JP2008134022A - Accumulator for refrigerating cycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an accumulator for a refrigerating cycle allowing easy replacement of only a strainer. <P>SOLUTION: The accumulator 4 has a tank 10 comprising a cylindrical drum 11 and a lid 12 joined to the upper end of the drum 11 and having a refrigerant inlet port 15 and a refrigerant outlet port 16; and an approximately U-shaped refrigerant discharge pipe 13 disposed in the tank 10, with a refrigerant discharge end of one end connected to the refrigerant outlet port 16 and with a refrigerant intake end of the other end located above the liquid level of a liquid-phase refrigerant stored in the tank. The strainer 20 is detachably inserted into the refrigerant inlet port 15 of the lid 12 from the outside. An intermediate part in the height direction of the inner peripheral surface of the refrigerant inlet port 15 is provided with an inwardly projecting support part 15d. An outward flange 23 provided at the strainer 20 is received by the support part 15d to make the strainer 20 attachable/detachable. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an accumulator for a refrigeration cycle.

  In this specification and claims, the top and bottom of FIG. Further, in this specification, the “supercritical refrigeration cycle” means a refrigeration cycle in which the refrigerant enters a supercritical state exceeding the critical pressure on the high pressure side, and the “supercritical refrigerant” It shall mean the refrigerant used in the refrigeration cycle.

  For example, as a car air conditioner mounted on an automobile, a refrigeration cycle including a compressor, a condenser, an evaporator, a decompressor, and a gas-liquid separator and using a chlorofluorocarbon refrigerant is widely used.

In recent years, from an environmental point of view, the compressor, the gas cooler, the evaporator, the decompressor, the gas-liquid separator, and the intermediate heat exchanger for exchanging heat between the refrigerant coming out of the gas cooler and the refrigerant coming out of the evaporator are provided. In addition, a supercritical refrigeration cycle in which a supercritical refrigerant such as CO ₂ (carbon dioxide) is used has been proposed.

  Conventionally, as a gas-liquid separator of the above-described refrigeration cycle and supercritical refrigeration cycle, a cylindrical metal cylinder having an upper end opened and a lower end closed, and the upper end opening of the cylinder closed by welding to the upper end of the cylinder And a tank made of a metal lid having a refrigerant inlet port and a refrigerant outlet port, and a refrigerant discharge end at one end connected to the refrigerant outlet port and a refrigerant suction end at the other end in the tank. And a substantially U-shaped refrigerant discharge pipe positioned above the liquid level of the liquid-phase refrigerant to be stored, a lubricating oil return hole is formed at the lower end of the bent part of the refrigerant discharge pipe, and the refrigerant discharge pipe is bent. An accumulator in which a strainer that removes foreign matter and prevents foreign matter from being mixed into the lubricating oil returned from the lubricating oil return hole is used at the portion (see Patent Document 1).

However, in the accumulator described in Patent Document 1, since the tank body and the lid are welded and the strainer is attached to the refrigerant discharge pipe disposed in the tank, there is a problem that it is not possible to replace only the strainer. is there.
Japanese Patent Laid-Open No. 2002-5545

  An object of the present invention is to provide an accumulator for a refrigeration cycle that solves the above-described problems and can easily replace only the strainer.

  In order to achieve the above object, the present invention comprises the following aspects.

1) A cylindrical metal cylinder having an upper end opened and a lower end closed, and a metal lid joined to the upper end of the cylinder to close the upper end opening of the cylinder and having a refrigerant inlet port and a refrigerant outlet port The tank is disposed in the tank, and the refrigerant discharge end at one end is connected to the refrigerant outlet port, and the refrigerant suction end at the other end is positioned above the liquid level of the liquid-phase refrigerant stored in the tank. In an accumulator for a refrigeration cycle having a letter-shaped refrigerant discharge pipe,
An accumulator for a refrigeration cycle in which a strainer is detachably inserted into the refrigerant inlet port of the lid from the outside.

  2) The refrigerant inlet port of the lid extends in the vertical direction, a support part protruding inward is provided at the height direction intermediate part of the inner peripheral surface of the refrigerant inlet port, and an outward flange provided on the strainer is provided. The accumulator for a refrigeration cycle according to 1) above, wherein the strainer is detachable by being received by the support portion.

  3) The strainer is a cylindrical shape having an upper end opened and a lower end closed, and has a frame having an outward flange. Openings are formed in the peripheral wall and the bottom wall of the frame, respectively. And is covered with a mesh fixed to the frame, a gap is formed between the peripheral wall of the frame and the inner peripheral surface of the refrigerant inlet port, and the lower end portion of the opening of the peripheral wall of the frame is lower than the lower end of the refrigerant inlet port The accumulator for a refrigeration cycle as described in 2) above, which is located above.

  4) The above 3), wherein a plurality of openings are formed in the peripheral wall of the strainer frame and one opening is formed in the bottom wall, and the total area of the openings in the peripheral wall is more than three times the area of the opening in the bottom wall. Accumulator for refrigeration cycle.

  5) The accumulator for a refrigeration cycle according to any one of 1) to 4) above, wherein the refrigerant suction end of the refrigerant discharge pipe is located above the lower end opening of the refrigerant inlet port.

  6) A downward projecting portion is integrally formed on the lower surface of the tank lid, the lower end of the refrigerant inlet port is open to the lower end surface of the lower projecting portion, and the refrigerant suction end of the refrigerant discharge pipe is formed on the lid. The accumulator for a refrigeration cycle according to 5) above, which is located above the lower end of the downward projecting portion.

  According to the accumulator of 1), since the strainer is detachably inserted from the outside into the refrigerant inlet port of the lid, only the strainer can be easily replaced.

  According to the accumulator of 2), the strainer can be attached to the tank lid relatively easily and detachably.

  According to the accumulator of the above 3), when the gas-phase refrigerant including the liquid-phase refrigerant flows into the tank through the refrigerant inlet port of the lid, a part of the refrigerant that has entered the frame of the strainer is formed on the peripheral wall. The air is blown toward the inner peripheral surface of the refrigerant inlet port through the opening, and flows down into the tank in a state where it hits the inner peripheral surface of the refrigerant inlet port and is killed. Therefore, the gas-liquid separation effect is excellent.

  According to the accumulator of the above 4), most of the refrigerant that has entered the frame of the strainer is blown toward the inner peripheral surface of the refrigerant inlet port through the opening formed in the peripheral wall, and the inner peripheral surface of the refrigerant inlet port In this state, since the momentum is killed, it flows downward and enters the tank, so that the gas-liquid separation effect is further improved.

  According to the accumulator of the above 5), the refrigerant suction end of the refrigerant discharge pipe is located above the lower end opening of the refrigerant inlet port formed in the lid, so that it is fed into the accumulator through the refrigerant inlet port. The liquid-phase refrigerant of the gas-liquid two-phase refrigerant that has flown is prevented from being sucked into the refrigerant suction end of the refrigerant discharge pipe by hitting the deflector and rebounding.

  According to the accumulator of the above 6), the refrigerant suction end of the refrigerant discharge pipe can be positioned relatively easily above the lower end opening of the refrigerant inlet port.

  Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the accumulator according to the present invention is applied to a supercritical refrigeration cycle.

  In the following description, the term “aluminum” includes aluminum alloys in addition to pure aluminum.

  FIG. 1 shows a supercritical refrigeration cycle, FIG. 2 shows the overall configuration of the accumulator, and FIGS. 3 to 5 show the configuration of the main part thereof.

In FIG. 1, the supercritical refrigeration cycle uses a supercritical refrigerant such as CO ₂ (carbon dioxide), and includes a compressor (1), a gas cooler (2), an evaporator (3), and a gas-liquid separator. As an accumulator (4), an expansion valve (5) as a pressure reducer, and an intermediate for heat exchange between the refrigerant coming out of the gas cooler (2) and the refrigerant coming out of the evaporator (3) and passing through the accumulator (4) And a heat exchanger (6). This supercritical refrigeration cycle is mounted on a vehicle such as an automobile as a car air conditioner, for example. As the supercritical refrigerant, ethylene, ethane, nitric oxide, or the like can be used instead of CO ₂ .

  As shown in FIG. 2, the accumulator (4) is welded to the cylindrical aluminum cylinder (11) whose upper end is open and whose lower end is closed, and the upper end of the cylinder (11). A tank (10) composed of an aluminum lid (12) for closing the upper end opening, an aluminum substantially U-shaped refrigerant discharge pipe (13) disposed in the tank (10), and a refrigerant discharge pipe (13) And an attached cap-shaped plastic deflector (14).

  The body (11) of the tank (10) includes a cylindrical peripheral wall (11a) and a bottom wall (11b) integrally formed at the lower end of the peripheral wall (11a). The lid (12) of the tank (10) is disk-shaped, and a short cylindrical annular hanging wall (12a) having the same thickness as the peripheral wall (11a) of the trunk (11) is integrated with the peripheral portion of the lower surface thereof. Is formed. The upper end portion of the peripheral wall (11a) of the trunk (11) and the lower end portion of the annular hanging wall (12a) of the lid (12) are welded. The weld is indicated by (W). A refrigerant inlet port (15) and a refrigerant outlet port (16) extending in the vertical direction are formed in the lid (12) in a penetrating manner. Two lower protrusions (17) and (18) are integrally formed on the lower surface of the lid (12). The refrigerant inlet port (15) and the refrigerant outlet port (16) are respectively connected to the upper surface of the lid (12). The lower projecting portions (17) and (18) are formed between the lower end surfaces of the lower projecting portions (17) and (18). The refrigerant inlet port (15) extends downward from the upper surface of the lid (12) and reaches the height position near the lower surface of the lid (12), and below the one lower protrusion (17). A large-diameter portion (15b) that extends upward from the end surface and reaches the same height as the lower surface of the lid (12), and a small-diameter portion that passes through the lower end of the medium-diameter portion (15a) and the upper end of the large-diameter portion (15b) ( 15c). The refrigerant outlet port (16) has a large diameter portion (16a) extending downward from the upper surface of the lid (12) and reaching a height position slightly above the lower end of the medium diameter portion (15a) of the refrigerant inlet port (15). A small diameter portion (16b) extending upward from the lower end surface of the other lower projecting portion (18) and reaching the same height as the lower surface of the lid (12), and a lower end and a small diameter portion (16b) of the large diameter portion (16a) ) And an intermediate diameter portion (16c) that is passed through the upper end of the upper portion. Although not shown, pipes constituting the supercritical refrigeration cycle are connected to the upper ends of the refrigerant inlet port (15) and the refrigerant outlet port (16) of the lid (12).

  In the refrigerant inlet port (15), a strainer (20) for removing foreign substances contained in the refrigerant is installed so as to be detachable from the outside of the tank (10). The strainer (20) includes a cylindrical plastic frame (21) having an upper end opened and a lower end closed. As shown in detail in FIGS. 3 and 4, openings (21a) and (21b) are respectively formed in the peripheral wall and the bottom wall of the frame (21), and these openings (21a) and (21b) are formed on the frame ( It is covered with a plastic mesh (22) made of nylon or the like fixed to 21). Here, the total area of the plurality of openings (21a) formed in the peripheral wall of the frame (21) is preferably at least three times the area of the opening (21b) formed in the bottom wall. The outer diameter of the peripheral wall of the frame (21) is sized so as to be inserted into the small diameter portion (15c) of the refrigerant inlet port (15), and the outer flange (23 ) Are integrally formed. The outward flange (23) is received by a shoulder portion (15d) (support portion) provided between the medium diameter portion (15a) and the small diameter portion (15c) of the refrigerant inlet port (15). The lower end of the frame (21) is at the same height as the lower end of the downward projecting portion (17) of the lid (12), or at a slightly higher height. Then, the strainer (20) is inserted into the refrigerant inlet port (15) of the lid (12) from above, and the outward flange (23) has a shoulder between the medium diameter part (15a) and the small diameter part (15c). By being received by the part (15d), the tank (10) is installed so as to be detachable from the outside. In the installed state, a predetermined gap is formed between the outer peripheral surface of the frame (21) of the strainer (20) and the inner peripheral surface of the large diameter portion (15b) of the refrigerant inlet port (15).

  The refrigerant discharge pipe (13) is composed of two straight pipe parts (13a) (13b) extending vertically and an arcuate part (13c) connecting the lower ends of both straight pipe parts (13a) (13b). The refrigerant discharge end at the upper end of the first straight pipe portion (13a) is connected to the refrigerant outlet port (16), and the refrigerant suction end at the upper end of the second straight pipe portion (13b) is connected to the refrigerant inlet port (15). It is located above the lower end (the lower end of the downward projecting portion (17)), that is, above the liquid level of the liquid-phase refrigerant (not shown) stored in the tank (10). The upper end portion of the first straight pipe portion (13a) of the refrigerant discharge pipe (13) is inserted into the refrigerant outlet port (16) until the upper end reaches the lower portion of the large diameter portion (16a), and the large diameter portion (15b ) Is fixed to the lid (12) by expanding the pipe. The expanded pipe is indicated by (24). In addition, in the portion of the refrigerant discharge pipe (13) that exists below the refrigerant outlet port (16), the positioning that engages with the peripheral edge of the lower end opening of the refrigerant outlet port (16) on the lower end surface of the lower protrusion (18). An annular bead (25) is formed. A lubricating oil return hole (26) is formed at the lower end of the arc-shaped portion (13c) of the refrigerant discharge pipe (13). The lubricating oil return hole (26) is positioned below the oil level of lubricating oil (not shown) accumulated in the tank (10).

  The deflector (14) includes a flat circular top wall (14a) and a conical peripheral wall (14b) formed integrally with the peripheral edge of the top wall (14a) and having a diameter expanded downward. Two pipe insertion holes (27) and (28) through which both straight pipe portions (13a) and (13b) of the refrigerant discharge pipe (13) are passed are formed in the top wall (14a). The inner diameter of the first pipe insertion hole (27) through which the first straight pipe portion (13a) of the refrigerant discharge pipe (13) is passed is slightly larger than the outer diameter of the first straight pipe portion (13a). . A cylindrical rising portion (30) is integrally formed at a portion around the first tube insertion hole (27) on the top surface (14a) of the deflector (14). The rising portion (30) has a conical shape whose diameter is reduced upward from the lower end. Two deflector holding annular beads (31), (32) are arranged in the first straight pipe portion (13a) of the refrigerant discharge pipe (13) in the vertical direction (the length direction of the first straight pipe portion (13a)). It is formed at the same interval as the height of the rising portion (30). The outer diameter of the upper annular bead (31) is larger than the inner diameter of the upper end opening of the rising portion (30) and is smaller than the inner diameter of the first tube insertion hole (27), so that the lower annular bead The outer diameter of (32) is larger than the inner diameter of the first tube insertion hole (27), so the outer diameter of the lower annular bead (32) is larger than the outer diameter of the upper annular bead (31). It is getting bigger. The upper annular bead (31) engages with the upper end of the rising portion (30) from above, and the lower annular bead (32) engages with the lower surface of the top wall (14a) of the deflector (14) from below. Accordingly, the vertical movement of the deflector (14) is prevented (see FIG. 5). Here, the outer diameter of the upper annular bead (31) rises when the first straight pipe portion (13a) is passed through the first pipe insertion hole (27) of the top wall (14a) of the deflector (14) from below. The positioning annular bead (25) is sized so that the portion (30) is elastically deformed and passes through the upper end opening of the rising portion (30), and is engaged with the lower end surface of the lower protrusion (17) described above. ) Is also equal to the outer diameter of the upper annular bead (31). The inner diameter of the second pipe insertion hole (28) through which the second straight pipe section (13b) on the refrigerant suction end side of the refrigerant discharge pipe (13) is passed is equal to or larger than the outer diameter of the second straight pipe section (13b). It is the size of. The second pipe insertion hole (28) may be formed across the top wall (14a) and the peripheral wall (14b) of the deflector (14).

  In the tank (10), between the straight pipe portions (13a) and (13b) of the refrigerant discharge pipe (13), a drying agent (33b) is put in a bag (33a) made of a synthetic resin cloth. An agent unit (33) is arranged.

  Here, the distance (L1) between the upper end of the deflector (14), that is, the top wall (14a), and the welded portion (W) of the trunk (11) and the lid (12) in the tank (10) is the trunk (11). At the time of welding the lid and the lid (12), the distance is set so as not to affect the deflector (14), for example, 50 mm or more. The distance (L2) between the lower end of the downward projecting portion (17) on the refrigerant inlet port (15) side on the lower surface of the lid (12) and the refrigerant suction end of the refrigerant discharge pipe (13) is the refrigerant of the liquid phase refrigerant In consideration of effectively preventing suction from the suction end into the refrigerant discharge pipe (13), it is preferably 5 mm or more.

  The accumulator (4) described above is manufactured as follows.

  First, the straight pipe portions (13a) (13b) of the refrigerant discharge pipe (13) are passed through the pipe insertion holes (27), (28) of the top wall (14a) of the deflector (14) from below. At this time, three annular beads (25), (31), and (32) are formed in the first straight pipe portion (13a) of the refrigerant discharge pipe (13), and the lubricating oil return hole ( 26) is formed, but the expanded portion (24) is not formed. When the first straight pipe portion (13a) is passed through the first pipe insertion hole (27), the rising portion (30) is elastically deformed, so that the positioning annular bead (25) and the upper annular bead for holding the deflector ( 31) passes through the upper end opening of the rising part (30). Thereafter, when the upper annular bead (31) for holding the deflector passes through the upper end opening of the rising portion (30), the rising portion (30) returns to its original state due to its own elasticity, and the upper annular bead (31) is returned to the rising portion. Engage with the upper end of (30) from above. At the same time, the lower annular bead engages with the lower surface of the top wall (14a) from below.

  Next, the upper end of the first straight pipe portion (13a) is inserted into the refrigerant outlet port (16) from below the lid (12), the upper end thereof reaches the lower portion of the large diameter portion (15b), and the positioning annular bead ( Insert until 25) engages with the lower end surface of the downward projection (18). Next, a portion of the first straight pipe portion (13a) existing in the large-diameter portion (16a) of the refrigerant outlet port (16) is expanded from above to form the expanded pipe portion (24), and the refrigerant discharge pipe (13 ) To the lid (12).

  Next, after disposing the desiccant unit (33) at a predetermined position, the lid (12) is disposed on the cylinder (11) so that the refrigerant discharge pipe (13) enters the cylinder (11), and the cylinder from the outside is arranged. The upper end of the peripheral wall (11a) of (11) and the lower end of the annular hanging wall (12a) of the lid (12) are welded. Finally, the strainer (20) is inserted into the refrigerant inlet port (15) from above. Thus, the accumulator (4) is manufactured.

  In the accumulator described above, the gas-phase refrigerant including the liquid-phase refrigerant that has passed through the evaporator (3) flows into the tank (10) through the refrigerant inlet port (15) of the lid (12). At this time, most of the refrigerant that has entered the frame (21) of the strainer (20) passes through the opening (21a) formed in the peripheral wall of the large diameter portion (15b) of the refrigerant inlet port (15). The air is blown toward the peripheral surface, hits the inner peripheral surface of the large-diameter portion (15b), flows down and enters the tank (10) while being killed. Further, the remaining refrigerant flows downward through the opening (21b) formed in the bottom wall of the frame (21) and enters the tank (10).

  The refrigerant that has entered the tank (10) hits the deflector (14) in a state where the momentum has been killed, thereby efficiently separating gas and liquid.

  The gas phase refrigerant passes through the desiccant unit (33) and is removed from the water, and is then sucked in from the refrigerant suction end of the refrigerant discharge pipe (13), and the refrigerant discharge pipe (13) and the refrigerant outlet port (16) It is discharged out of the tank (10) through, and sent to the compressor (1). On the other hand, the liquid-phase refrigerant and the compressor lubricating oil contained in the refrigerant are sprayed on the deflector (14), then fall in the tank (10) and are stored at the bottom in the tank (10). The compressor lubricating oil is sucked into the refrigerant discharge pipe (13) from the lubricating oil return hole (26) and returned to the compressor.

It is a figure which shows the structure of the supercritical refrigerating cycle in which the accumulator by this invention is used as a gas-liquid separator. It is a vertical longitudinal cross-sectional view which shows the whole structure of the accumulator by this invention. FIG. 3 is a partially enlarged view of FIG. 2. FIG. 4 is a sectional view taken along line AA in FIG. 3. FIG. 4 is a partially enlarged view of FIG. 2 showing a different part from FIG. 3.

Explanation of symbols

(4): Accumulator
(10): Tank
(11): Torso
(12): Lid
(13): Refrigerant discharge pipe
(15): Refrigerant inlet port
(15d): Shoulder (support)
(16): Refrigerant outlet port
(17): Downward protrusion
(20): Strainer
(21): Frame
(21a) (21b): Opening
(22): Mesh
(23): outward flange

Claims (6)

A cylindrical metal cylinder having an upper end opened and a lower end closed, and a tank made of a metal lid joined to the upper end of the cylinder to close the upper end opening of the cylinder and having a refrigerant inlet port and a refrigerant outlet port A substantially U-shape that is disposed in the tank and has one refrigerant discharge end connected to the refrigerant outlet port and the other refrigerant suction end positioned above the liquid level of the liquid-phase refrigerant stored in the tank. In the refrigeration cycle accumulator with a refrigerant discharge pipe,
An accumulator for a refrigeration cycle in which a strainer is detachably inserted into the refrigerant inlet port of the lid from the outside. The refrigerant inlet port of the lid extends in the vertical direction, a support portion protruding inward is provided at the height direction intermediate portion of the inner peripheral surface of the refrigerant inlet port, and an outward flange provided on the strainer is a support portion. 2. The accumulator for a refrigeration cycle according to claim 1, wherein the strainer is detachable by being received by the refrigeration cycle. The strainer has a cylindrical shape having an upper end opened and a lower end closed, and has a frame having an outward flange. Openings are formed in the peripheral wall and the bottom wall of the frame, respectively, and these openings are formed in the frame. And a gap is formed between the peripheral wall of the frame and the inner peripheral surface of the refrigerant inlet port, and the lower end of the opening of the peripheral wall of the frame is located above the lower end of the refrigerant inlet port. The accumulator for a refrigerating cycle according to claim 2, wherein the accumulator is located. The refrigeration according to claim 3, wherein a plurality of openings are formed in the peripheral wall of the frame of the strainer and one opening is formed in the bottom wall, and a total area of the openings in the peripheral wall is three times or more of an area of the opening in the bottom wall. Cycle accumulator. The accumulator for a refrigeration cycle according to any one of claims 1 to 4, wherein a refrigerant suction end of the refrigerant discharge pipe is located above a lower end opening of the refrigerant inlet port. A downward protruding portion is integrally formed on the lower surface of the tank lid, the lower end of the refrigerant inlet port is open to the lower end surface of the lower protruding portion, and the refrigerant suction end of the refrigerant discharge pipe is a downward protruding formed on the lid. The refrigeration cycle accumulator according to claim 5, wherein the accumulator is located above the lower end of the portion.

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