JP2007078340A - Ejector type refrigerating cycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance an evaporator refrigerating capacity while precluding the density of a compressor suction refrigerant from getting low, in an ejector type refrigerating cycle. <P>SOLUTION: A gas and a liquid of an exit side refrigerant of a condenser 13a are separated by a gas-liquid separator 13b, and a saturated liquid refrigerant of the gas-liquid separator 13b is super-cooled by a super cooler 13c. The saturated liquid refrigerant of the gas-liquid separator 13b is introduced into the ejector 15 to be decompression-expanded, and the refrigerant after passed through the ejector 15 is evaporated in the first evaporator 16. In the other hand, the super-cooled liquid refrigerant of the super cooler 13c is decompressed by a contraction means 18 and is evaporated in the second evaporator 19, and the refrigerant is sucked thereafter by the ejector 15. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ejector-type refrigeration cycle having an ejector serving as a refrigerant decompression means and a refrigerant circulation means, and is effective when applied to, for example, a refrigeration cycle of a vehicle air-conditioning refrigeration apparatus.

  Conventionally, in a vapor compression refrigeration cycle, an ejector refrigeration cycle using an ejector as a refrigerant decompression means and a refrigerant circulation means has been proposed in Patent Document 1.

  In this Patent Document 1, a first evaporator is connected to the refrigerant outlet side of the ejector, and a gas-liquid separator is disposed on the outlet side of the first evaporator, and the liquid refrigerant outlet side of the gas-liquid separator is connected to the ejector. The structure which connected the 2nd evaporator between these refrigerant | coolant suction openings is described.

  Patent Document 1 describes that heat absorption (cooling) can be exerted from separate spaces by the first and second evaporators or from the same space by the first and second evaporators (Patent Document 1). 1 paragraph 0192).

  Further, FIGS. 34 to 38 of Patent Document 1 show an outflow from the gas-liquid separator in an ejector-type refrigeration cycle in which an evaporator is disposed only between the liquid refrigerant outflow side of the gas-liquid separator and the suction port of the ejector. The structure which provides the internal heat exchanger which performs heat exchange between the low-pressure gaseous-phase refrigerant | coolant to perform and the exit side high-pressure refrigerant | coolant of a radiator is described.

  The present applicant has proposed an ejector refrigeration cycle provided with an internal heat exchanger in Japanese Patent Application No. 2006-36532. In this prior application, the first evaporator for evaporating the low-pressure refrigerant after passing through the ejector is provided on the downstream side of the ejector, while the branch passage for introducing the refrigerant branched on the upstream side of the ejector to the refrigerant suction port of the ejector is provided. And an internal heat exchanger for exchanging heat between the low pressure refrigerant on the compressor suction side and the high pressure refrigerant on the downstream side of the radiator. Provided.

According to Patent Document 1 and the prior application, the enthalpy of the first and second evaporator inlet refrigerant can be reduced by the heat exchange action in the internal heat exchanger, and the enthalpy difference between the evaporator inlet and outlet can be enlarged. Thereby, the refrigerating capacity of the first and second evaporators can be improved.
Japanese Patent No. 3322263

  However, in Patent Document 1 and the above-mentioned prior application, the degree of superheat of the refrigerant sucked by the compressor increases due to the heat exchange action in the internal heat exchanger, so that the density of the refrigerant sucked by the compressor is smaller than that in the case where there is no internal heat exchange. descend. This reduction in the density of the refrigerant sucked reduces the compressor discharge flow rate (mass flow rate), which causes a reduction in the refrigeration capacity of the first and second evaporators, and hence a reduction in cycle efficiency (COP).

  In view of the above points, an object of the present invention is to improve the evaporator refrigeration capacity in the ejector refrigeration cycle without causing a decrease in the density of refrigerant sucked by the compressor.

The present invention has been devised in order to achieve the above object, and a compressor (11) for sucking and compressing refrigerant,
A condenser (13a) for condensing the high-pressure refrigerant discharged from the compressor (11);
A high-pressure side gas-liquid separator (13b) for separating the gas-liquid of the outlet side refrigerant of the condenser (13a);
A supercooler (13c) for supercooling the saturated liquid refrigerant of the high-pressure side gas-liquid separator (13b);
A nozzle part (15a) that decompresses and expands the refrigerant downstream from the outlet part of the condenser (13a), and a refrigerant suction port (the refrigerant is sucked into the interior by a high-speed refrigerant flow injected from the nozzle part (15a)) 15b), and an ejector (15) having a pressure increasing portion (15d) for increasing the pressure by reducing the speed of the refrigerant flow obtained by mixing the high-speed refrigerant flow and the refrigerant sucked from the refrigerant suction port (15b) ,
Throttle means (18) for depressurizing the supercooled liquid refrigerant of the supercooler (13c);
An evaporator (19) connected between the downstream side of the throttle means (18) and the refrigerant suction port (15b) is provided.

  According to this, the low pressure refrigerant | coolant which decompressed the supercooled liquid refrigerant | coolant supercooled by the supercooler (13c) can be evaporated by the evaporator (19), and the refrigerating capacity of the evaporator (19) can be exhibited.

  Here, in the evaporator (19), the refrigerant can be evaporated at an evaporation pressure lower than the compressor suction pressure by an amount corresponding to the boosting effect in the ejector (15), and thereby the refrigerant evaporation temperature can be lowered. Moreover, the refrigerant enthalpy difference between the inlet and outlet of the evaporator (19) can be increased by the supercooling action in the supercooler (13c).

  And since the refrigerant | coolant enthalpy difference of an evaporator (19) can be expanded by the supercooling effect | action in a supercooler (13c), like the case of the cycle structure which provided the internal heat exchanger, the superheat degree of a refrigerant | coolant suction | inhalation refrigerant | coolant The phenomenon of increase → decrease in the density of refrigerant sucked in the compressor → decrease in compressor discharge flow rate (mass flow rate) does not occur.

  As a result, the refrigeration capacity of the evaporator (19) can be improved without reducing the cycle efficiency (COP).

In the present invention, specifically, the first evaporator (16) is connected to the downstream side of the ejector (14),
The evaporator on the downstream side of the throttle means (18) constitutes a second evaporator (19) having a refrigerant evaporation temperature lower than that of the first evaporator (16).

  According to this, in the cycle configuration including the first and second evaporators (16, 19) having different evaporation temperature ranges, the refrigeration capacity of the first and second evaporators (16, 19) can be efficiently improved.

  Specifically, the present invention includes a low-pressure side gas-liquid separator (23) that separates the gas-liquid of the downstream-side refrigerant of the ejector (15) and flows the gas-phase refrigerant to the suction side of the compressor (11). You may make it prepare.

  Further, in the present invention, specifically, the low-pressure side gas-liquid that separates the gas-liquid of the downstream-side refrigerant of the first evaporator (16) and flows the gas-phase refrigerant to the suction side of the compressor (11). A separator (23) may be provided.

  In the present invention, specifically, the refrigerant passage (26) for supplying the liquid-phase refrigerant separated by the low-pressure side gas-liquid separator (23) to the evaporator (19) on the downstream side of the throttle means (18). You may make it provide.

  According to this, both the low pressure refrigerant after passing through the throttle means (18) and the liquid phase refrigerant from the low pressure side gas-liquid separator (23) can be supplied to the evaporator (19) downstream of the throttle means (18). Therefore, the low-pressure refrigerant having a high ratio of liquid-phase refrigerant (low dryness) can be supplied to the evaporator (19) at all times, which can contribute to improving the performance of the evaporator (19).

  Further, the present invention specifically includes a check valve (25) that allows the refrigerant to flow only in one direction from the low-pressure gas-liquid separator (23) to the evaporator (19) in the refrigerant passage (26). Install.

  Thereby, the malfunction that the low-pressure refrigerant | coolant after passing through a throttle means (18) flows directly into a low-pressure side gas-liquid separator (23) can be prevented reliably.

  Specifically, in the present invention, the saturated liquid refrigerant of the gas-liquid separator (13b) is introduced into the ejector (15).

  Further, in the present invention, specifically, the supercooled liquid refrigerant of the supercooler (13c) may be introduced into the ejector (15).

  Further, in the present invention, specifically, the outlet refrigerant of the condenser (13a) may be introduced into the ejector (15).

  In particular, when the saturated liquid refrigerant of the gas-liquid separator (13b) is introduced into the ejector (15), the saturated liquid refrigerant that does not include the gas-phase refrigerant can be introduced into the ejector (15), so that the outlet of the condenser (13a) Unlike the refrigerant, the dryness does not change due to the change of the cycle operation condition, and the refrigerant density does not change, and the density of the ejector introduced refrigerant is stable. For this reason, a suitable nozzle part shape corresponding to the density of the ejector introduction refrigerant can be set.

  The saturated liquid refrigerant can increase the refrigerant enthalpy difference between the inlet and outlet of the ejector nozzle portion (15a) and can increase the ejector recovery energy compared to the supercooled liquid refrigerant. From the above, stable ejector performance can be secured by introducing the saturated liquid refrigerant of the gas-liquid separator (13b) into the ejector (15).

  Further, in the present invention, specifically, the ejector (15) and the throttle means (18) are configured as an integral structure.

  According to this, the decompression module (20) composed of the ejector (15) and the throttle means (18) can be configured, and compared with the case where the ejector (15) and the throttle means (18) are configured and arranged independently, the mounting space is reduced. Can be reduced in size and cost.

  In the present invention, specifically, the condenser (13a), the gas-liquid separator (13b), and the supercooler (13c) are configured as an integral structure.

  According to this, downsizing of the mounting space and cost reduction can be achieved by the integral structure of the above three parties (13a, 13b, 13c).

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

(First embodiment)
FIG. 1 shows an example in which an ejector refrigeration cycle 10 according to a first embodiment of the present invention is applied to a vehicle refrigeration cycle apparatus. In the ejector refrigeration cycle 10 of this embodiment, a compressor 11 that sucks and compresses refrigerant is rotationally driven by a vehicle travel engine (not shown) via a pulley 12 and a belt.

  The compressor 11 may be a variable capacity compressor that can adjust the refrigerant discharge capacity by changing the discharge capacity, or a fixed capacity type compressor that adjusts the refrigerant discharge capacity by changing the operating rate of the compressor operation by switching the electromagnetic clutch. Any of the machines 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 supercooler integrated condenser 13 is arranged on the refrigerant discharge side of the compressor 11. The supercooler integrated condenser 13 is composed of a condenser 13a, a gas-liquid separator 13b, and a supercooler 13c. The condenser 13a cools and condenses the high-pressure gas-phase refrigerant discharged from the compressor 11 with outside air (air outside the passenger compartment) blown by a cooling fan (not shown).

  Further, the gas-liquid separator 13b is connected to the outlet side of the condenser 13a, separates the gas-liquid of the outlet refrigerant of the condenser 13a and accumulates the liquid-phase refrigerant, and downstream the liquid-phase refrigerant, that is, the saturated liquid refrigerant. To the side.

  A branch point 13e is set in the liquid-phase refrigerant outlet passage 13d of the gas-liquid separator 13b, and one refrigerant passage branched at the branch point 13e is connected to the supercooler 13c. The supercooler 13c cools the saturated liquid refrigerant flowing out of the gas-liquid separator 13b with outside air (air outside the vehicle compartment) blown by a cooling fan (not shown).

  In this embodiment, the condenser 13a, the gas-liquid separator 13b, and the supercooler 13c are integrally configured as one assembly structure. As this one assembly structure, a fastening structure using mechanical fastening means such as a screw, an integrally joined structure by brazing, or the like can be adopted. In particular, the integrally joined structure by brazing allows the joints of the three parts of the condenser 13a, the gas-liquid separator 13b, and the supercooler 13c to be joined together at the same time in a brazing heating furnace, resulting in good productivity. .

  The other refrigerant passage 14 branched at the branch point 13e is connected to the inlet side of the ejector 15. The ejector 15 is a decompression means for decompressing the refrigerant, and is also a refrigerant circulation means (momentum transport pump) that circulates the refrigerant by a suction action of the refrigerant flow ejected at high speed.

  The ejector 15 includes a nozzle portion 15a for reducing the passage area of the high-pressure refrigerant (high-pressure saturated liquid refrigerant) flowing from the refrigerant passage 14 to a small pressure and expanding the high-pressure refrigerant in an isentropic manner, and a refrigerant outlet of the nozzle portion 15a. And a refrigerant suction port 15b for sucking a refrigerant (gas phase refrigerant) from an outlet of a second evaporator 19 to be described later.

  Further, on the downstream side of the nozzle portion 15a and the refrigerant suction port 15b, a mixing unit 15c that mixes the high-speed refrigerant flow from the nozzle portion 15a and the suction refrigerant from the refrigerant suction port 15b is provided. And the diffuser part 15d which makes | forms a pressure | voltage rise part is arrange | positioned downstream of the mixing part 15c. The diffuser portion 15d is formed in a shape that gradually increases the refrigerant passage area, and acts to decelerate the refrigerant flow to increase the refrigerant pressure, that is, to convert the velocity energy of the refrigerant into pressure energy. The first evaporator 16 is connected to the outlet side of the diffuser portion 15 d of the ejector 15, and the outlet side of the first evaporator 16 is connected to the suction side of the compressor 11.

  On the other hand, the downstream side of the subcooler 13 c is connected to the refrigerant suction port 15 b of the ejector 15 through the refrigerant passage 17. A throttle mechanism 18 is disposed in the refrigerant passage 17, and a second evaporator 19 is disposed on the downstream side of the throttle mechanism 18.

  The throttle mechanism 18 is a pressure reducing means for adjusting the flow rate of the refrigerant to the second evaporator 19, and can be specifically configured by a fixed throttle such as a capillary tube or an orifice. Further, the throttle mechanism 18 may be configured with a variable throttle that changes the passage throttle opening (passage area) according to the refrigerant temperature and pressure of the second evaporator 19. Note that an electric control valve whose passage throttle opening (valve opening) can be adjusted by an electric actuator may be used as the variable throttle.

  The aperture mechanism 18 and the ejector 15 are integrally configured as a decompression module 20 that forms one assembly structure. As the assembly structure of the decompression module 20, a fastening structure using a mechanical fastening means such as a screw or an integrally joined structure by brazing can be adopted.

  In the present embodiment, different cooling target spaces are cooled by the first evaporator 16 and the second evaporator 19, respectively. For example, the first evaporator 16 is used for cooling the interior of the vehicle, the air blown by an electric blower (not shown) is cooled by the first evaporator 16, and the cooling air (cold air) is blown out into the vehicle interior. Cool the room.

  On the other hand, the second evaporator 19 is used for cooling the in-vehicle refrigerator. Accordingly, the internal air blown by an electric blower (not shown) is cooled by the second evaporator 19, and the cooling air is recirculated into the internal compartment to cool the inside.

  The first evaporator 16 and the second evaporator 19 are combined to constitute one cooling unit, and this one cooling unit (that is, the combined unit of the first and second evaporators 16 and 19) is common. One space to be cooled may be cooled.

  Next, the operation of the first embodiment will be described. When the compressor 11 is driven by the vehicle engine, the high-temperature and high-pressure gas-phase refrigerant compressed and discharged by the compressor 11 first flows into the condenser 13 a of the subcooler-integrated condenser 13. In the condenser 13a, the high-temperature and high-pressure gas-phase refrigerant is cooled and condensed by outside air (air outside the vehicle compartment) blown by a cooling fan (not shown).

   The refrigerant that has passed through the condenser 13a flows into the gas-liquid separator 13b. In this gas-liquid separator 13b, the gas-liquid of the refrigerant condensed in the condenser 13a is separated. That is, using the difference in density between the gas-phase refrigerant and the liquid-phase refrigerant, the gas-phase refrigerant is separated above the internal space of the gas-liquid separator 13b, and the liquid-phase refrigerant is separated below the internal space. Here, since the gas-liquid interface of the refrigerant is formed in the internal space of the gas-liquid separator 13b, the saturated gas-phase refrigerant and the saturated liquid-phase refrigerant coexist.

  The gas-liquid separator 13b is provided with a liquid-phase refrigerant outlet passage 13d for taking out the saturated liquid-phase refrigerant, and a branch point 13e is set in the liquid-phase refrigerant outlet passage 13d. The flow of the phase refrigerant is branched into two, and the flow of one saturated liquid phase refrigerant flows into the ejector 15 through the refrigerant passage 14.

  The flow of the other saturated liquid phase refrigerant flows into the supercooler 13c and is supercooled. That is, in the supercooler 13c, the saturated liquid phase refrigerant flowing out from the gas-liquid separator 13b is cooled by the outside air (air outside the passenger compartment) blown by a cooling fan (not shown) and supercooled.

  The refrigerant flowing into the ejector 15 is decompressed and expanded by the nozzle portion 15a. Accordingly, the pressure energy of the refrigerant is converted into velocity energy at the nozzle portion 15a, and the refrigerant is ejected at a high velocity from the nozzle outlet of the nozzle portion 15a. The refrigerant (gas phase refrigerant) after passing through the second evaporator 19 is sucked from the refrigerant suction port 15b by the refrigerant suction action at this time.

  The refrigerant ejected from the nozzle portion 15a and the refrigerant sucked into the refrigerant suction port 15b are mixed in the mixing portion 15c on the downstream side of the nozzle portion 15a and flow into the diffuser portion 15d. In the diffuser portion 15d, the refrigerant speed is increased and the refrigerant pressure is increased by increasing the passage area.

  On the other hand, the supercooled liquid phase refrigerant after passing through the supercooler 13 c is decompressed by the throttle mechanism 18 of the refrigerant passage 17 to be in a low pressure gas-liquid two-phase state, and this low pressure refrigerant flows into the second evaporator 19. In the second evaporator 19, the refrigerant absorbs heat from the blown air of an electric blower (not shown) and evaporates. The gas-phase refrigerant after passing through the second evaporator 19 is sucked into the ejector 15 from the refrigerant suction port 15b.

  The low-pressure gas-liquid two-phase refrigerant that has flowed out of the diffuser portion 15 d of the ejector 15 flows into the first evaporator 16. In the first evaporator 16, the low-temperature low-pressure refrigerant absorbs heat from the blown air of the electric blower (not shown) and evaporates. The refrigerant that has passed through the first evaporator 16 is sucked into the compressor 11 and compressed again.

  As described above, according to the present embodiment, the refrigerant on the downstream side of the diffuser portion 15d of the ejector 15 is supplied to the first evaporator 16, and the refrigerant on the refrigerant passage 17 side is depressurized by the throttle mechanism 18 to thereby reduce the second evaporator 19. Therefore, the first and second evaporators 16 and 19 can simultaneously exert a cooling action.

  At that time, the refrigerant evaporating pressure of the first evaporator 16 is the pressure after the pressure is increased by the diffuser portion 15 d, while the outlet side of the second evaporator 19 is connected to the refrigerant suction port 15 b of the ejector 15. The lowest pressure immediately after the pressure reduction at the nozzle portion 15 a can be applied to the second evaporator 19.

  As a result, the refrigerant evaporation pressure (refrigerant evaporation temperature) of the second evaporator 19 can be made lower than the refrigerant evaporation pressure (refrigerant evaporation temperature) of the first evaporator 16 by an amount corresponding to the boosting action in the diffuser portion 15d. In the present embodiment, since the first evaporator 16 is used for cooling the vehicle interior and the second evaporator 19 is used for cooling the vehicle-mounted refrigerator, the cooling temperature in the vehicle-mounted refrigerator is made lower than the vehicle interior cooling temperature. be able to.

  Therefore, the cooling operation in the passenger compartment and the cooling operation in the refrigerator can be performed simultaneously in two high and low temperature ranges. At this time, since the suction pressure of the compressor 11 can be increased by the boosting action at the diffuser portion 15d of the ejector 15, the compression work of the compressor 11 can be reduced by the amount corresponding to the boosting action, and the power saving effect can be exhibited.

  Moreover, the refrigerant flow rate on the second evaporator 19 side can be independently adjusted by the throttle mechanism 18 without depending on the function of the ejector 15.

  Further, since the second evaporator 19 is arranged in parallel with the ejector 15, not only the refrigerant suction capability of the ejector 15 but also the refrigerant suction / discharge capability of the compressor 11 is used to supply the refrigerant to the second evaporator 19. It can circulate. Therefore, there is an advantage that it is easy to ensure the refrigerant flow rate of the second evaporator 19 and thus the refrigerating capacity of the second evaporator 19 even under an operating condition in which the input of the ejector 15 is small.

  On the other hand, according to the present embodiment, the saturated liquid phase refrigerant from the gas-liquid separator 13b outlet is supercooled by the supercooler 13c, and the supercooled liquid phase refrigerant is depressurized by the throttle mechanism 18 of the refrigerant passage 17 and then the second. It flows into the evaporator 19. Thereby, the enthalpy difference between the inlet and outlet of the second evaporator 19 can be enlarged by an amount corresponding to the supercooling in the supercooler 13c, and the refrigerating capacity of the second evaporator 19 can be improved.

  Moreover, since the supercooler 13c cools the high-pressure refrigerant by the outside air, as in the case of the cycle configuration using the internal heat exchanger, the superheat degree of the compressor suction refrigerant increases → the density of the compressor suction refrigerant decreases → the compressor A decrease in the discharge flow rate (mass flow rate) does not cause a decrease in the refrigeration capacity of the first and second evaporators 16 and 19. As a result, the refrigerating capacity of the second evaporator 19 can be improved without causing a decrease in cycle efficiency (COP).

  Further, since the saturated liquid phase refrigerant from the gas-liquid separator 13b is branched and introduced into the ejector 15, the saturated liquid phase refrigerant can be always flowed into the ejector 15, and the density of the ejector inflow refrigerant is stabilized. Thereby, the ejector performance can be stably exhibited for the reason described above.

(Second Embodiment)
In the first embodiment, a branch point 13e is set in the liquid-phase refrigerant outlet passage 13d of the gas-liquid separator 13b, and the flow of the saturated liquid-phase refrigerant is branched into two at the branch point 13e. The refrigerant flow is caused to flow into the ejector 15 through the refrigerant passage 14, but in the second embodiment, a branch point 21 is set in the refrigerant passage 17 on the outlet side of the subcooler 13c as shown in FIG. From the point 21, the supercooled liquid phase refrigerant is caused to flow into the ejector 15 through the refrigerant passage 14.

  According to the second embodiment, the supercooled liquid phase refrigerant supercooled by the supercooler 13c is decompressed by both the throttle mechanism 18 and the ejector 15, and is evaporated by the first and second evaporators 16 and 19. Compared to the first embodiment, the enthalpy difference between the inlet and outlet of the first evaporator 16 can be enlarged, and the refrigerating capacity of the first evaporator 16 can be improved.

(Third embodiment)
FIG. 3 shows a third embodiment. In the cycle configuration of the second embodiment, a throttle mechanism 22 is additionally installed upstream of the branch point 21 of the refrigerant passage 17. The diaphragm mechanism 22 may use either a fixed diaphragm or a variable diaphragm. In the third embodiment, the diaphragm mechanism 18, the diaphragm mechanism 22, and the ejector 15 are integrally configured as a decompression module 20.

  As a specific example of the throttle mechanism 22, if a temperature type expansion valve or an electric type expansion valve that controls the degree of superheat of the outlet refrigerant of the first evaporator 16 to a predetermined value is used, the return of the liquid refrigerant to the compressor 11 can be reliably prevented. it can.

(Fourth embodiment)
FIG. 4 shows a fourth embodiment, in which the throttle mechanism 22 of the third embodiment is arranged on the refrigerant passage 14 side downstream of the branch point 21.

  Also in the fourth embodiment, as a specific example of the throttle mechanism 22, if a temperature type expansion valve or an electric type expansion valve that controls the degree of superheat of the outlet refrigerant of the first evaporator 16 to a predetermined value is used, The return of liquid refrigerant can be reliably prevented.

(Fifth embodiment)
FIG. 5 shows a fifth embodiment in which the refrigerant passage 14 on the upstream side of the ejector 15 is connected to the outlet passage portion 13f of the condenser 13a. That is, the refrigerant passage 14 is connected between the outlet portion of the condenser 13a and the inlet portion of the gas-liquid separator 13b.

  Accordingly, in the fifth embodiment, the branch point 13g is set in the outlet passage portion 13f of the condenser 13a, the outlet refrigerant flow of the condenser 13a is branched into two, and one of the refrigerant flows enters the gas-liquid separator 13b. The other refrigerant flow passes through the refrigerant passage 14 and flows into the ejector 15.

  The refrigerant at the outlet of the condenser 13a may be in a gas-liquid two-phase state with a certain degree of dryness due to changes in cycle operating conditions, but is generally close to a saturated liquid phase state and has a low dryness. Since it is in a liquid two-phase state, the ejector performance is not significantly reduced as compared with the first embodiment. For the same reason, the refrigerating capacity of the first evaporator 16 is not greatly reduced as compared with the first embodiment.

(Sixth embodiment)
FIG. 6 shows a sixth embodiment. In the cycle configuration of the first embodiment of FIG. 1, the first evaporator 16 is eliminated, and instead, a low-pressure side gas-liquid separator 23 is provided on the downstream side of the ejector 15. ing. The gas-liquid separator 23 separates the gas-liquid of the low-pressure refrigerant on the downstream side of the ejector 15, stores liquid-phase refrigerant (saturated liquid-phase refrigerant), and sucks gas-phase refrigerant (saturated gas-phase refrigerant) into the compressor 11. Let it flow toward the side.

  Further, a liquid refrigerant outlet 24 for taking out a liquid phase refrigerant (saturated liquid phase refrigerant) is provided at the bottom of the gas-liquid separator 23 on the low pressure side, and the liquid refrigerant outlet 24 is provided with a check valve 25. A passage 26 is connected. The outlet of the refrigerant passage 26 is connected to a junction 27 between the downstream side of the throttle mechanism 18 and the upstream side of the evaporator 19. The check valve 25 allows the refrigerant to flow only in one direction from the liquid refrigerant outlet 24 toward the merging portion 27, and prevents the refrigerant flow in the opposite direction.

  FIG. 7 is a Mollier diagram of the refrigeration cycle according to the sixth embodiment, where point a is the state of refrigerant discharged from the compressor 11 (high pressure superheated refrigerant), and point b is the liquid phase of the high pressure side gas-liquid separator 13b. This is the refrigerant state (saturated liquid phase refrigerant) at the branch point 13e in the refrigerant outlet passage 13d. Point c is the state of the supercooled liquid phase refrigerant at the outlet of the supercooler 13c, and point d is the state of the low-pressure gas-liquid two-phase refrigerant at the outlet of the nozzle 15a of the ejector 15. Point e is the state of the low-pressure gas-liquid two-phase refrigerant at the outlet of the throttle mechanism 18, and point f is the state of the low-pressure gas-liquid two-phase refrigerant after merging at the merging point 27.

  The point g is the refrigerant state at the outlet of the evaporator 19. Point h is a refrigerant state after the suction refrigerant sucked from the outlet side of the evaporator 19 and the outlet refrigerant of the nozzle 15a are mixed. Point i indicates the refrigerant state after the mixed refrigerant is pressurized by the diffuser portion 15d.

  Point j is a saturated liquid phase refrigerant in the low-pressure side gas-liquid separator 23, and point k is a saturated gas-phase refrigerant in the low-pressure side gas-liquid separator 23. The pressure difference between point j and point f is the amount of pressure reduction due to the pressure loss of check valve 25 and refrigerant passage 26.

  FIG. 8 is a Mollier diagram of the refrigeration cycle according to the second embodiment (FIG. 2), and points a, c, d, e, g, i, and k indicate the same refrigerant state as in FIG. However, in FIG. 8, the enthalpy difference between the e point and the g point is the endothermic amount at the second evaporator 19, and the enthalpy difference between the i point and the k point is the endothermic amount at the first evaporator 16.

  The effects of the sixth embodiment will be described by comparing the Mollier diagrams of FIGS. 7 and 8. In the second embodiment (FIG. 2), the supercooled liquid refrigerant at the outlet of the supercooler 13c is branched into two flows. Thus, one supercooled liquid phase refrigerant is decompressed to the point d by the nozzle 15a of the ejector 15, and the other supercooled liquid phase refrigerant is decompressed to the point e by the throttle mechanism 18.

  7 and 8, ΔH1 and ΔH2 are refrigerant enthalpy differences before and after the nozzle 15a of the ejector 15. The refrigerant enthalpy differences ΔH1 and ΔH2 are expansion loss energy (hereinafter referred to as recovered energy) that can be recovered by the ejector 15. It is equivalent.

  In the case of the second embodiment, the supercooled liquid phase refrigerant supercooled by the supercooler 13c is depressurized by the nozzle 15a of the ejector 15. Therefore, the depressurization characteristic due to the isentropic change at the nozzle 15a is vertical on the Mollier diagram. As a result, the refrigerant enthalpy difference ΔH2 before and after the nozzle 15a becomes a relatively small value, and the recovered energy becomes small.

  On the other hand, in the sixth embodiment, since the saturated liquid phase refrigerant before being supercooled by the supercooler 13c is decompressed by the nozzle 15a of the ejector 15, as shown in FIG. 7, due to the isentropic change at the nozzle 15a. The pressure reduction characteristic is a characteristic that is inclined to the side away from the vertical line on the Mollier diagram than in the case of the second embodiment. As a result, the refrigerant enthalpy difference ΔH1 before and after the nozzle 15a becomes a relatively large value. That is, the relationship of ΔH1> ΔH2 is established, and the recovery energy in the ejector 15 increases, so that the efficiency of the ejector refrigeration cycle can be increased.

  On the other hand, in the fifth embodiment, as described above, the outlet refrigerant of the condenser 13a may be in a gas-liquid two-phase state having a certain degree of dryness due to a change in cycle operating conditions. In the sixth embodiment, The saturated liquid phase refrigerant separated by the high pressure side gas-liquid separator 13e can always be supplied to the nozzle 15a of the ejector 15, while the supercooled liquid phase refrigerant supercooled by the supercooler 13c is supplied to the throttle mechanism 18 side. Since the liquid refrigerant can be always supplied and the liquid refrigerant can be stably supplied, the refrigerant flow rate control to the ejector 15 side and the throttle mechanism 18 side becomes easier as compared with the case of supplying the gas-liquid two-phase refrigerant.

  When the supercooled liquid-phase refrigerant is decompressed by the nozzle 15a of the ejector 15 as in the second embodiment, the liquid-phase refrigerant almost passes through the throat (minimum passage diameter portion) of the nozzle 15a. The density of is large. Accordingly, in order to accurately control the flow rate of refrigerant passing through the nozzle, it is necessary to process the throat portion of the nozzle 15a with a small diameter and high accuracy, which increases the processing cost of the nozzle 15a.

  In contrast, in the sixth embodiment, since the saturated liquid phase refrigerant is decompressed by the nozzle 15a of the ejector 15, the saturated liquid phase refrigerant is transferred to the gas-liquid two phase refrigerant and the refrigerant density is reduced even with a slight amount of decompression. . Therefore, the diameter dimension of the throat portion of the nozzle 15a can be made larger than that in the second embodiment, the processing of the nozzle 15a is facilitated, and the processing cost of the nozzle 15a can be reduced. These effects can be exhibited not only in the sixth embodiment but also in the first embodiment.

  Furthermore, in the sixth embodiment, a low-pressure side gas-liquid separator 23 is provided as a configuration different from the first embodiment, and the liquid-phase refrigerant separated by the low-pressure side gas-liquid separator 23 and the throttle mechanism 18 are provided. Since both the gas-liquid two-phase refrigerant after passing are supplied to the second evaporator 19, a refrigerant having a high liquid-phase refrigerant ratio (a refrigerant having a low dryness) is always stably supplied to the second evaporator 19. It can supply and can contribute to the performance improvement of the 2nd evaporator 19. FIG.

  Further, since the gas-phase refrigerant separated by the low-pressure side gas-liquid separator 23 is supplied to the suction side of the compressor 11, the liquid refrigerant returns to the compressor 11 without controlling the superheat degree of the compressor suction refrigerant. Can be reliably prevented.

  Further, by providing the check valve 25, it is possible to reliably prevent the gas-liquid two-phase refrigerant that has passed through the throttle mechanism 18 from flowing directly into the low-pressure side gas-liquid separator 23.

(Seventh embodiment)
FIG. 9 shows the seventh embodiment, which corresponds to the cycle configuration of the sixth embodiment with the first evaporator 16 added.

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

  (1) In the above-described embodiment, an air-cooled cooling device in which the cooling fluid is air (outside air) is configured as a cooling device for the condenser 13a and the supercooler 13c, but the water-cooling type in which the cooling fluid is water. A cooling device may be configured, and the condenser 13a and the subcooler 13c may be cooled by the water-cooled cooling device.

  (2) An adsorption cooling device may be used as a cooling device for the condenser 13a and the subcooler 13c. In this adsorption cooling device, the cooling medium such as water undergoes a phase change (evaporation, condensation), so that the condenser 13a and the subcooler 13c can be cooled using latent heat (evaporation latent heat) at the time of the phase change of the cooling medium. .

  (3) In the first to fifth embodiments described above, the example in which the first evaporator 16 on the high temperature side and the second evaporator 19 on the low temperature side are provided has been described. However, the first evaporator 16 is eliminated. Thus, the present invention may be implemented in a cycle configuration in which only the second evaporator 19 on the low temperature side is provided.

  FIG. 10 shows this specific modification, and corresponds to a configuration in which the first evaporator 16 is eliminated in the cycle configuration of FIG. 1 (first embodiment).

  FIG. 11 shows still another modified example, which corresponds to a configuration in which a low-pressure side gas-liquid separator 23 is added to the cycle configuration of FIG.

  10 and 11 may be applied to the cycle configurations of FIGS. 2 to 5 in addition to the cycle configuration of FIG.

  Further, the first evaporator 16 on the high temperature side may be arranged in parallel with the ejector 15 instead of on the downstream side of the ejector 15. In this case, it is necessary to provide a throttle means dedicated to the first evaporator 16 separately from the ejector 15.

  (4) In the first to fifth embodiments described above, the example in which the first evaporator 16 on the high temperature side and the second evaporator 19 on the low temperature side are provided has been described, but both the evaporators 16 and 19 are provided. In addition, the present invention may be implemented in a cycle configuration in which a third evaporator that evaporates the refrigerant at the same evaporation temperature as that of the first evaporator 16 on the high temperature side is provided.

  (5) In each of the above-described embodiments, the throttle mechanism 18 and the ejector 15 are integrated as the decompression module 20 forming one assembly structure. However, the decompression module 20 is further integrated with the second evaporator 19. May be. Further, the evaporators 16 and 19 may be integrated, and the decompression module 20 may be further integrated with the integrated evaporators 16 and 19.

  (6) In each of the above-described embodiments, if an electric control valve such as a solenoid valve for opening and closing the passage is installed in the refrigerant passage 14 on the first evaporator 16 side and the refrigerant passage 17 on the second evaporator 19 side, The refrigerant flow to the first evaporator 16 and the second evaporator 19 can be freely selected.

  Here, if the throttle mechanism 18 of the refrigerant passage 17 is constituted by an electric control valve, the throttle mechanism 18 itself can also serve as a passage opening / closing valve means. Similarly, in the cycle configuration of the fourth embodiment (FIG. 4), if the throttle mechanism 22 of the refrigerant passage 14 is configured by an electric control valve, the throttle mechanism 22 itself can also serve as a passage opening / closing valve means. it can.

  (7) In each of the above-described embodiments, the ejector 15 is exemplified by the fixed ejector having the nozzle portion 15a having a constant passage area. However, as the ejector 15, the variable ejector having the variable nozzle portion capable of adjusting the passage area. 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.

It is a refrigerant circuit figure showing an ejector type refrigerating cycle by a 1st embodiment of the present invention. It is a refrigerant circuit diagram which shows the ejector-type refrigeration cycle by 2nd Embodiment. It is a refrigerant circuit figure which shows the ejector-type refrigerating cycle by 3rd Embodiment. It is a refrigerant circuit figure which shows the ejector type | mold refrigerating cycle by 4th Embodiment. It is a refrigerant circuit figure which shows the ejector-type refrigerating cycle by 5th Embodiment. It is a refrigerant circuit figure which shows the ejector-type refrigerating cycle by 6th Embodiment. It is a Mollier diagram of an ejector type refrigeration cycle according to a sixth embodiment. It is a Mollier diagram of an ejector type refrigeration cycle according to a second embodiment. It is a refrigerant circuit figure which shows the ejector-type refrigerating cycle by 7th Embodiment. It is a refrigerant circuit figure which shows the modification of 1st Embodiment. It is a refrigerant circuit figure which shows another modification of 1st Embodiment.

Explanation of symbols

11 ... Compressor, 13 ... Supercooler integrated condenser, 13a ... Condenser,
13b ... High pressure side gas-liquid separator, 13c ... Supercooler, 15 ... Ejector, 15a ... Nozzle part,
15b ... Refrigerant suction port, 15d ... Booster (diffuser part), 16 ... First evaporator,
18 ... throttle mechanism (throttle means), 19 ... second evaporator, 20 ... decompression module,
23 ... Low pressure side gas-liquid separator.

Claims (11)

A compressor (11) for sucking and compressing refrigerant;
A condenser (13a) for condensing the high-pressure refrigerant discharged from the compressor (11);
A high-pressure side gas-liquid separator (13b) for separating the gas-liquid of the outlet side refrigerant of the condenser (13a);
A supercooler (13c) for supercooling the saturated liquid refrigerant of the high-pressure side gas-liquid separator (13b);
A nozzle part (15a) that decompresses and expands the refrigerant downstream from the outlet part of the condenser (13a), and a refrigerant suction port (the refrigerant is sucked into the interior by a high-speed refrigerant flow injected from the nozzle part (15a)) 15b), and an ejector (15) having a pressure increasing portion (15d) for increasing the pressure by reducing the speed of the refrigerant flow obtained by mixing the high-speed refrigerant flow and the refrigerant sucked from the refrigerant suction port (15b) ,
Throttle means (18) for depressurizing the supercooled liquid refrigerant of the supercooler (13c);
An ejector refrigeration cycle comprising an evaporator (19) connected between a downstream side of the throttle means (18) and the refrigerant suction port (15b). A first evaporator (16) is connected to the downstream side of the ejector (14),
The ejector according to claim 1, wherein the evaporator on the downstream side of the throttle means (18) constitutes a second evaporator (19) having a refrigerant evaporation temperature lower than that of the first evaporator (16). Refrigeration cycle. A low-pressure side gas-liquid separator (23) for separating the gas-liquid of the downstream-side refrigerant of the ejector (15) and flowing out the gas-phase refrigerant to the suction side of the compressor (11) is provided. Item 2. An ejector refrigeration cycle according to Item 1. A low-pressure side gas-liquid separator (23) that separates the gas-liquid of the downstream-side refrigerant of the first evaporator (16) and flows out the gas-phase refrigerant to the suction side of the compressor (11) is provided. The ejector-type refrigeration cycle according to claim 2. The refrigerant passage (26) for supplying the liquid-phase refrigerant separated by the low-pressure side gas-liquid separator (23) to the evaporator (19) on the downstream side of the throttling means (18). 5. The ejector refrigeration cycle according to 3 or 4. The refrigerant passage (26) is provided with a check valve (25) that allows the refrigerant to flow only in one direction from the low-pressure side gas-liquid separator (23) to the evaporator (19). The ejector-type refrigeration cycle according to claim 5. The ejector type refrigeration cycle according to any one of claims 1 to 6, wherein a saturated liquid refrigerant of the high pressure side gas-liquid separator (13b) is introduced into the ejector (15). The ejector refrigeration cycle according to any one of claims 1 to 6, wherein the supercooled liquid refrigerant of the supercooler (13c) is introduced into the ejector (15). The ejector refrigeration cycle according to any one of claims 1 to 6, wherein an outlet refrigerant of the condenser (13a) is introduced into the ejector (15). The ejector refrigeration cycle according to any one of claims 1 to 9, wherein the ejector (15) and the throttle means (18) are configured as an integral structure. The ejector type according to any one of claims 1 to 10, wherein the condenser (13a), the gas-liquid separator (13b), and the supercooler (13c) are configured as an integral structure. Refrigeration cycle.

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