EP1574799B1 - Plate heat exchanger with indirect heating - Google Patents

Abstract

The radiator has one or more heating panels (1). A heating element (2) is built into the sole of the foot of the heating panel. This consists of two plates with circular channels stamped into them. The two plates are connected by a spot welding, and are made watertight by a Weld seam round the outer edge. The channels form a circular cross-section through which the heating water flows, and passes its heat to the filling fluid.

Description

Technical area:

The invention relates to a panel radiator, consisting of one or more heating plates, which is filled with chemically treated water or other Wärnieträgertlüssigkeit, filling liquid, wherein in the heating plate, a heating element is installed, which serves to transfer heat from the heating water to the filling liquid in the heating plate, wherein the heating water flows through the heating element as a heat exchanger and transfers its heat to the filling liquid, according to the preamble of claim 1.

State of the art:

Usually, the convective surfaces of a panel heater made of 0.5 mm thick sheet metal. The heating plates of the usual panel radiators are made of 1.25 mm thick sheet metal. For example, such a panel radiator has two heating plates and two convective surfaces, with a length of 960 mm, a height of 600 mm, a total heating surface 4.169 m2, a total weight of 33.96 kg and a heat output of 1833 watts at room temperatures of 24 ° C.

By the DE 27 30 541 A is a radiator for heating systems or the like with a vertically erectable hollow body has become known, which is hermetically sealed and partially filled with a negative pressure, serving as a heat carrier fluid and in the region of its lower edge has a profile which is the inclusion of a conduit for a Heat transfer within the plant serving additional liquid and allows a heat exchange causing contact with this conduit.

By the DE 196 53 440 A is a heater for heating systems with a flow and a return, with at least one radiator having at least one cavity, known, wherein between the flow and the return line runs a heating line through which a heating fluid can flow and in the cavity, a heat conduction fluid is included. The heating cable is designed as a tube. The heating cable is designed as profiling on the components of the radiator inside. The radiator or its cavity is constructed by at least two in particular halves components which have the profiling, which form the heating or heating cables by joining the components together. The profiling extends as a sheet or wire arrangement or the like between the flow and the return.

Technical task:

The invention has for its object to reduce the consumption of material in the production of panel radiators.

Disclosure of the invention and its advantages:

The solution of the problem is characterized by the features of claim 1. Further advantageous embodiments of the invention are characterized in the subclaims.

As a filling liquid, the chemically treated water is used with the addition of various inhibitors, whereby the mixed liquid is chemically resistant to corrosion.

The operating pressure of the heating system is limited only to the heating element and the pressure in the rest of the radiator remains atmospheric. This has the advantage that the heating plate made of thin sheet metal (0.5-0.6 mm) can be made, whereby the price level of the plate radiator is significantly reduced.

The heating element is a very efficient heat exchanger which can be made in two ways: Firstly, a sheet metal piece is made, with the dimensions 85mm wide, 1.5 - 2mm thick and a length that is about 100 mm shorter than the radiator ,

On the piece of sheet metal, the channels are impressed, the depth of which depends on the heat output. Two channels are connected to each other by means of the embossed sheets at the end of the heating element. The embossed sheets have the same depth as the impressions along the heating element. Thus, one achieves that the flow of supply is distributed over two channels, although have different lengths but are imprinted at the same distance from each other.

The return flow in the heating element is also composed of two partial streams. The uniform distribution of current over the entire width of the heating element ensures that the heat transfer from the heating element to the circulating liquid becomes more efficient.

The heating element consists of two completely identical shells, which are connected to each other by spot welding (spot welding takes place between the channels). The two shells are waterproof connected to each other by the weld.

On one of the two shells two openings are provided, to each of which a piece of pipe is welded. These pieces of pipe are welded waterproof together with the shell of the heating plate during assembly of the heating plate.

The surface of the heating element is ribbed with wart-shaped needle ribs. The needle ribs can be attached to the surface of the heating element by spot welding by means of an electrowelding device or automatically, with a tool specially made for this purpose. By tapping the outer surface of the heating element very high external heat transfer coefficients are achieved, order of magnitude of 2000 W / m2K.

By correctly dimensioning the flow velocity in the flow channel of the heating element (by 1m / s) high internal heat transfer coefficients (WÜK) in the heating element can be achieved. The two heat transfer coefficients, the inner and outer WÜK, result in a high heat transfer coefficient of the heating element.

Another, conventional, but not claimed, way to make the heating element is given in such a way that a U-shaped tube is used, the surface of which is ribbed with ribs of thin sheet metal (about 0.5 mm). This can also be very high heat transfer coefficients are achieved. This solution is in any case associated with higher production costs.

Thus, there is the heat transfer between the heating element and the filling liquid by the gravity movement of Füllfüssigkeit on the height of the heating element, instead. The heat transfer between the filling liquid and the outer wall of the heating plate also takes place by the gravity movement of the filling liquid along the vertical wall of the heating plate. In order to establish the difference in density of the rising and the falling flow in the heating plate, the heating element is installed in the designated foot channel of the heating plate.

The required circulation of the filling liquid is caused by the gravity movement in the heating plate. The gravity movement is caused by the density difference of the filling liquid in the rising and the falling column. The ascending and descending columns represent the impressed channels in the heating plate.

It is also a feature of this invention that the heating element is mounted only under the rising columns, that is, only the zone of ascending movement is heated. The zone under the sloping columns will not be heated. This results in the requirement that the total length of the heating element is shorter than the heating plate. This difference in length is about 100mm. It can be concluded that the "sloping zone" in the heating plate is very short, as short as it is necessary to generate the gravity movement.

The production of a hot plate is done in such a way that the trays are made in the classical manner, but with the difference that at the bottom of the shell, a channel is provided, in which the heating element is installed. Two shells are first fixed together by spot welding and then the edges of the heating plate are then sealed watertight by seam welding. In the bowls are during the preparation of the Outlet openings provided through which the supply and return pipes are passed and welded watertight to the shell. Depending on the heat output of a radiator is required, a panel radiator can be composed of one, two or three hot plates.

In each hotplate four openings are provided with the diameter of 15 mm, at the bottom of a discharge opening and at the top of a filling and ventilation opening.

• Wärmeabgabe durch die Strahlung ca. 60%
• Wärmeabgabe durch die Konvektion ca. 40%

The calculation shows that the total heat output of the front and back, front to the room and back to the wall, is composed of:

• Heat emission by the radiation approx. 60%
• Heat release by convection approx. 40%

From this fact follows that when two heating plates are placed against each other in a radiator, the radiation component is lost because the heating plates irradiate each other while absorbing the rays. For this reason, it will be necessary to provide on the inside of the heating plates, which are placed against each other, the convective surfaces to compensate for the loss of the radiation component. This is common in panel heater production, and these convective surfaces are usually made of sheet metal 0.5mm thick, in trapezoidal shape.

According to the present invention, the outer shells of the heating plate are made of 0.6 mm thick sheet metal, since the pressure in the heating element is identical to the pressure of the heating system.

Usually, the convective surfaces are made of 0.5 mm thick sheet metal. The heating plates of the usual panel radiators are made of 1.25 mm thick sheet metal.

• Nimmt man z.B. einen Plattenheizkörper aus der üblichen Produktion (z.B. Hersteller Firma "Buderus") mit folgenden Charakteristiken:
• Typ PKPK........................... (zwei Heizplatten+ zwei konvektive Flächen)
• Baulänge 960 mm
• Bauhöhe 600 mm
• Gesamte Heizfläche 4,189 m2 (laut Prospektunterlagen)
• Gesamtgewicht 33,96 kg
• Wärmeleistung 1833 Watt (bei Raumtemperaturen 24°C)

Based on the analysis carried out, it is close to the cost comparison of steel sheet consumption for the plate radiator according to this invention and the to use standard panel radiators as follows:

• If you take eg a panel radiator from the usual production (eg manufacturer company "Buderus") with the following characteristics:
• Type PKPK ........................... (two heating plates + two convective surfaces)
• Overall length 960 mm
• Construction height 600 mm
• Total heating surface 4.189 m2 (according to the prospectus documents)
• Total weight 33.96 kg
• Heat output 1833 Watt (at room temperature 24 ° C)

• Baulänge 960 mm
• Bauhöhe 600 mm
• Gesamtheizfläche:
  • Wärmeleistung: 1833 Watt (bei Raumtemperatur 22°C)
  • Gesamtgewicht: 22,84 kg

Opposite this plate radiator of the plate heater according to this invention has the following characteristics:

• Overall length 960 mm
• Construction height 600 mm
• Gesamtheizfläche:
  • Thermal output: 1833 watts (at room temperature 22 ° C)
  • Total weight: 22.84 kg

The total weight is composed as follows: - 2.304 m ² (2 hotplates), 0.6 mm thick 10.78 kg - 2 pieces of convective surfaces 0.5 mm thick 6.98 kg - 2 heating elements 3.00 kg - Cover profiles, retaining tabs, connections 2.08 kg - All in all: 22.84 kg

From this it can be concluded that with panel radiators according to this invention substantial spurs on steel sheet can be achieved. Assuming an annual plate radiator production of 500,000 units, it is easy to calculate that only the material costs of steel sheet can save 5560 tonnes.

The heating plates are filled with chemically treated water, which significantly reduces the susceptibility to corrosion. You can also use the hot plates fill with other heat transfer fluids, which completely exclude corrosion, but this raises the cost issue.

It is possible to make the heating plates from aluminum sheet, as well as from VA sheet metal, since they are depressurized. It should be mentioned, in particular, that this solution offers the possibility of designing the panel radiators as motif radiators, in that the front side is made of sheet metal (0.8 mm thick), whereby different motifs can be mounted on the front side.

Fig.1

eine Prinzipskizze des erfindungsgemäßen Plattenheizkörper mit der Seitenansicht

Fig. 1A

zur Verdeutlichung der Fig. 1

Fig. 1B

zur Verdeutlichung der Fig. 1

Fig. 1C

zur Verdeutlichung der Fig. 1

Fig. 2

eine Prinzipskizze des Heizelementes mit eingeprägten Kanälen, die Anordnung der Nadelrippen, sowie den Vor- und Rücklaufanschluss.

Fig. 2A

zur Verdeutlichung der Fig. 2

Fig. 2B

zur Verdeutlichung der Fig. 2

Fig. 2C

zur Verdeutlichung der Fig. 2

Fig. 3

die Verbindung der Wärmeheizplatten mit Füll-und Entleerungsventil

Fig. 3A

zur Verdeutlichung der Fig. 3

Fig. 3B

zur Verdeutlichung der Fig. 3

Fig. 3C

zur Verdeutlichung der Fig. 3

Fig. 3D

zur Verdeutlichung der Fig. 3

Fig. 3E

zur Verdeutlichung der Fig. 3

The invention is illustrated by way of example in the drawing, in which:

Fig.1

a schematic diagram of the panel heater according to the invention with the side view

Fig. 1A

to clarify the Fig. 1

Fig. 1B

to clarify the Fig. 1

Fig. 1C

to clarify the Fig. 1

Fig. 2

a schematic diagram of the heating element with embossed channels, the arrangement of the needle ribs, and the flow and return port.

Fig. 2A

to clarify the Fig. 2

Fig. 2B

to clarify the Fig. 2

Fig. 2C

to clarify the Fig. 2

Fig. 3

the connection of the heating plates with filling and emptying valve

Fig. 3A

to clarify the Fig. 3

Fig. 3B

to clarify the Fig. 3

Fig. 3C

to clarify the Fig. 3

Fig. 3D

to clarify the Fig. 3

Fig. 3E

to clarify the Fig. 3

Ways to carry out the invention:

According to the Fig. 1 the panel radiator is designed in such a way that at the foot of the two shells 1, a horizontal square channel is provided, in which an efficient heating element 2 is installed, which indirectly transfers the heat from the heating circuit to the filling liquid in the heating plate. The vertically embossed channels 3 in the heating plate are ascending, and the channels 4 descending. The filling liquid in the heating plate circulates through gravity, which is set by the density difference in the rising and falling channel in steady state operation.

In the Fig. 1A . Fig. 1B and Fig. 1C is clearly the positioning of the heating element 2 indicated. From the Fig. 1C the positioning of the forward and return port 5 and 6 can be seen.

In Fig. 2 the heating element 2 is shown, wherein it can be seen that the heating element is made of two sheet metal plates in such a way that four channels 7 are stamped lengthwise in the metal plate and that two plates are sealed together by seam welding waterproof. The indentations of the two plates form a channel with a circular cross-section, through which the heating water flows from the heating system. Two channels are connected to each other by means of the embossed sheets 8. The two channels at the foot of the heating element are connected by means of a pipe section 5 to the heating flow and the other two channels by means of the pipe section 6 to the heating return.

In Fig. 2B and Fig. 2C the plan view and side view of the heating element is shown enlarged. The surface of the heating element is provided with needle ribs 16 which serve to increase the heat transfer coefficients on the side of gravity flow.

In Fig. 3 the connection of the individual heating plates 1 is shown as a finished radiator. The connection of the heating plates by means of the pipe segments 5, 6, 9, 10 and 11. The pipe segments 5 and 6 are welded together watertight by means of a T-piece 13. The tees 13 are provided with threaded connection and serve as Heizungsvor- and return port, the pipe segments 9, 10 and 11 are also welded together by means of a tee 12. The T-pieces 12 are provided with screw plugs that serve to fill, vent and drain the radiator.

To cover the heating plate, because of the remaining embossing and to seam welding, is a frame, Fig. 3D - 14, made of L-profile with the dimension 17x20x 0.8 mm, which is attached to the front of the heating plate, so that no Aufsteckgitter or side Aufsteckdeckel more, as with conventional radiators are required. The spacing of the heating plates is 56 mm, which is perfect for a good convective air flow. At the rear of a convective surface 15 is attached, which is made of sheet 0.5 mm thick, made. The task of the convective surface is to settle the radiation loss.

Claims (13)

1. A plate radiator, consisting of one or more heating plates (1), which is filled with chemically treated water or another heat transfer fluid, filling fluid, whereby a heating element (2) is installed in the heating plate (1), said heating element (2) serving to transfer heat from the heating water to the filling fluid in the heating plate (1), whereby the heating water flows through the heating element (2) as a heat exchanger and transfers its heat to the filling fluid, and whereby the heating element (2) is installed in a foot channel of the heating plate (1),
   characterized in that
   the heating element (2) of the heating plate (1) is made up of two plates in which round channels (7) have been stamped, which lie on top of each other, thus forming a circular cross section through which the heating water flows, whereby the plates are joined to each other by spot welding and their outer edge is sealed water-tight by means of seam welding.
2. The plate radiator according to Claim 1, characterized in that, at the end of the heating element (2), the stamped channels (7) are joined to each other at the same depth by stamped arches (8).
3. The plate radiator according to Claim 1 or 2, characterized in that the stamped channels (7) are connected by two pipe pieces (5, 6) to the heater flow connection and by means of a T-piece (13) to the heater return connection.
4. The plate radiator according to any of the preceding Claims 1 to 3, characterized in that the stamped channels (7) are arranged in the heating plate in such a way that the water from the heater flow connection (5) is distributed over two or more partial flows in such a way that the flow resistances and the heat transfer are established optimally.
5. The plate radiator according to any of the preceding Claims 1 to 4, characterized in that the surface of the heating element (2) is provided with needle ribs (16) or with another kind of ribs.
6. The plate radiator according to any of Claims 1 to 5, characterized in that the foot channel at the foot of the heating plate (1) has a square cross section in which the heating element (2) is installed.
7. The plate radiator according to any of Claims 1 to 6, characterized in that the plate radiator has perpendicular columns stamped into the heating plate (1) which are partially ascending channels (3) and partially descending channels (4).
8. The plate radiator according to Claim 7, characterized in that the heating element (2) is only installed under the ascending columns (3) and the total length of the heating element (2) is shorter than the heating plate (1), so that only the zone of the ascending movement of the filling fluid is heated.
9. The plate radiator according to any of Claims 1 to 8, characterized in that the heating plates (1) are joined to each other by means of pipe segments (9, 10, 11) that are joined to each other by means of T-pieces that serve for filling, venting and emptying the radiator.
10. The plate radiator according to any of Claims 1 to 9, characterized in that the heating plates (1) are made of sheet steel or another material that is 0.5 mm to 0.6 mm or 0.8 mm thick and they are configured for an operating pressure of 20 bar or more in the heating installation.
11. The plate radiator according to any of Claims 1 to 10, characterized in that it can be heated with steam and can serve as a high-pressure radiator.
12. The plate radiator according to any of Claims 1 to 11, characterized in that it can serve as a design radiator, whereby various designs can be imprinted on the front.
13. The plate radiator according to either Claim 11 or Claim 12, characterized in that the front of a heating plate is made of smooth sheet steel, 0.8 mm to 1.0 mm thick.

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