Automated hot water distribution system

Abstract

Automated Hot Water Distribution Device This description relates to a hot water distribution device (60) comprising a main hot water generation and / or storage device (12), a first hot water supply pipe (16) from the main hot water generation and / or storage device (12) to a draw-off point (28), and a water storage device (62) configured to detect the activation of the draw-off point (28) by a user, and then to store at least a portion of the water present in the first pipe (16) and subsequently supply the stored water to the first pipe (16) when hot water supplied by the main hot water generation and / or storage device (12) arrives through the first pipe (16) such that the water flowing from the draw-off point (28) is a mixture of hot water and stored water. Figure for the abstract: Fig. 3

Description

Title of the invention: Automated hot water distribution device technical field

[0001] This description relates generally to hot water distribution devices, in particular domestic hot water. Previous technique

[0002] A hot water distribution device generally includes a hot water generation and / or storage device and a hot water supply pipe from the hot water generation and / or storage device to a point of use, for example a shower head.

[0003] During the time between two uses of the shower, the hot water in the hot water supply pipe cools to ambient temperature. Therefore, when a user activates the tap to obtain hot water, during an initial phase, the temperature of the water flowing from the tap remains lower than the temperature requested by the user for the time required for hot water to circulate in the hot water supply pipe from the hot water generation and / or storage device and reach the tap.

[0004] Generally, during the initial phase, the user waits for the water supplied at the tap to reach the desired temperature by letting the water run. This water is then collected by a collection device and discharged into the sewer. The volume of water in the hot water supply pipe that flows during the initial phase is therefore lost. Furthermore, this volume of water in the hot water supply pipe was heated during the previous use of the shower. Consequently, the electricity consumed by the hot water generation and / or storage device for heating unused water is wasted.

[0005] It is desirable to reduce, or even eliminate, the volume of water lost. It is also desirable to reduce, or even eliminate, the electrical consumption of the hot water generation and / or storage device that is lost. Summary of the invention

[0006] One embodiment overcomes all or part of the disadvantages of known hot water distribution devices.

[0007] One embodiment provides for a hot water distribution device comprising: - a main hot water generation and / or storage device; - a first supply pipe for hot water from the main hot water generation and / or storage system to a point of use; and - a water storage device configured to detect the activation of the tap by a user, and then to store at least part of the water present in the first pipe and then supply the water stored in the water storage device to the first pipe when hot water supplied by the main hot water generation and / or storage device arrives through the first pipe so that the water flowing from the tap is a mixture of hot water and water stored in the water storage device.

[0008] According to one embodiment, the water storage device includes an expansion vessel configured to store said at least a portion of the water present in the first pipe.

[0009] According to one embodiment, the water storage device further comprises: - a second pipe connecting the expansion vessel to the first pipe at a first connection point; - a first valve on the second pipe; - a third pipe connecting the expansion vessel to the first pipe at a second connection point, downstream of the first connection point with respect to the direction of water flow in the first pipe; - a second valve on the third pipe; and - a third valve on the first pipe between the first and second connection points.

[0010] According to one embodiment, the water storage device further comprises: - a first temperature sensor configured to measure a first water temperature at the first connection point; - a second temperature sensor configured to measure a second water temperature at the second connection point; and - a pressure sensor configured to measure water pressure at the second connection point.

[0011] According to one embodiment, the hot water distribution device further comprises: - a fourth cold water supply pipe; and - a mixer comprising a first inlet connected to the fourth pipe, a second inlet connected to the first pipe and an outlet connected to the point of use.

[0012] According to one embodiment, the mixer is a thermostatic mixer.

[0013] According to one embodiment, the hot water distribution device comprises in besides : - a device for collecting the water supplied by the tap; and - a fifth pipeline for transporting the water collected by the collection device and intended to be connected to the sewers.

[0014] One embodiment also provides for the use of the hot water distribution device as defined above, comprising the following steps in order: a) detection of the activation of the tap point by a user; b) storage of at least some of the water present in the first pipe in the water storage device; and c) supply of water stored in the water storage device to the first pipe when hot water supplied by the main hot water generation and / or storage device arrives through the first pipe so that the water flowing from the tapping point is a mixture of hot water and water stored in the water storage device.

[0015] According to one embodiment, the process comprises, in step b), opening the first valve, and closing the second and third valves, and further comprises, in step c), closing the first valve, and gradually opening the second and third valves.

[0016] According to one embodiment, the transition from stage b) to stage c) is carried out upon detection that the first temperature exceeds a temperature threshold. Brief description of the drawings

[0017] These features and advantages, as well as others, will be described in detail in the following description of particular embodiments, given by way of non-limiting example, in relation to the accompanying figures, among which:

[0018] Fig. 1 represents, in a partial and schematic way, an example of a domestic hot water distribution device;

[0019] [Fig.2] represents, in a partial and schematic way, another example of a domestic hot water distribution device;

[0020] [Fig.3] represents, in a partial and schematic way, an embodiment of a domestic hot water distribution device;

[0021] [Fig.4] is a block diagram of an embodiment of a method of operation of the domestic hot water distribution device according to the embodiment illustrated in [Fig.3];

[0022] [Fig.5] represents an expansion vessel in an empty state;

[0023] Figure 6 represents an expansion vessel in a full state; and

[0024] Fig. 7 represents another example of an expansion vessel. Description of the implementation methods

[0025] The same elements have been designated by the same reference numerals in the different figures. In particular, structural and / or functional elements common to the different embodiments may have the same reference numerals and may have identical structural, dimensional and material properties.

[0026] For the sake of clarity, only the steps and elements useful for understanding the described embodiments have been represented and are detailed.

[0027] Unless otherwise specified, when referring to two elements connected together, this means directly connected without intermediate elements other than conduits, and when referring to two elements coupled together, this means that these two elements can be connected or linked through one or more other elements.

[0028] In the following description, when reference is made to absolute position qualifiers, such as the terms "front", "back", "top", "bottom", "left", "right", etc., or relative position qualifiers, such as the terms "above", "below", "superior", "inferior", etc., or to orientation qualifiers, such as the terms "horizontal", "vertical", etc., reference is made, unless otherwise specified, to the orientation of the figures or to a hot water distribution device in a normal operating position.

[0029] Unless otherwise specified, the expressions "approximately", "roughly", and "on the order of" mean to within 10% or 10°, preferably to within 5% or 5°.

[0030] In the following description, unless otherwise indicated, a pressure value at a location in a hydraulic circuit is given relative to atmospheric pressure, i.e. the pressure value given is equal to the difference between the absolute pressure at the location of the hydraulic circuit and the surrounding atmospheric pressure.

[0031] An example of the application of a domestic hot water distribution device will be described for an application to a shower. However, it is clear that the domestic hot water distribution device can be used for other applications, for example the distribution of hot water to a sink or washbasin.

[0032] Fig. 1 represents, in a partial and schematic way, an example of a domestic hot water distribution device 10 for a shower.

[0033] Device 10 comprises: - a pipe 11 supplying cold domestic water at a temperature Tef at a pressure Near, for example of the order of 3 bars (300000 Pa) to 4 bars (400000 Pa) relative to atmospheric pressure, connected at one end to a cold water supply network, not shown; - a main domestic hot water generation and / or storage device 12 providing hot water at a temperature Tdec; - a pipe 13 supplying cold domestic water to the main domestic hot water generation and / or storage device 12, connected at one end to the pipe 11 supplying cold domestic water and connected at a second end, opposite to the first end, to the main domestic hot water generation and / or storage device 12; - a device 14 for protection against overpressure in the domestic hot water circuit on pipe 13; - a domestic hot water supply pipe 16 connected at one end to the main domestic hot water generation and / or storage device 12; - a mixer 18 comprising a first inlet 20 connected to a second end of the cold water supply pipe 11 and a second inlet 22 connected to a second end of the hot water supply pipe 16 and comprising an outlet 24; - a pipe 26 connected at one end to the outlet 24 of the mixer 18; - a tapping point 28, for example a shower head, connected to a second end of the pipe 26; - a device 30 for collecting water emitted at the point of extraction 28; - a wastewater drainage pipe 32 connected at one end to the collection device 30 and connected at a second end, opposite the first end, to the sewers, schematically represented by an arrow 34, for the transport of wastewater from the collection device 30 to the sewers; and - a pipe 36 connected at one end to the drainage pipe 32 and connected at a second end, opposite the first end, to the pressure regulating device 14.

[0034] The mixer 18 can be a thermostatic mixer. In this case, it includes a mechanism adapted to gradually open the first opening 20 and gradually close the second opening 22 according to the water temperature at the outlet 24 of the mixer 18, so that the water temperature at the outlet 24 of the mixer 18 reaches a shower temperature Tdou requested by a user. When a user activates the mixer 18 at the requested shower temperature Tdou, initially, the mixer 18 completely closes the first opening 20 connected to the cold water supply pipe 11 and fully opens the second opening 22 connected to the hot water supply pipe 16. As long as the water temperature supplied at the outlet 24 of the mixer 18 is lower than the requested shower temperature Tdou, this configuration remains unchanged.When the temperature of the water supplied at outlet 24 of mixer 18 reaches the temperature of . shower requested Tdou, the mixer mechanism 18 gradually opens the first opening 20 and gradually closes the second opening 22 to maintain the water temperature at the outlet 24 of the mixer 18 at the shower temperature requested Tdou.

[0035] During the time between two draw-offs at the shower, the hot water present in the domestic hot water supply pipe 16 cools down to the ambient temperature Tamb. Therefore, when a user activates the mixer 18 at the requested shower temperature Tdou, during an initial phase, the temperature of the water flowing from the draw-off point 28 remains lower than the requested shower temperature Tdou for the time necessary for the domestic hot water to circulate in the domestic hot water supply pipe 16 from the main domestic hot water generation and / or storage device 12 and reach the mixer 18.The draw-off point 28 may be located away from the main domestic hot water generation and / or storage device 12, so that the length of the domestic hot water supply pipe 16 may be more than a few meters and the duration of the initial phase may be more than a few seconds, or even more than 10 seconds.

[0036] In general, during the initial phase, the user waits for the water supplied at the tapping point 28 to reach the required shower temperature Tdou by letting the water run, which is collected by the collection device 30 and is discharged through the drain pipe 32 to the sewer 34. Indeed, in practice, the water supplied at the tapping point 28 during the initial phase is not collected in a container for hypothetical subsequent use (toilet, watering plants, manually rinsing dishes, etc.).

[0037] The volume of water Veau contained in the domestic hot water supply pipe 16 and flowing during the initial phase is therefore lost. Furthermore, this volume of water Veau contained in the domestic hot water supply pipe 16 was heated during the previous use of the shower. The electrical consumption of the main domestic hot water generation and / or storage device 12 for heating unused water is therefore wasted.

[0038] Fig. 2 represents, in a partial and schematic way, another example of a 50 domestic hot water distribution device for a shower.

[0039] The domestic hot water distribution device 50 shown in [Fig. 2] comprises all the elements of the domestic hot water distribution device 10 shown in [Fig. 1] and further comprises a recirculation pipe 52 connected at one end to the domestic hot water supply pipe 16 and connected at the other end to the domestic cold water supply pipe 14 to the main domestic hot water generation and / or storage device 12. The domestic hot water distribution device 50 further comprises a pump 54 on the pipe recirculation 52 which returns the water to the main domestic hot water generation and / or storage device 12.

[0040] Hot water circulates continuously in the loop formed by part of the domestic hot water supply pipe 16 and the recirculation pipe 52 from the main domestic hot water generation and / or storage device 12 until it returns to the main domestic hot water generation and / or storage device 12.

[0041] The domestic hot water distribution device 50, known as a recirculating device, may be required by regulation for reasons of prevention of the risks of legionella when the volume of water in the domestic hot water supply pipe 16 exceeds 3 liters and the volume of the main domestic hot water generation and / or storage device 12 is greater than 400 liters.

[0042] Since the water circulating in the loop formed by part of the domestic hot water supply pipe 16 and the recirculation pipe 52 is constantly hot, when a user activates the mixer tap 18 to take a shower, there may be little or no waiting time for the water flowing from the tap 28 to reach the desired shower temperature Tdou. Water losses can thus be reduced.

[0043] One drawback is that the recirculation pipe 52 must be installed, which is almost the same length as the domestic hot water supply pipe 16 and can therefore be quite long. Another drawback is that the operation of the recirculating domestic hot water distribution device 50 requires continuous electrical consumption by the recirculation pump 54. A further drawback is that the operation of the recirculating domestic hot water distribution device 50 results in increased energy consumption by the main domestic hot water generation and / or storage device 12 for heating the continuously recirculated water, so that the temperature of the water returning to the main domestic hot water generation and / or storage device 12 is always above 50°C.

[0044] Figure 3 partially and schematically represents an example of a domestic hot water distribution device 60 for a shower. An example of the application of the domestic hot water distribution device 60 concerns individual and multi-family residential dwellings.

[0045] The domestic hot water distribution device 60 shown in [Fig.3] includes all the elements of the domestic hot water distribution device 10 shown in [Fig.1] and includes, in addition, a compact water storage device 62 located on the side of the second end of the domestic hot water supply pipe 16 connected to the mixer 18.

[0046] The water storage device 62 comprises: - an expansion vessel 64, preferably thermally insulated; - a water supply pipe 66 to the expansion vessel 64 and connected at a first end at a connection point Ne to the domestic hot water supply pipe 16 and connected at a second end, opposite to the first end, to the expansion vessel 64; - a Vev valve on the water supply pipe 66 to the expansion vessel 64; - a CTev sensor of the temperature Tev of the water circulating in the domestic hot water supply pipe 16 just upstream, according to the direction of water flow, of the connection point Ne between the water supply pipe 66 to the expansion vessel 64 and the domestic hot water supply pipe 16; - a water supply pipe 68 from the expansion vessel 64 and connected at one end to the expansion vessel 64 and connected at a second end, opposite the first end, to the domestic hot water supply pipe 16 at a connection point Cs closer to the mixer 18 than the connection point Ce between the water supply pipe 66 to the expansion vessel 64 and the domestic hot water supply pipe 16; - a Vsv valve on the 68 water supply pipe from the expansion vessel 64; - a CTsv sensor of the temperature Tsv of the water circulating in the domestic hot water supply pipe 16 just downstream, according to the direction of water flow, of the connection point Ns between the water supply pipe 68 from the expansion vessel 64 and the domestic hot water supply pipe 16; - a CPsv pressure sensor Psv of the water in the domestic hot water supply pipe 16 just downstream of the connection point Ns between the water supply pipe 68 from the expansion vessel 64 and the domestic hot water supply pipe 16; - a Vbp valve on the domestic hot water supply pipe 16 between the connection point Ne between the water supply pipe 66 to the expansion vessel 64 and the domestic hot water supply pipe 16 and the connection point Ns between the water supply pipe 68 from the expansion vessel 64 and the domestic hot water supply pipe 16; and - a control circuit 70 for the valves Vev, Vsv, and Vbp, receiving signals from the temperature sensors CTev and CTsv and the pressure sensor CPsv.

[0047] The performance of the valves Vev, Vsv, and Vbp is to be adapted according to the dimensions of the domestic hot water distribution device 60. In one embodiment, the valves Vev, Vsv, and Vbp are solenoid valves sealed against a pressure differential of 7 bar (0.7 MPa). In one embodiment, the temperature sensors CTev and CTsv are electronic temperature sensors, and the pressure sensor CPsv is an electronic pressure sensor. In one embodiment, the control circuit 70 is a programmable electronic controller. In another embodiment, the control circuit 70 includes a microcontroller. Alternatively, the pressure sensor CPsv can be replaced by a flow detector in the water supply line 68 from the expansion vessel 64.

[0048] The water storage device 62 can be connected to the electrical network to supply power to the control circuit 70, the valves Vev, Vsv, and Vbp, the temperature sensors CTev and CTsv, and the pressure sensor CPsv. Alternatively, the water storage device 62 can be powered electrically by a battery of electrical accumulators or by batteries.

[0049] As an alternative, the valves Vev, Vsv, and Vbp, the temperature sensors CTev and CTsv and the pressure sensor CPsv can correspond to mechanical, thermomechanical and / or pneumatic components and the control circuit 70 can be replaced by a mechanical, thermomechanical and / or pneumatic control mechanism so that the water storage device 62 does not require an electrical supply.

[0050] In one embodiment, the expansion vessel 64 comprises a housing 71 containing a deformable reservoir 72 for storing water. The housing 71, together with the reservoir 72, defines a cavity 73 filled with a gas. In one embodiment, the deformable reservoir 72 comprises a water inlet 74 connected to the water supply pipe 66 and a water outlet 75 connected to the water supply pipe 68. The pressure Pvase in the deformable tank 72 is in equilibrium with the pressure in the cavity 73. The pressure Pvase increases with the volume of water Vvase present in the deformable tank 72. The pressure in the cavity 73 can be automatically adjusted with a compressor connected to the control circuit 70. Hereafter, Pvase refers interchangeably to the pressure in the deformable tank 72, the pressure in the cavity 73, or the pressure in the expansion vessel 64.

[0051] The operation of the domestic hot water distribution device 60 consists of managing a temporary storage, in the expansion vessel 64, of the domestic hot water contained in the domestic hot water supply pipe 16 and which is at the ambient temperature Tamb before starting to distribute water at the point of use 28, then mixing the stored water with the hot water supplied by the main water generation and / or storage device 12 to supply the point of use 28 with water at the desired temperature Tdou.

[0052] Fig. 4 is a block diagram of an embodiment of a method of operation of the domestic hot water distribution device 60 according to the embodiment illustrated in Fig. 3.

[0053] At step 80, there is no drawing in progress at the drawing point 28. Valve Vev is closed. Valve Vsv is closed. Valve Vbp is open, with the mixing valve 18 closed. The pressure Pvase in the expansion vessel 64 is at a low value, for example 0.5 bar (0.05 MPa) relative to atmospheric pressure. The process continues to step 82.

[0054] In step 82, at time t0, the user activates the mixer 18 to the desired shower temperature Tdou. In a conventional manner, the mixer 18 completely closes the first opening 20 connected to the cold water supply pipe 11 and fully opens the second opening 22 connected to the hot water supply pipe 16. The process continues in step 84.

[0055] In step 84, the control circuit 70 detects the user's request to draw water. In one embodiment, the draw-off request is detected by detecting a drop in pressure Psv measured by the pressure sensor CPsv at the outlet of the valve Vbp. In another embodiment, the draw-off request is detected by detecting a change in the water temperature Tsv measured by the temperature sensor CTsv at the outlet of the valve Vsv. In yet another embodiment, the draw-off request is detected by measuring the flow rate if the domestic hot water distribution device 60 includes a water flow sensor, for example, on the pipe 68. The process continues in step 86.

[0056] In step 86, the control circuit 70 commands the closing of valve Vbp and the opening of valve Vev. This results in the storage in expansion vessel 64 of the water that was present in the domestic hot water supply pipe 16 before time t0. The filling of expansion vessel 64 continues until hot water supplied by the main domestic hot water generation and / or storage device 12 reaches the temperature sensor CTev. When the temperature Tev measured by the temperature sensor CTev reaches a predetermined temperature Tua at time tf, the control circuit 70 commands the closing of valve Vev. The storage of water in vessel 64 is then stopped. The temperature threshold Tua is, for example, stored in the treatment circuit 70. In one embodiment, the treatment circuit 70 includes an interface that allows the user to modify the temperature threshold Tua.The temperature threshold Tua is, for example, equal to 40 °C. The process continues at step 88.

[0057] Figure 5 represents the expansion vessel 64 at time t0. The deformable reservoir 72 is substantially empty. The volume Vvase of water in the expansion vessel 64 at time t0 is assumed to be equal to 0 liters in the ideal case. However, as an alternative, the volume Vvase of water in the expansion vessel 64 at time t0 may be strictly greater than 0 liters, but is preferably reduced. The pressure Pvase in the expansion vessel 64 at time t0 is equal to PO. The volume Va(t0) of the cavity 73 at time t0 is equal to VO.

[0058] Figure 6 represents the expansion vessel 64 at time tf. The deformable reservoir 72 is filled with water. The volume Vvase of water in the expansion vessel 64 at time tf is equal to Vcan. Preferably, the maximum volume Vcan of water that the expansion vessel 64 can store is greater than the volume Veau contained in the domestic hot water supply pipe 16. The pressure Pvase in the expansion vessel 64 at time tf is equal to Pf. The volume of the cavity 73 at time tf is equal to Va(tf) and is equal to the difference between the volume VO and the volume Vcan.

[0059] The dimensioning of the expansion vessel 64 can be carried out in the following way. At time t0, the absolute pressure PO in the empty (waterless) expansion vessel 64 is approximately 1.5 bar (0.5 bar + 1 bar, with 1 bar corresponding to atmospheric pressure), or 0.15 MPa. The absolute pressure Pf in the expansion vessel 64 filled with water at time tf is equal to 4 bar (3 bar + 1 bar), or 0.4 MPa, which is approximately the pressure of the mains water supply. When the vessel is filled, the volume Va(tf) of cavity 73 is equal to Vcan. The ideal gas law can be applied to the volumes V0 and Va(tf), which gives a volume V0 of approximately 2.4 liters, assuming a volume Vcan of 1.5 liters.

[0060] The time tf can be estimated as follows. It is assumed that at time t0, the volume of water Veau in the domestic hot water supply pipe 16, which will be stored in the expansion vessel 64, is at ambient temperature Tamb. The expansion vessel 64 is filled with water at a decreasing filling rate 4W from time t0 to time tf. For example, the volume Vcan is assumed to be 2.4 liters. The product of the pressure PO and the volume V0 is equal to the product of the pressure Pf and the volume Va(tf). This leads to a pressure Pf equal to 1.5 bar relative (0.15 MPa), which is consistent with the pressure near the domestic water supply, which is generally around 3 bar (0.3 MPa).

[0061] The minimum filling flow rate d^tO of the expansion vessel 64 is obtained at time tf when the pressure Pvase of the expansion vessel 64 is equal to Pf, that is, when the pressure loss from the network pressure Près is minimal. The maximum filling time At, equal to the difference between time tf and time tO, at this minimum flow rate is defined by the following equation Math 1:

[0062] [Math.l] At_Vçan dt

[0063] The pressure loss Ap in a regular pipe is defined by the following Math 2 equation:

[0064] [Math.2] Ap=| DRC rhoF vF2

[0065] where L is the length of the domestic hot water supply pipe 16, Dh is the hydraulic diameter, rhoF is the density, DRC is the Darcy coefficient, and vF is related to the flow rate by the following Math 3 equation:

[0066] [Math.3] ^=vF n Dh2 / 4

[0067] A minimum flow rate of 7.3 l / min is obtained, resulting in a duration At of 0.33 minutes (20 seconds). This is the estimated (increased) waiting time without water exiting at the point of use 28, which corresponds to the time during which water would be allowed to flow to the sewer in the absence of the water storage device 62.

[0068] Referring again to [Fig. 4], in step 88, the control circuit 70 commands the gradual opening of the valves Vbp and Vsv to maintain the temperature Tsv at a value greater than or equal to the temperature threshold Tua (for example, approximately 40 °C) and the pressure Psv at approximately 0.5 bar (0.05 MPa) (which corresponds approximately to the relative pressure Pvase in the empty expansion vessel 64). This initiates the distribution of usable hot water at the hot inlet 22 of the mixing valve 18, and thus the start of a water supply phase at the draw-off point 28. Step 88 ends when the expansion vessel 64 is empty, i.e., when the pressure Psv is equal to a low pressure threshold, for example, 0.5 bar (0.05 MPa). When the pressure Psv measured by the pressure sensor CPsv is equal to the low pressure threshold, for example 0.5 bar (0.05 MPa), the control circuit 70 commands the closure of the valve Vsv and the full opening of the valve Vbp.According to another embodiment, the detection that the expansion vessel 64 is empty is achieved by detecting a variation in the water temperature Tsv measured by the temperature sensor CTsv at the outlet of the valve Vsv. According to another embodiment, the detection that the expansion vessel 64 is empty is achieved by a flow measurement in the case where the domestic hot water distribution device 60 includes a water flow sensor, for example on the pipe 68. The process continues in step 90.

[0069] With a volume Vcan equal to 2.4 liters and a temperature Tsv equal to 20 °C, water can be obtained at a usable temperature of 38 °C by mixing the volume Vcan with 2.5 liters of water at a temperature equal to 55 °C, to distribute 4.9 liters at 38 °C, which is feasible with regard to the average volume of water at a temperature of 38 °C of 30 liters per shower.

[0070] The minimum flow rate during the water supply phase at the draw-off point 28 occurs when the expansion vessel 64 is almost empty, which corresponds to a The pressure Pvase(tf) in the expansion vessel 64 is approximately 0.5 bar (0.05 MPa), resulting in a minimal pressure drop in the Vsv valve of 0.2 bar (0.02 MPa) (leaving 0.3 bar - 0.03 MPa - in the mixing valve 18). The minimum flow rate during the water supply phase at the draw-off point 28 is estimated at 7.7 liters / min, using a relationship similar to that in Math 1 for a Vsv regulating valve with a hydraulic passage reduction from 10 mm to 5 mm. The estimated duration (increased) of this phase is then 38 seconds.

[0071] In step 90, hot water is distributed by mixing hot water supplied by the domestic hot water supply pipe 16 and cold water supplied by the domestic cold water supply pipe 11 via the mixer tap 18. The user can operate the mixer tap in the usual way to change the desired shower temperature Tdou. The maximum flow rate at the desired shower temperature Tdou set by the user is obtained for the remainder of the shower. The process continues in step 92.

[0072] In step 92, the control circuit 70 detects the end of hot water draw-off when the pressure measured Psv by the pressure sensor CPsv increases to the static pressure near the network, for example, approximately 3 bar. In another embodiment, the end of hot water draw-off is detected by detecting a change in the water temperature Tsv measured by the temperature sensor CTsv at the outlet of the valve Vsv. In yet another embodiment, the end of hot water draw-off is detected by a flow measurement in the case where the domestic hot water distribution device 60 includes a water flow sensor, for example, on the pipe 68.

[0073] If the draw-off is interrupted before the expansion vessel 64 has been completely emptied, the waiting time for the next draw-off, which would be much later (i.e., one for which the water in the domestic hot water supply pipe 16 will have cooled down), is extended compared to the standard case by a duration corresponding to the residual stock volume from the previous draw-off. If the next draw-off is sooner, the residual stock from the previous draw-off is automatically used transparently to the user.

[0074] As an alternative, the mixer 18 or the tap 28 may be a mechanical mixer rather than a thermostatic mixer. In this case, the degree of opening of the first inlet 20 and the degree of opening of the second inlet 22 of the mixer 18 / tap 28 is set by the user and does not change over time unless the user intervenes. The operating method of the domestic hot water distribution device 60 is identical to that described previously, except that cold water flows from the start of the draw-off through the tap 28, depending on the user's action on the mixer 18 / tap 28.

[0075] Advantageously, the water storage device 62 can be compact and installed close to the mixing valve 28, so that the installation of the water storage device 62 may not require major work. Conversely, when installing the domestic hot water recirculation distribution device 50 illustrated in [Fig. 2], the installation of the recirculation pipe 52, which may be of considerable length, may require significant work.

[0076] According to one embodiment, the control circuit 70 includes means for communicating information to the user, for example a display screen. The following information can then be communicated to the user about a water draw in progress: - the water level / use level in the expansion vessel 64, for example to allow the user to stop drawing water after emptying the expansion vessel 64, the supplied water of which has been mixed with hot water; and - the estimated waiting time depending on the possible residual filling level of the expansion vessel 64 after a previous draw-off.

[0077] According to one embodiment, particularly in the case where the mixer 28 is a mechanical mixer, the control circuit 70 delays by a few seconds, for example 3 seconds, the taking into account of the user's request to draw water (therefore the start of the flow at the draw-off point 28 in the end) to allow time for the user to possibly redirect the mechanical mixer to cold water while it was in an intermediate position, for example for hand washing.

[0078] A simulation was performed to determine the savings in electrical consumption during the operation of the domestic hot water distribution device 60. For the simulation, a household of four people was considered, drawing hot water four times at intervals such that the temperature of the domestic hot water supply pipe 16 equalizes with the ambient temperature Tamb before each of the four showers. The cold water supply temperature Tef is 10°C. The ambient temperature Tamb is 20°C. The hot water temperature Tdec supplied by the main domestic hot water generation and / or storage device 12 is 55°C. The shower temperature Tdou requested by the user is 37°C. The volume Vdou consumed per shower at the requested shower temperature Tdou is 30 liters.The volume of water Veau in the domestic hot water supply pipe 16 between the main domestic hot water generation and / or storage device 12 and the draw-off point 28 is equal to 1.5 litres, which corresponds to a mass of water meau equal to 1.5 kg. The volumetric heat capacity of the water cp is equal to 1.16 Wh / (1.K).

[0079] In the absence of the domestic hot water distribution device 60 illustrated in [Fig. 3], i.e. for the domestic hot water distribution device 10 illustrated in [Fig.l], when showering with a volume Vdou equal to 30 liters, a volume of hot water Vecdou equal to 18 liters at a temperature Tdec of 55 °C and a volume of cold water Vefdou equal to 12 liters at a temperature Tef of 10 °C are used, i.e. a mixture of 0.6 at 55 °C and 0.4 at 10 °C to obtain the desired temperature Tdou of 37 °C.

[0080] A volume Veau of 1.5 liters of water is drawn from the domestic hot water supply pipe 16 at a temperature Tamb of 20 °C, which is not used directly and is discharged, then a mixture of 18 liters of water at a temperature Tef of 55 °C with 12 liters of water at a temperature Tdec of 10 °C is mixed. A total volume of 19.5 liters of water supplied by the domestic hot water supply pipe 16 is therefore used.

[0081] The energy Qdou,ec required to heat the hot water by the main domestic hot water generation and / or storage device 12 from a temperature Tef, equal to 10 °C, to a temperature Tdec, equal to 55 °C, is equal to 18 * 1.16 * 45, or 939.6 W for a shower. This corresponds to the consumption of the main domestic hot water generation and / or storage device 12, with an efficiency close to 100%.

[0082] Consider a main domestic hot water generation and / or storage device 12 comprising a 100-liter electric water heater. The volume of water drawn from the water heater (Vpuis) ​​for the four showers is equal to 4 * 19.5, or 78 liters, therefore the volume not drawn from the water heater (Vnpuis) ​​is equal to 22 liters. The heat loss coefficient of an electric water heater is typically equal to 0.225 / 24, or 0.009375 W / (Kl).

[0083] For one heating cycle per day in an electric water heater, with heat loss of the heated water not drawn from the storage tank before the day's draw-offs, on average at a temperature Tdec of approximately 55 °C with a cooling of 3 °C (in approximately 9 hours), a heating temperature setpoint TchfStck of 58 °C is required for the water heater. The energy EnChfStockjour consumed by the electric water heater is given by the following Math 4 equation:

[0084] [Math.4] EnChfStockjour=Vthen*cp*(TchfStck-Tef)+Vnthen*q)*(TchfStck-Tdec) = 4385 Wh

[0085] For a need of 4 showers of 939 Wh per day, the estimated storage efficiency is 3756 / 4385 or 86%.

[0086] When the domestic hot water distribution device 60 is present, for 1 shower, a saving of 1.5 litres of water is achieved, i.e. 5% (1.5 / 30) of water saved on the total volume of water Vdou used per shower.

[0087] A volume Vdou of 30 liters at the requested shower temperature Tdou of 37 °C corresponds to the sum of 1.5 liters at the temperature Tdec of 55 °C, 1.5 liters at the temperature Tamb of 20 °C, and 27 liters at the requested shower temperature Tdou of 37 °C. corresponding to the mixture of 16.2 litres at a temperature Tdec of 55 °C and 10.8 litres at a temperature Tef of 10 °C. The sum of 1.5 litres, 1.5 litres and 16.2 litres, i.e. 19.2 litres of water is drawn from the domestic hot water supply pipe 16, i.e. 0.3 litres (1.6%) less than for the domestic hot water distribution device 10 illustrated in [Fig.1] for which 19.5 litres are drawn.

[0088] This saving in heated water for a volume of water Vdou of 30 liters at a temperature Tdou of 37 °C, using the domestic hot water distribution device 60, results in a saving in heating energy. Assuming a main instantaneous domestic hot water generation and / or storage device 12 (for example, a gas boiler), the energy consumed to heat a volume of water equal to the sum of 16.2 liters and 1.5 liters from a temperature Tef of 10 °C to a temperature Tdec of 55 °C is 924 Wh. Compared to the 939 Wh for the domestic hot water distribution device 10 illustrated in [Fig. 1], this represents a saving in heated water energy of 15 Wh, or 1.6%.

[0089] In comparison, the energy consumed with the recirculating domestic hot water distribution device 50 illustrated in [Fig. 2] represents 55% of the energy consumed with the domestic hot water distribution device 10 illustrated in [Fig. 2], as described in the 2021 RAGE guide of the Scientific and Technical Committee for Climate Industries (COSTIC). The domestic hot water distribution device 60 is therefore 36% ((939*1.55-924) / (939*1.55)) more energy-efficient than the recirculating domestic hot water distribution device 50 illustrated in [Fig. 2], in exchange for the longer standby time without flow.

[0090] For a domestic hot water generation and / or storage device 12 of the type a 100-liter hot water tank, by consuming 1.6% less water supplied by the domestic hot water generation and / or storage device 12 per day by the domestic hot water distribution device 60, a drawn volume Vpuis of 76.8 liters and a non-drawn volume Vnpuis of 23.2 liters are obtained instead of the drawn volumes of 78 liters and non-drawn volumes of 22 liters of the domestic hot water distribution device 10. The estimated associated heating energy is 4357 Wh, i.e., 28 Wh (0.6%) less than for the domestic hot water distribution device 10. Part of the energy saving achieved by reducing the volume of water drawn is lost in heating the unused volume in the tank (estimated storage efficiency 4*924 / 4357= 85%, therefore slightly lower than in the case of domestic hot water distribution device 10).This results in an annual water saving for the household of 2190 litres (4*365*1.5).

[0091] Figure 7 represents a variant of the water storage device 62, in which the deformable reservoir 72 of the expansion vessel 64 has a single orifice 76 functioning as a water inlet into the deformable reservoir 72 and as a water outlet from the deformable reservoir 72. Pipes 66 and 68 are then partly merged to connect to the orifice 76. The operation of the domestic hot water distribution device 60 including the expansion vessel 64 illustrated in [Fig.7] is identical to the operation of the domestic hot water distribution device 60 including the expansion vessel 64 illustrated in [Fig.3].

[0092] The water storage device 62 shown in [Fig. 7] may advantageously be more compact than the water storage device 62 shown in [Fig. 3]. Furthermore, the hydraulic connections of the water storage device 62 shown in [Fig. 7] may advantageously be located in the same plane, which may facilitate the installation of the water storage device 62.

[0093] Various embodiments and variations have been described. A person skilled in the art will understand that certain features of these various embodiments and variations could be combined, and other variations will become apparent to a person skilled in the art.

[0094] Finally, the practical implementation of the embodiments and variants described is within the reach of a person skilled in the art, based on the functional indications given above.

Claims

Demands

1. Hot water distribution device (60) comprising: - a main hot water generation and / or storage device (12); - a first hot water supply pipe (16) from the main hot water generation and / or storage device (12) to a draw-off point (28); and - a water storage device (62) configured to detect the activation of the tapping point (28) by a user, and then to store at least part of the water present in the first pipe (16) and then supply the water stored in the water storage device (62) to the first pipe (16) when hot water supplied by the main hot water generation and / or storage device (12) arrives through the first pipe (16) so that the water flowing from the tapping point (28) is a mixture of hot water and water stored in the water storage device (62).

2. Hot water distribution device according to claim 1, wherein the water storage device (62) includes an expansion vessel (64) configured to store said at least a portion of the water present in the first pipe (16).

3. Hot water distribution device according to claim 2, wherein the water storage device (62) further comprises: - a second pipe (66) connecting the expansion vessel (64) to the first pipe (16) at a first connection point (Ne); - a first valve (Vev) on the second pipe (66); - a third pipe (68) connecting the expansion vessel (64) to the first pipe (16) at a second connection point (Ns), downstream of the first connection point (Ne) with respect to the direction of water flow in the first pipe (16); - a second valve (Vsv) on the third pipe (68); and - a third valve (Vbp) on the first pipe (16) between the first and second connection points (Ne, Ns).

4. Hot water distribution device according to claim 3, wherein the water storage device (62) further comprises: - a first temperature sensor (CTev) configured to measure a first temperature (Tev) of the water at the first connection point (Ne); - a second temperature sensor (CTsv) configured to measure a second temperature (Tsv) of the water at the second connection point (Ns); and - a pressure sensor (CPsv) configured to measure a pressure (Psv) of the water at the second connection point (Ns).

5. Hot water distribution device according to any one of claims 1 to 4, further comprising: - a fourth cold water supply pipe (11); and - a mixer (18) comprising a first inlet (20) connected to the fourth pipe (11), a second inlet (22) connected to the first pipe (16) and an outlet (24) connected to the draw-off point (28).

6. Hot water distribution device according to claim 5, wherein the mixer (28) is a thermostatic mixer.

7. Hot water distribution device according to any one of claims 1 to 6, further comprising: - a collection device (30) for the water supplied by the draw-off point (28); and - a fifth pipe (32) for transporting the water collected by the collection device (30) and intended to be connected to the sewers.

8. Use of the hot water distribution device (60) according to any one of claims 1 to 7, comprising the following steps in order: a) detection of the activation of the tapping point (28) by a user; b) storage of at least a portion of the water present in the first pipe (16) in the water storage device (62); and c) supply of the water stored in the water storage device (62) to the first pipe (16) when hot water supplied by the main hot water generation and / or storage device (12) arrives through the first pipe (16) such that the water flowing from the tapping point (28) is a mixture of the hot water and the water stored in the water storage device (62).

9. Use according to claim 8, wherein the hot water distribution device (60) is according to claim 3, comprising, in step b), the opening of the first valve (Vev), and the closing of the second valve (Vsv) and the third valve (Vbp), and further including, in step c), the closing of the first valve (Vev), and the gradual opening of the second valve (Vsv) and the gradual opening of the third valve (Vbp).

10. Use according to claim 8, wherein the hot water distribution device (60) is according to claim 4, wherein the transition from stage b) to stage c) is carried out upon detection that the first temperature (Tev) exceeds a temperature threshold.

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