[0001] The invention described here is a fired heat exchanger designed to be best used in
boilers and pre-heaters.
[0002] Taking into account the current state of technology, there are well-known and widely
utilised fired heat exchanger solutions where the combustion chambers and working
surfaces for heat exchange consist of multiple elements, which makes their structure
more complicated, rendering their construction and installation difficult. This solution
results in a lower heat exchange surface to weight ratio and larger overall dimensions
while maintaining the same heat exchanger rate.
[0003] An example of such a solution is a heat exchanger manufactured by the German Viessman
company. Its structure features a cylindrical casing combustion chamber to which specially
chattered plates have been welded. These plates constitute the working heat exchange
surface creating reciprocally parallel layers separated from each other. The media
taking part in the heat exchange process flow around the layers in a countercurrent
direction.
[0004] Another disadvantage of this current solution is the necessity to weld the plates
to the combustion chamber in order to ensure their full integration. Moreover, the
whole structure must also be housed in a specially designed casing in order to ensure
sealing and properly directed flow of the medium among the plates.
[0005] The invention for a fired heat exchanger described here contains a modular block
constituting a set of inseparably interconnected panel plates with a combustion chamber
located in its upper internal part. This layout ensures full integration of the combustion
chamber with the working heat exchange surface located in the lower part of the panel
plates. The working heat exchange surface is created by the lower lateral sides of
the panel plates and the chattered lamella bands mounted on them. The bands expand
the working heat exchange surface and the gasses created in the combustion chamber
flow around this surface. The circulation of the liquid heated medium in the unit
of interconnected panel plates has a flow velocity of the medium within the range
of 0.5 - 2 m/s and is of a two-stage type. During the first stage, the main process
of heat exchange on the working surface takes place. During the second stage, the
combustion chamber is cooled by the water jacket, constituting the upper part of panel
plates.
[0006] According to the invention, the structure of the fired heat exchanger ensures full
integration of the combustion chamber with the working heat exchange surface, which
provides effective cooling for the combustion chamber and a simple compact build obviating
the need for additional closing elements. High thermal efficiency has been achieved
by means of specially shaped chattered lamella bands filling the space between panel
plates expanding the working heat exchange surface, which provides the possibility
for combustion product condensation and turbulence. The vital advantage of this solution
is the high heat exchange surface to weight ratio.
[0007] This new invention facilitates power scaling by adding or removing additional panel
plates and utilising a condensation technique enabling the unit to use less fuel and
emit smaller amounts of detrimental compounds to the air. Thanks to this, the device
is ecologically efficient. Another important advantage of this solution is the simplified
production technology with the possibility of using full automation.
[0008] The invention is shown pictorially, where fig. 1 shows the perspective view of the
fired heat exchanger with a partial pre-installation setting-up of the heat exchanger
part, while Fig. 2 shows the perspective view of the heat exchanger elements set which,
having been connected, create a lamella plate together with a chattered lamella band
mounted on the lateral surface. Fig. 3 shows the axonometric view of the lamella plate
together with the chattered lamella band.
[0009] The invented fired heat exchanger described in this document contains a modular block
constituting a set of inseparably interconnected panel plates (1) with a combustion
chamber water jacket located in its upper part (2) and the working heat exchange surface
in the lower part. These surfaces create the lower lateral surfaces of the panel plates
(1) together with the chattered lamella bands mounted on them (3). They expand the
working heat exchange surface and the gasses created in the combustion chamber flow
around this surface. The circulation of the liquid heated medium in the unit of interconnected
panel plates has s flow velocity with a medium within the range 0.5 - 2 m/s. It is
a two-stage type: during the first stage, the main process of heat exchange on the
working surface takes place, while during the second stage, the combustion chamber
(2) is cooled by the water jacket constituting the upper part of the panel plates
(1).
1. The fired heat exchanger is characterised by the fact that it contains a modular block constituting a set of inseparably interconnected
panel plates (1) with a combustion chamber located in its upper internal part (2)
ensuring full integration of the combustion chamber (2) with the working heat exchange
surface located in the lower part of the panel plates (1). This surface is created
by the lower lateral surfaces of the panel plates (1) together with chattered lamella
bands mounted on them (3). They expand the working heat exchange surface and the gasses
created in the combustion chamber (2) flow around this surface. The circulation of
the liquid heated medium in the unit of interconnected panel plates (1) has a medium
flow velocity within the range 0.5 - 2 m/s and is of a two-stage type. During the
first stage, the main process of heat exchange on the working surface takes place.
During the second stage, the combustion chamber (2) is cooled by the water jacket
constituting the upper part of the panel plates (1).
