JP2007333292A - Ejector type refrigeration cycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the operating rate of an ejector type refrigeration cycle 10 by preventing the frost in two evaporators 15 and 18 in the ejector type refrigeration cycle 10 for cooling a common object space to be cooled by combining the first evaporator 15 on the downstream side of an ejector and the second evaporator 18 on the suction side of the ejector. <P>SOLUTION: The ejector type refrigeration cycle has an expansion valve 13 for adjusting the flow rate of a refrigerant on the downstream side of a radiator 12 by the degree of superheat SH brought by the temperature difference between the superheat temperature and saturation temperature of the refrigerant in the outlet of the first evaporator 15. As the flow rate of the refrigerant to the second evaporator 18 is controlled to an appropriate flow rate in this way, frosting in the second evaporator 18 is prevented by the control by a temperature sensor 40 and the quantity of supply of the refrigerant is excessive both in the first and second evaporators 15 and 18. Accordingly, frosting in the first and second evaporators can be prevented, and as a result, the operating rate of the cycle can be improved. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ejector-type refrigeration cycle having an ejector that functions as a refrigerant decompression unit and a refrigerant circulation unit, and a plurality of evaporators, and more particularly, to frost prevention of an evaporator. Alternatively, it is effective when applied to a vehicle refrigeration apparatus for freezing and refrigeration of on-vehicle luggage.

  Conventionally, this type of ejector-type refrigeration cycle is known from Patent Document 1 and the like. In this patent document 1, the first evaporator connected to the downstream side of the ejector and the second evaporator connected to the refrigerant suction port of the ejector are provided, and compared with the refrigerant evaporation temperature of the first evaporator. The refrigerant evaporation temperature of the two evaporators is lowered.

  The first and second evaporators cool the common space to be cooled, the first evaporator is disposed upstream in the flow direction of the air to be cooled, and the second is disposed downstream in the flow direction of the air to be cooled. An evaporator is arranged. Thus, an ejector refrigeration cycle is shown in which the first evaporator on the downstream side of the ejector and the second evaporator on the ejector suction side are combined to cool the common cooling target space.

  In Patent Document 2, as an evaporator suitable for use in the ejector-type refrigeration cycle as described above, tubes and tank portions are arranged in an even number of rows in the flow direction of the external fluid in one evaporator. An evaporator is shown in which the refrigerant flows while meandering in the tank.

Conventionally, in a general vapor compression refrigeration cycle, when the cooling load decreases or the temperature of the evaporator decreases, frost (frost formation) occurs in the evaporator and the cooling function does not function effectively. For this reason, a contact-type fin temperature sensor is inserted at an appropriate location on the fin of the evaporator to detect the fin surface temperature, or the air temperature on the downstream side of the evaporator is detected by a non-contact type air temperature sensor. Thus, the compressor is intermittently operated to prevent the evaporator from being frosted.
JP 2001-74388 A JP 2005-308384 A

  However, since the evaporator always has non-uniform refrigerant distribution and wind speed distribution, the above-described conventional method cannot be used to attach the temperature sensor anywhere in the evaporator. At this time, if the temperature of the temperature sensor detection part is high, the timing for stopping the compressor is delayed, the refrigerant supply amount becomes excessive, and the evaporator is frosted.

  This frost prevents air from flowing downwind, making cooling impossible, and the air temperature sensor senses a high air temperature despite the fact that it is frosted and keeps the compressor running, causing the cycle to fail or compression. There is a problem that the machine may break down. Moreover, although control is possible with a fin temperature sensor, a cycle cannot be started until a frost formation part melt | dissolves, and there exists a problem that a cooling operation rate falls.

  For this reason, conventionally, an appropriate position is determined by a large number of tests in order to attach a temperature sensor at a position where the fin temperature of the evaporator and the temperature of the blown air are lowest. The present invention has been made paying attention to such problems existing in the prior art. In addition, Patent Documents 1 and 2 mentioned above do not describe prevention of frost (frosting) of the evaporator.

  In the ejector-type refrigeration cycle in which the common cooling target space is cooled by combining the first evaporator on the downstream side of the ejector and the second evaporator on the ejector suction side, the present invention prevents frost of the two evaporators. The purpose is to improve the operating rate of the cycle.

  Another object of the present invention is to provide an ejector-type refrigeration cycle unit that is a heat exchanger through which a refrigerant sucked by an ejector flows and includes a temperature sensor at a position suitable for frost prevention control.

  Another object of the present invention is to facilitate the determination of the mounting position of the temperature sensor in performing the frost prevention control.

In order to achieve the above object, the present invention employs technical means described in claims 1 to 9. That is, in the invention according to claim 1, a compressor (11) for sucking and compressing refrigerant,
A radiator (12) that radiates heat of the high-pressure refrigerant discharged from the compressor (11);
Adjusting means (13) for adjusting the refrigerant flow rate on the downstream side of the radiator (12) so that the superheat degree (SH) of the suction side refrigerant of the compressor (11) becomes a predetermined value;
An ejector (14) having a refrigerant suction port (14b) for sucking the refrigerant by a high-speed refrigerant flow obtained by injecting the refrigerant on the downstream side from the nozzle section (14a);
A refrigerant branch passage (16) for guiding the refrigerant flow branched upstream of the refrigerant flow of the ejector (14) to the refrigerant suction port (14b);
A first heat exchanger (15) disposed downstream of the refrigerant flow of the ejector (14);
A second heat exchanger (18) disposed in the refrigerant branch passage (16);
A temperature sensor (40) for detecting frost in the second heat exchanger (18);
Control means (50) for performing frost prevention control according to the temperature detected by the temperature sensor (40) is provided.

  According to the first aspect of the present invention, heat is radiated so that the degree of superheat (SH) represented by the temperature difference between the superheat temperature and saturation temperature of the refrigerant at the outlet of the first heat exchanger (15) becomes a predetermined value. The device (12) has adjusting means (13) for adjusting the refrigerant flow rate on the downstream side. Thereby, the refrigerant | coolant flow rate to the 2nd heat exchanger (18) which is a low temperature side is controlled to an appropriate quantity. As a result, the frost of the second heat exchanger (18) is detected by the temperature sensor (40) and the frost prevention control is performed, so that the refrigerant supply amount of both the first and second heat exchangers (15, 18) is increased. Excessive frosting can be prevented and cycle utilization can be improved.

  In the invention according to claim 2, in the ejector-type refrigeration cycle according to claim 1, the temperature sensor (40) is supplied from the lower tank portion (18c) of the second heat exchanger (18). It is characterized in that it is arranged at a part (MC) that stands up and flows.

  This is because the lowest temperature region is found in the portion (MC) where the refrigerant flow rises from the lower tank portion (18c) in the second evaporator (18) on the low temperature side. According to the second aspect of the present invention, it is possible to easily determine the attachment position of the temperature sensor (40) in performing the frost prevention control.

  Moreover, in invention of Claim 3, in the ejector-type refrigeration cycle of Claim 1 or Claim 2, the first heat exchanger (15) and the second heat exchanger (18) have a common heat. It is characterized by cooling the exchange medium (Air). According to the third aspect of the present invention, the common heat exchange medium (Air) can be efficiently cooled.

  Moreover, in invention of Claim 4, in the ejector type | mold refrigerating cycle of Claim 3, a 1st heat exchanger (15) and a 2nd heat exchanger (18) are the 1st heat exchanger (15 The heat exchange medium (Air) after heat exchange with the second heat exchanger (18) is arranged so as to exchange heat. According to the fourth aspect of the present invention, the common heat exchange medium (Air) can be cooled more efficiently because the temperature of the second heat exchange section (18) is lower.

In the invention according to claim 5, an ejector (14) for sucking the refrigerant from the refrigerant suction port (14b) by a high-speed refrigerant flow injected from the nozzle portion (14a) for decompressing and expanding the refrigerant;
A heat exchange section (18) for evaporating the refrigerant sucked into the refrigerant suction port (14b);
A temperature sensor (40) for detecting frost of the heat exchange unit (18) is provided in a portion of the heat exchange unit (18) where the refrigerant flows from bottom to top.

  According to the invention described in claim 5, by integrally configuring the ejector (14), the heat exchanging portion (18), and the temperature sensor (40), these can be handled as an integrated object and transported. And handling in assembly can be improved.

  Further, the temperature sensor (40) is provided in the portion of the heat exchanging portion (18) where the refrigerant flows from the bottom to the top, as in the case of claim 2, wherein the lowest temperature region is in the heat exchanging portion (18). This is because it has been found that the refrigerant flow rises and flows from the lower tank portion (18c) (MC). According to this, when performing frost prevention control, the unit for ejector type refrigerating cycles to which the temperature sensor (40) was attached in the optimal position can be provided.

Moreover, in invention of Claim 6, the 1st heat exchange part (15) arrange | positioned upstream of the heat exchange medium (Air) which heat-exchanges with a refrigerant | coolant,
A second heat exchange part (18) disposed downstream of the six heat exchange medium (Air) with respect to the first heat exchange part (15),
A temperature sensor (40) for detecting frost,
6 The first heat exchange section (15) is an outflow refrigerant that has flowed out of the ejector (14) that sucks the refrigerant from the refrigerant suction port (14b) by the high-speed refrigerant flow injected from the nozzle section (14a) that decompresses and expands the refrigerant. Evaporate
6 At least a part of the second heat exchange section (18) is configured to evaporate the suction port side refrigerant sucked into the six refrigerant suction ports (14b),
6 temperature sensor (40) is arrange | positioned at 6 2nd heat exchange part (18), It is characterized by the above-mentioned.

  According to the sixth aspect of the present invention, the two heat exchanging parts (15, 18) and the temperature sensor (40) can be handled as an integrated object by carrying out the transportation and assembly. Can be improved in handling. The reason why the temperature sensor (40) is arranged in the second heat exchange part (18) is that the temperature of the second heat exchange part (18) is lower.

  In the invention according to claim 7, in the ejector refrigeration cycle unit according to claim 6, the temperature sensor (40) is supplied from the lower tank portion (18c) of the second heat exchange portion (18) to the refrigerant. It is characterized in that it is arranged at a site (MC) where the flow rises and flows.

  This is because, similarly to claim 2, the lowest temperature region of the second heat exchange portion (18) on the low temperature side becomes a portion (MC) where the refrigerant flow rises and flows from the lower tank portion (18c). This is due to the finding. According to the seventh aspect of the present invention, it is possible to provide an ejector-type refrigeration cycle unit in which the temperature sensor (40) is mounted at the optimum position for performing frost prevention control.

  The invention described in claim 8 is characterized in that, in the ejector-type refrigeration cycle unit described in claim 6 or 7, the ejector (14) is integrally formed.

  In the invention according to claim 9, in the ejector-type refrigeration cycle unit according to claim 6 or 7, the second heat exchange section (18) is further disposed upstream of the refrigerant flow in the second heat exchange section (18). The throttle mechanism (17) for adjusting the flow rate of the refrigerant supplied to the heat exchange unit (18) is integrally formed.

  According to the inventions according to the eighth and ninth aspects, the ejector (14), the throttle mechanism (17), or both of them are integrated with the heat exchangers (15, 18) which are relatively large. By mounting and configuring as an integrated unit (20), these components can be handled as a single unit.

  Therefore, the mounting work when mounting the ejector-type refrigeration cycle on an application target such as a vehicle can be made very efficient. In addition, by configuring the integrated unit (20) to shorten the length of each part connection passage, the cost can be reduced and the mounting space can be reduced.

  The term “integrated” as used in the present invention refers to a part of the casing of the ejector (14) or the throttle mechanism (17) and the tank portions (15b, 15c, 18b, 18c) of the heat exchange units (15, 18), etc. It may be integrated in a fused relationship such that the members are shared, or may be integrated in a relationship that is connected by a firm connection such as welding or a loose connection such as a clamp or screw. .

  In addition, the refrigerant flow path constituted by this integral can be embodied in various modes as shown in the embodiments and modifications thereof described later, and is limited to the embodiments and modifications shown below. is not. In addition, the code | symbol in the bracket | parenthesis of each said means described in the said each means and the claim is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

  Hereinafter, an embodiment of an ejector refrigeration cycle according to the present invention and an ejector refrigeration cycle unit used therefor will be described. The ejector-type refrigeration cycle unit can also be called an ejector-type refrigeration cycle evaporator unit or an evaporator unit with an ejector.

  Since the ejector-type refrigeration cycle unit constitutes a refrigeration cycle including an ejector, the ejector refrigeration cycle unit is connected to a radiator, which is another component of the refrigeration cycle, and a compressor via a pipe. In one form, the ejector-type refrigeration cycle unit is used as an indoor unit for cooling air. In addition, the ejector-type refrigeration cycle unit can also be used as an outdoor unit in another form.

  1 to 8 show an embodiment of the present invention, and FIG. 1 shows an example in which an ejector-type refrigeration cycle 10 according to the embodiment is applied to a vehicle refrigeration cycle apparatus. In the ejector refrigeration cycle 10 of the present embodiment, a compressor 11 that sucks and compresses refrigerant is rotationally driven by a vehicle travel engine (not shown) via an electromagnetic clutch 11a, a belt, and the like.

  The compressor 11 may be a variable capacity type compressor that can adjust the refrigerant discharge capacity by changing the compression capacity, or a fixed capacity type that adjusts the refrigerant discharge capacity by changing the operating rate of the compressor operation by switching the electromagnetic clutch 11a. Any of the compressors may be used. Further, if an electric compressor is used as the compressor 11, the refrigerant discharge capacity can be adjusted by adjusting the rotation speed of the electric motor. In FIG. 1, the electromagnetic clutch 11 a is controlled to be intermittently controlled by an output from a control device (ECU, control means) 50.

  A radiator 12 is disposed on the refrigerant discharge side of the compressor 11. The radiator 12 cools the high-pressure refrigerant by exchanging heat between the high-pressure refrigerant discharged from the compressor 11 and outside air (air outside the passenger compartment) blown by a cooling fan (not shown). Here, as the refrigerant of the ejector refrigeration cycle 10, a vapor compression subcritical cycle is configured using a refrigerant whose high pressure does not exceed the critical pressure, such as a refrigerant of chlorofluorocarbon and HC, in this embodiment. ing. For this reason, the radiator 12 acts as a condenser that condenses the refrigerant.

  A liquid receiver 12 a is provided on the outlet side of the radiator 12. As is well known, the liquid receiver 12a has a vertically long tank shape, and constitutes a gas-liquid separator that separates the gas-liquid refrigerant and accumulates the excess liquid refrigerant in the cycle. At the outlet of the liquid receiver 12a, liquid refrigerant is led out from the lower side inside the tank shape. In addition, the liquid receiver 12a is provided integrally with the heat radiator 12 in this example.

  Further, as the radiator 12, a heat exchanger for condensation located on the upstream side of the refrigerant flow, a liquid receiver 12a for introducing the refrigerant from the heat exchanger for condensation and separating the gas and liquid of the refrigerant, and the liquid receiver A known configuration having a supercooling heat exchange section for supercooling the saturated liquid refrigerant from the vessel 12a may be employed. A temperature type expansion valve 13 is disposed on the outlet side of the liquid receiver 12a. The temperature type expansion valve 13 is an adjusting means for adjusting the amount of liquid refrigerant from the liquid receiver 12 a and has a temperature sensing part 13 a disposed in the suction side passage of the compressor 11.

  As is well known, the temperature type expansion valve 13 detects the superheat degree SH of the compressor suction side refrigerant based on the temperature and pressure of the suction side refrigerant (evaporator outlet side refrigerant described later) of the compressor 11, and the compressor The valve opening degree (refrigerant flow rate) is adjusted so that the superheat degree SH of the suction side refrigerant becomes a predetermined value set in advance.

  An ejector 14 is disposed on the outlet side of the temperature type expansion valve 13. The ejector 14 is a pressure reducing means for reducing the pressure of the refrigerant, and is also a fluid circulating refrigerant circulating means (momentum transport type pump) that circulates the refrigerant by a suction action (winding action) of the refrigerant flow ejected at a high speed.

  In the ejector 14, the passage area of the refrigerant (intermediate pressure refrigerant) after passing through the expansion valve 13 is narrowed down, and the nozzle part 14a for further decompressing and expanding the refrigerant is disposed in the same space as the refrigerant outlet of the nozzle part 14a. A refrigerant suction port 14b for sucking a gas-phase refrigerant from a second evaporator (second heat exchanger, second heat exchange unit) 18 described later is provided.

  Furthermore, a mixing portion 14c that mixes the high-speed refrigerant flow from the nozzle portion 14a and the suction refrigerant of the refrigerant suction port 14b is provided in the refrigerant flow downstream portion of the nozzle portion 14a and the refrigerant suction port 14b. And the diffuser part 14d which comprises a pressure | voltage rise part is arrange | positioned in the refrigerant | coolant flow downstream of the mixing part 14c. The diffuser portion 14d is formed in a shape that gradually increases the refrigerant passage area, and serves to increase the refrigerant pressure by decelerating the refrigerant flow, that is, to convert the velocity energy of the refrigerant into pressure energy. .

  A first evaporator (first heat exchanger, first heat exchange unit) 15 is connected to the outlet side of the diffuser part 14 d of the ejector 14, and the outlet side of the first evaporator 15 is connected to the suction side of the compressor 11. It is connected. On the other hand, a refrigerant branch passage 16 is branched from the inlet side of the ejector 14 (an intermediate portion between the outlet side of the temperature type expansion valve 13 and the inlet side of the ejector 14), and the downstream side of the refrigerant branch passage 16 is connected to the ejector 14. It is connected to the refrigerant suction port 14b. z indicates a branch point of the refrigerant branch passage 16.

  A throttle mechanism 17 is arranged in the refrigerant branch passage 16, and a second evaporator 18 is arranged downstream of the refrigerant flow from the throttle mechanism 17. The throttling mechanism 17 is a pressure reducing means that adjusts the flow rate of the refrigerant to the second evaporator 18, and specifically includes a fixed throttle such as a capillary tube or an orifice.

  In the present embodiment, the two evaporators 15 and 18 are assembled into an integral structure with the configuration described later. The two evaporators 15 and 18 are housed in an air conditioning case (not shown), and air (cooled air) is blown as indicated by an arrow Air by an electric blower 19 common to the air passage configured in the air conditioning case. The blown air is cooled by the two evaporators 15 and 18. In this embodiment, air is the heat exchange medium. The electric blower 19 is an electric fan driven by a motor 19 a, and the motor 19 a is rotationally driven by a control voltage output from the control device 50.

  The cold air cooled by the two evaporators 15 and 18 is sent to a common cooling target space (not shown), and thereby the common cooling target space is cooled by the two evaporators 15 and 18. . When the ejector refrigeration cycle 10 of the present embodiment is applied to a vehicle air conditioning refrigeration cycle apparatus, the vehicle interior space becomes the cooling target space. Further, when the ejector refrigeration cycle 10 of the present embodiment is applied to a refrigeration cycle apparatus for a refrigeration vehicle, the space inside the refrigeration refrigerator of the refrigeration vehicle is a space to be cooled.

  Here, of the two evaporators 15 and 18, the first evaporator 15 connected to the main flow path on the downstream side of the ejector 14 is arranged on the upstream side (windward side) of the air flow Air, and the refrigerant suction port of the ejector 14 is arranged. The second evaporator 18 connected to 14b is arranged on the downstream side (leeward side) of the air flow Air. A temperature sensor 40 described later is provided in the second evaporator 18 on the leeward side as a detection means for detecting frost (frost formation) generated in the two evaporators 15 and 18. A temperature signal detected by the temperature sensor 40 is input to the control device 50, and frost prevention control described later is performed in accordance with the temperature signal.

  By the way, in this embodiment, the ejector 14, the first and second evaporators 15 and 18, the throttle mechanism 17 and the temperature sensor 40 are assembled as one integrated unit 20. Next, a specific example of the integrated unit 20 will be described with reference to FIGS. 2 is a perspective view showing an outline of the overall configuration of the integrated unit 20 (20A). FIG. 3 is a longitudinal (longitudinal) cross-sectional view of the upper tank portions 15b and 18b of the first and second evaporators 15 and 18. FIG. 4 is a cross-sectional view of the upper tank portion 18 b of the second evaporator 18.

  Next, a specific example of the integrated structure of the two evaporators 15 and 18 will be described with reference to FIG. In the example of FIG. 2, the two evaporators 15 and 18 are completely integrated as one evaporator structure. Therefore, the first evaporator 15 constitutes an upstream region of the air flow Air in one evaporator structure, and the second evaporator 18 constitutes a downstream region of the air flow Air in one evaporator structure. It has become.

  Note that the up, down, left and right arrows in FIG. 2 are viewed from the downstream side in the flow direction of the blown air shown by the arrow Air, and the ejector 14 is disposed on the side where the ejector 14 of the second evaporator 18 is disposed. The not-shown side is shown as the downward direction, the upstream side of the nozzle portion 14a of the ejector 14 is shown as the left direction, and the downstream side of the diffuser portion 14d of the ejector 14 is shown as the right direction. In the following description, the upper, lower, left, and right directions are similar directions.

  The basic configurations of the first and second evaporators 15 and 18 are the same, and the heat exchange core portions 15a and 18a and the tank portions 15b, 15c and 18b located on both upper and lower sides of the heat exchange core portions 15a and 18a, respectively. , 18c. Here, each of the heat exchange core portions 15a and 18a includes a plurality of tubes 21 extending in the vertical direction, and a passage through which the heat exchange medium, which is cooled in the present embodiment, passes between the plurality of tubes 21. Is formed. Further, fins 22 are disposed between the plurality of tubes 21 and the tubes 21 and the fins 22 are joined by brazing.

  The heat exchange core portions 15 a and 18 a have a laminated structure of tubes 21 and fins 22. The tubes 21 and the fins 22 are alternately stacked in the left-right direction of the heat exchange core portions 15a and 18a. As another embodiment, a configuration without the fins 22 may be used. Further, in FIG. 2, only a part of the laminated structure of the tube 21 and the fin 22 is illustrated, but the laminated structure of the tube 21 and the fin 22 is configured over the entire area of the heat exchange core portions 15a and 18a. The air blown by the electric blower 19 passes through the gap portion of the laminated structure.

  The tube 21 constitutes a refrigerant passage, and is formed of a flat tube whose cross-sectional shape is flat along the air flow direction Air. The fin 22 is a corrugated fin obtained by bending a thin plate material into a wave shape, and is joined to the flat outer surface side of the tube 21 to expand the air-side heat transfer area. The tube 21 of the heat exchange core portion 15a and the tube 21 of the heat exchange core portion 18a constitute independent refrigerant passages. The tank portions 15b and 15c on both the upper and lower sides of the first evaporator 15 and the second evaporator 18 The tank portions 18b and 18c on both the upper and lower sides constitute independent refrigerant passage spaces.

  The tank portions 15b and 15c on both the upper and lower sides of the first evaporator 15 have tube fitting hole portions (not shown) into which the upper and lower ends of the tube 21 of the heat exchange core portion 15a are inserted and joined. Both end portions communicate with the internal spaces of the tank portions 15b and 15c. Similarly, the tank portions 18b and 18c on both the upper and lower sides of the second evaporator 18 have tube fitting holes (not shown) into which the upper and lower ends of the tube 21 of the heat exchange core portion 18a are inserted and joined. The upper and lower end portions of 21 communicate with the internal spaces of the tank portions 18b and 18c.

  As a result, the tank portions 15b, 15c, 18b, and 18c on the upper and lower sides distribute the refrigerant flow to the plurality of tubes 21 of the corresponding heat exchange core portions 15a and 18a, respectively, or collect the refrigerant flows from the plurality of tubes 21. Or play a role. Since the two upper tank portions 15b, 18b and the two lower tank portions 15c, 18c are adjacent to each other, the two upper tank portions 15b, 18b and the two lower tank portions 15c, 18c are integrally formed. can do.

  Of course, the two upper tank portions 15b and 18b and the two lower tank portions 15c and 18c may be configured as independent members. In addition, as a concrete material of the evaporator components such as the tube 21, the fin 22, the tank portions 15 b, 15 c, 18 b, and 18 c, aluminum which is a metal excellent in thermal conductivity and brazing property is suitable. By forming each part with an aluminum material, the entire configuration of the first and second evaporators 15 and 18 is joined by integrated brazing after assembly.

  In the present embodiment, the first and second evaporators 15 and 18 are also brazed by the first and second connection blocks 23 and 24 of the refrigerant passage shown in FIG. It is designed to be assembled as a unit. On the other hand, since the ejector 14 forms a high-precision minute passage in the nozzle portion 14a, when the ejector 14 is brazed, a high temperature during brazing (a brazing temperature of aluminum: around 600 ° C.). The nozzle part 14a is thermally deformed, resulting in a problem that the passage shape and dimensions of the nozzle part 14a cannot be maintained as designed.

  Therefore, the ejector 14 is assembled to the evaporator side after the first and second evaporators 15 and 18, the first and second connection blocks 23 and 24 and the throttle mechanism 17 are integrally brazed. is there. More specifically, the assembly structure of the ejector 14, the throttle mechanism 17, and the first and second connection blocks 23 and 24 will be described. The throttle mechanism 17 and the first and second connection blocks 23 and 24 include Similarly, it is formed of an aluminum material.

  As shown in FIG. 3, the first connection block 23 is a member that is brazed and fixed to a side surface portion at one end in the longitudinal direction of the upper tank portions 15b and 18b of the first and second evaporators 15 and 18. The refrigerant inlet 25 and the refrigerant outlet 26 of the integrated unit 20 shown in FIG. In the middle of the thickness direction of the first connection block 23, the refrigerant inlet 25 forms a main passage 25 a that forms a first passage toward the inlet side of the ejector 14 and a second passage that extends toward the inlet side of the throttle mechanism 17. Branches to the branch passage 16.

  This branch passage 16 corresponds to an inlet portion of the branch passage 16 in FIG. Therefore, the branch point z in FIG. 1 is configured inside the first connection block 23. On the other hand, the refrigerant outlet 26 is constituted by one simple passage hole (circular hole or the like) penetrating in the thickness direction of the first connection block 23. The branch passage 16 of the first connection block 23 is sealed and joined to one end portion (the left end portion in FIGS. 2 and 3) of the throttle mechanism 17 by brazing.

  The second connection block 24 is a member that is disposed at a substantially central portion in the longitudinal direction of the internal space of the upper tank portion 18b of the second evaporator 18 and is brazed to the inner wall surface of the upper tank portion 18b. The second connection block 24 serves to partition the internal space of the upper tank portion 18b into two spaces in the tank longitudinal direction, that is, a left space 27 and a right space 28. As shown in FIG. 3, the other end side (right end side) of the throttle mechanism 17 passes through the support hole 24a of the second connection block 24 and opens into the right space 28 of the upper tank portion 18b.

  Since the space between the outer peripheral surface of the aperture mechanism 17 and the support hole 24a is sealed by brazing, the space between the left and right spaces 27 and 28 remains blocked. Of the ejector 14, the nozzle portion 14a is made of a material such as stainless steel or brass, and portions other than the nozzle portion 14a (housing portions forming the refrigerant suction port 14b, mixing portion 14c, diffuser portion 14d, etc.) are made of copper, aluminum, or the like. Although comprised with a metal material, you may comprise with resin (nonmetallic material).

  The ejector 14 passes through the hole shapes of the refrigerant inlet 25 and the main passage 25a of the first connection block 23 after the assembly process (the brazing process) for integrally brazing the first and second evaporators 15 and 18 and the like. Are inserted into the upper tank portion 18b. Here, the front end portion of the ejector 14 in the longitudinal direction is a portion corresponding to the outlet portion of the diffuser portion 14d in FIG. The tip of the ejector is inserted into the circular recess 24b of the second connection block 24, and is sealed with an O-ring 29a.

  The ejector tip communicates with the communication hole 24 c of the second connection block 24. In the upper tank portion 15b of the first evaporator 15, a partition plate 30 is disposed at a substantially central portion in the longitudinal direction of the internal space, and the internal space of the upper tank portion 15b is divided into two spaces in the longitudinal direction by the partition plate 30. That is, the left space 31 and the right space 32 are partitioned. The communication hole portion 24c of the second connection block 24 communicates with the right space 32 of the upper tank portion 15b of the first evaporator 15 through the through hole 33a of the intermediate wall surface 33 of both the upper tank portions 15b and 18b. .

  The left end in the longitudinal direction of the ejector 14 (the left end in FIG. 3) is a portion corresponding to the inlet of the nozzle portion 14a in FIG. 1, and this left end is the main connection block 23 using an O-ring 29b. It is fitted and fixed to the inner wall surface of the passage 25a. The ejector 14 may be fixed in the longitudinal direction using, for example, screw fixing means (not shown). The O-ring 29a is held in a groove (not shown) of the second connection block 24, and the O-ring 29b is held in a groove (not shown) of the first connection block 23.

  In the first connection block 23, the refrigerant outlet 26 communicates with the left space 31 of the upper tank portion 15 b, the main passage 25 a communicates with the left space 27 of the upper tank portion 18 b, and the branch passage 16 extends from the throttle mechanism 17. It is brazed to the side walls of the upper tank portions 15b, 18b in a state of communicating with the one end portion. Further, the refrigerant suction port 14 b of the ejector 14 communicates with the left space 27 of the upper tank portion 18 b of the second evaporator 18.

  In the present embodiment, the inside of the upper tank portion 18b of the second evaporator 18 is divided into left and right spaces 27, 28 by the second connection block 24, and the left space 27 serves as a collective tank that collects refrigerant from the plurality of tubes 21. The right space 28 serves as a distribution tank that distributes the refrigerant to the plurality of tubes 21. The ejector 14 has an elongated cylindrical shape extending in the axial direction of the nozzle portion 14a. The longitudinal direction of the elongated cylindrical shape is aligned with the longitudinal direction of the upper tank portion 18b, and the ejector 14 is parallel to the upper tank portion 18b. Is installed.

  With this configuration, the ejector 14 and the evaporator 18 can be arranged in a compact manner, and as a result, the physique of the entire unit can be gathered in a compact manner. Moreover, the ejector 14 is disposed in the left space 27 forming the collective tank, and the refrigerant suction port 14b is directly opened in the left space 27 forming the collective tank. This configuration makes it possible to reduce refrigerant piping.

  This configuration provides an advantage that the collection of refrigerant from the plurality of tubes 21 and the supply of refrigerant (refrigerant suction) to the ejector 14 can be realized with one tank. In the present embodiment, the first evaporator 15 is provided adjacent to the second evaporator 18, and the downstream end of the ejector 14 is connected to the distribution tank (the upper tank portion 15 b of the first evaporator 15). It is installed adjacent to the right space 32).

  In this configuration, even if the ejector 14 is disposed in the tank portion on the second evaporator 18 side, the refrigerant flowing out from the ejector 14 is firstly passed through a very short simple refrigerant passage (holes 24c and 33a). This provides the advantage that it can be supplied to the one evaporator 15 side. The refrigerant flow path of the entire integrated unit 20 in the above configuration will be specifically described with reference to FIGS.

  The refrigerant inlet 25 of the first connection block 23 is branched into a main passage 25 a and a branch passage 16. First, the refrigerant in the main passage 25a passes through the ejector 14 (nozzle part 14a → mixing part 14c → diffuser part 14d) and is decompressed, and the decompressed low-pressure refrigerant is communicated with the communication hole 24c, the intermediate wall surface of the second connection block 24. It flows into the right space 32 of the upper tank portion 15b of the first evaporator 15 through the through hole 33a of 33 as shown by the arrow a.

  The refrigerant in the right space 32 descends the plurality of tubes 21 on the right side of the heat exchange core portion 15a as indicated by an arrow bb and flows into the right side portion in the lower tank portion 15c. Since no partition plate is provided in the lower tank portion 15c, the refrigerant from the right side portion of the lower tank portion 15c moves to the left side as indicated by an arrow cc.

  The refrigerant on the left side of the lower tank portion 15c moves up the plurality of tubes 21 on the left side of the heat exchange core portion 15a as indicated by the arrow dd and flows into the left space 31 of the upper tank portion 15b. The refrigerant flows from the refrigerant to the refrigerant outlet 26 of the first connection block 23 as indicated by an arrow ee. On the other hand, the refrigerant in the branch passage 16 of the first connection block 23 first passes through the throttle mechanism 17 and is depressurized. The low-pressure refrigerant after this depressurization is the upper tank portion of the second evaporator 18 as indicated by the arrow ff. It flows into the right space 28 of 18b.

  The refrigerant in the right space 28 descends the plurality of tubes 21 on the right side of the heat exchange core portion 18a as indicated by an arrow gg and flows into the right side portion in the lower tank portion 18c. Since no partition plate is provided in the lower tank portion 18c, the refrigerant moves from the right side portion of the lower tank portion 18c to the left side as indicated by an arrow hh.

  The refrigerant on the left side of the lower tank portion 18c moves up the plurality of tubes 21 on the left side of the heat exchange core portion 18a as indicated by an arrow ii and flows into the left space 27 of the upper tank portion 18b. Since the refrigerant suction port 14b of the ejector 14 is opened in the left space 27, the refrigerant in the left space 27 is sucked into the ejector 14 from the refrigerant suction port 14b. Since the integrated unit 20 has the above-described refrigerant flow path configuration, the integrated unit 20 as a whole need only have one refrigerant inlet 25 in the first connection block 23, and the refrigerant outlet 26 also has the first connection. Only one block 23 needs to be provided.

  Moreover, the integrated unit 20 of this embodiment integrates the temperature sensor 40 for detecting the frost of the 1st, 2nd evaporators 15 and 18 with the heat exchange core part 18a of the 2nd evaporator 18 of the leeward side. Is prepared. The temperature sensor 40 used for such frost detection includes a contact-type fin temperature sensor that detects the temperature of the fin (evaporator) by inserting it into an appropriate portion of the fin of the evaporator, and a blower on the downstream side of the evaporator. There is a non-contact type air temperature sensor that detects the air temperature.

  FIG. 5A is a perspective view of the fin temperature sensor 40A, and FIG. 5B is a partial cross-sectional view showing the structure of the sensor portion 42 in FIG. FIG. 6 is a perspective view of the air temperature sensor 40B. First, the structure outline of the fin temperature sensor 40A will be described. The fin temperature sensor 40 </ b> A is configured on one end side of the lead wire 43 and is inserted into the fin portion together with the sensor portion 42 while holding the sensor portion 42 while being inserted into the fin portion of the evaporator 42 and fixed. It consists of a resin clamp 41 having an anchor portion 41a.

  As shown in FIG. 5 (b), the sensor unit 42 is formed by connecting a temperature-sensitive semiconductor 42a whose resistance value changes according to temperature to the tip of the lead wire 43 and hardening its periphery with an epoxy resin 42b or the like. Further, it is inserted into a case 42c made of aluminum (A1000 series) so as to fill the gap with a heat conductive filler 42d. A lead wire 43 is drawn out to output the resistance value at the sensor unit 42 as an electric signal to the control device, and a connector 44 for connecting to an electric circuit is connected to the other end side of the lead wire 43. .

  Further, as shown in FIG. 6, the air temperature sensor 40B includes a sensor portion 42 in which a temperature-sensitive semiconductor 42a is connected to the tip of the previous lead wire 43 and the periphery thereof is hardened with an epoxy resin 42b, etc. And the connector 44, and the vicinity of the sensor portion 42 is sandwiched between resin clamps 41. In both sensors, the anchor portion 41a of the clamp 41 is inserted into a fin portion at an appropriate position of the evaporator and fixed integrally.

  FIG. 7 is a temperature distribution diagram (air temperature: 10 ° C., humidity: 80% RH) of the second evaporator 18 as viewed from the downstream side of the air flow. As can be seen from FIG. 7, the uneven temperature distribution occurs in the portion where the refrigerant flow rises from the lower tank portion 18c and flows, and particularly in the lower tank portion 18c (the left side portion in this embodiment), the refrigerant stagnation (stagnation). As a result, this portion becomes the lowest temperature portion of the second evaporator 18 on the low temperature side.

  This tendency is common even if the refrigerant flow path pattern in the evaporator changes as shown in a modification example described later. In the present embodiment, the temperature sensor 40 is disposed at a portion MC (see FIGS. 2 and 7) where the refrigerant flow rises and flows from the lower tank portion 18c of the second evaporator 18 as a suitable place for installing the temperature sensor 40.

  The part MC is a part where the refrigerant flows from the bottom to the top. When the evaporator as the heat exchanging portion arranged on the suction side of the ejector 14 is provided with a plurality of portions MC where the refrigerant flows from the bottom to the top, the temperature sensor 40 is provided at the position where the frost is observed earliest. Can do. For example, the temperature sensor 40 can be provided at a position closest to the ejector 14 among the plurality of parts MC.

  Next, the operation of this embodiment will be described. When the compressor 11 is driven by the vehicle running engine, the high-temperature and high-pressure refrigerant compressed and discharged by the compressor 11 flows into the radiator 12. In the radiator 12, the high-temperature refrigerant is cooled and condensed by the outside air. The high-pressure refrigerant that has flowed out of the radiator 12 flows into the liquid receiver 12a, where the gas-liquid refrigerant is separated in the liquid receiver 12a, and the liquid refrigerant is led out from the liquid receiver 12a and passes through the expansion valve 13. .

  In the expansion valve 13, the valve opening degree (refrigerant flow rate) is adjusted so that the degree of superheat SH of the outlet refrigerant (compressor suction refrigerant) of the first evaporator 15 becomes a predetermined value, and the high-pressure refrigerant is decompressed. The refrigerant (intermediate pressure refrigerant) after passing through the expansion valve 13 flows into the refrigerant inlet 25 provided in the first connection block 23 of the integrated unit 20.

  Here, the refrigerant flow is divided into a refrigerant flow from the main passage 25 a of the first connection block 23 toward the ejector 14 and a refrigerant flow from the refrigerant branch passage 16 of the first connection block 23 toward the throttle mechanism 17. And the refrigerant | coolant flow which flowed into the ejector 14 is decompressed and expanded by the nozzle part 14a. Therefore, the pressure energy of the refrigerant is converted into velocity energy at the nozzle portion 14a, and the refrigerant is ejected at a high velocity from the outlet of the nozzle portion 14a.

  Due to the refrigerant pressure drop at this time, the refrigerant (gas phase refrigerant) after passing through the second evaporator 18 in the branch refrigerant passage 16 is sucked from the refrigerant suction port 14b. The refrigerant ejected from the nozzle portion 14a and the refrigerant sucked into the refrigerant suction port 14b are mixed in the mixing portion 14c on the downstream side of the nozzle portion 14a and flow into the diffuser portion 14d. In the diffuser portion 14d, the passage area is enlarged, so that the speed (expansion) energy of the refrigerant is converted into pressure energy, so that the pressure of the refrigerant rises.

  The refrigerant flowing out of the diffuser portion 14d of the ejector 14 flows through the refrigerant flow paths indicated by arrows aa to ee in FIG. During this time, in the heat exchange core portion 15a of the first evaporator 15, the low-temperature low-pressure refrigerant absorbs heat from the blown air in the direction of the arrow Air and evaporates. The vapor phase refrigerant after evaporation is sucked into the compressor 11 from the refrigerant outlet 26 and compressed again.

  On the other hand, the refrigerant flow that has flowed into the refrigerant branch passage 16 is decompressed by the throttle mechanism 17 to become low-pressure refrigerant, and this low-pressure refrigerant flows through the refrigerant flow paths indicated by arrows ff to ii in FIG. During this time, in the heat exchange core portion 18 a of the second evaporator 18, the low-temperature low-pressure refrigerant absorbs heat from the blown air that has passed through the first evaporator 15 and evaporates. The vapor phase refrigerant after evaporation is sucked into the ejector 14 from the refrigerant suction port 14b.

  As described above, according to the present embodiment, the refrigerant on the downstream side of the diffuser portion 14d of the ejector 14 is supplied to the first evaporator 15, and the refrigerant on the refrigerant branch passage 16 side also enters the second evaporator 18 through the throttle mechanism 17a. Since it can be supplied, the first and second evaporators 15 and 18 can simultaneously exhibit a cooling action. Therefore, the cooling target space can be cooled (cooled) by blowing the cool air cooled by both the first and second evaporators 15 and 18 to the cooling target space.

  At that time, the refrigerant evaporation pressure of the first evaporator 15 is the pressure after being increased by the diffuser portion 14d, while the outlet side of the second evaporator 18 is connected to the refrigerant suction port 14b of the ejector 14. The lowest pressure immediately after the pressure reduction at the nozzle portion 14 a can be applied to the second evaporator 18.

  Thereby, the refrigerant evaporation pressure (refrigerant evaporation temperature) of the second evaporator 18 can be made lower than the refrigerant evaporation pressure (refrigerant evaporation temperature) of the first evaporator 15. And since the 1st evaporator 15 with a high refrigerant | coolant evaporation temperature is arrange | positioned in the upstream with respect to the flow direction Air of blowing air, and the 2nd evaporator 18 with a low refrigerant | coolant evaporation temperature is arrange | positioned in the downstream, the 1st It is possible to secure both the temperature difference between the refrigerant evaporation temperature and the blown air in the evaporator 15 and the temperature difference between the refrigerant evaporation temperature and the blown air in the second evaporator 18.

  For this reason, both the cooling performance of the 1st, 2nd evaporators 15 and 18 can be exhibited effectively. Therefore, the cooling performance for the common space to be cooled can be effectively improved by the combination of the first and second evaporators 15 and 18. Further, the suction pressure of the compressor 11 can be increased by the pressure increasing action in the diffuser portion 14d, and the driving power of the compressor 11 can be reduced.

  Further, the refrigerant flow rate on the second evaporator 18 side can be adjusted independently by the throttle mechanism 17 without depending on the function of the ejector 14, and the refrigerant flow rate to the first evaporator 15 can be adjusted by the throttle characteristic of the ejector 14. . For this reason, the refrigerant | coolant flow volume to the 1st, 2nd evaporators 15 and 18 can be easily adjusted corresponding to each heat load.

  Further, under the condition where the cycle heat load is small, the high / low pressure difference of the cycle becomes small and the input of the ejector 14 becomes small. In the present embodiment, the refrigerant that has passed through the expansion valve 13 is branched at the upstream portion of the ejector 14, and this branched refrigerant is sucked into the refrigerant suction port 14 b through the refrigerant branch passage 16, so that the refrigerant branch passage 16 is connected to the ejector 14. Parallel connection relationship.

  For this reason, the refrigerant can be supplied to the refrigerant branch passage 16 by utilizing not only the refrigerant suction capability of the ejector 14 but also the refrigerant suction / discharge capability of the compressor 11. Thereby, even if the phenomenon that the input of the ejector 14 decreases and the refrigerant suction capacity of the ejector 14 decreases occurs, the degree of decrease in the refrigerant flow rate on the second evaporator 18 side can be reduced. Therefore, it is easy to ensure the cooling performance of the second evaporator 18 even under low heat load conditions.

  Next, frost (frosting) prevention control in the above configuration will be described. When the cooling capacity exceeds the cooling load, the refrigerant evaporation pressure decreases and the evaporator air side surface temperature becomes below freezing point. And the freezing of condensed water progresses, the flow of passing air is prevented, and the phenomenon that evaporation pressure falls further is reached. Therefore, in order to prevent such problems, the cooling capacity is controlled to prevent frost.

  In the present embodiment, as a control method, ON / OFF control of the compressor is performed. This ON-OFF control is “to turn off the compressor when the refrigerant evaporation temperature becomes 0 ° C. or lower”, and is the most common frost prevention method. Specifically, the fin temperature or the blown air temperature is detected by the temperature sensor 40 described above, and for example, when the temperature is 3 ° C., the current of the electromagnetic clutch 11a is turned off, and when the temperature rises to 4 ° C., the control is performed again. When a variable capacity compressor or an electric compressor is used as the compressor, compressor capacity control for controlling the discharge capacity of the compressor so as to reduce frost may be performed.

  Next, features and effects of this embodiment will be described. First, according to this embodiment, the refrigerant flow rate on the downstream side of the radiator 12 is set so that the degree of superheat SH represented by the temperature difference between the refrigerant superheat temperature at the outlet of the first evaporator 15 and the saturation temperature becomes a predetermined value. The expansion valve 13 to be adjusted is provided, whereby the refrigerant flow rate to the second evaporator 18 on the low temperature side is controlled to an appropriate amount. As a result, by detecting the frost of the second evaporator 18 with the temperature sensor 40 and performing the frost prevention control, the first and second evaporators 15 and 18 may be frosted due to excessive refrigerant supply. It is prevented and the operating rate of the cycle can be improved.

  FIG. 8 is a graph showing the relationship of the refrigeration operating rate with respect to the ratio of the refrigerant flow rate flowing through the second evaporator 18. As an index indicating the cooling operation performance, the relationship between the stop time by the temperature sensor 40 with respect to the cycle driving time under the same air condition is a ratio obtained by dividing the refrigerant amount flowing into the second evaporator 18 by the total refrigerant amount of the cycle (this is expressed as 2 represents the ratio of the flow rate of the refrigerant flowing through the evaporator 18, and the operation rate in the conventional cycle is set to 100.

  Even in the conventional cycle, if the total refrigerant flow rate is lowered, the frost property is improved, but the cooling performance is inevitably lowered with the reduction of the refrigerant flow rate. In the present embodiment, the cooling operation performance can be improved as compared with the related art in all proportions of the flow rate of the refrigerant flowing through the second evaporator 18. The smaller the air load (the lower the temperature and the lower the humidity) and the smaller the heat capacity of the air to be heat exchanged, the smaller the required amount of refrigerant and the more refrigerant is produced on the second evaporator 18 side. The effect is obtained in the range of 5 to 50 ° C. and relative humidity: 20 to approximately 100%.

  Further, the temperature sensor 40 is disposed at a portion MC where the refrigerant flow rises and flows from the lower tank portion 18 c of the second evaporator 18. This is because the lowest temperature region is found in the portion MC where the refrigerant flow rises from the lower tank portion 18c in the second evaporator 18 on the low temperature side. According to this, when performing frost prevention control, determination of the attachment position of the temperature sensor 40 can be made easy.

  The first evaporator 15 and the second evaporator 18 cool air Air as a common heat exchange medium. According to this, the common air Air can be efficiently cooled. The first evaporator 15 and the second evaporator 18 are arranged so that the air Air after heat exchange with the first evaporator 15 and the second evaporator 18 exchange heat. According to this, since the temperature of the second evaporator 18 becomes lower, the common air Air can be cooled more efficiently.

  Also, an ejector 14 that sucks the refrigerant from the refrigerant suction port 14b by a high-speed refrigerant flow that is injected from the nozzle portion 14a that decompresses and expands the refrigerant, a heat exchange unit 18 that evaporates the refrigerant sucked into the refrigerant suction port 14b, A temperature sensor 40 is provided in a portion of the heat exchange unit 18 where the refrigerant flows from the bottom to the top and detects the frost of the heat exchange unit 18.

  According to this, since the ejector 14, the heat exchanging portion 18, and the temperature sensor 40 are integrally configured, they can be handled as an integrated object, and handling properties in transportation and assembly can be improved. In addition, the temperature sensor 40 is provided in a portion of the heat exchanging portion 18 where the refrigerant flows from the bottom to the top, similarly to the above, the lowest temperature region of the heat exchanging portion 18 includes the refrigerant from the lower tank portion 18c. It is because it discovered that it became the site | part MC which a flow rises and flows. According to this, it is possible to provide an ejector refrigeration cycle unit in which the temperature sensor 40 is attached at an optimum position in performing frost prevention control.

  Further, the first heat exchanger 15 disposed on the windward side of the air flow Air that exchanges heat with the refrigerant, and the second heat exchanger 18 disposed on the leeward side of the air flow Air with respect to the first heat exchanger 15. And a temperature sensor 40 for detecting frost, the first heat exchanger 15 evaporates the refrigerant flowing out from the ejector 14, and the second heat exchanger 18 is a refrigerant of the ejector 14. The suction side refrigerant sucked into the suction port 14 b is evaporated, and the temperature sensor 40 is disposed in the second heat exchanger 18.

  According to this, by comprising the 1st, 2nd heat exchangers 15 and 18 and the temperature sensor 40 integrally, these can be handled as an integrated object and the handleability in conveyance and an assembly is improved. be able to. The reason why the temperature sensor 40 is disposed in the second heat exchanger 18 is that the temperature of the second heat exchanger 18 is lower.

  Furthermore, even when these are configured as an integral body, the temperature sensor 40 is disposed at a portion MC where the refrigerant flow rises and flows from the lower tank portion 18c of the second evaporator 18. This is because, similarly to the above, the lowest temperature region of the second heat exchanger 18 on the low temperature side has been found to be a portion MC where the refrigerant flow rises and flows from the lower tank portion 18c. According to this, it is possible to provide an ejector refrigeration cycle unit in which the temperature sensor 40 is attached at an optimum position in performing frost prevention control.

  Furthermore, the ejector 14 and the throttle mechanism 17 that is disposed upstream of the refrigerant flow of the second heat exchanger 18 and adjusts the refrigerant flow rate supplied to the second heat exchanger 18 are integrally configured. According to these, the first and second heat exchangers 15 and 18 which are relatively large ones are integrally mounted with the ejector 14 or the throttle mechanism 17 or both, and configured as an integrated unit 20, All of these can be handled as a single object.

  Therefore, the mounting work when mounting the ejector-type refrigeration cycle on an application target such as a vehicle can be made very efficient. In addition, by configuring the integrated unit 20 and shortening the length of each part connection passage, the cost can be reduced and the mounting space can be reduced.

  The term “integrated” as used in the present invention shares members with parts of the housing of the ejector 14 and the throttle mechanism 17 and the tank portions 15b, 15c, 18b, 18c of the first and second heat exchangers 15, 18. Such a united relationship may be used, or a united unit may be formed by a firm connection such as welding or a connection that is connected by a loose connection such as a clamp or a screw. In addition, the refrigerant flow path constituted by this integral can be embodied in various modes as shown in a modification example described later, and is not limited to the present embodiment or a modification example described later.

(First modification)
FIG. 9 is a schematic diagram of a vehicle ejector-type refrigeration cycle which is a premise in a modification of the present invention. In the first to fourth modifications described below, as shown in FIG. 9, the ejector 14, the first and second evaporators 15 and 18, and the temperature sensor 40 are integrally configured as one integrated unit 20. Yes.

  Needless to say, similarly to the above-described embodiment, the aperture mechanism 17 may be integrally configured. First, the specific structure of the integrated unit 20B of this modification will be described with reference to FIG. FIG. 10 is a perspective view showing a schematic configuration of the integrated unit 20B in the first modification of the present invention. In addition, the same code | symbol is attached | subjected to parts, such as the above-mentioned embodiment, and description is abbreviate | omitted.

  A separator 15e is disposed in the upper tank portion 15b of the first evaporator 15, and the upper tank so that the left inner space C ′ is approximately one third and the right inner space D ′ is approximately two thirds. The internal space of the portion 15b is partitioned. In addition, a separator 15f is disposed in the lower tank portion 15c of the first evaporator 15, so that the left inner space E ′ is approximately two thirds and the right inner space F ′ is approximately one third. The interior space of the lower tank portion 15c is partitioned.

  Separators 18e and 18f are arranged in the upper tank portion 18b of the second evaporator 18, and the inner space of the upper tank portion 18b is divided into the inner spaces G ′, H ′, and I ′ so as to be divided into approximately three equal parts. Yes. In addition, a separator 18g is disposed in the lower tank portion 18c of the second evaporator 18, so that the left inner space J ′ is approximately two thirds and the right inner space K ′ is approximately one third. The interior space of the lower tank portion 18c is partitioned.

  In the present embodiment, the internal space G ′ of the upper tank portion 18 b of the second evaporator 18 is connected to the downstream side of the refrigerant branch passage 16 and the internal space F ′ of the lower tank portion 15 c of the first evaporator 15. In the internal space K ′ of the lower tank portion 18c of the second evaporator 18, the refrigerant can flow through a communication hole (not shown).

  Next, the ejector 14 is arrange | positioned inside the upper tank part 18b of the 2nd evaporator 18, and is arrange | positioned so that the longitudinal direction of the ejector 14 and the longitudinal direction of the upper tank part 18b may become parallel. As described above, the nozzle portion 14 a of the ejector 14 is connected to the downstream side of the main passage 25 a, and the refrigerant suction port 14 b is disposed in the internal space H ′ of the upper tank portion 18 b disposed in the second evaporator 18. It attaches so that the exit side of the part 14d may be arrange | positioned in internal space I '.

  Accordingly, the refrigerant suction port 14b opens directly into the internal space H ′, and the refrigerant flowing out from the diffuser portion 14d flows directly into the internal space I ′. As shown in FIG. 10, the ejector 14, the first evaporator 15, the second evaporator 18, the respective tank portions 15 b... 18 c and the like are arranged with the first evaporator 15 upstream of the air flow Air. The second evaporator 18 is disposed downstream of the air flow Air and is completely integrated as one evaporator structure to constitute an integrated unit 20B.

  The ejector 14 is provided on the separators 18e and 18f from the end in the longitudinal direction of the upper tank portion 18b of the second evaporator 18 after the brazing process of integrally brazing the first evaporator 15 and the second evaporator 18 and the like. It inserts so that it may penetrate the through-hole which is not shown in figure, and is attached and fixed by fixing means, such as screwing.

  In addition, since the ejector 14 and the separators 18e and 18f are sealed and fixed via an O-ring (not shown), the refrigerant does not leak from the attachment portion (through hole) between the ejector 14 and the separators 18e and 18f. . Therefore, the internal spaces G ′ and H ′ and the internal spaces H ′ and I ′ do not communicate with each other via the mounting portion (through hole).

  The refrigerant flow path of the entire integrated unit 20B in the above configuration will be described. First, the downstream side of the main passage 25a flows in the direction of arrow aa and directly flows into the nozzle portion 14a of the ejector 14. And it passes through the ejector 14 (nozzle part 14a-> mixing part 14c-> diffuser part 14d), and is decompressed, and the low-pressure refrigerant after this decompression collects in the internal space I 'of the upper tank part 18b of the second evaporator 18.

  The refrigerant in the internal space I ′ is distributed to the plurality of tubes 21 on the right side of the second evaporator 18 and descends as indicated by an arrow bb to gather in the internal space K ′ of the lower tank portion 18c of the second evaporator 18. To do. Since the internal space K ′ communicates with the internal space F ′ of the lower tank portion 15c of the first evaporator 15, the refrigerant flows into the internal space F ′.

  The refrigerant in the internal space F ′ is distributed to the plurality of tubes 21 on the right side of the first evaporator 15 and rises as indicated by the arrow cc and flows into the internal space D ′ of the upper tank portion 15b of the first evaporator 15. To do. The refrigerant flowing into the internal space D ′ moves to the left inside the internal space D ′. The refrigerant that has moved to the left in the internal space D ′ is distributed to the plurality of tubes 21 at the center of the first evaporator 15, descends as indicated by the arrow dd, and flows into the internal space E ′ of the lower tank portion 15 c.

  The refrigerant flowing into the internal space E ′ moves to the left inside the internal space E ′. The refrigerant that has moved to the left in the internal space E ′ is distributed to a plurality of tubes on the left side of the first evaporator 15 and rises as indicated by an arrow ee to gather in the internal space C ′ of the upper tank portion 15b. The refrigerant gathered in the internal space C ′ flows out from the upper tank portion 15b as indicated by an arrow ff and flows out to the compressor 11 suction side. Therefore, the effluent refrigerant passing through the effluent refrigerant evaporator 18a 'and the first evaporator 15 of the second evaporator 18 changes the flow direction twice (one or more times) in the first evaporator 15 to change the first evaporation. A gas phase state having a superheat degree is obtained in the superheat degree region on the upper left side of the vessel 15.

  Next, the low-pressure refrigerant on the downstream side of the refrigerant branch passage 16 decompressed by the throttle mechanism 17 flows into the internal space G ′ of the upper tank portion 18 b of the second evaporator 18. The refrigerant in the internal space G ′ is distributed to the plurality of tubes 21 on the left side of the second evaporator 18 and descends as indicated by an arrow gg and flows into the internal space J ′ of the lower tank portion 18c of the second evaporator 18. To do.

  The refrigerant flowing into the internal space J ′ moves to the right inside the internal space J ′. The refrigerant that has moved to the right in the internal space J ′ is distributed to the plurality of tubes 21 at the center of the second evaporator 18 and rises as indicated by an arrow hh, and gathers in the internal space H ′ of the upper tank portion 18b. The refrigerant gathered in the internal space H ′ is sucked into the ejector 14 from the refrigerant suction port 14 b of the ejector 14.

  Therefore, the suction port side refrigerant passing through the suction port side refrigerant evaporator 18a of the second evaporator 18 changes the flow direction once in the second evaporator 18, and the degree of superheat on the left side of the first evaporator 15 is changed. A gas phase state having superheat in the region is obtained. Furthermore, the suction side refrigerant is heat-exchanged only in the region indicated by the arrow gg → hh in FIG.

  Here, the usage rate of the leeward side heat exchange unit, which is the rate occupied by the suction port side refrigerant evaporation unit 18a in the second evaporator 18, is approximately two thirds of the second evaporator 18 depending on the arrangement position of the separators 18f and 18g. (About 70%). Thus, the usage rate of the leeward side heat exchange part can be easily adjusted by the arrangement positions of the separators 18f and 18g. And the temperature sensor 40 is arrange | positioned in the site | part MC (in this modification, lower part of the flow part of the arrow hh) where the refrigerant | coolant flow rises and flows from the lower tank part 18c of the 2nd evaporator 18 similarly to the above-mentioned embodiment. is doing.

(Second modification)
In the first modified example described above, the ejector refrigeration cycle 10 employing the integrated unit 20B has been described. However, in the present modified example, the integrated unit 20C shown in FIG. FIG. 11 is a perspective view showing an outline of the overall configuration of the integrated unit 20C, and the basic configurations of the first evaporator 15 and the second evaporator 18 are the same as those of the first modification.

  The integrated unit 20C is different from the integrated unit 20B in the positions of the separators disposed in the tank portions 15b... 18c and the positions of the ejectors 14. Therefore, the refrigerant flow path is also different. First, the separator 15e ′ is disposed in the upper tank portion 15b of the first evaporator 15, so that the left inner space L ′ is approximately ½ and the right inner space M ′ is approximately halved. The internal space of the upper tank portion 15b is partitioned. Further, no separator is arranged in the lower tank portion 15c of the first evaporator 15, and one internal space N ′ is formed.

  A separator 18e 'is disposed in the upper tank portion 18b of the second evaporator 18, and the upper side is such that the left inner space O' is approximately one half and the right inner space P 'is approximately one half. The internal space of the tank portion 18b is partitioned. Further, no separator is arranged in the lower tank portion 18c of the second evaporator 18, and one internal space Q 'is formed. In this modification, the internal space O ′ of the upper tank portion 18 b of the second evaporator 18 is connected to the downstream side of the refrigerant branch passage 16.

  Next, the ejector 14 is disposed inside the upper tank portion 18b of the second evaporator 18, the nozzle portion 14a of the ejector 14 is connected to the downstream side of the main passage 25a, and the refrigerant suction port 14b is connected to the upper tank portion 18b. It is attached so as to be arranged in the internal space P ′. Therefore, the refrigerant suction port 14b opens directly to the internal space P ′.

  Further, the refrigerant flowing out from the diffuser part 14d flows into the internal space M ′ of the upper tank part 15b of the first evaporator 15 through a pipe (not shown) arranged outside the upper tank part 18b. Yes. Of course, you may comprise the channel | path which guides an outflow refrigerant | coolant to internal space M 'inside the upper side tank part 18b. Also in the integrated unit 20C, the ejector 14 performs the second evaporation in the same manner as in the first modification after the first and second evaporators 15, 18 and the tank portions 15b ... 18c are integrally brazed. It is assembled inside the upper tank portion 18b of the vessel 18.

  The refrigerant flow path of the whole integrated unit 20C in the above configuration will be described. First, the downstream side of the main passage 25a directly flows into the nozzle portion 14a of the ejector 14 as indicated by an arrow aa. The decompressed low-pressure refrigerant passes through the ejector 14 and flows into the internal space M ′ of the upper tank portion 15b of the first evaporator 15 through the piping outside the upper tank portion 18b.

  The refrigerant flowing into the internal space M ′ is distributed to the plurality of tubes 21 on the right side of the first evaporator 15 and descends as indicated by an arrow ii to the internal space N ′ of the lower tank portion 15 c of the first evaporator 15. Inflow. The refrigerant flowing into the internal space N ′ moves to the left inside the internal space N ′. The refrigerant that has moved to the left in the internal space N ′ is distributed to the plurality of tubes 21 on the left side of the first evaporator 15 and rises as indicated by an arrow jj and gathers in the internal space L ′ of the upper tank portion 15b.

  The refrigerant gathered in the internal space L ′ flows out from the upper tank portion 15b as shown by the arrow ff and flows out to the compressor 11 suction side. Therefore, the refrigerant flowing out of the diffuser 14d and passing through the first evaporator 15 changes its flow direction once in the first evaporator 15 and is superheated in the superheat degree region on the right side of the first evaporator 15. It becomes a gas phase state having a degree.

  Next, the low-pressure refrigerant on the downstream side of the refrigerant branch passage 16 decompressed by the throttle mechanism 17 flows into the internal space O ′ of the upper tank portion 18 b of the second evaporator 18. The refrigerant that has flowed into the internal space O ′ is distributed to the plurality of tubes 21 on the left side of the second evaporator 18 and descends as indicated by an arrow kk so that the internal space Q ′ of the lower tank portion 18c of the second evaporator 18 is lowered. Flow into. The refrigerant flowing into the internal space Q ′ moves to the right inside the internal space Q ′.

  The refrigerant that has moved to the right in the internal space Q ′ is distributed to the plurality of tubes 21 on the right side of the second evaporator 18 and rises as indicated by an arrow ll and gathers in the internal space P ′ of the upper tank portion 18b. The refrigerant gathered in the internal space P ′ is sucked into the ejector 14 from the refrigerant suction port 14 c of the ejector 14. Therefore, the suction side refrigerant passing through the second evaporator 18 changes the flow direction once in the second evaporator 18 and has a superheat degree in the superheat degree region on the right side of the second evaporator 18. It becomes a state.

  Since the refrigerant passes through the integrated unit 20C as described above, the second evaporator 18 constitutes only the suction side refrigerant evaporating part 18b and not the outflow refrigerant evaporating part 18a '. Other configurations are the same as those of the first modification. Then, the temperature sensor 40 (not shown) is similar to the above-described embodiment or modification, and is a part MC (in this modification, a flow part indicated by an arrow 11l) where the refrigerant flow rises and flows from the lower tank 18c of the second evaporator 18. (Lower side).

(Third Modification)
In the first modification described above, the ejector refrigeration cycle 10 that employs the integrated unit 20B has been described. However, in this modification, the ejector refrigeration cycle 10 employs the integrated unit 20D illustrated in FIG. FIG. 12 is a perspective view showing an outline of the overall configuration of the integrated unit 20D. The integrated unit 20D also includes the ejector 14, the first and second evaporators 15, 18 and the temperature sensor 40 in the same manner as the integrated unit 20B. It is constructed integrally.

  The basic configuration of the first and second evaporators 15 and 18 of the integrated unit 20D is the same as that of the first modified example, but the separators disposed in the tank portions 15b to 18c with respect to the integrated unit 20A. Are different from the arrangement position of the ejector 14. Accordingly, the refrigerant flow path is also different from that of the first modification.

  First, no separator is arranged in the upper tank portion 15b of the first evaporator 15, and one internal space R ′ is formed. In addition, a separator 15f ′ is disposed inside the lower tank portion 15c of the first evaporator 15, and the left inner space S ′ is approximately ½ and the right inner space T ′ is approximately halved. Thus, the internal space of the lower tank portion 15c is partitioned.

  A separator 18e 'is arranged in the upper tank portion 18b of the second evaporator 18, and the upper side is such that the left inner space O' is approximately one half and the right inner space P 'is approximately one half. The internal space of the tank portion 18b is partitioned. Further, a separator 18f ′ is disposed in the lower tank portion 18c of the second evaporator 18, and the left inner space U ′ is approximately ½ and the right inner space V ′ is approximately halved. In this way, the internal space of the lower tank portion 18c is partitioned.

  In this modification, the internal space U ′ of the lower tank portion 18c of the second evaporator 18 is connected to the downstream side of the refrigerant branch passage 16, and the internal space T of the lower tank portion 15c of the first evaporator 15 is set. 'And the internal space V' of the lower tank 18c below the second evaporator 18 are configured to allow refrigerant to flow through a communication hole (not shown).

  Next, the ejector 14 is disposed inside the upper tank portion 18b of the second evaporator 18, the nozzle portion 14a of the ejector 14 is connected to the downstream side of the main passage 25a, and the refrigerant suction port 14b is located inside the upper tank portion 18b. It arrange | positions in space O 'and is attached so that the exit of the diffuser part 14d may be arrange | positioned in internal space P' of the upper tank part 18b.

  Accordingly, the refrigerant suction port 14b opens directly into the internal space O ′, and the outlet of the diffuser portion 14d opens directly into the internal space P ′. Also in the integrated unit 20D, the ejector 14 performs integrated brazing joining of the first and second evaporators 15 and 18 and the tank portions 15b to 18c, and then the second evaporator 18 in the same manner as in the embodiment. Is assembled in the upper tank portion 18b.

  The refrigerant flow path of the entire integrated unit 20D in the above configuration will be described. First, the downstream side of the main passage 25a directly flows into the nozzle portion 14a of the ejector 14 as indicated by an arrow aa. Then, the pressure is reduced through the ejector 14, and the low-pressure refrigerant after the pressure reduction flows into the internal space P ′ of the upper tank portion 15 b of the first evaporator 15.

  The refrigerant in the internal space P ′ is distributed to the plurality of tubes 21 on the right side of the first evaporator 15 and descends as indicated by an arrow mm and gathers in the internal space V ′ of the lower tank portion 18c of the second evaporator 18. To do. Since the internal space V ′ communicates with the internal space T ′ of the lower tank portion 15c of the first evaporator 15, the refrigerant flows into the internal space T ′.

  The refrigerant flowing into the internal space T ′ is distributed to the plurality of tubes 21 on the right side of the first evaporator 15 and rises as indicated by an arrow nn and flows into the internal space R ′ of the upper tank portion 15b. The refrigerant flowing into the internal space R ′ moves to the left inside the internal space R ′. The refrigerant that has moved to the left in the internal space R ′ is distributed to the plurality of tubes 21 on the left side of the first evaporator 15 and descends as indicated by an arrow oo to the inside of the lower tank portion 15 c of the first evaporator 15. It flows into the space S ′.

  The refrigerant that has flowed into the internal space S ′ flows out from the lower tank portion 15c as indicated by the arrow pp and flows out to the compressor 11 suction side. Accordingly, the refrigerant flowing out of the diffuser 14d and passing through the first evaporator 15 changes its flow direction once in the first refrigerant 15 and the outflow refrigerant evaporation portion 18a 'of the second evaporator 18, and the first A gas phase state having a superheat degree is obtained in the superheat degree region on the lower left side of the evaporator 15.

  On the other hand, the low-pressure refrigerant on the downstream side of the refrigerant branch passage 16 decompressed by the throttle mechanism 17 flows into the internal space U ′ of the lower tank portion 18 c of the second evaporator 18. The refrigerant in the internal space U ′ is distributed to the plurality of tubes 21 on the left side of the second evaporator 18 and rises as indicated by the arrow qq to gather in the internal space O ′ of the upper tank portion 18b. The refrigerant collected in the internal space O ′ is sucked into the ejector 14 from the refrigerant suction port 14 c of the ejector 14.

  Accordingly, a gas phase state having a superheat degree is obtained in the superheat degree region on the upper left side of the second evaporator 18. Further, the suction side refrigerant is heat-exchanged only in the region indicated by the arrow qq in FIG. Accordingly, in this modification, the usage rate of the leeward side heat exchange unit is approximately one-half (about 50%) of the second evaporator 18 depending on the arrangement position of the separators 18e 'and 18f'.

  Therefore, the throttle mechanism 17 of this modification is adjusted so that the flow rate ratio Ge / G between the refrigerant flow rate Ge of the suction side refrigerant and the refrigerant flow rate G discharged from the compressor 11 is about 0.5. Other configurations are the same as those of the first modification. The temperature sensor 40 (not shown) is similar to the above-described embodiment or modification, and is a part MC (flow portion indicated by the arrow qq in this modification) where the refrigerant flow rises and flows from the lower tank portion 18c of the second evaporator 18. (Lower side).

(Fourth modification)
In the first modification described above, the ejector refrigeration cycle 10 that employs the integrated unit 20B has been described. However, in this modification, the ejector refrigeration cycle 10 employs the integrated unit 20E shown in FIG. FIG. 13 is a perspective view showing an outline of the overall configuration of the integrated unit 20E. The integrated unit 20E also includes the ejector 14, the first and second evaporators 15, 18 and the temperature sensor 40 in the same manner as the integrated unit 20B. It is constructed integrally.

  The basic configuration of the first and second evaporators 15 and 18 of the integrated unit 20E is the same as that of the first modified example, but the separators disposed in the tank portions 15b to 18c with respect to the integrated unit 20B. Are different from the arrangement position of the ejector 14. Accordingly, the refrigerant flow path is also different from that of the first modification.

  First, the separator 15e ″ is disposed in the upper tank portion 15b of the first evaporator 15, and the left inner space W ′ is approximately two thirds and the right inner space X ′ is approximately one third. In this way, the internal space of the upper tank portion 15b is partitioned. Further, a separator 15f ″ is disposed inside the lower tank portion 15c of the first evaporator 15, and the left inner space Y ′ is approximately one third and the right inner space Z ′ is approximately two thirds. The internal space of the lower tank portion 15c is partitioned so that

  A separator 18e 'is arranged in the upper tank portion 18b of the second evaporator 18, and the upper side is such that the left inner space O' is approximately one half and the right inner space P 'is approximately one half. The internal space of the tank portion 18b is partitioned. Further, no separator is disposed in the lower tank portion 18c of the second evaporator 18, and one internal space Q 'is formed. In this modification, the internal space P ′ of the upper tank portion 18 b of the second evaporator 18 is connected to the downstream side of the refrigerant branch passage 16.

  Next, as in the first modification, the ejector 14 is disposed inside the upper tank portion 18b of the second evaporator 18, and the nozzle portion 14a of the ejector 14 is connected to the downstream side of the main passage 25a, and the refrigerant suction port 14b is disposed in the inner space O ′ of the upper tank portion 18b, and the outlet of the diffuser portion 14d is attached to be disposed in the upper space of the inner space P ′ of the upper tank portion 18b. Accordingly, the refrigerant suction port 14b opens directly into the internal space O ′, and the outlet of the diffuser portion 14d opens directly into the internal space P ′.

  As described above, the refrigerant flowing out of the refrigerant branch passage 16 downstream side and the diffuser portion 14d flows into the internal space P ′. For this reason, in the present embodiment, the internal space P ′ is further divided into two independent spaces, a space into which the refrigerant on the downstream side of the refrigerant branch passage 16 flows and a space into which the refrigerant flowing out of the diffuser portion 14d flows.

  Specifically, a partition plate (not shown) that divides the internal space P ′ into two spaces in the vertical direction is provided, the diffuser 14d outflow refrigerant flows into the upper space, and the refrigerant branch passage 16 downstream refrigerant is on the lower side. Flows into the space. Further, the upper space and the internal space X ′ of the upper tank portion 15b of the first evaporator 15 are configured to allow refrigerant to flow through a communication hole (not shown).

  In addition, without dividing the internal space P ′ into two independent spaces, a passage for directly flowing the refrigerant flowing out of the diffuser portion 14d into the internal space P ′ without flowing into the internal space P ′ is provided in the upper tank portion 18b. It may be provided inside. Also in the integrated unit 20E, the ejector 14 performs the second evaporation in the same manner as in the first modified example after the first and second evaporators 15, 18 and the tank portions 15b ... 18c are integrally brazed and joined. It is assembled inside the upper tank portion 18b of the vessel 18.

  The refrigerant flow path of the entire integrated unit 20E in the above configuration will be described. First, the downstream side of the main passage 25a directly flows into the nozzle portion 14a of the ejector 14 as indicated by an arrow aa. The decompressed low-pressure refrigerant passes through the ejector 14, and the decompressed low-pressure refrigerant passes through the upper space P ′ of the upper tank portion 18 b of the second evaporator 18 to the upper tank portion 15 b of the first evaporator 15. It flows into the internal space X ′.

  The refrigerant flowing into the internal space X ′ is distributed to the plurality of tubes 21 on the right side of the first evaporator 15 and descends as indicated by an arrow rr to the internal space Z ′ of the lower tank portion 15c of the first evaporator 15. Inflow. The refrigerant that has flowed into the internal space Z ′ moves to the left inside the internal space Z ′. The refrigerant that has moved to the left inside the internal space Z ′ is distributed to a plurality of tubes 21 at the center of the first evaporator 15 and rises as indicated by an arrow ss, so that the internal space W of the upper tank portion 15b of the first evaporator 15 is increased. Flows into ´.

  The refrigerant that has flowed into the internal space W ′ moves to the left inside the internal space W ′. The refrigerant that has moved to the left inside the internal space W ′ is distributed to the plurality of tubes 21 on the left side of the first evaporator 15 and descends as shown by the arrow tt, and the internal space of the lower tank portion 15c of the first evaporator 15 is lowered. Collect at Y ′. The refrigerant gathered in the internal space Y ′ flows out from the lower tank portion 15c as shown by an arrow pp and flows out to the compressor 11 suction side.

  Accordingly, the refrigerant flowing out of the diffuser 14d and passing through the first evaporator 15 changes its flow direction twice (one or more times) in the first evaporator 15 and the superheater in the lower part on the left side of the first evaporator 15 is changed. It becomes a gas phase state having superheat degree in the temperature region. On the other hand, the low-pressure refrigerant on the downstream side of the refrigerant branch passage 16 decompressed by the throttle mechanism 17 flows into the lower space of the internal space P ′ of the upper tank portion 18 b of the second evaporator 18.

  The refrigerant flowing into the lower space of the internal space P ′ is distributed to the plurality of tubes 21 on the right side of the second evaporator 18 and descends as indicated by an arrow uu into the internal space Q ′ of the lower tank portion 18c. Inflow. The refrigerant that has flowed into the internal space Q ′ moves to the left inside the internal space Q ′. The refrigerant that has moved to the left inside the internal space Q ′ is distributed to the plurality of tubes 21 on the left side of the second evaporator 18 and rises as indicated by the arrow vv and gathers in the internal space O ′. The refrigerant gathered in the internal space O ′ is sucked into the ejector 14 from the refrigerant suction port 14 c of the ejector 14.

  Accordingly, a gas phase state having a superheat degree is obtained in the superheat degree region on the upper left side of the second evaporator 18. Since the refrigerant passes through the integrated unit 20E as described above, the second evaporator 18 constitutes only the suction side refrigerant evaporating part 18a and not the outflow refrigerant evaporating part 18a '. Other configurations are the same as those of the first modification. The temperature sensor 40 (not shown) is similar to the above-described embodiment or modification, and is a part MC (the flow portion indicated by the arrow vv in this modification) where the refrigerant flow rises and flows from the lower tank portion 18c of the second evaporator 18. (Lower side).

(Other embodiments)
The present invention is not limited to the above-described embodiments and modifications, and can be variously modified as described below.

  (1) In the above-described embodiment, when the members of the integrated unit 20A are assembled together, other members excluding the ejector 14, that is, the first and second evaporators 15, 18, the first and second connection blocks. 23, 24, the diaphragm mechanism 17 and the like are integrally brazed, but these members can be integrally assembled by using various fixing means such as screwing, caulking, welding, and adhesion in addition to brazing. it can.

  Moreover, although screwing is illustrated as a fixing means of the ejector 14 in the embodiment, any means other than screwing can be used as long as it is a fixing means that does not cause thermal deformation. Specifically, the ejector 14 may be fixed using fixing means such as caulking or bonding.

(2) In the above-described embodiment, a vapor compression subcritical cycle using a refrigerant such as a chlorofluorocarbon-based refrigerant or an HC-based refrigerant whose high pressure does not exceed the critical pressure has been described. However, carbon dioxide (CO ₂ ) is used as the refrigerant. Thus, the present invention may be applied to a vapor compression supercritical cycle using a refrigerant whose high pressure exceeds the critical pressure.

  However, in the supercritical cycle, the refrigerant discharged from the compressor is only dissipated in the supercritical state in the radiator 12, and does not condense. Therefore, in the liquid receiver 12a disposed on the high pressure side, the refrigerant gas-liquid separation action and The storage effect of the excess liquid refrigerant cannot be exhibited. Therefore, in the supercritical cycle, although not shown, a configuration in which an accumulator forming a low-pressure side gas-liquid separator is disposed on the outlet side of the first evaporator 15 may be employed.

  (3) In the above-described embodiment, the throttle mechanism 17 is configured by a fixed throttle hole such as a capillary tube or an orifice, but the throttle mechanism 17 can be adjusted in valve opening (passage throttle opening) by an electric actuator. The electric control valve may be configured. Further, the throttle mechanism 17 may be configured by a combination of a fixed throttle such as a capillary tube or a fixed throttle hole and an electromagnetic valve.

  (4) In the above-described embodiment, the fixed ejector having the nozzle portion 14a having a constant passage area is exemplified as the ejector 14. However, as the ejector 14, the variable ejector having the variable nozzle portion capable of adjusting the passage area is used. It may be used. As a specific example of the variable nozzle portion, for example, a mechanism may be used in which a needle is inserted into the passage of the variable nozzle portion and the passage area is adjusted by controlling the position of the needle with an electric actuator.

  (5) In the above-described embodiment, the case where the space to be cooled of the first and second evaporators 15 and 18 is a vehicle interior space or a space inside a refrigerator-freezer of a refrigerator car has been described. Is widely applicable to refrigeration cycles for various uses such as stationary use, not limited to these vehicles.

  (6) In the above-described embodiment, the temperature type expansion valve 13 and the temperature sensing unit 13a are configured separately from the ejector type refrigeration cycle unit. However, the temperature type expansion valve 13 and the temperature sensing part 13a may be integrally assembled to the ejector type refrigeration cycle unit. For example, the structure which accommodates the temperature type expansion valve 13 and the temperature sensing part 13a in the 1st connection block 23 of the integrated unit 20 is employable. In this case, the refrigerant inlet 25 is located between the liquid receiver 12 a and the temperature type expansion valve 13, and the refrigerant outlet 26 is located between the passage portion where the temperature sensing unit 13 a is installed and the compressor 11. .

It is a mimetic diagram of ejector type refrigeration cycle 10 for vehicles of an embodiment to which the present invention is applied. It is a perspective view which shows schematic structure of the integrated unit 20 (20A) in FIG. It is a longitudinal cross-sectional view of the upper tank parts 15b and 18b of the integrated unit 20 of FIG. It is a cross-sectional view of the upper tank part 18b of the integrated unit 20 of FIG. (A) is a perspective view of fin temperature sensor 40A, (b) is a fragmentary sectional view showing the structure of sensor part 42 in (a). It is a perspective view of air temperature sensor 40B. It is a temperature distribution figure of the 2nd evaporator 18 seen from the air flow downstream. 3 is a graph showing the relationship of the refrigeration operating rate with respect to the ratio of the refrigerant flow rate flowing through the second evaporator 18. It is a schematic diagram of the ejector type refrigeration cycle for vehicles which is a premise in the modified example of the present invention. It is a perspective view which shows schematic structure of the integrated unit 20B in the 1st modification of this invention. It is a perspective view which shows schematic structure of 20 C of integrated units in the 2nd modification of this invention. It is a perspective view which shows schematic structure of integrated unit 20D in the 3rd modification of this invention. It is a perspective view which shows schematic structure of the integrated unit 20E in the 4th modification of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Compressor 12 ... Radiator 13 ... Temperature type expansion valve (adjustment means)
DESCRIPTION OF SYMBOLS 14 ... Ejector 14a ... Nozzle part 14b ... Refrigerant suction port 15 ... 1st evaporator (1st heat exchanger, 1st heat exchange part)
16 ... refrigerant branch passage 17 ... throttling mechanism 18 ... second evaporator (second heat exchanger, second heat exchange section)
18c ... Lower tank part 40 ... Temperature sensor 50 ... Control device (control means)
Air ... Air (heat exchange medium)
MC: Refrigerant flow rises and flows SH: Superheat

Claims (9)

A compressor (11) for sucking and compressing refrigerant;
A radiator (12) that radiates heat of the high-pressure refrigerant discharged from the compressor (11);
Adjusting means (13) for adjusting the refrigerant flow rate on the downstream side of the radiator (12) so that the superheat degree (SH) of the suction side refrigerant of the compressor (11) becomes a predetermined value;
An ejector (14) having a refrigerant suction port (14b) for sucking the refrigerant by a high-speed refrigerant flow obtained by injecting a refrigerant on the downstream side of the adjusting means (13) from the nozzle part (14a);
A refrigerant branch passage (16) for guiding the refrigerant flow branched upstream of the refrigerant flow of the ejector (14) to the refrigerant suction port (14b);
A first heat exchanger (15) disposed downstream of the refrigerant flow of the ejector (14);
A second heat exchanger (18) disposed in the refrigerant branch passage (16);
A temperature sensor (40) for detecting frost in the second heat exchanger (18);
An ejector-type refrigeration cycle comprising: control means (50) for performing frost prevention control in accordance with the temperature detected by the temperature sensor (40).   The said temperature sensor (40) is arrange | positioned in the site | part (MC) where a refrigerant | coolant flow rises and flows from the lower tank part (18c) of the said 2nd heat exchanger (18), Ejector refrigeration cycle.   The ejector type according to claim 1 or 2, wherein the first heat exchanger (15) and the second heat exchanger (18) cool a common heat exchange medium (Air). Refrigeration cycle.   The first heat exchanger (15) and the second heat exchanger (18) exchange heat with the first heat exchanger (15) and the heat exchange medium (Air) and the second heat exchange. 4. The ejector refrigeration cycle according to claim 3, wherein the ejector refrigeration cycle is arranged to exchange heat with the vessel (18). An ejector (14) for sucking the refrigerant from the refrigerant suction port (14b) by a high-speed refrigerant flow injected from the nozzle portion (14a) for decompressing and expanding the refrigerant;
A heat exchange section (18) for evaporating the refrigerant sucked into the refrigerant suction port (14b);
An ejector comprising a temperature sensor (40) provided in a portion of the heat exchange section (18) where the refrigerant flows from bottom to top and detecting frost of the heat exchange section (18). Unit for refrigerating cycle. A first heat exchange section (15) disposed upstream of a heat exchange medium (Air) that exchanges heat with the refrigerant;
A second heat exchange section (18) disposed downstream of the heat exchange medium (Air) with respect to the first heat exchange section (15);
A temperature sensor (40) for detecting frost,
The first heat exchanging part (15) is an outflow refrigerant that has flowed out of the ejector (14) that sucks the refrigerant from the refrigerant suction port (14b) by the high-speed refrigerant flow injected from the nozzle part (14a) that decompresses and expands the refrigerant. Evaporate
At least a part of the second heat exchange part (18) evaporates the suction port side refrigerant sucked into the refrigerant suction port (14b),
The ejector refrigeration cycle unit, wherein the temperature sensor (40) is disposed in the second heat exchange section (18).   The said temperature sensor (40) is arrange | positioned in the site | part (MC) from which a refrigerant | coolant flow rises and flows from the lower tank part (18c) of the said 2nd heat exchange part (18), Unit for ejector type refrigeration cycle.   The ejector refrigeration cycle unit according to claim 6 or 7, wherein the ejector (14) is integrally formed.   Further, a throttle mechanism (17) that is arranged upstream of the refrigerant flow of the second heat exchange section (18) and adjusts the flow rate of the refrigerant supplied to the second heat exchange section (18) is integrally configured. The ejector-type refrigeration cycle unit according to claim 6 or 7, wherein:

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