown in FIGS. 8 and 9, the hot gas bypass circuit H includes a first bypass portion H1 to an eighth bypass portion H8. Here, the hot gas bypass circuit H branches from the discharge pipe A at the branch point A1 and extends to the hot gas bypass valve 27, and a portion further extending from the hot gas bypass valve 27 is the first bypass portion H1. The second bypass portion H2 extends from the end of the first bypass portion H1 to the blower chamber side in the vicinity of the back surface side. The third bypass portion H3 extends from the end of the second bypass portion H2 toward the front side. The fourth bypass portion H4 extends from the end of the third bypass portion H3 toward the left side that is the opposite side to the machine room side. The fifth bypass portion H5 extends from the end of the fourth bypass portion H4 toward the back side to a portion where a space can be ensured between the back panel 2e of the outdoor unit casing. The sixth bypass portion H6 extends from the end of the fifth bypass portion H5 to the right side that is the machine room side and toward the back side. The seventh bypass portion H7 extends from the end of the sixth bypass portion H6 toward the right side, which is the machine room side, in the blower chamber. The eighth bypass portion H8 extends in the machine room from the end of the seventh bypass portion H7. The ninth bypass portion H9 extends from the end of the eighth bypass portion H8 to the capillary tube 28. As described above, the hot gas bypass circuit H causes the refrigerant to flow in order from the first bypass portion H1 toward the ninth bypass portion H9 with the hot gas bypass valve 27 opened. For this reason, the refrigerant branched at the branch point A1 of the discharge pipe A extending from the compressor 21 flows on the first bypass portion H1 side before the refrigerant flowing through the ninth bypass portion H9. For this reason, since the refrigerant flowing through the hot gas bypass circuit H as a whole flows through the fourth bypass portion H4, the refrigerant flows into the fifth to eighth bypass portions H8, and thus the fourth bypass portion H4. The flow direction in which the refrigerant flowing through the refrigerant is likely to become higher than the refrigerant temperature flowing through the fifth to eighth bypass portions H8 is adopted.

  As described above, the hot gas bypass circuit H is disposed so as to pass through the vicinity of the lower part of the outdoor fan 26 and the lower part of the outdoor heat exchanger 23 in the bottom plate 2b of the outdoor unit casing. For this reason, without using a separate heat source such as a heater, the vicinity of the portion through which the hot gas bypass circuit H passes can be warmed by the high-temperature refrigerant branched and supplied from the discharge pipe A of the compressor 21. Therefore, even if the upper side of the bottom plate 2b gets wet by rain water or the drain water generated in the outdoor heat exchanger 23, ice grows below the outdoor fan 26 and below the outdoor heat exchanger 23 in the bottom plate 2b. Can be suppressed. As a result, it is possible to avoid a situation where the driving of the outdoor fan 26 is hindered by ice or a situation where the surface of the outdoor heat exchanger 23 is covered with ice and the heat exchange efficiency is reduced. Further, the hot gas bypass circuit H is arranged so as to pass under the outdoor fan 26 after branching at the branch point A1 of the discharge pipe A and before passing under the outdoor heat exchanger 23. For this reason, it is possible to prevent the growth of ice below the outdoor fan 26 more preferentially.

<1-6> Electromagnetic induction heating unit 6
FIG. 10 is a schematic perspective view of the electromagnetic induction heating unit 6 attached to the accumulator tube F. FIG. 11 shows an external perspective view of the electromagnetic induction heating unit 6 with the shielding cover 75 removed. In FIG. 12, sectional drawing of the electromagnetic induction heating unit 6 attached to the accumulation pipe | tube F is shown.

  The electromagnetic induction heating unit 6 is arranged so as to cover the magnetic body tube F2 that is a heat generating portion of the accumulator tube F from the outside in the radial direction, and heats the magnetic body tube F2 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 shown in FIG. 12 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 shown in FIG. 13 and attaching it to the outer surface of the magnetic tube F2. As shown in FIG. 12, 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. Fuse 15, as shown in FIG. 1 3, and a fuse sensing unit 15a, an asymmetrical shape 15b, and fuse wires 15d convey the detection result of the fuse sensing portion 15a to the control unit 11 in the 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. Coil 68 is connected to a control printed substrate (not shown) supplied with high frequency current. The output of the control printed circuit board is controlled by the control unit 11. As shown in FIG. 14, 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 pushed inward in the radial direction of the magnetic tube F2 by the leaf spring 17, 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. The first ferrite 98 and second ferrite 99, as shown at the cross section of the accumulator tube F and the electromagnetic induction heating unit 6 in FIG. 15, by forming a path for the magnetic flux takes in the magnetic field generated by the coil 68, The magnetic field is 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.

<1-7> 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.

  Hereinafter, the start-up will be described.

When the heating operation instruction is input from the user to the controller 90, the control unit 11 starts the heating operation. When the heating operation is started, the control unit 11 drives the indoor fan 42 after the compressor 21 is activated and waits for the pressure detected by the pressure sensor 29a to rise to 39 kg / cm 2. Thereby, at the stage where the refrigerant passing through the indoor heat exchanger 41 is not warmed, an unpleasant user's discomfort caused by causing an air flow in the unwarmed room is prevented. Here, electromagnetic induction heating using the electromagnetic induction heating unit 6 is performed in order to shorten the time until the pressure detected by the pressure sensor 29a rises to 39 kg / cm 2 after the compressor 21 is activated. In this electromagnetic induction heating, since the temperature of the accumulator tube F rises rapidly, the control unit 11 performs control to determine whether or not the electromagnetic induction heating can be started before the electromagnetic induction heating is started. Such determination, as shown in the time chart of FIG 6, a flow condition determination processing, and the sensor-separated detection process, there is a rapid pressure-increasing process or the like.

<1-8> Flow condition determination processing When electromagnetic induction heating is performed, in a situation where the refrigerant does not flow through the accumulation tube F, the heating load is applied to a portion of the accumulation tube F where the electromagnetic induction heating unit 6 is attached. It becomes only the refrigerant which is staying. When electromagnetic induction heating is performed by the electromagnetic induction heating unit 6 in a state where the refrigerant does not flow in the accumulation tube F as described above, the temperature of the accumulation tube F rises abnormally enough to deteriorate the refrigerator oil. . Further, the temperature of the electromagnetic induction heating unit 6 itself also rises, and the reliability of the device is lowered. Therefore, here, the accumulator tube is in a stage before starting the electromagnetic induction heating so that the electromagnetic induction heating by the electromagnetic induction heating unit 6 is not performed in a state where the refrigerant does not flow into the accumulator tube F in this way. Flow condition determination processing for confirming that the refrigerant is flowing in F is performed.

The flow condition determination processing, as shown in the flowchart of FIG 7, the following processes are performed.

  In step S11, the controller 11 determines whether or not the controller 90 has received a command for heating operation instead of cooling operation from the user. Since the refrigerant heating by the electromagnetic induction heating unit 6 is necessary in an environment where the heating operation is performed, such a determination is made.

  In step S12, the controller 11 starts the compressor 21 and gradually increases the frequency of the compressor 21.

  In step S13, the control unit 11 determines whether or not the frequency of the compressor 21 has reached the predetermined minimum frequency Qmin. If it is determined that the frequency has reached, the process proceeds to step S14.

In step S14, the control unit 11 starts the flow condition determination process, and the detected temperature data of the electromagnetic induction thermistor 14 when the frequency of the compressor 21 reaches the predetermined minimum frequency Qmin (see point a in FIG. 16 ). The temperature data detected by the outdoor heat exchanger temperature sensor 29c is stored, and the timer 95 starts counting the flow detection time. In a state where the frequency of the compressor 21 does not reach the predetermined minimum frequency Qmin, the refrigerant flowing through the accumulator tube F and the outdoor heat exchanger 23 is in a gas-liquid two-phase state and is maintained at a constant temperature at a saturation temperature. Therefore, the temperature detected by the electromagnetic induction thermistor 14 and the outdoor heat exchange temperature sensor 29c is constant at the saturation temperature and does not change. However, the frequency of the compressor 21 increases after a while, the refrigerant pressure in the outdoor heat exchanger 23 and the accumulator pipe F further decreases, and the saturation temperature starts to decrease, so that the electromagnetic induction thermistor 14 The temperature detected by the outdoor heat exchanger temperature sensor 29c also starts to decrease. Here, since the outdoor heat exchanger 23 is present on the downstream side of the accumulator pipe F with respect to the suction side of the compressor 21, the temperature of the refrigerant passing through the accumulator pipe F starts to decrease. The timing at which the temperature of the refrigerant passing through the outdoor heat exchanger 23 begins to decrease is earlier than the timing (see points b and c in FIG. 17 ).

  In step S15, the control unit 11 determines whether or not the flow detection time of 10 seconds has elapsed from the start of the count of the timer 95. If the flow detection time has elapsed, the control unit 11 proceeds to step S16. On the other hand, if the flow detection time has not yet elapsed, step S15 is repeated.

  In step S16, the control unit 11 detects the detected temperature data and the outdoor heat of the electromagnetic induction thermistor 14 in a state where the refrigerant temperature in the outdoor heat exchanger 23 and the accumulator tube F is lowered when the flow detection time has elapsed. The detected temperature data of the alternating temperature sensor 29c is acquired, and the process proceeds to step S17.

  In step S17, the control unit 11 determines whether or not the detected temperature of the electromagnetic induction thermistor 14 acquired in step S16 is lower by 3 ° C. or more than the detected temperature data of the electromagnetic induction thermistor 14 stored in step S14, and It is determined whether or not the detected temperature of the outdoor heat exchanger temperature sensor 29c acquired in step S16 is lower by 3 ° C. or more than the detected temperature data of the outdoor heat exchanger temperature sensor 29c stored in step S14. That is, it is determined whether or not a decrease in the refrigerant temperature has been detected during the flow detection time. Here, when either one of the detected temperature of the electromagnetic induction thermistor 14 or the detected temperature of the outdoor heat exchange temperature sensor 29c is lowered by 3 ° C. or more, the refrigerant is flowing through the accumulator tube F. The flow condition determination process is terminated when it is determined that the flow of the gas is secured, and the process proceeds to the rapid pressure increase process at the start-up that uses the output of the electromagnetic induction heating unit 6 to the maximum, or the sensor disconnection detection process, etc. To do.

  On the other hand, if neither the detected temperature of the electromagnetic induction thermistor 14 nor the detected temperature of the outdoor heat exchange temperature sensor 29c has decreased by 3 ° C. or more, the process proceeds to step S18.

  In step S <b> 18, the control unit 11 determines that the amount of refrigerant flowing through the accumulator tube F is insufficient for performing induction heating by the electromagnetic induction heating unit 6, and the control unit 11 displays a flow abnormality on the display screen of the controller 90. Output the display.

<1-9> Sensor detachment detection process The sensor detachment detection process is performed after the electromagnetic induction thermistor 14 is attached to the accumulator tube F and the installation of the air conditioner 1 is completed (after the installation is completed, the electromagnetic induction heating unit 6 This is a process for confirming the mounting state of the electromagnetic induction thermistor 14 that is performed when the heating operation is started for the first time. Specifically, after it is determined that the amount of refrigerant flowing in the accumulator tube F is secured in the above-described flow condition determination process, and the output of the electromagnetic induction heating unit 6 is maximized. Before performing the rapid pressure increase process at the time of startup, the control unit 11 performs a sensor detachment detection process.

  When the air conditioner 1 is carried in, unexpected vibrations or the like may be applied to the electromagnetic induction thermistor 14 in an unstable or detached state. The electromagnetic induction heating unit 6 is only activated after the carry-in. In particular, when the reliability is required and the operation of the electromagnetic induction heating unit 6 for the first time after being carried in is properly performed, it can be predicted to some extent that the subsequent operation is also performed stably. . For this reason, the sensor detachment detection process is performed at the timing described above.

In the sensor-separated detection process, as shown in the flowchart of FIG. 1 8, the following processes are performed.

In step S21, the control unit 11 secures the refrigerant flow amount in the accumulator pipe F confirmed by the flow condition determination process or a refrigerant flow amount higher than that, and ends the flow detection time (= sensor detachment detection time). while storing detected temperature data of the electromagnetic induction thermistor 14 at the start) (see point d of FIG. 1 6), it starts the power supply to the coil 68 of the electromagnetic induction heating unit 6. The supply of electric power to the coil 68 of the electromagnetic induction heating unit 6 here is a sensor outage detection with a power outage detection supply power M1 (1 kW) of 50%, which is an output smaller than a predetermined maximum supply power Mmax (2 kW). It takes only 20 seconds as time. At this stage, since it is not yet confirmed that the electromagnetic induction thermistor 14 is attached in a good state, the electromagnetic induction thermistor 14 is The output is suppressed to 50% so that the fuse 15 is not damaged due to the inability to detect an abnormal temperature rise and the resin member of the electromagnetic induction heating unit 6 is not melted. At the same time, since the continuous heating time by the electromagnetic induction heating unit 6 is set in advance so as not to exceed 10 minutes of the maximum continuous output time, the control unit 11 continues the output by the electromagnetic induction heating unit 6. The elapsed time is counted by the timer 95. The supply of electric power to the coil 68 of the electromagnetic induction heating unit 6 and the magnitude of the magnetic field generated around the coil 68 are values having a correlation.

  In step S22, the control unit 11 determines whether the sensor detachment detection time has ended. If the sensor detachment detection time has ended, the process proceeds to step S23. On the other hand, if the sensor detachment detection time has not ended yet, step S22 is repeated.

In step S23, the control unit 11 acquires the temperature detected by the electromagnetic induction thermistor 14 at the time when the sensor detachment detection time ends (see point e in FIG. 16 ), and proceeds to step S24.

  In step S24, the controller 11 detects that the detected temperature of the electromagnetic induction thermistor 14 at the time when the sensor disconnection detection time acquired in step S23 has ended is the electromagnetic induction thermistor at the start of the sensor disconnection detection time stored in step S21. It is determined whether or not the detected temperature data of 14 is higher by 10 ° C. or more. That is, it is determined whether or not the refrigerant temperature has increased by 10 ° C. or more due to induction heating by the electromagnetic induction heating unit 6 during the sensor detachment detection time. Here, when the detection temperature of the electromagnetic induction thermistor 14 is increased by 10 ° C. or more, the attachment state of the electromagnetic induction thermistor 14 with respect to the accumulator tube F is good, and induction heating by the electromagnetic induction heating unit 6 is performed. It is determined that it has been confirmed that the accumulator tube F has been appropriately warmed, the sensor detachment detection process is terminated, and the process proceeds to a rapid pressure increase process at the start-up that uses the output of the electromagnetic induction heating unit 6 to the maximum. On the other hand, if the detected temperature of the electromagnetic induction thermistor 14 has not risen by 10 ° C. or more, the process proceeds to step S25.

  In step S25, the control unit 11 counts the number of sensor detachment retry processes. If the number of retries is less than 10, the process proceeds to step S26. If the number of retries exceeds 10, the process proceeds to step S27 without proceeding to step S26.

In step S <b> 26, the control unit 11 performs a sensor removal retry process. Here, the detection temperature data (not shown in FIG. 16 ) of the electromagnetic induction thermistor 14 at the time when 30 seconds have passed is stored, and the coil 68 of the electromagnetic induction heating unit 6 is detected by the detected power supply M1. The power supply is performed for 20 seconds, the same processing as in steps S22 and S23 is performed, and when the detection temperature of the electromagnetic induction thermistor 14 is increased by 10 ° C. or more, the sensor detachment detection processing is terminated, and the output of the electromagnetic induction heating unit 6 Shift to rapid pressure increase processing at startup to make the best use of On the other hand, if the detected temperature of the electromagnetic induction thermistor 14 has not increased by 10 ° C. or more, the process returns to step S25.

  In step S <b> 27, the control unit 11 determines that the attachment state of the electromagnetic induction thermistor 14 to the accumulator tube F is unstable or not good, and outputs a sensor detachment abnormality display on the display screen of the controller 90.

<1-10> Rapid pressure increase processing After the flow condition determination processing and the sensor detachment detection processing are completed, sufficient refrigerant flow is ensured in the accumulator tube F, and the electromagnetic induction thermistor 14 is attached to the accumulator tube F. In a state where it is confirmed that the accumulator tube F has been appropriately heated by induction heating by the electromagnetic induction heating unit 6, the control unit 11 starts the rapid pressure increase processing.

  Here, even if the induction heating by the electromagnetic induction heating unit 6 is performed at a high output, it has been confirmed that the accumulator tube F does not rise abnormally, so the reliability of the air conditioner 1 can be improved. ing.

Rapidly at high pressure treatment, as shown in the flowchart of FIG. 19, the following processes are performed.

In step S31, the control unit 11 does not set the power supply to the coil 68 of the electromagnetic induction heating unit 6 as the detachment detection supply power M1 whose output is limited to 50% as in the sensor detachment detection process described above. A predetermined maximum supply power Mmax (2 kW) is assumed. Output by the electromagnetic induction heating unit 6 in this case, the pressure sensor 29a is continuously performed until a predetermined target high pressure P h.

  In order to prevent an abnormal increase in high pressure in the refrigeration cycle of the air conditioner 1, the control unit 11 forcibly stops the compressor 21 when the pressure sensor 29a detects an abnormal high pressure Pr. The target high pressure Ph in the rapid high pressure process is provided as a separate threshold value that is a pressure value smaller than the abnormal high pressure Pr.

  In step S32, the control unit 11 determines whether or not 10 minutes of the maximum continuous output time of the electromagnetic induction heating unit 6 that has started counting in step S21 of the sensor detachment detection process has elapsed. If the maximum continuous output time has not elapsed, the process goes to step S33. On the other hand, if the maximum continuous output time has elapsed, the process goes to step S34.

  In step S33, the control unit 11 determines whether or not the pressure detected by the pressure sensor 29a has reached the target high pressure Ph. If the target high pressure Ph has been reached, the process proceeds to step S34. On the other hand, if the target high pressure Ph is not reached, step S32 is repeated.

  In step S34, the control unit 11 starts driving the indoor fan 42, finishes the rapid pressure increase process, and shifts to the steady output process.

Here, when the process is changed from step S33 to step S34, the indoor fan 42 starts to operate in a state in which sufficiently warm conditioned air can be provided to the user. When subsequent Step S3 2 in step S34 is not yet ready to provide sufficient warm conditioned air to the user, elapsed time from the heating operation starts in a state that can provide a degree of warm conditioned air The warm air can be provided within a range that does not become too long.

<1-11> Steady Output Process In the steady output process, the steady supply power M2 (1.4 kW), which is an output that is not less than the detachment detection supply power M1 (1 kW) and less than the maximum supply power Mmax (2 kW), is a fixed output value. As described above, the power supply frequency of the electromagnetic induction heating unit 6 is PI controlled so that the detected temperature of the electromagnetic induction thermistor 14 is positioned at 80 ° C., which is the target accumulator temperature at startup.

In steady output process, as shown in the flowchart of FIG. 2 0, the following processes are performed.

  In step S41, the control unit 11 stores the detected temperature of the electromagnetic induction thermistor 14, and proceeds to step S42.

  In step S42, the control unit 11 compares the detected temperature of the electromagnetic induction thermistor 14 stored in step S41 with the activation target accumulator tube temperature of 80 ° C. so that the detected temperature of the electromagnetic induction thermistor 14 is equal to the activation target accumulator. It is determined whether or not a predetermined maintenance temperature lower than the tube temperature of 80 ° C. by a predetermined temperature is reached. If the temperature is equal to or lower than the predetermined maintenance temperature, the process proceeds to step S43. If the temperature is not lower than the predetermined maintenance temperature, step S41 is repeated.

  In step S43, the control part 11 grasps | ascertains the elapsed time since the power supply to the recent electromagnetic induction heating unit 6 was finished.

  In step S44, the control unit 11 continuously supplies power to the electromagnetic induction heating unit 6 while keeping the constant supply power M2 (1.4 kW) constant for 30 seconds, and sets the frequency of this set as the set. The PI control is performed to increase the frequency as the elapsed time grasped in step S43 is longer.

<1-12> Defrost process When the temperature detected by the outdoor heat exchange sensor 29c of the outdoor heat exchanger 23 is equal to or lower than a predetermined value while continuing the above-described steady output process, the outdoor heat exchanger 23 The defrost process which is the operation | movement which melt | dissolves the adhering frost is performed. Specifically, the connection state of the four-way switching valve 22 is set in the same manner as in the cooling operation (connection state indicated by the dotted line in FIG. 1), and the high-pressure high-temperature gas refrigerant discharged from the compressor 21 is supplied to the indoor heat exchanger 41. It is provided to the outdoor heat exchanger 23 before passing, and the frost adhering to the outdoor heat exchanger 23 is melted using the heat of condensation of the refrigerant.

In defrosting process, as shown in the flowchart of FIG. 2 1, the following processes are performed.

  In step S51, the control unit 11 is capable of performing electromagnetic induction heating by the flow condition determination process that the frequency of the compressor 21 is equal to or higher than the predetermined minimum frequency Qmin and a predetermined refrigerant circulation amount is secured. After confirming that the refrigerant flow amount is secured and that the attachment state of the electromagnetic induction thermistor 14 is appropriate by the sensor removal detection process, the process proceeds to step S52.

  In step S52, the control unit 11 determines whether or not the temperature detected by the outdoor heat exchanger temperature sensor 29c is less than 10 ° C. If it is lower than 10 ° C., the process proceeds to step S53. If it is not less than 10 ° C., step S52 is repeated.

  In step S <b> 53, the controller 11 stops the induction heating by the electromagnetic induction heating unit 6 and transmits it to the defrost signal.

  In step S54, after the defrost signal is transmitted, the control unit 11 sets the connection state of the four-way switching valve 22 to the connection state of the cooling operation, and further changes the connection state of the four-way switching valve 22 to the connection state of the cooling operation. After that, the elapsed time after defrosting is counted by the timer 95.

  In step S55, the control unit 11 determines whether or not 30 seconds have elapsed after the start of defrosting. If 30 seconds have elapsed, the process proceeds to step S56. If 30 seconds have not elapsed, step S55 is repeated.

  In step S56, the control unit 11 sets the power supply to the coil 68 of the electromagnetic induction heating unit 6 to a predetermined maximum supply power Mmax (2 kW), and the detected temperature of the electromagnetic induction thermistor 14 is 40 ° C., which is the target defrost temperature. Thus, PI control is performed on the frequency of induction heating by the electromagnetic induction heating unit 6 so as to be different (different from the startup target accumulator temperature during steady output processing). When the temperature detected by the outdoor heat exchanger temperature sensor 29a is lower than 0 ° C., the hot gas bypass valve 27 of the hot gas bypass circuit H is further opened, and the outdoor fan 26 on the upper surface of the bottom plate 2b of the outdoor unit 2 is opened. The high-temperature and high-pressure gas refrigerant is supplied below the outdoor heat exchanger 23 and below the outdoor heat exchanger 23, and the ice generated on the upper surface of the bottom plate 2b is removed. Here, since the connection state of the four-way switching valve 22 is switched to the cooling operation state, the high-temperature and high-pressure gas refrigerant discharged from the compressor 21 is joined from the branch junction point 23k of the outdoor heat exchanger 23 to the junction branch point. 23j, and merge at the merge branch point 23j to be combined into one, so that the flow rate becomes three times the flow rate of the branch pipe K and flows through the merge pipe J in a concentrated manner. Since this junction pipe J is located in the vicinity of the lower end of the outdoor heat exchanger 23, a large amount of condensation heat can be concentrated in the vicinity of the lower end of the outdoor heat exchanger 23. Thereby, the defrosting speed can be further accelerated.

  In step S57, the control unit 11 determines whether or not the elapsed time after the start of defrost has exceeded 10 minutes. If 10 minutes has not elapsed, the process proceeds to step S58. If 10 minutes have passed, the process proceeds to step S59. This prevents the passage of 10 minutes or more while the connection state of the four-way switching valve 22 remains in the cooling state, and makes it less likely to cause discomfort due to a decrease in room temperature.

  In step S58, the control unit 11 determines whether or not the temperature detected by the outdoor heat exchanger temperature sensor 29c exceeds 10 ° C. If it exceeds 10 ° C., the process proceeds to step S59. If the temperature does not exceed 10 ° C., the process returns to step S56 and is repeated.

  In step S59, the control unit 11 stops the compressor 21 and finishes induction heating by the electromagnetic induction heating unit 6 while equalizing high and low pressures in the refrigeration cycle.

  In step S60, the control part 11 switches the connection state of the four-way switching valve 22 to the connection state of heating operation.

  And the control part 11 transmits the signal which finishes defrost. Further, the control unit 11 increases the frequency of the compressor 21 to a predetermined minimum frequency Qmin or more, and performs a steady output process until the defrost process is performed again. Further, the hot gas bypass valve 27 of the hot gas bypass circuit H is closed after 5 seconds after a signal to finish defrosting is transmitted.

<Characteristics of the air conditioner 1 of the present embodiment>
In the air conditioner 1, by performing the rapid pressure increase processing, the output from the electromagnetic induction heating unit 6 is set to the maximum supply power Mmax (2 kW), and the high temperature and pressure increase of the refrigerant flowing toward the indoor heat exchanger 41 is quickly performed. Processing to achieve. Thereby, it is possible to shorten the time required from the start of the heating operation until warm air is provided to the user. Further, by performing steady output processing when the room is warmed to some extent, the steady supply power M2 (1.4 kW) in which the output from the electromagnetic induction heating unit 6 is limited to be smaller than the maximum supply power Mmax (2 kW) is set as a fixed output value. Yes. Thereby, it is possible to suppress the overshoot of the control due to excessive increase of the output of the electromagnetic induction heating unit 6.

  When electromagnetic induction heating is performed, in general, a rapid temperature increase is more likely to occur than a temperature increase due to a change in the circulation state of the refrigerant in the refrigeration cycle. On the other hand, in the electromagnetic induction heating unit 6 of the air conditioner 1, the electromagnetic induction thermistor 14 that is pressed against the magnetic tube F <b> 2 by the elastic force of the leaf spring 16 is used in the above-described steady output processing by electromagnetic induction heating. Responsiveness to rapid temperature changes due to induction heating is well maintained. For this reason, the responsiveness of the steady output process is improved, and the control overshoot can be further suppressed.

  In the defrost process, the induction heating by the electromagnetic induction heating unit 6 is performed with the maximum supply power Mmax (2 kW), so that the defrosting process can be speeded up. However, since the temperature detected by the electromagnetic induction thermistor 14 is set to 40 ° C., which is the target defrost temperature, and is kept lower than the target accumulator temperature at the time of steady output processing, the overshoot due to control is kept small. I have to.

<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 end of the rapid high pressure process in which the electromagnetic induction heating unit 6 outputs at the maximum supply power Mmax (2 kW) is the time when the pressure detected by the pressure sensor 29a reaches the target high pressure Ph. The case has been described as an example.

  However, the present invention is not limited to this.

  For example, at the end of the rapid pressure-increasing process for causing the electromagnetic induction heating unit 6 to output at the maximum supply power Mmax (2 kW), based on the temperature corresponding to the refrigerant of the target high-pressure pressure Ph that passes through the mounting portion of the pressure sensor 29a. The temperature determined by the electromagnetic induction thermistor 14 may be detected.

Even in this case, since it can be confirmed that the temperature of the refrigerant supplied to the indoor heat exchanger 41 is sufficiently high, it is used as a determination index for starting provision of warm conditioned air to the user at the start of the heating operation. It becomes possible.

For such an electromagnetic induction thermistor 14, for example, as shown in FIG. 22, temperature change detection when determining the end of the rapid pressure increase process is performed by using the magnetic pipe F <b> 2 in the refrigerant flow direction. The temperature may be the detection temperature of the electromagnetic induction downstream thermistor 214 that detects a temperature change in the vicinity of the downstream side of the accumulator pipe F2 that is provided, and is not limited to the one that detects the temperature of the accumulator pipe F.

(B)
In the above embodiment, the electromagnetic induction thermistor 14 is attached by detecting that the temperature detected by the electromagnetic induction thermistor 14 changes due to the electromagnetic induction heating unit 6 changing from a stopped state to generate a magnetic field. The case of confirming that the state is good has been described as an example.

  However, the present invention is not limited to this.

  For example, the mounting state of the electromagnetic induction thermistor 14 may be confirmed by changing from a state where the electromagnetic induction heating unit 6 generates a magnetic field to a state where no magnetic field is generated. In this case, it can be confirmed that the state of attachment of the electromagnetic induction thermistor 14 is good due to a change in the detection temperature that the detection temperature of the electromagnetic induction thermistor 14 decreases.

  Further, by simply changing the electric power supplied to the coil 68 of the electromagnetic induction heating unit 6, the magnitude of the magnetic field to be generated is changed, and the change in the detected temperature of the electromagnetic induction thermistor 14 caused by this change is examined, thereby electromagnetic induction. The attachment state of the thermistor 14 may be confirmed.

(C)
In the above embodiment, paying attention to the change in the detection temperature of the electromagnetic induction thermistor 14 that detects the temperature of the magnetic pipe F2 that forms the outside of the accumulator F, is the attachment state of the electromagnetic induction thermistor 14 good? The case of determining whether or not was described.

  However, the present invention is not limited to this.

  For example, while using a detection device such as a bimetal that detects whether the temperature is equal to or higher than a predetermined temperature, the predetermined temperature of the detection device is a value between the temperature before and after the sensor detachment detection process. By doing so, the temperature change of the accumulator tube F may be detected. In this case, even if it is not possible to detect a specific temperature when performing the sensor detachment detection process, the sensor mounting state can be confirmed by detecting the temperature change.

(D)
In the above embodiment, the case where the output frequency is controlled while fixing the output by the electromagnetic induction heating unit 6 for electromagnetic induction heating at 70% in the steady output processing has been described.

  However, the present invention is not limited to this.

  For example, in the steady output process, the output by the electromagnetic induction heating unit 6 may be controlled based on the detected temperature of the electromagnetic induction thermistor 14 while fixing the frequency of performing the electromagnetic induction heating.

  In the steady output process, both the frequency of electromagnetic induction heating and the output of the electromagnetic induction heating unit 6 may be controlled based on the temperature detected by the electromagnetic induction thermistor 14.

(E)
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.

(F)
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. 2 3, for example, a magnetic member F2a, and two stoppers F1a, but may be disposed in the interior of the refrigerant pipe as the accumulator tube F and the heating target. 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 the refrigerant to pass through at two locations inside the copper tube F1, but does not allow the magnetic member F2a to pass through. 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.

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

As shown in FIG. 2 4, for example, provided a bent portion FW at two locations in the copper pipe F1, the inside of the copper tube F1 may be arranged magnetic member F2a between the two locations of the bent portion FW. Even in this case, the movement of the magnetic member F2a can be suppressed while allowing the refrigerant to pass therethrough.

(H)
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. 25 , the coil 168 wound around the bobbin main body 165 may be disposed 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. 26 , the first bobbin lid 163 and the second bobbin lid 164 passing through the accumulator tube F are arranged in a state of being fitted to the bobbin main body 165. Also good.

Furthermore, as shown in FIG. 2 7, first bobbin lid 163 and second bobbin lid 164 may be fixed by being sandwiched by a first ferrite case 171 and a second ferrite case 172. In Figure 2 7, two ferrite cases are an example in which is arranged so as to sandwich the accumulator tube F, as in the above embodiment, may be arranged in four directions. 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.

  In the electromagnetic induction heating unit and the air conditioner for heating the refrigerant using electromagnetic induction, the present invention can be used to quickly secure the capacity at the time of startup and suppress the overshoot after startup to be small. It is particularly useful.

DESCRIPTION OF SYMBOLS 1 Air conditioning apparatus 6 Electromagnetic induction heating unit 10 Refrigerant circuit 11 Control part 14 Electromagnetic induction thermistor (temperature detection part)
15 Fuse (temperature detector)
16 Leaf spring (elastic member)
17 Leaf spring (elastic member)
DESCRIPTION OF SYMBOLS 21 Compressor 22 Four-way selector valve 23 Outdoor heat exchanger 24 Electric expansion valve 25 Accumulator 29a Pressure sensor 29b Outdoor air temperature sensor 29c Outdoor heat exchanger temperature sensor 41 Indoor heat exchanger 43 Indoor temperature sensor 44 Indoor heat exchanger temperature sensor 65 Bobbin main body 68 Coil (Magnetic field generator)
71-74 1st ferrite case-4th ferrite case 75 Shielding cover 90 Controller 95 Timer 98, 99 1st ferrite, 2nd ferrite F Accumulation pipe, refrigerant piping M1 Detachment detection supply power (first magnetic field level)
M2 steady supply power (first magnetic field limit reference value)
Mmax Maximum supply power (predetermined maximum output)

JP 2000-97510 A

Claims (11)

Air that uses a refrigeration cycle that includes a compression mechanism (21) that performs induction heating of the refrigerant pipe (F) and / or a member that is in thermal contact with the refrigerant flowing in the refrigerant pipe (F) and circulates the refrigerant. A harmony device (1),
A magnetic field generator (68) for generating a magnetic field for induction heating the heating target portion (F2) of the induction heating;
A refrigerant state quantity detection unit (14, 29a) for detecting a state quantity relating to the refrigerant flowing through the predetermined state quantity detection part (F) which is at least a part of the refrigeration cycle;
When starting the heating operation in the refrigeration cycle, the refrigerant starts from the time when the compression mechanism is in a driving state in which the output from the magnetic field generator (68) is set to a predetermined maximum output (Mmax). Start-up magnetic field generation control to be terminated when the state quantity detected by the state quantity detection unit (14, 29a) reaches the first predetermined target state quantity (P h );
Start-up performed after the start-up magnetic field generation control is terminated in a state where the first magnetic field limit reference value (M2) lower than the predetermined maximum output (Mmax) is set as an upper limit of the output of the magnetic field generation unit (68). Rear magnetic field generation control,
A control unit (11) for performing at least
An air conditioner (1) comprising: The heating target portion (F2) of the induction heating includes a magnetic material.
The air conditioner (1) according to claim 1. The predetermined state quantity detection part (F) is a part where a magnetic field is generated by the magnetic field generation part (68).
The air conditioner (1) according to claim 1 or 2. The state quantity detected by the refrigerant state quantity detection unit (14, 29a) is at least one of temperature and pressure related to the refrigerant flowing through the predetermined state quantity detection part (F).
The air conditioner (1) according to any one of claims 1 to 3. The refrigerant state quantity detector (14, 29a) is a temperature detector (14) that detects a temperature related to the refrigerant flowing through the predetermined state quantity detector (F).
In the post-startup magnetic field generation control, the control unit (11) causes the magnetic field generation unit (68) to generate a magnitude of a magnetic field so that the temperature detected by the temperature detection unit (14) is maintained at a target maintenance temperature. And / or performing post-startup magnetic field generation PI control for PI control of the frequency with which the magnetic field generation unit (68) generates a magnetic field,
The air conditioner (1) according to any one of claims 1 to 4. The refrigerant state quantity detector (14, 29a) is a temperature detector (14) that detects a temperature related to the refrigerant flowing through the predetermined state quantity detector (F).
The controller (11) performs the magnetic field level change process of increasing or decreasing the level of the magnetic field generated by the magnetic field generator (68) within a range lower than the predetermined maximum output (Mmax). Performing the startup magnetic field generation control after satisfying the magnetic field level increase condition that the detection temperature of the detection unit (14) is changed or the temperature detection unit (14) detects a temperature change;
The air conditioner (1) according to any one of claims 1 to 5. The maximum magnetic field level output in the magnetic field level change process (M1) is a value smaller than the first magnetic field restriction reference value (M2).
The air conditioner (1) according to claim 6. The refrigerant state quantity detector (14, 29a) is a temperature detector (14) that detects a temperature related to the refrigerant flowing through the predetermined state quantity detector (F).
The control unit (11) sets both compression mechanism states in which the output of the compression mechanism is different between the first compression mechanism state and the second compression mechanism state whose output level is higher than that of the first compression mechanism state to the compression mechanism. Determination of the magnetic field level increase condition after satisfying a flow condition that there is a change in the temperature detected by the temperature detector (14) between the first compression mechanism state and the second compression mechanism state when realized. Run the
The air conditioner (1) according to any one of claims 1 to 7. The refrigerant state quantity detector (14, 29a) is a temperature detector (14) that detects a temperature related to the refrigerant flowing through the predetermined state quantity detector (F).
The control unit (11) is configured to start the magnetic field generation control after the start and when the defrosting operation different from the heating operation is performed in the refrigeration cycle, the magnetic field generation unit (68) Defrosting operation output control for controlling the output by the magnetic field generator (68) based on the detected temperature of the temperature detector (14), with the upper limit of the output as the predetermined maximum output (Mmax),
The air conditioner (1) according to any one of claims 1 to 8. The controller (11) performs PI control so that the temperature detected by the temperature detector (14) is maintained at a second predetermined target temperature lower than the first predetermined target temperature during the defrosting operation output control. To perform defrost PI control
The air conditioner (1) according to claim 9. The refrigerant state quantity detector (14, 29a) is a temperature detector (14) that detects a temperature related to the refrigerant flowing through the predetermined state quantity detector (F).
An elastic member (16, 17) for applying an elastic force to the temperature detector (14);
The temperature detector (14) is in pressure contact with the predetermined state quantity detector (F) by the elastic force of the elastic members (16, 17).
The air conditioner (1) according to any one of claims 1 to 10.

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