This application claims priority to German Patent Application No. DE 10 2021 211 777.5, filed on Oct. 19, 2021, the contents of which is hereby incorporated by reference in its entirety.
The invention relates to a heat exchanger for the thermal coupling of two fluids.
Heat exchangers of this type are known. They are employed in particular in automotive engineering for the thermal coupling of two fluids so that heat energy can be exchanged between a first fluid and a second fluid. However, popular heat exchangers frequently exhibit a phenomenon called “cold spot”, which describes a highly inhomogeneous temperature distribution across the heat exchanger. As a consequence of the inhomogeneous temperature distribution, the efficiency of the heat exchanger decreases, which is undesirable.
The object of the invention therefore lies in stating an improved or at least another embodiment of a heat exchanger.
In the present invention, this object is solved in particular through the subject matter of the independent claim(s). Advantageous embodiments are the subject matter of the dependent claim(s).
The basic idea of the invention lies in improving the internal distribution of a heat exchanger fluid flowing through a heat exchanger, which is formed in particular by a two-phase refrigerant-oil mixture, over flat tubes of the heat exchanger.
For this purpose, the invention proposes a heat exchanger for the thermal coupling of two fluids which is equipped with an inflow pipe defining a pipe longitudinal centre axis and practically with an outflow pipe. On the inflow pipe, a fluid inlet for the inflow of a first fluid stream of heat exchanger fluid which is formed in particular by a two-phase refrigerant-oil mixture, and multiple flat tubes adjacent to the fluid inlet in the direction of the pipe longitudinal centre axis are arranged on the shell side, i.e. in particular on a longitudinal lower shell or on a longitudinal lower shell still described in the following. Along the pipe longitudinal centre axis, the flat tubes are spaced apart from one another. Furthermore, the flat tubes each lead into the inflow pipe so that the first fluid stream can flow along a first fluid path extending from the fluid inlet through the inflow pipe, through the flat tubes and further downstream if applicable through the outflow pipe. Away from the inflow pipe and from the outflow pipe, the flat tubes extend through a second fluid path for a second fluid stream of fluid, in particular air, so that the flat tubes can be flowed through by the first fluid stream and flowed about by the second fluid stream. In particular, a heat stream at this point can be exchanged between the two fluid streams, wherein the first fluid stream functions as heat sink and the second fluid stream as heat source, or vice versa. The heat exchanger according to the invention furthermore comprises a passage screen aperture that can be flowed through by the first fluid stream and interacts with the heat exchanger fluid, which passage screen aperture is fluidically connected in series with the flat tubes. The passage screen aperture interacts with the heat exchanger fluid so that when the heat exchanger fluid flows into the inflow pipe, swirl flows in the heat exchanger fluid generated in the region of the fluid inlet, which in practice are referred to as swirl flows, are dissolved or at least reduced. This has the effect that an optimal distribution of the first fluid stream over the flat tubes can be adjusted. This has the advantage that practically each flat tube is supplied with the same fluid volume flow or fluid mass flow of liquid phase and gas phase, as a result of which a relatively homogeneous temperature distribution can be achieved on the heat exchanger.
Practically it can be provided that the passage screen aperture is arranged upstream of the flat tubes with respect to the first fluid stream. At the same time, it can be provided downstream that the passage screen aperture is connected downstream of the fluid inlet with respect to the first fluid stream. By way of this, preferred positions for the passage screen aperture in the first fluid path are stated. The passage screen aperture positioned in such a position can realise an optimal reduction of the swirl flows in the heat exchanger fluid. Advantageously, the passage screen aperture can be positioned within the inflow pipe.
Furthermore, it can be provided that the passage screen aperture is arranged on a passage screen, which in the first fluid path is arranged between the fluid inlet and the flat tubes. In addition it has been recognised within the scope of tests that an arrangement of the passage screen between the fluid inlet and an immediately adjacent first flat tubes of the flat tubes located next to the said fluid inlet in the direction of the pipe longitudinal centre axis can be advantageous because an optimal reduction of the swirl flows in the heat exchanger fluid can thereby be realised and an excellent distribution of the existing gas and liquid phases of the first fluid stream over the flat tubes can be adjusted.
It is practical when between the passage screen aperture of the passage screen and a first flat tubes of the flat tubes located with respect to the fluid inlet next in the direction of the pipe longitudinal centre axis and directly adjacent a gap, to be measured parallel to the pipe longitudinal centre axis, is adjusted, which lies in a range between 2.0 mm to 9.0 mm, or preferably in a range between 3.0 mm and 6.0 mm. A passage screen arranged accordingly having a passage screen aperture can realise a preferred reduction of the swirl flows in the heat exchanger fluid.
It is practical, further, when the passage screen aperture is arranged on a passage screen which comprises a surrounding outer edge at least in portions, via which the passage screen supports itself at least in portions in a touching and optionally fluid-tight manner on at least one pipe inner circumferential surface of the inflow pipe. By way of this, the passage screen can be fixed if applicable in a fluid-tight manner on at least one pipe inner circumferential surface within the inflow pipe. Here, the passage screen can be practically fixed on the inflow pipe in the region of the outer edge, for example, by soldering or welding or alternatively or additionally by a positively and/or non-positively fixed connection.
It is practical, furthermore, when the outer edge comprises or forms a stiffening, reinforcing the passage screen against shape change in that it is embodied with a thickness in a range between 1.4 mm to 3.0 mm. This has the advantage that the passage screen can be produced so as to be relatively stiff in order to be relatively resistant to mechanical deformation. This generates the advantage that the passage screen during the manufacture of a heat exchanger can be provided in large quantities and as bulk material. This facilitates the manufacture of a heat exchanger.
It is practical, furthermore, when the passage screen aperture is arranged on a passage screen which comprises at least one insert tab projecting with respect to an passage screen centre of the passage screen projects radially to the outside, which for the positively and/or non-positively fixing of the passage screen on the inflow pipe is inserted into a tab groove arranged on the inflow pipe and formed complementarily with respect to the at least one insert tab. Practically, exactly two separate insert tabs or even more separate insert tabs can be provided on the passage screen, which each engage into their own tab groove arranged on the inflow pipe. By this constructive measure, the passage screen can be relatively easily arranged on the inflow pipe.
In this connection it can also be provided that between each two insert tabs projecting away with respect to the passage screen centre radially to the outside an acute angle is defined, preferably an angle in the range of smaller than 90°.
It can also be practical when at least one insert tab has two tab sides oriented opposite to one another and aligned parallel to one another and a tab front side connecting these two tab sides with one another. Here, the insert tabs can be embodied so that the tab sides, when the passage screen is mounted on the inflow pipe, lies against the inflow pipe touchingly and if applicable with a slide oversize fit. The tab front side can practically be arranged with respect to the passage screen centre of the passage screen on the inflow pipe radially without contact and if applicable form a protrusion radially protruding over the same.
Practically, the inflow pipe is embodied in two parts for the purpose of which it is divided along the pipe longitudinal centre axis into a longitudinal lower shell and a longitudinal upper shell, wherein the said outer edge of the passage screen is split into a first surrounding receiving portion for receiving the longitudinal lower shell and a second surrounding receiving portion, recessed with respect to the first receiving portion, for receiving the longitudinal upper shell. A corresponding inflow pipe, in particular a round pipe can be produced cost-effectively. The longitudinal lower shell, which in particular has a U-shape or C-shape and the longitudinal upper shell which likewise has in particular a U-shape or C-shape, can be relatively easily arranged on the passage screen with the help of the said first and second receiving portion. Here, the term “recessed” practically relates to the said passage screen centre of the passage screen, so that the first receiving portion thus describes a greater gap with respect to the passage screen centre than the second receiving portion. The first and second receiving portion can be configured complementarily to the longitudinal lower shell and to the longitudinal upper shell respectively. In this connection it can be advantageous when the passage screen has a substantially circular or a circular surface area.
It is practical further, when the passage screen aperture is arranged on a passage screen which comprises or forms at least one flow separation edge framing the passage screen aperture at least in portions. Furthermore, swirl flows in the heat exchanger fluid can be relatively favourably reduced in that the passage screen aperture defines a circular segment-shaped opening contour.
Swirl flows in the heat exchanger fluid can still be reduced relatively well in that the passage screen aperture defines a circular segment-shaped opening contour.
Furthermore, the passage screen aperture can be arranged on a passage screen defining a screen centre, wherein a plane runs through the screen centre, which plane runs parallel with respect to the pipe longitudinal centre axis and is oriented orthogonally with respect to flat tube centre axes, which are defined by the flat tubes, so that the plane divides the passage screen into a first side facing away from the flat tubes and a second side facing the flat tubes. The passage screen aperture is preferably arranged on the first side of the passage screen facing away from the flat tubes. By way of this, a preferred position of the passage screen aperture on the passage screen is stated.
It is practical, furthermore, when the passage screen aperture is arranged on a passage screen which defines an in particular flat surface area, wherein the passage area of the passage screen aperture is minimally 5% of the surface area. Alternatively or additionally, the passage area of the passage screen aperture can amount to maximally 50% of the surface area or more. It is practical when the passage area of the passage screen aperture amounts to minimally 5% and maximally 25% of the surface area. It is also conceivable that the passage area of the passage screen aperture amounts to 25% to 50% or 25% to 75%, or 25% or 50% or 75% of the surface area. Because of this, a preferred advantageous ratio between the passage screen aperture that can be flowed through and the surface area of the passage screen is stated.
In summary it remains to note: the present invention preferentially relates to a heat exchanger which comprises an inflow pipe defining a pipe longitudinal centre axis on which a fluid inlet for the inflow of a first fluid stream and in the direction of the pipe longitudinal centre axis adjacent to the fluid inlet flat tubes are arranged, which along the pipe longitudinal centre axis are spaced apart from one another and lead into the inflow pipe so that the first fluid stream can flow along a first fluid path extending from the fluid inlet through the flat tubes. The flat tubes extend away from the inflow pipe through a second fluid path for a second fluid stream, as a result of which the flat tubes can be flowed through by the first fluid stream and flowed about by the second fluid stream. Furthermore, the heat exchanger comprises a passage screen aperture that can be flowed through by the first fluid stream and interacts with the heat exchanger fluid, which is fluidically connected in series with the flat tubes.
Further important features and advantages of the invention are obtained from the subclaims, from the drawings and from the associated figure description by way of the drawings.
It is to be understood that the features mentioned above and still to be explained in the following cannot only be used in the respective combination stated but also in other combinations or by themselves without leaving the scope of the present invention.
Preferred exemplary embodiments of the invention are shown in the drawings and are explained in more detail in the following description, wherein same reference numbers relate to same or similar or functionally same components.
It shows, in each case schematically
Away from the inflow pipe 3 and from the outflow pipe 34, the said flat tubes 6, 12 extend through a second fluid path 9 for a second fluid stream 32 of cooling fluid, so that the flat tubes 6, 12 can be flowed through by the first fluid stream 5 and flowed about by the second fluid stream 32. This means that the two fluid streams 5, 32 intersect. By way of this, a heat energy stream can be exchanged between the two fluid streams 5, 32. Practically, the first fluid stream 5 functions as heat source and the second fluid stream 32 as heat sink or vice versa.
With respect to
The said passage screen 11 or the passage screen aperture 10 is arranged in the first fluid path 8 between the fluid inlet 4 and a first flat tube 12 of these flat tubes 6, 12 which with respect to the fluid inlet 4 is located next in the direction of the pipe longitudinal centre axis 2 and directly adjacent. Purely exemplarily, a gap 13 to be measured parallel to the pipe longitudinal centre axis 2 is adjusted between the passage screen 11 or the passage screen aperture 10 and the first flat tube 12. This gap can lie within a range between 2.0 mm to 9.0 mm or preferably within a range between 3.0 mm and 6.0 mm.
With respect to
In
In
Both in
With respect to
Number | Date | Country | Kind |
---|---|---|---|
10 2021 211 777.5 | Oct 2021 | DE | national |
Number | Name | Date | Kind |
---|---|---|---|
5842515 | Kim | Dec 1998 | A |
7073571 | Yu | Jul 2006 | B2 |
20090229800 | Bhatti | Sep 2009 | A1 |
20110220318 | Kopchick | Sep 2011 | A1 |
20140202673 | Wand | Jul 2014 | A1 |
20230108901 | Nakata | Apr 2023 | A1 |
20230111700 | Jiang | Apr 2023 | A1 |
20230124890 | Aul | Apr 2023 | A1 |
20230280112 | Komuro | Sep 2023 | A1 |
20230288145 | Maema | Sep 2023 | A1 |
20230332836 | Duerr | Oct 2023 | A1 |
Number | Date | Country |
---|---|---|
112013710 | Dec 2020 | CN |
3301394 | Apr 2018 | EP |
3916331 | Dec 2021 | EP |
Entry |
---|
English abstract for CN-1 12 013 710. |
Number | Date | Country | |
---|---|---|---|
20230124890 A1 | Apr 2023 | US |