JP4704167B2 - Refrigeration cycle equipment - Google Patents

Description

  The present invention relates to a refrigeration cycle apparatus, and more particularly to a refrigeration cycle apparatus incorporating an ejector that reduces expansion loss.

  In recent years, it has become important to deal with the problem of global warming caused by an increase in the amount of carbon dioxide in the atmosphere. Even in air conditioners and refrigerators, demands for reducing energy consumption by improving efficiency are increasing. Conventionally, as shown in FIGS. 9 and 10, as shown in FIGS. Improvements in the efficiency of the refrigeration cycle have been studied.

  The refrigeration cycle 51 shown in FIG. 9 uses the pressure difference between the first gas-liquid separator 52 and the injection port of the compressor 53 to drive the ejector 54 and has a lower pressure than the first gas-liquid separator 52. The refrigerant vapor extracted from the second gas-liquid separator 55 is sucked and pressurized, and then injected into the compressor 53. As a result, the refrigerant circulation amount flowing into the evaporator 56 is reduced, and the efficiency of the evaporator 56 is reduced while reducing the input due to the pressure loss of the evaporator 56 path, thereby improving the efficiency. However, in this method, most of the expansion loss in the expansion stroke, which is one cause of the efficiency reduction of the refrigeration cycle, cannot be used, and as a result, the effect on improving the efficiency is limited.

  Further, the refrigeration cycle 61 shown in FIG. 10 drives the ejector 64 by utilizing the difference between the condensation pressure and the compressor suction pressure, and sucks and boosts the refrigerant at the outlet of the evaporator 66 to recover the expansion work and compress the refrigerant vapor. Are simultaneously performed to reduce the input of the compressor 63. However, with this method, when the work of expansion decreases due to changes in usage conditions such as outside temperature and air conditioning temperature, or when the pressure loss in the evaporator path increases, the refrigerant suction amount decreases and efficiency decreases. There was something to do.

In addition, in patent document 1 and patent document 2, the proposal regarding the improvement of the refrigerating-cycle apparatus incorporating an ejector is made | formed for efficiency improvement.
JP 2003-83620 A JP 2004-108615 A

  The present invention has been made in consideration of the above-described circumstances, and an object of the present invention is to provide a refrigeration cycle apparatus capable of reducing the expansion loss in the refrigeration cycle and improving the efficiency irrespective of operating conditions and installation conditions. And

In order to achieve the above-described object, a refrigeration cycle apparatus according to the present invention sequentially connects a compressor, a condenser, a supercooling heat exchanger, an expansion device, an evaporator, and an ejector, and has one end connected to the condenser and the expansion. A bypass passage connected between the apparatuses and having the other end connected to the inlet side of the ejector drive nozzle of the ejector, the outlet side of the evaporator is connected to the suction portion of the ejector, and the diffuser of the ejector connect the outlet side to the suction side of the compressor and provided with a second expansion device in the bypass passage, the refrigerant in the second expansion device outlet and a refrigerant heat exchanger of the supercooling heat exchanger Thereafter, the refrigerant in the subcooling heat exchanger is cooled by the refrigerant in the bypass passage so as to be guided to the inlet side of the ejector .

  According to the refrigeration cycle apparatus according to the present invention, it is possible to provide a refrigeration cycle apparatus capable of reducing the expansion loss in the refrigeration cycle and improving the efficiency irrespective of the operating conditions and the installation conditions.

  Hereinafter, a refrigeration cycle apparatus according to a first embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a configuration diagram of a refrigeration cycle apparatus according to the first embodiment of the present invention.

  As shown in FIG. 1, the refrigeration cycle apparatus 1 of the first embodiment includes a compressor 2, a condenser 3, a supercooling heat exchanger 4, an expansion device 5, an evaporator 6, an ejector 7, and a supercooling heat exchanger. 4. The compressor 2 is configured to be sequentially connected in a circle by the refrigerant passage 8.

  Further, the refrigeration cycle apparatus 1 is provided with a bypass passage 9, and the bypass passage 9 connects between the condenser 3 and the expansion device 5 and the inlet side of the ejector drive nozzle 7 a of the ejector 7. Further, the outlet side of the evaporator 6 is connected to the suction part 7b of the ejector 7, and the outlet side of the diffuser 7c of the ejector 7 is connected to the suction side of the compressor 2 through the supercooling heat exchanger 4 in a heat transfer manner. To do. In addition, the arrow in a figure shows the flow of a refrigerant | coolant.

  FIG. 2 is a Mollier diagram (pressure-enthalpy diagram) for explaining the refrigeration cycle of the refrigeration cycle apparatus of the first embodiment. Each point of (1) to (10) shown in FIG. Corresponds to the points (1) to (10) of the refrigeration air conditioner described in FIG. 1, and represents the pressure-enthalpy state at each position.

  That is, (1) is the outlet of the compressor 2, (2) is the outlet of the condenser 3, (3) is the outlet of the supercooling heat exchanger 4, (4) is the inlet of the evaporator 6, ( 5) is an outlet portion of the evaporator 6, (6) is a suction portion 7b of the ejector 7, (7) is a mixing portion of the ejector 7, (8) is an outlet portion of the diffuser 7c of the ejector 7, and (9) is supercooled. An outlet part on the cooling side of the heat exchanger 4, (10) is an outlet part of the ejector drive nozzle 7a.

  As shown in FIGS. 1 and 2, according to the refrigeration cycle apparatus of the first embodiment having the above-described configuration, as shown by arrows in the drawing, a high-temperature and high-pressure refrigerant discharged from the compressor 2, for example, The vapor of R410A has the highest pressure and enthalpy (point (1) in the figure), is condensed by the condenser 3 to become a liquid refrigerant (point (2) in the figure), and further cooled by the supercooling heat exchanger 4 (Point (3) in the figure), the pressure is reduced by the expansion device 5 (point (4) in the figure), flows into the evaporator 6 (point (4) in the figure), and evaporates in the evaporator 6 to evaporate. 6 to the exit portion (point (5) in the figure).

  On the other hand, a part of the refrigerant on the outlet side of the condenser 3 (point (2) in the figure) flows into the ejector drive nozzle 7a, obtains a speed, is reduced in pressure (point (10) in the figure, and flows out from the evaporator 6). The refrigerant (point (6) in the figure) guided to the suction section 7b of the ejector 7 is sucked in. The refrigerant flowing out from the ejector drive nozzle 7a and the refrigerant sucked from the suction section 7b in the ejector 7 are mixed in the ejector 7 mixing section. 7d (point (7) in the figure) and the pressure is increased by Δp1 by the diffuser 7c of the ejector 7. The refrigerant (point (8) in the figure) boosted by the diffuser 7c of the ejector 7 is a supercooling heat exchanger. After being heated and vaporized on the cooling side 4 (point (9) in the figure), the flow returns to the compressor 2.

  On the other hand, the remaining refrigerant is sucked into the compressor 2 after the low-pressure refrigerant has been boosted by the ejector 7 in this way, so that the amount of compression work in the compressor 2 is reduced. In addition, the pressure loss corresponding to the suction part 7b of the ejector 7 is carried in from the evaporator exit supposing the separation-type air conditioner in the refrigerating cycle.

  As described above, according to the present embodiment, a refrigeration cycle that can efficiently recover the expansion work of the refrigeration cycle and reduce the compression work regardless of the operating conditions and the installation conditions is realized. .

  Next, a refrigeration cycle apparatus according to a second embodiment of the present invention will be described.

  In the first embodiment, the supercooling heat exchanger exchanges heat with the refrigerant on the ejector outlet side, whereas in the second embodiment, the supercooling heat exchanger includes a refrigerant in the bypass passage provided with the second expansion device. Exchange heat.

  For example, as shown in FIG. 3, in the refrigeration cycle apparatus 11 of the second embodiment, a bypass passage 19 is provided, and by this bypass passage 19, the ejector is driven between the condenser 3 and the first expansion device 5 </ b> A and the ejector 7. The inlet side of the nozzle 7a is connected. The bypass passage 19 is provided with a second expansion device 5 </ b> B, and is further configured to exchange heat with the refrigerant of the supercooling heat exchanger 4 by the refrigerant of the bypass passage 19. In addition, since another structure is not different from the refrigerating cycle apparatus shown in FIG. 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  Accordingly, the refrigerant vapor discharged from the compressor 2 is condensed by the condenser 3, and after a part of the refrigerant is decompressed by the second expansion device 5B and the refrigerant of the supercooling heat exchanger 4 is cooled, the ejector drive nozzle 7a The refrigerant flowing in the evaporator 6 is compressed while sucking out the refrigerant flowing out of the evaporator 6, and the remaining refrigerant is cooled by the supercooling heat exchanger 4, then depressurized by the first expansion device 5 </ b> A and flows into the evaporator 6. . Thereby, the refrigerant | coolant which cooled the supercooling heat exchanger with the intermediate pressure collect | recovers the expansion work which decompresses to a low pressure, and can reduce a compressor input by pressurizing an evaporator exit refrigerant | coolant.

  In the present embodiment, the refrigerant flowing into the supercooling heat exchanger is branched from the condenser outlet, but may be branched from the outlet side of the supercooling heat exchanger.

  A refrigeration cycle apparatus according to the third embodiment of the present invention will be described.

  The third embodiment is obtained by adding the first embodiment to the second embodiment, that is, a bypass passage in which the first supercooling heat exchanger includes the second expansion device as in the second embodiment. Similarly to the first embodiment, the second supercooling heat exchanger exchanges heat with the refrigerant in the refrigerant passage connected to the outlet side of the ejector and the suction side of the compressor.

  For example, as shown in FIG. 4, in the refrigeration cycle apparatus 21 of the third embodiment, one end is connected between the condenser 3 and the first expansion device 5A, and the other end is the inlet side of the ejector drive nozzle 7a of the ejector 7. The bypass passage 19 connected to the second expansion device 5B is provided to further exchange heat between the refrigerant in the bypass passage 19 and the refrigerant in the first subcooling heat exchanger 4A. Further, the refrigerant passage 8 is connected to the outlet side of the diffuser 7c of the ejector 7 and the suction side of the compressor 2, and the refrigerant on the outlet side of the diffuser 7c exchanges heat with the refrigerant of the second supercooling heat exchanger 4B. Further, the suction part 7 b of the ejector 7 is connected to the evaporator 6.

  Therefore, a second supercooling heat exchanger is added and cooled by the refrigerant on the ejector outlet side. As a result, the state of the refrigerant at the ejector outlet becomes a gas-liquid two-phase state, preventing liquid from returning to the compressor, and at the same time increasing the amount of supercooling, thereby reducing the amount of refrigerant circulating in the evaporator. Thus, loss due to pressure loss can be reduced and efficiency can be improved. Moreover, in this 3rd Embodiment, the cooling temperature of a subcooling heat exchanger is made into multiple, and an expansion work is driven by driving the corresponding ejector with the refrigerant | coolant of the intermediate pressure heated with each subcooling heat exchanger. It can be recovered efficiently.

  A refrigeration cycle apparatus according to a fourth embodiment of the present invention will be described.

  In the fourth embodiment, a second ejector is provided between the suction port of the ejector of the third embodiment and the evaporator 6.

  For example, as shown in FIG. 5, in the refrigeration cycle apparatus 31 of the fourth embodiment, one end of the suction unit 7Ab of the first ejector 7A connected in the same manner as the third embodiment is connected to the condenser 3 and the first The second ejector 7B, to which the ejector drive nozzle 7Ba is connected, is connected to the second bypass passage 19B connected between the expansion devices 5A, and the outlet of the evaporator 6 is connected to the second ejector 7B suction part 7Bb. The side is connected.

  FIG. 6 is a Mollier diagram (pressure-enthalpy diagram) for explaining the refrigeration cycle of the refrigeration cycle apparatus of the fourth embodiment. Each point of (11) to (24) shown in FIG. Corresponds to the points (11) to (24) of the refrigeration air conditioner described in FIG. 5 and represents the pressure-enthalpy state at each position.

  That is, (11) is the outlet of the compressor 2, (12) is the outlet of the condenser 3, (13) is the outlet of the first subcooling heat exchanger 4A, and (14) is the second subcooling. The outlet part of the heat exchanger 4B, (15) is the inlet part of the evaporator 6, (16) is the outlet part of the evaporator 6, (17) is the suction part 7Bb of the second ejector 7B, and (18) is the second part. (19) is the outlet of the diffuser 7Ac of the first ejector 7A, (20) is the outlet of the cooling side of the second supercooling heat exchanger 4B, and (21) is the outlet of the diffuser 7Bc of the ejector 7B. The outlet part of the ejector driving nozzle 7Ba of the second ejector 7B, (22) the outlet part of the second expansion device 5B, (23) the outlet part on the cooling side of the first subcooling heat exchanger 4A, (24 ) Is the outlet of the ejector drive nozzle 7Aa of the first ejector 7A.

  Accordingly, as can be seen from the state diagram of the refrigeration cycle according to the fourth embodiment shown in FIG. 6, both the boost Δp2 by the first ejector 7A and the boost Δp3 by the second ejector 7B are obtained. Compared with the state diagram of the refrigeration cycle of the first embodiment shown, the amount of pressurization by the ejector is increased, the compression work is further reduced, the recovery of the expansion work is further increased, and the efficiency is improved. FIG. 7 shows a gas pressure loss-COP comparison result of the fourth embodiment, a conventional example of a refrigeration cycle equipped with an ejector, and a refrigeration cycle not equipped with an ejector. As can be seen from FIG. 7, in the conventional ejector cycle shown in FIG. 10, when the pressure loss of the evaporator outlet pipe increases, the efficiency is remarkably lowered, and there is a region that is worse than the normal refrigeration cycle. In the ejector cycle of the embodiment, the efficiency is higher than that of a normal refrigeration cycle over the entire region. The comparison shown in FIG. 7 is an efficiency comparison result under specific operating conditions. When the recoverable work amount in the ejector is reduced due to a decrease in the condensation temperature or an increase in the evaporation temperature, a lower pressure is obtained. The loss reduces the efficiency of the conventional ejector cycle.

  In addition, a refrigeration cycle apparatus according to a fifth embodiment of the present invention will be described.

  The fifth embodiment adds a third supercooling heat exchanger to the fourth embodiment, one end is connected between the condenser and the expansion device, the other end is connected to the suction side of the compressor, and A second bypass passage having a third expansion device is provided to exchange heat with the third supercooling heat exchanger.

  For example, as shown in FIG. 8, in the refrigeration cycle apparatus 41 of the fifth embodiment, one end is connected between the condenser 3 and the first expansion device 5A, and the other end is connected to the suction side of the compressor 2 and The third bypass passage 19C provided with the third expansion device 5C is provided to exchange heat with the third supercooling heat exchanger 5C.

  Thereby, the amount of supercooling can be further increased and the efficiency of the refrigeration cycle can be increased.

  In each of the above embodiments, only one of cooling or heating is shown in the refrigeration cycle configuration, but a four-way valve or the like can be appropriately configured as a reversible cycle. Moreover, although each component, such as an ejector and a supercooling heat exchanger, is individually illustrated for convenience, if the refrigeration cycle function is the same, the configuration can be simplified by integration or the like.

The block diagram of the refrigerating-cycle apparatus which concerns on 1st Embodiment of this invention. The Mollier diagram of the refrigerating cycle device concerning a 1st embodiment of the present invention. The block diagram of the refrigerating-cycle apparatus which concerns on 2nd Embodiment of this invention. The block diagram of the refrigerating-cycle apparatus which concerns on 3rd Embodiment of this invention. The block diagram of the refrigerating-cycle apparatus which concerns on 4th Embodiment of this invention. The Mollier diagram of the refrigerating cycle device concerning a 4th embodiment of the present invention. The gas pressure loss-COP diagram of the refrigerating cycle device concerning a 4th embodiment of the present invention. The block diagram of the refrigerating-cycle apparatus which concerns on 5th Embodiment of this invention. The block diagram of the conventional refrigeration cycle apparatus. The block diagram of the conventional refrigeration cycle apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Refrigeration cycle apparatus, 2 ... Compressor, 3 ... Condenser, 4 ... Supercooling heat exchanger, 5 ... Expansion device, 6 ... Evaporator, 7 ... Ejector, 7a ... Ejector drive nozzle, 7b ... Suction port, 7c ... diffuser, 8 ... refrigerant passage, 9 ... bypass passage.

Claims (2)

A compressor, a condenser, a supercooling heat exchanger, an expansion device, an evaporator, and an ejector are sequentially connected, and one end is connected between the condenser and the expansion device, and the other end is an ejector drive nozzle of the ejector. a bypass passage is provided which is connected to the inlet side, connect connect vital outlet side of the evaporator to the suction portion of the ejector, the outlet side of the diffuser of the ejector to the suction side of the compressor and of the bypass passage The second expansion device is provided with the refrigerant in the bypass passage so that the refrigerant on the outlet side of the second expansion device is exchanged with the refrigerant of the supercooling heat exchanger and then guided to the inlet side of the ejector. The refrigerant of the supercooling heat exchanger is cooled by the refrigeration cycle apparatus characterized by the above. A second supercooling heat exchanger is provided between the supercooling heat exchanger and the expansion device, and the refrigerant on the ejector outlet side exchanges heat with the refrigerant of the second supercooling heat exchanger, and then the suction side of the compressor 2. The refrigeration cycle apparatus according to claim 1, wherein

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