JP2017089940A - Air conditioner and control method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an indoor heat exchanger which prevents frost formation and achieves improvement of the energy efficiency in dehumidification operation in an environment where an outdoor temperature is low.SOLUTION: An air conditioner includes: a compressor 10; a first indoor heat exchanger 61 connected to the compressor through a first pipeline 91; an expansion valve 50a connected to the first indoor heat exchanger through a second pipeline 92; and a second indoor heat exchanger 60 connected to the expansion valve through a third pipeline 93. Further, the air conditioner has: a bypass pipeline 94 connected between the first pipeline and the third pipeline; a first electromagnetic valve 81 provided in the bypass pipeline, and a control device 100 which controls the opening/closing state of the first electromagnetic valve according to a temperature in a house.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an air conditioner and a method for controlling the air conditioner.

  When the air conditioner is used in a cold region, there is a problem that the heat exchanger is frosted and the efficiency of heat exchange between the refrigerant and the outside air in the heat exchanger is reduced.

  Patent document 1 is disclosing the technique which defrosts an outdoor heat exchanger by providing the defrost operation mode which uses the bypass line which flows a high temperature refrigerant | coolant to an outdoor heat exchanger at the time of heating operation.

JP 2014-196017 A

  However, there is a problem that frost forms not only the outdoor heat exchanger but also the indoor heat exchanger. In particular, during the dehumidifying operation, the indoor heat exchanger is dehumidified by cooling the indoor air having high humidity and condensing moisture in the air, so that there is a high risk of frost formation on the indoor heat exchanger. When indoor air is low temperature, the possibility of frosting on the indoor heat exchanger is further increased. The technique disclosed in Patent Document 1 does not disclose a technique for preventing frost formation of the indoor heat exchanger, and cannot solve the problem of frost formation on the indoor heat exchanger during a dehumidifying operation in a cold region.

  This invention is for solving the above subjects, and it aims at preventing the frost formation of an indoor heat exchanger in the dehumidification driving | operation in the environment where external temperature is low.

In order to achieve the above object, an air conditioner according to a first aspect of the present invention includes:
A compressor for compressing the refrigerant;
A first indoor heat exchanger connected to the compressor via a first conduit;
An expansion valve connected to the first indoor heat exchanger via a second conduit;
A second indoor heat exchanger connected to the expansion valve via a third conduit;
A bypass line connected between the first line and the third line;
A first solenoid valve provided in the bypass line;
A control device for controlling the open / close state of the first electromagnetic valve according to the temperature in the house;
It is characterized by providing.

  The control device may control an inflow amount of the refrigerant flowing into the bypass pipe by adjusting an opening / closing degree of the slot of the first electromagnetic valve based on a temperature in the house.

The air conditioner
Four sides having a first port connected to the compressor, a second port connected to the accumulator, a third port connected to the second indoor heat exchanger, and a fourth port connected to the first conduit A valve,
An outdoor heat exchanger connected from the fourth port of the four-way valve via a fourth pipe provided by branching from the first pipe;
A fifth pipe connecting the outdoor heat exchanger and the expansion valve;
A second solenoid valve provided in the first conduit;
A third solenoid valve provided in the fourth pipeline;
A fourth solenoid valve provided in the fifth pipeline,
The control device further includes connection states of the first, second, third, and fourth ports of the four-way valve, the first electromagnetic valve, the second electromagnetic valve, the third electromagnetic valve, and the fourth electromagnetic valve. The open / close state of the solenoid valve may be controlled.

The controller is
In the cooling operation mode,
The first solenoid valve and the second solenoid valve are closed, the third solenoid valve and the fourth solenoid valve are opened, and the four-way valve is connected to the first port and the fourth port; In the first state where the second port and the third port are connected,
In heating mode,
The first solenoid valve and the second solenoid valve are closed, the third solenoid valve and the fourth solenoid valve are opened, and the four-way valve is connected to the first port and the third port. And the second state in which the second port and the fourth port are connected,
In normal dehumidifying operation mode,
Opening the second solenoid valve, closing the first solenoid valve, the third solenoid valve, and the fourth solenoid valve, setting the four-way valve to the first state,
In the defrosting and dehumidifying operation mode,
The first solenoid valve is opened at an opening corresponding to the temperature in the house, the second solenoid valve is opened, the third solenoid valve and the fourth solenoid valve are closed, and the four-way The valve may be in the first state.

The controller is
In dehumidifying chlorofluorocarbon reverse operation mode,
The first solenoid valve, the second solenoid valve, and the fourth solenoid valve may be closed, the third solenoid valve may be opened, and the four-way valve may be in the second state.

The control method of the air conditioner according to the second aspect is as follows:
In an air conditioner having a cooling operation mode, a heating operation mode, and a dehumidifying operation mode,
Before operating in the dehumidifying operation mode, after providing a step of removing the refrigerant remaining in the outdoor heat exchanger out of the outdoor heat exchanger, the operation is performed in the dehumidifying operation mode.

The control method of the air conditioner according to the third aspect is as follows:
In an air conditioner having a cooling operation mode, a heating operation mode, a dehumidifying operation mode, and a dehumidifying non-frost operating mode,
When switching from the operation in the dehumidifying operation mode to the operation in the dehumidifying non-frost operating mode, the threshold temperature or threshold humidity for switching the operation is the indoor heat exchanger in order to prevent frost formation on the indoor heat exchanger. It is set higher than the temperature at which frost formation occurs.

  ADVANTAGE OF THE INVENTION According to this invention, the frost formation of an indoor heat exchanger can be prevented in the dehumidification driving | operation in an environment with low external temperature.

It is a figure which shows the structure of the air conditioning apparatus which concerns on embodiment of this invention. It is a figure which shows the structure of the control apparatus which comprises an air conditioner. It is a figure for demonstrating the air_conditioning | cooling operation mode of an air conditioner. It is a flowchart for demonstrating the air_conditioning | cooling operation mode of an air conditioner. It is a figure for demonstrating the allowable setting range of an air conditioner. It is a figure for demonstrating the heating operation mode of an air conditioner. It is a flowchart for demonstrating the heating operation mode of an air conditioner. It is a figure for demonstrating the dehumidification Freon reverse operation mode of an air conditioner. It is a figure for demonstrating the normal dehumidification operation mode of an air conditioner. It is a figure for demonstrating the dehumidification non-frost operation mode of an air conditioner. It is a flowchart for demonstrating the dehumidification operation mode of an air conditioner.

  Hereinafter, an air conditioner and an air conditioner control method according to an embodiment of the present invention will be described with reference to the drawings. This embodiment demonstrates the example of the air conditioner applied to the house for cultivating a plant. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

(Embodiment 1)
As shown in FIG. 1, the air conditioner 1 according to the first embodiment includes a control device 100, an outdoor unit 200, and an indoor unit 300.

  The outdoor unit 200 includes an accumulator 10, a compressor 20, a four-way valve 30, an outdoor heat exchanger 40, an expansion valve 50, a first electromagnetic valve 81, a second electromagnetic valve 82, a third electromagnetic valve 72, and a fourth electromagnetic valve 71. Composed. The indoor unit 300 includes a first indoor heat exchanger 61, a second indoor heat exchanger 60, and a blower 62.

  The accumulator 10 is for preventing liquid refrigerant from being sucked into the compressor 20. The accumulator 10 has a function of separating the liquid refrigerant and the gaseous refrigerant and supplying only the gaseous refrigerant to the compressor 20. The compressor 20 has a function of compressing the refrigerant, and includes an electric compressor or the like.

  The four-way valve 30 includes a first port P1 connected to the compressor 20, a second port P2 connected to the accumulator 10, a third port P3 connected to the second indoor heat exchanger 60, and outdoor heat exchange. And a fourth port P4 connected to the first pipe 91. The control device 1 controls the first port P1 to the fourth port P4 in the four-way valve 30 in accordance with each of the cooling operation mode, the heating operation mode, the dehumidification fron reverse operation mode, the normal dehumidification operation mode, and the dehumidification non-frost operation mode. The connection state of is appropriately changed.

  The outdoor heat exchanger 40 exchanges heat between the refrigerant and the outdoor air. That is, the heat of the high-temperature refrigerant is radiated during the cooling operation. Further, during the heating operation, the outside air temperature is absorbed by the refrigerant. In the expansion valve 50, the temperature decreases as the refrigerant diffuses and expands.

  The second indoor heat exchanger 60 exchanges heat between the refrigerant and room air. The second indoor heat exchanger 60 cools indoor air with a low-temperature refrigerant during cooling operation, and warms indoor air with a high-temperature refrigerant during heating operation. In addition, during the dehumidifying operation, the indoor air is dehumidified by condensing moisture contained in the indoor air with a low-temperature refrigerant.

  The first indoor heat exchanger 61 warms the air cooled by the second indoor heat exchanger 60 with a high-temperature refrigerant during the dehumidifying operation. The blower 62 sends indoor air to the second indoor heat exchanger 60 and the first indoor heat exchanger 61. The 1st indoor heat exchanger 61 is installed in the lee of the air ventilated with the air blower 62 rather than the 2nd indoor heat exchanger 60. FIG.

  The fourth port P4 of the four-way valve 30 and the first indoor heat exchanger 61 are connected via a first pipe 91. The outdoor heat exchanger 40 and the expansion valve 50 are connected via a fifth pipe 96. The first indoor heat exchanger 61 is connected to the fifth pipe 96 through the second pipe 92. The expansion valve 50 and the second indoor heat exchanger 60 are connected via a third conduit 93. The fourth port P4 of the four-way valve 30 and the outdoor heat exchanger 40 are connected via a fourth pipe 95. The third port P3 of the four-way valve 30 and the second indoor heat exchanger 60 are connected via a sixth pipeline 97. The first pipeline 91 and the third pipeline 93 are connected via a bypass pipeline 94.

  The bypass line 94 is for bypassing a part of the refrigerant flowing to the expansion valve 50 to the third line 93 on the downstream side of the expansion valve 50 during the dehumidifying non-frost operation.

  The first electromagnetic valve 81 is provided in the bypass conduit 94. The first electromagnetic valve 81 is constituted by, for example, a proportional control valve, and changes the flow rate of the refrigerant flowing through the bypass conduit 94 according to a control signal input from the control device 1.

  The second electromagnetic valve 82 is provided in the first pipeline 91. The third electromagnetic valve 72 is provided in the fourth pipeline 95. The fourth electromagnetic valve 71 is provided in the fifth pipe 96.

  The control device 100 controls the outdoor unit 200 and the indoor unit 300 based on temperature and humidity information acquired from temperature sensors and humidity sensors provided in the house, the outdoor unit 200, and the indoor unit 300. As illustrated in FIG. 2, the control device 100 includes a control unit 110, a storage unit 120, an input unit 130, a display unit 140, and a bus 150.

  The control unit 110 includes a RAM (Random Access Memory) and a CPU (Central Processing Unit). The RAM functions as a work area for the CPU. The CPU reads the control program stored in the storage unit 120 into the RAM and executes it, thereby changing the connection state of the ports inside the four-way valve 30, the first electromagnetic valve 81, the second electromagnetic valve 82, the third electromagnetic valve. The opening / closing states of the slots of the solenoid valve 72 and the fourth solenoid valve 71 are changed.

  The storage unit 120 includes an external storage device, and stores an allowable temperature setting range, an allowable humidity setting range, a threshold temperature T1 for switching to a dehumidifying non-frost operation mode, which will be described later, and the like. The storage unit 120 stores a control program for the air conditioner 1. The input unit 130 includes a switch, a keyboard, a touch panel, and the like. The input unit 130 acquires an operation mode, an operating temperature, an operating humidity, and the like set by the user. The display unit 140 includes an LED lamp, a liquid crystal display, and the like. The display unit 140 displays the operating mode during operation, the temperature and humidity set by the user, the temperature and humidity measured by the temperature and humidity sensor, and the like. The display unit 140 displays an error when the set temperature / humidity input by the user is outside the allowable range, and displays a failure when the apparatus is out of order. The bus 150 connects the control unit 110, the storage unit 120, the input unit 130, and the display unit 140.

  Next, the operation of the air conditioner 1 having the above configuration will be described. Since the air conditioner 1 operates in the cooling operation mode, the heating operation mode, and the dehumidifying operation mode set by the user from the control device 100, the operation in each operation mode will be sequentially described.

(Cooling operation mode)
The cooling operation process executed by the air conditioner 1 will be described with reference to the flowcharts shown in FIGS. 3 and 4. FIG. 3 is a diagram illustrating the flow of the refrigerant during the cooling operation. A thick solid line indicates a pipeline through which the refrigerant flows. A dotted line indicates a pipeline through which no refrigerant flows. This cooling operation process is started when the temperature is set by the user and the operation mode is set to the cooling operation mode. In addition, the control unit 110 continues operating the blower 62 during the cooling operation process.

  At this time, as shown in FIG. 3, the controller 110 closes the first electromagnetic valve 81 and the second electromagnetic valve 82, and opens the third electromagnetic valve 72 and the fourth electromagnetic valve 71. Further, the inside of the four-way valve 30 is set to a first state in which the first port P1 and the fourth port P4 are connected and the second port P2 and the third port P3 are connected.

  Thereby, the refrigerant is compressor 20 → four-way valve 30 → third electromagnetic valve 72 → fourth pipe 95 → outdoor heat exchanger 40 → fourth electromagnetic valve 71 → fifth pipe 96 → expansion valve 50 → third. It circulates in order of the pipe line 93 → the second indoor heat exchanger 60 → the sixth pipe line 97 → the four-way valve 30 → the accumulator 10 → the compressor 20.

  When the cooling operation is started, the control unit 110 determines whether or not the set temperature input by the user is within the allowable set temperature range (step S11). Specifically, when the allowable temperature setting range of the air conditioner 1 is the range shown in FIG. 5, the control unit 110 determines whether or not the set temperature input by the user is in the range of 15 ° C. to 30 ° C. Determine.

  When it is determined that the set temperature input by the user is within the allowable temperature range (step S11: Yes), the control unit 110 determines whether the temperature acquired from the temperature sensor provided in the house is equal to or higher than the set temperature. It is determined whether or not (step S12). When the temperature in the house is equal to or higher than the set temperature (step S12: Yes), the control unit 110 operates the compressor 20 (step S13). At this time, in the outdoor heat exchanger 40, the refrigerant is cooled by exchanging heat between the refrigerant compressed to high temperature and high pressure by the compressor 20 and the outside air. The expansion valve 50 is further cooled when the refrigerant cooled in the outdoor heat exchanger 40 is diffused and expanded. In the second indoor heat exchanger 60, the air in the house is cooled by exchanging heat between the air in the house and the cooled refrigerant.

  On the other hand, when the temperature in the house is lower than the set temperature input by the user (step S12: No), the control unit 110 stops the operation of the compressor 20 (step S14).

  Further, when determining that the set temperature is outside the allowable temperature range (step S11: No), the control unit 110 turns on the error display lamp of the display unit 140 (step S15). Thereafter, the control unit 110 ends the cooling operation process.

(Heating operation mode)
The heating operation process executed by the air conditioner 1 will be described with reference to the flowcharts shown in FIGS. 6 and 7. FIG. 6 is a diagram illustrating the flow of the refrigerant during the heating operation. A thick solid line indicates a pipeline through which the refrigerant flows. A dotted line indicates a pipeline through which no refrigerant flows. This heating operation process starts when the temperature is set by the user and the operation mode is set to the heating operation mode. Moreover, the control part 110 continues operating the air blower 62 during a heating operation process.

  At this time, as shown in FIG. 6, the controller 110 closes the first electromagnetic valve 81 and the second electromagnetic valve 82, and opens the third electromagnetic valve 72 and the fourth electromagnetic valve 71. Further, the inside of the four-way valve 30 is brought into a second state in which the first port P1 and the third port P3 are connected and the second port P2 and the fourth port P4 are connected.

  Thereby, the refrigerant is compressor 20 → four-way valve 30 → sixth pipe 97 → second indoor heat exchanger 60 → third pipe 93 → expansion valve 50 → fifth pipe 96 → fourth electromagnetic valve 71 → The outdoor heat exchanger 40 circulates in the order of the fourth pipe 95 → the third electromagnetic valve 72 → the four-way valve 30 → the accumulator 10 → the compressor 20.

  When the heating operation is started, the control unit 110 determines whether or not the set temperature input by the user is within the allowable set temperature range (step S31). Specifically, when the allowable temperature setting range of the air conditioner 1 is the range shown in FIG. 5, the control unit 110 determines whether or not the temperature set by the user is in the range of 0 ° C. to 28 ° C. To do.

  When it is determined that the set temperature input by the user is within the allowable temperature range (step S31: Yes), the control unit 110 determines whether the temperature acquired from the temperature sensor provided in the house is equal to or lower than the set temperature. It is determined whether or not (step S32). Control part 110 operates compressor 20 when the temperature in a house is below preset temperature (Step S32: Yes) (Step S33).

  At this time, the second indoor heat exchanger 60 warms the air in the house by heat exchange between the high-temperature and high-pressure refrigerant compressed by the compressor 20 and the air in the house. In the expansion valve 50, the refrigerant radiated by the second indoor heat exchanger 60 is diffused and expanded. In the outdoor heat exchanger 40, heat exchange is performed between the diffused and expanded refrigerant and the outside air.

  On the other hand, when the temperature in the house is higher than the set temperature input by the user (step S32: No), the control unit 110 stops the operation of the compressor 20 (step S34).

  Further, when determining that the set temperature is outside the allowable temperature range (step S31: No), the control unit 110 turns on the error display lamp of the display unit 140 (step S35). Thereafter, the control unit 110 ends the heating operation process.

  As described above, since the air conditioner 1 supplies the refrigerant after radiating heat in the second indoor heat exchanger 60 to the outdoor heat exchanger 40, the loss of heat energy due to the refrigerant being cooled by the outside air is reduced. Can do.

(Dehumidifying operation mode)
Dehumidifying operation processing executed by the air conditioner 1 will be described with reference to the flowcharts shown in FIGS. 8 to 10 and 11. In the dehumidifying operation mode, the air conditioner 1 according to the present embodiment is a dehumidifying flon reverse operation mode for reducing the amount of refrigerant remaining in the outdoor heat exchanger 40 when starting the dehumidifying operation, and a normal dehumidifying operation mode. In addition, it has three operation modes of a dehumidification non-frost operation mode having a defrosting function. FIG. 8 is a diagram showing the refrigerant flow in the dehumidifying operation in the dehumidifying chlorofluorocarbon reverse operation mode, FIG. 9 in the normal dehumidifying operation mode, and FIG. 10 in the dehumidifying non-frost operating mode. A thick solid line indicates a pipeline through which the refrigerant flows. A dotted line indicates a pipeline through which no refrigerant flows. The dehumidifying operation process starts when the humidity is set by the user and the operation mode is set to the dehumidifying operation mode. Moreover, the control part 110 continues operating the air blower 62 during a dehumidification driving | operation process.

  When the dehumidifying operation mode is set, the control unit 110 transitions the operation mode to the dehumidifying chlorofluorocarbon reverse operation mode (step S51).

(Dehumidification Freon reverse operation mode)
The dehumidifying chlorofluorocarbon reverse operation mode is an operation mode for reducing the amount of refrigerant remaining in the outdoor heat exchanger 40. For example, when the operation mode before starting the dehumidifying operation is the cooling operation mode, a large amount of refrigerant may remain in the outdoor heat exchanger 40. When the dehumidifying operation is switched while a large amount of refrigerant remains in the outdoor heat exchanger 40, the dehumidifying operation is performed in a state where the refrigerant remaining in the outdoor heat exchanger 40 cannot be used. The refrigerant cannot be used efficiently. In order to solve this problem, the dehumidifying chlorofluorocarbon reverse operation is performed before the dehumidifying operation.

  When transitioning to the dehumidifying chlorofluorocarbon reverse operation mode, the control unit 110 closes the first electromagnetic valve 81, the second electromagnetic valve 82, and the fourth electromagnetic valve 71 as shown in FIG. Open. Further, the inside of the four-way valve 30 is brought into a second state in which the first port P1 and the third port P3 are connected and the second port P2 and the fourth port P4 are connected.

  The control unit 110 drives the refrigerant remaining in the outdoor heat exchanger 40 to the accumulator 10 side via the four-way valve 30 and the rotary compressor, the four-way valve 30 and the compressor 20 of the outdoor heat exchanger 40 (not shown). And control.

  Returning to FIG. 11, after operation for a predetermined time (for example, about 20 seconds) in the dehumidifying flon reverse operation mode (step S <b> 52), the control unit 110 determines whether the set humidity input by the user is within the allowable set humidity range. It is determined whether or not (step S53). Specifically, when the allowable humidity setting range of the air conditioner 1 is the range shown in FIG. 5, the control unit 110 determines whether or not the set humidity input by the user is in the range of 50% to 90%. Determine. The predetermined time (for example, about 20 seconds) is determined in consideration of the time required for the amount of refrigerant remaining in the outdoor heat exchanger 40 to decrease.

  When the controller 110 determines that the set humidity input by the user is within the allowable humidity range (step S53: Yes), the temperature in the house acquired from the temperature sensor provided in the house is the threshold temperature T1 ( For example, it is determined whether the temperature is 15 ° C. or less (step S55). The threshold temperature T1 is set to a temperature at which frost formation starts on the second indoor heat exchanger 60.

  When the temperature in the house is equal to or higher than a threshold temperature T1 (for example, 15 ° C.) (step S55: No), the control unit 110 changes the operation mode to the normal dehumidification operation mode (step S56).

(Normal dehumidifying operation mode)
When transitioning to the normal dehumidifying operation mode, the controller 110 opens the second solenoid valve 82 and closes the first solenoid valve 81, the third solenoid valve 72, and the fourth solenoid valve 71, as shown in FIG. Put it in a state. Further, the four-way valve 30 is set to the first state.

  Thereby, the refrigerant is the compressor 20 → four-way valve 30 → second electromagnetic valve 82 → first pipe 91 → first indoor heat exchanger 61 → second pipe 92 → expansion valve 50 → third pipe 93 → It circulates in order of 2nd indoor heat exchanger 60-> 6th pipe line 97-> four-way valve 30-> accumulator 10-> compressor 20.

  In the normal dehumidifying operation mode, the control unit 110 determines whether or not the humidity acquired from the humidity sensor provided in the house is equal to or higher than the set humidity input by the user (step S58). When the humidity in the house is higher than the set humidity (step S58: Yes), the control unit 110 operates the compressor 20 (step S59).

  At this time, the refrigerant is diffused and expanded by the expansion valve 50 and cooled. In the second indoor heat exchanger 60, heat is exchanged between the air in the house and the cooled refrigerant, and moisture in the air passing through the second indoor heat exchanger 60 is cooled and condensed, so that the inside of the house Air is dehumidified. Moreover, the 1st heat exchanger 61 installed in the lee of the 2nd indoor heat exchanger 60 warms the air cooled with the 2nd indoor heat exchanger 60 with the high temperature refrigerant | coolant.

  On the other hand, when the humidity in the house is lower than the set humidity (step S58: No), the control unit 110 stops the compressor 20 (step S60).

  Moreover, when the temperature in a house is below threshold temperature T1 (for example, 15 degreeC) (step S55: Yes), the control part 110 changes operation mode to dehumidification non-frost operation mode (step S57).

  In step S55, the control unit 110 determines whether the operation mode transitions to the normal dehumidification operation mode or the dehumidification non-frost operation mode by determining whether or not the temperature is equal to or lower than the threshold temperature T1. It was. However, the control unit 110 may determine by determining whether or not the humidity in the house is equal to or lower than a threshold humidity H1 (for example, any one of 80 to 90%).

(Dehumidification non-frost operation mode)
If the dehumidifying operation is performed when the air in the house is equal to or lower than the threshold temperature T1 (or lower than the threshold humidity H1), the second indoor heat exchanger 60 that has become cold may be frosted. For this reason, it is preferable to set the threshold temperature T1 higher than the temperature at which frost formation occurs. Before the frost formation (for example, when the temperature becomes 15 ° C. or lower), the operation in the dehumidifying non-frost operation mode is performed, so that the second indoor heat exchanger 60 is prevented from frosting and the second is dehumidified. The air cooled by the indoor heat exchanger 60 can be warmed.

  When transitioning to the dehumidifying non-frost operation mode, the control unit 110 opens the first electromagnetic valve 81 at an opening degree corresponding to the temperature in the house and opens the second electromagnetic valve 82, as shown in FIG. The third solenoid valve 72 and the fourth solenoid valve 71 are closed. Further, the inside of the four-way valve 30 is set to the first state.

  Thereby, the refrigerant is the compressor 20 → four-way valve 30 → second electromagnetic valve 82 → first pipe 91 → first indoor heat exchanger 61 → second pipe 92 → expansion valve 50 → third pipe 93 → It circulates in order of 2nd indoor heat exchanger 60-> 6th pipe line 97-> four-way valve 30-> accumulator 10-> compressor 20.

  Further, the control unit 110 controls the opening / closing degree of the slot of the first electromagnetic valve 81 according to the temperature in the house. Thereby, a part of the refrigerant flowing through the first pipe 91 is diverted to the bypass pipe 94, bypassing the first indoor exchanger 61 and the expansion valve 50, and supplied to the second indoor heat exchanger 60.

  The operation control (steps S58, S59, S60) of the compressor 20 is the same as in the normal dehumidifying operation mode.

  In the dehumidifying non-frost operation mode, the controller 110 adjusts the amount of refrigerant flowing through the bypass conduit 94 by adjusting the degree of opening and closing of the first electromagnetic valve 81 provided in the bypass conduit 94. Thereby, the control part 110 adjusts the temperature of the refrigerant | coolant in the 2nd indoor heat exchanger 60, and prevents that the 2nd indoor heat exchanger 60 forms frost.

  Moreover, the refrigerant | coolant which flows through the 1st indoor heat exchanger 61 provided in the lee of the air blower 62 with respect to the 2nd indoor heat exchanger 60 is a high temperature / high pressure state. Therefore, the air cooled by the second indoor heat exchanger 60 at the time of dehumidification is reheated by the first indoor heat exchanger 61 and then discharged into the house. The control unit 110 controls the first electromagnetic valve 81 to adjust the amount of refrigerant branched to the bypass conduit 94, thereby adjusting the temperature of the refrigerant flowing through the second indoor heat exchanger 60 and discharging it into the house. Adjust the air temperature.

  Further, when the control unit 110 determines that the set humidity input by the user is outside the allowable humidity range (step S53: No), the control unit 110 turns on the error display lamp of the display unit 140 (step S54). Thereafter, the control unit 110 ends the dehumidifying operation process.

  As described above, the air conditioner 1 according to this embodiment can defrost the second indoor heat exchanger 60 by having the dehumidifying non-frost operation mode using the bypass line 94.

  Moreover, the air conditioner 1 defrosts the 2nd indoor heat exchanger 60 according to the temperature in the indoor unit 300 by adjusting the quantity of the refrigerant | coolant bypassed to the bypass pipe line 94 by the 1st solenoid valve 81. I can do it.

  Further, the air conditioner 1 can prevent the air cooled by the second indoor heat exchanger 60 from being discharged into the house as it is by providing the first indoor heat exchanger 61. Moreover, the air conditioner 1 adjusts the quantity of the refrigerant | coolant which flows into the 1st indoor heat exchanger 61 by adjusting the quantity of the refrigerant | coolant bypassed to the bypass pipe line 94 by the 1st solenoid valve 81, and discharges it in a house. It is possible to adjust the temperature of the air.

  In addition, the air conditioner 1 according to the present embodiment includes a step of removing the refrigerant remaining in the outdoor heat exchanger 40 out of the outdoor heat exchanger 40 before performing the dehumidifying operation. Thereby, the air conditioner 1 can prevent the dehumidification operation in a state where the refrigerant remaining in the outdoor heat exchanger 40 cannot be used, and can efficiently use the refrigerant.

  In addition, the air conditioner 1 controls the refrigerant not to circulate through the outdoor heat exchanger 40 during the dehumidifying operation. Thereby, the air conditioner 1 can prevent a decrease in energy efficiency due to cooling of the refrigerant by the outdoor heat exchanger 40 even during a dehumidifying operation in a cold region. Moreover, since the air conditioner 1 does not need to defrost the outdoor heat exchanger 40, the energy used for the defrosting of the outdoor heat exchanger 40 can be reduced.

  In the above description, the case where the control device 100, the outdoor unit 200, and the indoor unit 300 are mounted in separate devices has been described. However, the scope of the present invention need not be limited to this. For example, only the input unit 130 and the display unit 140 may be mounted on the control device 100, and the control unit 110 and the storage unit 120 may be mounted in the outdoor unit 200 or the indoor unit 300. Moreover, you may make it mount the control apparatus 100 and the outdoor unit 200 in the same apparatus.

  In the above description, the threshold temperature T1 for switching to the dehumidifying non-frost operation mode has been described from the temperature sensor provided in the house. However, this temperature sensor may be provided in the indoor unit 300.

  In the above description, the threshold temperature T1 is set to a temperature at which the second indoor heat exchanger 60 starts frosting. However, the threshold temperature T1 is a temperature at which the second indoor heat exchanger 60 starts to frost. It doesn't have to be. Specifically, defrosting may be performed after the second indoor heat exchanger 60 is frosted by setting the threshold temperature T1 to a temperature lower than the temperature at which frosting starts. Moreover, you may set threshold temperature T1 to the temperature which does not produce a cold damage to the plant in a house.

  Moreover, although the above description demonstrated the case where only temperature conditions were used as conditions which transfer to dehumidification non-frost driving | operation, you may combine with humidity conditions. For example, when the humidity is low, the possibility of frost formation at the same temperature is lower than when the humidity is high. Therefore, it is good also as a transition condition which combined temperature and humidity.

  In the above description, the electromagnetic valve is used as the valve (71, 72, 81, 82) for setting the refrigerant flow path. However, the valve for setting the refrigerant flow path is an electric valve. Also good.

  Moreover, the temperature / humidity information and the control signal transmitted / received between the control device 100 and the outdoor unit 200 and the indoor unit 300 may be transmitted / received wirelessly or may be transmitted / received wired.

DESCRIPTION OF SYMBOLS 1 ... Air conditioning apparatus, 10 ... Accumulator, 20 ... Compressor, 30 ... Four-way valve, 40 ... Outdoor heat exchanger, 50 ... Expansion valve, 60 ... Second indoor heat exchanger, 61 ... First indoor heat exchanger, 62 DESCRIPTION OF SYMBOLS ... Blower, 71 ... 4th solenoid valve, 72 ... 3rd solenoid valve, 81 ... 1st solenoid valve, 82 ... 2nd solenoid valve, 91 ... 1st pipe line, 92 ... 2nd pipe line, 93 ... 3rd pipe 94, bypass pipe, 95 ... fourth pipe, 96 ... fifth pipe, 97 ... sixth pipe, 100 ... control device, 110 ... control section, 120 ... storage section, 130 ... input section, 140 ... Display unit, 150 ... Bus, 200 ... Outdoor unit, 300 ... Indoor unit

Claims (7)

A compressor for compressing the refrigerant;
A first indoor heat exchanger connected to the compressor via a first conduit;
An expansion valve connected to the first indoor heat exchanger via a second conduit;
A second indoor heat exchanger connected to the expansion valve via a third conduit;
A bypass line connected between the first line and the third line;
A first solenoid valve provided in the bypass line;
A control device for controlling the open / close state of the first electromagnetic valve according to the temperature in the house;
An air conditioner. The control device controls the amount of refrigerant flowing into the bypass pipe by adjusting the opening / closing degree of the slot of the first electromagnetic valve based on the temperature in the house.
The air conditioner according to claim 1. Four sides having a first port connected to the compressor, a second port connected to the accumulator, a third port connected to the second indoor heat exchanger, and a fourth port connected to the first conduit A valve,
An outdoor heat exchanger connected from the fourth port of the four-way valve via a fourth pipe provided by branching from the first pipe;
A fifth pipe connecting the outdoor heat exchanger and the expansion valve;
A second solenoid valve provided in the first conduit;
A third solenoid valve provided in the fourth pipeline;
A fourth solenoid valve provided in the fifth pipeline,
The control device further includes connection states of the first, second, third, and fourth ports of the four-way valve, the first electromagnetic valve, the second electromagnetic valve, the third electromagnetic valve, and the fourth electromagnetic valve. Control the open / close state of the solenoid valve,
The air conditioner according to claim 1 or 2. The controller is
In the cooling operation mode,
The first solenoid valve and the second solenoid valve are closed, the third solenoid valve and the fourth solenoid valve are opened, and the four-way valve is connected to the first port and the fourth port; In the first state where the second port and the third port are connected,
In heating mode,
The first solenoid valve and the second solenoid valve are closed, the third solenoid valve and the fourth solenoid valve are opened, and the four-way valve is connected to the first port and the third port. And the second state in which the second port and the fourth port are connected,
In normal dehumidifying operation mode,
Opening the second solenoid valve, closing the first solenoid valve, the third solenoid valve, and the fourth solenoid valve, setting the four-way valve to the first state,
In the defrosting and dehumidifying operation mode,
The first solenoid valve is opened at an opening corresponding to the temperature in the house, the second solenoid valve is opened, the third solenoid valve and the fourth solenoid valve are closed, and the four-way The valve is in the first state;
The air conditioner according to claim 3. The controller is
In dehumidifying chlorofluorocarbon reverse operation mode,
The first solenoid valve, the second solenoid valve, and the fourth solenoid valve are closed, the third solenoid valve is opened, and the four-way valve is placed in the second state.
The air conditioner according to claim 4. In an air conditioner having a cooling operation mode, a heating operation mode, and a dehumidifying operation mode,
Before operating in the dehumidifying operation mode, after providing a step of removing the refrigerant remaining in the outdoor heat exchanger outside the outdoor heat exchanger, it operates in the dehumidifying operation mode.
Control method for air conditioner. In an air conditioner having a cooling operation mode, a heating operation mode, a dehumidifying operation mode, and a dehumidifying non-frost operating mode,
When switching from the operation in the dehumidifying operation mode to the operation in the dehumidifying non-frost operating mode, the threshold temperature or threshold humidity for switching the operation is the indoor heat exchanger in order to prevent frost formation on the indoor heat exchanger. Set higher than the temperature at which frost formation occurs
Control method for air conditioner.

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