Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F1/00—Tubular elements; Assemblies of tubular elements
  • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
  • F28F1/12—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
  • F28F1/126—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element consisting of zig-zag shaped fins
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B39/00—Evaporators; Condensers
  • F25B39/02—Evaporators
  • F25B39/022—Evaporators with plate-like or laminated elements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
  • F25B9/002—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the refrigerant
  • F25B9/008—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the refrigerant the refrigerant being carbon dioxide
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D1/00—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators
  • F28D1/02—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid
  • F28D1/04—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits
  • F28D1/053—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits the conduits being straight
  • F28D1/0535—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits the conduits being straight the conduits having a non-circular cross-section
  • F28D1/05366—Assemblies of conduits connected to common headers, e.g. core type radiators
  • F28D1/05383—Assemblies of conduits connected to common headers, e.g. core type radiators with multiple rows of conduits or with multi-channel conduits
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2309/00—Gas cycle refrigeration machines
  • F25B2309/06—Compression machines, plants or systems characterised by the refrigerant being carbon dioxide
  • F25B2309/061—Compression machines, plants or systems characterised by the refrigerant being carbon dioxide with cycle highest pressure above the supercritical pressure
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2500/00—Problems to be solved
  • F25B2500/01—Geometry problems, e.g. for reducing size
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
  • F28D2021/0019—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for
  • F28D2021/008—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for for vehicles
  • F28D2021/0085—Evaporators

Definitions

• the present invention relates to a device for exchanging heat.
• the device will be described in relation to an air conditioning system, especially in motor vehicles. It should be noted, however, that the device according to the invention can also be used in other air conditioning systems or refrigeration circuits.
• BESTATIGUNGSKOPIE same geometry or the same dimensions of the refrigeration cycle can be used as in the use of conventional refrigerants, a very high weight and also causes high manufacturing costs, which cause the manufacture of the devices is uneconomical.
• the object of the invention is to adapt individual devices for exchanging heat in terms of their dimensions to the use of CO 2 as a refrigerant, that a more cost-effective and low-weight production is possible.
• the object is to adapt the devices by adapting certain dimensions to the effect that, especially when using the refrigerant CO2, an improvement of the device is achieved, in particular but not exclusively with regard to its production costs, power, weight, etc.
• Another object is also to improve devices for the exchange of heat, which use as refrigerant R 134a.
• the evaporator is reduced as a component in its specific cooling capacity in the order in which the reaction in the refrigeration cycle in the vehicle cab can still be accepted. It can be accepted that the performance level of a refrigerant circuit using conventional refrigerant (R143a) is no longer clearly outbid as before, but at a comparable level. More specifically, the evaporator should be designed so that it is comparable in terms of its cooling capacity of its weight and its production costs compared to evaporators with conventional refrigerants.
• essential geometric variables of the evaporator are optimized in such a way that, as part of the overall system, the most favorable cost / benefit ratio arises.
• the inventive device for exchanging heat has a plurality of flow tubes for the forwarding of a fluid, wherein the device has a predetermined depth - hereinafter also referred to as depth - and some flow tubes are arranged at least in sections at a predetermined distance from each other.
• the ratio between the depth and the predetermined distance is less than 7.
• the depth of the heat exchange device results essentially from the depth of the individual flow tubes, as will be explained in detail with reference to the figures.
• the pipe pitch is hereinafter referred to as rib height.
• the distance is understood as the shortest geometric distance between the flow tubes.
• the tubes need not necessarily have the same distance from each other along their entire length.
• first group of tubes has a first distance from one another and a second group of tubes has a second distance from one another. This will also be explained in detail in connection with the figures.
• the ratio V is less than 6.5, preferably less than 6.3, and more preferably less than 5.9.
• the flow tubes are arranged at least partially parallel to each other. In this way, a substantially constant distance between the individual flow tubes can be ensured.
• the flow tubes are parallel to each other substantially along their entire length and thus point along the essentially their entire length a constant, predetermined first distance from each other.
• the flow tubes have a flat tube-like cross section. Under a flat-tube-like
• Cross-section is understood to mean a cross-section in which one side far surpasses another side in terms of its length, such as an elongated rectangle, an elongated rectangle with rounded edges
• the fluid is a refrigerant and preferably R 744 (CO 2 ).
• a first plurality of flow tubes at least in sections a first predetermined distance from each other, and a second plurality of flow devices a second, substantially predetermined distance from each other, wherein the ratio V between the depth and at least one of the predetermined distances less than 7 is.
• both the first predetermined distance and the second predetermined distance may be such that the ratio between the depth and the two predetermined distances is in each case less than 7.
• a first plurality of flow devices is offset laterally relative to a second plurality of flow devices.
• the individual predetermined distances of the first and the second plurality can be selected the same or different. Also, the predetermined distances may vary within the same plurality of flow devices.
• cooling fins are arranged between the flow tubes. These cooling fins serve to improve the heat exchange with the surrounding air. As mentioned, the height of these cooling ribs is essentially determined by the predetermined distance between the respective flow tubes.
• the wall thickness of the individual cooling fins is between 0.04 and 0.2 mm, preferably between 0.05 and 0.12 mm and particularly preferably between 0.06 and 0.1 mm.
• the rib density is between 40 and 90 Ri / dm, preferably between 50 and 80 Ri / dm and more preferably between 60 and 70 Ri / dm.
• the device has a depth between 10 mm and 60 mm, preferably between 20 mm and 50 mm and particularly preferably between 25 and 45 mm. These different depths are in particular due to the intended use, ie, for example, whether the device should be used in a small car, a mid-range car or a luxury car.
• the predetermined distance between the flow tubes between 4 mm and 12 mm, preferably between 4.5 mm and 10 mm. These distances are also determined by the particular applications.
• a depth between 30 mm and 50 mm preferably a depth between 35 mm and 45 mm, a predetermined distance between 5 mm and 12 mm, preferably between 5.5 mm and 10 mm assigned.
• it is rather larger-sized devices for exchanging heat, which can be found in particular, but not exclusively, in air conditioners in mid-range cars or cars of the upper class application.
• a depth between 15 mm and 40 mm preferably a depth between 20 mm and 35 mm, a predetermined distance between 3 mm and 10 mm, preferably assigned between 4 mm and 8.5 mm.
• These dimensions or dimensions find particular application in air conditioning systems of small cars and cars of the middle class. Even with these dimensions, a ratio of less than 7 should be maintained substantially. In this case, however, a ratio of essentially 7 is also understood as meaning a ratio which slightly exceeds the value of 7.
• the flow tubes have a width between 1 mm and 3 mm, preferably between 1, 5 mm and 2 mm and particularly preferably between 1, 7 mm and 1, 9 mm.
• the wall thickness of the flow tubes is between 0.1 mm and 0.6 mm, preferably between 0.2 mm and 0.4 mm and particularly preferably in the range of about 0.3 mm.
• the device according to the invention is preferably an evaporator, which is a component of a refrigerant circuit of a motor vehicle air conditioning system.
• the invention is further directed to an air conditioning system, in particular for a motor vehicle, which has at least one device according to the invention for the exchange of heat.
• the invention is further directed to a method for dimensioning devices for exchanging heat, wherein in a first step a first dimension of the device is determined, in a further step a second dimension of the device is determined, in a further step at least two first Target parameter of the device are determined, in a further step, at least one dimension is changed, determined from the changed dimensions, in turn, two second target parameters of the device with the changed dimension and finally the more favorable target parameters are selected from a comparison of the first and second target parameters.
• the first and second dimensions are selected from a group of dimensions including the depth, the fin height of the cooling fins, the spacing of the flow tubes, and the like.
• dimensions such as the rib density per dm and the like can also be understood as dimensions.
• Target parameters are preferably selected from a group of parameters that includes the package depth, the cooling capacity, the air side pressure drop, the weight, and the manufacturing cost.
• the essential dimensions of the device for exchanging heat can be varied and thus the respective stated output quantities can be determined so as to arrive at a device dimensioned such that a satisfactory, sufficient cooling capacity can be achieved with acceptable production costs and / or acceptable costs acceptable weight is achieved.
• the target parameters are often determined in particular for different dimensions and from this thus obtained plurality of sets of target parameters obtained the most favorable rates determined by parameters.
• the target parameters are preferably weighted according to predetermined criteria.
• Fig. 1 is a fragmentary plan view of the invention
• Fig. 2 is a side view of the device according to the invention.
• Fig. 3 is a schematic representation of another
• Fig. 5 is a schematic representation of another
• Fig. 6 is a schematic representation for illustrating the
• Fig. 7 is a diagram for illustrating the achieved cooling
• 9a is a graphical representation of the relationship between the refrigeration capacity and the weight of the device according to the invention.
• Fig. 9b is an illustration of the air side pressure drop
• Fig. 15 shows a representation of the power in relation to the costs as a function of the ratio of the overall depth to the rib height.
• Fig. 1 shows a fragmentary plan view of the inventive device for the exchange of heat! This has a plurality of first flow tubes 3 and a second plurality of second flow tubes 5.
• the refrigerant flows through the plurality of first flow tubes 3 in one direction, for example, out of the leaf plane, and in the second plurality of flow tubes 5 in an opposite direction, ie, into the leaf plane.
• Reference numeral 7 denotes a chamber of the flow tube.
• the flow tubes are divided into a plurality of chambers or channels.
• the first flow tubes 3 and second flow tubes 5 are separated from one another by a gap 8.
• This space 8 is used for thermal insulation, since in the flow tubes 3 and 5, the refrigerant may have a different temperature and heat transfer should not take place.
• the flow tubes can also be arranged continuously along the depth T; d. h., Only a plurality of flat tubes may be provided.
• a chamber or a channel 7 is preferably performed blind, d. H. no refrigerant flows in this channel.
• the reference numeral 4 refers to ribs arranged between the flow tubes 3 and 5, which are shown here in plan view from above.
• the size H Ri characterizes the fin height and is essentially determined by the distance between the individual flow tubes 3 and 5, more precisely by the distance between the respective mutually facing sides of the respective flow tubes 3 and 5.
• the reference symbol T denotes the overall depth, which, as mentioned above, represents a significant geometric size of the device.
• the ribs 4 extend substantially along the full depth T and are preferably not interrupted by gaps.
• the above-mentioned ratio V is determined by the ratio of the depth T to the height of the rib H R J.
• FIG. 2 shows a side view of the partial illustration of the device for exchanging heat shown in FIG.
• b denotes the tube width of the individual flow tubes.
• the width of the tubes is between 2 and 4 mm, preferably between 2.5 and 3 mm.
• the width of the tubes preferably in the range of 1, 2 to 2 mm.
• the device has a width between 120 and 400 mm, preferably between 215 and 350 mm, and particularly preferably between 250 and 315 mm.
• a likewise advantageous width is between 120 and 315 mm.
• the height of the device according to the invention is between 140 and 300 mm, preferably between 200 and 300 mm, particularly preferably between 220 and 250 mm.
• a likewise advantageous height is between 140 and 270 mm.
• the device is essentially made of aluminum or a material containing aluminum.
• the reference character A denotes the so-called transverse division, d. H. the distance between the respective geometric centers of the individual
• Rib height R H ⁇ if in addition still the respective tube width b is considered, ie, the rib height and the transverse distribution are directly related.
• the transverse division can be used as a measure of the rib height, if due to the cross section of the flow tubes 3, 5 no geometrically unique and constant indication of the rib height or the distance of the flow tubes is present, for. B. when the distance of the flow tubes in Fig. 2 changes in a direction perpendicular to the sheet plane, which is possible for example in a circular profile of the flow tubes.
• the ratio according to the invention is to be replaced by the depth and spacing of the tubes for the depth and pitch.
• a further embodiment of the device according to the invention is shown schematically.
• the reference numerals 3 and 5 respectively refer to plan views of the individual flow tubes.
• the flow tubes 3 and the flow tubes 5 are offset laterally relative to one another. This means that the distance between the flow tubes can be determined separately for the flow tubes 3 and 5 for the flow tubes.
• the distance HR, the flow tubes 3 is identical to the distance H R
• the flow tubes 3 have a greater distance H R , from each other than the flow tubes 5, which have a distance H R
• H R preferably at least one of the two distances HR, I or HR, 2 , in this case at least the distance H R , i is selected so that the ratio of the depth T and the distance HR, I is less than 7.
• Fig. 5 is another embodiment of the invention.
• the distances between the individual flow tubes vary only within the
• Embodiment must be ensured that at least one of the distances H R
• Fig. 6 shows a schematic representation for illustrating the definition of the distance H R ,. While the flow tubes in FIGS. 3 to 5 each have rectilinear longitudinal sides which at the same time directly determine the distance, the flow tubes in the embodiment shown in FIG. 6 have an elliptical cross section. In this case, the distance between the flow tubes is defined as the distance between the two tangents T, which are respectively applied to the flow tubes 3.
• FIG. 7 shows the simulation of a cooling curve for a luxury vehicle.
• comparable cooling curves for the coolant R 134a here represented by the curves 11 and 12, and for R 744, here represented by the curves 14 and 15, respectively applied in IdIe- operating point.
• the upper curves 12 and 14 show the temperature profile in the vehicle interior, the lower curves 11 and 15 show the temperature development at the evaporator itself.
• the R 744 evaporator has a construction depth that is 25 mm smaller, namely a construction depth of 40 mm, whereas the R 134a evaporator has a construction depth of 65 mm.
• Time is plotted in minutes on the ordinate, and the temperature in degrees Celsius on the coordinate.
• the simulation is subdivided into several periods I to IV, whereby the section I relates to a third gear at 32 km / h, the section II to a fourth gear at 64 km / h, the third section the idling (IdIe) and the section IV on a second gear at 64 km / h.
• FIG. 8 shows a performance comparison of different evaporator designs at a typical operating point. This operating point is defined so that it allows comparisons independently of the refrigeration cycle.
• the diamonds indicate the values determined for the refrigerant R 744 (CO 2 ); the ellipses indicate the values determined for the refrigerant R 134a.
• the rib density is 70 Ri / dm for the evaporator with the refrigerant R 744 and 60 Ri / dm for the evaporator with the refrigerant R 134a.
• the overall depth in mm is plotted on the ordinate, and the total power in kW on the coordinate.
• the registered value pairs or points 31 to 39 are functions of the temperature T, the fin height H R , the fin density z r ⁇ and the so-called transverse pitch s q .
• the transverse division denotes the distance of the respective centers of the individual flow tubes from each other.
• a field is spanned by the individual value pairs or points 31 to 39, which covers the level of performance in refrigeration cycles of different vehicle classes.
• the upper curve 22 is assigned to the upper-class or Van segment, the lower limit curve 23 shows the power requirement of small cars.
• the values for the refrigerant R 744 are plotted.
• the values for the refrigerant R 134a are plotted.
• a uniform rib density of 70 Ri / dm was chosen for the measuring points 31 to 35, while for the points 36 to 39 a uniform rib density of 60 Ri / dm was chosen.
• the diagram shows that the overall depth of R 744 is significantly reduced while maintaining the same level of performance as the coordinate. This means that the assignment of the construction depth T to the rib height HRJ or the ratio shifts.
• R 134a While in the case of R 134a a depth of 65 mm is assigned to a rib height of 7 to 10 mm and a depth of 40 mm a rib height of 4 to 6 mm, when using the refrigerant R 744 a depth of 40 mm, a rib height of 7 to 10 mm and a depth of 27 mm, a rib height of 5 to 8 mm assigned.
• the assignment or dimensioning of R 134a was adopted for the refrigerant R 744. This resulted in significantly higher performance compared to R 134a, but also to additional weight and additional costs, which is due, among other things, to the significantly higher pressures required for R 744.
• These significantly higher power values are exemplified by the points 41 and 42. Points 41 and 42 result in benefits that are more than 15% higher than the maximum required benefits.
• R 744 The considerably higher potential of R 744 is due to the fact that due to the high specific flow rate of the R 744 compressor in the R 744 circuit, a pressure drop in the low-pressure part is achieved more quickly. This leads to a higher dynamics and at the evaporator to a higher driving temperature gradient between the air and the refrigerant.
• the refrigerant-side pressure drop in the evaporator is of comparable magnitude, with 1 bar pressure drop at R 134a cause about 9K temperature response, and R 744 only 1 K. This leads on average over the flow length in the evaporator to a significantly higher driving temperature gradient between air and refrigerant (the R 744 evaporator offers a significantly colder surface temperature on average).
• a depth of 65 mm is rather too large for the existing performance level; According to estimates, a 55 mm deep design, which reaches the level of 65 mm depth, would be more favorable. However, such an embodiment may result in higher costs and less favorable airside pressure drop. As for the performance particularly favorable for the refrigerant R 134a, a depth of 40 mm has been found; however, disadvantages in terms of cost and airside pressure drop are to be expected in this case. These considerations show the extremely complicated interplay of different aspects in the assessment and evaluation of the evaporator to be produced.
• FIG. 9 illustrates some of the advantages of the invention.
• the weight of the evaporator with respect to the achievable cooling capacity is shown in the designated with Fig. 9a partial diagram.
• the physical boundary conditions, such as the air mass flow GLV, are identical to those conditions that were used in the description of FIG. 8. Also, the same evaporator dimensions were chosen.
• measuring points 44 and 45 which refer to small cars and vehicles of the middle class, can show, by adaptation of the geometric
• Measuring point 44 for the refrigerant R 744 and the measuring point 45 for the Refrigerant R 134a was determined.
• a mean depth and a rib density of 60 Ri / dm are used.
• a depth less than 45, a smaller cross-section, and a higher rib density were chosen.
• the two measuring points 46 and 47 which refer to devices for luxury vehicles, show a significantly reduced weight of the R 744 evaporator at the same cooling capacity.
• a higher overall depth T a predetermined fin density and a higher transverse dimension s q were selected.
• a smaller depth T than at point 46 was chosen for the R744 evaporator, a rib density equal to 46 and a corresponding equal pitch. Therefore, there is a significant reduction in weight due to the smaller overall depth with otherwise the same cross distribution and even weight advantages over the respective equivalent performance R 134a evaporator. Due to the smaller depth, only lower material costs and thus a cost reduction arise.
• the air-side pressure drop shown on the coordinate can also be reduced.
• the blocks 51 to 53 refer to the refrigerant 134a, the blocks 54 to 55 to the refrigerant R 744. It can be seen that when using R 744 also a significant reduction of the air-side pressure drop is achieved by about 50%. This leads to a higher amount of air for the air conditioning of Vehicle, to a lower power consumption in the fan and also offers potentials to reduce the noise level of the air conditioner.
• the power values of individual evaporators are plotted over the depth as ordinate.
• the evaporators with the same fin height are always aligned.
• the reference numeral 63 denotes the line listening to a large fin height, which will be referred to as the first fin height
• the reference numeral 62 denotes the line associated with a second minor fin height (hereinafter referred to as second fin height)
• the reference numeral 61 indicates the line which is associated with an even smaller rib height (referred to below as the third rib height) compared to the second rib height.
• the individual lines 61 to 63 have relatively similar slopes, which suggests a proportional dependence on power and construction depth with otherwise identical construction or rib height. Furthermore, it can be seen that evaporators with smaller fin heights, but otherwise the same size, cause higher performance due to the enlargement of the heat-transferring surface.
• the hatched areas 60 and 70 limit the required or meaningful performance values.
• the performance limits were determined inter alia by simulating a vehicle cabin cooling. While in the upper area 60, further increase in performance brings no further benefits, below the lower limit in the area 70, cabin cooling is no longer acceptable.
• Reference numerals 65 to 68 show measured values which lie within the required power range. They designate devices of different construction.
• the reference numeral 67 refers to a large-depth R 134a evaporator having the first above-mentioned fin height.
• the reference numeral 65 refers to an R 134a evaporator having the third above-mentioned fin height and a smaller overall depth.
• the reference numeral 66 refers to an R 134a evaporator having the second fin height and a mean depth.
• the reference numeral 68 refers to an R 134a evaporator having the first fin height and a mean depth.
• the reference numerals 71 to 74 represent the measured values of such evaporators which are no longer in the tolerable range 75 lying between the regions 60 and 70.
• the reference numeral 71 denotes an evaporator with a small depth and the first rib height
• the reference numeral 72 an R744 evaporator with the third rib height and a very small overall depth
• the reference numeral 73 a CO 2 evaporator with a small overall depth and the third rib height
• the reference numeral 74 a CO 2 - evaporator with a high depth and the first rib height.
• the CO 2 evaporators have significantly higher power values than the R 134a evaporators at the given overall depths and rib heights.
• a CO 2 evaporator which has a small overall depth, for example, at the second rib height, as can be seen from line 76, could be of interest for the application.
• the ellipses 140, 141 indicate areas in which favorable dimensions lie.
• FIG. 11 shows the power-to-weight ratio as a function of the overall depth.
• the quantities referred to power / weight were re-weighted among each other in order to meet the varying importance of the individual sizes.
• the power and the cost are considered as equivalent quantities, while the weight and the fin height play a subordinate role.
• the triangles refer to CO 2 -
• the evaporator designated by the reference numeral 81 proves particularly favorable with a mean depth, a second rib height mentioned above and the evaporator with a small overall depth and the third rib height marked with the reference numeral 83.
• evaporator with the first rib height would still be low in relation to the ratio of power to weight, but its absolute performance would not be acceptable for the cooling of small cars. It would be conceivable for this evaporator type, the use, for example, in a rear system. Likewise, for example, an evaporator with the same rib height in the region of the second rib height could be regarded as a further alternative for the small and / or middle car category.
• the evaporators represented by the reference numerals 86 and 87 are of small depth with high fin height and the evaporator shown by the reference numeral 88 with shallow depth and favor the third rib height.
• the marked with the reference numeral 89 evaporator with less depth is finally still relatively cheap, but is borderline in terms of its performance.
• the evaporator 91 fails in direct comparison to the first fin height. In addition, this evaporator is already above the currently required upper performance limit.
• Reference lines 95 and 96 refer to trend lines established based on the measured values. Based on this trend line can be determined or estimated for which dimensions of the evaporator favorable interpretations, such as a favorable power / weight ratio, are to be expected.
• trend line 95 refers to CO 2 evaporator and the trend line 96 to R 134a evaporator.
• the medium-depth evaporator 101 having a first fin height has the best power / cost ratio.
• this evaporator has a low output and is therefore in the
• the trend line 115 for the R 134a evaporators and the dividing line 116 for the CO 2 evaporators are, as above, respectively, in which geometries Particularly favorable results for the evaporator are to be expected.
• the evaporator with a third rib height indicated by the reference numeral 102 cuts off significantly less favorably, in this case the advantage of the small overall depth with respect to the evaporators designated by the reference line 104-106 must be taken into account.
• the good power / cost ratio of the designated by the reference numerals 107 and 108 evaporator with first or just below the underlying rib height remains, but also that of the reference numeral 110 marked evaporator with first rib height.
• the third-fin height evaporator indicated by reference numeral 111 is somewhat less favorable due to the high packing density, which has a negative impact on the cost side.
• An evaporator with a second rib height would logically be between those with third or first rib height and would be quite an interesting alternative.
• the said ratio is finally at the marked with the reference numeral 112 evaporator with greater depth at the third rib height and the marked 113 with low depth.
• the evaporator designated by the reference numeral 114 which corresponds to the evaporator shown by the reference numeral 93 in Fig. 11, remains disregarded due to the above reasons.
• FIGS. 13 to 15 correlate to the first illustrations shown in FIGS. 10 to 12. However, in the figures shown in FIGS. 13 to 15, the dimension "depth" plotted on the ordinate or abscissa was replaced by the weighted ratio V of the depth and the sum of the rib height + 10 mm.
• the weight-related power is over that related to the weighted rib height
• Cost, performance and weight can be determined and weighed against each other, in particular by different weighting, which variants are in the end the most favorable embodiments. In this way, with the inventive method by using different weighting, which variants are in the end the most favorable embodiments. In this way, with the inventive method by using different weighting, which variants are in the end the most favorable embodiments. In this way, with the inventive method by using different weighting, which variants are in the end the most favorable embodiments. In this way, with the inventive method by using different
• Specially developed programs are preferably used for the method, which allow the user to specify any criteria, specify the target parameters arbitrarily, so as to meet the requirements of, for example, the air conditioning of a motor vehicle.
• it is necessary to introduce or combine the experiences gained in each case by measurement and / or complex thermodynamic considerations.
• the invention is therefore also directed to a software which makes it possible to carry out the method according to the invention computer-aided.
• the CO 2 evaporator it proved to be particularly favorable overall depths in the range from 20 to 45 mm with a rib height of 4.0 to 10.0 mm.

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• 2004
  • 2004-11-23 DE DE102004056557A patent/DE102004056557A1/de not_active Ceased
• 2005
  • 2005-11-17 JP JP2007541785A patent/JP2008520489A/ja active Pending
  • 2005-11-17 BR BRPI0518471-1A patent/BRPI0518471A2/pt not_active IP Right Cessation
  • 2005-11-17 US US11/720,014 patent/US20080029242A1/en not_active Abandoned
  • 2005-11-17 WO PCT/EP2005/012304 patent/WO2006056360A1/de active Application Filing
  • 2005-11-17 CN CN2005800400520A patent/CN101065635B/zh not_active Expired - Fee Related
  • 2005-11-17 EP EP05813950A patent/EP1831632A1/de not_active Withdrawn

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