EP0563474A1 - Stapelverdampfer - Google Patents

Stapelverdampfer Download PDF

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Publication number
EP0563474A1
EP0563474A1 EP92307402A EP92307402A EP0563474A1 EP 0563474 A1 EP0563474 A1 EP 0563474A1 EP 92307402 A EP92307402 A EP 92307402A EP 92307402 A EP92307402 A EP 92307402A EP 0563474 A1 EP0563474 A1 EP 0563474A1
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EP
European Patent Office
Prior art keywords
tubular elements
evaporator
coolant
stack type
header portion
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP92307402A
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English (en)
French (fr)
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EP0563474B1 (de
Inventor
Okuda Nobuyuki
Kojima Masahiro
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Showa Aluminum Can Corp
Original Assignee
Showa Aluminum Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP4131153A external-priority patent/JP2677485B2/ja
Application filed by Showa Aluminum Corp filed Critical Showa Aluminum Corp
Publication of EP0563474A1 publication Critical patent/EP0563474A1/de
Application granted granted Critical
Publication of EP0563474B1 publication Critical patent/EP0563474B1/de
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Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F17/00—Removing ice or water from heat-exchange apparatus
    • F28F17/005—Means for draining condensates from heat exchangers, e.g. from evaporators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B39/00—Evaporators; Condensers
    • F25B39/02—Evaporators
    • F25B39/022—Evaporators with plate-like or laminated elements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B47/00—Arrangements for preventing or removing deposits or corrosion, not provided for in another subclass
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D1/00—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators
    • F28D1/02—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid
    • F28D1/03—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with plate-like or laminated conduits
    • F28D1/0308—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with plate-like or laminated conduits the conduits being formed by paired plates touching each other
    • F28D1/0325—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with plate-like or laminated conduits the conduits being formed by paired plates touching each other the plates having lateral openings therein for circulation of the heat-exchange medium from one conduit to another
    • F28D1/0333—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with plate-like or laminated conduits the conduits being formed by paired plates touching each other the plates having lateral openings therein for circulation of the heat-exchange medium from one conduit to another the plates having integrated connecting members
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
    • F28D2021/0019—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for
    • F28D2021/008—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for for vehicles
    • F28D2021/0085—Evaporators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F2245/00—Coatings; Surface treatments
    • F28F2245/02—Coatings; Surface treatments hydrophilic

Definitions

  • the present invention relates to an evaporator for use in a car air conditioner, and more particularly relates to a stack type evaporator which is improved not to cause the condensed waterdrop to fly and to be free from the problem of bad smell.
  • the stack type evaporators of this kind usually comprise plate-like tubular elements each composed of a pair of dish-like core plates 60 as shown in Fig. 11. These core plates face one another and are adjoined at their peripheries 60a. Such tubular elements are stacked side by side in the direction of thickness, with fin members each being interposed between the adjacent tubular elements. An inlet and outlet header portions 60b and 60c are formed at an end of each tubular element to form a coolant flow path. A coolant flowing through the inlet header portion 60b into the flow path in the tubular element will travel towards another end thereof, and makes one U-turn before coming back into the outlet header portion 60c. These tubular elements thus build the "one-sided header" stack type evaporator which are employed widely in this field.
  • the "one-sided header" structure is somewhat disadvantageous in that due to the U-turn which the coolant makes, it cannot flow evenly through the tubular elements but flows in an offset manner. This will inevitably reduce the effective heat transfer area of each tubular element.
  • This evaporator comprises the tubular element each having the inlet header portion at its one end and the outlet header portion at its other end.
  • the prior art stack type evaporators employ such recessed ribs 70 which are distributed over each core plate 60 as shown in Fig. 11. Those ribs are intended to render turbulent the coolant stream within the tubular elements so as to improve the heat transfer.
  • many recessed ribs 70 protrude inwardly of two dish-like core plates 60 which are secured one to another at their peripheries to construct each tubular element ( see for example Japanese Utility Model Publication Sho. 56-6847 and ibid. 63-33100 ).
  • a prior art invention disclosed on the Japanese Patent Publication Sho. 60-45776 was made to resolve such a problem.
  • the tubular elements and fin members are covered with a hydrophilic surface coating.
  • the hydrophilic coating reduces the contact angle between the surface of tubular element or fin member and the waterdrop. Consequently, the condensed water forms on the surfaces a thin layer which will decrease the air flow resistance along the surface, and the thin layer does not stay thereon but is drained smoothly to resolve the problem of flying waterdrop.
  • each tubular element is formed with a plurality of recessed ribs. Those ribs extend straight and in parallel with one another from an upper header portion to a lower header portion of said element. Because such ribs do function as drainage canals, the condensed water flows downwards to be discharged from the lower header portion. Thus, the condensed water sticking to the surface of tubular elements is removed smoothly through the recessed ribs, providing an improved property of "water repelling".
  • corrugated fins are each interposed between two adjacent tubular elements and are so highly water-bearing that the condensed water cannot move readily from the fins onto the recessed ribs on tubular elements.
  • the condensed water on the fins at their outer regions or outer ends adjoined to the tubular elements will readily move onto the latter and into their recessed ribs, the condensed water present deep in concaves of the corrugated fins will tend to stay there due to a strong surface tension. In other words, some fractions of the condensed water on the fins are not necessarily removed through the recessed ribs of the tubular elements.
  • hydrophilic coating composed of water glass or synthetic resin also for the tubular elements which are formed with the straight recessed ribs serving as the improved drainage canals.
  • An object of the present invention which has been made to resolve the problems inherent in the prior art evaporators, is therefore to provide a novel stack type evaporator which neither causes the waterdrop flying, nor emits bad smell, so that it can be used advantageously in air-conditioning apparatuses.
  • the present inventors have carried out their research and studies to improve the stack type evaporator, which was already proposed by them to comprise tubular elements having vertical recessed ribs as summarized hereinbefore, in such a manner that the recessed ribs can function as more effective straight canals for draining the condensed water.
  • the inventors have found a fact that a hydrophilic resin coating on the surface of tubular elements must be formed of a particular resin composition such that the contact angle thereof falls within a specific range.
  • a stack type evaporator which comprises tubular elements formed with a plurality of recessed ribs serving as straight drain canals and extending between an upper and lower header portions of each tubular element, in such a state that the condensed water is guided along the ribs towards the lower header portion so as to be discharged out of the tubular element.
  • the evaporator in this invention further comprises a specific hydrophilic resin coating which is free from bad smell and covers both the surfaces of each fin and each tubular element, whereby the condensed water is readily transferred from the fin onto the tubular element and smoothly moves from a flat surface thereof into the outer recess of each rib.
  • a stack type evaporator which comprises: a plurality of plate-like tubular elements each composed of a pair of facing dish-like core plates which are adjoined one to another at their peripheries so as to define a coolant path therebetween; a plurality of radiating fins each interposed between the two adjacent tubular elements which are stacked side by side in the direction of their thickness; an upper and lower header portions respectively formed at an upper and lower ends of each tubular element, with the header portions being connected to the other corresponding header portions so as to unite the tubular elements to form the evaporator; a plurality of recessed ribs protruding inwardly from each core plate and extending vertically in parallel with one another from the upper header portion towards the lower header portion, wherein an inner end of each rib of one core plate faces and is bonded to a flat portion between the ribs of the other core plate, and wherein the coolant path formed through each tubular element is divided by the ribs into a
  • a stack type evaporator which comprises: a plurality of plate-like tubular elements each composed of a pair of facing dish-like core plates which are adjoined one to another at their peripheries so as to define a coolant path therebetween; a plurality of radiating fins each interposed between the two adjacent tubular elements which are stacked side by side in the direction of their thickness; an upper and lower header portions respectively formed at an upper and lower ends of each tubular element, with the header portions being connected to the other corresponding header portions so as to unite the tubular elements to form the evaporator; a plurality of recessed ribs protruding inwardly from each core plate and extending vertically in parallel with one another from the upper header portion towards the lower header portion, wherein an inner end of each rib of one core plate faces and is bonded to a flat portion between the ribs of the other core plate, and wherein the coolant path formed through each tubular element is divided by the ribs into
  • the resin coating may preferably contain further ingredients including a film hardener, a surface active agent ( hereinafter referred to as "surfactant” ), and a microbicide such as an antibacterial agent, a bactericide or a mold-suppressing agent which inhibit any bad smelling mold or mildew to grow on the surfaces of evaporator.
  • a desirable recipe of such a resin coating includes: 30 - 65 parts by weight of polyvinyl alcohol resin as the main component; 20 - 65 parts by weight of polyamide and/or polyvinyl pyrrolidone resins as the hydrophilic agent; 1 - 15 parts by weight of the film hardener; 0.1 - 2.0 parts by weight of the surfactant; and 3 - 30 parts by weight of the microbicide.
  • the film hardener may either be a phenolic resin or a polyurea resin, though the former is less stinking and therefore more preferable.
  • a preferable surfactant is a nonionic surface active agent.
  • microbicides include: bis-(2-pyridylthio)-zinc 1,1'-diphoxide; methyl benzimidazole carbamate; and 2-(4-thiazolyl)-1H-benzimidazole.
  • the contact angle ⁇ of the hydrophilic resin coating is an important factor in the present invention. An angle less than 5° causes the condensed water to be excessively adherent to the surfaces of tubular elements and fins, whereas a greater angle above 20° undesirably renders the condensed water to be unadherent but less mobile with regard to the straight drain canals. In these cases, the straight canals will fail to fully function as the drainage canals. Therefore, the contact angle ⁇ should be 5° - 20°, and more desirably 7° to 13°.
  • the inwardly protruding recessed ribs provide the straight drain canals which must, for better drainage, be designed such that their canal width "W”, canal depth “D” and canal pitch “P” are included respectively in ranges given below. Also, an area ratio (%) of the canals to an entire surface area of each core plate, from which the area of expanded portions located on both sides of said core plate is subtracted, should fall within a range given below.
  • the canal width "W" is from 1 - 3 mm, or more preferably 1.3 - 2.4 mm.
  • the canal depth "D" is from 1 - 2.5 mm, or more preferably 1.5 - 2.1 mm.
  • the canal pitch "P" is from 7 - 14 mm, or more preferably 8 - 11 mm.
  • the area ratio (%) of the canals is 5 - 40 %, or more preferably 15 - 25 %.
  • each tubular element and fin members are advantageous in that any amount of condensed water on the tubular elements and fin members smoothly flows along the ribs towards outside. Then, the condensed water will quickly leave the evaporator, without causing any problem of waterdrop flying.
  • the hydrophilic resin coating which covers the outer surfaces of the tubular elements and fin members and comprises polyvinyl alcohol resin as main component as well as polyamide and/or polyvinyl pyrrolidone resins as the hydrophilic agent, does not emit any bad smell which has been unavoidable in the water glass coating.
  • the resin coating of the specific composition in the present invention advantageously cooperates with the inwardly protruding recessed ribs, i.e., the straight drain canals, to enhance a water-repelling property to facilitate the drainage of condensed water.
  • the problem of waterdrop flying is more completely avoided in the evaporator provided by the invention.
  • Embodiments of the invention which are applied to a stack type evaporator made of aluminum or its alloys for use in a car air-conditioner will now be described in detail.
  • the evaporator comprises a plurality of plate-like tubular elements 1 which are disposed upright and stacked side by side.
  • the evaporator also comprises corrugated fin members 2, most of which are interposed between two adjacent tubular elements 1, with the other ones being disposed outside the outer-most tubular elements 1.
  • the corrugated fin members 2 are brazed to the tubular elements so as to be integral therewith.
  • Each tubular element 1 is, as shown in Figs. 1 to 7, provided with an upper and lower header portions 1a and 1b which are bulky and disposed respectively at opposite ends in a longitudinal direction of the element.
  • Unit coolant paths 1c extending longitudinally of the element 1 are formed intermediate between and in fluid communication with the header portions 1a and 1b, the unit coolant paths 1c constituting as a whole a flat coolant path.
  • the adjacent tubular elements 1 are tightly combined one with another at their header portions 1a and 1b, which portions are connected in fluid communication with each other through coolant-flowing openings 1d.
  • Each tubular element 1 is made by arranging two dish-like core plates 6 into an inside-to-inside relation and by subsequently brazing them at their peripheries 6a to be integral with each other.
  • the core plates 6 are manufactured by the pressing of a brazing sheet which comprises a core sheet having its front and back surfaces covered with a brazing agent layer.
  • the brazing agent layer is applied by the cladding technique so that the core plates 6 are easily brazed together and also brazed to the adjacent corrugated fins 2.
  • each core plate 6 except for outer core plates 6 constituting the outermost tubular elements 1, respectively protrude outwardly to provide expanded portions 9.
  • Each outer core plate 6 has, as shown in Fig. 6, both ends formed flat and comprising three coolant-flowing openings 1d arranged in a transverse direction.
  • each corrugated fin 2 is interposed between the adjacent tubular elements 1, which are brazed together in this state due to the brazing agent layer mentioned above.
  • a coolant inlet pipe 3 is connected to the lower header portion 1b of right-hand outermost tubular element 1, in fluid communication therewith.
  • a coolant outlet pipe 4 is connected likewise to the lower header portion 1b of left-hand outermost tubular element 1, also in fluid communication therewith.
  • the coolant entering the evaporator through the inlet pipe 3 is caused to advance in a zigzag pattern, as shown in Fig. 8, changing its flow direction at every boundary between adjacent groups of the tubular elements, before the coolant leaves the evaporator through the outlet pipe 4.
  • heat exchange is effected between the coolant flowing in this way and air streams passing through air paths, each air path being formed in a gap between the adjacent tubular elements and including the intervening fin member 2.
  • the reference numeral 5 in Figs. 6 and 7 denotes a side plate disposed outside the outermost corrugated fin member.
  • the "groups" in this embodiment comprise the same number of the tubular elements 1, whereby an excellent property of heat exchange is enhanced to the evaporator.
  • the total number of the tubular elements may occasionally make it impossible to divide them into the groups of even number of constituent tubular elements.
  • the inlet and outlet pipes 3 and 4 are connected to the lower portions of the outermost tubular elements, despite the uneven numbers of said elements in the groups, it is desirable to constitute one of the groups connected to the inlet with a larger number of said elements than the other groups.
  • recessed ribs 7 are formed on an inner surface of each core plate 6, between its two expanded portions 9, and at regular intervals transversely of the core plate. The positions of recessed ribs are however offset transversely towards one of longitudinal sides of said core plate.
  • the inwardly protruding recessed ribs 7 which extend straight from one expanded portion 9 to the other one will function as straight drain canals, as will be detailed later.
  • a couple of two core plates 6 having the ribs 7 are brought into close contact and are brazed at their peripheries 6a integral with one another. As seen in Figs. 1 and 3, the ribs 7 of one core plate 6 shown by rigid lines and those of the other core plate shown by phantom lines alternate with each other.
  • straight drain canals 7a are defined by the inwardly protruding recessed ribs 7.
  • the parameters or dimensions of said drainage canals such as their width "W”, depth "D” and pitch "P" as shown in Fig. 3, as well as area ratio (%) of said canals to the core plate's 6 surface area from which the expanded portions 9 are excluded.
  • the canal width preferably falls within a range from 1 to 3 mm. If the canals are narrower than 1 mm, then the condensed water cannot flow smooth into them, thus the straight canals failing to effectively function as drainage grooves. With the canals being set broader than 3 mm, the coolant unit flow paths 1e are too narrow to maintain the pressure loss of coolant below a certain limit.
  • the most desirable range of said width is thus from 1.3 - 2.4 mm.
  • the canal depth preferably falls within a range from 1 to 2.5 mm. If the canals are made shallower than 1 mm, then the unit flow paths 1e become too small to keep the coolant pressure loss below the certain limit, and the condensed water cannot flow at a sufficient rate through them, thus the straight canals failing to function as drainage grooves. With the canals being set deeper than 3 mm, the hydraulic diameter of the unit flow paths becomes too large to ensure an excellent property of heat exchange. The most desirable range of said depth is thus from 1.5 - 2.1 mm.
  • a preferable range of the canal pitch is from 7 to 14 mm. If the pitch is smaller than 7 mm, then the unit flow paths 1e become too small to keep the coolant pressure loss below the certain limit. With the canal pitch greater than 14 mm, the condensed water cannot flow smooth into canals. The most desirable pitch is thus from 8 - 11 mm.
  • the area ratio (%) of the straight drain canals to the core plate's 6 surface area except for the expanded portions 9 should fall within a range of 5 - 40 %. If the ratio is not included in this range, then the straight canals are any longer good grooves for drainage, because an excessive amount of condensed water is retained by the core plate.
  • Fig. 12 shows a graph representing such an condition, in which the area ratio (%) of straight canal area to the amount of retained water for a unit surface in contact with air is given taking as a reference value (i.e., 100 % ) for a case wherein no canals are formed on the core plate.
  • the drain canals having the area ratio above 40 % the flow path 1c becomes too narrow to maintain the pressure loss of coolant below a permissible limit.
  • the most desirable ratio is from 15 - 25 %.
  • the amount of retained water in the graph means an amount of water retained by tested evaporators which are immersed in a water vessel and weighed 30 minutes after withdrawal therefrom.
  • the cross-section of the inwardly protruding recessed ribs 7 need not necessarily be of such a rectangular shape as shown in Fig. 3, but may be of a trapezoid shape having a width gradually reduced towards its inner bottom, or any other shape.
  • the illustrated shape in this embodiment is desirable for ensuring the good drainage function of the straight canals.
  • the side plates 5, which are disposed outside the outermost corrugated fins 2, comprise a plurality of groove-like recesses 5a formed on their inner surfaces.
  • the recesses 5a extend vertically in parallel with one another so as to provide another plurality of additional vertical drainage canals between the outermost fins and the side plates secured to the outer surface thereof. Therefore, the water condensed in the clearances between the outermost tubular elements and the side plates flows downwards through the additional canals, whereby drainage is improved also for those air paths defined through said clearances.
  • a coating "S" composed of a hydrophilic resin covers the surfaces of the tubular elements 1, the corrugated fins 2 and the side plates 5, as illustrated in Fig. 5.
  • the hydrophilic resin must comprise a polyvinyl alcohol which is contained as a main component and is blended with a polyamide and/or polyvinyl pyrrolidone resins, for the following reasons. Firstly, this resin composition is free from an unpleasant smell which the prior art water glass resin coating itself has been emitting to impair the environment within an automobile cabin or room. In other words, the air-conditioned room of automobile can be maintained pleasant if the resin coating provided in the present invention is used as the coating of the evaporator. Secondly, the resin coating of such a composition can also prevent an underlying oxide layer from emitting its odor. Thus, the problem of the smelling evaporator is resolved more completely.
  • such a resin coating as provided together with the straight drain canals in the present invention is advantageous in that the canals can function more effectively as the grooves for drainage.
  • the condensed water is excessively adherent to the water glass coating to such a degree that the straight drain canals cannot fully perform their draining function.
  • the prior art resin coating causes the condensed water less adherent but less mobile so that the straight drain canals are hindered from performing their function, also failing to prevent the problem of waterdrop flying.
  • the novel resin coating in the present invention is of a nature intermediate the water glass coating and the prior art resin coating, whereby the straight drain canals can perform their draining function to a satisfactory degree.
  • the polyvinyl alcohol resin as the main component of said hydrophilic resin may either be blended with polyamide resin, or with a polyvinyl pyrrolidone resin. However, it is more desirable that both of the polyamide and polyvinyl pyrrolidone resins are added to the polyvinyl alcohol resin in order that the resin coating has a better initial hydrophilic property as well as a better durability thereof.
  • a film hardener such as a phenolic resin or polyurea resin
  • a surfactant such as a nonionic surface active agent
  • a microbicide for example: bis-(2-pyridylthio)-zinc 1,1'-diphoxide; methyl benzimidazole carbamate; or 2-(4-thiazolyl)-1H-benzimidazole, may be blended with the mixture.
  • the phenolic resin as the film hardener is less stinking, and therefore better than polyurea resin.
  • the preferable contents of the polyvinyl alcohol resin, hydrophilic agent, film hardener, surfactant and microbicide are respectively 30 - 65 parts, 20 - 65 parts, 1 - 15 parts, 0.1 - 2.0 parts, and 3 - 30 parts, all by weight.
  • the reasons therefor are as follows.
  • the content of polyvinyl alcohol resin which is contained as the main component to be a base material of the hydrophilic resin coating, is below 30 parts by weight, then the coating will not be hydrophilic to a sufficient degree and also will be too thin to have the microbicide dispersed therein.
  • a higher content thereof above 65 parts by weight however raises the manufacture cost of the hydrophilic coating, and at the same time impairs its hydrophilic property.
  • a more desirable content of the polyvinyl alcohol resin is therefore 40 - 60 parts by weight.
  • hydrophilic agent which is added to improve the hydrophilic property of the resin coating, is below 20 parts by weight, then the coating cannot be hydrophilic to a sufficient degree.
  • a content exceeding 65 parts by weight of said hydrophilic agent causes a superfluous solubility of the resin coating. In a case wherein the microbicide is contained, it will be lost when the coating is dissolved, thus failing to prevent growth of the mold or mildew.
  • a more desirable content of said hydrophilic agent is 35 - 45 parts by weight.
  • the film hardener which adjusts a hardness of the coating to a desirable level, is contained at a poor content below 1 part by weight, that will produce an unhardened coating, whereas a rich content above 15 parts by weight will cause its reaction with the hydrophilic atom groups in the hydrophilic resin molecules, consequently failing to enhance the hydrophilic property.
  • a more desirable content of the film hardener is thus 5 - 10 parts by weight.
  • the surfactant is added to stabilize the resin solution, in which the evaporator or its part are immersed to form the hydrophilic coating, so that it will not become bubbly when used. Therefore, its content below 0.1 parts by weight is too poor to prevent the solution from bubbling. Such a poor content is also insufficient to disperse the microbicide homogeneously in the resin coating, but an excessive content above 2.0 parts by weight will also produce many bubbles in resin solution, resulting in an unevenness of the hardened resin coating. A more desirable content of the surfactant is therefore 0.5 - 1.5 parts by weight.
  • the microbicide includes in this specification an anti-bacterial agent, bactericide, mold-suppressing agent or the like.
  • the hydrophilic resin containing such a microbicide protects the evaporator from getting mildewed in spite of the existence of adherent condensed water, lest the mold or mildew should emit a stinking odor.
  • the surfactant mentioned above is effective also to disperse such a microbicide within the resin solution.
  • microbicide Three to thirty parts by weight of the microbicide may be added to said resin. Although a poor content below 3 parts by weight is not effective to perfectly prevent the breeding of mildew, an excessive content above 30 parts by weight will produce a white powder of the microbicide on the surface of evaporator. Such a powder is likely to fly and enter the air-conditioned automobile room, thus impairing its comfortableness. Therefore, a more desirable content is 5 - 15 parts by weight.
  • the thickness of the abovedescribed hydrophilic resin coating "S" is preferably from 0.2 - 1.5 ⁇ m.
  • a resin coating thinner than 0.2 ⁇ m cannot perform the functions needed to the hydrophilic coating, but with a thickness more than 1.5 um an inherent odor of the resin itself becomes conspicuous.
  • a more desirable range of the thickness is from 0.5 - 1.3 ⁇ m.
  • the inventors have found the fact that in relation to the straight drain canals 7a the hydrophilic resin coating needs to have a contact angle 5° to 20° in order that those canals can fully function as the grooves for drainage.
  • the contact angle must be as small as possible.
  • the present inventors have revealed a fact that the contact angle below 5° renders the condensed water excessively adherent to the evaporator surfaces and thus impairs the inherent high drainage capacity possessed by the straight canals 7a.
  • a greater contact angle above 20° on the other hand has also proved inappropriate, since a poor adhesion of she condensed water was observed to similarly impair the drainage of straight canals 7a.
  • a desirable range of the contact angle is from 5° to 20°, and more preferably from 7° to 13°.
  • the hydrophilic resin coating "S" may be formed for example in the following manner.
  • the stack type evaporator After assembled to have the described structure, the stack type evaporator will be subjected to a pretreatment, an acid washing process and a rinsing process, in this order and under usual conditions. Then, a chromate primer is formed on the thus prepared surface, by an appropriate process using a mixed solution of phosphate and chromate compounds or using a solution of an appropriate chromate compound. This primer will enhance the surface by giving it a higher corrosion resistance and enable the resin to closely adhere to the surface.
  • the stack type evaporator will be washed to be successively submerged in a hydrophilic resin solution of such a recipe as described above. An unhardened resin coating is formed on the surface in this way, and finally, the evaporator is subjected to a baking process to harden and finish the coating.
  • the evaporator which comprises the tubular elements each having the inwardly protruding and vertically extending recessed ribs and which has its surfaces covered with the specific hydrophilic resin coating according to the present invention, is superior to all the other reference samples of evaporator in respect of not only their odor but also of their draining property.
  • both the problem of waterdrop flying and the bad smell are eliminated at the same time by the invention.
  • the data on water retention per unit surface area in contact with air has established a fact that the specific resin coating in the invention does match well the straight drain canals to give the best drainage.
  • the resin composition in the invention ( having a contact angle of 20° or less, and 7° - 13° in the embodiment ) is not necessarily more hydrophilic than the water glass coating ( being most hydrophilic heretofore, and having a contact angle of 5° or less ), the former is less retentive of water than the latter. This indicates an "organic" and effective combination of the specific resin coating with the straight drain canals.
  • Figs. 13 to 15 give the result of comparative tests which were executed on: their cooling capacity for varied coolant pressure at outlet; their coolant flow resistance for varied flow rate of coolant; and their air flow resistance for varied air flow rate.
  • the cooling capacity of the reference No. 2 decreases sharply with increasing coolant pressure at outlet, whereas the capacity of the sample No. 1 ( invention ) decreases gradually.
  • the evaporator provided by the invention is improved in its cooling capacity for the varied outlet coolant pressures.
  • the sample No. 1 proved less resistive to coolant flow than the reference No. 2 by ca. 0.1 Kg/cm2 or more, for varied coolant flow rates.
  • the sample No. 1 proved less resistive to air flow then No.2 by ca. 2 mmAq, for varied air flow rates.
  • the evaporator in the present invention comprises the tubular elements each having the inlet header portion at its one end and the outlet header portion at its other end.
  • Each tubular element is composed of the pair of core plates, and each of them comprises the recessed ribs protruding inwardly thereof and vertically extending in parallel with one another between the header portions.
  • the unit flow paths are formed for coolant which flows through the tubular element in such a manner that any offset flow or turbulent flow takes place therein.
  • the ribs protruding from one core plate alternate with the other ribs of the other core plate in each couple of the core plates.
  • the inner end surfaces of those ribs from one core plate do face and are tightly adjoined to the flat portions of the other one.
  • the outer recesses of the recessed ribs inwardly protruding and vertically extending parallel between the upper and lower header portions of each tubular element do function as the straight drainage grooves or canals for discharging the condensed water.
  • the water condensed on the surfaces of the tubular elements and fin members smoothly flows downwards along the ribs through the straight canals and is quickly removed from the evaporator.
  • the resin composition in the invention comprises polyvinyl alcohol as the main component as well as the hydrophilic agent (i.e., polyamide and/or polyvinyl pyrrolidone resins ) blended therewith.
  • This composition does not emit such a stinking odor as is the case for the water glass coating, also contributing to the better environment in the automobile cabin.
  • the "antimold" effect becomes much higher while ensuring the good drainage through the straight canals.
  • the hydrophilic resin coating has the contact angle ⁇ of 5° to 20° between it and the waterdrop, drainage effect of the straight drain canals will be doubled so that the stack type evaporator becomes free from the waterdrop flying and from the bad smell so as to be advantageously employed in the air conditioner.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
  • Photovoltaic Devices (AREA)
  • Control Of Motors That Do Not Use Commutators (AREA)
  • Laminated Bodies (AREA)
  • Led Devices (AREA)
  • Paints Or Removers (AREA)
  • Secondary Cells (AREA)
  • Air-Conditioning For Vehicles (AREA)
EP92307402A 1992-04-03 1992-08-13 Stapelverdampfer Expired - Lifetime EP0563474B1 (de)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP8246792 1992-04-03
JP82467/92 1992-04-03
JP4131153A JP2677485B2 (ja) 1992-04-03 1992-05-22 積層型蒸発器
JP131153/92 1992-05-22

Publications (2)

Publication Number Publication Date
EP0563474A1 true EP0563474A1 (de) 1993-10-06
EP0563474B1 EP0563474B1 (de) 1996-01-31

Family

ID=26423477

Family Applications (1)

Application Number Title Priority Date Filing Date
EP92307402A Expired - Lifetime EP0563474B1 (de) 1992-04-03 1992-08-13 Stapelverdampfer

Country Status (7)

Country Link
EP (1) EP0563474B1 (de)
CN (1) CN1078340C (de)
AT (1) ATE133778T1 (de)
AU (1) AU656429B2 (de)
CA (1) CA2075686C (de)
DE (1) DE69208076T2 (de)
ES (1) ES2083693T3 (de)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0619468A3 (de) * 1993-04-06 1995-04-26 Gen Motors Corp Wärmetauscher-Verdampfer.
WO1997001656A1 (de) * 1995-06-27 1997-01-16 Behr Gmbh & Co. Plasmapolymer-oberflächenschicht, beschichtungsverfahren hierfür und damit beschichteter wärmeübertrager
WO1999013284A1 (en) * 1997-09-11 1999-03-18 Long Manufacturing Ltd. Stepped dimpled mounting brackets for heat exchangers
WO1999013282A1 (en) * 1997-09-11 1999-03-18 Long Manufacturing Ltd. Baffle insert for heat exchangers
WO2003047893A1 (de) * 2001-12-04 2003-06-12 Volkswagen Aktiengesellschaft Verdampfereinheit für eine klimaanlage
US6796374B2 (en) 2002-04-10 2004-09-28 Dana Canada Corporation Heat exchanger inlet tube with flow distributing turbulizer
WO2005100901A1 (fr) * 2004-03-16 2005-10-27 Valeo Systemes Thermiques Tubes d'echangeur de chaleur favorisant le drainage des condensats
EP2012081A1 (de) * 2007-07-05 2009-01-07 Valeo Systemes Thermiques Hydrophile Beschichtung für einen Wärmetauscher
US8191872B2 (en) 2003-10-17 2012-06-05 Oxycom Beheer B.V. Heat exchange laminate

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10003273B4 (de) * 2000-01-26 2005-07-21 Ballard Power Systems Ag Vorrichtung zum Verdampfen und/oder Überhitzen eines Mediums
CA2323026A1 (en) 2000-10-10 2002-04-10 Long Manufacturing Ltd. Heat exchangers with flow distributing orifice partitions
SE532344C2 (sv) * 2007-12-21 2009-12-22 Alfa Laval Corp Ab Packningsstöd i värmeväxlare och värmeväxlare innefattande packningsstöd
CN101995172B (zh) * 2010-11-02 2013-01-02 金龙精密铜管集团股份有限公司 微通道换热器以及应用该微通道换热器的设备
JP5816841B2 (ja) * 2011-02-28 2015-11-18 パナソニックＩｐマネジメント株式会社 冷却装置のドレン水蒸発装置
CN103090596A (zh) * 2011-11-03 2013-05-08 上海瀚艺冷冻机械有限公司 翅片式换热器
JP6088818B2 (ja) * 2012-12-27 2017-03-01 株式会社ケーヒン・サーマル・テクノロジー 蓄冷機能付きエバポレータ
JP6642542B2 (ja) * 2017-08-30 2020-02-05 トヨタ自動車株式会社 放熱シート
DE102018214890A1 (de) * 2018-08-31 2020-03-05 Bayerische Motoren Werke Aktiengesellschaft Klimatisierungseinrichtung für einen Innenraum eines Kraftfahrzeugs sowie Verfahren zum Betreiben einer Klimatisierungseinrichtung

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0409130A1 (de) * 1989-07-17 1991-01-23 Nippondenso Co., Ltd. Aluminium-Wärmetauscher und Verfahren zu dessen Herstellung
EP0415584A2 (de) * 1989-08-30 1991-03-06 Honda Giken Kogyo Kabushiki Kaisha Stapelverdampfer

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JPH07109355B2 (ja) * 1986-05-20 1995-11-22 日本パ−カライジング株式会社 アルミニウム製熱交換器及びその製造方法

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EP0409130A1 (de) * 1989-07-17 1991-01-23 Nippondenso Co., Ltd. Aluminium-Wärmetauscher und Verfahren zu dessen Herstellung
EP0415584A2 (de) * 1989-08-30 1991-03-06 Honda Giken Kogyo Kabushiki Kaisha Stapelverdampfer

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Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0619468A3 (de) * 1993-04-06 1995-04-26 Gen Motors Corp Wärmetauscher-Verdampfer.
WO1997001656A1 (de) * 1995-06-27 1997-01-16 Behr Gmbh & Co. Plasmapolymer-oberflächenschicht, beschichtungsverfahren hierfür und damit beschichteter wärmeübertrager
WO1999013284A1 (en) * 1997-09-11 1999-03-18 Long Manufacturing Ltd. Stepped dimpled mounting brackets for heat exchangers
WO1999013282A1 (en) * 1997-09-11 1999-03-18 Long Manufacturing Ltd. Baffle insert for heat exchangers
DE19882664B4 (de) * 1997-09-11 2004-08-19 Long Mfg. Ltd., Oakville Klammerelement zum Herstellen eines Wärmetauschers, Anordnung eines Klammerelements sowie Wärmetauscher mit einer derartigen Anordnung
WO2003047893A1 (de) * 2001-12-04 2003-06-12 Volkswagen Aktiengesellschaft Verdampfereinheit für eine klimaanlage
US6796374B2 (en) 2002-04-10 2004-09-28 Dana Canada Corporation Heat exchanger inlet tube with flow distributing turbulizer
US8191872B2 (en) 2003-10-17 2012-06-05 Oxycom Beheer B.V. Heat exchange laminate
WO2005100901A1 (fr) * 2004-03-16 2005-10-27 Valeo Systemes Thermiques Tubes d'echangeur de chaleur favorisant le drainage des condensats
EP2012081A1 (de) * 2007-07-05 2009-01-07 Valeo Systemes Thermiques Hydrophile Beschichtung für einen Wärmetauscher
FR2918447A1 (fr) * 2007-07-05 2009-01-09 Valeo Systemes Thermiques Revetement hydrophile pour un echangeur de chaleur
EP2045559A1 (de) * 2007-07-05 2009-04-08 Valeo Systemes Thermiques Hydrophile Beschichtung für einen Wärmetauscher
EP2045559B1 (de) 2007-07-05 2018-08-22 Valeo Systèmes Thermiques Hydrophile Beschichtung für einen Wärmetauscher

Also Published As

Publication number Publication date
AU656429B2 (en) 1995-02-02
AU2747692A (en) 1993-10-07
ES2083693T3 (es) 1996-04-16
DE69208076T2 (de) 1996-07-04
CA2075686A1 (en) 1993-10-04
CN1080387A (zh) 1994-01-05
EP0563474B1 (de) 1996-01-31
CN1078340C (zh) 2002-01-23
DE69208076D1 (de) 1996-03-14
ATE133778T1 (de) 1996-02-15
CA2075686C (en) 2003-02-11

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