Refrigerator

Abstract

In a refrigerator, there are provided a compressor that compresses refrigerant, a condenser that condenses the refrigerant compressed by the compressor, an expander that expands the refrigerant condensed by the condenser, a liquid film type evaporator that evaporates the refrigerant expanded by the expander, and an ejector that sucks the refrigerant stored in the evaporator by generating a flow velocity difference and a pressure difference in the refrigerant expanded by the expander.

Description

Technical Field

[0001] This invention relates to a refrigeration machine equipped with a liquid film evaporator. Background Technology

[0002] A refrigeration unit consists of a compressor, a condenser, an expansion valve, and an evaporator. In the refrigeration cycle, the compressor compresses the refrigerant; the condenser condenses the high-temperature, high-pressure refrigerant through heat exchange; the expansion valve expands the condensed liquid refrigerant; and the evaporator evaporates the refrigerant by exchanging heat with the medium being cooled. Evaporators are used, for example, to cool the interior of a freezer.

[0003] As evaporators used in refrigeration units, there are flooded evaporators. In a flooded evaporator, heat transfer tubes are immersed in liquid refrigerant within the casing, and the liquid refrigerant evaporates through pool boiling. Therefore, a large amount of liquid refrigerant needs to be stored inside the casing, leading to increased costs. On the other hand, there are film evaporators. In a film evaporator, liquid refrigerant evaporates by flowing downwards through heat transfer tubes within the casing. Therefore, it is not necessary to store a large amount of liquid refrigerant inside the casing, reducing the amount of refrigerant required.

[0004] As a conventional evaporator, there are, for example, the evaporator described in the following patent documents.

[0005] Previous technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2019-158203

[0008] Patent Document 2: Japanese Patent Application Publication No. 2004-239493 Summary of the Invention

[0009] The technical problem to be solved by the invention

[0010] The aforementioned liquid film evaporator requires the refrigerant liquid exceeding the evaporation rate to flow downwards through the heat transfer tubes, while the unevaporated refrigerant liquid is stored in the lower part of the casing. Therefore, it is necessary to circulate the unevaporated refrigerant liquid to the upper part of the casing via a pump or the like, which leads to the problem of increasing the size and cost of the device.

[0011] The purpose of this invention is to solve the above-mentioned problems and to provide a refrigerator that reduces the size and cost of the suppression device.

[0012] means for solving technical problems

[0013] The refrigeration machine of the present invention for achieving the above-mentioned objectives comprises: a compressor for compressing a refrigerant; a condenser for condensing the refrigerant compressed by the compressor; an expander for expanding the refrigerant condensed by the condenser; a liquid film evaporator for evaporating the refrigerant expanded by the expander; and an ejector for drawing the refrigerant stored in the evaporator by utilizing the pressure difference between the inlet and outlet.

[0014] Invention Effects

[0015] The refrigeration machine according to the present invention can suppress the increase in size and cost of the device. Attached Figure Description

[0016] Figure 1 This is a schematic structural diagram of the refrigeration unit according to the first embodiment.

[0017] Figure 2 This is a schematic structural diagram of the refrigeration unit according to the second embodiment.

[0018] Figure 3 This is a schematic structural diagram of the refrigeration unit according to the third embodiment.

[0019] Figure 4 This is a schematic structural diagram of the refrigeration unit according to the fourth embodiment.

[0020] Figure 5 This is a schematic structural diagram of the refrigeration unit according to the fifth embodiment.

[0021] Figure 6 This is a schematic structural diagram of the refrigeration unit according to the sixth embodiment. Detailed Implementation

[0022] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to these embodiments, and when multiple embodiments exist, it also includes embodiments formed by combining various embodiments. Furthermore, the constituent elements in the embodiments include elements readily conceived by those skilled in the art, substantially identical elements, and elements of so-called equivalent scope.

[0023] [First Implementation]

[0024] <Structure of a Refrigeration Unit>

[0025] Figure 1 This is a schematic structural diagram of the refrigeration unit according to the first embodiment.

[0026] In the first embodiment, such as Figure 1As shown, the refrigeration unit 10 includes a compressor 11, a condenser 12, an expansion valve (expander) 13, an evaporator 14, and an ejector 15. Additionally, a subcooler (heat exchanger) may be installed between the condenser 12 and the expansion valve 13.

[0027] Compressor 11 is a single-stage compressor, for example, driven by electric motor 21. Compressor 11 is connected to condenser 12 via refrigerant path 31. Compressor 11 compresses refrigerant gas (refrigerant) 101 to generate high-temperature, high-pressure refrigerant gas (refrigerant) 102. Condenser 12 is connected to expansion valve 13 via refrigerant path 32. Condenser 12 condenses the high-temperature, high-pressure refrigerant gas 102 compressed by compressor 11, thereby generating refrigerant liquid (refrigerant) 103. Expansion valve 13 is connected to ejector 15 via refrigerant path 33. Expansion valve 13 expands by depressurizing the refrigerant liquid 103 condensed by condenser 12, thereby generating low-pressure refrigerant liquid (refrigerant) 104.

[0028] The ejector 15 is connected to the evaporator 14 via the refrigerant path 34. The ejector 15 injects low-pressure refrigerant liquid 104, expanded by the expansion valve 13, as refrigerant liquid (refrigerant) 105 into the refrigerant path 34. At this time, the ejector 15 utilizes the pressure difference between the refrigerant liquid 104 and the refrigerant liquid (refrigerant) 105 to draw refrigerant liquid (refrigerant) 106 stored in the evaporator 14. The evaporator 14 is connected to the compressor 11 via the refrigerant path 35. The evaporator 14 is a liquid film type. Furthermore, the refrigerant liquids 104 and 105 are either liquid refrigerant or two-phase refrigerant.

[0029] The evaporator 14 includes a housing 22, a plurality of heat transfer tubes 23, a refrigerant supply section 24, and a refrigerant discharge section 25. The housing 22 has a plurality of heat transfer tubes 23 disposed inside it. The plurality of heat transfer tubes 23 are arranged horizontally and spaced apart from each other at predetermined intervals. The cooling medium flows through the interior of the plurality of heat transfer tubes 23. The refrigerant supply section 24 is located at the upper part of the housing 22 and is connected to the downstream end of the refrigerant path 34. The refrigerant discharge section 25 is disposed adjacent to the refrigerant supply section 24 at the upper part of the housing 22. The refrigerant discharge section 25 is connected to the upstream end of the refrigerant path 35. Furthermore, the lower part of the housing 22 and the ejector 15 are connected via a refrigerant path 36.

[0030] Although not shown, the ejector 15 typically includes a main body, a diffuser, and a nozzle. In the ejector 15, the diffuser is connected to the main body, and the nozzle is located within the main body. Furthermore, the refrigerant path 36 is connected to the main body, the refrigerant path 34 is connected to the diffuser, and the refrigerant path 33 is connected to the nozzle. Therefore, if refrigerant liquid 104 from the refrigerant path 33 is ejected at high speed from the nozzle, it is discharged as refrigerant liquid 105 from the diffuser into the refrigerant path 34. At this time, the interior of the main body becomes low-pressure, drawing in refrigerant liquid 106 via the refrigerant path 36, and discharging it as refrigerant liquid 105 from the diffuser into the refrigerant path 34. However, the ejector 15 is not limited to this structure.

[0031] Evaporator 14 evaporates refrigerant liquid 105 containing refrigerant liquid 106 to generate refrigerant gas (refrigerant) 101. Refrigerant supply section 24 causes refrigerant liquid 105 supplied from refrigerant path 34 to flow downwards within housing 22. The downwardly flowing refrigerant liquid 105 comes into contact with multiple heat transfer tubes 23 through which the cooled medium flows, a portion of which evaporates to become refrigerant gas 101, and the remainder becomes refrigerant liquid 106 stored in the lower part of housing 22.

[0032] <Refrigeration Cycle of a Refrigeration Machine>

[0033] The refrigeration cycle based on the refrigerator 10 is a single-stage refrigeration cycle. The compressor 11 compresses the refrigerant gas 101 from the evaporator 14, transforming it into a high-temperature, high-pressure refrigerant gas 102 (compression stroke). The condenser 12 condenses the high-temperature, high-pressure refrigerant gas 102, transforming it into a refrigerant liquid 103 (condensation stroke). The expansion valve 13 expands the condensed refrigerant liquid 103, transforming it into a low-pressure refrigerant liquid 104 (expansion stroke). The ejector 15 ejects the low-pressure refrigerant liquid 104 towards the evaporator 14. In this way, the suction force generated by the ejection of the refrigerant liquid 104 acts on the refrigerant path 36, drawing the refrigerant liquid 106 stored in the lower part of the evaporator 14 through the refrigerant path 36. That is, the ejector 15 supplies the refrigerant liquid 106 stored in the evaporator 14 together with the refrigerant liquid 104 expanded by the expansion valve 13 to the evaporator 14. The evaporator 14 allows refrigerant liquid 105 to flow downwards from the refrigerant supply section 24, and brings the liquid phase of the refrigerant liquid 105 into contact with a plurality of heat transfer tubes 23, thereby generating refrigerant gas 101 (evaporation stroke), which is then supplied to the compressor 11. Furthermore, in the evaporator 14, unevaporated refrigerant liquid 106 is stored in the lower part of the housing 22, but as described above, it returns to the refrigerant supply section 24 via the ejector 15.

[0034] Here, the temperature and pressure of the refrigerant liquid 105 supplied to the evaporator 14 need to be adjusted to a specified temperature and pressure. Conventionally, the temperature or pressure of the refrigerant liquid 105 supplied to the evaporator 14 is adjusted by reducing the pressure by expanding the refrigerant liquid 103 using the expansion valve 13. On the other hand, in the first embodiment, the temperature or pressure of the refrigerant liquid 105 supplied to the evaporator 14 is adjusted by reducing the pressure by expanding the refrigerant liquid 103 using the expansion valve 13 and the ejector 15. That is, a portion of the pressure loss in the expansion valve 13, which was previously wasted, is used as the working power for the ejector 15. Therefore, without using an additional pump or the like, the refrigerant liquid 106 stored in the lower part of the evaporator 14 can be returned to the refrigerant supply section 24. In addition, it is also possible to adjust the opening degree of the expansion valve 13, thereby making it possible to adjust the distribution of the pressure reduction caused by the expansion valve 13 and the ejector 15.

[0035] [Second Implementation]

[0036] Figure 2 This is a schematic structural diagram of the refrigerator according to the second embodiment. Furthermore, components having the same functions as those in the first embodiment described above are labeled with the same symbols, and detailed descriptions are omitted.

[0037] In the second embodiment, such as Figure 2 As shown, the refrigeration unit 10A includes a compressor 41, a condenser 12, an expansion valve 42, an evaporator 14, an ejector 15, and an economizer (first gas-liquid separator) 43.

[0038] Compressor 41 is a multi-stage compressor (a two-stage compressor in this embodiment), having a first compressor 51 and a second compressor 52. Compressor 41 is driven, for example, by an electric motor 21. The first compressor 51 and the second compressor 52 are connected via a refrigerant path 53. The second compressor 52 is connected to the condenser 12 via a refrigerant path 31. Compressor 41 compresses the refrigerant gas 101 to generate a high-temperature, high-pressure refrigerant gas 102.

[0039] The condenser 12 condenses the high-temperature, high-pressure refrigerant gas 102 compressed by the compressor 41, thereby generating refrigerant liquid 103. The expansion valve 42 has a first expansion valve 54 and a second expansion valve 55. The first expansion valve 54 and the second expansion valve 55 are arranged in series in the discharge path of the refrigerant liquid 103 condensed by the condenser 12. An economizer 43 is disposed between the first expansion valve 54 and the second expansion valve 55. That is, the condenser 12 is connected to the first expansion valve 54 via refrigerant path 32. The first expansion valve 54 is connected to the economizer 43 via refrigerant path 56. The economizer 43 is connected to the second expansion valve 55 via refrigerant path 57 and to refrigerant path 53 via refrigerant path 58. The second expansion valve 55 is connected to the ejector 15 via refrigerant path 33.

[0040] The first expansion valve 54 reduces pressure by expanding the refrigerant liquid 103 condensed by the condenser 12, thereby generating a low-pressure refrigerant liquid (refrigerant) 111. The economizer 43 separates the low-pressure refrigerant liquid 111 into refrigerant liquid (refrigerant) 112 and refrigerant gas (refrigerant) 113. The second expansion valve 55 reduces pressure by expanding the refrigerant liquid 112, thereby generating a low-pressure refrigerant liquid 104. On the other hand, the refrigerant gas 113 is supplied to the second compressor 52.

[0041] The ejector 15 is connected to the refrigerant supply section 24 of the evaporator 14 via the refrigerant path 34, and is connected to the lower part of the housing 22 via the refrigerant path 36. The ejector 15 injects low-pressure refrigerant liquid 104, expanded by the second expansion valve 55, as refrigerant liquid 105 into the refrigerant path 34. At this time, the ejector 15 draws refrigerant liquid 106 stored in the evaporator 14 by generating a flow rate difference and a pressure difference in the refrigerant liquid 104.

[0042] Evaporator 14 is connected to compressor 11 via refrigerant path 35. Evaporator 14 is a liquid film type. Evaporator 14 evaporates refrigerant liquid 105 containing refrigerant liquid 106 to generate refrigerant gas 101. A portion of refrigerant liquid 105 evaporates to become refrigerant gas 101 and is supplied to compressor 41, while the remainder becomes refrigerant liquid 106 stored in the lower part of housing 22.

[0043] The refrigeration cycle based on the refrigerator 10A is a two-stage compression and two-stage expansion refrigeration cycle. The compressor 41 compresses the refrigerant gas 101 from the evaporator 14, transforming it into a high-temperature, high-pressure refrigerant gas 102. The condenser 12 condenses the high-temperature, high-pressure refrigerant gas 102, transforming it into a refrigerant liquid 103. The first expansion valve 54 expands the condensed refrigerant liquid 103, transforming it into a low-pressure refrigerant liquid 111. The economizer 43 separates the low-pressure refrigerant liquid 111 into refrigerant liquid 112 and refrigerant gas (refrigerant) 113, and supplies the refrigerant gas 113 to the second compressor 52. The second expansion valve 55 depressurizes the refrigerant liquid 112 by expanding it, thereby generating a low-pressure refrigerant liquid 104. The ejector 15 sprays the low-pressure refrigerant liquid 104 towards the evaporator 14 and draws in the refrigerant liquid 106 from the lower part of the evaporator 14. That is, the ejector 15 supplies the refrigerant liquid 106 stored in the evaporator 14 together with the refrigerant liquid 104 expanded by the expansion valve 13 to the evaporator 14. The evaporator 14 evaporates a portion of the refrigerant liquid 105 to generate refrigerant gas 101, which is then supplied to the compressor 11. Furthermore, in the evaporator 14, the unevaporated refrigerant liquid 106 is stored in the lower part of the housing 22, but returns to the refrigerant supply section 24 through the ejector 15.

[0044] [Third Implementation]

[0045] Figure 3 This is a schematic structural diagram of the refrigerator according to the third embodiment. Furthermore, components having the same functions as those in the second embodiment described above are labeled with the same symbols, and detailed descriptions are omitted.

[0046] In the third embodiment, such as Figure 3 As shown, the refrigeration unit 10B includes a compressor 41, a condenser 12, an expansion valve 44, an evaporator 14, an ejector 15, and an economizer (first heat exchanger) 45.

[0047] Compressor 41 has a first compressor 51 and a second compressor 52. The first compressor 51 and the second compressor 52 are connected via a refrigerant path 53. The second compressor 52 is connected to the condenser 12 via a refrigerant path 31. Compressor 41 compresses refrigerant gas 101 to generate high-temperature and high-pressure refrigerant gas 102.

[0048] The condenser 12 condenses the high-temperature, high-pressure refrigerant gas 102 compressed by the compressor 41, thereby generating refrigerant liquid 103. The expansion valve 44 has a first expansion valve 61 and a second expansion valve 62. The first expansion valve 61 and the second expansion valve 62 are arranged side-by-side in the discharge path of the refrigerant liquid 103 condensed by the condenser 12. An economizer 45 is disposed between the first expansion valve 61 and the second expansion valve 62. That is, the condenser 12 is connected to two branching refrigerant paths 63 and 64. One refrigerant path 63 is connected to the first expansion valve 61, which is connected to refrigerant path 53 via refrigerant path 65. The other refrigerant path 64 is connected to the second expansion valve 62, which is connected to the ejector 15 via refrigerant path 33. The economizer 45 is disposed between refrigerant paths 64 and 65.

[0049] The first expansion valve 61 reduces pressure by expanding the refrigerant liquid 103 condensed by the condenser 12, thereby generating a low-pressure refrigerant liquid (refrigerant) 121. The economizer 45 generates refrigerant gas (refrigerant) 122 by exchanging heat between the refrigerant liquid (second refrigerant) 103 flowing through the refrigerant path 64 and the refrigerant liquid (first refrigerant) 121 flowing through the refrigerant path 65. The refrigerant gas 122 is supplied to the second compressor 52. The second expansion valve 62 reduces pressure by expanding the refrigerant liquid 123 that has undergone heat exchange with the economizer 45, thereby generating a low-pressure refrigerant liquid 104.

[0050] The ejector 15 is connected to the refrigerant supply section 24 of the evaporator 14 via the refrigerant path 34, and is connected to the lower part of the housing 22 via the refrigerant path 36. The ejector 15 injects low-pressure refrigerant liquid 104, expanded by the second expansion valve 62, as refrigerant liquid 105 into the refrigerant path 34. At this time, the ejector 15 draws refrigerant liquid 106 stored in the evaporator 14 by generating a flow rate difference and a pressure difference in the refrigerant liquid 104.

[0051] Evaporator 14 is connected to compressor 11 via refrigerant path 35. Evaporator 14 is a liquid film type. Evaporator 14 evaporates refrigerant liquid 105 containing refrigerant liquid 106 to generate refrigerant gas 101. A portion of refrigerant liquid 105 evaporates to become refrigerant gas 101 and is supplied to compressor 41, while the remainder becomes refrigerant liquid 106 stored in the lower part of housing 22.

[0052] The refrigeration cycle based on the refrigerator 10B is a two-stage compression and one-stage expansion refrigeration cycle. The compressor 41 compresses the refrigerant gas 101 from the evaporator 14, transforming it into a high-temperature, high-pressure refrigerant gas 102. The condenser 12 condenses the high-temperature, high-pressure refrigerant gas 102, transforming it into a refrigerant liquid 103. The first expansion valve 61 expands the condensed refrigerant liquid 103, transforming it into a low-pressure refrigerant liquid 121. The economizer 45 performs heat exchange between the refrigerant liquid 103 and the refrigerant liquid 121 to generate refrigerant gas 122, which is then supplied to the second compressor 52. The second expansion valve 62 depressurizes the refrigerant liquid 123 by expanding it, thereby generating a low-pressure refrigerant liquid 104. The ejector 15 sprays the low-pressure refrigerant liquid 104 towards the evaporator 14 and draws in the refrigerant liquid 106 from the lower part of the evaporator 14. That is, the ejector 15 supplies the refrigerant liquid 106 stored in the evaporator 14 together with the refrigerant liquid 104 expanded by the expansion valve 13 to the evaporator 14. The evaporator 14 evaporates a portion of the refrigerant liquid 105 to generate refrigerant gas 101, which is then supplied to the compressor 11. Furthermore, in the evaporator 14, the unevaporated refrigerant liquid 106 is stored in the lower part of the housing 22, but returns to the refrigerant supply section 24 through the ejector 15.

[0053] [Fourth Implementation]

[0054] Figure 4 This is a schematic structural diagram of the refrigeration unit according to the fourth embodiment. Furthermore, components having the same functions as those in the first embodiment described above are labeled with the same symbols, and detailed descriptions are omitted.

[0055] In the fourth embodiment, such as Figure 4 As shown, the refrigeration unit 10C includes a compressor 11, a condenser 12, an expansion valve 13, an evaporator 14, an ejector 15, and an auxiliary pump 46.

[0056] Compressor 11 is connected to condenser 12 via refrigerant path 31. Compressor 11 compresses refrigerant gas 101 to generate high-temperature, high-pressure refrigerant gas 102. Condenser 12 is connected to expansion valve 13 via refrigerant path 32. Condenser 12 cools and condenses the high-temperature, high-pressure refrigerant gas 102 compressed by compressor 11, thereby generating refrigerant liquid 103. Expansion valve 13 is connected to ejector 15 via refrigerant path 33. Expansion valve 13 depressurizes the pressure by expanding the refrigerant liquid 103 condensed by condenser 12, thereby generating low-pressure refrigerant liquid 104.

[0057] The ejector 15 is connected to the refrigerant supply section 24 of the evaporator 14 via the refrigerant path 34, and is connected to the lower part of the housing 22 via the refrigerant path 36. The ejector 15 injects low-pressure refrigerant liquid 104, expanded by the second expansion valve 62, as refrigerant liquid 105 into the refrigerant path 34. At this time, the ejector 15 draws refrigerant liquid 106 stored in the evaporator 14 by generating a flow rate difference and a pressure difference in the refrigerant liquid 104.

[0058] Although not shown, the auxiliary pump 46 is driven by an electric motor. The auxiliary pump 46 supplies the refrigerant liquid 106 stored in the evaporator 14 to the refrigerant path 34, which serves as the discharge path for the ejector 15. The lower part of the housing 22 in the evaporator 14 and the refrigerant path 34 are connected via the refrigerant path 71. The auxiliary pump 46 is located in the refrigerant path 71.

[0059] Evaporator 14 is connected to compressor 11 via refrigerant path 35. Evaporator 14 is a liquid film type. Evaporator 14 evaporates refrigerant liquid 105 containing refrigerant liquid 106 to generate refrigerant gas 101. A portion of refrigerant liquid 105 evaporates to become refrigerant gas 101 and is supplied to compressor 41, while the remainder becomes refrigerant liquid 106 stored in the lower part of housing 22.

[0060] The refrigeration cycle based on the refrigerator 10C is a single-stage refrigeration cycle. The compressor 41 compresses the refrigerant gas 101 from the evaporator 14, transforming it into a high-temperature, high-pressure refrigerant gas 102. The condenser 12 condenses the high-temperature, high-pressure refrigerant gas 102, transforming it into a refrigerant liquid 103. The expansion valve 13 expands the condensed refrigerant liquid 103, transforming it into a low-pressure refrigerant liquid 104. The ejector 15 sprays the low-pressure refrigerant liquid 104 towards the evaporator 14 and draws in the refrigerant liquid 106 from the lower part of the evaporator 14. Furthermore, the auxiliary pump 46 supplies the refrigerant liquid 106 stored in the evaporator 14 to the refrigerant path 34. That is, the refrigerant liquid 106 stored in the evaporator 14, along with the refrigerant liquid 104 expanded by the expansion valve 13, is supplied to the evaporator 14 via the ejector 15 and the auxiliary pump 46. The evaporator 14 evaporates a portion of the refrigerant liquid 105 to generate refrigerant gas 101, which is then supplied to the compressor 11. Furthermore, in the evaporator 14, the unevaporated refrigerant liquid 106 is stored in the lower part of the housing 22, but is returned to the refrigerant supply section 24 via the ejector 15 and the auxiliary pump 46.

[0061] The refrigerant liquid 106 stored in the lower part of the evaporator 14 is returned to the refrigerant supply section 24 of the evaporator 14 via the ejector 15 and the auxiliary pump 46. At this time, when the pressure difference between the inlet of the ejector 15 (the outlet of the expansion valve 13) and the inlet of the evaporator 14 is above a predetermined value, the refrigerant liquid 106 in the lower part of the evaporator 14 can be returned to the refrigerant supply section 24 of the evaporator 14 solely through the ejector 15. On the other hand, when the pressure difference between the inlet of the ejector 15 (the outlet of the expansion valve 13) and the inlet of the evaporator 14 is below a predetermined value, it is difficult to return the required amount of refrigerant liquid 106 in the lower part of the evaporator 14 to the refrigerant supply section 24 of the evaporator 14 solely through the ejector 15. In this case, the auxiliary pump 46 is used as an auxiliary means to return the refrigerant liquid 106 in the lower part of the evaporator 14 to the refrigerant supply section 24 of the evaporator 14 via the ejector 15 and the auxiliary pump 46.

[0062] Even when the refrigeration unit 10C is operating at its rated capacity, the auxiliary pump 46 is activated when the required amount of refrigerant liquid 106 from the lower part of the evaporator 14 cannot be returned to the refrigerant supply section 24 of the evaporator 14 solely through the operation of the ejector 15. Furthermore, when the refrigeration unit 10C is operating under partial load, the pressure difference between the inlet of the ejector 15 and the inlet of the evaporator 14 is small, making it difficult for the required amount of refrigerant liquid 106 from the lower part of the evaporator 14 to be returned to the refrigerant supply section 24 of the evaporator 14 solely through the operation of the ejector 15.

[0063] In this case, although not shown, a sensor can be installed to detect the amount of refrigerant liquid 106 stored in the lower part of the housing 22 within the evaporator 14. The control device can then control the operation of the auxiliary pump 46 based on the amount of refrigerant liquid 106 detected by the sensor. Specifically, if the amount of refrigerant liquid 106 exceeds a preset upper limit, the control device activates the auxiliary pump 46; if the amount of refrigerant liquid 106 falls below a preset lower limit, the auxiliary pump 46 stops operating. Alternatively, manual control based on the control device can also be implemented by an operator.

[0064] [Fifth Implementation]

[0065] Figure 5 This is a schematic structural diagram of the refrigeration unit according to the fifth embodiment. Furthermore, components having the same functions as those in the fourth embodiment described above are labeled with the same symbols, and detailed descriptions are omitted.

[0066] In the fifth embodiment, such as Figure 5 As shown, the refrigeration unit 10D includes a compressor 11, a condenser 12, an expansion valve 13, an evaporator 14, an ejector 15, and a bubble pump (auxiliary pump) 47.

[0067] Compressor 11 is connected to condenser 12 via refrigerant path 31. Compressor 11 compresses refrigerant gas 101 to generate high-temperature, high-pressure refrigerant gas 102. Condenser 12 is connected to expansion valve 13 via refrigerant path 32. Condenser 12 cools and condenses the high-temperature, high-pressure refrigerant gas 102 compressed by compressor 11, thereby generating refrigerant liquid 103. Expansion valve 13 is connected to ejector 15 via refrigerant path 33. Expansion valve 13 depressurizes the pressure by expanding the refrigerant liquid 103 condensed by condenser 12, thereby generating low-pressure refrigerant liquid 104.

[0068] The ejector 15 is connected to the refrigerant supply section 24 of the evaporator 14 via the refrigerant path 34, and is connected to the lower part of the housing 22 via the refrigerant path 36. The ejector 15 injects low-pressure refrigerant liquid 104, expanded by the second expansion valve 62, as refrigerant liquid 105 into the refrigerant path 34. At this time, the ejector 15 draws refrigerant liquid 106 stored in the evaporator 14 by generating a flow rate difference and a pressure difference in the refrigerant liquid 104.

[0069] A bubble pump 47 supplies refrigerant liquid 106 stored in the evaporator 14 to the refrigerant path 34, which serves as the discharge path for the ejector 15. The bubble pump 47 is located at the lower part of the housing 22 within the evaporator 14. The bubble pump 47 is connected to the refrigerant path 34 via a refrigerant path 72, on which an on / off valve 73 is provided. The bubble pump 47 is U-shaped, with one end connected to the lower part of the housing 22 within the evaporator 14 and the other end connected to the refrigerant path 72. The refrigerant path 74 branches off from the refrigerant path 31 connecting the compressor 11 and the condenser 12. The refrigerant path 74 is equipped with an on / off valve 75 and is connected to the lower part of the bubble pump 47. The bubble pump 47 supplies refrigerant gas (refrigerant) 102 from the refrigerant path 74 to the lower part of the U-shape. The bubble pump 47 uses the density difference between the refrigerant gas 102 supplied to the lower part and the refrigerant liquid 106 stored in the lower part of the evaporator 14 to supply the refrigerant liquid 106 in the evaporator 14 to the refrigerant path 34 through the refrigerant path 72 by means of the refrigerant gas 102.

[0070] Evaporator 14 is connected to compressor 11 via refrigerant path 35. Evaporator 14 is a liquid film type. Evaporator 14 evaporates refrigerant liquid 105 containing refrigerant liquid 106 to generate refrigerant gas 101. A portion of refrigerant liquid 105 evaporates to become refrigerant gas 101 and is supplied to compressor 41, while the remainder becomes refrigerant liquid 106 stored in the lower part of housing 22.

[0071] The refrigeration cycle based on the refrigerator 10D is a single-stage refrigeration cycle. The compressor 11 compresses the refrigerant gas 101 from the evaporator 14, transforming it into a high-temperature, high-pressure refrigerant gas 102. The condenser 12 condenses the high-temperature, high-pressure refrigerant gas 102, transforming it into a refrigerant liquid 103. The expansion valve 13 expands the condensed refrigerant liquid 103, transforming it into a low-pressure refrigerant liquid 104. The ejector 15 sprays the low-pressure refrigerant liquid 104 towards the evaporator 14 and draws in the refrigerant liquid 106 from the lower part of the evaporator 14. Furthermore, if the on / off valves 73 and 75 are opened, the bubble pump 47 operates, supplying the refrigerant liquid 106 from the evaporator 14 from the refrigerant path 72 to the refrigerant path 34 using the refrigerant gas 102. That is, through the ejector 15 and the bubble pump 47, the refrigerant liquid 106 stored in the evaporator 14 and the refrigerant liquid 104 expanded by the expansion valve 13 are supplied to the evaporator 14 together. The evaporator 14 evaporates a portion of the refrigerant liquid 105 to generate refrigerant gas 101, which is then supplied to the compressor 11. Furthermore, in the evaporator 14, the unevaporated refrigerant liquid 106 is stored in the lower part of the housing 22, but is returned to the refrigerant supply section 24 via the ejector 15 and the auxiliary pump 46.

[0072] Furthermore, the operating conditions of the bubble pump 47 are the same as those of the auxiliary pump 46 described in the fourth embodiment.

[0073] [Sixth Implementation]

[0074] Figure 6 This is a schematic structural diagram of the refrigerator according to the sixth embodiment. Furthermore, components having the same functions as those in the first embodiment described above are labeled with the same symbols, and detailed descriptions are omitted.

[0075] In the sixth embodiment, such as Figure 6 As shown, the refrigeration unit 10E includes a compressor 11, a condenser 12, an expansion valve 13, an evaporator 14, an ejector 15, a plate heat exchanger (second heat exchanger) 48, and a gas-liquid separator (second gas-liquid separator) 49.

[0076] Compressor 11 is connected to condenser 12 via refrigerant path 31. Compressor 11 compresses refrigerant gas 101 to generate high-temperature, high-pressure refrigerant gas 102. Condenser 12 is connected to expansion valve 13 via refrigerant path 32. Condenser 12 cools and condenses the high-temperature, high-pressure refrigerant gas 102 compressed by compressor 11, thereby generating refrigerant liquid 103. Expansion valve 13 is connected to plate heat exchanger via refrigerant path 81. Expansion valve 13 depressurizes the pressure by expanding the refrigerant liquid 103 condensed by condenser 12, thereby generating low-pressure refrigerant liquid 104.

[0077] Plate heat exchanger 48 is connected to gas-liquid separator 49 via refrigerant path 82. Gas-liquid separator 49 is connected to ejector 15 via refrigerant path 33 and to refrigerant path 53 via refrigerant path 83. Plate heat exchanger 48 heats low-pressure refrigerant liquid 104 and discharges it as refrigerant liquid 141. At this time, a portion of the low-pressure refrigerant liquid 104 evaporates into refrigerant gas. Gas-liquid separator 49 separates refrigerant liquid 141 into refrigerant liquid 104 and refrigerant gas (refrigerant) 142. Refrigerant liquid 104 is supplied to ejector 15, and refrigerant gas 142 is supplied to compressor 11.

[0078] The ejector 15 is connected to the refrigerant supply section 24 of the evaporator 14 via the refrigerant path 34, and is connected to the lower part of the housing 22 via the refrigerant path 36. The ejector 15 injects low-pressure refrigerant liquid 104, expanded by the second expansion valve 62, as refrigerant liquid 105 into the refrigerant path 34. At this time, the ejector 15 draws refrigerant liquid 106 stored in the evaporator 14 by generating a flow rate difference and a pressure difference in the refrigerant liquid 104.

[0079] The auxiliary pump 46 supplies the refrigerant liquid 106 stored in the evaporator 14 to the refrigerant path 34 of the ejector 15. The lower part of the housing 22 in the evaporator 14 and the refrigerant path 34 are connected via the refrigerant path 71. The auxiliary pump 46 is located in the refrigerant path 71.

[0080] Evaporator 14 is connected to compressor 11 via refrigerant path 35. Evaporator 14 is a liquid film type. Evaporator 14 evaporates refrigerant liquid 105 containing refrigerant liquid 106 to generate refrigerant gas 101. A portion of refrigerant liquid 105 evaporates to become refrigerant gas 101 and is supplied to compressor 41, while the remainder becomes refrigerant liquid 106 stored in the lower part of housing 22.

[0081] The refrigeration cycle based on the refrigerator 10E is a single-stage refrigeration cycle. The compressor 11 compresses the refrigerant gas 101 from the evaporator 14, transforming it into a high-temperature, high-pressure refrigerant gas 102. The condenser 12 condenses the high-temperature, high-pressure refrigerant gas 102, transforming it into a refrigerant liquid 103. The expansion valve 13 expands the condensed refrigerant liquid 103, transforming it into a low-pressure refrigerant liquid 104. The plate heat exchanger 48 heats the refrigerant liquid 104, transforming it into a refrigerant liquid 141. The gas-liquid separator 49 separates the refrigerant liquid 141 into refrigerant liquid 104 and refrigerant gas 142. The refrigerant liquid 104 is supplied to the ejector 15, and the refrigerant gas 142 is supplied to the compressor 11. The ejector 15 sprays the low-pressure refrigerant liquid 104 towards the evaporator 14 and draws in the refrigerant liquid 106 from the lower part of the evaporator 14. Furthermore, the auxiliary pump 46 operates as needed to supply the refrigerant liquid 106 stored in the evaporator 14 to the refrigerant path 34. That is, the refrigerant liquid 106 stored in the evaporator 14, along with the refrigerant liquid 104 expanded by the expansion valve 13, is supplied to the evaporator 14 via the ejector 15 and the auxiliary pump 46. The evaporator 14 evaporates a portion of the refrigerant liquid 105 to generate refrigerant gas 101, which is then supplied to the compressor 11. Additionally, the unevaporated refrigerant liquid 106 is stored in the lower part of the housing 22 in the evaporator 14, but returns to the refrigerant supply section 24 via the ejector 15 and the auxiliary pump 46.

[0082] [Effects of this implementation method]

[0083] The refrigeration unit includes compressors 11 and 41 for compressing refrigerant, a condenser 12 for condensing the refrigerant compressed by compressors 11 and 41, expansion valves (expanders) 13, 42 and 44 for expanding the refrigerant condensed by condenser 12, a liquid film evaporator 14 for evaporating the refrigerant expanded by expansion valves 13, 42 and 44, and an ejector 15 for drawing refrigerant stored in evaporator 14 by utilizing the pressure difference between the inlet and outlet.

[0084] In the refrigeration unit according to the first method, the compressor 11 compresses the refrigerant, the condenser 12 condenses the refrigerant, the expansion valve 13 expands the refrigerant, and the liquid film evaporator 14 evaporates the refrigerant. At this time, the ejector 15 draws in the refrigerant stored in the evaporator 14 using the pressure difference between its inlet and outlet and supplies it to the evaporator 14. That is, by using a portion of the pressure loss in the expansion valve 13 as the operating power of the ejector 15, the circulation of the refrigerant in the evaporator 14 can be achieved. Therefore, there is no need to use additional pumps, etc., which can prevent the unit from becoming too large and costly.

[0085] In the refrigeration unit according to the second method, the compressor 41 is a multi-stage compressor, and the expansion valve 42 has a first expansion valve 54 and a second expansion valve 55 arranged in series on the refrigerant path (discharge path) 32, 56, 57 of the refrigerant condensed by the condenser 12. An economizer (first gas-liquid separator) 43 is provided between the first expansion valve 54 and the second expansion valve 55. The economizer 43 supplies the refrigerant gas separated from the refrigerant to the second stage and beyond of the compressor 41. Thus, as a two-stage compression and two-stage expansion refrigeration cycle, efficiency can be improved, and the large size and high cost of the device can be suppressed.

[0086] In the refrigeration unit according to the third method, the compressor 41 is a multi-stage compressor, and the expansion valve 44 has a first expansion valve 61 and a second expansion valve 62 arranged side by side on the refrigerant path (discharge path) 63, 64 of the refrigerant condensed by the condenser 12, and is provided with an economizer (first heat exchanger) 45, which causes the refrigerant liquid (first refrigerant) 121 after expansion by the first expansion valve 61 to exchange heat with the refrigerant liquid (second refrigerant) 103 before expansion by the second expansion valve 62, and supplies the refrigerant gas (first refrigerant) 122 to the second stage and beyond of the compressor 41. Thus, as a two-stage compression and one-stage expansion refrigeration cycle, efficiency can be improved, and the large size and high cost of the device can be suppressed.

[0087] In the refrigeration unit involved in the fourth method, an auxiliary pump 46 is provided, which supplies the refrigerant stored in the evaporator 14 to the refrigerant path (discharge path) 65 of the ejector 15. Thus, the auxiliary pump 46 is operated as needed, so that the circulation of refrigerant in the evaporator 14 can be properly implemented regardless of the operating state of the refrigeration unit.

[0088] In the refrigeration unit involved in the fifth method, a bubble pump 47 is provided as an auxiliary pump. As a result, the bubble pump 47 can be operated by the refrigerant compressed by the compressors 11 and 41, for example, eliminating the need for an electric motor or the like as a drive source for the auxiliary pump, thus simplifying the device and reducing operating costs.

[0089] In the refrigeration units involved in the fourth and fifth embodiments, a control device is provided that controls the operation of the auxiliary pump 46 and the bubble pump 47 according to the amount of refrigerant stored in the evaporator 14. Thus, regardless of the operating state of the refrigeration unit, the circulation of refrigerant in the evaporator 14 can be appropriately implemented.

[0090] In the refrigeration unit according to the sixth method, a plate heat exchanger (second heat exchanger) 48 is provided to evaporate the refrigerant expanded by the expansion valve 13; and a gas-liquid separator (second gas-liquid separator) 49 is provided to supply the refrigerant separated from the refrigerant that has undergone heat exchange in the plate heat exchanger 48 to the compressor 11. Thus, the function of refrigerant evaporation is distributed between the evaporator 14 and the plate heat exchanger 48, enabling miniaturization of the evaporator 14 and the plate heat exchanger 48, and reducing the amount of refrigerant used in the evaporator 14, thereby suppressing the increase in operating costs.

[0091] Symbol Explanation

[0092] 10, 10A, 10B, 10C, 10D, 10E - Refrigeration unit; 11, 41 - Compressor; 12 - Condenser; 13, 42, 44 - Expansion valve; 14 - Evaporator; 15 - Ejector; 21 - Motor; 22 - Housing; 23 - Heat transfer tube; 24 - Refrigerant supply section; 25 - Refrigerant discharge section; 31, 32, 33, 34, 35, 36, 53, 56, 57, 58, 63, 64, 65, 71, 72, 74, 81, 82, 83 - Refrigerant path; 43 - Eco-friendly device (first gas-liquid separator); 45 - Eco-friendly device (first heat exchanger) 46-Auxiliary pump, 47-Bubble pump (auxiliary pump), 48-Plate heat exchanger (second heat exchanger), 49-Gas-liquid separator (second gas-liquid separator), 51-First compressor, 52-Second compressor, 54, 61-First expansion valve (first expander), 55, 62-Second expansion valve (second expander), 73, 75-On / off valve, 101, 102, 113, 122, 142-Refrigerant gas (refrigerant), 103, 104, 105, 106, 111, 112, 121, 123, 131, 141-Refrigerant liquid (refrigerant).

Claims

1. A refrigeration unit, comprising: The compressor compresses the refrigerant; A condenser that condenses the refrigerant compressed by the compressor; An expander that expands the refrigerant condensed by the condenser; A liquid film evaporator causes the refrigerant expanded by the expander to evaporate; and An ejector draws in the refrigerant stored in the evaporator using the pressure difference between its inlet and outlet. The refrigeration unit is equipped with an auxiliary pump, which supplies the refrigerant stored in the evaporator to the discharge path of the ejector.

2. The refrigeration unit according to claim 1, wherein, The auxiliary pump is a bubble pump.

3. The refrigeration machine according to claim 1 or 2, wherein a control device is provided, the control device controlling the operation of the auxiliary pump according to the amount of refrigerant stored in the evaporator.

4. The refrigeration unit according to claim 1 or 2, wherein, The compressor is a multi-stage compressor, and the expander has a first expander and a second expander connected in series in the discharge path of the refrigerant condensed by the condenser. A first gas-liquid separator is provided between the first expander and the second expander. The first gas-liquid separator supplies the refrigerant gas separated from the refrigerant to the second stage and beyond of the compressor.

5. The refrigeration unit according to claim 1 or 2, wherein, The compressor is a multi-stage compressor. The expander has a first expander and a second expander arranged side by side on the discharge path of the refrigerant condensed by the condenser, and is provided with a first heat exchanger. The first heat exchanger allows the first refrigerant after expansion by the first expander to exchange heat with the second refrigerant before expansion by the second expander and supplies the first refrigerant to the second stage and beyond of the compressor.

6. The refrigeration machine according to claim 1 or 2, comprising: a second heat exchanger for evaporating the refrigerant expanded by the expander; and a second gas-liquid separator for supplying refrigerant gas separated from the refrigerant after heat exchange in the second heat exchanger to the compressor.

Images