DE102006055837A1 - Heat exchanger i.e. evaporator, for vehicle air conditioning system, has two heat exchanger registers with respective ports that are arranged diagonally and third heat exchanger register with third port that is arranged on same side - Google Patents

Abstract

The heat exchanger has three heat exchanger registers (1, 2, 3) arranged in three planes. The heat exchanger registers (1, 2) exhibit respective ports (4, 5) that are arranged alternatively/diagonally and the heat exchanger register (3) exhibit a port that is arranged on a same side. The ports (4, 5) serve for the integration of the heat exchanger into a refrigerant circuit. Another port is connected with the port of the heat exchanger register (3) by a junction unit (6), where a passage section of the junction unit amounts to 60 percentage of a passage section of collector lines (7).

Description

The The invention relates to an arrangement for optimized flow of Heat exchangers, in particular for the Use as evaporator in air conditioning systems of vehicles.

in the Evaporator of an air conditioner, the refrigerant absorbs heat from the airflow and evaporates. By the heat extraction from the air stream this is cooled.

Heat exchanger As evaporators in vehicle air conditioners are available in various designs known.

In most cases, two-row heat exchangers are used as evaporators in vehicle air conditioning systems. In order to lengthen the flow path and thus to increase the refrigerant-side temperature spread across the heat exchanger, according to the EP 1 058 070 A2 the manifolds divided by partitions. This creates a double-row heat exchanger from four successively flowed through heat transfer registers. In this way, a better temperature spread is achieved and thus a greater transmission power can be realized.

on the other hand is the temperature distribution over the outlet cross section of the air flow uneven. As well the pressure loss is over the heat exchanger through the frequent flow deflection increased. adversely is also that the introduction of the partitions a comparatively high requires technological effort and the positions of the partitions at Dimensional changes respectively be re-determined.

Similar flow variants can be found in the DE 103 12 780 A1 for disc and flat tube evaporators; in the EP 0 769 665 B1 , of the EP 0 862 035 B1 and the US 6,047,769 A for disk evaporator.

In the WO 2005/100900 A1 should be achieved by installing throttle levels in the manifolds a uniform flow through the individual evaporator tubes within the register. This allows registers to flow evenly through each located on the same side connections. On the other hand, the installation of the throttle stages associated with a lot of effort, causing additional pressure losses and is especially for each size separately to dimension and manufacture. Thus, these heat exchangers are also very expensive.

Double row Evaporators have the disadvantage that the temperature distribution of leaking air over the cross section of the heat exchanger is uneven. Furthermore, it is desirable that for the heat exchanger preferably Little space is required in the vehicle. Therefore, a great heat transfer performance to aim for in a small space.

The can by a big one Heat transfer surface and / or by an advantageous arrangement and flow through the evaporator tubes, such. B. in Gegenstromwärmeübertragern or cross flow heat exchangers, will be realized. In particular, a good heat transfer from the heat transfer medium or refrigerant to aim for the airflow. Therefore, a series connection of individual heat exchanger register beneficial to over the entire heat exchanger surface a highest possible Temperature difference between the heat transfer medium and the air to realize. In this regard, well-sized, three-row heat exchangers Advantages.

on the other hand are located in three-row heat exchangers the connection lines usually on different sides and thus require a more expensive pipe guide. At the same time it will the assembly difficult.

In the DE 102 20 533 A1 . 6 and 7 , a three-row heat exchanger is described, whose connections are located on the same side. However, the register, which is not uniformly flowed through because of the unilaterally arranged connections, is arranged last before the air outlet from the heat exchanger. This requires that no uniform temperature distribution over the outlet cross-section of the air flow can be realized.

adversely is with all known heat exchangers, that either the evaporator tubes are arranged in two rows or that in three-row evaporator tubes, the connections of the Manifolds, in which the evaporator tubes are integrated, on different sides and thus the management of the manifolds consuming or the flow the evaporator tubes is not optimal or for better refrigerant distribution additional Built-in components, such as cutting discs or throttle stages, into the manifolds required are.

The Ultimately, the problem is that every advantage is the disadvantageous one change one or more other parameters.

Of the Invention is therefore the object of a heat exchanger in such a way that over the cross section of the air outlet a uniform temperature distribution feasible is.

Farther should the two connections of the heat exchanger be on the same side without a complicated pipe guide or Fittings in the manifolds is required.

The The object is achieved in that that in airflow first and last heat exchanger registers diagonally arranged connections has and the connections the middle heat exchanger register located on the same page. As a result, the heat exchanger connections are on one side and the connections between the first and the middle as well as the middle and the second heat exchanger register opposite arranged and are thus formed at a short distance from each other. In particular, by the diagonally connected last heat transfer register due to the same pressure losses across all flat tubes of the register one very even refrigerant distribution and thus a uniform surface temperature of the heat exchanger register realized. This interconnection is also referred to as the Tichelmann system. In the consequence leads the arrangement to the desired, on the outlet cross-section distributed very evenly Air temperature.

Farther the construction of the manifolds is simplified; a provision the partitions and / or throttling the evaporator is not required. As well can be high internal pressures in the Refrigerant circulation, especially for Systems with carbon dioxide as a refrigerant (R744 systems), through simpler ways of manifold construction better control.

The Connection lines of the heat exchanger are attached on the same side. This eliminates a costly additional Pipe guide.

Thereby, that the hydraulic passage cross-section of the connecting elements At least 60% of the passage cross-section of the manifolds is a slight pressure loss over the heat exchanger guaranteed.

advantageous embodiments the heat exchanger, in particular as evaporator of vehicle air conditioning systems, arise from the dependent claims.

A advantageous embodiment of the invention gives the optimal passage cross-section to the connecting elements. As a result, on the one hand, the pressure losses kept low and on the other hand, a simple production and assembly the connecting elements possible. Likewise, the space required by the fasteners space of the heat exchanger reduced. The optimal passage cross section of the connecting elements is then 75-110 % of the passage cross section of the manifolds.

According to one Further development of the invention, the connecting elements are designed as 180 ° pipe bends. The Put 180 ° pipe bends a simple connection that is easy and inexpensive with Standard components is feasible.

According to one Another advantageous embodiment, the fasteners designed as a connection pipe socket. This will be a special Space and material-saving connection of the manifolds shown.

The Connecting pipe sockets are pierced at the front accordingly to the Lateral surface of the Manifolds adapted and z. B. soldered.

To a further advantageous embodiment of the invention is the Heat transfer surface Multi-channel flat tube evaporator tubes formed in the manifolds are involved. With flat tube evaporators, in particular multi-channel flat tube evaporators, can be inexpensively flexible sizes and variants realize. Multi-channel flat tube evaporators are inexpensive and can be produced with little mechanical effort as extruder profile. They are particularly suitable for the use with high operating pressure at the same time good specific Heat transfer performance.

In a development of the invention is a connection extension line arranged so that a heat exchanger connection is extended into the connection area of the other heat exchanger connection. this makes possible the spatial Near both connections of the heat exchanger. Through one or even two extension leads can both Heat exchanger connections arranged so be that an advantageous installation of the heat exchanger in the vehicle and easier assembly of the heat exchanger allows becomes. Likewise both heat exchanger connections to one common Wärmeübertrageranschlussstück be summarized.

As a development of the invention, the upper and the lower manifolds are combined to form collector blocks. In a collector block, the corresponding passages of the manifolds and the connecting pieces are introduced for the integration of the evaporator tubes. Thus, a simplification of the production of the heat exchanger is achieved by a reduction of the components. The collector block can z. B. made of extruded material by the meter and is therefore easy and inexpensive to produce. The collector blocks are therefore also for the modular Manufacturing suitable, configurable for various sizes, outputs and connection variants and easy to assemble.

In In a further development, the passages of the manifolds with Connection holes connected according to the desired guidance of the refrigerant. The connection holes can simply be introduced through hole in the collector block. Corresponding The necessity is the connection holes and passages of the manifolds closed with plugs.

A Another advantageous embodiment of the invention is characterized by the Arrangement of end blocks as connecting elements on the front sides realized the collector block. This is a compact design the entire piping (manifolds, fasteners) feasible. The endblocks can for fixing the heat transfer register by receiving the manifolds and the attachment of the heat exchanger in total by additional Attach appropriate brackets serve. Also arise Simplification of the assembly and standardization of the Components.

Corresponding are the endblocks, especially in that they are made of connecting plates and end plates are assembled, for different designs of the heat exchanger in terms of performance, Arrangement and integration in the refrigerant circuit variable.

In Another embodiment of the invention are in the connection plates provided connection channels according to the position of the manifolds to be connected, which are closed by the end plates.

In order to becomes an advantageous connection of the individual manifolds realized the collector block and a simple production and a standardized modular design of the heat exchanger allows.

In According to one embodiment of the invention, the heat exchanger connections are integrated into the end blocks. This allows the heat exchanger overall compact design and in particular by the reduction the items are made easy to install.

Of the Heat exchanger is made up of modular components. By the modular Construction is a simple design of the heat exchanger with different performance sizes, dimensions and Connection variants well feasible.

Especially advantageous is the heat exchanger in air conditioners with the refrigerant R744 can be used. R744 (carbon dioxide) requires high operating pressures, which the heat exchanger, in particular by the high pressure resistant executable Mehrkanalflachrohre and collector's blocks, with appropriate dimensioning of the components withstands.

By the inventive arrangement the heat exchanger tubes in three series and the summary to heat exchanger registers is one good distribution of the liquid refrigerant realizable. It is particularly advantageous that thereby a uniform temperature distribution of the heat exchanger exiting air flow ensured is.

One Advantage of the solution according to the invention exists Furthermore, in that the heat carrier side Pressure losses are minimized and the structure of the heat exchanger is simplified. Likewise, the heat exchanger is through the modular Easy to build in different sizes and can be easily extended or reduced and thus flexible to the respective conditions be adjusted.

Further Details, features and advantages of the invention will become apparent the following description of embodiments with reference on the associated Drawings. Show it:

1 : Schematic diagram of the heat exchanger with three heat exchanger registers,

2 : Detail view with connecting pipe connection and integration of the evaporator pipes,

3 : Connection variant of the heat exchanger with connection extension line,

4 : Detail view with header block and connection hole,

5 : Detail view with collector block and end block of connecting plate and end plate and

6 : Detail view of the integration of the evaporator tubes with three flow channels into the manifolds.

The heat exchanger, in particular as an evaporator for air conditioners in vehicle air conditioning systems, is realized as follows:
In 1 is a schematic diagram of the heat exchanger with three heat exchanger registers 1 . 2 . 3 shown. The evaporator tubes 9 , optionally provided with lamellae for surface enlargement, are each with the manifolds 7 connected by soldering. The manifolds 7 the heat exchanger register 1 . 2 . 3 are each on one side, z. B. by soldering with a cap closed. The connections of the manifolds 7 are each at the opposite end. At the first heat exchanger register 1 and the third heat exchanger register 2 the connections are mutually arranged.

According to 1 there is a connection of the first heat exchanger register 1 , who is also the connection 4 of the heat exchanger for integration into the refrigerant circuit is, on the lower manifold 7 On the right side. Here, the liquid refrigerant enters the first heat exchanger register 1 and distributes itself to the individual parallel-flowed evaporator tubes 9 , The other connection of the heat exchanger register 1 is in the overhead manifold 7 arranged on the left.

From there, through the connecting element 6 (eg soldered 180 ° pipe bend) the connection to the second heat exchanger register 3 , Again, the parallel arranged and flowed evaporator tubes 9 in the manifolds 7 involved. The connection of the lower manifold 7 is here on the left side again. As a result, the flow through the evaporator tubes 9 slightly closer to the connection than in the evaporator tubes, which are more remote from the connections 9 , The lower connection is in turn by a connecting element 6 (180 ° pipe bend) with the connection of the third heat exchanger register 2 connected. The parallel arranged evaporator tubes 9 are flowed through evenly and in the upper manifold 7 merged. The second port is on the right side of the manifold 7 - So diagonally opposite to the other connection - and also serves as a heat exchanger connection 5 of the heat exchanger for integration in the refrigerant circuit. On the way through the evaporator tubes 9 the heat exchanger register 1 . 2 . 3 the refrigerant evaporates through the out of the air stream 18 absorbed heat completely or overheated depending on the process and thus cools the air flow 18 from. The airflow 18 flows opposite to the flow of the refrigerant from the third / last 2 to the first heat exchanger register 1 , The arrangement of the connections of the heat exchanger register 1 . 2 . 3 done so that each right through left connections and upper through lower manifolds 7 and vice versa are replaceable.

In another embodiment according to 2 become the fasteners 6 as connecting pipe socket 8th executed. They are corresponding to the shell shape of the manifolds 7 adapted and with this z. B. soldered. Due to the fact that the connecting pipe sockets 8th between the manifolds 7 are arranged, no additional space is needed.

By additionally attaching a connection extension line 10 , as in 3 shown, both connectors can 4 . 5 the heat exchanger are brought together immediately. For a connection arrangement is possible, which further simplifies the installation of the heat exchanger.

Advantageous is the design of the manifolds 7 according to 4 , In this case, instead of the tubes, the respective upper and lower manifolds 7 all heat exchanger registers 1 . 2 . 3 in a collector's block 11 summarized and z. B. introduced by drilling or milling. Likewise, the production of the collector block of extruded profile is possible. The evaporator tubes 9 be in the connecting pieces 12 soldered. At the same time can to the collector block 11 also the fasteners 6 as connection holes 13 introduced and optionally closed by plugging.

Advantageous are the compact design of the heat exchanger and the simple mounting options on the collector block 11 ,

In 5 are as connecting elements 6 Endblocks made up of a connecting plate 14 with connection channel 16 and an end plate 15 exist, on the front sides of the collector blocks 11 appropriate. The connection channel 16 is so in the connection plate 14 arranged that the desired flows between the manifolds 7 be enabled. There, where no connection channel 16 in the connection plate 14 milled, no refrigerant flow is possible. The end plate 15 closes the connection channel 16 , The connection plate 14 and the end plate 15 be z. B. by screws and seals with the collector block 11 connected. In another embodiment, the addition of additional manifold connection plates, the end blocks also designed as pipes manifolds 7 used. The manifold connection plates have the dimensions of the connecting plates and are provided with correspondingly arranged holes for connection to the manifolds. You are with the manifolds, z. B. by soldering, connected. The connecting plates adjoining the manifold connecting plates 14 give the desired flow options by arranging the connection channels 16 free.

In 6 are the evaporator tubes 9 designed so that an evaporator tube 9 one or more flow channels each 17 per heat exchanger register 1 . 2 . 3 provides.

1

first Wärmeübertragerregister

2

third (last) heat exchanger register

3

second (middle, intermediate) heat exchanger register

4

Wärmeübertrageranschluss (cold) / supply line (return line)

5

Wärmeübertrageranschluss (Warm) Norlaufleitung

6

Fasteners, elbows

7

Headers / manifolds

8th

Connecting pipe socket

9

Flat tube evaporator / multichannel flat tube evaporator / evaporator tube

10

Port extension cable

11

collector block

12

spigot for evaporator tubes / flat tube evaporator

13

connecting bores

14

connecting plate

15

endplate

16

connecting channel

17

flow channel

18

airflow

Claims (13)

Heat exchanger, in particular as an evaporator of vehicle air conditioners, consisting of three arranged in three levels and refrigerant side in series flow through heat transfer registers that transmit the heat of the air flowing past the heat transfer register flowing through and thereby evaporating liquid, the heat transfer register from integrated in manifolds, parallel flowed through heat transfer tubes exist and the connections of the heat exchanger register in each case via one end of the manifolds, characterized in that the connections of the first heat exchanger register ( 1 ) and the third heat exchanger register ( 2 ) are arranged alternately / diagonally and the connections of the second heat exchanger register ( 3 ) are arranged on the same side, with one connection ( 4 . 5 ) of the first heat transfer register ( 1 ) and the third heat exchanger register ( 2 ) for the integration of the heat exchanger in the refrigerant circuit is used and in each case a further connection by a correspondingly arranged connecting element ( 6 ) with the connections of the second heat exchanger register ( 3 ), wherein the passage cross-section of the connecting elements ( 6 ) at least 60% of the passage cross-section of the manifolds ( 7 ) is. Heat exchanger according to claim 1, characterized in that the optimum passage cross section of the connecting elements ( 6 ) 75 to 110% of the passage cross-section of the manifolds ( 7 ) is. Heat exchanger according to claim 1 or 2, characterized in that the connecting elements ( 6 ) are designed as 180 ° pipe bends. Heat exchanger according to one of claims 1 to 3, characterized in that the connecting elements ( 6 ) as connecting pipe socket ( 8th ) are executed whose end faces to the apertured lateral surfaces of the manifolds ( 7 ) are adjusted. Heat exchanger according to one of claims 1 to 4, characterized in that the heat transfer register ( 1 . 2 . 3 ) into the collecting lines ( 7 ) integrated multi-channel flat tube evaporators ( 9 ) are executed. Heat exchanger according to one of claims 1 to 5, characterized in that a connection extension line ( 10 ) is arranged so that a heat exchanger connection ( 4 . 5 ) in the connection area of the other heat exchanger connection ( 5 . 4 ) is extended. Heat exchanger according to one of claims 1 to 6, characterized in that in each case the upper and the lower manifolds ( 7 ) in a collector block ( 11 ) into which the corresponding passages of the collecting lines ( 7 ) and the connecting pieces ( 12 ) for the integration of the flat tube evaporator ( 9 ) are introduced. Heat exchanger according to claim 7, characterized in that in the collector blocks ( 11 ) as connecting elements ( 6 ) between each two manifolds ( 7 ) Connection holes ( 13 ) are introduced. Heat exchanger according to claim 7, characterized in that on the end faces of the collector block ( 11 ) Endblocks made from connection plate ( 14 ) and end plate ( 15 ), as connecting elements ( 6 ) are mounted. Heat exchanger according to claim 9, characterized in that in the connecting plates ( 14 ) a connection channel ( 16 ) according to the position of the manifolds ( 7 ) and that an end plate ( 15 ) is provided, which the connecting channel ( 16 ) closes. Heat exchanger according to claim 9 or 10, characterized in that in the end block, a heat exchanger connection ( 4 . 5 ) is provided. Heat exchanger according to one of claims 1 to 11, characterized in that the heat transformer is constructed from modular components. Heat exchanger according to one of claims 1 to 12, characterized in that the heat exchanger from the refrigerant R744 can be flowed through is trained.