JP2010236707A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger connected to a refrigerant circuit performing a refrigerating cycle, which is usable as an evaporator or a radiator, and for avoiding dry-out when used as the evaporator. <P>SOLUTION: An indoor heat exchanger (1) includes: a body part (2) with a flow divider (6), a gas-liquid separator (5), and a heat transmission part (3) connected thereto; an ejector (8) arranged in an end on the flow divider (6) side in the body part (2); a communicating piping (9) communicating the liquid side opening of the gas-liquid separator (5) and the suction opening of the ejector (8); and an opening/closing valve (10) for opening/closing the communicating piping (9). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a heat exchanger that constitutes at least one of an evaporator and a radiator of a refrigerant circuit that performs a refrigeration cycle.

  Conventionally, a heat exchanger connected to a refrigerant circuit that performs a refrigeration cycle is known. This heat exchanger is used to radiate or evaporate the refrigerant circulating in the refrigerant circuit.

  Patent Document 1 discloses a cross fin tube type heat exchanger as an example of this type of heat exchanger. This heat exchanger is connected to the refrigerant circuit of the air conditioner.

  This cross fin tube type heat exchanger includes a heat transfer tube group having a plurality of heat transfer tubes and a heat transfer fin group having a plurality of heat transfer fins. The heat transfer tube group is formed by arranging a plurality of heat transfer tubes vertically. On the other hand, the heat transfer fin group includes rectangular heat transfer fins that are fixed by being passed through the heat transfer tubes of the heat transfer tube group, with a predetermined interval along the length direction of the heat transfer tubes. They are arranged in a row so that they are parallel.

And the refrigerant | coolant of the said refrigerant circuit flows through the pipe | tube inside of the said heat exchanger tube group, and a refrigerant | coolant and air heat-exchange by air flowing through the pipe | tube outer side.
Japanese Patent Laid-Open No. 06-26666

  By the way, for example, when this heat exchanger is used as a use side heat exchanger in an air conditioner for both cooling and heating, this heat exchanger becomes an evaporator during cooling operation and becomes a radiator during heating operation.

  Here, when the heat exchanger is used as an evaporator, dryout may occur near the refrigerant outlet of the heat exchanger. That is, in the vicinity of the refrigerant outlet of the heat exchanger, the refrigerant flow state may become a spray flow, and in that case, the inner peripheral surface near the refrigerant outlet of the heat exchanger is dried, and the atomized refrigerant evaporates. It becomes difficult. For this reason, when this dry-out occurs, the evaporation heat transfer performance is drastically lowered at that portion.

  The present invention has been made in view of such points, and its purpose is a heat exchanger connected to a refrigerant circuit that performs a refrigeration cycle, and can be used as an evaporator or a radiator. An object of the present invention is to provide a heat exchanger capable of avoiding dryout when used as an evaporator.

  1st invention presupposes the heat exchanger which comprises at least one of the evaporator and heat radiator of a refrigerant circuit (20) which perform a refrigerating cycle.

  The heat exchanger includes a heat transfer section (3) having a plurality of heat transfer passages (4) through which the refrigerant of the refrigerant circuit (20) flows, and a branch flow connected to one end side of the heat transfer section (3) The main body part (2) having the vessel part (6) and the gas-liquid separation part (5) connected to the other end of the heat transfer part (3), and the refrigerant evaporates in the heat transfer part (3). The flow divider part which becomes the refrigerant inlet part of the main body part (2) in the first state and becomes the refrigerant outlet part of the main body part (2) in the second state in which the refrigerant dissipates heat in the heat transfer part (3) The first refrigerant passage (14) connected to the end (6a) of (6) and the refrigerant outlet portion of the main body (2) in the first state, and the main body (2 The second refrigerant passage (15) connected to the gas side opening (5b) of the gas-liquid separator (5) and the ejector connected to the first refrigerant passage (14) as the refrigerant inlet Part (8) and the above A communication path (9) that connects the liquid side opening of the liquid separation section (5) and the suction port of the ejector section (8), and an open / close mechanism (10) that can open and close the communication path (9). It is characterized by having.

  Here, the first state is a state in which the heat exchanger according to the present invention becomes an evaporator, and the second state is a state in which the heat exchanger according to the present invention radiates heat while the phase of the refrigerant changes. In this case, it is a state of a condenser.

  In the first invention, the opening / closing mechanism (10) is set to open in the first state. In this state, the refrigerant flows from the first refrigerant passage (14) into the ejector portion (8) of the main body portion (2). In the ejector part (8), the refrigerant is accelerated under reduced pressure, and the liquid refrigerant in the gas-liquid separation part (5) is sucked through the communication path (9) by the negative pressure generated by the acceleration of the refrigerant. Then, after the liquid refrigerant in the communication path (9) and the refrigerant in the first refrigerant path (14) merge in the ejector section (8), the merged refrigerant is ejected from the ejector section (8). .

  The refrigerant ejected from the ejector section (8) flows to the flow divider section (6), and after being diverted by the flow divider section (6), flows into the heat transfer passages (4), and the heat transfer paths. Evaporates in the passage (4). The refrigerant evaporated in each heat transfer passage (4) flows to the gas-liquid separator (5) and is gas-liquid separated in the gas-liquid separator (5). The gas refrigerant after gas-liquid separation in the gas-liquid separation part (5) flows out from the main body part (2) through the second refrigerant passage (15). On the other hand, the liquid refrigerant after the gas-liquid separation in the gas-liquid separation part (5) is sucked into the ejector part (8) through the communication path (9) as described above.

  Here, since the gas-liquid separator (5) is connected to the heat transfer section (3), the refrigerant can flow out from the heat transfer section (3) in a two-phase state. Further, since the communication path (9) is provided, the liquid refrigerant in the gas-liquid separation part (5) is returned to the ejector part (8) through the communication path (9), and again the heat transfer part (3 ) Can be sent to.

  In the second state, the opening / closing mechanism (10) is closed. In this state, the refrigerant flows from the second refrigerant passage (15) into the gas-liquid separator (5) of the main body (2). This refrigerant is in a gas state or a supercritical state. The refrigerant flowing into the gas-liquid separator (5) is divided into the heat transfer passages (4). At this time, gas-liquid separation is not performed in the gas-liquid separator (5), and the gas-liquid separator (5) functions as a header. Further, since the opening / closing mechanism (10) is set to be closed, the refrigerant that has flowed into the gas-liquid separation part (5) does not flow out to the ejector part (8) through the communication path (9).

  The refrigerant divided into each heat transfer passage (4) radiates heat in the heat transfer passage (4), then flows into the flow divider section (6), and joins at the flow divider section (6). The refrigerant combined in the flow divider section (6) flows out of the first refrigerant passage (14) after being expanded in the ejector section (8).

  Thus, by setting the opening / closing mechanism (10) to be closed, the refrigerant flowing into the gas-liquid separation unit (5) does not flow to the ejector unit (8), but to the heat transfer passage (4). It will be able to flow.

  According to a second invention, in the first invention, the refrigerant having the first flow path (11b) and the second flow path (11a) and flowing through the first flow path (11b) and the second flow path (11a) ), And the first flow path (11b) communicates with the first refrigerant path (14), and the second flow path (11a) is the second. It is characterized by communicating with the refrigerant passage (15).

  For example, during the first state, the heat load of the heat transfer section (3) increases rapidly, and a large amount of two-phase refrigerant temporarily flows from the heat transfer section (3) to the gas-liquid separation section (5). May flow in. If it becomes like this, the liquid refrigerant which could not be gas-liquid-separated in the said gas-liquid separation part (5) will flow out through a 2nd refrigerant path (15). Since a compressor is connected to the downstream side of the second refrigerant passage (15), the compressor sucks the liquid refrigerant in the second refrigerant passage (15), which is not preferable.

  In the second invention, even in such a case in the first state, the heating heat exchanger (11) causes the refrigerant in the second refrigerant passage (15) to be the refrigerant in the first refrigerant passage (14). Can be heated.

  According to a third invention, in the second invention, a bypass passage (16) for bypassing the second flow path (11a) of the heating heat exchange section (11), and the second flow path (11a) in the first state. ) And the bypass passage position for closing the bypass passage (16) and the bypass opening position for opening the bypass passage (16) and closing the second flow path (11a) in the second state. And a switching mechanism (CV1, CV2).

  Here, in the second state, if the heating heat exchanging part (11) is used, the heating heat before the refrigerant flowing through the second refrigerant passage (15) dissipates heat in the heat transfer part (3). Heat is also dissipated in the replacement part (11). For this reason, compared with the case where the said heating heat exchange part (11) is not used, the thermal radiation amount of the refrigerant | coolant in the said heat-transfer part (3) reduces.

  In the third invention, the heating heat exchanger (11) is used in the first state, and in the second state, the heating heat exchanger (11) is bypassed to flow the refrigerant by bypassing the heating heat exchanger (11). ) Can be avoided.

  According to a fourth invention, in any one of the first to third inventions, a part of the communication passage (9) forms a heat transfer passage (4) of the main body (2). It is a feature.

  In the fourth invention, in the first state, the liquid refrigerant in the gas-liquid separator (5) is heat-exchanged in the same manner as the refrigerant flowing in the heat transfer passage (4), and then the ejector part (8 ).

  According to a fifth invention, in any one of the first to fourth inventions, the gas-liquid separation part (5) has a cylindrical casing whose upper and lower ends are closed, and the inner peripheral surface of the casing is The heat transfer passage (4) of the main body (2) is connected to the casing so that the refrigerant is supplied in the tangential direction.

  In the fifth invention, the refrigerant that has flowed out of the heat transfer passage (4) of the main body (2) can be swung along the inner peripheral surface of the casing. The centrifugal separation action by the swirl facilitates the gas-liquid separation.

  The sixth invention is characterized in that, in any one of the first to fifth inventions, the refrigerant flowing through the main body (2) is carbon dioxide.

  Here, in the conventional heat exchanger, when carbon dioxide is used as a refrigerant, when the heat exchanger is used as an evaporator, the above-described dryout is likely to occur near the refrigerant outlet of the heat exchanger.

  In 6th invention, since a refrigerant | coolant can be flowed out in the two-phase state from the said heat-transfer part (3), the dryness of the exit refrigerant | coolant in the said heat-transfer part (3) can be set low, and the said heat-transfer part ( It is possible to prevent dryout from occurring near the refrigerant outlet in 3).

  According to a seventh invention, in any one of the first to fifth inventions, the refrigerant flowing through the main body (2) has a saturation pressure with respect to an evaporation temperature of 0 ° C. of 0.4 MPa or less. Examples of the refrigerant include HFC134a and HFO1234yf.

  Here, in the conventional heat exchanger, when HFC134a, HFO1234yf, or the like is used as a refrigerant, when the heat exchanger is used as an evaporator, the evaporator performance is likely to deteriorate due to the pressure loss of the refrigerant flowing through the heat exchanger. .

  In the seventh invention, since the refrigerant can flow out from the heat transfer section (3) in a two-phase state, the dryness of the outlet refrigerant in the heat transfer section (3) can be set low, and the heat exchange of the present invention The pressure loss of the refrigerant flowing through the vessel can be suppressed as much as possible.

  According to the present invention, the refrigerant in the two-phase state can be allowed to flow out from the heat transfer section (3) in the first state. Thereby, the dryness of a refrigerant | coolant can be restrained low and a dryout can be avoided. In the second state, the open / close mechanism (10) that was set to open in the first state is set to the closed state, so that the refrigerant that has flowed into the gas-liquid separation unit (5) flows to the ejector unit (8). Without flowing, it can flow to the heat transfer passage (4). Thereby, the refrigerant branched from the gas-liquid separator (5) can be reliably radiated through the heat transfer passage (4).

  For example, during the first state, the heat load of the heat transfer section (3) may increase rapidly, and a large amount of two-phase refrigerant may temporarily flow into the gas-liquid separation section (5). In this case, it is conceivable that liquid refrigerant that could not be gas-liquid separated by the gas-liquid separator (5) flows into the second refrigerant passage (15).

  According to the second invention, even in such a case, the liquid refrigerant can be heated by the heating heat exchange section (11). As a result, after the refrigerant flowing through the second refrigerant passage (15) is brought into an overheated state, it can be sucked into the compressor, and the compressor can be prevented from being wet.

  According to the third aspect of the invention, the heating heat exchanging part (11) is used in the first state, and in the second state, the heating heat exchanging part (11) is bypassed to flow the refrigerant. It is possible not to use the heat exchanger (11). Thereby, the heat loss of the heat transfer section (3) in the second state can be eliminated.

  According to the fourth aspect of the invention, in the first state, the evaporation temperature of the refrigerant flowing through the communication passage (9) is a heat transfer passage (other than the heat transfer passage (4) of the communication passage (9) ( Since the evaporation temperature of the refrigerant flowing through 4) is lower, the evaporation temperature of the heat transfer section (3) can be set higher because the evaporation temperature of the refrigerant flowing through the communication passage (9) is lower.

  Thereby, the efficiency of the air conditioning apparatus which has the refrigerant circuit which connected the heat exchanger of this invention can be improved.

  Moreover, according to the said 5th invention, the refrigerant | coolant which flowed out from the heat-transfer channel | path (4) of the said main-body part (2) can be swirled so that the inner peripheral surface of a casing may be met. Thereby, the refrigerant is easily separated into gas and liquid by the centrifugal action by the turning, and the gas-liquid separation efficiency in the gas-liquid separation unit (5) can be improved reliably.

  According to the sixth aspect of the invention, even when carbon dioxide is used as the refrigerant, the dryness of the refrigerant flowing out from the heat transfer section (3) is set low in the first state. Thus, it is possible to prevent dryout from occurring in the vicinity of the refrigerant outlet of the heat transfer section (3). Thereby, even if carbon dioxide is used as the refrigerant of the heat exchanger of the present invention, the performance of the heat exchanger can be prevented from being reduced as much as possible.

  Further, according to the seventh aspect, since the saturation pressure with respect to the evaporation temperature of 0 ° C. is 0.4 MPa or less, the saturation pressure is relatively low, and the evaporation temperature drop due to pressure loss is large, the air conditioning performance of the air conditioner Even when a refrigerant that greatly affects the flow rate is used, the density of the refrigerant flowing through the heat exchanger of the present invention is increased by setting the dryness of the refrigerant flowing out from the heat transfer section (3) to be low. By reducing the flow rate, the pressure loss can be suppressed as much as possible. Thereby, even when the refrigerant | coolant whose saturation pressure with respect to 0 degreeC of evaporation temperature is 0.4 Mpa or less is used as a refrigerant | coolant, the fall of the performance of the heat exchanger of this invention can be suppressed.

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

  First, after describing the air conditioner including the heat exchanger of the present embodiment, the heat exchanger will be described.

-Air conditioner-
The air conditioner is a separate type that includes an outdoor unit and an indoor unit. This air conditioner can perform indoor heating and cooling operations by installing the outdoor unit outdoors and installing the indoor unit indoors.

  FIG. 1 shows a refrigerant circuit diagram of the air conditioner. The outdoor unit is provided with an outdoor circuit (20a), and the indoor unit is provided with an indoor circuit (20b). A refrigerant circuit (20) that performs a vapor compression supercritical refrigeration cycle is configured by connecting both ends of the outdoor circuit (20a) and both ends of the outdoor circuit (20a). In this refrigerant circuit (20), carbon dioxide is used as a refrigerant.

  Connected to the refrigerant circuit (20) are a compressor (21), a four-way selector valve (22), an outdoor heat exchanger (23), and an indoor heat exchanger (1) as a heat exchanger of the present invention. Yes.

  The four-way selector valve (22) has four ports, and a cooling position (state indicated by a solid line in FIG. 1) in which the first port and the fourth port communicate with each other and the second port and the third port communicate with each other. The heating port can be switched to a heating position (state indicated by a broken line in FIG. 1) in which the first port and the third port communicate with each other and the second port and the fourth port communicate with each other.

  The compressor (21) is a hermetically sealed type, and has a variable capacity by an inverter (not shown) electrically connected to the compressor (21). The compressor (21) is configured to compress the sucked refrigerant to a predetermined pressure and discharge it. A discharge pipe (23) extending from the discharge side of the compressor (21) is connected to a first port of the four-way switching valve (22), and a refrigerant pipe extending from the fourth port of the four-way switching valve (22) ( 26) is connected to one end of the outdoor heat exchanger (23).

  The outdoor heat exchanger (23) constitutes an air heat exchanger in which heat is exchanged between refrigerant and outdoor air taken in by an outdoor fan (not shown) provided in the vicinity of the outdoor heat exchanger (23). Yes. A refrigerant pipe (25) extending from the other end of the outdoor heat exchanger (23) is connected to the indoor heat exchanger (1). The indoor heat exchanger (1) will be described in detail later. A refrigerant pipe (24) extending from the indoor heat exchanger (1) is connected to a third port of the four-way selector valve (22), and an intake pipe (27 extending from the second port of the four-way selector valve (22) ) Is connected to the suction side of the compressor (21).

  When the four-way selector valve (22) is set to the cooling position, the outdoor heat exchanger (23) serves as a radiator and the indoor heat exchanger (1) serves as an evaporator to perform a cooling operation. . On the other hand, when the four-way selector valve (22) is set to the heating position, the outdoor heat exchanger (23) serves as an evaporator, and the indoor heat exchanger (1) serves as a radiator to perform heating operation. .

-Indoor heat exchanger-
Next, the indoor heat exchanger (1) as a heat exchanger that is a feature of the present invention will be described.

  As shown in FIG. 2, the indoor heat exchanger (1) has a main body in which a flow divider (6), a heat transfer unit (3), and a gas-liquid separator (gas-liquid separator) (5) are connected. Part (2).

  A plurality of branch pipes (7) are connected to the flow divider (6). The end of this branch pipe (7) is connected to one end of a heat transfer pipe (heat transfer passage) (4) constituting the heat transfer section (3).

  This heat transfer section (3) is configured as a so-called cross fin and tube type, and penetrates through the heat transfer tube group (not shown) in which a plurality of the above heat transfer tubes (4) are arranged vertically and the heat transfer tube of the heat transfer tube group. A group of heat transfer fins (not shown) in which the rectangular heat transfer fins that are fixed are arranged in a row so as to be parallel to each other with a predetermined interval along the length direction of the heat transfer tubes; have.

  And as shown in FIG. 5, each edge part of the said some heat exchanger tube (4) is connected to the said gas-liquid separator (5).

  The gas-liquid separator (5) is composed of a sealed container formed in a vertically long cylindrical shape. A gas side opening (5b) is formed at the top of the sealed container, and a liquid side opening is formed at the bottom of the sealed container. A plurality of inflow openings are formed along the length direction on the side peripheral surface of the closed container. The other end of each heat transfer tube (4) described above is connected to each inflow opening. Thereby, the refrigerant that has flowed out of the heat transfer tubes (4) can be swung along the inner peripheral surface of the sealed container.

  The main body (2) is connected to first and second refrigerant pipes (14, 15). The first refrigerant pipe (14) is connected to the opening (6a) of the flow divider (6), and the second refrigerant pipe (15) is a gas side of the casing (10) in the gas-liquid separator (5). It is connected to the opening (5b). The first refrigerant pipe (14) is provided with an ejector (8).

  The ejector (8) has a drive flow path, a suction passage, and an ejection flow path (not shown). The driving refrigerant flowing in from the inlet of the ejector (8) is expanded by a nozzle provided in the driving channel when passing through the driving channel. The nozzle hole diameter is variable. Due to this expansion, the flow of the refrigerant is accelerated at the outlet of the nozzle, and the negative pressure generated by this acceleration sucks the suction refrigerant from the suction port of the ejector (8) into the suction passage, and flows through the suction passage. And the refrigerant | coolant which passed the said drive flow path and the refrigerant | coolant which passed the said suction flow path are mixed, and it flows in into the said ejection flow path. The refrigerant that has flowed into the ejection channel is decelerated and pressurized by a diffuser provided in the ejection channel, and then ejected from the ejection port of the ejector (8).

  The main body (2) is provided with a communication pipe (communication path) (9) that connects the liquid side opening of the gas-liquid separator (5) and the suction port of the ejector (8). The communication pipe (9) is provided with an open / close valve (open / close mechanism) (10).

-Operation of indoor heat exchanger-
Next, the operation of the indoor heat exchanger (1) will be described. First, after describing the operation in the first state (the air conditioner is in the cooling operation), the second state (the air conditioner is in the heating operation) will be described.

<First state>
In the first state, the on-off valve (10) is set to open. In that state, the refrigerant radiated by the outdoor heat exchanger (23) flows into the ejector (8) of the indoor heat exchanger (1) through the first refrigerant pipe (14).

  In the ejector (8), the inflowing refrigerant flows through the driving passage, and the refrigerant is depressurized and accelerated by the nozzle of the driving passage. Due to the negative pressure generated by the acceleration of the refrigerant, the liquid refrigerant in the gas-liquid separator (5) is sucked into the suction passage of the ejector (8). Then, after the refrigerant in the drive passage and the liquid refrigerant in the suction passage are mixed in the ejection passage of the ejector (8), the pressure is reduced by the diffuser in the ejection passage and the pressure is increased. The pressurized refrigerant flows out of the ejection passage and flows to the flow divider (6).

  In the flow divider (6), the refrigerant that has flowed is divided and flows into the heat transfer pipe (4) of the heat transfer section (3) through each branch pipe (7). The refrigerant flowing into the heat transfer tube (4) absorbs heat from indoor air sent from an indoor fan (not shown) provided in the vicinity of the indoor heat exchanger (1) and evaporates, and then the heat transfer tubes ( 4) Escape from. At this time, the indoor air is cooled by removing heat from the refrigerant, and the cooled indoor air is supplied into the room.

  Here, the refrigerant in the heat transfer tube (4) does not flow out of the heat transfer tube (4) in a completely evaporated state, but flows out in a two-phase state. The two-phase refrigerant flows into the gas-liquid separator (5). In the gas-liquid separator (5), the refrigerant flowing in is separated into liquid refrigerant and gas refrigerant, and the liquid refrigerant is sucked into the ejector (8) as described above. On the other hand, the gas refrigerant is sucked into the compressor (21) through the second refrigerant pipe (15).

  The gas refrigerant in the second refrigerant pipe (15) is sucked into the compressor (21) and compressed to a predetermined pressure, and then the four-way switching valve (22), the outdoor heat exchanger (23), After passing through, it flows into the indoor heat exchanger (1) again from the first refrigerant pipe (14).

<Second state>
In the second state, the on-off valve (10) is set to be closed. In this state, the gas refrigerant compressed by the compressor (21) flows into the gas-liquid separator (5) of the indoor heat exchanger (1) through the second refrigerant pipe (15).

  In the gas-liquid separator (5), the refrigerant that has flowed in is branched and flows into the heat transfer tube (4) of the heat transfer section (3). At this time, the gas-liquid separator (5) does not perform gas-liquid separation, and the gas-liquid separator (5) functions as a header.

  The refrigerant flowing into the heat transfer tube (4) radiates heat to the indoor air sent from the indoor fan of the indoor heat exchanger (1) and then flows out from the heat transfer tubes (4). At this time, the room air is heated from the refrigerant, and the heated room air is supplied into the room. The refrigerant that has flowed out of the heat transfer pipe (4) passes through the branch pipe (7) of the flow divider (6), merges in the flow divider (6), and then flows into the ejector (8). Then, after being expanded by the ejector (8), it is sucked into the compressor (21) through the first refrigerant pipe (14).

  The refrigerant in the first refrigerant pipe (14) evaporates in the outdoor heat exchanger (23), then is sucked into the compressor (21) and compressed to a predetermined pressure, and then the four-way switching valve. After passing through (22), it flows into the indoor heat exchanger (1) again from the second refrigerant pipe (15).

  According to this embodiment, the refrigerant in the two-phase state can be caused to flow out from the heat transfer section (3) during the first state. Thereby, the dryness of a refrigerant | coolant can be restrained low and a dryout can be avoided. In the second state, the on-off valve (10) that was set to open in the first state is set to the closed state, so that the refrigerant that has flowed into the gas-liquid separation unit (5) flows to the ejector unit (8). Without flowing, it can flow to the heat transfer tube (4). Thereby, the refrigerant branched from the gas-liquid separator (5) can be reliably radiated by the heat transfer tube (4).

  In addition, according to the present embodiment, since the refrigerant can flow out from the heat transfer section (3) in a two-phase state, the degree of dryness of the outlet refrigerant in the heat transfer section (3) can be lowered, and the heat transfer section It is possible to prevent dryout from occurring in the vicinity of the refrigerant outlet of the section (3). Thereby, even when carbon dioxide is used as the refrigerant of the air conditioner, the performance of the air conditioner can be prevented from being reduced as much as possible.

  Moreover, according to this embodiment, the refrigerant | coolant which flowed out from the heat exchanger tube (4) of the said main-body part (2) can be swirled along the internal peripheral surface of a gas-liquid separator (5). Thereby, the refrigerant is easily separated into gas and liquid by the centrifugal action by the swirling, and the gas-liquid separation efficiency in the gas-liquid separator (5) can be reliably improved.

-Modification 1 of embodiment-
The difference between the indoor heat exchanger of Modification 1 shown in FIG. 3 and the indoor heat exchanger shown in the above embodiment is that the heating heat exchanger (11), the bypass pipe (bypass passage) (16), the first and the second Two check valves (switching mechanisms) (CV1, CV2) are provided.

  The heating heat exchanger (11) has a first flow path (11b) and a second flow path (11a), and a first refrigerant pipe (14) is connected to the first flow path (11b). A second refrigerant pipe (15) is connected to the second flow path (11a).

  In this case, the refrigerant in the second refrigerant pipe (15) can be heated by the refrigerant in the first refrigerant pipe (14). That is, for example, in the first state, the heat load of the heat transfer section (3) increases rapidly, and the liquid refrigerant that cannot be gas-liquid separated by the gas-liquid separator (5) becomes the second refrigerant pipe (15 ). Even in such a case, the liquid refrigerant can be heated by the heating heat exchanger (11). As a result, after the refrigerant flowing through the second refrigerant pipe (15) is overheated, it can be sucked into the compressor, and the compressor can be prevented from being wet.

  The bypass pipe (16) is connected to the second refrigerant pipe (15) so as to bypass the second flow path (11a) of the heating heat exchanger (11). In addition, the bypass pipe (16) has a first check in a direction that allows a refrigerant flow toward the gas-liquid separator (5) of the main body (2) and prohibits a refrigerant flow in the reverse direction. A valve (CV1) is provided. Further, the flow of the refrigerant toward the connection portion of the bypass pipe (16) is allowed between the heating heat exchanger (11) and the connection portion of the bypass pipe (16) in the second refrigerant pipe (15). In addition, a second check valve (CV2) is provided in a direction to prohibit the flow of refrigerant in the reverse direction.

  In this way, the indoor heat exchanger is configured to open the second flow path (11a) by the second check valve (CV2) in the first state and the bypass passage (CV1) by the first check valve (CV1). 16) closes the bypass, and opens the bypass passage (16) by the first check valve (CV1) in the second state, and opens the second flow path (CV2) by the second check valve (CV2). 11a) can be set to the bypass open state that closes. Thereby, the heat loss of the heat transfer section (3) in the second state can be eliminated.

-Modification 2 of embodiment-
The difference between the indoor heat exchanger of Modification 2 and the indoor heat exchanger shown in the above embodiment is that a part of the communication pipe (9) constitutes a heat transfer tube of the heat transfer section (3). And a flow rate adjusting valve (13) in place of the on-off valve (10).

  In this way, in the first state, the liquid refrigerant in the gas-liquid separator (5) is exchanged in the same manner as the refrigerant flowing in the heat transfer tube (4) and then returned to the ejector (8). become able to. Thereby, at the said 1st state, the evaporation temperature of the refrigerant | coolant which flows through the said communication pipe (9) is higher than the evaporation temperature of the refrigerant | coolant which flows through heat transfer pipes (4) other than the heat transfer pipe (4) of the said communication pipe (9). Since the evaporation temperature of the refrigerant flowing through the communication pipe (9) is low, the evaporation temperature of the heat transfer section (3) can be set high.

  In addition, the refrigerant return amount to the ejector (8) can be adjusted to the optimum value by the flow rate adjusting valve (13) in accordance with the suction amount of the ejector (8) due to the difference in the operating state. As described above, the efficiency of the air conditioner including this indoor heat exchanger (1) can be improved.

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

  In this embodiment, although the heat exchanger of this invention was used as an indoor heat exchanger of an air conditioning apparatus, it is not limited to this, You may use the heat exchanger of this invention as an outdoor heat exchanger.

  In this embodiment, carbon dioxide is used as the refrigerant. However, the present invention is not limited to this. For example, a refrigerant such as HFC134a or HFO1234yf, that is, a refrigerant having a saturation pressure with respect to an evaporation temperature of 0 ° C. is 0.4 MPa or less. Also good. In this case, the dryness of the refrigerant flowing out from the indoor heat exchanger (1) is adjusted to be low. By doing so, the pressure loss of the indoor heat exchanger (1) can be suppressed as much as possible, and the air conditioning performance of the air conditioner can be prevented from being reduced as much as possible.

  In the present embodiment, carbon dioxide is used as the refrigerant. However, the present invention is not limited to this. For example, the saturation pressure with respect to the evaporation temperature of 0 ° C. is 0.4 MPa or less, the saturation pressure is relatively low, and the pressure loss. A refrigerant that greatly affects the air conditioning performance of the air conditioner may be used because the evaporation temperature drop due to the air is large. Examples of such a refrigerant include HFC134a and HFO1234yf. When such a refrigerant is used, the dryness of the refrigerant outlet of the indoor heat exchanger (1) is adjusted to be low. By doing so, the density of the refrigerant can be increased, the flow rate can be lowered, and the pressure loss of the indoor heat exchanger (1) can be suppressed as much as possible, so the effect is great.

  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 heat exchanger that constitutes at least one of an evaporator and a radiator of a refrigerant circuit that performs a refrigeration cycle.

It is a refrigerant circuit figure of the air harmony device to which the heat exchanger concerning the embodiment of the present invention was connected. It is a refrigerant | coolant system | strain diagram of the heat exchanger which concerns on embodiment of this invention. It is a refrigerant | coolant system | strain diagram of the heat exchanger which concerns on the modification 1 of embodiment of this invention. It is a refrigerant | coolant system | strain diagram of the heat exchanger which concerns on the modification 2 of embodiment of this invention. It is sectional drawing which shows the connection part of the heat exchanger tube and gas-liquid separator in the heat exchanger of this invention.

1 Indoor heat exchanger
4 Heat transfer tube (heat transfer flow path)
5 Gas-liquid separator (gas-liquid separator)
6 Current divider
8 Ejector (Ejector part)
9 Communication piping (communication passage)
10 Open / close valve (open / close mechanism)
20 Refrigerant circuit
22 Four-way selector valve
23 Outdoor heat exchanger

Claims (7)

A heat exchanger constituting at least one of an evaporator and a radiator of a refrigerant circuit (20) that performs a refrigeration cycle,
A heat transfer section (3) having a plurality of heat transfer passages (4) through which the refrigerant of the refrigerant circuit (20) flows, a shunt section (6) connected to one end side of the heat transfer section (3), and the heat transfer section A main body (2) having a gas-liquid separation part (5) connected to the other end of the heat part (3);
It becomes the refrigerant inlet part of the main body (2) during the first state where the refrigerant evaporates in the heat transfer section (3), and the main body section (2 when the refrigerant radiates heat in the heat transfer section (3). A first refrigerant passage (14) connected to the end (6a) of the flow divider (6) serving as a refrigerant outlet of
The gas-side opening part (5) of the gas-liquid separation part (5) which becomes the refrigerant outlet part of the main body part (2) in the first state and becomes the refrigerant inlet part of the main body part (2) in the second state ( A second refrigerant passage (15) connected to 5b);
An ejector portion (8) connected to the first refrigerant passage (14);
A communication path (9) communicating the liquid side opening of the gas-liquid separation part (5) and the suction port of the ejector part (8);
A heat exchanger comprising an opening / closing mechanism (10) capable of opening and closing the communication path (9). In claim 1,
Heating heat exchange having a first flow path (11b) and a second flow path (11a) and heat exchange between the refrigerant flowing through the first flow path (11b) and the refrigerant flowing through the second flow path (11a) Part (11)
The heat exchanger, wherein the first flow path (11b) communicates with the first refrigerant passage (14), and the second flow path (11a) communicates with the second refrigerant passage (15). In claim 2,
A bypass passage (16) for bypassing the second flow path (11a) of the heating heat exchange section (11);
In the first state, the second flow path (11a) is opened and the bypass passage (16) is closed, and in the second state, the bypass passage (16) is opened and the second flow path ( A heat exchanger comprising a switching mechanism (CV1, CV2) that can be switched to a bypass opening position that closes 11a). In any one of Claims 1-3,
A part of the communication path (9) forms a heat transfer path (4) of the main body (2). In any one of Claims 1-4,
The gas-liquid separation part (5) has a cylindrical casing whose upper and lower ends are closed,
The heat exchanger, wherein the heat transfer passage (4) of the main body (2) is connected to the casing so that the refrigerant is supplied in a tangential direction of the inner peripheral surface of the casing. In any one of claims 1 to 5,
The heat exchanger, wherein the refrigerant flowing through the main body (2) is carbon dioxide. In any one of claims 1 to 5,
The refrigerant flowing through the main body (2) has a saturation pressure with respect to an evaporation temperature of 0 ° C. of 0.4 MPa or less.

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