Heat exchanging apparatus and method for transferring heat

A jet-flow heat exchanging device for transferring heat from or to one or more heat transfer surfaces comprises one or more orifice groups, each for directing a heat carrier medium onto the heat transfer surface with at least one of the orifice groups including a main orifice for generating a main jet-stream, and at least two control orifices associated with the main orifice and configured to generate control jet-streams for interacting with the main jet-stream, so as to cause the heat carrier medium of the main jet-stream to swirl.

BACKGROUND OF THE INVENTION

The present invention relates to an apparatus and a method for transferring heat between one or more heat transfer surfaces and a heat carrier medium in either a liquid or two-phase state, particularly for cooling of electronic devices.

Heat dissipation in technical devices, particularly in electronic devices such as power electronic devices, microprocessors or lasers, imposes serious issues regarding the design of technical systems, particularly with respect to system integration and performance. To avoid overheating of these devices, cooling measures are commonly applied. Owing to the increasing power density of such devices, cooling methods have steadily developed.

Most technical systems, in which cooling of a high-power density device is required, utilize a cooling medium that is forced to stream over a cold plate of a device or a surface coupled thereto, so that heat dissipated by the high-power density device is transferred to the cooling medium.

In contrast to air as a heat carrier medium, usage of liquids requires creation and organization of passageways within enclosed volume of a heat exchanging apparatus. Hence, such apparatuses become increasingly complex as the amount of thermal energy to be transported increases. Usually increase of heat exchange efficiency is achieved by turbulization of the flow that causes higher hydrodynamic losses within a cooling device. In view of a minimum flow rate required for transporting heat away from or towards to a serviced device, these hydrodynamic losses negatively affect the system, requiring bigger, more powerful pumps, increasing system's noise level and power consumption, and decreasing its reliability and uptime.

As increasing the transfer surface between the cooling liquid and the device to be cooled turned out not to be sufficient in high-power density devices, new techniques have been developed recently to cope with managing high heat densities of devices to be cooled. For instance, synthetic jets have been developed which are based on piezoelectric vibrations applied to the cooling liquid.

Furthermore, impingement jets are used which include jet streams of a cooling medium that are directed to a heat transfer surface. The cooling medium experiences a significant turbulization in the vicinity of the heat transfer surface which might result in an uneven heat transfer from the heat transfer surface, so that localized hot spots with reduced heat transfer characteristics will occur. This effect is even more dominant for higher jet velocities and/or inlet pressures.

For lower velocities, impingement jets have a more laminar flow with no or a low swirling tendency and therefore only a low heat transfer rate to the cooling medium due to the formation of a boundary layer between the jet and the heat transfer surface is obtained.

Artificial turbulization of the flow inside heat exchanger allows to achieve heat transfer rates common for turbulent flow at much lower velocities, and therefore with much less energy and much higher reliability. To achieve such an effect the swirling of a jet is essential. In document US 2011/0042041 A1, this has been achieved by directing jets with opposite flow directions over a heat dissipation surface in an interleaved, i.e. in a comb-shaped manner, so that the jets pass side by side with neighboring jets having transverse flow directions. Between two neighboring jets, vortices are generated which destroy the boundary layers between the jet and the heat dissipation surface and thereby improve the heat dissipation. However, the hydrodynamic losses are high due to alternating streams and a complex structure requiring low tolerance is necessary for generating those interleaved jets.

In view of the above, it is desirable to provide a heat transfer from or to a heat transfer surface by means of a heat carrier medium in a liquid or a two-phase state flowing along the heat transfer surface while providing low hydrodynamic losses and uniform heat flow rate, i.e. by avoiding local hot spots.

SUMMARY OF THE INVENTION

Embodiments of the present invention are indicated by a jet-flow heat exchanging device for transferring heat from or to one or more heat transfer surfaces, as well as systems and methods, embodiments of which are discussed herein.

According to a first aspect, a jet-flow heat exchanging device for transferring heat from or to one or more heat transfer surfaces is provided, comprising:one or more orifice groups, each for directing a heat carrier medium onto the heat transfer surface;wherein at least one of the orifice groups includes:a main orifice for generating a main jet-stream; andtwo or more control orifices associated with the main orifice and configured to generate control jet-streams for interacting with the main jet-stream, so as to cause the heat carrier medium of the main jet-stream to swirl.

One idea of the above jet-flow heat exchanging apparatus is to provide at least one main jet-stream and two respectively associated control jet-streams substantially flowing in parallel, wherein the control jet-streams are arranged in proximity of or around the main jet-stream to allow interacting with the main jet-stream so as to cause the heat carrier medium, such as a cooling medium, a coolant and the like, to swirl. This swirling occurs because the main jet-stream dynamically changes its direction so as to wipe irregularly across an area of the heat transfer surface in a fan-like manner, wherein the area is substantially larger than the area which would be covered by the main jet-stream without the existence of the control jet-streams. Thereby turbulization is achieved, i.e. a heat-transfer process which involves the interaction of a heat transfer surface with a surrounding fluid while a boundary layer is destroyed in order to intensify the convective heat transfer. Furthermore, local static vortices and the like, where hot spots might occur, can be avoided. Instead, the flow direction of the main jet-stream is dynamically curved and forced to swing with sudden movements transversely to the main flow direction.

Furthermore, the flow direction of the one or more control jet-streams may be substantially equal to the flow direction of the main jet.

According to an embodiment, an area of a cross-section of one or more control orifices may have a size of about 1 to 60% of the area of the cross-section of an opening of the main orifice that is directed to the heat transfer surface.

It may be provided that the one or more control orifices are distanced from the main orifice by between 1% and 50% of a largest cross-sectional dimension of the main orifice.

Furthermore, the two or more control orifices may be symmetrically arranged around the associated main orifice, wherein the symmetry is at least with respect to a first cross-axis of the main orifice, wherein the first cross-axis is, in particular, substantially perpendicular to the heat transfer surface.

Alternatively, three or more control orifices may be symmetrically arranged around the main orifice of a respective orifice group, wherein symmetry lines go through the geometrical center of the main orifice the number of which corresponds to the number of control orifices associated to the main orifice.

Moreover, wherein at least two of the control orifices are offset from a selected one of the symmetry lines or a further symmetry line through the main orifice towards the heat transfer surface, wherein the two control orifices are located between the selected or further symmetry line and the heat transfer surface, causing the main jet stream to flow in a curved manner towards the heat transfer surface.

According to an embodiment, each of the main orifices and each of the control orifices of each orifice group have a cross-section selected from a square, rectangular, triangular, circular and elliptical cross-section.

The main orifice within an orifice group may be of any shape in any orientation. Shape, size, and orientation (of the cross-sectional shape with respect to the flow direction) of the main orifice are dictated by the shape, size and location of the local spot onto heat transfer surface that this particular orifice group is servicing.

Each control orifice within an orifice group may be of any shape in any orientation. Shape, size, and orientation of each control orifice are dictated by the shape, size and location of the local spot onto heat transfer surface that this particular orifice group is servicing.

It may be provided that at least one of the main orifices and/or one or more of the control orifices within at least one of the orifice groups are tapered. Depending on a particular goal an orifice can be tapered either in the downstream or in the upstream direction.

According to an embodiment, one or more orifice groups may be supplied by an inlet manifold having a common volume to supply the heat carrier medium to each orifice within each orifice group under substantially the same pressure.

Furthermore, one or more of the orifice groups are incorporated in a orifice plate in a straight alignment extending substantially parallel to the heat transfer surface.

Moreover, one or more of the heat transfer surfaces are included in an enclosure through which the heat carrier medium is passed.

One or more of the heat transfer surfaces may include one or more protrusions and/or one or more dimples arranged relative to one of the orifice groups, so that the main jet-stream of at least one of the orifice groups engages with the one or more protrusions and/or the one or more dimples.

Furthermore, it may be provided that arrangements of one or more aligned pins are located downstream of at least one of the control orifices of at least one of the orifice groups along the control jet-stream path, and/or wherein arrangements of one or more aligned pins are located downstream of the main orifice of at least one of the orifice groups along the main jet-stream path.

Moreover, one or more chambers may be provided which include one or more heat transfer surface, wherein the one or more chambers are limited by at least one orifice plate including the one or more orifice groups.

Particularly, a plurality of chambers may be arranged within an enclosure of a housing of the device either in series or in parallel or in a combination of parallel and serial arrangement.

According to a further aspect, a system is provided comprising:the above device; andan element providing the heat transfer surface or being thermally coupled to the heat transfer surface.

According to a further aspect, a method for transferring heat from or to one or more heat transfer surfaces is provided, comprising the steps of:providing a main jet-stream of a heat carrier medium in liquid or two-phase state that is directed onto the heat transfer surface; andproviding at least two control jet-streams for interacting with the main jet-stream, so as to cause heat carrier medium to swirl.

DETAILED DESCRIPTION

FIG. 1shows a cross-sectional view depicting an exemplary embodiment of a first heat exchanging apparatus100having a housing101. The housing101may be formed by two housing plates102being spaced apart by an enclosure element108encompassing a chamber104to form an enclosure with a closed volume.

One of the housing plates102forming the housing101is provided as a thermal coupling wall having a high thermal conductivity. The thermal coupling wall is used for coupling to a device from or to which heat shall be transferred, such as a heat source device, e.g. an electronic semiconductor device or an integrated circuit device. The thermal coupling wall has an inner surface which serves as a heat transfer surface120.

A heat carrier medium in either liquid, such as water, or ethylene glycol, or propylene glycol, or two-phase state (liquid-gas or liquid-vapor) is forced to flow through the chamber104of the housing101. The heat carrier medium can be a coolant or a cooling liquid.

The heat carrier medium is supplied to the first heat exchanging apparatus100through the supply port110and is discharged from the chamber104through the discharge port109. The supply port110and the discharge port109are fed through one of the housing plates102. In the present example, the supply port110and the discharge port109are fed through the housing plate102which is not carrying the heat transfer surface120. Alternatively, the supply port110and the discharge port109might be fed through enclosure element108

Within the housing101, an inlet manifold103is formed by partitioning the enclosure within the housing101by means of an orifice plate105. So the chamber104and the inlet manifold103form different partitions of the enclosure of the housing101. The inlet manifold103is directly connected to the inlet of the supply port110.

The orifice plate105provides through-holes106,107connecting the inlet manifold103to the chamber104. The through-holes106,107are configured to form orifices, so that the heat carrier medium in the inlet manifold103, which is forced to flow through the through-holes106,107in the orifice plate105, forms a jet-stream of the heat carrier medium in the chamber104. In the present embodiment the through-holes are substantially cylindrically in shape.

The orifice plate105comprises one or more orifice groups115, one type of which is exemplarily shown inFIG. 2.FIG. 2shows a cutout cross-sectional view of the orifice plate105along the cutting plane A-A. The illustrated orifice group115comprises a main orifice106(also referred to as main nozzle) as one type of through-hole and two control orifices107(also referred to as supplementary nozzle) as another type of the through-holes arranged around the main orifice106.

The control orifices107have a substantially smaller cross-section area (perpendicular to the flow axis) which may be about 10% of the cross-section area of the main orifice106. Generally, the cross-section area of the control orifices107may be about 1% to 50% of the cross-section area of the main orifice106, preferable 5% to 30%, more preferred 10% to 20%.

The distance (center to center) between the main orifice106and the control orifices107is between 1% and 80% of a largest cross-sectional dimension of the main orifice, particularly between 1% and 50%, particularly between 1% and 30%, particularly between 5% and 20%.

Furthermore, the control orifices107are arranged symmetrically around a first axis (first symmetry line)121through a (geometrical) center of the main orifice106, wherein the first axis121is perpendicular to the flow direction through the main orifice106and perpendicular to the heat transfer surface120in the chamber104.

Furthermore, a second axis (second symmetry line)122going through the center of the main orifice106and being perpendicular to the first axis121and to the flow direction is provided, wherein the control orifices107are offset from the second axis122towards the heat transfer surface120.

Although only one orifice group115is depicted inFIG. 2, a plurality of orifice groups115can be provided in the orifice plate105which are arranged along the orifice plate105along the direction of the heat transfer surface120. Particularly, the plurality of orifice groups115can be provided in the orifice plate105and be aligned in parallel to the heat transfer surface120.

In operation, a heat carrier medium ant is supplied via the supply port110to pass via the inlet manifold103and through the orifices106,107in the orifice plate105to the chamber104. After being received in the chamber104, the heat carrier medium is discharged through a discharge port109carrying away heat received from the heat transfer surface120.

InFIG. 3, a perspective view of the interior of the housing101of the first heat exchanging apparatus100is shown. It can be seen that a portion of the orifice plate105separates the inlet manifold103and the chamber104. The orifice plate105is illustrated with one exemplary orifice group115having one main orifice106and two laterally displaced control orifices107. In this merely exemplary embodiment, both the cross-sections of the main orifice106and the control orifices107have a rectangular shape.

When heat carrier medium is supplied via the supply port110, the inlet manifold103is pressurized, so that the heat carrier medium is forced to flow through the main orifice106and the control orifices107with substantially the same pressure. The heat carrier medium flowing through the main orifice106forms a main jet-stream indicated by the dashed arrows F and the heat carrier medium flowing through the control orifices107forms control jet-streams indicated by the dashed lines C. The present arrangement of the control orifices107in association with the main orifice106exhibits two important effects:1. The control jet-streams C generated by the control orifices107cause a constant dynamic pressure imbalance with respect to the main jet-stream F. Since the control jet-streams C are in proximity to the main jet-stream F, the pressure imbalances interact with the main jet stream F, so that the main jet-stream F alternatively swings between stream paths111,112and113creating the swirling jet114or vortexes, respectively. Basically, the degree of turbulization of the main jet-stream depends on the thickness of the jet-streams, their velocities and the distances between the main jet stream and the control jet-streams.2. Due to the offset from the second axis122through the main orifice106, the control orifices107generating control jet-streams C with a lower flow rate partly decelerate the main jet-stream F, so that the main jet-stream F is bent or respectively curved towards the direction of the displacement offset of the control orifices107, i.e. in the direction towards the heat transfer surface120.

FIGS. 4ato 4kshow different configurations of orifice groups115including the main orifice106and the control orifices107to be arranged in the orifice plate105. In contrast to the orifice group115shown inFIG. 2, the orifice groups115differ with respect to the cross-sectional shape of the orifices, the displacement of the whole orifice group115with respect to the heat transfer surface120, the orientations of the cross-sectional shapes of the main orifice106and/or the control orifices107, and the offset of the control orifices107with respect to the second axis122.

FIG. 4ashows a configuration where the main orifice106and the control orifices107both have a circular cross-section (in the flow direction), wherein the outer walls of the control orifices107abut the outer wall of the main orifice106with the control orifices107being symmetrically arranged with respect to the first axis121and offset with respect to the second axis122.

InFIG. 4b, the cross-sectional shapes of the main orifice106and the control orifices107are square, with the control orifices107being symmetrically arranged with respect to the first axis121and offset from a second axis122.

InFIG. 4c, the main orifice106and the control orifices107still have square cross-sections, while a first axis121is inclined towards the heat transfer surface120. The control orifices107are symmetrically arranged with respect to the first axis121and arranged on the second axis122(no offset), with both axes121,122going through a center of the main orifice106and being perpendicular to the flow direction.

FIG. 4dshows an orifice group115where the main orifice106and the control orifices107are arranged in the orifice plate105, both having edges which are aligned with the heat transfer surface120or the end of the orifice plate105in offset displacement direction, respectively.

FIG. 4eshows a main orifice106having a rectangular shape in cross-section, with the control orifices107being arranged symmetrically along the first axis121and offset from a second axis122having a circular cross-sectional shape. The rectangular-shaped cross-section of the main orifice106has its longer dimension parallel to the heat transfer surface120and its shorter dimension in a direction perpendicular to the heat transfer surface120.

FIG. 4fshows an arrangement where the rectangular-shaped cross-section of the main orifice106abuts the heat transfer surface120, while two control orifices107are arranged symmetrically with respect to the first axis121and along the second axis122, having no offset therefrom.

InFIG. 4g, the main orifice106has an elliptical shape in cross-section, while the longer dimension of the elliptical shape is parallel to the heat transfer surface120. The control orifices107are arranged symmetrically with respect to the first axis121and offset from the second axis122and have a rectangular cross-sectional shape, also with its longer dimension parallel to a heat transfer surface120.

FIG. 4hshows the main orifice106having an elliptical shape with a longer dimension parallel to the heat transfer surface120and with control orifices107having an edge which abuts either the heat transfer surface120or an end in direction of the offset displacement, respectively.

FIG. 4ishows an orifice group115with a main orifice106having an elliptical shape in cross-section, with its longer dimension parallel to the heat transfer surface120and with control orifices107symmetrically arranged with respect to the first axis121and offset from a second axis122, wherein the control orifices107have an elliptical shape with its longer dimension perpendicular to the heat transfer surface120, i.e. perpendicular to the direction of the longer dimension of the main orifice106.

FIG. 4jshows an orifice group115with a main orifice106having a rectangular shape in cross-section, with its longer dimension perpendicular to the heat transfer surface120and with control orifices107symmetrically arranged with respect to the first axis121and offset from a second axis122perpendicular thereto, wherein the control orifices107have a rectangular shape with its longer dimension in parallel to the heat transfer surface120, i.e. perpendicular to the direction of the longer dimension of the main orifice106.

FIG. 4kshows an orifice group115with a main orifice106having a circular shape in cross-section and three circular control orifices107symmetrically arranged with respect to the three symmetry axes (symmetry lines)131,132133arranged by an angle of 60° with respect to each other. Each two of the control orifices107are symmetrically arranged with respect to one of the symmetry axes. Generally, this concept is adaptable to different cross-section shapes and orientations of the orifices106,107and scalable to more than three control orifices107being symmetrically arranged around the main orifice106with respect to a corresponding number of symmetry axes.

InFIG. 5, a perspective view of the interior of the heat exchanging apparatus100is shown with the orifice plate105having orifice groups115with orifices having different shapes, arrangements and displacements with respect to each other. It can be seen that the swirling of the main jet-stream F can be achieved irrespective of the (cross-sectional) shape the main orifice106or the control orifices107. To compact the orifice group115aligned in the orifice plate105, two neighboring orifice groups115can be configured to overlap, so that for a first orifice group115, the control orifices107have an offset towards the heat transfer surface120with respect to the second axis122, wherein the neighboring orifice group115has control orifices107which are offset with respect to the second axis122away from the heat transfer surface120. This may lead to an overlapping of control orifices107of neighboring orifice groups115in the direction of alignment of the orifice groups115.

According to a further embodiment, the orifice groups115can be as shown inFIG. 6, i.e. having two or more adjacent main orifices106wherein each two of the main orifices106are serviced by one common control orifice107′ located between the two adjacent main orifices106. Common control orifices107′ which are located between two adjacent main orifices106can have a different shape (rectangular inFIG. 6) and an orientation of its longer cross sectional dimension perpendicular to the direction of alignment of the main orifices106. Additionally or alternatively, control orifices107which are not commonly associated to two adjacent main orifices may have different offsets from a cross axis (symmetry line of the main orifices). Such an arrangement may particularly replace configurations of overlapping control orifices107, as indicated in the embodiment ofFIG. 5. According to one embodiment the control orifices are located with the same distance from the two adjacent main orifices106.

InFIG. 7, a second heat exchanging apparatus200is shown having elements substantially similar to those of the first heat exchanging apparatus100. Identical elements or elements having a similar function are indicated by identical two last numbers in the reference signs.

Thus, the second heat exchanging apparatus200has two housing plates202spaced apart by an enclosure element208forming an enclosure with an inlet manifold203and a chamber204. An orifice plate205having orifice groups215a,215bis provided to separate the inlet manifold203from the chamber204. A supply port210is arranged at the enclosure element208which encompasses the chamber204and the inlet manifold203, while the discharge port209is also arranged substantially on an end opposite the enclosure element208.

The control jet-streams C generated by the control orifices207a,207bcause a constant dynamic pressure imbalance with respect to the main jet-stream F. Since the control jet-streams C are close to the main jet-stream F, the pressure imbalances interact with the main jet-stream F, so that the main jet-stream F alternatively swings between the stream paths211a,212a,213a,211b,212band213bcreating the swirling jets214a,214b.

In contrast to the first heat exchange apparatus100both housing plates202serve as heat transfer surfaces220, therefore orifice plate205may contain two sets of orifice groups215, each associated with one of the heat transfer surfaces220.

InFIG. 8, a cutout cross-sectional view along the cutting plane A-A is shown and it can be seen that two main orifices206a,206bof two orifice groups215a,215bare shown, each of which is accompanied by two control orifices207a,207b. However, the control orifices207a,207bare offset from their second axes222a,222bin different directions so as to curve the swirling jets214a,214btowards a respective one of the heat transfer surfaces220.

InFIG. 9, a third heat exchanging apparatus300is illustrated having elements substantially similar to those of the first heat exchanging apparatus100. Identical elements or elements having a similar function are indicated by identical last two numbers in the reference signs.

Thus, the third heat exchanging apparatus300has two housing plates302spaced apart by an enclosure element308forming an enclosure of a housing301with a first and a second inlet manifold303a,303band a chamber304between the first and the second inlet manifold303a,303b. A first orifice plate305ato separate the first inlet manifold303afrom the chamber304and having orifice groups315a,315bis provided. A first and a second supply port310a,310bare arranged at opposite ends of the enclosure element308which encompasses the chamber304and the inlet manifolds303a,303bto supply heat carrier medium into the inlet manifolds303a,303b. A discharge port309is provided through one of the housing plates302opposite to the heat transfer surface320to discharge the heat carrier medium from the chamber304.

Each of the orifice plates305a,305bhas a plurality of orifice groups315a,315baligned substantially parallel to the heat transfer surface320. As above, the orifice groups315a,315beach have a main orifice306a,306band control orifices307a,307bassociated thereto, respectively.

The control jet-streams C generated by the control orifices307a,307bcause a constant dynamic pressure imbalance with respect to the main jet-stream F. Since the control jet-streams C are close to the main jet-stream F, the pressure imbalances interact with the main jet-stream F, so that the main jet-stream F alternatively swings between the stream paths311a,312a,313a,311b,312band313bcreating the swirling jets314a,314b.

FIGS. 10aand 10bshow cross-sectional views of the first and second orifice plates305a,305balong the cutting planes A-A and B-B, respectively. It can be seen that the first orifice plate305a(FIG. 10a) on the left-hand side has its orifice groups315adisplaced from the heat transfer surface320with a smaller distance than the orifice groups315bof the second orifice plate305bon the right-hand side. The resulting swirling jets314a,314bare directed towards each other, but impinge on the heat transfer surface320at different angles due to the different distance of the respective orifice groups315a,315bfrom the heat transfer surface320.

FIG. 11shows a fourth heat exchanging apparatus400which is similar to the third heat exchanging apparatus300ofFIG. 9. InFIG. 11, identical elements or elements having a similar function are indicated by identical last two numbers in the reference signs.

Thus, the fourth heat exchanging apparatus400has two housing plates402spaced apart by an enclosure element408which encompasses a chamber404and forming an enclosure of a housing401. The enclosure of the housing401includes a first and a second inlet manifold403a,403band the chamber404between a first and the second orifice plates405a,405b. A first orifice plate405aincorporates one or more orifice groups415a, each consisting of main orifice406aand two or more control orifices407aper each main orifice406a. The second orifice plate405bincorporates one or more orifice groups415b, each consisting of main orifice406band two or more control orifices407bper each main orifice406b. A first and a second supply port410a,410bare arranged at opposite ends of the housing401and supply the heat carrier medium into the inlet manifolds403aand403b. A discharge port409is provided through the housing plate402, opposite the heat transfer surface420to discharge the heat carrier medium from the chamber404. The corresponding orifice groups415a,415bincluding the main orifices406a,406band the control orifices407a,407bare arranged as shown inFIGS. 10aand10b.

In contrast to the third heat exchanging apparatus300, the heat transfer surface420is provided with one or more pin416as elevated structures.

As shown inFIGS. 11aand 11b, the heat transfer surface420may be provided with a structure of elevated pins416arranged, for at least one orifice group415, two rows of a plurality of pins (here 3) aligned in the direction of flow from the control orifice407. Pins416in at least a first row are located directly in front (downstream) of a control orifice407splitting flow from it into two stream paths. This creates control jet-streams of reduced sizes while utilizing relatively large (in terms of cross-sectional area) control orifices407allowing for more precise control while making manufacturing more economical. It also allows generating deeper swirling zones by including further rows of pins416into swirling creating process

As shown inFIGS. 11cand 11d, the heat transfer surface420may be provided additionally with a structure of elevated pins416arranged in one row of a plurality of pins (here 2) aligned in the direction of flow from the main orifice406. Additionally to the row of pins in front of the control orifices406pins416in at least a further row are located directly in front (downstream) of the main orifice406splitting main jet-stream into two stream paths. This creates main jet-streams of reduced sizes while utilizing relatively large (in terms of cross-sectional area) main orifices406making manufacturing more economical. The pin rows associated to the control orifices and the pin rows associated to the main orifices might be arranged staggered.

FIG. 12shows a fifth heat exchanging apparatus, wherein identical elements or elements having a similar function are indicated by identical last two numbers in the reference signs.

Thus, the fifth heat exchanging apparatus500has two housing plates502spaced apart by an enclosure element508forming an enclosure of a housing501with a first and a second inlet manifold503a,503band a chamber504between the first and the second inlet manifold503a,503b. A first orifice plate505ato separate the first inlet manifold503afrom the chamber504and having orifice groups515aand a second orifice plate505bto separate the second inlet manifold503bfrom the chamber504and having orifice groups415bare provided. A first and a second supply port510a,510bare arranged at opposite ends of the enclosure element508which encompasses the chamber504and the inlet manifolds503a,503bto supply heat carrier medium into the inlet manifolds503a,503b. A discharge port509is provided on another side of the enclosure element508to discharge the heat carrier medium from the chamber504.

The corresponding orifice groups515a,515bare arranged as shown inFIGS. 13aand 13b. In the present embodiment, the orifice groups515aof the first orifice plate505acomprise control orifices507awith an offset displaced towards one (the lower) of the housing plates502and the orifice groups515bof the second orifice plate505bcomprise control orifices507bwith an offset displaced towards another (the upper) of the housing plates502.

In contrast to the fourth embodiment, both housing plates502forming the housing501provide a heat transfer surface520while the discharge port509is also arranged at the side of the enclosure element508which forms the enclosure of the housing501. The orifice plates505a,505bare each provided with one or more orifice groups515a,515b, both of which include orifice groups from which the swirling jet514is directed to one or both of the heat transfer surfaces520, so that with both orifice plates505a,505bswirling jets514a,514bare directed to both heat transfer surfaces520.

FIG. 14shows a sixth heat exchanging apparatus600similar to the third heat exchanging apparatus300shown inFIG. 9. Identical elements or elements having a similar function are indicated by identical last two numbers in the reference signs.

Thus, the sixth heat exchanging apparatus600has two housing plates602spaced apart by an enclosure element608forming an enclosure of a housing601with an inlet manifold603, first cell chambers604a,604b, and second cell chambers619a,619b. First cell chambers604a,604bare created between first orifice plates605a,605beach containing one or more orifice groups615a,615band second orifice plates617a,617bcontaining one or more orifice groups618a,618b, respectively.

Second cell chambers619a,619bare created between the first orifice plates605a,605beach containing one or more first orifice groups615a,615band enclosure element608which encompasses the first order cell chambers604a,604band the second cell chambers619a,619b. A first and a second discharge ports609a,609bare arranged at opposite ends of the enclosure element608. A supply port610is provided through one of the housing plates602opposite the heat transfer surface620to supply the heat carrier medium to the second cell chambers619a,619bwhich act as supply manifolds.

Each of the first and second orifice plates605a,605b,617a,617bhas a plurality of orifice groups615a,615bwhich can be aligned substantially parallel to the heat transfer surface620.

As shown in the top cross-sectional view ofFIG. 14a, the control jet-streams Ca generated by the control orifices in second orifice plates617b, within the (left) first cell chamber604bcause a constant dynamic pressure imbalance with respect to the main jet-stream Fa within first cell chamber604b. Since, within first cell chamber604b, the control jet-streams Ca are close to the main jet-stream Fa, the pressure imbalances interact with the main jet-stream Fa, so that the main jet-stream Fa alternatively swings between the stream paths611b,612band613bcreating the swirling jet614b.

Similarly, the control jet-streams Cb generated by the control orifices in first orifice plate605bwithin second cell chamber619bcause a constant dynamic pressure imbalance with respect to the main jet-stream Fb within second cell chamber619b. Since within second cell chamber604bthe control jet-streams Cb are close to the main jet-stream Fb, the pressure imbalances interact with the main jet-stream Fb creating a second swirling jet.

Although not specifically shown in the drawings, the same configuration is mirrored for the left side ofFIG. 14, concerning elements604a,605a,617a,619a.

In contrast to the third heat exchanging apparatus300ofFIG. 9, the chamber is comprised of a plurality of cascaded cell chambers of at least two types: the first cell chamber604a,604bdefined by first and second orifice plates605a,605band617a,617b; and the second cell chambers619a,619bdefined by at least one first orifice plate605aand enclosure element608.

It is possible to cascade more than two cell chambers in series between the supply port610and one discharge port609in the above described manner.

First orifice plates605aand605bcontain each at least one orifice group615aand615brespectively. Each orifice group615a,615bis comprised of a main orifice606a,606band at least two control orifices607a,607b. Orifice plates617aand617bcontain each at least one orifice group618aand618brespectively. Orifice plates605a,605band617a,617bmight be either identical to each other or different from each other, containing different number of orifice groups, or orifice groups of various shapes, orientations, configurations and profiles. This allows to achieve uniform temperature distribution under uneven distribution of the intensity of heat exchange, eliminating possibility of local overheating within serviced equipment.

FIG. 15shows a seventh heat exchanging apparatus which substantially corresponds to the first heat exchanging apparatus100.

The seventh heat exchanging apparatus700has elements substantially similar to those of the first heat exchanging apparatus100. Identical elements or elements having a similar function are indicated by identical last two numbers in the reference signs.

Thus, the seventh heat exchanging apparatus700has two housing plates702spaced apart by an enclosure element708forming an enclosure with an inlet manifold703and a chamber704. An orifice plate705having one or more orifice groups715is provided to separate the inlet manifold703from the chamber704. A supply port710is arranged at the enclosure element708which encompasses the chamber704and the inlet manifold703, while the discharge port709is also arranged substantially on an end opposite the enclosure element708.

The control jet-streams C generated by the control orifices707cause a constant dynamic pressure imbalance with respect to the main jet-stream F. Since the control jet-streams C are close to the main jet stream F, the pressure imbalances interact with the main jet-stream F, so that the main jet stream F alternatively swings between stream paths711,712,713creating the swirling jet714.

In contrast to the first heat exchanging apparatus100, the orifices may be tapered (cone-shaped) along the flowing direction of the heat carrier medium from the inlet manifold703to the chamber704, so that the inlet of each orifice has a larger cross-section than the outlet thereof. The tapering of orifices can be applied to any of the orifices of the embodiments described herein. Furthermore, only one of the main orifice706and the control orifices707can be tapered while the respective other one has a substantially cylindrical shape (cross-section parallel to flow direction).

FIG. 16shows a cross-sectional view of the cutting plane indicated by A-A inFIG. 15. It can be seen that each of the nozzles, i.e. the main orifice706and the control orifices707which are exemplarily shown with a circular shape, but not limited thereto, is provided with a cross-section narrowing towards the chamber704.

The tapering of each of the corresponding orifices706,707can be directed in both ways either widening towards the chamber704or narrowing towards the chamber704depending on the effect to be achieved. If hydraulic resistance shall be decreased the orifices should widen towards the chamber704if the turbulization should be spread over a larger area of the heat transfer surface the orifices should narrowing towards the chamber704.

FIG. 17shows an eighth heat exchanging apparatus800of the type of the third heat exchanging apparatus300ofFIG. 9. The eighth heat exchanging apparatus800has elements substantially similar to those of the third heat exchanging apparatus300. Identical elements or elements having a similar function are indicated by identical last two numbers in the reference signs.

Thus, the eighth heat exchanging apparatus800has two housing plates802spaced apart by an enclosure element808forming an enclosure of a housing801with a first and a second inlet manifold803a,803band a chamber804between the first and the second inlet manifold803a,803b. A main orifice plate805aseparates inlet manifold803afrom a chamber804and contains one or more main orifices806, while a control orifice plate805bseparates inlet manifold803bfrom a chamber804and contains at least two control orifices807for each main orifice806located in the main orifice plate805. A first and a second supply port810a,810bare connected to the inlet manifolds803a,803bto supply heat carrier medium into the inlet manifolds. A discharge port809is provided through one of the housing plates802opposite the heat transfer surface820to discharge the heat carrier medium from the chamber804.

In contrast to the third embodiment, the main orifices806are located in the main orifice plate805aand the control orifices807are located in control orifice plate805b, wherein the main orifice plate805aand the control orifice plate805boppose each other. One main orifice806and the associated control orifices807form one orifice group815as explained above. While the main orifice plate805ais supplied with the heat carrier medium through a first supply port810athrough a first manifold803a, the control orifice plate805bis supplied with the heat carrier medium through a second supply port810bthrough a second manifold803b. Orifice plates805aand805bare arranged in such a way that each main orifice located in the main orifice plate805ais located straight in between corresponding control orifices located in control orifice plate805b. This arrangement allows to achieve better control and elimination of local overheating spots when area of local overheating is comparable in size with cross-section of the created jet-stream itself.

In other words, the main orifices806and the control orifices807are arranged opposite each other, so that a main jet-stream F and control jet-streams C are generated having opposite flowing directions while still interacting with each other causing the main jet-stream F to swirl as described in more detail in conjunction with the first heat exchanging apparatus100ofFIG. 1.

FIG. 18ashows a cross-section of the first orifice plate805aalong the plane A-A, andFIG. 18bshows a cross-section of the second orifice plate along the plane B-B. While the main orifice806is not tapered, the control orifices807have a tapered profile, wherein the outlet opening is widening towards the chamber804.