FR3030028A1 - DEVICE FOR HEATING A WATER FLOW BY THERMAL EXCHANGE WITH A DRAINAGE WATER FLOW - Google Patents

Abstract

The subject of the invention is a device for heating a fluid flow (F) by heat exchange with a drainage water flow (FF), comprising: - an outer tube (2), - an assembly (3) of circulation ducts (4) of said fluid to be heated (F), each of the ducts (4) extending helically along a portion of an inner wall (5) of said outer tube (2), and the ducts ( 4) being parallel to each other, and - an inlet (7) of said drainage water flow (FF) configured to cooperate with said outer tube (2) and / or said set (3) of conduits (4), so that said set (3) of ducts (4) form guide channel (10) of the drainage water (FF).

Description

The invention relates to a device for heating a fluid flow by heat exchange with a flow of drainage water. Drainage water is any waste water, that is any water intended to be conveyed to a treatment plant. In particular, the term drainage water includes greywater, that is domestic sanitary wastewater, with the exception of toilet flushing water. The fluid F is preferably intended to feed directly or indirectly a home hot water or a working fluid of a thermodynamic loop of the house. The first fluid flow F is subsequently called water to heat F.

It is known to recover the thermal energy of the drainage water for heating the water flow F, which reduces the cost necessary for heating the water while ensuring a better respect for the environment. Nevertheless, such a recovery of the thermal energy of the drainage water may prove to be a delicate operation insofar as the temperature of the drainage water, in particular the gray water, does not exceed 40 °. C, which typically corresponds to a desired preheating temperature for the water to be heated. Preheating reduces the energy required to reach a desired final temperature for the water to be heated.

An optimization of the heating device is therefore required to improve the heat exchange between the drainage water and the water to be heated. The object of the invention is to overcome this disadvantage.

For this purpose, the subject of the invention is a device for heating a flow of a fluid by heat exchange with a flow of drainage water, comprising: an external tube, a set of circulating said stream of water to be heated, each of the ducts extending helically along a portion of an inner wall of said outer tube, and the ducts being parallel to each other, and - an inlet of said stream of water drainage system configured to cooperate with said outer tube and / or said duct assembly, so that said duct assembly forms a drainage water guiding channel. The device according to the present invention ensures an improved heat exchange between the drainage water and the water to be heated (when the flow of fluid is water to be heated) due to the direct contact between the drainage water. and the conduits on the one hand, and the water to be heated and the conduits on the other hand. According to another characteristic of the invention, the outer tube extends all along the whole of the ducts. According to another characteristic of the invention, the device comprises a unit for supplying fluid to each of the ducts of all the ducts and / or a unit for extracting said fluid out of the device.

According to another characteristic of the invention, the outer tube is made from a plastic material, preferably polyvinyl chloride. According to another characteristic of the invention, the ducts have a circular or rectangular section.

The subject of the invention is also a method of heating a flow of a fluid by a flow of drainage water, said process comprising: a step of circulating said stream of water to be heated in at least one conduit; a set of ducts extending helically along a portion of an inner wall of an outer tube, and the ducts being parallel to each other, - a step of circulating said flow of drainage water from an inlet of said drainage water flow configured to cooperate with said outer tube and / or said set of ducts so that all of the conduits form a channel for guiding the flow of drainage water, into said flow channel; guidance, the circulation stages of the water flow to be heated in each duct and circulation of the drainage water flow in the guide channel being at least partly simultaneous, so that there is a thermal exchange between the flow of drainage water and the flow of fluid ( possibly, water to heat). According to another characteristic of the invention, the drainage water flows against the conduits of the guide channel.

Preferably, the drainage water flows only against the ducts of the guide channel.

The subject of the invention is also a device for heating a flow of a fluid by heat exchange with a drainage water flow, comprising: a central tube; a set of circulation ducts of said flow of water; fluid, each of the ducts extending helically along a portion of an outer wall of said central tube, and the ducts being parallel to each other, and each of the helical ducts being delimited at least partially by a fin and 10 - an outer tube. Other features and advantages of the invention will become apparent on reading the description which follows. This is purely illustrative and should be read with reference to the accompanying drawings, in which: FIG. 1 is a perspective view of a heating device according to a first embodiment of the invention, FIG. a sectional view along an axis X of the device of FIG. 1 according to a first variant; FIG. 3 is a sectional view along the X axis of the device of FIG. 1 according to a second variant; FIG. a timing diagram of a heating method according to the present invention; - FIG. 5 is a top view of a heating device according to a second embodiment of the invention, and FIG. 6 is a sectional view. along the X axis of the device of FIG.

As illustrated in the figures, the subject of the invention is a device 1 for heating a first fluid flow F by heat exchange with a second flow FF. The first fluid flow F is preferably intended to supply 5 directly or indirectly a home in hot water or a fluid from a thermodynamic loop of the house. The first fluid flow F is preferably liquid monophasic, or liquid and gaseous bi-phasic. The first fluid flow F is subsequently called water to heat F.

The second flow FF is a flow of water preferably from the dwelling that the water of the first flow F will feed, and is subsequently called drainage water. Drainage water is any waste water, that is any water intended to be conveyed to a treatment plant. In particular, the term drainage water includes greywater, that is domestic sanitary wastewater, with the exception of toilet flushing water, for example from a closed circuit in a dwelling. The invention will now be described in connection with FIGS. 1 to 4 illustrating the first embodiment.

As can be seen in FIGS. 2 to 4, the heating device 1 comprises an outer tube 2, and a set 3 of conduits 4 for circulating the flow F of water to be heated. The outer tube 2 has a preferably circular cross section and is delimited by an inner longitudinal wall 5 and an outer longitudinal wall 25. The inner wall 5 defines an internal space E. The walls 5 and 6 extend along an axis X. The X axis is preferably vertical, as will be explained hereinafter. The outer tube 2 is advantageously made from a plastic material, preferably polyvinyl chloride. Each of the ducts 4 extends helically along a portion of the inner wall 5 of the outer tube 2. In other words, the ducts 4 are disposed in the internal volume E of the tube 2. The assembly 3 delimits an internal space E 'in the internal space E. As shown in the figures, the ducts 4 are directed parallel to each other. Preferably, each duct 4 is in contact with the adjacent duct or ducts. The plurality of ducts 4 ensures that the pressure drop is minimized during the flow of the flow F in the device 1.

In the figures are illustrated four ducts 4. Of course, this number is not limiting. The ducts 4 consist of a material having good thermal conduction properties, such as copper. As seen in FIGS. 1 to 3, the flux FF is directed along the X axis, which coincides with the vertical axis from top to bottom. The flow FF is directed in the opposite direction to the flow F, that is to say that the flow of water to be heated F up the ducts 4 from bottom to top. In the figures, the outer tube 2 extends all along the assembly 3 of ducts 4.

The outer tube 2 seals the device 1 in the case where the sealing of the guide channel 10 formed by the assembly 3 would be imperfect. The device 1 also comprises an inlet 7 of the water flow FF configured to cooperate with the outer tube 2 and / or the set of ducts 4, so that the assembly 3 of ducts 4 forms a guide channel 5 of FIG. drainage water FF. In other words, the flow of water FF circulates in the guide channel 10 constituted by the set 3 of conduits 4. The guide channel 10 extends mainly along the axis X. As can be seen in the figures, the inlet 7 has a general shape 10 of a cylindrical tube, one end 8 of which is intended to be connected to a pipe of the dwelling. Another end 9 of the tube 7 is blown into the guide channel 10. The device 1 comprises a unit 11 for supplying water to heat at least one of the ducts 4 of the assembly 3. In the figures, the unit 11 4. As shown in Figure 1, the unit 11 is arranged at the bottom of the device 1, so that the flow of water F back in the ducts 4, as already mentioned.

The device 1 also comprises a unit 12 for extracting the water out of the device 1. According to the first variant illustrated in FIG. 2, each duct 4 has a section of generally circular shape. According to the second variant illustrated in Figure 3, each duct 4 has a section of generally rectangular shape. The rectangular general section avoids a detachment of the flux 3030028 8 FF and ensures an optimized energy transfer. The operation of the device 1 will now be described in connection with the method of heating the water flow F with the FF flow of drainage water according to the present invention.

As can be seen in FIG. 4, the method 20 comprises: a step 21 for circulating the water flow F in at least one duct 4 of the assembly 3; a circulation stage 22 for the flow FF of water of drainage from the inlet into the guide channel 10.

The circulation stages 21 and 22 are at least partly simultaneous, so that there is a heat exchange between the drainage water flow and the water flow to be heated. In particular, the device 1 ensures that the heat exchange between the drainage water and the water to be heated is optimized since each duct 4 forms the only interface between the two water flows F and FF. Preferably, the device 1 is arranged vertically, so that the X axis coincides substantially with a vertical axis. As already mentioned, the flow flow F is against the flow FF.

The two-way circulation makes it possible to ensure that the temperature of the water flow F at the outlet of the device 1 is close to the desired final temperature, since the temperature of the water of the flow FF is the highest at the level of the water. input 7 then decreases as the flow of water FF goes down in the device 1.

The vertical arrangement of the device 1 ensures an easy circulation of the drainage flow FF by gravity at the same time as it does not constitute an obstacle to the rise of the water in each duct 4, since each duct carries a larger mass. low water compared to the drainage water mass in the guide channel 10. Preferably, in the vertical position of the device 1, the drainage water FF flows against the ducts 4 of the guide channel 10, rather than at the center of the guide channel, which facilitates thermal transfer regardless of the flow rate of the draining water flow FF. The invention will now be described in connection with FIGS. 5 and 6 illustrating a second embodiment of the invention.

As can be seen in FIGS. 5 and 6, the invention also relates to a device 30 for heating a water flow F by heat exchange with a drainage water flow FF, comprising: a central tube 31 a set 33 of ducts 34 for circulating the flow of water F to be heated, and - an external tube 32. The central tube 31 comprises an inner longitudinal wall 35 and an outer longitudinal wall 36. The inner wall 35 delimits a internal space E.

The walls 35 and 36 extend along an axis X. The axis X is preferably vertical, as explained for the first embodiment. Each of the ducts 34 extends helically along a portion of the outer wall 36 of the central tube 31. The outer tube 32 is coaxial with the central tube 31 and the ducts 34.

As shown in FIG. 5, each duct 34 is partially delimited by a fin A.

Preferably, each duct 34 is delimited by two consecutive walls 38 of the fin A as well as by the outer wall 36 of the central tube 31 and the inner wall of the outer tube. A fin is an element known to those skilled in the art from a deformation of a thermal conductive material, such as copper. In the figures, the ducts 34 extend over the entire length of the outer wall 35, that is to say that the portion 38 extends over the entire length of the wall 35. Nevertheless, the ducts 34 may not extend only partially on the wall 35, the portion 38 then coinciding with only part of the wall 35. The ducts 34 are arranged in the internal volume E of the tube 32. The assembly 33 defines an internal space E 'in the inner space E. As shown in the figures, the walls 38 are directed parallel to each other. The walls 38 extend radially between the central tube 31 and the outer tube 32. The fin A ensures that the pressure drop is minimized during the flow flow F in the device 1.

In the figures, the outer tube 32 extends all along the set 3 of conduits 34. The outer tube 32 seals the device 1. The device 1 also comprises an inlet 37 of the water flow FF in the device 30.

The FF water flow circulates mainly vertically, from top to bottom. As can be seen in FIGS. 5 and 6, the flux FF is directed along the X axis, which coincides with the vertical axis, from top to bottom. The flow FF is directed in the opposite direction to the flow F, that is to say that the flow of water to be heated F back the ducts 34 from bottom to top. Preferably, in the vertical position of the device 1, the draining water 5 FF flows against the ducts 34, rather than in the center of the guide channel, which facilitates the heat transfer whatever the flow rate of the flow of water. drainage water FF. In the embodiment illustrated in FIGS. 5 and 6, the heat exchange takes place between the flows F and FF, a single interface between the two flows consisting of the central tube 31, since the walls 38 extend radially and do not form a barrier during the heat exchange between the two flows F and FF.

Claims (9)

REVENDICATIONS1. Device for heating a flow of a fluid (F) by heat exchange with a drainage water flow (FF), comprising: an outer tube (2), a set (3) of circulation ducts (4) said fluid to be heated (F), each of the conduits (4) extending helically along a portion of an inner wall (5) of said outer tube (2), and the conduits (4) being parallel to each other; other, and an inlet (7) of said drainage water flow (FF) configured to cooperate with said outer tube (2) and / or said duct assembly (3), so that said assembly (3) of ducts (4) forming a guide channel (10) of the drainage water (FF) constituting a single heat exchange interface between the fluid flow (F) and the drainage water flow (FF). 2. Heating device according to claim 1, wherein the outer tube (2) extends all along the assembly (3) of conduits (4). 3. Heating device according to one of claims 1 or 2, comprising a unit (11) for supplying water to heat each of the ducts (4) of the assembly (3) ducts. 4. Heating device according to any one of the preceding claims, wherein the outer tube (2) is made from a plastic material, preferably polyvinyl chloride. 5. Heating device according to any one of the preceding claims, wherein the ducts (4) have a circular or rectangular section. 6. A method of heating a flow of a fluid by a flow of drainage water, said method comprising: a step of circulating (21) said fluid to be heated (F) in at least one conduit (4) an assembly (3) of ducts (4) extending helically along a portion of an inner wall (5) of an outer tube (2), and the ducts (4) being parallel to each other; Another 5, a step of circulating (22) said drainage water flow (FF) from an inlet (7) of said drainage water flow (FF) configured to cooperate with said outer tube (2) and / or said together (3) of conduits (4) so that the assembly (3) of the ducts (4) forms the guiding channel of the drainage water flow (FF) into said guide channel (10), circulating stages (21) of the fluid to be heated (F) in each duct (4) and circulation (22) of the drainage water flow (FF) in the guide channel (10) being at least partly simultaneous , so that there is an ec thermal hange between the drainage water flow (FF) and the fluid flow to be heated (F). 7. Heating method according to the preceding claim, characterized in that the drainage water (FF) flows against the ducts (4) of the guide channel (10). 20 8. Heating method according to claim 7, characterized in that the drainage water (FF) flows only against the ducts (4) of the guide channel (10). 9. A device for heating a flow of a fluid (F) by heat exchange with a drainage water flow (FF), comprising: a central tube (31) for guiding the flow of drainage water ( FF), an assembly (33) of conduits (34) for circulating said stream of water to be heated, each of the ducts extending helically along a portion of an external wall of said central tube, the ducts being parallel to the to each other, and each of the helical conduits being delimited at least partially by a fin (A), said fin (A) comprising at least two walls (38) extending radially so that the central tube (31) constitutes unique heat exchange interface between the fluid flow (F) and the drainage water flow (FF), and an outer tube (32).