JP5287820B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner including a heat storage tank that stores a heat storage material that stores heat generated by a compressor, and a heat storage heat exchanger that performs heat exchange by heat storage of the heat storage material.

  Conventionally, when the outdoor heat exchanger is frosted during the heating operation by the heat pump air conditioner, defrosting is performed by switching the four-way valve from the heating cycle to the cooling cycle. In this defrosting method, although the indoor fan is stopped, there is a disadvantage that a feeling of heating is lost because cold air is gradually discharged from the indoor unit.

  Accordingly, a heat storage device is provided in the compressor provided in the outdoor unit, and the one that is defrosted using the waste heat of the compressor stored in the heat storage tank during the heating operation has been proposed (for example, Patent Document 1).

  FIG. 7 shows an example of a refrigeration cycle apparatus that employs such a defrosting method. The compressor 100, the four-way valve 102, the outdoor heat exchanger 104, the capillary tube 106, the indoor unit provided in the outdoor unit are shown. Is connected to the indoor heat exchanger 108 provided by the refrigerant pipe, the first bypass circuit 110 for bypassing the capillary tube 106, and the discharge side of the compressor 100 to the indoor heat exchanger 108 via the four-way valve 102. A second bypass circuit 112 is provided in which one end is connected to the connecting pipe and the other end is connected to the pipe extending from the capillary tube 106 to the outdoor heat exchanger 104. The first bypass circuit 110 is provided with a two-way valve 114, a check valve 116, and a heat storage heat exchanger 118, and the second bypass circuit 112 is provided with a two-way valve 120 and a check valve 122. Yes.

  Further, a heat storage tank 124 is provided around the compressor 100, and the heat storage tank 124 is filled with a heat storage material 126 for exchanging heat with the heat storage heat exchanger 118.

  In this refrigeration cycle, during the defrosting operation, the two two-way valves 114 and 120 are opened, a part of the refrigerant discharged from the compressor 100 flows to the second bypass circuit 112, and the remaining refrigerant is the four-way valve. 102 and the indoor heat exchanger 108. In addition, after the refrigerant flowing through the indoor heat exchanger 108 is used for heating, a small amount of refrigerant flows to the outdoor heat exchanger 104 through the capillary tube 106, while the remaining most of the refrigerant passes through the first bypass circuit. 110 flows into the heat storage heat exchanger 118 through the two-way valve 114, takes heat from the heat storage material 126, passes through the check valve 116, and then merges with the refrigerant that has passed through the capillary tube 106 to the outdoor. It flows to the heat exchanger 104. After that, it merges with the refrigerant flowing through the second bypass circuit 112 at the inlet of the outdoor heat exchanger 104, performs defrosting using the heat of the refrigerant, passes through the four-way valve 102, and then enters the compressor 100. Inhaled.

  In this refrigeration cycle apparatus, by providing the second bypass circuit 112, the hot gas discharged from the compressor 100 during defrosting is guided to the outdoor heat exchanger 104 and the pressure of the refrigerant flowing into the outdoor heat exchanger 104 Therefore, the defrosting ability can be increased, and the defrosting can be completed in a very short time.

JP-A-3-31666

  However, in a conventional air conditioner having a heat storage material, heat is accumulated in the heat storage material with the operation of the compressor regardless of heating operation or cooling operation, and the temperature of the heat storage material increases. When the temperature of the heat storage material rises excessively, it has a problem of promoting the deterioration of the heat storage material.

  This invention solves the said conventional subject, and it aims at providing the air conditioner which can prevent deterioration of the thermal storage material which accumulate | stores the heat which generate | occur | produced with the compressor.

In order to achieve the above object, the air conditioner of the present invention is connected so that the refrigerant flows in the order of the compressor, the four-way valve, the indoor heat exchanger, the expansion valve, the outdoor heat exchanger, and the four-way valve during heating operation. A refrigeration cycle, a heat storage material that stores heat generated in the compressor, a heat storage tank that contains a heat storage heat exchanger, a space between the indoor heat exchanger and the expansion valve, a four-way valve, and a compressor A heat storage bypass circuit connecting between the suction port, a defrosting bypass circuit connecting between the expansion valve and the outdoor heat exchanger, and between a discharge port of the compressor and the four-way valve, and the compression An air conditioner provided with a compressor temperature detecting means for detecting the temperature of the compressor, wherein the heat storage heat exchanger and a heat storage two-way valve are arranged in the heat storage bypass circuit, and detected by the compressor temperature detection means When the measured temperature exceeds the first predetermined temperature, the heat storage two-way valve is opened. Your was carried out, lowering the temperature of the heat storage material, the further the detected compressor temperature detector temperature exceeds a second predetermined temperature higher than the first predetermined temperature, stopping the compressor By preventing excessive temperature rise of the heat storage material, especially because the heat storage material is provided along the periphery of the compressor, it is possible to suppress the local boiling of the heat storage material located in the portion in contact with the compressor, Can suppress deterioration of the heat storage material.

  ADVANTAGE OF THE INVENTION According to this invention, the air conditioner which can prevent deterioration of the thermal storage material which accumulate | stores the heat which generate | occur | produced with the compressor can be provided.

The block diagram of the air conditioner in Embodiment 1 of this invention The block diagram of the air conditioner in Embodiment 1 Flowchart showing control of defrosting / heating operation in the first embodiment The block diagram of the air conditioner in Embodiment 1 Schematic which shows protection control of the thermal storage material in Embodiment 1 Timing chart showing opening and closing control of the heat storage two-way valve at the time of protection control of the heat storage material in the first embodiment Schematic diagram showing the configuration of a conventional refrigeration cycle apparatus

In the air conditioner of the first invention, during the heating operation, the compressor, the four-way valve, the indoor heat exchanger, the expansion valve, the outdoor heat exchanger, the refrigeration cycle connected so that the refrigerant flows in the order of the four-way valve, A heat storage material that stores heat generated by the compressor, a heat storage tank that contains a heat storage heat exchanger, a space between the indoor heat exchanger and the expansion valve, a space between the four-way valve, and a suction port of the compressor. A heat storage bypass circuit to be connected, a defrost bypass circuit for connecting between the expansion valve and the outdoor heat exchanger, a discharge port of the compressor, and the four-way valve, and detecting the temperature of the compressor An air conditioner provided with a compressor temperature detecting means, wherein the heat storage bypass circuit is provided with the heat storage heat exchanger and a heat storage two-way valve, and the temperature detected by the compressor temperature detection means is first. When the predetermined temperature is exceeded, the heat storage two-way valve is controlled to open, and the heat storage material Lowering the temperature, the more the detected compressor temperature detector temperature exceeds a second predetermined temperature higher than the first predetermined temperature, by stopping the compressor, excessive temperature of the heat storage material Since the heat storage material is provided along the circumference of the compressor, particularly, the local boiling of the heat storage material located at the portion in contact with the compressor can be suppressed, and thus the deterioration of the heat storage material can be suppressed. it can.

  In the air conditioner of the second invention, particularly in the first invention, when the temperature detected by the compressor temperature detecting means detects a predetermined temperature, the heat storage two-way valve is opened and the operating frequency of the compressor is further lowered. Thus, by using both the control for opening the heat storage two-way valve and the control for lowering the operating frequency of the compressor, it is possible to effectively suppress an excessive temperature increase of the heat storage material.

  In the air conditioner of the third invention, particularly in the first or second invention, when the temperature detected by the compressor temperature detecting means detects a predetermined temperature, the heat storage two-way valve is opened, and after a predetermined time has elapsed, the heat storage By repeating the series of operations to close the two-way valve periodically, there is a delay in the time from the opening of the heat storage two-way valve until the temperature of the heat storage material decreases. If the two-way valve is held open, the air conditioning capacity will be reduced, so the time to open the heat storage two-way valve is determined in advance and the opening / closing operation is repeated to suppress the decline in air conditioning capacity as much as possible. And the excessive temperature rise of a thermal storage material can be suppressed.

  In the air conditioner of the fourth invention, particularly in the third invention, the time for opening the heat storage two-way valve is set shorter than the time for closing the heat storage two-way valve, so that the heat storage can be performed without impairing the air conditioning environment as much as possible Deterioration of the material can be suppressed.

  In the air conditioner of the fifth invention, particularly in the third or fourth invention, the open / close cycle of the heat storage two-way valve is set shorter than the open / close cycle of the cooling operation in the open / close cycle of the heat storage two-way valve. Therefore, in order to flow the liquid phase refrigerant that has passed through the indoor heat exchanger during the heating operation and the two-phase (gas phase and liquid phase) refrigerant that has passed through the outdoor heat exchanger during the cooling operation, the refrigerant is more effective during the cooling operation. Therefore, it is possible to efficiently suppress deterioration of the heat storage material by making the open / close cycle of the heat storage two-way valve different between the heating operation and the cooling operation.

  In the air conditioner of the sixth invention, particularly in one of the third to fifth inventions, the maximum number of opening and closing operations of the heat storage two-way valve is provided, and the number of opening and closing operations does not exceed the maximum number of times. Suppresses impairing the reliability of the heat storage two-way valve.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a configuration of an air conditioner that is a refrigeration cycle apparatus according to the present invention, and the air conditioner includes an outdoor unit 2 and an indoor unit 4 that are connected to each other through a refrigerant pipe.

  As shown in FIG. 1, a compressor 6, a four-way valve 8, a strainer 10, an expansion valve 12, and an outdoor heat exchanger 14 are provided inside the outdoor unit 2. A heat exchanger 16 is provided, and these are connected to each other via a refrigerant pipe to constitute a refrigeration cycle.

  More specifically, the compressor 6 and the indoor heat exchanger 16 are connected via a refrigerant pipe 18 provided with the four-way valve 8, and the indoor heat exchanger 16 and the expansion valve 12 are refrigerant provided with the strainer 10. It is connected via a pipe 20. The expansion valve 12 and the outdoor heat exchanger 14 are connected via a refrigerant pipe 22, and the outdoor heat exchanger 14 and the compressor 6 are connected via a refrigerant pipe 24.

  A four-way valve 8 is disposed in the middle of the refrigerant pipe 24, and an accumulator 26 for separating the liquid-phase refrigerant and the gas-phase refrigerant is provided in the refrigerant pipe 24 on the refrigerant suction side of the compressor 6. . The compressor 6 and the refrigerant pipe 22 are connected via a refrigerant pipe 28, and the refrigerant pipe 28 is provided with a defrosting two-way valve (for example, an electromagnetic valve) 30.

  Further, a heat storage tank 32 is provided around the compressor 6, and a heat storage heat exchanger 34 is provided inside the heat storage tank 32, and a heat storage material for exchanging heat with the heat storage heat exchanger 34 (for example, An ethylene glycol aqueous solution) 36 is filled, and the heat storage tank 32, the heat storage heat exchanger 34, and the heat storage material 36 constitute a heat storage device.

  In addition, the refrigerant pipe 20 and the heat storage heat exchanger 34 are connected via a refrigerant pipe 38, and the heat storage heat exchanger 34 and the refrigerant pipe 24 are connected via a refrigerant pipe 40. A valve (for example, a solenoid valve) 42 is provided.

  In addition to the indoor heat exchanger 16, an indoor fan 16a, upper and lower blades (not shown), and left and right blades (not shown) are provided inside the indoor unit 4, and the indoor heat exchanger 16 is The indoor air sucked into the interior of the indoor unit 4 by the blower fan is exchanged with the refrigerant flowing through the interior of the indoor heat exchanger 16, and the air warmed by the heat exchange is blown into the room during heating. Sometimes air cooled by heat exchange is blown into the room. The upper and lower blades change the direction of air blown from the indoor unit 4 up and down as necessary, and the left and right blades change the direction of air blown from the indoor unit 4 to right and left as needed.

  The outdoor heat exchanger 14 is provided with an outdoor heat exchanger inlet temperature detecting means 44 and an outdoor heat exchanger outlet temperature detecting means 46 for detecting the refrigerant inlet temperature and the refrigerant outlet temperature during heating operation, respectively. The exchanger 16 is provided with an indoor heat exchanger temperature detecting means 48 that detects the temperature of the indoor heat exchanger 16. Furthermore, the heat storage tank 32 is provided with a heat storage tank temperature detection means 50 for detecting the temperature of the heat storage tank 32, and the outdoor unit 2 is provided with an outside air temperature detection means 52 for detecting the outside air temperature.

  In addition, the compressor 6, the blower fan, the upper and lower blades, the left and right blades, the four-way valve 8, the expansion valve 12, the defrost two-way valve 30, the heat storage two-way valve 42, the outdoor heat exchanger inlet temperature detection means 44, the outdoor heat exchanger The outlet temperature detection means 46, the indoor heat exchanger temperature detection means 48, the heat storage tank temperature detection means 50, the outside air temperature detection means 52 and the like are electrically connected to a controller 54 (for example, a microcomputer), and the compressor 6, the blower fan, The operation or operation of the upper and lower blades, the left and right blades, the four-way valve 8 and the expansion valve 12 is controlled based on a control signal from the controller 54, and the defrosting two-way valve 30 and the heat storage two-way valve 42 are supplied from the controller 54. Opening and closing is controlled based on the control signal.

  In the refrigeration cycle apparatus according to the present invention having the above-described configuration, the mutual connection relationship and function of each component will be described together with the flow of the refrigerant taking the case of heating operation as an example.

  The refrigerant discharged from the discharge port of the compressor 6 reaches the indoor heat exchanger 16 from the four-way valve 8 through the refrigerant pipe 18. The refrigerant condensed by exchanging heat with the indoor air in the indoor heat exchanger 16 passes through the refrigerant pipe 20 through the indoor heat exchanger 16, passes through the strainer 10 that prevents foreign matter from entering the expansion valve 12, and then the expansion valve. To 12. The refrigerant decompressed by the expansion valve 12 reaches the outdoor heat exchanger 14 through the refrigerant pipe 22, and the refrigerant evaporated by exchanging heat with the outdoor air in the outdoor heat exchanger 14 is the refrigerant pipe 24, the four-way valve 8, and the accumulator. 26 and returns to the suction port of the compressor 6.

  The refrigerant pipe 28 branched from the compressor 6 discharge port of the refrigerant pipe 18 and the four-way valve 8 is interposed between the expansion valve 12 of the refrigerant pipe 22 and the outdoor heat exchanger 14 via the defrosting two-way valve 30. Have joined.

Furthermore, the heat storage tank 32 in which the heat storage material 36 and the heat storage heat exchanger 34 are housed is disposed so as to be in contact with and surround the compressor 6, and heat generated in the compressor 6 is stored in the heat storage material 36, and refrigerant piping The refrigerant pipe 38 branched from the indoor heat exchanger 16 and the strainer 10 from 20 is a heat storage two-way valve 4.
2, the refrigerant pipe 40 that reaches the inlet of the heat storage heat exchanger 34 and exits from the outlet of the heat storage heat exchanger 34 joins between the four-way valve 8 and the accumulator 26 in the refrigerant pipe 24.

  Next, the operation during normal heating will be described with reference to FIG. 2 schematically showing the operation during normal heating and the flow of the refrigerant of the air conditioner shown in FIG.

  During the normal heating operation, the defrosting two-way valve 30 and the heat storage two-way valve 42 are closed, and the refrigerant discharged from the discharge port of the compressor 6 as described above passes through the refrigerant pipe 18 and the four-way valve 8. To the indoor heat exchanger 16. The refrigerant condensed by exchanging heat with the indoor air in the indoor heat exchanger 16 exits the indoor heat exchanger 16 and reaches the expansion valve 12 through the refrigerant pipe 20. The refrigerant decompressed by the expansion valve 12 is refrigerant pipe 22. Through the outdoor heat exchanger 14. The refrigerant evaporated by exchanging heat with outdoor air in the outdoor heat exchanger 14 returns from the four-way valve 8 to the suction port of the compressor 6 through the refrigerant pipe 24.

  Further, the heat generated in the compressor 6 is accumulated in the heat storage material 36 housed in the heat storage tank 32 from the outer wall of the compressor 6 through the outer wall of the heat storage tank 32.

  Next, the operation during defrosting / heating will be described with reference to FIG. 3 schematically showing the operation of the air conditioner shown in FIG. 1 during defrosting / heating and the flow of refrigerant. In the figure, the solid line arrows indicate the flow of the refrigerant used for heating, and the broken line arrows indicate the flow of the refrigerant used for defrosting.

  When the outdoor heat exchanger 14 is frosted during the above-described normal heating operation and the frosted frost grows, the ventilation resistance of the outdoor heat exchanger 14 increases and the air flow decreases, and the evaporation in the outdoor heat exchanger 14 increases. The temperature drops. As shown in FIG. 1, an air conditioner that is a refrigeration cycle apparatus according to the present invention is provided with an outdoor heat exchanger inlet temperature detection means 44 that detects the refrigerant inlet temperature of the outdoor heat exchanger 14 during heating operation. When the outdoor heat exchanger inlet temperature detecting means 44 detects that the evaporation temperature has decreased as compared with the time of non-frosting, the controller 54 outputs an instruction from the normal heating operation to the defrosting / heating operation. .

  When the normal heating operation is shifted to the defrosting / heating operation, the defrosting two-way valve 30 and the heat storage two-way valve 42 are controlled to open, and in addition to the refrigerant flow during the normal heating operation described above, from the discharge port of the compressor 6. A part of the gas-phase refrigerant that has exited passes through the refrigerant pipe 28 and the defrosting two-way valve 30, joins the refrigerant that passes through the refrigerant pipe 22, heats the outdoor heat exchanger 14, and condenses into a liquid phase. Then, the refrigerant returns to the suction port of the compressor 6 through the refrigerant pipe 24 and the four-way valve 8 and the accumulator 26.

  The refrigerant pipe 28 connecting the expansion valve 12 and the outdoor heat exchanger 14 and between the discharge port of the compressor 6 and the four-way valve 8 heats the outdoor heat exchanger 14 to perform defrosting. Therefore, it can also be referred to as a defrosting bypass circuit.

  In addition, a part of the liquid-phase refrigerant that is divided between the indoor heat exchanger 16 and the strainer 10 in the refrigerant pipe 20 passes through the refrigerant pipe 38 and the heat storage two-way valve 42, and absorbs heat from the heat storage material 36 in the heat storage heat exchanger 34. Then, it evaporates and vaporizes, merges with the refrigerant passing through the refrigerant pipe 24 through the refrigerant pipe 40, and returns from the accumulator 26 to the suction port of the compressor 6.

  Note that the refrigerant pipe 38 and the refrigerant pipe 40 that connect between the indoor heat exchanger 16 and the expansion valve 12 and between the four-way valve 8 and the suction port of the compressor 6 pass through the heat storage heat exchanger 34. Since heat is absorbed from the heat storage material 36, these two refrigerant pipes 38 and 40 can also be called a heat storage bypass circuit.

The refrigerant returning to the accumulator 26 includes the liquid phase refrigerant returning from the outdoor heat exchanger 14. By mixing this with the high-temperature gas phase refrigerant returning from the heat storage heat exchanger 34, The evaporation of the phase refrigerant is promoted, and the liquid phase refrigerant does not return to the compressor 6 through the accumulator 26, so that the reliability of the compressor 6 can be improved.

  The temperature of the outdoor heat exchanger 14 that has become below freezing due to the attachment of frost at the start of defrosting and heating is heated by the gas-phase refrigerant discharged from the discharge port of the compressor 6, and the frost is melted near zero degrees. When melting is finished, the temperature of the outdoor heat exchanger 14 begins to rise again. When the temperature rise of the outdoor heat exchanger 14 is detected by the outdoor heat exchanger outlet temperature detecting means 46, it is determined that the defrosting is completed, and the controller 54 outputs an instruction from the defrosting / heating operation to the normal heating operation. The

  Next, the operation of the heat storage two-way valve 42 and the defrost two-way valve 30 during the defrosting / heating operation will be described. Since the amount of heat accumulated in the heat storage material 36 is finite, this control shifts from the normal heating operation to the defrosting / heating operation in order to effectively use the heat amount accumulated in the heat storage material 36, and the When opening the two-way valve 30 and the heat storage two-way valve 42, the defrosting two-way valve 30 is first opened and a predetermined time (for example, 10 to 20 seconds) has elapsed since the opening control of the defrosting two-way valve 30. Thereafter, the heat storage two-way valve 42 is controlled to be opened.

  The defrosting / heating operation is performed for the first time when both the defrosting two-way valve 30 and the heat storage two-way valve 42 are open, but the heat storage two-way valve 42 is controlled to open before the defrosting two-way valve 30. Then, the amount of heat accumulated in the heat storage material 36 is wasted, and if both the defrost two-way valve 30 and the heat storage two-way valve 42 are simultaneously controlled to open, the refrigerant from the outdoor heat exchanger 14 and the indoor Since the refrigerant from the heat exchanger 16 is sucked into the compressor 6 at the same time, there is a risk of causing a pressure fluctuation. Therefore, the open control of the defrost two-way valve 30 and the open control of the heat storage two-way valve 42 are performed. By setting an appropriate time difference, it is possible to suppress pressure fluctuations as much as possible, and to prevent liquid refrigerant from flowing into the compressor 6 and improve the reliability of the compressor 6.

  For this reason, as shown in FIG. 1, the controller 54 is provided with a timer 56 that counts time. When the normal heating operation is shifted to the defrosting / heating operation, the defrosting two-way valve 30 is opened. The elapsed time from the control is counted by the timer 56, and when the time counted by the timer 56 reaches the predetermined time described above, the heat storage two-way valve 42 is controlled to open. Hereinafter, this control will be described in detail with reference to the flowchart of FIG.

  In step S1, it is determined whether the temperature detected by the indoor heat exchanger temperature detecting means 48 is a predetermined temperature Ta (for example, 45 ° C.). If the detected temperature is equal to the predetermined temperature Ta, the process proceeds to step S5. On the other hand, if they are not equal, the process proceeds to step S2 to determine whether or not the detected temperature exceeds a predetermined temperature Ta. If the detected temperature exceeds the predetermined temperature Ta, the operating frequency of the compressor 6 is decreased in step S3, whereas if the detected temperature is lower than the predetermined temperature Ta, the compressor 6 is determined in step S4. Increase the operating frequency. When the frequency control of the compressor 6 in step S3 or S4 is completed, the process returns to step S1. Although the predetermined temperature Ta is described as 45 ° C. here, it is not limited to this.

  That is, the pressure fluctuation in the refrigeration cycle controls the opening of the defrosting two-way valve 30 and the heat storage two-way valve 42 when the temperature of the indoor heat exchanger 16 is high and the pressure difference between the high pressure side and the low pressure side is large. Therefore, if the temperature detected by the indoor heat exchanger temperature detecting means 48 exceeds the predetermined temperature Ta, the indoor heat exchanger temperature detecting means 48 may be generated. The operation frequency of the compressor 6 is lowered until the temperature detected in step 1 reaches the predetermined temperature Ta, and control is performed to reduce the pressure on the high pressure side.

Further, in order to effectively use the heat quantity of the refrigerant after heat exchange in the indoor heat exchanger 16 during the defrosting operation, the temperature detected by the indoor heat exchanger temperature detecting means 48 is less than the predetermined temperature Ta. Increases the operating frequency of the compressor 6 until the detected temperature reaches a predetermined temperature Ta, thereby improving the efficiency of the defrosting operation after the heating operation.

  In step S1, when the temperature detected by the indoor heat exchanger temperature detecting means 48 reaches a predetermined temperature Ta, a normal heat storage defrosting operation for performing a defrosting operation while effectively using the heat accumulated in the heat storage tank 32 is started. To do. In this defrosting operation, the defrosting two-way valve 30 is controlled to open in step S5 and the refrigerant discharged from the compressor 6 is guided to the outdoor heat exchanger 14, and in step S6, the defrosting two counted by the timer 56 is guided. It is determined whether or not the time from the opening control of the direction valve 30 has reached the above-described predetermined time. If the predetermined time has been reached, the heat storage two-way valve 42 is controlled to open in step S7 and passes through the indoor heat exchanger 16. While the conducted refrigerant is guided to the heat storage heat exchanger 34, if the predetermined time has not been reached, the process returns to step S6.

  When the heat storage two-way valve 42 is controlled to open in step S7, in step S8, the temperature detected by the outdoor heat exchanger outlet temperature detecting means 46 and a predetermined temperature Tb (for example, 6 ° C.) serving as an index for the completion of the defrosting operation. If the former is less than the latter, it is determined that there is residual frost, or there is no residual frost, but the substrate (upper and lower portions of the outdoor heat exchanger 14) is still frozen, The defrosting operation is continued and the process proceeds to step S9.

  In step S9, if the time from the opening control of the defrosting two-way valve 30 counted by the timer 56 has not reached a predetermined time (for example, 7 minutes), the process returns to step S8, while the outdoor heat exchanger outlet temperature If the temperature detected by the detection means 46 is equal to or higher than the predetermined temperature Tb, it is determined that there is no residual frost and that the substrate has been frozen, and the defrosting two-way valve 30 and the heat storage two-way valve 42 are simultaneously set in step S10. Close control is performed, the defrosting operation is terminated, and the normal heating operation is resumed.

  If the time counted by the timer 56 in step S9 has reached a predetermined time, the process proceeds to step S10 regardless of the temperature detected by the outdoor heat exchanger outlet temperature detecting means 46, and the defrosting two-way valve 30 is moved. The heat storage two-way valve 42 is closed and controlled at the same time, the defrosting operation is terminated and the normal heating operation is resumed, and the count time of the timer 56 is reset.

  In addition, when the time counted by the timer 56 in step S9 reaches a predetermined time, the defrosting operation is forcibly terminated because the heat storage amount of the heat storage tank 32 is limited and consumed in the predetermined time. This is because even if the defrosting operation is continued beyond a predetermined time, there is no heat storage amount, and there is no point in performing the defrosting operation.

  Further, in the present embodiment, the temperature detected by the outdoor heat exchanger inlet temperature detecting means 44 is always compared with the outside air temperature from the start of the defrosting operation to the end of the defrosting operation. When the outdoor air temperature is higher than the outdoor heat exchanger inlet temperature, the operation of an outdoor fan (not shown) that is provided in the outdoor unit 2 and blows air to the outdoor heat exchanger 14 is continued. By controlling in this way, defrosting of the outdoor heat exchanger 14 can be promoted by effectively utilizing the amount of heat of the outside air temperature.

  However, once it is determined that the outdoor heat exchanger inlet temperature is higher than the outside air temperature during the defrosting operation, the outdoor heat exchanger inlet temperature only rises, so the outdoor fan must be turned off until the defrosting operation ends. It is not driven.

  Next, protection control of the heat storage material 36 will be described. When the heat storage tank 32 having the heat storage material 36 inside is disposed in contact with the periphery of the compressor as in the present embodiment, the temperature of the compressor 6 itself increases excessively depending on the operation of the compressor 6. In particular, there is a problem that the heat storage material 36 near the heat storage tank 32 in contact with the compressor 6 causes local boiling and the heat storage material 36 deteriorates.

  In the present invention, if the temperature of the heat storage material 36 is excessively increased, the heat storage material 36 itself may be altered (for example, oxidation) or water boiling of the heat storage material 36 may be caused and the heat storage material 36 may deteriorate. The controller 54 performs protection control of the heat storage material based on the temperature of the compressor 6, thereby preventing the heat storage material 36 from being deteriorated.

  This is because the temperature of the compressor 6 closely correlates with the temperature of the heat storage material 36, and the temperature of the heat storage material 36 increases as the temperature of the compressor 6 increases. The protection control of the heat storage material is performed not only during the heating operation but also during the cooling operation.

  Hereinafter, control based on the compressor temperature will be described. As shown in FIG. 4, in this control, a compressor temperature detecting means 58 for detecting the temperature of the compressor 6 is provided, and when the temperature detected by the compressor temperature detecting means 58 exceeds a first predetermined temperature. Then, the heat storage two-way valve 42 is controlled to open, and the refrigerant that has passed through the indoor heat exchanger 16 at the time of heating and the outdoor heat exchanger 14 at the time of cooling to the heat storage heat exchanger 34 is guided to the heat storage heat exchanger 34. The temperature of 36 is lowered. The compressor temperature detecting means 58 may be a thermistor that can detect the temperature.

  More specifically, as shown in FIG. 5, when the temperature detected by the compressor temperature detecting means 58 exceeds a first predetermined temperature (for example, 95 ° C.), the heat storage two-way valve 42 is controlled to open, The maximum operating frequency of the compressor 6 is limited. When the heat storage two-way valve 42 is opened, an excessive temperature rise of the heat storage material 36 can be prevented. In particular, since the heat storage material 36 is disposed along the periphery of the compressor 6, It is possible to prevent local boiling of the portion in contact with the heat storage material 36 and to reduce evaporation of the heat storage material 36 as much as possible.

  Thereafter, when the temperature detected by the compressor temperature detecting means 58 further exceeds a second predetermined temperature (for example, 103 ° C.) higher than the first predetermined temperature, the compressor 6 is stopped.

  In addition, when the temperature detected by the compressor temperature detecting means 58 exceeds a first predetermined temperature (for example, 95 ° C.), control for lowering the operating frequency of the compressor 6 instead of opening control of the heat storage two-way valve 42. It is also possible to perform the control for lowering the operating frequency of the compressor 6 simultaneously with the opening control of the heat storage two-way valve 42. That is, if the operating frequency of the compressor 6 is lowered, the temperature of the compressor 6 is lowered, and local boiling of the heat storage material 36 located in the vicinity of the compressor 6 can be prevented.

  Further, after the temperature detected by the compressor temperature detecting means 58 exceeds the second predetermined temperature, the temperature detected by the compressor temperature detecting means 58 gradually decreases by stopping the compressor 6, When the temperature falls below a third predetermined temperature lower than a predetermined temperature of 2 (for example, 5 ° C.), the compressor 6 starts operating again, but the heat storage two-way valve 42 is still open, and the compressor temperature detecting means When the temperature detected at 58 further decreases and falls below a fourth predetermined temperature lower than the first predetermined temperature (for example, 5 ° C.), the heat storage two-way valve 42 is closed.

  The third predetermined temperature and the fourth predetermined temperature in the temperature decreasing direction are set lower than the first predetermined temperature and the second predetermined temperature in the temperature increasing direction, respectively. This is to prevent frequent repetition (hunting) of ON / OFF of the machine 6. In this embodiment, a value 5 ° C. lower than the first predetermined temperature is set as the fourth predetermined temperature, and a value 5 ° C. lower than the second predetermined temperature is set as the fourth predetermined temperature. However, the value is limited to 5 ° C. There is no problem as long as the value can prevent hunting.

The first predetermined temperature varies depending on the boiling point of the heat storage material 36, but is a heat storage material of an ethylene glycol aqueous solution (75% water, 25% ethylene glycol) used in the present embodiment. If present, the boiling point is about 105 ° C. under atmospheric pressure of 1013 hPa. Therefore, the first predetermined temperature is set at a temperature not exceeding the boiling point.

  That is, the first predetermined temperature is defined by an expression satisfying the boiling point of the heat storage material 36−the predetermined temperature α. At this time, the predetermined temperature α is a numerical value that can suppress the local boiling obtained experimentally and is uniquely determined. Can not. However, if the predetermined temperature α is in the range of about 5 ° C. to 20 ° C., a certain amount of heat is stored in the heat storage material 36 and deterioration of the heat storage material 36 can be suppressed. In particular, if the atmospheric pressure at the place where the air conditioner is installed is lowered, the boiling point of the heat storage material 36 is also lowered.

  Instead of the above-described opening control of the heat storage two-way valve 42, as shown in FIG. 6, it is preferable to perform opening / closing control that periodically repeats the valve opening state and the valve closing state. In the case of heating / closing control, for example, when heating, for example, 10 seconds of opening and 30 seconds of closing are repeated a maximum of 10 times, and during cooling, for example, 30 seconds of opening and, for example, 90 seconds of closing are closed up to 10 times. repeat.

  The open / close control of the heat storage two-way valve 42 in this way does not immediately decrease the temperature of the heat storage material 36 even if the heat storage two-way valve 42 is controlled to open, but after a certain time delay, the heat storage material 36 This is a consideration of the followability problem in which the temperature of the film gradually decreases.

  The opening time and closing time of the heat storage two-way valve 42 during heating are set shorter than the valve opening time and valve closing time of the heat storage two-way valve 42 during cooling. While the liquid-phase refrigerant that has passed through the storage unit 16 passes through the heat storage two-way valve 42, during cooling, the two-phase (gas phase and liquid phase) refrigerant that has passed through the outdoor heat exchanger 14 passes through the heat storage two-way valve 42. This is because the liquid-phase refrigerant has a higher density and a larger amount of refrigerant than the two-phase refrigerant.

  Further, the opening / closing control of the heat storage two-way valve 42 is limited to a maximum of 10 times in consideration of the durability of the heat storage two-way valve 42.

  As mentioned above, in this Embodiment, when the temperature of the compressor 6 rises too much, deterioration of a thermal storage material can be suppressed by performing control which opens the thermal storage two-way valve 42. FIG.

  Since the air conditioner according to the present invention can perform an efficient defrosting operation using a finite amount of heat stored in the heat storage device, it is also effectively used for other refrigeration cycle devices that may be frosted in winter. can do.

2 outdoor unit 4 indoor unit 6 compressor 8 four-way valve 10 strainer 12 expansion valve 14 outdoor heat exchanger 16 indoor heat exchanger 26 accumulator 30 defrost two-way valve 32 heat storage tank 34 heat storage heat exchanger 36 heat storage material 42 heat storage two-way Valve 44 Outdoor heat exchanger inlet temperature detection means 46 Outdoor heat exchanger outlet temperature detection means 48 Indoor heat exchanger temperature detection means 50 Thermal storage tank temperature detection means 52 Outdoor air temperature detection means 54 Controller,
56 Timer 58 Compressor temperature detection means

Claims (6)

During heating operation, a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, an outdoor heat exchanger, a refrigeration cycle connected so that refrigerant flows in this order, and heat storage that accumulates heat generated by the compressor A heat storage tank containing a material and a heat storage heat exchanger, a heat storage bypass circuit connecting between the indoor heat exchanger and the expansion valve, and between the four-way valve and the suction port of the compressor, and the expansion valve And an outdoor heat exchanger, a defrost bypass circuit for connecting the discharge port of the compressor and the four-way valve, and an air conditioner having a compressor temperature detecting means for detecting the temperature of the compressor When the heat storage heat exchanger and the heat storage two-way valve are arranged in the heat storage bypass circuit and the temperature detected by the compressor temperature detection means exceeds a first predetermined temperature, the heat storage Control the opening of the direction valve, lower the temperature of the heat storage material, and When detected by the compressor temperature detecting means temperature exceeds a second predetermined temperature higher than the first predetermined temperature, the air conditioner characterized by stopping the compressor. The air conditioner according to claim 1, wherein when the temperature detected by the compressor temperature detecting means detects a predetermined temperature, the heat storage two-way valve is opened and the operating frequency of the compressor is further lowered. When the temperature detected by the compressor temperature detecting means detects a predetermined temperature, the heat storage two-way valve is opened, and after a predetermined time has elapsed, a series of operations for closing the heat storage two-way valve is periodically repeated. The air conditioner according to claim 1 or 2. The air conditioner according to claim 3, wherein a time for opening the heat storage two-way valve is set shorter than a time for closing the heat storage two-way valve. 5. The air conditioner according to claim 3, wherein an open / close cycle of the heat storage two-way valve is set shorter than an open / close cycle of the cooling operation in an open / close cycle of the heat storage two-way valve. The air conditioner according to any one of claims 3 to 5, wherein a maximum number of opening / closing operations of the heat storage two-way valve is provided, and the number of opening / closing operations does not exceed the maximum number.