EP2295888B1 - Water heater - Google Patents

Description

Background of the invention

The present invention relates to a water heater or a water heater, in particular a pipe connection of a water heater.

State of the art

The energy saving is always a focus in the development of a water heater. In general, the previously known water heaters include an inner storage tank or a hot water tank, a housing enclosing this and a heat insulating layer located between inner storage vessel and housing. This is typically made of a heat-insulating material and can keep most of the heat from the inner storage vessel from the housing. Nevertheless, a part of this heat can be transferred from the inner storage vessel to the housing because there are also necessary connecting parts such as pipe connections between the inner storage vessel and the housing. This heat losses are connected. Normally, an inlet and an outlet tube made of metal are welded to the inner storage vessel, which are coupled via pipe connections with external water pipes. Since the pipe joints are mostly made of metal, the heat stored in the inner storage vessel is transferred to the housing via the inlet and outlet pipes as well as the metallic pipe joints.

A number of measures for solving this problem are already known from the prior art. For example, in the Chinese Patent Application ZL 02233893.4 describes a pipe joint, which consists of an insulating material such as plastic and thus can prevent heat transfer. But since the plastic pipe joints and the metallic inlet and outlet pipes are made of different materials and therefore have a different hardness, they are difficult to firmly connect with each other. This has the consequence that the joints are loose after a long time, so that leaks occur. This is in the Chinese patent application ZL 02267925.1 discloses an alternative in which male and female inlet and outlet tubes are provided which are welded to an inner storage vessel. In addition, a pipe connection is provided, which comprises a base body made of plastic, a metal nut with internal thread and a metal screw with external thread, which are molded in one piece with the plastic base body. In this case, the metallic nut is connected to the inlet and outlet tube on the inner storage vessel and the metallic screw to external water pipes. With such a construction, on the one hand prevents heat transfer from the inner storage vessel to the outside and on the other hand, a loose connection can be avoided due to the material variance between pipe joint and inlet and outlet pipe. However, such a design can lead to difficulties in manufacturing and assembly. For assembly, since the inlet and outlet pipes must be welded to the inner storage vessel by clamping these externally threaded pipes in a clamping device, the external thread of the clamping device may be damaged, making a secure connection between pipe joint and inlet or outlet pipe impossible ,

The publication FR 1 124 819 A discloses a hot water heater according to the preamble of claim 1, in which a plastic pipe joint is used to reduce the heat losses.

The problem underlying the invention

The object of the present invention is to provide a water heater with improved thermal insulation, in particular between storage vessel and housing, which is also easy to manufacture and assemble.

Inventive solution

According to the invention the object is achieved by a water heater according to claim 1, with an inner storage vessel for receiving water to be heated, an inlet pipe and an outlet pipe, which are connected to the inner storage vessel and for transferring into the inner storage vessel entering or from the inner storage vessel At least at either the inlet pipe or the outlet pipe, an internal thread is formed, a heat source for heating water stored in the internal storage vessel, a pipe joint comprising a heat insulating body and a first, integrally molded therewith metal pipe, wherein at the first metal connection pipe a matched to the internal thread external thread is formed. With such a structure, a heat transfer Well prevented from the inner storage vessel via the pipe connections to the housing and at the same time the manufacture and assembly are simplified.

According to the invention, the pipe connection additionally comprises a second metal connection pipe, which is injection-molded in one piece with the heat insulation body and on which an external thread matched to an external water pipe is formed. Thus, the heat insulation can be improved, and the pipe joint has a correspondingly high rigidity, which further improves the handle during assembly.

Preferred embodiment of the invention

In a further development of the present invention, the pipe joint comprises a sealing element, with which a seal between the pipe joint and the internally threaded inlet or outlet pipe can be produced. The sealing element ensures a high watertightness at the connection point.

In a further development of the present invention, the first metal connecting tube has at the end of its external thread a groove in which the sealing element is accommodated.

In a further development of the present invention, the first metal connecting pipe has in the middle of its external thread a groove in which the sealing element is accommodated.

In a further development of the present invention, the heat insulating body has a flow channel penetrating the first metal connecting pipe.

In a further development of the present invention, the flow channel continues to project into the interior of the inner storage vessel.

In a further development of the present invention, the water heater also comprises a housing enclosing the inner storage vessel and a heat insulating layer located between the housing and the inner storage vessel.

In a further development of the present invention, the heat insulating body is accommodated at least partially in the heat insulating layer.

In a further development of the present invention, the water heater next to a hood which encloses the located within the heat insulating layer portion of the Wärmeisolierkörpers.

Compared to the prior art, the present invention offers the following advantages: The fact that, in a pipe connection according to the invention, the heat insulating body and the metallic connecting pipes are integrally formed by injection molding, heat transfer via the pipe connection can be prevented. In addition, the first metal connection pipe with an external thread and the associated inlet or outlet pipe is provided with an internal thread, whereby a thread destruction when welding the inlet and outlet pipe to the inner storage vessel can be avoided.

Brief description of the drawing

Further advantageous embodiments will be described in more detail below with reference to an embodiment shown in the drawing, to which the invention is not limited.

Fig. 1

einen schematischen Längsschnitt durch einen Wassererwärmer gemäß einer Ausführungsform der vorliegenden Erfindung,

Fig. 2

eine seitliche Vergrößerung einer Rohrverbindung für Einlassrohre gemäß Fig. 1,

Fig. 3

eine vergrößerte Darstellung einer Rohrverbindung für Auslassrohre gemäß Fig. 1,

Fig. 4

in entsprechender Darstellung wie in Fig. 2 eine weitere Ausführungsform einer Rohrverbindung für Einlassrohre,

Fig. 5

in entsprechender Darstellung wie in Fig. 3 eine weitere Ausführungsform einer Rohrverbindung für Auslassrohre, und

Fig. 6

einen schematischen Längsschnitt durch einen Wassererwärmer gemäß einer weiteren Ausführungsform der vorliegenden Erfindung.

Showing:

Fig. 1

a schematic longitudinal section through a water heater according to an embodiment of the present invention,

Fig. 2

a lateral enlargement of a pipe connection for inlet pipes according to Fig. 1 .

Fig. 3

an enlarged view of a pipe connection for outlet pipes according to Fig. 1 .

Fig. 4

in corresponding representation as in Fig. 2 a further embodiment of a pipe connection for inlet pipes,

Fig. 5

in corresponding representation as in Fig. 3 a further embodiment of a pipe connection for outlet pipes, and

Fig. 6

a schematic longitudinal section through a water heater according to another embodiment of the present invention.

Detailed description based on an embodiment

In Fig. 1 an embodiment of a water heater according to the invention or water heater is shown. The water heater 100 consists of an inner storage tank or hot water tank 1 for storing heated water, a housing 3 enclosing the inner storage vessel 1 and an inner storage vessel 1 and housing 3, with a foam (eg, polyurethanes) filled Wärmeisolierschicht 4. Das inner storage vessel 1 has a substantially cylindrical shape with a cylindrical wall (no reference numeral) and is usually made of ferrous metal such as steel or iron. In the present embodiment, the water heater 100 is mounted horizontally, that is, the elongated wall 11 of the inner storage vessel extends in the horizontal direction. Further, the water heater 100 for heating cold water includes a heat source that can be made different. Using the example of in Fig. 1 shown electric Wassererwärmers may at one longitudinal end of the inner storage vessel 1, a flange (not shown) may be present, on which an electric heating tube 2 is mounted and protrudes into the water stored in the inner storage vessel. In addition, the heating tube may include a high impedance resistance wire with the plus and minus terminals of the resistance wire on the flange and connected to a 220V or 110V AC power supply. In other water heaters, the liquid in the inner storage vessel, for example, be heated by a combustion chamber arranged outside of this storage chamber in the case of a gas water heater.

Again Fig. 1 can be removed, are formed in the wall of the inner storage vessel 1, an inlet pipe 11 for introducing cold water into the inner storage vessel and an outlet pipe 12 for discharging hot water. In the present embodiment, the inlet and outlet pipes 11, 12 made of metallic material such as copper and are fixed by welding to the outside of the cylinder of the inner storage vessel. On the inside of the inlet and outlet pipe, an internal thread 111 (only indicated once) formed. Further, a pipe joint for inlet pipes 5 and a pipe joint for exhaust pipes 6 are connected to the inlet and outlet pipes 11, 12, respectively. In this embodiment, the pipe connection for inlet pipes 5, as in Fig. 2 an inlet heat insulating body 51 and a first, integrally molded therewith, metallic inlet connection pipe 52. The heat insulating body is made of a heat-insulating material such as plastic. Trapped recesses (not marked) are formed at the joint between the first metallic inlet connecting pipe 52 and the inlet thermal insulating body 51, through which the injection molding compound can flow in order to reliably connect the metal connecting pipe and the thermal insulating body to one another. On the outer side of those portions of the first metallic inlet connection pipe 52 which are not covered by the inlet heat insulating body, an external thread 521 is provided, at the end of which a groove 522 is formed. In this case, the external thread 521 of the first metallic inlet connection pipe 52 is matched to the internal thread 111 of the inlet pipe 11. In addition, the pipe connection for inlet pipes 5 comprises a sealing element 54, which is designed here as an O-ring and engages in the groove 522 of the first metallic inlet connection pipe 52. When installing the pipe joint for inlet pipes 5 into the inlet pipe 11, the sealing element 54 is pressed between inlet pipe 11 and pipe joint for inlet pipes 5 such that there is a secure seal therebetween. According to the invention, the pipe joint for inlet pipes 5 additionally includes a second metallic inlet port pipe 53 integrally molded with the inlet heat insulating body 51 and located at an end opposite to the first metallic inlet port pipe 52 for connection to an external water pipe. The second metallic inlet connection pipe, like the first metallic inlet connection tube 52, is constructed and also provided with a sealing element. Moreover, in the inlet heat insulating body 51, there is disposed an inlet flow passage 511 penetrating the first and second metallic inlet connection pipes 52, 53, through which water can be introduced from the external water pipe into the inner storage tank.

How out Fig. 3 1, the pipe joint for exhaust pipes 6 according to the present embodiment is constructed similarly to the pipe joint for intake pipes 5. That is, it also includes an outlet heat insulating body 61 and first and second metallic outlet connecting pipes 62, 63 integrally molded thereon. On the first metallic outlet connecting pipe 62, there is formed an external thread 621 tuned to an internal thread (not shown) of the outlet pipe 12 is. Also at the end of the external thread 621 of the first metallic outlet connection pipe 62, a groove 622 is provided, which serves to receive a sealing element 64 in order to ensure a seal between outlet pipe 12 and pipe connection for outlet pipes 6. The second metallic outlet connection pipe 63 and the sealing element arranged thereon are constructed in the same way as the first metallic outlet connection pipe 62 or its sealing element, so that no further details are given in detail. Here, care should be taken that an outlet flow channel 611 is provided in the outlet heat insulating body 61, but not only penetrates the first and second metallic outlet connection pipes 62, 63, but also protrudes into the interior of the inner storage vessel 1.

In Fig. 4 Another embodiment of a pipe joint for inlet pipes is shown. The pipe connection shown here for inlet pipes 7 has a substantially similar structure as the embodiment described above. That is, it also consists of an inlet Wärmeisolierkörper 71, a first and a second metallic inlet connection pipe 72, 73. The difference is in particular that in the middle of the external thread 721 (only indicated once) of the first and second metallic inlet connection pipe 72, 73 a Groove 722 is formed, in which a sealing element 74 (only indicated once) is added. With such a configuration, the sealing effect against a sealing element located at the end of an external thread can be realized more easily.

In Fig. 5 a further embodiment of a pipe connection for exhaust pipes is shown. The pipe connection shown here for outlet pipes 8 has a substantially similar structure as the embodiment described above. That is to say, it also consists of an outlet heat insulating body 81, a first and a second metallic outlet connection pipe 82, 83. The difference lies in the fact that in the middle of the external thread 821 (only indicated once) of the first and second metallic outlet connection pipe 82, 83 a Groove 822 is formed, in which a sealing element 84 (only indicated once) is added. With such a configuration, the sealing effect can be compared to a sealing element located at the end of an external thread easier to realize.

How out Fig. 1 As can be seen, the pipe connection for inlet pipes 5 and the pipe connection for outlet pipes 6 are at least partially received in the heat insulating layer 4 after being installed in the inlet and outlet pipes 11, 12, respectively. These sections of the pipe connections are enclosed by the foam and thus reliably fixed in the housing. In Fig. 6 another embodiment of the water heater according to the invention is shown, which differs from the embodiment described above in particular in that on the unit of inlet pipe 11 and pipe connection for inlet pipes 5 and the unit of outlet pipe 12 and pipe connection for outlet pipes 6 each have a circumferential hood. 9 is appropriate. In the present embodiment, the hood 9 is made of heat-insulating material such as expanded polystyrene (EPS) and has a substantially cylindrical receiving space (not designated) for receiving the inlet pipe 11 and the pipe joint for inlet pipes 5 and the outlet pipe 12 and the pipe connection for outlet pipes 6. When mounting the hood 9 is first attached to an associated location and then filled to form the heat insulating layer 4, a foam. This can prevent molten foam from flowing into the receiving space before the formation of a foam layer. With such a construction, the pipe joint for inlet and outlet pipes 5, 6, if they are damaged and maintenance or replacement is necessary, can be easily dismantled.

Characterized in that in the pipe joint of the present invention, the heat insulating body and the metallic connecting pipe are integrally formed by injection molding, a heat transfer via the pipe connection can be prevented. In addition, the metal connection pipe with an external thread and the associated inlet or outlet pipe is provided with an internal thread, whereby a thread destruction when welding the inlet and outlet pipe to the inner storage vessel can be avoided. Furthermore, the heat insulating body is both heat and electricity insulating, so that the charges possibly applied to the inner storage vessel can not be transferred to the housing. In this way the security is increased.

The above-described represents preferred embodiments of the present invention. The pipe joint according to the invention may be in an inlet pipe or at a Outlet tube can be used.

Claims (9)

1. Water heater (100), comprising

   - an inner storage vessel (1) for receiving water to be heated,

   - an intake pipe (11) and an outlet pipe (12) which are connected to the inner storage vessel (1) and serve to convey water entering the inner storage vessel (1) or exiting the inner storage vessel (1), whereby at least one internal thread (111) is formed on either the inlet pipe (11) or the outlet pipe (12),

   - a heat source for heating water stored in the inner storage vessel (1),

   - a pipe connection (5, 6) comprising a heat insulation element (51) and a first metal connecting pipe, wherein an external thread (521) aligned to the internal thread (111) is formed on the first metal connecting pipe,

   characterised in that
   the first metal connecting pipe is formed by injection moulding integrally with the heat insulation element (51), and
   the pipe connection (5, 6) additionally comprises a second metal connecting pipe which is formed by injection moulding integrally with the heat insulation element (51), and at which an external thread aligned to an external water pipe is formed.
2. Water heater (100) according to claim 1, characterised in that the pipe connection comprises a sealing element (54), with which a seal can be produced between the pipe connection and the inlet (11) or outlet pipe (12) which is provided with an internal thread (111).
3. Water heater (100) according to claim 2, characterised in that the first metal connecting pipe has a groove (522) at the end of its external thread (521), in which the sealing element (54) is accommodated.
4. Water heater (100) according to claim 2 or 3, characterised in that the first metal connecting pipe has a groove (522) in the middle of its external thread (521), in which the sealing element (54) is accommodated.
5. Water heater (100) according to one of the preceding claims, characterised in that the heat insulation element (51) has a flow channel (511, 611) which penetrates the first metal connecting pipe.
6. Water heater (100) according to claim 5, characterised in that the flow channel (511, 611) extends further into the interior of the inner storage vessel (1).
7. Water heater (100) according to one of the preceding claims, characterised in that the water heater (100) furthermore comprises a housing (3) enclosing the inner storage vessel (1) and a heat insulation layer (4) located between housing (3) and inner storage vessel (1).
8. Water heater (100) according to claim 7, characterised in that the heat insulation element (51) is accommodated at least partially in the heat insulation layer (4).
9. Water heater (100) according to one of the preceding claims, characterised in that the water heater (100) in addition comprises a hood which surrounds the partial section of the heat insulation element (51) located inside the heat insulation layer (4).

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