JP2008190763A - Internal heat exchanger structure for air conditioning system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an internal heat exchanger structure for an air conditioning system, which reduces the rate of heat exchange of the internal heat exchanger 6 in heating operation by a simple structure. <P>SOLUTION: A plate member 18 as a flow control means having a different amount of resistance according to a flow direction, is arranged in a passage 13a on the high-pressure side of the internal heat exchanger 13. Since the internal heat exchanger functions as a heat pump in heating operation, the flow rate of a refrigerant is changed by inverting a flow in the passage 13a on the high-pressure side by changeover of a selector valve 12, and the internal heat exchanger 13 varies a quantity of heat to be heat-exchanged between the cooling operation and the heating operation. The extra heat exchange is not performed in the heating operation, therefore, while optimizing the temperature of the refrigerant up to the suction opening 1a of a compressor 1 and maintaining cooling efficiency in the cooling operation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention mainly relates to a cooling system used in a vehicle such as an automobile and having an internal heat exchanger, and more particularly to an internal heat exchanger structure of an air conditioning system using a carbon dioxide refrigeration cycle.

  Conventionally, an air conditioning system using an internal heat exchanger as shown in FIG. 9 is known (see, for example, Patent Document 1).

  First, in terms of configuration, in this conventional air conditioning system 10, a compressor 1 that obtains driving force from a vehicular travel engine or the like and compresses carbon dioxide on the discharge side in a gas phase is a radiator (gas cooler). 2 is connected.

  The outdoor heat exchanger 2 is configured to heat and exchange the carbon dioxide gas compressed by the compressor 1 with the outside air or the like.

  Further, an expansion valve 3 as a pressure control valve is provided on the outlet side of the outdoor heat exchanger 2, and by reducing the pressure of the carbon dioxide gas, the low-temperature low-pressure gas-liquid two-phase carbon dioxide gas is provided. It is comprised so that.

  When the gas-liquid two-phase carbon dioxide evaporates in the evaporator 4, it takes heat from the air in the passenger compartment and cools the air in the passenger compartment.

Further, the evaporator 4 is connected to a low-pressure side passage 6b in the internal heat exchanger 6 through an accumulator 5 that temporarily stores liquid phase CO ₂ .

  Further, in the internal heat exchanger 6, a high-pressure side passage 6a interposed between the outdoor heat exchanger 2 and the expansion valve 3 is disposed adjacent to the low-pressure side passage 6b.

  And it is comprised so that heat exchange may be performed between these high voltage | pressure side channel | paths 6a and the low voltage | pressure side channel | path 6b.

  Further, in this air conditioning system, a bypass passage 7 that changes the flow of low-temperature and low-pressure carbon dioxide gas passing through the low-pressure side passage 6 b is provided by an electromagnetic valve 8 so as to be opened and closed.

  Next, the function and effect of the conventional air conditioning system 10 will be described.

  In the air conditioning system 10 using the conventional internal heat exchanger 6 configured as described above, for example, during the cooling operation, the expansion valve 3 is opened when the constant pressure exceeds 10.7 MPa (BC in FIG. 10). Then, the carbon dioxide gas undergoes a phase change from a gas phase to a gas-liquid two-phase state (CD in FIG. 10) while being decompressed, flows into the evaporator 4 and evaporates (DA in FIG. 10). ).

  For this reason, heat is taken from the air in the passenger compartment, and the passenger compartment air is cooled.

  Further, when the carbon dioxide gas flowing out from the accumulator 5 bypasses the low pressure side passage 6b of the internal heat exchanger 6 by the bypass passage 7, the low pressure carbon dioxide gas in the low pressure side passage 6b and the high pressure carbon dioxide in the high pressure passage 6a are used. Heat exchange with the gas is not performed, and the suction side of the compressor 1 is not heated.

  Accordingly, the suction side carbon dioxide gas temperature of the compressor 1 can be lowered as compared with the case where carbon dioxide is sucked into the compressor 1 via the internal heat exchanger 6.

  For this reason, the carbon dioxide gas temperature can be lowered in the carbon dioxide gas passage from the suction side to the discharge side of the compressor 1, and the compressor 1 can be prevented from being damaged.

In addition, a configuration is also known in which the flow of the high-pressure side passage 6a of the internal heat exchanger 6 is reversed so that the heat pump is used in winter and can be applied to heating (see, for example, Patent Document 2). ).
JP 11-151568 (paragraphs 0022 to 0066, FIG. 1) JP 2000-130878 (paragraphs 0012 to 0040, FIGS. 1 and 3)

  However, in the internal heat exchanger structure of the conventional air conditioning system configured as described above, when it is configured to be used for heating by converting to a heat pump, the outside air temperature is low and the pressure is also reduced during heating operation. It is known that the cycle balance is different from that during cooling operation.

  For this reason, at the time of heating operation, the amount of the heat exchanger of the heat exchanger 6 of the internal heat exchanger 6 becomes excessive, and there is a problem that the temperature of the carbon dioxide gas reaching the suction opening 1a of the compressor 1 increases excessively.

  Then, this invention makes it a subject to provide the internal heat exchanger structure of the air conditioning system which can reduce the heat exchange amount of the internal heat exchanger 6 at the time of heating operation with simple structure.

  In order to achieve the above object, the invention described in claim 1 is used in a heat pump cycle capable of switching between heating and cooling, and sucks refrigerant and compresses the sucked refrigerant between the outdoor air and the refrigerant. Between the outdoor heat exchanger for exchanging heat, the indoor heat exchanger for exchanging heat between the indoor air blown into the room and the refrigerant, the outdoor heat exchanger and the indoor heat exchanger. The decompressor for decompressing the refrigerant, and the high-pressure refrigerant before being decompressed by the decompressor and the low-pressure refrigerant sucked into the compressor are inserted into the high-pressure side passage and the low-pressure side passage, respectively, during the cooling operation. An internal heat exchanger that increases a specific enthalpy difference between the inlet side and the outlet side of the indoor heat exchanger by performing heat exchange, and flows in the high-pressure side passage of the internal heat exchanger during heating operation. Can be converted to a heat pump by reversing In the internal heat exchanger structure of the air conditioning system, the flow rate restricting means having a different resistance depending on the flow direction flows in the high-pressure side passage of the internal heat exchanger, and flows in the high-pressure side passage of the internal heat exchanger. It features an internal heat exchanger structure of an air conditioning system that incorporates flow restricting means with different resistances depending on the direction.

  Further, in the present invention, a plurality of high-pressure side passages of the internal heat exchanger are provided in parallel, and the resistance amount of each of the high-pressure side passages varies depending on the flow direction. The internal heat exchanger structure according to claim 1, wherein the flow rate restricting means is built in.

  According to a third aspect of the present invention, the flow restriction means is mounted in the high-pressure side passage, and a convex burring hole is formed penetrating toward the downstream side in the refrigerant flow direction during cooling operation. An internal heat exchanger structure of an air conditioning system according to claim 1 or 2 having a plate member.

  Further, according to a fourth aspect of the present invention, the internal heat exchanger includes a pair of upper and lower passages constituting the high-pressure side passage, and left and right end openings of the upper and lower passages. And a header member having a substantially cylindrical shape connected to each other, and the flow restricting means is locked and attached to the inner surface of the header member. It is characterized by the internal heat exchanger structure of the air conditioning system according to one item.

  In the invention according to claim 1 configured as described above, since the flow rate control means having different resistance amounts according to the flow direction is provided in the high-pressure side passage of the internal heat exchanger, the heat pump can be converted into a heat pump during the heating operation. When the flow in the high-pressure side passage is reversed, the flow rate ratio of the refrigerant in each high-pressure side passage can be changed, and the amount of heat exchanged can be varied between the cooling operation and the heating operation.

  For this reason, it is possible to optimize the temperature of the refrigerant reaching the suction opening of the compressor and maintain the cooling efficiency during the cooling operation while preventing excessive heat exchange during the heating operation.

  Further, according to the second aspect of the present invention, since the amount of resistance of the plurality of high-pressure side passages provided in parallel differs depending on the flow direction by the flow rate restricting unit, When the flow of the side passages is reversed, the flow rate ratio of the refrigerant in each high-pressure side passage can be changed, and the amount of heat exchanged can be varied between the cooling operation and the heating operation.

  For this reason, it is possible to optimize the temperature of the refrigerant reaching the suction opening of the compressor and maintain the cooling efficiency during the cooling operation while preventing excessive heat exchange during the heating operation.

  Further, according to a third aspect of the present invention, the flow restricting means is mounted on the inner side surface constituting the high-pressure side passage, and has a convex burring toward the downstream side in the refrigerant flow direction during cooling operation. The plate member has a hole formed therethrough.

  For this reason, in the flow direction of the refrigerant during the cooling operation, the resistance amount of the refrigerant passing through the burring hole of the plate member is reduced, and when the flow of the high-pressure side passage is reversed during the heating operation, the resistance amount of the refrigerant Will increase.

  Therefore, only the amount of heat necessary for heat pumping during heating operation can be inserted into the high-pressure side passage of the internal heat exchanger to exchange heat, and the temperature of the refrigerant sucked into the compressor may rise too much. There is no.

  Further, according to a fourth aspect of the present invention, in the internal heat exchanger, the flow rate restricting means is locked and attached to the inner side surface of the header member.

  For this reason, without changing the structure of the part that performs heat exchange of the internal heat exchanger, the intake temperature of the compressor during heating and The discharge temperature can be adjusted.

  Next, the internal heat exchanger structure of the air conditioning system of the best mode for carrying out the present invention will be described based on the drawings.

  In addition, the same code | symbol is attached | subjected and demonstrated about the part thru | or equivalent to the said prior art example.

  1 to 8 show an internal heat exchanger structure of an air conditioning system according to the best mode of the present invention.

  First, the overall configuration will be described with reference to FIG. 1 and FIG. 2. In the internal heat exchanger structure of the air conditioning system 11 of this embodiment, a driving force from a vehicular traveling engine or the like is obtained to obtain a gas phase state. A compressor 1 for compressing carbon dioxide gas as the refrigerant is provided.

  In the case of the cooling shown in FIG. 1, the compressor 1 is connected to the outdoor heat exchanger 2 via the switching valve 12 on the discharge opening 1b side, and to the internal heat exchanger 13 on the suction opening 1a side. Connected with.

  Among these, the said outdoor heat exchanger 2 is comprised so that the carbon dioxide gas compressed with the said compressor 1 may be heat-exchanged with external air etc., and may be cooled.

  Moreover, the 1st throttle valve 14 as one pressure control valve is provided in the exit part side of this outdoor heat exchanger 2, and when the said carbon dioxide gas is pressure-reduced, low-temperature low-pressure gas-liquid It is configured to be a two-phase carbon dioxide gas.

  When the gas-liquid two-phase carbon dioxide evaporates in the indoor heat exchanger 16 corresponding to the conventional evaporator 4 connected via the second throttle valve 15 as the other pressure control valve, Heat is taken from the air in the passenger compartment to cool the passenger compartment air.

Further, the indoor heat exchanger 16 is connected to the low-pressure side passage 13b in the internal heat exchanger 13 via an accumulator 5 that temporarily stores liquid phase CO ₂ .

  In the internal heat exchanger 13, a high-pressure side passage 13a interposed between the outdoor heat exchanger 2 and the indoor heat exchanger 16 is disposed adjacent to the low-pressure side passage 13b. Heat exchange is performed between the side passage 13a and the low-pressure side passage 13b.

  Further, as shown in FIG. 1, the switching valve 12 communicates the discharge opening 1b side of the compressor 1 to the outdoor heat exchanger 2 side so that the refrigerant from the indoor heat exchanger 16 is As shown in FIG. 2, the cooling operation switching position to be returned to the accumulator 5 and the discharge opening 1 b side of the compressor 1 are communicated with the indoor heat exchanger 16 and sent from the outdoor heat exchanger 2. The heating operation switching position for returning the refrigerant to the accumulator 5 can be selectively switched.

  Next, the configuration of the internal heat exchanger 13 of this embodiment will be described in detail with reference to FIGS.

  In the internal heat exchanger 13 of this embodiment, the high-pressure side passage 13a formed of a porous tube has a pair of an upper passage 13c and a lower passage 13d arranged in parallel on the upper and lower sides, so that the flow direction is substantially the same. It is provided to be horizontal.

  Further, in the high-pressure side passage 13a, the left and right end openings of the upper passage 13c and the lower passage 13d are connected to the opposing side surfaces of the header member 13g and the header member 13h each having a substantially cylindrical shape. And each inside is communicated.

  Among these members, the header member 13g extends along the internal passage in a substantially vertical direction, and the lower opening 13k connected to the second throttle valve 15 extends downward from the lower surface. Has been issued.

  In addition, a plate member 18 serving as a flow rate restricting unit having a different resistance according to the flow direction is built in the header member 13g.

  As shown in FIG. 6, the plate member 18 has a substantially annular shape in a plan view and is substantially in the center of a substantially flat annular portion 18 b on the downstream side in the refrigerant flow direction (in the direction of arrow a in FIG. 3) during cooling operation. A convex burring hole 18c is formed so as to penetrate the peripheral wall 18d in a cylindrical shape.

In general, the passage resistance of the flow path reduction portion, the enlargement portion, and the pipe inlet portion can be expressed by Equation 1 below.
Passage resistance = Loss coefficient x Flow velocity ^ 2 x Density / 2 (Equation 1)
The loss coefficient is significantly smaller when flowing from the flat portion side of the annular portion 18b than when flowing the refrigerant from the standing wall portion side 18d side of the burring hole portion 18c.

  For this reason, in the upper and lower side passages 13c and 13d provided in the upper and lower sides, the plate member 18 provided at a substantially intermediate position in the vertical direction of the header member 13g causes the flow direction between the cooling operation and the heating operation. Accordingly, the amount of resistance passing through each of the upper and lower passages 13c and 13d is set to be different.

  Further, a pair of locking pieces 18a and 18a are provided so as to protrude from both sides of the plate member 18 on the opposite side of the annular portion 18b.

  The locking pieces 18a and 18a are respectively engaged with the slits 17 and 17 formed on the inner side surfaces of the semi-cylindrical members 13i and 13j constituting the header member 13g divided in the vertical direction. By being stopped, the cylindrical header member 13g is assembled and attached to the inner side surface constituting the high-pressure side passage 13a.

  Further, in the plate member 18 of this embodiment, a portion where the end opening of the upper passage 13c is connected and an end opening of the lower passage 13d are connected in the longitudinal direction of the header member 13g. It is mounted so as to be positioned between the parts.

  Further, an upper opening 13m connected to the first throttle valve 14 extends upward on the upper surface of the header member 13h.

  Further, the low pressure side passage 13b of the internal heat exchanger 13 is constituted by a perforated pipe, and an upper passage 13e and a lower passage 13f which are arranged adjacent to each other along the upper passage 13c and the lower passage 13d. The upper and lower sides are arranged in parallel so that the flow path direction is substantially horizontal.

  Further, in the low-pressure side passage 13b, the left and right end openings of the upper passage 13e and the lower passage 13f are respectively connected to opposite side surfaces of the header member 13n and the header member 13p having a substantially cylindrical shape. And the inside is communicated with each other.

  Among them, the header member 13n has an internal passage extending substantially along the vertical direction, and an outlet side opening 13q connected to the suction opening 1a side of the compressor 1 from the lower surface portion. It is extended downward.

  Further, the internal passage of the header member 13p extends substantially along the vertical direction, and an inlet-side opening 13r connected to the accumulator 5 extends downward from the upper surface. Yes.

  Next, the effect of the internal heat exchanger structure of the air conditioning system of this embodiment will be described.

  In the internal heat exchanger structure of the air conditioning system of the embodiment configured as described above, when the cooling operation is performed, as illustrated in FIG. 1, when the switching position of the switching valve 12 is the cooling operation switching position, The discharge opening 1 b side of the compressor 1 is connected to the outdoor heat exchanger 2 side, and the refrigerant from the indoor heat exchanger 16 is connected to return to the accumulator 5.

  Further, the first throttle valve 14 is opened, the second throttle valve 15 is throttled, and the high-pressure refrigerant discharged from the compressor 1 and sent from the high-pressure side passage 13a of the internal heat exchanger 13 is decompressed. As a result, the low-temperature low-pressure gas-liquid two-phase carbon dioxide is evaporated in the indoor heat exchanger 16.

  For this reason, heat is taken from the air in the passenger compartment, and the passenger compartment air is cooled.

  At this time, heat exchange is performed between the refrigerant in the high-pressure side passage 13a of the internal heat exchanger 13 and the refrigerant in the low-pressure side passage 13b, and the specific enthalpy of the refrigerant on the inlet side of the indoor heat exchanger 16 is achieved. However, it is smaller than when heat exchange is not performed.

  Accordingly, the specific enthalpy difference between the inlet side and the outlet side of the indoor heat exchanger 16 is larger than that in the case where heat exchange is not performed in the internal heat exchanger 6, so that the refrigerating capacity is improved. .

  In the air conditioning system 11 of this embodiment, during the cooling operation, the plate member 18 provided on the inner surface of the header member 13g located on the downstream side of the high-pressure side passage 13a has the cooling operation as shown in FIG. The heat-exchanged high-pressure refrigerant is allowed to pass through the convex burring hole 18c with a small loss coefficient toward the downstream side in the refrigerant flow direction (arrow a direction in FIG. 3).

  For this reason, among the high-pressure side passages 13a of the internal heat exchanger 13, the upper-side passage 13c and the lower-side passage 13d positioned above and below the low-pressure side passages 13b that are arranged adjacent to each other through the refrigerant flowing over the entire area. Heat exchange can be sufficiently performed between the upper passage 13e and the lower passage 13f.

  Therefore, the cooling efficiency during the cooling operation is maintained substantially equal to the case where the plate member 18 is not present.

  Further, during the heating operation, as shown in FIG. 2, the discharge opening 1 b side of the compressor 1 communicates with the indoor heat exchanger 16, and the refrigerant sent from the outdoor heat exchanger 2 flows. , Connected to return to the accumulator 5.

  Further, the second throttle valve 15 is opened and the first throttle valve 14 is throttled.

  The high-pressure refrigerant discharged from the compressor 1 and flowing in the high-pressure side passage 13a of the internal heat exchanger 13 in the opposite direction to that during the cooling operation is decompressed, whereby the low-temperature and low-pressure gas-liquid 2 The phase-state carbon dioxide gas absorbs heat from the outdoor air and is evaporated in the outdoor heat exchanger 2.

  For this reason, the heat absorbed from the outdoor air is radiated into the passenger compartment air by the indoor heat exchanger 3.

  At this time, the plate member 18 provided on the inner surface of the header member 13g located on the upstream side in the high-pressure side passage 13a of the internal heat exchanger 13, as shown in FIG. Although it tends to flow in the flow direction (arrow b direction in FIG. 4), since the burring hole 18c has a relatively large loss coefficient, the refrigerant hardly passes.

  Therefore, most of the refrigerant that passes through the high-pressure passage 13a exchanges heat with the refrigerant that passes through the lower passage 13d and passes through the lower passage 13f of the adjacent low-pressure passage 13b. Since the amount of heat exchange between the upper passage 13c of the high pressure side passage 13a and the upper passage 13e of the low pressure side passage 13b is reduced, the heat exchange amount of the internal heat exchanger 13 during the heating operation is reduced. Can be reduced and optimized.

  For example, the amount of heat exchange during the heating operation is decreased, and the temperature of the suction opening 1a and the temperature of the discharge opening 1b of the compressor 1 is reduced, thereby causing the compressor 1 due to the refrigerant to become hot. Can be prevented from being damaged.

  Thus, in the internal heat exchanger structure of the air conditioning system of this embodiment, the plate member 18 as the flow rate control means having a different resistance amount according to the flow direction is provided on the high-pressure side passage 13a of the internal heat exchanger 13. Is provided.

  For this reason, when the flow of the high-pressure side passage 13a is reversed by switching the switching valve 12 in order to make a heat pump during heating operation, the high-pressure side upper passage 13c and the high-pressure side lower passage 13d of the internal heat exchanger 13 are switched. The flow rate ratio of the refrigerant is changed, and the amount of heat exchanged by the internal heat exchanger 13 can be varied between the cooling operation and the heating operation.

  Accordingly, it is possible to optimize the temperature of the refrigerant reaching the suction opening 1a of the compressor 1 and maintain the cooling efficiency during the cooling operation while preventing excessive heat exchange during the heating operation.

  Further, the plate member 18 as the flow rate restricting means is engaged with the slits 17 and 17 of the header member 13g constituting the high-pressure side passage 13a so that the locking pieces 18a and 18a are locked. It is mounted so as to be located in the passage.

  A convex burring hole 18c is formed through the plate member 18 toward the downstream side in the refrigerant flow direction during the cooling operation.

  Therefore, in the refrigerant flow direction a during the cooling operation shown in FIG. 3, the resistance of the refrigerant passing through the burring hole 18c of the plate member 18 is small, and during the heating operation, the switching valve 12 is switched, When the flow of the high-pressure side passage 13a shown in FIG. 4 is reversed so as to be in the flow direction b, the resistance of the refrigerant increases.

  Accordingly, only the amount of heat necessary for heat pumping during heating operation can be exchanged by the internal heat exchanger 13, and there is no possibility that the temperature of the refrigerant sucked into the compressor 1 will rise too much.

  In this embodiment, the shape of the burring hole 18c of the plate member 18 is changed, or the formation positions of the slits 17 and 17 of the header member 13g are changed, so that the high-pressure side passage can be easily formed. The amount of the refrigerant circulating in 13a can be changed.

  At this time, the plate member 18 inside the header member 13g can be locked without changing the structure of the portion that performs heat exchange, such as the porous tube shapes of the high-pressure side passage 13a and the low-pressure side passage 13b of the internal heat exchanger 13. Since it is only necessary to change the position or the shape, the suction temperature and the discharge temperature of the compressor 1 during heating can be easily adjusted.

  FIG. 8 shows the internal structure of the header member 13g of the high-pressure side passage, which is used in the internal heat exchanger structure of the air-conditioning system of the present invention. Shows what was applied.

  Note that portions that are the same as or equivalent to those in the above-described embodiment are described with the same reference numerals.

  In the internal heat exchanger structure of the air conditioning system according to the first embodiment, the plate member 28 has a substantially annular shape in a plan view and is substantially in the center of a substantially circular ring portion 28b. 3 (in the direction of arrow a in FIG. 3) A convex burring hole 28c is formed in a cylindrical shape by penetrating a peripheral wall 28d upright.

  A tapered surface portion 28e is formed in a circumferential shape on the outer peripheral surface on the lower end side of the standing wall portion 28d.

  Next, the effect of the internal heat exchanger structure of the air conditioning system of the first embodiment will be described.

  In the internal heat exchanger structure of the air conditioning system according to Example 1 configured as described above, in addition to the function and effect of the above embodiment, the shape of the tapered surface portion 28e is further changed to change the shape. In the heating operation as shown in FIG. 4 of the embodiment, the flow rate of the refrigerant passing through the burring hole 28c can be changed by changing the flow direction of the refrigerant along the tapered surface 28e. For this reason, the suction temperature and the discharge temperature of the compressor 1 during heating can be easily adjusted.

  The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific configuration is not limited to this embodiment, and design changes that do not depart from the gist of the present invention are not limited to this embodiment. Included in the invention.

  That is, in the embodiment, the plate member 18 as one flow rate restricting means is built in the header member 13g. However, the present invention is not limited to this, and two plate members 18 or Three or more sheets may be provided, and the shape, quantity, and material of the plate member 18 are not particularly limited.

  Further, the high-pressure side passage 13a is divided into two upper and lower portions as an upper passage 13c and a lower passage 13d. However, the present invention is not limited to this. For example, a single piece or a plurality of three pieces or more are provided. The shape, quantity, and material of the high-pressure side passage 13a are not particularly limited as well as the adjacent low-pressure side passage 13b.

  Further, in the first embodiment, the high-pressure side passage 13a of the internal heat exchanger 13 has a plurality of the upper and lower side passages 13c and 13d in parallel, and depending on the flow direction, the upper and lower side passages 13c and 13d The amount of resistance is configured to be different depending on the plate member 18 built in the header member 13g. However, the resistance is not limited to this, and the plate member 18 serving as a flow rate restricting means is not limited to this. May be provided so that the refrigerant passes through all of the plate members 18 during the heating operation.

  That is, when the amount of resistance in the high-pressure side passage 13a of the internal heat exchanger 13 is increased, the pressure of the upper opening 13m located at the outlet decreases.

  For this reason, when such a resistance amount is large, the specific enthalpy increases and the heat exchange amount of the internal heat exchanger 13 decreases as compared with the case where the resistance amount is small.

  In this case, a flow rate restricting means is incorporated in the header member 13g on the inlet side of the internal heat exchanger 13 during the heating operation or in the vicinity of the connecting portion between the upper and lower passages 13c and 13d and the header member 13g. That's fine.

  As a built-in flow restricting means, as in the first embodiment, the plate member 18 formed so as to penetrate the convex burring hole portion 18c toward the downstream side in the refrigerant flow direction during the cooling operation is formed as the inner side surface shape of the passage. Any shape, quantity and material may be used, such as applying to the above.

1 is a schematic circuit configuration diagram of an air-conditioning system illustrating an overall configuration in an internal heat exchanger structure of an air-conditioning system according to a best embodiment of the present invention, showing a cooling operation. It is an internal heat exchanger structure of the air-conditioning system of an embodiment, and is the whole typical circuit lineblock diagram showing the time at the time of heat pump cycle heating operation. It is a partial cross section front view explaining the refrigerant | coolant flow direction at the time of air_conditionaing | cooling operation with the structure of an internal heat exchanger by the internal heat exchanger structure of the air conditioning system of embodiment. It is a partial cross section front view explaining the refrigerant | coolant flow direction at the time of heating operation with the structure of an internal heat exchanger by the internal heat exchanger structure of the air conditioning system of embodiment. It is an internal heat exchanger structure of the air conditioning system of an embodiment, and is a top view of an internal heat exchanger. It is an internal heat exchanger structure of the air conditioning system of an embodiment, and is an exploded perspective view explaining composition of a header member of an internal heat exchanger. It is an internal heat exchanger structure of the air-conditioning system of embodiment, and is a longitudinal cross-sectional view in the header member of the part vicinity where the plate member is mounted | worn. It is an internal heat exchanger structure of the air-conditioning system of Example 1 of an embodiment, and is a longitudinal section in a header member near a portion to which a plate member is attached. It is a typical circuit diagram explaining the whole structure with the air conditioning system of a prior art example. It is a Mollier diagram of an air conditioning system of a conventional example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 1a Suction opening 11 Air conditioning system 13 Internal heat exchanger 13a High pressure side passage 13b Low pressure side passage 16 Indoor heat exchangers 18, 28 Plate member (flow rate restricting means)
18c, 28c
Burring hole

Claims (4)

Used in a heat pump cycle that can be switched between air conditioning and heating, sucks refrigerant, compresses the sucked refrigerant, an outdoor heat exchanger that exchanges heat between the outdoor air and the refrigerant, indoor air and refrigerant blown into the room Between the indoor heat exchanger that exchanges heat with the outdoor heat exchanger and the indoor heat exchanger, and a decompressor that decompresses the refrigerant, and during the cooling operation, the decompressor The high-pressure refrigerant before being decompressed and the low-pressure refrigerant sucked into the compressor are inserted into the high-pressure side passage and the low-pressure side passage, respectively, to perform heat exchange, whereby the inlet side and the outlet side of the indoor heat exchanger An internal heat exchanger that increases the specific enthalpy difference between the internal heat exchanger and the internal heat exchanger structure of an air conditioning system that can be converted into a heat pump by reversing the flow of the high-pressure side passage of the internal heat exchanger during heating operation Because
An internal heat exchanger structure for an air conditioning system, characterized in that a flow rate restricting means having a different resistance depending on the flow is incorporated in the high-pressure side passage of the internal heat exchanger.   The high-pressure side passage of the internal heat exchanger has a plurality of high-pressure side passages in parallel, and the flow rate restricting means is incorporated in the high-pressure side passage so that the resistance amount of each of the high-pressure side passages varies depending on the flow direction. The internal heat exchanger structure described.   The flow rate restricting means includes a plate member that is mounted in the high-pressure side passage and has a burring hole that protrudes toward the downstream side in the refrigerant flow direction during cooling operation. The internal heat exchanger structure of the air conditioning system according to 1 or 2.   The internal heat exchanger has a substantially cylindrical shape in which a pair of upper and lower passages constituting the high-pressure side passage and left and right end openings of the upper and lower passages are connected to each other. 4. The air conditioning system according to claim 1, further comprising: a header member, wherein the flow restricting unit is locked and attached to an inner surface of the header member. 5. Internal heat exchanger structure.

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