A bi-functional electric boiler

Abstract

Bi-functional electric boiler comprises an external jacket (1) closed on both sides with lids (top (2) and bottom (3)), electric heating elements (4), inlet (5) and outlet (6) stub pipes for boiler water, and inlet (9) and outlet (10) stub pipes for domestic water. There are electric heating elements (4) fitted in the bottom lid (2) positioned in the bottom part of the boiler, where the elements are encased in an internal jacket (7). Between the external jacket (1) and the internal jacket (7) there is a chamber with a pipe coil (8) placed therein, the pipe coil fitted with an inlet stub pipe (9) for domestic water and an outlet stub pipe (10) for heated domestic water. The chamber within the internal jacket (7) is connected in the top part of the boiler to the said chamber formed between the external jacket (1) and internal jacket (7), the inlet stub pipe (5) for boiler water is connected to the chamber within the internal jacket (7), and the outlet stub pipe (6) for heated boiler water is connected to the chamber formed between the external jacket (1) and the internal jacket (7). The said inlet stub pipe (5) for boiler water, outlet stub pipe (6) for heated boiler water, and the inlet stub pipe (9) for domestic water are positioned in the bottom part of the boiler, whereas the outlet stub pipe (10) for heated domestic water is positioned in the top part of the boiler.

Description

[0001] The invention concerns a bi-functional electric boiler to be used in central heating and / or domestic water installations.

[0002] Known from the description in Polish patent application P.323023 is a universal electric boiler with a small-capacity tank fixed to the body on the outside, where placed inside the tank is an electric heating element which heats water up to the desired temperature. The top part of the tank is connected to the top part of the body with a pipe through which hot water from the tank flows to the top part of the body of the electric boiler. At the bottom, the tank is connected to the bottom part of the body via a coupler through which cold water in the tank is replenished. Fixed to the bottom part of the body is a pipe which supplies cold water, where there is a blocking element fitted above its inlet. There is a pipe coil fitted inside the body, where the hot water from the central heating system is supplied through the pipe coil inlet, and once the water gives up the heat, it is discharged to the central heating system via the outlet. Fixed to the top part of the body is an external pipe through which hot water from the body is fed for drawing.

[0003] Known from patent document WO 2009 / 096508 A1 is a device which heats water and supplies hot water, incorporating a container for storing hot domestic water heated by a heat pump. Fitted in the said container there is a pipe coil and electric heating element. The hot water container features the first water outlet opening positioned near and above the electric heating element, and the water return opening positioned in the bottom part of the container.

[0004] Known from patent document US 2003 / 0007790 is a pressureless electric water heater for domestic use having a cylindrical double-walled tank for holding a quantity of a heat transfer liquid such as water. Cold water enters a copper coil immersed in the heat transfer liquid. The heat transfer liquid is heated by an electric heating element that extends down a tank.

[0005] Known from patent document DE 1 057 312 is a continuous water heater in gravity heating systems with an internal heating coil for domestic water, which is connected between the flow line to the radiators and the return line and has an electric radiator inside.

[0006] The described invention solves the problem of boiler water circulation in a bi-functional electric boiler which combines boiler water system and domestic water system in a single device.

[0007] The purpose of the invention is to minimise the size of the device supplying boiler water to the central heating installation and hot domestic water. Another purpose of the invention is to simplify the structure of a bi-functional electric boiler while retaining its high thermal performance.

[0008] According to this invention, a bi-functional electric boiler including an external jacket closed on both sides with a top and bottom lid, electric heating elements, an inlet stub pipe and an outlet stub pipe for boiler water, and an inlet stub pipe and an outlet stub pipe for domestic water, said electric heating elements being fitted in the bottom lid positioned in the bottom part of the boiler, where the electric heating elements are encased in an internal jacket, and where between the external jacket and the internal jacket there is a first chamber with a pipe coil placed therein, the pipe coil fitted with the inlet stub pipe for the domestic water and the outlet stub pipe for the heated domestic water, where a second chamber within the internal jacket is connected in a top part of the boiler to the said first chamber formed between the external jacket and internal jacket, the inlet stub pipe for boiler water is connected to the second chamber within the internal jacket, and the outlet stub pipe for the heated boiler water is connected to the first chamber formed between the external jacket and the internal jacket, where the said inlet stub pipe for the boiler water, the outlet stub pipe for the heated boiler water, and the inlet stub pipe for the domestic water are positioned in the bottom part of the boiler, is characterised in that the second chamber formed within the internal jacket is connected to the first chamber formed between the external jacket and the internal jacket through slots formed along a top edge of the internal jacket between the top edge of the internal jacket and the top lid or via openings formed in the internal jacket along its top edge, the outlet stub pipe for heated domestic water is positioned in the top part of the boiler, and the boiler has an additional outlet stub pipe for the heated boiler water, positioned in the top lid. Preferably, the inlet stub pipe for domestic water is positioned in the bottom lid, and the outlet stub pipe for the heated domestic water is positioned in the top lid.

[0009] Using the boiler water flow in the configuration according to the invention allows to reduce the size of the entire device and simplify its structure, and guarantees counter-current flow in the domestic water heating system.

[0010] An illustrative embodiment of the invention is shown on a drawings, where: Fig. 1 presents the bi-functional electric boiler in axial section with the circulation of boiler water and domestic water marked thereon; Fig. 2 shows the boiler as in Fig 1 with boiler water circulation marked thereon.

[0011] According to the illustrative invention embodiment, the boiler incorporates an external jacket 1 closed on both sides with lids: the bottom lid 2 positioned in the bottom part of the boiler and the top lid 3 positioned in the top part of the boiler opposite the bottom lid 2, electric heating elements 4, inlet stub pipe 5 for boiler water, and outlet stub pipe 6 for heated boiler water. Fitted in the bottom lid 2 are electric heating elements 4 encased in the internal jacket 7. Between the external jacket 1 and the internal jacket 7 there is a chamber with a pipe coil 8 placed therein, fitted with an inlet stub pipe 9 for domestic water and outlet stub pipe 10 for heated domestic water. The chamber within the internal jacket 7 is connected to the said chamber formed between the external jacket 1 and the internal jacket 7 in the top part of the boiler. The inlet stub pipe 5 for the boiler water is connected to the chamber within the internal jacket 7, whereas the outlet stub pipe 6 for heated boiler water is connected to the chamber formed between the external jacket 1 and the internal jacket 7. The inlet stub pipe 5 for boiler water and the outlet stub pipe 6 for heated boiler water are positioned in the bottom part of the boiler, above the bottom lid 2. The inlet stub pipe 9 for domestic water is positioned in the bottom lid 2, and the outlet stub pipe 10 for heated domestic water is positioned in the top lid 3. The chamber formed within the internal jacket 7 is connected to the chamber formed between the external jacket 1 and the internal jacket 7 along the top edge 11 of the internal jacket which is shaped so that there are slits 11a formed between the said top edge 11 of the internal jacket 7 and the top lid 3.

[0012] In another embodiment (not shown on the drawing) the chamber formed within the internal jacket 7 is connected to the chamber formed between the external jacket 1 and the internal jacket 7 via the openings in the internal jacket 7 positioned along its top edge 11.

[0013] The circulation of boiler water and domestic water in the boiler described above, as shown in Fig. 1, is as follows. Boiler water flows through the stub pipe 5 positioned above the bottom lid 2 into the chamber within the internal jacket 7 and pressure forces its transport up towards the top lid 3, where water flows around the hot heating elements 4 fitted in the bottom lid 2. Heated boiler water flows through slits 11a into the chamber between the external jacket 1 and internal jacket 7 and flows down towards the lid 2, flowing around the pipe coil 8, following which it flows out through the stub pipe 6 positioned above the bottom lid 2 and then is directed into the central heating installation, whereupon it is returned to the boiler through the inlet stub pipe 5 (where in this embodiment the additional outlet stub pipe 12 for heated boiler water is either closed or the boiler is devoid of it altogether). Domestic cold water, on the other hand, flows into the pipe coil 8 through the stub pipe 9 positioned in the bottom lid 2 and pressure forces its transport up towards the top lid 3, in counter-current direction with respect to the heated boiler water which flows around the pipe coil 8 and heats the domestic water contained therein. The heated domestic water leaves the boiler via the outlet stub pipe 10 positioned in the top lid 3.

[0014] In another embodiment, the boiler described above is fitted with an additional outlet stub pipe 12 for heated boiler water, positioned in the top lid 3. In this embodiment, the system of domestic water circulation is closed and the outlet stub pipe 6 for the heated boiler water is closed, whereas the heated boiler water which flows to the top lid 3 is discharged through the outlet stub pipe 12 and further directed to the central heating installation, following which it is returned to the boiler via the inlet stub pipe 5, as shown in Fig. 2.List of numerical references

[0015] 1 - external jacket 2 - bottom lid 3 - top lid 4 - electric heating elements 5 - inlet stub pipe boiler water 6 - outlet stub pipe heated boiler water 7 -internal jacket 8 - pipe coil 9 - inlet stub pipe for domestic water 10 - outlet stub pipe for heated domestic water 11 - top edge of the internal jacket 11a - slits between the top edge of the internal jacket and the top lid 12 - additional outlet stub pipe for the heated boiler water

Claims

1. Bi-functional electric boiler including an external jacket closed on both sides with a top and bottom lid, electric heating elements, an inlet stub pipe and an outlet stub pipe for boiler water, and an inlet stub pipe and an outlet stub pipes for domestic water, said electric heating elements (4) being fitted in the bottom lid (2) positioned in a bottom part of the boiler, where the electric heating elements (4) are encased in an internal jacket (7), and where between the external jacket (1) and the internal jacket (7) there is a first chamber with a pipe coil (8) placed therein, the pipe coil fitted with the inlet stub pipe (9) for domestic water and the outlet stub pipe (10) for heated domestic water, where a second chamber within the internal jacket (7) is connected in a top part of the boiler to the said first chamber formed between the external jacket (1) and internal jacket (7), the inlet stub pipe (5) for boiler water is connected to the second chamber within the internal jacket (7), and the outlet stub pipe (6) for heated boiler water is connected to the first chamber formed between the external jacket (1) and the internal jacket (7), where the said inlet stub pipe (5) for boiler water, the outlet stub pipe (6) for heated boiler water, and the inlet stub pipe (9) for domestic water are positioned in the bottom part of the boiler, characterised in that the second chamber formed within the internal jacket (7) is connected to_ the first chamber formed between the external jacket (1) and the internal jacket (7) through slots (11a) formed along a top edge (11) of the internal jacket (7) between the top edge (11) of the internal jacket (7) and the top lid (3) or via openings formed in the internal jacket (7) along its top edge (11), the outlet stub pipe (10) for heated domestic water is positioned in the top part of the boiler, and the boiler has an additional outlet stub pipe (12) for the heated boiler water, positioned in the top lid (3).

2. The boiler according to Claim 1, characterised in that the inlet stub pipe (9) for domestic water is positioned in the bottom lid (2), and the outlet stub pipe (10) for the heated domestic water is positioned in the top lid (3).

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