Heat exchanger
The heat exchanger addresses thermal exchange and phase transition challenges by employing turbulators for carbon dioxide and working fluid circuits, enhancing efficiency and mechanical resistance, thus effectively managing thermal powers and flow rates.
Patent Information
- Application Number
- PCT/IB2025/056937
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-07-10
- Filing Date
- 2025-07-09
- Publication Date
- 2026-01-15
AI Technical Summary
Existing carbon dioxide heat exchangers in the automotive sector face challenges in effectively managing thermal exchange and phase transition, particularly in efficiently handling the thermal powers required for vehicle operation while minimizing pressure drops and ensuring reliable thermal management.
A heat exchanger design featuring distinct turbulators for carbon dioxide and working fluid circuits, with optimized passage sections and orientations to enhance turbulence and reduce pressure drops, while maintaining mechanical resistance and thermal efficiency.
The design achieves efficient thermal exchange, increased mechanical resistance, and reduced pressure drops, enabling the handling of higher thermal powers and flow rates with improved thermal management capabilities.
Smart Images
Figure IB2025056937_15012026_PF_FP_ABST
Abstract
Description
HEAT EXCHANGERDESCRIPTIONField of Application
[0001] The present invention concerns a heat exchanger.
[0002] In particular, the heat exchanger is specific for carbon dioxide thermal management systems. That is, in the heat exchanger, carbon dioxide performs a thermal exchange with a working fluid, and the thermal exchange involves, results in the phase transition of the carbon dioxide itself.
[0003] Preferably, the heat exchanger is an evaporator.
[0004] According to the present invention, the working fluid is a water-based fluid, for example water and glycol, or is a dielectric fluid, for example a dielectric oil, or an oil-based fluid.
[0005] According to the present invention, the heat exchanger is used in the automotive field, that is, mountable on a vehicle.Prior Art
[0006] In the prior art, solutions of heat exchangers applied to the automotive sector are known. In fact, optimally managing the temperature of an operating group, for example the battery pack of an electric or hybrid vehicle, improves its efficiency and extends its lifecycle, enhancing the performance and the life cycle of the entire vehicle. Therefore, in the circuits suitable for managing the temperature of said operating groups, the presence of suitable heat exchangers is known to be provided. The heat exchanger affects the characteristics of the circulating fluids therein: the fluids passage in a heat exchanger in fact affects their respective temperatures, but also determines pressure drops in the respective working circuits.
[0007] In the prior art, carbon dioxide heat exchangers are also known, as it is the use thereof in the automotive field.
[0008] In particular, carbon dioxide is the refrigerant fluid suitable for performing the thermal exchange with the working fluid. For example, by refrigerant fluid of carbon dioxide type is meant one of normally used fluids in refrigeration cycles, such as R744.
[0009] A typical problem of said carbon dioxide heat exchangers is that of effectively managing the thermal exchange between carbon dioxide and working fluid, effectively managing the phase transition of the carbon dioxide.
[0010] In fact, carbon dioxide is a refrigerant fluid with lower environmental impact compared to traditional refrigerant fluids, such as R134a. A problem related tothe development of these heat exchangers is that of offering reliable thermal management solutions able of efficiently handling the thermal powers required for vehicle operation.Solution of the Invention
[0011] There is therefore the strong need to make available a heat exchanger that meets the above-mentioned demands of the sector.
[0012] Scope of the present invention is to provide a heat exchanger, for carbon dioxide thermal management systems, which meets said need.
[0013] Said scope is achieved by means of the heat exchanger claimed in claim 1. The claims dependent therefrom show preferred embodiments entailing further advantageous aspects.Description of the Drawings
[0014] Further features and advantages of the invention will appear from the description below of its preferred embodiments, given by way of non-limiting example, with reference to the attached figures, in which:- Figure 1 shows a perspective view of a heat exchanger in accordance with the present invention, according to a preferred embodiment;- Figures 2 and 2' respectively illustrate a sectional view along the plane V-V of figure 1 and an enlargementthereof;- Figure 3 shows a perspective view of a heat exchanger in accordance with the present invention, according to a further preferred embodiment;- Figures 4 and 4' respectively illustrate a sectional view along the plane VI-VI of figure 3 and an enlargement thereof;- Figures 5 and 5' respectively illustrate a sectional view along the plane VII-VII of figure 3 and an enlargement thereof;- Figures 6a and 6b respectively represent a top view and a front view of a portion of a working fluid turbulator comprised in the exchanger object of the present invention, according to a first preferred embodiment;- Figures 7a and 7b respectively represent a top view and a front view of a portion of a working fluid turbulator comprised in the exchanger object of the present invention, in accordance with a second preferred embodiment;- figures 8a and 8b respectively represent a top view and a front view of a portion of a carbon dioxide turbulator comprised in the exchanger object of the present invention, according to a further preferred embodiment. Detailed Description
[0015] With reference to the attached figures, number 1 isa heat exchanger in accordance with the present invention.
[0016] The heat exchanger 1 is suitable for performing a thermal exchange action between a working fluid, for example water-based or of dielectric type, and carbon dioxide, each circulating in a respective circuit of the vehicle.
[0017] Preferably, the heat exchanger 1 is an evaporator.
[0018] The heat exchanger 1 is in fact connectable to the respective circuits in such a way that in the circulation channels provided within it the working fluid and the carbon dioxide respectively flow.
[0019] In accordance with the present invention, the heat exchanger 1 comprises a working fluid inlet mouth 11 and a working fluid outlet mouth 12 through which the working fluid flows in and out.
[0020] Furthermore, in accordance with the present invention, the heat exchanger 1 comprises a carbon dioxide inlet mouth 13 and a carbon dioxide outlet mouth 14 through which the carbon dioxide flows in and out.
[0021] The heat exchanger 1 comprises plate-like end elements 102, 103 and intermediate plate-like elements 104.
[0022] The heat exchanger 1 is obtained by joining said plate-like elements. In particular, the plate-likeelements are stacked with one another along a preferential vertical stacking direction.
[0023] In particular, the heat exchanger 1 extends in height with respect to a vertical axis V-V, longitudinally with respect to a longitudinal axis X-X and transversally with respect to a transversal axis Y-Y, the latter axes lying on a same imaginary plane orthogonal to the V-V axis.
[0024] Preferably, the plate-like elements extend substantially orthogonally to said vertical axis V-V. That is, the plate-like elements extend longitudinally with respect to the longitudinal axis X-X and transversally with respect to the transversal axis Y-Y.
[0025] It is emphasized that the directions of the axes are not limiting for any use position of the heat exchanger 1 object of the present invention in the vehicle.
[0026] Preferably, the plate-like end elements 102, 103 are axially spaced along the vertical axis V-V. In accordance with a preferred embodiment, a plate-like end element 102 is indicated as upper, whereas the other plate-like end element 103 is indicated as lower.
[0027] According to a preferred embodiment, each plate-like end element comprises a single plate-like body.
[0028] According to an alternative embodiment, at least one, or both, the plate-like end elements comprise aplurality, for example two or three, plate-like bodies aligned along the vertical axis V-V.
[0029] In accordance with the present invention, the working fluid inlet mouth 11, the working fluid outlet mouth 12, the carbon dioxide inlet mouth 13, and the carbon dioxide outlet mouth 14 are obtained on said plate-like end elements 102, 103.
[0030] In a preferred embodiment, all the mouths 11, 12, 13, 14 are obtained on the upper plate-like element 102.
[0031] In accordance with a preferred embodiment, the carbon dioxide inlet mouth 13 and the carbon dioxide outlet mouth 14 have a smaller section than the section of the working fluid inlet mouth 11 and the working fluid outlet mouth 12.
[0032] In accordance with the present invention, the intermediate plate-like elements 104 are specifically shaped so as to delimit, together with the upper platelike element 102 and the lower plate-like element 103, a working fluid region 15 in which the working fluid flows and a carbon dioxide region 16 in which the carbon dioxide flows.
[0033] According to a preferred embodiment, the intermediate plate-like elements 104, with the characteristics described in detail below, are obtained by mechanical operations of stamping and / or cuttingand / or bending carried out starting from a sheet.
[0034] Preferably, the intermediate plate-like elements 104 and the plate-like end elements 102, 103 are made of aluminium alloy.
[0035] The working fluid region 15 comprises vertical working fluid segments 151, 152, respectively for inlet and outlet, in fluid communication respectively with the working fluid inlet mouth 11 and the working fluid outlet mouth 12, and planar working fluid segments 153.
[0036] Preferably, the vertical working fluid segments 151, 152 are aligned along the vertical axis V-V respectively with the working fluid inlet mouth 11 and the working fluid outlet mouth 12.
[0037] Preferably, said planar working fluid segments 153 extend mutually parallel to one another.
[0038] The carbon dioxide region 16 comprises vertical carbon dioxide segments 161, 162, respectively for inlet and outlet, in fluid communication respectively with the carbon dioxide inlet mouth 13 and the carbon dioxide outlet mouth 14, and planar carbon dioxide segments 163.
[0039] Preferably, the vertical carbon dioxide segments 161, 162 are aligned along the vertical axis V-V respectively with the carbon dioxide inlet mouth 13 and the carbon dioxide outlet mouth 14.
[0040] Preferably, said planar carbon dioxide segments 163extend mutually parallel to one another.
[0041] In accordance with the present invention, the planar carbon dioxide segments 163 are positioned alternating with the planar working fluid segments 153.
[0042] Preferably, a planar working fluid segment 153 is directly proximal to the upper plate-like element 102. That is, the upper planar segment is a planar working fluid segment 153.
[0043] Preferably, a planar working fluid segment 153 is directly proximal to the lower plate-like element 103. That is, the lower planar segment is a planar working fluid segment 153.
[0044] In accordance with a preferred embodiment, each vertical working fluid segment 151, 152 and each vertical carbon dioxide segment 161, 162 has a respective passage section.
[0045] According to a preferred embodiment, the passage section of at least one vertical carbon dioxide segment 161, 162 is smaller than the passage section of both vertical working fluid segments 151, 152.
[0046] According to a further preferred embodiment, the passage section of both vertical carbon dioxide segments 161, 162 is smaller than the passage section of both vertical working fluid segments 151, 152.
[0047] According to a further preferred embodiment, thepassage sections of the vertical carbon dioxide segments161, 162 are mutually different, both being smaller than the passage section of both vertical working fluid segments 151, 152.
[0048] According to a preferred embodiment, each planar working fluid segment 153 has a planar working fluid segment height H2'.
[0049] According to a preferred embodiment, each planar carbon dioxide segment 163 has a planar carbon dioxide segment height H3'.
[0050] In accordance with a preferred embodiment, the planar working fluid segment height H2' is greater than the planar carbon dioxide segment height H3'.
[0051] In accordance with the present invention, the heat exchanger 1 comprises:- a working fluid turbulator 2 in each planar working fluid segment 153;- a carbon dioxide turbulator 3 in each planar carbon dioxide segment 163.
[0052] The working fluid turbulator 2 is made from a sheet having a working fluid turbulator thickness S2.
[0053] Preferably, the working fluid turbulator 2 is made of aluminium alloy.
[0054] According to a preferred embodiment, the working fluid turbulator 2 has a working fluid turbulator heightH2.
[0055] Preferably, the working fluid turbulator height H2 is the height of the sheet before brazing operations.
[0056] Preferably, the working fluid turbulator height H2 substantially corresponds to the planar working fluid segment height H2'.
[0057] The working fluid turbulator 2 comprises a plurality of working fluid turbulator rows 20.
[0058] Preferably, the working fluid turbulator 2 comprises a plurality of working fluid turbulator rows 20, wherein each of said turbulator rows 20 presents vertically a substantially wavy shape.
[0059] Preferably, each working fluid turbulator row 20 comprises working fluid turbulator peaks 202 and working fluid turbulator bases 203.
[0060] Preferably, each working fluid turbulator row 20 comprises working fluid turbulator side walls 201 connecting working fluid turbulator peaks 202 and working fluid turbulator bases 203.
[0061] Preferably, the working fluid turbulator rows 20 are mutually staggered. In other words, peaks and bases of two adjacent working fluid turbulator rows 20 are mutually staggered, forming working fluid turbulator passage openings A2 in the space defined between side walls 201 of proximal components comprised on adjacentrows.
[0062] In other words, said working fluid turbulator passage openings A2 are formed as a result of the staggering of two adjacent rows along the development direction of said rows.
[0063] For example, in figures 6b and 7b, the respective working fluid turbulator passage openings A2 are indicated.
[0064] Preferably, each working fluid turbulator row 20 presents a working fluid turbulator pitch P2 between one working fluid turbulator base 202 and a subsequent working fluid turbulator base 202.
[0065] Each working fluid turbulator row 20 has a working fluid turbulator row width L2.
[0066] Preferably, two adjacent rows of the working fluid turbulator 2 define a plurality of working fluid turbulator passage openings A2. Preferably, the main dimension of said working fluid turbulator passage opening A2 is measured at the mid-height of the working fluid turbulator 2.
[0067] Preferably, said working fluid turbulator passage opening A2 is about 0.26 millimetres.
[0068] Preferably, said working fluid turbulator passage opening A2 is about 0.80 millimetres
[0069] The carbon dioxide turbulator 3 is made from a sheethaving a carbon dioxide turbulator thickness S3.
[0070] Preferably, the carbon dioxide turbulator 3 is made of aluminium alloy.
[0071] According to a preferred embodiment, the carbon dioxide turbulator 3 has a carbon dioxide turbulator height H3.
[0072] Preferably, the carbon dioxide turbulator height H3 is the height of the sheet before brazing operations.
[0073] Preferably, the carbon dioxide turbulator height H3 substantially corresponds to the planar carbon dioxide segment height H3'.
[0074] The carbon dioxide turbulator 3 comprises a plurality of carbon dioxide turbulator rows 30.
[0075] Preferably, the carbon dioxide turbulator 3 comprises a plurality of carbon dioxide turbulator rows 30, wherein each of said carbon dioxide turbulator rows 30 presents vertically a substantially wavy shape.
[0076] Preferably, each carbon dioxide turbulator row 30 comprises carbon dioxide turbulator peaks 302 and carbon dioxide turbulator bases 303.
[0077] Preferably, each carbon dioxide turbulator row 30 comprises carbon dioxide turbulator side walls 301 connecting carbon dioxide turbulator peaks 302 and carbon dioxide turbulator bases 303.
[0078] Preferably, the carbon dioxide turbulator rows 30are mutually staggered. In other words, peaks and bases of two adjacent carbon dioxide turbulator rows 30 are mutually staggered, forming carbon dioxide turbulator passage openings A3 in the space between side walls 310 of proximal components comprised on adjacent rows.
[0079] In other words, said carbon dioxide turbulator passage openings A3 are formed as a result of the staggering of two adjacent rows along the development direction of said rows.
[0080] For example, in figure 8b, the carbon dioxide turbulator passage opening A3 is indicated.
[0081] Preferably, each wavy carbon dioxide turbulator row 30 presents a carbon dioxide turbulator pitch P3 between one carbon dioxide turbulator base 302 and a subsequent carbon dioxide turbulator base 302.
[0082] Each carbon dioxide turbulator row 30 has a carbon dioxide turbulator row width L3.
[0083] Preferably, two adjacent rows of the carbon dioxide turbulator define a plurality of carbon dioxide turbulator passage openings A3 detectable in the space between side walls 310 of proximal components. Preferably, the main dimension of said carbon dioxide turbulator passage opening A3 is measured at the midheight of the carbon dioxide turbulator 3.
[0084] Preferably, said carbon dioxide turbulator passageopening A3 presents a value of 0.22 millimetres.
[0085] In accordance with the present invention, the working fluid turbulator 2 and the carbon dioxide turbulator 3 have different characteristics.
[0086] In fact, the carbon dioxide turbulator row width L3 is greater than the working fluid turbulator row width L2.
[0087] Preferably, the working fluid turbulator row width L2 is comprised between 0.7 millimetres and 1 millimetre, whereas the carbon dioxide turbulator row width L3 is greater than 1 millimetre, preferably 1.25 millimetres.
[0088] Furthermore, the carbon dioxide turbulator thickness S3 is greater than the working fluid turbulator thickness52.
[0089] Preferably, the carbon dioxide turbulator thickness53 is about 0.4 millimetres, whereas the working fluid turbulator thickness S2 is comprised between 0.2 and 0.3 millimetres, preferably 0.2 millimetres.
[0090] According to a preferred embodiment, the planar working fluid segment height H2' is greater than the planar carbon dioxide segment height H3'.
[0091] According to a preferred embodiment, the working fluid turbulator height H2 is greater than the carbon dioxide turbulator height H3.
[0092] Preferably, the working fluid turbulator height H2is about 2.4 millimetres, whereas the carbon dioxide turbulator height H3 is about 2 millimetres.
[0093] According to a preferred embodiment, the working fluid turbulator pitch P2 is greater than the carbon dioxide turbulator pitch P3.
[0094] Preferably, the working fluid turbulator pitch P2 is about 3.4 millimetres, whereas the carbon dioxide turbulator pitch P3 is about 3.2 millimetres.
[0095] In accordance with a preferred embodiment, the rows of the carbon dioxide turbulator 3 are mutually staggered by a smaller value compared to the rows of the working fluid turbulator 2.
[0096] According to a preferred embodiment, the adjacent rows of both turbulators 2, 3 form passage openings A2, A3 for the circulation of the respective fluids.
[0097] Preferably, the main dimension of the carbon dioxide turbulator passage opening A3, measured in the row development direction, is smaller than the working fluid turbulator passage opening A2 measured in the same direction .
[0098] According to a preferred embodiment, the waves of each turbulator extend between two plate-like elements 102, 103, 104, contacting them.
[0099] In other words, each turbulator, both the working fluid turbulator 2 and the carbon dioxide turbulator 3,engages a respective plate-like element at the top and at the bottom.
[0100] According to a preferred embodiment, the working fluid turbulator 2 comprises working fluid turbulator rows 20 which extend in width inclined by an inclination angle a comprised between 0° and 30°.
[0101] Preferably, said inclination angle a is comprised between 10° and 20°.
[0102] Preferably, said inclination angle a is substantially 15°.
[0103] Preferably, two adjacent working fluid turbulator rows 20 are inclined in opposite directions.
[0104] Preferably, two adjacent working fluid turbulator rows 20 are inclined in opposite directions at the same inclination angle.
[0105] According to a preferred embodiment, the working fluid flows in the planar working fluid segment 153 in a working fluid direction and the working fluid turbulator 2 is positioned in such a way that the working fluid turbulator rows 20 extend substantially orthogonally to the working fluid direction, while the carbon dioxide flows in the planar carbon dioxide segment 163 in a carbon dioxide direction and the carbon dioxide turbulator 3 is positioned in such a way that the carbon dioxide turbulator rows 30 extend substantiallyorthogonally to the carbon dioxide direction.
[0106] Preferably, in this embodiment, the working fluid and the carbon dioxide flow inside their respective planar segment impacting the respective turbulator on the side having the lower resistance.
[0107] According to an alternative embodiment variant, the working fluid flows in the planar working fluid segment 153 in a working fluid direction and the working fluid turbulator 2 is positioned in such a way that the working fluid turbulator rows 20 extend substantially orthogonally to the working fluid direction, while the carbon dioxide flows in the planar carbon dioxide segment 163 in a carbon dioxide direction and the carbon dioxide turbulator 3 is positioned in such a way that the carbon dioxide turbulator rows 30 extend substantially parallel to the carbon dioxide direction.
[0108] Preferably, in this embodiment, the working fluid flows inside its respective planar segment impacting the working fluid turbulator 2 on the side having lower resistance, while the carbon dioxide flows inside its respective planar segment impacting the carbon dioxide turbulator 3 on the side having higher resistance.
[0109] According to a preferred embodiment, each peak 202, 302 and each base 203, 303 comprises respectively aplanar peak portion and a planar base portion suitable for resting on respective walls of the heat exchanger 1. In particular, the respective planar peak portions and the planar base portions are suitable for engaging the respective plate-like elements 102, 103, 104 of the heat exchanger 1.
[0110] Preferably, even in the presence of said planar peak portions and said planar base portions, the values of height, thickness, width and pitch remain as previously described.
[0111] Preferably, the turbulators are structural support elements engaging the respective walls of the heat exchanger 1.
[0112] According to a preferred embodiment, the platelike end elements 102, 103, the plurality of intermediate plate-like elements 104, the working fluid turbulators 2, and the carbon dioxide turbulators 3 are mutually stacked and integrally joined by means of a brazing process, preferably vacuum brazing.
[0113] Innovatively, the heat exchanger fully achieves the scope of the present invention by overcoming the typical problems of the known art.
[0114] Advantageously, the heat exchanger presents efficient thermal exchange and increased mechanical resistance.
[0115] Advantageously, in fact, the turbulators are suitable for making both the flow of carbon dioxide and the flow of working fluid turbulent, avoiding the occurrence of a high pressure drop.
[0116] Advantageously, the turbulators are suitable for making large thermal exchange surfaces available and reduce head losses, making the heat exchanger able of handling greater temperature differences between the circulating fluids, with consequent more efficient thermal exchange.
[0117] Advantageously, the heat exchanger is suitable for withstanding the high pressures of carbon dioxide.
[0118] Advantageously, the carbon dioxide turbulator presents a greater thickness and greater row width than the working fluid turbulator, offering increased mechanical resistance to the heat exchanger due to the greater resistant section of the side walls and the greater contact surface made available for forming brazing joints between base portions and peak portions of the turbulator with the intermediate plate-like elements of the exchanger and / or with the end plates.
[0119] Advantageously, the exchanger presents a carbon dioxide turbulator reinforced with respect to the working fluid turbulator and vertical carbon dioxide segments with smaller section with respect to the vertical workingfluid segments, increasing the pressure resistance of the exchanger on the carbon dioxide circuit.
[0120] Advantageously, the heat exchanger for carbon dioxide thermal management systems comprises turbulators on both the carbon dioxide circuit and the working fluid circuit, enabling the handling of greater circulation flow rates, lower head losses, and higher thermal powers with respect to carbon dioxide exchangers that use calibrated-section flow channels without turbulators or elements able of increasing the passage surface on the carbon dioxide flow circuit.
[0121] It is clear that a person skilled in the art, in order to meet contingent needs, could make modifications to the invention described above, all included within the scope of protection as defined by the following claims.List of reference numbers:I heat exchangerII working fluid inlet mouth12 working fluid outlet mouth13 carbon dioxide inlet mouth14 carbon dioxide outlet mouth15 working fluid region151 vertical working fluid segment (inlet)152 vertical working fluid segment (outlet)153 planar working fluid segments 16 carbon dioxide region161 vertical carbon dioxide segment (inlet)162 vertical carbon dioxide segment (outlet)163 planar carbon dioxide segments102 upper plate-like end element 104 intermediate plate-like element103 lower plate-like end element2 working fluid turbulator20 working fluid turbulator row201 working fluid turbulator side wall 202 working fluid turbulator peak203 working fluid turbulator base3 carbon dioxide turbulator30 carbon dioxide turbulator row301 carbon dioxide turbulator side wall302 carbon dioxide turbulator peak303 carbon dioxide turbulator base L2 working fluid turbulator row widthL3 carbon dioxide turbulator row widthS2 working fluid turbulator thicknessS3 carbon dioxide turbulator thicknessH2 working fluid turbulator height H3 carbon dioxide turbulator heightH2' planar working fluid segment heightH3' planar carbon dioxide segment heightP2 working fluid turbulator pitchP3 carbon dioxide turbulator pitch A2 working fluid turbulator passage openingA3 carbon dioxide turbulator passage openingX-X longitudinal axisY-Y transversal axisV-V vertical axis a inclination angle
Claims
CLAIMS1. A heat exchanger (1) for carbon dioxide thermal management systems, preferably an evaporator, comprising a working fluid inlet mouth (11) and a working fluid outlet mouth (12), and a carbon dioxide inlet mouth (13) and a carbon dioxide outlet mouth (14), wherein the heat exchanger (1) comprises:- plate-like end elements (102, 103), upper and lower, wherein said mouths (11, 12, 13, 14) are obtained on said plate-like end elements (102, 103);- a plurality of intermediate plate-like elements (104), axially stacked and defining, with the plate-like end elements (102, 103), a working fluid region (15), comprising vertical working fluid segments (151, 152) in fluid communication with the working fluid inlet mouth (11) and with the working fluid outlet mouth (12) and planar working fluid segments (153), and a carbon dioxide region (16), comprising vertical carbon dioxide segments (161, 162) in fluid communication with the carbon dioxide inlet mouth (13) and with the carbon dioxide outlet mouth (14) and planar carbon dioxide segments (163), wherein said planar carbon dioxide segments (163) are positioned alternating with the planar working fluid segments (153);wherein the heat exchanger (1) comprises:- a working fluid turbulator (2) in each planar working fluid segment (153), wherein said working fluid turbulator (2) comprises a plurality of substantially wavy, mutually staggered working fluid turbulator rows (20), wherein each row has a working fluid turbulator row width (L2), wherein said working fluid turbulator (2) is made of a sheet having a working fluid turbulator thickness (S2);- a carbon dioxide turbulator (3) in each planar carbon dioxide segment (163), wherein said carbon dioxide turbulator (3) comprises a plurality of substantially wavy, mutually staggered carbon dioxide turbulator rows (30), wherein each row has a carbon dioxide turbulator row width (L3), wherein said carbon dioxide turbulator (3) is made of a sheet having a carbon dioxide turbulator thickness (S3); wherein the carbon dioxide turbulator row width (L3) is greater than the working fluid turbulator row width (L2) and the carbon dioxide turbulator thickness (S3) is greater than the working fluid turbulator thickness (S2).
2. Heat exchanger (1) according to claim 1, wherein the working fluid turbulator row width (L2) is between 0.7and 1 millimeter and wherein the carbon dioxide turbulator row width (L3) is greater than 1 millimeter, preferably of about 1.25 millimeters.
3. Heat exchanger (1) according to any one of the preceding claims, wherein each planar working fluid segment (153) has a planar working fluid segment height (H2'), and each planar carbon dioxide segment has a planar carbon dioxide segment height (H3'), wherein the planar working fluid segment height (H2') is greater than the planar carbon dioxide segment height (H3').
4. Heat exchanger (1) according to any one of the preceding claims, wherein the waves of the rows of each turbulator extend between two plate-like elements (102, 103, 104), thus contacting them.
5. Heat exchanger (1) according to any one of the preceding claims, wherein each row of the working fluid turbulator (2) comprises working fluid turbulator side walls (201) extending inclined by an inclination angle (a) between 0° and 30°, preferably between 10° and 20°, preferably of about 15°.
6. Heat exchanger (1) according to claim 5, wherein two adjacent working fluid turbulator rows (20) are inclined by the same inclination angle (a), in opposite directions.
7. Heat exchanger (1) according to any one of claims 1 to6, wherein the working fluid flows in the planar working fluid segment (153) in a working fluid direction and the working fluid turbulator (2) is positioned so that the working fluid turbulator rows (20) extend substantially orthogonally to the working fluid direction, wherein the carbon dioxide flows in the planar carbon dioxide segment (163) in a carbon dioxide direction and the carbon dioxide turbulator (3) is positioned so that the carbon dioxide turbulator rows (30) extend substantially orthogonally to the carbon dioxide direction.
8. Heat exchanger (1) according to any one of claims 1 to 6, wherein the working fluid flows in the planar working fluid segment (153) in a working fluid direction and the working fluid turbulator (2) is positioned so that the working fluid turbulator rows (20) extend substantially orthogonally to the working fluid direction, wherein the carbon dioxide flows in the planar carbon dioxide segment (163) in a carbon dioxide direction and the carbon dioxide turbulator (3) is positioned so that the carbon dioxide turbulator rows (30) extend substantially parallel to the carbon dioxide direction.
9. Heat exchanger (1) according to any one of the preceding claims, wherein plate-like end elements (102, 103), a plurality of intermediate plate-like elements(104), working fluid turbulators (2), carbon dioxide turbulators (3) are mutually stacked and integrally joined by means of a brazing process, preferably a vacuum brazing process.
10. Heat exchanger according to any one of claims 1 to 9, wherein each vertical working fluid segment (151, 152) and each vertical carbon dioxide segment (161, 162) comprise respective passage sections, wherein the passage sections of at least one vertical carbon dioxide segment (161, 162) is smaller than the passage section of both vertical working fluid segments (151, 152).
11. Heat exchanger (1) according to any one of claims 1 to 9, wherein each vertical working fluid segment (151, 152) and each vertical carbon dioxide segment (161, 162) comprise respective passage sections, wherein the passage sections of both vertical carbon dioxide segments (161, 162) is smaller than the passage section of both vertical working fluid segments (151, 152).
12. Heat exchanger (1) according to any one of the preceding claims, wherein the adjacent rows of both turbulators (2, 3) form passage openings (A2, A3) for the circulation of the respective fluids, wherein the main dimension of the passage opening (A3) of the carbon dioxide turbulator, measured in the row extension direction, is smaller than the passage opening (A2) ofthe working fluid turbulator (2) measured in the same direction.
13. Heat exchanger (1) according to any one of the preceding claims, wherein the rows of the carbon dioxide turbulator (3) are mutually staggered by a smaller value as compared to the rows of the working fluid turbulator (2).
14. Heat exchanger (1) according to any one of the preceding claims, wherein a planar working fluid segment (153) is directly proximal to the upper plate-like element (102), and a planar working fluid segment (153) is directly proximal to the lower plate-like element(103).