US3384160A - Non-isothermal evaporation type heat transfer apparatus - Google Patents

Non-isothermal evaporation type heat transfer apparatus Download PDF

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US3384160A
US3384160A US561131A US56113166A US3384160A US 3384160 A US3384160 A US 3384160A US 561131 A US561131 A US 561131A US 56113166 A US56113166 A US 56113166A US 3384160 A US3384160 A US 3384160A
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liquid
enclosure
heat
cooling
sub
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Charles A Beurtheret
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Compagnie Francaise Thomson Houston SA
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Compagnie Francaise Thomson Houston SA
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F27/00—Control arrangements or safety devices specially adapted for heat-exchange or heat-transfer apparatus
    • 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
    • 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
    • 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
    • F28D7/00—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
    • F28D7/16—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being arranged in parallel spaced relation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00—Tubular elements; Assemblies of tubular elements
    • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
    • F28F1/12—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F13/00—Arrangements for modifying heat-transfer, e.g. increasing, decreasing
    • F28F13/18—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by applying coatings, e.g. radiation-absorbing, radiation-reflecting; by surface treatment, e.g. polishing
    • F28F13/185—Heat-exchange surfaces provided with microstructures or with porous coatings
    • F28F13/187—Heat-exchange surfaces provided with microstructures or with porous coatings especially adapted for evaporator surfaces or condenser surfaces, e.g. with nucleation sites
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F21/00—Constructions of heat-exchange apparatus characterised by the selection of particular materials
    • F28F21/06—Constructions of heat-exchange apparatus characterised by the selection of particular materials of plastics material
    • F28F21/067—Details
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F9/00—Casings; Header boxes; Auxiliary supports for elements; Auxiliary members within casings
    • F28F9/005—Other auxiliary members within casings, e.g. internal filling means or sealing means
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
    • H01J1/02—Main electrodes
    • H01J1/36—Solid anodes; Solid auxiliary anodes for maintaining a discharge
    • H01J1/42—Cooling of anodes; Heating of anodes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
    • F28D2021/0019—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for
    • F28D2021/0028—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for for cooling heat generating elements, e.g. for cooling electronic components or electric devices
    • F28D2021/0029—Heat sinks
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F2265/00—Safety or protection arrangements; Arrangements for preventing malfunction
    • F28F2265/12—Safety or protection arrangements; Arrangements for preventing malfunction for preventing overpressure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2893/00—Discharge tubes and lamps
    • H01J2893/0048—Tubes with a main cathode
    • H01J2893/0051—Anode assemblies; screens for influencing the discharge
    • H01J2893/0054—Cooling means

Definitions

  • the present invention stems partly from a recognition, by the applicant, that the said earlier non-isotherm heat transfer structures could have their operating efiiciency even further increased if the recondensation of the vaporized liquid, instead of taking place outside the boiler, could be made to occur within the body of vaporizable liquid at a relatively small distance from the heat-dissipating surface and its extensions.
  • Vapotron non-isotherm
  • surface boiling can quite easily be induced in an evaporation cooling system simply by maintaining the over-all temperature of the vaporizable liquid at a value sutficiently lower than the saturation temperature of the liquid at the pressure used in operation, i.e. subcooling the liquid.
  • subcooling can be produced in either of two principal ways: (1) circulating the liquid through the boiler at a suificiently high flow velocity, or (2) providing a secondary heat exchanger, such as a cooling coil through which a secondary coolant is circulated, in the boiler, in which case the body of main or primary vaporizable liquid can be maintained stationary in the boiler.
  • Objects of this invention are to provide improved evaporation heat-dissipating structures of the non-isotherm type, whose operating efliciency and heat dissipating capacity are yet further increased; to provide such structures in which the liquid is subcooled to recondense the vapor substantially immediately as it is formed, and which will nevertheless operate smoothly and silently; to provide non-isotherm heat dissipating or cooling apparatus capable of operating at very high dissipating rates, using a body of vaporizable liquid under substantial static pressure, and yet silent and smooth in operation; to provide such structures that can operate satisfactorily in any attitude with respect to the vertical, i.e. upright, oblique, horizontal, or inverted, as well as being operable in the absence of a gravitational field. Other objects will appear.
  • a non-isotherm heat dissipating structure wherein the heat dissipating surface is provided with heat-dissipating extensions or protuberances in accordance with the applicants earlier teachings, is used in conjunction with a body of vaporisable liquid in contact with said surface, which in operation is subcooled to a temperature substantially lower than the saturating temperature of said liquid at the pressure of operation.
  • the vapor bubbles vaporized adjacent said protuberances are caused to recondense in the subcooled liquid substantially as said bubbles are formed.
  • Further means are provided in pressure-transmitting relation with said liquid in the enclosure adapted for elastic contraction and expansion in response to pressure fluctuations created by said vaporization and recondensation effects, whereby substantially to damp out such fluctuations.
  • the elastically expansible damping means may, in one embodiment, comprise at least one recessed member made of rubber-like sheet material partly inflated with gas, which may resemble a partly deflated balloon, arranged in the enclosure.
  • the expansible damping means may comprise a flexible diaphragm mounted to have one side exposed to the liquid in the enclosure and its other side exposed to a body of gas at suitable pressure.
  • the expansible damping means may simply comprise a vapor pocket arranged to be maintained in operation in an upper portion of the enclosure above the liquid therein.
  • FIG. 1 is a simplified view in axial cross section showing heat dissipating structure according to the invention as used for cooling the anode of a high-power electron tube, and including a stationary body of vaporizable liquid together with a secondary heat exchanger in the form of a cooling coil to subcool said liquid;
  • FIG. 2 is a partial view in section showing a modification
  • FIG. 3 similarly shows a further modification
  • FIG. 4 is a view generally similar to FIG. 1 wherein the elastically expansible damping means of the invention is differently shaped (in the form of a toroid) and is differently positioned;
  • FIG. 5 is a generally similar view of an embodiment wherein the body of vaporizable liquid is continuously circulated through the boiler to provide for the desired subcooling effect;
  • FIG. 6 shows a modification of the embodiment of FIG. 5
  • FIG. 7 is a simplified view in axial section of an embodiment in which the elastically expausible damping means is provided as a pocket of vapor collecting in the top of the boiler;
  • FIGS. 8 and 9 relate to the prior art, and illustrate in partial cross section two preferred forms of construction of the heat dissipating protuberances in accordance with the applicants earlier Patent No. 3,235,064 and copending application Ser. No. 512,090 filed Dec. 7, 1965, respectively, and
  • FIG. 10 illustrates 'an embodiment of the invention which constitutes a preferred modification of the embodiment shown in FIG. 7.
  • the reference it designates a heated object that is to be cooled by means of the heat-transfer apparatus of the invention.
  • the object 1 is by way of illustration shown as comprising the anode of a high-power electron tube, and is in the form of a recessed, generally cylindrical body closed at its upper end.
  • the internal components of the tube are not here shown, and may include the usual high-temperature cathode from which electrons are emitted towards the inner surface of the anode 1, as well as any number of conventional control electrodes and the like.
  • the inner surface of the anode 1 is thus, in operation, heated by the electron bombardment at a very high rate, and this heat is dissipated by the apparatus of the invention, now to 'be described.
  • the heat dissipating apparatus comprises a base 2 in the form of a flat disk surrounding the base of the anode structure 1 and sealingly secured around the anode periphery by a brazed or other suitable joint.
  • a bell shaped cover 3 mounted on the base 2 is a bell shaped cover 3 having its bottom periphery brazed or otherwise sealingly secured to the upper periphery of base 2 and defining a sealed boiler chamber thereover and around the anode 1.
  • the bell cover 3 is provided with a filling aperture in its top sealed by a screw plug 10. In use, the boiler cavity is filled through said aperture with a body 9 of suitable liquid, usually distilled water.
  • a cooling coil 6 Positioned within the boiler cavity defined by bell 3 is a cooling coil 6 of conventional type, in the form of a helically Wound tube of suitable heat conductive metal such as copper, here shown as having two internested helical sections coaxially surrounding the periphery of anode 1.
  • the extremities of the tubular coil 6 are led out through the sidewall of bell 3 to provide an inlet 7' and an outlet 8 for circulating a cooling liquid through the coil, from a conventional fluid circulating system not shown.
  • the cooling coil 6 thus constitutes a secondary heat exchanger serving to impart energetic cooling to the body of primary heat exchange fluid 9.
  • the outer surface of the anode 1 is shown formed with an array of outwardly projecting extensions, protuberances or ribs 5.
  • extensions or protuberances when appropriately dimensioned, have the remarkable property of stabilizing the temperature over the heat dissipating surface. Intense temperature gradients become established over the side surfaces of the protuberances 5, so that these surfaces will include temperatures both below and above the so-called critical temperature at which, in the absence of such continuous temperature gradient, the temperature would tend to run away to excessively high values leading to local burnout of the metal.
  • the provision of the protuberances 5 imparts a non-isotherm characteristic to the heat dissipating surface, with a number of high, stable temperature gradients present thereover, and as explained in the aforementioned patents and applications as a consequence of this characteristic it becomes possible to operate the cooling system at very much higher temperatures and greater heat fluxes without danger of burn-out, than was possible in the absence of the protuberances. While these earlier devices according to applicants earlier patents had a cooling efficiency greatly superior to that of comparable devices lacking the temperature-stabilizing protuberances, it appeared desirable to achieve even higher heat dissipating rates and cooling efliciencies through an operative combination of the applicants non-isotherm heat dissipating surfaces with the surface boiling concept described above. Difiiculties were encountered however.
  • the expansible damping means is provided in the form of one or more recessed elements such as 12 made of a suitable flexible material such as natural or synthetic rubber sheet, containing a sealed body of gas therein, e.g. air.
  • the expansible members 12 may be in the form of balloons initially inflated to a pressure substantially less than the desired operating pressure.
  • the inflated expansible damping means 12 shown in FIG. 1 may be generally spherical or may be toroidal, and may be loosely attached to the upper dome-shaped part of the boiler shown in FIG. 1 as by means'of one or more suitable collars, or otherwise.
  • FIG. 2 One convenient means of maintaining the expansible damping means away from the heat exchange surfaces without interfering with its expansion and contraction as required for the operation of the invention, .is shown in FIG. 2.
  • the filling aperture at the top of the boiler bell 3 is made somewhat wider than what is shown in FIG. 1, and the solid screw plug 10 of that figure is replaced with a recessed screw plug 13.
  • a generally spheroidal inflated damping balloon 11 is shown positior ed within the recess of the plug, and is prevented from escaping out of that recess into the main body of liquid 9 by means of a perforate grid or the like as shown at 14 positioned across the base of the recessed plug.
  • the expansible damping means comprises a spherical two-part attachment consisting of a lower hemisphere 15 and an upper hemisphere 15.
  • the lower hemisphere member 15 is provided with an externally screw threaded bottom orifice 18 adapted to be screwed into an internally threaded orifice formed in the boiler bell 3, e.g. in place of the screw plug 10 shown in FIG. 1.
  • the upper hemisphere member 16 is provided with a plugged orifice 19 for introducing pressure gas, e.g. air, into the upper part of the appliance as will presently become apparent.
  • the hemisphere members 15 and 16 are flanged at their mating peripheries, and a flexible diaphragm 17 has its periphery sealingly clamped between the flanges.
  • a gas e.g. air
  • the movements of the diaphragm 17 will then serve to damp the pressure fluctuations within the boiler in a manner similar to that described for the inflated elements 11 and 12 in FIGS. 1 and 2. It will be observed that the damping appliance illustrated in FIG.
  • the outer hemisphere 16 may be open to the atmosphere or may be altogether omitted.
  • the boiler enclosure 3 is in the form of an annular casing secured around the turface of the tubular body 1 that is to be cooled, which in this case extends completely through the boiler enclosure.
  • the hot body while it may be the anode or collector of a high-power electron discharge tube as in FIG. 1 is here assumed to be a cylinder of an internal combustion engine.
  • Heat-dissipating protuberances 5 are provided.
  • Boiler casing 3 has a plugged filling orifice it) for introduction of the body of primary cooling liquid 9.
  • a secondary cooler is provided in the form of a copper cooling coil 6 having inlet and outlets 7 and 8 extending through -a sidewall of casing 3 for connection with a liquid circulating system, the coil 6 being arranged coaxially in casing 3 around the heated surface 4 and radially spaced from it.
  • An expansible damping member is provided in the form of an annular or toroidal element 20 made of flexible material and partly inflated with gas, e.g. air, at an initial pressure somewhat less than the prescribed operating pressure in the liquid 9.
  • the toroidal damper 20 is arranged around the heated body 1 in the space between it and the cooling coil 6.
  • annular deflector baffle 21 is shown positioned in the annular space between the outer surface of body 1 and the toroidal element 20, being supported in position through any suitable means, not shown, preferably from the wall of casing 3.
  • the baffle 21 serves to hold the toroidal damper member 20 in position and prevent it from coming onto contact with the heated surface while allowing it to contract and expand.
  • the annular baffle 21 has outturned end flanges 22 to contribute to retain the damping member 20 in position.
  • the annular deflector or baffle also serves to promote convection movement of the liquid 9 by creating a thermosyphon effect whereby the heated liquid adjacent to the heat-dissipating protuberances 5' rises along the inner surface of the baffle 21 and the cooler liquid adjacent the cooling coil 6 descends along the outer side of the baffle.
  • convection movement promotes the rapid recondensation of the large vapor bubbles in the subcooled liquid.
  • the subcoolin g of the evaporated liquid required to ensure surface boiling may be accomplished by means other than the provision of a cooling coil in which a secondary cooling fluid is circulated.
  • the subcool of the main body of liquid may be effected by cooling a wall portion of the boiler casing 3, at a sufliciently energetic rate, as by circulating a secondary cooling fluid in contact with the outer surface of such wall portion; and/or by providing cooling fins projecting from said outer surface into an airstream or the like.
  • the subcooling of the evaporating liquid may further be accomplished by circulating sa'id primary liquid 9 through the boiler enclosure.
  • FIG. 5 Such a form of embodiment of the invention is illustrated in FIG. 5.
  • the general arrangement is similar to that of FIG. 4, except that the secondary cooling coil 6 and the associated secondary cooling fluid circulating system is here omitted.
  • the boiler enclosure is provided with inlet and outlet means for circulating the main body of evaporating or primary liquid therein.
  • the body 1 to be cooled such as a combustion engine cylinder or electron tube casing, has heat-dissipating protuberances 5 formed on its external surface to provide the non-isotherm, temperature-stabilizing function in accordance with the applicants earlier patents as already described.
  • An annular boiler casing 23 is sealingly secured around the heat dissipating surface portion 4 of the part 1 being cooled, and includes a lower domed manifold section 25 and an upper manifold section 28.
  • An inlet 24 connects with manifold section 25 and an outlet 29 connects with section 28, the inlet and outlet being connectable to a flow system, not shown, including a pump for circulating the primary cooling liquid through the boiler casing 23 at a sufliciently high rate to ensure that the desired subcooling of the liquid to an overall temperature below the normal boiling temperature of the liquid at the operating pressure used, as required for the surface boiling effect described herein, is ensured.
  • a toroidal damping element 20 made of suitable natural or synthetic rubberlike sheet material partially inflated with gas, e.g.
  • annular separator or baflie plate 26 supported through means not shown from the wall of casing 23.
  • the baflie plate 20 has an outturned radial lower flange 27 on which the base of annular damper 20 rests, being if desired loosely attached thereto by any suitable means as schematically indicated.
  • Flange 27 preferably extends to the side wall of casing 23 in order to separate the damping member 20 from the inlet section ,of the liquid circulation path.
  • baflle plate 26 serves the additional function of promoting thermosyphon circulation of the liquid upward along its radially inner surface and downward along outer surface, thereby promoting recondensation of the vapor bubbles that form in contact with the hot wall 4.
  • a grid-like member 30, made of wire or other suitable perforate member, is positioned across the upper end of the annular channel defined between the hot surface 4 and annular deflector baffle 20. The grid 30 acts to break up the large vapor bubbles as they issue from said upper end of said channel and promotes recondensation in contact with the cool liquid at the outer side of separator 20.
  • the arrangement is very similar to that of FIG. 5 and will not be described in detail anew.
  • the perforate grid 30 is omitted, and instead the annular deflector baffle 26 is. formed with perforations 31 along its length.
  • the annular baffle 26 is formed with L-shaped outturned flanges both at its upper and lower end with the lower flange separating damper 20 from the liquid inlet.
  • the deformable damping means of the invention need not take the form of specially provided inflated members as above described, and the damping function may be accomplished by a suitable vapor chamber provided in the boiler, FIG. 7 illustrates one such embodiment of the invention, suitable for use in cases where the cooling structure is ensured of retaining a generally upright condition at all times in operation.
  • the structure shown comprises a tubular part 1 to be cooled, such as the outer anode or collector structure of a high-power electron tube, an internal combustion motor cylinder, or the like having a sealed upper end 34 and temperature-stabilizing protuberances 5-.
  • a boiler chamber is defined around and above the part 1 by a disk-like base and a bell-shaped, domed casing 3 sealingly secured over said base and around part 1.
  • An inlet for the cooling liquid is provided by a connection 24 at the lower part of the sidewall of bell casing 3.
  • An outlet for said liquid is provided in the form of a vertical riser pipe 29 extending upward through an opening in the top of said bell 3, and having a flared open lower end 33 overlying the sealed top 34 of the part 1, at a slight vertical spacing thereabove.
  • An annular deflect-or plate 26 is supported coaxially between the heated surface 4 and the sidewall of easing 3 and spaced from both walls.
  • primary cooling liquid such as water is circulated at a relatively high rate through the inlet 24 into the boiler chamber and out through the upper outlet 29 from and to a conventional circulating system not shown.
  • the liquid vaporizes in the immediate vicinity of said protuberances, and some of the bubbles burst so that vapor accumulates in the upper space 35 under the dome shaped top the boiler casing 3, which preferably is not subjected to substantial cooling.
  • the free surface of the liquid becomes established at a certain :level 35 above the open lower end of the outlet pipe 29, and during the subsequent circulation of the liquid the amount of vapor in the upper space 32 does not increase.
  • the vapor bubbles then rise along the inner surface of annular deflector 26 and recondense in the cooler liquid which tends to fall along the outer surface of the deflector, creating a convection circulation around the latter.
  • the body of accumulated vapor in the upper space 32 is not involved in this circulation.
  • FIG. 10 A modification of the invention in which this difliculty is eliminated is illustrated in FIG. 10.
  • the general arrangement is similar to that of FIG. 7, except that the inlet pipe 24A instead :of opening into the hollow of the boiler 3 terminates at a level within the boiler corresponding to the desired average free level 35 for the body of liquid therein.
  • said inlet pipe 24A is shown as having a sealed end and as being formed with a plurality of small orifices 24B through its sidewall, such that the cool liquid will issue into the boiler space in a plurality of narrow, generally horizontally directed jets.
  • the orifices 24B may have any desired shape, such as round holes or slots.
  • the heat dissipating surface is formed with structure that defines grooves or channels between heat-conductive extensions or protuberances which, in operation, will exhibit over their surfaces a non-isotherm pattern of temperature distribution encompassing the critical temperature, in order to create the stable temperature gradients which permit the attainment of high average temperatures over the surface without danger of burnout.
  • FIG. 8 illustrates in cross section the shape of heat dissipating protuberances constructed in accordance with the applicants Patent No. 3,235,004.
  • the protuberances 5 are in the form of parallel ridges or blocks of generally rectangular cross sectional shape separated by relatively narrow channels or grooves, preferably extending parallel to the generatrices of the generally cylindrical surface 4 of the tubular part 1 to :be cooled.
  • the protuberances are proportioned so as to satify two conditions.
  • the first condition is that the average width d of the intervening channels should be less than one third of their depth b d 1/ 312
  • FIG. 9 similarly illustrates the general shape of heat dissipating protuberances constructed in accordance with applicants co-pending patent application Ser. No. 512,090 filed Dec. 7, 1965.
  • the protuberances 5 are here provided in the form of ridges or bosses having substantial contiguous bases and outwardly tapered over at least a substantial part of their total length k
  • the construction should satisfy the following conditions:
  • s and s are, respectively, the root area of the protuberance and the toal side area thereof c is the heat conductivity factor of the constituent material; q the critical value of the heat transfer flux density relating to the liquid used at the selected operating pressure, as indicated by tables available in the literature; 0 the specified temperature difference tolerated between the root and tip of a protuberance, i.e. the total extent of the temperaure gradient created along the side of a protuberance; the maximum value of the heat flux density per unit area of the heat input surface; k a numerical safety factor selectable in the range from 1 to 2; and p a numerical efficiency factor selectable in the range from 0.8 to 1.6.
  • the above quantities can be expressed in any coherent system of units.
  • the invention in that it combines the safe high operating temperature capability of the applicant's prior non-isotherm heat dissipating surfaces, as exemplified in FIGS. 8 and 9, with the benefits of surface boiling such as high flow velocity of a subcooled liquid under pressure and the high peak fluxes attainable therewith, makes possible greatly improved performance as compared to any earlier type of evaporation cooling system.
  • the provision of the expansible elastic means for damping the sharp pressure fluctuations that would otherwise tend to occur with such a combination enables attainment of heat dissipation fluxes two or more times higher than could be attained in a comparable system lacking the damping means of the invention without the appearance of unacceptable noise, impacts and cavitation.
  • a system of the type shown in FIG. 5 or 6 has been used to dissipate many hundreds of kilowatts power with a heat flux density of the order of l or 2 kilowatts per sq. cm. area, using as the cooling liquid distilled water circulated at a rate of about 0.35 liter per minute and per kilowatt dissipated heat.
  • the resulting temperature elevation of the water was about 40 C., with an input temperature of 50 C., at the inlet 24 and a discharge temperature of 90 C. at the outlet 29.
  • the pumping system used maintained a static pressure of somewhat more than 4 atmospheres within the boiler 3.
  • the saturation temperature of the water is about 140 C., and it is therefore seen that the water in such a system was subcooled to a temperature below the saturation temperature by an amount at no point less than 50 C.
  • the system of the invention may .be operated with any suitable static pressure of the body of vaporizable liquid, a suitable pressure being two atmospheres or more.
  • Heat transfer apparatus comprising:
  • a wall of heat conductive material having one side exposed to a source of heat; means defining an enclosure with the other side of the Wall and containing a body of a vaporizable liquid;
  • pressure shock absorption means in pressure-transmitting relation with said liquid in the enclosure; said pressure shock absorption means comprising prestressed elastic means adapted for elastic contraction and expansion in response to sudden pressure fiuctations created by said vaporization and recondensation effects whereby to contribute to the damping out of such fluctuations.
  • Apparatus according to claim 1, wherein said heat dissipating extensions are so shaped as to have substantially contiguous bases and taper over at least a substantial part of their height, and are so dimensioned as to verify substantially the relations
  • b represents the height of an extension, .9 and s the base area and total side surface area of an extension respectively, 0 the heat conductivity coefficient of the wall material, q the critical value of heat flux density of said liquid at the operating pressure, 0 a specified temperature drop from the base to the apex of an extension, p the maximum specified value of heat flux density per unit area of the heat input surface, It a numerical safety factor selectable over the range from 1 to 2, and p a nu merical efliciency factor selectable over the range from 0.8 to 1.6.
  • said pressure shock absorption means comprises a closed balloonlike member pertially inflated with a gas.
  • said pressure shock absorption means comprises means accumulating a substantial pocket of vapor of said liquid, vaporized by heat supplied by said heat dissipating extension subjected to said source of heat.
  • Heat transfer apparatus comprising:
  • Apparatus according to claim 7, including means for retaining said member in a part of the enclosure spaced from said heat dissipating well while not interfering with the elastic contraction and expansion of the member.
  • said enclosure includes a section detachably connected with a main section of the enclosure, and means are provided for retaining said member in said detachably connected section while not interfering with the elastic contraction and expansion of the member.
  • said flexible sealing means constitutes a diaphragm, and means mounting said diaphragm to seal off a surface portion of said body of liquid from said gas.
  • said enclosure includes a first section detachably connected with a main enclosure section, a second section detachably connected with said first detachable section and containing said body of gas, and said diaphragm is mounted between said first and second detachable sections so as to seal olf the liquid in said main enclosure section from gas in said second detachable section.
  • Apparatus according to claim 6, including means for circulating said liquid through the enclosure, means defining a circulation path through the enclosure from a liquid inlet past said heat dissipating wall surface to a liquid outlet, separating means for defining a liquid inlet compartment and a liquid outlet compartment in the enclosure, and said flexible sealing means is arranged to be freely exposed to the liquid in said outlet compartment while being substantially isolated from said inlet compartment by said separating means.
  • Apparatus according to claim 6, including means for circulating said liquid through the enclosure, means defining a circulation path through the enclosure from a liquid inlet past said heat dissipating surface to a liquid outlet, and including deflector means for channelizing to flow of liquid past said heat dissipating surface in a relatively narrow hot region adjacent thereto from said inlet towards said outlet whereby to define a relatively cooler region in said liquid body on the side of said deflector means remote from said surface, and wherein said flexible sealing means is arranged to be exposed to said relatively cooler region.
  • Apparatus according to claim 14 including gridlike structure positioned across the end of said narrow region adjacent the heat dissipating surface directed towards said liquid outlet.
  • Heat transfer apparatus comprising:
  • Apparatus according to claim 17, including means for circulating said liquid through the enclosure, means defining a circulation path through the enclosure past said heat dissipating wall surface and including a liquid inlet connected with said enclosure, and a liquid outlet comprising a riser pipe having its lower end opening at an elevation in the enclosure substantially below the upper end of said enclosure whereby to permit accumulation of said vapor pocket in operation.
  • Apparatus according to claim '17 including means for circulating said liquid through the enclosure, means defining a circulation path through the enclosure past said heat dissipating wall surface and including a liquid inlet and a liquid outlet, said liquid outlet comprising a riser pipe having its lower end opening at an elevation in the enclosure substantially below the upper end of said enclosure whereby to permit accumulation of said vapor pocket in operation, and said liquid inlet comprising orifice means positioned and arranged for discharging at least one narrow laterally-directed liquid jet into the enclosure at an elevation somewhat above the elevation at which said riser pipe opens, whereby the elevation of said inlet jet will substantially determine the average elevalion of the free surface of the liquid body in the enclosure and the volume capacity of said vapor pocket.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Geometry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Measuring Fluid Pressure (AREA)
  • Hybrid Cells (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
US561131A 1965-07-07 1966-06-28 Non-isothermal evaporation type heat transfer apparatus Expired - Lifetime US3384160A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR23832A FR1476550A (fr) 1965-07-07 1965-07-07 Perfectionnements aux échangeurs de chaleur à ébullition de surface

Publications (1)

Publication Number Publication Date
US3384160A true US3384160A (en) 1968-05-21

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ID=8584018

Family Applications (1)

Application Number Title Priority Date Filing Date
US561131A Expired - Lifetime US3384160A (en) 1965-07-07 1966-06-28 Non-isothermal evaporation type heat transfer apparatus

Country Status (11)

Country Link
US (1) US3384160A (fr)
AT (1) AT262344B (fr)
BE (1) BE683421A (fr)
CH (1) CH522191A (fr)
FR (1) FR1476550A (fr)
GB (1) GB1126265A (fr)
IL (1) IL26024A (fr)
LU (1) LU51470A1 (fr)
NL (1) NL6609517A (fr)
NO (1) NO119640B (fr)
SU (1) SU361591A3 (fr)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2579309A1 (fr) * 1985-03-21 1986-09-26 Valeo Boite a eau d'un echangeur de chaleur pour vehicule automobile, contenant un radiateur d'huile
US5959406A (en) * 1995-08-23 1999-09-28 Hughes Electronics Corporation Traveling wave tube with expanding resilient support elements
US20040200442A1 (en) * 2002-12-12 2004-10-14 Perkins Engines Company Cooling arrangement and method with selected surfaces configured to inhibit changes in boiling state
US20070227701A1 (en) * 2006-03-31 2007-10-04 Bhatti Mohinder S Thermosiphon with flexible boiler plate
US20120012282A1 (en) * 2007-05-15 2012-01-19 Asetek A/S Direct air contact liquid cooling system heat exchanger assembly
US20130319039A1 (en) * 2011-02-09 2013-12-05 Vahterus Oy Device for separating droplets
US20140144605A1 (en) * 2011-08-05 2014-05-29 Behr Gmbh & Co. Kg Motor vehicle air conditioning unit
CN109185192A (zh) * 2018-09-29 2019-01-11 瑞安市宇宙汽车部件有限公司 一种散热器风扇总成
US11598518B2 (en) * 2011-05-13 2023-03-07 Rochester Institute Of Technology Devices with an enhanced boiling surface with features directing bubble and liquid flow and methods thereof

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3304587A1 (de) * 1983-02-10 1984-08-16 Motorenfabrik Hatz Gmbh & Co Kg, 8399 Ruhstorf Fluessigkeitsgekuehlte kraft- bzw. arbeitsmaschine mit schwingungsdaempfung
ITMI20110817A1 (it) * 2011-05-11 2012-11-12 Eni Sp A "sistema di scambio termico"

Citations (6)

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US2777009A (en) * 1953-02-19 1957-01-08 Gen Electric Vaporization cooled transformers
US2882449A (en) * 1957-12-02 1959-04-14 Thomson Houston Comp Francaise Anode cooling device for electronic tubes
US2961476A (en) * 1958-06-24 1960-11-22 Westinghouse Electric Corp Electrical apparatus
US2984773A (en) * 1960-03-09 1961-05-16 Cottrell Res Inc Alternating current rectifying assembly
US3043900A (en) * 1958-07-15 1962-07-10 Reisinger Franz Transformer
US3293349A (en) * 1964-05-13 1966-12-20 Int Rectifier Corp Liquid immersed rectifier assembly

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2777009A (en) * 1953-02-19 1957-01-08 Gen Electric Vaporization cooled transformers
US2882449A (en) * 1957-12-02 1959-04-14 Thomson Houston Comp Francaise Anode cooling device for electronic tubes
US2961476A (en) * 1958-06-24 1960-11-22 Westinghouse Electric Corp Electrical apparatus
US3043900A (en) * 1958-07-15 1962-07-10 Reisinger Franz Transformer
US2984773A (en) * 1960-03-09 1961-05-16 Cottrell Res Inc Alternating current rectifying assembly
US3293349A (en) * 1964-05-13 1966-12-20 Int Rectifier Corp Liquid immersed rectifier assembly

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2579309A1 (fr) * 1985-03-21 1986-09-26 Valeo Boite a eau d'un echangeur de chaleur pour vehicule automobile, contenant un radiateur d'huile
EP0196257A1 (fr) * 1985-03-21 1986-10-01 Valeo Boîte à eau d'un échangeur de chaleur pour véhicule automobile, contenant un radiateur d'huile
US5959406A (en) * 1995-08-23 1999-09-28 Hughes Electronics Corporation Traveling wave tube with expanding resilient support elements
US20040200442A1 (en) * 2002-12-12 2004-10-14 Perkins Engines Company Cooling arrangement and method with selected surfaces configured to inhibit changes in boiling state
US7028763B2 (en) * 2002-12-12 2006-04-18 Caterpillar Inc. Cooling arrangement and method with selected surfaces configured to inhibit changes in boiling state
US20070227701A1 (en) * 2006-03-31 2007-10-04 Bhatti Mohinder S Thermosiphon with flexible boiler plate
US20120012282A1 (en) * 2007-05-15 2012-01-19 Asetek A/S Direct air contact liquid cooling system heat exchanger assembly
US20130319039A1 (en) * 2011-02-09 2013-12-05 Vahterus Oy Device for separating droplets
US9366464B2 (en) * 2011-02-09 2016-06-14 Vahterus Oy Device for separating droplets
US11598518B2 (en) * 2011-05-13 2023-03-07 Rochester Institute Of Technology Devices with an enhanced boiling surface with features directing bubble and liquid flow and methods thereof
US20140144605A1 (en) * 2011-08-05 2014-05-29 Behr Gmbh & Co. Kg Motor vehicle air conditioning unit
US9975395B2 (en) * 2011-08-05 2018-05-22 Mahle International Gmbh Motor vehicle air conditioning unit
CN109185192A (zh) * 2018-09-29 2019-01-11 瑞安市宇宙汽车部件有限公司 一种散热器风扇总成

Also Published As

Publication number Publication date
GB1126265A (en) 1968-09-05
LU51470A1 (fr) 1967-01-04
AT262344B (de) 1968-06-10
CH522191A (fr) 1972-04-30
NO119640B (fr) 1970-06-15
DE1501485A1 (de) 1969-10-23
FR1476550A (fr) 1967-04-14
SU361591A3 (fr) 1972-12-07
NL6609517A (fr) 1967-01-09
DE1501485B2 (de) 1975-10-16
IL26024A (en) 1970-09-17
BE683421A (fr) 1966-12-30

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