WO2005106331A1

WO2005106331A1 - Water heater recovering heat from a flue gas flow

Info

Publication number: WO2005106331A1
Application number: PCT/FI2005/000183
Authority: WO
Inventors: Matti Huttunen
Original assignee: Savumax Oy
Priority date: 2004-05-04
Filing date: 2005-04-13
Publication date: 2005-11-10
Also published as: FI20040635A0

Abstract

The invention relates to a multi-function pipe, which has a heat recovery assembly, comprising a water-space (1), which is to be heated by means of heat recovery from a flue gas flow, the water-space being disposed in connection with a flue gas channel (s), being led to the multi-function pipe from a heat source, such as a combustion chamber, firebox and/or the like, the water-space being formed from a jacket structure that surrounds the flue gas channel (s) uniformly. The water-space is furthermore arranged as a tank charger operating on so called boiler water principle by providing it with one or several heat transfer coils (2a). The jacket structure (1'), surrounding said water-space (1), is arranged as a so called open expansion tank, being provided with means (x) particularly for eliminating evaporation, taking place from the water surface, and oxidation of water.

Description

Multi-function pipe

The invention relates to a multi-function pipe, which has a heat recovery assembly, comprising a water space, which is to be heated by means of heat recovery from a flue gas flow, the water-space being disposed in connection with a flue gas channel, being led to the multi-function pipe from a heat source, such as a combustion chamber, firebox and/or the like, the water-space being formed from a jacket structure that surrounds the flue gas channel uniformly. The water- space is arranged furthermore as a tank charger, operating on so called boiler water principle by providing it with one or several heat transfer coils.

Very many kinds of solutions may be found from prior art, in which heat is being recovered from different kinds of flue gas channels by means of a tank charger existing therewith. This type of solutions are being used e.g. in a way that water, being heated in a tank charger, is used as such as service water, whereby such a problem is involved therewith that heat can not be recovered after the temperature of the water-space has raisen adequately due to low service water consumption.

Furthermore e.g. from French application document 2 615 273 it is known to exploit a tank charger in connection with a flue gas channel, whereby heat is being recovered by means of a heat transfer coil. On the other hand, in Finnish utility model No. 5196 there has been presented an apparatus , which comprises a water-space to be heated by heat, being recovered from a flue gas flow. The apparatus is meant particularly as a tank charger for warm service water, such as a boiler or like, wherein it is formed from a jacket structure, such as a pipe or box structure or like, surrounding the flue gas channel uniformly. Particularly with the type of the solutions described above, because the water-spaces thereof are totally closed structures, such a problem is involved that a separate expansion tank must be used due to temperature variations of the water, in addition to which the flue gas channel and the jacket structure surrounding the same must be coupled with each other in a pressure resistant way and by joint arrangements enabling their mutual movement, such as by bellow joints. These kinds of arrangements are, however, very risky particularly in chimney use with respect to tightness of the expansion joints typically due to bursts caused by metal fatique in long lasting use.

It is an aim of a multi-function pipe, equipped with a heat recovery assembly, according to the present invention, to achieve a decisive improvement in the problems described above and thus to raise essentially the level of prior art. In order to carry out this aim, the invention is mainly characterized by that the jacket structure, surrounding said water-space, is arranged to operate as a so called open expansion tank, being provided with means particularly for eliminating evoporation, taking place from the water surface, and oxidation of water.

As the most important advantages of the multi-function pipe according to the invention, thanks to it being non-pressurized, may be mentioned the simplicity and efficiency of its structure and operation. The above advantages are first of all due to the fact that separate expansion tanks as well as expansion joints between the tank charger and the flue gas channel that are linked up with traditional pressurized arrangements may be avoided. On the other hand, thanks to the invention, it is furthermore possible to avoid those problems, related to open-type tank chargers, first of all with a view to natural evaporation from heated water and on the other hand with a view to water oxidation, which causes corrosion of pipes and devices. On the other hand, the invention makes also possible supply of a multi-function pipe, being equipped with a heat recovery assembly, according to the invention, to an installation site in each desired composition in a ready finished state or as parts that can easily be put together, in which case also its service may be carried out easily e.g. by replacing the part entireties belonging to the same. One crucial advantage of the multi-function pipe according to the invention is also the fact that its need for space is very minimal, since a traditional service water tank charger, to be placed usually separately indoors, is not needed, either.

One further significant advantage of the multifunction pipe according to the invention is the fact that, when being carried out as an advantageous embodiment as an integral chimney element, it is possible to provide the same in an integral manner with heat recovery, charging of warm service water and e.g. energy production for floor heating, as well as heat recovery for energy produced by e.g. a solar charger or the like. Thus the invention makes possible a very integral heat recovery entirety, operating e.g. as an integral heat center of a one-family house, the investment, installation and operating costs of which are significantly lower than the same of those present heating, plumbing and air conditioning arrangements, based on totally separate devices . Thanks to the invention, also a heat leakage, heating inconveniently spaces surrounding a traditional chimney e.g. during heating of a sauna, may be totally eliminated, whereby the "left over energy" gets charged to the multifunction pipe's water-space. As an advantageous embodiment, the multi-function pipe is furthermore totally insulated, which for its part also minimizes heat leakage to the environment .

Advantageous embodiments of the multi-function pipe according to the invention have been presented in the dependent claims related to the same.

In the following specification, the invention is being depicted in greater detail with reference to the accompanying drawings, in which

in figure 1 is shown a longitudinal cross section of an advantageous embodiment of a multi-function pipe according to the invention,

in figure 2 is shown a cross section of an alternative multi-function pipe embodiment with respect to the one shown in figure 1,

in figure 3 is shown an advantageous cross section of a multi-function pipe according to the invention, and

in figure 4 is shown an alternative embodiment particularly with respect to the one shown in figure 3.

The invention relates to a multi-function pipe, which has a heat recovery assembly, comprising a water-space 1, which is to be heated by means of heat recovery from a flue gas flow, the water-space being disposed in connection with a flue gas channel s, being led to the multi-function pipe from a heat source, such as a combustion chamber, firebox and/or the like, the water-space being formed from a jacket structure that surrounds the flue gas channel s uniformly. The water- space is arranged furthermore as a tank charger, operating on so called boiler water principle by providing it with at least one heat transfer coil 2a. The jacket structure 1', surrounding said water-space 1, is arranged as a so called open expansion tank, being provided with means x particularly for eliminating evaporation, taking place from the water surface, and oxidation of water.

As a particularly advantageous embodiment with reference to the enclosed drawings, the multi-function pipe suits particularly well for being used as a so called integral chimney element or like. In this case the jacket structure 1', surrounding said water-space 1, is formed from a uniform pipe or box structure that surrounds a flue gas channel s from at least one heat source, such as a heating boiler, and which is provided with a bottom part bp, equipped with necessary leading-through openings and being fastened by welding or a like manner in connection with the flue gas channel s . Said water-space 1 is arranged non-pressurized by providing its upper end with pressure balancing assemblies y, such as air flow openings or the like disposed in its end plate ep.

Furthermore as an advantageous embodiment, the means x for eliminating evaporation from the water surface and oxidation of water are carried out by a material layer xl, disposed on the surface of the water-space 1 and being lighter than water. This kind of a material layer xl, preventing evaporation and oxidation, may be carried out advantageously by an oil-, gel-, silicon-based and/or the like medium, the height h of which being e.g. in the range of 30 - 400 mm. Particularly vegetable based oils, such as rapeoil, due to being environmentally friendly, have been found in practice to have technical potential in this kind of purpose.

Depending on the composition of the medium acting as the material layer, it may be advantageous to mix it up e.g. with a preservation and/or colour substance. Furthermore it is naturally possible to add e.g. a corrosion prevention substance to the water existing in the water-space.

Furthermore as an advantageous embodiment, the jacket structure 1 ' is coupled by its upper part in connection with the flue gas channel s by means of a coupling assembly enabling free mutual longitudinal movement of said parts (this kind of an arrangement has not been shown in greater detail in the drawings) . Furthermore, at the upper part of the water-space 1 is disposed an overflow pipe yp, being led advantageously to a sewage point, such as a floor drain, which makes sure that the level of water can not raise too high in the water-space 1. This overflow pipe may advantageously act also as a pressure balancing assembly of the kind, being described above.

Furthermore, as an advantageous embodiment a monitoring means 3, such as an observing glass or like for observing visually the fluid level, is disposed at the upper part of the jacket structure 1' . In this connection it is possible to use also different kinds of float or swimmer indicators as mechanical and/or electronic embodiments.

Particularly with reference to the embodiment shown in figures 2 and 4, the flue gas channel s and one or several heat transfer coils 2a in the water-space 1, such as a service water-, floor heating- or solar heating-coil, are disposed eccentrically, such as side by side or in a corresponding manner, when viewed in a cross section.

As an advantageous embodiment of the invention, the flue gas channel s and the jacket structure l¹ of a multi-function pipe, being placed vertically on the ground supported by feet 4 belonging thereto, are manufactured e.g. from acid-resistant steel. Furthermore the water-space 1 surrounding the flue gas channel may be equipped e.g. with safety valves, which are not necessarily needed thanks to the open expansion principle being exploited. Furthermore it is naturally possible to exploit a heat recovery assembly as shown e.g. in figures 1 or 2 in a way that a cooling flow e.g. for floor heating of an outdoor space or a like utility purpose, is initiated through one heat transfer coil, when the temperature starts to raise .

A multi-function pipe according to the invention may be exploited furthermore in a way that the water inside the water-space 1 is being circulated e.g. for floor heating or central heating purposes . On the other hand it is also possible to provide the water- space 1 with electric resistors 5, by means of which heating of the water-space 1 can be secured, in case the energy consumption from the water-space occasionally exceeds its heat charging capacity.

It is clear that the invention is not limited to the embodiments presented or described above, but instead it can be varied according to the needs of any given time within the scope of the invention's basic idea. It is thus naturally clear that first of all the means for preventing evaporation, taking place from the water surface, and oxidation of water, may be carried out by a mechanical film or lid moving in the direction of height along with the water level, carrying out of which adequately reliably is, however, more difficult than carrying out the same with a material layer in liquid form of the type described above. On the other hand, the multi-function pipe according to the invention may be carried out in very many ways also for the part of those couplings and equipmentation related to heating, plumbering and air conditioning. Furthermore the total volume of the water-space to be heated may naturally by suited according to the needs of any given time in a way that it surrounds the flue gas channel for an adequately long distance in order to achieve an adequate total volume for the charger. The thickness of the water jacket, surrounding the flue gas channel, is as an advantageous embodiment e.g. approximately 50 - 150 mm. From the point of view of manufacturing costs, it is naturally most advantageous to manufacture the jacket structure, forming the heated water-space, from round pipe, but naturally it is also possible to use, e.g. as shown in figure 4, oval-shaped or e.g. four- cornered forms, which may further exploitation of the invention when equipping old structures.

Claims

Claims :

1. Multi-function pipe, which has a heat recovery assembly, comprising a water-space (1) , which is to be heated by means of heat recovery from a flue gas flow, the water-space being disposed in connection with a flue gas channel (s) , being led to the multifunction pipe from a heat source, such as a combustion chamber, firebox and/or the like, the water-space being formed from a jacket structure that surrounds the flue gas channel (s) uniformly and, the water- space being arranged as a tank charger, operating on so called boiler water principle by providing it with at least one heat transfer coil (2a) , characterized in that the jacket structure (1'), surrounding said water-space (1), is arranged as a so called open expansion tank, being provided with means (x) particularly for eliminating evaporation, taking place from the water surface, and oxidation of water.

2. Multi-function pipe according to claim 1 being used particularly as a so called integral chimney element or like, wherein the jacket structure (l¹), surrounding said water-space (1), is formed from a uniform pipe or box structure that surrounds a flue gas channel (s) from at least one heat source, such as a heating boiler, and which is provided with a bottom part (bp) , equipped with necessary leading-through openings and being fastened by welding or a like manner in connection with the flue gas channel (s) , characterized in that said water-space (1) is arranged non-pressurized by providing its upper end with pressure balancing assemblies (y) , such as air flow openings or the like disposed in its end plate (ep) .

3. Multi-function pipe according to claim 1 or 2 above, characterized in that the means (x) for eliminating evaporation from the water surface and oxidation of water are carried out by a material layer (xl) , disposed on the surface of the water-space (1) and being lighter than water.

4. Multi-function pipe according to claim 3, characterized in that the material layer (xl) preventing evaporation and oxidation is carried out by an oil-, gel-, silicon-based and/or the like medium, the height (h) of which being in the range of 30 - 400 mm.

5. Multi-function pipe according to any of the preceding claims 1 - 4, characterized in that the jacket structure (1') is coupled by its upper part in connection with the flue gas channel (s) by means of a coupling assembly enabling free mutual longitudinal movement of said parts .

6. Multi-function pipe according to any of the preceding claims 1 - 5, characterized in that at the upper part of the water-space (1) is disposed an overflow pipe (yp) , being led preferably to a sewage point .

7. Multi-function pipe according to any of the preceding claims 1 - 6, characterized in that a monitoring means (3), such as an observing glass, float indicator or like for observing visually the fluid level, is disposed at the upper part of the jacket structure (1').

8. Multi-function pipe according to any of the preceding claims 1 - 7, characterized in that the flue gas channel (s) and one or several heat transfer coils (2a) in the water-space (1) , such as a service water-, floor heat-, solar heating-coil and/or like are disposed eccentrically, such as side by side or in a corresponding manner, when viewed in a cross section.