WO2010106821A1 - Air conditioning device - Google Patents

Abstract

An air conditioning device which can, with the use of a simple configuration, quickly obtain a refrigerant pressure required for supplying warm air at the time of the start of heating. An air conditioning device (1) for performing a refrigeration cycle by including at least a compressor (21), an indoor heat exchanger (41), an indoor fan (42), an outdoor electric expansion valve (24), and an outdoor heat exchanger (23). The air conditioning device (1) is equipped with an indoor heat exchanger temperature sensor (44) and a control unit (11). The control unit (11) understands the degree of supercooling of a refrigerant from the value detected by the indoor heat exchanger temperature sensor (44). The control unit (11) performs control for adjusting the degree of opening of the outdoor electric expansion valve (24) according to the degree of supercooling, and also performs control for starting the compressor (21) with the degree of opening of the outdoor electric expansion valve (24) maintained as the fixed degree (DS) of opening. The fixed degree (DS) of opening is the degree of opening which is reduced to a degree which is less than the degree of opening of the outdoor electric expansion valve (24) when supercooling degree-constant control is performed under the same condition as the operating condition of the refrigeration cycle other than the outdoor electric expansion valve (24) and as the ambient temperature condition of the refrigeration cycle.

Description

Air conditioner

The present invention relates to an air conditioner.

With respect to an air conditioner capable of heating operation, techniques as disclosed in the following patent documents have been proposed for the purpose of improving problems that may occur when heating is started.
For example, in the air conditioner of Patent Document 1 (Japanese Patent Application Laid-Open No. 2000-111126), when heating is started, the direction of the blowing air is adjusted by changing the angle of the louver, and the draft feeling due to unwarmed room air is given to the user It prevents it from giving.
Further, in the air conditioner disclosed in Patent Document 2 (Japanese Patent Laid-Open No. 2000-105015), when heating is started, the supply of refrigerant to the indoor unit side is shut off, and the refrigerant is circulated between the compressor and the outdoor heat exchanger. By doing so, the operation of quickly raising the refrigerant temperature is performed. Thereby, since the temperature of a refrigerant | coolant can be raised rapidly, it can be made to provide a user with warm air in a short time after the heating start time.

Further, in the air conditioner of Patent Document 3 (Japanese Patent Laid-Open No. 11-101522), in an environment where the heating operation is overloaded, the problem that the pressure on the high-pressure side of the refrigeration cycle abnormally increases at the start of the heating operation is avoided. Therefore, control for increasing the air volume of the indoor fan in an environment where the room temperature is 25 ° C. or higher is proposed.

With the techniques described in Patent Documents 1 and 3 described above, warm air cannot be quickly supplied to the user when heating is started. That is, in the technique described in Patent Document 1, since the wind direction is determined by the louver, the user cannot be warmed unless the space around the user is warmed. Moreover, in the technique described in Patent Document 3, the heating operation is premised on an overloaded environment. Furthermore, it is premised on that the pressure on the high-pressure side has risen to a level just before the abnormally rising pressure, and there is no indication of increasing the pressure on the high-pressure side quickly.
In addition, the technique described in Patent Document 2 requires a circuit configuration and control capable of circulating the refrigerant between the compressor and the outdoor heat exchanger, and is complicated.
The present invention has been made in view of the above-described points, and an object of the present invention is to provide air conditioning that can quickly ensure the refrigerant pressure required for supplying hot air when heating is started with a simple configuration. To provide an apparatus.

An air conditioner according to a first aspect is an air conditioner that performs a refrigeration cycle including at least a compression mechanism, an indoor heat exchanger, an indoor fan, an expansion mechanism, and an outdoor heat exchanger, and includes a refrigerant state grasping unit and a control Department. The refrigerant state grasping unit grasps at least one of the degree of supercooling of the refrigerant from the indoor heat exchanger toward the expansion mechanism and the degree of superheating of the refrigerant flowing on the suction side of the compression mechanism. The control unit performs post-startup heating operation control that adjusts the opening degree of the expansion mechanism according to the value obtained by the refrigerant state grasping part, and activation that starts the compression mechanism while maintaining the opening degree of the expansion mechanism as a fixed opening degree. Time fixed opening degree control. The fixed opening is the expansion mechanism when the post-startup heating operation control is performed under the same conditions as the operating conditions of the refrigeration cycle other than the expansion mechanism and the ambient temperature condition of the refrigeration cycle when the fixed opening control at the time of starting is executed. The opening is narrowed to be narrower than the opening corresponding to the refrigerant state.

In this air conditioner, by performing a fixed opening degree control at start-up that makes the expansion mechanism feel like a throttle, the pressure of the refrigerant sent from the compression mechanism to the indoor heat exchanger is controlled after the start-up heating operation. In comparison, it can be raised more quickly. Such a rapid increase in pressure can be easily achieved simply by adjusting the opening of the expansion mechanism. Thereby, it becomes possible to further shorten the time required from the start of the heating operation to the start of the supply of warm air to the user with a simple configuration.

The air conditioner according to the second aspect is the air conditioner according to the first aspect, wherein the post-startup heating operation control is performed so that the refrigerant state of the refrigeration cycle is stabilized according to the value obtained by the refrigerant state grasping unit. This is stabilization control after startup that adjusts the opening of the expansion mechanism. The opening corresponding to the refrigerant state is the expansion when the post-startup stabilization control is performed under the same conditions as the operating condition of the refrigeration cycle other than the expansion mechanism and the ambient temperature condition of the refrigeration cycle when executing the fixed opening control at the time of starting The opening of the mechanism.

In this air conditioner, the expansion mechanism is fixed during startup fixed opening control rather than the expansion mechanism opening when the opening is adjusted so that the refrigerant state of the refrigeration cycle is stabilized in the stabilization control after startup. The opening is further narrowed down. As a result, the pressure of the refrigerant sent from the compression mechanism to the indoor heat exchanger during the startup fixed opening degree control can be increased more quickly.

The air conditioner according to the third aspect is the air conditioner according to the second aspect, wherein the stabilization of the refrigerant state of the refrigeration cycle in the post-startup stabilization control is at least one of the following three examples: One. The first is to maintain the degree of change in the refrigerant distribution state in the refrigeration cycle for the first predetermined time within the first predetermined distribution state or the first predetermined distribution range. The second is to maintain the degree of supercooling of the refrigerant from the indoor heat exchanger toward the expansion mechanism within a second predetermined value or a second predetermined range for a second predetermined time. Third, the degree of superheat of the refrigerant flowing on the suction side of the compression mechanism is maintained for a third predetermined time within a third predetermined value or a third predetermined range.
In this air conditioner, the refrigeration cycle can be stabilized more reliably, and the opening for rapidly increasing the pressure of the refrigerant sent from the compression mechanism to the indoor heat exchanger as the fixed opening It becomes possible to make it more certain to select.

The air conditioner according to a fourth aspect is the air conditioner according to any one of the first aspect to the third aspect. In the fixed opening degree control at startup, the control unit immediately before starting the startup capacity increase control. By the time, the frequency of the compression mechanism is made to reach the first predetermined target frequency while maintaining the state where the opening degree of the expansion mechanism is maintained at the fixed opening degree. In the start-up capacity increase control, the opening degree of the expansion mechanism is set to the first opening degree that is wider than the fixed opening degree while raising the frequency of the compression mechanism to be the second predetermined target frequency that is higher than the first predetermined target frequency. Control.
In this air conditioner, it is possible to increase the capacity of the refrigerant by increasing the amount of refrigerant circulation while reducing the time required to start supplying warm air to the user from the start of heating operation.

In an air conditioner according to a fifth aspect, in the air conditioner according to the fourth aspect, in the startup capacity increase control, the control unit opens the expansion mechanism while maintaining the frequency of the compression mechanism at the second predetermined target frequency. Immediately before the control for adjusting the degree according to the value grasped by the refrigerant state grasping unit, the opening degree of the expansion mechanism is once increased to the first opening degree.
In this air conditioner, when the capacity of the refrigeration cycle changes slightly when the refrigerant circulation rate is increased, the opening degree of the expansion mechanism is opened according to the grasp value of the refrigerant state grasping unit. Adjusted in degrees. As a result, it becomes possible to increase the capacity while ensuring flexibility with respect to the load.

In the air conditioner according to the sixth aspect, the air conditioner according to the sixth aspect is the air conditioner according to the fourth aspect or the fifth aspect, and when the control unit has passed a predetermined fixed activation time from the start time of the fixed opening control at the time of activation, Start capacity increase control at startup.
In this air conditioner, by starting the startup capacity increase control when a predetermined fixed startup time has elapsed after starting the startup fixed opening control, the fixed opening control is started after starting the fixed opening control at startup. When the time has elapsed, the frequency of the compression mechanism can be forcibly increased. As a result, the ability can be forcibly raised, and the situation where the ability cannot be raised forever can be avoided.

The air conditioner according to a seventh aspect is the air conditioner according to the sixth aspect, wherein the control unit sets the start timing of the post-startup heating operation control to a time point after the start point of the start time capacity increase control. To do.
In this air conditioner, heating capacity control at the start of the post-startup heating operation control is facilitated by starting the post-startup heating operation control after the capacity is increased by the startup capacity increase control.

An air conditioner according to an eighth aspect is the air conditioner according to any one of the fourth to seventh aspects, wherein the control unit sets the frequency of the compression mechanism to the second predetermined target frequency in the start-up capacity increase control. The startup stage capacity control is performed so that the opening degree of the expansion mechanism is set to a second opening degree that is wider than the first opening degree while the frequency is raised to a predetermined maximum frequency that is higher than the first opening degree.
In this air conditioner, in the starting stage capacity control after the starting fixed opening degree control, at least two frequency stages of the first predetermined target frequency and the second predetermined target frequency are provided before raising to the predetermined maximum frequency. It has been. For this reason, before maximizing the capacity of the compression mechanism, the capacity of the compression mechanism can be increased in stages, and the opening degree of the expansion mechanism can also be expanded in stages. It can be increased. Thereby, it is possible to suppress liquid compression in the compression mechanism due to sudden increase in capacity and a sudden abnormal increase in refrigerant pressure from the compression mechanism toward the indoor heat exchanger.

An air conditioner according to a ninth aspect is the air conditioner according to any one of the first aspect to the eighth aspect, wherein the refrigerant pressure grasps the pressure of the refrigerant sent from the compression mechanism to the indoor heat exchanger. The unit is further provided. The control unit determines that the pressure grasped by the refrigerant pressure grasping unit is higher than the air volume by the indoor fan until the pressure grasped by the refrigerant pressure grasping unit exceeds the predetermined high pressure threshold after the start-up fixed opening degree control is started. Start-up fan control is performed in which the airflow from the indoor fan after the threshold is exceeded is greater.
In this air conditioner, the time required from the start of the heating operation to the start of the supply of warm air to the user is further reduced while suppressing the supply of cold air to the user immediately after the start of the heating operation. It can be made.

An air conditioner according to a tenth aspect is the air conditioner according to the ninth aspect, wherein the control unit determines that the pressure grasped by the refrigerant pressure grasping unit exceeds a predetermined high-pressure threshold from the start of startup fixed opening degree control. Until then, the air flow from the indoor fan is set to zero.

In this air conditioner, since the supply of air from the indoor fan to the indoor heat exchanger is interrupted, the condensing capacity in the indoor heat exchanger is reduced, and the time from startup to the predetermined high pressure threshold is further shortened. be able to.

An air conditioner according to an eleventh aspect is the air conditioner according to any one of the first to tenth aspects, wherein the refrigerant is in thermal contact with the refrigerant pipe on the suction side of the compression mechanism or flows in the refrigerant pipe. A heat generating part that includes a magnetic material, and a magnetic field generating part that generates a magnetic field for induction heating of the heat generating part. , Is further provided. The control unit causes the heating unit to be induction-heated in the startup fixed opening degree control.
In this air conditioner, since the heat generating portion can generate heat by electromagnetic induction heating, it is possible to shorten the time required to achieve the predetermined high pressure threshold in the startup fan control.

In the air conditioner according to the first aspect, with a simple configuration, the time required from the start of heating operation to the start of the supply of warm air to the user can be further shortened.
In the air conditioner according to the second aspect, the pressure of the refrigerant sent from the compression mechanism toward the indoor heat exchanger when performing the fixed opening degree control at start-up can be increased more quickly. .
In the air conditioner according to the third aspect, it is possible to more reliably select the opening degree for quickly increasing the pressure of the refrigerant sent from the compression mechanism to the indoor heat exchanger.
In the air conditioner according to the fourth aspect, it is possible to increase the capacity by increasing the refrigerant circulation amount while shortening the time required from the start of the heating operation to the start of the supply of warm air to the user. Become.

In the air conditioner according to the fifth aspect, the capability can be increased while ensuring flexibility with respect to the load.
In the air conditioner according to the sixth aspect, the capacity can be forcibly increased, and the situation where the capacity cannot be increased forever can be avoided.
In the air conditioning apparatus according to the seventh aspect, it becomes easy to ensure the heating capacity at the start of the post-startup heating operation control.
In the air conditioner according to the eighth aspect, it is possible to suppress liquid compression in the compression mechanism due to sudden increase in capacity and a sudden abnormal increase in refrigerant pressure from the compression mechanism toward the indoor heat exchanger. .
In the air conditioning apparatus according to the ninth aspect, it is possible to further shorten the time required from the time when the heating operation is started until the warm air supply to the user is started.

In the air conditioning apparatus according to the tenth aspect, it is possible to further shorten the time from the start to the predetermined high pressure threshold.
In the air conditioner according to the eleventh aspect, it is possible to shorten the time required to achieve the predetermined high pressure threshold in the startup fan control.

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 sectional drawing which shows the mode of magnetic flux. 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 graph which shows the temperature range conditions in which high temperature blowing control is performed. It is a figure which shows the flowchart of an introduction determination process. It is a figure which shows the flowchart of starting capability increase control. It is a figure which shows the flowchart (the 1) of high temperature blowing start control. It is a figure which shows the flowchart (the 2) of high temperature blowing start control. It is a figure which shows the flowchart of heating operation control after starting. 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 discharge pipe A is provided with a discharge temperature sensor 29d for detecting the temperature of the refrigerant passing therethrough. Note that the power supply unit 21 e supplies power to the compressor 21. The amount of power supplied from the power supply unit 21e is detected by the compressor power detection unit 29f.

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 a copper tube F1 in which a coolant is flowing inside, and a magnetic tube provided so as to cover the periphery of the copper tube F1. F2 is configured (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 type, a martensite type, and a combination of these two types. However, the magnetic material is ferromagnetic and has a relatively high electric resistance, which is higher than the operating temperature range. A material having a high Curie temperature is preferred. 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 tube F, or may be formed only on the inner surface of the accumulator tube F, and is contained in the material constituting the accumulator tube F. 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 heating operation, the capillary tube 28 is a chamber by supplying hot gas to the outdoor liquid pipe D through the hot gas bypass circuit H. 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. With respect to the outdoor heat exchanger 23, an outdoor air temperature sensor 29b for detecting the outdoor air temperature is provided on the windward side of the outdoor fan 26 in the air flow direction. 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.
The control unit 11 has a controller 90 that accepts a setting input from the user.
<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 configured by 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 joining pipe J shown in FIG. 7 has an area equivalent to the 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 in comparison with 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, as shown in FIG. 7, the joining pipe J is configured by connecting the first joining pipe part J1, the second joining pipe part J2, the third joining pipe part J3, and the fourth joining pipe part J4 to each other. 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 | coolant in the refrigerant circuit 10 is put together into one, and the outdoor heat exchanger 23's It arrange | positions so that the lowest end part may reciprocate once. Here, the 1st confluence | merging piping part J1 is extended from the confluence | merging branch point 23j to the heat exchanger fin 23z arrange | positioned in the outermost edge part of the outdoor heat exchanger 23. FIG. 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 part J3 is a U-shaped pipe that connects the second joining pipe part J2 and the fourth joining pipe part 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 has a first bypass portion H1 to an eighth bypass portion H8 and a ninth bypass portion H9 (not shown). 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 on the right side which 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 from the first bypass portion H1 to the ninth bypass portion H9 in order with the hot gas bypass valve 27 being 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, the refrigerant flowing through the hot gas bypass circuit H as a whole, the refrigerant after flowing through the fourth bypass portion H4 flows to the fifth to eighth bypass portions H8, and therefore the fourth bypass portion H4. Is more likely to be higher than the refrigerant temperature flowing through the fifth to eighth bypass portions H8.

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 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 shows 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 disposed so as to cover the magnetic tube F2 that is a heat generating portion of the accumulator tube F from the outside in the radial direction, and causes the magnetic tube F2 to generate heat by electromagnetic induction heating. The heat generating portion of the accumulator tube F has a double tube structure having an inner copper tube F1 and an outer magnetic tube F2.
The electromagnetic induction heating unit 6 includes a first hexagon nut 61, a second hexagon nut 66, a first bobbin lid 63, a second bobbin lid 64, a bobbin body 65, a first ferrite case 71, a second ferrite case 72, and a third ferrite. A case 73, a fourth ferrite case 74, a first ferrite 98, a second ferrite 99, a coil 68, a shielding cover 75, an electromagnetic induction thermistor 14, a fuse 15 and the like are provided.
The first hexagon nut 61 and the second hexagon nut 66 are made of resin, and stabilize the fixed state between the electromagnetic induction heating unit 6 and the accumulator pipe F using a C-shaped ring (not shown). The first bobbin lid 63 and the second bobbin lid 64 are made of resin and cover the accumulator tube F from the radially outer side at the upper end position and the lower end position, respectively. The first bobbin lid 63 and the second bobbin lid 64 have four screw holes for screws 69 for screwing first to fourth ferrite cases 71 to 74, which will be 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 (see FIG. 14). 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. As shown in FIG. 13, the fuse 15 includes a fuse detection unit 15a, an asymmetric shape 15b, and a fuse wiring 15d that transmits a detection result of the fuse detection unit 15a to the control unit 11 as a signal. Receiving the notification of temperature detection exceeding the predetermined limit temperature from the fuse 15, the control unit 11 performs control to stop the power supply to the coil 68 to avoid thermal damage of the device. The bobbin main body 65 is made of resin, and the coil 68 is wound around it. The coil 68 is wound spirally around the outside of the bobbin main body 65 with the direction in which the accumulator tube F extends as the axial direction. The coil 68 is connected to a control printed board (not shown) and is supplied with a 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 has a first bobbin lid 63 and a second bobbin lid 64 sandwiched from the direction in which the accumulator tube F extends, and is screwed and fixed by 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 a high magnetic permeability. As shown in the sectional view of the accumulator tube F and the electromagnetic induction heating unit 6 in FIG. 15 and the magnetic flux explanatory diagram in FIG. By forming it, the magnetic field is made difficult to leak outside. The shielding cover 75 is disposed on the outermost peripheral portion of the electromagnetic induction heating unit 6 and collects magnetic flux that cannot be drawn by the first ferrite 98 and the second ferrite 99 alone. Almost no leakage magnetic flux is generated outside 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 the refrigeration cycle is operated for heating, when assisting the heating capacity, and when performing the defrost operation. Control is performed to generate heat in the magnetic tube F2. Here, as control focusing on the electromagnetic induction heating unit 6, (i) flow condition determination processing, (ii) sensor detachment detection processing, (iii) rapid high pressure processing, (iv) steady output processing, and (v) Defrost processing will be described.

In the following, a description will be given particularly regarding startup.
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 causes the timer 95 to start counting the elapsed heating start time, and the pressure detected by the pressure sensor 29a increases to 39 kg / cm ² after the compressor 21 is started. The indoor fan 42 is driven after waiting. 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, 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, electromagnetic induction heating using the electromagnetic induction heating unit 6 is performed. 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 includes a flow condition determination process, a sensor detachment detection process, a rapid pressure increase process, and the like, as shown in the time chart of FIG.
(I) Flow condition determination process When electromagnetic induction heating is performed, in a situation where the refrigerant does not flow through the accumulator tube F, the heating load stays in a portion of the accumulator tube F where the electromagnetic induction heating unit 6 is attached. It becomes only the refrigerant that is. 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.

In the flow condition determination process, the following processes are performed as shown in the flowchart of FIG.
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. 17) and The temperature data detected by the outdoor heat exchange 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 exists downstream 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.
(Ii) 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, power is supplied to the electromagnetic induction heating unit 6. This is a process for confirming the attachment 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 in the above-described flow condition determination process that the amount of refrigerant flowing in the accumulator pipe F is secured, the output of the electromagnetic induction heating unit 6 is maximized. Before performing the rapid pressure increase process at the time of start-up, 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 detachment detection process, the following processes are performed as shown in the flowchart of FIG.
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). The power supply to the coil 68 of the electromagnetic induction heating unit 6 is started while storing the detected temperature data of the electromagnetic induction thermistor 14 (see the point d in FIG. 17) at the time of 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. 17), 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 detected temperature data (not shown in FIG. 17) of the electromagnetic induction thermistor 14 at the time when another 30 seconds have elapsed is stored in the coil 68 of the electromagnetic induction heating unit 6 and the electric power at the detected power supply M1 is detected. Supply is performed for 20 seconds, and the same processing as in steps S22 and S23 is performed. 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 is output. Shift to rapid high pressure processing at start-up for maximum use. On the other hand, if the detected temperature of the electromagnetic induction thermistor 14 has not risen 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.
(Iii) 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 attachment state of the electromagnetic induction thermistor 14 to the accumulator tube F is good. In the state where it is confirmed that the accumulator tube F is appropriately heated by induction heating by the electromagnetic induction heating unit 6, the controller 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.

In the rapid pressure increase process, the following processes are performed as shown in the flowchart of FIG.
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. The output by the electromagnetic induction heating unit 6 here is continuously performed until the pressure sensor 29a reaches a predetermined target high pressure Ph.
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. After step S32 to step S34, it has not reached a state in which sufficient warm conditioned air can be provided to the user, but is in a state in which a certain amount of warm conditioned air can be provided, and the elapsed time from the start of heating operation. Provision of warm air can be started within a range that does not become too long.
(Iv) Steady output process In the steady output process, the steady supply power M2 (1.4 kW), which is an output that is greater than or equal to the detection power supply M1 (1 kW) and less than or equal to the maximum supply power Mmax (2 kW), is used as a fixed output value. 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 maintained at 80 ° C., which is the target accumulator temperature at startup.

In the steady output process, the following processes are performed as shown in the flowchart of FIG.
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, the process continues to wait until the temperature is lower than the predetermined maintenance temperature.
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.
(V) Defrost process When the above-described steady output process is continued, if the detected temperature of the outdoor heat exchanger temperature sensor 29c of the outdoor heat exchanger 23 becomes a predetermined value or less, it adheres to the outdoor heat exchanger 23. The defrost process which is the driving | operation which melts the frost which is carrying out 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 the defrost process, the following processes are performed as shown in the flowchart of FIG.
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 S53, the control unit 11 stops the induction heating by the electromagnetic induction heating unit 6, and transmits a 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 29c 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, defrosting can be made quicker.

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 difficult for the user to feel uncomfortable due to a decrease in the 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.
<1-8> Air-conditioning activation control In the above-described electromagnetic induction overheating control, paying attention to the electromagnetic induction heating unit 6, (i) flow condition determination processing, (ii) sensor detachment detection processing, (iii) rapid pressure increase processing, (Iv) The steady output process and (v) the defrost process have been described.

Here, air-conditioning activation control for enabling rapid high-temperature blowing is performed by using such electromagnetic induction overheat control.
As shown in the time chart of FIG. 22, this air conditioning activation control includes (vi) introduction determination control, (vii) startup capacity increase control, (viii) high temperature blowing start control, and (ix) post-startup heating operation control. I do.
(Vi) Introduction determination control In the introduction determination control, the medium temperature blowing control is performed in a situation where the ambient temperature is weak and the user is not particularly required to supply special warm air, or the ambient temperature is Whether to perform high-temperature blowing control for supplying warmer conditioned air to the user when the temperature is low is determined based on the ambient temperature.

In the introduction determination control, the following processes are performed as shown in the flowchart of FIG.
In step S61, when the user inputs an instruction for starting the heating operation while inputting the set temperature by using an input button (not shown) of the controller 90, the control unit 11 receives the information on the heating operation instruction, and the room temperature at the start time is received. The detection temperature of the sensor 43 and the detection temperature of the outdoor air temperature sensor 29b are acquired.
In step S62, the control part 11 judges whether it is the temperature condition which can perform heating operation based on the indoor temperature and outdoor temperature which were acquired by step S61. Specifically, when the relationship between the indoor temperature and the outdoor temperature as shown in FIG. 24 is satisfied, it is determined that the heating operation is possible, and the process proceeds to step S63. Here, the range in which the heating operation can be performed is an environment in which the outdoor air temperature is cooler than the indoor air temperature, and the temperature condition range in which the refrigeration cycle of the air conditioner 1 can perform the heating operation in advance. The control unit 11 holds the data shown in FIG.

In step S63, the control unit 11 determines whether or not the temperature condition is such that the high-temperature blowing control can be performed based on the indoor temperature and the outdoor temperature acquired in step S61 and the relationship data between the indoor temperature and the outdoor temperature illustrated in FIG. Determine whether. Specifically, it is determined that the high temperature blowing control is performed when the temperature range of the high temperature blowing control indicated by hatching in FIG. 24 is satisfied, and the process proceeds to step S65. If it is determined that the high temperature blowing control is not performed, it is determined that the medium temperature blowing control is performed, and the process proceeds to step S64.
In step S64, the control part 11 starts medium temperature blowing control. Although detailed description is avoided in this central blowout control, the indoor fan 42 is not started until the temperature detected by the indoor heat exchanger temperature sensor 44 reaches a predetermined temperature at the start after the heating operation is started, and reaches the predetermined temperature. This is the control for starting the activation of the indoor fan 42 after this.

In step S65, the control unit 11 determines whether or not the operation is started after the defrost process. Here, if it is the operation start after a defrost process, it will transfer to step S66. If the operation is not started after the defrost process, the process proceeds to step S67.
In step S66, the control unit 11 starts thermo-on control described later.
In step S67, the control unit 11 determines whether or not the load is larger than the thermo-on condition for starting the thermo-on control. Here, the situation where the load is greater than the thermo-on condition is a condition where the set temperature−the detected temperature of the room temperature sensor 43−0.5 ° C. is greater than 1. That is, the thermo-on control is an operation resumption process in a situation where the room temperature is warmed to some extent. On the other hand, when the heating operation is started, an operation start process is performed in an environment where the room temperature is low, the degree of deviation from the set temperature is large, and the user desires to supply warmer conditioned air. If it is determined that the load is greater than the thermo-on condition, the process proceeds to step S68. If it is determined that the load is not greater than the thermo-on condition, the process proceeds to step S66.

In step S68, the control part 11 starts high temperature blowing control, and complete | finishes an introduction determination process. As described in the electromagnetic induction overheat control, the high-temperature blowout control does not start the indoor fan 42 until the detected pressure of the pressure sensor 29a reaches the target high pressure Ph at the start after the heating operation is started. In this control, the indoor fan 42 is started after the high pressure Ph is reached.
(Vii) Start-up capacity increase control In the rapid pressure increase process described above, the control for shortening the time required from the start of heating operation until the detected pressure of the pressure sensor 29a reaches the target high pressure Ph has been described. In the start-up capacity increase control, when the above-described high-temperature blowing control is started, in order to shorten the time to reach the target high-pressure pressure Ph, the opening degree of the outdoor electric expansion valve 24 is narrowed to be fixed at start-up. After the degree control is performed, the opening degree of the outdoor electric expansion valve 24 is gradually increased as the frequency of the compressor 21 increases.

In the startup capacity increase control, as shown in the flowchart of FIG. 25, the following processes are performed.
In step S71, the control unit 11 keeps the opening degree of the outdoor electric expansion valve 24 fixed at the fixed opening degree DS (see point g in FIG. 22), and sets the frequency of the compressor 21 for a predetermined time from the start of the heating operation. A fixed opening degree control at start-up is performed to reach the predetermined minimum frequency Qmin within 2 minutes.
This fixed opening DS is an opening that is throttled so that the opening of the outdoor electric expansion valve 24 becomes narrower than the opening corresponding to the refrigerant state. This refrigerant state-corresponding opening degree is the value of the outdoor electric expansion valve 24 that is controlled when it is assumed that after-starting heating operation control to be described later is performed under the same conditions as the conditions at the time of starting fixed opening degree control. Opening degree. The conditions at the time of starting fixed opening control are the operating conditions of the refrigeration cycle other than the opening of the outdoor electric expansion valve 24 (the frequency of the compressor 21, the air volume of the indoor fan 42, the air volume of the outdoor fan 26, etc. ) And ambient temperature conditions (outdoor temperature conditions, indoor temperature conditions, etc.) of the refrigeration cycle. The post-startup heating operation control is performed so that the refrigerant state of the refrigeration cycle is stabilized so that the degree of supercooling of the refrigerant flowing on the outdoor electric expansion valve 24 side of the indoor heat exchanger 41 is constant at a predetermined value. This is control for adjusting the opening degree of the outdoor electric expansion valve 24.

In step S72, the control unit 11 determines whether or not two minutes of the heating start elapsed time counted by the timer 95 has elapsed since the start of the heating operation in a state where the frequency of the compressor 21 has reached the predetermined minimum frequency Qmin. Judging. When two minutes of the heating start elapsed time has elapsed since the start of the heating operation in a state where the predetermined minimum frequency Qmin has been reached, the process proceeds to step S73. If the predetermined minimum frequency Qmin has not been reached or if 2 minutes of the heating start elapsed time has not elapsed since the start of the heating operation, step S72 is repeated.
In step S73, the controller 11 starts raising the frequency of the compressor 21 to the first frequency R1 at the same time as raising the opening of the outdoor electric expansion valve 24 to the first opening D1 larger than the fixed opening DS.
In step S74, the control unit 11 controls the frequency of the compressor 21 to be the first frequency R1, and the opening degree of the outdoor electric expansion valve 24 flows on the outdoor electric expansion valve 24 side of the indoor heat exchanger 41. Control is performed so that the degree of supercooling of the refrigerant becomes constant at a predetermined value.

In step S75, the control unit 11 determines whether or not the frequency of the compressor 21 has reached the first frequency R1. When the frequency reaches the first frequency R1, the process proceeds to step S76. If it has not reached the first frequency R1, it waits to reach the first frequency R1.
In step S76, the control unit 11 starts increasing the frequency of the compressor 21 to the second frequency R2 at the same time as increasing the opening of the outdoor electric expansion valve 24 to the second opening D2 larger than the first opening D1. Hereinafter, such control is repeated until the frequency of the compressor 21 reaches the maximum frequency Rmax and the opening degree of the outdoor electric expansion valve 24 reaches the maximum opening degree Dmax (see point m in FIG. 22). When the frequency of the compressor 21 becomes the maximum frequency Rmax and the opening degree of the outdoor electric expansion valve 24 becomes the maximum opening degree Dmax, the process proceeds to step S77. When the frequency of the compressor 21 is not the maximum frequency Rmax or when the opening degree of the outdoor electric expansion valve 24 is not the maximum opening degree Dmax, step S76 is repeated.

In step S77, the control unit 11 maintains the frequency of the compressor 21 at the maximum frequency Rmax, and sets the degree of opening of the outdoor electric expansion valve 24 so that the amount of refrigerant flowing on the outdoor electric expansion valve 24 side of the indoor heat exchanger 41 is excessive. The degree of cooling is controlled to be constant at a predetermined value.
It should be noted that the above startup capacity increase control is performed until the temperature detected by the indoor temperature sensor 43 reaches the set temperature for the first time after the heating operation is started, and after that, the heating operation is started again while the heating operation control is performed after the startup. The start-up capacity increase control is not performed until is performed.
Thus, the refrigeration capacity can be gradually increased by gradually increasing the refrigerant circulation amount of the refrigeration cycle. Then, the refrigeration capacity is not increased to the maximum at a time, but is gradually increased, so that the compressor 21 sucks the refrigerant in the liquid state, or the detected pressure of the pressure sensor 29a increases abnormally. Can be avoided.
(Viii) High-temperature blowing start control Since the indoor temperature at the start of heating operation is generally low, when the indoor fan 42 is driven from the beginning at the time of activation, an air flow due to cold air is often formed in the room. For this reason, by performing the high temperature blowing start control, after starting the heating operation, the temperature of the conditioned air supplied from the indoor unit 4 to the room is first increased to a certain level to reduce discomfort to the user.

Furthermore, the drive of the indoor fan 42 is maintained in a stopped state so that a state where conditioned air having a sufficiently high temperature can be supplied as early as possible from the start of the heating operation is maintained as the temperature of the conditioned air that can be provided indoors. The condensation capacity in the heat exchanger 41 is kept low. Thereby, the refrigerant | coolant pressure which goes to the indoor heat exchanger 41 from the compressor 21 is raised rapidly, and it is made high temperature high pressure.
In the high temperature blowing start control, as shown in the flowcharts of FIGS. 26 and 27, the following processes are performed.
In step S81, the control unit 11 confirms the state in which the indoor fan 42 is stopped and maintains it in the stopped state.
In step S82, the controller 11 determines whether or not the detected pressure of the pressure sensor 29a has reached the target high pressure Ph. If the target high pressure Ph has been reached (see point f in FIG. 22), the process proceeds to step S86. If the target high pressure Ph has not been reached, the process proceeds to step S83.

In step S83, the control unit 11 determines whether or not 2 minutes 30 seconds as the predetermined fixed activation time Tx has elapsed since the start of the heating operation. If the predetermined fixed activation time has elapsed, the process proceeds to step S86 even if the pressure detected by the pressure sensor 29a has not reached the target high pressure Ph. If the predetermined fixed activation time has not elapsed, the process proceeds to step S84. Thereby, it can avoid that the state where warm air is not blown out continues even if it passes after heating operation starts.
In step S84, the controller 11 determines whether or not the temperature of the refrigerant passing through the discharge pipe A detected by the discharge temperature sensor 29d has exceeded a predetermined discharge temperature Tp of 110 degrees. If it exceeds the predetermined discharge temperature Tp, the process proceeds to step S86 even if the detected pressure of the pressure sensor 29a does not reach the target high pressure Ph. When it does not exceed the predetermined discharge temperature Tp, the process proceeds to step S85. Thereby, the abnormal rise of a high voltage | pressure can be prevented and deterioration of refrigerating machine oil can be avoided, preventing the burden to an apparatus.

In step S85, the control unit 11 determines whether or not the amount of power supplied by the power supply unit 21e detected by the compressor power detection unit 29f exceeds a predetermined power value Eh. If it exceeds the predetermined power value Eh, the process proceeds to step S86 even if the detected pressure of the pressure sensor 29a does not reach the target high pressure Ph. If the predetermined power value Eh is not exceeded, the process returns to step S82. Thereby, generation | occurrence | production of the damage of an electrical component can be avoided.
The indoor fan 42 is set to four stages of airflow in the order of “LL”, which is a weak airflow, “L”, which is a weak airflow, “M” which is a medium airflow, and “H” which is a maximum airflow. In step S86, the control unit 11 drives the indoor fan 42 with the weak air volume “LL” and simultaneously starts counting the timer after starting the indoor fan. (See point h or l in FIG. 22). And here, the start with "LL" which is the smallest air volume is started. In this way, the indoor heat exchanger 41 is only given the weakest “LL” air volume, so the pressure detected by the pressure sensor 29a does not drop rapidly, and the supply of warm air to the room continues. be able to.

In step S87, the control unit 11 has maintained the state where the timer count after starting the indoor fan is 30 seconds or more and the predetermined high-pressure threshold Pm is exceeded for 10 seconds or more (see points n and o in FIG. 22). ) Or 10 minutes have passed since the start of heating operation. If it is determined that the timer count has exceeded 30 seconds after the indoor fan has started and the target high pressure has been maintained for 10 seconds or more, or 10 minutes have elapsed since the start of heating operation, The process proceeds to S91. If it is determined that the timer count has not elapsed for 30 seconds or more after starting the indoor fan, or the target high pressure has not been maintained for 10 seconds or more, and 10 minutes have not elapsed since the start of heating operation, The process proceeds to S88. Here, by waiting for the timer to count for 30 seconds or more after the indoor fan is activated, it is prevented that the control immediately exits the control.

In step S88, the control unit 11 determines whether the detected pressure of the pressure sensor 29a is less than the predetermined low pressure threshold Pl, which is less than 36 kg / cm ² before 5 seconds have elapsed after the indoor fan is started, or is set in advance. It is determined whether 10 seconds have elapsed. Here, if it is less than the predetermined low pressure threshold Pl (see point i in FIG. 22) or 10 seconds have elapsed, the process proceeds to step S89. If it is not less than the predetermined low pressure threshold value Pl and 10 seconds have not elapsed, step S88 is repeated.
In step S89, the control unit 11 stops the indoor fan 42, sets the air volume to “0”, and resets the timer after starting the indoor fan (see point j in FIG. 22).
In step S90, the control unit 11 determines whether the pressure detected by the pressure sensor 29a is larger than 37 kg / cm ² which is the predetermined return high pressure threshold Pm (see point k in FIG. 22) or after the indoor fan 42 has stopped. It is determined whether or not the predetermined 10 seconds have elapsed. When it becomes larger than the predetermined return high pressure threshold Pm or when 10 seconds have passed after the indoor fan 42 has stopped, the process proceeds to step S86. If it is not greater than the predetermined return high pressure threshold Pm and 10 seconds have not elapsed after the indoor fan 42 has stopped, step S90 is repeated.

In step S91, the control part 11 complete | finishes high temperature blowing start control, starts heating operation control after starting, and can implement | achieve the air volume more than "L", without restrict | limiting the air volume of the indoor fan 42 to "LL". The state is set (see point p in FIG. 22).
(Ix) Heating operation control after activation Heating operation control after activation is performed so that the refrigerant state of the refrigeration cycle is stabilized by constant control of the degree of supercooling of the refrigerant flowing on the outdoor electric expansion valve 24 side of the indoor heat exchanger 41. This is control for adjusting the opening degree of the outdoor electric expansion valve 24.
In the post-startup heating operation control, the following processes are performed as shown in the flowchart of FIG.
In step S92, the controller 11 determines whether or not the controller 90 has received a heating stop instruction from the user. Here, when it is determined that the heating stop instruction has been received, the heating operation control after the start is ended. When the heating stop instruction has not been received, the process proceeds to step S93.

In step S <b> 93, the control unit 11 does not limit the air volume of the indoor fan 42 to “LL”, but performs an air volume of “L” or more as the set air volume set by the user with the controller 90.
In step S94, the control unit 11 determines whether or not the thermo-off condition is satisfied. Specifically, the thermo-off condition that the set temperature−the detected temperature of the indoor temperature sensor 43−0.5 ° C. becomes 1 or less (the detected temperature of the indoor temperature sensor 43 exceeds Ty at the point q in FIG. 22). Determine if it is satisfied. When the thermo-off condition is satisfied, the process proceeds to step S95. If the thermo-off condition is not satisfied, step S94 is repeated.
In step S95, the control unit 11 reduces the opening degree of the outdoor electric expansion valve 24 while reducing the frequency of the compressor 21 to the minimum frequency Qmin.

In step S96, the control unit 11 determines whether or not the thermo-on condition is satisfied. Specifically, whether the thermo-on condition that the detected temperature of the set temperature−the indoor temperature sensor 43 is 2 ° C. or higher (the detected temperature of the indoor temperature sensor 43 is lower than Tz at the point s in FIG. 22) is satisfied. Judge whether or not. If the thermo-on condition is satisfied, the process proceeds to step S97. If the thermo-on condition is not satisfied, step S96 is repeated.
In step S97, the control part 11 performs control which raises the opening degree of the outdoor electric expansion valve 24, raising the frequency of the compressor 21, and returns to step S92 and repeats. At this time, the operation such as the high temperature blowing start control is not performed. This is because the room is already close to the set temperature and is sufficiently warm.
<Characteristics of the air conditioner 1 of the present embodiment>
In the air conditioner 1, it is necessary for the detected pressure of the pressure sensor 29 a to reach the target high pressure Ph from the start of the heating operation by performing a fixed opening degree control at start-up that makes the opening degree of the outdoor electric expansion valve 24 narrow. The time can be shortened.

As described above, the opening time of the outdoor electric expansion valve 24 is gradually increased as the frequency of the compressor 21 is increased by performing start-up capacity increase control while reducing the time required to reach the target high pressure Ph. The capacity can be secured by increasing the circulation amount. Thus, it is possible to prevent the compressor 21 from sucking the liquid refrigerant or abnormally increasing the high-pressure side pressure by increasing the performance stepwise rather than abruptly.
<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 said embodiment, the case where stabilization of the refrigerant | coolant state of a refrigerating cycle was performed by supercooling degree constant control was mentioned as an example, and was demonstrated.

However, the present invention is not limited to this.
For example, the supercooling degree may be controlled not to be maintained at a certain value but to be within a certain range.
(B)
In the said embodiment, the case where stabilization of the refrigerant | coolant state of a refrigerating cycle was performed by supercooling degree constant control was mentioned as an example, and was demonstrated.
However, the present invention is not limited to this.
For example, the degree of change in the refrigerant distribution state in the refrigeration cycle may be controlled to be maintained for a predetermined time in a predetermined distribution state or within a predetermined distribution range. As the detection of the refrigerant distribution state, for example, the refrigerant distribution state is grasped by grasping the liquid level of the refrigerant by, for example, providing a sight glass in the condenser of the refrigeration cycle, and this distribution state is a predetermined distribution state or Stabilization control may be performed so as to be within a predetermined distribution range.

Furthermore, the control may be performed so that the superheat degree of the refrigerant flowing on the suction side of the compressor 21 is maintained for a predetermined time within a predetermined value or a predetermined range.
(C)
In the above embodiment, the case where the control unit 11 reduces the frequency of the compressor 21 to the minimum frequency Qmin when the thermo-off condition is satisfied has been described.
However, the present invention is not limited to this.
For example, when the thermo-off condition is satisfied, the control unit 11 may completely stop the driving of the compressor 21.
(D)
In the above embodiment, the case where the predetermined return high pressure threshold Pm and the target high pressure Ph are different pressure values has been described.

However, the present invention is not limited to this.
For example, the predetermined return high pressure threshold Pm and the target high pressure Ph may be controlled as the same pressure value.
(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. 29, for example, the magnetic member F2a and the two stoppers F1a and F1b may be disposed inside the accumulator pipe F or the refrigerant pipe to be heated. Here, the magnetic member F2a contains a magnetic material, and is a member that generates heat by electromagnetic induction heating in the above embodiment. The stoppers F1a and F1b always allow the refrigerant to pass through at two locations inside the copper tube F1, but do 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 stoppers F1a and F1b.

As illustrated in FIG. 30, for example, the copper pipe F1 may be provided with two bent portions FW, and the magnetic member F2a may be disposed inside the copper pipe F1 between the two bent portions FW. Even in this case, the movement of the magnetic member F2a can be suppressed while allowing the refrigerant to pass therethrough.
(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. 31, the coil 168 wound around the bobbin main body 165 may be arranged around the accumulator tube F without being wound around the accumulator tube F. Here, the bobbin main body 165 is disposed so that the axial direction is substantially perpendicular to the axial direction of the accumulator tube F. Further, the bobbin main body 165 and the coil 168 are arranged separately in two so as to sandwich the accumulator tube F.

In this case, for example, as shown in FIG. 32, even if the first bobbin lid 163 and the second bobbin lid 164 passing through the accumulator tube F are disposed in a state of being fitted to the bobbin main body 165. Good.
Furthermore, as shown in FIG. 33, the first bobbin lid 163 and the second bobbin lid 164 may be sandwiched and fixed by the first ferrite case 171 and the second ferrite case 172. In FIG. 33, the case where the two ferrite cases are arranged so as to sandwich the accumulator tube F is taken as an example, but may be arranged in four directions as in the above embodiment. Moreover, you may accommodate the ferrite similarly to the said embodiment.
(I)
In the above embodiment, the air conditioner 1 having one indoor unit 4 and one outdoor unit 2 has been described as an example.

However, the present invention is not limited to this.
For example, an air conditioner in which a plurality of indoor units are connected in parallel or in series to one outdoor unit may be used. In this case, you may make it set the priority order regarding the order with high blowing temperature etc. for every indoor unit.
Moreover, the air conditioning apparatus with which the several outdoor unit was connected in parallel or in series with respect to one indoor unit may be sufficient. In this case, the target high pressure Ph can be reached more quickly, and the capacity can be further increased.
Furthermore, an air conditioner in which a plurality of outdoor units are connected in parallel or in series to a plurality of indoor units may be used.
<Others>
The embodiments of the present invention have been described above with some examples, but the present invention is not limited to these. For example, combined embodiments obtained by appropriately combining different portions of the above-described embodiments within the scope that can be implemented by those skilled in the art from the above description are also included in the present invention.

If the present invention is used, the refrigerant pressure required for supplying hot air at the time of heating start-up can be ensured quickly with a simple configuration, and thus it is particularly useful in an air conditioner in which heating operation is performed.

DESCRIPTION OF SYMBOLS 1 Air conditioning apparatus 6 Electromagnetic induction heating unit 10 Refrigerant circuit 11 Control part (refrigerant state grasping part)
14 Electromagnetic induction thermistor 21 Compressor (compression mechanism)
23 outdoor heat exchanger 24 outdoor electric expansion valve (expansion mechanism)
29a Pressure sensor (refrigerant pressure grasping part)
29b Outdoor air temperature sensor 29c Outdoor heat exchange temperature sensor 41 Indoor heat exchanger 42 Indoor fan 43 Indoor temperature sensor 44 Indoor heat exchange temperature sensor (refrigerant state grasping unit)
68 Coil (Magnetic field generator)
90 Controller DS Fixed opening D1 1st opening D2 2nd opening F Accumulation pipe, refrigerant piping Mmax Maximum supply power Ph Target high pressure (predetermined high pressure threshold)
R1 first frequency (first predetermined target frequency)
R2 second frequency (second predetermined target frequency)
Rmax Predetermined maximum frequency

JP 2000-111126 A JP 2000-105015 A JP-A-11-101522

Claims (11)

1. An air conditioner (1) that performs a refrigeration cycle including at least a compression mechanism (21), an indoor heat exchanger (41), an indoor fan (42), an expansion mechanism (24), and an outdoor heat exchanger (23). ,
   Refrigerant state grasping unit (44, 11) that grasps at least one of the degree of supercooling of the refrigerant from the indoor heat exchanger toward the expansion mechanism and the degree of superheating of the refrigerant flowing on the suction side of the compression mechanism (21). )When,
   A post-startup heating operation control that adjusts the opening degree of the expansion mechanism (24) according to the value grasped by the refrigerant state grasping part (44, 11), and the opening degree of the expansion mechanism (24) is a fixed opening degree ( A control unit (11) for performing a fixed opening degree control at the time of starting the compression mechanism (21) while being maintained as DS),
   With
   The fixed opening (DS) is an opening narrowed to be narrower than the refrigerant state corresponding opening,
   The refrigerant state-corresponding opening includes the operating condition of the refrigeration cycle excluding the expansion mechanism (24) when the startup fixed opening control is executed, and the startup time when the starting fixed opening control is executed. The opening degree of the expansion mechanism (24) when the post-startup heating operation control is performed under the same conditions as the ambient temperature condition of the refrigeration cycle,
   Air conditioner (1).
2. In the post-startup heating operation control, the opening of the expansion mechanism (24) is adjusted so that the refrigerant state of the refrigeration cycle is stabilized according to the value obtained by the refrigerant state grasping unit (44, 11). Post-stabilization control,
   The air conditioner (1) according to claim 1.
3. Stabilization of the refrigerant state of the refrigeration cycle in the post-startup stabilization control is
   Maintaining the degree of supercooling of the refrigerant from the indoor heat exchanger (41) toward the expansion mechanism (24) within a second predetermined value or a second predetermined range for a second predetermined time; and
   Maintaining the degree of superheat of the refrigerant flowing on the suction side of the compression mechanism (21) for a third predetermined time within a third predetermined value or a third predetermined range;
   At least one of
   The air conditioner (1) according to claim 2.
4. In the startup fixed opening degree control, the control unit (11)
   While increasing the frequency of the compression mechanism (21) to be a second predetermined target frequency (R2) higher than the first predetermined target frequency (R1), the opening of the expansion mechanism (24) is increased to the fixed opening (DS ) Until the first opening degree (D1) that is wider than just before starting the start-up capability increase control,
   Causing the frequency of the compression mechanism (21) to reach the first predetermined target frequency (R1) while maintaining a state in which the opening degree of the expansion mechanism (24) is maintained at the fixed opening degree (DS).
   The air conditioner (1) according to any one of claims 1 to 3.
5. In the startup capacity increase control, the control unit (11)
   While maintaining the frequency of the compression mechanism (21) at the second predetermined target frequency (R2), the opening degree of the expansion mechanism (24) is adjusted according to the value grasped by the refrigerant state grasping part (44, 11). Immediately before performing control
   The opening degree of the expansion mechanism (24) is once increased to the first opening degree (D1).
   The air conditioner (1) according to claim 4.
6. The control unit (11) starts the startup capacity increase control when a predetermined fixed startup time (Tx) has elapsed from the start of the startup fixed opening degree control.
   The air conditioner (1) according to claim 4 or 5.
7. The control unit (11) sets the start timing of the post-startup heating operation control to a time point after the start point of the start time capacity increase control.
   The air conditioner (1) according to claim 6.
8. In the startup capacity increase control, the control unit (11) sets the frequency of the compression mechanism (21) to a predetermined maximum frequency (Rmax) that is predetermined as a frequency higher than the second predetermined target frequency (R2). Performing start-up stage capability control to increase the opening degree of the expansion mechanism (24) while increasing the second opening degree (D2) wider than the first opening degree (D1).
   The air conditioner (1) according to any one of claims 4 to 7.
9. A refrigerant pressure grasping part (29a) for grasping the pressure of the refrigerant sent from the compression mechanism (21) toward the indoor heat exchanger (41);
   The control unit (11) includes the indoor fan (42) from the start of the startup fixed opening degree control until the pressure grasped by the refrigerant pressure grasping unit (29a) exceeds a predetermined high pressure threshold (Ph). The fan control at the time of starting is performed in which the air volume by the indoor fan (42) after the pressure grasped by the refrigerant pressure grasping part (29a) exceeds the predetermined high pressure threshold (Ph) is larger than the air volume by
   The air conditioner (1) according to any one of claims 1 to 8.
10. The control unit (11) is configured to start the fixed opening degree control at the time of starting and before the pressure grasped by the refrigerant pressure grasping unit (29a) exceeds the predetermined high pressure threshold (Ph). Set the air volume by the fan (42) to 0,
    The air conditioner (1) according to claim 9.
11. A magnetic field generator (68) that generates a magnetic field for induction heating the refrigerant pipe (F) on the suction side of the compression mechanism and / or the member that is in thermal contact with the refrigerant flowing in the refrigerant pipe (F). )
    The control unit (11) performs the induction heating at least during execution of the startup fixed opening degree control.
    The air conditioner (1) according to any one of claims 1 to 10.

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