JP5213372B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner having a function of adjusting a room temperature by controlling a flow of a refrigerant to an indoor / outdoor condenser.

Some conventional air conditioners are provided with a liquid reservoir for accumulating excess refrigerant generated by switching operation modes or the like (see, for example, Patent Document 1).
Excess refrigerant tends to accumulate in the condenser unless it is held in a liquid reservoir, etc.Therefore, unless measures such as enlarging the condenser are taken, an increase in high-pressure pressure, an increase in discharge temperature and a decrease in performance caused by them. This may cause a compressor failure.

Japanese Patent Laid-Open No. 2003-262429 (5th item, Fig. 1)

  However, in the air conditioner provided with a liquid reservoir as shown in the above-mentioned Patent Document 1, the cost is increased by the amount of the liquid reservoir and its connecting pipe, and the amount of refrigerant filled is further increased by the amount of the liquid reservoir installed. There is a problem that it is necessary and causes an increase in cost due to an increase in the amount of refrigerant. Further, since the liquid reservoir is a high-pressure side container and it is necessary to ensure the thickness, the cost tends to be higher than that of an accumulator or the like that is a low-pressure container.

  The present invention has been made to solve the above-described problems. By providing an extra refrigerant in the refrigerant circuit in the low-pressure vessel without providing a liquid reservoir that increases the cost, The purpose is to prevent problems such as high pressure rise and to suppress cost increase.

  An air conditioner according to the present invention is a refrigerant circuit in which a compressor, a condenser, a throttling device, a cooler, and a low-pressure side container are sequentially arranged, and the condenser includes an indoor condenser and an outdoor condenser, The refrigerant circuit in which the indoor condenser and the outdoor condenser are configured in parallel refrigerant circuits, and the throttling device to detect the excess refrigerant in the refrigerant circuit and hold the excess refrigerant in the low-pressure side container. An air conditioner comprising: a control device for controlling an opening degree of the air-cooling apparatus; a cooling operation mode for dehumidifying the interior of the air conditioner while cooling the room using the outdoor condenser and the cooler; and the indoor condenser and the cooling And a dehumidifying operation mode for dehumidifying while heating the room using a cooler, and the control device is configured so that the degree of superheat at the outlet of the cooler is constant in the cooling operation mode in which excess refrigerant is not generated. Control the superheat Are those previously set to perform supercooling to allow supercooling of the outlet portion of the condenser in the drying mode of the refrigerant occurs are used becomes a predetermined value.

The air conditioner according to the present invention includes a control device that detects excess refrigerant in the refrigerant circuit and controls the opening of the expansion device so as to hold the excess refrigerant in the low-pressure side container. Therefore, it is possible to prevent problems such as an increase in high pressure due to excess refrigerant without providing a liquid reservoir.
A bypass circuit communicating from the high-pressure side refrigerant circuit on the outlet side of the indoor condenser and / or the outdoor condenser to the low-pressure side refrigerant circuit on the inlet side of the low-pressure side container; And a control device that opens and closes the bypass circuit so as to be held in the low-pressure side container, it is possible to prevent inconveniences such as an increase in high pressure due to excess refrigerant without providing a liquid reservoir that increases costs.

Embodiment 1 FIG.
1 is a refrigerant circuit diagram of an air conditioner according to Embodiment 1 of the present invention. This refrigerant circuit constitutes a refrigeration cycle device, and includes a compressor 1, an outdoor solenoid valve 2, an outdoor condenser 3, an outdoor condenser check valve 4 for preventing a refrigerant backflow to the outdoor condenser 3, and a throttle device 5. A cooler (evaporator) 6 and a low-pressure vessel (hereinafter referred to as an accumulator) 7 are sequentially connected by refrigerant pipes 11 to 16. In addition, an indoor solenoid check valve 10, which branches from between the compressor 1 and the outdoor solenoid valve 2 and prevents the refrigerant backflow to the indoor condenser 9, and the indoor condenser 9, is sequentially provided. A refrigerant circuit connected by the refrigerant pipes 17 and 18 and joined by the expansion device 5 is provided. As can be seen from FIG. 1, in this refrigerant circuit, the condenser comprises an outdoor condenser 3 and an indoor condenser 9, and these outdoor condenser 3 and indoor condenser 9 constitute a parallel refrigerant circuit. Furthermore, an outdoor fan 20 that promotes refrigerant condensation in the outdoor condenser 3 and an indoor fan 21 that promotes refrigerant evaporation in the cooler 6 and refrigerant condensation in the indoor condenser 9 to circulate indoor air are provided. .

The refrigerant circuit includes a cooler outlet pressure sensor 102, a condenser outlet pressure sensor 103, a cooler outlet temperature sensor 104, a condenser outlet temperature sensor 105, a high pressure sensor 107, a low pressure sensor 108, and a discharge temperature sensor 109. It is possible to detect the internal pressure state and temperature state.
Out of the constituent parts constituting these air conditioners, the outdoor fan 20 and the outdoor condenser 3 are arranged outdoors, and the others are arranged indoors. In the following, the refrigerant pipes 11 to 18 are called according to the function of the refrigerant pipe, the refrigerant pipes 11, 12, and 17 are discharge pipes, the refrigerant pipes 13, 14, and 18 are liquid pipes, and the refrigerant pipes 15 and 16 are connected. Is called a suction pipe.

FIG. 2 is a block diagram showing an electrical configuration of the air conditioner of FIG. The air conditioner includes an operation unit 100 for inputting various settings such as a target temperature, and a storage unit 101 for storing various information such as input information. Also, a cooler outlet pressure sensor 102 for detecting the pressure and temperature in the refrigerant circuit, a condenser outlet pressure sensor 103, a condenser outlet temperature sensor 104, a condenser outlet temperature sensor 105, a high pressure sensor 107, and a discharge And a temperature sensor 109. Each of these devices is electrically or optically connected to the control device 106. The control device 106 includes a CPU, a RAM that stores various data, and a ROM (none of which is shown) that stores a program for performing operation control in each operation mode described below. According to the program, the outdoor solenoid valve 2, the indoor solenoid valve 8, the expansion device 5, the outdoor blower 20, and the indoor blower 21 are appropriately controlled to perform a cooling operation, a dehumidifying operation, an intermediate operation, and various operation controls described later.
Note that the various sensors shown in FIG. 2 are not always used, but are selectively used according to the control mode.

  This air conditioner controls the heat release amount in the outdoor condenser 3 by controlling the opening and closing of the outdoor solenoid valve 2 and the indoor solenoid valve 8, and adjusts the temperature while dehumidifying the room. Specifically, cooling operation (operation to dehumidify while cooling the room), dehumidification operation (operation to dehumidify while heating the room), intermediate operation (weak heating and cooling the room by controlling the heat radiation inside and outside the room) Or the operation | movement which dehumidifies, maintaining indoor temperature). Hereinafter, each of these operations will be described sequentially.

<Cooling operation>
During the cooling operation, the outdoor solenoid valve 2 is in the open state and the indoor solenoid valve 8 is in the closed state. Accordingly, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows into the outdoor condenser 3 through the discharge pipes 11 and 12, and dissipates heat by exchanging heat with the outdoor air blown by the outdoor blower 20, and the gas refrigerant is Condensed liquid. Then, the pressure is reduced by the expansion device 5 through the liquid pipe 13 and becomes a gas-liquid two-phase refrigerant and enters the cooler 6. The gas-liquid two-phase refrigerant that has entered the cooler 6 exchanges heat with the indoor air blown by the indoor blower 21 to absorb heat, is converted into low-temperature and low-pressure gas, and returns to the compressor 1. Here, the air circulated by the indoor blower 21 is cooled by the low-temperature low-pressure gas-liquid two-phase refrigerant in the cooler 6, the temperature is lowered to a dew point or less, and moisture in the indoor air is condensed on the surface of the cooler 6. Dehumidified. That is, the indoor air is cooled and dehumidified at the same time.

<Dehumidifying operation>
During the dehumidifying operation, the outdoor solenoid valve 2 is closed and the indoor solenoid valve 8 is open. Accordingly, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows into the indoor condenser 9 through the discharge pipes 11 and 17, and exchanges heat with the indoor air that has passed through the cooler 6 blown by the indoor blower 21. Heat is dissipated and the gas refrigerant is condensed and liquefied. Then, the pressure is reduced by the expansion device 5 through the liquid pipe 18 and becomes a gas-liquid two-phase refrigerant and enters the cooler 6. The gas-liquid two-phase refrigerant that has entered the cooler 6 exchanges heat with the indoor air blown by the indoor blower 21 to absorb heat, is converted into low-temperature and low-pressure gas, and returns to the compressor 1. Here, the air circulated by the indoor blower 21 is cooled by the low-temperature low-pressure gas-liquid two-phase refrigerant in the cooler 6, the temperature is lowered to a dew point or less, and moisture in the indoor air is condensed on the surface of the cooler 6. Dehumidified. Thereafter, the air that has passed through the cooler 6 is heated by the high-temperature and high-pressure gas refrigerant in the indoor condenser 9 to increase the temperature, and the relative humidity decreases. In this way, by closing the outdoor solenoid valve 2 and performing all the heat radiation in the refrigeration cycle indoors, theoretically, the operation of heating the room by the amount of latent heat of condensation of the input of the compressor 1 and water vapor in the air is performed. Do. That is, the room air is heated and dehumidified at the same time.

<Intermediate operation>
During the intermediate operation, both the outdoor solenoid valve 2 and the indoor solenoid valve 8 are open. Accordingly, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows into the outdoor condenser 3 through the discharge pipe 12 and flows into the indoor condenser 9 through the discharge pipe 17. The refrigerant radiated and liquefied by the outdoor condenser 3 and the indoor condenser 9 merges in the liquid pipe 14 via the liquid pipes 13 and 18. Then, the pressure is reduced by the expansion device 5 through the liquid pipe 14 and becomes a gas-liquid two-phase refrigerant and enters the cooler 6. The heat is absorbed and gasified by the cooler 6 and is sucked into the compressor 1 through the suction pipe 15, the accumulator 7, and the suction pipe 16. In such an intermediate operation, the outdoor blower 20 performs ON-OFF control according to the outdoor temperature and high pressure, and the indoor blower 21 performs control to be always turned on.

  Next, in the air conditioner having the above-described mode, the situation where surplus refrigerant is generated will be organized. During the intermediate operation, the outdoor condenser 3 and the indoor condenser 9 are both used, and the amount of refrigerant required tends to increase compared to the cooling operation and the dehumidifying operation. Conversely, surplus refrigerant is generated during the cooling operation or the dehumidifying operation. For example, when switching from the intermediate operation to the dehumidifying operation, the outdoor solenoid valve 2 is closed, but the liquid pipe 13 is in an open state without a closing solenoid valve, and the inside of the outdoor condenser 3 and the liquid pipe 13 is closed. Some of the refrigerant flows into the liquid pipe 14. On the other hand, due to the outdoor condenser check valve 4 from the liquid pipe 14 to the liquid pipe 13 and the outdoor electromagnetic valve 2 being closed from the discharge pipe 11, the refrigerant does not flow out of the room to the outside. As a result, surplus refrigerant is generated during the dehumidifying operation. Similarly, during the cooling operation, surplus refrigerant is generated for the reason corresponding to the dehumidifying operation.

  Next, the control of the diaphragm device 5 in the first embodiment will be described. In the intermediate operation that requires the largest amount of refrigerant, so-called superheat control is performed to control the expansion device 5 so that the superheat degree at the outlet of the cooler 6 is constant. Here, the degree of superheat is represented by the difference (Ts−Te) between the temperature detected by the cooler outlet temperature sensor 104 (Ts) and the saturation temperature (Te) of the pressure detected by the cooler outlet pressure sensor 102, This represents the degree of refrigerant superheat at the outlet of the cooler 6. In the intermediate operation with the largest amount of refrigerant, a slight change in ambient temperature or the like tends to cause a shortage of refrigerant. In the refrigerant shortage state, the degree of opening of the expansion device becomes small in order to secure the degree of supercooling in the below-described supercooling control, but in the degree of superheat control, the degree of superheat is larger than the target, so growing. Therefore, in the intermediate operation, the degree of superheat is controlled so that the opening degree of the expansion device 5 is reduced and the capacity is not reduced, and the opening degree of the expansion device 5 is used in a large state to secure the capacity.

  On the other hand, in the dehumidifying operation, the opening degree of the expansion device 5 is controlled by the degree of supercooling detected by a predetermined sensor. Here, the degree of supercooling refers to the difference (Tc−Tl) between the saturation temperature (Tc) of the pressure detected by the condenser outlet pressure sensor 103 and the temperature (Tl) detected by the condenser outlet temperature sensor 105. It represents how much the refrigerant at the outlet of the condenser 9 has been supercooled after completion of condensation. In this embodiment, in response to the increase in the degree of supercooling, the opening degree of the expansion device 5 is increased, the refrigerant state at the outlet of the cooler 6 is changed to the two-phase state, and the accumulator 7 is passed through the suction pipe 15. A two-phase refrigerant is allowed to flow into the. The two-phase refrigerant is separated into gas and liquid by the accumulator 7, the liquid refrigerant is held in the accumulator 7, and the saturated gas refrigerant returns to the compressor 1 through the suction pipe 16. The liquid refrigerant is held in the accumulator 7 by increasing the opening degree of the expansion device 5 until the degree of supercooling at the outlet of the indoor condenser 9 reaches a specified value, for example, 3K. That is, when the control device 106 detects (determines) the generation of excess refrigerant based on the degree of supercooling calculated by obtaining information from a predetermined sensor, the control device 106 has the target degree of supercooling. Thus, so-called supercooling control for controlling the expansion device 5 is performed.

  As described above, according to the first embodiment, when the control device 106 detects surplus refrigerant based on the refrigerant supercooling degree, the expansion device 5 is controlled based on the supercooling degree to the accumulator 7. Since the excess refrigerant is retained, a highly reliable air conditioner that can process the excess refrigerant at a low cost without providing a liquid reservoir can be obtained.

In the above description, the throttle device 5 is controlled based on the degree of supercooling, but it can also be controlled based on the high pressure detected by the high pressure sensor 107. That is, when excess refrigerant is generated and the degree of supercooling is increased, the heat transfer area that can be utilized for refrigerant condensation in the indoor condenser 9 is reduced and the high pressure is increased. Since the high pressure of the air conditioner is determined for each air conditioner when the low pressure is determined, an appropriate high pressure operating point for each low pressure is stored in advance in the storage unit 101 and the control device 106 If the high pressure is higher than appropriate, it is determined that surplus refrigerant has been generated, and the same effect as described above can be obtained by increasing the opening of the expansion device 5 until it becomes appropriate.
In addition, when the control device 106 receives information from the discharge temperature sensor 109 that indicates an increase in the compressor discharge refrigerant temperature accompanying an increase in the high pressure, and detects (determines) the generation of excess refrigerant based on the temperature information, A similar effect can be obtained by increasing the opening of the expansion device 5 based on the temperature information.

  Further, with respect to the expansion device 5, a control mode in which the dehumidifying operation in which the surplus refrigerant is generated is supercooling control and the intermediate operation in which the surplus refrigerant is not generated is superheat control is incorporated in the device control 106 in advance. Similar effects can be obtained.

  In addition, although the example at the time of dehumidification operation was demonstrated above, when the excess refrigerant | coolant generate | occur | produces also at the time of cooling operation, the same effect can be acquired by adjusting the opening degree of the expansion apparatus 5. FIG.

Reference form 1 .
FIG. 3 is a refrigerant circuit diagram of the air conditioner according to Embodiment 1 of the present invention. The difference from Embodiment 1 in FIG. 1 is that a bypass circuit connected from the outlet side (high pressure side) of the outdoor compressor 3 and the indoor compressor 9 to the suction pipe 15 (low pressure side) before the accumulator 7 is added. It is. This bypass circuit is arranged in the middle of the bypass pipe 31, the bypass pipe 31, the bypass solenoid valve 32 that opens and closes the refrigerant circuit that bypasses the refrigerant from the outdoor condenser 3 and the indoor condenser 9 to the suction pipe 15, and the suction A bypass circuit check valve 33 for preventing the refrigerant from flowing backward from the pipe 15 to the liquid pipe 14 is provided. If only the dehumidifying operation is considered, it is sufficient to provide a bypass circuit from the outlet side (high pressure side) of the indoor condenser 9 to the suction pipe 15 (low pressure side) before the accumulator 7, and only the cooling operation is considered. In this case, a bypass circuit connected from the outlet side (high pressure side) of the outdoor condenser 3 to the suction pipe 15 (low pressure side) before the accumulator 7 may be provided.
FIG. 4 is a block diagram showing an electrical configuration of the air conditioner according to the first embodiment . The difference from FIG. 2 of the first embodiment is that a bypass electromagnetic valve 32 is added to the control target of the control device 106.

Next, control of excess refrigerant in the air conditioner of Reference Embodiment 1 will be described. As described in Embodiment 1, when surplus refrigerant is generated in the dehumidifying operation, surplus refrigerant accumulates at the outlet of the indoor condenser 9 and the degree of supercooling increases. However, in this case as well, when the control device 106 detects an increase in the degree of supercooling based on information from a predetermined sensor and detects (determines) the generation of surplus refrigerant based on this, the control device 106 detects that the bypass electromagnetic The surplus refrigerant is held in the accumulator 7 via the bypass pipe 31 and the suction pipe 15 by opening the valve 32.

In the reference mode 1 , as described above, when the control device 106 detects (determines) the generation of excess refrigerant, the bypass electromagnetic valve 32 is controlled and the excess refrigerant is held in the accumulator 7 via the bypass circuit. Therefore, it is possible to obtain a highly reliable air conditioner that can process surplus refrigerant without providing a liquid reservoir.

  In the above description, the opening and closing of the bypass solenoid valve 32 is controlled by detecting the degree of supercooling. However, as in the first embodiment, the generation of excess refrigerant is detected (determined) by high-pressure pressure detection or compressor discharge refrigerant temperature detection. The same effect can be obtained by controlling the opening and closing of the bypass solenoid valve 32 based on the high pressure and the refrigerant discharge refrigerant temperature so that the accumulator 7 holds the refrigerant.

  Moreover, although the example at the time of a dehumidification operation was demonstrated above, when an excess refrigerant | coolant generate | occur | produces also at the time of cooling operation, the same effect can be acquired by performing the same operation control.

Embodiment 2 FIG.
FIG. 5 is a refrigerant circuit diagram of an air conditioner according to Embodiment 2 of the present invention. The difference from FIG. 1 of the first embodiment is that, instead of the common expansion device 5 for the outdoor condenser 3 and the indoor condenser 9, expansion devices 5a and 5b are provided in the outdoor condenser 3 and the indoor condenser 9, respectively. It is a point. Further, instead of the condenser outlet pressure sensor 103 and the condenser outlet temperature sensor 105, the outdoor condenser outlet pressure sensor 103a and the outdoor condenser outlet temperature sensor 105a are provided at the outlet portions of the outdoor condenser 3 and the indoor condenser 9, respectively. 1 differs from FIG. 1 of the first embodiment also in that an indoor condenser outlet pressure sensor 103b and an indoor condenser outlet temperature sensor 105b are provided.
FIG. 6 is a block diagram showing an electrical configuration of the air conditioner according to the second embodiment. The difference from Embodiment 1 in FIG. 2 is that the control target of the control device 106 is the outdoor and indoor condenser outlet pressure sensors 103a and 103b instead of the condenser outlet pressure sensor 103, and the condenser outlet temperature sensor 105 is replaced. Thus, the outdoor and indoor condenser outlet pressure sensors 105a and 105b are used, and instead of the expansion device 5, the outdoor and indoor expansion devices 5a and 5b are used.

Here, the generation of excess refrigerant in the outdoor condenser 3 and the indoor condenser 9 during the intermediate operation will be described below.
During the intermediate operation, the outdoor condenser 3 and the indoor condenser 9 are used in parallel, but the temperature conditions may differ between the outdoor and indoor. For example, when the indoor temperature is low and the outdoor temperature is high, excess refrigerant accumulates in the indoor condenser 9 having a low temperature. The refrigerant tends to move from a high temperature to a low temperature, and a large amount of refrigerant flows into the room due to a temperature difference between the outdoor and indoor areas, and surplus refrigerant is generated in the indoor condenser 9. In some cases, the outdoor condenser 3 becomes insufficient in that amount. That is, excess refrigerant accumulates in the indoor condenser 9, but the performance deteriorates by the amount of excess refrigerant accumulated. In order to prevent such performance degradation, a method for holding the surplus refrigerant with the accumulator 7 will be described below.

  For example, when the indoor temperature is low and the outdoor temperature is high, excess refrigerant accumulates in the indoor condenser 9 and as a result, the degree of supercooling of the indoor condenser 9 increases. Here, the degree of supercooling of the indoor condenser 9 refers to the difference between the temperature (Tlb) detected by the indoor condenser outlet temperature sensor 105b and the saturation temperature (Tcb) of the pressure detected by the indoor condenser outlet pressure sensor 103b. (Tcb−Tlb), which is larger than that of the outdoor condenser 3. The control device 106 calculates the degree of supercooling from information received from a predetermined sensor, and detects (determines) the generation of excess refrigerant based on the degree of supercooling. When the control device 106 determines that surplus refrigerant is generated, the opening degree of the expansion device 5b is increased. For example, the expansion device 5b is controlled so that the degree of supercooling is 3K. As a result, the excess refrigerant accumulated in the indoor condenser 9 is expelled to have an appropriate degree of supercooling, and the capacity of the air conditioner is maintained appropriately.

  As described above, it is possible to obtain a high-performance air conditioner by effectively using both the indoor and outdoor condensers 9 and 3 by individually controlling the indoor and outdoor condensers 9 and 3 by controlling the expansion devices. .

  In the above description, the room is described based on an example where the temperature is lower than the outdoor temperature. However, when the outdoor temperature is lower than the indoor temperature, excess refrigerant accumulates in the outdoor condenser 3. In that case, the same effect can be obtained by increasing the opening of the expansion device 5a in accordance with the above control mode and expelling excess refrigerant accumulated in the outdoor condenser 3.

Embodiment 3 FIG.
In the first and second embodiments and the first embodiment , the air conditioner has three modes of operation modes, that is, a cooling operation, a dehumidifying operation, and an intermediate operation. However, surplus refrigerant is also generated in the two-mode air conditioner of the cooling operation and the dehumidifying operation. Also in that case, the same effect as in Embodiments 1 and 2 and Reference Embodiment 1 can be obtained by holding the excess refrigerant in the accumulator 7.

  Here, generation | occurrence | production of the excess refrigerant | coolant in the air conditioner of 2 operation modes is demonstrated. When the cooling operation and the dehumidifying operation are compared, the amount of refrigerant generally required for the cooling operation increases. In the cooling operation, since the refrigerant once goes out of the room and then passes through a circuit that returns to the room again, the discharge pipe and the liquid pipe are longer than the dehumidifying operation of the refrigerant circuit only in the room. The outdoor unit in the air conditioner is installed on the roof of the building where the indoor unit is installed, so that both the discharge pipe and the liquid pipe may be about 30 m. Therefore, the amount of refrigerant required for the cooling operation is required for the dehumidifying operation. It becomes larger compared to the amount of refrigerant. Furthermore, the capacity of the indoor condenser is often smaller than that of the outdoor condenser. The capacity of the condenser is determined by the condenser intake air temperature when the amount of blown air is considered constant, and a higher capacity condenser is required as the intake air temperature is higher. The indoor temperature is generally 40 ° C. or less in consideration of the environment where people enter and exit, whereas the outdoor temperature is generally considered to be equivalent to 43 ° C. Further, the intake air of the indoor condenser is a cooler. Since it is guided after being cooled at, it becomes even lower. That is, the amount of refrigerant required for the cooling operation is larger than that of the dehumidifying operation due to the difference in capacity between the discharge / liquid piping and the condenser.

Next, a method for holding the surplus refrigerant generated as described above by the accumulator 7 will be described below. As described above, surplus refrigerant is also generated during the dehumidifying operation in the air conditioner in the two operation mode. Even in such a case, as already described, the control device 106 detects the generation of surplus refrigerant using the degree of supercooling, the high pressure sensor 107, or the discharge temperature sensor 109, and the like in the refrigerant circuit. When it is determined that surplus refrigerant is generated in the controller, the control device 106 increases the opening degree of the expansion device 5 and causes the accumulator 7 to hold the surplus refrigerant refrigerant. Thereby, the same effects as those of the first and second embodiments and the reference embodiment 1 can be obtained.

  As for the expansion device 5, a control mode in which the dehumidifying operation in which the surplus refrigerant is generated is supercooling control and the cooling operation in which the surplus refrigerant is not generated is superheat control is also incorporated in the control device 106 in advance. The effect of can be obtained.

Further, in the air conditioner in the 2-operation mode, the refrigerant is held in the accumulator 7 by using the same configuration as that described in the reference embodiment 1 and the embodiment 2 in the case of the 3-operation mode, so that the surplus Various problems caused by the refrigerant can be solved without providing a liquid reservoir.

It is a refrigerant circuit figure of the air conditioner in Embodiment 1 of this invention. 3 is a block diagram showing an electrical configuration of the air conditioner in Embodiment 1. FIG. It is a refrigerant circuit figure of the air conditioner in reference form 1 of this invention. It is a block diagram which shows the electric constitution of the air conditioner in the reference form 1 . It is a refrigerant circuit figure of the air conditioner in Embodiment 2 of this invention. 6 is a block diagram showing an electrical configuration of an air conditioner according to Embodiment 2. FIG.

  1 compressor, 2 outdoor solenoid valve, 3 outdoor condenser, 4 outdoor condenser check valve, 5 throttle device, 5a outdoor refrigerant throttle device, 5b indoor refrigerant throttle device, 6 cooler, 7 accumulator, 8 indoor Solenoid valve, 9 indoor condenser, 10 check valve for indoor condenser, 11 discharge pipe, 12 discharge pipe, 13 liquid pipe, 14 liquid pipe, 15 suction pipe, 16 suction pipe, 17 discharge pipe, 18 liquid pipe, 20 Outdoor blower, 21 Indoor blower, 31 Bypass piping, 32 Bypass solenoid valve, 33 Bypass circuit check valve, 100 Operation section, 101 Storage section, 102 Cooler outlet pressure sensor, 103 Condenser outlet pressure sensor, 103a Outdoor condensation Condenser outlet pressure sensor, 103b indoor condenser outlet pressure sensor, 104 cooler outlet temperature sensor, 105 condenser outlet temperature sensor, 105 The outdoor condenser outlet temperature sensor, 105b indoor condenser outlet temperature sensor, 106 control unit, 107 high-pressure sensor, 109 discharge temperature sensor.

Claims (4)

A refrigerant circuit in which a compressor, a condenser, a throttling device, a cooler, and a low-pressure side container are sequentially arranged, and the condenser includes an indoor condenser and an outdoor condenser, and the indoor condenser and the outdoor condenser A refrigerant circuit configured as a parallel refrigerant circuit, and a control device that detects an excess refrigerant in the refrigerant circuit and controls an opening degree of the expansion device so as to hold the excess refrigerant in the low-pressure side container. In an air conditioner equipped with
A cooling operation mode for dehumidifying while cooling the room using the outdoor condenser and the cooler; and a dehumidifying operation mode for dehumidifying while heating the room using the indoor condenser and the cooler. Have
The control device performs superheat control so that the superheat degree of the outlet portion of the cooler is constant in the cooling operation mode in which surplus refrigerant is not generated, and is used in the dehumidification operation mode in which surplus refrigerant is generated. An air conditioner that is set in advance to perform supercooling control so that the degree of supercooling at the outlet of the condenser becomes a predetermined value. In the case of further comprising an intermediate operation mode for dehumidifying the room while maintaining the room temperature by weakly heating the room, using the outdoor condenser, the indoor condenser and the cooler, or maintaining the indoor temperature,
The controller performs superheat control so that the superheat degree of the outlet of the cooler is constant in the intermediate operation mode in which no surplus refrigerant is generated, and is used in the dehumidifying operation mode in which surplus refrigerant is generated. The air conditioner according to claim 1, wherein the air conditioner is preset so as to perform supercooling control so that the degree of supercooling at the outlet of the condenser becomes a predetermined value. In the case of further comprising an intermediate operation mode for dehumidifying the room while maintaining the room temperature by weakly heating the room, using the outdoor condenser, the indoor condenser and the cooler, or maintaining the indoor temperature,
The control device performs superheat degree control so that the superheat degree of the outlet portion of the cooler is constant in the intermediate operation mode in which no surplus refrigerant is generated, and is used in the cooling operation mode in which the surplus refrigerant is generated. The air conditioner according to claim 1, wherein the air conditioner is preset so as to perform supercooling control so that the degree of supercooling at the outlet of the condenser becomes a predetermined value. Providing the expansion device at the outlet of the indoor condenser and the outdoor condenser,
The air conditioner according to any one of claims 1 to 3, wherein the control device individually adjusts the opening degree of each expansion device.

Images