JP6813373B2 - Accumulator with internal heat exchanger and refrigeration cycle equipped with it - Google Patents

Description

The present invention relates to an accumulator with an internal heat exchanger having a heat exchange function and a refrigeration cycle including the accumulator.

As an accumulator with an internal heat exchanger of this type, for example, an accumulator including an internal heat exchanger for an air conditioning system described in Patent Document 1 has been proposed.
The accumulator described in Patent Document 1 includes a tubular housing and an internal heat exchanger housed in the housing. The internal heat exchanger includes a tubular structure having a high-pressure line formed on the outside and a low-pressure line formed on the inside, which is smaller than the inner diameter of the housing, and a liquid container having a smaller diameter inside the tubular structure. Is placed.

A gas-liquid two-phase refrigerant is supplied to the liquid container via a tubular element and separated into a gas-phase refrigerant and a liquid-phase refrigerant, and the separated vapor-phase refrigerant goes down a low-pressure line formed in a tubular structure. It is discharged through. The high-pressure refrigerant flows from the lower end side to the upper end in the high-pressure line of the tubular structure, so that the high-pressure refrigerant and the low-pressure refrigerant exchange internal heat in the tubular structure.

Japanese Patent No. 5350578

By the way, in the accumulator described in Patent Document 1, a liquid container and an internal heat exchanger are arranged inside the housing so that the low-pressure refrigerant exchanges internal heat with the high-pressure refrigerant. For this reason, the internal structure of the housing becomes complicated, and the high-pressure line is arranged inside the housing, so that it is difficult to detect when an internal leakage of the high-pressure refrigerant occurs, and an internal leakage defect during manufacturing There is a problem that it cannot be found.
Therefore, the present invention has been made by paying attention to the problems of the conventional example described in the above-mentioned Patent Document 1, and includes an internal heat exchanger that can easily detect a leak of a high-pressure refrigerant with a simple configuration. It is an object of the present invention to provide an accumulator and a refrigeration cycle equipped with the accumulator.

In order to solve the above problems, one aspect of the accumulator with an internal heat exchanger according to the present invention is arranged on the upstream side of the compressor provided in the circulation path for circulating the refrigerant in the refrigeration cycle, and is a gas-liquid two-phase refrigerant. An accumulator that separates gas and liquid, and has a gas-liquid separation part having a double-tube structure into which a gas-liquid two-phase refrigerant is introduced, and a flat pipe through which a high-pressure refrigerant wound around the outer circumference of the gas-liquid separation part passes. The internal heat exchange is performed between the gas-liquid separation part and the flat pipe.

Further, one aspect of the refrigeration cycle according to the present invention is a compressor that sucks and compresses the refrigerant, a radiator that cools the refrigerant compressed by the compressor, and a decompressor that decompresses the refrigerant cooled by the radiator. The evaporator that evaporates the refrigerant decompressed by this decompressor and the gas-liquid two-phase refrigerant that flows out from this evaporator are separated into a gas-phase refrigerant and a liquid-phase refrigerant, and the separated vapor-phase refrigerant is used as a compressor. The above-mentioned accumulator with an internal heat exchanger is provided, and the gas-liquid two-phase refrigerant is supplied to the gas-liquid separation section of the accumulator with an internal heat exchanger, and the separated vapor-phase refrigerant is supplied to the compressor to dissipate heat. The high-pressure refrigerant flowing out of the vessel is supplied to the flat tube, and the high-pressure refrigerant discharged from the flat tube is supplied to the decompressor.

According to one aspect of the present invention, since the flat pipe through which the high-pressure refrigerant flows is arranged outside the gas-liquid separation portion, an internal heat exchanger that can easily detect the leakage of the high-pressure refrigerant with a simple configuration. An accumulator with an accumulator and a refrigeration cycle equipped with the accumulator can be provided.

It is an overall block diagram which shows one Embodiment of the refrigeration cycle which concerns on this invention. It is a perspective view which shows the 1st Embodiment of the accumulator with an internal heat exchanger which concerns on this invention. It is a top view of the accumulator with an internal heat exchanger which concerns on this invention. It is sectional drawing on the IV-IV line of FIG. It is a front view of the accumulator with an internal heat exchanger which concerns on this invention. It is sectional drawing on the VI-VI line of FIG. It is a perspective view which shows the double tube. It is a top view of a double pipe. It is a perspective view which shows the 2nd Embodiment of the accumulator with an internal heat exchanger which concerns on this invention. It is a top view of the 2nd Embodiment. It is sectional drawing on the XI-XI line of FIG. It is sectional drawing on the XII-XII line of FIG. It is a front view of the 2nd Embodiment. It is sectional drawing on the XIV-XIV line of FIG.

Next, an embodiment of the present invention will be described with reference to the drawings. In the description of the drawings below, the same or similar parts are designated by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the plane dimension, the ratio of the thickness of each layer, etc. are different from the actual ones. Therefore, the specific thickness and dimensions should be determined in consideration of the following explanation. In addition, it goes without saying that the drawings include parts having different dimensional relationships and ratios from each other.

In addition, the embodiments shown below exemplify devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention describes the material, shape, structure, and the like of the components. The arrangement etc. is not specified as the following. The technical idea of the present invention may be modified in various ways within the technical scope specified by the claims stated in the claims.

[First Embodiment]
First, a refrigeration cycle representing one aspect of the present invention will be described with reference to FIG.
As shown in FIG. 1, the refrigeration cycle according to the present invention constitutes, for example, a vehicle air conditioner. The refrigeration cycle 1 circulates a CO ₂ refrigerant (hereinafter, simply referred to as a refrigerant), which is a natural refrigerant, to air-condition the interior of the vehicle. The refrigeration cycle 1 is installed from the engine room 3 provided with the engine 2 to the vehicle interior 4.

Specifically, the refrigeration cycle 1 includes a compressor 11 driven by an engine 2, a radiator 12, an accumulator 13 with an internal heat exchanger, an expansion valve 14, and an evaporator 15.
The compressor 11 sucks and compresses the vapor phase refrigerant to raise the temperature and raise the pressure, and can be selected from compressors such as a reciprocating compressor, a rotary compressor, and a scroll compressor. The refrigerant compressed by the compressor 11 is supplied to the radiator 12 through the refrigerant pipe RP1.

The radiator 12 cools the refrigerant compressed by the compressor 11 by exchanging heat with the outside air. The high-pressure refrigerant cooled by the radiator 12 is supplied to the flat pipe 31 described later provided in the accumulator 13 with an internal heat exchanger via the refrigerant pipe RP2. The high-pressure refrigerant flowing out of the accumulator 13 with an internal heat exchanger is decompressed by the expansion valve 14 as a decompressor arranged in the refrigerant pipe RP3 and supplied to the evaporator 15 as a low-pressure refrigerant.

The evaporator 15 cools the vehicle interior air by exchanging heat with the vehicle interior air of the refrigerant decompressed by the expansion valve 14. The gas-liquid two-phase refrigerant flowing out of the evaporator 15 is supplied to the accumulator 13 with an internal heat exchanger via the refrigerant pipe RP4 and separated into the liquid-phase refrigerant and the gas-phase refrigerant, and the vapor-phase refrigerant is separated into the refrigerant pipe RP5. It is supplied to the compressor 11 via.
The accumulator 13 with an internal heat exchanger exchanges internal heat with the high-pressure refrigerant supplied from the radiator 12 for the low-pressure gas-phase refrigerant having a low gas-liquid separation temperature, and then supplies the compressor 11 to the compressor 11.

As shown in FIGS. 2, 3 and 4, the specific configuration of the accumulator 13 with an internal heat exchanger is such that the gas-liquid separation unit 21 and the internal heat exchanger are wound around the outer peripheral surface of the gas-liquid separation unit 21. It is composed of a flat tube 31 to be formed.
As shown in FIG. 4, the gas-liquid separation unit 21 includes, for example, a cylindrical double pipe 22 having both ends open, a first cap 23 attached to the upper end of the double pipe 22, and a double pipe 22. It is provided with a second cap 24 attached to the lower end portion of the.

As shown in FIGS. 4, 6, 7, and 8, the double pipe 22 is made of an extruded product obtained by extruding a metal material such as aluminum or an aluminum alloy having high thermal conductivity, and has a thick wall thickness. It includes a thick outer cylinder 22a and an inner cylinder 22b having a smaller diameter and a thinner wall than the outer cylinder 22a.
As shown in FIG. 4, the outer cylinder 22a and the inner cylinder 22b are formed so that the upper end is flush with each other and the lower end is long so that the inner cylinder 22b projects downward from the outer cylinder 22a. Further, as shown in FIGS. 4, 7 and 8, the outer cylinder 22a and the inner cylinder 22b are connected by a partition wall 22c extending in the axial direction formed at a predetermined interval in the circumferential direction. The space surrounded by the inner peripheral surface of the outer cylinder 22a, the outer peripheral surface of the inner cylinder 22b, and the two adjacent partition walls 22c is a gas phase refrigerant passage 22d through which the vapor phase refrigerant passes. Therefore, a plurality of (for example, 18) gas phase refrigerant passages 22d are formed between the outer cylinder 22a and the inner cylinder 22b in the circumferential direction.

Further, at the upper end of the inner cylinder 22b, a communication groove 22e that communicates the inner surface of the inner cylinder 22b and each gas phase refrigerant passage 22d is formed.
The first cap 23 is formed of, for example, the same metal material as the double pipe 22, and as shown in FIGS. 2 to 4, a disc portion 23a that closes the upper end of the double pipe 22 and the disc portion 23a. A ring-shaped flange portion 23b that extends downward from the outer peripheral surface of the double pipe 22 and fits on the outer peripheral surface of the outer cylinder 22a of the double pipe 22 is provided. An inflow pipe 23c for flowing the gas-liquid two-phase refrigerant supplied from the evaporator 15 into the inner cylinder 22b of the double pipe 22 is formed through the central portion of the disk portion 23a.

The second cap 24 is formed of, for example, the same metal material as the double pipe 22, and as shown in FIGS. 2 and 4, a disc portion 24a that closes the lower end of the inner cylinder 22b of the double pipe 22 and the disc portion 24a thereof. It is provided with a ring-shaped flange portion 24b that extends upward from the outer peripheral surface of the disk portion 24a and fits onto the outer peripheral surface of the outer cylinder 22a of the double pipe 22.
The second cap 24 has a liquid reservoir 26 for storing the liquid phase refrigerant and lubricating oil separated on the lower end side of the inner cylinder 22b by the disc portion 24a closing the lower end of the inner cylinder 22b of the double pipe 22. The outer peripheral surface of the inner cylinder 22b, the disk portion 24a, and the flange portion 24b form a vapor-phase refrigerant reservoir 24c that temporarily stores the vapor-phase refrigerant flowing out of the vapor-phase refrigerant passage 22d.

Then, the discharge pipe 24d that supplies the vapor phase refrigerant temporarily stored in the vapor phase refrigerant reservoir 24c between the outer peripheral surface of the inner cylinder 22b of the double pipe 22 of the disk portion 24a and the flange portion 24b to the compressor 11. Is formed through. Here, the opening surface of the discharge pipe 24d to the gas phase refrigerant reservoir 24c opens to the gas phase refrigerant reservoir 24c of the discharge pipe 24d so as to open at a position about half the height of the vapor phase refrigerant reservoir 24c. The protrusion height of is set.

Further, an oil return groove 27 that returns the oil stored in the liquid reservoir 26 to the adjacent vapor-phase refrigerant reservoir 24c at a position on the lower end surface of the inner cylinder 22b of the double pipe 22 opposite to the discharge pipe 24d side. Is formed.
The double pipe 22 and the first cap 23 and the second cap 24 may be joined by welding or brazing in the fitted state, and the first cap is formed on the male threaded portions formed at both ends of the outer cylinder 22a. The female threaded portion formed on the 23 and the second cap 24 may be screwed.

As shown in FIGS. 2 to 6, the flat pipe 31 is wound so as to cover the outer peripheral surface of the double pipe 22 exposed from the first cap 23 and the second cap 24. The flat pipe 31 is made of a metal material such as aluminum or an aluminum alloy having high thermal conductivity like the double pipe 22 and is made of an extruded product by extrusion molding. Further, as shown in FIG. 4, a plurality of high-pressure refrigerant passages 31a through which the high-pressure refrigerant passes at predetermined intervals in the axial direction of the double pipe 22 are formed in the flat pipe 31. Further, the flat pipe 31 has an inner peripheral length set shorter than the outer peripheral length of the outer cylinder 22a, and as shown in FIGS. 2 and 3, both ends of the flat pipe 31 in the circumferential direction of the outer cylinder 22a. It is connected to the first connecting pipe 32 and the second connecting pipe 33 arranged along the outer peripheral surface in the axial direction.

As shown in FIG. 6, the first connecting pipe 32 is formed of a cylindrical body having both upper and lower ends closed, and as shown in FIG. 5, an inflow port 32a for flowing a high-pressure refrigerant is formed on the lower end side, and in FIG. A fitting hole 32b for fitting one end of the flat tube 31 is formed on the left side surface extending in the axial direction. Then, one end of the flat pipe 31 is fitted and connected to the fitting hole 32b of the first connecting pipe 32, and the inside of the first connecting pipe 32 and each high-pressure refrigerant passage 31a of the flat pipe 31 are communicated with each other.

As shown in FIG. 6, the second connecting pipe 33 is formed of a cylindrical body having both upper and lower ends closed like the first connecting pipe 32, and as shown in FIG. 5, the discharge port 33a for discharging the high-pressure refrigerant to the upper end. Is formed, and a fitting hole 33b for fitting the other end of the flat tube 31 is formed so as to extend in the axial direction on the right side surface as seen in FIG. Then, the other end of the flat pipe 31 is fitted and connected to the fitting hole 33b of the second connecting pipe 33, and the inside of the second connecting pipe 33 and each high-pressure refrigerant passage 31a of the flat pipe 31 are communicated with each other.

Then, the inflow port 32a of the first connecting pipe 32 of the accumulator 13 with an internal heat exchanger is connected to the refrigerant pipe RP2, and the discharge port 33a of the second connecting pipe 33 is connected to the expansion valve 14 via the refrigerant pipe RP3. There is. Further, the inflow pipe 23c of the first cap 23 of the accumulator 13 with an internal heat exchanger is connected to the refrigerant discharge port of the evaporator 15 via the refrigerant pipe RP4, and the discharge pipe 24d of the second cap 24 is connected via the refrigerant pipe RP5. Is connected to the compressor 11.

Next, the operation of the first embodiment will be described.
In the refrigeration cycle 1, the vapor phase refrigerant is compressed by the compressor 11 and supplied to the radiator 12 as a high-pressure refrigerant. This high-pressure refrigerant is cooled by heat exchange with the outside air by the radiator 12. In this cooling step, the temperature of the high-pressure refrigerant changes while being substantially isobaric.
The cooled high-pressure refrigerant is supplied to the inflow port 32a of the first connecting pipe 32 of the accumulator 13 with an internal heat exchanger, and is distributed and flows into each high-pressure refrigerant passage 31a of the flat pipe 31 by the first connecting pipe 32. The high-pressure refrigerant discharged from the other end side of the high-pressure refrigerant passage 31a is collected by the second connecting pipe 33 and supplied to the expansion valve 14 from the discharge port 33a.

The refrigerant decompressed and expanded by the expansion valve 14 is supplied to the evaporator 15 and exchanges heat with the vehicle interior air, and is used as a gas-liquid two-phase refrigerant as an inflow pipe 23c of the first cap 23 of the accumulator 13 with an internal heat exchanger. Is supplied to.
In the accumulator 13 with an internal heat exchanger, the gas-liquid two-phase refrigerant flowing from the inflow pipe 23c of the first cap 23 flows into the inner cylinder 22b of the double pipe 22 and is separated into gas and liquid, and has the highest specific gravity. A large amount of oil is stored in the lowermost layer in the liquid storage portion 26 formed on the lower end side of the inner cylinder 22b, and a separated liquid phase refrigerant having a small specific gravity with respect to the oil is stored on the lowermost layer.

Further, the separated vapor-phase refrigerant moves to the second cap 24 side through the communication groove 22e formed at the upper end of the inner cylinder 22b and further through the gas-phase refrigerant passage 22d formed between the outer cylinder 22a and the inner cylinder 22b. To do. At this time, the flat pipe 31 is wound around the outside of the vapor phase refrigerant passage 22d, and the high-temperature high-pressure refrigerant from the radiator 12 is passed through the high-pressure refrigerant passage 31a of the flat pipe 31. Internal heat exchange is performed between the high-pressure refrigerant and the low-pressure vapor-phase refrigerant at a low temperature. Therefore, the high-temperature high-pressure refrigerant is cooled, and the low-temperature gas-phase refrigerant is heated. Then, the vapor-phase refrigerant whose temperature has risen due to internal heat exchange returns to the compressor 11 from the vapor-phase refrigerant reservoir 24c of the second cap 24 through the discharge pipe 24d while maintaining the vapor phase state.

Further, the oil stored in the liquid reservoir 26 of the accumulator 13 with an internal heat exchanger is returned to the gas phase refrigerant reservoir 24c through the oil return groove 27 formed at the lower end of the inner cylinder 22b, and the upper surface of the oil is discharged. When it exceeds the upper surface of the pipe 24d, it is returned to the compressor 11 together with the vapor phase refrigerant.
As described above, according to the first embodiment, the flat tube 31 through which the high-pressure refrigerant flows is wound around the outer peripheral side of the gas-liquid separation unit 21 constituting the accumulator 13 with an internal heat exchanger to form the internal heat exchanger. Therefore, in order to secure a sufficient liquid storage volume, it is only necessary to increase the outer diameter of the double pipe 22 constituting the gas-liquid separation portion 21 and increase the inner diameters of the outer cylinder 22a and the inner cylinder 22b.

Further, since the flat pipe 31 through which the high-pressure refrigerant flows is wound around the outer peripheral side of the gas-liquid separation portion 21, if the high-pressure refrigerant leaks from the flat pipe 31, it can be easily detected by using the CO ₂ sensor. can do. Further, when the CO ₂ sensor cannot be used, the leakage of the high-pressure refrigerant can be easily detected by attaching the accumulator 13 with an internal heat exchanger in the liquid and visually recognizing the presence or absence of air bubbles. Further, the leakage of the high-pressure refrigerant at the completion of the production of the accumulator 13 with the internal heat exchanger can be detected in the same manner.

Further, in the first embodiment, the gas-liquid separation portion 21 of the accumulator 13 with an internal heat exchanger is closed to the double pipe 22 and both ends of the double pipe individually with the first cap 23 and the second cap. The configuration can be as simple as providing 24, and can be easily configured with a small number of parts. Moreover, since the double tube 22 can be made of an extruded product obtained by extruding a metal material having a high thermal conductivity, it can be easily manufactured.

Further, since the opening position of the discharge pipe 24d formed in the second cap 24 is higher than the bottom surface of the gas phase refrigerant reservoir 24c, the liquid phase refrigerant can be discharged from the oil return groove 27 formed at the lower end of the inner cylinder 22b. When the gas-phase refrigerant reservoir 24c leaks, the leaked liquid-phase refrigerant can be accumulated up to the opening position of the discharge pipe 24d, preventing the liquid-phase refrigerant from being discharged from the discharge pipe 24d to the compressor 11. can do.

Further, the flat pipe 31 is internally formed with a plurality of high-pressure refrigerant passages 31a spaced apart in the axial direction, and the high-pressure refrigerant is distributed and supplied from the first connecting pipe 32 to each high-pressure refrigerant passage 31a. Since the high-pressure refrigerant in the high-pressure refrigerant passage 31a is recovered by the second connecting pipe 33, the high-pressure refrigerant can be uniformly flowed, and the internal heat exchange can be efficiently performed.
In the first embodiment, the case where the flat pipe 31 is formed to be wide covering the exposed portion of the double pipe 22 has been described, but the present invention is not limited to this, and a plurality of flat pipes 31 are provided in the axial direction. The divided flat pipes may be connected in parallel to the first connecting pipe 32 and the second connecting pipe 33.

Next, a second embodiment of the present invention will be described with reference to FIGS. 9 to 14.
In this second embodiment, a plurality of rows of flat pipes are wound around the outer circumference of the double pipes, and the flow direction of the high-pressure refrigerant is reversed for each row of the flat pipes.
That is, in the second embodiment, as shown in FIGS. 9 and 13, a plurality of accumulators 13 with an internal heat exchanger are provided on the outer peripheral surface of the double pipe 22 exposed from the first cap 23 and the second cap 24, for example. It is configured by winding four rows of flat tubes 41A, 41B, 41C and 41D in the axial direction of a double tube at predetermined intervals. As shown in FIGS. 11 and 12, a plurality of, for example, seven high-pressure refrigerant passages 41a to 41d are formed in parallel in each of the flat pipes 41A to 41D in the width direction which is the axial direction of the double pipe 22. Has been done.

Then, one end of each of the flat pipes 41A to 41D is connected to the first connecting pipe 42, and the other end is connected to the second connecting pipe 43.
As shown in FIG. 11, the first connecting pipe 42 is formed of a cylindrical body having both ends closed, and a partition plate 44a is provided at a position corresponding to between the flat pipes 41A and 41B in the internal space. A partition plate 44b is provided at a position corresponding to the flat pipes 41C and 41D, and three communication spaces 45a, 45b and 45c are formed. A high-temperature high-pressure refrigerant inflow port 46a is formed on the lower end side of the communication space 45a, and a high-pressure refrigerant discharge port 46b is formed on the upper end side of the communication space 45c.

As shown in FIG. 12, the second connecting pipe 43 is composed of a cylindrical body having both ends closed, like the first connecting pipe 42, and the internal space is partitioned between the flat pipes 41B and 41C at positions corresponding to each other. A plate 44c is provided to form two communication spaces 47a and 47b.
Therefore, the high-temperature high-pressure refrigerant supplied from the radiator 12 to the inflow port 46a is evenly distributed to each high-pressure refrigerant passage 41a of the flat pipe 41A in the communication space 45a of the first connected pipe 42, and each high pressure is supplied. It flows through the refrigerant passage 41a toward the communication space 47a of the second connecting pipe 43 as shown by the solid line arrow in FIG.

The high-pressure refrigerant that has passed through the high-pressure refrigerant passages 41a of the flat pipe 41A merges on the lower side of the communication space 47a of the second connecting pipe 43 and enters each high-pressure refrigerant passage 41b of the flat pipe 41B from the upper side of the communication space 47a. It is evenly distributed and flows in each high-pressure refrigerant passage 41a in the direction opposite to the flow in the flat pipe 41A as shown by the solid line arrow in FIG. 13 toward the communication space 45b of the first connected pipe 42.
The high-pressure refrigerant that has passed through each of the high-pressure refrigerant passages 41b of the flat pipe 41B merges on the lower side of the communication space 45b of the first connected pipe 42, and enters each high-pressure refrigerant passage 41c of the flat pipe 41C from the upper side of the communication space 45b. It is evenly distributed and flows through each high-pressure refrigerant passage 41a in the direction opposite to the flow in the flat pipe 41B as shown by the solid line arrow in FIG. 13 toward the communication space 47b of the second connected pipe 43.

The high-pressure refrigerant that has passed through each high-pressure refrigerant passage 31c of the flat pipe 31C merges on the lower side of the communication space 47b of the second connected pipe 43, and enters each high-pressure refrigerant passage 41d of the flat pipe 31D from the upper side of the communication space 47b. It is evenly distributed and flows through each high-pressure refrigerant passage 41d in the direction opposite to the flow in the flat pipe 41C as shown by the solid line arrow in FIG. 13 toward the communication space 45c of the first connected pipe 32.
The high-pressure refrigerant that has passed through the high-pressure refrigerant passage 41a of the flat pipe 41D merges in the communication space 45c of the first connecting pipe 42 and is discharged to the expansion valve 14 from the discharge port 46b on the upper side.

Other configurations have the same configurations as those of the first embodiment described above, and the parts corresponding to the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.
Next, the operation of the second embodiment will be described.
Since the gas-liquid separation unit 21 has the same configuration as that of the first embodiment described above, the low-pressure gas-liquid two-phase refrigerant flowing from the inflow pipe 23c of the first cap 23 is contained in the double pipe 22. An oil layer is formed in the lower layer of the liquid reservoir 26 due to the difference in specific gravity introduced into the cylinder 22b, and a liquid phase refrigerant layer is formed in the upper layer. Further, the separated vapor-phase refrigerant flows down through the gas-phase refrigerant passage 22d between the outer cylinder 22a and the inner cylinder 22b, and is discharged to the compressor 11 from the discharge pipe 24d of the second cap 24. The oil in the oil layer accumulated in the lower layer of the liquid reservoir 26 is merged with the vapor phase refrigerant through the oil return groove 27 and returned to the compressor 11.

At this time, the low-temperature low-pressure vapor-phase refrigerant flowing down through the gas-phase refrigerant passage 22d between the outer cylinder 22a and the inner cylinder 22b passes through the flat pipes 41A to 41D wound around the outer periphery of the double pipe 22. The temperature rises due to internal heat exchange with the high-pressure refrigerant.
In the flat pipes 41A to 41D, the high-pressure refrigerant flowing from the inflow port 46a of the first connecting pipe 32 flows into the high-pressure refrigerant passage 41a of the lowermost flat pipe 41A toward the second connecting pipe 43, and the pressure is high on the opposite side. After the refrigerant merges through the communication space 47a of the second connecting pipe 43, it is evenly distributed to the high-pressure refrigerant passage 41b of the flat pipe 41B and flows in the direction opposite to the flow in the flat pipe 41A.

After that, the high-pressure refrigerant sequentially passes through the communication space 45b of the first connecting pipe 42, the high-pressure refrigerant passage 41c of the flat pipe 41C, the communication space 47b of the second connecting pipe 43, and the high-pressure refrigerant passage 41d of the flat pipe 41D of the first connecting pipe 42. It reaches the communication space 45c and is discharged to the expansion valve 14 from the discharge port 46b of the communication space 45c.
As described above, according to the second embodiment, since the gas-liquid separation unit 21 has the same configuration as that of the first embodiment described above, the same action and effect as that of the first embodiment can be obtained. ..

Regarding the internal heat exchange function, the high-pressure refrigerant continuously reaches from the lowest flat pipe 41A to the uppermost flat pipe 41D by the plurality of flat pipes 41A to 41D, the first connecting pipe 42, and the second connecting pipe 43. High-pressure refrigerant passage is formed. Therefore, by utilizing the circumferential lengths of the flat tubes 41A to 41D, the total length of the high-pressure refrigerant flow paths can be significantly lengthened as compared with the first embodiment described above, which is efficient. Internal heat exchange can be performed.

Here, the high-pressure refrigerant flowing in from the lowermost flat pipe 41A reaches the uppermost flat pipe 41D while repeating distribution and merging in the first connecting pipe 42 and the second connecting pipe 43. Therefore, the temperature unevenness of the high-pressure refrigerant can be eliminated, and uniform heat exchange becomes possible, so that more efficient internal heat exchange can be performed. Further, the high-pressure refrigerant passes through the plurality of high-pressure refrigerant passages 41a to 41d in the flat pipes 41A to 41D, so that the flow velocity increases and the stirring of the high-pressure refrigerant in the first connecting pipe 42 and the second connecting pipe 43 is promoted. To.

Further, a continuous high-pressure refrigerant passage can be formed only by winding a plurality of flat pipes 41A to 41D in parallel and individually connecting both ends thereof to the first connecting pipe 42 and the second connecting pipe 43. The flat pipes 41A to 41D are not complicatedly processed, and the flat pipes 41A to 41D, the first connecting pipe 42 and the second connecting pipe 43 can be easily attached to the outer peripheral surface of the gas-liquid separation portion 21. it can.

Moreover, the high-pressure refrigerant flows through the flat tubes 41A to 41D in order from the bottom to the top outside the gas-liquid separation section 21, while the gas-phase refrigerant separated by the gas-liquid separation section 21 flows from the upper end of the inner cylinder 22b to the communication groove 22e. Further, it flows down to the second cap 24 side through the gas-phase refrigerant passage 22d formed between the outer cylinder 22a and the inner cylinder 22b. Therefore, the gas phase refrigerant and the high pressure refrigerant form a counter flow (countercurrent), and the heat exchange efficiency can be further improved.

In the second embodiment, the case where the inflow port 46a is formed in the first connecting pipe 42 has been described, but the present invention is not limited to this, and the first connecting pipe 42 and the second connecting pipe 43 are used. The left and right may be swapped.
Further, in the second embodiment described above, the case where four flat tubes 41A to 41D are used has been described, but the present invention is not limited to this, and two or three flat tubes, further five or more flat tubes are used. You may wrap it around. In this case, when an odd number of flat pipes are provided, the inflow port 46a (or the discharge port 46b) is formed in the first connecting pipe 42, and the discharge port 46b (or the inflow port 46a) is formed in the second connecting pipe 43. Since the position of the partition plate is only upside down, the first connecting pipe 42 and the second connecting pipe 43 can be made common parts, and the first connecting pipe 42 and the second connecting pipe 43 can be used as common parts. The production cost can be reduced as compared with the case where the products are manufactured separately.

Further, the first connecting pipe 42 and the second connecting pipe 43 form the first connecting pipe 42 and the second connecting pipe 43 by partitioning one cylindrical body in the axial direction instead of forming them separately. You can also do it. In this case, the first connecting pipe 42 and the second connecting pipe 43 can be manufactured with one part, and the number of parts can be reduced to reduce the production cost.
Further, in the second embodiment, the case where the communication space between the first connecting pipe 42 and the second connecting pipe 43 is partitioned by the partition plates 44a to 44c has been described, but the present invention is not limited to this, and the first connection is not limited to this. For the pipe 42, three cylinders having communication spaces 45a to 45c may be connected, and for the second connecting pipe 43, two cylinders having communication spaces 47a and 47b may be connected.

Further, in the first and second embodiments, the case where the bottom surface of the inner cylinder 22b of the double pipe 22 is closed by the second cap 24 to form the liquid reservoir 26 has been described, but the present invention is limited to this. Instead, the bottom surface of the inner cylinder 22b may be closed by a bottom plate of a member different from the second cap 24. In this case, it is not necessary for the inner cylinder 22b to protrude from the outer cylinder 22a, and the bottom surface of the inner cylinder 22b can be flush with the bottom surface of the outer cylinder 22a.

Further, in the first and second embodiments, the case where a plurality of gas phase refrigerant passages are formed between the outer cylinder 22a and the inner cylinder 22b has been described, but the gas phase refrigerant passages are set to an arbitrary number of 1 or more. be able to. In this case, the partition wall 22c can be omitted, but in order to make the double pipe 22 an extruded product, it is necessary to form one or more partition walls 22c. Further, the outer cylinder 22a and the inner cylinder 22b may be separated and joined by a joining means such as welding or brazing to form the double pipe 22.

Further, in the first and second embodiments, the case where the accumulator 13 with an internal heat exchanger is independently configured has been described, but the present invention is not limited to this, and the compressor 11, the radiator 12 and the evaporation are not limited thereto. It can also be integrally configured with any of the vessels 15. In short, it suffices if the accumulator 13 with an internal heat exchanger can supply the gas phase medium to the gas phase medium suction portion of the compressor 11.
Further, in the first and second embodiments, the refrigeration cycle 1 applied to the air conditioner for automobiles has been described, but the present invention is not limited to this, and the refrigeration cycle used for refrigeration showcases, vending machines, etc. The present invention can also be applied to.

11 ... Compressor, 12 ... Dissipator, 13 ... Accumulator with internal heat exchanger, 14 ... Expansion valve, 15 ... Evaporator, 21 ... Gas-liquid separator, 22 ... Double pipe, 22a ... Outer cylinder, 22b ... Inner Cylinder, 22c ... partition wall, 22d ... gas phase refrigerant passage, 22e ... communication groove, 23 ... first cap, 23c ... inflow pipe, 24 ... second cap, 24c ... vapor phase refrigerant reservoir, 24d ... discharge pipe, 26 ... Liquid reservoir, 27 ... Oil return groove, 31 ... Flat pipe, 31a ... High-pressure refrigerant passage, 32 ... First connecting pipe, 32a ... Inflow port, 33 ... Second connecting pipe, 33a ... Discharge port, 41A to 41D ... Flat pipes, 41a to 41d ... high pressure refrigerant passages, 42 ... first connecting pipes, 43 ... second connecting pipes, 44a to 44c ... partition plates, 45a to 45c ... communication spaces, 46a ... inflow ports, 46b ... discharge ports, 47a , 47b ... Communication space

Claims (7)

An accumulator that is located on the upstream side of a compressor provided in a circulation path that circulates a refrigerant in a refrigeration cycle and separates gas-liquid two-phase refrigerant.
A gas-liquid separation unit having a double-tube structure into which the gas-liquid two-phase refrigerant is introduced,
A flat pipe that is wound around the outer circumference of the gas-liquid separation portion and through which a high-pressure refrigerant passes is provided.
Internal heat exchange is performed between the gas-liquid separation unit and the flat pipe .
The gas-liquid separation unit includes a double pipe provided with an inner cylinder for gas-liquid separation of the gas-liquid two-phase refrigerant and an outer cylinder for forming a gas-phase refrigerant passage through which the separated gas-phase refrigerant passes, and the double. A first cap attached to the upper end of the pipe to guide the gas-liquid two-phase refrigerant into the inner cylinder and a first cap attached to the lower end of the double pipe to discharge the gas-phase refrigerant in the vapor-phase refrigerant passage to the outside. With a second cap
The second cap includes a disk portion that closes the lower end of the inner cylinder, and a flange portion that extends upward from the outer peripheral surface of the disk portion and fits into the outer peripheral surface of the outer cylinder. By closing the lower end of the inner cylinder with the plate portion, a liquid reservoir portion for storing the separated liquid phase refrigerant and lubricating oil is formed on the lower end side of the inner cylinder, and the outer peripheral surface of the inner cylinder and the disk are formed. A gas phase refrigerant reservoir portion for temporarily storing the vapor phase refrigerant flowing out from the vapor phase refrigerant passage is formed by the portion and the flange portion.
A discharge pipe for discharging the gas phase refrigerant temporarily stored in the gas phase refrigerant reservoir is formed in the disk portion, and at the same time.
An oil return groove is formed in the inner cylinder to return the lubricating oil stored in the liquid reservoir to the gas phase refrigerant reservoir.
An accumulator with an internal heat exchanger, wherein the opening position of the discharge pipe to the gas phase refrigerant reservoir is set higher than the bottom surface of the vapor phase refrigerant reservoir . Before SL double tube, the plurality of the gas-phase refrigerant passage by a plurality of barrier ribs formed at a distance in the circumferential direction between the outer cylinder and the inner cylinder is formed, the inner cylinder and the first cap The accumulator with an internal heat exchanger according to claim 1, wherein a communication hole for communicating the inner surface of the inner cylinder and the gas-phase refrigerant passage is formed between them. The flat pipe is opened at both ends in the winding direction, and a plurality of high-pressure refrigerant passages are formed in parallel at intervals in the axial direction of the double pipe, and the plurality of high-pressure refrigerants are formed at one end in the winding direction of the flat pipe. A first connecting pipe that communicates with the passage to form a high-pressure refrigerant flow path is connected, and a second connection that communicates with the plurality of high-pressure refrigerant passages at the other end of the flat pipe in the winding direction to form a high-pressure refrigerant flow path. The accumulator with an internal heat exchanger according to claim 2, wherein the tubes are connected. The flat pipe is wound in a plurality of rows around the double pipe, and the plurality of flat pipes pass through a continuous refrigerant passage in which the high-pressure refrigerant flows in the opposite direction for each row through the first connecting pipe and the second connecting pipe. The accumulator with an internal heat exchanger according to claim 3, wherein the accumulator is formed. The first connecting pipe and the second connecting pipe are connected so as to discharge the high-pressure refrigerant supplied from the second cap side from the first cap side via the flat pipe. The accumulator with an internal heat exchanger according to claim 3 or 4. The first cap includes an inflow pipe for supplying a low-pressure refrigerant into the inner cylinder of the double pipe, and the second cap discharges the gas phase refrigerant passing through the gas phase refrigerant passage of the double pipe to the outside. The accumulator with an internal heat exchanger according to any one of claims 2 to 5, further comprising a discharge pipe. A compressor that sucks and compresses the refrigerant, a radiator that cools the refrigerant compressed by the compressor, a decompressor that decompresses the refrigerant cooled by the radiator, and a decompressor that evaporates the refrigerant decompressed by the decompressor. Any of claims 1 to 6 in which the evaporator and the gas-liquid two-phase refrigerant flowing out of the evaporator are separated into a gas-phase refrigerant and a liquid-phase refrigerant, and the separated vapor-phase refrigerant is supplied to the compressor. Equipped with an accumulator with an internal heat exchanger as described in item 1.
The gas-liquid two-phase refrigerant is supplied to the gas-liquid separation portion of the accumulator with an internal heat exchanger, the separated vapor-phase refrigerant is supplied to the compressor, and the high-pressure refrigerant flowing out of the radiator is supplied to the flat pipe. A refrigeration cycle characterized in that a high-pressure refrigerant that is supplied and discharged from the flat pipe is supplied to the decompressor.

Images