US20230023677A1

US20230023677A1 - Evaporator

Info

Publication number: US20230023677A1
Application number: US17/872,780
Authority: US
Inventors: Gottfried Duerr; Timo PEIFER; Axel Dolderer; Thomas Spranger; Frank-Heiner Schenk; Vjekoslav Bosnjak; Guenther Feuerecker; Rudolf Huegel
Original assignee: Mahle International GmbH
Current assignee: Mahle International GmbH
Priority date: 2021-07-26
Filing date: 2022-07-25
Publication date: 2023-01-26
Also published as: DE102021208038A1

Abstract

An evaporator with a finned tube block with tubes and fins, wherein the tubes are arranged in rows and the fins are arranged between the tubes, with a first collection and distribution box and with a second collection and distribution box. Each of the two collection and distribution boxes has a bottom and a box lid. The respective bottom has openings for inserting the tube ends of the tubes of the finned tube block. The finned tube block is divided into evaporator flows to which groups of tubes of the finned tube block are assigned. The tubes of an evaporator flow each merge end-side into a box area of a collection and distribution box. The respective bottom of the collection and distribution boxes is designed with rim holes for inserting the tube ends in the openings.

Description

This nonprovisional application claims priority under 35 U.S.C. § 119(a) to German Patent Application No. 10 2021 208 038.3, which was filed in Germany on Jul. 26, 2021, and which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to an evaporator, in particular for an air conditioning unit, in particular for an air conditioning system of a motor vehicle.

Description of the Background Art

Evaporators of air conditioning units of motor vehicles are well known in the prior art, for example by WO 2004/005827 A1, which corresponds to US 2006/0037740, which is incorporated herein by reference. Such evaporators are multi-flow with multiple evaporator flows and have a finned tube block and, on both sides of the finned tube block, in each case a collection and distribution box to distribute the refrigerant in the evaporator to a number of tubes of a respective evaporator flow or to collect the refrigerant from a number of tubes of a respective evaporator flow. For this purpose, the collection and distribution boxes are divided into different box areas, which are fluid-connected to each other as required. The collection and distribution boxes each have a bottom in which openings are provided, into which the tubes of the finned tube block are inserted and form a fluid connection.
In cross-section, the bottom of evaporator is typically essentially rectangular and has two rows of openings for the tubes, wherein the width of the bottom in the direction of air flow or the width of the two rows of tubes in the direction of air flow defines the evaporator width.
It is particularly evident in the case of narrow evaporators having a width in the direction of air flow of about 50 mm or below that due to the design of the collection and distribution boxes, damage can result from temperature changes in the operation of the evaporator, causing unwanted failure of the evaporator, which should be avoided.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide an evaporator having a rather narrow width viewed in the direction of air flow, so that compared to the prior art it exhibits less tendency to damage due to temperature changes, so that the failure rates are reduced or related failures can be completely avoided.
An exemplary embodiment of the invention relates to an evaporator, in particular for an air conditioning unit, in particular for an air conditioning system of a motor vehicle, with a finned tube block having a plurality of tubes and fins, wherein the tubes are arranged in two rows, so that in the in each case two tubes are arranged one after in the other direction of air flow and the fins are arranged between the tubes, with a first collection and distribution box and with a second collection and distribution box, wherein each of the collection and distribution boxes is connected to one of the tube ends of the tubes of the finned tube block, wherein each of the two collection and distribution boxes has a bottom and a box lid, wherein the respective bottom has openings for inserting the tube ends of the tubes of the finned tube block, wherein in the two collection and distribution boxes, partition walls are arranged, which divide the respective interior of the collection and distribution boxes into box areas, wherein the finned tube block is divided into evaporator flows to which groups of tubes of the finned tube block are assigned, wherein the tubes of an evaporator flow each merge end-side in a box area of a collection and distribution box, wherein the respective bottom of the collection and distribution boxes are designed with rim holes for inserting the tube ends in the openings, wherein the rim holes are formed circumferentially around the openings and protrude from the bottom on an outer side of the bottom to the fins of the finned tube block. Due to the design and arrangement of the rim holes on the outer side of the bottom, the rim holes reinforce the bottom particularly well against temperature AC voltages, so that temperature change damage is less pronounced and the service life of the evaporator can thus be significantly improved.
It is particularly useful if the finned tube block is divided into six evaporator flows, wherein in particular three evaporator flows are arranged on the air inflow side and three evaporator flows on the air outflow side. As a result, successive flow of the refrigerant through the evaporator flows is achieved, so that the refrigerant from evaporator flow to evaporator flow is heated by the air flow which flows through or around on the air side and absorbs heat from the cooling air. The arrangement of the six evaporator flows, in particular, achieves that the air flowing through the evaporator is cooled more evenly and thus a more homogeneous temperature profile of the air is achieved, wherein this way lower air temperatures can also be achieved.
It is particularly advantageous if the evaporator has a width (BV) in the direction of air flow and the respective bottom has a width (BB) in the air flow direction, so that the width of the evaporator (BV) is in the range of 60 mm or less, in particular in the range of 50 mm or less and/or that the width of the bottom (BB) is in the range of 55 mm or less, in particular in the range of 50 mm or less. The design of the rim holes around the openings on the outer side of the bottom is particularly important for narrow evaporators since the narrow evaporators, in their width in the direction of air flow, are otherwise not rigid enough and suffer particularly from the stresses of temperature changes and the resulting AC temperature voltages.
It is particularly advantageous if the finned tube block is divided into six evaporator flows, wherein the three evaporator flows are first flowed through on the air outflow side by the refrigerant flowing through the evaporator and then the three evaporator flows on the air flow inflow side. This homogenizes the temperature distribution of the air flow and lower air temperatures are achieved when the evaporator is discharged.
It is also advantageous if the evaporator has two broad sides having the air inflow side and the air outflow side as well as two narrow sides arranged in the direction of air flow, wherein the three evaporator flows on the air outflow side are flowed through from a first narrow side to a second narrow side and then the three evaporator flows on the air inflow side are flowed through from the second narrow side to the first narrow side. This also homogenizes the temperature distribution of the air flow and lower air temperatures are achieved when the evaporator is discharged.
It is particularly advantageous if the box lid is formed by lid areas projecting from the bottom, which are curved from a respective edge of the bottom to the center of the bottom. As a result, the box lid with its lid areas is formed one-piece with the bottom, which facilitates production and reduces costs because it is not necessary for different parts to be manufactured and joined. At the same time, a connection that needs to be sealed is omitted at the bending point, which basically promotes tightness. At the same time, bending the material of the bottom at the transition to the box lid additionally promotes the stiffness of the collection and distribution box.
It is also advantageous if the lid areas have outwardly projecting bulges and/or inwardly projecting bulges for reinforcing the box lid. This also achieves the stiffness of the collection and distribution box.
It is also expedient if the lid areas have inwardly projecting beads for supporting partition walls for separating box areas and/or end walls for the end-side closure of the collection and distribution box. It is preferred if the inwardly-projecting beads occur in pairs and a partition wall and/or end wall can be accommodated between the beads. It is also an alternative if only one bead is provided for adjoining a partition wall and/or end wall to its side. This defines the position of the partition wall and/or the end wall so that the partition wall or end wall remains in place during soldering and the soldering is sealed. Also, the respective, provided bead serves to support the partition wall or end wall in case of lateral application of force.
It is also expedient if the bottom has inwardly and/or outwardly projecting beads and/or nubs for supporting at least one partition wall for separating box areas and/or at least one end wall for the end-side closure of the collection and distribution box and/or for reinforcing the bottom. As a result, in addition to reinforcing the bottom, an adjoining of a partition wall and/or end wall are also achieved.
It is also advantageous if the bottom between two rim holes of two adjacent openings has a bead projecting inwards and/or outwards and/or a nub for reinforcing the bottom. This further increases the stiffness of the bottom against pressure changes and temperature changes.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes, combinations, and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

FIG. 1 is a schematic, perspective view of an embodiment of an evaporator according to the invention,

FIG. 2 is a schematic, perspective view of a collection and distribution box of the evaporator according to FIG. 1 ,

FIG. 3 is a partial side view of the collection and distribution box of the evaporator according to FIGS. 1 and 2 ,

FIG. 4 is a schematic sectional view of the bottom of the collection and distribution box of the evaporator according to FIG. 3 , and

FIG. 5 is a schematic sectional view of the collection and distribution box of the evaporator according to FIG. 2 .

DETAILED DESCRIPTION

In a schematic and perspective view, FIG. 1 shows an embodiment of an evaporator 1 according to the invention. The evaporator 1 is particularly suitable for an air conditioning unit, in particular for an air conditioning system of a motor vehicle, so that it can be used in the air conditioning unit, on the one hand to be flowed through by a refrigerant and on the other hand to be flowed through by air, so that by heat transfer from the air to the refrigerant, the air flowing through the evaporator is cooled and the refrigerant is heated and evaporated.
The evaporator 1 has a finned tube block 2 with a plurality of tubes 3 and fins 4. The tubes 3 and fins 4 are essentially arranged alternately transversely to the air flow direction 5, so that the air can flow in air flow direction 5 through the fins 4 and the fins 4 are arranged between the tubes 3. At the two lateral edges 6 of the finned tube block 2, fins 4 can also be arranged, which are only attached to a tube 3 on one side. The fins 4 are essentially arranged between two tubes 3, viewed transversely to the air flow direction 5, and are thus in heat transfer with the tubes 3, so that an air flow flowing through the fins 4 is in heat transfer with the refrigerant flowing through the tubes 3.
The evaporator 1 is designed, for example, as a narrow evaporator 1. Such a narrow evaporator 1 has a width BV in air flow direction 5 and the respective bottom 11 has a width BB in air flow direction 5, such that the width BV of the evaporator 1 is in the range of 60 mm or less, in particular in the range of 50 mm or less and/or that the width BB of the bottom 11 is in the range of 55 mm or less, in particular in the range of 50 mm or less.
Preferably, the tubes 3 are arranged in air flow direction 5 in two rows 7, so that in air flow direction 5 in each case two tubes 3 are arranged one after the other. The tubes 3 of the two rows 7 may be formed independently of each other or be connected by a material bridge.
The fins 4 can be formed separately per row 7 or the fins 4 can be formed jointly connected for both rows 7.
The finned tube block 2 is formed with a first collection and distribution box 8 and with a second collection and distribution box 9, wherein in each case one of the collection and distribution boxes 8, 9 is connected to one of the tube ends 10 of the tubes 3 of the finned tube block 2.
According to FIGS. 2, 3 and 5 , each of the two collection and distribution boxes 8, 9 has a bottom 11 and a box lid 12. The box lid 12 covers the bottom 11 and thus defines, together with the bottom 11, a box volume 13 as the interior of the collection and distribution box 8, 9.
The respective bottom 11 has openings 14 for inserting the tube ends 10 of the tubes 3 of the finned tube block 2, see FIG. 4 or FIG. 5 .
Within the two collection and distribution boxes 8, 9, partition walls 15 are arranged, which divide the respective interior of the collection and distribution boxes 8, 9 into box areas 16, wherein the finned tube block 2 is divided into evaporator flows 17. The evaporator flows 17 correspond to the box areas 16.
Also, groups of tubes 3 of the finned tube block 2 are assigned to the evaporator flows 17, wherein the tubes 3 of an evaporator flow 17 each merge end-side into a box area 16 of a collection and distribution box 8, 9.
According to FIGS. 4 and 5 , it can be seen that the respective bottom 11 of the collection and distribution boxes 8, 9 is designed with rim holes 18 for inserting the tube ends 10 in the openings 14, wherein the rim holes 18 are circumferentially formed around the openings 14 and protrude from the bottom 11 on an outer side 34 of the bottom 11 to the ribs 4 of the finned tube block 2.
In this case, the rim holes 18 are produced by a stamping and/or drawing and/or embossing process in the preparation of the respective opening 14 or after the preparation of the respective opening 14, around which opening the rim hole 18 is arranged circumferentially.
The finned tube block 2 may be divided into six evaporator flows 17, see FIG. 1 , wherein three evaporator flows 17 are arranged on the air inflow side 19 and three evaporator flows 17 are arranged on the air outflow side 20.
Thus, the finned tube block 2 is divided into six evaporator flows 17, wherein the three evaporator flows 17 on the air outflow side 20 are first flowed through by the refrigerant flowing through the evaporator 1 and then the three evaporator flows 17 on the air inflow side 19. Accordingly, the refrigerant inlet 21 is provided in an evaporator flow 17 on the air outflow side and the refrigerant outlet 22 is provided in an evaporator flow 17 on the air inflow side.
FIG. 1 also shows that the evaporator 1 has two broad sides 23 with the air inflow side 19 and the air outflow side 20, and two narrow sides arranged in the direction of air flow 24, wherein the three evaporator flows 17 on the air outflow side 20 are flowed through from a first narrow side 24 to a second narrow side 24 and then the three evaporator flows 17 on the airflow side 19 are flowed through from the second narrow side 24 to the first narrow side 24. This allows for the temperature profile of the air flowing through to be relatively uniform downstream of the evaporator 1 and, at the same time, it is achieved that the refrigerant inlet 21 and the refrigerant outlet 22 are arranged on the same narrow side 24. This has advantages in respect of connecting the evaporator 1 to the refrigerant circuit.
FIG. 5 shows that the box lid 12 is formed by lid areas 25 projecting from the bottom 11, which are curved from a respective edge 26 of the bottom 11 to the middle 27 of the bottom 11. Thus, it is advantageously achieved that only one component is used, which is deformed, wherein in particular a solder connection is omitted at the bending lines at the edge 26.
Preferably, the lid areas 25 are designed in such a way that outwardly projecting bulges 28 and/or inwardly projecting bulges 29 are provided for reinforcing the box lid 12.
Also, the lid areas 25 can have inwardly-projecting beads 30 for the support of partition walls 31 for the separation of box areas 16 and/or end walls 32 for the end-side closure of the collection and distribution box 8, 9.
Also, the bottom 11 may have inwardly and/or outwardly projecting beads and/or nubs 33 to support at least one partition wall 31 for separating box areas 16 and/or at least one end wall 32 for the end-side closure of the collection and distribution box 8, 9 and/or to reinforce the bottom 11.
Also, between two rim holes 18 of two adjacent openings 14, the bottom 11 may have an inwardly and/or outwardly projecting bead 30 and/or nub 33 for reinforcing the bottom 11.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.

Claims

What is claimed is:

1. An evaporator for an air conditioning unit, the evaporator comprising:

a finned tube block with a plurality of tubes and fins, wherein the tubes are arranged in two rows so that in each case two tubes are arranged one after the other in a direction of air flow and the fins are arranged between the tubes;

a first collection and distribution box; and

a second collection and distribution box, wherein at least one of the first or second collection and distribution boxes is connected with one of the tube ends of the tubes of the finned tube block,

wherein the first and second collection and distribution boxes each have a bottom and a box lid, the bottom having openings for inserting the tube ends of the tubes of the finned tube block,

wherein in the first and second collection and distribution boxes, partition walls are arranged, which divide the respective interior of the first and second collection and distribution boxes into box areas,

wherein the finned tube block is divided into evaporator flows to which groups of tubes of the finned tube block are assigned,

wherein the tubes of an evaporator flow each merge end-side in a box area of at least one of the first or second collection and distribution boxes,

wherein the respective bottom of the first or second collection and distribution boxes is designed with rim holes for inserting the tube ends in the openings, and

wherein the rim holes are formed circumferentially around the openings and protrude from the bottom on an outer side of the bottom to the fins of the finned tube block.

2. The evaporator according to claim 1, wherein the finned tube block is divided into six evaporator flows, and wherein three evaporator flows are arranged on the air inflow side and three evaporator flows are arranged on the air outflow side.

3. The evaporator according to claim 1, wherein the evaporator has a width in the direction of air flow and the respective bottom has a width in the direction of air flow such that the width of the evaporator is in the range of 60 mm or less, in particular in the range of 50 mm or less and/or such that the width of the bottom is in the range of 55 mm or less, in particular in the range of 50 mm or less.

4. The evaporator according to claim 1, wherein the finned tube block is divided into six evaporator flows, wherein the three evaporator flows on the air outflow side are first flowed through by the refrigerant flowing through the evaporator and then the three evaporator flows on the air inflow side.

5. The evaporator according to claim 4, wherein the evaporator has two broad sides having the air inflow side and the air outflow side, and two narrow sides arranged in the direction of air flow, wherein the three evaporator flows on the air outflow side are flowed through from a first narrow side to a second narrow side, and then the three evaporator flows on the air inflow side are flowed through from the second narrow side to the first narrow side.

6. The evaporator according to claim 1, wherein the box lid is formed by lid areas projecting from the bottom, which are curved from a respective edge of the bottom to the middle of the bottom.

7. The evaporator according to claim 1, wherein the lid areas have outwardly projecting bulges and/or inwardly projecting bulges for reinforcing the box lid.

8. The evaporator according to claim 1, wherein the lid areas have inwardly projecting beads for supporting partition walls for separating box areas and/or end walls for the end-side closure of the collection and distribution box.

9. The evaporator according to claim 1, wherein the bottom has inwardly and/or outwardly projecting beads and/or nubs for supporting at least one partition wall for separating box areas and/or at least one end wall for the end-side closure of the collection and distribution box and/or for reinforcing the bottom.

10. The evaporator according to claim 1, wherein the bottom between two rim holes of two adjacent openings has an inwardly and/or outwardly projecting bead and/or nub for reinforcing the bottom.

11. The evaporator according to claim 1, wherein the air conditioning unit is an air conditioning system of a motor vehicle.