FR2619200A1 - HEATING BOILER BODY WITH FLUID HEAT PUMP - Google Patents

Abstract

The invention relates to a heat-transfer fluid heating boiler body which is intended to receive at least one burner and is surrounded at least partially by a jacket (3) for circulation of said fluid, said jacket (3) comprising an outlet (5) for the heated fluid, which is arranged in the bottom part of the latter, and an inlet (4) for the cooled return fluid, which is arranged in the top part of said water jacket (3). The body of the boiler according to the invention is characterised in that the inlet (4, 4', 4'') of the return fluid is arranged in such a manner that the fluid is distributed into said jacket in a number of places at the same time.

Description

The invention relates to a boiler body for fluid heating

  coolant, intended to receive at least one burner and which

  is at least partially wrapped in a circular shirt

  said fluid, which constitutes the heat exchanger of the

boiler.

  In a conventional boiler provided with a body of the aforementioned type, the fluid used is usually water. When the boiler is in operation, because of differences in density, the water is distributed up and down according to its temperature, the water of the upper zone having a temperature

  significantly higher than the water from the bottom area.

  It is then conventional to arrange a departure of the heated water, to radiators or tubes embedded in a soil for example, in the top of the shirt, and an arrival of cooled water back, in the bottom of said shirt, ie in the coldest zone. In this way there is a very important temperature gradient between the top and the bottom which has the major drawbacks of increasing the risks of boiling in the

  top and condensation in the bottom.

  It is clear that the inner wall of the water jacket serves as a heat exchange surface between the combustion gases from the burner and the water flowing in the jacket. However, he knows that the combustion gases in contact with a relatively cold surface undergo the phenomenon of

  condensation also known as the phenomenon of dew.

  It is also known that such a condensation of the combustion gases leads to the formation of sulfuric acid that is particularly corrosive to the apparatus, especially when the fuel used is domestic fuel oil or heavy fuel oil, because

their high percentage of sulfur.

  The phenomenon of condensation appears when the

  temperature drops below about 55 degrees C, but it is

  that the temperature of the return water from the

  or at least 20 degrees C. Up to now, the risk of condensation and therefore of corrosion has been limited by the large volume of the shirts.

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  of conventional water, in which the cold water

  mix with hot water before matching their inner wall.

  However, for a reduced volume water jacket, which is increasingly sought to reduce congestion, the aforementioned phenomena are of great importance, especially at the chosen location for the return of the cooled water, in what

  concerns condensation and therefore corrosion.

  In addition, when the vertically arranged water jacket has a small thickness (for the reasons mentioned above), it appears a stratification phenomenon, that is to say that the temperature of the water varies from one end to the other of the

  boiler in slices or isothermal layers.

  To solve the problems of condensation it is obviously possible to use materials such as stainless steel or cast iron ... However, the inventor has solved the problem by means of several original solutions. He first overcame a prejudice by imagining a remarkable boiler body in that the arrival of the return fluid is arranged in the upper part of the water jacket while the departure of the

  heated fluid is arranged in the lower part of said jacket.

  Thus the cooled water arrives in the hottest zone so that, on the one hand, the condensation phenomenon is at least partially solved and, on the other hand, this arrangement makes it possible to obtain homogenization of the temperature by natural convection avoiding the use of a conventional circulation pump generally intended to circulate the water between

  the bottom and the top of the water shirt.

  To further reduce the harmful effects of condensation and in particular to remove the traditional "cold spot" (place of arrival of the return water), while promoting the homogenization of the temperature, the arrival is advantageously arranged so such as the fluid is

  distributed in said folder in several places at the same time.

  According to one embodiment, the inlet comprises a pipe which terminates in a geometrically open ring, the latter being provided with a plurality of orifices through which

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  the fluid is dispensed.

  In order, on the one hand, to preheat the return water before feeding into the liner and, on the other hand, to provide an arrival in the low or median zone to avoid connection errors due to the force of the the inventor's practice of installers proposes an embodiment which is remarkable in that the arrival comprises a pipe which is connected in the lower or middle part of the jacket and which goes up in it

towards its upper part.

  For similar reasons of usual branch, the departure advantageously comprises a pipe that originates in the lower part of the shirt and goes back into it

  to get out in the upper part.

  The invention will be well understood on reading the

  description which will follow and which refers to the attached drawings

  in which: - there figure 1 shows in perspective with tearing

  partial, the body of a boiler, according to the invention.

  FIG. 2 is a longitudinal section of the body of the

figure 1.

  FIG. 3 is a section along III-III of FIG.

  In the drawings we can see a body 1 formed at least in part by a cylinder arranged vertically and intended to receive, generally in the lower part, a burner (no

represented), fuel for example.

  The body 1 is surrounded by another cylinder 2 coaxial and of a diameter greater than that which forms said body and which is closed so that a volume is formed between the walls of said cylinders, in which water circulates. This volume thus comprised between the body 1 and the cylinder 2 constitutes a water circulation jacket 3 which envelops the major part of said body 1. The jacket 3 here has a relatively low volume, the

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  height being quite important for a particularly small thickness. The water jacket 3 is provided with an inlet pipe 4 for the return water coming from the heating apparatus of the installation (radiators or other) and a starting pipe for the heated water which is sent to said heaters. As clearly shown in FIGS. 1 and 2, the inlet pipe 4 is connected in the jacket 3 substantially under its median horizontal plane, and goes up in said jacket by a vertical portion 4 'to end in a ring shape.

  geometrically open 4 "(Figures 1 to 3).

  The ring 4 "is disposed in a substantially horizontal plane and has a plurality of orifices such as 6 intended

  to distribute the return water in the upper part of the shirt 3.

  The starting pipe 5, originates in the lower part of the jacket 3, and goes up by a vertical part 5 'in

  said jacket 3 to exit at the top of it.

  If FIGS. 2 and 3 show diametrically opposed pipes 4 and 5, contrary to FIG. 1, it is clear that it is for the sake of clarity of the drawings that the connection of the pipe 4 with respect to the outlet of FIG. driving 5 can of course be located in other places than

the one represented.

  The drawings clearly show how the inlet pipe 4, which seems to be plugged downwards, distributes the water in fact at the top of the jacket after having bathed by 4 'in said jacket so as to allow preheating of the cooling water. return. The latter is uniformly distributed around the circumference of said jacket 3 thanks to the orifices 6 formed in the part of

ring 4 ".

  Given the high position of the distribution of the return water, the natural circulation of the latter by convection from bottom to top is thwarted by the forced circulation which is imposed on it from the top to the bottom so that it brewing results in mixing and homogenization of the

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  temperature. Temperature measurements have found that it is fairly uniform throughout the jacket, so much so that it is possible to have the measuring probe of the control aquastat of the burner, substantially in the middle of said jacket. Moreover, this is why the departure of the hot water can then advantageously be provided as shown by the drawings in FIG.

bottom of the shirt.

  It is interesting to point out again the role of the reversals of position between the connection of the inlet pipe 4 towards the bottom (whereas it goes up in a hidden way upwards) and the exit of the starting pipe 5 towards the top

  (while she is born in the bottom).

  Apart from the aforementioned advantages, these non-mandatory provisions make it possible to avoid connection errors, because if it is customary to differentiate by marking the departure and arrival lines, there could be a risk of reversal of connection by habit, during installation, if said inlet pipes 4 and the departure 5 were arranged in part respectively high and low, which shows, if necessary, the prejudice that had to be overcome to adopt such a provision. It is clear that the general shape of the boiler body shown in the drawings can be any. Indeed, if it is advantageous to make said body and the outer casing by means of cylinders of revolution, this is not mandatory, and it is possible to imagine other shapes,

polygonal for example.

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Claims (4)

  1) heat transfer heating boiler body for receiving at least one burner and which is at least partially enveloped by a jacket (3) for circulating said fluid, which jacket (3) comprises a flow (5) for the fluid heated and an inlet (4) of the cooled return fluid, boiler body characterized in that the inlet (4,4 ', 4 ") of the return fluid is arranged in the upper part of the water jacket (3 ) while the flow (5,5 ') of the heated fluid is   arranged in the lower part of said shirt.   2) boiler body according to claim 1 characterized in that the inlet (4,4 ', 4 ") is arranged in such a way that the fluid is distributed in said jacket in several places in same time.   3) Boiler body according to one of claims 1 and   2 characterized in that the inlet comprises a pipe (4,4 ') which terminates in a geometrically open ring (4 "), the latter being provided with a plurality of orifices (6) through which the distribution of the fluid.   4) Boiler body according to one of claims 1 to 3   characterized in that the inlet comprises a pipe (4) which is connected in the lower or middle part of the jacket (3) and which   up (4 ') in it towards its upper part.   Boiler body according to one of claims 1 to 4   characterized in that the departure comprises a pipe (5) which originates in the lower part of the jacket (3) and which   go up (5 ') in it to get out in its upper part.