Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
  • F24H1/00—Water heaters, e.g. boilers, continuous-flow heaters or water-storage heaters
  • F24H1/48—Water heaters for central heating incorporating heaters for domestic water
• • 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
  • F28D7/0066—Multi-circuit heat-exchangers, e.g. integrating different heat exchange sections in the same unit or heat-exchangers for more than two fluids
• • 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
  • F28D7/0066—Multi-circuit heat-exchangers, e.g. integrating different heat exchange sections in the same unit or heat-exchangers for more than two fluids
  • F28D7/0083—Multi-circuit heat-exchangers, e.g. integrating different heat exchange sections in the same unit or heat-exchangers for more than two fluids with units having particular arrangement relative to a supplementary heat exchange medium, e.g. with interleaved units or with adjacent units arranged in common flow of supplementary heat exchange medium

Definitions

• the present invention relates to a combined heat exchanger for heating tap water and central heating water by means of hot gases, comprising tap water ducts and central heating water ducts.
• Such combined heat exchangers are generally known, this in the form of heat exchangers manufactured from copper pipes. There are herein always two separate pipes, wherein one of the pipes forms a duct for tap water and the other pipe forms the duct for central heating water. It is further pointed out that it is generally known to apply heat exchangers in so-called combination boilers for the combined heating of tap water and central heating water, which heat exchangers are only suitable for heat ⁇ ing central heating water, wherein the tap water is heated by a second heat exchanger. It is noted that tap water is also designated as sanitary water.
• a combined heat exchanger for heating tap water and central heating water by means of hot gases comprising tap water ducts and central heating water ducts, by which the tap water ducts and the central heating water ducts are incorporated in a single heat exchanger body is known.
• the central heating water ducts are arranged in a first plane and the tap water ducts are arranged in a second plane, located further from the ducts for the flue gases.
• the transfer of heat to the tap water ducts is thus not optimal, the more as the tap water ducts comprise a separate pipe embedded in the body of the heat exchanger.
• the aim of the invention is the avoiding of those problems .
• the heat exchanger body is manufactured from aluminium or an alloy containing aluminium and the tap water ducts are provided with an internal layer.
• aluminium enables a further decrease in the flue gas temperatures; possible condensation moisture formed when the dew point is reached does not adversely affect the aluminium.
• Ducts for tap water may not come into contact with aluminium, this being prevented by applying the internal layer, which is manufactured for instance from Teflon.
• figure 1 shows a partly broken away perspective view of a first embodiment of the heat exchanger according to the invention
• figure 2 shows a sectional view of a second embodi- ment of a heat exchanger according to the invention
• figure 3 shows a sectional view of a third embodi ⁇ ment of a heat exchanger according to the invention
• figure 4 is a diagram explaining a fourth embodiment of the present invention.
• FIG. 1 Shown in figure 1 is a heat exchanger which is designated as a whole with 1. Such a heat exchanger is for instance used in a so-called combination boiler for combined heating of central heating water and tap water.
• the heat exchanger 1 comprises a heat exchanger body 2 for instance cast from aluminium and a burner which is designated with 3.
• the burner 3 is of course provided with various auxiliary provisions, such as pre-mix taps and the like, although since they do not form the subject of the present invention they are not shown in the draw ⁇ ing.
• the burner 3 is provided with burner openings 4 and the flames and flue gases exiting therefrom are guided along the heat exchanger body 2 by means of a guide plate 5.
• the flue gases herein move in downward direction.
• On arrival at the underside the relevant flue gases are guided under the heat exchanger body 2, wherein they are released on the other side of the heat exchanger body 2.
• a basic body 6 to which the heat exchanger body 2 is fixed, as is guide plate 5.
• the construction described thus far corresponds with usual heat exchangers.
• the heat exchanger body is provid- ed on its side facing the burner 3 with protrusions 7 whereby the heat-transferring surface is enlarged.
• Pro ⁇ trusions 7 herein take a shortened form at the position of the burner in respect of the temperatures prevailing there.
• the guide plate is also provided there with an internal covering 8 of heat-resistant material.
• ducts 9 for central heating water and ducts 10 for tap water are arranged alternating in the heat exchanger body 2.
• a possibility is thus hereby provided of simultaneously being able to heat tap water by means of tap water ducts 10 as well as central heating water by means of central heating ducts 9, wherein the prior art drawbacks of applying two heat exchangers connected in cascade and the required high temperature of the flue gases associated therewith are avoided.
• the tap water ducts are provided with an internal layer, for instance of Teflon, not shown in the drawings.
• the heat exchanger body 2 is connected to a supply duct 11 for central heating water, in addition to an outlet duct 12 for central heating water and a supply duct 13 for tap water and an outlet duct 14 for tap water.
• the ducts 9,10 extend transversely of the flow direction of heating gases from the burner 3.
• U-shaped guide pieces 15 are placed on the heat exchanger body 2; when applying the relevant casting techniques it is possible to cause the relevant changes in direction of the ducts to take place inside the actual casting, wherein the U-shaped pieces 15 are unnecessary.
• the tap water ducts 10 and the central heating ducts 9 have the same diameter. It is not otherwise essential that this is the case; this depends of course on the relevant dimensioning of the boiler; the configuration will usually be such that the tap water ducts have a slightly smaller diameter than the central heating ducts.
• FIG. 2 An example thereof is shown in figure 2.
• the ducts 10 have a smaller dimension than the ducts 9 for heating the central heat ⁇ ing water. It is also pointed out here that the surface of the ducts 10 which is directed toward the protrusions 7 from which the heat transfer takes place is smaller than the corresponding surface of central heating ducts 9. This results in a larger part of the heat transferred from the flue gases being supplied to the liquid flowing inside the central heating ducts 9.
• FIG. 3 Another embodiment is shown in figure 3, wherein central heating ducts 9 and tap water ducts 10 both have a trapezium-shaped cross-section. However, adjacent trapezium shapes are herein turned relative to each other. This means that the heat-transferring surfaces of both types of duct differ only slightly from each other,- the heat-transferring surface to the tap water ducts 10 is only a little smaller than that to the central heating water ducts 9.
• the dimensioning of the ducts depends on the expected liquid pressure and flow rate.
• the cross section of the tap water ducts 10 in figure 3 is much smaller however than that of the central heating water ducts 9, so that it is easier to reach a higher temperature in tap water ducts 10.
• this geometry it can however be anticipated that on reaching a certain equilibrium temperature in tap water ducts 10 more heat transfer will take place to the liquid in the ducts 9.
• it is possible to apply other duct configurations,- operation is thus possible for instance with triangular ducts, or with a combination of triangular and trapezoidal . This is a question of general dimensioning.
• figure 4 shows a diagram of a heat exchang ⁇ er according to the invention.
• the zigzag-shaped ducts are here incorporated in the body of the heat exchanger 2.
• the tap water ducts 10 are designated with dashed lines and the central heating ducts 10 are designated with a full line.
• the heating ducts for heating tap water 10 extend only over a part of the full height of the heat exchanger; this is also a question of dimensioning.
• ducts 9 for heating central heating water do extend over the full height of the heat exchanger.
• This embodiment further differs in that a short- circuit conduit 17 is arranged in the central heating circuit.
• This short-circuit line 17 extends from the outlet side 12 for central heating water to the supply 11 for central heating water.
• a pump 18 is arranged in this short-circuit line 17, while a three-way valve 19 is arranged for controlling the water stream flowing through the short-circuit line 17. It is however very well possi ⁇ ble that by applying an accurate pump control of pump 18 and the use of a blocking pump 18 the three-way valve becomes unnecessary.
• This configuration serves for the situation in which the central heating is not in use, for instance in the summer period, and wherein a large quan ⁇ tity of heated tap water is required.

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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)
• Combustion & Propulsion (AREA)
• Details Of Fluid Heaters (AREA)
• Fuel Cell (AREA)
• Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)

Applications Claiming Priority (3)

Publications (2)

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ID=19762930

Family Applications (1)

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Cited By (1)

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• 1996
  • 1996-05-28 NL NL1003215A patent/NL1003215C2/nl not_active IP Right Cessation
• 1997
  • 1997-05-22 WO PCT/NL1997/000288 patent/WO1997045681A1/fr active IP Right Grant
  • 1997-05-22 EP EP97923327A patent/EP0902869B1/fr not_active Expired - Lifetime
  • 1997-05-22 DE DE69703106T patent/DE69703106T2/de not_active Expired - Lifetime
  • 1997-05-22 AT AT97923327T patent/ATE196355T1/de not_active IP Right Cessation

Non-Patent Citations (1)

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