Device for producing hot liquid

Abstract

Device (1) for producing hot liquid, comprising: - a tank (2) of liquid, - a system (6) for heating the contents of the tank (2), - a heat exchanger (7) comprising a primary circuit (8) equipped with a fluid inlet (8A) and a fluid outlet (8B), a secondary circuit (9) equipped with a fluid inlet (9A) and a fluid outlet (9B) and a region (10) for exchanging heat energy between the primary circuit (8) and the secondary circuit (9), - a circuit (11) for circulation in a loop between the tank (2) and the primary circuit (8) of the heat exchanger (7), and - a pump (12) arranged on the circuit (11) for circulation in a loop. The device (1) comprises a valve (31) arranged on the circuit (11) for circulation in a loop between the tank (2) and the primary circuit (8) of the heat exchanger (7), a member (32) for moving the valve (31) between an open position and a closed position, a control unit (17) for controlling at least the pump (12) and the member (32) for moving the valve (31).

Description

[0001] The present invention relates to a device for producing hot fluid, in particular domestic hot water.

[0002] It relates more particularly to a device for producing hot fluid comprising: a liquid receiving tank equipped with at least one fluid inlet and one fluid outlet, at least the so-called inner part of the tank capable of being in contact with the liquid filling the tank being made of synthetic material, a system for heating the contents of the tank, a heat exchanger comprising a primary circuit equipped with at least one fluid inlet and one fluid outlet, a secondary circuit equipped with at least one fluid inlet and one fluid outlet and a heat exchange zone between the primary and secondary circuits arranged outside the tank, a loop circulation circuit between the tank and the primary circuit of the heat exchanger, and a pump arranged on the loop circulation circuit, the inlet of the secondary circuit of the heat exchanger being connectable to a source of fluid to be heated to allow the production of hot fluid at the outlet of the secondary circuit.

[0003] Such a device for producing hot fluid, particularly in the case of an application to domestic hot water, is known as illustrated by patent DE-4206074. However, the design of current devices is not entirely satisfactory in terms of longevity, maintenance and efficiency of the device. In particular, the quantity of hot water that can be produced is generally found to be low compared to the quantity of water stored. Similarly, the control of the temperature of the fluid to be heated at the start of the draw is often imperfect.

[0004] An aim of the invention is to propose a hot fluid production device whose design allows, for an equal volume of the tank with a tank of a hot fluid production device of the state of the art, to optimize the quantity of hot fluid produced in relation to the quantity of liquid stored in the tank without harming the quality of the control of the temperature of the fluid to be heated at the start of drawing.

[0005] To this end, the invention relates to a device for producing hot fluid, in particular domestic hot water, defined in claim 1. This device comprises: a liquid receiving tank equipped with at least one fluid inlet and one fluid outlet, at least the so-called inner part of the tank capable of being in contact with the liquid filling the tank being made of synthetic material a system for heating the contents of the tank, a heat exchanger comprising a primary circuit equipped with at least one fluid inlet and one fluid outlet, a secondary circuit equipped with at least one fluid inlet and one fluid outlet and a heat exchange zone between the primary and secondary circuits arranged outside the tank, a loop circulation circuit between the tank and the primary circuit of the heat exchanger, and a pump arranged on the loop circulation circuit, the inlet of the secondary circuit of the heat exchanger being connectable at least to a source of fluid to be heated to allow the production of hot fluid at the outlet of the secondary circuit,the device further comprising a valve arranged on the loop circulation circuit between the tank and the primary circuit of the heat exchanger, a member for driving the valve between an open position and a closed position, a control unit at least for the pump and the member for driving the valve, the control unit being configured to control the actuation of the member for driving the valve and consequently the passage of the valve from the open position to the closed position or vice versa depending on the on / off state of the pump.

[0006] The position of the heat exchange zone of the heat exchanger outside the tank makes it possible to free up the useful space of the tank for storing liquid and the production of the part of the tank in contact with the liquid in synthetic material makes it possible to increase the heating temperature of said liquid, these two characteristics contributing to the optimization of the quantity of hot fluid produced in relation to the quantity of liquid stored in the tank, without harming the longevity of the device or its ease of maintenance. The design of the device can make it possible to dispense with a thermostatic mixing valve at the point of use of the hot fluid.

[0007] In addition, the presence of a controlled valve on the loop circulation circuit between the tank and the primary circuit of the heat exchanger allows thermosiphon phenomena to be perfectly controlled.

[0008] According to one embodiment of the invention, the device comprises a clock and the control unit is configured to control the actuation of the drive member for moving the valve in the direction of opening the valve in parallel with the control of starting the pump and configured to control the actuation of the drive member for moving the valve in the direction of closing the valve in the stopped state of the pump after stopping the pump for a predetermined period of time.

[0009] This particularly motorized pilot valve initially allows a thermosiphon to be initiated and then stops this phenomenon in order to keep the heat exchanger as cold as possible to ensure the temperature of the fluid to be heated at the start of the draw is reliable.

[0010] According to one embodiment of the invention, the pump is a variable flow rate pump and the device comprises means for regulating the flow rate of said pump, these means for regulating the flow rate of the pump comprising a flow meter arranged, preferably, at the inlet of the secondary circuit, and at least two temperature probes, at least one of which is arranged on the circulation circuit in a loop between the tank and the primary circuit of the heat exchanger, and the control unit is configured to control the pump at least as a function of the data provided by the temperature probes and the flow meter.

[0011] The presence of an adjustable flow pump makes it possible to respect the desired hot fluid temperature setting.

[0012] The control means provide very good responsiveness and instant production of hot water at a temperature close to the desired set temperature. Although the flow meter can be in another location, the presence of the flow meter at the inlet of the secondary circuit can allow the pump to be operated only when a flow rate is detected, which limits wear on the pump and limits the energy consumption of the device.

[0013] According to one embodiment of the invention, the device comprises, at the inlet of the secondary circuit, in the zone of connection of the inlet of the secondary circuit to at least one source of fluid to be heated, a conduit arranged at least partially in the thickness of the tank, this so-called inlet conduit coupling at one end to the inlet of the secondary circuit of the heat exchanger dividing on the opposite end side of connection to at least one source of fluid to be heated into two branches, one equipped with a shut-off member, the other with a flow meter.

[0014] This arrangement allows the heat exchanger to be supplied with cold fluid from the network of fluid to be heated or with hot fluid from a hot fluid distribution network to allow immediate hot fluid output during withdrawal.

[0015] According to one embodiment of the invention, the loop circulation circuit between the tank and the primary circuit of the heat exchanger comprises a forward branch arranged between the outlet of the tank and the inlet of the primary circuit and a return branch arranged between the outlet of the primary circuit and the inlet of the tank, the pump and the valve being arranged, preferably, on the forward branch of the loop circulation circuit.

[0016] According to one embodiment of the invention, the tank is equipped with an orifice for filling the tank with liquid, this filling orifice being connected by a closable fluid connection to the portion of the secondary circuit extending between the inlet of the secondary circuit and the heat exchange zone between the primary and secondary circuits of the heat exchanger.

[0017] Preferably, the closable fluid connection is provided at the filling orifice with a connection piece to the tank, this connection piece being provided with a vent, an overflow orifice and an additional orifice acting as an overflow or vent depending on the filling level of the tank. This arrangement makes it possible to safely prevent mixing of the "dead" water contained in the tank with the tank filling liquid from a network.

[0018] Preferably, the connecting part to the tank equipping the closable fluid connection at the filling orifice is provided with a closure member mounted to move between a closed position and an open position and returned under the effect of its own weight to the closed position. Preferably, this closure member is a pivoting valve. The presence of such a closure member at this level makes it possible to prevent the formation of condensation at the cover of the casing.

[0019] According to one embodiment of the invention, the tank is equipped with a so-called lower level sensor and a so-called upper level sensor arranged at different heights in the tank, the closable fluid connection is provided with a closure member equipped with an electrical control circuit and the electrical control circuit is configured to switch from the closed state corresponding to the open position of the closure member to the open state corresponding to the closed position of the closure member at least in the activated state of the upper level sensor. Thanks to this configuration, the risks of overflowing of the tank are reduced.

[0020] According to one embodiment of the invention, the outlet of the tank connectable to the inlet of the primary circuit is arranged in the upper third of the interior volume of the tank and the inlet of the tank connectable to the outlet of the primary circuit is arranged in the lower third of the interior volume of the tank. Thanks to this arrangement of the inlet and outlet of the tank, the temperature stratification, also called thermal stratification, of the liquid inside the tank is maintained. This allows better control of the temperature of the liquid at the outlet of the tank.

[0021] According to one embodiment of the invention, at least part of the heating system is housed in the tank and the inlet of the tank connectable to the outlet of the primary circuit of the heat exchanger opens into the tank at a level lower than the level occupied by the part of the heating system housed in the tank. Again, this arrangement makes it possible to maintain the temperature stratification of the liquid inside the tank.

[0022] According to the invention, the tank comprises, in the lower half of the tank, on the outer surface of the tank, a reservation inside which the heat exchanger which is a counter-current heat exchanger, preferably a plate heat exchanger, is able to be housed to extend at least partially inside the overall size of the tank. This positioning of the heat exchanger in the lower part of the tank offers an advantage in terms of thermosiphon of the heat exchanger and in terms of maintaining the thermal stratification of the liquid contained in the tank.

[0023] In addition, this arrangement allows savings in terms of thermal insulation of the pipes of the various circuits.

[0024] According to one embodiment of the invention, the heat exchanger is, in the state connected to the tank, arranged at a level lower than the level occupied by the inlet of the tank connectable to the outlet of the primary circuit of said heat exchanger. This arrangement allows emptying by thermosiphon of the hot liquid that may be contained in the primary circuit of the heat exchanger, which allows better control of the temperature of the fluid to be heated at the start of the draw. Indeed, it has been found that if hot liquid stagnates in the primary circuit of the heat exchanger, it disrupts the control of the temperature of the fluid to be heated at the start of the draw. Finally, part of the hot liquid stagnating in the forward branch of the loop circuit between the tank and the heat exchanger can be reintroduced into the tank to be used during a next draw.

[0025] According to one embodiment of the invention, the tank comprises an enclosure, a casing at least partially surrounding the enclosure and an insulator disposed between the enclosure and the casing.

[0026] According to one embodiment of the invention, at least a part of the heating system is housed in the tank and the thickness of the tank taken between the external face of the casing and the internal face of the enclosure is in the part of the tank extending above the part of the heating system housed inside the tank at least locally greater than that of the thickness of the tank extending below the part of the heating system housed inside the tank. The reinforcement of the insulation in the upper part of the tank makes it possible to keep the upper part of the tank as hot as possible.

[0027] According to one embodiment of the invention, at least the heat exchanger, the pump, which is variable flow, and the valve with its moving drive member, which is preferably a motor, form a ready-to-install assembly. This results in easier maintenance and manufacturing.

[0028] According to one embodiment of the invention, the heating system comprises at least one electrical resistor housed inside the tank, the tank comprises, at the level of the, or at least one of the electrical resistors, two facing orifices, one arranged in the enclosure, the other in the casing, these orifices being connected by a housing body with a pierced bottom forming a sheath for connecting said orifices together, this housing body extending at least partially inside the enclosure, and the electrical resistor is in the form of an elongated body provided with a seal threaded onto the electrical resistor, this seal in sealed bearing contact with the electrical resistor sealingly closing the drilling in the bottom of the housing body in the state in which said drilling is passed through by the electrical resistor. Brève description des dessins

[0029] The invention will be clearly understood upon reading the following description of exemplary embodiments, with reference to the appended drawings in which: [ Fig. 1 ] represents a schematic view of a domestic hot water production device in a configuration in which the pump operates; [ Fig. 2 ] represents a schematic view of a domestic hot water production device in a configuration in which the pump is not operating to illustrate the thermosiphon draining of the heat exchanger; [ Fig. 3 ] represents a perspective view, in exploded position of the elements constituting it, of a hot water production device; [ Fig. 4 ] represents a diagram of the operation of the hot water production device; in this diagram of operation, the fact that, according to the invention, the heat exchanger is capable of being housed inside the reservation formed on the external surface of the tank, is not represented; [ Fig. 5 ] represents a partial perspective view of the lower part of the device in the removed state of the cover closing the compartment formed by a reservation made in the tank, this compartment serving to house the heat exchanger; [ Fig. 6 ] represents a partial schematic view, partly in longitudinal section, of the device; [ Fig. 7 ] represents a perspective view, in exploded position of the elements, of the connection means equipping the cold part of the heat exchanger; [ Fig. 8 ] represents a perspective view, in exploded position of the elements, of the connection means equipping the hot part of the heat exchanger; [ Fig. 9 ] represents a sectional view of an electrical resistance in the state inserted in the tank; and [ Fig. 10 ] represents a perspective view, in exploded position of the elements, of an electrical resistance capable of being inserted into the tank.

[0030] As mentioned above, the subject of the invention is a device 1 for producing fluid, in particular hot liquid. In the example described below, the device 1 is a device for producing hot water, preferably sanitary, for instantaneous production of hot water but such a device can be applied to the production of other types of hot liquids depending on the source of liquid to be heated chosen without departing from the scope of the invention.

[0031] This hot liquid production device can be a domestic hot water production device suitable for installation in any type of construction.

[0032] The hot water production device 1 therefore includes: a liquid receiving tank 2 equipped with at least one fluid inlet 3 and one fluid outlet 4, a system 6 for heating the contents of the tank 2, a heat exchanger 7 comprising a primary circuit 8 equipped with at least one fluid inlet 8A and one fluid outlet 8B, a secondary circuit 9 equipped with at least one fluid inlet 9A and one fluid outlet 9B and a zone 10 for exchanging calories between the primary 8 and secondary 9 circuits, a loop circulation circuit 11 between the tank 2 and the primary circuit 8 of the heat exchanger 7, and a pump 12 arranged on the loop circulation circuit 11, the inlet 9A of the secondary circuit 9 of the heat exchanger 7 being connectable at least to a source of domestic water to allow the production of domestic hot water at the outlet of the secondary circuit 9 a valve 31 arranged on the loop circulation circuit 11 between the tank 2 and the primary circuit 8 of the heat exchanger 7, a member 32, such as a motor,for driving the valve 31 between an open position and a closed position, and a unit 17 for controlling at least the pump 12 and the member 32 for driving the valve 31. This control unit 17 being configured to control the actuation of the member 32 for driving the valve 31 in the direction of opening or closing the valve 31 depending on the on / off state of the pump 12.

[0033] The liquid contained in tank 2 is therefore heated to supply the primary circuit 8 of the heat exchanger before returning to the tank. The cold water from the building's sanitary water circuit, which is a pressurized water circuit, supplies the secondary circuit 9 of the heat exchanger 7.

[0034] This cold sanitary water is heated at the level of the heat exchanger 7 by exchanging calories with the primary circuit 8 of said exchanger before being distributed to any of the water points in the building.

[0035] Due to this operation, the liquid contained in the tank is said to be dead. In fact, this liquid is not intended to be distributed but simply to heat the cold water in the sanitary water network.

[0036] In this device 1 for producing hot water, the tank 2 for receiving liquid, which may be water or an aqueous solution, or any other type of liquid, is a tank with a vertical axis. Indeed, this tank 2 has a face forming a bottom for resting on the ground and a top face, the longitudinal axis of the tank 2 passing through said faces. In the example shown, the tank is generally parallelepiped in shape.

[0037] At least the so-called inner part of the tank 2 capable of being in contact with the filling liquid of the tank 2 is made of synthetic material, in particular polyolefin such as polypropylene. This tank 2 stores the liquid at atmospheric pressure. At least one safety vent 36 which will be described in more detail below may be provided to prevent any overpressure inside the tank 2.

[0038] To prevent heat loss, the tank 2 comprises an enclosure 51, a jacket 52 at least partially surrounding the enclosure 51, and an insulator 53 disposed between the enclosure 51 and the jacket 52. The liquid is contained inside the enclosure 51. The enclosure 51 is therefore equipped with the liquid inlet 3 and outlet 4 with the liquid outlet 4 disposed at a level higher than the level occupied by the liquid inlet 3 of the tank. This enclosure 51 is made of synthetic material, preferably polyolefin.

[0039] The casing 52 is here formed of a body open on the top and a cover for closing the body. The enclosure 51 is thus inserted into the casing 52 which, in the closed state, completely surrounds the enclosure 51.

[0040] The insulator 53 is, for its part, formed by a foam, for example, injected into the envelope in the inserted state of the enclosure in the envelope 52 in the space left free between the exterior of the enclosure 51 and the interior of the envelope 52.

[0041] The tank 2 comprises, in the lower half of the tank 2, on the outer surface of the tank 2, a reservation 16 inside which the heat exchanger 7 is able to be housed to extend at least partially inside the overall size of the tank 2. This reservation 16 is formed by a recess of said tank 2 formed in the side wall of the tank at the level of the area of ​​the side wall of the tank adjoining the bottom of the tank. This reservation thus forms a housing for the heat exchanger outside the tank which can be closed by a cover. The heat exchanger 7 is thus arranged outside the tank in the lower part of the tank 2, that is to say at the level of the lower half of the tank 2, near the bottom of the tank.

[0042] This heat exchanger 7 is, in the state connected to the tank 2, arranged at a level lower than the level occupied by the inlet 3 of the tank 2 connectable to the outlet 8B of the primary circuit 8 of said heat exchanger 7.

[0043] In the examples shown, the heat exchanger 7 is a counter-current exchanger, in particular a plate exchanger, with the plates extending horizontally, that is to say substantially parallel to the face forming the bottom supporting the ground of the tank.

[0044] The inlets and outlets of the primary and secondary circuits of the heat exchanger are, in the example shown, arranged on the same face of the block containing the plates of the exchanger 7.

[0045] To allow a loop circulation between the tank 2 and the primary circuit 8 of the heat exchanger 7, the loop circulation circuit 11 between the tank 2 and the primary circuit 8 of the heat exchanger 7 comprises a forward branch 11A arranged between the outlet 4 of the tank 2 and the inlet 8A of the primary circuit 8 and a return branch 11B arranged between the outlet 8B of the primary circuit 8 and the inlet 3 of the tank, the pump 12 and the valve 31 being here arranged on the forward branch 11A of the loop circulation circuit 11, which constitutes a preferred solution although the pump 12 and the valve 31 can also be arranged on the return branch.

[0046] The forward branch 11A is formed by a conduit, one end of which is permanently fixed to the inlet 3 of the tank 2. This conduit has a length of conduit embedded in the insulation of the tank followed by a length of conduit which extends into the reservation 16 of the tank 2 to be connected to the inlet 8A of the primary circuit 8 of the heat exchanger 7.

[0047] The liquid circulates in the primary circuit 8 of the heat exchanger before exiting the heat exchanger at the heat exchanger outlet 8B. Again, a conduit connects this heat exchanger outlet 8B to the inlet 3 of the tank enclosure and forms the return branch 11B of circuit 11.

[0048] This connection between the inlet 3 of the tank and the outlet 8B of the primary circuit of the exchanger is of shorter length than the connection between the outlet 4 of the tank and the inlet 8A of the primary circuit 8 of the heat exchanger 7. Indeed, the outlet 4 of the tank connectable to the inlet 8A of the primary circuit 8 is arranged in the upper third of the interior volume of the tank 2 and the inlet of the tank 2 connectable to the outlet 8B of the primary circuit 8 is arranged in the lower third of the interior volume of the tank 2, it being understood that the upper third and the lower third are taken by reference to the total height of the interior volume of the enclosure of the tank, this height being taken between the highest point of the interior volume and the lowest point of the interior volume in the state positioned on the ground of the tank resting by its bottom face on a horizontal surface.

[0049] In practice, the tank enclosure has a maximum filling level and the tank outlet is generally arranged below this maximum filling level in the upper third of the tank. Conversely, the inlet 3 of the tank 2 connectable to the outlet 8B of the primary circuit 8 of the heat exchanger opens into the tank 2 at a level lower than the level occupied by the part 6 of the heating system housed in the tank 2.

[0050] The aim is to extract liquid from the tank at the hot zone of the tank and to reintroduce liquid into the tank at the cold zone of the tank to avoid a disturbance of the thermal stratification which would cause turbulence generating a loss in volume of the usable hot liquid volume.

[0051] The pump 12 which is used for this loop circulation of the liquid between the tank and the heat exchanger is a variable flow pump 12, such as a pump with a "brushless" motor. The presence of the valve 31 and the adjustment of the pump flow rate make it possible to respect the temperature setpoint of the domestic hot water to be distributed. This temperature setpoint is predefined.

[0052] In practice, the device 1 comprises a clock 171 whose data can be addressed to the control unit 17. The control unit 17 is configured to control the actuation of the member 32 for driving the valve 31, i.e. the motor for driving the valve 31, in the direction of opening the valve 31 in parallel with the control of starting the pump 12. The control unit 17 is further configured to control the actuation of the member 32 for driving the valve 31 in the direction of closing the valve 31 as a function of the data provided by the clock 171. In particular, the control unit 17 is further configured to control the actuation of the member 32 for driving the valve 31 in the direction of closing the valve 31 in the stopped state of the pump 12 after stopping the pump 12 for a predetermined period of time.This predetermined period of time, which can be fixed or variable, is generally of the order of a few minutes.

[0053] To control the transition from the on state to the off state of the pump 12 or vice versa using the control unit 17, the device 1 comprises means 13 for regulating the flow rate of said pump 12. These means 13 for regulating the flow rate of the pump 12 comprise a flow meter 14 preferably arranged at the inlet of the secondary circuit 9, and at least two temperature probes 131 and 132, at least one of which, shown at 132 in the figures, is arranged on the loop circulation circuit 11 between the tank 2 and the primary circuit 8 of the heat exchanger 7. The control unit 17 is configured to control the pump 12, and consequently, of course, the valve 31, at least as a function of the data provided by the temperature probes 131 and 132 and the flow meter 14. One of the temperature probes shown at 131 in the figures is arranged at the inlet of the secondary circuit 9.Other temperature probes such as a probe placed at the output of the secondary circuit 9 can also be provided.

[0054] The device 1 comprises, at the inlet of the secondary circuit 9 in the connection zone of the inlet 9A of the secondary circuit 9 to the domestic cold water network, a conduit 18 arranged at least partially in the thickness of the tank 2. In particular, this conduit 18 is here partially embedded in the insulation 53 of the tank 2.

[0055] The end of the conduit 18 opposite that connected to the inlet 9A of the secondary circuit 9 of the heat exchanger is divided into two branches, one, connectable to the domestic cold water circuit and shown at 18B in the figures, the other, shown at 18A in the figures, connectable to a hot water circuit to allow immediate distribution of hot water at the outlet of the heat exchanger.

[0056] Branch 18B is equipped with flow meter 14 which forms one of the means of regulating pump 12. The other branch 18A of conduit 18 is equipped with a shut-off member 20, such as a solenoid valve.

[0057] A temperature probe 131 is arranged on the conduit 18, downstream of the connection zone of the branches 18A and 18B between them, between this connection zone and the inlet 9A of the secondary circuit of the heat exchanger. This temperature probe 131 forms the temperature probe, arranged at the inlet of the secondary circuit of the heat exchanger, and capable of assisting in the regulation of the pump 12.

[0058] In the same way, the device 1 comprises at the outlet 9B of the secondary circuit 9, in the connection zone of the outlet 9B of the secondary circuit to a hot water distribution network, a conduit 19 arranged at least partially in the thickness of the tank 2. In particular, this conduit 19 is here partially embedded in the insulation 53 of the tank 2.

[0059] A temperature probe can be placed on this conduit 19.

[0060] The temperature probe 132 for assisting in regulating the pump 12 arranged on the loop circulation circuit 11 between the tank 2 and the primary circuit 8 of the heat exchanger 7 can be arranged in the tank 2 as in the example shown or at the inlet of the primary circuit 8 on the conduit forming the outgoing branch 11A of the loop circuit between the tank 2 and the heat exchanger 7.

[0061] Finally, the device comprises, as mentioned above, a unit 17 for controlling at least the pump 12 and the valve 31, this control unit being configured to control the pump 12 and consequently the valve 31 at least as a function of the data provided by the temperature probes 131, 132 and the flow meter 14. The flow rate instruction is given by the control member for opening a water point of the construction.

[0062] This control unit 17 is in the form of an electronic and computer system which comprises, for example, a microprocessor and a working memory. According to a particular aspect, the control unit may have the form of a programmable automaton. In other words, the functions and steps described may be implemented in the form of a computer program or via hardware components, for example programmable port networks, in particular, the functions and steps operated by the control unit or these modules may be implemented by instruction sets and / or computers implemented in a process or controller or be implemented by these dedicated electronic components or FPGA or ASIC type components. It is also possible to combine computer parts and electronic parts.

[0063] Where it is specified that the unit or means or modules of said unit are configured to carry out a given operation, this means that the unit comprises computer instructions and the corresponding execution means which enable said operation to be carried out and / or that the unit comprises corresponding electronic components.

[0064] The pump control therefore uses at least the following input data: the domestic cold water inlet temperature in the heat exchanger, the tank water inlet temperature in the heat exchanger, the domestic hot water temperature setpoint, and the domestic water flow rate.

[0065] Based on this data, the pump flow rate is chosen.

[0066] To enable the connection of the conduit 18 and the return branch 11B of the loop circuit 11 to the heat exchanger, the heat exchanger comprises, at its cold part formed by the inlet 9A of the secondary circuit 9 and the outlet 8B of the primary circuit 8 arranged side by side on one face of the heat exchanger, a part 27 for connecting said inlet and outlet respectively to the conduit 18 and to the return branch 11B.

[0067] This connecting piece 27, which comprises two sections of conduit for said connections, forms the support for a drain valve 25 capable of allowing the tank to be drained via the return branch 11B. This connecting piece 27 also ensures the fixing of the heat exchanger 7 on the tank 2 and the fixing of the temperature probes.

[0068] In the same way, the heat exchanger 7 comprises, at its hot part formed by the inlet 8A of the primary circuit and the outlet 9B of the secondary circuit arranged side by side on the same face of the heat exchanger, a part 26 for connecting said inlet and outlet respectively to the forward branch 11A of the loop circuit and to the conduit 19.

[0069] This connecting piece 26, which comprises two sections of conduit for said connections, also forms a means of connecting the pump 12. This connecting piece also supports some of the temperature probes.

[0070] Thanks to this embodiment, at least the heat exchanger, the pump 12 which is variable flow, the valve 31 and its displacement drive member 32 and the means 13 for regulating the flow of the pump 12 form a ready-to-assemble assembly.

[0071] To enable the heat exchanger to operate, it is necessary to heat the temperature of the tank to a temperature generally close to 70°C in the upper part of the tank, this temperature being able to be controlled using a temperature probe 28 positioned as close as possible to the heating system 6, for example in the housing body 23 presented below.

[0072] The heating system 6 can take a large number of forms. In the example shown, the tank 2 comprises two electrical resistors, namely an upper electrical resistor and a lower electrical resistor, housed inside the tank, and a control unit for said electrical resistors.

[0073] The control unit is configured to selectively control said electrical resistors. This control unit is also configured to control the electrical resistors at different temperature setpoints.

[0074] This control unit can be implemented in common with the pump control unit 17 and is formed in the same way as that described for the pump control unit of an electronic and computer system which comprises, for example, a microprocessor and a working memory.

[0075] The set temperature of the lower electrical resistance is less than or equal to the set temperature of the upper electrical resistance. The upper electrical resistance has priority.

[0076] To allow simplified mounting of each electrical resistor, the tank 2 comprises, at the level of each of the electrical resistors, two facing orifices 21, 22, one 21, in the enclosure 51, the other 22, in the casing 52, these orifices 21, 22 being connected by a housing body 23 with a pierced bottom 231 forming a sheath for connecting said orifices 21, 22 together. This housing body 23, made of synthetic material, bears by its bottom on the enclosure 51 while extending at least partially inside the enclosure 51. In particular, the drilling of the bottom of the housing is bordered externally by a rim to form a tubular projection inserted into the orifice of the enclosure. The tubular projection of the housing body inserted into the hole of the enclosure comprises two glove fingers open towards the inside of the housing body, each glove finger being made in one piece with the housing body.A temperature probe is positionable inside one of the glove fingers and a cut-off thermostat is positionable inside the other of the glove fingers. Each electrical resistor 61, 62 is in the form of an elongated body provided with a seal 24 threaded onto the body of the resistor. This electrical resistor 61 or 62 is slidably introduced inside the housing body 23, passes through the bore 2311 of the bottom 231 of the housing body 23 to extend at least partially inside the tank 2. In particular, this electrical resistor 61 or 62 is positionable inside the housing body coaxially with the bore 2311 of the bottom of the housing body to project via said bore inside the enclosure, and is slidably movable inside the housing body.In the positioned state of the electrical resistor 61 or 62 projecting at least partially inside the tank 2, and in the state crossed by the bore 2311 by the electrical resistor 61 or 62, the seal 24 in sealed bearing contact with the resistor 61 or 62 seals the bore 2311 of the bottom 231 of the housing body 23. A part 30 can also be slipped onto the body of the resistor to cover the seal 24. This part 30 is fixed by screwing the housing body to prevent any untimely exit of the seal 24. This fixing part can therefore be slipped onto the electrical resistor following the seal and can be coupled by screwing to the housing body, this housing body comprising at least one screw well made in one piece with said body.

[0077] The housing body 23 is closed by a cover 29 masking the resistance which can be removed from the tank by simply pulling on the electrical resistance. This cover is housed in a reinforcement of the casing provided at the level of the orifice of the casing.

[0078] It is noted in the examples shown that the housing body comprises a bottom and a peripheral side wall and that the peripheral side wall of the housing body is provided with an external peripheral collar arranged to bear on the part of the internal surface of the casing surrounding the orifice of the casing.

[0079] Alternatively, the tank may only include an electrical resistance.

[0080] Each resistor is a hairpin electrical resistor comprising a tubular body inside which is housed a resistive wire and at least one thermofusible, the ends of the hairpin made in the form of two parallel branches each being provided with an electrical connector onto which the seal is capable of being slipped.

[0081] In addition, the heating means may comprise a heat pump and a loop circulation circuit between the contents of the tank and the heat pump. The heating system may also comprise, in addition or as a variant, a solar collector 63 and means 64 for circulating the contents of the tank through said solar collector 63 as shown in figure 4 The heating system may also include a boiler, for example gas, connected to the tank.

[0082] Finally, to allow the tank to be filled, particularly when the hot water production device is first used, or in the event of evaporation of the liquid contained in the tank 2, the tank 2 is equipped, in its upper third, with an orifice 33 for filling the tank 2 with liquid. This filling orifice 33 is connected by a closable fluid connection 35 to the portion of the secondary circuit 9 extending between the inlet 9A of the secondary circuit 9 and the zone 10 for exchanging calories between the primary 8 and secondary 9 circuits of the heat exchanger 2. This closable fluid connection 35 is provided at the filling orifice 33 with a part 34 for connection to the tank 2. This connection part 34 is provided with a vent 36, an overflow orifice 37 and an additional orifice 38 acting as an overflow or vent depending on the filling level of the tank 2.The additional orifice 38 is arranged at a higher level than the overflow orifice 37. This additional orifice 38 is also arranged at a lower level than that occupied by the vent 36. The configuration of this connecting part makes it possible to prevent any rise of “dead” water from the tank 2 into the filling liquid distribution network during the tank filling operation.

[0083] This part 34 for connection to the tank 2 is also equipped with a closure member 43. This closure member 43 is, in the example shown, a pivoting valve pivotally mounted about a so-called horizontal axis extending perpendicular to the longitudinal axis of the connection part 34 which is a tubular part. This closure member 43 is shaped and dimensioned to be returned to the closed position under the effect of its own weight. This normally closed closure member 43 is therefore capable of moving from the closed position to the open position under the effect, for example, of the tank being filled. The presence of such a closure member makes it possible to limit the appearance of condensation at the cover 54 of the casing, in particular at the part of the cover 54 shown at 44 in the figures which at least partially overlaps the connection part 34.

[0084] To improve the safety of the installation and limit the risk of untimely filling of the tank 2, the tank 2 is equipped with a so-called lower level sensor 39 and a so-called upper level sensor 40 arranged at different heights in the tank 2. In the examples shown, these sensors are floats axially offset along a rod inside the tank 2. The closable fluid connection 35 is provided with a closing member 41, such as a solenoid valve. This closing member 41 is equipped with an electrical control circuit 42. The electrical control circuit 42 is configured to switch from the closed state corresponding to the open position of the closing member 41 to the open state corresponding to the closed position of the closing member 41 at least in the activated state of the upper level sensor 40.Thus, when the filling level of the tank 2 reaches the upper level sensor 40, i.e. in the activated state of the upper level sensor 40, the latter acts as a switch for the electrical circuit 42 for controlling the closure member 41 and switches the latter to open it. Thus, further filling of the tank 2 from the fluid connection is prevented.

[0085] The operation of the device is as follows: When a draw-off is detected, this detection being carried out using the flow meter, temperature data measured by the various temperature probes arranged at the inlet and / or outlet of the primary and secondary circuits as well as the measured flow rate value are sent to the control unit 17 which opens the valve 31 and regulates the flow rate of the pump 12 according to said data to allow heating of the domestic cold water to the predetermined set temperature.

[0086] At the end of the draw-off, the pump 12 is stopped and the heat exchanger 7 is drained by thermosiphon to prevent any stagnation of hot water inside the heat exchanger. After a predetermined period of time, the valve 31 is closed to prevent any further circulation of fluid. Indeed, apart from a draw of domestic hot water, the pump is stopped. When the pump stops, the cold water contained in the bottom of the tank pushes back the warm water from the exchanger which rises in the tank via the forward branch of the circuit 11 in a loop between the tank and the heat exchanger until the level of separation between cold water and hot water at the level of the cold water in the tank and in the water pipe of the forward branch of the loop circuit is the same.

[0087] Thus, the warm water from the exchanger is replaced by cold water from the bottom of the tank by a thermosiphon phenomenon.

[0088] This reverse circulation is represented in the figure 2 This reverse circulation is prevented once valve 31 is closed, this closing of valve 31 occurring a few minutes after stopping pump 12, once the cooling of the heat exchanger is complete.

Claims

1. A device (1) for producing hot fluid, in particular domestic hot water, comprising: - a tank (2) for receiving liquid, equipped with at least one fluid inlet (3) and one fluid outlet (4), at least the part of the tank (2) called the inner part, suitable for being in contact with the liquid filling the tank (2), being made of synthetic material, - a system (6) for heating the contents of the tank (2), - a heat exchanger (7) comprising a primary circuit (8) equipped at least with a fluid inlet (8A) and a fluid outlet (8B), a secondary circuit (9) equipped at least with a fluid inlet (9A) and a fluid outlet (9B), and a zone (10), for heat exchange between the primary (8) and secondary (9) circuits, which is arranged outside the tank (2), - a loop circulation circuit (11) between the tank (2) and the primary circuit (8) of the heat exchanger (7), and - a pump (12) arranged on the loop circulation circuit (11), the inlet (9A) of the secondary circuit (9) of the heat exchanger (7) being connectable at least to a source of fluid to be heated, in order to allow the production of hot fluid at the outlet of the secondary circuit (9), - a valve (31) arranged on the loop circulation circuit (11) between the tank (2) and the primary circuit (8) of the heat exchanger (7), - a drive member (32) for moving the valve (31) between an open position and a closed position, - a unit (17) for controlling at least the pump (12) and the drive member (32) for moving the valve (31), the control unit (17) being configured to control the actuation of the drive member (32) for moving the valve (31) and thus the passage of the valve (31) from the open position to the closed position, or vice versa, depending on the on / off state of the pump (12), characterized in that the tank (2) comprises, in the lower half of the tank (2), on the outer surface of the tank (2), a reservation (16) inside which the heat exchanger (7), which is a counter-current exchanger (7), preferably with plates, is able to be housed in order to extend at least partially within the overall contour of the tank (2).

2. The device (1) as claimed in claim 1, characterized in that the device (1) comprises a clock (171), and in that the control unit (17) is configured to control the actuation of the drive member (32) for moving the valve (31) in the sense of opening the valve (31) in parallel with the control of the start-up of the pump (12) and is configured to control the actuation of the drive member (32) for moving the valve (31) in the sense of closing the valve (31) in the stopped state of the pump (12), after the pump (12) has been stopped for a predetermined period of time.

3. The device (1) as claimed in either of claims 1 and 2, characterized in that the pump (12) is a pump with a variable flow rate, in that the device (1) comprises means (13) for regulating the flow rate of said pump (12), these means (13) for regulating the flow rate of the pump (12) comprising a flowmeter (14) preferably arranged at the inlet of the secondary circuit (9), and at least two temperature probes (131, 132), at least one of which is arranged on the loop circulation circuit (11) between the tank (2) and the primary circuit (8) of the heat exchanger (7), and in that the control unit (17) is configured to control the pump (12) at least according to the data supplied by the temperature probes (131, 132) and the flowmeter (14).

4. The device (1) as claimed in claim 3, characterized in that the device (1) comprises, at the inlet of the secondary circuit (9), in the zone of connection of the inlet (9A) of the secondary circuit (9) to at least one source of fluid to be heated, a duct (18) arranged at least partially in the thickness of the tank (2), this duct (18), called the inlet duct, being able to be coupled at one end to the inlet (9A) of the secondary circuit (9) of the heat exchanger (2) and dividing, at the end opposite the connection to at least one source of fluid to be heated, into two branches (18A, 18B), which are equipped one (18A) with a closure member (20) and the other (18B) with the flowmeter (14).

5. The device (1) as claimed in one of claims 1 through 4, characterized in that the loop circulation circuit (11) between the tank (2) and the primary circuit (8) of the heat exchanger (7) comprises an outward branch (11A) arranged between the outlet (4) of the tank (2) and the inlet (8A) of the primary circuit (8), and a return branch (11B) arranged between the outlet (8B) of the primary circuit (8) and the inlet (3) of the tank (2), the pump (12) and the valve (31) being preferably arranged on the outward branch (11A) of the loop circulation circuit (11).

6. The device (1) as claimed in one of claims 1 through 5, characterized in that the tank (2) is equipped with an orifice (33) for filling the tank (2) with liquid, this filling orifice (33) being connected by a closable fluidic connection (35) to the portion of the secondary circuit (9) extending between the inlet (9A) of the secondary circuit (9) and the zone (10) for heat exchange between the primary (8) and secondary (9) circuits of the heat exchanger (2).

7. The device (1) as claimed in claim 6, characterized in that the closable fluidic connection (35) is provided, at the level of the filling orifice (33), with a part (34) for connection to the tank (2), this connection part (34) being provided with a vent (36), an overflow orifice (37), and an additional orifice (38) acting as an overflow or vent depending on the filling level of the tank (2).

8. The device (1) as claimed in either of claims 6 and 7, characterized in that the tank (2) is equipped with a lower level sensor (39) and an upper level sensor (40), which are arranged at different heights in the tank (2), in that the closable fluidic connection (35) is provided with a closure member (41) equipped with an electrical control circuit (42), and in that the electrical control circuit (42) is configured to pass from the closed state, corresponding to the open position of the closure member (41), to the open state, corresponding to the closed position of the closure member (41) at least in the activated state of the upper level sensor (40).

9. The device (1) as claimed in one of claims 1 through 8, characterized in that the outlet (4) of the tank (2), connectable to the inlet (8A) of the primary circuit (8), is arranged in the upper third of the internal volume of the tank (2), and the inlet of the tank (2), connectable to the outlet (8A) of the primary circuit (8), is arranged in the lower third of the internal volume of the tank (2), in that at least part of the heating system (6) is housed in the tank (2), and in that the inlet (3) of the tank (2), connectable to the outlet (8B) of the primary circuit (8) of the heat exchanger (2), opens into the tank (2) at a level lower than the level occupied by the part of the heating system (6) housed in the tank (2).

10. The device (1) as claimed in one of claims 1 through 9, characterized in that the heat exchanger (7), when connected to the tank (2), is arranged at a level lower than the level occupied by the inlet of the tank (2) connectable to the outlet (8B) of the primary circuit (8) of said heat exchanger (7).

11. The device (1) as claimed in one of claims 1 through 10, characterized in that the tank (2) comprises an enclosure (51), a casing (52) at least partially surrounding the enclosure (51), and an insulator (53) arranged between the enclosure (51) and the casing (52).

12. The device (1) as claimed in claim 11, characterized in that at least part of the heating system (6) is housed in the tank (2), and in that the thickness of the tank (2), taken between the outer face of the casing (52) and the inner face of the enclosure (51), is, in the part of the tank (2) extending above the part of the heating system (6) housed inside the tank (2), at least locally greater than the thickness of the tank extending below the part of the heating system (6) housed inside the tank (2).

13. The device (1) as claimed in one of claims 1 through 12, characterized in that at least the heat exchanger (7), the pump (12), which has a variable flow rate, and the valve (31), with its drive member (32) for moving it, which is preferably a motor, form a ready-to-install assembly.

14. The device (1) as claimed in one of claims 1 through 13, in combination with either of claims 11 and 12, characterized in that the heating system (6) comprises at least one electrical resistance (61, 62) housed inside the tank (2), in that the tank (2) comprises, at the level of the, or at least one of the, electrical resistance(s) (61, 62), two mutually opposite orifices (21, 22) formed one (21) in the enclosure (51) and the other (22) in the casing (52), these orifices (21, 22) being connected by a housing body (23) with a drilled bottom (231) forming a connecting sleeve between said orifices (21, 22), this housing body (23) extending at least partially inside the enclosure (51), and in that the electrical resistance (61, 62) is in the form of an elongate body provided with a seal (24) engaged on the electrical resistance (61, 62), this seal (24), in leaktight contact with the electrical resistance (61, 62), sealingly closing the bore (2311) in the bottom (231) of the housing body (23) in the state with the electrical resistance (61, 62) extending through said bore (2311).

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