JP2014016057A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner which reduces power consumption from high load time, such as operation start time, to low load time, such as stable operation time, during cooling operation using a simpler system.SOLUTION: An air conditioner 1 includes: a main circuit 12 where a compressor 2, an outdoor heat exchanger 4, an over-cooling heat exchanger 9, an expansion valve 5, and an indoor heat exchanger 6 are sequentially connected by a coolant pipeline and a coolant circulates therein; and a bypass circuit 13 which is branched from the main circuit 12 between the outdoor heat exchanger 4 and the over-cooling heat exchanger 9 and connects with the main circuit 12 between the indoor heat exchanger 6 and the compressor 2 through an over-cooling expansion valve 8 and the over-cooling heat exchanger 9. The over-cooling heat exchanger 9 includes a heat storage tank 10 for conducting heat exchange with the coolant of the main circuit 12 and the bypass circuit 13 which flows in the over-cooling heat exchanger 9.

Description

  The present invention relates to an air conditioner including a supercooling heat exchanger that supercools a refrigerant.

  In recent years, energy-saving operation for air conditioners has been demanded from the viewpoint of global warming. In addition, there is a problem of shortage of supply at peak power usage due to increase in power demand, reducing air conditioner power consumption during peak usage hours such as hot summer days in summer, that is, refrigeration cycle at high load. High efficiency is required.

  As a conventional means for improving the efficiency of a refrigeration cycle, Patent Literature 1 discloses a refrigeration cycle including a supercooling heat exchanger that supercools condensed refrigerant. Specifically, Patent Document 1 discloses a main circuit for flowing refrigerant from a compressor in the order of a condenser, a double-tube supercooler, a main expansion mechanism, an evaporator, a four-way switching valve, and an accumulator, Disclosed is a refrigerant circuit having a bypass circuit that branches from the main circuit between the condenser and the subcooler, and merges with the main circuit between the four-way switching valve and the accumulator via the bypass expansion mechanism and the supercooler. . The refrigerant discharged from the compressor is condensed by a condenser that radiates heat to outdoor air, and then branched into a main circuit and a bypass circuit. The bypass flow refrigerant flowing in the bypass circuit is decompressed by the bypass expansion mechanism and then flows to the subcooler, and the main flow refrigerant flowing in the main circuit flows to the subcooler and is heat-exchanged with the bypass flow refrigerant to be supercooled. Is done. The supercooler is formed in a double tube shape having a heat transfer tube and an outer tube provided concentrically on the outside of the heat transfer tube. Flow bypass refrigerant through the heat pipe. The supercooler is composed of a counter-flow heat exchanger, and is set so that the main-flow refrigerant and the bypass-flow refrigerant flow in opposite directions with respect to the heat transfer pipe wall. In addition, a method of using cold energy stored in ice is also described as means for supercooling the refrigerant.

  On the other hand, Patent Literature 2 discloses a regenerative air conditioner that supercools a refrigerant by a heat storage medium of a heat storage tank that stores cold heat. Specifically, Patent Document 2 discloses that a refrigerant circulates in a main refrigeration circuit including a compressor, an outdoor heat exchanger, a supercooling heat exchanger, a first automatic expansion valve, an indoor heat exchanger, and an accumulator. An air conditioner is disclosed in which a heat storage tank is connected to a supercooling heat exchanger of a refrigeration circuit, a heat storage medium exchanges heat with a refrigerant in the supercooling heat exchanger, and circulates through a pipe. In addition, a bypass pipe is provided between the liquid pipe and the suction pipe between the outdoor heat exchanger and the supercooling heat exchanger of the main refrigeration circuit, and the second automatic expansion valve and the heat storage coil are provided in the bypass pipe. Provided. The heat storage coil is provided in the heat storage tank, and heat is exchanged between the refrigerant and the heat storage medium. The supercooling action of the refrigerant flowing through the main refrigeration circuit is performed via the heat storage medium cooled by the heat storage coil.

Japanese Patent Laid-Open No. 10-054616 Japanese Patent Laid-Open No. 1-10063

  However, in Patent Document 1, the enthalpy is reduced by cooling the mainstream refrigerant with the bypass refrigerant in the subcooler, but the cooled mainstream refrigerant is in contact with the outside air because the temperature is lower than the outdoor air. The heat quantity of the air is absorbed from the outer tube surface, and the desired enthalpy is not lowered, and the performance improvement rate is lowered. Further, in the supercooling cycle as in Patent Document 1, the larger the refrigerant circulation amount and the larger the pressure loss on the evaporation side, the greater the effect of improving the efficiency when the supercooling cycle is not performed, but the circulation amount is small and the evaporation side pressure loss is small. The effect is small in the region where the cooling capacity is small. That is, although the effect is large at the time of starting with a heavy load, the effect is small at the time of stable operation.

  Further, in Patent Document 2, since heat is transferred via a heat storage medium, a power source such as a pump for circulating the medium is required, and not only the number of components increases and the structure becomes complicated, but also the system The overall power consumption is not reduced.

  It is an object of the present invention to provide an air conditioner that can reduce power consumption from a high load at the start of operation to a low load at the time of stable operation with a simpler system during cooling operation. And

  The air conditioner of the present invention includes a compressor, an outdoor heat exchanger, a supercooling heat exchanger, an expansion valve, and a main circuit in which an indoor heat exchanger is sequentially connected by a refrigerant pipe to circulate the refrigerant, and an outdoor heat exchange Branch from the main circuit between the heat exchanger and the supercooling heat exchanger, and connect to the main circuit between the indoor heat exchanger and the compressor via the supercooling expansion valve and the supercooling heat exchanger The supercooling heat exchanger includes a heat storage tank for exchanging heat with the main circuit flowing in the supercooling heat exchanger and the refrigerant of the bypass circuit.

  ADVANTAGE OF THE INVENTION According to this invention, the power consumption of an air conditioner can be reduced with the simpler system at the time of air_conditionaing | cooling operation from the time of high load, such as operation start, to the time of low load, such as the time of stable operation.

Air conditioner refrigerant circuit configuration diagram Configuration diagram of heat exchanger for supercooling Element device operation table for each operation mode of the air conditioner Mollier diagram showing normal refrigeration cycle and supercooling cycle Air conditioner operation mode selection flowchart The figure which showed time change of room temperature, heat storage material temperature, compressor rotation speed in cooling operation

  Embodiments of the present invention will be described below with reference to the drawings. The air conditioner of this embodiment includes a compressor, an outdoor heat exchanger, a supercooling heat exchanger, an expansion valve, and an indoor heat exchanger that are sequentially connected by a refrigerant pipe to circulate the refrigerant, and an outdoor heat Branches from the main circuit between the exchanger and the supercooling heat exchanger, and enters the main circuit between the indoor heat exchanger and the compressor via the supercooling expansion valve and the supercooling heat exchanger. And a bypass circuit to be connected, and the supercooling heat exchanger includes a heat storage tank for exchanging heat with the main circuit flowing in the supercooling heat exchanger and the refrigerant of the bypass circuit. Since the heat storage tank provided in the supercooling heat exchanger and the refrigerant in the main circuit and the bypass circuit exchange heat, according to the operation of the bypass circuit, the refrigerant in the main circuit is supercooled by the refrigerant in the bypass circuit at high load. Cold heat is stored in the heat storage tank, and the stored cold heat can be applied to the refrigerant in the main circuit at low load, so during cooling operation, from high load such as when starting operation to low load during stable operation Until then, the power consumption of the air conditioner can be reduced.

  FIG. 1 is a configuration diagram of a refrigerant circuit of an air conditioner, and is a basic configuration diagram showing each component constituting the air conditioner 1 and their connection relationship. The air conditioner 1 includes a compressor 2, a flow path switching valve (for example, a four-way valve) 3, an outdoor heat exchanger 4, a supercooling heat exchanger (for example, a double pipe heat exchanger) 10, an expansion valve 5, and indoor heat. Branched at a branch circuit 13a between the main circuit 12 in which the exchanger 6 and the suction tank 7 are connected in an annular shape, and the outdoor heat exchanger 4 and the supercooling heat exchanger 9, and the supercooling expansion valve 8 and the supercooling Bypass which joins the main circuit 12 at a junction 13b between the suction tank 7 and the flow path switching valve 3 (a junction 13b between the outdoor heat exchanger 4 and the compressor 2) through the heat exchanger 9 The circuit 13 is configured. The supercooling heat exchanger 9 is covered with a heat storage tank 10, and the heat storage tank 10 is filled with a heat storage material 11.

  FIG. 2 is a configuration diagram of the supercooling heat exchanger, and shows a detailed diagram of a configuration example of the heat storage tank 10 and the supercooling heat exchanger 9. The supercooling heat exchanger 9 is a double pipe and is composed of an inner pipe 9a and an outer pipe 9b. The heat storage tank 10 is configured to cover the entire double pipe, and the heat storage material 11 is filled therein. The inner tube 9a and the outer tube 9b are made of a metal such as copper having good thermal conductivity, and a spiral groove for expanding the heat transfer area and fluid agitation on the inner or outer surface of the inner tube to improve the heat transfer coefficient of the refrigerant. Etc. may be provided. Furthermore, it is desirable to configure the flow direction of the inner pipe and the outer pipe to be opposite flows when using supercooling. Thereby, the temperature difference of the refrigerant | coolant which flows inside and outside can be taken large, and heat exchange can be performed efficiently.

  The heat storage material 11 can be a liquid sensible heat storage material such as water or ethylene glycol that does not change phase when storing heat, a solid sensible heat storage material such as butylene rubber, or a latent heat storage material such as paraffin that changes phase when storing heat. . In addition, since the temperature at the time of heat storage of the heat storage material used in the present embodiment is about 15 to 20 ° C., the heat storage material can be obtained by using a latent heat storage material such as paraffin that changes phase (liquid to solid) in this temperature range. The heat capacity per unit volume can be increased.

  In order to reduce heat dissipation loss to the outside air, it is desirable that the heat storage tank 10 has a relatively low thermal conductivity such as general-purpose plastic. Further, the heat storage tank 10 may be covered with a heat insulating material such as urethane foam.

  The operation of the air conditioner 1 will be described. FIG. 3 is an element device operation table for each operation mode of the air conditioner, and shows an operation mode and an operation table of main elements in each mode. In the cooling operation, the cooling supercooling heat storage operation 104 is performed when the indoor / outdoor load is large, and the operation is switched to the cooling heat storage use operation 105 when the load is small. During the heating operation, the operation is the same as a general cycle except for the operation of closing the supercooling expansion valve 9, and the description thereof is omitted.

  Next, the operation of each cycle element in the cooling supercooling heat storage operation 104 and the cooling heat storage utilization operation 105 will be described with reference to FIGS. 1, 3, and 4.

  First, as shown in FIG. 3, in the cooling supercooling heat storage operation 104, the flow path switching valve 3 is switched so as to flow in the cooling direction, that is, in the direction of the solid arrow, and the expansion valve 5 is adjusted to an appropriate opening degree according to the air conditioning load. The subcooling expansion valve 8 is adjusted to an appropriate opening degree. In the air conditioner 1 of FIG. 1, the refrigerant (for example, R22 or R410A can be used) in the direction of the solid line arrow in FIG. 1 (counterclockwise direction in FIG. 1), the compressor 2 and the flow path switching valve 3. (Path connecting compressor 2 discharge and outdoor heat exchanger 4), outdoor heat exchanger 4 working as a condenser, inner pipe of heat exchanger 9 for supercooling, expansion valve 5, indoor heat exchanger 6 working as an evaporator The flow path switching valve 3 (path connecting the indoor heat exchanger 6 and the suction tank 7) and the suction tank 7 flow in the main circuit 12 in this order.

  Moreover, a part of refrigerant | coolant after passing the outdoor heat exchanger 4 branches to the bypass circuit 13 shown with a broken line at the branch point 15b. The branched refrigerant flows through the bypass circuit 13 in the order of the supercooling expansion valve 8 and the outer pipe of the supercooling heat exchanger 9, and joins the main circuit 12 at the junction 13 b upstream of the suction tank 7.

  Furthermore, the heat storage material 11 in the heat storage tank 10 exchanges heat with the refrigerant flowing in the bypass circuit.

  FIG. 4 is a Mollier diagram showing a normal refrigeration cycle and a supercooling cycle. The effect of the cycle of the air conditioner 1 in the cooling supercooling heat storage operation 104 will be described with reference to the Mollier diagram shown in FIG. In FIG. 4, a normal (general) refrigeration cycle is indicated by a broken line with reference signs A1 to A4, and a supercooling cycle at the time of the cooling supercooling heat storage operation of the air conditioner 1 is indicated by a solid line with reference signs C1 to C4.

  In the supercooling cycle (solid line in FIG. 3), gas refrigerant is condensed into liquid refrigerant in the outdoor heat exchanger 4 which is a condenser from C1 to C20. The refrigerant sufficiently condensed and liquefied by the outdoor heat exchanger 4 branches into the main circuit 12 and the bypass circuit 13 at the branch point 13a. That is, the liquid refrigerant that has flowed into the bypass circuit 13 is depressurized (C22) by the supercooling expansion valve 8, and is exchanged with the refrigerant of the main circuit 12 flowing through the inner pipe by the outer pipe of the supercooling heat exchanger 9 ( C23) and gasify. Thereafter, the refrigerant merges with the refrigerant in the main circuit 12 at the junction 13b. On the other hand, the liquid refrigerant flowing into the main circuit 12 exchanges heat (C20 to C21) with the refrigerant in the bypass circuit 13 that flows through the outer pipe in the inner pipe of the supercooling heat exchanger 9, and the temperature of the liquid refrigerant decreases. . Thereafter, decompression expansion (C21 to C3) is performed by the expansion valve 5, gasification is performed by the indoor heat exchanger 6 that is an evaporator, and the refrigerant is merged with the refrigerant in the bypass circuit 13 at the junction 13b, and flows into the suction tank 7, and the compressor Return to 2. Thereby, the specific enthalpy of the condensation outlet decreases from h1 to h2, and accordingly, the specific enthalpy difference on the evaporation side becomes large (h3-h2> h3-h1), and the unit mass in the indoor heat exchanger 6 per unit mass is increased. Increases cooling capacity.

  At this time, the amount of the refrigerant branched into the bypass circuit 13 is adjusted to 10 to 20% of the total refrigerant flow rate by the opening degree of the supercooling expansion valve 8. Therefore, the refrigerant flow rate to the indoor heat exchanger 6 as an evaporator is reduced by 10 to 20%, and the pressure loss of the refrigerant is reduced. As a result, the suction pressure of the compressor 1 increases from p1 to p2, and the pressure ratio decreases. As a result, compared with a normal refrigeration cycle, the power of the compressor 2 of the air conditioner 1 can be reduced, and the efficiency is improved. In general, in such a supercooling cycle, as the cooling capacity is large as the refrigerant circulation amount is large and the pressure loss on the evaporation side is large, the efficiency improvement effect for the case where it is not the supercooling cycle is great.

  At this time, the heat storage material 11 in the heat storage tank 10 is cooled by exchanging heat with the two-phase refrigerant flowing in the outer pipe reduced in pressure (C22) by the above-described supercooling expansion valve 8.

  Next, as shown in FIG. 3, in the cooling heat storage utilization operation 105, the flow path switching valve 3 is switched so as to flow in the cooling direction, that is, in the direction of the solid arrow, and the expansion valve 5 is adjusted to an appropriate opening degree according to the air conditioning load. Then, the supercooling expansion valve 8 is closed so that the refrigerant does not flow. In the air conditioner 1 of FIG. 1, the refrigerant connects the compressor 2 and the flow path switching valve 3 (discharge of the compressor 2 and the outdoor heat exchanger 4) in the direction of the solid line arrow in FIG. 1 (counterclockwise direction in FIG. 1). Path), an outdoor heat exchanger 4 that functions as a condenser, an inner pipe of a supercooling heat exchanger 9, an expansion valve 5, an indoor heat exchanger 6 that functions as an evaporator, and a flow path switching valve 3 (with an indoor heat exchanger 6) The main circuit 12 flows in the order of the path connecting the suction tank 7) and the suction tank 7. Since the subcooling expansion valve 8 is closed, the refrigerant does not flow into the bypass circuit 13.

  Furthermore, the heat storage material 11 in the heat storage tank 10 exchanges heat with the refrigerant flowing through the main circuit 12 via the refrigerant in the bypass circuit 13. As will be described later, the cooling heat storage operation 105 is performed after the above-described cooling supercooling heat storage operation 104, so that the heat storage material 11 is cooled at the start of the operation.

  After the operation is started, the high-temperature gas refrigerant exiting the compressor 2 is condensed in the outdoor heat exchanger 4 which is a condenser to become a liquid refrigerant, and then the bypass circuit 13 in the inner pipe of the supercooling heat exchanger 9. The heat is exchanged with the heat storage material 11 via the refrigerant inside, and the temperature decreases. Thereafter, the refrigerant is decompressed and expanded by the expansion valve 5, evaporated by the indoor heat exchanger 6, which is an evaporator, becomes a gas refrigerant, and then returns to the compressor 2.

  The heat storage material 11 in the heat storage tank 10 is heat-exchanged with the refrigerant in the main circuit 12 so that the temperature rises until it reaches the same temperature as the refrigerant.

  Here, by cooling with the heat storage material at the condensation outlet, the specific enthalpy at the condensation outlet is reduced, and accordingly, the specific enthalpy difference on the evaporation side is increased, and cooling per unit mass in the indoor heat exchanger 6 is performed. Ability increases. This effect lasts for the heat capacity of the heat storage material. While the effect continues, the efficiency is improved because the cooling capacity increases with the same compressor power. That is, the larger the amount of heat storage material and the larger the heat transfer surface with the refrigerant, the longer the effect, but since the mounting volume is limited, a large effect can be expected when used in a region with a small cooling capacity.

  The specific switching method of the operation method described above will be described with reference to FIGS. FIG. 5 is an operation mode selection flowchart of the air conditioner. FIG. 6 is a diagram showing temporal changes in the room temperature, the heat storage material temperature, and the compressor rotational speed in the cooling operation, and shows the temporal changes in the indoor temperature Tin, the thermal storage material temperature Tm, and the compressor rotational speed R in the cooling operation. Yes.

  After starting operation 100, an operation mode is selected according to the indoor / outdoor load and the user's preference (101). For example, when the cooling operation 102 is selected, a command compressor rotation speed R is determined according to a determination unit (not shown), for example, a difference dT between the set room temperature Tset and the current room temperature Tin (for example, dT> 7 ° C.) (for example, R = 6000 min-1), the operation is started. If the command compressor rotational speed R at this time is equal to or higher than a predetermined compressor rotational speed Rc (for example, R = 3000 min−1) (103), the efficiency of the supercooling cycle is greatly improved and the operation mode is cooling. The supercooled cold storage operation 104 is selected. The cooling supercooling cold storage operation 104 is operated with higher efficiency than when the supercooling cycle is not used, and the heat storage material is cooled by the low-temperature bypass refrigerant (for example, Tm = 20 ° C.).

  When the difference between the set room temperature and the current room temperature becomes small after a certain period of time, the command compression speed R gradually decreases as shown in FIG. 6 (second half of the section 104 in the figure), and is less than the compressor speed Rc ( 103) (for example, R = 2900 min-1 <Rc). At this time, since the effect of improving the cycle efficiency by the supercooling cycle is reduced, the cooling heat storage utilization operation 105 is selected as the operation mode.

  The effect of increasing the specific enthalpy difference on the evaporation side lasts for the heat capacity of the heat storage material 11 (for example, about 10 minutes with 300 mL of water). That is, as shown in FIG. 6, the heat storage material 11 gradually increases in temperature until the same temperature as the refrigerant (for example, Tm = 35 ° C.) after the cooling heat storage use operation (105) (section 105 in the figure). While the effect continues, the cooling capacity increases with the same compressor power, so that the time to reach the set temperature is shortened with the same power consumption as compared with the case where the present embodiment is not applied.

  In addition, although conventional R22 and R410A were applied as the refrigerant, it is more preferable to apply the R32 refrigerant in the refrigerant cycle of the present embodiment. That is, the R32 refrigerant has a smaller GWP (global warming potential when GWP: CO2 = 1) than the R22 or R410A refrigerant. Furthermore, since the R32 refrigerant has a larger latent heat of vaporization at the same temperature than R410A and R22, a larger capacity can be obtained with the same refrigerant circulation flow rate. When R32 refrigerant is applied, high discharge temperature is a problem with high capacity with a large refrigerant circulation flow rate, but by increasing the bypass flow rate, the dryness of the suction refrigerant is reduced and the discharge capacity is maintained while maintaining the evaporation capacity. The temperature can be lowered. Furthermore, heat exchange to the heat storage tank is promoted by increasing the bypass flow rate.

  Further, in the present embodiment, the effect in the air conditioner capable of cooling / heating operation provided with the flow path switching valve is shown, but the same effect is also obtained in the air conditioner and the refrigeration apparatus dedicated to cooling without the flow path switching valve. Is obtained.

  As described above, the air conditioner of the present embodiment is configured such that the compressor, the outdoor heat exchanger, the supercooling heat exchanger, the expansion valve, and the indoor heat exchanger are sequentially connected by the refrigerant pipe to circulate the refrigerant. Branching from the main circuit between the circuit and the outdoor heat exchanger and the supercooling heat exchanger, and via the supercooling expansion valve and the supercooling heat exchanger, the indoor heat exchanger and the compressor A bypass circuit connected to the main circuit therebetween, and the supercooling heat exchanger includes a heat storage tank for exchanging heat with the main circuit flowing in the supercooling heat exchanger and the refrigerant of the bypass circuit. Since the heat storage tank provided in the supercooling heat exchanger and the refrigerant in the main circuit and the bypass circuit exchange heat, according to the operation of the bypass circuit, the refrigerant in the main circuit is supercooled by the refrigerant in the bypass circuit at high load. Since cold energy is stored in the heat storage tank and the stored cold energy can be given to the refrigerant in the main circuit at low load, in cooling operation, from high load such as when starting operation to low load during stable operation The power consumption of the air conditioner can be reduced.

  In particular, during cooling operation, by opening the expansion valve and the supercooling expansion valve to a predetermined opening, in the heat exchanger for supercooling, the refrigerant of the main circuit and the refrigerant of the bypass circuit exchange heat, and the bypass circuit Is stored in the heat storage tank in the supercooling heat exchanger by opening the expansion valve at a predetermined opening and closing the expansion valve for supercooling. In the cooling operation, as described above, in the cooling operation, air is applied from a high load at the start of operation to a low load at the stable operation. The power consumption of the harmony machine can be reduced.

  In addition, after operating in the supercooling cold storage operation mode, the heat storage tank is stored in the supercooling cold storage operation mode before the cold storage usage operation mode by shifting to the cold storage usage operation mode. In addition, cold storage in the heat storage tank can be applied to the refrigerant in the main circuit.

  In particular, the effect of the supercooling operation and the cold storage use operation is achieved by operating in the supercooled cold storage operation mode at the start of the cooling operation when the load is high, and then shifting to the cold storage use operation mode when the load is low. In consideration of the above, the power consumption of the air conditioner can be more effectively reduced from a high load at the time of starting operation to a low load at the time of stable operation.

DESCRIPTION OF SYMBOLS 1 ... Air conditioner, 2 ... Compressor, 3 ... Flow path switching valve, 4 ... Outdoor heat exchanger, 5 ... Expansion valve, 6 ... Indoor heat exchanger, 7 ... Suction tank, 8 ... Expansion valve for supercooling, DESCRIPTION OF SYMBOLS 9 ... Heat exchanger for supercooling, 9a ... Inner pipe, 9b ... Outer pipe, 10 ... Heat storage tank, 11 ... Heat storage material, 12 ... Main circuit, 13 ... Bypass circuit, 13a ... Branch point, 13b ... Junction point,

Claims (9)

A main circuit in which a compressor, an outdoor heat exchanger, a supercooling heat exchanger, an expansion valve, and an indoor heat exchanger are sequentially connected by a refrigerant pipe to circulate the refrigerant;
Branching from the main circuit between the outdoor heat exchanger and the supercooling heat exchanger, the indoor heat exchanger and the compression via the supercooling expansion valve and the supercooling heat exchanger A bypass circuit connected to the main circuit between the machine,
The said supercooling heat exchanger is an air conditioner provided with the thermal storage tank which heat-exchanges with the refrigerant | coolant of the said main circuit and the said bypass circuit which flow through the inside of the said supercooling heat exchanger. In claim 1,
The supercooling heat exchanger is a double pipe having an inner channel and an outer channel configured to cover the inner channel,
The main circuit constitutes the inner flow path;
The bypass circuit constitutes the outer flow path;
An air conditioner arranged so that the heat storage tank covers the outer flow path.   3. The air conditioner according to claim 2, wherein the main circuit and the bypass circuit in the double pipe are configured to counteract the flow.   4. The air conditioner according to claim 1, wherein during cooling operation, the cold energy stored in the heat storage tank is applied to the refrigerant through the supercooling heat exchanger. In claim 4, during cooling operation,
By opening the expansion valve and the supercooling expansion valve to a predetermined opening, in the supercooling heat exchanger, the refrigerant of the main circuit and the refrigerant of the bypass circuit exchange heat, and the bypass circuit A supercooled cold storage operation mode for storing the cold heat of the refrigerant in the heat storage tank;
Cold storage use for providing cold heat stored in the heat storage tank to the refrigerant of the main circuit in the supercooling heat exchanger by opening the expansion valve to a predetermined opening and closing the supercooling expansion valve An air conditioner comprising an operation mode.   6. The air conditioner according to claim 5, wherein the air conditioner operates in the supercooled regenerative operation mode and then shifts to the regenerative use operation mode.   The air conditioner according to claim 6, wherein the air conditioner operates in the supercooled regenerative storage operation mode when the cooling operation is started, and then shifts to the regenerative storage operation mode.   8. The air conditioner according to claim 6, wherein when the rotation speed of the compressor becomes a predetermined value or less during operation in the supercooling cold storage operation mode, the air conditioner shifts to the cold storage operation mode.   9. An air conditioner according to claim 1, wherein R32 is used as the refrigerant.