JP2008051426A - Accumulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an accumulator comprised by rationally providing an internal heat exchanger. <P>SOLUTION: The accumulator 600 is used in a refrigerating cycle 1 provided with the internal heat exchanger 700 carrying out heat exchange between a high pressure side coolant and a low pressure side coolant, and it is comprised by providing the internal heat exchanger in its interior. The internal heat exchanger is provided with a gaseous phase coolant circulation container 710 circulating a gaseous phase coolant, and heat exchange tubes 720a, 720b arranged in an interior of the gaseous phase circulation container, and it is composed such that a high pressure side coolant is circulated in the heat exchange tubes. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an accumulator for a refrigeration cycle, in which an internal heat exchanger for exchanging heat between a high-pressure side refrigerant and a low-pressure side refrigerant is provided.

  A vapor compression refrigeration cycle that circulates refrigerant can improve the refrigeration efficiency by exchanging heat between the high-pressure side refrigerant and the low-pressure side refrigerant. What performs such heat exchange is an internal heat exchanger. Particularly in recent years, a supercritical refrigeration cycle is also known in which CO2 is used as a refrigerant and the pressure inside the radiator exceeds the critical point of the refrigerant. The effect of the internal heat exchanger is remarkable in such a supercritical refrigeration cycle.

Moreover, as an internal heat exchanger, the thing integrated with an accumulator is proposed as it is indicated by patent documents 1 thru | or 3. The advantages of integrating them include effective use of installation space and simplification of assembly work of the refrigeration cycle. In the first place, an accumulator is a pressure vessel that circulates a low-pressure side refrigerant. Therefore, it is considered reasonable to exchange heat by circulating a high-pressure side refrigerant inside.
Japanese Patent Laid-Open No. 2004-100804 JP 2004-176949 A JP-T-2004-526934

  Now, with regard to accumulators and internal heat exchangers for refrigeration cycles, improvement of pressure resistance and heat exchange efficiency, as well as reduction of installation space and reduction of manufacturing costs are considered as very important issues. Even when they are integrated, further structural ingenuity is demanded in light of these issues.

  For example, an accumulator used in a supercritical refrigeration cycle is elongated in the vertical direction when the diameter is reduced to secure an installation space. In this respect, the ones disclosed in Patent Documents 1 to 3 are such that the flow path of the heat exchange tube that circulates the high-pressure side refrigerant extends in the horizontal direction. Is constrained. Or manufacture becomes difficult. That is, it is not suitable for reducing the diameter.

  This invention is made | formed in view of this situation, The objective is to provide the accumulator which provides an internal heat exchanger rationally.

  The invention described in claim 1 of the present application includes a compressor that compresses a refrigerant, a radiator that cools the refrigerant compressed by the compressor, and a decompressor that expands by depressurizing the refrigerant cooled by the radiator. An evaporator that evaporates the refrigerant decompressed by the decompressor, an accumulator that separates the refrigerant flowing out of the evaporator into an air layer and a liquid layer, and sends the refrigerant in the gas layer to the compressor, and the refrigerant on the high pressure side And an internal heat exchanger for exchanging heat with the refrigerant on the low-pressure side, the accumulator is provided with the internal heat exchanger therein, and the internal heat The exchanger includes a gas-phase refrigerant distribution container that circulates the gas-layer refrigerant, and a heat exchange tube disposed inside the gas-layer refrigerant distribution container, and distributes the high-pressure side refrigerant to the heat exchange tube. It is the configuration of the accumulator that.

  The invention described in claim 2 of the present application is the accumulator according to claim 1, wherein the heat exchange tube is an extruded tube in which fins are integrally formed on an outer surface thereof.

  The invention described in claim 3 of the present application is the accumulator according to claim 1, wherein the heat exchange tube is an extruded tube having fins attached to the outer surface thereof.

  According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, the heat exchange tube includes a first heat exchange tube that circulates the high-pressure side refrigerant from above to the lower side, and the high-pressure side. It is an accumulator of the structure provided with the 2nd heat exchange tube which distribute | circulates the said refrigerant | coolant from the downward direction upwards.

  The invention described in claim 5 of the present application is the heat exchange tube according to any one of claims 1 to 4, wherein the heat exchange tube is formed by integrally forming a plurality of flow paths, and is provided at an end of the heat exchange tube. Is an accumulator having an end member that communicates the plurality of flow paths.

  The invention recited in claim 6 of the present application is the structure according to any one of claims 1 to 5, wherein the gas-phase refrigerant circulation container is a cylindrical container having a hollow penetrating portion penetrating in the vertical direction. It is an accumulator.

  The invention described in claim 7 of the present application is the gas-phase refrigerant inlet according to any one of claims 1 to 6, wherein the gas-layer refrigerant circulation container flows into the gas-layer refrigerant separated inside the accumulator. And a gas-phase refrigerant outlet for allowing the gas-layer refrigerant to flow out of the accumulator.

  The invention described in claim 8 of the present application is the gas-phase refrigerant circulation container according to any one of claims 1 to 7, wherein the high-pressure refrigerant inlet portion that introduces the high-pressure side refrigerant into the heat exchange tube; The accumulator is configured to penetrate through a high-pressure refrigerant outlet portion through which a high-pressure side refrigerant flows out of the heat exchange tube.

  The invention described in claim 9 of the present application is the accumulator according to any one of claims 1 to 8, wherein a partition body for restricting the flow of refrigerant in the gas layer is provided inside the gas layer refrigerant circulation container. It is.

  The invention described in claim 10 of the present application is any one of claims 1 to 9, wherein the refrigerant in the gas layer flowing through the gas-layer refrigerant circulation container and the high-pressure side refrigerant flowing through the heat exchange tube are The accumulator has a configuration in which the flows are opposed to each other.

  The invention described in claim 11 of the present application is the accumulator according to any one of claims 1 to 10, wherein a positioning means for positioning the gas-layer refrigerant circulation container is provided on the inner surface of the accumulator.

  The invention described in claim 12 of the present application is the accumulator according to any one of claims 1 to 11, wherein the accumulator is provided with an oil circulation means for sending oil accumulated in the accumulator to the compressor. is there.

  The invention described in claim 13 of the present application is the accumulator according to any one of claims 1 to 12, wherein the refrigeration cycle is a supercritical refrigeration cycle in which a pressure inside the radiator exceeds a critical point of the refrigerant. It is.

  According to the present invention, it is possible to obtain an accumulator that is rationally provided with an internal heat exchanger.

  Embodiments of the present invention will be described below with reference to the drawings. A refrigeration cycle 1 shown in FIG. 1 is for in-vehicle air conditioning mounted on an automobile, and includes a compressor 200 that compresses a refrigerant, a radiator 300 that cools the refrigerant compressed by the compressor 200, and a radiator 300. The decompressor 400 expands by decompressing the refrigerant cooled in Step 1, the evaporator 500 that evaporates the refrigerant decompressed by the decompressor 400, and the refrigerant flowing out of the evaporator 500 is separated into a gas layer and a liquid layer, An accumulator 600 that sends the refrigerant to the compressor 200 and an internal heat exchanger 700 that exchanges heat between the high-pressure side refrigerant and the low-pressure side refrigerant are provided. The white arrow in the figure indicates the direction in which the high-pressure side refrigerant flows, and the black arrow indicates the direction in which the low-pressure side refrigerant flows.

  As the refrigerant, CO 2 is adopted, and the pressure inside the radiator 300 exceeds the critical point of the refrigerant depending on the use conditions such as the temperature. Here, the critical point is the limit on the high temperature side where the gas layer and the liquid layer coexist, that is, the limit on the high pressure side, and is the end point on one side of the vapor pressure curve. The pressure, temperature, and density at the critical point are the critical pressure, critical temperature, and critical density, respectively. When the pressure exceeds the critical point of the refrigerant inside the radiator, the refrigerant is not condensed.

  As shown in FIGS. 2 and 3, the accumulator 600 of this example is provided with an internal heat exchanger 700 therein. The accumulator 700 includes a cylindrical housing 610 that is vertically elongated with an upper opening 611 closed by a lid member 620, and a low-pressure refrigerant that guides a low-pressure side refrigerant downward in the housing 610 as a pressure vessel. An introduction pipe 630 and an internal heat exchanger 700 are arranged. The lid member 620 is provided with a first opening 621a, a second opening 621b, a third opening 621c, and a fourth opening 621d. The first opening 621a is connected to the pipe 101 through which the refrigerant flows from the evaporator 500, the second opening 621b is connected to the pipe 102 through which the refrigerant flows out to the compressor 200, and the third opening 621c is connected to the third opening 621c. The pipe 103 through which the refrigerant flows from the radiator 300 is connected, and the pipe 104 through which the refrigerant flows out to the decompressor 400 is connected to the fourth opening 621d.

  As shown in FIGS. 4 to 10, the internal heat exchanger 700 of the present example includes an air-layer refrigerant circulation container 710 that circulates the gas-phase refrigerant, and a plurality of heats arranged inside the gas-layer refrigerant circulation container 710. Exchange tubes 720a and 720b are provided, and a high-pressure side refrigerant is circulated through these heat exchange tubes 720a and 720b. In the case of this example, the heat exchange tubes include a first heat exchange tube 720a that circulates the high-pressure side refrigerant from above to below, and a second heat exchange tube 720b that circulates the high-pressure side refrigerant from below to above. I have. The gas-phase refrigerant circulation container 710 is a cylindrical resin container provided with a hollow through portion 710a penetrating in the vertical direction. The side surface of the gas-phase refrigerant circulation container 710 and the inner surface of the housing 610 are configured to coincide with each other with a slight clearance. Positioning means 612 for positioning the gas-phase refrigerant circulation container 710 is provided at a key point on the inner surface of the accumulator 600, that is, the inner surface of the housing 610. The gas-layer refrigerant distribution container 710 is positioned at the upper part of the housing 610. ing. The positioning means 612 shown in FIGS. 2 and 3 is a convex portion that comes into contact with the lower surface of the gas-phase refrigerant circulation container 710.

  The low-pressure refrigerant introduction pipe 630 of the accumulator 600 is inserted through the hollow through portion 710a. A flange body 631 is provided at an important point of the low-pressure refrigerant introduction pipe 630, and the low-pressure refrigerant introduction pipe 630 is positioned by locking the flange body 631 on the upper surface of the gas-layer refrigerant circulation container 710. Further, the upper end of the low-pressure refrigerant introduction pipe 630 is connected to the first opening 621a of the lid member 620. Note that a gap is formed between the flange body 631 and the gas-phase refrigerant circulation container 710, and only the gas layer penetrates the refrigerant brought into the lower part of the housing 610 through the low-pressure refrigerant introduction pipe 630. It rises through the portion 710a and goes around the upper surface of the gas-phase refrigerant circulation container 710.

  A gas phase refrigerant inlet portion 711 and a gas phase refrigerant outlet portion 712 are provided on the upper surface of the gas phase refrigerant circulation container 710, and the high pressure refrigerant inlet portion 701 and the high pressure refrigerant outlet portion 702 are further penetrated. The gas-phase refrigerant inlet 711 is an opening-like part through which the gas-phase refrigerant that has entered the upper surface of the gas-phase refrigerant circulation container 710 flows into the gas-layer refrigerant circulation container 710. The gas-phase refrigerant outlet 712 is a pipe-like portion that allows the gas-layer refrigerant to flow out of the gas-phase refrigerant circulation container 710 to the outside of the accumulator 600 and is connected to the second opening 621b of the lid member 620. The high-pressure refrigerant inlet 701 is a pipe-like part that allows the high-pressure side refrigerant to flow into the first heat exchange tube 720 a and is connected to the third opening 621 c of the lid member 620. The high-pressure refrigerant outlet part 702 is a pipe-like part through which the high-pressure side refrigerant flows out from the second heat exchange tube 720b, and is connected to the fourth opening 621d of the lid member 620.

  Each of the heat exchange tubes 720a and 720b is an extruded tube in which heat radiation fins 721 are integrally formed on the outer surface thereof. The cross sections of the heat exchange tubes 720a and 720b each have an arc shape so as to be accommodated in the gas-phase refrigerant circulation container 710.

  These heat exchange tubes 720a and 720b are formed by integrally forming a plurality of flow paths 722, and a plurality of flow paths are provided at each end of the first heat exchange tube 720a and the second heat exchange tube 720b. End members 730 a, 730 b, and 730 c each having a communication portion 731 that communicates 722 are provided. At the upper end of the first heat exchange tube 720a, a first end member 730a that connects the high pressure refrigerant inlet 701 to the communication portion 731 is provided, and the lower end of the first heat exchange tube 720a and the second heat exchange tube 720b. A second end member 730b that communicates the heat exchange tubes 720a and 720b is provided at the lower end of the second heat exchange tube, and a high-pressure refrigerant outlet portion 702 is communicated with the communication portion 731 at the upper end of the second heat exchange tube 720b. A third end member 730c is provided. At the ends of the heat exchange tubes 720a and 720b, the fins 721 are partially removed after extrusion to connect the end members 730a, 730b, and 730c.

  A partition 713 that restricts the flow of the refrigerant in the gas layer is provided inside the gas-layer refrigerant circulation container 710. The partition 713 is provided between the first heat exchange tube 720a and the second heat exchange tube 720b from the uppermost part inside the gas-phase refrigerant circulation container 710 to the second end member 730b. The refrigerant in the gas phase flowing in from the gas phase refrigerant inlet 711 sequentially passes through the gap between the gas phase refrigerant circulation container 710 and the third end member 730c, and from the upper side to the lower side with respect to the second heat exchange tube 720b. Circulates, passes through the gap between the gas-phase refrigerant circulation container 710 and the second end member 730b, and circulates from the lower side to the upper side with respect to the first heat exchange tube 720a. It passes through the gap with the member 730a and flows out from the gas-phase refrigerant outlet 712. The refrigerant in the gas layer (low-pressure side refrigerant) and the high-pressure side refrigerant exchange heat with heat transmitted to the heat exchange tubes 720a and 720b. The refrigerant in the gas layer that circulates through the gas-phase refrigerant circulation container 710 and the refrigerant on the high-pressure side that circulates in the heat exchange tubes 720a and 720b are opposed to each other. Therefore, it is possible to ensure excellent heat exchange efficiency.

  As described above, the accumulator of the present example is manufactured by providing an air-layer refrigerant circulation container in the interior and arranging a heat exchange tube inside the gas-layer refrigerant circulation container to constitute an internal heat exchanger. This is achieved by reducing the installation space, reducing the installation space, and improving the heat exchange efficiency of the internal heat exchanger. A major feature different from the prior art is that a gas-phase refrigerant circulation container that circulates a gas-layer refrigerant is provided inside a housing that is a pressure vessel. This gas-phase refrigerant circulation container does not simply divide the interior of the housing, but is itself independent as a container. That is, the container has a double structure, the pressure resistance is ensured by the outer container (housing), and the internal heat exchange is unitized by the inner container (gas-layer refrigerant circulation container). This is a technical idea for improving manufacturability and functionality. In particular, since the heat exchange tubes are arranged inside the accumulator in the vertical direction, there is an advantage that the accumulator can be reduced in diameter in the supercritical refrigeration cycle. In addition, it is needless to say that the configuration of each part in the present example can be appropriately changed in design within the technical scope described in the claims, and is not limited to that illustrated in the drawings.

  Next, a second embodiment of the present invention will be described with reference to FIGS. The accumulator of this example is provided with an oil circulation means for sending the lubricating oil accumulated inside to the compressor 200. The refrigeration cycle 1 circulates a part of the lubricating oil of the compressor 200 together with the refrigerant, and the lubricating oil accumulates at the bottom of the housing 610 of the accumulator 600. The oil circulation means of this example is provided with an oil return pipe 800 that guides the lubricating oil accumulated at the bottom of the housing 610 to the inside of the gas-phase refrigerant circulation container 710. The lubricating oil ascends the oil return pipe 800 due to the pressure difference, mixes with the refrigerant in the gas layer inside the gas-phase refrigerant circulation container 710, and is sent to the compressor 200. Other basic configurations are the same as those in the above-described embodiment. The accumulator 600 may be provided with such oil circulation means.

  Next, a third embodiment of the present invention will be described with reference to FIGS. The gas-phase refrigerant circulation container 710 of this example includes a rectangular first storage unit 714 that stores the first heat exchange tube 720a and the first end member 730a, a second heat exchange tube 720b, and a third end member 730c. The rectangular second storage portion 715 to be stored, the third storage portion 716 that connects the lower portions of the first storage portion 714 and the second storage portion 715 and stores the second end member 720b, and the positioning means 612 are positioned. And a circular flange 717. The third storage portion 716 and the flange portion 717 are provided with a hollow through portion 710a. Here, the first end member 730a, the second end member 730b, and the third end member 730c are different in shape but have the same functions and structures as those of the above-described embodiments, and therefore, common symbols are used. The illustration is omitted.

  Further, the first heat exchange tube 720a and the second heat exchange tube 720b are flat extruded tubes having separate fins 723 mounted on the outer surfaces thereof. A plurality of first heat exchange tubes 720a and second heat exchange tubes 720b are provided. The fins 723 have a shape in which waves having different phases are arranged at predetermined intervals in the flow direction of the refrigerant in the gas layer (the arrow direction in FIG. 17). According to such fins 723, turbulent flow is generated in the refrigerant in the gas layer, and thus there is an advantage that heat exchange efficiency is reliably improved. The fins 721 in the above-described embodiment are extruded integrally with the tubes 720a and 720b, but can be replaced with the fins 723 as in this example. Other basic configurations are the same as those in the above-described embodiment.

  As described above, the fins 723 may be attached to the tubes 720a and 720b. In addition, the shape of the gas-phase refrigerant circulation container 710 can be appropriately set according to the configuration of each of the tubes 720a and 720b and the fins 723.

  The accumulator of the present invention is an internal heat exchanger integrated type, and can be used very suitably as an accumulator used in a supercritical refrigeration cycle.

It is explanatory drawing of the refrigerating cycle in connection with the Example of this invention. (A) is a front view of the accumulator, (b) is a top view of the accumulator, and (c) is a front sectional view of the accumulator according to the embodiment of the present invention. 1 is an exploded front sectional view of an accumulator according to an embodiment of the present invention. 1 is a perspective view of an internal heat exchanger according to an embodiment of the present invention. 1 is a top view of an internal heat exchanger according to an embodiment of the present invention. It is a front sectional view of an internal heat exchanger concerning an example of the present invention, and is an AA section arrow line view of Drawing 5. FIG. 6 is a side cross-sectional view of the internal heat exchanger according to the embodiment of the present invention, and is a cross-sectional view taken along the line B-B in FIG. 5. FIG. 7 is a top sectional view of the internal heat exchanger according to the embodiment of the present invention, and is a sectional view taken along the line aa in FIG. 6. FIG. 6 is a top view of a first end member and a third end member according to the embodiment of the present invention. FIG. 6 is a top view of a second end member according to the embodiment of the present invention. It is a front sectional view of an accumulator concerning an example of the present invention. It is a front sectional view of an internal heat exchanger concerning an example of the present invention. 1 is a perspective view of an internal heat exchanger according to an embodiment of the present invention. 1 is a top view of an internal heat exchanger according to an embodiment of the present invention. It is an upper surface sectional view of an internal heat exchanger concerning an example of the present invention. It is a perspective view of a fin concerning an example of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Refrigeration cycle 101 Piping 102 Piping 103 Piping 104 Piping 200 Compressor 300 Radiator 400 Decompressor 500 Evaporator 600 Accumulator 610 Housing 611 Upper opening 612 Positioning means 620 Lid member 621a First opening 621b Second opening 621c Third opening 621d 4th opening part 630 Low pressure refrigerant introduction pipe 631 Flange body 700 Internal heat exchanger 701 High pressure refrigerant inlet part 702 High pressure refrigerant outlet part 710 Gas layer refrigerant circulation container 710a Hollow through part 711 Gas layer refrigerant inlet part 712 Gas layer refrigerant outlet part 713 Partition 714 First storage portion 715 Second storage portion 716 Third storage portion 717 Hook 720a First heat exchange tube 720b Second heat exchange tube 721 Fin 722 Flow path 723 Fin 730a First end member 730 b Second end member 730c Third end member 731 Communication portion 800 Oil return pipe

Claims (13)

A compressor that compresses the refrigerant; a radiator that cools the refrigerant compressed by the compressor; a decompressor that decompresses and expands the refrigerant cooled by the radiator; and a refrigerant that is decompressed by the decompressor. Heat exchange is performed between the evaporator that evaporates, the accumulator that separates the refrigerant flowing out of the evaporator into a gas layer and a liquid layer, and sends the refrigerant in the gas layer to the compressor, and the refrigerant on the high-pressure side and the refrigerant on the low-pressure side In an accumulator used for a refrigeration cycle with an internal heat exchanger,
The accumulator is provided with the internal heat exchanger therein,
The internal heat exchanger includes an air-layer refrigerant circulation container that circulates the gas-layer refrigerant, and a heat exchange tube that is disposed inside the gas-layer refrigerant circulation container. An accumulator characterized by circulating a refrigerant.   The accumulator according to claim 1, wherein the heat exchange tube is an extruded tube having fins integrally formed on an outer surface thereof.   The accumulator according to claim 1, wherein the heat exchange tube is an extruded tube having fins attached to the outer surface thereof.   The heat exchange tube includes a first heat exchange tube that circulates the high-pressure side refrigerant from above to below, and a second heat exchange tube that circulates the high-pressure side refrigerant from below to above. The accumulator according to any one of claims 1 to 3.   The heat exchange tube is formed by integrally forming a plurality of flow paths, and an end member that communicates the plurality of flow paths is provided at an end of the heat exchange tube. The accumulator according to any one of claims 1 to 4.   The accumulator according to any one of claims 1 to 5, wherein the gas-phase refrigerant circulation container is a cylindrical container provided with a hollow penetrating portion that penetrates the gas-phase refrigerant circulation container in the vertical direction.   In the gas-phase refrigerant circulation container, an air-layer refrigerant inlet portion into which the gas-layer refrigerant separated inside the accumulator flows, and a gas-layer refrigerant outlet portion from which the gas-layer refrigerant flows out of the accumulator The accumulator according to claim 1, wherein the accumulator is provided.   The gas-phase refrigerant circulation container has penetrated through a high-pressure refrigerant inlet part through which the high-pressure side refrigerant flows into the heat exchange tube and a high-pressure refrigerant outlet part through which the high-pressure side refrigerant flows out of the heat exchange tube. The accumulator according to claim 1, wherein:   The accumulator according to any one of claims 1 to 8, wherein a partition body for regulating a flow of the refrigerant in the gas layer is provided inside the gas-layer refrigerant circulation container.   The refrigerant of the gas layer that circulates through the gas-layer refrigerant circulation container and the refrigerant at the high-pressure side that circulates through the heat exchange tube are configured so that their flows are opposed to each other. Item 10. The accumulator according to any one of Items 1 to 9.   The accumulator according to any one of claims 1 to 10, wherein positioning means for positioning the gas-phase refrigerant circulation container is provided on an inner surface of the accumulator.   The accumulator according to any one of claims 1 to 11, wherein the accumulator is provided with oil circulation means for sending oil accumulated in the accumulator to the compressor.   The accumulator according to any one of claims 1 to 12, wherein the refrigeration cycle is a supercritical refrigeration cycle in which a pressure inside the radiator exceeds a critical point of the refrigerant.

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