Refrigeration apparatus

Abstract

To surely cool an evaporator to a desired low temperature in a refrigerating device using a non-azeotrope refrigerant.SOLUTION: The condenser 19 is composed of a first condensing part 43 on the upstream side and a second condensing part 44 on the downstream side, and the second flow passage 22 is branched from between both condensing parts 43, 44. Of the non-azeotropic refrigerant mixture in a gas-liquid mixed phase cooled in the first condensing part 43, a first fluid portion in a gas phase flows toward the second condensing part 44, and a second fluid portion in a liquid phase flows toward the second passage 22. The second flow path 22 is provided with an electromagnetic valve 47, a pressure reducing unit 48, and a heat absorbing unit 49. A heat radiating part 55 paired with the heat absorbing part 49 and constituting a heat exchanger 56 is provided between the second condensing part 44 of the first flow passage 21 and the expansion valve 20. When the temperature of the second fluid portion measured on the outlet side of the pressure reducer 48 becomes higher than the temperature of the first fluid portion measured on the outlet side of the condenser 19 by a predetermined temperature or more, it is assumed that the gaseous cooling medium flows into the second channel 22, and the electromagnetic valve 47 is switched to the closed state.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a refrigeration system that utilizes a non-azeotropic refrigerant mixture. [Background technology]

[0002] Refrigeration systems that use a mixture of two or more refrigerants with different boiling points, i.e., a non-azeotropic refrigerant mixture, use a refrigerant with a relatively high boiling point to cool (condense) a refrigerant with a low boiling point, and then send the cooled refrigerant to an evaporator to cool the object to a low temperature. Because this type of refrigeration system typically uses only one compressor, it can be manufactured more compactly and inexpensively than a cascade refrigeration system with two compressors.

[0003] A refrigeration system using such a non-azeotropic refrigerant mixture (hereinafter simply referred to as a "mixed refrigerant") is disclosed in, for example, Patent Document 1 and is well known. The refrigeration system of Patent Document 1 includes a compressor, a first condenser, a second condenser, a first expansion valve, and an evaporator, which constitute a refrigeration cycle, as well as a gas-liquid separator that separates the mixed refrigerant into a gas phase and a liquid phase. The gas-liquid separator is disposed between the first condenser and the second condenser and includes an inlet port that receives the gas-liquid mixed refrigerant from the first condenser, a gas outlet port that discharges the first fluid portion of the mixed refrigerant in the gas phase toward the second condenser, and a liquid outlet port that discharges the second fluid portion in the liquid phase. The first fluid portion is primarily composed of the first refrigerant with a relatively low boiling point, and the second fluid portion is primarily composed of the second refrigerant with a relatively high boiling point. The second fluid portion discharged from the liquid outlet port is decompressed by the second expansion valve and reaches the second condenser, where it cools the first fluid portion flowing therethrough. The first fluid portion, which has been cooled and condensed by the second fluid portion, is decompressed by the first expansion valve and then reaches the evaporator, where it cools an object to be cooled. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2021-148354 Summary of the Invention [Problem to be solved by the invention]

[0005] In the refrigeration system of Patent Document 1, the first fluid portion of the gas phase discharged from the gas-liquid separator passes through the second condenser and the first expansion valve to reach the evaporator, and the opportunity for cooling the first fluid portion by heat exchange is limited to the second condenser. Therefore, for example, in an environment where the outside air temperature is extremely high, the air cooling of the mixed refrigerant in the first condenser may be insufficient, and the first fluid portion may reach the second condenser at a relatively high temperature, which may result in the first fluid portion and, ultimately, the evaporator being unable to be cooled to the desired low temperature.

[0006] An object of the present invention is to reliably cool an evaporator to a desired low temperature in a refrigeration system that uses a non-azeotropic refrigerant mixture. [Means for solving the problem]

[0007] The present invention is directed to a refrigeration system in which a non-azeotropic refrigerant mixture is sealed. The refrigeration system includes a first flow path 21 formed by connecting at least a compressor 18, a condenser 19, an expansion valve 20, and an evaporator 11 in a loop shape with refrigerant piping, and a second flow path 22 branching off from the first flow path 21 and bypassing the expansion valve 20 and the evaporator 11. The condenser 19 is composed of a first condensing section 43 on the upstream side and a second condensing section 44 on the downstream side, and the second flow path 22 branches off between the two condensing sections 43 and 44. Of the gas-liquid multiphase non-azeotropic refrigerant mixture cooled in the first condensing section 43, the first gas-phase fluid portion flows toward the second condensing section 44, and the second liquid-phase fluid portion flows toward the second flow path 22. The second flow path 22 includes: an electromagnetic valve 47 that opens and closes the second flow path 22; A pressure reducing section 48 that reduces the pressure of the second fluid portion and a heat absorbing section 49 that vaporizes the second fluid portion after the pressure reduction are provided. A heat radiating section 55 that is paired with the heat absorbing section 49 and constitutes a heat exchanger 56 is provided between the second condensing section 44 of the first flow path 21 and the expansion valve 20, and in the heat exchanger 56, the first fluid portion cooled in the second condensing section 44 exchanges heat with the second fluid portion and is further cooled. A first temperature sensor 51 is provided on the outlet side of the condenser 19 in the first flow path 21, and a second temperature sensor 52 is provided on the outlet side of the pressure reducing section 48 in the second flow path 22. When the temperature of the second fluid portion measured by the second temperature sensor 52 becomes higher by a predetermined temperature or more than the temperature of the first fluid portion measured by the first temperature sensor 51, it is determined that gaseous refrigerant is flowing into the second flow path 22, and the solenoid valve 47 switches from an open state to a closed state. It is characterized by:

[0008] The condenser 19 is configured as a microchannel heat exchanger having a cylindrical inlet header 25 and an outlet header 26, a number of tubes 27 connecting the headers 25 and 26, and heat dissipation fins 28 arranged between adjacent tubes 27. Each header 25 and 26 is divided into upstream sections 34 and 38 and downstream sections 35 and 39 by partitions 33 and 37. The upstream section 34 of the inlet header 25 is provided with a start port 36 connected to the discharge pipe of the compressor 18. The upstream section 38 of the outlet header 26 is provided with a first flow path 21 and a second flow path 22. An intermediate port 40 is provided as a branch point to the inlet header 25 and the outlet header 26, and a terminal port 41 is provided in a downstream portion 39 of the outlet header 26, which is connected to a heat dissipation portion 55 of the heat exchanger 56. A first condensing section 43 is made up of a group of tubes 27 that guides the refrigerant from the upstream portion 34 of the inlet header 25 to the upstream portion 38 of the outlet header 26. A second condensing section 44 is made up of a group of tubes 27 that guides the refrigerant from the upstream portion 38 of the outlet header 26 to the downstream portion 35 of the inlet header 25, and a group of tubes 27 that guides the refrigerant from the downstream portion 35 to the downstream portion 39 of the outlet header 26. do.

[0009] The pressure reducing section 48 of the second flow path 22 is formed of a capillary tube, and the first fluid portion flowing from the second condenser section 44 to the heat dissipation section 55 of the heat exchanger 56 is cooled by heat exchange with the second fluid portion flowing through the pressure reducing section 48. do.

[0010] The first fluid portion flowing from the second condenser portion 44 to the heat radiating portion 55 of the heat exchanger 56 is cooled by heat exchange with the first fluid portion flowing from the evaporator 11 to the compressor 18. do. [Effects of the Invention]

[0011] In the cooling device according to the present invention, the condenser 19 is composed of an upstream first condensing section 43 and a downstream second condensing section 44, and of the gas-liquid mixed-phase non-azeotropic refrigerant that has passed through the first condensing section 43 and been cooled, the first fluid portion in the gas phase flows toward the second condensing section 44, and the second fluid portion in the liquid phase flows toward the second flow path 22 that branches off from between the condensing sections 43 and 44. Here, the main component of the first fluid portion is a refrigerant with a relatively low boiling point that constitutes the non-azeotropic refrigerant, and the main component of the second fluid portion is a refrigerant with a relatively high boiling point.

[0012] In addition, in the present invention, a pressure reducing section 48 and a heat absorbing section 49 are provided in the second flow path 22, and a heat radiating section 55 is provided in the first flow path 21 between the second condenser section 44 and the expansion valve 20. In a heat exchanger 56 formed by the heat radiating section 55 and the heat absorbing section 49, the first fluid portion cooled in the second condenser section 44 is further cooled by heat exchange with the second fluid portion. In this way, by cooling the first fluid portion separated from the second fluid portion at multiple locations, the first fluid portion and, ultimately, the evaporator 11 can be reliably cooled to a desired low temperature.

[0013] When the inflow of gaseous refrigerant into the second flow path 22 is detected, the solenoid valve 47 that opens and closes the second flow path 22 can be switched from an open state to a closed state, thereby preventing breakdowns and malfunctions caused by the gaseous refrigerant continuing to flow through the pressure reduction section 48.

[0014] When the temperature of the second fluid portion at the outlet side of pressure reduction section 48 becomes higher by a predetermined temperature or more than the temperature of the first fluid portion at the outlet side of condenser 19, it can be assumed that gaseous refrigerant is flowing into second flow path 22. Accordingly, by simply providing temperature sensors 51 and 52 that measure the temperatures of the respective fluid portions, the inflow of gaseous refrigerant can be detected at low cost.

[0015] The condenser 19 according to the present invention can be configured as a microchannel heat exchanger in which an inlet header 25 and an outlet header 26 are connected by a large number of tubes 27. Specifically, each header 25, 26 is divided by partitions 33, 37 into upstream sections 34, 38 and downstream sections 35, 39, with a starting port 36 provided in the upstream section 34 of the inlet header 25, an intermediate port 40 serving as a branch point to the second flow path 22 provided in the upstream section 38 of the outlet header 26, and a terminal port 41 provided in the downstream section 39 of the outlet header 26. The first condenser section 43 can be configured from a group of tubes 27 that guides the refrigerant from the upstream section 34 of the inlet header 25 to the upstream section 38 of the outlet header 26, and the second condenser section 44 can be configured from a group of tubes 27 that guides the refrigerant from the upstream section 38 of the outlet header 26 to the downstream section 35 of the inlet header 25, and another group of tubes 27 that guides the refrigerant from the downstream section 35 to the downstream section 39 of the outlet header 26. In this way, by providing the first condenser section 43 and the second condenser section 44 in one condenser 19, it is possible to reduce the size and manufacturing costs of the refrigeration device compared to when each condenser section 43, 44 is formed by an individual condenser with a gas-liquid separator disposed between them. Reducing the number of components that make up the refrigeration device also contributes to reducing the number of welding points during manufacturing, thereby reducing the risk of refrigerant leakage.

[0016] By constructing the pressure reduction section 48 of the second flow path 22 using a capillary tube and allowing the first fluid portion flowing from the second condenser section 44 to the heat dissipation section 55 of the heat exchanger 56 to be cooled by heat exchange with the second fluid portion flowing through the pressure reduction section 48, the opportunity for the first fluid portion to be cooled is further increased, and the first fluid portion and therefore the evaporator 11 can be more reliably cooled to the desired low temperature.

[0017] By cooling the first fluid portion flowing from the second condenser section 44 to the heat dissipation section 55 of the heat exchanger 56 by heat exchange with the first fluid portion flowing from the evaporator 11 to the compressor 18, the opportunity for the first fluid portion to be cooled before pressure reduction is further increased, thereby more reliably cooling the first fluid portion and therefore the evaporator 11 to the desired low temperature. [Brief explanation of the drawings]

[0018] [Figure 1]1 is a circuit diagram of a refrigeration device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a front view of a quick freezer equipped with the refrigeration device. [Figure 3] FIG. 2 is a perspective view of a container and a cold storage material cooled in the flash freezer. [Figure 4] FIG. 2 is a diagram illustrating the configuration of a condenser that constitutes the refrigeration device. [Figure 5] FIG. 2 is a cross-sectional view of a tube that constitutes a condenser. [Figure 6] FIG. 4 is a configuration diagram of a condenser that constitutes a refrigeration device according to a second embodiment of the present invention. [Figure 7] FIG. 6 is a configuration diagram of a condenser that constitutes a refrigeration device according to a third embodiment of the present invention. [Figure 8] FIG. 10 is a circuit diagram of a refrigeration device according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] (First Embodiment) A first embodiment in which the refrigeration device of the present invention is applied to a quick freezer for cold storage materials is shown in Figures 1 to 5. In this embodiment, front, back, left, right, and up and down refer to the crossed arrows shown in Figures 2 and 4 and the symbols near each arrow. In Figure 2, quick freezer 1 comprises main body 2, which is an insulated box with an opening at the front, and door 3 for opening and closing the opening. The interior 4 enclosed by main body 2 and door 3 is divided by a vertical partition wall 5 into a storage chamber 6 on the left side and a cooling chamber 7 on the right side. Storage chamber 6 has shelves 8 with multiple vents arranged in multiple vertical rows, and containers C (see Figure 3) for storing cold storage materials M are placed on each shelf 8. The walls of container C also have multiple vents.

[0020] An evaporator 11 that constitutes a refrigeration unit 10 is provided in the center of the top and bottom of the cooling chamber 7, and internal fans 12 are provided above and below it. A group of outlet holes 13 is formed in the partition wall 5 in a portion directly facing each internal fan 12, and a group of suction holes 14 is formed in a portion directly facing the evaporator 11. When the internal fan 12 is driven, the internal air cooled by the evaporator 11 is blown out from the outlet holes 13 into the storage chamber 6, cools the containers C on the shelves 8, and then is sucked into the cooling chamber 7 through the suction holes 14.

[0021] A machine room 17 defined above the main body 2 accommodates a compressor 18, a condenser 19, and the like which, together with the evaporator 11, constitute the refrigeration device 10. In Fig. 1, the refrigeration device 10 includes a first flow path 21 formed by connecting the compressor 18, the condenser 19, an expansion valve 20, the evaporator 11, and the like in a loop with refrigerant piping, and a second flow path 22 which branches off from the first flow path 21 midway through the condenser 19 and joins the first flow path 21 between the evaporator 11 and the compressor 18. A non-azeotropic mixed refrigerant (hereinafter simply referred to as mixed refrigerant) formed by mixing two types of refrigerants with different boiling points is sealed in the refrigeration device 10.

[0022] As shown in Figure 4, the condenser 19 is composed of a microchannel heat exchanger and includes a vertically extending hollow inlet header 25 and outlet header 26, multiple flat tubes 27 extending horizontally connecting the headers 25 and 26, and heat dissipation fins 28 arranged between adjacent tubes 27. Each tube 27 contains multiple channels 29 with a diameter of a few millimeters or less, which are affected by surface tension (see Figure 5). Each fin 28 is curved in a wavy shape and abuts against the tubes 27 above and below it. A condenser fan 30 (see Figure 1) delivers heat exchange air to the condenser 19 in a direction parallel to the narrow space enclosed by the tubes 27 and fins 28 (perpendicular to the plane of the paper in Figure 4).

[0023] The inlet header 25 is divided into an upper upstream section 34 and a lower downstream section 35 by a partition 33 located above the vertical center of the condenser 19, and a start port 36 connected to the discharge pipe of the compressor 18 is provided in the upstream section 34. The outlet header 26 is divided into an upper upstream section 38 and a lower downstream section 39 by a partition 37 located below the vertical center of the condenser 19. The upstream section 38 of the outlet header 26 is provided with an intermediate port 40 that forms a branch point from the first flow path 21 to the second flow path 22, and the downstream section 39 is provided with a terminal port 41 that connects to the expansion valve 20 via a heat exchanger 56, which will be described later.

[0024] The gaseous mixed refrigerant discharged from the compressor 18 flows into the upstream section 34 of the inlet header 25 through the start port 36 and then flows through the tubes 27 toward the upstream section 38 of the outlet header 26. The group of tubes 27 connecting the upstream sections 34 and 38 of the inlet header 25 and outlet header 26 and carrying the mixed refrigerant constitutes the first condenser section 43 of the present invention. As it flows through the first condenser section 43, the mixed refrigerant is air-cooled and a portion of it condenses. In other words, the mixed refrigerant flows into the upstream section 38 of the outlet header 26 in a gas-liquid mixed phase state. The gas phase portion of the mixed refrigerant in the upstream section 38 is hereinafter referred to as the first fluid portion, and the liquid phase portion is hereinafter referred to as the second fluid portion. Of the low-boiling-point refrigerant and high-boiling-point refrigerant that make up the mixed refrigerant, the former is the main component of the first fluid portion, and the latter is the main component of the second fluid portion.

[0025] The first fluid portion (gas phase) of the mixed refrigerant that reaches the upstream portion 38 of the outlet header 26 moves to the lower half of the upstream portion 38 and flows from there through the tubes 27 toward the downstream portion 35 of the inlet header 25. The first fluid portion that reaches the downstream portion 35 of the inlet header 25 moves to the lower half of the downstream portion 35 and then flows through the tubes 27 toward the downstream portion 39 of the outlet header 26, finally reaching the terminal port 41 provided in the downstream portion 39. In other words, the first fluid portion is separated from the second fluid portion in the upstream portion 38 of the outlet header 26, and then flows through the two tubes 27 and is air-cooled. The group of tubes 27 that guide the first fluid portion from the upstream portion 38 of the outlet header 26 to the downstream portion 35 of the inlet header 25 and the group of tubes 27 that guide the first fluid portion from the downstream portion 35 to the downstream portion 39 of the outlet header 26 constitute a second condenser section 44 of the present invention.

[0026] Meanwhile, the second fluid portion (liquid phase) of the mixed refrigerant drips down the upstream portion 38 of the outlet header 26 toward the upper surface of the partition 37. An intermediate port 40 is formed in the wall surface of the outlet header 26 facing the upper surface, and the second fluid portion is configured to flow out from this intermediate port 40 into the second flow path 22. As shown enlarged in FIG. 4, the vertical position of the lower edge of the intermediate port 40 is approximately the same as the upper surface of the partition 37. The vertical position of the partition 37 is between the vertically adjacent tubes 27 and below the midpoint between them. In this way, by positioning the partition 37 close to the lower tube 27 and making the vertical distance from the partition 37 to the tube 27 located above it greater than the vertical distance from the partition 37 to the intermediate opening 40, in other words, by moving the tube 27 farther from the top surface of the partition 37 than the intermediate opening 40, the second fluid portion that passes through the first condenser section 43 and drips onto the top surface of the partition 37 can be preferentially directed toward the intermediate opening 40, i.e., the second flow path 22, and the second fluid portion can be prevented from flowing out toward the tube 27 (second condenser section 44).

[0027] 1, in second flow path 22, there are arranged, in this order from upstream, a solenoid valve 47 that opens and closes flow path 22, a pressure reducing section 48 formed of a capillary tube, and a heat absorbing section 49 that vaporizes the second fluid portion after pressure reduction. The second fluid portion vaporized in heat absorbing section 49 flows into first flow path 21 downstream of evaporator 11, passes through accumulator 50, and returns to compressor 18.

[0028] The solenoid valve 47 is normally maintained in an open state. However, when the refrigeration system 10 is overloaded, the first condenser 43 (condenser 19) may not condense the refrigerant sufficiently due to insufficient heat dissipation, resulting in gaseous refrigerant flowing into the second flow path 22. In such a case, the solenoid valve 47 is switched to a closed state to protect the pressure reducing unit 48. To enable this control, a first temperature sensor 51 is provided on the outlet side of the condenser 19 in the first flow path 21, and a second temperature sensor 52 is provided on the outlet side of the pressure reducing unit 48 in the second flow path 22. When the temperature T2 of the second fluid portion measured by the second temperature sensor 52 becomes higher than the temperature T1 of the first fluid portion measured by the first temperature sensor 51 by a predetermined temperature α or more (T2≧T1+α), the solenoid valve 47 is switched to a closed state, assuming that gaseous refrigerant is flowing through the second flow path 22. When a predetermined time (e.g., 10 minutes) has elapsed since the solenoid valve 47 was closed, the solenoid valve 47 is opened again.

[0029] Meanwhile, the first fluid portion flowing out from the terminal port 41 of the condenser 19 passes through the dryer 53 and first passes near the pressure reduction section 48 of the second flow path 22, where it is cooled by heat exchange with the second fluid portion flowing through the pressure reduction section 48. In other words, the pressure reduction section 48, together with the refrigerant piping of the first flow path 21 passing nearby, constitutes an auxiliary heat exchanger 57. The first fluid portion that has passed through the auxiliary heat exchanger 57 reaches the self-heat exchanger 54. In this self-heat exchanger 54, heat exchange occurs between the high-pressure (upstream side of the expansion valve 20) and low-pressure (downstream side of the evaporator 11) first fluid portions. More specifically, the high-pressure first fluid portion flowing from the auxiliary heat exchanger 57 is cooled by the low-pressure first fluid portion flowing from the evaporator 11 to the accumulator 50.

[0030] The high-pressure first fluid portion that has passed through the auxiliary heat exchanger 57 and the self heat exchanger 54 reaches the heat dissipation section 55. This heat dissipation section 55 is paired with the heat absorption section 49 of the second flow path 22 to form a heat exchanger 56. The second fluid portion that has been decompressed in the decompression section 48 flows through the heat absorption section 49, and when this second fluid portion vaporizes, it absorbs heat from the heat dissipation section 55, thereby effectively cooling the first fluid portion.

[0031] As described above, the first fluid portion separated from the second fluid portion after passing through the first condensing section 43 of the condenser 19 passes through the second condensing section 44, auxiliary heat exchanger 57, self heat exchanger 54, and heat exchanger 56 (heat dissipation section 55) in that order, and is sufficiently cooled and condensed while flowing through these sections. The condensed first fluid portion is depressurized by the expansion valve 20 and then reaches the evaporator 11, where it appropriately cools the air inside the deep freezer 4. By branching the second fluid portion, which is primarily composed of a high-boiling-point refrigerant, into the second flow path 22 and directing only the first fluid portion, which is primarily composed of a low-boiling-point refrigerant, to the evaporator 11, it is possible to reduce the phenomenon of the refrigerant temperature rising from the inlet to the outlet of the evaporator 11, known as temperature glide.

[0032] Constructing the condenser 19 as a microchannel heat exchanger in which the inlet header 25 and the outlet header 26 are connected by a large number of tubes 27, and providing a first condenser section 43 and a second condenser section 44 in one condenser 19, enables the refrigeration system 10 to be made smaller and the manufacturing costs reduced compared to when each condenser section 43, 44 is constructed as an individual condenser with a gas-liquid separator disposed between them. Reducing the number of components that make up the refrigeration system 10 also reduces the number of welding points during manufacturing, contributing to a lower risk of refrigerant leakage.

[0033] When the vertical distance from the partition 37 of the outlet header 26 to the tubes 27 located above it is made larger than the vertical distance from the partition 37 to the intermediate port 40, in other words, when the tubes 27 are positioned farther from the upper surface of the partition 37 than the intermediate port 40, the second fluid portion that passes through the first condenser section 43 and drips onto the upper surface of the partition 37 is preferentially directed toward the intermediate port 40, i.e., the second flow path 22, and the second fluid portion is prevented from flowing toward the tubes 27 (second condenser section 44). By preventing the liquid-phase second fluid portion from mixing with the gas-phase first fluid portion flowing toward the second condenser section 44 in this way, the first fluid portion can be efficiently cooled in the second condenser section 44 and the phenomenon of the refrigerant temperature rising from the inlet to the outlet of the evaporator 11, known as temperature glide, can be reduced.

[0034] Second Embodiment A condenser 19 of a refrigeration system according to a second embodiment of the present invention is shown in FIG. 6. This condenser 19 differs from the first embodiment in that it includes a gap 60 where the tubes 27 are spaced apart at a greater distance than in the other regions. The vertical dimension of the gap 60 is approximately three times the pitch of the tubes 27 excluding the gap 60. The partition 37 and intermediate port 40 of the outlet header 26 are located to the sides of the lower end of the gap 60. Resistance members 61 are also located in the gap 60 to increase ventilation resistance. Specifically, the resistance members 61 are composed of two metal plates 62 parallel to the tubes 27 and three spacers 63 sandwiching the plates 62 from above and below. The plates 62 have the same thickness as the tubes 27, and the spacers 63 are formed of the same material and shape as the fins 28. The plates 62 are made of aluminum, which has high thermal conductivity, and together with the spacers 63, they provide heat dissipation. Since the other parts are the same as those in the first embodiment, the same members are denoted by the same reference numerals and the description thereof will be omitted. The same applies to the third and subsequent embodiments.

[0035] By providing a gap section 60 in which the spacing between adjacent tubes 27 is larger than in other sections and arranging a partition 37 of the outlet header 26 to the side of it, the tubes 27 located above the partition 37 can be moved further away from the upper surface of the partition 37, thereby further preventing the second fluid portion in the liquid phase from flowing out toward the tube 27 (second condenser section 44).

[0036] By disposing a resistance member 61 that increases the ventilation resistance of the gap 60, the heat exchange airflow flowing through the condenser 19 can be prevented from concentrating in the gap 60 and can be directed toward the upper and lower tube groups, thereby accurately cooling the refrigerant flowing through each tube 27. Furthermore, if the resistance member 61 includes a plate 62 that is parallel to the tubes 27 and spacers 63 that have the same shape as the fins 28 and sandwich the plate 62 from above and below, this resistance member 61 can support the tube group above the gap 60. Furthermore, by supporting the resistance member 61 itself by the tube group below the gap 60, the overall strength of the condenser 19 can be increased.

[0037] Third Embodiment A condenser 19 of a refrigeration device according to a third embodiment of the present invention is shown in Fig. 7. This condenser 19 differs from the first embodiment in that the entire condenser 19 is gently sloping downward from the inlet header 25 to the outlet header 26. The upper surface of the partition 37 of the outlet header 26 also slopes downward toward the intermediate port 40, which more reliably directs the second fluid portion dripping onto the upper surface of the partition 37 toward the intermediate port 40, i.e., the second flow path 22, thereby more reliably preventing the second fluid portion from flowing out toward the tubes 27 (second condenser section 44).

[0038] (Fourth embodiment) A fourth embodiment of the refrigeration system according to the present invention is shown in Fig. 8. In this embodiment, the first condenser section 43 and the second condenser section 44 are each formed by an individual condenser, for example, a fin-tube heat exchanger, and a gas-liquid separator 70 is disposed between the two condenser sections 43 and 44. The inlet port of the gas-liquid separator 70 is connected to the outlet of the first condenser section 43, the gas outlet port is connected to the inlet of the second condenser section 44, and the liquid outlet port forms a branch point from the first flow path 21 to the second flow path 22.

[0039] The application of the refrigeration device according to the present invention is not limited to the quick freezer for cold storage materials shown in the first embodiment, but can also be applied to various cooling devices such as freezers for food, freezer showcases, or ice makers. [Explanation of symbols]

[0040] 10 Refrigeration equipment 11 Evaporator 18 Compressor 19 Condenser 20 Expansion valve 21 First Channel 22 Second Channel 25 Inlet Header 26 Exit Header 27 tubes 28 Finn 33 Inlet header divider 34 Upstream of inlet header 35 Downstream of inlet header 36 Starting point 37 Outlet header divider 38 Upstream of outlet header 39 Downstream of the outlet header 40 Intermediate Exit 41 Termination port 43 First condenser 44 Second condenser 48 Pressure reducing section 49 Heat absorption section 51 First temperature sensor 52 Second temperature sensor 54 Self heat exchanger 55 Heat dissipation part 56 Heat exchanger 57 Auxiliary heat exchanger

Claims

1. A refrigeration device in which a non-azeotropic refrigerant mixture is sealed, The refrigerant ... The condenser (19) is composed of a first condenser section (43) on the upstream side and a second condenser section (44) on the downstream side, and a second flow path (22) branches off from between the two condenser sections (43, 44), The system is configured such that, of the gas-liquid mixed-phase non-azeotropic refrigerant cooled in the first condenser section (43), a first fluid portion in a gas phase flows toward the second condenser section (44) and a second fluid portion in a liquid phase flows toward the second flow path (22), The second flow path (22) is provided with a solenoid valve (47) for opening and closing the second flow path (22), a pressure reducing section (48) for reducing the pressure of the second fluid portion, and a heat absorbing section (49) for vaporizing the second fluid portion after the pressure reduction, a heat radiating section (55) that is paired with a heat absorbing section (49) and constitutes a heat exchanger (56) is provided between the second condenser section (44) of the first flow path (21) and the expansion valve (20); In the heat exchanger (56), the first fluid portion cooled in the second condenser section (44) is further cooled by heat exchange with the second fluid portion, a first temperature sensor (51) is provided on the outlet side of the condenser (19) in the first flow path (21); a second temperature sensor (52) is provided on the outlet side of the pressure reducing section (48) in the second flow path (22); When the temperature of the second fluid portion measured by the second temperature sensor (52) becomes higher by a predetermined temperature or more than the temperature of the first fluid portion measured by the first temperature sensor (51), it is determined that gaseous refrigerant is flowing into the second flow path (22), and the solenoid valve (47) switches from an open state to a closed state.

2. The condenser (19) is composed of a microchannel heat exchanger including a cylindrical inlet header (25) and an outlet header (26), a number of tubes (27) connecting the headers (25, 26), and heat dissipation fins (28) arranged between adjacent tubes (27), Each header (25, 26) is divided into an upstream section (34, 38) and a downstream section (35, 39) by a partition (33, 37), An inlet header (25) has an upstream portion (34) provided with a start port (36) connected to a discharge pipe of the compressor (18), An intermediate port (40) is provided in an upstream portion (38) of the outlet header (26) as a branch point from the first flow path (21) to the second flow path (22), A terminal port (41) connected to a heat dissipation section (55) of a heat exchanger (56) is provided at a downstream section (39) of the outlet header (26), the first condenser section (43) is composed of a group of tubes (27) that guide the refrigerant from the upstream section (34) of the inlet header (25) to the upstream section (38) of the outlet header (26); 2. The refrigeration system according to claim 1, wherein the second condenser section (44) comprises a group of tubes (27) that guide the refrigerant from the upstream portion (38) of the outlet header (26) to the downstream portion (35) of the inlet header (25), and a group of tubes (27) that guide the refrigerant from the downstream portion (35) to the downstream portion (39) of the outlet header (26).

3. The pressure reducing section (48) of the second flow path (22) is composed of a capillary tube, 3. The refrigeration device according to claim 1, wherein a first fluid portion flowing from the second condenser section (44) to the heat dissipation section (55) of the heat exchanger (56) is cooled by heat exchange with a second fluid portion flowing through the pressure reduction section (48).

4. A refrigeration device as described in claim 1 or 2, wherein the first fluid portion flowing from the second condenser section (44) to the heat dissipation section (55) of the heat exchanger (56) is cooled by heat exchange with the first fluid portion flowing from the evaporator (11) to the compressor (18).

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