JP2008025862A - Ejector type refrigerating cycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inhibit generation of vapor lock in a throttling means for decompressing and expanding a refrigerant branched at an upstream side of a nozzle portion of an ejector. <P>SOLUTION: When this ejector type refrigerating cycle comprising an internal heat exchanger 21 for exchanging heat between a refrigerant on an outlet side of a radiator 12 and a refrigerant on a suction side of a compressor 11, is applied in an air conditioner for a vehicle, a refrigerant passage is formed outside of a vehicle interior to guide the refrigerant on the outlet side of the radiator 12, from an outlet side of the internal heat exchanger 21 to an inlet side of the throttling means 17. As the refrigerant flowing into the throttling means 17 can be cooled by low-temperature outside air even under an operating condition where the refrigerant on the outlet side of the radiator 12 is heated by the internal heat exchanger 21, like an operation at low outside air temperature in winter, the refrigerant flowing into the throttling means 17 is prevented from being brought into a gas-liquid two phase state, and the generation of vapor lock in the throttling means 17 can be prevented. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ejector-type refrigeration cycle having an ejector.

  Conventionally, in Patent Document 1, the flow of the refrigerant is branched at a branching portion on the downstream side of the radiator that dissipates the refrigerant discharged from the compressor and on the upstream side of the nozzle portion of the ejector, and one of the branched refrigerants is directed to the nozzle portion side. An ejector-type refrigeration cycle is disclosed in which the other refrigerant flows into the refrigerant suction port side of the ejector.

  In the ejector-type refrigeration cycle of Patent Document 1, a first evaporator that evaporates the refrigerant that has flowed out of the ejector is disposed downstream of the diffuser portion of the ejector, and further, the refrigerant is placed between the branch portion and the refrigerant suction port of the ejector. A throttle mechanism for depressurization and a second evaporator that evaporates the refrigerant and flows out to the upstream side of the refrigerant suction port are arranged so that the refrigerant can exert an endothermic effect in both evaporators.

Further, the refrigerant evaporating pressure (refrigerant evaporating temperature) in the first evaporator is raised above the refrigerant evaporating pressure (refrigerant evaporating temperature) in the second evaporator by the pressure increasing action of the diffuser portion of the ejector, and the respective evaporators are different. The refrigerant can be evaporated in the temperature range. Further, by connecting the downstream side of the first evaporator to the compressor suction side and increasing the compressor suction refrigerant pressure, the compressor drive power is reduced and cycle efficiency (COP) is improved.
JP 2005-308380 A

  Furthermore, the present inventors previously disclosed in Japanese Patent Application No. 2006-36532 (hereinafter referred to as the prior application example) the ejector-type refrigeration cycle of Patent Document 1 to the refrigerant 12 outlet side refrigerant and the compressor 11 suction. A cycle (shown in FIG. 6) provided with an internal heat exchanger 21 for exchanging heat with the side refrigerant is proposed.

  Here, the operation of the internal heat exchanger 21 during the normal operation of the cycle of this prior application will be described with reference to FIG. FIG. 7 is a Mollier diagram showing the state of the refrigerant in the cycle of the prior application example. The state of the refrigerant during normal operation is shown by a broken line, and the two-dot chain line shows an isotherm.

  As shown by the broken line in FIG. 7, during the normal operation of the cycle of the prior application example, the internal heat exchanger 21 reduces the enthalpy of the refrigerant on the outlet side of the radiator 12 as indicated by a → b, and the compressor 11 It acts to increase the enthalpy of the suction side refrigerant as shown by c → d. As a result, the refrigerant enthalpy difference between the refrigerant inlet and outlet in each of the evaporators 15 and 18 can be increased, so that the refrigeration capacity of the cycle can be increased.

  By the way, when the cycle of the prior application example is applied to a vehicle air conditioner, the cycle is operated for the purpose of dehumidifying the air blown into the vehicle interior when the vehicle interior is heated at a low outdoor temperature in winter (hereinafter referred to as this This type of operation is sometimes called dehumidifying operation at low outside temperature.) The cold air dehumidified in each of the evaporators 15 and 18 is reheated by a heater core using engine cooling water as a heat source and blown out into the passenger compartment.

  During this low outside air temperature dehumidifying operation, the refrigeration capacity required for the refrigeration cycle is reduced compared to the normal operation in which the passenger compartment is cooled, so that the refrigerant discharge capacity of the compressor is reduced in comparison with the normal operation. The cycle is operated.

  Therefore, the high-low pressure difference between the high-pressure side refrigerant pressure and the low-pressure side refrigerant pressure in the refrigeration cycle becomes smaller than in normal operation, and the refrigerant flow rate circulating in the refrigeration cycle is also reduced. Specifically, as shown by the solid line in FIG. 7, the state of the refrigerant during the low outside air temperature dehumidifying operation is higher or lower during the low outside air temperature dehumidifying operation than the high / low pressure difference ΔPn of the high / low pressure refrigerant during normal operation. The pressure difference ΔPdh is reduced.

  Furthermore, during the low outside air temperature dehumidifying operation, the high pressure side refrigerant exchanges heat with the low temperature outside air in the radiator 12 to sufficiently dissipate heat, and the low pressure side refrigerant exchanges heat with the high temperature inside air in each of the evaporators 15 and 18. As a result, the radiator 12 outlet-side refrigerant temperature may be lower than the compressor 11 suction-side refrigerant temperature.

  And if the radiator 12 exit side refrigerant | coolant temperature becomes lower than the compressor 11 suction | inhalation side refrigerant | coolant temperature, the internal heat exchanger 21 will show the enthalpy of the radiator 12 exit side refrigerant | coolant to e → f of FIG. Thus, the enthalpy of the refrigerant on the suction side of the compressor 11 acts to decrease as shown by g → h in FIG.

  In other words, in the internal heat exchanger 21, an undesirable heat exchange is performed in which the enthalpy difference of the refrigerant between the refrigerant inlet and outlet in each of the evaporators 15 and 18 is reduced to reduce the cycle refrigerating capacity. End up.

  Further, during the dehumidifying operation of the low outside air temperature, the vehicle interior temperature is higher than the outside air temperature. Therefore, if the refrigerant passage for guiding the refrigerant on the outlet side of the radiator 12 to the inlet side of the throttle means 17 is arranged in the vehicle interior, The refrigerant passing through the refrigerant passage may be heated by the cabin air and increase enthalpy.

  Due to the unfavorable heat exchange in the internal heat exchanger 21 and the heating when passing through the refrigerant passage, the enthalpy of the refrigerant on the outlet side of the radiator 12 is increased to be in a gas-liquid two-phase state. When the refrigerant flows into the throttle means 17, bubbles present in the liquid phase refrigerant block the refrigerant passage with a small opening of the throttle means 17 and block the refrigerant flow.

  Further, as described above, during the low outside air temperature dehumidifying operation, the flow rate of the refrigerant circulating in the cycle is reduced, so that the bubbles cannot be pushed away. Therefore, the refrigerant is not supplied to the second evaporator 18, and a problem that the cycle cannot exhibit a desired refrigeration capacity (dehumidification capacity) (so-called vapor lock problem) occurs.

  The present invention has been made in view of the above points, and an object of the present invention is to suppress the occurrence of a vapor lock in a throttle means for decompressing and expanding a refrigerant branched upstream of a nozzle portion of an ejector.

  In order to achieve the above object, in the present invention, a compressor (11) that compresses and discharges a refrigerant, a radiator (12) that dissipates high-pressure refrigerant discharged from the compressor (11), and a radiator ( 12) The branch portion (Z) that branches the flow of the outlet side refrigerant, and the high-speed refrigerant flow that is injected from the nozzle portion (14a) that decompresses and expands one of the refrigerant branches at the branch portion (Z) An ejector (14) sucked from the refrigerant suction port (14b), a throttle means (17) for decompressing and expanding the other refrigerant branched by the branch portion (Z), and a low-pressure refrigerant downstream of the throttle means (17) An evaporator (18) that evaporates by exchanging heat with the air blown into the air-conditioning target space and flows out to the upstream side of the refrigerant suction port (14b), and includes a throttle means (17) from the outlet side of the radiator (12). ) Less of the refrigerant passage leading to the inlet side Some and also makes the refrigerant cycle, which is arranged outside the air conditioning target space and the first feature.

  According to this, since at least a part of the refrigerant passage extending from the radiator (12) outlet side to the throttle means (17) inlet side is arranged outside the air conditioning target space, the temperature outside the air conditioning target space In an operating condition where the temperature is lower than the temperature of the air-conditioning target space, the refrigerant passing through the refrigerant passage can be radiated to the outside of the air-conditioning target space to be cooled.

  For example, when the ejector-type refrigeration cycle having the first characteristic is applied to a vehicle air conditioner, the outside air temperature (temperature outside the air-conditioning target space) is the vehicle interior temperature (air conditioning) as in the low outside air dehumidifying operation described above. A cycle configuration in which the refrigerant flowing through the refrigerant passage and flowing into the throttle means (17) is cooled by low-temperature outside air under an operating condition lower than the temperature of the target space can be easily realized.

  Thereby, since it can suppress that the enthalpy of the refrigerant | coolant which flows into a throttle means (17) through a refrigerant path increases, it can suppress that the refrigerant | coolant which flows into a throttle means (17) becomes a gas-liquid two-phase state. . As a result, the occurrence of vapor lock in the squeezing means (17) can be suppressed.

  Of course, when the ejector-type refrigeration cycle having the first feature is applied to a vehicle air conditioner, there is no problem that the refrigerant passing through the refrigerant passage is heated by the outside air at the high outdoor temperature in summer. The reason is that the refrigerant passing through the refrigerant passage dissipates heat by exchanging heat with the outside air in the radiator (12), so that the temperature of the refrigerant passing through the refrigerant passage does not become lower than the outside air temperature.

  In addition, the air-conditioning target space in the present invention means a space that is processed and adjusted so that temperature, humidity, and the like suit the purpose. Accordingly, it not only means an indoor space to be cooled and heated, but also includes a refrigerator internal space for storing at low temperature in order to prevent corruption of foods, a freezer space for freezing and storing foods and the like.

  The ejector refrigeration cycle of the first feature further includes an internal heat exchanger (21) for exchanging heat between the radiator (12) outlet-side refrigerant and the compressor (11) suction-side refrigerant, The site | part arrange | positioned outside the air-conditioning object space may be provided in the downstream rather than the internal heat exchanger (21).

  According to this, for example, when the refrigerant on the outlet side of the radiator (12) is heated in the internal heat exchanger (21) as in the low outside temperature dehumidifying operation when applied to the vehicle air conditioner. Even if it exists, since the site | part arrange | positioned outside the air conditioning object space among refrigerant paths is provided in the downstream rather than an internal heat exchanger (21), the refrigerant | coolant which flows into a throttle means (17) is ensured. It can be cooled by low temperature outside air.

  In the present invention, the compressor (11) that compresses and discharges the refrigerant, the radiator (12) that radiates the high-pressure refrigerant discharged from the compressor (11), and the refrigerant on the outlet side of the radiator (12) A branch section (Z) that branches the flow, an internal heat exchanger (21) that exchanges heat between one refrigerant branched by the branch section (Z) and the compressor (11) suction-side refrigerant, and an internal heat exchanger (21) The ejector (14) that sucks the refrigerant from the refrigerant suction port (14b) and the branch part (Z) are branched by the high-speed refrigerant flow injected from the nozzle (14a) that decompresses and expands the outlet-side refrigerant. Ejector comprising a throttle means (17) for decompressing and expanding the other refrigerant, and an evaporator (18) for evaporating the low-pressure refrigerant on the downstream side of the throttle means (17) and flowing out to the upstream side of the refrigerant suction port (14b). The second refrigeration cycle is a second feature.

  According to this, among the refrigerants branched at the branch part (Z), the refrigerant that does not exchange heat with the compressor (11) suction-side refrigerant in the internal heat exchanger (21) flows into the throttle means (17). Therefore, for example, even when the dehumidifying operation is performed at a low outside temperature when applied to a vehicle air conditioner, the refrigerant flowing into the throttle means (17) is not heated by the internal heat exchanger (21). .

  Therefore, the enthalpy of the refrigerant flowing into the throttling means (17) is not increased and the gas-liquid two-phase state is not caused. As a result, no vapor lock occurs in the throttle means (17).

  In the present invention, the compressor (11) that compresses and discharges the refrigerant, the radiator (12) that radiates the high-pressure refrigerant discharged from the compressor (11), and the refrigerant on the outlet side of the radiator (12) The refrigerant is sucked into the refrigerant suction port (14b) by the high-speed refrigerant flow injected from the branch part (Z) that branches the flow and the nozzle part (14a) that decompresses and expands one of the refrigerants branched at the branch part (Z). An ejector (14) sucked from the refrigerant, a throttle means (17) for decompressing and expanding the other refrigerant branched by the branch portion (Z), and a low-pressure refrigerant on the downstream side of the throttle means (17) are evaporated to obtain a refrigerant suction port. (14b) an evaporator (18) that flows out to the upstream side, and at least part of the refrigerant passage from the radiator (12) outlet side to the throttle means (17) inlet side includes the inside and outside of the refrigerant passage. Insulating material (16a) to suppress heat transfer with Is an ejector type refrigeration cycle is the third characteristic.

  According to this, at least a part of the refrigerant passage extending from the radiator (12) outlet side to the throttle means (17) inlet side includes a heat insulating material (16a) that suppresses heat transfer between the inside and outside of the refrigerant passage. ) Is provided, it is possible to prevent the refrigerant from being heated in the refrigerant passage under operating conditions in which the temperature outside the refrigerant passage is higher than the temperature of the refrigerant passing through the refrigerant passage.

  As a result, similar to the ejector-type refrigeration cycle of the first feature, the refrigerant flowing into the throttle means (17) is suppressed from entering a gas-liquid two-phase state, and the occurrence of vapor lock in the throttle means (17) is suppressed. it can.

  In the present invention, the compressor (11) that compresses and discharges the refrigerant, the radiator (12) that radiates the high-pressure refrigerant discharged from the compressor (11), and the air toward the radiator (12). Radiator means (13) for blowing air, a branch part (Z) for branching the flow of the refrigerant on the outlet side of the radiator (12), and a nozzle part for decompressing and expanding one of the refrigerants branched at the branch part (Z) An ejector (14) that sucks the refrigerant from the refrigerant suction port (14b) by a high-speed refrigerant flow injected from (14a), and a throttle means (17) that decompresses and expands the other refrigerant branched by the branch portion (Z). ) And the throttle means (17) for evaporating the low-pressure refrigerant on the downstream side and flowing out to the refrigerant suction port (14b) upstream side, and for the evaporator for blowing air toward the evaporator (18) From the blower means (20) and the discharge side of the compressor (11) Detecting the difference between the high and low pressures of the high pressure side refrigerant pressure in the refrigerant passage leading to the inlet means (17) and the low pressure side refrigerant pressure in the refrigerant passage leading from the outlet means side to the refrigerant suction port (14b). An ejector-type refrigeration cycle provided with pressure difference detection means (33, 34) and configured to increase the pressure of the refrigerant flowing into the throttle means (17) when the high-low pressure difference becomes a predetermined value or less. 4 features.

  According to this, when the high-low pressure difference between the high-pressure side refrigerant pressure and the low-pressure side refrigerant pressure is equal to or less than a predetermined value, the pressure of the refrigerant flowing into the throttle means (17) is increased. The high / low pressure difference between the upstream side and the downstream side of the throttle means (17) can be maintained at a predetermined value or more. That is, the refrigerant flow rate passing through the refrigerant flow path of the throttle means (17) can be maintained at a predetermined flow rate or higher.

  Therefore, for example, the throttle means (17) can be used even under operating conditions in which the gas-liquid two-phase refrigerant is liable to flow into the throttle means (17), such as during low-air temperature dehumidifying operation when applied to a vehicle air conditioner. The pressure difference between the upstream side and the downstream side can be maintained at a value higher than or equal to the value that can blow away the bubbles that block the refrigerant passage of the throttle means (17). As a result, the occurrence of vapor lock in the squeezing means (17) can be suppressed.

  In the ejector refrigeration cycle of the fourth feature, specifically, the high / low pressure difference detecting means (33, 34) is based on a difference between the actual high pressure side refrigerant pressure and the actual low pressure side refrigerant pressure. The pressure difference may be detected. According to this, since the high / low pressure difference can be reliably detected, the pressure difference between the upstream side and the downstream side of the throttle means (17) can be reliably maintained at a predetermined value or more.

  Further, the high / low pressure difference detecting means may detect the high / low pressure difference based on the difference between the air blowing amount of the radiator blower means (13) and the air blowing amount of the evaporator blower means (20).

  Generally, the high-pressure side refrigerant pressure decreases as the amount of air blown by the radiator fan means (13) increases, and the low-pressure side refrigerant pressure increases when the amount of air blown by the evaporator fan means (20) increases. Therefore, the high / low pressure difference can be detected on the basis of the difference between the blower amount of the radiator blower means (13) and the blower amount of the evaporator blower means (20).

  In addition, if an electric blower is employ | adopted as the ventilation means for radiator (13) and the ventilation means for evaporator (20), for example, each ventilation volume can be detected with the power supply voltage supplied to an electric blower.

  Further, the high / low pressure difference detecting means may detect the high / low pressure difference based on the difference between the blowing air temperature of the radiator blowing means (13) and the blowing air temperature of the evaporator blowing means (20). .

  Generally, when the blowing air temperature of the radiator means (13) rises, the high-pressure side refrigerant pressure decreases, and when the blowing air temperature of the evaporator blowing means (20) rises, the low-pressure side refrigerant pressure rises. Therefore, a high-low pressure difference can be detected based on the difference between the blower air temperature of the radiator blower means (13) and the blower air temperature of the evaporator blower means (20).

  In the ejector refrigeration cycle having the fourth feature described above, the bypass passage (31) for guiding the refrigerant discharged from the compressor (11) to the downstream side of the radiator (12) and the opening / closing means for opening and closing the bypass passage (31) ( 32) and a control means (30) for controlling the operation of the opening / closing means (32), and the control means (30) opens the bypass passage (31) when the high-low pressure difference becomes a predetermined value or less. Thus, the opening / closing means (32) may be operated.

  According to this, when the high-low pressure difference becomes equal to or less than a predetermined value, the opening / closing means (32) is opened, so that the refrigerant discharged from the compressor (11) is not cooled in the radiator (12). Therefore, the amount of condensation of the refrigerant discharged from the compressor (11) can be reduced, and the high-pressure side refrigerant pressure can be increased. As a result, the pressure of the refrigerant flowing into the throttle means (17) can be increased.

  The ejector-type refrigeration cycle of the fourth feature described above further comprises control means for controlling the operation of the radiator blower means (13), and the control means dissipates heat when the high-low pressure difference becomes equal to or less than a predetermined value. You may stop the action | operation of the air blower means (13).

  According to this, when the high-low pressure difference becomes equal to or less than a predetermined value, the radiator blower means (13) stops operating, so that the refrigerant discharged from the compressor (11) is not cooled in the radiator (12). As a result, the pressure of the refrigerant flowing into the throttle means (17) can be increased.

  In the ejector refrigeration cycle of the fourth feature described above, the ejector refrigeration cycle includes a shut-off mechanism that shuts off the flow of blown air from the radiator blower means (13), and a control means that controls the operation of the shut-off mechanism. The shut-off mechanism may be operated so as to shut off the flow of the blown air when the high-low pressure difference becomes equal to or less than a predetermined value.

  According to this, when the high / low pressure difference becomes equal to or less than a predetermined value, the shut-off mechanism shuts off the flow of the blown air, so that the refrigerant discharged from the compressor (11) is not cooled in the radiator (12). As a result, the pressure of the refrigerant flowing into the throttle means (17) can be increased.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
An example in which the ejector refrigeration cycle 10 of the present invention is applied to a vehicle refrigeration cycle apparatus will be described with reference to FIGS. FIG. 1 is an overall configuration diagram of an ejector refrigeration cycle 10 of the present embodiment. In the ejector refrigeration cycle 10, a compressor 11 that sucks and compresses refrigerant is rotated by a vehicle engine (not shown) through an electromagnetic clutch 11a, a belt, and the like.

  As the compressor 11, a variable capacity compressor that can adjust the refrigerant discharge capacity by changing the discharge capacity, or a fixed capacity type that adjusts the refrigerant discharge capacity by changing the operating rate of the compressor operation by intermittently connecting 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.

  A radiator 12 is connected to 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 the outside air (air outside the vehicle compartment) blown by the electric blower 13 constituting the radiator blower.

  The electric blower 13 is configured to rotate a known centrifugal multiblade fan by an electric motor 13a, and the number of rotations of the electric motor 13a is controlled by a control voltage output from an air conditioning control device 30 described later. .

  In the ejector refrigeration cycle 10 of the present embodiment, a normal chlorofluorocarbon refrigerant is employed as the refrigerant, and a subcritical cycle in which the high-pressure side refrigerant pressure does not exceed the critical pressure of the refrigerant is configured. Therefore, the radiator 12 functions as a condenser that condenses the refrigerant.

  Further, the radiator 12 of the present embodiment includes a condensing heat exchange unit that condenses the refrigerant, a receiver 12a that separates the gas and liquid of the refrigerant cooled by the condensing heat exchange unit, and a saturated liquid from the receiver 12a. And a supercooling heat exchanging part for supercooling the phase refrigerant. That is, the radiator 12 of this embodiment is a so-called subcool condenser.

  The high-pressure side refrigerant flow path 21a of the internal heat exchanger 21 is connected to the radiator 12 outlet side. The internal heat exchanger 21 performs heat exchange between the radiator 12 outlet-side refrigerant passing through the high-pressure side refrigerant flow path 21a and the compressor 11 suction-side refrigerant passing through the low-pressure side refrigerant flow path 21b. .

  As the specific configuration of the internal heat exchanger 21, various configurations can be adopted, but in the present embodiment, a double-pipe heat exchanger configuration is adopted. Specifically, the inner pipe that forms the low-pressure side refrigerant flow path 21b is arranged inside the outer pipe that forms the high-pressure side refrigerant flow path 21a.

  A branch point Z for branching the refrigerant flow is provided on the outlet side of the high-pressure side refrigerant flow path 21a of the internal heat exchanger 21, and one of the refrigerants branched at the branch point Z is on the nozzle part 14a side of the ejector 14 The other refrigerant flows into the refrigerant suction port 14 b side of the ejector 14 through the refrigerant branch passage 16.

  The ejector 14 is a depressurizing unit that depressurizes the refrigerant, and is also a refrigerant circulating unit that circulates the refrigerant by suction of a refrigerant flow ejected at high speed.

  Further, the ejector 14 includes a nozzle portion 14a for reducing the passage area of the high-pressure refrigerant flowing from the outlet side of the high-pressure side refrigerant flow passage 21a of the internal heat exchanger 21 to an isentropic decompression expansion, and a nozzle portion The refrigerant suction port 14b is arranged so as to communicate with the refrigerant jet port 14a and sucks the refrigerant flowing out from the second evaporator 18 described later.

  Further, a mixing portion 14c for mixing the high-speed refrigerant flow ejected from the nozzle portion 14a and the suction refrigerant from the refrigerant suction port 14b is provided in the refrigerant flow downstream portion of the nozzle portion 14a and the refrigerant suction port 14b. A diffuser portion 14d forming a pressure increasing portion is provided on the refrigerant flow downstream side of the mixing portion 14c.

  The diffuser portion 14d is formed in a shape that gradually increases the refrigerant passage area, and functions to increase the refrigerant pressure by decelerating the refrigerant flow, that is, to convert the velocity energy of the refrigerant into pressure energy. Further, the first evaporator 15 is connected to the outlet side of the diffuser portion 14 d of the ejector 14.

  The first evaporator 15 is a heat absorber that evaporates the refrigerant and exerts an endothermic effect by exchanging heat with the low-pressure refrigerant passing through the inside and the air (inside air or outside air) blown by the electric blower 19. The electric blower 19 has the same configuration as the electric blower 13 described above, and the number of rotations of the electric motor 19 a of the electric blower 19 is also controlled by a control voltage output from the air conditioning control device 30.

  The first evaporator 15 is disposed in a case that forms an air passage of an indoor air conditioning unit (not shown) of the vehicle air conditioner, and cools the air that passes through the case and blows into the vehicle interior. The cooling means is configured. That is, in this embodiment, the 1st evaporator 15 is used for vehicle interior air conditioning, and the air-conditioning object space of the 1st evaporator 15 becomes a vehicle interior.

  Further, a heater core (not shown) constituting a heating means for heating the air is disposed in the case of the indoor air conditioning unit on the downstream side of the air flow of the first evaporator 15, and the heater core is heated depending on the degree of heating of the heater core. The temperature-controlled and humidity-adjusted conditioned air is blown out from the air outlet (not shown) at the downstream end of the case into the vehicle compartment.

  The refrigerant outlet side of the first evaporator 15 is connected to the low-pressure side refrigerant passage 21b of the internal heat exchanger 21 described above, and the compressor 11 suction side is connected to the outlet side of the low-pressure side refrigerant passage 21b. .

  On the other hand, the other refrigerant branched at the branch point Z flows into the refrigerant suction port 14 b side of the ejector 14 through the refrigerant branch passage 16. A throttle means 17 is arranged in the refrigerant branch passage 16, and a second evaporator 18 is arranged downstream of the refrigerant flow from the throttle means 17. The throttle unit 17 is a decompression unit that decompresses and expands the refrigerant flowing into the second evaporator 18, and specifically includes a fixed throttle such as a capillary tube or an orifice.

  The second evaporator 18 is a heat absorber that evaporates the refrigerant and exerts an endothermic effect by exchanging heat with the low-pressure refrigerant passing through the inside and the air blown by the electric blower 20 that is the blowing means for the evaporator. The electric blower 20 has the same configuration as the electric blowers 13 and 19, and the number of rotations of the electric motor 20 a of the electric blower 20 is also controlled by a control voltage output from the air conditioning control device 30.

  In addition, the 2nd evaporator 18 comprises the cooling means which cools the air which blows off into the refrigerator arrange | positioned in a vehicle interior. That is, in the present embodiment, the second evaporator 18 is used for cooling in the refrigerator, and the air-conditioning target space (cooling target space) of the second evaporator 18 is in the refrigerator. Moreover, the electric blower 20 blows the air in the refrigerator toward the second evaporator 18, and the cold air cooled by the second evaporator 18 is circulated in the refrigerator.

  Further, in the present embodiment, as shown by a thick broken line in FIG. 1, among the above configurations, the compressor 11, the radiator 12, the internal heat exchanger 21, the branch portion Z, and the throttle unit 17 upstream of the refrigerant branch passage 16. The side is located outside the passenger compartment.

  The term “outside of the passenger compartment” in the present embodiment means the outside of the passenger compartment in which the occupant is boarded, and the inside of the engine compartment, the under floor of the passenger compartment, and the like are also included outside the passenger compartment. This is because the traveling wind caused by the vehicle traveling dynamic pressure (ram pressure) flows in the engine room and under the floor of the vehicle compartment, and therefore, the temperature environment can be the same as that outside the vehicle compartment.

  More specifically, in this embodiment, the compressor 11, the radiator 12 and the internal heat exchanger 21 are arranged in the engine room, and the branch portion Z on the downstream side of the high-pressure side refrigerant flow path 21a of the internal heat exchanger 21 is arranged. The upstream side of the throttle means 17 of the refrigerant branch passage 16 is disposed below the vehicle floor. Further, the outside of the passenger compartment of the present embodiment corresponds to the outside of the air conditioning target space.

  On the other hand, among the above configurations, the ejector 14, the first evaporator 15, the throttle means 17, and the second evaporator 18 are arranged in the vehicle interior. In addition, the vehicle interior of the present embodiment does not mean only the interior of the vehicle cabin in which the occupant is boarded, but also includes the vehicle interior side from the dash panel that partitions the engine room and the vehicle interior.

  That is, a space between the dash panel and the instrument panel on which the vehicle instrument panel and the like are arranged is also included in the vehicle interior. The indoor air conditioning unit described above is disposed in a space between the dash panel and the instrument panel.

  The air conditioning control device 30 includes a known microcomputer including a CPU, a ROM, a RAM, and the like and peripheral circuits thereof. The air conditioning control device 30 performs various calculations and processes based on a control program stored in the ROM, and controls the operations of various electric actuators 13a, 19a, 20a and the like.

  In addition, the air conditioning control device 30 includes various detection signals from an operation panel provided with a detection value of a sensor group such as an outside air sensor for detecting an outside air temperature (a temperature outside the passenger compartment), an operation switch for operating a vehicle air conditioner, and the like. Is entered. In FIG. 1, the air conditioning control device 30 is also disposed in the vehicle interior, but the air conditioning control device 30 may be disposed outside the vehicle interior.

  Next, the operation of the present embodiment in the above configuration will be described. First, the normal operation of cooling the passenger compartment and cooling the refrigerator will be described. When the operation switch of the operation panel is turned on, the driving force is transmitted to the compressor 11 by the vehicle engine. The high-temperature and high-pressure gas-phase refrigerant compressed and discharged by the compressor 11 flows into the radiator 12.

  In the heat exchanger for condensation of the radiator 12, the high-temperature and high-pressure gas-phase refrigerant is cooled and condensed by the outside air, and the condensed refrigerant is separated into the gas-phase refrigerant and the liquid-phase refrigerant in the receiver 12a. In the supercooling heat exchange section, it is further cooled and flows into the high-pressure side refrigerant flow path 21 a of the internal heat exchanger 21.

  Here, the operation of the internal heat exchanger 21 during normal operation of the ejector refrigeration cycle of the present embodiment will be described with reference to FIG. FIG. 2 is a Mollier diagram showing the state of the refrigerant in the ejector-type refrigeration cycle of the present embodiment. The state of the refrigerant during normal operation is indicated by a broken line, and the refrigerant state during dehumidifying operation at a low outside temperature described later is shown. The state is indicated by a solid line, and the two-dot chain line indicates an isotherm.

  During normal operation, heat exchange is performed in the internal heat exchanger 21 between the high-temperature high-pressure liquid phase refrigerant in the high-pressure side refrigerant flow path 21a and the low-temperature low-pressure refrigerant in the low-pressure side refrigerant flow path 21b. Therefore, similarly to the cycle of the prior application example, the internal heat exchanger 21 reduces the enthalpy of the refrigerant on the outlet side of the radiator 12 as indicated by a → b, and reduces the enthalpy of the refrigerant on the suction side of the compressor 11 to c → It acts to increase as shown in d.

  The refrigerant flowing out from the high-pressure side refrigerant flow path 21a of the internal heat exchanger 21 is divided into a refrigerant flow toward the ejector 14 and a refrigerant flow toward the branch refrigerant passage 16 at the branch point Z.

  The refrigerant flow flowing into the ejector 14 is decompressed and expanded by the nozzle portion 14a. Thereby, 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 suction action at this time, the 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 that has flowed out of the diffuser portion 14 d of the ejector 14 flows into the first evaporator 15. In the first evaporator 15, the low-pressure refrigerant absorbs heat from the air blown from the electric blower 19 and evaporates. The refrigerant that has passed through the first evaporator 15 flows into the low-pressure side refrigerant passage 21b of the internal heat exchanger 21 and exchanges heat with the high-pressure refrigerant in the high-pressure side refrigerant passage 21a of the internal heat exchanger 21. And the gaseous-phase refrigerant | coolant after passing the low voltage | pressure side refrigerant flow path 21b is suck | inhaled by the compressor 11, and is compressed again.

  On the other hand, the refrigerant flow flowing into the branch refrigerant passage 16 is decompressed by the throttle means 17 to become a low-pressure refrigerant, and this low-pressure refrigerant flows into the second evaporator 18. In the second evaporator 18, the low-pressure refrigerant absorbs heat from the blown air of the electric blower 20 and evaporates. The gas-phase refrigerant after passing through the second evaporator 18 is sucked into the ejector 14 from the refrigerant suction port 14b.

  Since the refrigerant can be supplied to both the first and second evaporators 15 and 18 by operating as described above, the first and second evaporators 15 and 18 can simultaneously exert a cooling action. At that time, the refrigerant evaporation pressure of the first evaporator 15 becomes the pressure after being increased by the diffuser part 14d, while the refrigerant evaporation pressure of the second evaporator 18 becomes the pressure immediately after the pressure reduction at the nozzle part 14a.

  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. In the present embodiment, since the first evaporator 15 is used for air conditioning in the vehicle interior and the second evaporator 18 is used for cooling in the refrigerator, the cooling temperature in the in-vehicle refrigerator-freezer is set higher than the cooling temperature in the vehicle interior. Can be lowered.

  In addition, since the compression work of the compressor 11 can be reduced by the amount by which the suction pressure of the compressor 11 can be increased by the pressure increasing action at the diffuser portion 14d of the ejector 14, the power saving effect of the compressor 11 can be obtained. Furthermore, since the enthalpy difference of the refrigerant between the refrigerant inlet and outlet in the first and second evaporators 15 and 18 can be increased by the action of the internal heat exchanger 21, the refrigeration capacity of the cycle can be increased. As a result, cycle efficiency (COP) can be improved.

  By the way, in a vehicle air conditioner, an ejector-type refrigeration cycle may be operated for the purpose of dehumidifying the air blown into the passenger compartment and maintaining the temperature in the refrigerator even at low outdoor temperatures in winter. Such an operating condition may be an operating condition in which the temperature outside the passenger compartment is lower than the temperature of the air-conditioning target space (cooling target space) of the second evaporator 18. That is, the same operation as the above-described low outside temperature dehumidifying operation may be performed.

  In such a low outside air temperature dehumidifying operation, as described with reference to FIG. 7, the refrigeration capacity required for the refrigeration cycle is reduced compared to the normal operation, and the cycle heat load is reduced. As the difference between the high and low pressures of the cycle becomes smaller, there is a concern about vapor lock in the throttling means 17 due to undesirable heat exchange of the internal heat exchanger 21.

  In contrast, in the present embodiment, a part of the refrigerant passage extending from the high-pressure side refrigerant flow path 21a outlet side of the internal heat exchanger 21 to the throttle means 17 inlet side is disposed outside the vehicle compartment. Therefore, the refrigerant passing through the refrigerant passage extending from the high-pressure side refrigerant flow path 21a outlet side of the internal heat exchanger 21 to the throttle means 17 inlet side can be cooled by the low-temperature outside air outside the vehicle compartment during the low outside air temperature dehumidifying operation.

  That is, even when the refrigerant on the outlet side of the radiator 12 is heated due to undesired heat exchange of the internal heat exchanger 21 at the time of dehumidifying the low outside air temperature, the refrigerant flowing into the throttle means 17 is reliably recooled by the low temperature outside air. be able to.

  Specifically, even when the internal heat exchanger 21 increases the enthalpy of the refrigerant on the outlet side of the radiator 12 as shown by e → f in FIG. By doing so, it can be decreased again as shown by f → e ′. Therefore, it can suppress that the refrigerant | coolant which flows in into the expansion means 17 becomes a gas-liquid two-phase state. As a result, the occurrence of vapor lock in the throttle means 17 can be suppressed.

  Here, the case where the vehicle air conditioner having the above-described configuration is operated at a high outdoor temperature in summer will be described. Of course, at the time of high outdoor temperature in summer, the temperature outside the passenger compartment is higher than the temperature of the air conditioning target space (cooling target space) of the second evaporator 18. Further, in this state, the internal heat exchanger 21 acts to reduce the enthalpy of the radiator 12 outlet side refrigerant.

  Therefore, there is a concern that the refrigerant passing through the refrigerant passage extending from the outlet side of the high-pressure side refrigerant passage 21a of the internal heat exchanger 21 to the inlet side of the throttle means 17 is reheated by the high-temperature air outside the passenger compartment. However, although the refrigerant discharged from the compressor 11 radiates heat by exchanging heat with the outside air in the radiator 12, it is not necessarily cooled to the same temperature as the outside air.

  Therefore, the temperature difference between the refrigerant flowing out of the high-pressure side refrigerant passage 21a cooled by the internal heat exchanger 21 and the outside air temperature is only a small value. Therefore, even if the refrigerant passage extending from the outlet side of the high-pressure side refrigerant flow path 21a of the internal heat exchanger 21 to the inlet side of the throttle means 17 is disposed outside the passenger compartment, the effect of increasing the refrigerating capacity by the internal heat exchanger 21 is greatly increased. There is no loss.

(Second Embodiment)
In the first embodiment described above, the branching portion Z is arranged on the downstream side of the high-pressure side refrigerant flow path 21a of the internal heat exchanger 21, but in this embodiment, as shown in FIG. The branch part Z is arranged between the side and the inlet side of the internal heat exchanger 21 (specifically, the inlet side of the high-pressure refrigerant passage 21a of the internal heat exchanger 21). Furthermore, a part of the refrigerant branch passage 16 on the downstream side of the branch portion Z is disposed in the vehicle interior. Other configurations are the same as those of the first embodiment.

  The operation of the present embodiment in the above configuration will be described. First, during normal operation of cooling the passenger compartment and operating the refrigerator, the high-temperature and high-pressure gas-phase refrigerant compressed and discharged by the compressor 11 flows into the radiator 12 as in the first embodiment. It is cooled and condensed by the outside air. Of the refrigerant separated from the gas and liquid by the receiver 12a, the liquid-phase refrigerant is branched at the branch portion Z, and one refrigerant flows into the high-pressure side refrigerant passage 21a of the internal heat exchanger 21. .

  As in the first embodiment, the refrigerant flowing into the high-pressure side refrigerant flow path 21a of the internal heat exchanger 21 is reduced in enthalpy, flows into the nozzle portion 14a of the ejector 14, is decompressed, and expands.

  Then, the refrigerant injected from the nozzle portion 14a is mixed with the refrigerant that has passed through the second evaporator 18 sucked from the refrigerant suction port 14b, is pressurized by the diffuser portion 14d, and flows into the first evaporator 15. . The refrigerant that has flowed into the first evaporator 15 absorbs heat from the blown air of the electric blower 19 and evaporates, and is sucked into the compressor 11 via the low-pressure side refrigerant passage 21 b of the internal heat exchanger 21.

  On the other hand, the refrigerant flow flowing into the branch refrigerant passage 16 is decompressed by the throttle means 17 to become a low-pressure refrigerant, and this low-pressure refrigerant flows into the second evaporator 18. The refrigerant flowing into the second evaporator 18 absorbs heat from the blown air of the electric blower 20 and evaporates. The gas-phase refrigerant after passing through the second evaporator 18 is sucked into the ejector 14 from the refrigerant suction port 14b.

  By operating as described above, during the normal operation, the first and second evaporators 15 and 18 can exhibit the cooling action simultaneously in different temperature zones as in the first embodiment. In addition, since the enthalpy difference of the refrigerant between the refrigerant inlet and outlet in the first evaporator 15 can be increased by the action of the internal heat exchanger 21, cycle efficiency (COP) can be improved.

  Furthermore, in this embodiment, since the branch part Z is arrange | positioned between the heat radiator 12 exit side and the internal heat exchanger 21 entrance side, the refrigerant | coolant which flows in into the expansion means 17 passes the internal heat exchanger 21. FIG. There is nothing. Therefore, for example, even in the above-described low outside temperature dehumidifying operation, the refrigerant flowing into the expansion means 17 is not heated by the internal heat exchanger 21. As a result, it is possible to suppress the occurrence of vapor lock in the throttle means 17 as in the first embodiment.

(Third embodiment)
In the first embodiment described above, in the ejector refrigeration cycle 10, the compressor 11, the radiator 12, the internal heat exchanger 21, the branch part Z, and the throttle means 17 upstream side of the refrigerant branch passage 16 are arranged outside the vehicle compartment. However, in the present embodiment, as shown in FIG. 4, a part of the refrigerant branch passage 16 on the downstream side of the branch portion Z is disposed in the vehicle interior.

  Further, a heat insulating material 16 a that suppresses heat transfer between the inside and the outside of the refrigerant branch passage 16 is provided on the outer periphery of a portion of the refrigerant branch passage 16 disposed in the vehicle interior. Specifically, a resin foam or the like is employed as the heat insulating material 16 a and is wound around the outer periphery of the refrigerant branch passage 16. Other configurations are the same as those of the first embodiment.

  The operation of the present embodiment in the above configuration will be described. First, during the above-described normal operation, the operation is the same as in the first embodiment. Therefore, the same effect as the first embodiment can be obtained.

  Furthermore, in the present embodiment, since the heat insulating material 16a is provided on the outer periphery of the portion of the refrigerant branch passage 16 disposed in the vehicle interior, for example, as in the low outside temperature dehumidifying operation described above, the refrigerant branch passage 16 is provided. It is possible to prevent the refrigerant from being heated in the refrigerant passage under operating conditions in which the vehicle interior temperature outside the refrigerant passage is higher than the temperature of the refrigerant passing through the refrigerant passage.

  As a result, similarly to the first embodiment, it is possible to suppress the refrigerant flowing into the throttle means 17 from entering a gas-liquid two-phase state, and to suppress the occurrence of vapor lock in the throttle means 17.

(Fourth embodiment)
In the first embodiment described above, in the ejector refrigeration cycle 10, the compressor 11, the radiator 12, the internal heat exchanger 21, the branch part Z, and the throttle means 17 upstream side of the refrigerant branch passage 16 are arranged outside the vehicle compartment. However, in this embodiment, as shown in FIG. 5, a part of the refrigerant branch passage 16 on the downstream side of the branch portion Z is disposed in the vehicle interior.

  Further, a bypass passage 31 that bypasses the refrigerant discharged from the compressor 11 downstream of the radiator 12, an electromagnetic valve 32 that constitutes an opening / closing means that opens and closes the bypass passage 31, and a high-pressure sensor 33 that detects refrigerant pressure downstream of the radiator 12. A low pressure sensor 34 for detecting the refrigerant pressure downstream of the second evaporator 18 is provided.

  The electromagnetic valve 32 is opened and closed by a control voltage output from the air conditioning control device 30, and detection signals from the high pressure sensor 33 and the low pressure sensor 34 are input to the air conditioning control device 30.

  Here, since the high pressure sensor 33 is a detecting means for detecting the high pressure side refrigerant pressure and the low pressure sensor 34 is a detecting means for detecting the low pressure side refrigerant pressure, the pressure sensors 33 and 34 constitute a high / low pressure difference detecting means. The Further, in the present embodiment, the air conditioning control device 30 opens the electromagnetic valve 32 when the high / low pressure difference becomes equal to or less than a predetermined value.

  The operation of the present embodiment in the above configuration will be described. First, during the above-described normal operation, the operation is the same as in the first embodiment. Therefore, the same effect as the first embodiment can be obtained.

  Further, in the present embodiment, when the high / low pressure difference becomes small, the air conditioning control device 30 opens the electromagnetic valve 32. For example, under the operating conditions where the high / low pressure difference becomes small like the low outside temperature dehumidifying operation, the compressor 11 A part of the discharged refrigerant can be guided to the downstream side of the radiator 12 through the bypass passage 31.

  A part of the refrigerant discharged from the compressor 11 that has passed through the bypass passage 31 is guided to the downstream side of the radiator 12 without being cooled by the radiator 12, and therefore, the amount of condensation of the refrigerant discharged from the compressor 11 in the radiator 12. And the high-pressure side refrigerant pressure can be increased. Therefore, the pressure of the refrigerant flowing into the throttle means 17 can be increased more than before the solenoid valve 32 is opened.

  As a result, the pressure difference between the upstream side and the downstream side of the throttle means 17 can be increased, and the flow rate of the refrigerant passing through the throttle means 17 can be increased. Therefore, bubbles that cause the occurrence of vapor lock during the low outside temperature dehumidifying operation However, even if the refrigerant passage of the throttle means 17 is blocked, the bubbles can be pushed away. As a result, the occurrence of vapor lock in the throttle means 17 can be suppressed.

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

  (1) In each of the above-described embodiments, the first evaporator 15 is used for air conditioning in the vehicle interior, and the second evaporator 18 is used for cooling in the refrigerator. However, the first and second evaporators 15 and 18 are used. Is not limited to this.

  For example, the first and second evaporators 15 and 18 may be used for vehicle interior air conditioning. That is, the same air-conditioning target space (cooling target space) may be cooled by the first and second evaporators 15 and 18. In this case, since one of the electric blowers 19 and 20 can be eliminated, a cost reduction effect can be obtained by reducing the number of parts.

  Further, when the same air-conditioning target space (cooling target space) is cooled by the first and second evaporators 15 and 18, the first and second evaporators 15 and 18 are made of the same material (for example, aluminum material). Then, it may be integrated by brazing means. Furthermore, for example, in the ejector refrigeration cycle of the first embodiment, the first evaporator 15, the second evaporator 18, the throttle means 17, and the ejector 14 may be integrated.

  Specifically, the ejector 14 is accommodated inside the header tank of the second evaporator 18, and the throttle means 17 constituted by a capillary tube is provided along the header tank outer wall surface of the first evaporator 15 and the second evaporator 18. What is necessary is just to make it the structure to join.

  (2) In each embodiment described above, the first evaporator 15 is disposed on the downstream side of the diffuser portion 14d of the ejector 14, but the first evaporator 15 may be eliminated. Furthermore, in this case, the receiver 12a of the radiator 12 is abolished, and an accumulator that forms a gas-liquid separator that separates the gas-liquid refrigerant is disposed between the diffuser portion 14d outlet side and the compressor 11 suction side. Thus, the gas-phase refrigerant may be supplied from the accumulator to the suction side of the compressor 11.

  Of course, in the cycle configurations of the above-described embodiments, the receiver 12a may be eliminated and the accumulator may be provided.

  (3) In each of the above-described embodiments, the throttle means 17 is constituted by a fixed throttle such as a capillary tube or an orifice. However, in order to further suppress the vapor lock, the throttle shape of the throttle means 17 of each embodiment is changed. May be. Specifically, when a capillary tube is employed, the inner diameter of the tube may be increased or the tube length may be shortened. If an orifice is employed, the refrigerant passage area may be increased.

  (4) The heat insulating material 16a of the third embodiment may be applied to the ejector refrigeration cycle of the second embodiment described above. That is, in the configuration of the second embodiment, the heat insulating material 16a may be provided on the outer periphery of the portion of the refrigerant branch passage 16 disposed in the vehicle interior.

  According to this, since the refrigerant flowing into the throttle means 17 is not heated in either the internal heat exchanger 21 or the refrigerant passage during the low external temperature dehumidifying operation, the refrigerant flowing into the throttle means 17 is further increased. Can be prevented from being heated to increase enthalpy.

  (5) In the above-described fourth embodiment, the high and low pressure difference detecting means is constituted by the high pressure sensor 33 and the low pressure sensor 34, but the high and low pressure difference detecting means is not limited to this.

  For example, the high-low pressure difference may be detected based on the difference between the air flow rate of the electric blower 13 that is the blower means for the radiator and the air flow rate of the electric blower 20 that is the blower means for the evaporator. Generally, when the amount of air blown by the radiator fan increases, the high-pressure side refrigerant pressure decreases, and when the amount of air blown by the evaporator fan increases, the low-pressure side refrigerant pressure increases. Therefore, it is possible to detect the high / low pressure difference based on the difference between the blower amount of the radiator blower unit and the blower unit of the evaporator blower unit.

  Specifically, for example, in the cycle of the fourth embodiment, a map indicating the relationship between the control voltage output from the air-conditioning control device 30 to each electric blower 13, 20 and the amount of air blown by each electric blower 13, 20, electric A map showing the relationship between the air flow rate of the blower 13 and the high-pressure side refrigerant pressure, a map showing the relationship between the air flow rate of the electric blower 20 and the low-pressure side refrigerant pressure, and the like are stored in the air-conditioning control device 30 in advance. In step 30, the high / low pressure difference may be determined by referring to each of the above maps based on each control voltage.

  Further, the high / low pressure difference may be detected based on the difference between the blower air temperature of the radiator blower and the blower air temperature of the evaporator blower. Generally, when the blown air temperature of the radiator blower rises, the high-pressure side refrigerant pressure decreases, and when the blower air temperature of the evaporator blower rises, the low-pressure refrigerant pressure rises. Therefore, a high-low pressure difference can be detected based on the difference between the blown air temperature of the radiator blower and the blower air temperature of the evaporator blower.

  Specifically, for example, in the cycle of the fourth embodiment, an outside air temperature sensor for detecting the outside temperature of the passenger compartment and an inside temperature sensor for detecting the inside temperature of the refrigerator are provided, and the air temperature of the blower means for the radiator is provided by the outside air temperature sensor. And the blown air temperature of the blowing means for the evaporator is detected by the internal temperature sensor.

  Further, a map showing the relationship between the blowing air temperature of the radiator blowing means and the high pressure side refrigerant pressure, a map showing the relationship between the blowing air temperature of the evaporator blowing means and the low pressure side refrigerant pressure, and the like are stored in the air conditioning controller 30 in advance. The air-conditioning control device 30 may calculate the high / low pressure difference with reference to the maps based on the detected values of the outside air temperature sensor and the internal temperature sensor.

  (6) In the fourth embodiment described above, the bypass passage 31 for bypassing the refrigerant discharged from the compressor 11 to the downstream side of the radiator 12 and the electromagnetic valve 32 constituting the opening / closing means for opening and closing the bypass passage 31 are provided, and the high-low pressure difference is preliminarily set. When the pressure falls below a predetermined value, the high pressure side refrigerant pressure is increased by opening the solenoid valve 32, but means for increasing the high pressure side refrigerant pressure is not limited to this.

  For example, a control means for controlling the operation of the air blower means for the radiator may be provided so that the control means stops the operation of the air blower means for the heat radiator when the high / low pressure difference becomes a predetermined value or less. Specifically, in the cycle of the fourth embodiment described above, the air conditioning control device 30 may stop the operation of the electric blower 13 when the high-low pressure difference becomes equal to or less than a predetermined value.

  Also, a shut-off mechanism that shuts off the flow of the blown air of the blower means for the radiator and a control means that controls the operation of the shut-off mechanism are provided, and when the high-low pressure difference becomes a predetermined value or less, the control means The shut-off mechanism may be operated so as to shut off the flow.

  Specifically, in the cycle of the above-described fourth embodiment, a shut-off mechanism that is operated by a control signal of the air conditioning control device 30 is disposed between the electric blower 13 and the radiator 12. As this blocking mechanism, a slide-type opening / closing door or the like can be adopted. Then, when the high / low pressure difference becomes equal to or less than a predetermined value, the air conditioning control device 30 may operate the shut-off mechanism so as to shut off the flow of the blown air.

  (7) In each of the above-described embodiments, the refrigeration cycle for a vehicle has been described. However, the present invention is not limited to a vehicle and can be similarly applied to a refrigeration cycle for stationary use.

  (8) In the above embodiment, the radiator 12 is an outdoor heat exchanger that exchanges heat between the refrigerant and the outside air, and the first and second evaporators 15 and 18 are indoor heat exchangers. Although applied for cooling, conversely, the first and second evaporators 15 and 18 are configured as outdoor heat exchangers that absorb heat from a heat source such as outside air, and the radiator 12 is heated fluid such as air or water. You may apply this invention to the heat pump cycle comprised as an indoor side heat exchanger which heats.

It is a whole block diagram of the ejector-type refrigerating cycle of 1st Embodiment. It is a Mollier diagram of the ejector type refrigeration cycle of the first embodiment. It is a whole block diagram of the ejector type refrigerating cycle of 2nd Embodiment. It is a whole block diagram of the ejector-type refrigerating cycle of 3rd Embodiment. It is a whole block diagram of the ejector-type refrigerating cycle of 4th Embodiment. It is a whole block diagram of the ejector type refrigeration cycle of the example of a prior application. It is a Mollier diagram of the ejector type refrigeration cycle of the prior application example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Compressor, 12 ... Radiator, 13, 20 ... Electric blower, 14 ... Ejector,
14a ... Nozzle part, 14b ... Refrigerant suction port, 16a ... Heat insulating material, 17 ... Throttle means,
18 ... second evaporator, 21 ... internal heat exchanger, 30 ... air conditioning control device, 31 ... bypass passage,
32 ... Solenoid valve, 33 ... High pressure sensor, 34 ... Low pressure sensor.

Claims (11)

A compressor (11) for compressing and discharging the refrigerant;
A radiator (12) for radiating heat from the high-pressure refrigerant discharged from the compressor (11);
A branch part (Z) for branching the flow of the refrigerant on the radiator (12) outlet side,
An ejector (14) for sucking the refrigerant from the refrigerant suction port (14b) by a high-speed refrigerant flow injected from the nozzle part (14a) for decompressing and expanding one of the refrigerants branched at the branch part (Z);
Throttle means (17) for decompressing and expanding the other refrigerant branched at the branch portion (Z);
An evaporator (18) that evaporates the low-pressure refrigerant on the downstream side of the throttle means (17) by exchanging heat with the air blown into the air-conditioning target space and flows out upstream of the refrigerant suction port (14b). Prepared,
An ejector type refrigeration cycle, wherein at least a part of a refrigerant passage extending from the radiator (12) outlet side to the throttle means (17) inlet side is disposed outside the air-conditioning target space. An internal heat exchanger (21) for exchanging heat between the radiator (12) outlet-side refrigerant and the compressor (11) suction-side refrigerant;
2. The ejector refrigeration cycle according to claim 1, wherein a portion of the refrigerant passage disposed outside the air-conditioning target space is provided downstream of the internal heat exchanger (21). . A compressor (11) for compressing and discharging the refrigerant;
A radiator (12) for radiating heat from the high-pressure refrigerant discharged from the compressor (11);
A branch part (Z) for branching the flow of the refrigerant on the radiator (12) outlet side,
An internal heat exchanger (21) for exchanging heat between one of the refrigerants branched at the branch part (Z) and the compressor (11) suction-side refrigerant;
An ejector (14) for sucking the refrigerant from the refrigerant suction port (14b) by a high-speed refrigerant flow injected from the nozzle (14a) for decompressing and expanding the refrigerant on the outlet side of the internal heat exchanger (21);
Throttle means (17) for decompressing and expanding the other refrigerant branched at the branch portion (Z);
An ejector refrigeration cycle comprising: an evaporator (18) that evaporates the low-pressure refrigerant on the downstream side of the throttle means (17) and flows out upstream of the refrigerant suction port (14b). A compressor (11) for compressing and discharging the refrigerant;
A radiator (12) for radiating heat from the high-pressure refrigerant discharged from the compressor (11);
A branch part (Z) for branching the flow of the refrigerant on the radiator (12) outlet side,
An ejector (14) for sucking the refrigerant from the refrigerant suction port (14b) by a high-speed refrigerant flow injected from the nozzle part (14a) for decompressing and expanding one of the refrigerants branched at the branch part (Z);
Throttle means (17) for decompressing and expanding the other refrigerant branched at the branch portion (Z);
An evaporator (18) that evaporates the low-pressure refrigerant on the downstream side of the throttle means (17) and flows out to the upstream side of the refrigerant suction port (14b);
At least a part of the refrigerant passage from the radiator (12) outlet side to the throttle means (17) inlet side is provided with a heat insulating material (16a) that suppresses heat transfer between the inside and outside of the refrigerant passage. An ejector-type refrigeration cycle characterized by that. A compressor (11) for compressing and discharging the refrigerant;
A radiator (12) for radiating heat from the high-pressure refrigerant discharged from the compressor (11);
A radiator means (13) for radiator which blows air toward the radiator (12);
A branch part (Z) for branching the flow of the refrigerant on the radiator (12) outlet side,
An ejector (14) for sucking the refrigerant from the refrigerant suction port (14b) by a high-speed refrigerant flow injected from the nozzle part (14a) for decompressing and expanding one of the refrigerants branched at the branch part (Z);
Throttle means (17) for decompressing and expanding the other refrigerant branched at the branch portion (Z);
An evaporator (18) that evaporates the low-pressure refrigerant on the downstream side of the throttle means (17) and flows out upstream of the refrigerant suction port (14b);
An evaporator blowing means (20) for blowing air toward the evaporator (18);
The high pressure side refrigerant pressure in the refrigerant passage extending from the discharge side of the compressor (11) to the inlet side of the throttle means (17) and the refrigerant passage extending from the outlet side of the throttle means (17) to the refrigerant suction port (14b). High / low pressure difference detecting means (33, 34) for detecting a high / low pressure difference from the low pressure side refrigerant pressure;
An ejector-type refrigeration cycle, wherein the pressure of the refrigerant flowing into the throttle means (17) is increased when the high-low pressure difference becomes equal to or less than a predetermined value. The high / low pressure difference detecting means (33, 34) detects the high / low pressure difference based on a difference between the actual high pressure side refrigerant pressure and the actual low pressure side refrigerant pressure. The ejector-type refrigeration cycle according to claim 5. The high / low pressure difference detecting means is adapted to detect the high / low pressure difference based on a difference between an air blowing amount of the radiator air blowing means (13) and an air blowing amount of the evaporator air blowing means (20). The ejector refrigeration cycle according to claim 5, wherein The high / low pressure difference detecting means detects the high / low pressure difference based on the difference between the blowing air temperature of the radiator blowing means (13) and the blowing air temperature of the evaporator blowing means (20). The ejector refrigeration cycle according to claim 5. A bypass passage (31) for guiding the refrigerant discharged from the compressor (11) to the downstream side of the radiator (12);
Opening and closing means (32) for opening and closing the bypass passage (31);
Control means (30) for controlling the operation of the opening and closing means (32),
The control means (30) operates the opening / closing means (32) to open the bypass passage (31) when the high-low pressure difference becomes equal to or less than a predetermined value. The ejector type refrigeration cycle according to any one of 8. Comprising control means for controlling the operation of the air blower means (13) for the radiator;
The said control means stops the action | operation of the said air blower means (13) for a heat radiator, when the said high-low pressure difference becomes below a predetermined value, The operation | movement of any one of Claim 5 thru | or 8 characterized by the above-mentioned. Ejector refrigeration cycle. A shut-off mechanism for shutting off the flow of blown air from the radiator blower means (13);
Control means for controlling the operation of the shut-off mechanism,
The said control means operates the said interruption | blocking mechanism so that the flow of the ventilation air may be interrupted when the said high-low pressure difference becomes below a predetermined value. The ejector-type refrigeration cycle described in 1.

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