JP2018151082A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem in which heat stored in a heat storage tank escapes to the surrounding outside air during a heating operation, and to improve heating performance during a heating operation.SOLUTION: In an air conditioner, a compressor, a four-way valve, an indoor heat exchanger, an expansion valve and an outdoor heat exchanger are connected sequentially. A heat storage tank for storing heat generated in the compressor and an auxiliary heat exchanger for recovering the heat in the heat storage tank are arranged so as to surround the compressor. Between the outdoor heat exchanger and the four-way valve, a flow passage switching mechanism is provided capable of switching between a path for flowing a refrigerant to the four-way valve from the outdoor heat exchanger and a path for flowing the refrigerant to a suction pipe of the compressor through the auxiliary heat exchanger from the outdoor heat exchanger. During a defrosting operation, the refrigerant which has flowed in the indoor heat exchanger and the outdoor heat exchanger is flowed to the auxiliary heat exchanger. During a heating operation, the refrigerant which has flowed in the indoor heat exchanger and the outdoor heat exchanger is flowed to both the four-way valve and the auxiliary heat exchanger.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an air conditioner using heat stored in a heat storage material during a defrosting operation for melting frost attached to an outdoor heat exchanger.

  Conventionally, as an air conditioner equipped with this type of heat storage material, a heat storage tank containing the heat storage material is arranged around the compressor, and heat generated from the compressor during the heating operation is stored in the heat storage tank, and defrosting is performed. The thing using the heat at the time of operation is proposed (for example, refer to patent documents 1).

  FIG. 5 is a schematic diagram showing a refrigerant flow during heating operation of a conventional air conditioner. A heat storage tank 32 is provided around the compressor 6, and a heat storage material is provided inside the heat storage tank 32. 36 and an auxiliary heat exchanger 34 are provided. In such a configuration, during the heating operation, by operating the flow path switching mechanism 42, the refrigerant flows only from the outdoor heat exchanger 14 to the four-way valve 8, and the heat generated from the compressor 6 is stored in the heat storage tank 32. To store. On the other hand, during the defrosting operation, by operating the flow path switching mechanism 42, the refrigerant flows from the outdoor heat exchanger 14 to the auxiliary heat exchanger 34, and the heat stored in the heat storage tank 32 is recovered in the refrigeration cycle. And used for defrosting.

  In this way, the heat generated from the compressor during the heating operation is stored in the heat storage tank, and the heat is used during the defrosting operation, thereby improving the comfort during the defrosting operation without auxiliary power such as a heater. ing.

JP 2013-104623 A

  However, in the conventional example, heat is stored in the heat storage tank even during the heating operation that does not require defrosting, so the heat stored in the heat storage tank escapes to the surrounding outside air during the heating operation and the heating performance is improved during the heating operation. There was room for.

  The present invention solves the above-described conventional problems, and an object thereof is to improve the heating performance by utilizing heat generated from the compressor during the heating operation for the heating operation.

  In order to achieve the above object, the present invention comprises a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger that are connected in sequence, and stores heat generated by the compressor. A tank and an auxiliary heat exchanger that recovers the heat of the heat storage tank are arranged so as to surround the compressor, and between the outdoor heat exchanger and the four-way valve, from the outdoor heat exchanger to the four-way valve A flow path switching mechanism that enables switching between a path for flowing the refrigerant and a path for flowing the refrigerant from the outdoor heat exchanger to the suction pipe of the compressor through the auxiliary heat exchanger is provided, and is attached to the outdoor heat exchanger. In the air conditioner configured to flow the refrigerant that has flown through the indoor heat exchanger and the outdoor heat exchanger to the auxiliary heat exchanger during the defrosting operation for melting frost, the indoor heat exchanger during the heating operation The refrigerant flowing through the outdoor heat exchanger is It is intended to flow to both of the auxiliary heat exchanger.

According to the present invention, since the refrigerant flows through the auxiliary heat exchanger even during the heating operation, the temperature of the heat storage tank is lowered, and the amount of heat that escapes from the heat storage tank to the surrounding outside air can be suppressed. At the same time, since the heat generated in the compressor can be recovered in the refrigeration cycle by the auxiliary heat exchanger, the heating performance during the heating operation can be improved.

The schematic diagram which shows the flow of the refrigerant | coolant at the time of the heating operation of the air conditioner which concerns on Embodiment 1 of this invention. Schematic diagram showing the flow of refrigerant during the defrosting operation of the air conditioner Operation flow chart of flow path switching mechanism of air conditioner External view and operation schematic diagram of the flow path switching mechanism of the air conditioner Schematic diagram showing the flow of refrigerant during heating operation of a conventional air conditioner

  The first invention comprises a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger connected in sequence, a heat storage tank for storing heat generated by the compressor, and the heat storage tank An auxiliary heat exchanger that collects the heat of the refrigerant is disposed so as to surround the compressor, and a path for flowing a refrigerant from the outdoor heat exchanger to the four-way valve between the outdoor heat exchanger and the four-way valve, and the A defrosting unit that provides a flow path switching mechanism that enables switching between a path through which refrigerant flows from the outdoor heat exchanger to the suction pipe of the compressor through the auxiliary heat exchanger, and dissolves frost adhering to the outdoor heat exchanger. In an air conditioner in which the refrigerant that has flowed through the indoor heat exchanger and the outdoor heat exchanger flows into the auxiliary heat exchanger during operation, the indoor heat exchanger and the outdoor heat exchanger are disposed during heating operation. Flowed refrigerant to both the four-way valve and the auxiliary heat exchanger And wherein the Succoth. Thereby, the temperature of the heat storage tank during the heating operation is lowered, and the amount of heat that escapes from the heat storage tank to the surrounding outside air can be suppressed. At the same time, since the heat generated in the compressor can be recovered in the refrigeration cycle by the auxiliary heat exchanger, the heating performance during the heating operation can be improved.

  The second invention is an air conditioner that switches the flow path by the flow path switching mechanism according to the temperature of the outdoor heat exchanger during heating operation, particularly in the air conditioner of the first invention. If the temperature of the outdoor heat exchanger is equal to or lower than a predetermined value, the refrigerant flowing through the indoor heat exchanger and the outdoor heat exchanger is caused to flow to the four-way valve, and the temperature of the outdoor heat exchanger is a predetermined value. If it is above, the refrigerant | coolant which flowed through the said indoor heat exchanger and the said outdoor heat exchanger will be flowed to both the said four-way valve and the said auxiliary heat exchanger. Thereby, since the heat of a heat storage tank is utilized for heating operation only on the conditions which do not form frost on an outdoor heat exchanger, heat can be reliably stored in a heat storage tank on the conditions which require defrost.

  According to a third aspect of the invention, in particular, in the air conditioner of the first or second aspect of the invention, the temperature of the outdoor heat exchanger is less than a predetermined value and the temperature between the outside air temperature and the temperature of the outdoor heat exchanger during heating operation. If the difference is less than a predetermined value, the refrigerant that has flowed through the indoor heat exchanger and the outdoor heat exchanger is caused to flow to both the four-way valve and the auxiliary heat exchanger. Thereby, even under conditions where frost formation may actually occur, the heat of the heat storage tank can be used for heating operation only when the amount of frost formation in the outdoor heat exchanger is small or when there is almost no frost formation. Therefore, the range in which the heat of the heat storage tank can be used for heating operation can be further expanded, and heat can be reliably stored in the heat storage tank when the frost is gradually increased and defrosting is necessary thereafter. .

In a fourth aspect of the invention, in particular, in the air conditioner of any one of the first to third aspects of the invention, if the temperature of the heat storage tank is less than the outside air temperature during heating operation, the indoor heat exchanger and the outdoor heat exchange It is characterized in that the refrigerant that has flowed through the vessel does not flow to the auxiliary heat exchanger. This is because if the temperature of the heat storage tank is lower than the ambient outside air temperature, heat does not escape from the heat storage tank to the surrounding outside air, and thus heat recovery from the heat storage tank becomes unnecessary. In addition, if the temperature of the heat storage tank falls below the outside air temperature, condensation or frost formation may occur in the heat storage tank, which may cause problems with the safety and reliability around the heat storage tank. And reliability can be ensured.

  Hereinafter, embodiments of an air conditioner 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 the flow of refrigerant during heating operation of an air conditioner according to Embodiment 1 of the present invention, and the air conditioner is composed of an outdoor unit 2 and an indoor unit 4 connected to each other through a refrigerant pipe. Has been.

  As shown in FIG. 1, a compressor 6, a four-way valve 8, an expansion valve 12, and an outdoor heat exchanger 14 are provided inside the outdoor unit 2, and an indoor heat exchanger is provided inside the indoor unit 4. 16 are provided, and these are connected to each other through 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 connected via a second pipe 20. 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 four-way valve 8 are connected via a fourth pipe 24 and an eighth pipe 41, and the four-way valve 8. And the compressor 6 are connected by a fifth pipe 25. A flow path switching mechanism 42 is connected between the outdoor heat exchanger 14 and the four-way valve 8 via a fourth pipe 24 and an eighth pipe 41. 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 an auxiliary heat exchanger 34 is provided inside the heat storage tank 32, and a heat storage material (for example, for exchanging heat with the auxiliary heat exchanger 34) An ethylene glycol aqueous solution) 36 is filled.

  The flow path switching mechanism 42 and the auxiliary 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 auxiliary heat exchanger 34 is connected via the seventh pipe 40.

  In addition to the indoor heat exchanger 16, a blower fan (not shown) is provided inside the indoor unit 4. The indoor heat exchanger 16 is a room that is sucked into the indoor unit 4 by the blower fan. Heat exchange is performed between the air and the refrigerant flowing inside the indoor heat exchanger 16, and air heated by heat exchange is blown out into the room during heating.

  The outdoor unit 2 includes an outdoor temperature sensor 50 (not shown) that measures the outdoor temperature, an outdoor heat exchanger temperature sensor 51 (not shown) that measures the temperature of the outdoor heat exchanger 14, and a heat storage tank 32. A heat storage tank temperature sensor 52 (not shown) for measuring the temperature is provided.

  The compressor 6, the blower fan, the four-way valve 8, the expansion valve 12, the flow path switching mechanism 42, the outside air temperature sensor 50, the outdoor heat exchanger temperature sensor 51, the heat storage tank temperature sensor 52, etc. are controlled by a control device (not shown). For example, it is electrically connected to a microcomputer and input / output is controlled by a control device.

  Next, the operation during the defrosting operation will be described. When the outdoor heat exchanger 14 is frosted during the heating operation and the frosted frost grows, the ventilation resistance of the outdoor heat exchanger 14 increases, the air volume decreases, and the temperature of the outdoor heat exchanger 14 decreases. The air conditioner according to the present invention outputs an instruction to switch from the heating operation to the defrosting operation from the control device when detecting that the temperature of the outdoor heat exchanger 14 is lower than that at the time of non-frosting. The timing for entering the defrosting operation described above is only an example, and the timing for entering the defrosting operation may be any condition.

  FIG. 2 is a schematic diagram showing a refrigerant flow during the defrosting operation of the air conditioner according to Embodiment 1 of the present invention. When the heating operation is shifted to the defrosting operation, the refrigerant during the heating operation described above is The two-phase refrigerant that leaves the indoor heat exchanger 16, reaches the expansion valve 12 through the second pipe 20, and is decompressed with an appropriate throttle amount by the expansion valve 12 passes through the third pipe 22 to the outdoor heat exchanger. 14 is heated and condensed to form a liquid phase, and then the flow path switching mechanism 42 is reached. The flow path switching mechanism 42 causes the refrigerant from the outdoor heat exchanger 14 to flow through the sixth pipe 38, is decompressed by the capillary tube (throttle mechanism) 43 and becomes low temperature, and the auxiliary heat exchanger 34 absorbs the heat of the heat storage material 36. Return to the suction port of the compressor 6.

  By doing in this way, the heat generated from the compressor during the heating operation is stored in the heat storage tank, and by using the heat of the heat storage tank during the defrosting operation, it is possible to perform the defrosting operation without auxiliary power such as a heater. Improves comfort.

  Next, in the air conditioner according to the present invention configured as described above, details of the flow path switching method during heating operation will be described. FIG. 3 is an operation flowchart of the flow path switching mechanism of the air conditioner according to Embodiment 1 of the present invention. When the heating operation is started, it is determined whether or not the defrosting operation is being performed in Step S2, and the defrosting is performed. If not in operation, the heat storage and recovery conditions are determined in step S3.

  Here, the heat storage and recovery condition is when the following condition a or condition b is satisfied.

  Condition a: outdoor heat exchanger temperature ≧ predetermined value A and heat storage tank temperature ≧ outside air temperature.

  Condition b: outdoor heat exchanger temperature <predetermined value A and heat storage tank temperature ≧ outside air temperature and outside air temperature−outdoor heat exchanger temperature <predetermined value B.

  In the condition a, the predetermined value A is a temperature at which the outdoor heat exchanger 14 is never frosted (for example, 0 ° C.). Accordingly, the heat recovery from the heat storage tank 32 is determined.

  On the other hand, under the condition b, the temperature of the outdoor heat exchanger 14 is a temperature at which frost may be formed, but the temperature difference between the outdoor temperature and the outdoor heat exchanger 14 is less than a predetermined value B (for example, 3 ° C.). Thus, when the amount of frost is small or almost no frost, defrosting is unnecessary and heat recovery can be performed. However, if frost formation proceeds thereafter and the temperature of the outdoor heat exchanger 14 further decreases from the outside air temperature, it is determined that defrosting will be necessary in the future, and heat recovery from the heat storage tank 32 is stopped, and the heat storage tank 32 stores heat.

  Here, as a condition that the outdoor heat exchanger 14 never gets frosted, the temperature of the outdoor heat exchanger 14 is set to a predetermined value A or higher, but the same is true even if the outdoor air temperature is set to a predetermined value 3 (for example, 6 ° C.) or higher. An effect is obtained.

  Further, the case where the amount of frost is small or almost no frost is determined based on the temperature difference between the outside air temperature and the outdoor heat exchanger 14, but other methods may be used.

  Based on the above determination, if the heat storage recovery condition is not satisfied in step S3, the flow path switching mechanism 42 is set to the A position in step S4. The path switching mechanism 42 is set to the B position.

  If the defrosting operation is being performed in step S2, the flow path switching mechanism 42 is set to the C position in step S6.

Next, operation details of the flow path switching mechanism 42 will be described. FIG. 4 shows the first embodiment of the present invention.
It is the figure which showed typically the external appearance and operation | movement of the flow-path switching mechanism of the air conditioner which concerns, The flow-path switching mechanism 42 is a coil part for electrically driving a valve in the upper part, and the middle part switches a flow path For this purpose, the valve portion and the lower part are composed of a fourth pipe 24, an eighth pipe 41 and a sixth pipe 38. The figure in the table is a view of the flow path switching mechanism as viewed from above, and shows the slide valve 44 and a hole through which the valve opens and closes in perspective.

  The position A in the figure is a case where heat is stored in the heat storage tank 32 in preparation for defrosting, and the outdoor valve 14 is completely closed by the slide valve 44 of the valve portion connected to the heat storage tank 32. Refrigerant flows from the four-way valve 8 only. On the other hand, the B position is a case where heat is recovered from the heat storage tank 32, and the slide valve 44 is between the eighth pipe 41 connected to the four-way valve 8 and the sixth pipe 38 connected to the heat storage tank 32, and the fourth pipe 24 and The eighth pipe 41 and the sixth pipe 38 are all in communication with each other, and the refrigerant from the outdoor heat exchanger 14 flows into both the heat storage tank 32 and the four-way valve 8. The C position is a case where defrosting is performed, and the refrigerant from the outdoor heat exchanger 14 flows only into the heat storage tank 32 by completely closing the eighth pipe 41 connected to the four-way valve 8 by the slide valve 44.

  As mentioned above, in this Embodiment, since a refrigerant | coolant is flowed to an auxiliary heat exchanger during heating operation, the temperature of a thermal storage tank falls, and it can suppress the calorie | heat amount which escapes from the thermal storage tank to the surrounding external air. At the same time, since the heat generated in the compressor can be recovered in the refrigeration cycle by the auxiliary heat exchanger, the heating performance during the heating operation can be improved.

  In addition, by limiting the condition that the refrigerant flows to the auxiliary heat exchanger when defrosting is not required, the heat of the heat storage tank can be used for heating operation in a wider range, and when the defrost is necessary, the heat storage tank is reliably heated. Can be stored.

  In addition, if the temperature of the heat storage tank falls below the ambient outside air temperature, it is possible to eliminate unnecessary heat recovery of the heat storage tank by preventing the refrigerant from flowing into the auxiliary heat exchanger, and to improve the safety and reliability around the heat storage tank. Can be secured.

  As described above, the air conditioner according to the present invention relates to the effective use of waste heat from the compressor, so that it is not only a home air conditioner, but also a refrigerator, a heat pump water heater, a vehicle air conditioner, etc. It can also be applied to.

DESCRIPTION OF SYMBOLS 2 Outdoor unit 4 Indoor unit 6 Compressor 8 Four-way valve 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 Auxiliary heat exchanger 36 Heat storage material 38 6th piping 40 7th piping 41 8th piping 42 Channel switching mechanism 43 Capillary tube (throttle mechanism)
44 Slide valve

Claims (4)

A compressor, a four-way valve, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger are sequentially connected, and a heat storage tank for storing heat generated by the compressor, and an auxiliary for recovering the heat of the heat storage tank A heat exchanger is disposed so as to surround the compressor, and between the outdoor heat exchanger and the four-way valve, a path for flowing a refrigerant from the outdoor heat exchanger to the four-way valve and the outdoor heat exchanger A flow path switching mechanism is provided that enables switching to a path through which the refrigerant flows to the suction pipe of the compressor through an auxiliary heat exchanger, and during the defrosting operation to dissolve frost adhering to the outdoor heat exchanger, the indoor heat In the air conditioner configured to flow the refrigerant flowing through the exchanger and the outdoor heat exchanger to the auxiliary heat exchanger, the refrigerant flowing through the indoor heat exchanger and the outdoor heat exchanger during heating operation is It flows to both the four-way valve and the auxiliary heat exchanger Air conditioner to be. During the heating operation, the air conditioner switches the flow path by the flow path switching mechanism according to the temperature of the outdoor heat exchanger, and if the temperature of the outdoor heat exchanger is equal to or lower than a predetermined value, The refrigerant that has flowed through the indoor heat exchanger and the outdoor heat exchanger is caused to flow to the four-way valve, and if the temperature of the outdoor heat exchanger is equal to or higher than a predetermined value, the refrigerant flows through the indoor heat exchanger and the outdoor heat exchanger. The air conditioner according to claim 1, wherein the refrigerant flows through both the four-way valve and the auxiliary heat exchanger. If the temperature of the outdoor heat exchanger is less than a predetermined value and the temperature difference between the outdoor temperature and the temperature of the outdoor heat exchanger is less than a predetermined value during heating operation, the indoor heat exchanger and the outdoor heat exchanger are The air conditioner according to claim 1 or 2, wherein the flowing refrigerant is allowed to flow to both the four-way valve and the auxiliary heat exchanger. 2. The refrigerant flowing through the indoor heat exchanger and the outdoor heat exchanger is not allowed to flow to the auxiliary heat exchanger if the temperature of the heat storage tank is lower than the outside air temperature during heating operation. To 3. The air conditioner according to 3.

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