JP2012077921A - Refrigeration apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a capacity of a heat source side heat exchanger during heating in a refrigeration apparatus of which the heat source side heat exchanger includes a main heat exchanging part and an auxiliary heat exchanging part and which can switch from a cooling operation to a heating operation and vice versa.SOLUTION: In an air conditioner (10), a refrigeration apparatus has an outdoor heat exchanger (40) including the main heat exchanging part (50) and the auxiliary heat exchanging part (55). A four-way valve (60) is installed in a refrigerant circuit (20). In cooling operation, the four-way valve (60) is set at a first state for the outdoor heat exchanger (40) to be in a series connection state and a refrigerant condenses while passing through the main heat exchanging part (50) and then supercools while passing through the auxiliary heat exchanging part (55). In heating operation, the four-way valve (60) is set at a second state for the outdoor heat exchanger (40) to be in a parallel connection state, and part of the refrigerant flows through the main heat exchanging part (50) and the remainder flows through the auxiliary heat exchanging part (55). The refrigerant evaporates while passing through the main heat exchanging part (50) or the auxiliary heat exchanging part (55).

Description

  The present invention relates to a refrigeration apparatus capable of switching between a cooling operation and a heating operation.

  Conventionally, a refrigeration apparatus capable of performing a refrigeration cycle by circulating a refrigerant in a refrigerant circuit and cooling an object (for example, air or water) with the refrigerant and an operation for heating the object with the refrigerant. Are known. For example, Patent Document 1 discloses an air conditioner configured by this type of refrigeration apparatus. In an air conditioner during cooling operation that cools indoor air, the outdoor heat exchanger functions as a condenser, and the indoor heat exchanger functions as an evaporator. On the other hand, in an air conditioner during heating operation that heats indoor air, the indoor heat exchanger functions as a condenser and the outdoor heat exchanger functions as an evaporator.

  Patent Document 2 also discloses an air conditioner that performs a refrigeration cycle. The refrigerant circuit of this air conditioner is provided with an outdoor heat exchanger that exchanges heat between the refrigerant and outdoor air. This outdoor heat exchanger is constituted by a heat exchanger having two headers each formed in a cylindrical shape and a number of flat heat transfer tubes provided between the two headers.

  A heat exchanger having a header and a flat heat transfer tube is also disclosed in Patent Document 3. The heat exchanger of patent document 3 functions as a condenser. In this heat exchanger, a main heat exchanging section for condensation and an auxiliary heat exchanging section for supercooling are formed. The refrigerant that has flowed into the heat exchanger is condensed while passing through the main heat exchanging section to be substantially in a liquid single-phase state, and thereafter flows into the auxiliary heat exchanging section to be further cooled.

JP 2008-064447 A Japanese Patent Laid-Open No. 09-014698 JP 2010-025447 A

  Incidentally, in the refrigeration apparatus disclosed in Patent Document 1 (that is, a refrigeration apparatus capable of switching between a cooling operation and a heating operation), the heat exchanger disclosed in Patent Document 3 (that is, a header and a flat heat transfer tube) It is conceivable to use a heat exchanger having a main heat exchanger for condensation and an auxiliary heat exchanger for subcooling as a heat source side heat exchanger for exchanging heat between the refrigerant and outdoor air. . However, simply applying the heat exchanger of Patent Document 3 as the heat source side heat exchanger of the refrigeration apparatus of Patent Document 1 causes the following problems.

  Normally, in the heat source side heat exchanger of the refrigeration apparatus, the flow direction of the refrigerant during the cooling operation and the flow direction of the refrigerant during the heating operation are opposite to each other. That is, in the heat source side heat exchanger functioning as a condenser during the cooling operation, the refrigerant flowing from one end on the gas side is condensed and flows out from the other end on the liquid side. On the other hand, in the heat source side heat exchanger functioning as an evaporator during the heating operation, the refrigerant flowing from the other end on the liquid side evaporates and flows out from one end on the gas side.

  Therefore, when only the heat exchanger of Patent Document 3 is applied as the heat source side heat exchanger of the refrigeration apparatus of Patent Document 1, the refrigerant flowing into the heat source side heat exchanger functioning as an evaporator is transferred to the auxiliary heat exchange unit. And evaporate while passing through the main heat exchanger. That is, in the heat source side heat exchanger functioning as an evaporator, the refrigerant evaporates even in the process of passing through the auxiliary heat exchange unit.

  If the ratio of the gas refrigerant in a refrigerant | coolant increases, the flow rate of the refrigerant | coolant in a heat exchanger tube will rise, and the pressure loss of the refrigerant | coolant during passing a heat exchanger tube will increase. For this reason, when only the heat exchanger of patent document 3 is applied as the heat source side heat exchanger of the refrigerating apparatus of patent document 1, the refrigerant when passing through the heat source side heat exchanger functioning as an evaporator is used. The pressure loss, particularly the refrigerant pressure loss when passing through the auxiliary heat exchanging portion is increased.

  In the state where the heat source side heat exchanger functions as an evaporator, if the pressure loss of the refrigerant when passing through the auxiliary heat exchange section increases, the refrigerant pressure at the inlet of the auxiliary heat exchanger and the inlet of the main heat exchange section The difference increases, and as a result, the refrigerant temperature difference between the inlet of the auxiliary heat exchanger and the inlet of the main heat exchanger also increases. For this reason, there is a problem that the temperature difference between the refrigerant and the outdoor air in the auxiliary heat exchange unit is reduced, and the heat absorption amount of the refrigerant in the auxiliary heat exchange unit cannot be sufficiently secured.

  The present invention has been made in view of such points, and the object thereof is to use a heat exchanger having a main heat exchange part and an auxiliary heat exchange part as a heat source side heat exchanger, and to switch between a cooling operation and a heating operation. In a possible refrigeration apparatus, the capacity of the heat source side heat exchanger is improved during the heating operation.

  The first invention is provided with a compressor (31), a heat source side heat exchanger (40) for exchanging heat between the refrigerant and outdoor air, and a use side heat exchanger (32) for exchanging heat between the refrigerant and an object. And a refrigerant circuit (20) for performing a refrigeration cycle, the refrigerant condenses in the heat source side heat exchanger (40), and the refrigerant evaporates in the use side heat exchanger (32) to cool the object. A refrigeration apparatus capable of switching between a cooling operation and a heating operation in which the refrigerant condenses in the use side heat exchanger (32) and the refrigerant evaporates in the heat source side heat exchanger (40) to heat the object. set to target. And the said heat source side heat exchanger (40) is provided with the main heat exchange part (50) and the auxiliary heat exchange part (55), and the said main heat exchange part (50) and the said auxiliary heat exchange part (55) Each has a first header (51, 56), a second header (52, 57), one end connected to the first header (51, 56), and the other end to the second header (52, 57). A plurality of flat heat transfer tubes (53,58) connected to the heat transfer tubes, and fins (54,59) joined to the heat transfer tubes (53,58), provided in the auxiliary heat exchange section (55). The number of heat transfer tubes (58) is smaller than the number of heat transfer tubes (53) provided in the main heat exchange section (50), and the heat source side heat exchanger (40) is replaced by the refrigerant in the main heat exchange. Part of the refrigerant passes through the main heat exchanging part (50) and the rest passes through the auxiliary heat exchanging part (55). To switch to a parallel state that passes In the cooling operation, the switching mechanism (35) places the heat source side heat exchanger (40) in series, and in the heating operation, the switching mechanism (35) is in the heat source side heat exchanger ( 40) is in parallel.

  In the first invention, the cooling operation and the heating operation can be switched in the refrigeration apparatus (10). During the cooling operation, the refrigerant evaporates in the heat source side heat exchanger (40), and the object (for example, air or water) is cooled in the use side heat exchanger (32). During the heating operation, the refrigerant evaporates in the heat source side heat exchanger (40), and the object is heated in the use side heat exchanger (32). In this invention, the heat source side heat exchanger (40) is provided with a main heat exchange part (50) and an auxiliary heat exchange part (55), and the heat transfer tube (58) of the auxiliary heat exchange part (55) is the main heat exchange. The number is smaller than that of the heat transfer tube (53) of the section (50). In each of the main heat exchange part (50) and the auxiliary heat exchange part (55), the refrigerant passes through one of the first header (51, 56) and the second header (52, 57) in the heat transfer pipe (53, 58). Flows from one side to the other, during which heat is exchanged with outdoor air.

  In the first invention, the refrigeration apparatus (10) is provided with the switching mechanism (35). During the cooling operation, the switching mechanism (35) places the heat source side heat exchanger (40) in series. In the heat source side heat exchanger (40) during the cooling operation, the refrigerant passes through the auxiliary heat exchange section (55) after passing through the main heat exchange section (50), and radiates heat to the outdoor air in the process. On the other hand, during the heating operation, the switching mechanism (35) places the heat source side heat exchanger (40) in parallel. In the heat source side heat exchanger (40) during the heating operation, a part of the refrigerant passes through the main heat exchange part (50) and the rest passes through the auxiliary heat exchange part (55), and the main heat exchange part ( 50) or absorbs heat from outdoor air in the process of passing through the auxiliary heat exchanger (55).

  In a second aspect based on the first aspect, the auxiliary heat exchanging portion (55) is disposed below the main heat exchanging portion (50) or near the lower end of the heat source side heat exchanger (40). Is.

  In the second invention, the auxiliary heat exchange section (55) is disposed at a predetermined position in the heat source side heat exchanger (40). In the heat source side heat exchanger (40) during the cooling operation, the refrigerant condensed in the main heat exchange unit (50) is sent to the auxiliary heat exchange unit (55) by both pressure difference and gravity.

  According to a third aspect, in the second aspect, the refrigerant discharged from the compressor (31) is used as the heat source in order to melt frost attached to the heat source side heat exchanger (40) during the heating operation. The defrosting operation supplied to the side heat exchanger (40) can be executed, and in the defrosting operation, the switching mechanism (35) puts the heat source side heat exchanger (40) in parallel.

  In the refrigeration apparatus (10) of the third invention, a cooling operation, a heating operation, and a defrosting operation can be performed. During the defrosting operation, the switching mechanism (35) places the heat source side heat exchanger (40) in parallel, and the refrigerant discharged from the compressor (31) is supplied to the heat source side heat exchanger (40). . A part of the refrigerant flowing into the heat source side heat exchanger (40) passes through the main heat exchange part (50), and the rest passes through the auxiliary heat exchange part (55). During the defrosting operation, the refrigerant flowing in the heat transfer tubes (53, 58) dissipates heat and condenses, and the frost attached to the heat source side heat exchanger (40) is heated and melted by the refrigerant. Thus, during the defrosting operation, the switching mechanism (35) places the heat source side heat exchanger (40) in a parallel state, although the refrigerant condenses in the heat source side heat exchanger (40).

  According to a fourth invention, in any one of the first to third inventions, the refrigerant circuit (20) has one end connected to the first header (51) of the main heat exchange section (50). A gas side pipe (21) whose end communicates with the discharge side or suction side of the compressor (31), and a liquid side pipe (23) connected to the liquid side end of the use side heat exchanger (32) In the heat source side heat exchanger (40), the second header (52) of the main heat exchanger (50) and the second header (57) of the auxiliary heat exchanger (55) communicate with each other, A first port (71) connected to the gas side pipe (21), a second port (72) connected to the first header (56) of the auxiliary heat exchange section (55), and the liquid side pipe (23) And a fourth port (74) connected to the second header (52) of the main heat exchanger (50) or the second header (57) of the auxiliary heat exchanger (55). And The four-way valve (60) is provided as the switching mechanism (35), and the four-way valve (60) has a second port (72) when the heat source side heat exchanger (40) is placed in series. When the first port (71) communicates with the third port (73) and the first port (71) and the fourth port (74) are closed, and the heat source side heat exchanger (40) is in a parallel state, The port (71) communicates with the second port (72) and the third port (73) communicates with the fourth port (74).

  In the fourth invention, the four-way valve (60) is provided in the refrigeration apparatus (10) as the switching mechanism (35). The four-way valve (60) includes four ports (71 to 74), and switches between the first state and the second state.

  In the four-way valve (60) in the first state, the second port (72) communicates with the third port (73), and the first port (71) and the fourth port (74) are closed. During the cooling operation, the four-way valve (60) is set to the first state, and the refrigerant discharged from the compressor (31) flows only into the first header (51) of the main heat exchange section (50). In the main heat exchange section (50), the refrigerant flows in the heat transfer tube (53) from the first header (51) toward the second header (52). The refrigerant that has flowed into the second header (52) of the main heat exchange section (50) flows into the second header (57) of the auxiliary heat exchange section (55). In the auxiliary heat exchange section (55), the refrigerant flows in the heat transfer tube (58) from the second header (57) toward the first header (56). The refrigerant that has flowed out of the first header (56) of the auxiliary heat exchanger (55) flows into the second port (72) of the four-way valve (60), and the third port (73) of the four-way valve (60). Flows into the liquid side pipe (23). Thus, when the four-way valve (60) is set to the first state, the heat source side heat exchanger (40) is in a series state.

  On the other hand, in the four-way valve (60) in the second state, the first port (71) communicates with the second port (72), and the third port (73) communicates with the fourth port (74). During the heating operation, the four-way valve (60) is set to the second state, and the refrigerant flowing out from the liquid side end of the use side heat exchanger (32) passes through the liquid side pipe (23). It flows into the third port (73) of (60). Thereafter, the refrigerant flows from the fourth port (74) of the four-way valve (60) to at least the second header (52) of the main heat exchange unit (50) and the second header (57) of the auxiliary heat exchange unit (55). Flows into one side. The second header (52) of the main heat exchange part (50) and the second header (57) of the auxiliary heat exchange part (55) communicate with each other. For this reason, the refrigerant flowing into at least one of the second header (52) of the main heat exchange section (50) and the second header (57) of the auxiliary heat exchange section (55) is transferred to the main heat exchange section (50). It flows separately into the heat pipe (53) and the heat transfer pipe (58) of the auxiliary heat exchange section (55). The refrigerant that has flowed into the first header (51) of the main heat exchange section (50) is sucked into the compressor (31) through the gas side pipe (21). The refrigerant that has flowed into the first header (51) of the auxiliary heat exchanger (55) flows into the second port (72) of the four-way valve (60), and the first port (71) of the four-way valve (60). Flows into the gas side pipe (21) and is then sucked into the compressor (31). Thus, when the four-way valve (60) is set to the second state, the heat source side heat exchanger (40) is in a parallel state.

  In the present invention, the heat source side heat exchanger (40) is provided with a main heat exchange part (50) and an auxiliary heat exchange part (55), and the heat transfer tube (58) of the auxiliary heat exchange part (55) is the main heat exchange. The number is smaller than that of the heat transfer tube (53) of the section (50). In the present invention, the refrigeration apparatus (10) is provided with the switching mechanism (35).

  In the refrigeration apparatus (10) during the cooling operation, the switching mechanism (35) places the heat source side heat exchanger (40) in series, and after the refrigerant passes through the main heat exchange section (50), the auxiliary heat exchange section (55) is turned on. pass. Since the refrigerant condenses in the process of passing through the main heat exchange section (50), the specific volume of the refrigerant flowing into the auxiliary heat exchange section (55) is larger than the specific volume of the refrigerant flowing into the main heat exchange section (50). Get smaller. On the other hand, the number of heat transfer tubes (58) of the auxiliary heat exchange section (55) is smaller than that of the heat transfer tubes (53) of the main heat exchange section (50). For this reason, also in the auxiliary heat exchange part (55) in which the specific volume of the refrigerant flowing in becomes small, a decrease in the flow rate of the refrigerant in the heat transfer tube (58) can be suppressed, and the amount of heat exchange between the refrigerant and the outdoor air is reduced. Is suppressed.

  In the refrigeration system (10) during the heating operation, the switching mechanism (35) places the heat source side heat exchanger (40) in parallel, a part of the refrigerant passes through the main heat exchanger (50), and the rest is auxiliary heat. In the process of passing through the exchanger (55) and passing through the main heat exchanger (50) or the auxiliary heat exchanger (55), it absorbs heat from the outdoor air and evaporates. As the ratio of the gas refrigerant in the refrigerant increases, the specific volume of the refrigerant increases. However, the refrigerant flowing into the heat source side heat exchanger (40) is divided into both the heat transfer tubes (53) of the main heat exchange section (50) and the heat transfer tubes (58) of the auxiliary heat exchange section (55). Inflow. For this reason, an increase in the pressure loss of the refrigerant while passing through the heat transfer tubes (53, 58) is suppressed.

  In the present invention, the switching mechanism (35) places the heat source side heat exchanger (40) in parallel during the heating operation. Therefore, in the heat source side heat exchanger (40) during the heating operation, the heat source side heat exchanger (40) is compared with the case where the refrigerant sequentially passes through the auxiliary heat exchange unit (55) and the main heat exchange unit (50). The pressure loss of the refrigerant during the passage can be reduced. As a result, the pressure and temperature of the refrigerant flowing into the heat source side heat exchanger (40) can be lowered, and the heat absorption amount of the refrigerant in the heat source side heat exchanger (40) can be increased.

  Thus, according to the present invention, during the cooling operation, the switching mechanism (35) places the heat source side heat exchanger (40) in a series state, thereby reducing the heat radiation amount of the refrigerant in the heat source side heat exchanger (40). During the heating operation, the switching mechanism (35) may increase the heat absorption amount of the refrigerant in the heat source side heat exchanger (40) by placing the heat source side heat exchanger (40) in parallel. it can. Therefore, according to the present invention, the capability of the heat source side heat exchanger (40) can be improved not only in the cooling operation but also in the heating operation.

  In the said 2nd invention, the auxiliary heat exchange part (55) is arrange | positioned under the main heat exchange part (50) or the lower end of the heat source side heat exchanger (40). For this reason, in the heat source side heat exchanger (40) during the cooling operation, the refrigerant condensed in the main heat exchange part (50) can be smoothly sent to the auxiliary heat exchange part (55) by both pressure difference and gravity. The pressure loss of the refrigerant while passing through the heat source side heat exchanger (40) can be reduced.

  In the third aspect, the switching mechanism (35) places the heat source side heat exchanger (40) in parallel during the defrosting operation in which the refrigerant condenses in the heat source side heat exchanger (40). For this reason, it becomes possible to melt | dissolve the frost adhering to a heat source side heat exchanger (40) reliably. Here, the reason will be described.

  When the auxiliary heat exchanger (55) is arranged below the main heat exchanger (50) or near the lower end of the heat source side heat exchanger (40), the heat source side heat exchanger (40) during the heating operation The condensed water generated in the main heat exchange section (50) may flow down to the auxiliary heat exchange section (55) and freeze. Also, during the defrosting operation, the frost that has adhered to the main heat exchange part (50) may fall without melting and the heating operation is performed with the fallen frost in contact with the auxiliary heat exchange part (55). When is restarted, frost that has fallen from the main heat exchange section (50) may adhere to the auxiliary heat exchange section (55). Therefore, when the auxiliary heat exchanger (55) is arranged below the main heat exchanger (50) or near the lower end of the heat source side heat exchanger (40), the amount of frost adhering to the auxiliary heat exchanger Tends to be larger than the amount of frost adhering to the main heat exchange section (50).

  If the switching mechanism (35) puts the heat source side heat exchanger (40) in series during the defrosting operation (as in the cooling operation), the heat source side heat exchanger (40 ), The refrigerant supplied from the compressor (31) flows into the auxiliary heat exchange section (55) after passing through the main heat exchange section (50). That is, while the amount of frost adhering to the auxiliary heat exchanging part (55) is larger than that of the main heat exchanging part (50), it passes through the main heat exchanging part (50) during the defrosting operation. The refrigerant that has radiated heat flows into the auxiliary heat exchange section (55). For this reason, it is difficult to reliably melt the frost attached to the auxiliary heat exchange section (55), and the capability of the heat source side heat exchanger (40) may not be sufficiently exhibited during the heating operation.

  In contrast, in the third invention, the switching mechanism (35) places the heat source side heat exchanger (40) in parallel during the defrosting operation, and the compressor (31) to the heat source side heat exchanger (40 ) Is introduced not only into the main heat exchange section (50) but also into the auxiliary heat exchange section (55). Therefore, according to the present invention, the switching mechanism (35) flows into the auxiliary heat exchange section (55) during the defrosting operation as compared with the case where the switching mechanism (35) places the heat source side heat exchanger (40) in series during the defrosting operation. The temperature of the refrigerant to be increased can be increased, and it is possible to reliably melt both the frost adhering to the main heat exchanging part (50) and the frost adhering to the auxiliary heat exchanging part (55).

  According to the fourth aspect of the present invention, the heat source side heat exchanger (40) can be switched between the series state and the parallel state by one four-way valve (60). Therefore, according to the present invention, it is possible to improve the capacity of the heat source side heat exchanger (40) in both the cooling operation and the heating operation while minimizing the complication of the refrigeration apparatus (10).

It is a refrigerant circuit figure of the air conditioner of Embodiment 1, Comprising: The state at the time of air_conditionaing | cooling operation is shown. It is a refrigerant circuit figure of the air conditioner of Embodiment 1, Comprising: The state at the time of heating operation is shown. It is a refrigerant circuit figure of the air conditioner of Embodiment 1, Comprising: The state at the time of a defrost operation is shown. It is a schematic perspective view of the heat exchanger unit which comprises the outdoor heat exchanger of Embodiment 1. It is a schematic front view which shows the heat exchanger unit which comprises the outdoor heat exchanger of Embodiment 1. It is an expansion perspective view which abbreviate | omits the main part of the heat exchange unit of Embodiment 1, and shows it. It is a schematic block diagram of the four-way valve of Embodiment 1, Comprising: (A) shows a 1st state and (B) shows a 2nd state. It is a refrigerant circuit figure of the air conditioner of the modification 1 of Embodiment 1. FIG. It is a refrigerant circuit figure of the air conditioner of the modification 2 of Embodiment 1. FIG. It is a schematic block diagram of the four-way valve of Embodiment 2, (A) shows a 1st state, (B) shows a 2nd state. It is a refrigerant circuit figure of the air conditioner of Embodiment 2, Comprising: The state at the time of air_conditionaing | cooling operation is shown. It is a refrigerant circuit figure of the air conditioner of Embodiment 2, Comprising: The state at the time of heating operation is shown. It is a refrigerant circuit figure of the air conditioner of the 1st modification of other embodiments, and shows the state at the time of air conditioning operation. It is a refrigerant circuit figure of the air conditioner of the 1st modification of other embodiments, and shows the state at the time of heating operation. It is a refrigerant circuit figure of the air conditioner of the 1st modification of other embodiments, and shows the state at the time of defrosting operation. It is a refrigerant circuit diagram of the air conditioner of the 2nd modification of other embodiment, Comprising: The state at the time of air_conditionaing | cooling operation is shown. It is a refrigerant circuit figure of the air conditioner of the 2nd modification of other embodiments, and shows the state at the time of heating operation. It is a refrigerant circuit figure of the air conditioner of the 2nd modification of other embodiments, and shows the state at the time of defrosting operation. It is a front view of the heat exchanger unit which comprises the outdoor heat exchanger of the 2nd modification of other embodiment, (A) shows a main heat exchanger unit, (B) shows an auxiliary heat exchanger unit. Show. It is a refrigerant circuit figure of the air conditioner of the 3rd modification of other embodiments, and shows the state at the time of air conditioning operation. It is a refrigerant circuit figure of the air conditioner of the 3rd modification of other embodiments, and shows the state at the time of heating operation. It is a refrigerant circuit figure of the air conditioner of the 3rd modification of other embodiments, and shows the state at the time of defrosting operation. It is a front view of the auxiliary heat exchanger unit which comprises the outdoor heat exchanger of the 3rd modification of other embodiment. It is a perspective view of the 2nd main heat exchanger unit and auxiliary heat exchanger unit which constitute the outdoor heat exchanger of the 4th modification of other embodiments.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Embodiment 1 of the Invention
A first embodiment of the present invention will be described. The present embodiment is an air conditioner (10) configured by a refrigeration apparatus.

<Overall configuration of air conditioner>
As shown in FIG. 1, the air conditioner (10) of this embodiment is provided with the indoor unit (12) which is a utilization side unit, and the outdoor unit (11) which is a heat source side unit one by one. In the air conditioner (10), the refrigerant circuit (20) is formed by connecting the outdoor unit (11) and the indoor unit (12) with a pipe.

  The number of indoor units (12) and outdoor units (11) is merely an example. That is, in the air conditioner (10) of this embodiment, the refrigerant circuit (20) may be formed by connecting a plurality of indoor units (12) to a single outdoor unit (11), or a plurality of refrigerant circuits (20) may be formed. The refrigerant circuit (20) may be formed by connecting a single outdoor unit (11) and a plurality of indoor units (12) to each other.

  The refrigerant circuit (20) includes a compressor (31), an outdoor heat exchanger (40) that is a heat source side heat exchanger, an indoor heat exchanger (32) that is a use side heat exchanger, an expansion valve ( 33) and a four-way selector valve (34). The refrigerant circuit (20) is provided with a four-way valve (60) as a switching mechanism (35). The compressor (31), the outdoor heat exchanger (40), the expansion valve (33), the four-way switching valve (34), and the four-way valve (60) are accommodated in the outdoor unit (11). The indoor heat exchanger (32) is accommodated in the indoor unit (12). Although not shown, the outdoor unit (11) is provided with an outdoor fan for supplying outdoor air to the outdoor heat exchanger (40), and the indoor unit (12) is connected to the indoor heat exchanger (32) indoors. An indoor fan for supplying air is provided.

  The compressor (31) is a hermetic rotary compressor or scroll compressor. In the refrigerant circuit (20), the compressor (31) has a discharge pipe connected to the first port of the four-way switching valve (34) via a pipe, and a suction pipe connected to the second port of the four-way switching valve (34). Connected through a pipe.

  The outdoor heat exchanger (40) includes a first header member (46) and a second header member (47) that are erected and a large number of heat transfer tubes (53, 58), and exchanges heat between the refrigerant and outdoor air. Let The detailed structure of the outdoor heat exchanger (40) will be described later. The indoor heat exchanger (32) is a so-called cross fin type fin-and-tube heat exchanger, and exchanges heat between the refrigerant and room air.

  The expansion valve (33) is a so-called electronic expansion valve (33). The four-way switching valve (34) has four ports, the first state where the first port communicates with the third port and the second port communicates with the fourth port (the state shown in FIG. 1), The first port is switched to the second state (the state shown in FIG. 2) in which the first port communicates with the fourth port and the second port communicates with the third port. The four-way valve (60) includes four ports (71 to 74). The detailed structure of the four-way valve (60) will be described later.

  The refrigerant circuit (20) is provided with a first gas side pipe (21), a second gas side pipe (22), and a liquid side pipe (23). The first gas side pipe (21) has one end connected to the third port of the four-way switching valve (34) and the other end connected to the upper end of the first header member (46) of the outdoor heat exchanger (40). Has been. The second gas side pipe (22) has one end connected to the fourth port of the four-way switching valve (34) and the other end connected to the gas side end of the indoor heat exchanger (32). One end of the liquid side pipe (23) is connected to the third port (73) of the four-way valve (60), and the other end is connected to the liquid side end of the indoor heat exchanger (32). An expansion valve (33) is provided in the middle of the liquid side pipe (23).

  The refrigerant circuit (20) is provided with a gas side connection pipe (24), a liquid side connection pipe (25), and a connection pipe (26). One end of the gas side connection pipe (24) is connected to the first port (71) of the four-way valve (60), and the other end is connected to the first gas side pipe (21). One end of the liquid side connection pipe (25) is connected to the fourth port (74) of the four-way valve (60), and the other end is the lower end of the second header member (47) of the outdoor heat exchanger (40). It is connected to the. The connection pipe (26) has one end connected to the second port (72) of the four-way valve (60) and the other end connected to the lower end of the first header member (46) of the outdoor heat exchanger (40). Has been.

<Structure of outdoor heat exchanger>
The detailed structure of the outdoor heat exchanger (40) will be described with reference to FIGS. The outdoor heat exchanger (40) of the present embodiment is configured by one heat exchanger unit (45).

  As shown in FIGS. 4 and 5, the heat exchanger unit (45) constituting the outdoor heat exchanger (40) includes one first header member (46), one second header member (47), and A large number of heat transfer tubes (53,58) and a large number of fins (54,59) are provided. The first header member (46), the second header member (47), the heat transfer tubes (53, 58), and the fins (54, 59) are all made of an aluminum alloy and are joined to each other by brazing. ing.

  Each of the first header member (46) and the second header member (47) is formed in an elongated hollow cylindrical shape whose both ends are closed. In FIG. 5, the first header member (46) is erected at the left end of the heat exchanger unit (45), and the second header member (47) is erected at the right end of the heat exchanger unit (45). That is, the first header member (46) and the second header member (47) are installed in a posture in which the respective axial directions are in the vertical direction.

  As shown in FIG. 6, the heat transfer tubes (53, 58) have a flat shape, and a plurality of refrigerant flow paths (49) are formed in a row therein. In the heat exchanger unit (45), the heat transfer tubes (53, 58) have the first header member (46) and the second header member (47) in a posture in which the respective axial directions are in the left-right direction and the side surfaces face each other. Are arranged at predetermined intervals in the axial direction. That is, in the heat exchanger unit (45), the heat transfer tubes (53, 58) are arranged in parallel to each other from the first header member (46) to the second header member (47). Each heat transfer tube (53, 58) has one end inserted into the first header member (46) and the other end inserted into the second header member (47). One end of the refrigerant flow path (49) in each heat transfer tube (53, 58) communicates with the internal space of the first header member (46), and the other end communicates with the internal space of the second header member (47). is doing.

  The fins (54, 59) are provided between the adjacent heat transfer tubes (53, 58). Each fin (54, 59) is formed in a corrugated plate shape that snakes up and down, and is installed in such a posture that the corrugated ridge line is the front-rear direction of the heat exchanger unit (45) (the direction perpendicular to the paper surface of FIG. 5). Has been. In the heat exchanger unit (45), air passes in a direction perpendicular to the paper surface of FIG.

  As shown in FIG. 5, the first header member (46) is provided with a disk-shaped partition plate (48). The internal space of the first header member (46) is partitioned up and down by a partition plate (48). On the other hand, the internal space of the second header member (47) is a single undivided space.

  In the heat exchanger unit (45), the upper part of the partition plate (48) constitutes the main heat exchange part (50), and the lower part of the partition plate (48) is the auxiliary heat exchange part (55). Is configured.

  Specifically, in the first header member (46), the upper part of the partition plate (48) constitutes the first header (51) of the main heat exchange section (50) and is lower than the partition plate (48). The side portion constitutes the first header (56) of the auxiliary heat exchange section (55). The heat transfer tubes (53,58) provided in the heat exchanger unit (45) are connected to the first header (51) of the main heat exchange section (50), and the heat transfer tubes of the main heat exchange section (50) ( 53), and what is connected to the first header (56) of the auxiliary heat exchange section (55) is the heat transfer tube (58) of the auxiliary heat exchange section (55). The fins (54, 59) provided in the heat exchanger unit (45) are provided between the heat transfer tubes (53) of the main heat exchange part (50), and the main heat exchange part (50) The fin (54) is provided between the heat transfer tubes (58) of the auxiliary heat exchange section (55) to form the fin (59) of the auxiliary heat exchange section (55). In the second header member (47), the portion where the heat transfer tube (53) of the main heat exchange part (50) is inserted constitutes the second header (52) of the main heat exchange part (50), and the auxiliary heat exchange part The portion where the heat transfer tube (58) of (55) is inserted constitutes the second header (57) of the auxiliary heat exchange section (55).

  In the outdoor heat exchanger (40) of the present embodiment, the number of heat transfer tubes (58) of the auxiliary heat exchange unit (55) is less than the number of heat transfer tubes (53) of the main heat exchange unit (50). Yes. Specifically, the number of heat transfer tubes (58) in the auxiliary heat exchange section (55) is about 1/9 of the number of heat transfer tubes (53) in the main heat exchange section (50). The number of heat transfer tubes (53,58) shown in FIGS. 4 and 5 is different from the number of heat transfer tubes (53,58) provided in the actual outdoor heat exchanger (40).

  As described above, in the refrigerant circuit (20), the first gas side pipe (21) is at the upper end of the first header member (46), and the connection pipe (26) is at the lower end of the first header member (46). The liquid side connection pipe (25) is connected to the lower end of the second header member (47), respectively (see FIG. 1). That is, in the outdoor heat exchanger (40), the first gas side pipe (21) is connected to the first header (51) of the main heat exchanger (50), and the first header (56) of the auxiliary heat exchanger (55). The connection pipe (26) is connected to the second header (57) of the auxiliary heat exchange section (55), and the liquid side connection pipe (25) is connected to the second header (57).

<Structure of four-way valve>
The detailed structure of the four-way valve (60) will be described with reference to FIG. The four-way valve (60) includes a valve body (61) and a pilot valve (62).

  The valve body (61) includes a case member (65), a valve seat member (70), and a piston member (80). The case member (65) is a hollow cylindrical member whose both ends are closed. The valve seat member (70) is a thick plate-like member, and is provided so as to penetrate the side portion of the case member (65). The valve seat member (70) is formed with four ports (71 to 74) arranged in a line. Each port (71-74) is a through-hole which penetrates the valve seat member (70) in the thickness direction. Each port (71 to 74) has one end opened on the outer surface of the valve seat member (70) and the other end opened on the inner surface of the valve seat member (70).

  The piston member (80) is accommodated in the case member (65). The piston member (80) is provided with a first piston (81) at one end (left end in FIG. 7) and a second piston (82) at the other end (right end in FIG. 7). Each of the first piston (81) and the second piston (82) is formed in a disk shape whose outer peripheral surface is in sliding contact with the inner peripheral surface of the case member (65). The internal space of the case member (65) is divided into three parts by the first piston (81) and the second piston (82). That is, in the internal space of the case member (65), the left part of the first piston (81) in FIG. 7 constitutes the first chamber (66), and the right part of the second piston (82) in FIG. A second chamber (67) is formed, and a portion between the first piston (81) and the second piston (82) forms a central space (68).

  A valve element (83) is provided between the first piston (81) and the second piston (82) of the piston member (80). That is, the valve body (83) is disposed in the central space (68). The valve body (83) includes a dome portion (84) and a leg portion (85). The dome part (84) is formed in a cup shape. The leg portion (85) is formed in a flat plate shape extending outward from the open end (the upper end in FIG. 7) of the dome portion (84). The surface of the leg portion (85) opposite to the dome portion (84) is a flat surface and is in sliding contact with the inner surface of the valve seat member (70). The space inside the dome portion (84) is a space in the dome (86) surrounded by the valve body (83) and the valve seat member (70).

  The four-way valve (60) is provided with a first pressure guiding pipe (63) and a second pressure guiding pipe (64). One end of the first pressure guiding pipe (63) is connected to the pilot valve (62), and the other end is connected between the expansion valve (33) and the indoor heat exchanger (32) in the liquid side pipe (23). Yes. The second pressure guiding pipe (64) has one end connected to the pilot valve (62) and the other end connected to the gas side connecting pipe (24).

  The pilot valve (62) is connected to each of the first chamber (66) and the second chamber (67) in the case member (65) via a pipe. The pilot valve (62) is in a first state in which the first pressure guiding pipe (63) communicates with the first chamber (66) and the second pressure guiding pipe (64) communicates with the second chamber (67) (FIG. 7 ( A state shown in FIG. 7A) and a second state in which the first pressure guiding pipe (63) communicates with the second chamber (67) and the second pressure guiding pipe (64) communicates with the first chamber (66) (FIG. The state shown in B).

  First, as shown in FIG. 7A, when the pilot valve (62) is in the first state, the pressure in the second chamber (67) becomes higher than the pressure in the first chamber (66), and the piston member (80 ) Moves toward the left end in the figure. In this state, the open ends of the second port (72) and the third port (73) on the inner surface of the valve seat member (70) are covered with the dome portion (84) of the valve body (83). The first port (71) communicates with the outer portion of the valve body (83) in the central space (68), and the second port (72) and the third port (73) communicate with the inner dome space (86). The fourth port (74) is blocked by the leg (85) of the valve body (83). A portion outside the valve body (83) in the central space (68) is a closed space that does not communicate with the outside of the case member (65). Accordingly, the first port (71) is substantially closed. Thus, when the pilot valve (62) is in the first state, the valve body (61) of the four-way valve (60) has the second port (72) communicating with the third port (73) and the first port. (71) and the fourth port (74) are in the first state closed. That is, in the four-way valve (60) in the first state, both the pilot valve (62) and the valve body (61) are in the first state.

  In the valve body (61) in the first state, the central space (68) communicates with the first gas side pipe (21) via the first port (71). Accordingly, during the cooling operation described later, the pressure in the portion outside the valve body (83) in the central space (68) becomes higher than the pressure in the space in the dome (86). For this reason, the valve body (83) is pressed against the inner surface of the valve seat member (70), and the amount of refrigerant leaking from the gap between the valve body (83) and the valve seat member (70) is kept low.

  Next, as shown in FIG. 7B, when the pilot valve (62) is in the second state, the pressure in the first chamber (66) becomes higher than the pressure in the second chamber (67), and the piston member ( 80) moves closer to the right edge in the figure. In this state, the open ends of the first port (71) and the second port (72) on the inner surface of the valve seat member (70) are covered with the dome portion (84) of the valve body (83). The first port (71) and the second port (72) communicate with the inner dome space (86), and the third port (73) and the fourth port (74) communicate with the valve body (83 in the central space (68). ) Communicate with the outer part. Thus, when the pilot valve (62) is in the second state, the valve body (61) of the four-way valve (60) has the first port (71) communicating with the second port (72) and the third port. (73) is in the second state communicating with the fourth port (74). That is, in the four-way valve (60) in the second state, both the pilot valve (62) and the valve body (61) are in the second state.

-Driving action-
The operation of the air conditioner (10) will be described. The air conditioner (10) performs a cooling operation that is a cooling operation and a heating operation that is a heating operation. Further, during the heating operation, the air conditioner (10) performs a defrosting operation in order to melt the frost attached to the outdoor heat exchanger (40).

<Cooling operation>
The operation of the air conditioner (10) during the cooling operation will be described with reference to FIG.

  During the cooling operation, both the four-way switching valve (34) and the four-way valve (60) are set to the first state. The opening degree of the expansion valve (33) is adjusted so that the degree of superheat of the refrigerant flowing out from the gas side end of the indoor heat exchanger (32) becomes a predetermined target value (for example, 5 ° C.). Further, during the cooling operation, outdoor air is supplied to the outdoor heat exchanger (40) by the outdoor fan, and indoor air is supplied to the indoor heat exchanger (32) by the indoor fan.

  In the four-way valve (60) in the first state, the first port (71) and the fourth port (74) are closed, and the second port (72) and the third port (73) communicate with each other. For this reason, the outdoor heat exchanger (40) is in a series state in which the refrigerant passes through the auxiliary heat exchange section (55) after passing through the main heat exchange section (50).

  In the refrigerant circuit (20), the refrigerant discharged from the compressor (31) sequentially passes through the four-way switching valve (34) and the first gas side pipe (21), and then passes through the first heat exchanger (50). It flows into 1 header (51). The refrigerant that has flowed into the first header (51) flows separately into the heat transfer tubes (53) of the main heat exchange section (50) and passes through the refrigerant flow paths (49) of the heat transfer tubes (53). Heat is condensed to the outdoor air. The refrigerant that has passed through each heat transfer tube (53) flows into and merges with the second header (52) of the main heat exchange section (50), and then enters the second header (57) of the auxiliary heat exchange section (55). run down. The refrigerant that has flowed into the second header (57) flows separately into the heat transfer tubes (58) of the auxiliary heat exchange section (55) and passes through the refrigerant flow paths (49) of the heat transfer tubes (58). Heat is dissipated to the outdoor air, resulting in a supercooled state. The refrigerant that has passed through each heat transfer tube (58) flows into and merges with the first header (56) of the auxiliary heat exchange section (55).

  The refrigerant flowing into the connection pipe (26) from the first header (56) of the auxiliary heat exchange section (55) flows into the liquid side pipe (23) after passing through the four-way valve (60), and then expands into the expansion valve (33). It expands (pressure drop) when passing through and flows into the liquid side end of the indoor heat exchanger (32). The refrigerant flowing into the indoor heat exchanger (32) absorbs heat from the indoor air and evaporates. The indoor unit (12) supplies the sucked room air to the indoor heat exchanger (32), and sends the room air cooled in the indoor heat exchanger (32) back into the room.

  The refrigerant evaporated in the indoor heat exchanger (32) flows into the second gas side pipe (22) from the gas side end of the indoor heat exchanger (32). Thereafter, the refrigerant is sucked into the compressor (31) through the four-way switching valve (34). The compressor (31) compresses the sucked refrigerant and discharges it.

<Heating operation>
The operation of the air conditioner (10) during the heating operation will be described with reference to FIG.

  During the heating operation, both the four-way switching valve (34) and the four-way valve (60) are set to the second state. The opening degree of the expansion valve (33) is adjusted so that the degree of superheat of the refrigerant flowing out from the outdoor heat exchanger (40) becomes a predetermined target value (for example, 5 ° C.). Further, during the heating operation, outdoor air is supplied to the outdoor heat exchanger (40) by the outdoor fan, and indoor air is supplied to the indoor heat exchanger (32) by the indoor fan.

  In the four-way valve (60) in the second state, the first port (71) and the second port (72) communicate with each other, and the third port (73) and the fourth port (74) communicate with each other. For this reason, the outdoor heat exchanger (40) is in a parallel state in which a part of the refrigerant passes through the main heat exchange part (50) and the rest passes through the auxiliary heat exchange part (55).

  In the refrigerant circuit (20), the refrigerant discharged from the compressor (31) sequentially passes through the four-way switching valve (34) and the second gas side pipe (22), and then the gas in the indoor heat exchanger (32). It flows into the side edge. The refrigerant flowing into the indoor heat exchanger (32) dissipates heat to the indoor air and condenses. The indoor unit (12) supplies the sucked indoor air to the indoor heat exchanger (32), and sends the indoor air heated in the indoor heat exchanger (32) back into the room.

  The refrigerant flowing into the liquid side pipe (23) from the liquid side end of the indoor heat exchanger (32) expands (pressure drop) when passing through the expansion valve (33), and then the four-way valve (60) and liquid It passes through the side connection pipe (25) in order and flows into the second header (57) of the auxiliary heat exchange section (55). The second header (57) of the auxiliary heat exchange part (55) communicates with the second header (57) of the main heat exchange part (50). For this reason, a part of the refrigerant that has flowed into the second header (57) of the auxiliary heat exchange section (55) flows into the heat transfer pipe (58) of the auxiliary heat exchange section (55), and the rest is the main heat. It flows separately from the second header (57) of the exchange section (50) to the heat transfer tube (53). The refrigerant flowing into each heat transfer tube (53, 58) absorbs heat from the outdoor air and evaporates while passing through the refrigerant flow path (49).

  The refrigerant that has passed through each heat transfer tube (53) of the main heat exchange section (50) flows into the first header (51) of the main heat exchange section (50) and merges, and then the first gas side pipe (21 ). On the other hand, the refrigerant that has passed through each heat transfer pipe (58) of the auxiliary heat exchange section (55) flows into the first header (56) of the auxiliary heat exchange section (55) and joins, and then the connection pipe (26) And the four-way valve (60) and the gas-side connecting pipe (24) in that order and flow into the first gas-side pipe (21). The refrigerant flowing through the first gas side pipe (21) passes through the four-way switching valve (34) and is sucked into the compressor (31). The compressor (31) compresses the sucked refrigerant and discharges it.

<Defrosting operation>
When heating operation is performed in a state where the temperature of the outdoor air is low (for example, 0 ° C. or less), frost adheres to the outdoor heat exchanger (40) functioning as an evaporator. When frost adheres to the outdoor heat exchanger (40), the flow of outdoor air that attempts to pass through the outdoor heat exchanger (40) is hindered, and the heat absorption amount of the refrigerant in the outdoor heat exchanger (40) decreases. Therefore, in an operating state where frost is expected to adhere to the outdoor heat exchanger (40), the air conditioner (10), for example, every time the duration of the heating operation reaches a predetermined value (for example, several tens of minutes) The defrosting operation is performed.

  The operation of the air conditioner (10) during the defrosting operation will be described with reference to FIG.

  During the defrosting operation, the four-way switching valve (34) is set to the first state, and the four-way valve (60) is set to the second state. The opening degree of the expansion valve (33) is maintained at a predetermined opening degree. Further, during the heating operation, the outdoor fan and the indoor fan are stopped.

  During the defrosting operation, the four-way valve (60) is set to the second state. For this reason, the outdoor heat exchanger (40) has a parallel state in which a part of the refrigerant passes through the main heat exchange part (50) and the rest passes through the auxiliary heat exchange part (55) as in the heating operation. Become.

  In the refrigerant circuit (20), the refrigerant discharged from the compressor (31) flows into the first gas side pipe (21) through the four-way switching valve (34). A part of the refrigerant flowing through the first gas side pipe (21) flows into the first header (51) of the main heat exchange section (50), and the rest of the refrigerant flows into the gas side connection pipe (24) and the four-way valve ( 60) and the connecting pipe (26) in order, and flows into the first header (56) of the auxiliary heat exchange section (55). In the main heat exchanging section (50), the refrigerant flowing into the first header (51) is divided and flows into each heat transfer tube (53). In the auxiliary heat exchanger (55), the refrigerant that has flowed into the first header (56) is divided into the heat transfer tubes (58) and flows in. The refrigerant flowing into each heat transfer tube (53, 58) dissipates heat and condenses while flowing through the refrigerant flow path (49). The frost adhering to the outdoor heat exchanger (40) is melted by being warmed by the refrigerant flowing through the heat transfer tubes (53, 58).

  The refrigerant that has passed through each heat transfer tube (53) of the main heat exchange section (50) flows into and merges with the second header (52) of the main heat exchange section (50), and then the auxiliary heat exchange section (55). It flows down to the second header (57). The refrigerant that has passed through each heat transfer tube (58) of the auxiliary heat exchange unit (55) flows into the second header (57) of the auxiliary heat exchange unit (55), and each heat transfer tube (53 of the main heat exchange unit (50)) ) Merged with the refrigerant that passed through. The refrigerant flowing from the second header (57) of the auxiliary heat exchange section (55) into the liquid side connection pipe (25) flows into the four-way valve (60), the liquid side pipe (23), the indoor heat exchanger (32), In order to flow into the second gas side pipe (22), and then sucked into the compressor (31) through the four-way switching valve (34). The compressor (31) compresses the sucked refrigerant and discharges it.

-Effect of Embodiment 1-
In the air conditioner (10) of this embodiment, the outdoor heat exchanger (40) is provided with a main heat exchanging part (50) and an auxiliary heat exchanging part (55), and a heat transfer tube ( 58) is smaller than the heat transfer tube (53) of the main heat exchange section (50). The air conditioner (10) of the present embodiment is provided with a four-way valve (60).

  In the air conditioner (10) during cooling operation, the four-way valve (60) places the outdoor heat exchanger (40) in series, and after the refrigerant passes through the main heat exchanger (50), the auxiliary heat exchanger (55) pass. Since the refrigerant condenses in the process of passing through the main heat exchange section (50), the specific volume of the refrigerant flowing into the auxiliary heat exchange section (55) is larger than the specific volume of the refrigerant flowing into the main heat exchange section (50). Get smaller. On the other hand, the number of heat transfer tubes (58) of the auxiliary heat exchange section (55) is smaller than that of the heat transfer tubes (53) of the main heat exchange section (50). For this reason, also in the auxiliary heat exchange part (55) in which the specific volume of the refrigerant flowing in becomes small, a decrease in the flow rate of the refrigerant in the heat transfer tube (58) is suppressed. As a result, a decrease in the heat transfer coefficient between the refrigerant and the heat transfer tube (58) is suppressed, and a decrease in the amount of heat exchange between the refrigerant and the outdoor air is suppressed.

  In the air conditioner (10) during heating operation, the four-way valve (60) places the outdoor heat exchanger (40) in parallel. The refrigerant flowing through the outdoor heat exchanger (40) partially passes through the main heat exchange section (50) and the rest passes through the auxiliary heat exchange section (55), and the main heat exchange section (50) or In the process of passing through the auxiliary heat exchanger (55), it absorbs heat from the outdoor air and evaporates. As the ratio of the gas refrigerant in the refrigerant increases, the specific volume of the refrigerant increases. However, the refrigerant flowing into the outdoor heat exchanger (40) is divided into both the heat transfer tubes (53) of the main heat exchanger (50) and the heat transfer tubes (58) of the auxiliary heat exchanger (55). To do. For this reason, the flow velocity of the refrigerant in the refrigerant flow path (49) of the heat transfer tube (53, 58) is suppressed low, and an increase in the pressure loss of the refrigerant while passing through the heat transfer tube (53, 58) is suppressed.

  In the air conditioner (10) of the present embodiment, the four-way valve (60) places the outdoor heat exchanger (40) in parallel during the heating operation. For this reason, compared with the case where a refrigerant | coolant passes an auxiliary heat exchange part (55) and a main heat exchange part (50) in order in the outdoor heat exchanger (40) in heating operation, it passes an outdoor heat exchanger (40). It is possible to reduce the pressure loss of the refrigerant. For this reason, the pressure and temperature of the refrigerant flowing into the outdoor heat exchanger (40) can be reduced. As a result, the temperature difference between the refrigerant and the outdoor air in the outdoor heat exchanger (40) increases, and the heat absorption amount of the refrigerant in the outdoor heat exchanger (40) increases.

  Thus, according to the air conditioner (10) of the present embodiment, during the cooling operation, the four-way valve (60) places the outdoor heat exchanger (40) in a series state so that the outdoor heat exchanger (40) The amount of heat released from the refrigerant in the outdoor heat exchanger (40) can be increased by setting the outdoor heat exchanger (40) in parallel with the four-way valve (60) during heating operation. Can be increased. Therefore, according to this embodiment, the capability of an outdoor heat exchanger (40) can be improved not only in cooling operation but also in heating operation.

  In the outdoor heat exchanger (40) of this embodiment, the auxiliary heat exchange part (55) is arrange | positioned under the main heat exchange part (50). For this reason, in the outdoor heat exchanger (40) during the cooling operation, the refrigerant condensed in the heat transfer tube (53) of the main heat exchange section (50) and flowing into the second header (52) is converted into a pressure difference and gravity. By both, it can send smoothly to the 2nd header (57) of an auxiliary heat exchange part (55). Therefore, according to this embodiment, the pressure loss of the refrigerant while passing through the outdoor heat exchanger (40) can be reduced.

  In the air conditioner (10) of the present embodiment, the four-way valve (60) places the outdoor heat exchanger (40) in parallel during the defrosting operation in which the refrigerant condenses in the outdoor heat exchanger (40). For this reason, it becomes possible to melt | dissolve the frost adhering to an outdoor heat exchanger (40) reliably. Here, the reason will be described.

  When the auxiliary heat exchanger (55) is disposed below the main heat exchanger (50), in the outdoor heat exchanger (40) during heating operation, the condensed water generated in the main heat exchanger (50) It may flow down to the auxiliary heat exchanger (55) and freeze. In addition, during the defrosting operation, the frost adhering to the main heat exchange part (50) may fall without melting, and the heating operation is performed with the fallen frost in contact with the auxiliary heat exchange part (55). When is restarted, frost that has fallen from the main heat exchange section (50) may adhere to the auxiliary heat exchange section (55). Therefore, when the auxiliary heat exchanging part (55) is arranged below the main heat exchanging part (50), the amount of frost adhering to the auxiliary heat exchanger is the frost adhering to the main heat exchanging part (50). Tend to be more than the amount of.

  If the four-way valve (60) puts the outdoor heat exchanger (40) in series during the defrosting operation (similar to during cooling operation), the outdoor heat exchanger (40) during the defrosting operation is assumed. Then, the refrigerant supplied from the compressor (31) flows into the auxiliary heat exchange section (55) after passing through the main heat exchange section (50). That is, while the amount of frost adhering to the auxiliary heat exchanging part (55) is larger than that of the main heat exchanging part (50), it passes through the main heat exchanging part (50) during the defrosting operation. The refrigerant that has radiated heat flows into the auxiliary heat exchange section (55). For this reason, it becomes difficult to melt the frost adhering to the auxiliary heat exchanger (55) with certainty, and the capacity of the outdoor heat exchanger (40) may not be sufficiently exhibited during the heating operation.

  In contrast, in the air conditioner (10) of the present embodiment, the four-way valve (60) has the outdoor heat exchanger (40) in parallel during the defrosting operation, and the outdoor heat exchange from the compressor (31). The high-temperature and high-pressure gas refrigerant supplied to the vessel (40) is introduced not only into the main heat exchange unit (50) but also into the auxiliary heat exchange unit (55). Therefore, according to this embodiment, compared with the case where the four-way valve (60) places the outdoor heat exchanger (40) in series during the defrosting operation, the auxiliary heat exchange unit (55) is operated during the defrosting operation. The temperature of the refrigerant flowing in can be raised, and it is possible to surely melt both the frost attached to the main heat exchange part (50) and the frost attached to the auxiliary heat exchange part (55).

  In the air conditioner (10) of the present embodiment, one four-way valve (60) is provided in the refrigerant circuit (20) as a switching mechanism (35), and the outdoor heat exchanger ( 40) is switched between a serial state and a parallel state. Therefore, according to the present embodiment, it is possible to improve the capacity of the outdoor heat exchanger (40) in both the cooling operation and the heating operation while minimizing the complexity of the air conditioner (10).

-Modification 1 of Embodiment 1-
As shown in FIG. 8, in the air conditioner (10) of the present embodiment, three electromagnetic valves (91, 92, 93) are provided as switching mechanisms (35) instead of the four-way valve (60). Also good. Here, the difference between the refrigerant circuit (20) of the air conditioner (10) of the present modification and the refrigerant circuit (20) of FIG. 1 will be described.

  In the refrigerant circuit (20) of this modification, one end of the liquid side pipe (23) is connected to one end of the first electromagnetic valve (91), and one end of the connection pipe (26) is connected to the other of the first electromagnetic valve (91). One end of the gas side connecting pipe (24) is connected to the connecting pipe (26), and one end of the liquid side connecting pipe (25) is connected to the expansion valve (33) and the first electromagnetic wave in the liquid side pipe (23). Connected between valves (91). A second electromagnetic valve (92) is provided in the middle of the gas side connecting pipe (24), and a third electromagnetic valve (93) is provided in the middle of the liquid side connecting pipe (25). In the present modification, the first electromagnetic valve (91), the second electromagnetic valve (92), and the third electromagnetic valve (93) constitute a switching mechanism (35). The other end of the liquid side pipe (23), gas side connection pipe (24), liquid side connection pipe (25), and connection pipe (26) is the same as the refrigerant circuit (20) of FIG. is there.

  The switching mechanism (35) of this modification is switched between the first state and the second state. In the first state, the first solenoid valve (91) is opened and the second solenoid valve (92) and the third solenoid valve (93) are closed. In the second state, the first solenoid valve (91) is closed and the second solenoid valve (92) and the third solenoid valve (93) are opened. When the switching mechanism (35) is in the first state, the outdoor heat exchanger (40) is in a series state, and the refrigerant passes through the auxiliary heat exchange unit (55) after passing through the main heat exchange unit (50). On the other hand, when the switching mechanism (35) is in the second state, the outdoor heat exchanger (40) is in a parallel state, a part of the refrigerant passes through the main heat exchange part (50), and the rest is the auxiliary heat exchange part (55). )

-Modification 2 of Embodiment 1
As shown in FIG. 9, the air conditioner (10) of this embodiment may be provided with two three-way valves (96, 97) as a switching mechanism (35) instead of the four-way valve (60). . Here, the difference between the refrigerant circuit (20) of the air conditioner (10) of the present modification and the refrigerant circuit (20) of FIG. 1 will be described.

  In the refrigerant circuit (20) of this modification, one end of the liquid side pipe (23) is connected to the first port of the first three-way valve (96), and one end of the connection pipe (26) is the second three-way valve (97). The one end of the gas side connecting pipe (24) is connected to the third port of the second three-way valve (97), and one end of the liquid side connecting pipe (25) is connected to the first three-way valve (96). Is connected to the third port. The second port of the first three-way valve (96) and the second port of the second three-way valve (97) are connected to each other via a pipe. In this modification, the first three-way valve (96) and the second three-way valve (97) constitute a switching mechanism (35). The other end of the liquid side pipe (23), gas side connection pipe (24), liquid side connection pipe (25), and connection pipe (26) is the same as the refrigerant circuit (20) of FIG. is there.

  The switching mechanism (35) of this modification is switched between the first state and the second state. In the first state, each of the first three-way valve (96) and the second three-way valve (97) is set in a state where the first port communicates with the second port and is blocked from the third port. In the second state, each of the first three-way valve (96) and the second three-way valve (97) is set in a state where the first port communicates with the third port and is blocked from the second port. When the switching mechanism (35) is in the first state, the outdoor heat exchanger (40) is in a series state, and the refrigerant passes through the auxiliary heat exchange unit (55) after passing through the main heat exchange unit (50). On the other hand, when the switching mechanism (35) is in the second state, the outdoor heat exchanger (40) is in a parallel state, a part of the refrigerant passes through the main heat exchange part (50), and the rest is the auxiliary heat exchange part (55). )

<< Embodiment 2 of the Invention >>
A second embodiment of the present invention will be described. In the present embodiment, the configuration of the four-way valve (60) is changed in the air conditioner (10) of the first embodiment. Here, the difference between the four-way valve (60) of the present embodiment and the four-way valve (60) of the first embodiment will be described.

  As shown in FIG. 10, the pilot valve (62) is omitted in the four-way valve (60) of the present embodiment. In the four-way valve (60), one end of the first pressure guiding pipe (63) is connected to one end face (left end face in FIG. 10) of the case member (65), and one end of the second pressure guiding pipe (64) is It is connected to the other end surface (right end surface in FIG. 10) of the case member (65). That is, in this four-way valve (60), the first pressure guiding pipe (63) is always in communication with the first chamber (66) in the case member (65), and the second pressure guiding pipe (64) is the case member (65). It always communicates with the second chamber (67). In addition, the connection destination of the other end of the first pressure guiding pipe (63) and the second pressure guiding pipe (64) is the same as that of the four-way valve (60) of the first embodiment.

-Driving action-
When the four-way switching valve (34) switches from one of the first state and the second state to the other, the four-way valve (60) of the present embodiment automatically receives the first control signal without receiving an external control signal. Switching from one of the first state and the second state to the other. That is, when the four-way switching valve (34) switches from the first state to the second state, the four-way valve (60) also switches from the first state to the second state. When the four-way switching valve (34) switches from the second state to the first state, the four-way valve (60) also switches from the second state to the first state.

  As shown in FIG. 11, in the refrigerant circuit (20) during the cooling operation, the four-way switching valve (34) is set to the first state. In this state, high-pressure gas refrigerant discharged from the compressor (31) flows through the first gas-side pipe (21) to which the gas-side connecting pipe (24) is connected. Further, in the portion of the liquid side pipe (23) between the expansion valve (33) and the indoor heat exchanger (32), refrigerant that has expanded and decreased in pressure when passing through the expansion valve (33) flows. ing. For this reason, in the valve body (61) of the four-way valve (60), the pressure in the first chamber (66) communicating with the liquid side pipe (23) via the first pressure guiding pipe (63) is the second pressure guiding pipe. It becomes lower than the pressure of the second chamber (67) communicating with the gas side connecting pipe (24) through (64). For this reason, as shown in FIG. 10A, in the four-way valve (60), the piston member (80) is positioned closer to the left end in the figure. Therefore, the four-way valve (60) is in the first state in which the second port (72) communicates with the third port (73) and the first port (71) and the fourth port (74) are closed.

  As shown in FIG. 12, in the refrigerant circuit (20) during the heating operation, the four-way switching valve (34) is set to the second state. In this state, low-pressure gas refrigerant sucked into the compressor (31) flows through the first gas-side pipe (21) to which the gas-side connecting pipe (24) is connected. Moreover, in the part between the expansion valve (33) and the indoor heat exchanger (32) in the liquid side pipe (23), the liquid flows out from the indoor heat exchanger (32) before reaching the expansion valve (33). High-pressure refrigerant is in circulation. For this reason, in the valve body (61) of the four-way valve (60), the pressure in the second chamber (67) communicating with the gas side connection pipe (24) via the second pressure guiding pipe (64) is the first guide. The pressure is lower than the pressure in the first chamber (66) communicating with the liquid side pipe (23) via the pressure pipe (63). For this reason, as shown in FIG. 10B, in the four-way valve (60), the piston member (80) is positioned closer to the right end in the figure. Therefore, the four-way valve (60) is in the second state in which the first port (71) communicates with the second port (72) and the third port (73) communicates with the fourth port (74).

  As described above, in the air conditioner (10) of the present embodiment, when the four-way switching valve (34) switches from one of the first state and the second state to the other, the four-way valve (60) also automatically changes to the first one. Switching from one of the first state and the second state to the other. Therefore, in the air conditioner (10) of this embodiment, it is not necessary to perform a control operation for the four-way valve (60). However, in the air conditioner (10) of the present embodiment, when the four-way switching valve (34) is set to the first state in order to perform the dehumidifying operation, the four-way valve (60) is also in the first state. Therefore, in the defrosting operation, the outdoor heat exchanger (40) is in series, and the high-temperature refrigerant supplied from the compressor (31) to the outdoor heat exchanger (40) passes through the main heat exchanger (50). Later, it passes through the auxiliary heat exchanger (55).

<< Other Embodiments >>
About each said embodiment, it is good also as following structures.

-First modification-
In the air conditioner (10) of each of the above embodiments, the outdoor heat exchanger (40) may be composed of a plurality of heat exchanger units (45a, 45b).

  In the air conditioner (10) of the present modification shown in FIG. 13, the outdoor heat exchanger (40) is composed of two heat exchanger units (45a, 45b). The number of heat exchanger units (45a, 45b) constituting the outdoor heat exchanger (40) may be three or more.

  The structure of each heat exchanger unit (45a, 45b) constituting the outdoor heat exchanger (40) of the present modification is the same as the heat exchanger unit (45) constituting the outdoor heat exchanger (40) of the first embodiment. The structure is exactly the same. The first heat exchanger unit (45a) includes a first main heat exchange part (50a) and a first auxiliary heat exchange part (55a). The second heat exchanger unit (45b) includes a second main heat exchange section (50b) and a second auxiliary heat exchange section (55b).

  As shown in FIG. 13, the first gas side pipe (21) of the present modification is bifurcated, and one of the branches is the first header member (46a) of the first heat exchanger unit (45a). The upper end of the first header member (46b) of the second heat exchanger unit (45b) is connected to the upper end (that is, the first header (51a) of the first main heat exchange section (50a)). (That is, connected to the first header (51b) of the second main heat exchange section (50b)). Moreover, the liquid side connection pipe (25) of this modification is bifurcated, and one of the bifurcations is the lower end of the second header member (47a) of the first heat exchanger unit (45a). 1 is connected to the second header (57a) of the auxiliary heat exchange section (55a), and the other branched is the lower end of the second header member (47b) of the second heat exchanger unit (45b) (ie, the second auxiliary It is connected to the second header (57b) of the heat exchange part (55b). Further, the connecting pipe (26) of the present modification is bifurcated, and one of the branched pipes is the lower end of the first header member (46a) of the first heat exchanger unit (45a) (ie, the first auxiliary Connected to the first header (56a) of the heat exchange part (55a) and the other branched is the lower end of the first header member (46b) of the second heat exchanger unit (45b) (ie, the second auxiliary heat exchange) Part (55b) of the first header (56b)).

  As shown in FIG. 13, during the cooling operation, both the four-way switching valve (34) and the four-way valve (60) are set to the first state in the air conditioner (10) of the present modification. The refrigerant flowing into the first header (51a, 51b) of each main heat exchange section (50a, 50b) from the first gas side pipe (21) passes through the heat transfer pipe (53) of the main heat exchange section (50a, 50b). After passing through the heat transfer pipe (58) of the auxiliary heat exchange section (55a, 55b), and then through the first header (56a, 56b) of each auxiliary heat exchange section (55a, 55b), the connection pipe (26) Flow into.

  As shown in FIG. 14, during the heating operation, both the four-way switching valve (34) and the four-way valve (60) are set to the second state in the air conditioner (10) of the present modification. A part of the refrigerant flowing from the liquid side connection pipe (25) into the second header (57a, 57b) of each auxiliary heat exchange section (55a, 55b) is a heat transfer pipe of the main heat exchange section (50a, 50b) ( 53), and the remainder passes through the heat transfer tubes (58) of the auxiliary heat exchangers (55a, 55b). The refrigerant that has passed through the heat transfer pipe (53) of the main heat exchange section (50a, 50b) passes through the first header (51a, 51b) of the main heat exchange section (50a, 50b), and the first gas side pipe (21) Flow into. The refrigerant that has passed through the heat transfer pipe (58) of the auxiliary heat exchange section (55a, 55b) flows into the connection pipe (26) through the first header (56a, 56b) of the auxiliary heat exchange section (55a, 55b). Then, it flows into the first gas side pipe (21) through the gas side connection pipe (24).

  As shown in FIG. 15, during the defrosting operation, also in the air conditioner (10) of this modification, the four-way switching valve (34) is set to the first state and the four-way valve (60) is set to the second state. Is done. A part of the refrigerant flowing through the first gas side pipe (21) flows into the first header (51a, 51b) of each main heat exchange section (50a, 50b), and the rest is the gas side connection pipe (24). And flow into the first header (56a, 56b) of the auxiliary heat exchange section (55a, 55b) after passing through the connecting pipe (26). The refrigerant that has passed through the heat transfer pipe (53) of the main heat exchange section (50a, 50b) passes through the second header (52a, 52b) of the main heat exchange section (50a, 50b) to the liquid side connection pipe (25). Inflow. The refrigerant that has passed through the heat transfer pipe (58) of the auxiliary heat exchange section (55a, 55b) passes through the second header (57a, 57b) of the auxiliary heat exchange section (55a, 55b) to the liquid side connection pipe (25). Inflow.

-Second modification-
In the air conditioner (10) of each of the above embodiments, the outdoor heat exchanger (40) may be composed of a main heat exchanger unit (41, 42) and an auxiliary heat exchanger unit (43). In the outdoor heat exchanger (40) of this modification, the main heat exchanger unit (41, 42) constitutes the main heat exchange part (50a, 50b), and the auxiliary heat exchanger unit (43) is the auxiliary heat exchange part. (55) is configured.

  In the air conditioner (10) of this modification shown in FIG. 16, the outdoor heat exchanger (40) is composed of two main heat exchanger units (41, 42) and one auxiliary heat exchanger unit (43). ing. Note that the number of main heat exchanger units (41, 42) constituting the outdoor heat exchanger (40) may be one or plural. Further, the number of auxiliary heat exchanger units (43) constituting the outdoor heat exchanger (40) may be one or plural.

  Moreover, in the outdoor heat exchanger (40) of this modification, an auxiliary heat exchanger unit (43), a second main heat exchanger unit (42), and a first main heat exchanger unit ( 41) and are arranged. That is, in the outdoor heat exchanger (40) of the present modification, the auxiliary heat exchanger unit (43) is located below the two main heat exchanger units (41, 42) and of the outdoor heat exchanger (40). It is provided at a position near the lower end.

  As shown in FIG. 19A, each main heat exchanger unit (41, 42) is an air heat exchanger of the same type as the heat exchanger unit (45) of the first embodiment, and includes a first header. (51a, 51b), a second header (52a, 52b), a heat transfer tube (53), and a fin (54). That is, in each main heat exchanger unit (41, 42), the first header (51a, 51b) is erected on one of the left end and the right end, and the second header (52a, 52b) is erected on the other side, and the heat transfer tube ( 53) is connected to the first header (51a, 51b) and the other end is connected to the second header (52a, 52b), and the fin (54) is arranged between the adjacent heat transfer tubes (53). Yes.

  As shown in FIG. 19B, the auxiliary heat exchanger unit (43) is an air heat exchanger of the same type as the heat exchanger unit (45) of the first embodiment, and includes a first header (56). And a second header (57), a heat transfer tube (58), and a fin (59). That is, in the auxiliary heat exchanger unit (43), the first header (56) is erected on one of the left end and the right end, the second header (57) is erected on the other, and one end of the heat transfer tube (58) is the first end. The other end of the header (56) is connected to the second header (57), and the fin (59) is disposed between the adjacent heat transfer tubes (58).

  In the outdoor heat exchanger (40) of this modification, the number of heat transfer tubes (58) of the auxiliary heat exchanger unit (43) is the number of the first main heat exchanger unit (41) and the second main heat exchanger unit ( It is about 1/9 of the number of heat transfer tubes (53) in 42).

  As shown in FIG. 16, the refrigerant circuit (20) of the present modification is provided with a header connecting pipe (27). One end of the header connection pipe (27) is bifurcated, and one of the branches is connected to the lower end of the second header (52a) of the first main heat exchanger unit (41) and the other is branched. Is connected to the lower end of the second header (52b) of the second main heat exchanger unit (42). The other end of the header connection pipe (27) is connected to the lower end of the second header (57) of the auxiliary heat exchanger unit (43). In addition, the first gas side pipe (21) of this modification is bifurcated, and one of the branches is connected to the upper end of the first header (51a) of the first main heat exchanger unit (41). The other branched side is connected to the first header (51b) of the second main heat exchanger unit (42). In addition, the liquid side connection pipe (25) of this modification is connected to the header connection pipe (27). Moreover, the connection pipe (26) of this modification is connected to the lower end of the first header (56) of the auxiliary heat exchanger unit (43).

  As shown in FIG. 16, during the cooling operation, both the four-way switching valve (34) and the four-way valve (60) are set to the first state in the air conditioner (10) of the present modification. The refrigerant flowing from the first gas side pipe (21) into the first header (51a, 51b) of each main heat exchanger unit (41, 42) passes through the heat transfer pipe (53) and the second header (52a, 52b). It passes in order and flows into the 2nd header (57) of an auxiliary heat exchanger unit (43) through the header connection pipe (27). Thereafter, the refrigerant sequentially passes through the heat transfer tube (58) and the first header (56) of the auxiliary heat exchanger unit (43) and flows into the connection tube (26).

  As shown in FIG. 17, during the heating operation, both the four-way switching valve (34) and the four-way valve (60) are set to the second state also in the air conditioner (10) of the present modification. The refrigerant flowing through the liquid side connection pipe (25) includes the second header (52a) of the first main heat exchanger unit (41), the second header (52b) of the second main heat exchanger unit (42), It flows separately into the second header (57) of the auxiliary heat exchanger unit (43). The refrigerant that has flowed into the second header (52a, 52b) of each main heat exchanger unit (41, 42) passes through the heat transfer tube (53) and the first header (51a, 51b) in this order, and reaches the first gas side. It flows into the pipe (21). The refrigerant flowing into the second header (57) of the auxiliary heat exchanger unit (43) sequentially passes through the heat transfer pipe (58) and the first header (56) and then flows into the connection pipe (26). It flows into the first gas side pipe (21) through the gas side connection pipe (24).

  As shown in FIG. 18, during the defrosting operation, also in the air conditioner (10) of this modification, the four-way switching valve (34) is set to the first state and the four-way valve (60) is set to the second state. Is done. A part of the refrigerant flowing through the first gas side pipe (21) flows into the first header (51a, 51b) of each main heat exchanger unit (41, 42), and the rest of the refrigerant flows into the gas side connection pipe (24 ) And the connecting pipe (26) and then flows into the first header (56) of the auxiliary heat exchanger unit (43). The refrigerant flowing into the first header (51a, 51b) of each main heat exchanger unit (41, 42) passes through the heat transfer pipe (53) and the second header (52a, 52b) and is connected to the header connection pipe (27). Then flows into the liquid side connecting pipe (25). The refrigerant that has flowed into the first header (56) of the auxiliary heat exchanger unit (43) flows into the liquid side connection pipe (25) through the heat transfer pipe (58) and the second header (57).

-Third modification-
In the air conditioner (10) of the second modified example, a plurality of auxiliary heat exchange units (55) may be formed in one auxiliary heat exchanger unit (43).

  In the air conditioner (10) of the present modification shown in FIG. 20, two auxiliary heat exchange units (55a, 55b) are formed in one auxiliary heat exchanger unit (43). That is, in the auxiliary heat exchanger unit (43) of the present modification, the same number of auxiliary heat exchange units (55a, 55b) as the main heat exchanger units (41, 42) are formed.

  As shown in FIG. 23, in the auxiliary heat exchanger unit (43) of this modification, partition plates (48a, 48b) are provided on the first header (56) and the second header (57), respectively. The internal space of the first header (56) is partitioned vertically by the partition plate (48a), and the internal space of the second header (57) is partitioned vertically by the partition plate (48b). As for the 1st header (56), the part above a partition plate (48a) comprises the 1st header (56a) of a 1st auxiliary heat exchange part (55a), and the part below a partition plate (48a) Constitutes the first header (56b) of the second auxiliary heat exchange section (55b). As for the 2nd header (57), the part above a partition plate (48a) comprises the 2nd header (57a) of a 1st auxiliary heat exchange part (55a), and the part below a partition plate (48a) Constitutes the second header (57b) of the second auxiliary heat exchange section (55b).

  As shown in FIG. 20, the refrigerant circuit (20) of the present modification is provided with a first header connection pipe (28) and a second header connection pipe (29). The first header connecting pipe (28) has one end connected to the lower end of the second header (52a) of the first main heat exchanger unit (41) and the other end connected to the first auxiliary heat exchanging part (55a). Is connected to the lower end of the second header (57a). The second header connection pipe (29) has one end connected to the lower end of the second header (52b) of the second main heat exchanger unit (42) and the other end connected to the second auxiliary heat exchange part (55b). Is connected to the lower end of the second header (57b). Moreover, the liquid side connection pipe (25) of this modification is bifurcated, one of the branches is connected to the first header connection pipe (28), and the other is branched to the second header connection pipe ( 29) is connected. Moreover, the connecting pipe (26) of this modification is bifurcated, and one of the branched pipes is connected to the lower end of the first header (56a) of the first auxiliary heat exchange section (55a), and the other branched. Is connected to the lower end of the first header (56b) of the second auxiliary heat exchange section (55b).

  As shown in FIG. 20, during the cooling operation, both the four-way switching valve (34) and the four-way valve (60) are set to the first state in the air conditioner (10) of the present modification. In each main heat exchanger unit (41, 42), the refrigerant flowing into the first header (51a, 51b) from the first gas side pipe (21) passes through the heat transfer pipe (53) and passes through the second header (52a). , 52b). The refrigerant that has flowed into the second header (52a) of the first main heat exchanger unit (41) passes through the first header connecting pipe (28), and the second header (57a) of the first auxiliary heat exchanger (55a). ). The refrigerant that has flowed into the second header (52b) of the second main heat exchanger unit (42) passes through the second header connection pipe (29), and the second header (57b) of the second auxiliary heat exchange section (55b). ). The refrigerant that has flowed into the second header (57a, 57b) of each auxiliary heat exchange section (55a, 55b) flows into the first header (56a, 56b) through the heat transfer pipe (58), and then the connection pipe ( 26).

  As shown in FIG. 21, during the heating operation, both the four-way switching valve (34) and the four-way valve (60) are set to the second state also in the air conditioner (10) of the present modification. The refrigerant flowing through the liquid side connection pipe (25) includes the second header (52a) of the first main heat exchanger unit (41), the second header (52b) of the second main heat exchanger unit (42), It flows separately into the second header (57a) of the first auxiliary heat exchanger (55a) and the second header (57b) of the second auxiliary heat exchanger (55b). The refrigerant that has flowed into the second header (52a, 52b) of each main heat exchanger unit (41, 42) passes through the heat transfer tube (53) and the first header (51a, 51b) in this order, and reaches the first gas side. It flows into the pipe (21). The refrigerant that has flowed into the second header (57a, 57b) of each auxiliary heat exchange section (55) passes through the heat transfer tube (58) and the first header (56a, 56b) in order and flows into the connection tube (26). Then, it flows into the first gas side pipe (21) through the gas side connection pipe (24).

  As shown in FIG. 22, during the defrosting operation, also in the air conditioner (10) of the present modification, the four-way switching valve (34) is set to the first state and the four-way valve (60) is set to the second state. Is done. A part of the refrigerant flowing through the first gas side pipe (21) flows into the first header (51a, 51b) of each main heat exchanger unit (41, 42), and the rest of the refrigerant flows into the gas side connection pipe (24 ) And the connecting pipe (26) and then flows into the first header (56a, 56b) of each auxiliary heat exchange section (55a, 55b). The refrigerant flowing into the first header (51a, 51b) of each main heat exchanger unit (41, 42) passes through the heat transfer pipe (53) and the second header (52a, 52b), and then the liquid side connection pipe Flows into (25). The refrigerant that has flowed into the first header (56a, 56b) of each auxiliary heat exchanger (55a, 55b) passes through the heat transfer pipe (58) and the second header (57a, 57b), and then the liquid side connection pipe ( To 25).

-Fourth modification-
As shown in FIG. 24, in the outdoor heat exchangers (40) of the second and third modifications, the auxiliary heat exchanger unit (43) is not below the second main heat exchanger unit (42), You may arrange | position so that it may overlap with the lower end part of a 2nd main heat exchanger unit (42). That is, in the outdoor heat exchanger (40) of this modification, the auxiliary heat exchanger unit (43) is disposed near the lower end of the outdoor heat exchanger (40). In addition, the auxiliary heat exchanger unit (43) is arranged upstream of the second main heat exchanger unit (42) in the direction of the flow of outdoor air passing through the outdoor heat exchanger (40).

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or its use.

  As described above, the present invention is useful for a refrigeration apparatus capable of switching between a cooling operation and a heating operation.

10 Air conditioner (refrigeration equipment)
20 Refrigerant circuit
21 First gas side piping
23 Liquid side piping
31 Compressor
32 Indoor heat exchanger (use side heat exchanger)
35 Switching mechanism
40 Outdoor heat exchanger (heat source side heat exchanger)
50 Main heat exchanger
51 First header
52 Second header
53 Heat transfer tube
54 fins
55 Auxiliary heat exchanger
56 First header
57 Second header
58 Heat transfer tube
59 Fins
60 Four way valve
71 1st port
72 Second port
73 3rd port
74 4th port

Claims (4)

A compressor (31), a heat source side heat exchanger (40) for exchanging heat between the refrigerant and outdoor air, and a use side heat exchanger (32) for exchanging heat between the refrigerant and the object are provided to perform a refrigeration cycle. With refrigerant circuit (20)
A cooling operation in which the refrigerant condenses in the heat source side heat exchanger (40) and the refrigerant evaporates in the usage side heat exchanger (32) to cool the object, and in the usage side heat exchanger (32) A refrigerating apparatus capable of switching between a heating operation in which the refrigerant condenses and the refrigerant evaporates in the heat source side heat exchanger (40) to heat the object,
The heat source side heat exchanger (40) includes a main heat exchange part (50) and an auxiliary heat exchange part (55),
Each of the main heat exchange part (50) and the auxiliary heat exchange part (55) has a first header (51, 56), a second header (52, 57), and one end of each of the first header (51 , 56) and a plurality of flat heat transfer tubes (53, 58) whose other ends are connected to the second header (52, 57), and fins (54, 54) joined to the heat transfer tubes (53, 58). , 59)
The number of heat transfer tubes (58) provided in the auxiliary heat exchange section (55) is less than the number of heat transfer tubes (53) provided in the main heat exchange section (50),
In the heat source side heat exchanger (40), the refrigerant passes through the auxiliary heat exchange section (55) after passing through the main heat exchange section (50), and a part of the refrigerant is in the main heat exchange section ( 50) and a switching mechanism (35) for switching to a parallel state in which the remainder passes through the auxiliary heat exchanger (55).
In the cooling operation, the switching mechanism (35) places the heat source side heat exchanger (40) in series, and in the heating operation, the switching mechanism (35) places the heat source side heat exchanger (40) in parallel. Refrigeration equipment characterized. In claim 1,
The auxiliary heat exchanger (55) is disposed below the main heat exchanger (50) or near the lower end of the heat source side heat exchanger (40). The refrigerant discharged from the compressor (31) is supplied to the heat source side heat exchanger (40) in order to melt frost attached to the heat source side heat exchanger (40) during the heating operation. To perform the defrosting operation,
In the defrosting operation, the switching mechanism (35) places the heat source side heat exchanger (40) in a parallel state. In any one of Claims 1 thru | or 3,
The refrigerant circuit (20) has one end connected to the first header (51) of the main heat exchange section (50) and the other end connected to the discharge side or suction side of the compressor (31). (21) and a liquid side pipe (23) connected to the liquid side end of the use side heat exchanger (32),
In the heat source side heat exchanger (40), the second header (52) of the main heat exchange unit (50) and the second header (57) of the auxiliary heat exchange unit (55) communicate with each other,
A first port (71) connected to the gas side pipe (21), a second port (72) connected to the first header (56) of the auxiliary heat exchange section (55), and the liquid side pipe (23 ) Connected to the third port (73) connected to the second header (52) of the main heat exchanger (50) or the second header (57) of the auxiliary heat exchanger (55) ( 74) is provided as the switching mechanism (35),
The four-way valve (60)
When the heat source side heat exchanger (40) is placed in series, the second port (72) communicates with the third port (73) and the first port (71) and the fourth port (74) are closed. The first state,
When the heat source side heat exchanger (40) is placed in parallel, the first port (71) communicates with the second port (72) and the third port (73) communicates with the fourth port (74). A refrigeration apparatus having two states.

Images