JP2013104623A - Refrigeration cycle device and air conditioner with the same - Google Patents

Abstract

[PROBLEMS] To effectively use the amount of heat stored in a heat storage heat exchanger, and even when the heat source has a small amount of heat, the temperature of the indoor unit can be adjusted by changing the capacity of the indoor heat exchanger. To provide a refrigeration cycle apparatus capable of suppressing a decrease in room temperature during frost operation.
SOLUTION: A fifth pipe 25 for flowing a refrigerant directly from the outdoor heat exchanger 14 to the suction pipe of the compressor 6 between the outdoor heat exchanger 14 and the four-way valve 8 and the outdoor heat exchange. A three-way valve (switching device) 42 that enables switching from the condenser 14 to the sixth pipe 38 that flows the refrigerant to the suction pipe of the compressor 6 through the heat storage heat exchanger (auxiliary heat exchanger) 34 for refrigerant heating, During the defrosting operation, the three-way valve (switching device) 42 is controlled so that the refrigerant flowing through the indoor heat exchanger 16 and the outdoor heat exchanger 14 is stored in the heat storage heat exchanger (auxiliary heat exchanger) via the three-way valve 42. 34 and the flow rate to the four-way valve 8 can be adjusted.
[Selection] Figure 3

Description

  The present invention relates to a refrigeration cycle apparatus having a mechanism for switching a path for directly flowing a refrigerant dissolving frost attached to an outdoor heat exchanger to a compressor and a path for flowing the refrigerant through an auxiliary heat exchanger for heating the refrigerant, and It relates to air conditioners.

  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.

  Then, what has provided the heat storage tank used as a heat source in the compressor provided in the outdoor unit, and defrosted using the waste heat of the compressor stored in the heat storage tank during heating operation is proposed. (For example, refer to Patent Document 1).

  FIG. 4 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. Are connected to the indoor heat exchanger 108 provided by the refrigerant pipe, the first bypass circuit 110 for bypassing the capillary tube 106, and one end to the discharge side pipe of the compressor 100, and the other end is connected to the capillary tube 106. A second bypass circuit 112 connected to a pipe extending from the outdoor heat exchanger 104 to the outdoor heat exchanger 104 is provided. 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.

  Furthermore, a heat storage tank 124 is provided around the compressor 100, and the heat storage tank 124 is filled with a latent 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 controlled to open, 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 The defrosting ability is improved by keeping high.

JP-A-3-31666

  However, in the conventional configuration, when the heat source has a small amount of heat, it is necessary to guide most of the hot gas discharged from the compressor 100 to the outdoor heat exchanger, and accordingly, the pressure of the indoor heat exchanger decreases. Therefore, there is a problem that the capacity of the indoor unit is reduced and the comfort is impaired, and in response to the problem, a three-way valve is provided between the outdoor heat exchanger and the four-way valve, and the path through which the refrigerant flows can be switched. It is considered to improve the heat absorption capacity from the auxiliary heat exchanger, but if the heat source of the auxiliary heat exchanger has a small amount of heat, the heat absorption from the auxiliary heat exchanger cannot be sufficient, and the indoor heat exchange There was a problem that the capacity of the indoor unit was reduced and the comfort was impaired because the pressure of the vessel decreased.

  This invention solves the said conventional subject, and it aims at providing the air conditioner which provides the refrigeration cycle apparatus and improves the comfort at the time of heating operation.

  In order to achieve the above object, the present invention provides a compressor, an indoor heat exchanger connected to the compressor, an expansion valve connected to the indoor heat exchanger, and an outdoor connected to the expansion valve. A refrigeration cycle apparatus comprising a heat exchanger, wherein the outdoor heat exchanger and the compressor are connected via a four-way valve, further comprising an auxiliary heat exchanger for heating the refrigerant, and the outdoor heat exchange A path for flowing the refrigerant directly from the outdoor heat exchanger to the four-way valve, and a path for flowing the refrigerant from the outdoor heat exchanger to the suction pipe of the compressor through the auxiliary heat exchanger A switching device that enables switching, and during the defrosting operation for melting frost adhering to the outdoor heat exchanger, the switching device was controlled to flow through the indoor heat exchanger and the outdoor heat exchanger. The flow rate of the refrigerant to the auxiliary heat exchanger and the four-way valve In which the flow rate was to be adjusted to flow.

  According to the present invention, the refrigerant after passing through the indoor heat exchanger and the outdoor heat exchanger can be adjusted in flow rate through the auxiliary heat exchanger during the defrosting operation. It becomes possible to adjust, the temperature of the indoor unit is adjusted, the temperature reduction due to the defrosting operation during the heating operation is suppressed, and the comfort can be improved.

The block diagram of the air conditioner provided with the refrigeration cycle apparatus which concerns on Embodiment 1 of this invention. The schematic diagram which shows the flow of the refrigerant | coolant at the time of normal heating in the air conditioner provided with the same refrigeration cycle apparatus The schematic diagram which shows the flow of the refrigerant | coolant at the time of defrost and heating in the air conditioner provided with the same refrigeration cycle apparatus Configuration diagram of an air conditioner equipped with a conventional refrigeration cycle apparatus

  A first invention includes a compressor, an indoor heat exchanger connected to the compressor, an expansion valve connected to the indoor heat exchanger, and an outdoor heat exchanger connected to the expansion valve. The outdoor heat exchanger and the compressor are connected to each other through a four-way valve, further comprising an auxiliary heat exchanger for heating the refrigerant, and the outdoor heat exchanger and the four-way valve. In between, switching that enables switching between a path for flowing the refrigerant directly from the outdoor heat exchanger to the four-way valve and a path for flowing the refrigerant from the outdoor heat exchanger to the suction pipe of the compressor through the auxiliary heat exchanger A defrosting operation that melts frost adhering to the outdoor heat exchanger, the switching device is controlled so that the refrigerant flowing through the indoor heat exchanger and the outdoor heat exchanger is The flow rate to the exchanger and the flow rate to the four-way valve can be adjusted. Because it is configured, it is possible to adjust the pressure of the indoor heat exchanger, adjust the blowout temperature of the indoor unit, and suppress the decrease in room temperature due to the defrosting operation during heating operation, thereby improving comfort .

  In particular, in the refrigeration cycle apparatus according to the first aspect of the present invention, the refrigerant path switching device is a three-way valve in the refrigeration cycle apparatus according to the first aspect of the invention. .

  In particular, in the refrigeration cycle apparatus according to the first or second invention, the third invention keeps the pressure of the indoor heat exchanger higher by adjusting the opening of the expansion valve during the defrosting operation. Therefore, it is possible to further improve comfort by suppressing a decrease in room temperature due to the defrosting operation during the heating operation.

  In a fourth aspect of the invention, in particular, in the refrigeration cycle apparatus of any one of the first to third aspects, an auxiliary heat exchanger for heating the refrigerant is disposed so as to surround the compressor, and a heat source of the auxiliary heat exchanger Is a heat storage material that stores the heat generated in the compressor, so that defrosting of the outdoor heat exchanger can be completed in a short time with no auxiliary power such as a heater or the supply of minimum auxiliary power. .

  Hereinafter, embodiments of the refrigeration cycle apparatus of the present invention will be described with reference to the drawings as examples mounted on an air conditioner. Note that the present invention is not limited to the embodiments.

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

  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 first pipe 18 provided with a four-way valve 8, and the indoor heat exchanger 16 and the expansion valve 12 are provided with a strainer 10. The second pipe 20 is connected. The expansion valve 12 and the outdoor heat exchanger 14 are connected via a third pipe 22, and the outdoor heat exchanger 14 and the compressor 6 are connected via a fourth pipe 24 and a fifth pipe 25, and outdoor heat exchange is performed. A four-way valve 8 is arranged between the fourth pipe 24 and the fifth pipe 25 connecting the compressor 14 and the compressor 6. Further, a three-way valve (switching device) 42 is connected between the four-way valve 8 and the outdoor heat exchanger 14 via a fourth pipe 24. Further, the fifth pipe 25 on the compressor refrigerant suction side is provided with an accumulator 26 for separating the liquid phase refrigerant and the gas phase refrigerant.

  Further, a heat storage tank 32 is provided around the compressor 6, and a heat storage heat exchanger (auxiliary heat exchanger) 34 is provided inside the heat storage tank 32, and heat exchange with the heat storage heat exchanger 34 is performed. The heat storage material (for example, 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.

  The three-way valve 42 and the heat storage heat exchanger 34 are connected via a sixth pipe 38 including a capillary tube (throttle mechanism) 43, and the fifth pipe 25 connecting the four-way valve 8 and the compressor 6 is the seventh. The heat storage heat exchanger 34 is connected via the pipe 40.

In addition to the indoor heat exchanger 16, an air blower fan (not shown), upper and lower blades (not shown), and left and right blades (not shown) are provided inside the indoor unit 4, and indoor heat exchange is performed. The unit 16 exchanges heat between the indoor air sucked into the interior of the indoor unit 4 by the blower fan and the refrigerant flowing through the interior of the indoor heat exchanger 16, and blows out the air warmed by heat exchange into the room during heating. On the other hand, air cooled by heat exchange is blown into the room during cooling. 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 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 electromagnetic valve 30, the three-way valve 42, and the like are electrically connected to a control device (not shown, for example, a microcomputer) for control. It is controlled and operated by the device.

  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 in the 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 first pipe 18. The refrigerant condensed by exchanging heat with the indoor air in the indoor heat exchanger 16 passes through the second pipe 20 through the indoor heat exchanger 16, expands through the strainer 10 that prevents foreign matter from entering the expansion valve 12. To valve 12. The refrigerant depressurized by the expansion valve 12 reaches the outdoor heat exchanger 14 through the third pipe 22, and the refrigerant evaporated by exchanging heat with the outdoor air in the outdoor heat exchanger 14 is the fourth pipe 24 and the three-way valve 42. And the four-way valve 8, the fifth pipe 25, and the accumulator 26, and then returns to the compressor 6 through the suction port of the compressor 6.

  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.

  One side of the three-way valve 42 is connected to the fourth pipe 24 leading to the outdoor heat exchanger 14, the other side is connected to the fifth pipe 25 via the four-way valve 8, and the other side is connected to the three-way valve 42 and the heat storage heat. The controller 34 is connected to a sixth pipe 38 that connects to the exchanger 34, and the control device guides the refrigerant from the outdoor heat exchanger 14 to the four-way valve 8 through the fourth pipe 24, and the outdoor heat exchanger 14 It is possible to switch the route through which the refrigerant is guided to the suction port of the compressor 6 through the heat storage heat exchanger 34 through the six pipes 38.

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

  During the normal heating operation, the refrigerant discharged from the discharge port of the compressor 6 passes through the first pipe 18 and reaches the indoor heat exchanger 16 from the four-way valve 8. The refrigerant condensed by exchanging heat with the indoor air in the indoor heat exchanger 16 exits the indoor heat exchanger 16, passes through the second pipe 20, reaches the expansion valve 12, and the refrigerant decompressed by the expansion valve 12 is the third refrigerant. It reaches the outdoor heat exchanger 14 through the pipe 22. During the normal heating operation, the three-way valve 42 is controlled to be a path for leading the refrigerant from the outdoor heat exchanger 14 to the four-way valve 8, and the refrigerant evaporated by exchanging heat with outdoor air in the outdoor heat exchanger 14 is Then, the fourth pipe 24 is passed to the four-way valve 8. Thereafter, the refrigerant that has passed through the four-way valve 8 passes through the fifth pipe 25 and returns to the suction port of the compressor 6.

  The heat generated in the compressor 6 is stored 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 at the time of defrosting / heating will be described with reference to FIG. 3 schematically showing the operation of the air conditioner at the time of defrosting / heating and the flow of the refrigerant.

  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. 3, the air conditioner according to the present invention is provided with a temperature sensor 44 that detects the piping temperature of the outdoor heat exchanger 14, and the evaporation temperature is lower than that during non-frosting. When this is detected by the temperature sensor 44, an instruction to switch from the normal heating operation to the defrosting / heating operation is output from the control device. The timing for entering the defrosting / heating operation described above is only an example, and the timing for entering the defrosting / heating operation may be any condition.

  When the normal heating operation is shifted to the defrosting / heating operation, the refrigerant in the normal heating operation described above exits the indoor heat exchanger 16, passes through the second pipe 20, reaches the expansion valve 12, and the expansion valve 12 is appropriate. The two-phase refrigerant depressurized by the throttle amount heats the outdoor heat exchanger 14 through the third pipe 22, condenses into a liquid phase, and then reaches the three-way valve 42.

  During the defrosting / heating operation, the three-way valve 42 adjusts and controls the opening degree to the path for guiding the refrigerant from the outdoor heat exchanger 14 to the heat storage heat exchanger 34, that is, the path where the fourth pipe 24 and the sixth pipe 38 communicate. Then, a part of the refrigerant that has passed through the three-way valve 42 is depressurized by the capillary tube 43 to become a low temperature, absorbs heat of the heat storage material 36 by the heat storage heat exchanger 34 and flows to the seventh pipe 40, while the remaining refrigerant is The four-way valve 8 and the fifth pipe 25 flow. After that, they merge at the inlet of the accumulator 26 and return to the suction port of the compressor 6. At this time, the liquid refrigerant that has flowed through the four-way valve 8 and the fifth pipe 25 is appropriately adjusted in flow rate by the three-way valve 42 and merges with the gasified refrigerant that absorbs the heat of the heat storage material 36 so that it can be evaporated. To do. As a result, the liquid refrigerant does not return to the compressor 6 and the reliability of the compressor 6 can be improved.

  By doing in this way, it becomes possible to adjust the pressure of the refrigerant of the indoor heat exchanger 16, the outdoor heat exchanger 14, and the heat storage heat exchanger 34, and the blowout temperature of the indoor unit 4 can be adjusted. A decrease in room temperature during heating / defrosting operation can be suppressed. In addition, a sufficient temperature difference between the refrigerant passing through the heat storage heat exchanger 34 and the heat storage material 36 can be secured, and the heat absorption capacity from the heat storage material 36 can be improved.

  Further, when the refrigerant passing through the heat storage heat exchanger 118 is a bypass path as in FIG. 4 of the prior art, the circulation amount of the refrigerant passing through the heat storage heat exchanger 118 is reduced, and the temperature of the heat storage material 126 is high. In the latter half of the heat storage heat exchanger 118, the degree of superheat increases and the amount of heat exchange decreases, so that the defrosting ability may not be fully exhibited. In this configuration, the flow rate of the refrigerant flowing to the heat storage heat exchanger 34 is reduced. Since it is set as the structure which can be adjusted, the heat exchange amount fall by taking too much superheat can be prevented, and a defrosting capability can fully be exhibited.

  The temperature of the outdoor heat exchanger 14 that has become below freezing due to the attachment of frost at the start of defrosting / heating is heated by a refrigerant mixed with a liquid phase or a gas-liquid two-phase refrigerant returned from the indoor heat exchanger 16, and is near zero degrees. When the frost is melted and the frost is completely melted, the temperature of the outdoor heat exchanger 14 starts to rise again. When the temperature sensor 44 detects the temperature rise of the outdoor heat exchanger 14, it is determined that the defrosting is completed, and an instruction to switch from the defrosting / heating operation to the normal heating operation is output from the control device.

  In this configuration, the capillary tube 43 is provided in the sixth pipe 38 extending from the three-way valve 42 to the heat storage heat exchanger 34. Instead of this configuration, the three-way valve 42 communicating with the heat storage heat exchanger 34 is used. In this case, the capillary tube 43 can be removed, and a low-cost and compact configuration is possible.

The refrigeration cycle apparatus according to the present invention not only improves the comfort by adjusting the pressure of the indoor heat exchanger, but also reduces the return of liquid refrigerant to the compressor as much as possible, and improves the reliability of the compressor. Therefore, it can also be applied to air conditioners, refrigerators, heat pump water heaters, and the like.

DESCRIPTION OF SYMBOLS 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 18 1st piping 20 2nd piping 22 3rd piping 24 4th piping 25 5th piping 26 Accumulator 32 Thermal storage tank 34 Thermal storage heat exchanger (auxiliary heat exchanger)
36 Heat storage material 38 Sixth piping 40 Seventh piping 42 Three-way valve (switching device)
43 Capillary tube (throttle mechanism)
44 Temperature sensor

Claims (4)

A compressor, an indoor heat exchanger connected to the compressor, an expansion valve connected to the indoor heat exchanger, and an outdoor heat exchanger connected to the expansion valve, the outdoor heat exchanger And a compressor connected via a four-way valve, further comprising an auxiliary heat exchanger for heating the refrigerant, between the outdoor heat exchanger and the four-way valve, the outdoor heat A switching device that enables switching between a path for flowing the refrigerant directly from the exchanger to the four-way valve and a path for flowing the refrigerant from the outdoor heat exchanger to the suction pipe of the compressor through the auxiliary heat exchanger, At the time of defrosting operation for melting frost adhering to the outdoor heat exchanger, the switching device is controlled to flow the refrigerant that has flowed through the indoor heat exchanger and the outdoor heat exchanger to the auxiliary heat exchanger. The flow rate to the four-way valve can be adjusted. Refrigeration cycle apparatus according to claim. 2. The refrigeration cycle apparatus according to claim 1, wherein a three-way valve is used for the switching device. The refrigeration cycle apparatus according to claim 1 or 2, wherein the opening degree of the expansion valve is adjusted during a defrosting operation for melting frost adhering to the outdoor heat exchanger. The auxiliary heat exchanger is disposed so as to surround the compressor, and a heat source of the auxiliary heat exchanger is a heat storage material that stores heat generated by the compressor. The refrigeration cycle apparatus according to claim 1.