Classifications

• • 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
  • F28D15/00—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies
  • F28D15/02—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes
  • F28D15/0266—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes with separate evaporating and condensing chambers connected by at least one conduit; Loop-type heat pipes; with multiple or common evaporating or condensing chambers
• • 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
  • F28D15/00—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies
  • F28D15/02—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes
  • F28D15/025—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes having non-capillary condensate return means
• • 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
  • F28D15/00—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies
  • F28D15/02—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes
  • F28D15/04—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes with tubes having a capillary structure
• • 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
  • F28D15/00—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies
  • F28D15/02—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes
  • F28D15/04—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes with tubes having a capillary structure
  • F28D15/043—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes with tubes having a capillary structure forming loops, e.g. capillary pumped loops
• • 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
  • F28D15/00—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies
  • F28D15/02—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes
  • F28D2015/0216—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes having particular orientation, e.g. slanted, or being orientation-independent

Definitions

• the invention relates to heat transfer systems and more particularly to two-phase cooling loops. This type of system is used to cool various devices and in particular to cool one or more processors of an electronic card.
• main circuit in a fluid loop the main circuit being devoid of mechanical or capillary or gravity pumping means, with a fluid loop circulation direction
• At least one evaporator assembly arranged as a bypass of the main circuit with:
• At least one intake pipe drawing liquid fluid from the main circuit
• an evaporator including a porous capillary pumping element coupled to a hot source to be cooled, at least one outlet pipe having an ejection nozzle which injects the predominantly vapor phase fluid into the main circuit at least in the loop circulation direction,
• At least one heat exchanger comprising a portion of the main loop circuit and a heat exchanger coupled to a cold source, for evacuating calories.
• the injection of steam from the outlet pipe into the main circuit causes a drive effect by transfer of momentum.
• the jet of steam forms a motor effect for the main loop circuit and a forced circulation of the working fluid in the main loop is obtained.
• the fluid can be according to a first application case in substantially two-phase form in the main loop circuit, namely in vapor form and in liquid form, the cooling exchanger being in this case a conventional condenser assembly.
• the cooling exchanger being in this case a conventional condenser assembly.
• the fluid may be in a second application case in essentially liquid form in the main loop circuit and the heat exchanger is then a sub-cooling exchanger; which has the advantage of minimizing the pressure drop of circulation of fluids low pressures in the main loop circuit; condensation of the vapor exiting the ejector occurs in the portion of the immediately adjacent main circuit downstream of the vapor injection point.
• the sub-cooling exchanger ensures sufficient subcooling so that the liquid phase in the main circuit remains liquid even in the presence of parasitic thermal leaks.
• the advantage of having essentially liquid in the main circuit is that the operation of the system is very little affected by accelerations undergone, for example in a vehicle with changing directions and an eminently variable intensity and that it allows to use low pressure fluids without causing loss of prohibitive charges.
• evaporator assemblies can be arranged, each arranged as a bypass of the main circuit; it is thus possible to cool two or more processors of an electronic card, and / or a plurality of dissipative heat sources; there is also an effect of addition of the drive due to the steam injections of each evaporator assembly.
• the main loop circuit may advantageously extend in a substantially horizontal plane with respect to gravity; advantageously the fluid can circulate in the main loop without using a thermosiphon effect, the motor effect in the main circuit being obtained by injections of vapor from the evaporator (s).
• the evaporator (s) is (are) positioned below the main circuit;
• a local siphon effect for supplying liquid from the main pipe to the porous element, and incidentally the rise of vapor bubbles and / or non-condensable gas towards the main pipe is promoted.
• the evaporator (s) can (can) be positioned above the main circuit so as to ensure a minimum presence of vapor in contact with the porous element of the evaporator during the start-up phase. .
• a secondary wick interposed between the porous element (also called primary wick) and the main pipe; this allows a good evacuation of vapor bubbles and / or non-condensable gas (NCG) by a capillary link, even in the absence of gravity, while ensuring the supply of liquid primary wick.
• NCG non-condensable gas
• the ejection nozzle may be disposed in the main circuit line, namely inside the pipe itself. This optimizes the drive effect and momentum transfer.
• the ejection nozzle may be disposed parietalally on the wall of the main pipe.
• a Y-shaped connection piece easy to implement from the point of view of sealing.
• the system may further include a common reservoir connected to the main loop; It is thus possible to control the operating conditions of the loop by controlling the saturation temperature Tsat, and this also provides a role of expansion vessel, it is thus possible to avoid providing a reservoir function in each evaporator assembly.
• the main pipe may comprise a portion formed by a plurality of sub-channels arranged in parallel, in order to limit the hydraulic head losses through this portion belonging to to the condenser assembly.
• the system may further include one or more thermal bridge (s) thermally connecting the main pipe with one or more additional heat source (s).
• thermal bridge thermally connecting the main pipe with one or more additional heat source (s).
• FIG. 1 is a block diagram of the system according to a first embodiment of the invention, with moreover only one evaporator assembly,
• FIG. 2 is a schematic diagram of the system according to the invention with several evaporator assemblies
• FIG. 3 is a sectional view of an evaporator according to a first arrangement
• FIG. 4 is a more detailed partial sectional view of the evaporator of FIG. 3
• FIGS. 5A and 5B are sectional views of FIG. outlet pipe forming an injector at the point where it joins the main loop circuit
• FIG. 6 is a sectional view of an evaporator according to a second arrangement
• FIG. 7 is a diagram illustrating the use of the thermal transfer system according to the invention in a multiprocessor server board
• FIG. 8 shows an example of configuration of the main pipe at a condenser
• FIG. 9 is similar to FIG. 1 and shows a second embodiment which is in fact a variant in which the fluid is essentially in the liquid phase in the main loop,
• FIG. 10 is similar to FIG. 2 but according to the second embodiment, namely with the fluid essentially in the liquid phase in the main loop,
• FIG. 11 illustrates the mass flow equations
• FIG. 12 gives an example of result charts for different fluids.
• Figure 1 shows a heat transfer system 10 using a two-phase working fluid 7 for taking heat from a hot source 9 and discharging them away from the hot source. More specifically, the heat transfer system 10 comprises a main loop circuit 1. The heat transfer system 10 contains in one volume interior, sealed from the external environment, a given amount of working fluid 7.
• main circuit 1 loop a pipe or pipe 11 which re-loop on itself thus forming a closed circuit for the working fluid 7, so we speak of "main pipe” as opposed to the other pipes used to connect the evaporators arranged in parallel.
• the main circuit is also called “thermal bus” and / or "general thermal collector”.
• the main circuit generally does not contain any obstructing element which may impede the free circulation of the working fluid, which circulation occurs in a preferred circulation direction represented by the marker F.
• the working fluid which circulates in the main circuit generally comprises the two phases, that is to say liquid phase and vapor phase, without excluding the fact that there are where the fluid is essentially liquid 7L and other places where the fluid is essentially vapor 7V.
• the working fluid circulating in the main circuit is essentially in the liquid phase 7L.
• the main circuit itself is devoid of mechanical pumping means or capillary or gravity.
• the main circuit forms a loop which can have a circular, rectangle, square or any other general shape; similarly, the main circuit can be formed in two dimensions (that is to say essentially flat) or can be formed in three dimensions that is to say not flat.
• the section of the pipeline can be substantially constant; however, it is not excluded that the section of the pipe may vary along the main circuit.
• This evaporator assembly 2 comprises:
• an evaporator 4 including a porous element 3 forming capillary pumping and coupled to a hot source to be cooled,
• At least one outlet pipe 22 having at least one ejection nozzle that injects the predominantly vapor phase fluid in the main circuit in the F loop circulation direction.
• the hydraulic interface of the evaporator assembly 2 with the main circuit 1 is limited to a liquid fluid sampling connection and to a liquid share a steam injection outlet.
• the steam injection into the main pipe may be parietal as shown in Figure 5B or disposed completely within the main pipe section as shown in Figure 5A.
• the steam injection occurs at a high speed which causes a transfer of momentum to the surrounding working fluid in the main pipe, as will be illustrated in more detail below.
• the intake pipe 21 is distinct from the outlet pipe 22, so that the evaporator assembly is similar to a loop called 'CPL' (Capillary Pumped Loop) according to a classification known to the man of the 'art.
• 'CPL' Capillary Pumped Loop
• the intake ducts 21 and outlet 22 could be contiguous or contiguous.
• each of the inlet and outlet pipes 21 and 21 could be reduced to a simple passage without necessarily that there is a tubular pipe or equivalent; in Figure 3 it is drawn in dashed lines a case in which the main pipe is adjacent to the evaporator and in this case one and / or the other of the inlet pipe 21 and outlet 22 could be reduced to a simple passage.
• the sampling point 25 of liquid via the inlet pipe 21 is upstream (with respect to the flow direction F) with respect to the outlet point 26 of steam of the outlet pipe in the main pipe 11.
• the system includes a condenser assembly 5 which vents the calories transported by the main line away from the hot source (s).
• the condenser assembly 5 is formed by a portion of the main pipe itself and a heat exchanger coupled to a cold source; this heat exchanger is deliberately not detailed here, it can be of any type known in the art, for example an air exchanger with fins, optionally with a forced convection with a fan, it can also be for example a liquid exchanger, for example a cross-flow exchanger with another liquid, for example water.
• the main circuit removes the calories formed at the processor level, away from the server board, in a conventional water circulation circuit (Fig. 7).
• the amount of working fluid inside the heat transfer system is constant because the system has an overall tightness with respect to the environment.
• the two-phase flow regime in the main pipeline can be either stratified, annular, laminar or turbulent, with pockets of larger size vapor. or less important.
• the flow regime and design of the injection zone will be selected to achieve the most efficient driving effect by minimizing viscous losses for the intended temperature and power ranges.
• the main pipe may be, in certain portions, of a section such that the vapor and liquid phases separate, stratify, naturally either by the action of gravity or by the action of a centrifugal force or any other separation devices that would be implemented depending on the environmental conditions under gravity or weightlessness and depending on the characteristics of the flow.
• the advantage of this separation of the phases is to allow the conveyance of large volume flows of vapor, at high vapor speed, compared to the low liquid volume flow rate as generally required in two-phase transport systems. This separation of the phases makes it possible to appreciably reduce the pressure drop of the main pipe.
• the theoretical ratio of the vapor flow / liquid flow is proportional to the density ratio between the liquid and that of the vapor.
• the injectors would preferably be arranged in the vapor phase, which by direct effect or drive communicates part of the momentum to the liquid phase.
• the two-phase pipeline could be of any shape to allow this phase separation. Since an ovoid shape that would allow the steam to locate preferentially in the widened part of the top of the pipe and the liquid part in the narrowed part of the bottom of the pipe.
• the main pipe could even consist of several parts in parallel. A steam pipe and another liquid.
• the vapor pressure losses would exert a pumping effect on line sections arranged parallel to the main pipe.
• the parallel line or lines at low speed of circulation, being arranged to be occupied preferentially liquid while allowing the entrainment of any vapor bubbles.
• the heat transfer system makes it possible to evacuate the calories from several hot sources 9 by means of several respective evaporator assemblies 2,2 'which are identical or merely similar in principle. It will be noted that these evaporator assemblies are all arranged in shunt of the main pipe, at different successive positions along this main circuit.
• evaporator assemblies are all arranged in shunt of the main pipe, at different successive positions along this main circuit.
• evaporator assemblies 4 on the main circuit; in one example, one can alternately have an evaporator followed by a condenser and so on, and of course it is understood from Figure 2 that the number of condensers can be any vis-à-vis the number of evaporators. Similarly, the order and relative position of the various evaporators and condensers, and the space between them, can be arbitrary.
• the evaporator 4 comprises a hot plate 40 receiving calories from the hot source 9 and in which grooves 31 or steam channels have been made facilitating the evacuation of the vapor 7V which is formed at this point. spot by spray.
• the porous element 3 also called primary wick, is in contact with the hot plate 40 (groove side). It provides a pumping effect as known in the art due to the filling of the interstices of the porous structure 3 with fluid in the liquid phase.
• the porous element 3 can be made of stainless steel, nickel, ceramic or even copper (see below).
• the fluid in the liquid phase comes from the intake pipe 21; a concern known in the art is to prevent a plug of vapor phase and non-condensable gas blocking the intake of liquid, and thus drains the supply of liquid phase of the vaporization zone and defuses the capillary pumping.
• vapor bubbles can be formed in the liquid arrival zone either because of a poor capillary sealing or because of a parasitic heat flow (parasitic heating 'liquid side).
• the parasitic flux can be considered as an auxiliary heat source which requires in the devices known to those skilled in the art a liquid flow undercooled to prevent defusing or temperature rise of saturation. As a result in the known devices, it follows a degradation of the overall conductance of the device.
• the vapor and / or the non-condensable gas are naturally vented to the main circuit via the steam core of the secondary capillary link without the need for subcooling.
• the overall conductance of the device is maintained by the present invention even when the evaporator has parasitic leaks or non-condensable gas.
• the system becomes more robust than the capillary devices (CPL and LHP) known to those skilled in the art.
• gravity can be used if it prevails in the place of application, forming a local siphon in which the gas bubbles rise and the liquid goes down, as shown in Figure 3.
• водород wick 32 which is located on the opposite side of the primary wick with respect to the hot plate 40.
• This secondary wick 32 extends into the body of the evaporator. and may also extend into the intake duct 21 at least in part; in fact, the secondary wick 32 is interposed between the primary wick 3 and the pipe 11 of the main circuit.
• This secondary wick 32 forms a channel for evacuating any gas bubbles that would have formed at this point, that is to say on the wrong side of the primary wick 3; in this way it is avoided that a possible steam plug prevents the continuous supply of liquid fluid from the main pipe to the primary wick 3 of the evaporator 4.
• the secondary wick 32 may be formed by a wire mesh as shown in Figure 4. It is formed, in the corners or at the intersections of the mesh son of the secondary wick, meniscus 39 of liquid that ensure good supply of liquid from the primary wick.
• a parasitic heat flux irrespective of the orientation of the evaporator, can be compensated by the management of the evacuation of the vapor bubbles formed on the inlet side of the porous element and without the need for a flow rate of subcooled liquid.
• the hot plate 40 is located above the hot source 9 to be cooled, the porous element 3 is above the hot plate 40, and the liquid arrival zone 30 containing the optional secondary wick is above the porous element 3.
• the evaporator comprises the hot plate 40 receiving calories arranged on the top, with the grooves 31 placed below in contact with the porous element 3 and again below the secondary wick 32.
• the liquid inlet to the porous element is marked by the arrows 38a, 38b, while the evacuation of any bubbles of vapor and / or non-condensable gas reaches the vapor pocket 12 according to the arrows marked 37b, 37a .
• the parasitic heat flux is tolerated by the system and has no impact on its performance.
• the orientation of the evaporator relative to the gravity can be arbitrary, because of the presence of the secondary wick 32 which provides the liquid feed by capillary pumping and incidentally the steam outlet (cf. above).
• the absence of impact of the thermal conductivity characteristics on the parasitic flux of the porous wick 3 makes it possible to use copper (which is disadvised in the prior art because it is too good as a thermal conductor) as a porous element, which greatly improves performance of the spray area.
• the relative positions of the evaporator assembly 2 and the main pipe 11 may be such that, as shown in FIG. 6, at the time of starting, the grooves of the evaporator are not filled with liquid . So, starting is facilitated by the presence of steam in the grooves.
• the secondary wick contributes to the good liquid supply of the liquid arrival zone and the return of steam bubbles to the main pipe.
• the invention presented here can be used in a microgravity situation, that is to say in space, but also of course in gravity (terrestrial application).
• the invention can of course be used on board transport equipment (road, rail, air, etc.) that undergo accelerations in one or more directions, the secondary wick 32 for managing the supply of liquid fluid and the return of any vapor bubbles.
• the outlet pipe may be connected by a Y-shaped connection shape marked 63; as shown in FIG. 5A, the outlet pipe can be connected with a perpendicular inlet 61 and a bend 62.
• the direction of injection of the vapor G has a main component in the circumferential direction F, even if it also comprises another component, radial, as in the case of Figure 5B.
• the injection of steam is by means of an ejection nozzle 60, which may have a cylindrical shape or a conical shape.
• the injector 60 at the outlet of the evaporator could advantageously consist of a self-adjusting section orifice allowing both to develop a maximum amount of movement at low flow rates, low thermal loads, the evaporator while limiting its pressure drop below the capillary pumping pressure of the evaporator for large flow rates.
• This self-adjustment can be usefully obtained by the spring effect of a closing blade of the injector, the thermal expansion of a bimetallic strip, or by any other device producing the same effect.
• the injection nozzles may be formed by the ends of the vapor collecting grooves 31 of the evaporator, which open obliquely directly into the main pipe; thus one could have as many injection nozzles as 31 collector grooves.
• this optional tank serves as an expansion vessel for the excess working fluid depending on the operating temperature; this tank is also used to actively control if necessary the Tsat saturation temperature prevailing at the vapor-liquid interface in this tank, and which consequently affects the temperature and equilibrium pressure throughout the system.
• auxiliary hot-springs 98 of lesser power instead of adding a capillary evaporator to them, it is also possible to form a thermal bridge 8, by a part with a good coefficient of thermal conduction, a conventional thermal bridge or by a conventional heat pipe .
• the calories are transferred to the working fluid 7 mainly by convective boiling at the contact between the thermal bridge 8 and the main pipe 11; this convective boiling takes place with a good heat exchange coefficient.
• FIG. 7 illustrates the use of a heat transfer system as explained above in the case of its application to a multiprocessor server card 90, which comprises several processors 9 to be cooled by capillary evaporator and optionally also secondary components as memories 98 to cool by thermal bridge 8.
• each processor 9 is surmounted by an evaporator assembly 2, 2A, 2B, 2C, the main circuit 11 extends along the card 90 and passes in the vicinity of each of the evaporators, either on the side, either on the top. Moreover, thermal bridges thermally connect the memory strips 98 to the main circuit 11. Moreover, a condenser 5 is disposed on one end of the card 90 and allows a heat exchange between the working fluid 7 of the main circuit and a control circuit.
• common general water 95 for example several server cards.
• a modular system that is to say a main circuit that can be standardized on which can be grafted in parallel a variable number of evaporators according to the configuration of the server card to be processed.
• an evaporator assembly can be added or removed without changing the design and design of the rest of the system.
• the transverse dimension of the main pipe may range from 2 mm to 25 mm and its cross section may range from 3 mm 2 to 10 cm 2 ; the transverse dimension of the injection nozzle may be of the same size, of smaller size, or of a significantly smaller size.
• the ratio between the section of the nozzle and the section of the main pipe can range from 1 to 1/30.
• the speed of the two-phase flow in the general pipe can range from 1m / s to 100m / s.
• the fluid used may be methanol, ethanol, acetone, R245fa, HFE-7200, R134A, or their equivalents.
• FIG. 8 illustrates a portion of the main circuit 11 which belongs to a condenser assembly 5; in this portion, the main pipe is subdivided into several sub-channels 50, which increases the heat exchange by limiting the pressure losses hydraulic through this area.
• the distribution of the two-phase flow coming from the main pipe is carried out by a distributor 51 according to the state of the art so as to ensure the most homogeneous distribution possible of the liquid and vapor phases in each of the branches 50 (vapor head ).
• FIGS. 9 and 10 illustrate a second embodiment of the present invention, in which the fluid flowing in the main loop is generally undercooled relative to the condensing temperature Tsat, and consequently the fluid is essentially in the liquid phase except for the exit areas of the ejection nozzles 22,26.
• the heat exchanger of the system which discharges the calories to the outside here 5 ' is a' Sub Cooler 'type of exchanger device (ie say a sub-cooling exchanger) which cools the liquid 7L-SC below the condensing temperature Tsat.
• the change of state from the vapor phase to the liquid phase occurs in a portion of the main circuit line just downstream of the ejection nozzle which forms the outlet of the evaporator 4.
• This condensation occurs in contact with the undercooled liquid that arrives from the upstream flow due to the circulation F, and also potentially in contact with the wall of the pipe which itself is at a temperature close to TcondOUT corresponding to that of the liquid under cooled 7L-SC.
• the steam is propelled in the form of a jet at the exit of the ejection nozzle, in some cases for example in the form of steam bubbles which are propelled in turbulent regime; and the size and number of bubbles decrease as one moves away from the ejection nozzle due to the condensation process.
• FIG 9 there is illustrated a configuration with a single evaporator assembly 2 and a single heat exchanger undercooler 5 '.
• FIG. 10 a configuration with four evaporator sets 2.2 'is illustrated. and two exchangers under cooler 5 ', the other elements being similar to what has already been described for FIG. 2.
• a condensation zone 15 is noted downstream of each steam outlet coming from an evaporator assembly.
• the mass flow rates for the configuration with an evaporator assembly are studied and a heat exchanger under cooler, in steady state.
• the mass flow is defined in the main circuit:
• the mass flow in parallel of the evaporator is defined:
• coefficient ⁇ characterizes the mass amplification effect provided by the high speed ejection in the main circuit.
• the mass flow rate in the main circuit is ⁇ times greater than the mass flow rate in the evaporator.
• the concept of acceleration also refers to the acceleration of the gravity that is to say that the relative position of the heat exchanger relative to the evaporator. This position has a limited impact on the performance of the system when the main circuit is mainly occupied by the liquid. It should be noted that, as regards the first embodiment, it is also possible to define a coefficient ⁇ which varies between 5 and 50, preferably between 10 and 25, and generally less than that of the second embodiment.

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• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Cooling Or The Like Of Electrical Apparatus (AREA)
• Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)

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• 2015
  • 2015-01-27 FR FR1550591A patent/FR3032027B1/fr not_active Expired - Fee Related
  • 2015-09-11 WO PCT/EP2015/070883 patent/WO2016119921A1/fr active Application Filing
  • 2015-09-11 US US15/546,618 patent/US10352623B2/en active Active
  • 2015-09-11 CN CN201580073254.9A patent/CN107208980B/zh active Active
  • 2015-09-11 ES ES15766100T patent/ES2699092T3/es active Active
  • 2015-09-11 EP EP15766100.0A patent/EP3250870B1/de active Active
  • 2015-09-11 JP JP2017536554A patent/JP6578361B2/ja active Active

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