DE102014113793A1 - Refrigerant accumulator, in particular for motor vehicle refrigerant circuits - Google Patents

Abstract

The invention relates to a refrigerant accumulator (1) comprising a battery container (2) and a suction tube arrangement (3) arranged therein, wherein the suction tube arrangement (3) is formed by an outer suction tube (4) and an inner suction tube (5) which are coaxial and arranged at a distance from one another and a flow path (8) are connected to one another via a connecting part (6) at the lower ends of the suction tubes (4, 5) and that an oil snubbing bore (7) is arranged radially in the connecting part (6). 9) of the battery container (2) connects to the flow path (8) in the intake manifold (3).

Description

The invention relates to a refrigerant accumulator, in particular for motor vehicle refrigerant circuits. Refrigerant accumulators, also referred to as refrigerant accumulators, are used in refrigerant circuits to separate liquid refrigerant from the refrigerant vapor, and also the refrigerant oil is separated and collected. The refrigerant accumulator is further used to add the refrigerant oil to the refrigerant vapor in the finest distribution so that the refrigerant oil is supplied to the refrigerant compressor.

In certain refrigerant circuits, it may be advantageous to implement in the refrigerant accumulator another function. In this case, a heat exchanger is integrated as an internal heat exchanger in the component, for example as a subcooling countercurrent. In refrigerant circuits with R744 as the refrigerant, this can be advantageously used, for example.

Refrigerant accumulators have thus summarized the task of separation of liquid and gas phase. Furthermore, with the construction of the refrigerant accumulators via the suction of the gas phase, the oil return into the refrigerant compressor is realized and, in addition, a filter for the liquid phase is implemented in the refrigerant accumulator.

Various forms of refrigerant accumulators are known in the art. From the US 2005 0229632 A1 is a Kältemittelakkumulator for the liquid phase of an air conditioning system is known, which is designed specifically for the requirements of a CO ₂ as the refrigerant using refrigeration system. The extraction of the refrigerant takes place via a pipe system whose end is centered in the upper region of the accumulator. An internal heat exchanger is not integrated in this Kältemittelakkumulator and the tube for the extraction of the refrigerant vapor is guided from the axially centered upper end down in an arc of the contour of the soil back up to the decentered output.

After US 2004 0093894 A1 a refrigerant accumulator for the liquid phase of an air conditioning system is known, which has an axially centered straight pipe for the suction of the refrigerant with the input in the upper region and the output to the bottom.

The US 2008 0041093 A1 discloses a refrigerant accumulator for air conditioners with a piping system of coaxially arranged outer and inner tube with the input in the upper region of the accumulator in the outer tube and the output at the axially centered output of the inner tube upwardly from the accumulator.

The object of the invention is to provide a refrigerant accumulator, in particular for motor vehicle refrigerant circuits, which permits effective separation of liquid and gas phase and, moreover, has a pipe for sucking off the gas phase including oil recirculation. The Kältemittelakkumulator should be inexpensive to produce and manufacturing technology inexpensive to produce. Furthermore, the functionality of the component should be ensured by the integrability of a filter arrangement for the refrigerant oil to be returned over longer periods.

The object is achieved by an article having the features according to patent claim 1. Further developments are specified in the dependent claims.

In particular, the object of the invention is achieved by a refrigerant accumulator for motor vehicle refrigerant circuits, which includes a battery container and a suction tube arrangement arranged therein. The suction tube assembly consists of an outer suction tube and an inner suction tube, which are arranged coaxially centered and spaced apart in the battery container. The outer suction pipe and the inner suction pipe is connected to each other via a connecting part at the respective lower ends of the suction pipes. About this connection part, the flow path of the refrigerant in the annular gap between the outer and inner intake pipe from above comes into the connecting part, where it is deflected inwards and continues to extend over the inner suction pipe upwards. Arranged radially in the connecting part is an oil sniffing bore which connects an oil sump area of the rechargeable battery container to the flow path in the intake manifold arrangement.

According to a preferred embodiment of the invention, the Ölschnüffelbohrung is arranged in the connecting part in the amount of half the distance between the lower end of the inner suction pipe and the lower end of the connecting part.

Preferably, the connecting part is surrounded in the region of the oil sniffing bore by a filter which filters the sucked-in oil from the oil sump area before it enters the oil sniffing bore.

The connecting part is specially designed for 180 ° flow reversal of the flow path for the pressure loss minimization. Preferably, a ring-like bulged contour is provided, so that the flow path is directed radially from outside to inside and turning by 180 °.

For receiving the outer suction tube, a connecting part at the upper end of a Christmas tree profile is provided, on which the outer suction tube can be shrunk manufacturing technology in a simple manner.

The connecting part preferably has a wall thickness of 0.4 mm to 3 mm in the region of the oil sniff bore.

The Ölschnüffelbohrung itself preferably has a diameter of 0.2 mm to 3 mm.

For concentration of the refrigerant oil in the battery container, the oil sump area is conically tapered downwards, so that even with low refrigerant oil volume a relatively high level of the refrigerant oil level is reached and thus the oil sniff hole is always in the range of the separated refrigerant oil below the liquid refrigerant.

The filter for the refrigerant oil is preferably formed as a filter ring. For receiving the filter ring annular beads are advantageously arranged on the connecting part. According to an advantageous embodiment, the battery container is arranged in a pressure-resistant outer container and between the battery container and the outer container, an internal heat exchanger for the refrigerant circuit is placed. The formation of the inner heat exchanger is targeted in the annular gap between the battery container and the outer container as a tube coil. It has proved to be particularly advantageous that the battery container is made of plastic. An additional advantage arises when the plastic with low water absorption, such as polybutylene terephthalate, polyethylene or polypropylene, is formed.

The battery container is closed at the top by a battery container cover, which has an opening in the region of a bend, which opening is designed to be closable with a cap. For the efficient separation of the liquid vapor mixture, it is advantageous to design the battery container lid as a cyclone for separating this mixture.

Functionally separates the accumulator not only liquid refrigerant but also refrigerant oil. However, the refrigerant oil has to be conveyed out of the sump of the accumulator and returned to the refrigerant mass flow circulating in the circuit again to or to the refrigerant compressor. This is done via a suction pipe through which the gaseous refrigerant flows to the outlet. In the accumulator sump a small oil sniffing hole is arranged, through which the gas flow on or sucks the refrigerant oil. However, not only refrigerant oil but also liquid refrigerant, which applies a liquid fraction to the outflowing gas phase, enters the refrigerant vapor stream through the oil sniffing bore. This unavoidable proportion of liquid should generally not exceed 10% of the total mass flow. In order to minimize this problem, the appropriate diameter of the oil sniffer bore was determined, which is usually very small and is between 0.2 to 3 mm. Conventional manufacturing tolerances thus fall very quickly functionally significant. The geometrical arrangement of the oil sniff bore also has a considerable influence on the sensitivity and the amount of extracted liquid. According to one aspect of the invention, the geometric arrangement is decisive for whether manufacturing tolerances can be compensated for or not, or whether the amount of liquid extracted is always in the specified range.

The advantages of the invention are the cost-efficient production possibility of the refrigerant accumulator. Furthermore, the Kältemittelakkumulatorbehälter is made of plastic, whereby a good thermal insulation from the environment can be realized. Structurally results in a great deal of creative freedom, which is particularly advantageous in the construction of the cyclone as a liquid separator. The conically tapering oil sump area minimizes the sump volume and enables reliable extraction of refrigerant oil and a relatively low proportion of refrigerant liquid.

In the embodiment of the refrigerant accumulator as a combined component with the integration of the accumulator and the internal heat exchanger in a component, the interior heat exchanger is arranged coaxially around the battery container. This has the additional advantage that the wall of the battery container is not heated by the warm engine compartment, but is isolated from the low pressure side of the inner heat exchanger against heat input from the engine compartment.

Further details, features and advantages of embodiments of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. Show it:

1 : Longitudinal section of refrigerant accumulator

2 : Longitudinal section of the battery container with suction tube arrangement

3 : Lower end of the battery container and intake manifold assembly

4 : Lower end of the battery container and intake manifold assembly

5 : Refrigerant accumulator without outer container

6 : Bottom area of the battery container with flow paths for the refrigerant

7a , b: Battery container lid

8th : Lower section of intake manifold with filter in section and oil snubber bore.

In 1 is a refrigerant accumulator 1 as combi component with integrated internal heat exchanger 15 shown in longitudinal section. The outer container 14 of the refrigerant accumulator 1 consists in this embodiment of a cover part 18 and a bottom part 19 , which have a cylinder jacket 20 connected to each other. The outer container 14 is executed pressure-resistant with its components and in its interior, the individual components of the combi component are arranged. A combined component is understood to mean a refrigerant accumulator which, in addition to the accumulator function for the refrigerant, also implements the function of an internal heat exchanger.

In the cylinder jacket 20 of the outer container 14 , the cylindrical connecting part 6 from bottom part 19 and lid part 18 , Radially from outside to inside are first the heat exchanger 15 as coiled tubing, the battery container 2 for receiving the liquid refrigerant and the intake manifold 3 arranged to guide the refrigerant vapor stream each concentric with the cylinder axis. The lower part of the battery container 2 is called oil sump area 9 referred to, which is formed conically tapering down to concentrate there and settling refrigerant oil and collect.

2 shows a longitudinal section of the battery container 2 and the suction tube assembly 3 , The suction tube arrangement 3 is made of inner suction tube 5 and outer suction tube 4 constructed, with the suction pipes 4 . 5 via a connecting part 6 at the lower ends of the suction pipes 4 . 5 connected to each other. The battery container 2 is cylindrical and is top of a battery container lid 16 locked. In the lower area is the battery container 2 as an oil sump area 9 formed tapered, the oil sump area 9 in the area of the connecting part 6 from outer intake manifold 4 and inner suction tube 5 lies.

In the 3 and 4 is the lower part of the battery container 2 excerpts are shown enlarged. A constructional feature of the refrigerant accumulator 1 consists in the connection of outer suction tube 4 and inner suction tube 5 , This connection is via the connection part 6 realized. The connecting part 6 has at its upper end a Christmas tree profile 13 for receiving the outer suction tube 4 , An advantage of this structural design is that despite high pressures of the refrigerant of the battery container 2 itself must withstand any pressure, as this on the inside and outside of the battery container 2 , the low pressure side of the refrigerant circuit, is approximately equal except for the pressure difference due to flow losses through the component. Thus, the battery container 2 Made of plastic, which leads to various advantages. In particular, plastics are generally associated with heat-insulating properties, so that they act against the environment and the interior heat exchanger heat-insulating. Thus, the heat is only in the low pressure part of the interior heat exchanger 15 transferred and not in the battery container 2 , where else additional refrigerant liquid in the battery container 2 would evaporate and therefore this refrigerant is not as desired in the battery container 2 is stored.

In the outer wall of the connecting part 6 , which controls the flow of the low pressure flow from the outer intake manifold 4 into the inner suction tube 5 takes over, is an oil snubbing hole 7 arranged, via which the refrigerant vapor stream with the oil sump area 9 and the accumulating there refrigerant oil is connected. About the oil sniffing hole 7 oil comes from the oil sump area 9 in the refrigerant vapor stream, which at the end of the connecting part 6 is deflected by 180 ° and into the inner intake manifold 5 flows up into it. At the connection part 6 are two ring bulges 12 molded, which for sealingly receiving a filter 10 serve in the form of a filter ring.

The outer intake manifold 4 is by means of a shrink connection on the Christmas tree profile 13 of the connecting part 6 applied.

The ring bulges 12 form sealing diameter for the filter 10 the oil sniffing hole 7 protects against contamination.

According to a further embodiment, the desiccant is in the oil sump area 9 of the battery container 2 arranged so that the oil sniffer bore 7 still from the filter 10 is protected. A disc-shaped sieve or filter then presses on the surface of the desiccant granule filling to avoid swirling or flying around the granules. The sieve, not shown, has an outer diameter, the inner diameter, or the contour of the battery container 2 equivalent. In the middle there is a corresponding opening for the intake manifold 3 ,

The oil sniffing hole 7 is radial with respect to the tank axis of the refrigerant accumulator 1 and below the lower end of the inner draft tube 5 , approximately half the distance between the lower end of the inner suction tube 5 and the lower end of the connecting part 6 arranged. The oil sniffing hole 7 has a diameter between 0.29 mm to 2.1 mm.

The wall thickness of the connecting part 6 corresponds to the length of the oil sniff hole 7 and is between 0.49 mm to 2.1 mm.

In 5 is the embodiment of the refrigerant accumulator 1 in the version as combi component with internal heat exchanger 15 without the pressure-resistant cylinder jacket 20 shown in perspective.

The refrigerant accumulator 1 is limited in the axial direction by the cover part 18 and from the bottom part 19 , In the upper area is the interior heat exchanger 15 arranged. The battery container 2 is with its lower area below the interior heat exchanger 15 to see.

In 6 are the flow path 8th for the vaporous refrigerant within the intake manifold 3 shown schematically. The flow path 8th of the refrigerant passes along the annular gap between the outer suction pipe 4 and the inner suction tube 5 downward. In the lower part of the battery container 2 is the connecting part 6 , which externally via a shrink connection, the outer intake manifold 4 receives and is connected to this. The connecting part 6 then extends further towards the bottom of the battery container 2 , where webs for receiving and centering for the inner intake manifold 5 are provided.

Similarly, a cover plate holding and spacing the outer draft tube holds and spaces 4 protects against suction of liquid refrigerant, the inner intake manifold 5 in the upper area. The cover plate is on the outer intake manifold 4 attached and has three webs, the inner suction tube 5 in the outer intake manifold 4 lead and ensure that an annular gap arises. These bars are also in the connection part 6 intended. Axial becomes the inner intake manifold 5 over the lid 16 against the connecting part 6 held.

The flow path 8th the refrigerant vapor mixture passes between the connecting part 6 and the inner suction tube 5 continue to the axial end of the connecting part 6 where the flow path 8th is deflected by 180 ° first inward and then upwards. Thus, the vaporous refrigerant enters the inner intake manifold 5 and flows up again. In the oil sump area 9 of the battery container 2 is in the connecting part 6 an oil sniff hole 7 in the radial direction relative to the axis of the refrigerant accumulator 1 arranged. Through the oil sniffing hole 7 is the flow path 8th within the connection part 6 with the oil sump area 9 in substance, leaving oil from the oil sump area 9 through the oil sniff hole 7 is sucked through by vaporous refrigerant and entrained.

In the lower part of the connecting part 6 are adjacent to the Christmas tree profile 13 for receiving the outer suction tube 4 annular beads 12 above and below the oil sniff hole 7 arranged, the inclusion of a filter 10 serve.

For deflecting the flow path 8th 180 ° at the lower end of the connecting part 6 is in this one ring-shaped bulging contour 11 incorporated the flow reversal of the flow path 8th flow mechanics perform as low loss.

In 7a and 7b is a battery container lid 16 shown which in 7a with unlocked opening and in 7b with through a cap 17 sealed opening is shown. The battery container lid 16 is preferably like the battery container 2 also made of plastic and has the functionality of a cyclone for separating the liquid from the gaseous phase of the inflowing refrigerant. Due to the complexity of the battery case lid 16 with integrated cyclone not in one piece as injection molded part produced. For demolding in the production by injection molding, the battery container lid 16 in the area of the manifold for incoming two-phase refrigerant, an opening through which a cap 17 is closed.

In 8th is the lower portion of the intake manifold 3 shown. The outer intake manifold 4 is about the fir tree profile 13 of the connecting part 6 shrunk. The oil sniffing hole 7 in the lower part of the connecting part 6 is protected to the outside from contamination and thus from possible blockage and blocking by a filter 10 as a ring filter of the oil sniffer bore 7 upstream. After a peculiarity of the construction of the refrigerant accumulator 1 in the embodiment as a combined component with integrated internal heat exchanger 15 is the filter 10 though in the refrigerant accumulator 1 but integrated outside the container for the liquid refrigerant in the area of the oil sump 9 arranged. In addition to the filter 10 is below the battery container 2 in the area of the tapered oil sump area 9 another filter is used, the total refrigerant mass flow at the outlet of the low pressure side of the internal heat exchanger 15 filters.

For the refrigerant accumulator 1 This results in a 100% filter directly before the Low-pressure side outlet of the refrigerant vapor, ie after the inner heat exchanger 15 , As the refrigerant accumulator 1 has a very large inner surface, the potential for the accidental introduction of dirt is comparatively high. A filter directly in front of the outlet of the combi component offers the advantage of a certain intrinsic safety with regard to impermissible impurities.

Desiccant must be present in the refrigerant circuit, usually in the refrigerant accumulator 1 is housed. For this purpose, for example, bags made of textile fabric are used, which are filled with silica gel as a desiccant. According to an advantageous embodiment of the invention hygroscopic plastics are used which can absorb up to 2 to 3% water. This corresponds to up to 50% of the absorption capacity of the desiccant. Therefore, refrigerant accumulators need 1 from hygroscopic plastic either during production and handling and transport are protected from ambient moisture or the desiccant amount must be increased equivalent. The latter, however, reduces the storage capacity of the refrigerant accumulator 1 for liquid refrigerant. To reduce the risk plastics with very low water absorption, such as PBT, PE or PP are used.

An advantageous embodiment of the invention is to take advantage of the ability of plastics absorb moisture and use this moisture absorption capacity for the refrigerant drying. Thus, cost savings for the desiccant and an increase in the storage capacity of the accumulator for more liquid refrigerant can be achieved.

LIST OF REFERENCE NUMBERS

1

 refrigerant accumulator

2

 battery container

3

 suction tube

4

 outer suction tube

5

 inner suction tube

6

 connecting part

7

 Oil leak detecting port

8th

 flow path

9

 Oil sump area

10

 filter

11

 ring-shaped convex contour

12

 torus

13

 Tannenbaum profile

14

 outer container

15

 Internal heat exchanger

16

 Battery container cover

17

 cap

18

 cover part

19

 the bottom part

20

 cylinder surface

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 20050229632 A1 [0004]
• US 20040093894 A1 [0005]
• US 20080041093 A1 [0006]

Claims (15)

Refrigerant accumulator ( 1 ), in particular for motor vehicle refrigerant circuits, comprising a battery container ( 2 ) and a suction tube arrangement arranged therein ( 3 ), wherein the suction tube arrangement ( 3 ) from an outer suction tube ( 4 ) and an inner suction tube ( 5 ), which are arranged coaxially and spaced from each other and via a connecting part ( 6 ) at the lower ends of the suction tubes ( 4 . 5 ) with each other a flow path ( 8th ) and that in the connection part ( 6 ) radially a Ölschnüffelbohrung ( 7 ), which has an oil sump area ( 9 ) of the battery container ( 2 ) with the flow path ( 8th ) in the intake manifold ( 3 ) connects. Refrigerant accumulator ( 1 ) according to claim 1, characterized in that the oil sniffing bore ( 7 ) in the connection part ( 6 ) in the amount of half the distance between the lower end of the inner suction tube ( 5 ) and the lower end of the connecting part ( 6 ) is arranged. Refrigerant accumulator ( 1 ) according to claim 1 or 2, characterized in that the connecting part ( 6 ) in the area of the oil sniffing bore ( 7 ) of a filter ( 10 ), which filters the sucked oil. Refrigerant accumulator ( 1 ) according to one of claims 1 to 3, characterized in that the connecting part ( 6 ) for 180 ° flow reversal of the flow path ( 8th ) for the pressure loss minimization a ring-like curved contour ( 11 ) having. Refrigerant accumulator ( 1 ) according to one of claims 1 to 4, characterized in that the connecting part ( 6 ) for receiving the outer suction tube ( 4 ) a fir tree profile ( 13 ) having. Refrigerant accumulator ( 1 ) according to one of claims 1 to 5, characterized in that the connecting part ( 6 ) in the area of the oil sniffing bore ( 7 ) has a wall thickness of 0.4 mm to 3 mm. Refrigerant accumulator ( 1 ) according to one of claims 1 to 6, characterized in that the oil sniffing bore ( 7 ) has a diameter of 0.2 mm to 3 mm. Refrigerant accumulator ( 1 ) according to one of claims 1 to 7, characterized in that the battery container ( 2 ) in the oil sump area ( 9 ) is conically tapered. Refrigerant accumulator ( 1 ) according to one of claims 1 to 8, characterized in that the filter ( 10 ) is designed as a filter ring. Refrigerant accumulator ( 1 ) according to claim 9, characterized in that at the connecting part ( 6 ) for receiving the filter ring and the formation of a liquid layer in front of the Ölschnüffelbohrung ( 7 ) Annular beads ( 12 ) are arranged. Refrigerant accumulator ( 1 ) according to one of claims 1 to 10, characterized in that the battery container ( 2 ) in a pressure-resistant outer container ( 14 ) and that between the battery container ( 2 ) and the outer container ( 14 ) an internal heat exchanger ( 15 ) is arranged for the refrigerant circuit. Refrigerant accumulator ( 1 ) according to one of claims 1 to 11, characterized in that the battery container ( 2 ) is formed of plastic. Refrigerant accumulator ( 1 ) according to claim 12, characterized in that the battery container ( 2 ) is formed of plastic with low water absorption, such as polybutylene terephthalate, polyethylene or polypropylene. Refrigerant accumulator ( 1 ) according to one of claims 1 to 13, characterized in that the battery container ( 2 ) from a battery container lid ( 16 ) is closed at the top and that the battery container lid ( 16 ) in the region of a bend has an opening which is provided with a cap ( 17 ) is formed closable. Refrigerant accumulator ( 1 ) according to claim 14, characterized in that the battery container lid ( 16 ) is designed as a cyclone for a refrigerant vapor-liquid mixture.

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