EP0924465B1 - Water activated hot water generator - Google Patents

Description

The present invention relates to a hot water generator and particular to a domestic hot water generator.

• une conduite d'entrée d'eau froide reliée à un circuit eau froide,
• une conduite de sortie d'eau chaude reliée à un circuit eau chaude,
• un échangeur de chaleur interposé entre le circuit eau froide et le circuit eau chaude,
• un brûleur à combustible fluide transférant de la chaleur vers l'échangeur de chaleur,
• des moyens de restriction de la conduite d'entrée d'eau froide séparant ladite conduite en un tronçon amont et un tronçon aval et provoquant, lors du passage d'eau froide, une différence de pression entre le tronçon amont et le tronçon aval,
• une enceinte divisée, par un élément déplaçable, en une chambre amont et une chambre aval, la chambre amont étant soumise à la pression régnant dans le tronçon amont de la conduite d'entrée d'eau froide, et la chambre aval étant soumise à la pression régnant dans le tronçon aval de la conduite d'entrée d'eau froide, ledit élément étant déplaçable sous la différence de pression existant entre lesdites deux chambres amont et aval, et
• une alimentation en combustible fluide qui délivre une quantité de combustible asservie au passage d'eau froide dans la conduite d'entrée d'eau froide par l'intermédiaire des déplacements dudit élément déplaçable, les moyens de restriction comprenant :
• au moins un clapet comportant un siège de clapet,
• un organe de fermeture mobile entre une position fermée dans laquelle l'organe est en butée contre le siège de clapet et une position ouverte dans laquelle ledit organe est dégagé dudit siège de clapet, et
• un orifice de communication permanente entre le tronçon amont et le tronçon aval de la conduite d'entrée d'eau froide.

The hot water generators commonly encountered usually include, as known by FR 47477 (addition of patent FR 789 425):

• a cold water inlet pipe connected to a cold water circuit,
• a hot water outlet pipe connected to a hot water circuit,
• a heat exchanger interposed between the cold water circuit and the hot water circuit,
• a fluid fuel burner transferring heat to the heat exchanger,
• means for restricting the cold water inlet pipe separating said pipe into an upstream section and a downstream section and causing, during the passage of cold water, a pressure difference between the upstream section and the downstream section,
• an enclosure divided, by a movable element, into an upstream chamber and a downstream chamber, the upstream chamber being subjected to the pressure prevailing in the upstream section of the cold water inlet pipe, and the downstream chamber being subjected to the pressure prevailing in the downstream section of the cold water inlet pipe, said element being displaceable under the pressure difference existing between said two upstream and downstream chambers, and
• a fluid fuel supply which delivers a quantity of fuel subject to the passage of cold water in the cold water inlet pipe by means of the displacements of said displaceable element, the restriction means comprising:
• at least one valve comprising a valve seat,
• a movable closure member between a closed position in which the member is in abutment against the valve seat and an open position in which said member is released from said valve seat, and
• a permanent communication orifice between the upstream section and the downstream section of the cold water inlet pipe.

This hot water generator is a hot water generator variable power insofar as there is progressive opening of the supply of fluid fuel as a function of the water flow through the cold water inlet pipe. The fuel flow is proportional to the water flow in order to have a constant temperature rise at the outlet of the device.

Even if this type of generator allows an elevation of temperature over a wide range of water flow values, maintenance of such a device is made difficult by the poor accessibility of the elements constitutive.

The object of the present invention is to remedy the drawbacks mentioned above by providing a hot water generator whose maintenance is simplified.

• ledit clapet a une forme adaptée pour créer une perte de charge proportionnelle au débit d'eau qui traverse le siège de clapet,
• l'ensemble comprenant le tronçon amont, les moyens de restriction et le tronçon aval forme un élément modulaire pouvant être rapporté en une pièce sur le générateur d'eau chaude ou désolidarisé de celui-ci,
• ledit tronçon amont de la conduite d'entrée comporte un limiteur de débit,
• un conduit de dérivation est rapporté sur la conduite d'entrée d'eau froide, une première extrémité dudit conduit de dérivation étant reliée au tronçon amont de ladite conduite d'entrée d'eau froide et une deuxième extrémité dudit conduit de dérivation étant reliée au tronçon aval de ladite conduite d'entrée ; et
• ledit conduit de dérivation comporte des moyens de fermeture ou d'obturation à commande manuelle.

To this end, according to the invention, a hot water generator of the aforementioned type, is essentially characterized in that:

• said valve has a shape adapted to create a pressure drop proportional to the flow of water passing through the valve seat,
• the assembly comprising the upstream section, the restriction means and the downstream section forms a modular element which can be attached in one piece to the hot water generator or separated from it,
• said upstream section of the inlet pipe includes a flow limiter,
• a bypass duct is attached to the cold water inlet pipe, a first end of said bypass duct being connected to the upstream section of said cold water inlet pipe and a second end of said bypass duct being connected to the downstream section of said inlet pipe; and
• said bypass conduit comprises closing or closing means with manual control.

• l'organe de fermeture dudit au moins un clapet est de forme hémisphérique et est monté mobile sur un ressort de compression de raideur prédéterminée, le siège de clapet étant de forme complémentaire de celle de l'organe de fermeture,
• les moyens de restriction comprennent un seul clapet,
• les moyens de restriction comprennent un premier et un deuxième clapets montés respectivement sur un premier et un deuxième ressorts de compression, le premier ressort de compression étant de raideur supérieure à celle du deuxième ressort pour que le deuxième clapet s'ouvre avant le premier clapet,
• ledit conduit de dérivation prend la forme d'un passage traversant ménagé dans une cloison entre le tronçon amont et le tronçon aval, ledit passage traversant comprenant lesdits moyens de fermeture ou d'obturation à commande manuelle,
• l'orifice de communication permanente est ménagé dans l'un au moins des organes de fermeture mobiles, et
• le générateur d'eau chaude est un générateur d'eau chaude sanitaire.

The hot water generator according to the invention may optionally further include one or more of the following characteristics:

• the closure member of said at least one valve is of hemispherical shape and is movably mounted on a compression spring of predetermined stiffness, the valve seat being of shape complementary to that of the closure member,
• the restriction means comprise a single valve,
• the restriction means comprise a first and a second valve mounted respectively on a first and a second compression spring, the first compression spring being of greater stiffness than that of the second spring so that the second valve opens before the first valve,
• said bypass duct takes the form of a through passage formed in a partition between the upstream section and the downstream section, said through passage comprising said manually operated closing or closing means,
• the permanent communication orifice is formed in at least one of the movable closing members, and
• the hot water generator is a domestic hot water generator.

As a variant, the generator may conform to one of the claims 7 and 8.

• la figure 1 est une vue schématique d'un premier mode de réalisation d'un générateur d'eau chaude selon la présente invention,
• la figure 2 est une vue schématique d'un deuxième mode de réalisation d'un générateur d'eau chaude selon l'invention,
• la figure 3 est un graphe montrant l'ouverture de l'alimentation en combustible fluide en fonction du débit d'eau demandé par l'utilisateur ; et
• la figure 4 est une vue schématique d'un troisième mode de réalisation d'un générateur d'eau chaude selon l'invention.

Three embodiments of the invention will now be described with reference to the accompanying drawings, in which:

• FIG. 1 is a schematic view of a first embodiment of a hot water generator according to the present invention,
• FIG. 2 is a schematic view of a second embodiment of a hot water generator according to the invention,
• FIG. 3 is a graph showing the opening of the supply of fluid fuel as a function of the water flow rate requested by the user; and
• Figure 4 is a schematic view of a third embodiment of a hot water generator according to the invention.

The hot water generator 1 shown in the figure 1 comprises, in a manner known per se, an inlet pipe cold water 2 connected to a cold water circuit 3, a hot water outlet pipe 4 connected to a water circuit hot 5, a heat exchanger 6 interposed between the cold water circuit 3 and hot water circuit 5 and below which is a fluid fuel burner 7. This fuel is for example natural gas.

The burner 7 is supplied with gas by a feed 15 which delivers a quantity of fuel subject to the passage of cold water in the inlet pipe cold water 2. For the sake of clarity, only components of this power supply 15 required to the understanding of the invention were represented, it is why the part of the power supply 15 connected to the burner 7 has not been shown.

This supply 15 consists of a conduit 20 comprising an inlet 21 through which the gas arrives and a output 22 intended to be connected to the burner 7. Input 21 is closed by a valve 23 which includes a valve seat 24, a valve head 25 and a valve stem 26 connected to said head 25. The valve head 25 is urged to bear against the valve seat 24 by a compression spring 27, this spring bearing on a shoulder 28 formed in conduit 20.

The hot water generator 1 further comprises a enclosure 11 divided, by a movable element 12, into a upstream chamber 13 and a downstream chamber 14. The movable element 12 is for example a membrane of deformable material and produced by molding. The opposite end of the rod 26 to that connected to the valve head 25, is integral with this displaceable element 12 or resting thereon.

Over part of its length, the inlet pipe cold water 2 includes restriction means 8 which separate this pipe into an upstream section 9 and into a downstream section 10. These restriction means cause, during cold water passage in the direction of arrow F in the line 2, a pressure difference between said section upstream 9 and said downstream section 10.

The upstream chamber 13 of the enclosure 11 is connected to the cold water inlet pipe 2, upstream of said means of restriction 8, through a conduit 30. The downstream chamber 14 of the enclosure 11 is connected to the inlet pipe 2, downstream said restriction means 8, via a conduit 31.

The pressure difference created by the means of restriction 8 between the upstream section 9 and the downstream section 10 of this pipe causes the same pressure difference between the upstream 13 and downstream 14 chambers of the enclosure 11. This pressure difference therefore applies to the displaceable element 12 which deforms during passage cold water 2, towards the upper part of the enclosure 11 and causes, in its movement, the displacement of the rod of valve 26. This rod releases valve head 25 from its seat 24, against the action of the compression spring 27. Gas then flows through line 20 towards the burner 7.

We therefore understand that the fuel supply 15 fluid delivers a quantity of fuel to the burner 7 which is controlled by the passage of cold water in the pipe cold water inlet 2 via displacements of said movable element 12.

In the first embodiment of the invention, the restriction means 8 comprise a valve 35 thus a partition 36 crossed by an orifice 37.

The valve 35 consists of a valve seat 38, a movable closure member 39 and a spring compression 40 on which the closure member is mounted 39.

Port 37 is a communication port permanent between the upstream 9 and downstream 10 sections of the pipe cold water inlet 2.

As a variant, the orifice 37 is formed in the member movable closure 39.

During a drawing, cold water enters according to the direction of arrow F in inlet line 2 and pushes back the closing member 39 against the spring 40. The valve 35 opens more or less depending on the water flow in the inlet line, which causes, in combination with orifice 37, a more or less strong depression between the upstream section 9 and the downstream section 10 and therefore between the upstream 13 and downstream 14 chambers of the enclosure 11. This depression causes the valve stem 26 to lift.

Curve B of the graph in Figure 3 shows the proportionality between the flow admitted in the pipe inlet 2 and the lifting of the valve stem 26. We understand as well as according to the stiffness of the compression spring 40, the slope of curve B, at the start of the drawing, is more or less strong. We also note that, as long as the water flow maximum admissible by the generator is not reached, this is not the construction architecture of this generator which limits the flow of water but the user who needs more or less hot water. In addition, the elevation of temperature is constant within the limit of the power of the generator, and beyond, the temperature rise decreases up to a value dependent on the maximum water flow of the generator.

In this embodiment, the closure member 39 of valve 35 is hemispherical in shape and comes into abutment on the valve seat 38 of complementary shape. However, we understand that depending on the shape of the desired curve B, the valve can have a different shape in combination with a spring with predetermined characteristics (preload, stiffness), to create a pressure drop linked to the water flow which passes through the valve seat 38 bound by a law of proportionality different from that illustrated by the curve B.

The permanent opening 37 makes it possible to reduce the flow cold water in inlet line 2 to cause movement of the valve stem 26. The user obtains thus hot water at a lower flow rate.

Furthermore, the upstream section 9 of the pipe cold water inlet 2 has a flow limiter 41 which allows to calibrate the maximum cold water flow. We will note, for reasons of clarity, that this flow limiter has not been shown on the same scale as the valve 35 and orifice 37.

The hot water generator 1 further comprises a bypass duct 42 mounted on the inlet pipe cold water 2. A first end 43 of this conduit 42 is connected to the upstream section 9 of this pipe 2 and a second end 44 of conduit 42 is connected to the section downstream 10. Manually operated closing means 45 are mounted on this bypass duct 42. These means take for example the shape of a tap actuated by a user. Opening or closing this tap allows to admit cold water from the upstream section 9 to the downstream section 10 without this quantity of cold water being subjected a pressure drop due to the restriction means 8.

The user therefore opens tap 45 when he wishes that, for the same quantity of hot water drawn, the pressure drop created is lower and therefore the lifting of the lower valve stem 26, thereby allowing decrease the temperature rise for the same flow of water.

The second embodiment of the generator according to the present invention, shown in Figure 2, differs from first embodiment only by the number of valves constituting the restriction means 8. Also, the constituent elements common to the two embodiments will bear the same references.

Restriction means 8 of the inlet pipe 2 now have a second valve 50 placed adjacent to the first valve 35. This second valve 50 has a compression spring 51 whose stiffness and the preload is lower than the first compression spring 40 of the first valve 35. It also has a member closure 53 intended to abut against a seat of valve 52 whose diameter is less than the first seat of valve 38 of the first valve 35.

As a variant, the communication orifice 37 is formed in at least one of the two closing members mobiles 39 and 53.

In the generator drawing position, the second valve 50 opens before the first valve 35. The first valve 35 opens when the water flow increases in the inlet line 2.

Thus, the pressure drop caused by these two valves increases much more gradually than in the first embodiment. We thus obtain the valve stem 26 raised more proportional to flow water admitted. Ideally, we get a straight line substantially identical to curve C shown in figure 3.

Alternatively, the valves 35 and 50 could be held, not by compression springs, but by springs working in traction or even by deformable elements integrated directly into these valves.

The third embodiment shown in Figure 4 differs from the first embodiment of Figure 1 only by installing the bypass duct 42. This conduit takes the form of a through passage 60 formed in the partition 36. A first end 61 of this passage opens into the upstream section 9 of the inlet pipe cold water 2 and a second end 62 of passage 60 leads into the downstream section 10. In this second end 62 is placed a valve 63 which can be controlled by a user to more or less block the passage crossing 60. The function of this passage 60 is the same as that of the bypass duct 42 described opposite the figure 1.

Furthermore, the flow limiter 41 is placed in the upstream section 9, as close as possible to an area neighboring the conduit 30 and restriction means 8. A water filter 64 is placed in section 9, upstream of the limiter flow 41 and in the vicinity thereof.

The assembly thus constituted by the upstream section 9, restriction means 8 and the downstream section 10 forms a compact module that can be easily attached to the hot water generator or separated from it. This module can therefore be delivered tested and maintenance is Easy.

Of course, the module described above can also be adapted to the second embodiment of the figure 2.

Claims (9)

1. A hot water boiler comprising :

   a cold water inlet pipe (2) connected to a cold water circuit (3);

   a hot water outlet pipe (4) connected to a hot water circuit (5);

   a heat exchanger (6) interposed between the cold water circuit (3) and the hot water circuit (5);

   a fluid fuel burner (7) transferring heat to the heat exchanger (6);

   means of restriction (8) of the cold water inlet pipe (2) separating said pipe (2) into an upstream section (9) and a downstream section (10) and causing, during the passage of cold water, a pressure difference between the upstream section (9) and the downstream section (10);

   an enclosure (11) divided by a movable element (12) into an upstream chamber (13) and a downstream chamber (14), the upstream chamber (13) being subjected to the pressure existing in the upstream section (9) of the cold water inlet pipe (2), and the downstream chamber (14) being subjected to the pressure existing in the downstream section (10) of the cold water inlet pipe (2), said element (12) being movable under the pressure difference between said two upstream (13) and downstream (14) chambers; and

   a fluid fuel supply (15) which delivers a quantity of fuel controlled by the passage of cold water in the cold water inlet pipe (2) by means of the movements of said movable element (12), the means of restriction (8) comprising:

   at least one valve (35 ; 50) comprising a valve seat (38 ; 52),

   a closing part (39 ; 53) movable between a closed position in which the part (39 ; 53) is abutted against the valve seat (38 ; 52) and an open position in which said part (39 ; 53) is disengaged from said valve seat (38 ; 52), and

   a permanent communication orifice (37) between the upstream section (9) and the downstream section (10) of the cold water inlet pipe (2),

   characterised in that:

   said valve (35 ; 50) has a shape adapted to create a pressure loss proportional to the rate of water flow through the valve seat (38, 52),

   the assembly including the upstream section (9), the means of restriction (8) and the downstream section (10) forms a modular element that can be connected in one piece to the hot water boiler or dismantled from it,

   said upstream section (9) of the inlet pipe (2) comprises a flow limiter (41),

   a by-pass pipe (42) is connected to the cold water inlet pipe (2), a first end (43) of said by-pass pipe (42) being connected to the upstream section (9) of said cold water inlet pipe (2) and a second end (44) of said by-pass pipe (42) being connected to the downstream section (10) of said inlet pipe (2), and

   said by pass pipe (42) comprises manually controlled closing or sealing means (45).
2. A hot water boiler according to claim 1, characterised in that the closing part (39 ; 53) of said at least one valve (35 ; 50) is of hemispherical shape and is movably mounted on a compression spring (40 ; 51) of prespecified rigidity, the valve seat (38 ; 52) being of complementary shape to that of the closing part (39 ; 53).
3. A hot water boiler according to any one of claims 1 and 2, characterised in that the means of restriction (8) include a single valve (35).
4. A hot water boiler according to any one of claims 1 and 2, characterised in that the restriction means (8) include a first (35) and a second valve (50) mounted respectively on a first (40) and a second (51) compression spring, the first compression valve (40) being of greater rigidity than the second valve (51) so that the second valve (50) opens before the first valve (35).
5. A hot water boiler according to any one of claims 1 to 4, characterised in that said by-pass pipe (42) takes the form of a through passage (60) extending through a partition (36) between the upstream section (9) and the downstream section (10), said through passage (60) including said manually controlled closing or sealing means (63).
6. A hot water boiler according to any one of claims 1 to 5, characterised in that the permanent communication orifice (37) is arranged in one at least of the movable closing parts (39 ; 53).
7. A hot water boiler according to claim 5, characterised in that said partition (36) is passed through by said permanent communication orifice (37).
8. A hot water boiler according to any one of claims 1 to 7, characterised in that a water filter (64) is placed in said upstream section (9) of said cold water inlet pipe (2), upstream of and near to the flow limiter (41).
9. A hot water boiler according to any one of claims 1 to 8, characterised in that the hot water boiler (1) is a bathroom hot water boiler.

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