Refrigeration device

Abstract

To provide a refrigeration device including an air-cooled condenser capable of adjusting a condensation capacity.SOLUTION: In an air-cooled condenser 16 of an air and water-cooled refrigeration device 11 which uses both the air-cooled condenser 16 and a water-cooled condenser 17, a flow passage allowing a refrigerant to circulate has a microchannel structure, and a first condensation part 31 and a second condensation part 32 divided so as to be connectable each other are provided. The condensation capacity of the air-cooled condenser 16 is designed to a value required by an air-cooled refrigeration device using only the air-cooled condenser. In the air and water-cooled refrigeration device 11, the first condensation part 31 of the air-cooled condenser 16 is connected to the upstream side of the water-cooled condenser 17, and the second condensation part 32 of the air-cooled condenser 16 is connected to the downstream side of the water-cooled condenser 17.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a refrigeration system equipped with an air-cooled condenser. [Background technology]

[0002] Ice makers capable of producing large quantities of ice blocks are favorably used in cafes, restaurants, and other facilities, as well as in other kitchens. Ice makers come in a variety of types, including a flow-down type, in which ice-making water flows down a vertically or diagonally positioned ice-making plate to freeze the ice; a jet-type, in which a tiltable water tray blocks the ice-making chamber from below and jets water into the chamber to freeze the ice; and an auger type, in which ice frozen in a freezing cylinder is scraped off with a rotating auger. In ice makers, the refrigeration device includes an evaporator tube disposed in an ice-making section, such as an ice-making plate, ice-making chamber, or freezing cylinder. Refrigerant gas compressed by a compressor is condensed through a condenser, expanded through an expansion means, and then evaporated through the evaporator tube and circulated back to the compressor to cool the ice-making section.

[0003] As the refrigeration device, there are air-cooled refrigeration devices that use an air-cooled condenser that is cooled by air (see, for example, Patent Document 1), and air-water-cooled refrigeration devices that have a circuit configuration in which a water-cooled condenser is connected in series with an air-cooled condenser in order to reduce the exhaust heat of the air-cooled condenser and increase the efficiency of the condensation process (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-223729 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-53168 Summary of the Invention [Problem to be solved by the invention]

[0005] The air-cooled condenser used in the air-cooled refrigeration unit is designed to meet the condensing capacity (heat dissipation capacity) required for high-load operation in an ice maker. Therefore, if the air-cooled condenser of an air-cooled refrigeration unit is used in conjunction with a water-cooled condenser, the condensing capacity of the air-cooled condenser is so large that the combined condensing capacity of both condensers is not adequate to meet the condensing capacity required by the ice maker, resulting in overkill. Therefore, when manufacturing an air-cooled refrigeration unit and an air-water-cooled refrigeration unit, it is necessary to manufacture separate air-cooled condensers designed to provide the appropriate condensing capacity for each unit, which has the drawback of increasing manufacturing costs.

[0006] Furthermore, in the air-water-cooled refrigeration system, the heat exchange ratio between the air-cooled condenser and the water-cooled condenser varies significantly depending on temperature conditions, such as the ambient temperature and the temperature of the cooling water. Therefore, in a circuit in which the refrigerant flows from the air-cooled condenser to the water-cooled condenser, or vice versa, the amount of refrigerant required varies significantly depending on the temperature conditions. For example, in a circuit in which the refrigerant flows from the air-cooled condenser to the water-cooled condenser, if the ambient temperature is high and the amount of heat dissipated by the air-cooled condenser is small, the air-cooled condenser is filled with gaseous refrigerant and the amount of refrigerant required is small. On the other hand, in the same circuit, if the ambient temperature is low and the refrigerant is almost completely liquefied in the air-cooled condenser, the water-cooled condenser is filled with liquid refrigerant, and the amount of refrigerant required is large. In such a circuit, in order to absorb fluctuations in the amount of refrigerant required, it is necessary to increase the capacity of the receiver tank (liquid receiver) located downstream of the water-cooled condenser and to increase the amount of refrigerant charged into the circuit, which has been pointed out as a drawback in terms of increased costs.

[0007] The present invention has been proposed in consideration of the above-mentioned problems inherent in the prior art, and aims to provide a refrigeration system equipped with an air-cooled condenser that can change the condensing capacity and can be adapted to the presence or absence of a water-cooled condenser. [Means for solving the problem]

[0008] In order to overcome the above problems and achieve the intended purpose, the first means is: A refrigeration device equipped with an air-cooled condenser, The air-cooled condenser has a condensation path having a microchannel structure between a pair of headers through which a refrigerant can flow, the condensation path is divided into a plurality of condensation sections that can be connected to each other, an inlet through which the refrigerant flows and an outlet through which the refrigerant flows are provided corresponding to each of the condensation sections; The gist of this invention is that a refrigeration circuit is constructed using an air-cooled condenser to which any number of condensation sections can be connected by connecting the outlet of the condensation section on the upstream side in the refrigerant flow direction to the inlet of the condensation section on the downstream side. With this configuration, the condensing capacity can be adjusted by changing the number of connections (connection pattern) of the multiple divided condensing sections, allowing a refrigeration circuit to be configured with an appropriate condensing capacity. In other words, a common air-cooled condenser can be used to obtain the appropriate condensing capacity for a refrigeration circuit that uses only an air-cooled condenser and a refrigeration circuit that uses both an air-cooled condenser and a water-cooled condenser. This eliminates the need to design and manufacture air-cooled condensers according to the different condensing capacities required for each model, thereby reducing manufacturing costs. Furthermore, by using an air-cooled condenser with a microchannel structure, the refrigerant can be efficiently condensed in each condensing section, allowing the air-cooled condenser to be made more compact.

[0009] the second means comprises a water-cooled condenser; The gist is that a refrigeration circuit is configured by dividing the condensing sections of the air-cooled condenser and connecting them in series before and after the direction of refrigerant flow to the water-cooled condenser. According to this configuration, if a refrigeration circuit is used in which the refrigerant is condensed in the condensing section of an air-cooled condenser before and after the water-cooled condenser, fluctuations in the amount of refrigerant required due to changes in ambient temperature can be reduced, so the amount of refrigerant required can be reduced and the receiver tank can be made smaller, thereby reducing manufacturing costs.

[0010] the third means comprises a water-cooled condenser; The gist of the present invention is that at least one of the condensing sections of the air-cooled condenser is connected in series to the upstream side of the water-cooled condenser in the direction of refrigerant flow, and the refrigerant flowing out of the water-cooled condenser is supplied to an evaporator of a refrigeration circuit. According to this configuration, a refrigeration circuit that uses both an air-cooled condenser and a water-cooled condenser can be constructed without excessive equipment by using part of the condensing section of an air-cooled condenser designed and manufactured with the condensation capacity required for the refrigeration circuit.

[0011] The fourth means is that the air-cooled condenser is configured such that a detection means for detecting a refrigerant temperature is provided at a connection part that connects the plurality of condensation parts in series, and the refrigerant flowing out from the last condensation part in the refrigerant flow direction is supplied to an evaporator of a refrigeration circuit, The present invention is characterized in that when the temperature detected by the detecting means is equal to or higher than an upper limit temperature, the operation of the compressor of the refrigeration circuit is stopped. With this configuration, the refrigerant flowing from the upstream condenser to the downstream condenser connected in series is in a gas-liquid mixed (equilibrium) state, so the refrigerant pressure can be determined by detecting the temperature of this gas-liquid mixed state (saturation temperature).If the detected temperature is equal to or higher than the upper limit temperature, the compressor operation is stopped, thereby protecting the compressor from deviating from the specified pressure.

[0012] a fifth means including an air-cooling fan for cooling the air-cooled condenser; The present invention is characterized in that when the temperature detected by the detecting means is equal to or lower than a lower limit temperature, the rotation speed of the cooling fan is reduced. According to this configuration, when the temperature detected by the detection means is below the lower limit temperature, the rotation speed of the air-cooled fan is reduced to prevent excessive condensation of the refrigerant, thereby maintaining the condensation capacity of the air-cooled condenser at an appropriate level.

[0013] The sixth means is characterized in that, when the plurality of condensation sections are connected in series, a receiver is provided between the second-to-last condensation section and the last condensation section in the direction of refrigerant flow. With this configuration, the last condenser connected in series can function as a subcooler. In other words, without providing a dedicated subcooler, it is possible to prevent the refrigerant from flashing into gas due to incomplete condensation, and to improve cooling capacity by lowering the temperature of the liquid refrigerant. Furthermore, by providing a liquid receiver, even if the heat dissipation ratio between the air-cooled condenser and the water-cooled condenser changes, the amount of liquid refrigerant in the receiver increases or decreases to buffer the change, preventing excessive refrigerant volume (liquid refrigerant accumulating in the air-cooled condenser, resulting in an increase in high pressure) and insufficient refrigerant volume (refrigerant not liquefied before the expansion means, resulting in a decrease in cooling capacity). [Effects of the Invention]

[0014] According to the refrigeration system of the present invention, the condensing capacity of the air-cooled condenser can be adjusted to a value corresponding to the required condensing capacity to configure a refrigeration circuit. That is, a common air-cooled condenser can be used to obtain an appropriate condensing capacity for a refrigeration circuit that uses only an air-cooled condenser and a refrigeration circuit that uses both an air-cooled condenser and a water-cooled condenser. This eliminates the need to design and manufacture air-cooled condensers according to the different condensing capacities required for each model, thereby reducing manufacturing costs. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic diagram showing an ice-making machine of a first embodiment. [Figure 2] FIG. 1 is a schematic diagram showing an air-cooled condenser. [Figure 3] FIG. 10 is a schematic diagram showing a modified example of the air-cooled condenser. [Figure 4] FIG. 10 is a schematic diagram showing a modified example of the liquid injection circuit. [Figure 5] FIG. 10 is a schematic diagram showing a main part of a refrigeration device according to a second embodiment. [Figure 6] FIG. 10 is a schematic diagram showing an ice-making machine according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] Next, a preferred embodiment of the refrigeration system according to the present invention will be described below with reference to the accompanying drawings. In the embodiment, a refrigeration system used in an auger-type ice maker will be described as an example, but the ice maker may be a flow-down type or a jet-type. [Example]

[0017] The auger-type ice maker of Example 1 shown in Figure 1 includes an ice-making unit 10 and a refrigeration unit 11 that cools the ice-making unit 10. Ice-making unit 10 includes an evaporator tube (evaporator) 13 that constitutes refrigeration unit 11 tightly wound around the outer periphery of a cylindrical refrigeration casing 12. Refrigerant is circulated through evaporator tube 13 during ice-making operation, forcibly cooling casing 12. Ice-making water is supplied to casing 12 from an ice-making water tank (not shown) at a predetermined level. When ice-making operation is started and casing 12 is forcibly cooled, the ice-making water gradually begins to freeze from the inner wall surface of the casing, forming thin layers of ice. An auger screw 14 driven by an auger motor (not shown) is rotatably disposed within casing 12. Thin ice that has frozen on the inner wall surface of casing 12 is scraped off by the rotating auger screw 14 and transported upward. The flake ice is scraped off by the auger screw 14 and transported upward, and as it passes through the pressing head 15 arranged inside the upper part of the freezer casing 12, it is compressed and moisture is removed, producing compressed ice, which is then released into the ice storage room and stored there.

[0018] As shown in Figure 1, the refrigeration system 11 employs an air-water-cooled refrigeration system 11 that combines an air-cooled condenser 16 and a water-cooled condenser 17. The air-water-cooled refrigeration system 11 includes a compressor 18 that compresses a refrigerant, the air-cooled condenser 16 and the water-cooled condenser 17 that cool and liquefy the refrigerant pressure-fed from the compressor 18, an expansion valve 19 as expansion means that expands the liquefied refrigerant liquefied in the condensers 16 and 17 to form a low-pressure liquefied refrigerant, and the evaporator pipe 13 that vaporizes the liquefied refrigerant expanded by the expansion valve 19. The air-water-cooled refrigeration system 11 connects the compressor 18, the condensers 16 and 17, the expansion valve 19, and the evaporator pipe 13 in a ring shape via refrigerant pipes 20, 21, 22, 23, 24, and 25 to form a refrigeration circuit in which the refrigerant circulates in this order. The air-water-cooled refrigeration system 11 also includes a cooling fan 26 that air-cools the air-cooled condenser 16. The cooling fan 26 is composed of a fan 26a and a motor 26b that rotates the fan 26a, and is configured to blow air toward the air-cooled condenser 16 to air-cool it by rotating the fan 26a with the motor 26b.

[0019] The air-cooled condenser 16 employs a condenser in which the flow path through which the refrigerant flows has a microchannel structure. As shown in Fig. 2, the air-cooled condenser 16 has a hollow first refrigerant header (header) 27 and a hollow second refrigerant header (header) 28 spaced a predetermined distance apart, a plurality of heat transfer tubes 29 arranged in parallel to connect the refrigerant headers 27, 28, and a plurality of heat dissipation fins 30 disposed between the refrigerant headers 27, 28 and in contact with the heat transfer tubes 29. The plurality of heat transfer tubes 29 connecting the pair of refrigerant headers 27, 28 form a condensation path M through which the refrigerant can flow. The heat transfer tubes 29 are microchanneled, forming narrow paths through which the refrigerant flows, enabling a high heat transfer coefficient to be obtained.

[0020] In the air-cooled condenser 16, a condensation path M including the refrigerant headers 27, 28 is divided into a plurality of (two in the first embodiment) condensation sections 31, 32 that condense the refrigerant so as to be interconnected. As shown in Fig. 2, the interior of the first refrigerant header 27 is partitioned into a first internal space 36, a second internal space 37, a third internal space 38, and a fourth internal space 39, in that order from the top, by a first upper partition plate 33, a first middle partition plate 34, and a first lower partition plate 35 that are spaced apart in the longitudinal direction (the up-down direction in Fig. 2). The interior of the second refrigerant header 28 is partitioned into an upper fifth internal space 41 and a lower sixth internal space 42 by a second middle partition plate 40 that is disposed at the same height as the first middle partition plate 34. The first and second internal spaces 36, 37 defined within the first refrigerant header 27 are connected to a fifth internal space 41 defined within the second refrigerant header 28 via a plurality of heat transfer tubes 29, thereby forming a first condenser section 31. The third and fourth internal spaces 38, 39 defined within the first refrigerant header 27 are connected to a sixth internal space 42 defined within the second refrigerant header 28 via a plurality of heat transfer tubes 29, thereby forming a second condenser section 32.

[0021] 2, the first refrigerant header 27 is provided with a first refrigerant inlet 31a communicating with an upper part of the first internal space 36, and a first refrigerant outlet 31b communicating with a part below approximately the middle in the vertical direction of the second internal space 37. The first refrigerant header 27 is also provided with a second refrigerant inlet 32a communicating with an upper part of the third internal space 38, and a second refrigerant outlet 32b communicating with a part below approximately the middle in the vertical direction of the fourth internal space 39. That is, refrigerant inlets (inlets) 31a, 32a through which the refrigerant flows in and refrigerant outlets (outlets) 31b, 32b through which the refrigerant flows out are provided corresponding to the condensers 31, 32. The air-cooled condenser 16 is configured so that the first refrigerant outlet 31b of the first condenser section 31 on the upstream side in the refrigerant flow direction can be connected to the second refrigerant inlet 32a of the second condenser section 32 on the downstream side, and the first condenser section 31 or the second condenser section 32 can be used alone, or the first and second condenser sections 31, 32 can be connected and used, thereby making it possible to configure air-cooled condensers 16 with different condensing capacities.

[0022] Here, in the air-water-cooled refrigeration system 11, in order to minimize fluctuations in the amount of refrigerant required due to changes in ambient temperature, it is required to have a circuit configuration in which the refrigerant is condensed in the air-cooled condensers 16 before and after (upstream and downstream) the refrigerant flow direction relative to the water-cooled condenser 17. Therefore, in the air-water-cooled refrigeration system 11 of the first embodiment, as shown in Fig. 1, a first refrigerant pipe 20 extending from a refrigerant discharge port 18a of the compressor 18 is connected to a first refrigerant inlet 31a, one end of a second refrigerant pipe 21 connected to a first refrigerant outlet 31b is connected to the refrigerant inlet 17a of the water-cooled condenser 17, and the other end of a third refrigerant pipe 22 connected to a refrigerant outlet 17b of the water-cooled condenser 17 is connected to a second refrigerant inlet 32a. Furthermore, one end of the fourth refrigerant pipe 23, which is connected to the second refrigerant outlet 32b, is connected to a refrigerant inlet 43a of a receiver tank (liquid receiver) 43 that separates the refrigerant into gas and liquid. That is, the refrigerant discharged from the compressor 18 flows into the first internal space 36 of the first refrigerant header 27 via the first refrigerant pipe 20 and the first refrigerant inlet 31a, and then flows through the plurality of heat transfer tubes 29 into the fifth internal space 41 of the second refrigerant header 28. The refrigerant that has flowed into the fifth internal space 41 flows through the plurality of heat transfer tubes 29 into the second internal space 37 of the first refrigerant header 27, and the refrigerant that has flowed into the second internal space 37 flows into the water-cooled condenser 17 via the second refrigerant pipe 21. The refrigerant condensed in the water-cooled condenser 17 flows into the third internal space 38 of the first refrigerant header 27 through the third refrigerant pipe 22 and the second refrigerant inlet 32a, and flows into the sixth internal space 42 of the second refrigerant header 28 through the heat transfer pipes 29. The refrigerant that flows into the sixth internal space 42 flows into the fourth internal space 39 of the first refrigerant header 27 through the heat transfer pipes 29, and the refrigerant that flows into the fourth internal space 39 flows into the receiver tank 43 through the fourth refrigerant pipe 23. That is, in the air-water-cooled refrigeration system 11 of the first embodiment, the refrigerant that has been primarily condensed by air-cooling in the first condensing section 31 of the air-cooled condenser 16 is secondarily condensed by water-cooling in the water-cooled condenser 17, and the refrigerant condensed in the water-cooled condenser 17 is tertiarily condensed by air-cooling in the second condensing section 32 of the air-cooled condenser 16.

[0023] The condensation capacity of the air-cooled condenser 16 is the sum of the condensation capacity of the first condenser section 31 and the condensation capacity of the second condenser section 32, and is designed to be the condensation capacity required by an air-cooled refrigeration device 76 (described later) that configures a refrigeration circuit using only the air-cooled condenser 16. In the first embodiment, the condensation capacity of the first condenser section 31 is set to be greater than the condensation capacity of the second condenser section 32, but the condensation capacity of each condenser section 31, 32 can be set arbitrarily in relation to the condensation capacity required for the refrigeration circuit to be used.

[0024] The water-cooled condenser 17 is connected to a water supply source (not shown) via a cooling water pipe 44, and is configured to circulate water (cooling water) supplied from the water supply source through a water passage defined inside the water-cooled condenser 17 to cool (condense) the refrigerant flowing through a refrigerant passage defined inside the water-cooled condenser 17. A thermistor 45 is provided to detect the temperature of the refrigerant flowing through the second refrigerant pipe 21, and based on the temperature detected by the thermistor 45, a water supply valve (not shown) provided in the cooling water pipe 44 is opened and closed to control the supply and stop of cooling water to the water-cooled condenser 17.

[0025] As shown in FIG. 1 , in the air-water-cooled refrigeration system 11, a fifth refrigerant pipe 24 extending from a refrigerant outlet 43b of the receiver tank 43 is connected to a refrigerant inlet 13a of the evaporator pipe 13. A sixth refrigerant pipe 25 connected to the refrigerant outlet 13b of the evaporator pipe 13 is connected to a refrigerant suction port 18b of a compressor 18. A dryer 46 for removing moisture contained in high-pressure liquid refrigerant is disposed in the fifth refrigerant pipe 24, and a heat exchanger 47 is disposed in the fifth refrigerant pipe 24 downstream of the dryer 46 so as to be in close proximity to or in contact with the sixth refrigerant pipe 25 over a predetermined length. The heat exchanger 47 is configured to exchange heat between the liquid refrigerant flowing through the fifth refrigerant pipe 24 and the gas refrigerant flowing through the sixth refrigerant pipe 25. A temperature sensing bulb 48 for detecting the temperature of the refrigerant gas flowing out of the evaporator pipe 13 is disposed in the sixth refrigerant pipe 25, and the opening of the expansion valve 19 is adjusted based on the temperature detected by the temperature sensing bulb 48. Additionally, a check valve 49 is disposed in the sixth refrigerant pipe 25 downstream of the heat exchanger 47, and is configured to prevent the refrigerant from flowing back from the downstream side to the upstream side of the check valve 49. Additionally, an accumulator 50 is provided in the sixth refrigerant pipe 25 between the compressor 18 and the check valve 49 to separate the refrigerant that has flowed into the container into gas and liquid and return the gas refrigerant to the compressor 18.

[0026] The air-water-cooled refrigeration system 11 of the first embodiment is equipped with a liquid injection circuit 51 that cools the inside of the compressor 18 with low-temperature liquefied refrigerant flowing out from the air-cooled condenser 16. As shown in Fig. 1, the liquid injection circuit 51 has a liquid bypass pipe 52 whose inlet is connected to the fifth refrigerant pipe 24 between the dryer 46 and the heat exchanger 47, and whose outlet is connected to the compressor 18. That is, the low-temperature liquefied refrigerant flowing out from the air-cooled condenser 16 is supplied to the compressor 18 via the liquid bypass pipe 52 (so-called liquid injection), thereby cooling the inside of the compressor. In addition, a capillary tube 53 is disposed midway through the liquid bypass pipe 52. In the air-water-cooled refrigeration system 11 of the first embodiment, by appropriately setting the pipe diameter and length of the capillary tube 53 in the liquid bypass pipe 52, it is possible to control the amount of liquid-phase refrigerant supplied to the compressor 18 (liquid injection amount) in accordance with fluctuations in the load of the compressor 18, without including a solenoid valve, a relay, a thermostat, or the like. That is, when the load of the compressor 18 is high, the pressure of the liquid-phase refrigerant increases accordingly, the pressure difference between both ends of the capillary tube 53 increases, and the liquid-phase refrigerant is supplied from the capillary tube 53 to the compressor 18. On the other hand, when the load of the compressor 18 is low, the pressure of the liquid-phase refrigerant is also low, so the pressure difference between both ends of the capillary tube 53 decreases, and the amount of liquid-phase refrigerant supplied to the compressor 18 decreases.

[0027] [Operation of Example 1] Next, the operation of the refrigeration apparatus according to the first embodiment will be described.

[0028] The air-cooled condenser 16 used in the air-water-cooled refrigeration system 11 of the first embodiment has two condensing sections 31, 32, and the condensing capacity (the sum of the condensing capacities of the two condensing sections 31, 32) when the two condensing sections 31, 32 are connected in series and the refrigerant flows continuously through both condensing sections 31, 32 is set to a value corresponding to the condensing capacity required for the air-cooled refrigeration system 76 described below. In the first embodiment, the two condensing sections 31, 32 of the air-cooled condenser 16 are not connected in series, but the first condensing section 31 is connected in series upstream of the water-cooled condenser 17 and the second condensing section 32 is connected in series downstream of the water-cooled condenser 17, so that the refrigerant does not condense too much in the air-cooled condenser 16 and flows into the water-cooled condenser 17, allowing for appropriate condensation. In other words, when two condensation sections 31, 32 are connected in series and the refrigerant flows continuously through both condensation sections 31, 32, the condensing capacity of the air-cooled condenser 16 becomes excessive when used in conjunction with the water-cooled condenser 17. However, by dividing the refrigerant into sections before and after the water-cooled condenser 17 and flowing it through the condensation sections 31, 32, the refrigerant can be condensed appropriately.

[0029] In this way, the refrigeration circuit of the air-water-cooled refrigeration unit 11, used in combination with the water-cooled condenser 17, can be configured using an air-cooled condenser 16 designed and manufactured so that the condensing capacity when all condensing sections 31, 32 are connected in series corresponds to the condensing capacity required for the air-cooled refrigeration unit 76 using only an air-cooled condenser. That is, a common air-cooled condenser 16 can be used for a refrigeration circuit using only an air-cooled condenser 16 and a refrigeration circuit using both an air-cooled condenser 16 and a water-cooled condenser 17, achieving the appropriate condensing capacity. This eliminates the need to design and manufacture air-cooled condensers 16 according to the different condensing capacities required for each model, thereby reducing manufacturing costs. Furthermore, a configuration in which the air-cooled condensers 16 condense the refrigerant before and after the water-cooled condenser 17 minimizes fluctuations in the required refrigerant amount due to changes in ambient temperature. This reduces the amount of refrigerant required and the receiver tank 43 can be made smaller, thereby reducing manufacturing costs.

[0030] Because a condenser with a microchannel structure is used as the air-cooled condenser 16, the refrigerant can be efficiently condensed in each condensing section 31, 32, allowing for a reduction in the size of the air-cooled condenser 16. Furthermore, the air-cooled condenser 16 of Example 1 has the large condensing capacity required for an air-cooled refrigeration system 76 that uses only an air-cooled condenser, so using the air-cooled condenser 16 in the air-water-cooled refrigeration system 11 creates a margin in the condensing capacity of the air-water-cooled refrigeration system 11, which can contribute to improved ice-making capacity and reduced power consumption. Furthermore, it is possible to reduce the size of the fan 26a in the cooling fan 26 and to downsize the specifications of the motor 26b, thereby reducing the manufacturing cost of the refrigeration system.

[0031] (Example of changing air-cooled condenser) FIG. 3 shows a modified example of the air-cooled condenser, and the same components as those already described or components having the same functions are given the same reference numerals and detailed description thereof will be omitted.

[0032] In the modified air-cooled condenser 54, a condensation path M including refrigerant headers 27, 28 is divided into three interconnected condensation sections 55, 56, 57. As shown in Fig. 3, inside the first refrigerant header 27, a first internal space 60, a second internal space 61, and a third internal space 62 are defined in this order from the top by a first upper partition plate 58 and a first lower partition plate 59 that are spaced apart in the longitudinal direction (the up-down direction in Fig. 3). The interior of the second refrigerant header 28 is partitioned, in order from above, into a fourth internal space 66, a fifth internal space 67, a sixth internal space 68, and a seventh internal space 69 by a second upper partition 63 disposed at the same height as the first upper partition 58, a second middle partition 64 disposed below approximately the middle of the second refrigerant header 28 in the vertical direction, and a second lower partition 65 disposed at the same height as the first lower partition 59. The first internal space 60 defined in the first refrigerant header 27 is connected to the fourth internal space 66 defined in the second refrigerant header 28 by a plurality of heat transfer tubes 29, thereby forming the first condenser section 55. Furthermore, a second internal space 61 defined within the first refrigerant header 27 is connected to fifth and sixth internal spaces 67, 68 defined within the second refrigerant header 28 via a plurality of heat transfer tubes 29, thereby forming a second condenser section 56. Furthermore, a third internal space 62 defined within the first refrigerant header 27 is connected to a seventh internal space 69 defined within the second refrigerant header 28 via a plurality of heat transfer tubes 29, thereby forming a third condenser section 57. Note that the heat transfer tubes 29 are microchanneled, as in the first embodiment.

[0033] The air-cooled condenser 54 of the modified example includes a receiver tank (liquid receiver) 70. The receiver tank 70 is fixedly connected to the second refrigerant header 28. The first refrigerant header 27 is provided with a first refrigerant inlet 55a communicating with the first internal space 60 and a third refrigerant outlet 57b communicating with the third internal space 62. The second refrigerant header 28 is also provided with a first refrigerant outlet 55b communicating with the fourth internal space 66, a second refrigerant inlet 56a communicating with the fifth internal space 67, a second refrigerant outlet 56b connecting the sixth internal space 68 to the receiver tank 70, and a third refrigerant inlet 57a connecting the seventh internal space 69 to the receiver tank 70. That is, the refrigerant that flows into the first condenser section 55 from the first refrigerant inlet 55a is condensed before flowing out from the first refrigerant outlet 55b, the refrigerant that flows into the second condenser section 56 from the second refrigerant inlet 56a is condensed before flowing out from the second refrigerant outlet 56b into the receiver tank 70, and the refrigerant that flows into the third condenser section 57 from the third refrigerant inlet 57a (the refrigerant that has been completely liquefied in the second condenser section 56) is further cooled before flowing out from the third refrigerant outlet 57b.

[0034] When the modified air-cooled condenser 54 is used in the air-water-cooled refrigeration system 11, the compressor 18 is connected to the first refrigerant inlet 55a of the first condenser section 55, the first refrigerant outlet 55b of the first condenser section 55 is connected to the refrigerant inlet 17a of the water-cooled condenser 17, the refrigerant outlet 17b of the water-cooled condenser 17 is connected to the second refrigerant inlet 56a, and the third refrigerant outlet 57b is connected to the refrigerant inlet 13a of the evaporation tube 13. As a result, the refrigerant discharged from the compressor 18 flows into the evaporation tube 13 after passing through the first condenser section 55 → the water-cooled condenser 17 → the second condenser section 56 → the receiver tank 70 → the third condenser section 57. When the modified air-cooled condenser 54 is used, a receiver tank 70 is provided between the second condenser section 56 and the third condenser section 57. Therefore, when the heat dissipation ratio between the air-cooled condenser 54 and the water-cooled condenser 17 changes, the amount of liquid refrigerant in the receiver tank 70 increases or decreases to buffer the change. This prevents an excessive amount of refrigerant (liquid refrigerant accumulating in the air-cooled condenser, increasing high pressure) or an insufficient amount of refrigerant (refrigerant not liquefied before the expansion valve, resulting in reduced ice-making capacity). Furthermore, providing the receiver tank 70 between the second condenser section 56 (the penultimate condenser section in the refrigerant flow direction) and the third condenser section 57 (the last condenser section) allows the third condenser section 57 to function as a subcooler. This means that, without providing a dedicated subcooler, flash gasification due to incomplete condensation can be prevented, and cooling capacity can be improved by lowering the temperature of the liquid refrigerant.

[0035] (Example of liquid injection circuit modification) FIG. 4 shows a modified example of the liquid injection circuit, and the same components as those already described or components having the same functions are given the same reference numerals and detailed description thereof will be omitted.

[0036] In the liquid injection circuit 71 of the modified example, a first capillary tube 72 is disposed midway through the liquid bypass pipe 52, and a second capillary tube 73 and a solenoid valve 74 are connected in parallel to the liquid bypass pipe 52 on the side of the connection point with the fifth refrigerant pipe 24 from the position where the first capillary tube 72 is disposed. The solenoid valve 74 is controlled to open and close based on the temperature detected by ambient temperature detection means (not shown) that detects the ambient temperature. That is, when the temperature detected by the ambient temperature detection means is equal to or higher than a preset upper limit temperature, the solenoid valve 74 is opened, and when the temperature detected by the ambient temperature detection means is equal to or lower than a preset lower limit temperature, the solenoid valve 74 is closed. As a result, when the ambient temperature is equal to or higher than the upper limit temperature, the solenoid valve 74 opens so that the liquid refrigerant flowing through the liquid bypass pipe 52 does not flow into the second capillary tube 73, and the liquid refrigerant flowing through the liquid bypass pipe 52 is throttled only by the first capillary tube 72, increasing the amount of liquid refrigerant supplied to the compressor 18 and effectively preventing overheating of the compressor 18 when the ambient temperature is high. On the other hand, when the ambient temperature is equal to or lower than the lower limit temperature, the solenoid valve 74 closes so that the liquid refrigerant flowing through the liquid bypass pipe 52 also flows into the second capillary tube 73, and the liquid refrigerant flowing through the liquid bypass pipe 52 is throttled by the first and second capillary tubes 72, 73, reducing the amount of liquid refrigerant supplied to the compressor 18. This prevents the compressor 18 from being overcooled when the ambient temperature is low, maintains the oil temperature of the compressor 18, and prevents the refrigerant from dissolving in the oil, resulting in a decrease in oil viscosity and poor lubrication.

[0037] According to the modified liquid injection circuit 71, multiple (two in the illustrated example) capillary tubes 72, 73 are connected in series, and the flow rate of the liquid injection is controlled by whether or not some of the capillary tubes 73 are short-circuited by the solenoid valve 74, thereby preventing the compressor 18 from overheating or overcooling.

[0038] To control the liquid injection flow rate in response to ambient temperature fluctuations, conventional liquid injection circuits use two parallel capillary tubes, one or both of which are equipped with solenoid valves. The solenoid valves adjust the flow rate based on the detected ambient temperature. Because the capillary tube is thin and has low rigidity, its rigidity suddenly changes at the connections to the liquid bypass pipes (thicker than the capillary tube) at both ends. This can cause stress to concentrate at the welds connecting the capillary tube and the pipes, potentially resulting in damage. To prevent this, the pipes at both ends of the capillary tube are secured together with cable ties or other measures to prevent stress from being applied to the capillary tube or its welds. In this case, the pipes before and after the capillary tube are sometimes covered with cushioning material to prevent excessive stress from vibrations transmitted from the compressor. For this reason, in the conventional circuit configuration, it was necessary to bundle together the three pipes, including the two capillary tubes and the pipe after the junction, and to cover the pipes upstream of each of the two capillary tubes with cushioning material. This not only made the piping structure around the compressor more complex, but also increased material costs due to the need to attach cushioning material to the two capillary tubes.

[0039] In contrast, in the liquid injection circuit 71 of the modified example, two capillary tubes 72, 73 are connected in series, and therefore, a measure to prevent stress from being applied to the welded portion is to simply bundle the two pipes (liquid bypass pipe 52) at both ends of the first capillary tube 72. This prevents the structure near the compressor from becoming complicated compared to a conventional circuit configuration in which two capillary tubes are connected in parallel. In addition, the second capillary tube 73 can be placed near the solenoid valve 74, providing a high degree of freedom in placement. In other words, the liquid injection circuit 71 of the modified example prevents overheating or excessive cooling of the compressor 18 without complicating the piping structure around the compressor, which tends to be congested and makes assembly and after-sales service difficult. [Example]

[0040] FIG. 5 is a schematic diagram showing the main parts of an air-water cooled refrigeration device in an auger type ice maker according to a second embodiment. The same components as those in the first embodiment or components having the same functions are designated by the same reference numerals, and detailed descriptions thereof will be omitted.

[0041] In the air-water-cooled refrigeration system 75 of the second embodiment, a refrigeration circuit is configured using only the water-cooled condenser 17 and the first condensing section 31 of the air-cooled condenser 16 used in the first embodiment. That is, a third refrigerant pipe 22 extending from a refrigerant outlet 17b of the water-cooled condenser 17 is connected to a refrigerant inlet 43a of the receiver tank 43. In the air-water-cooled refrigeration system 75 of the second embodiment, the refrigerant discharged from the compressor 18 is primarily condensed in the first condensing section 31 of the air-cooled condenser 16, and then secondarily condensed in the water-cooled condenser 17, and then supplied to the evaporation tube 13 via the receiver tank 43.

[0042] In the second embodiment, when the condensing capacity of the first and second condensing sections 31, 32 of the air-cooled condenser 16 becomes excessive, the condensing capacity of the entire condensers 16, 17 can be adjusted to an appropriate value simply by changing the connection destination of the third refrigerant pipe 22 leading out from the refrigerant outlet 17b of the water-cooled condenser 17, while using the air-cooled condenser 16 itself having the same structure as in the first embodiment. In other words, there is no need to manufacture a dedicated air-cooled condenser designed with a small condensing capacity to be used in combination with the water-cooled condenser 17 as the air-cooled condenser 16, and manufacturing costs can be reduced.

[0043] In other words, in the case of a model in which the condensation capacity required for the air-water-cooled refrigeration device 11 is low, a refrigeration circuit with appropriate condensation capacity can be constructed using an air-cooled condenser 16 of the same structure by configuring the refrigeration circuit to use only a portion of the condensation section 31 (the first condensation section 31 in the illustrated example) of the air-cooled condenser 16 designed for a condensation capacity that can be used in an air-cooled refrigeration device 76 that uses only an air-cooled condenser. [Example]

[0044] FIG. 6 shows a schematic configuration of an auger type ice making machine according to a third embodiment, and the same components as those in the first embodiment or components having the same functions are given the same reference numerals and detailed description thereof will be omitted.

[0045] The auger type ice maker of Example 3 employs an air-cooled refrigeration unit 76 that uses only an air-cooled condenser 16 as the refrigeration unit that cools ice-making unit 10. Air-cooled condenser 16 has the same structure as air-cooled condenser 16 used in air-water-cooled refrigeration unit 11 of Example 1, and is configured as a single air-cooled condenser in which refrigerant flows continuously through first condenser unit 31 and second condenser unit 32, with first refrigerant outlet 31b of first condenser unit 31 connected in series to second refrigerant inlet 32a of second condenser unit 32 via connecting pipe (connecting unit) 77, and is configured to supply refrigerant flowing out of second condenser unit 32, which is the last in the refrigerant flow direction, to evaporator tube 13.

[0046] The fifth refrigerant pipe 24 extending from the second refrigerant outlet 32b of the second condenser 32 is connected to the refrigerant inlet 13a of the evaporator pipe 13 via an expansion valve 19 whose opening is adjusted according to the temperature detected by a temperature sensing bulb 48, and the sixth refrigerant pipe 25 extending from the refrigerant outlet 13b of the evaporator pipe 13 is connected to the refrigerant suction port 18b of the compressor 18 via a check valve 49 and an accumulator 50. In the third embodiment, a dryer 46 is disposed in the fifth refrigerant pipe 24 between the heat exchanger 47 and the expansion valve 19, and a strainer 78 for removing impurities such as dust from the refrigerant is disposed in the liquid bypass pipe 52 branching off from the fifth refrigerant pipe 24 upstream of the capillary tube 53 (toward the connection with the fifth refrigerant pipe 24).

[0047] A straight section 77a is provided in the connecting pipe 77, and a temperature detection means (detection means) 79 such as a thermistor for detecting the refrigerant temperature is provided in the straight section 77a, so that the temperature of the refrigerant in a gas-liquid mixed state can be detected in an intermediate portion of the refrigerant flow path in the air-cooled condenser 16. In the air-cooled refrigeration system 76 of the third embodiment, operation of the compressor 18 and the cooling fan 26 is controlled based on the temperature detected by the temperature detection means 79. Specifically, when the temperature detected by the temperature detection means 79 is equal to or higher than a preset upper limit temperature, operation of the compressor 18 is controlled to stop, thereby protecting the compressor 18 from deviating from a specified pressure. That is, the refrigerant flowing from the first condenser section 31 on the upstream side to the second condenser section 32 on the downstream side, which are connected in series, is in a gas-liquid mixed (equilibrium) state. Therefore, the refrigerant pressure can be determined by detecting the temperature of the gas-liquid mixed state (saturation temperature). Therefore, the compressor 18 can be protected by controlling the compressor 18 to stop based on the detected temperature. Furthermore, when the temperature detected by the temperature detection means 79 is equal to or lower than a preset lower limit temperature, the rotation speed of the cooling fan 26 is reduced to keep the condensation capacity of the air-cooled condenser 16 low, thereby preventing excessive condensation of the refrigerant and maintaining an appropriate condensation capacity of the air-cooled condenser 16. Furthermore, by providing the straight portion 77a in the connecting pipe 77, it is easy to attach the temperature detection means 79 to the straight portion 77a.

[0048] In the auger type ice maker of Example 3, when configuring air-cooled refrigeration device 76, a refrigeration circuit can be configured using air-cooled condenser 16 of the same structure as used in air-water-cooled refrigeration device 11 of Example 1, thereby reducing the cost of designing and manufacturing a dedicated air-cooled condenser for air-cooled refrigeration device 76. In other words, by using air-cooled condenser 16 of the example, in which the condensation path is divided into multiple condensation sections and any number of condensation sections can be connected, a refrigeration device with appropriate condensation capacity can be configured depending on whether or not a water-cooled condenser is present.

[0049] 3 can be used as the air-cooled condenser used in the air-cooled refrigeration system 76 of the third embodiment. For example, when the air-cooled condenser 54 of the modified example is used in the air-cooled refrigeration system 76, the first refrigerant outlet 55b of the first condenser section 55 is connected to the second refrigerant inlet 56a, and the second refrigerant outlet 56b is directly connected to the third refrigerant inlet 57a without going through the receiver tank 70. Then, the compressor 18 is connected to the first refrigerant inlet 55a, and the third refrigerant outlet 57b is connected to the refrigerant inlet 13a of the evaporation tube 13. As a result, the refrigerant discharged from the compressor 18 flows into the evaporation tube 13 after passing through the first condenser section 55, the second condenser section 56, and the third condenser section 57.

[0050] Furthermore, when the modified air-cooled condenser 54 is used in an air-cooled refrigeration system 76, a circuit configuration can be adopted in which the first refrigerant outlet 55b of the first condenser 55 is connected to the second refrigerant inlet 56a, and the second refrigerant header 28 is connected to the receiver tank 70 via the second refrigerant outlet 56b and the third refrigerant inlet 57a. The compressor 18 is then connected to the first refrigerant inlet 55a, and the third refrigerant outlet 57b is connected to the refrigerant inlet 13a of the evaporation tube 13. In this circuit configuration, the refrigerant discharged from the compressor 18 flows through the first condenser 55, the second condenser 56, the receiver tank 70, and the third condenser 57 before flowing into the evaporation tube 13. In this way, by adopting a circuit configuration in which the receiver tank 70 is connected between the second-to-last condenser (second condenser 56) and the last condenser (third condenser 57) connected in series, the last condenser (third condenser 57) can function as a subcooler. That is, as described above, without providing a dedicated supercooler, the condensing section of the air-cooled condenser 16 can prevent the refrigerant from being completely condensed and becoming a flash gas, and can improve the cooling capacity by lowering the temperature of the liquid refrigerant.

[0051] [Example of change] The present application is not limited to the configurations of the above-described examples, etc., and other configurations may be adopted as appropriate. Furthermore, the configurations described in the examples, etc., are not limited to the following modifications, and various embodiments may be adopted within the scope of the gist of the present invention. (1) In the examples and the like, the air-cooled condenser is configured to be divided into two or three condensation sections, but it may also be configured to have a condensation section divided into four or more sections. The air-water-cooled refrigeration system of Example 1 can be configured such that multiple condensation sections connected in series are connected to the upstream side of the water-cooled condenser in the refrigerant flow direction, and multiple condensation sections connected in series are also connected to the downstream side. Furthermore, by providing multiple condensation sections with the same or different condensation capacities and setting the condensation capacities of the individual or interconnected condensation sections to be different depending on the number and combination of the condensation sections connected in series, it is possible to configure multiple types of refrigeration systems with different refrigeration capacities using a single air-cooled condenser. (2) In the modified example shown in Figure 5, only the first condenser section is connected to the water-cooled condenser. However, in an air-cooled condenser designed so that the condensing capacities of the first condenser section and the second condenser section are different, a configuration in which only the second condenser section is connected to the water-cooled condenser can be adopted depending on the condensing capacity required for the model being used. Also, in an air-cooled condenser having three or more condenser sections, a configuration in which multiple condenser sections connected in series are connected to the water-cooled condenser can be adopted. That is, in the modified example shown in Figure 5, the number of condenser sections connected to the water-cooled condenser only needs to be at least one, and a configuration in which two or more condenser sections connected in series are connected to the water-cooled condenser can be adopted. (3) In the modified air-cooled condenser shown in FIG. 3, a receiver tank is provided between the second condenser section (the penultimate condenser section in the refrigerant flow direction) and the third condenser section (the final condenser section). However, by increasing the internal volume of the refrigerant header connecting the penultimate condenser section and the final condenser section, the refrigerant header can function as a receiver tank. That is, in the air-cooled condenser used in the circuit configuration of the first embodiment, by appropriately designing the condensing capacity of each condenser section, fluctuations in the required refrigerant amount become smaller. If the volume of such fluctuations is equal to or less than the internal volume of the internal space in the refrigerant header functioning as the receiver tank, the internal space functions as a receiver tank. The function of the internal space functioning as a receiver tank is the same as that of the receiver tank in the modified example, and a separate receiver tank is not required. (4) In the examples, the present invention is used as a refrigeration device for an ice maker, but it can also be used as a refrigeration device for a refrigerator or other refrigerators. [Explanation of symbols]

[0052] 13 Evaporator tube (evaporator), 16 Air-cooled condenser, 17 Water-cooled condenser, 18 Compressor 26 cooling fan, 27 first refrigerant header (header), 28 second refrigerant header (header) 31 first condenser (condenser), 31a first refrigerant inlet (inlet) 31b first refrigerant outlet (outlet), 32 second condenser (condenser) 32a second refrigerant inlet (inlet), 32b second refrigerant outlet (outlet), 54 air-cooled condenser 55 First condenser (condenser), 55a First refrigerant inlet (inlet) 55b first refrigerant outlet (outlet), 56 second condenser (condenser) 56a 2nd refrigerant inlet (inlet), 56b 2nd refrigerant outlet (outlet) 57 third condenser (condenser), 57a third refrigerant inlet (inlet) 57b third refrigerant outlet (outlet), 70 receiver tank (liquid receiver), 77 connecting pipe (connection part) 79 Temperature detection means (detection means), M Condensation path

Claims

1. A refrigeration system having an air-cooled condenser (16, 54), The air-cooled condenser (16, 54) has a condensation path having a microchannel structure between a pair of headers (27, 28) through which a refrigerant can flow, the condensation path is divided into a plurality of condensation sections (31, 32, 55, 56, 57) that can be connected to each other; Inlets (31a, 32a, 55a, 56a, 57a) through which the refrigerant flows and outlets (31b, 32b, 55b, 56b, 57b) through which the refrigerant flows are provided corresponding to the condensation sections (31, 32, 55, 56, 57), The refrigeration circuit is configured by an air-cooled condenser (16, 54) to which any number of condensation sections (31, 32, 55, 56, 57) can be connected by connecting an outlet (31b, 55b, 56b) of the condensation section (31, 55, 56) on the upstream side in the flow direction of the refrigerant to an inlet (32a, 56a, 57a) of the condensation section (32, 56, 57) on the downstream side. A refrigeration device characterized by:

2. A water-cooled condenser (17) is provided.

2. The refrigeration system according to claim 1, wherein the condensing sections (31, 32, 55, 56, 57) of the air-cooled condensers (16, 54) are connected in series before and after the direction of refrigerant flow through the water-cooled condenser (17) to form a refrigeration circuit.

3. A water-cooled condenser (17) is provided.

2. The refrigeration system according to claim 1, wherein at least one of the condensing sections (31, 32, 55, 56, 57) of the air-cooled condensers (16, 54) is connected in series to the water-cooled condenser (17) upstream in a refrigerant flow direction, and the refrigerant flowing out of the water-cooled condenser (17) is supplied to an evaporator (13) of a refrigeration circuit.

4. The air-cooled condenser (16) is configured such that a detecting means (79) for detecting a refrigerant temperature is provided at a connection part (77) connecting the plurality of condensation parts (31, 32, 55, 56, 57) in series, and the refrigerant flowing out of the last condensation part (32, 57) in the refrigerant flow direction is supplied to an evaporator (13) of a refrigeration circuit, 2. The refrigeration system according to claim 1, wherein the operation of the compressor (18) of the refrigeration circuit is stopped when the temperature detected by the detection means (79) is equal to or higher than an upper limit temperature.

5. an air-cooling fan (26) for cooling the air-cooled condenser (16, 54); 5. The refrigeration system according to claim 4, wherein the rotational speed of the air-cooling fan is reduced when the temperature detected by the detecting means is equal to or lower than a lower limit temperature.

6. 6. The refrigeration system according to claim 1, wherein when the plurality of condensation sections (55, 56, 57) are connected in series, a receiver (70) is provided between the penultimate condensation section (56) and the last condensation section (57) in a refrigerant flow direction.

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