JP6477306B2 - Refrigerant evaporator - Google Patents

Description

  The present invention is applied to a vapor compression refrigeration cycle, and relates to a refrigerant evaporator that cools a cooling target fluid by absorbing heat from the cooling target fluid and evaporating the refrigerant.

  As this type of refrigerant evaporator, a configuration is known in which two evaporators are arranged in series in the flow direction of the fluid to be cooled, and one tank part in each evaporator is connected via a pair of communicating parts. (For example, refer to Patent Document 1).

  In the refrigerant evaporator disclosed in Patent Literature 1, when the refrigerant that has flowed through the heat exchange core portion of the first evaporation portion is caused to flow to the heat exchange core portion of the second evaporation portion, the flow of the refrigerant is reduced to that of the heat exchange core portion. It replaces in the width direction (left-right direction).

  Specifically, in the refrigerant evaporator of Patent Document 1, the refrigerant flowing on one side in the width direction of the heat exchange core part of the first evaporation part is transferred to the second evaporation part by one communication part of the pair of communication parts. The heat exchange core portion is configured to flow on the other side in the width direction. Moreover, the refrigerant evaporator of patent document 1 makes the refrigerant | coolant which flows through the width direction other side of the heat exchange core part of a 1st evaporation part by the other communication part among a pair of communication parts, the heat exchange core part of a 2nd evaporation part. It is the composition which flows to one side in the width direction.

JP 2014-228161 A

  By the way, the refrigerant circulating in the refrigeration cycle contains refrigeration oil for protecting the compressor. However, in the refrigerant evaporator disclosed in Patent Document 1, a part of the refrigeration oil stays inside the refrigerant evaporator. As a result, the amount of refrigerating machine oil returned to the refrigerant suction side of the compressor may decrease.

  This point will be described. First, in the refrigerant evaporator of Patent Document 1, the refrigerant in the gas-liquid two-phase state is introduced from one side in the width direction of the first evaporator, and one side in the width direction of the second evaporator. The refrigerant is derived from the refrigerant.

  In such a configuration, when the amount of refrigerant flowing into the refrigerant evaporator is small, the flow rate of the refrigerant introduced into the refrigerant evaporator is slowed down. And, in the width direction one side of the heat exchange core part of the first evaporation part near the refrigerant introduction part, compared to the other side in the width direction of the heat exchange core part of the first evaporation part far from the refrigerant introduction part, It becomes easy for the refrigerant in the liquid phase to flow in.

  As a result, in the first refrigerant flow path from one side in the width direction of the heat exchange core part of the first evaporation part to the other side in the width direction of the heat exchange core part of the second evaporation part, the liquid phase refrigerant is mainly used. Flowing. Further, in the second refrigerant flow path from the other side in the width direction of the heat exchange core part of the first evaporation part to the one side in the width direction of the heat exchange core part of the second evaporation part, the liquid state refrigerant is slightly Just flowing, the gas phase refrigerant mainly flows.

  When the amount of refrigerant flowing into the refrigerant evaporator is small as described above, the flow rate (mass flow rate) of the refrigerant is reduced in the second refrigerant flow path as compared with the first refrigerant flow path. For this reason, in the second refrigerant flow path, the evaporation of the refrigerant is completed at an early stage, and the gas-phase refrigerant having a superheat degree with low heat exchange efficiency flows.

  When the evaporation of the refrigerant is completed early in the second refrigerant flow path, the refrigerating machine oil is separated from the refrigerant, so that the refrigerating machine oil separated from the refrigerant stagnates in the lower part of the second refrigerant flow path. End up. This contributes to a decrease in the amount of refrigerating machine oil returned to the refrigerant suction side of the compressor.

  Further, when the compressor stops and the flow of the refrigerant into the refrigerant evaporator stops, the liquid phase refrigerant stagnates in the refrigerant evaporator in a state of being biased toward the first refrigerant flow path. Such a state in which the liquid-phase refrigerant is biased toward the first refrigerant flow path is maintained even when the compressor is restarted. When the compressor is restarted, the amount of refrigerant flowing from the first refrigerant passage side where a large amount of refrigerant remains to the refrigerant suction side of the compressor is large and the amount of refrigerant flowing from the second refrigerant passage side is small. It becomes difficult to sufficiently return the refrigeration oil staying on the second refrigerant passage side to the compressor. This also contributes to a decrease in the amount of refrigerating machine oil returned to the refrigerant suction side of the compressor.

  An object of this invention is to provide the refrigerant evaporator which can ensure the return amount of the refrigerating machine oil to a compressor in view of the said point.

  The invention described in claim 1 and claim 2 is applied to a vapor compression refrigeration cycle (1) for circulating a refrigerant containing refrigeration oil, and absorbs heat from a fluid to be cooled to evaporate the refrigerant, thereby cooling the object. Intended for refrigerant evaporators that cool fluids.

In order to achieve the above object, the invention described in claim 1
A first evaporator (20) and a second evaporator (10) arranged in series with respect to the flow direction of the fluid to be cooled;
Each of the first evaporation section and the second evaporation section is formed on the heat exchange core section (11, 21) in which a plurality of tubes (111, 211) that extend in the vertical direction and the refrigerant flows are stacked, and on both ends of the plurality of tubes. It has a pair of tank parts (12, 13, 22, 23) that are connected and collect refrigerant flowing through a plurality of tubes or distributing refrigerant to the plurality of tubes,
The heat exchange core part which comprises a 1st evaporation part contains the tube group different from the 1st core part (21a) comprised including some tube groups among some tubes, and some tube groups. A second core portion (21b) configured by:
The heat exchange core part which comprises a 2nd evaporation part is a 3rd core part comprised including the tube group which opposes at least one part of a 1st core part in the flow direction of the cooling target fluid among several tubes ( 11a), having a fourth core part (11b) configured to include a tube group facing at least a part of the second core part in the flow direction of the fluid to be cooled;
Of the pair of tank parts constituting the first evaporation part, the lower tank part (23) has a first refrigerant collecting part (23a) for collecting refrigerant from the first core part and a second core part. A second refrigerant collecting portion (23b) for collecting the refrigerant is provided;
Of the pair of tank parts constituting the second evaporation part, in the lower tank part (13), the first refrigerant distribution part (13a) for distributing the refrigerant collected in the second refrigerant collection part to the third core part. A second refrigerant distribution section (13b) for distributing the refrigerant collected in the first refrigerant collection section to the fourth core section is provided,
Among the pair of tank parts constituting the first evaporation part, the upper tank part (22) has a first core part and a second core in a part closer to the first core part than the second core part. A refrigerant introduction part (22a) for introducing a gas-liquid two-phase refrigerant to be distributed to the part from outside is provided,
Among the pair of tank parts constituting the second evaporation part, the upper tank part (12) has a third core part and a fourth core in a part closer to the third core part than the fourth core part. A refrigerant derivation section (12a) for deriving the refrigerant having passed through the section to the refrigerant suction side of the compressor (2) of the refrigeration cycle together with the refrigeration oil,
Resistance portions (121, 232, 34, 31a) serving as a flow resistance of the refrigerant flowing from the first refrigerant assembly portion toward the refrigerant outlet portion are set in the refrigerant flow path from the first refrigerant assembly portion to the refrigerant outlet portion. and,
The pressure loss in the flow path in the refrigerant flow path from the first refrigerant collecting section to the refrigerant deriving section is larger by the resistance section than in the refrigerant flow path from the second refrigerant collecting section to the refrigerant deriving section. It is said.

The invention according to claim 2
A first evaporator (20) and a second evaporator (10) arranged in series with respect to the flow direction of the fluid to be cooled;
Each of the first evaporation section and the second evaporation section is formed on the heat exchange core section (11, 21) in which a plurality of tubes (111, 211) that extend in the vertical direction and the refrigerant flows are stacked, and on both ends of the plurality of tubes. It has a pair of tank parts (12, 13, 22, 23) that are connected and collect refrigerant flowing through a plurality of tubes or distributing refrigerant to the plurality of tubes,
The heat exchange core part which comprises a 1st evaporation part contains the tube group different from the 1st core part (21a) comprised including some tube groups among some tubes, and some tube groups. A second core portion (21b) configured by:
The heat exchange core part which comprises a 2nd evaporation part is a 3rd core part comprised including the tube group which opposes at least one part of a 1st core part in the flow direction of the cooling target fluid among several tubes ( 11a), having a fourth core part (11b) configured to include a tube group facing at least a part of the second core part in the flow direction of the fluid to be cooled;
Of the pair of tank parts constituting the first evaporation part, the lower tank part (23) has a first refrigerant collecting part (23a) for collecting refrigerant from the first core part and a second core part. A second refrigerant collecting portion (23b) for collecting the refrigerant is provided;
Of the pair of tank parts constituting the second evaporation part, in the lower tank part (13), the first refrigerant distribution part (13a) for distributing the refrigerant collected in the second refrigerant collection part to the third core part. A second refrigerant distribution section (13b) for distributing the refrigerant collected in the first refrigerant collection section to the fourth core section is provided,
Among the pair of tank parts constituting the first evaporation part, the upper tank part (22) has a first core part and a second core in a part closer to the first core part than the second core part. A refrigerant introduction part (22a) for introducing a gas-liquid two-phase refrigerant to be distributed to the part from outside is provided,
Among the pair of tank parts constituting the second evaporation part, the upper tank part (12) has a third core part and a fourth core in a part closer to the third core part than the fourth core part. A refrigerant derivation section (12a) for deriving the refrigerant having passed through the section to the refrigerant suction side of the compressor (2) of the refrigeration cycle together with the refrigeration oil,
In the refrigerant flow path from the first refrigerant assembly part to the area where the refrigerant from the fourth core part flows in the tank part above the second evaporation part, resistance parts (121, 232, 34, 31a) is set ,
The pressure loss in the flow path in the refrigerant flow path from the first refrigerant collecting section to the refrigerant deriving section is larger by the resistance section than in the refrigerant flow path from the second refrigerant collecting section to the refrigerant deriving section. It is said.

  According to this, even when the amount of the refrigerant introduced into the refrigerant evaporator is small, it is possible to suppress the liquid-phase refrigerant from flowing in the refrigerant flow path from the first refrigerant assembly part to the refrigerant outlet part. As a result, the refrigerant in the liquid phase flows through the refrigerant flow path from the second refrigerant assembly part to the refrigerant outlet part, so that when the amount of refrigerant introduced into the refrigerant evaporator is small or when the compressor is restarted, etc. 2 Refrigerating machine oil remaining in the refrigerant flow path from the refrigerant collecting section to the refrigerant outlet section can be returned to the compressor. Therefore, it is possible to ensure a sufficient return amount of the refrigeration oil to the compressor.

  In addition, the code | symbol in the parenthesis of each means described in this column and the claim shows an example of a correspondence relationship with the specific means described in the embodiment described later.

It is a typical lineblock diagram of the refrigerating cycle containing the refrigerant evaporator concerning a 1st embodiment. It is a typical perspective view of the refrigerant evaporator concerning a 1st embodiment. FIG. 3 is a schematic exploded perspective view of the refrigerant evaporator shown in FIG. 2. It is a typical perspective view of the intermediate tank part concerning a 1st embodiment. It is sectional drawing which shows the principal part of the windward evaporation part of the refrigerant evaporator which concerns on 1st Embodiment. It is explanatory drawing for demonstrating the flow of the refrigerant | coolant in the refrigerant evaporator which concerns on 1st Embodiment. It is a typical front view of the leeward side evaporation part of the refrigerant evaporator which concerns on a prior art form. It is a typical front view of the windward evaporation part in the refrigerant evaporator which concerns on a prior art form. It is a typical front view of the leeward side evaporation part in the refrigerant evaporator which concerns on 1st Embodiment. It is a typical front view of the windward evaporation part in the refrigerant evaporator which concerns on 1st Embodiment. It is a typical exploded perspective view of the refrigerant evaporator concerning a 2nd embodiment. It is a perspective view which shows the assembly internal resistance which concerns on 2nd Embodiment. It is a typical front view of the leeward side evaporation part in the refrigerant evaporator which concerns on 2nd Embodiment. It is a disassembled perspective view which shows the modification of the refrigerant evaporator which concerns on 2nd Embodiment. It is typical sectional drawing which shows the internal structure of each lower tank part and intermediate | middle tank part which concerns on 3rd Embodiment. It is a typical front view of the leeward side evaporation part in the refrigerant evaporator which concerns on 3rd Embodiment. It is a typical front view of the leeward side evaporation part in the refrigerant evaporator which concerns on 4th Embodiment. It is a typical front view of the leeward side evaporation part in the refrigerant evaporator which concerns on 4th Embodiment. It is typical sectional drawing of the intermediate | middle tank part which concerns on 4th Embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. Note that, in each of the following embodiments, parts that are the same as or equivalent to the matters described in the preceding embodiment are denoted by the same reference numerals, and the description thereof may be omitted.

  Moreover, in each embodiment, when only a part of the component is described, the component described in the preceding embodiment can be applied to the other part of the component.

  The following embodiments can be partially combined with each other even if they are not particularly specified as long as they do not cause any trouble in the combination.

(First embodiment)
This embodiment will be described with reference to FIGS. The refrigerant evaporator 5 of the present embodiment is a heat exchanger that constitutes a vapor compression refrigeration cycle 1 of a vehicle air conditioner that adjusts the temperature in the passenger compartment. As shown in FIG. 1, the refrigeration cycle 1 is configured as a closed circuit in which a compressor 2, a condenser 3, an expansion valve 4, a refrigerant evaporator 5 and the like are sequentially connected by piping.

  The compressor 2 is a device that sucks in a gas phase refrigerant and compresses and discharges the sucked refrigerant. The condenser 3 is a radiator that radiates the refrigerant discharged from the compressor 2. The expansion valve 4 is a decompression mechanism that decompresses and expands the refrigerant that has flowed out of the condenser 3. The refrigerant evaporator 5 is a heat absorber that cools the cooling target fluid by absorbing heat from the cooling target fluid and evaporating the gas-liquid two-phase refrigerant.

  In the refrigeration cycle 1 of the present embodiment, an HFC-based refrigerant (for example, R134a) is adopted as the refrigerant, and a vapor compression subcritical refrigeration cycle in which the refrigerant pressure on the high pressure side in the cycle does not exceed the critical pressure of the refrigerant. It is composed. Of course, as the refrigerant, an HFO refrigerant (for example, R1234yf), carbon dioxide, or the like may be employed.

  The refrigerant of the refrigeration cycle 1 is mixed with refrigeration oil in order to suppress a decrease in compression efficiency due to wear inside the compressor 2 and a decrease in the durability life of the compressor 2. The refrigerating machine oil circulates in the cycle together with the refrigerant.

  In the refrigeration cycle 1 of the present embodiment, an accumulator 6 is provided between the refrigerant outlet side of the refrigerant evaporator 5 and the refrigerant suction side of the compressor 2, and constitutes a so-called accumulator cycle. The accumulator 6 separates the gas-liquid refrigerant flowing into the gas-liquid separator and causes the separated gas-phase refrigerant and the lubricating oil contained in the refrigerant to flow out to the refrigerant suction side of the compressor 2. It is.

  The refrigerant evaporator 5 of the present embodiment is a heat exchanger that cools air blown into the vehicle interior, which is a fluid to be cooled, and is disposed inside an indoor air conditioning unit in a vehicle air conditioner (not shown).

  Next, a detailed configuration of the refrigerant evaporator 5 according to the present embodiment will be described with reference to FIGS. In addition, the arrow which shows up and down shown in drawings, such as FIG. 2, has shown the up-down direction at the time of mounting the refrigerant evaporator 5 in a vehicle.

  As shown in FIG. 2, the refrigerant evaporator 5 includes two evaporators 10 and 20 arranged in series in the flow direction of the blown air. For convenience of explanation, in the present embodiment, for the two evaporators 10 and 20, the evaporator disposed on the upstream side of the blown air flow is referred to as the windward evaporator 10, and the evaporator disposed on the downstream of the blown air flow is This is called the leeward evaporation unit 20. In the present embodiment, the windward evaporator 10 constitutes a “second evaporator”, and the leeward evaporator 20 constitutes a “first evaporator”.

  The windward evaporator 10 includes a heat exchange core 11 in which a plurality of tubes 111 through which refrigerant flows are stacked, a collection of refrigerants connected to both ends of each tube 111 and flowing through each tube 111, or to each tube 111. It has a pair of tank parts 12 and 13 which distribute a refrigerant. For convenience of explanation, in this embodiment, the heat exchange core part of the windward evaporator 10 is referred to as the windward heat exchange core part 11. In the present embodiment, of the pair of tank parts 12 and 13 of the windward evaporator 10, the upper tank part is called the windward upper tank part 12, and the lower tank part is the windward lower tank part 13. Call it.

  In addition, the leeward side evaporation unit 20 includes a heat exchange core unit 21 in which a plurality of tubes 211 through which refrigerant flows are stacked, a collection of refrigerants connected to both ends of each tube 211 and flowing through each tube 211, or each tube 211. It has a pair of tank parts 22 and 23 which distribute a refrigerant to. For convenience of explanation, in this embodiment, the heat exchange core part of the leeward side evaporation unit 20 is referred to as a leeward side heat exchange core part 21. In the present embodiment, of the pair of tank parts 22 and 23 of the leeward side evaporation part 20, the upper tank part is referred to as the leeward upper tank part 22, and the lower tank part is referred to as the leeward lower tank part 23. Call it. In the present embodiment, the stacking direction of the tubes 111 and 211 corresponding to the width direction of the heat exchange core portions 11 and 12 may be referred to as a tube stacking direction.

  In each of the heat exchange core portions 11 and 12 of this embodiment, fins 112 and 212 are joined between adjacent tubes 111 and 211. Each heat exchange core part 11 and 12 of this embodiment is comprised by the laminated body by which each tube 111, 211 extended along an up-down direction and each fin 112, 212 were laminated | stacked alternately.

  Each of the tubes 111 and 211 of the present embodiment is formed of a flat tube having a refrigerant passage through which a refrigerant flows, and a flat cross section extending along the flow direction of the blown air. The tubes 111 and 211 of the present embodiment are arranged such that the longitudinal direction thereof extends along the vertical direction.

  In addition, the fins 112 and 212 of the present embodiment are constituted by corrugated fins formed by bending a thin plate material into a wave. Each fin 112 and 212 is joined to the flat outer surface side in the tubes 111 and 211, and functions as a heat exchange promoting part for expanding the heat transfer area between the blown air and the refrigerant.

  Further, in the laminated body of the tubes 111 and 211 and the fins 112 and 212 of the present embodiment, side plates 113 and 213 that reinforce the heat exchange core parts 11 and 12 are arranged at both ends in the tube laminating direction. ing. The side plates 113 and 213 are joined to the fins 112 and 212 arranged on the outermost side in the tube stacking direction.

  As shown in FIG. 3, the windward heat exchange core part 11 includes a first windward core part 11 a and a first windward core part 11 a configured to include some tube groups among the plurality of tubes 111. The second upwind core portion 11b includes a tube group different from the tube group.

  Specifically, in the windward heat exchange core part 11 of the present embodiment, when viewed from the flow direction AF of the blown air, the right half of the tube stacking direction corresponds to the first windward core part 11a. The left half of the tube stacking direction corresponds to the second upwind core portion 11b. In this embodiment, the 1st windward core part 11a comprises a "3rd core part", and the 2nd windward core part 11b comprises the "4th core part."

  The leeward side heat exchange core part 21 is the first leeward side core part 21a configured to include a part of the plurality of tubes 211, and the tube group constituting the first leeward side core part 21a. It has the 2nd leeward side core part 21b comprised including a different tube group.

  Specifically, the leeward side heat exchange core portion 21 of the present embodiment corresponds to the first leeward side core portion 21a in the right half of the tube stacking direction when viewed from the flow direction AF of the blown air. The left half of the tube stacking direction corresponds to the second leeward core portion 21b. In the present embodiment, the first leeward core portion 21a constitutes a “first core portion”, and the second leeward core portion 21b constitutes a “second core portion”.

  In this embodiment, the 1st leeward side core part 11a and the 1st leeward side core part 21a are arrange | positioned so as to oppose the flow direction AF of blowing air. In the present embodiment, the second leeward core portion 11b and the second leeward core portion 21b are arranged so as to face the flow direction AF of the blown air.

  The windward upper tank section 12 is formed of a cylindrical member having an opening formed at one end in the tube stacking direction and closed at the other end in the tube stacking direction. In the present embodiment, the opening formed in the windward upper tank portion 12 constitutes a refrigerant derivation portion 12 a that leads the refrigerant from the inside of the windward upper tank portion 12 to the outside.

  The refrigerant outlet 12a is connected to the refrigerant pipe via an outlet connector (not shown). The refrigerant outlet 12a of the present embodiment is provided at the right end of the upwind upper tank 12 when viewed from the flow direction AF of the blown air.

  The windward upper tank portion 12 is joined to each tube 111 in a state where the upper end side of each tube 111 is inserted into a through hole formed in the lower portion. That is, the windward upper tank portion 12 is configured such that the internal space thereof communicates with each tube 111 of the windward heat exchange core portion 11, and each windward core portion 11 a of the windward heat exchange core portion 11 is configured. It functions as a refrigerant collecting unit that collects the refrigerant from 11b.

  In the windward upper tank portion 12 of the present embodiment, the left half of the tube stacking direction corresponds to a region where the refrigerant from the second windward core portion 11b flows when viewed from the flow direction AF of the blown air. . The windward upper tank portion 12 of the present embodiment has a right half portion in the tube stacking direction in a region where the refrigerant from the first windward core portion 11a flows when viewed from the flow direction AF of the blown air. It corresponds.

  The leeward upper tank unit 22 is formed in a cylindrical shape in which an opening is formed at one end of the tube stacking direction and the other end of the tube stacking direction is closed, similar to the windward upper tank unit 12. It is composed of members. In the present embodiment, the opening formed in the leeward upper tank portion 22 constitutes a refrigerant introduction portion 22 a that introduces the refrigerant from the outside to the inside of the leeward upper tank portion 22.

  The refrigerant introduction part 22a is connected to the refrigerant pipe via an inlet side connector (not shown). The refrigerant introduction part 22a of the present embodiment is provided at the right end of the leeward upper tank part 22 when viewed from the flow direction AF of the blown air.

  The leeward side upper tank part 22 is joined to each tube 211 in a state where the upper end side of each tube 211 is inserted into a through hole formed in the lower part. That is, the leeward side upper tank part 22 is configured such that the internal space thereof communicates with each tube 211 of the leeward side heat exchange core part 21, and each leeward side core part 21 a of the leeward side heat exchange core part 21, It functions as a refrigerant distributor that distributes the refrigerant to 21b.

  The upwind side lower tank part 13 is comprised with the cylindrical member with which the tube lamination direction both ends were obstruct | occluded. The upwind lower tank portion 13 is joined to each tube 111 in a state where the lower end side of each tube 111 is inserted into a through hole formed in the upper portion. That is, the windward lower tank portion 13 is configured such that the internal space thereof communicates with each tube 111.

  In addition, a partition member 131 is disposed inside the windward lower tank portion 13 at a central position in the tube stacking direction. By this partition member 131, the space in which the internal space of the windward lower tank portion 13 communicates with the tubes 111 constituting the first windward core portion 11a and the tubes 111 constituting the second windward core portion 11b communicate with each other. It is partitioned into a space to perform.

  In the present embodiment, among the internal space of the upwind lower tank portion 13, the space communicating with each tube 111 constituting the first upwind core portion 11a distributes the refrigerant to the first upwind core portion 11a. The refrigerant distribution unit 13a is configured. Moreover, in this embodiment, the space connected to each tube 111 which comprises the 2nd windward core part 11b among the internal spaces of the windward lower tank part 13 distributes a refrigerant | coolant to the 2nd windward core part 11b. The 2nd refrigerant distribution part 13b is comprised.

  The leeward side lower tank portion 23 is formed of a cylindrical member that is closed at both ends in the tube stacking direction. This leeward side lower tank part 23 is joined to each tube 211 in a state where the lower end side of each tube 211 is inserted into a through hole formed in the upper part. That is, the leeward side lower tank portion 23 is configured such that its internal space communicates with each tube 211.

  A partition member 231 is disposed inside the leeward side lower tank portion 23 at a central position in the tube stacking direction, and the partition member 231 allows the internal space of the leeward side lower tank portion 23 to be the first leeward side core portion 21a. Are partitioned into a space in which the tubes 211 composing each other communicate with each other and a space in which each tube 211 constituting the second leeward core portion 21b communicates with each other.

  In the present embodiment, among the internal space of the leeward side lower tank portion 23, the spaces communicating with the respective tubes 211 constituting the first leeward side core portion 21a collect the refrigerant from the first leeward side core portion 21a. 1 refrigerant | coolant gathering part 23a is comprised. Moreover, in this embodiment, the space which each tube 211 which comprises the 2nd leeward side core part 21b communicates comprises the 2nd refrigerant | coolant collection part 23b which collects the refrigerant | coolant from the 2nd leeward side core part 21b.

  The lower tank portions 13 and 23 are connected via the refrigerant replacement portion 30. The refrigerant replacement unit 30 is configured to exchange the refrigerant flow in the core width direction in each of the heat exchange core units 11 and 21. That is, the refrigerant replacement unit 30 is configured to guide the refrigerant in the first refrigerant collecting unit 23a to the second refrigerant distributing unit 13b and to guide the refrigerant in the second refrigerant collecting unit 23b to the first refrigerant distributing unit 13a. ing.

  Specifically, the refrigerant replacement unit 30 includes a pair of collecting side connection portions 31a and 31b, a pair of distribution side connection portions 32a and 32b, and an intermediate tank portion 33. In addition, in FIG. 3, in order to clarify the connection relation of each connection part 31a, 31b, 32a, 32b, the length in the flow direction AF of the blowing air of each connection part 31a, 31b, 32a, 32b is a real thing (FIG. 2)).

  Each of the pair of collecting side connecting portions 31a and 31b is formed of a cylindrical member in which a refrigerant flow path through which a refrigerant flows is formed, and one end side thereof is connected to the leeward lower tank portion 23 and the other end The side is connected to the intermediate tank 33.

  Of the pair of collecting side connecting portions 31a and 31b, the first collecting side connecting portion 31a constituting one is connected to the leeward lower tank portion 23 so that one end side communicates with the first refrigerant collecting portion 23a. Further, the first collecting side connecting portion 31a is connected to the intermediate tank portion 33 so that the other end side communicates with a first refrigerant channel 33a in the intermediate tank portion 33 described later.

  The second collecting side connecting portion 31b constituting the other of the pair of collecting side connecting portions 31a and 31b is connected to the leeward lower tank portion 23 so that one end side thereof communicates with the second refrigerant collecting portion 23b. Yes. The second collecting side connecting portion 31b is connected to the intermediate tank portion 33 so that the other end side communicates with a second refrigerant flow path 33b in the intermediate tank portion 33 described later.

  Each of the pair of distribution side connecting portions 32a and 32b is configured by a cylindrical member in which a refrigerant flow path through which the refrigerant flows is formed, and one end side thereof is connected to the windward lower tank portion 13 and the other end. The side is connected to the intermediate tank 33.

  Of the pair of distribution side connection parts 32a and 32b, the first distribution side connection part 32a constituting one is connected to the upwind lower tank part 13 so that one end side communicates with the first refrigerant distribution part 13a. Further, the first distribution side connecting portion 32a is connected to the intermediate tank portion 33 so that the other end side communicates with a second refrigerant flow path 33b in the intermediate tank portion 33 described later. Accordingly, the first distribution side connection portion 32a communicates with the above-described second collecting side connection portion 31b via the second refrigerant flow path 33b of the intermediate tank portion 33.

  Of the pair of distribution side connection portions 32a and 32b, the second distribution side connection portion 32b constituting the other is connected to the upwind lower tank portion 13 so that one end side communicates with the second refrigerant distribution portion 13b. Further, the second distribution side connecting portion 32b is connected to the intermediate tank portion 33 so that the other end side communicates with a first refrigerant flow path 33a in the intermediate tank portion 33 described later. Therefore, the second distribution side connection portion 32b communicates with the first collecting side connection portion 31a via the first refrigerant flow path 33a of the intermediate tank portion 33.

  The intermediate tank portion 33 is configured by a cylindrical member that is closed at both ends in the tube stacking direction. The intermediate tank portion 33 is disposed between the leeward lower tank portion 13 and the leeward lower tank portion 23.

  As shown in FIG. 4, a partition member 331 is disposed inside the intermediate tank portion 33, and the partition member 331 allows the internal space of the intermediate tank portion 33 to be connected to the first refrigerant flow path 33 a and the second refrigerant flow. It is partitioned off from the path 33b. The 1st refrigerant | coolant flow path 33a comprises the refrigerant | coolant flow path which guide | induces the refrigerant | coolant from the 1st gathering side connection part 31a to the 2nd distribution side connection part 32b. On the other hand, the second refrigerant flow path 33b constitutes a refrigerant flow path that guides the refrigerant from the second collecting side connection part 31b to the first distribution side connection part 32a.

  In the present embodiment, the first collecting side coupling portion 31a, the first refrigerant flow path 33a, and the second distribution side coupling portion 32b in the refrigerant replacement unit 30 are connected to the first leeward side core portion 21a and the second windward side core portion 11b. The 1st communication part which communicates is comprised.

  In the present embodiment, the second collecting side connecting part 31b, the second refrigerant flow path 33b, and the first distribution side connecting part 32a in the refrigerant replacement part 30 are the second leeward side core part 21b and the first upside core part. The 2nd communication part which connects 11a is comprised.

  Here, in the refrigerant flow path from the first refrigerant collecting portion 23a of the leeward lower tank portion 23 to the refrigerant deriving portion 12a, there is a flow resistance of the refrigerant flowing from the first refrigerant collecting portion 23a toward the refrigerant deriving portion 12a. A lead-out resistor 121 is provided as a resistor.

  The refrigerant flow path from the first refrigerant collecting portion 23a of the leeward lower tank portion 23 to the refrigerant outlet portion 12a is from the second upwind core portion 11b in the upwind upper tank portion 12 from the first refrigerant collecting portion 23a. A refrigerant flow path that reaches the region into which the refrigerant flows is configured.

  The lead-out resistor 121 of the present embodiment is provided inside the windward upper tank portion 12. Specifically, as shown in FIG. 5, the lead-out side resistor 121 includes a portion to which each tube 111 constituting the first upwind core portion 11a is joined and each of the second upwind core portion 11b. It arrange | positions between the site | parts where the tube 111 is joined.

  The lead-out side resistor 121 of the present embodiment is disposed so as to extend in the direction (vertical direction) intersecting the flow direction of the refrigerant flowing in the windward upper tank portion 12 along the tube stacking direction. The derivation-side resistor 121 of the present embodiment is smaller than the cross-sectional area of the refrigerant channel that guides the refrigerant that has passed through the first windward core portion 11a inside the windward upper tank portion 12 to the refrigerant derivation portion 12a side. It is comprised with the plate-shaped member in which the opening part 121a was formed. In the lead-out side resistor 121 of the present embodiment, one through hole is formed as the opening 121a. Note that the opening 121a formed in the lead-out resistor 121 may be formed by a plurality of through holes.

  In the refrigerant evaporator 5 of the present embodiment, the refrigerant flow path extending from the second windward core portion 11b to the refrigerant derivation portion 12a reaches from the first windward core portion 11a to the refrigerant derivation portion 12a by the derivation-side resistor 121. The pressure loss in the flow path is larger than that of the refrigerant flow path.

  Next, the refrigerant flow in the refrigerant evaporator 5 of the present embodiment will be described with reference to FIG. As shown in FIG. 6, the low-pressure refrigerant in the gas-liquid two-phase state decompressed by the expansion valve 4 in FIG. 1 is introduced from the refrigerant introduction part 22 a into the leeward upper tank part 22 as indicated by an arrow A. The refrigerant introduced into the leeward upper tank portion 22 descends the first leeward core portion 21a of the leeward heat exchange core portion 21 as indicated by an arrow B, and at the leeward side heat exchange core portion 21 as indicated by an arrow C. The second leeward core portion 21b is lowered.

  The refrigerant descending the first leeward core portion 21a flows into the first refrigerant collecting portion 23a of the leeward lower tank portion 23 as indicated by an arrow D. On the other hand, the refrigerant descending the second leeward core portion 21b flows into the second refrigerant collecting portion 23b of the leeward lower tank portion 23 as indicated by an arrow E.

  The refrigerant flowing into the first refrigerant collecting portion 23a flows into the first refrigerant flow path 33a of the intermediate tank portion 33 through the first collecting side connecting portion 31a as indicated by the arrow F. The refrigerant that has flowed into the second refrigerant collecting portion 23b flows into the second refrigerant flow path 33b of the intermediate tank portion 33 through the second collecting side connecting portion 31b as indicated by an arrow G.

  The refrigerant that has flowed into the first refrigerant flow path 33a flows into the second refrigerant distribution portion 13b of the windward lower tank portion 13 through the second distribution side connecting portion 32b as indicated by an arrow H. Further, the refrigerant flowing into the second refrigerant flow path 33b flows into the first refrigerant distribution portion 13a of the windward lower tank portion 13 through the first distribution side connecting portion 32a as indicated by an arrow I.

  The refrigerant that has flowed into the second refrigerant distribution unit 13b of the upwind lower tank unit 13 ascends the second upwind core unit 11b of the upwind heat exchange core unit 11 as indicated by an arrow J. On the other hand, the refrigerant that has flowed into the first refrigerant distribution unit 13a ascends the first upwind core unit 11a of the upwind heat exchange core unit 11 as indicated by an arrow K.

  The refrigerant that has moved up the second upwind core portion 11 b flows into the upwind upper tank portion 12 as indicated by an arrow L. Further, the refrigerant that has moved up the first upwind core portion 11a flows into the upwind upper tank portion 12 as indicated by an arrow M. Then, the refrigerant that has flowed into the windward upper tank portion 12 from each of the windward core portions 11a and 11b flows toward the refrigerant derivation portion 12a and flows out from the refrigerant derivation portion 12a to the refrigerant suction side of the compressor 2 as indicated by an arrow N. To do.

  Here, the refrigeration cycle 1 of the present embodiment is configured such that the gas-liquid refrigerant is separated by the accumulator 6 and the refrigerant in the gas phase state flows into the compressor 2 to the refrigerant suction side. For this reason, even if the refrigerant derived from the refrigerant deriving unit 12a of the refrigerant evaporator 5 includes a liquid-phase refrigerant, liquid compression in the compressor 2 can be prevented.

  Next, features of the refrigerant evaporator 5 according to the present embodiment will be described with reference to FIGS. 7 and 8 are diagrams showing the flow rate of the refrigerant flowing through the respective evaporation units 10 and 20 of the refrigerant evaporator 5A according to the conventional embodiment when the amount of refrigerant flowing into the refrigerant evaporator 5 is small. 9 and 10 are diagrams showing the flow rate of the refrigerant flowing through the respective evaporation units 10 and 20 of the refrigerant evaporator 5 according to the present embodiment when the amount of refrigerant flowing into the refrigerant evaporator 5 is small. 7 to 10 are schematic front views when the refrigerant evaporators 5 and 5A are viewed from the direction opposite to the air flow direction (the direction of the arrow RAF in FIG. 2).

  As shown in FIG. 8, the refrigerant evaporator 5 </ b> A according to the conventional mode is different from the refrigerant evaporator 5 according to the present embodiment in that the lead-out side resistor 121 is not provided inside the windward upper tank unit 12. ing. In addition, the other component of 5 A of refrigerant | coolant evaporators which concern on a conventional form is comprised similarly to the refrigerant | coolant evaporator 5 which concerns on this embodiment.

  Under operating conditions where the heat load in the refrigeration cycle 1 is small, the amount of refrigerant circulating in the refrigeration cycle 1 decreases in order to suppress heat exchange in the refrigerant evaporator 5. As a result, the amount of refrigerant flowing into the refrigerant evaporator 5 is reduced. And if the refrigerant | coolant amount which flows in into the refrigerant | coolant evaporator 5 decreases, the flow rate of the refrigerant | coolant which flows in into the inside of the leeward side upper tank part 22 from the refrigerant | coolant introduction part 22a will become low.

  In this case, the inertial force of the refrigerant when flowing into the leeward upper tank unit 22 is small, and the high density liquid phase refrigerant flows from the vicinity of the refrigerant introduction part 22a of the leeward upper tank unit 22 to the leeward side. It flows into the heat exchange core part 21. For this reason, in the refrigerant evaporator 5A according to the conventional embodiment, as shown in FIG. 7, a large amount of liquid-phase refrigerant (shaded portion in the figure) flows into the first leeward core portion 21a near the refrigerant introduction portion 22a. However, a large amount of refrigerant in the gas phase flows into the second leeward core portion 21b far from the refrigerant introduction portion 22a. Then, in the windward evaporator 10, as shown in FIG. 8, a large amount of refrigerant in the liquid phase (shaded area in the drawing) flows through the second windward core part 11b communicating with the first leeward core part 21a. A large amount of refrigerant in the gas phase flows through the first leeward core portion 11a communicating with the second leeward core portion 21b.

  Here, since the refrigerant in the gas phase flows in the first upwind core portion 11a, the evaporation of the refrigerant is completed at an early stage, and the refrigerant in the gas phase having a superheat degree with low heat exchange efficiency flows. become. When the evaporation of the refrigerant is completed early in the first upwind core portion 11a, the refrigeration oil is separated from the refrigerant, and the separated refrigeration oil is stagnated in the upwind lower tank portion 13.

  In this state, when the compressor 2 is stopped and the supply of the refrigerant to the refrigerant evaporator 5A is stopped, the liquid-phase refrigerant is biased toward the refrigerant flow path from the first leeward core portion 21a to the refrigerant outlet portion 12a. In this state, the refrigerant stays inside the refrigerant evaporator 5. Such a bias of the liquid-phase refrigerant is maintained even when the compressor 2 is restarted.

  When the compressor 2 is restarted, a large amount of refrigerant flows from the refrigerant flow path from the first leeward core portion 21a where the refrigerant remains to the refrigerant outlet portion 12a to the refrigerant suction side of the compressor 2, The amount of refrigerant flowing through the refrigerant flow path from the leeward core portion 21b to the refrigerant outlet portion 12a is reduced. For this reason, it becomes difficult to sufficiently return the refrigerating machine oil accumulated on the refrigerant flow path side extending from the second leeward core portion 21b to the refrigerant outlet portion 12a to the compressor 2.

  Further, in the refrigerant evaporator 5A according to the conventional form, in the windward evaporator 10, the liquid-phase refrigerant that has flowed into the second windward core part 11b does not completely evaporate and flows into the windward upper tank part 12. There is. In this case, when a part of the refrigerant in the liquid phase flows in the windward upper tank portion 12 toward the refrigerant derivation portion 12a, the refrigerant may flow into the first windward core portion 11a (reverse flow).

  When the refrigerant in the liquid phase flows into the first windward core portion 11a from the windward upper tank portion 12, the flow of the gas-phase refrigerant flowing through the first windward core portion 11a is prevented from flowing to the windward upper tank portion 12. . In this case, the refrigerant flow tends to stagnate in the first upwind core portion 11a. When the refrigerant stagnates inside the first upwind core portion 11a, the refrigeration oil also stagnates accordingly, so that the return amount of the refrigeration oil to the compressor 2 decreases.

  On the other hand, in the refrigerant evaporator 5 of the present embodiment, the refrigerant flow path extending from the first refrigerant collecting section 23a to the refrigerant deriving section 12a and the refrigerant flow path extending from the second refrigerant collecting section 23b to the refrigerant deriving section 12a. On the other hand, it is configured to make a difference in the flow resistance of the refrigerant. That is, in the refrigerant evaporator 5 according to the present embodiment, the refrigerant flow into the upwind upper tank portion 12 in the refrigerant flow path from the first refrigerant collecting portion 23a of the leeward lower tank portion 23 to the refrigerant derivation portion 12a. A lead-out side resistor 121 is disposed as a resistance portion that serves as a flow resistance.

  According to this, the flow rate of the refrigerant flowing from the second upwind core portion 11b to the refrigerant outlet portion 12a via the upwind upper tank portion 12 is limited. For this reason, even when the amount of refrigerant flowing into the refrigerant evaporator 5 is small, as shown in FIGS. 9 and 10, the liquid phase state is present in the refrigerant flow path from the first refrigerant collecting portion 23a to the refrigerant outlet portion 12a. It is suppressed that the refrigerant | coolant flows unevenly.

  As a result, the liquid phase refrigerant easily flows through the refrigerant flow path from the second refrigerant collecting portion 23b to the refrigerant outlet portion 12a. For this reason, when the amount of refrigerant introduced into the refrigerant evaporator 5 is small or when the compressor 2 is restarted, the compressor oil remaining in the refrigerant flow path from the second refrigerant assembly portion 23b to the refrigerant outlet portion 12a is compressed. It is possible to return to the refrigerant suction side of the machine 2.

  Therefore, according to the refrigerant evaporator 5 of the present embodiment, it is possible to ensure a sufficient return amount of the refrigerating machine oil to the compressor 2.

  In particular, as in the refrigerant evaporator 5 of the present embodiment, when the resistance portion serving as the refrigerant flow resistance is configured by the lead-out side resistor 121, the refrigerant flow path in the refrigerant evaporator 5 is not significantly changed. This is advantageous in that the flow resistance of the refrigerant in the evaporator 5 can be adjusted.

  By the way, since the refrigerant which has passed through the leeward evaporator 20 and is in a gas phase easily flows to the windward evaporator 10, the cooling performance of the blown air in the windward evaporator 10 is low. It tends to be lower than the cooling performance of the blown air. In addition, since the refrigerant | coolant of a gaseous state only absorbs sensible heat from blowing air, the cooling effect of blowing air is not fully exhibited.

  Therefore, in the refrigerant evaporator 5 of the present embodiment, the windward evaporator 10 is disposed upstream of the blast air evaporator 20 in the flow direction X of the blown air. According to this, the temperature difference between the refrigerant evaporation temperature of each of the evaporation units 10 and 20 and the blown air can be secured, and the blown air can be efficiently cooled.

  Here, in this embodiment, although the example comprised by the plate-shaped member which has the opening part 121a as the derivation | leading-out side resistor 121 was demonstrated, it is not limited to this. The derivation-side resistor 121 only needs to have a shape that extends in a direction that intersects the flow direction of the refrigerant flowing through the windward upper tank portion 12. For example, the lead-out resistor 121 may be configured by a plate-like member having a slit-like through hole. Further, the lead-out side resistor 121 is disposed so as to extend in a direction (for example, the tube stacking direction) intersecting the flow direction (vertical direction) of the refrigerant flowing into the windward upper tank part 12 from the second windward core part 11b. May be.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIGS. This embodiment is different from the first embodiment in that the in-collection-part resistor 232 is provided in the first refrigerant gathering part 23a as a resistance part that serves as a refrigerant flow resistance. In this embodiment, the derivation-side resistor 121 is not provided, but the derivation-side resistor 121 may be provided.

  As shown in FIG. 11, the in-collector resistor 232 is in a direction (for example, a tube stacking direction) intersecting the flow direction (vertical direction) of the refrigerant flowing in the first refrigerant collective portion 23 a in the leeward lower tank portion 23. It has an extending shape. Specifically, the in-collection-part resistor 232 of the present embodiment is arranged in the first refrigerant gathering part 23a in the leeward lower tank part 23 so as to extend from one end side in the tube stacking direction to the partition member 231.

  As shown in FIG. 12, the collective part internal resistor 232 according to the present embodiment has a refrigerant flow path that guides the refrigerant from the second leeward core part 21 b to the second collective side connection part 31 b inside the leeward lower tank part 23. It is comprised with the plate-shaped member in which the opening part 232a smaller than a flow-path cross-sectional area was formed. A plurality of slit-shaped through holes arranged in the tube stacking direction are formed as openings 232a in the in-collection-part resistor 232 of the present embodiment. Note that the opening 232a formed in the in-aggregate resistor 232 may be formed by a single through hole.

  In the refrigerant evaporator 5 of the present embodiment, the refrigerant flow path from the first windward core portion 11a to the refrigerant derivation portion 12a is extended from the second windward core portion 11b to the refrigerant derivation portion 12a by the collective part internal resistor 232. The pressure loss in the flow path is larger than that of the refrigerant flow path.

  Other configurations are the same as those of the first embodiment. In the refrigerant evaporator 5 of the present embodiment, among the refrigerant flow paths from the first refrigerant assembly portion 23a of the leeward lower tank portion 23 to the refrigerant outlet portion 12a, the refrigerant flow resistance is provided inside the first refrigerant assembly portion 23a. As the resistance part, the in-collection-part resistor 232 is arranged.

  According to this, the amount of refrigerant flowing from the first leeward core portion 21a to the first refrigerant assembly portion 23a is limited. As a result, as shown in FIG. 13, it is suppressed that the liquid-phase refrigerant flows in the refrigerant flow path from the first refrigerant collecting portion 23a to the refrigerant deriving portion 12a, and the refrigerant is led out from the second refrigerant collecting portion 23b. The refrigerant in the liquid phase can easily flow through the refrigerant flow path reaching the portion 12a.

  As a result, when the amount of refrigerant introduced into the refrigerant evaporator 5 is small or when the compressor 2 is restarted, the compressor oil remaining in the refrigerant flow path from the second refrigerant assembly portion 23b to the refrigerant outlet portion 12a is compressed. It is possible to return to the refrigerant suction side of the machine 2. Therefore, according to the refrigerant evaporator 5 of the present embodiment, it is possible to ensure a sufficient return amount of the refrigerating machine oil to the compressor 2.

(Modification of the second embodiment)
In the above-described embodiment, the example in which the in-collection-part resistor 232 is disposed in the first refrigerant gathering part 23a of the leeward lower tank part 23 as the resistance part serving as the refrigerant flow resistance has been described, but the present invention is not limited thereto.

  As shown in FIG. 14, the resistor 132 in which the opening 132 a is formed in the same manner as the collective portion resistor 232 may be disposed in the second refrigerant distribution portion 13 b of the windward lower tank portion 13. According to this, the pressure loss of the refrigerant flow path from the first refrigerant collecting portion 23a to the refrigerant deriving portion 12a is larger than the pressure loss of the refrigerant flow path from the second refrigerant collecting portion 23b to the refrigerant deriving portion 12a. For this reason, it is suppressed that the liquid-phase state refrigerant flows unevenly in the refrigerant flow path from the first refrigerant collecting section 23a to the refrigerant deriving section 12a, and the refrigerant flow path extending from the second refrigerant collecting section 23b to the refrigerant deriving section 12a. In addition, the liquid phase refrigerant can easily flow.

(Third embodiment)
Next, a third embodiment will be described with reference to FIGS. 15 and 16. The present embodiment is different from the first embodiment in that a communication portion internal resistor 34 is provided inside the intermediate tank portion 33 of the refrigerant replacement portion 30 as a resistance portion serving as a refrigerant flow resistance. In this embodiment, the derivation-side resistor 121 is not provided, but the derivation-side resistor 121 may be provided.

  FIG. 15 is a schematic cross-sectional view of a portion including the lower tank portions 13 and 23 and the intermediate tank portion 33 in the refrigerant evaporator 5 according to the present embodiment. As shown in FIG. 15, in the intermediate tank portion 33 of the present embodiment, a communicating portion internal resistor 34 is disposed on the refrigerant inlet side of the second distribution side connecting portion 32 b.

  The communicating portion internal resistor 34 of the present embodiment has a shape that extends in a direction that intersects the flow direction of the refrigerant flowing through the second distribution side connecting portion 32b. Specifically, the in-communication portion resistor 34 of the present embodiment is configured by a plate-like member in which an opening 34a smaller than the opening area on the refrigerant inlet side of the first distribution side connecting portion 32a is formed. One through hole is formed in the communicating portion internal resistor 34 of the present embodiment as the opening 34a. Note that the opening 34a formed in the communicating portion internal resistor 34 may be formed by a plurality of through holes.

  In the refrigerant evaporator 5 of the present embodiment, the refrigerant flow from the first refrigerant collecting portion 23a to the refrigerant deriving portion 12a is caused to flow from the second refrigerant collecting portion 23b to the refrigerant deriving portion 12a by the communicating portion internal resistor 34. The pressure loss in the flow path is larger than the path.

  Other configurations are the same as those of the first embodiment. In the refrigerant evaporator 5 of the present embodiment, the in-communication-part resistor 34 is disposed on the refrigerant inlet side of the first distribution side connection part 32a as a resistance part that serves as a refrigerant flow resistance.

  According to this, the amount of the refrigerant flowing from the first refrigerant flow path 33a of the intermediate tank portion 33 to the first distribution side connection portion 32a is limited. As a result, as shown in FIG. 16, the liquid phase refrigerant is prevented from flowing in the refrigerant flow path extending from the first refrigerant assembly 23a to the refrigerant outlet 12a, and the refrigerant is derived from the second refrigerant assembly 23b. The refrigerant in the liquid phase can easily flow through the refrigerant flow path reaching the portion 12a.

  As a result, when the amount of refrigerant introduced into the refrigerant evaporator 5 is small or when the compressor 2 is restarted, the compressor oil remaining in the refrigerant flow path from the second refrigerant assembly portion 23b to the refrigerant outlet portion 12a is compressed. It is possible to return to the refrigerant suction side of the machine 2.

  Here, in this embodiment, although the example which arrange | positions the communication part internal resistor 34 in the refrigerant | coolant inlet side of the 2nd distribution side connection part 32b was demonstrated, it is not limited to this. For example, the in-communication portion resistor 34 may be disposed on the refrigerant inlet side of the first collecting side connection portion 31 a or the first refrigerant flow path 33 a of the intermediate tank portion 33.

(Fourth embodiment)
Next, a fourth embodiment will be described with reference to FIGS. The present embodiment is different from the first embodiment in that the resistance portion serving as the refrigerant flow resistance is configured by an internal flow path formed inside the intermediate tank portion 33. In this embodiment, the derivation-side resistor 121 is not provided, but the derivation-side resistor 121 may be provided.

  As shown in FIGS. 17 and 18, in the intermediate tank portion 33 of the present embodiment, the flow path of the first refrigerant flow path 33a is smaller than the flow path of the second refrigerant flow path 33b. Specifically, in the intermediate tank portion 33 of the present embodiment, as shown in FIG. 19, the cross-sectional area of the first refrigerant flow path 33a is larger than the cross-sectional area of the second refrigerant flow path 33b. Also, the position of the partition member 331 is set to a position closer to the upper part than the lower part of the intermediate tank part 33 so as to be smaller.

  Thus, the flow passage cross-sectional area of the first refrigerant flow passage 33a is smaller than the flow passage cross-sectional area of the second refrigerant flow passage 33b. Thereby, in the refrigerant evaporator 5 of the present embodiment, the refrigerant flow path from the first refrigerant collecting portion 23a to the refrigerant deriving portion 12a flows more than the refrigerant flow path from the second refrigerant collecting portion 23b to the refrigerant deriving portion 12a. Pressure loss in the road is increasing.

  Other configurations are the same as those of the first embodiment. In the refrigerant evaporator 5 of this embodiment, the flow passage cross-sectional area of the first refrigerant flow passage 33a is smaller than the flow passage cross-sectional area of the second refrigerant flow passage 33b, and the first refrigerant flow passage 33a It functions as a resistance part that becomes a distribution resistance.

  According to this, the amount of the refrigerant flowing through the first refrigerant flow path 33a is limited. Thereby, it is suppressed that the refrigerant in a liquid phase flows unevenly in the refrigerant flow path from the first refrigerant collecting section 23a to the refrigerant deriving section 12a, and the refrigerant flow path from the second refrigerant collecting section 23b to the refrigerant deriving section 12a. In addition, the liquid phase refrigerant can easily flow.

  As a result, when the amount of refrigerant introduced into the refrigerant evaporator 5 is small or when the compressor 2 is restarted, the compressor oil remaining in the refrigerant flow path from the second refrigerant assembly portion 23b to the refrigerant outlet portion 12a is compressed. It is possible to return to the refrigerant suction side of the machine 2.

  In particular, in the present embodiment, the first refrigerant flow path 33a is made to function as a resistance portion that serves as a refrigerant flow resistance. According to this, it is not necessary to add another member. For this reason, according to this embodiment, it becomes possible to implement | achieve the refrigerant | coolant evaporator 5 which can ensure the return amount of the refrigeration oil to the compressor 2 with a simple structure, without increasing a number of parts.

(Other embodiments)
As mentioned above, although embodiment of this invention was described, this invention is not limited to the above-mentioned embodiment, In the range described in the claim, it can change suitably. For example, various modifications are possible as follows.

  (1) In each of the above-described embodiments, the example in which the refrigerant evaporator 5 of the present invention is applied to the refrigeration cycle 1 including the accumulator 6 has been described, but the present invention is not limited to this. The refrigerant evaporator 5 of the present invention can be applied to a refrigeration cycle including a receiver that separates the gas-liquid refrigerant flowing out from the refrigerant outlet side of the condenser 3, a refrigeration cycle not including a gas-liquid separator, and the like. It is.

  (2) In the above-described first to third embodiments, the resistor constituted by a plate-like member in which a through hole is formed is illustrated as the resistance portion serving as the refrigerant flow resistance. The refrigerant evaporator 5 of each embodiment has a flow path structure in which the flow direction of the refrigerant is greatly changed. For this reason, it is desirable to form a through hole in the entire plate surface of the resistor and add a rectifying function for rectifying the flow of the refrigerant.

  (3) In each of the above-described embodiments, the example in which the refrigerant introduction portion 22a and the refrigerant outlet portion 12a are provided at the end portions of the upper tank portions 22 and 12 in the tube longitudinal direction has been described, but the present invention is not limited thereto. As long as the refrigerant introduction part 22a is a part close to the first leeward side core part 21a among the leeward side core parts 21a and 21b in the leeward side upper tank part 22, the refrigerant introduction part 22a may be provided other than the end part in the tube longitudinal direction. . Similarly, if the refrigerant | coolant derivation | leading-out part 12a is a site | part close | similar to the 1st windward core part 11a among each windward core parts 11a and 11b in the windward upper tank part 12, it will provide other than the edge part of a tube longitudinal direction. May be.

  (4) In each of the above-described embodiments, the example in which the refrigerant replacement unit 30 is configured by the pair of collecting side connection portions 31a and 31b, the pair of distribution side connection portions 32a and 32b, and the intermediate tank portion 33 has been described. It is not limited to. For example, the intermediate tank unit 33 of the refrigerant replacement unit 30 may be eliminated and the connecting members 31a, 31b, 32a, and 32b may be directly connected to each other.

  Further, in each of the above-described embodiments, the refrigerant replacement unit 30 is provided separately from the lower tank units 13 and 23. However, as described in Japanese Patent Application Laid-Open No. 2014-13104, the refrigerant replacement unit is provided in each lower tank unit 13. , 23 may be provided.

  In short, in the present invention, the two evaporating units 10 and 20 allow the refrigerant flowing out from the first leeward core portion 21a to flow into the second leeward core portion 11b and the refrigerant flowing out from the second leeward core portion 21b. May be configured to flow into the first windward core portion 11a.

  (5) In each above-mentioned embodiment, when it sees from the flow direction AF of blowing air as the refrigerant evaporator 5, all the 1st leeward side core parts 11a and all the 1st leeward side core parts 21a overlap. Although the example arrange | positioned in was demonstrated, it is not limited to this. The refrigerant evaporator 5 may be disposed so that the first windward core portion 11a and the first leeward core portion 21a partially overlap when viewed from the flow direction of the blown air.

  Further, in each of the above-described embodiments, as the refrigerant evaporator 5, when viewed from the flow direction AF of the blown air, all of the second windward core portion 11b and all of the second leeward core portion 21b are superposed. Although the example arrange | positioned in was demonstrated, it is not limited to this. The refrigerant evaporator 5 may be arranged such that a part of the second windward core portion 11b and the second leeward core portion 21b overlap when viewed from the flow direction of the blown air.

  In short, when viewed from the flow direction of the blown air, the first leeward core portion 11a and the first leeward core portion 21a are arranged so that at least a part of them overlaps, and the second leeward core portion 11b and the second leeward windward are located. What is necessary is just to arrange | position so that at least one part of the side core part 21b may overlap.

  (6) In each of the above-described embodiments, the example in which the heat exchange core parts 11 and 21 of the two evaporation parts 10 and 20 have the two core parts has been described. 11 and 21 may have three or more core parts. That is, the windward heat exchange core part 11 includes a first windward core part 11a constituted of a part of the plurality of tubes 111 and a tube group different from the tube group. What is necessary is just to have the 2 upwind core part 11b. Similarly, the leeward side heat exchange core part 21 is comprised by the tube group different from the 1st leeward side core part 21a comprised by some tube groups among the some tubes 211, and the tube group. What is necessary is just to have the 2nd leeward side core part 21b.

  (7) Although it is desirable to arrange the windward evaporator 10 in the refrigerant evaporator 5 on the upstream side of the blast air evaporator 20 in the flow direction AF of the blown air as in the above-described embodiments, the present invention is not limited to this. . For example, you may make it arrange | position the windward evaporation part 10 in the downstream of the flow direction AF of blowing air rather than the leeward evaporation part 20. FIG.

  (8) In each of the above-described embodiments, the example in which each of the heat exchange core portions 11 and 21 includes the plurality of tubes 111 and 211 and the fins 112 and 212 has been described. Each heat exchange core part 11 and 21 may be comprised only by 211. FIG.

  Moreover, when each heat exchange core part 11 and 21 is comprised with the some tubes 111 and 211 and the fins 112 and 212, the fins 112 and 212 may be comprised not only with the corrugated fin but with the plate fin.

  (9) In each above-mentioned embodiment, although the structure where the tube and the tank part were constituted by a separate member was adopted as refrigerant evaporator 5, it is not limited to this. For example, as described in Japanese Patent Application Laid-Open No. 2014-13104, a plurality of tube units that constitute a tube and a part of a tank portion are laminated by joining a pair of core plates, so that the tube and the tank portion are integrated. The formed laminated structure may be adopted.

  (10) In each of the above-described embodiments, the example in which the refrigerant evaporator 5 is applied to the refrigeration cycle of the vehicle air conditioner has been described. However, the present invention is not limited thereto, and is applicable to other refrigeration cycles used in, for example, a water heater. May be.

  (11) In the above-described embodiment, the elements constituting the embodiment are not necessarily essential unless explicitly stated as essential and clearly considered essential in principle. Needless to say.

  (12) In the above-described embodiment, when numerical values such as the number, numerical value, quantity, range, etc. of the constituent elements of the embodiment are mentioned, it is clearly indicated that it is essential and clearly specified in principle. It is not limited to the specific number except in a limited case.

  (13) In the above-described embodiment, when referring to the shape, positional relationship, etc. of the component, etc., its shape, unless otherwise specified and in principle limited to a specific shape, positional relationship, etc. The positional relationship is not limited.

1 Refrigeration cycle 10 Upwind evaporator (second evaporator)
11 Windward side heat exchange core part 11a 1st windward side core part (3rd core part)
11b 2nd windward core part (4th core part)
12 Upwind upper tank section (tank section above the second evaporation section)
12a Refrigerant outlet part 121 Leader side resistor (resistor part)
20 leeward evaporation section (first evaporation section)
21 leeward side heat exchange core part 21a first leeward side core part (first core part)
21b 2nd leeward side core part (2nd core part)
22 leeward upper tank part (tank part above the first evaporation part)
22a Refrigerant introduction part

Claims (9)

A refrigerant evaporator that is applied to a vapor compression refrigeration cycle (1) for circulating a refrigerant containing refrigeration oil and that cools the cooling target fluid by absorbing heat from the cooling target fluid and evaporating the refrigerant,
A first evaporator (20) arranged in series with respect to the flow direction of the fluid to be cooled, and the second evaporator (10),
Each of the first evaporation section and the second evaporation section includes a heat exchange core section (11, 21) in which a plurality of tubes (111, 211) extending in the vertical direction and through which a refrigerant flows are stacked, and the plurality of tubes It has a pair of tank parts (12, 13, 22, 23) that are connected to both ends and perform a collection of refrigerant flowing through the plurality of tubes or distributing the refrigerant to the plurality of tubes,
The heat exchange core part constituting the first evaporation part is different from the first core part (21a) including a part of the plurality of tubes and the part of the tube groups. A second core portion (21b) configured to include a tube group;
The heat exchange core part constituting the second evaporation part includes a tube group that faces at least a part of the first core part in the flow direction of the cooling target fluid among the plurality of tubes. A third core portion (11a), and a fourth core portion (11b) configured to include a tube group facing at least a part of the second core portion in the flow direction of the cooling target fluid;
Of the pair of tank parts constituting the first evaporation part, the lower tank part (23) has a first refrigerant collecting part (23a) for collecting refrigerant from the first core part, and the second tank part (23). A second refrigerant collecting part (23b) for collecting refrigerant from the core part is provided;
Of the pair of tank parts constituting the second evaporation part, in the lower tank part (13), the first refrigerant distribution for distributing the refrigerant gathered in the second refrigerant gathering part to the third core part Part (13a), a second refrigerant distribution part (13b) for distributing the refrigerant collected in the first refrigerant collecting part to the fourth core part is provided,
Of the pair of tank parts constituting the first evaporation part, the upper tank part (22) includes the first core at a position closer to the first core part than the second core part. And a refrigerant introduction part (22a) for introducing a gas-liquid two-phase refrigerant to be distributed to the second core part from the outside,
Among the pair of tank parts constituting the second evaporation part, the upper tank part (12) has the third core at a position closer to the third core part than the fourth core part. And a refrigerant derivation section (12a) for deriving the refrigerant that has passed through the fourth core section together with the refrigeration oil to the refrigerant suction side of the compressor (2) of the refrigeration cycle,
In the refrigerant flow path from the first refrigerant collecting portion to the refrigerant deriving portion, resistance portions (121, 232, 34, 31a) that serve as a flow resistance of the refrigerant flowing from the first refrigerant collecting portion toward the refrigerant deriving portion. ) Is set ,
Due to the resistance section, the pressure loss in the flow path in the refrigerant flow path from the first refrigerant collecting section to the refrigerant deriving section is larger than that in the refrigerant flow path from the second refrigerant collecting section to the refrigerant deriving section. refrigerant evaporator, characterized in that is. A refrigerant evaporator that is applied to a vapor compression refrigeration cycle (1) for circulating a refrigerant containing refrigeration oil and that cools the cooling target fluid by absorbing heat from the cooling target fluid and evaporating the refrigerant,
A first evaporator (20) arranged in series with respect to the flow direction of the fluid to be cooled, and the second evaporator (10),
Each of the first evaporation section and the second evaporation section includes a heat exchange core section (11, 21) in which a plurality of tubes (111, 211) extending in the vertical direction and through which a refrigerant flows are stacked, and the plurality of tubes It has a pair of tank parts (12, 13, 22, 23) that are connected to both ends and perform a collection of refrigerant flowing through the plurality of tubes or distributing the refrigerant to the plurality of tubes,
The heat exchange core part constituting the first evaporation part is different from the first core part (21a) including a part of the plurality of tubes and the part of the tube groups. A second core portion (21b) configured to include a tube group;
The heat exchange core part constituting the second evaporation part includes a tube group that faces at least a part of the first core part in the flow direction of the cooling target fluid among the plurality of tubes. A third core portion (11a), and a fourth core portion (11b) configured to include a tube group facing at least a part of the second core portion in the flow direction of the cooling target fluid;
Of the pair of tank parts constituting the first evaporation part, the lower tank part (23) has a first refrigerant collecting part (23a) for collecting refrigerant from the first core part, and the second tank part (23). A second refrigerant collecting part (23b) for collecting refrigerant from the core part is provided;
Of the pair of tank parts constituting the second evaporation part, in the lower tank part (13), the first refrigerant distribution for distributing the refrigerant gathered in the second refrigerant gathering part to the third core part Part (13a), a second refrigerant distribution part (13b) for distributing the refrigerant collected in the first refrigerant collecting part to the fourth core part is provided,
Of the pair of tank parts constituting the first evaporation part, the upper tank part (22) includes the first core at a position closer to the first core part than the second core part. And a refrigerant introduction part (22a) for introducing a gas-liquid two-phase refrigerant to be distributed to the second core part from the outside,
Among the pair of tank parts constituting the second evaporation part, the upper tank part (12) has the third core at a position closer to the third core part than the fourth core part. And a refrigerant derivation section (12a) for deriving the refrigerant that has passed through the fourth core section together with the refrigeration oil to the refrigerant suction side of the compressor (2) of the refrigeration cycle,
In the refrigerant flow path from the first refrigerant collecting section to the area where the refrigerant from the fourth core section in the tank section on the upper side of the second evaporation section flows, a resistance section (121 that serves as a refrigerant flow resistance) (121 232, 34, 31a) are set ,
Due to the resistance section, the pressure loss in the flow path in the refrigerant flow path from the first refrigerant collecting section to the refrigerant deriving section is larger than that in the refrigerant flow path from the second refrigerant collecting section to the refrigerant deriving section. refrigerant evaporator, characterized in that is.   3. The refrigerant evaporation according to claim 1, wherein the resistance portion includes a lead-out side resistor (121) provided in the upper tank portion of the second evaporation portion. vessel.   The refrigerant evaporator according to any one of claims 1 to 3, wherein the resistance portion includes an in-collection resistor (232) provided in the first refrigerant assembly portion. .   The said resistance part is comprised including the resistance body (132) provided in the said lower tank part in a said 2nd evaporation part, The structure of any one of Claim 1 thru | or 4 characterized by the above-mentioned. Refrigerant evaporator. A first communication portion (31a, 32b, 33a) for guiding the refrigerant collected in the first refrigerant collecting portion to the second refrigerant distributing portion;
A second communication part (31b, 32a, 33b) for guiding the refrigerant collected in the second refrigerant collecting part to the first refrigerant distributing part,
The refrigerant evaporator according to any one of claims 1 to 5, wherein the resistance portion includes a communication portion internal resistor (34) provided in the first communication portion. A first communication portion (31a, 32b, 33a) for guiding the refrigerant collected in the first refrigerant collecting portion to the second refrigerant distributing portion;
A second communication part (31b, 32a, 33b) for guiding the refrigerant collected in the second refrigerant collecting part to the first refrigerant distributing part,
The flow passage cross-sectional area in the first communication portion is smaller than the flow passage cross-sectional area in the second communication portion,
The refrigerant evaporator according to any one of claims 1 to 6, wherein the resistance portion includes a refrigerant flow path (31a) formed inside the first communication portion. .   The refrigerant evaporator according to any one of claims 1 to 7, wherein the first evaporator is disposed on the downstream side of the flow of the cooling target fluid with respect to the second evaporator.   The refrigeration cycle is provided with an accumulator (6) that separates the gas-liquid refrigerant derived from the refrigerant deriving unit and causes the separated refrigerant in a gas phase state to flow to the refrigerant suction side of the compressor. The refrigerant evaporator according to any one of claims 1 to 8, wherein

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