JP2024022092A - Refrigeration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably cool an evaporator to a desired low temperature, in a refrigeration device utilizing a non-azeotropic mixture refrigerant.

SOLUTION: A condenser 19 is composed of an upstream-side first condensation portion 43 and a downstream-side second condensation portion 44, and a second flow channel 22 is branched from a part between the condensation portions 43 and 44. A first fluid part of a gas phase of a non-azeotropic mixture refrigerant of a gas-liquid mixture phase cooled at the first condensation portion 43, is directed to the second condensation portion 44, and a second fluid part of a liquid phase is directed to the second flow channel 22. The second flow channel 22 is provided with a decompression portion 48 for decompressing the second fluid part, and a heat absorption portion 49 for vaporizing the second fluid part after the decompression. A heat radiation portion 55 constituting a heat exchanger 56 by being paired with the heat absorption portion 49 is disposed between the second condensation portion 44 of a first flow channel 21 and an expansion valve 20. In the heat exchanger 56, the first fluid part cooled at the second condensation portion 44 is further cooled by heat exchange with the second fluid part.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a refrigeration system that uses a non-azeotropic mixed refrigerant.

A refrigeration system that uses a mixture of two or more refrigerants with different boiling points, that is, a non-azeotropic mixed refrigerant, cools (condenses) a refrigerant with a lower boiling point with a refrigerant with a relatively higher boiling point, and evaporates the latter refrigerant at a lower temperature. The object to be cooled is cooled down to a low temperature. Since this refrigeration system is usually equipped with one compressor, it can be manufactured in a smaller size and at a lower cost than a binary refrigeration system equipped with two compressors.

A refrigeration system using such a non-azeotropic mixed refrigerant (hereinafter simply referred to as mixed refrigerant) is disclosed in Patent Document 1, for example, and is well known. In addition to a compressor, a first condenser, a second condenser, a first expansion valve, and an evaporator that constitute a refrigeration cycle, the refrigeration system of Patent Document 1 includes a gas-liquid system that separates a mixed refrigerant into a gas phase and a liquid phase. Equipped with a separator. The gas-liquid separator is disposed between the first condenser and the second condenser, and has an inflow port that receives a gas-liquid mixed-phase mixed refrigerant from the first condenser, and a first gas-phase refrigerant of this mixed refrigerant. A gas outlet port for discharging a fluid portion toward a second condenser and a liquid outlet port for discharging a second fluid portion in a liquid phase. The primary component of the first fluid portion is a relatively low boiling point first refrigerant, and the primary component of the second fluid portion is a relatively high boiling point second refrigerant. The second fluid portion discharged from the liquid outflow port is depressurized by the second expansion valve and then reaches the second condenser to cool the first fluid portion flowing therethrough. The first fluid portion cooled and condensed by the second fluid portion is reduced in pressure by the first expansion valve, and then reaches the evaporator to cool the object to be cooled.

Japanese Patent Application Publication No. 2021-148354

In the refrigeration system of Patent Document 1, the first fluid portion of the gas phase discharged from the gas-liquid separator reaches the evaporator via the second condenser and the first expansion valve, and heats the first fluid portion. Opportunities for cooling by replacement are limited to only the second condenser. Therefore, for example, in an environment where the outside air temperature is extremely high, air cooling of the mixed refrigerant in the first condenser becomes insufficient, and the first fluid portion reaches the second condenser while remaining at a relatively high temperature, resulting in There is a possibility that the evaporator cannot be cooled down to the desired low temperature.

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 mixed refrigerant.

The present invention is directed to a refrigeration system in which a non-azeotropic mixed refrigerant is sealed. The refrigeration system includes a first flow path 21 in which at least a compressor 18, a condenser 19, an expansion valve 20, and an evaporator 11 are connected in a loop through refrigerant piping, and an expansion valve 20 branched from the first flow path 21. and a second flow path 22 that bypasses the evaporator 11. The condenser 19 includes 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 from between both the condensing sections 43 and 44. Of the gas-liquid multiphase non-azeotropic mixed refrigerant cooled in the first condensing section 43, the first fluid portion in the gas phase goes to the second condensing section 44, and the second fluid portion in the liquid phase flows through the second flow path 22. It is configured to go to. The second flow path 22 is provided with a pressure reducing section 48 that reduces the pressure of the second fluid portion, and a heat absorption section 49 that vaporizes the second fluid portion after being depressurized. A heat dissipation section 55 is provided between the second condensation section 44 of the first flow path 21 and the expansion valve 20, and the heat dissipation section 55 is paired with the heat absorption section 49 and constitutes the heat exchanger 56. The first fluid portion cooled in the second condensing section 44 is further cooled by exchanging heat with the second fluid portion.

The condenser 19 includes a cylindrical inlet header 25 and an outlet header 26, a large number of tubes 27 connecting the headers 25 and 26, and heat radiation fins 28 disposed between adjacent tubes 27. Each header 25, 26 is divided into upstream parts 34, 38 and downstream parts 35, 39 by partitions 33, 37, and a compressor is installed in the upstream part 34 of the inlet header 25. A starting end port 36 is provided that is connected to the 18 discharge pipes, and an intermediate port 40 that serves as a branching point from the first flow path 21 to the second flow path 22 is provided at the upstream portion 38 of the outlet header 26. A terminal port 41 that connects to the heat radiating section 55 of the heat exchanger 56 is provided at the downstream section 39 of the outlet header 26 , and the first condensing section 43 connects from the upstream section 34 of the inlet header 25 to the outlet header 26 . The second condensing section 44 includes a group of tubes 27 that guide the refrigerant to the upstream section 38 and a group of tubes 27 that guide the refrigerant from the upstream section 38 of the outlet header 26 to the downstream section 35 of the inlet header 25. A group of tubes 27 guiding the refrigerant from the downstream section 35 to the downstream section 39 of the outlet header 26 can be adopted.

The intermediate opening 40 faces the upper surface of the partition 37 of the outlet header 26, and the vertical distance from the partition 37 of the exit header 26 to the tube 27 located above it is equal to the vertical distance from the partition 37 to the intermediate opening 40. It can take on a larger form.

It is possible to provide a gap portion 60 at one location of the condenser 19 in which the spacing between adjacent tubes 27 is larger than the other portions, and to arrange the partition 37 of the outlet header 26 on the side of the gap portion 60.

A resistance member 61 that increases the ventilation resistance of the gap portion 60 can be arranged.

The resistance member 61 may include a plate 62 parallel to the tube 27 and a spacer 63 having the same shape as the fin 28 and sandwiching the plate 62 from above and below.

A configuration may be adopted in which the upper surface of the partition 37 is sloped downward toward the intermediate opening 40.

A solenoid valve 47 that opens and closes the second flow path 22 is provided, and when an inflow of gaseous refrigerant into the second flow path 22 is detected, the solenoid valve 47 switches from an open state to a closed state. Can be done.

A first temperature sensor 51 is provided on the exit side of the condenser 19 in the first flow path 21, a second temperature sensor 52 is provided on the exit side of the pressure reducing section 48 in the second flow path 22, and a When the temperature of the second fluid portion measured by the temperature sensor 52 becomes higher than the temperature of the first fluid portion measured by the first temperature sensor 51 by a predetermined temperature or more, the gaseous refrigerant flows into the second flow path 22. The electromagnetic valve 47 may be switched to the closed state by assuming that the state is in the closed state.

The pressure reducing part 48 of the second flow path 22 is configured with a capillary tube, and the first fluid part flowing from the second condensing part 44 to the heat radiation part 55 of the heat exchanger 56 is the second fluid part flowing through the pressure reducing part 48. It can be cooled by heat exchange.

A configuration may be adopted in which the first fluid portion heading from the second condensing section 44 to the heat radiation section 55 of the heat exchanger 56 is cooled by exchanging heat with the first fluid section heading from the evaporator 11 to the compressor 18.

In the cooling device according to the present invention, the condenser 19 is configured with a first condensing section 43 on the upstream side and a second condensing section 44 on the downstream side, and the gas-liquid mixed phase cooled by passing through the first condensing section 43 is Of the non-azeotropic mixed refrigerant, the first fluid part in the gas phase heads to the second condensing part 44, and the second fluid part in the liquid phase goes to the second flow path 22 which branches from between both the condensing parts 43 and 44. I started heading there. Here, the main component of the first fluid portion is a relatively low boiling point refrigerant constituting a non-azeotropic mixed refrigerant, and the main component of the second fluid portion is a relatively high boiling point refrigerant.

In addition, in the present invention, the second flow path 22 is provided with a pressure reducing section 48 and a heat absorption section 49, and a heat radiation section 55 is provided between the second condensing section 44 of the first flow path 21 and the expansion valve 20. In the heat exchanger 56 composed of the heat radiation part 55 and the heat absorption part 49, the first fluid part cooled in the second condensing part 44 is further cooled by exchanging heat with the second fluid part. . In this way, by cooling the first fluid portion separated from the second fluid portion at a plurality of locations, the first fluid portion and thus the evaporator 11 can be reliably cooled to a desired low temperature.

The condenser 19 according to the present invention can be configured with a microchannel heat exchanger in which an inlet header 25 and an outlet header 26 are connected by a plurality of tubes 27. Specifically, each header 25 , 26 is divided into upstream parts 34 , 38 and downstream parts 35 , 39 by partitions 33 , 37 , a starting end port 36 is provided in the upstream part 34 of the inlet header 25 , and a starting end port 36 is provided in the upstream part 34 of the inlet header 25 . An intermediate port 40 serving as a branching point to the second flow path 22 is provided in the section 38 , and a terminal port 41 is provided in the downstream section 39 of the outlet header 26 . The first condensing section 43 is constituted by 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, and the second condensing section 44 is configured from the upstream section 38 of the outlet header 26. It can be comprised of a group of tubes 27 that guide the refrigerant to the downstream section 35 of the inlet header 25 and a group of tubes 27 that guide the refrigerant from the downstream section 35 to the downstream section 39 of the outlet header 26 . In this way, when the first condensing section 43 and the second condensing section 44 are provided in one condenser 19, each condensing section 43 and 44 is constituted by an individual condenser, and a gas-liquid separator is arranged between them. Compared to the conventional case, the refrigeration equipment can be made smaller and the manufacturing cost can be reduced. Reducing the number of members constituting a refrigeration system also contributes to reducing the number of welding points during manufacturing, thereby reducing the risk of refrigerant leakage.

If the vertical distance from the partition 37 of the exit header 26 to the tube 27 located above is larger than the vertical distance from the partition 37 to the intermediate opening 40, in other words, the distance from the upper surface of the partition 37 to the tube 27 When the fluid is moved away from the intermediate port 40, the second fluid portion that has passed through the first condensing section 43 and dripped onto the upper surface of the partition 37 is directed preferentially toward the intermediate port 40, that is, the second flow path 22. , it is possible to suppress the second fluid portion from flowing out to the tube 27 (second condensing section 44) side. In this way, by suppressing the mixing of the liquid phase second fluid portion into the gas phase first fluid portion heading toward the second condensing portion 44, the first fluid portion can be efficiently cooled in the second condensing portion 44. Furthermore, it is possible to reduce the so-called temperature glide, a phenomenon in which the temperature of the refrigerant increases from the inlet to the outlet of the evaporator 11.

By providing a gap portion 60 in which the distance between adjacent tubes 27 is larger than the other gap portions and arranging the partition 37 of the outlet header 26 on the side thereof, the tubes 27 located above the partition 37 are further moved away from the upper surface of the partition 37. This makes it possible to further suppress the second fluid portion of the liquid phase from flowing out to the tube 27 (second condensing section 44) side.

If the gap portion 60 were hollow, the heat exchange air flowing through the condenser 19 would concentrate on the gap portion 60, and as a reaction, the heat exchange air flowing through the tube groups above and below the gap portion 60 would be insufficient, causing each tube 27 to There is a risk that the flowing refrigerant may not be sufficiently cooled. Therefore, in the present invention, a resistance member 61 that increases the ventilation resistance of the gap portion 60 is arranged. Thereby, the heat exchange air can be directed toward the upper and lower tube groups, and the refrigerant flowing through each tube 27 can be accurately cooled.

If the resistance member 61 includes a plate 62 parallel to the tube 27 and a spacer 63 having the same shape as the fin 28 and sandwiching the plate 62 from above and below, the resistance member 61 can support the tube group above the gap part 60. Can be done. Further, the resistance member 61 itself is supported by the tube group below the gap portion 60, so that the overall strength of the condenser 19 can be increased.

When the upper surface of the partition 37 is sloped downward toward the intermediate port 40, the second fluid portion dripping onto the upper surface of the partition 37 is more reliably directed toward the intermediate port 40, that is, the second flow path 22, and It is possible to further suppress the fluid portion from flowing out to the side of the tube 27 (second condensing section 44).

When the inflow of gaseous refrigerant into the second flow path 22 is detected and the solenoid valve 47 that opens and closes the flow path 22 is switched from the open state to the closed state, the gaseous refrigerant continues to flow through the pressure reducing part 48. Failures and malfunctions thereof can be prevented.

When the temperature of the second fluid portion on the outlet side of the pressure reducing part 48 becomes higher than the temperature of the first fluid portion on the outlet side of the condenser 19 by a predetermined temperature or more, gaseous refrigerant is flowing into the second flow path 22. It can be considered as According to this, the inflow of the gaseous refrigerant can be detected at low cost by simply providing the temperature sensors 51 and 52 that measure the temperature of each fluid portion.

The pressure reduction part 48 of the second flow path 22 is configured with a capillary tube, and the first fluid part going from the second condensation part 44 to the heat radiation part 55 of the heat exchanger 56 exchanges heat with the second fluid part flowing through the pressure reduction part 48. By cooling the first fluid portion, the chances of the first fluid portion being cooled are further increased, and the first fluid portion and thus the evaporator 11 can be more reliably cooled to a desired low temperature.

When the first fluid portion heading from the second condensing section 44 to the heat radiation section 55 of the heat exchanger 56 is cooled by exchanging heat with the first fluid section heading from the evaporator 11 to the compressor 18, the first fluid It is possible to further increase the chance that the portion is cooled before depressurization, thereby more reliably cooling the first fluid portion and thus the evaporator 11 to the desired low temperature.

FIG. 1 is a circuit diagram of a refrigeration system according to a first embodiment of the present invention. It is a front view of a deep freezer equipped with the same freezing device. It is a perspective view of the cold storage material and container cooled by the same deep freezer. It is a block diagram of the condenser which comprises the same refrigeration apparatus. It is a sectional view of the tube which constitutes a condenser. It is a block diagram of the condenser which comprises the refrigeration apparatus based on 2nd Embodiment of this invention. It is a block diagram of the condenser which comprises the refrigeration apparatus based on 3rd Embodiment of this invention. It is a circuit diagram of a refrigeration system concerning a 4th embodiment of the present invention.

(First Embodiment) A first embodiment in which a refrigeration apparatus according to the present invention is applied to a deep freezer for cold storage material is shown in FIGS. 1 to 5. In this embodiment, front and back, left and right, and up and down follow the cross arrows shown in FIGS. 2 and 4 and the front and back, left and right, and up and down indications written near each arrow. In FIG. 2, the deep freezer 1 includes a refrigerator main body 2 made of a heat insulating box with an open front, and a door 3 that opens and closes the opening. A refrigerator interior 4 surrounded by a refrigerator body 2 and a 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. In the storage chamber 6, shelf boards 8 having a large number of ventilation holes are installed in a vertically multi-tiered manner, and a container C (see FIG. 3) containing a cold storage material M is placed on each shelf board 8. A large number of ventilation holes are also formed on the wall of the container C.

An evaporator 11 constituting the refrigeration system 10 is provided in the upper and lower center of the cooling chamber 7, and an internal fan 12 is provided above and below the evaporator 11, respectively. In the partition wall 5, a group of blow-off holes 13 are formed 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 hole 13 into the storage chamber 6, and after cooling the container C on the shelf board 8, the air is blown out from the suction hole 14. It is sucked into the cooling chamber 7.

A machine room 17 defined above the storage body 2 houses a compressor 18, a condenser 19, and the like that constitute the refrigeration system 10 together with the evaporator 11. In FIG. 1, the refrigeration system 10 includes a first flow path 21 formed by connecting a compressor 18, a condenser 19, an expansion valve 20, an evaporator 11, etc. in a loop through refrigerant piping, and a first flow path 21 in the middle of the condenser 19. The second flow path 22 is branched from the first flow path 21 and joins the first flow path 21 between the evaporator 11 and the compressor 18. This refrigeration device 10 is sealed with a non-azeotropic mixed refrigerant (hereinafter simply referred to as mixed refrigerant), which is a mixture of two types of refrigerants having different boiling points.

As shown in FIG. 4, the condenser 19 is composed of a microchannel heat exchanger, and includes a hollow inlet header 25 and an outlet header 26 that extend vertically, and a large number of hollow inlet headers 25 and 26 that extend horizontally by connecting the headers 25 and 26. , and heat dissipation fins 28 disposed between the vertically adjacent tubes 27, 27, respectively. A large number of channels 29 having a diameter of several millimeters or less are formed inside each tube 27 (see FIG. 5), where the influence of surface tension occurs. Each fin 28 is curved in a wave-like manner and abuts the tube 27 above and below it, and the condenser fan 30 (see FIG. 1) is parallel to the elongated space surrounded by the tube 27 and the fin 28 (in FIG. The heat exchange air (in the direction perpendicular to the direction) is fed to the condenser 19.

The inlet header 25 is divided into an upper upstream section 34 and a lower downstream section 35 by a partition 33 arranged above the vertical center of the condenser 19. A starting end port 36 connected to 18 discharge pipes is provided. The outlet header 26 is divided into an upper upstream section 38 and a lower downstream section 39 by a partition 37 arranged below the vertical center of the condenser 19 . An upstream portion 38 of the outlet header 26 is provided with an intermediate port 40 that constitutes a branch point from the first flow path 21 to the second flow path 22, and a heat exchanger 56 (described later) is provided in the downstream portion 39 of the outlet header 26. A terminal port 41 is provided which connects to the expansion valve 20 via the terminal port 41 .

The gaseous mixed refrigerant discharged from the compressor 18 flows into the upstream portion 34 of the inlet header 25 via the start port 36 and from there flows through the tube 27 toward the upstream portion 38 of the outlet header 26 . A group of tubes 27 that connect the upstream sections 34 and 38 of the inlet header 25 and the outlet header 26 and allow the mixed refrigerant to flow constitute the first condensing section 43 of the present invention. The mixed refrigerant is air-cooled while flowing through the first condensing section 43, and a portion thereof is condensed. That is, the mixed refrigerant flows into the upstream portion 38 of the outlet header 26 in a gas-liquid multiphase state. Hereinafter, the gas phase portion of the mixed refrigerant in the upstream portion 38 will be referred to as a first fluid portion, and the liquid phase portion will be referred to as a second fluid portion. Of the low boiling point refrigerant and the high boiling point refrigerant constituting the mixed refrigerant, the former becomes the main component of the first fluid portion, and the latter becomes the main component of the second fluid portion.

The first fluid portion (gas phase) of the mixed refrigerant that has reached the upstream section 38 of the outlet header 26 moves to the lower half of the upstream section 38 and from there toward the downstream section 35 of the inlet header 25 through the tube 27. flows. The first fluid portion that reaches the downstream section 35 of the inlet header 25 travels to the lower half of the downstream section 35 and from there flows through the tube 27 towards the downstream section 39 of the outlet header 26 and finally reaches the downstream section 35 of the inlet header 25. It reaches a terminal port 41 provided in the downstream section 39. That is, after the first fluid portion is separated from the second fluid portion at the upstream portion 38 of the outlet header 26, it flows through the two tubes 27 and is air cooled. a group of tubes 27 leading a first fluid portion from an upstream portion 38 of the outlet header 26 to a downstream portion 35 of the inlet header 25; and a group of tubes guiding a first fluid portion from the downstream portion 35 to a downstream portion 39 of the outlet header 26. 27 constitutes the second condensing section 44 of the present invention.

On the other hand, 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 thereof, and the second fluid portion is configured to flow out from the intermediate port 40 into the second flow path 22 . As shown in an enlarged view in FIG. 4, the upper and lower positions of the lower edge of the intermediate opening 40 are approximately equal to the upper surface of the partition 37. The vertical position of the partition 37 is between the vertically adjacent tubes 27 and below the middle thereof. In this way, the partition 37 is arranged closer to the lower tube 27 so that the vertical distance from the partition 37 to the tube 27 located above it is longer than the vertical distance from the partition 37 to the intermediate opening 40. In other words, when the tube 27 is moved further away from the upper surface of the partition 37 than the intermediate port 40, the second fluid portion that has passed through the first condensation section 43 and dripped onto the upper surface of the partition 37 is transferred to the intermediate port 40. That is, it is possible to suppress the second fluid portion from flowing out toward the tube 27 (second condensing section 44) by preferentially directing it toward the second flow path 22 side.

As shown in FIG. 1, the second flow path 22 includes a solenoid valve 47 that opens and closes the flow path 22, a pressure reducing section 48 that is composed of a capillary tube, and a heat absorption section 49 that vaporizes the second fluid portion after pressure reduction. are arranged in the order listed from the upstream side. The second fluid portion vaporized in the heat absorption section 49 flows into the first flow path 21 on the downstream side of the evaporator 11 and returns to the compressor 18 via the accumulator 50 .

The solenoid valve 47 is normally kept open. However, when the refrigeration system 10 is overloaded, heat radiation is insufficient in the first condensing section 43 (condenser 19), and the refrigerant is not sufficiently condensed, resulting in gaseous refrigerant flowing into the second flow path 22. In such a case, the solenoid valve 47 is switched to the closed state to protect the pressure reducing part 48. To enable this control, a first temperature sensor 51 is provided on the exit side of the condenser 19 in the first flow path 21, and a second temperature sensor 52 is provided on the exit side of the pressure reducing section 48 in the second flow path 22. is provided. When the temperature T2 of the second fluid portion measured by the second temperature sensor 52 is 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 second It is assumed that gaseous refrigerant is flowing through the flow path 22, and the solenoid valve 47 is switched to the closed state. When a predetermined period of time (for example, 10 minutes) has elapsed since the solenoid valve 47 was closed, the solenoid valve 47 is opened again.

On the other hand, 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 reducing section 48 of the second flow path 22, and heats up with the second fluid portion flowing through the pressure reducing section 48. It is replaced and cooled. In other words, the pressure reducing section 48 constitutes the auxiliary heat exchanger 57 together with the refrigerant pipe of the first flow path 21 passing near it. The first fluid portion that has passed through the auxiliary heat exchanger 57 reaches the autogenous heat exchanger 54 . In the self-heat exchanger 54, heat is exchanged between the high pressure (upstream side of the expansion valve 20) and low pressure (downstream side of the evaporator 11) first fluid portions. Specifically, a high pressure first fluid portion flowing from the auxiliary heat exchanger 57 is cooled by a low pressure first fluid portion flowing from the evaporator 11 to the accumulator 50 .

The high-pressure first fluid portion that has passed through the auxiliary heat exchanger 57 and the self-heat exchanger 54 reaches the heat radiation section 55 . This heat radiation part 55 forms a pair with the heat absorption part 49 of the second flow path 22 and constitutes a heat exchanger 56. A second fluid portion whose pressure has been reduced by the pressure reducing portion 48 flows through the heat absorption portion 49, and when this second fluid portion vaporizes, it removes heat from the heat radiation portion 55, thereby effectively reducing the first fluid portion. cooled down.

As described above, the first fluid part separated from the second fluid part through the first condensing part 43 of the condenser 19 is connected to the second condensing part 44, the auxiliary heat exchanger 57, the self-heat exchanger 54, and the heat exchanger. 56 (heat radiation part 55) in order, and while flowing through these, it is sufficiently cooled and condensed. The condensed first fluid portion is depressurized by the expansion valve 20 and then reaches the evaporator 11, where it accurately cools the air in the interior 4 of the deep freezer. If the second fluid portion containing a high boiling point refrigerant as a main component is branched to the second flow path 22 and only the first fluid portion containing a low boiling point refrigerant as a main component is led to the evaporator 11, the inlet of the evaporator 11 It is possible to reduce the so-called temperature glide, a phenomenon in which the temperature of the refrigerant increases toward the outlet.

The condenser 19 is constituted by a microchannel heat exchanger in which an inlet header 25 and an outlet header 26 are connected with a plurality of tubes 27, and one condenser 19 is provided with a first condensing section 43 and a second condensing section 44. Compared to the case where each of the condensing sections 43 and 44 is configured with an individual condenser and a gas-liquid separator is disposed between them, the refrigeration apparatus 10 can be made smaller and the manufacturing cost can be reduced. Reducing the number of members constituting the refrigeration device 10 also contributes to reducing the number of welding points during manufacturing, thereby reducing the risk of refrigerant leakage.

When the tube 27 is moved away from the upper surface of the partition 37 of the outlet header 26 than the intermediate port 40, the second fluid portion that has passed through the first condensing section 43 and dripped onto the upper surface of the partition 37 is transferred to the intermediate port 40, that is, the second flow. It is possible to preferentially head to the road 22 side. In this way, by suppressing the mixing of the liquid phase second fluid portion into the gas phase first fluid portion heading toward the second condensing portion 44, the first fluid portion can be efficiently cooled in the second condensing portion 44. Also, temperature glide in the evaporator 11 can be reduced.

(Second Embodiment) FIG. 6 shows a condenser 19 of a refrigeration system according to a second embodiment of the present invention. This condenser 19 differs from the first embodiment in that it includes a gap portion 60 in which the intervals between adjacent tubes 27 are larger than those of the other tubes. The vertical dimension of the gap part 60 is set to about three times the adjacent pitch of the tubes 27 excluding the gap part 60, and the partition 37 of the outlet header 26 and the intermediate opening 40 are arranged on the side of the lower end of the gap part 60. is located. Further, a resistance member 61 is arranged in the gap portion 60 to increase its ventilation resistance. Specifically, the resistance member 61 is composed of two metal plates 62 parallel to the tube 27 and three spacers 63 that sandwich these plates 62 from above and below. The plate 62 has the same vertical thickness as the tube 27, and the spacer 63 is made of the same material and has the same shape as the fin 28. The plate 62 is made of aluminum with high thermal conductivity, and works together with the spacer 63 to dissipate heat. Since the rest is the same as in the first embodiment, the same members are given the same reference numerals and their explanations will be omitted. The same applies to the third embodiment and subsequent embodiments.

By providing a gap portion 60 in which the distance between adjacent tubes 27 is larger than the other gap portions and arranging the partition 37 of the outlet header 26 on the side thereof, the tubes 27 located above the partition 37 are further moved away from the upper surface of the partition 37. This makes it possible to further suppress the second fluid portion of the liquid phase from flowing out to the tube 27 (second condensing section 44) side.

By arranging the resistance member 61 that increases the ventilation resistance of the gap portion 60, the heat exchange air flowing through the condenser 19 is prevented from concentrating on the gap portion 60, and is directed toward the upper and lower tube groups, thereby increasing the airflow resistance of each tube 27. It is possible to accurately cool the flowing refrigerant. Further, if the resistance member 61 includes a plate 62 parallel to the tube 27 and a spacer 63 having the same shape as the fin 28 and sandwiching the plate 62 from above and below, the resistance member 61 supports the tube group above the gap portion 60. be able to. Further, the resistance member 61 itself is supported by the tube group below the gap portion 60, so that the overall strength of the condenser 19 can be increased.

(Third Embodiment) FIG. 7 shows a condenser 19 of a refrigeration system according to a third embodiment of the present invention. This condenser 19 differs from the first embodiment in that the entire condenser is sloped gently downward from the inlet header 25 toward the outlet header 26. The upper surface of the partition 37 of the outlet header 26 is also sloped downward toward the intermediate port 40. Accordingly, the second fluid portion dripping onto the upper surface of the partition 37 is more reliably directed to the intermediate port 40, that is, the second flow. By directing it toward the path 22, it is possible to further suppress the second fluid portion from flowing out toward the tube 27 (second condensing section 44).

(4th Embodiment) 4th Embodiment of the refrigeration apparatus based on this invention is shown in FIG. In this embodiment, the first condensing section 43 and the second condensing section 44 are each composed of an individual condenser, for example, a fin-tube heat exchanger, and a gas-liquid separator 70 is provided between the two condensing sections 43 and 44. It is located. The inflow port of the gas-liquid separator 70 is connected to the outlet of the first condensing section 43, the gas outflow port is connected to the inlet of the second condensing section 44, and the liquid outflow port is connected from the first flow path 21 to the second flow path 22. Configure a branch point to.

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 types of cooling equipment such as food freezers, frozen showcases, and ice makers. Can be done.

10 Refrigeration device 11 Evaporator 18 Compressor 19 Condenser 20 Expansion valve 21 First channel 22 Second channel 25 Inlet header 26 Outlet header 27 Tube 28 Fin 33 Inlet header partition 34 Upstream part of inlet header 35 Inlet header Downstream section 36 Start port 37 Partition of the outlet header 38 Upstream section of the outlet header 39 Downstream section of the outlet header 40 Intermediate port 41 Terminal port 43 First condensing section 44 Second condensing section 48 Pressure reducing section 49 Heat absorption section 51 First temperature sensor 52 Second temperature sensor 54 Self-heat exchanger 55 Heat radiation section 56 Heat exchanger 57 Auxiliary heat exchanger 60 Gap section 61 Resistance member 62 Plate 63 Spacer 70 Gas-liquid separator

Claims (11)

A refrigeration device sealed with a non-azeotropic mixed refrigerant,
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 through refrigerant piping; ) is provided with a second flow path (22) that branches off from the expansion valve (20) and bypasses 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 a second flow path ( 22) is branched,
Of the gas-liquid multiphase non-azeotropic mixed refrigerant cooled in the first condensing part (43), the first fluid part in the gas phase goes to the second condensing part (44), and the second fluid part in the liquid phase goes to the second condensing part (44). 2 flow path (22),
The second flow path (22) is provided with a pressure reducing part (48) that reduces the pressure of the second fluid part, and a heat absorption part (49) that vaporizes the second fluid part after the pressure reduction.
Between the second condensing section (44) and the expansion valve (20) of the first flow path (21), a heat dissipating section (55) which pairs with the heat absorbing section (49) and constitutes the heat exchanger (56) is provided. It is provided,
A refrigeration system characterized in that, in the heat exchanger (56), the first fluid portion cooled in the second condensing section (44) exchanges heat with the second fluid portion to be further cooled. A condenser (19) is located between a cylindrical inlet header (25) and an outlet header (26), a number of tubes (27) connecting the headers (25 and 26), and adjacent tubes (27). It consists of a microchannel heat exchanger with heat dissipation fins (28) arranged,
Each header (25, 26) is divided into an upstream part (34, 38) and a downstream part (35, 39) by a partition (33, 37),
A starting end port (36) connected to the discharge pipe of the compressor (18) is provided at the upstream portion (34) of the inlet header (25),
An intermediate port (40) serving as a branching point from the first flow path (21) to the second flow path (22) is provided at the upstream portion (38) of the outlet header (26).
A terminal port (41) connected to the heat dissipation section (55) of the heat exchanger (56) is provided in the downstream section (39) of the outlet header (26),
The first condensing 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);
A second condensing section (44) comprises a group of tubes (27) that conduct refrigerant from an upstream section (38) of the outlet header (26) to a downstream section (35) of the inlet header (25); 2. A refrigeration system according to claim 1, comprising a group of tubes (27) conducting the refrigerant from the outlet header (26) to the downstream part (39) of the outlet header (26). The intermediate opening (40) faces the top surface of the partition (37) of the exit header (26),
The vertical distance from the partition (37) of the outlet header (26) to the tube (27) located above it is larger than the vertical distance from the partition (37) to the intermediate opening (40). Refrigeration equipment as described. A gap portion (60) is provided at one location of the condenser (19), where the interval between adjacent tubes (27) is larger than the other gap portions;
The refrigeration system according to claim 3, wherein the partition (37) of the outlet header (26) is arranged on the side of the gap (60). The refrigeration system according to claim 4, further comprising a resistance member (61) that increases the ventilation resistance of the gap portion (60). The refrigeration device according to claim 5, wherein the resistance member (61) includes a plate (62) parallel to the tube (27), and a spacer (63) having the same shape as the fin (28) and sandwiching the plate (62) from above and below. . The refrigeration system according to claim 3, wherein the upper surface of the partition (37) of the outlet header (26) is sloped downward toward the intermediate port (40). Equipped with a solenoid valve (47) that opens and closes the second flow path (22),
The refrigeration system according to any one of claims 1 to 7, wherein the electromagnetic valve (47) switches from an open state to a closed state when the inflow of gaseous refrigerant into the second flow path (22) is detected. 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 part (48) in the second flow path (22),
When the temperature of the second fluid portion measured by the second temperature sensor (52) is higher than the temperature of the first fluid portion measured by the first temperature sensor (51) by a predetermined temperature or more, the temperature of the second fluid portion measured by the second temperature sensor (52) becomes higher than the temperature of the first fluid portion measured by the first temperature sensor (51). 9. The refrigeration system according to claim 8, wherein the electromagnetic valve (47) is switched to the closed state by assuming that the gaseous refrigerant is flowing into the refrigerant. The pressure reducing part (48) of the second flow path (22) is composed of a capillary tube,
Claim 1: The first fluid portion flowing from the second condensing portion (44) to the heat radiating portion (55) of the heat exchanger (56) is cooled by exchanging heat with the second fluid portion flowing through the pressure reducing portion (48). 7. The refrigeration device according to any one of 7. The first fluid portion going from the second condensing section (44) to the heat radiation section (55) of the heat exchanger (56) exchanges heat with the first fluid section going from the evaporator (11) to the compressor (18). The refrigeration device according to any one of claims 1 to 7, wherein the refrigeration device is cooled.

Images