EP1519135A2

EP1519135A2 - Heat exchanger construction

Info

Publication number: EP1519135A2
Application number: EP04018161A
Authority: EP
Inventors: Giandomenico Lovato
Original assignee: Ferroli SpA
Current assignee: Ferroli SpA
Priority date: 2003-09-29
Filing date: 2004-07-30
Publication date: 2005-03-30
Also published as: ITMI20031862A1; EP1519135A3; CN1603733A; CN1603733B

Abstract

A heat exchanger construction (1) comprising a plurality of tubular elements (2), therebetween at least a continuous or discontinuous zig-zag shape or fretted blade element (3) is arranged, said blade element (3) being made rigid with said tubular elements (2) so as to provide heat transmission between a secondary fluid, circulating through the tubular elements (2), and a primary fluid, which is cross-directed through the assembly of the tubular elements (2) and blade element or elements (3).

Description

BACKGROUND OF THE INVENTION

The present invention relates to a heat exchanger construction.
More specifically, the inventive heat exchanger construction is provided for conveying or transmitting heat between a primary fluid, in a gaseous status, or in a liquid status, and one or more secondary fluids, also in either a gaseous or liquid status, and being preferably, but not exclusively, designed for use in thermal generators for heating purposes and/or for providing sanitary use hot water and/or for air conditioning and/or heat recovery purposes.
As is known, heat exchangers are conventionally used in several fields.

SUMMARY OF THE INVENTION

The aim of the present invention is to provide such a heat exchanger which is improved with respect to prior heat exchangers for the same applications.
Within the scope of the above mentioned aim, a main object of the invention is to provide such a heat exchanger construction which allows to arrange several heat exchanger circuits in a single construction, while providing an efficient and full separation of said heat exchanger circuits.
Another object of the present invention is to provide such a heat exchanger which can be used in heat generators including burners of an atmospheric, premixed, blown, catalytic type, operating on gaseous, solid and liquid fuels, or heat generators using other he4at sources.
Another object of the present invention is to provide such a heat exchanger which can be made of different materials and which can be easily used in different types of heat generators, such as conventional heat generators, condensation heat generators and so on.
Yet another object of the present invention is to provide such a heat exchanger which can also be used in heat recovery or refrigerating apparatus.
Yet another important object of the present invention is to provide such a heat exchanger allowing to make very compact boiler bodies, with the built-in necessary hydraulic circuits, for heating, sanitary hot water purposes, and for recovering heat from combustion fumes, for refrigerating applications and so on.
Yet another important object of the present invention is to provide such a heat exchanger which allows to highly automatize the related making process.
According to one aspect of the present invention, the above mentioned aim and objects, as well as yet other objects, which will become more apparent hereinafter, are achieved by a heat exchanger construction, characterized in that said heat exchanger construction comprises a plurality of tubular elements, therebetween at least a continuous zig-zag or fretted blade element is arranged, said blade element being made rigid with said tubular elements to provide a heat transmission between a secondary fluid, circulating in the tubular elements, and a primary fluid cross-traversing the tubular element and blade assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the present invention will become more apparent hereinafter from the following disclosure of a preferred, though not exclusive, embodiment of the invention, which is illustrated, by way of an indicative, but not limitative, example in the accompanying drawings, where:
Figure 1a is a front elevation view of a heat exchanger construction according to the present invention;
Figure 1b is a top plan view of the heat exchanger construction shown in figure 1a;
Figure 2 is a further front elevation view of a heat exchanger construction according to a further aspect of the invention, with a plurality of tubes arranged at several levels;
Figure 3a is a further front elevation view of a heat exchanger construction according to a further aspect of the invention, with tubes coupled in a series relationship on a single level;
Figure 3b is a top plan view of the heat exchanger construction shown in figure 3a;
Figure 4a is a front elevation view of a heat exchanger construction, according to a further aspect of the invention, with heat exchanger tube coupled in parallel on a single level;
Figure 4b is a top plan view of the heat exchanger construction shown in figure 4a;
Figure 5a is a front elevation view of a heat exchanger construction according to a further aspect or embodiment of the invention, with heat exchanger tubes coupled in series on several levels;
Figure 5b is a top plan view of the heat exchanger construction of the preceding figure;
Figure 6a is a further front elevation view of a heat exchanger construction, according to a further aspect or embodiment of the present invention, with heat exchanger tubes coupled in parallel on several levels;
Figure 6b is a top plan view of the heat exchanger construction of the preceding figure;
Figure 7a is a front elevation view of a heat exchanger construction, according to a further aspect of the invention, with heat exchanger tubes coupled in series on several levels and with independent circuits;
Figure 7b is a top plan view of the heat exchanger construction of the preceding figure;
Figure 8a is a front elevation view of a heat exchanger construction according to yet another aspect or embodiment of the present invention, with heat exchanger tubes coupled in parallel on several levels and with independent circuits; and
Figure 8b is a top plan view of the heat exchange construction of the preceding figure.

DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to the number references of the above mentioned figures, the heat exchanger construction, according to the present invention, which has been generally indicated by the reference number 1 comprises, in a basic embodiment thereof shown in figures 1a and 1b, a plurality of heat exchanger tubes 2 having preferably, though not exclusively, a circular, oval, rectangular, flattened and/or contoured configuration, which tubes are preferably, but not exclusively, mutually parallel and therethrough one or more secondary fluids are conveyed.
In the space between two adjoining tubes, a continuous or discontinuous zig-zag or fretted blade element 3 is arranged.
Each said blade element 3, in particular, is made rigid with said tubes contacted thereby by a welding process, or an analogous process, and/or by a mechanical type of coupling, thereby allowing heat to be transmitted between the secondary fluid F2 circulating through the tubes 2, and a primary fluid which is cross-conveyed through the assembly of the tubes 2 and blade elements 3 which cooperate to provide the subject heat exchanger 1.
The tubes 2, in particular, can be arranged on several levels, as shown, for example, in figure 2, which shows, by way of an exemplary and not limitative example, three arrangement levels.
The heat exchanger forming tubes, moreover, can also be mutually coupled with a series and/or parallel relationship on each individual level and/or in a series and/or parallel relationship between different levels, or with series/parallel combinations on a single level or between different levels.
Figures 3a-8b show some coupling possibilities, given by way of an example and not of limitation, since the subject heat exchanger has been specifically designed for fitting to a very high number of coupling combinations and circuits.
Figures 3a-3b show a heat exchanger 101 with heat exchanger tubes 2 coupled in a series relationship, by fitting elements 22, or being formed starting from a single tube, on a single level.
Figures 4a-4b show a heat exchanger 201 with heat exchanger tube 2 coupled in a parallel relationship, by fitting elements 222, on a single level.
Figures 5a-5b show a heat exchanger 301, with heat exchanger tube 2 coupled in a series relationship, by fitting elements 22, or being formed from a single tube, on several levels.
Figures 6a-6b show a heat exchanger 401 with tubes 2 coupled in a parallel relationship, by fitting elements 222, on several levels.
Figures 7a and 7b show an exemplary embodiment of a heat exchanger, generally indicated by the reference number 501, including independent heat exchanger circuits on several levels and with a series coupling relationship.
The heat exchanger of the shown embodiment comprises three independent circuits, each arranged on a different level, with a series type of coupling, and being preferably, but not exclusively, traversed by a different secondary fluid.
More specifically, the secondary fluid F2 sequentially passes through the heat exchanger tubes 2 at the first level from the left to the right, with reference to the figures.
The secondary fluid F3 sequentially passes through the tubes 2 of the heat exchanger on the middle level from the right to the left, whereas the secondary fluid F4 sequentially passes through the heat exchanger on the third level, from the left to the right.
Figures 8a and 8b show a further exemplary embodiment of a heat exchanger, generally indicated by the reference number 601, with independent circuits arranged on several levels, and with a series and parallel coupling.
The heat exchanger of the shown embodiment comprises three independent circuits, each of which being arranged on a different level, i.e. two with a parallel coupling and the other with a series coupling, and each being traversed by a different secondary fluid.
More specifically, the secondary fluid F2 passes in parallel through the tubes of the heat exchanger on the first level.
The secondary fluid F3 sequentially passes through the tubes of the heat exchanger on the middle level from the left to the right, whereas the secondary fluid F4 passes in parallel through the tubes of the third level heat exchanger.
Thus, the heat exchanger according to the present invention can comprise a plurality of mutually independent secondary circuits, with different characteristics and being traversed by different nature and/or purpose fluids, such as, for example, heating water, sanitary water, refrigerating gas, and so on.
In particular, each secondary circuit can operate in an independent manner from the other secondary circuits: simultaneously with the other, or alternatively with the other, with different or like exchanged powers and fluid flow rates.
In this connection, it should be pointed out that all the secondary fluids are separated from one another by a double-wall.
This feature is such as preventing any mutual polluting of the fluid in all the operating conditions, thereby providing a heat exchanger which is very useful in hygienic parasanitary applications, in which this safety is required.
Moreover, the heat exchanger according to the present invention can be made of different materials, depending on its applications, but, preferably though not exclusively, being made of copper, steel, stainless steel, aluminium, plastics materials, and so on.
It has been found that the invention fully achieves the intended aim and objects.
In fact, the invention provides an improved heat exchanger construction, which comprises a lot of advantageous features.
In particular, the heat exchanger according to the present invention allows to combine a plurality of heat exchanger circuits to form an individual construction, while providing a full separation of the heat exchanger circuits, owing to the provision of the above mentioned double wall, thereby the subject heat exchanger can be advantageously used in boilers, preferably though not exclusively provided for producing hot water for heating purposes and warm water for hygienic-sanitary uses.
The specifically designed features of the heat exchanger according to the present invention allow it to be used in heat generators including atmospheric premixed, blown, catalytic burners, operating based on gaseous, solid and liquid fuels, or generators using other heat sources.
Thus, the possibility of using different materials for making the heat exchanger according to the present invention allow said heat exchanger to be used in different types of generators, such as conventional heat generators, condensation generators, and so on.
Moreover, the heat exchanger according to the present invention can also be used in heat recovery or refrigerating apparatus.
In fact, the constructional feature and combination of several separated circuits into a single heat exchanger, allow to obtain a lot of different advantages.
The boiler bodies, in particular, can be of a very compact construction, with built in hydraulic circuits for heating purposes, providing hot water, recovering heat from combustion fumes, refrigerating purposes, and so on.
As stated, the heat exchanger circuits are completely independent from one another, both from an operation standpoint and from a heat exchanging capability (flow rates, exchanged powers and so on) standpoint.
The inner circuits of the subject heat exchanger, furthermore, operate in a very efficient manner, which will allow the subject heat exchanger to be used in condensation boilers for providing sanitary use hot water.
Actually, prior thermal generators have a sanitary hot water efficiency which is much less than that of the subject heat exchanger.
Moreover, the heat exchanger according to the present invention has a small heat exchanger mass, allowing to greatly reduce its overall thermal inertia, while providing a high speed in responding to thermal load variations and reducing to a minimum undesired thermal leakages.
Moreover, the blade elements associated to the heat exchanger tubes can be made with a very low making waste, since they can be constructed without using molding and shearing operations, as it would be necessary in conventional finned heat exchanger, thereby providing a great reduction in the material and operating cost.
In addition to the foregoing, it is to be further added that it is possible to make the subject heat exchanger by a fully automatized making process, and this owing to the specifically designed mechanical construction of the heat exchanger.
Furthermore, the heat exchanger according to the present invention operates with a very small load loss at the primary fluid side, with a great reduction of the atmospheric pollution.
Furthermore, in the case in which the heat exchanger is used with gas burners, the above mentioned small load loss will provide a great reduction of the CO and NOx emissions, and a very low electric consume for driving the primary fluid conveying members, including, for example, fans, pumps, and so on.
In this connection it should be moreover pointed out that the subject heat exchanger can comprise any desired numbers of operating levels, depending on its applications and uses.
Actually, the subject heat exchanger construction comprises a plurality of tubes which can have either an equal circular, rectangular, flattened and/or contoured cross section.
As stated, the subject heat exchanger comprises one or more independent heat exchanger circuits therethrough different fluid can be conveyed with different and independent features and flow rates.
The subject heat exchanger construction, as stated, comprises any desired number of operating levels, depending on its use and applications.
In practicing the invention, the used materials, as well as the contingent size and shapes, can be any, according to requirements.

Claims

A heat exchanger construction, characterized in that said heat exchanger construction comprises a plurality of tubular elements, therebetween at least a continuous zig-zag or fretted blade element is arranged, said blade element being made rigid with said tubular elements to provide a heat transmission between a secondary fluid, circulating in the tubular elements, and a primary fluid cross-traversing the tubular element and blade assembly.
A heat exchanger construction, according to claim 1, characterized in that each said blade or fin element is made rigid with said tubes therewith said blade elements is in contact, by welding, glueing methods or the like coupling methods and/or by a mechanical type of coupling.
A heat exchanger construction, according to claim 1 or 2, characterized in that said tubes are arranged on several levels.
A heat exchanger construction, according to one or more of the preceding claims, characterized in that said tubes are series coupled, on a single level.
A heat exchanger construction, according to one or more of the preceding claims, characterized in that said tubes are coupled in parallel on a single level.
A heat exchanger construction, according to one or more of the preceding claims, characterized in that said tubes are series coupled on several levels.
A heat exchanger construction, according to one or more of the preceding claims, characterized in that said tubes are coupled in parallel on several levels.
A heat exchanger construction, according to one or more of the preceding claims, characterized in that said heat exchanger construction comprises independent circuits on several levels and being series coupled.
A heat exchanger construction, according to one or more of the preceding claims, characterized in that said heat exchanger construction comprises a plurality of independent circuits, each arranged on one or more different levels, with a series coupling, and being traversed by a different secondary fluid.
A heat exchanger construction, according to one or more of the preceding claims, characterized in that a first secondary fluid passes through the exchanger tube on a first level, a second secondary fluid passes through the exchanger tubes of the second level, and further "n" secondary fluids pass through the exchanger tube on subsequent "n" levels.
A heat exchanger construction, according to one or more of the preceding claims, characterized in that said heat exchanger construction comprises independent heat exchanger circuits on several levels with a series, parallel coupling, or with a series/parallel combined coupling.
A heat exchanger construction, according to one or more of the preceding claims, characterized in that said heat exchanger construction comprises a plurality of independent circuits, each arranged on a different level, some of said circuits being coupled in parallel and other of said circuits being coupled in series, and each being traversed by a different secondary fluid; a first secondary fluid passing through the tubes of the exchanger on the first level; a second secondary fluid passing through the tubes of the exchanger of the second level, whereas further "n" secondary fluids pass through the exchanger tubes on the following "n" levels.
A heat exchanger construction, according to one or more of the preceding claims, characterized in that said heat exchanger construction comprises a greater or smaller number of levels, depending on its applications and uses.
A heat exchanger construction, according to one or more of the preceding claims, characterized in that said heat exchanger forming tubes have a circular, oval, rectangular, flattened and/or contoured cross section.
A heat exchanger construction, according to one or more of the preceding claims, characterized in that each said independent circuit is traversed by fluids having different and independent characteristic flow rates.
A heat exchanger construction, according to one or more of the preceding claims, characterized in that said heat exchanger construction comprises a plurality of heat exchanger bodies or parts which are discrete and/or mutually connected.
A heat exchanger construction, according to one or more of the preceding claims, characterized in that said heat exchanger construction has a small mass and thermal inertia, with a high response speed with respect to thermal load variations and with a great reduction of undesired thermal leakages.
A heat exchanger construction, according to one or more of the preceding claims, characterized in that said heat exchanger construction has a small load loss on the primary fluid side, thereby operating with a very low polluting operation level.
A heat exchanger construction, according to one or more of the preceding claims, characterized in that said heat exchanger construction comprises one or more of the disclosed and/or illustrated features.