AU2008357596A1 - Heat exchanger block, and a method for wetting a heat exchanger block - Google Patents

Description

P.7771/ir/Pa A-HEAT ALLIED HEAT EXCHANGE TECHNOLOGY AG, 5 Ganghoferstrasse 31, D-80339 Munchen, Germany Heat exchanger block and a method for wetting a heat exchanger block 10 The invention relates to a heat exchanger block as well as to a method for wetting a heat exchanger block in accordance with the preamble of the independent claims 1 and 13. 15 The use of heat exchange systems is known in a practically innumerable number of applications from the prior art. Heat exchangers are used in refrigeration systems such as in common domestic refrigerators, in air conditioning systems for buildings or in vehicles of all kinds, above all in motor vehicles, aircraft and ships, as water coolers or as oil coolers in 20 combustion engines, as condensers or evaporators in refrigerant circuits and in further innumerable different applications which are all well-known to the person of ordinary skill in the art. In this respect, there are different possibilities of sensibly classifying the 25 heat exchangers from very different applications. One attempt is to carry out a distinguishing by the structure or by the manufacture of the different types of heat exchangers.

2 A division can thus be made by so-called "lamella heat exchangers", on the one hand, and "minichannel" or "microchannel" heat exchangers, on the other hand. 5 The lamella heat exchangers which have been well-known for a very long time serve, like all types of heat exchangers, for the transfer of heat between two media, e.g., but not only, for the transfer from a cooling medium to air or vice versa, such as is known, for example, from a classical domestic refrigerator in which heat is emitted to the environment 10 air via the heat exchanger for the production of a cooling capacity in the interior of the refrigerator. The environmental medium outside the heat exchanger, that is e.g. water, oil or frequently simply the environmental air which takes up the heat, for 15 example, or from which heat is transferred to the heat exchanger, is either cooled or heated accordingly in this process. The second medium can e.g. be a liquid cold carrier or heat carrier or an evaporating or condensing refrigerant. In any case, the environmental medium, that is e.g. the air, has a substantially lower heat transfer coefficient than the second 20 medium, that is e.g. the refrigerant, which circulates in the heat exchanger system. This is balanced by highly different heat transfer surfaces for the two media. The medium with the high heat transfer coefficient flows in the pipe which has a very enlarged surface at which the heat transfer e.g. to the air takes place by thin metal sheets (ribs, 25 lamellae) at the outer side. Fig. 1 shows a simple example of a lamella heat exchanger 41' which is known per se'. In practice, a total heat exchanger block 1' is frequently formed by a plurality of such elements in accordance with Fig. 1. In the 30 simplest case, such a lamella heat exchanger 41' is formed by a plurality 3 of cooling lamellae 413', whereby the heat exchanging surface 7' can be hugely increased. In the operating state, a heating agent 6' flows through the coolant lines 411' so that the heating agent 6' can mainly exchange heat with the environment, usually with the environmental air 5', via the 5 cooling lamellae 413', in that the environmental air 5' is transported as a transport fluid 5' for the transport of the heat through the heat exchanger 41', for example with the help of a fan, in the direction of the arrow 5' in accordance with Fig. 1. 10 It must be pointed out at this point that features of known apparatus from the prior art are provided with a dash within the framework of this application, whereas features of embodiments in accordance with the invention do not have a dash. 15 The ratio of the outer surface to the inner surface depends in this respect on the lamella geometry (= pipe diameter, pipe arrangement and pipe spacing) as well as on the lamella spacing d'. The lamella spacing is selected differently for different applications. However, it should be as small as possible from a thermodynamic aspect, but not so small that the 20 pressure loss on the air side is too large. An efficient optimum is at approximately 2 mm, which is a typical value for condensers and dry coolers. The manufacture of these so-called lamella heat exchangers 41' takes 25 place in accordance with a standardized process known for a long time. The cooling lamellae 413' are punched with a press and a special tool and are punched out in accordance with a predetermined scheme and the punched holes 412' are provided with collars 414' for spacings. The cooling lamellae 413' are then placed in packets with respect to one 30 another. The pipes which should later transport the heating agent 6', that 4 is the coolant lines 411', are subsequently pushed into the collars 414' and thus through the punched holes 412' and are widened either mechanically or hydraulically so that a very good contact and thus a good heat transfer arises between the coolant line 411' and the cooling lamellae 5 413'. The individual pipes are then connected to one another, often soldered to one another, by bends and inlet and outlet pipes. For reasons of clarity, the inlet and outlet pipes are not shown in Fig. 1. To illustrate the construction of the heat exchanger 41' in accordance with 10 Fig. 1, a section of a plan view of the heat exchanger from the direction R is shown schematically in Fig. 2. In particular the collars 414' are important through which the coolant lines 411' are conducted since it is thereby ensured that the cooling lamellae 413' maintain a defined spacing d'. 15 The efficiency is in this respect substantially determined by the fact that the heat which is transferred between the lamella surface and the air has to be transferred to the pipe via heat conduction through the lamellae. This heat transfer is the more effective, the higher the conductivity or the 20 thickness of the lamella is, but also the smaller the spacing between the pipes is. One speaks of lamella efficiency here. Aluminum is therefore primarily used as the lamella material today which has a high heat conductivity (approx. 220 W/mK) at economic conditions. The pipe spacing should be as small as possible; however, this results in the 25 problem that many pipes are needed. Many pipes mean high costs since the pipes (made from copper as rule) are considerably more expensive than the thin aluminum lamellae. These material costs could be reduced in that the pipe diameter and the wall thickness are reduced, i.e. a heat exchanger is made with a large number of small pipes instead of with a 30 few larger pipes. This solution would be ideal thermodynamically: Very 5 many pipes at small distances with small diameters. A substantial cost factor is, however, also the working time for the widening and soldering of the pipes. It would increase extremely with such a geometry. 5 A new class of heat exchangers, so-called minichannel or also microchannel heat exchangers, was therefore already developed some years ago which are manufactured using a completely different process and almost correspond to the ideal of a lamella heat exchanger: many small pipes at small intervals. 10 Instead of small pipes, however, extruded aluminum sections are used in the minichannel heat exchanger which have a large number of small channels with a diameter of e.g. approximately 1 mm. Such a microchannel heat exchanger block 1' likewise known per se is shown 15 schematically in Fig. 3. The microchannel heat exchanger block 1' of Fig. 3 is in this respect formed by two heat exchangers 42' known per se in the form of extruded sections 42'. The two extruded sections 42' of Fig. 3 are preferably in thermal contact with a wavy cooling lamella 413' so that the heating agent 6', which is conveyed through the microchannels 421', can 20 better exchange its heat with the transport fluid 5', preferably air 5', which is, for example, conveyed through the heat exchanger block 1' in the direction of the arrows 5' by a fan not shown. In practice in this respect, a heat exchanger block 1' can already manage, 25 depending on the required heat capacity, with one single extruded section 42' as a central heat exchange element. To be able to achieve higher heat transfer capacities, a plurality of extruded sections 42' can naturally also be provided simultaneously in one single heat exchanger block 1' which are connected to one another, e.g. soldered to one another, in suitable 6 combinations, for example via inlet feeds ad outlet feeds, which is not shown in Fig. 3 for reasons of clarity. Such extruded sections can e.g. be manufactured in suitable extrusion 5 processes simply and in a variety of shapes from a plurality of materials. However, other manufacturing processes are also known for the manufacture of microchannel heat exchangers such as the assembly of suitably shaped sectional metal sheets or other suitable processes. 10 These sections cannot, and also do not have to, be widened and they are also not pushed into stamped lamella packets. Instead, for example, sheet metal strips, as explained in Fig. 3, in particular aluminum strips, are placed between two sections disposed close to one another (common spacings, for example, < 1 cm) so that a heat exchanger packet arises by 15 alternating placing of sheet metal strips and sections next to one another. This packet is then soldered completely in a soldering furnace. A heat exchanger having a very high lamella efficiency and a very small filling volume (inner channel side) arises due to the narrow spacings and 20 the small channel diameters. The further advantages of this technique are the avoidance of material pairings (corrosion), the low weight (no copper), the high pressure stability (approx. 100 bar) as well as the compact construction shape (typical depth of a heat exchanger e.g. 20 mm). 25 Minichannel heat exchangers became established in mobile use in the course of the 1990s. The low weight, the small block depth as well as the limited dimensions required here are the ideal requirements for this. Automotive radiators as well as condensers and evaporators for automotive air-conditioning systems are today realized almost exclusively 30 with minichannel heat exchangers.

7 In the stationary area, larger heat exchangers are usually needed, on the one hand; on the other hand, the emphasis here is less on the weight and the compact design and more on the ideal price-performance ratio. 5 Minichannel heat exchangers were previously too limited in dimensions to be considered for this purpose. Many small modules would have had to be connected to one another in a complex and/or expensive manner. In addition, the use of aluminum in the extruded sections is relatively high so that a cost advantage was also practically not be expected from the 10 material use aspect. Due to the high volumes in the automotive sector, the manufacturing processes for minichannel heat exchangers have become standardized and have improved so that this technology can today be called mature. The 15 soldering furnace size has also increased in the meantime so that heat exchangers can already be produced in the size of approximately 1 x 2 m. The initial difficulties with the connection system have been remedied. In the meantime, there are a plurality of patented processes on how the inlet and outlet pipes can be soldered in. 20 However, above all the price of copper, which has increased greatly with respect to aluminum, has had the result that this technology is also becoming increasingly interesting for stationary use. 25 In this respect, it has long been known that two to three times more heat can be dissipated by evaporation of water on air-cooled heat exchanger surfaces than by convection, and indeed at a lower temperature level, because the decisive air temperature in evaporation is the humidity temperature. 30 8 This fact is used inter alia, but not only, with dry coolers. The humidifying of the heat exchanger surface takes place in the prior art by spraying by means of nozzles in front of the heat exchanger block on the air intake side. 5 The above-described wetting processes may, in another respect, not be confused with so-called adiabatic cooling. Here, water is atomized before the heat exchanger on the intake side such that the fine water droplets are absorbed by the air and the temperature of the air taken in drops to the 10 vicinity of the wet-ball temperature as a consequence of the evaporation of the droplets. This process has a number of problems in practice and is not very popular with customers for various reasons. 15 On the one hand, the cooling water cannot be effectively transferred to the entire heat exchanging surface of the heat exchanger with such hybrid coolers. On the other hand, in many applications a direct application of cooling water is indicated. It must thus be taken into account with a 20 condenser in which the upper part is used as a heater that this upper part may not be wetted due to the high temperatures which occur. However, this cannot be avoided if, as described above, the humidification of the heat exchanger surfaces in the known processes takes place by 25 spraying by means of nozzles before the heat exchanger block at the air intake side. A further problem results from the fact that the added cooling water is simultaneously also used for cleaning the heat exchanger. For this 30 purpose, however, it has previously had to be worked with eight to tenfold 9 excess water in order effectively to wash out contamination of the heat exchanger. This has the result that much more coolant water or cleaning water has to be supplied to the heat exchanger than is ultimately vaporized in the actual cooling procedure. The excess cooling water 5 therefore has to be collected in collection troughs and reprocessed in a laborious manner. In addition, it is feared that aerosols with pathogens can enter into the breathing air via the collection troughs and can thus be spread. 10 It is therefore the object of the invention to provide an improved heat exchanger, in particular a hybrid heat exchanger, which overcomes the problems known from the prior art. This in particular means that a heat exchanger block should be provided by the invention with which heat can be transferred very effectively and in a very resource saving manner from a 15 heat exchanger to a transport fluid, preferably, but not only, to air, and which can simultaneously be cleaned and operated very effectively and in an environmentally friendly manner. It is furthermore an object of the invention to provide a particularly 20 effective method for wetting a heat exchanger block. The subject matters of the invention satisfying these objects are characterized by the features of the independent claims 1 and 13. 25 The dependent claims relate to particularly advantageous embodiments of the invention. The invention thus relates to a heat exchanger block including a heat exchanger arranged between an inflow surface and an outflow surface so 30 that the transport fluid can be supplied via the inflow surface to a heat 10 exchanging surface of the heat exchanger, can be brought into flowing contact with the heat exchanger surface and can be conducted away from the heat exchanger again via the outflow surface for the exchange of heat between a transport fluid and a heating agent flowing through the heat 5 exchanger in the operating state. In accordance with the invention, a perforated coolant lance is provided so that a coolant can be introduced between two heat exchanging surfaces of the heat exchanger via the coolant lance. 10 It is thus an essential recognition of the invention that the heat exchange between the heat exchanger and the transport fluid, that is e.g. between the heat exchanger and air which is conducted through the heat exchanger, can be substantially improved in that a coolant, which is preferably, but not necessarily, water, is brought directly into the interior 15 of the heat exchanger via a coolant lance onto the surfaces to be heat exchanged in the heat exchanger. For this purpose, in accordance with the invention, a perforated pipe or a perforated or porous hose is provided at the heat exchanger block by 20 which the coolant can be introduced between two heat exchanging surfaces of the heat exchanger. This meant that the heat exchanging surfaces of the heat exchanger can be wetted with coolant in a direct and controlled manner by the coolant 25 lance. Depending on how the coolant lances are positioned in the heat exchanger, a very uniform cooling capacity can thus be set over the total heat exchanger, for example. In another case, e.g. with a condenser, it may be sensible to provide the heat exchanger block only partly with coolant lances so that, for example, the part, usually the upper part, of 30 the heat exchanger operated as a heater, for example, is not additionally 11 cooled by the liquid coolant, whereas the remaining, lower, part is supplied with coolant via the coolant lances. In this respect, a non-uniform spread of the cooling capacity in the heat 5 exchanger block can naturally also be achieved by other measures. It is thus possible, for example, that different coolant lances are used in different regions of the heat exchanger block which supply different quantities of coolant to the different regions. The different coolant lances can thus e.g. have different perforations, that is e.g. different large holes 10 or bores, through which the coolant is introduced between the two heat exchanging surfaces. It is also possible to use different thick coolant lances so that the throughput of coolant is different in different regions of the heat 15 exchanger. The cooling capacity can also be simply and efficiently controlled and/or regulated in dependence on the time with a heat exchanger block in accordance with the invention in that, for example, the working pressure 20 of the coolant in all coolant lances or in specific coolant lances is controlled and/or regulator in dependence on the time and/or in dependence on the location. At the same time, a direct and very efficient cleaning of the heat exchanger 25 block in accordance with the invention is possible by use of the coolant lances. Since the coolant is brought into the heat exchanger at the location where it is directly needed, it can be metered very simply and efficiently and it is in particular not necessary to work with multifold quantities of excess water. In many cases, a collection trough is therefore 30 also omitted since no excess water arises in the operating state. The 12 formation of polluted aerosols is thereby also substantially prevented and valuable coolant is saved. The laborious cleaning of excess cooling water is also dispensed with. 5 It is even possible that, in systems in which in principle no additional coolant is required, nevertheless to provide coolant lances in accordance with the present invention which then only serve for the cleaning of the heating exchanger block. 10 Either for cleaning during operation in that work is only carried out with a very small quantity of coolant irrelevant for the cooling. Or, for example, in that the coolant lances are used for cleanings the heat exchanger block in operating breaks. 15 The wetting method proposed by the present invention thus especially includes the fact that, for example with a lamella heat exchanger, a first pipe row, viewed in the air direction, is replaced by coolant lances in the form of pipes or porous tubes which are provided with small holes or nozzles from which the wetting water, that is the coolant, exits and is thus 20 introduced into the lamella packet. So that the wetting water can spread well over the surfaces of the lamellae, the perforation of the first pipe row of the lamellae or collars, that is is made without spacers. The pipes or hoses which are used as coolant lances are preferably not widened or otherwise fixed in some manner, but are rather inserted loosely. 25 A pipe row, in particular a first pipe row, of the lamella packet of the air cooled heat exchanger can be provided, for example, in part or completely, with cooling lances. A part placement is, as already mentioned, in particular sensible when the heat exchanger is used as a condenser and 30 the upper part thereof as a heater which may not be wetted with coolant 13 due to the high temperatures. The regulation of the coolant amount can, if necessary, takes place via the working pressure of the coolant, for example. 5 It is understood that instead of only equipping the first pipe row with coolant lances, the coolant lances can also be positioned in any desired sensible arrangement in the lamella packet and can be provided with a corresponding perforation. 10 Instead of removing coolant lines in the lamella packet and replacing them with coolant lances, which automatically results in a loss of heat exchanging capacity, separate bores can also be provided, preferably without collars and specifically with smaller diameters, at the lamellae in a preset arrangement. 15 Instead of the coolant lances in the form of wetting pipes with holes or nozzles, so-called filter hoses can also be used, also sometimes called sweating hoses, which clean the coolant, that is, for example, the wetting water, with the degree of purity of the filtered coolant depending on the 20 quality of the filter hose. The hoses can also be cleaned of the filtrate by flushing. Depending on the application, special coolants or wetting liquids are used instead of normal water, e.g. demineralized or distilled water or water 25 especially changed in a different manner or, in very special cases, also other coolants known to the skilled person. In accordance with the present invention, the same principle can naturally also be used for the wetting and cooling of microchannel heat exchangers 30 of the initially described kind. The special feature in this respect is that 14 here flat pipes are preferably, but not necessarily, used for the wetting which are loosely inserted between the protruding lamellae after the soldering together of the microchannel heat exchanger. If the coolant lances made as flat pipes were to be soldered together with the MPE pipes, 5 there would be the risk that the holes or the slots of the flat pipe would be closed by solder and would thus no longer be available for the wetting with coolant. It is understood that more or less round pipes or hoses can also be used 10 as coolant lances in a heat exchanger block which is formed from microchannel heat exchangers and that, conversely, flat pipes can also advantageously be used as coolant lances in special cases in lamella heat exchangers. 15 The heat exchanger is thus made as a lamella heat exchanger in a particularly preferred embodiment of a heat exchanger block in accordance with the invention, wherein a coolant line is provided in a punched hole of a coolant lamella. 20 In an embodiment important for practice, the coolant lance is provided in a separate bore in the cooling lamella so that the number of the coolant lines is not reduced by the introduction of the coolant lance. In this respect, it is, however, naturally also possible that a coolant line is removed and the coolant lance is provided in the punched hole of the 25 coolant lamella. It is understood that in one and the same heat exchanger coolant lines can in part be replaced by coolant lances and simultaneously separate bores can be provided for further coolant lances. 30 15 In a further important embodiment of a heat exchanger block in accordance with the invention, the heat exchanger is formed by a plurality of microchannels as a microchannel heat exchanger. In this case, the coolant lance is preferably a pipe perforated in the form of holes and/or 5 slits and is in particular provided in the form of a flat pipe. As already mentioned, in particular when the coolant has to have a specific purity, a filter hose can be provided as a coolant lance so that the coolant is automatically purified from specific contaminants before the 10 application to the heat exchanger surface. For very specific applications, a heat exchanger block in accordance with the invention can be formed as a combination block of the lamella heat exchanger and the microchannel heat exchanger. This can be, for 15 example, when different conditions are present at different locations with one and the same heat exchanger block and/or when different heating capacities have to be provided. In a manner known per se, a cooling device for cooling the heat exchanger, 20 in particular a fan for generating or amplifying a gas flow of the transport fluid, can naturally additionally be provided between the heating agent and the transport fluid to increase a heat transfer rate. To control and/or regulate the heat exchanger block, a control unit known 25 per se, in particular a control unit having a data processing device, can advantageously be provided for controlling a cooling machine and/or a cooling device and/or the supply of the coolant via the coolant lance and/or an operating parameter or state parameter of the heating agent and/or another operating parameter of the heat exchanger block. 30 16 The heat exchanger and/or the heat exchanger block is/are preferably made from a metal and/or from a metal alloy, in particular from a single metal or from a single metal alloy, in particular from stainless steel, specifically made from aluminum or from an aluminum alloy and/or made 5 from a metal combination, e.g. from aluminum and copper, wherein a sacrificial metal is preferably provided as corrosion protection and/or wherein the heat exchanger block is provided at least partly with a protection layer, in particular with a corrosion protection layer. 10 A heat exchanger block in accordance with the invention can e.g. be a cooler, a condenser or an evaporator for a mobile or stationary heating plant, cooling plant or air conditioning unit, in particular a cooler apparatus for a machine, a data processing device or for a building. 15 The invention further more relates to a method for wetting a heat exchanger block including a heat exchanger arranged between an inflow surface and an outflow surface so that a transport fluid is supplied via the inflow surface to a heat exchanger surface of the heat exchanger, is brought into flowing contact with the heat exchanging surface and is 20 conducted away from the heat exchanger again via the outflow surface for the exchange of heat between the transport fluid and a heating agent flowing through the heat exchanger. In accordance with the invention, a perforated coolant lance is provided at the heat exchanger block and a coolant is introduced between two heat exchanging surfaces of the heat 25 exchanger via the coolant lance. In a preferred embodiment, the heat exchanger is a lamella heat exchanger and/or a microchannel heat exchanger and a regulation of a wetting quantity of the coolant is carried out and is preferably carried out 30 by setting a working pressure of the coolant.

17 Specifically, the wetting of the heat exchanger with coolant is carried out for cleaning and/or for increasing the cooling capacity of the heat exchanger. 5 The invention will be explained in more detail in the following with reference to the drawing. There are shown in a schematic representation: Fig. 1 a lamella heat exchanger known from the prior art; 10 Fig. 2 the heat exchanger in accordance with Fig. 1 in section; Fig. 3 a microchannel heat exchanger known from the prior art; 15 Fig. 4 a heat exchanger block in accordance with the invention with a lamella heat exchanger; Fig. 5 the heat exchanger in accordance with Fig. 4 in section; 20 Fig. 6 a heat exchanger block in accordance with the invention with a microchannel heat exchanger; and Fig. 7: a coolant lance in the form of a flat pipe. 25 Figs. 1 to 3, which show two heat exchangers known from the prior art, were already initially discussed in detail and therefore no longer need to be looked at separately in the following. It must be pointed out again as a reminder that the features of 30 embodiments in accordance with the invention are provided with reference 18 numerals which do not bear a dash, whereas the reference numerals in Fig. 1 to Fig. 3 which show known heat exchangers are provided with dashes. 5 A heat exchanger block in accordance with the invention having a lamella heat exchanger is shown schematically in a perspective representation in Fig. 4. For reasons of clarity, only a lamella heat exchanger 4, 41 is shown of the 10 heat exchanger block in accordance with Fig. 4, which is labeled in total in the following by the reference numeral 1. It is understood that in practice the heat exchanger block 1 as a rule has even further components in a manner known per se such as fans, further heat exchangers 4, 41, collection lines as well as inflow and outflow lines for a heating agent 6 15 which flows through the heat exchanger 4, 41 to exchange heat, etc. The heat exchanger block 1 in accordance with the invention of Fig. 4 includes a heat exchanger 4, 41 arranged between an inflow surface 2 and an outflow surface 3 so that the transport fluid 5 can be supplied via the 20 inflow surface 2 to a heat exchanger surface of the heat exchanger 4, 41, can be brought into flow contact with the heat exchanger surface 7 and can be led away from the heat exchanger 4, 41 again via the outflow surface 3 for the exchange of heat between a transport fluid 5 and a heating agent 6 flowing through the heat exchanger 4, 41 in the operating 25 state. In this respect, in accordance with the present invention, the heat exchanger block 1 includes a perforated coolant lance 8 so that a coolant 9 can be introduced between two heat exchanging surfaces 7 of the heat exchanger 4,41 via the coolant lance 8.

19 In the specific embodiment of Fig. 4, the heat exchanger 4 is made as a lamella heat exchanger 41. As already initially described in detail in the discussion of the prior art, coolant lines 411 are provided in a manner known per se in punched holes 412 of the cooling lamellae 413. 5 The lamella heat exchanger 41 is thus formed by a plurality of cooling lamellae 413, whereby the heat exchanger surface 7 is hugely increased. In the operating state, a heating agent 6 flows through the coolant lines 411 so that the heating agent 6 can exchange heat with the environment, 10 usually with the environmental air 5, mainly via the cooling lamellae 413, in that the environmental air 5 is transported as a transport fluid 5 for the transport of the heat through the heat exchanger 41, for example with the help of a fan not shown in Fig. 4, in the direction of the arrow 5'. 15 In the example of Fig 4, coolant lines 411 selected in accordance with a preset scheme have been removed from their punched hole 412 or have not been inserted into the associated punched holes 412 in the first place on the manufacture of the heat exchanger 41. Instead, coolant lances 8 have been provided in these punched holes 412 of the cooling lamellae 20 413 through which coolant 9, frequently water 9 in practice, preferably, but not necessarily demineralized water 9, can be introduced between two heat exchanging surfaces 7 of the lamella heat exchanger 41. The collars 414 with which a presettable spacing can be set between the cooling lamellae 413 and through which the cooling lines are conducted have 25 likewise been removed at the punched holes 412 through which the coolant lances are guided or have not been inserted in the first place on the manufacture of the heat exchanger 41. Since the collars 414 at the coolant lances 8 have been dispensed with, an ideal distribution of the coolant over the heat exchanging surfaces 7 is guaranteed. 30 20 It is understood that the coolant lances 8 can also be provided in a separate bore in addition to the existing coolant lines 411 in the cooling lamella 413. This has the great advantage that the heat exchanging capacity of the heat exchanger 41 is practically not reduced by the 5 presence of the coolant lances 8 since the number of the coolant lines 411 remains unchanged by the presence of the coolant lances 8 in the packing of the coolant lamellae 413. To illustrate the construction of the heat exchanger 41 in accordance with 10 Fig. 4, a section of a plan view of the heat exchanger 41 from the direction R, as defined in Fig. 4, is shown schematically in Fig. 5. It is important to note that the collars 414 are missing at the punched holes 412 through which the coolant lances 8 are conducted through the cooling lamellae 413, whereas at the punched holes 412 through which the coolant lines 15 411 are conducted the collars 414 are also still present in the heat exchanger block 1 in accordance with the invention, whereby it is ensured that the cooling lamellae 413 maintain a defined spacing d. It can be recognized very clearly with reference to Fig. 5 how the coolant 9 20 can be ideally introduced and distributed between two heat exchanging surfaces 7 of the heat exchanger 41 by the use of the coolant lances 8. A further very important embodiment of a heat exchanger block 1 in accordance with the invention is shown partially and schematically in a 25 perspective representation in Fig. 6. The heat exchanger 4 in accordance with Fig. 6 is formed by a plurality of microchannels 421 also known, as mentioned as microchannel heat exchangers 42. Instead of small pipes, as initially mentioned, extruded aluminum sections 30 are used in the microchannel heat exchanger 42 which have a large 21 number of small channels with a diameter of e.g. approximately 1 mm. The heat exchanger block 1 of Fig. 6 is in principle such a microchannel heat exchanger block 1 known per se, wherein the heat exchanger block 1 in accordance with the invention shown in Fig. 6 differs from the known 5 heat exchanger blocks l' as shown, for example, in Fig. 3, in that here a perforated coolant lance 8 designed in the form of a flat pipe 8 is present, whereas this was previously unknown in the prior art. The microchannel heat exchanger block 1 of Fig. 6 is formed in a manner 10 known per se by two or more heat exchangers 42 known per se in the form of extruded sections 42. Oppositely disposed extruded sections 42 of Fig. 6 are preferably in thermal contact with a wavy cooling lamella 413 so that the heating agent 6, which is conveyed through the microchannels 421, can better exchange its heat with the transport fluid 5', preferably air 15 5, which is, for example, conveyed through the heat exchanger block 1 in the direction of the arrows 5 by a fan not shown. In practice in this respect, a heat exchanger block 1 can already manage, depending on the required heat capacity, with only one pair of extruded 20 sections 42 as a central heat exchanging element. To be able to achieve higher heat transfer capacities, a plurality of extruded sections 42' can naturally also be provided simultaneously in one single heat exchanger block I which are connected to one another, e.g. soldered to one another, in suitable combinations, for example via inlet feeds ad outlet feeds, which 25 is not shown in Fig. 6 for reasons of clarity. In the heat exchanger block 1 of Fig. 6, a flat pipe 8 is provided which is perforated in the form of holes 81 and/or slits 81 and which, as shown, is inserted between two extruded sections so that coolant can be applied 30 from the flat pipe 8 over the heat exchanging surfaces 7 which are 22 arranged in wavy form between two oppositely disposed extruded sections 42. Such a perforated flat pipe 8 is shown again separately in Fig. 7 for 5 illustration. The flat pipe is provided at the side which faces the heat exchanging surfaces of the heat exchanger block 1 in the installed state with a plurality of perforations, that is holes or slits, so that the coolant 9 can be applied ideally over the heat exchanging surfaces in the operating state. 10 It is understood that in specific cases, instead of perforated flat pipes 8, perforated round pipes 8, perforated hoses 8 or also filter hoses 8, in particular sweating hoses 8, or any other coolant lance 8, can also advantageously be used in a heat exchanger block 1 in accordance with 15 the invention, even if the heat exchanger block 1 is made up of microchannel heat exchangers 42. It is understood that the embodiments described within the framework of this application are only to be understood as examples. This means that 20 the invention is not solely restricted to the specific embodiments described. All suitable combinations of the presented special embodiments are in particular likewise covered by the invention.

Claims (15)

1. A heat exchanger block including a heat exchanger (4, 41, 42) which is arranged between an inflow surface (2) and an outflow surface (3) 5 so that a transport fluid (5) can be supplied via the inflow surface (2) to a heat exchanging surface (7) of the heat exchanger (4, 41, 42), can be brought into flowing contact with the heat exchanging surface (7) and can be led away from the heat exchanger (4, 41, 42) again via the outflow surface (3) for the exchange of heat between 10 the transport fluid (5) and a heating agent (6) flowing through the heat exchanger (4, 41, 42) in the operating state, characterized in that the heat exchanger block includes a perforated coolant lance (8) so that a coolant (9) can be introduced between two heat exchanging surfaces (7) of the heat exchanger (4, 41, 42) via the coolant lance 15 (8).

2. A heat exchanger block in accordance with claim 1, wherein the heat exchanger (4) is made as a lamella heat exchanger (41), wherein a coolant line (411) is provided in a punched hole (412) of a 20 cooling lamella (413).

3. A heat exchanger block in accordance with claim 2, wherein the coolant lance (8) is provided in a separate bore in the cooling lamella (413). 25

4. A heat exchanger block in accordance with claim 2 or claim 3, wherein a coolant line (411) is removed and the coolant lance (8) is provided in the punched hole (412) of the coolant lamellae (413). 24

5. A heat exchanger block in accordance with claim 1, wherein the heat exchanger (4) is formed by a plurality of microchannels (421) as a microchannel heat exchanger (42). 5

6. A heat exchanger block in accordance with claim 5, wherein a pipe (8), in particular a flat pipe (8), perforated in the form of holes (81) and/or slits (81) is provided as the coolant lance (8).

7. A heat exchanger block in accordance with any one of the preceding 10 claims, wherein a filter hose is provided as the coolant lance (8).

8. 'A heat exchanger block in accordance with any one of the preceding claims, wherein the heat exchanger block is formed as a combination block of the lamella heat exchanger (41) and the 15 microchannel heat exchanger (42).

9. A heat exchanger block in accordance with any one of the preceding claims, wherein a cooling device for cooling the heat exchanger (4, 41, 42), in particular a fan for generating a gas flow, is provided to 20 increase a heat transfer rate between the heating agent (6) and the transport fluid (5).

10. A heat exchanger block in accordance with any one of the preceding claims, wherein a control unit, in particular a control unit having a 25 data processing device for controlling a cooling machine and/or a cooling device and/or the supply of the coolant (9) via the coolant lance (8) and/or an operating parameter or state parameter of the heating agent (6) and/or another operating parameter of the heat exchanger block is provided for controlling and/or regulating the 30 heat exchanger block. 25

11. A heat exchanger in accordance with any one of the preceding claims, wherein the heat exchanger (4, 41, 42) and/or the total heat exchanger block is/are made from a metal and/or from a metal 5 alloy, in particular from a single metal or from a single metal alloy, in particular from stainless steel, is specifically made from aluminum or from an aluminum alloy and/or made from a metal combination, e.g. from aluminum and copper, wherein a sacrificial metal is preferably provided as corrosion protection and/or wherein 10 the heat exchanger block is provided at least partly with a protection layer, in particular with a corrosion protection layer.

12. A heat exchanger block in accordance with any one of the preceding claims, wherein the heat exchanger block is a cooler, a condenser or 15 an evaporator for a mobile or stationary heating plant, cooling plant or air conditioning system, in particular a cooler apparatus for a machine, a data processing device or for a building.

13. A method for wetting a heat exchanger block (1) including a heat 20 exchanger (4, 41, 42) which is arranged between an inflow surface (2) and an outflow surface (3) so that a transport fluid (5) is supplied via the inflow surface (2) to a heat exchanging surface (7) of the heat exchanger (4, 41, 42), is brought into flowing contact with the heat exchanging surface (2) and is led away from the heat exchanger (4, 25 41, 42) again via the outflow surface (3) for the exchange of heat between a transport fluid (5) and a heating agent (6) flowing through the heat exchanger (4, 41, 42), characterized in that a perforated coolant lance (8) is provided at the heat exchanger block and a coolant (9) is introduced between two heat exchanging surfaces (7) 30 of the heat exchanger (4, 41, 42) via the coolant lance (8). 26

14. A method in accordance with claim 13, wherein the heat exchanger (4) is a lamella heat exchanger (41) and/or a microchannel heat exchanger (42) and a regulation of a wetting quantity of the coolant 5 (9) is carried out, preferably by setting a working pressure of the coolant (9).

15. A method in accordance with claim 14, wherein the wetting of the heat exchanger (4, 41, 42) is carried out using coolant (9) for 10 cleaning and/or for increasing the cooling capacity of the heat exchanger (4, 41, 42).