EP3877705B1

EP3877705B1 - Heat exchanger with gas discharge system

Info

Publication number: EP3877705B1
Application number: EP20722695.2A
Authority: EP
Inventors: Yalcin OTER
Original assignee: Emas Makina Sanayi AS
Current assignee: Emas Makina Sanayi AS
Priority date: 2020-01-29
Filing date: 2020-01-29
Publication date: 2021-12-22
Anticipated expiration: 2040-01-29
Also published as: EP3877705A1; WO2021154166A1

Description

Field of the Invention

The present invention relates to a heat exchanger which provides an exhaust gas discharge system which is more efficient than the heat exchangers in the state of the art.

Background of the Invention

Heat exchangers are used to transfer heat from one fluid to another. Heat exchangers can transfer heat from gas to liquid, liquid to gas, liquid to liquid or gas to gas. Heat exchangers are widely used in cooling, air conditioning, heating, power generation and chemical processes. In other words, the heat exchanger is the circuit element that provides heat transfer among two fluids ― liquid or gas ― with different temperatures without any physical contact therebetween (without mixing). In the state of the art, heat exchangers are divided into three types: Tubular heat exchangers, Plate type heat exchangers (Detachable type, Welded type, Semi-welded type, Soldered type), Special purpose heat exchangers (Plate Coil Heat Exchangers, Econocoil Heat Exchangers, Spiral Heat Exchangers). In the combi boilers, the heat exchangers carry out the process of transferring the heat of the burning gas to the liquid.
European patent document no. EP2984415B1 , an application in the state of the art, discloses a heat exchanger system. The gas burning in the center of the heat exchanger, which has a cylindrical body, travels through the helical tubes and is discharged through an external discharge chamber located at the base of the body; and as the gas starts to move through the tubes, the tubes warm up and the liquid in the tubes warm up. In the said patent document, the gas passing through the tubes is collected in a separate discharge chamber and then discharged, but this increases the gas pressure value and also reduces the heat exchange efficiency as it slows down the discharge of the gas.
European patent document no. EP3485203 , an application in the state of the art, discloses a heat exchanger system. The gas burning in the center of the heat exchanger, which has a cylindrical body, travels through the helical tubes and is discharged from the body through a channel located at the base of the body; and as the gas starts to move through the tubes, the tubes warm up and the liquid in the tubes warm up. In the said patent document, the gas passing through the tubes is collected in a separate discharge chamber and then discharged, but this increases the gas pressure value and also reduces the heat exchange efficiency as it slows down the discharge of the gas.
WO 2015/140713 A1 discloses a heat exchanger according to the preamble of claim 1.

Summary of the Invention

The objective of the present invention is to provide a heat exchanger that enables the gases burning in the heat exchanger body to move with low pressure.
Another objective of the present invention is to provide a heat exchanger that achieves high efficiency within the entire thermal capacity range thanks to the circular gas flow that is generated.
A further objective of the present invention is to provide a heat exchanger which ensures that the fluids entering the system are directed to the condensation collection channel, and at the same time, the stability of the combustion efficiency of the burner is achieved in a sustainable manner.

Description of the Figures

The heat exchanger system developed to fulfill the objectives of the present invention is illustrated in the accompanying figures, in which:

Figure 1 is a perspective view of the heat exchanger.
Figure 2 is the exploded perspective view of the heat exchanger.
Figure 3 is the front perspective view of the body.
Figure 4 is a view of the A-A section of the heat exchanger.
Figure 5 is a view of the gas flow in the A-A section of the heat exchanger.

The components in the figures are each given reference numbers as follows:

1. Heat exchanger
2. Body
- 21. Front cover
- 22. Discharge opening
- 23. Second chamber
- 24. Plate
- 25. Flue opening
3. Tube

Detailed Description of the Invention

The heat exchanger (1) of the present invention essentially comprises

at least one body (2) which is in the form of a hollow cylinder consisting of two parts,
an ellipse shaped tube (3) with a spiral structure arranged inside the body (2),
at least one front cover (21) arranged so to cover the opening provided on the flat surface of the body (2),
a burner arranged on the front cover (21),
at least one discharge opening (22) provided on the cylindrical surface of the body (2) to allow the gas exiting the burner to circulate around the tube (3), travel through the cylindrical surface of the body (2) and exit the body (2),
at least one second chamber (23) which has an inner space and is formed so as to cover the said discharge opening (22),
at least one flue opening (25) provided on the second chamber (23),
at least one plate (24) which partially covers the discharge opening (22) to prevent the condensed liquid or rainwater entering through the flue opening (25) from reaching the tube (3).

The heat exchanger (1) of the present invention comprises a body (2) which is in the form of a hollow cylinder consisting of two parts. The body (2) is preferably manufactured from sheet metal material. In a preferred embodiment of the invention, the body (2) is made of a heat insulating plastic material. A tube (3) having a spiral structure is arranged inside the body (2). The tube (3) is manufactured as a single piece and is twisted to form spirals. The inlet and outlet parts of the tube (3) can be positioned such that they project from the body (2) or remain inside the body; and the fluid material entering the said tube (3) through the inlet part passes through the spiral structure of the tube (3) inside the body (2) and exits through the outlet part. There is provided a separator between each layer of the spiral tube (3), so that the parts of the tube (3) placed inside the body (2) in a spiral manner do not contact each other. The flat surface of the body (2) having a cylindrical structure is open and there is provided a front cover (21) having a disc shape for covering the said opening. A burner is placed on the said front cover (21) and the burner is positioned so that the burning part of the burner enters the body (2). A discharge opening (22) is provided on the cylindrical surface of the body (2) to allow the gas exiting the burner to circulate around the tube (3), travel through the cylindrical surface of the body (2) and exit the body (2). Thus, thanks to the circular gas flow that is generated in the body (2), high efficiency is achieved within the entire thermal capacity range. In other words, the gas leaving the burner passes through the layers of the tube which is spirally placed inside the body (2), reaches the inner wall of the body (2) and travels parallel to the inner wall of the cylindrical body (2), thereby reaching the discharge opening (22).
The gas discharged from the body (2) through the discharge opening (22) is collected in a second chamber (23) positioned so as to cover the discharge opening (22). In a preferred embodiment of the invention, the second chamber (23) has a shape parallel to the cylindrical surface of the body (2); in other words, its wide surface is in the form of an arc extending parallel to the body (2). Thanks to its arc shape, the second chamber (22) allows the gas to move at low pressure. In a preferred embodiment of the invention, the second chamber (23) is in the form of a rectangular prism. A flue opening (25) is provided on the second chamber (23). There is provided a plate (24) which partially covers the discharge opening (22) in order to prevent the liquid entering through the flue opening (25) from reaching the tube (3) and at the same time to facilitate the transport of the gas moving on the inner surface of the body (2) to the second chamber (23). According to the invention, the plate (24) has an arc shape and is placed over the discharge opening (22) without completely closing the aperture of the discharge opening (22). In a preferred embodiment of the invention, the plate (24) has a rectangular shape. The plate (24) prevents rainwater from entering into the body (2) through the flue opening (25).
According to the invention, the plate (24) is placed on the discharge opening (22), so that two symmetrical spaces are formed on opposite sides of the plate (24); said spaces are arranged to be symmetrical to each other. Thanks to the said spaces, the gas in the body (2) is allowed to pass into the second chamber (23) in a balanced manner and the gases are enabled to be mixed in a balanced manner. An insulating plate is placed on the flat surface of the cylindrical body (2). The said insulating plate prevents the heat generated by combustion of the burner from heating the flat surface of the body (2), i.e. the wall that cannot be cooled. The heat exchanger (1) of the present invention enables the gases burning in the body (2) to move with low pressure.
In a preferred embodiment of the invention, there are protrusions on the cylindrical inner surface of the body (2) for directing the gas to the discharge opening (22), and the said protrusions allow the laminar flow of the gas as well as reducing the gas pressure. In a preferred embodiment of the invention, there are recesses on the cylindrical inner surface of the body (2) for directing the gas to the discharge opening (22), and the said recesses allow the laminar flow of the gas as well as reducing the gas pressure.
In the heat exchanger (1) of the present invention, after the combustion takes place within the burner, the hot combustion gasses pass through the apertures of the tube (3) and transfer heat to the liquid passing through the tube (3). The combustion gases, which transfer their heat to the liquid within the tube (3), that is to say, which have low energy, are directed from the cylindrical inner surface of the body (2) to the second chamber (23). There is provided a plate (24), which partially covers the discharge opening (22) on the second chamber (23), so that the combustion gases can enter the second chamber (23) through a laminar flow. At the same time, the plate (24) prevents the rainwater or condensate coming from the flue opening (25), i.e. chimney, from directly contacting the burner part where the combustion takes place.
In a preferred embodiment of the invention, the process of directing the combustion gases generated by the burner to the chimney at the flue opening (25) is enabled by the help of a manifold channel provided on the inner wall of the body (2). In a preferred embodiment of the invention, a plurality of manifold channels is arranged inside the body (2). Thanks to the manifold channels, there is no need for a separate collection chamber to direct the combustion gases to the chimney. Manifold channel is a solution that allows to reduce the condensing heat exchanger depth as much as the size of the collection chamber. The condensate liquid formed in the chimney and body (2) is directed to the condensate discharge channel provided in the body (2) by following the boundaries set by the manifold channels. This way, the heat exchanger (1) ensures that the fluids entering the body (2) are directed to the condensation collection channel and at the same time, the stability of the combustion efficiency of the burner is achieved in a sustainable manner.

Claims

A heat exchanger (1) for combi boilers comprising at least one body (2) which is in
the form of a hollow cylinder consisting of two parts; at least one tube (3) with a

spiral structure arranged inside the body (2); at least one front cover (21) arranged so to cover an opening provided on a flat surface of the body (2); a burner arranged on the front cover (21); at least one discharge opening (22) provided on the cylindrical surface of the body (2) to allow a gas exiting the burner to circulate around the tube (3), travel through the cylindrical surface of the body (2) and exit the body (2);

at least one second chamber (23) which has an inner space and is formed so as to cover the discharge opening (22);

at least one flue opening (25) provided on the second chamber (23); at least one arc shaped plate (24) which partially covers the discharge opening (22) to prevent the condensed liquid or rainwater entering through the flue opening (25) from reaching the tube (3); characterized in that said arc shaped plate (24) is placed over the discharge opening (22) so that two symmetrical spaces are formed on opposite sides of the plate (24) and that the gas in the body (2) is allowed to pass into the second chamber (23) in a balanced manner.
A heat exchanger (1) according to Claim 1, wherein the body (2) is manufactured from a sheet metal material.
A heat exchanger (1) according to Claim 1, wherein the body (2) is manufactured from a plastic material.
A heat exchanger (1) according to Claim 1, wherein the second chamber (23) has a wide surface in the form of an arc extending parallel to the body (2).
A heat exchanger (1) according to Claim 1, wherein the second chamber (23) is in the form of rectangular prism.
A heat exchanger (1) according to Claim 1, 4 or 5, wherein the arc shaped plate (24) has a rectangular form.
A heat exchanger (1) according to Claim 1, 2 or 3, comprising a protrusion positioned on the cylindrical inner surface of the body (2) for directing the gas to the discharge opening (22).
A heat exchanger (1) according to Claim 1, 2 or 3, comprising a recess positioned on the cylindrical inner surface of the body (2) for directing the gas to the discharge opening (22).