IMPROVEMENT OF A DEVICE AND AN ASSOCIATED METHOD FOR SAVING HEATING ENERGY AND WATER IN A SANITARY FACILITY

Description

Technical field.

[0001] The invention relates to installations intended to deliver domestic hot water quickly without waste to draw-off points, for example taps or mixers. The invention relates in particular to a device and an associated method for regulating the flow of domestic hot water in these installations. Prior art.

[0002] The figure numbers and references to these figures cited in this “Prior Art” paragraph are those of international application WO2017216432.

[0003] Patent application WO2017216432 describes an installation intended to quickly deliver domestic hot water without waste to draw-off points, for example taps or mixers. Several embodiments are shown, including that of the [ Fig.2] (from wo2017216432) which includes pressure reducers. This embodiment compared to the other two embodiments ( Figures 3 And 4 from wo2017216432) optimizes energy savings when multiple circuits are used at the same time.

[0004] There [ Fig.2] (from wo2017216432) shows an operating mode that uses pressure reducers (9) which are naturally internally controlled, because the pressure information is detected in the pressure reducer which makes it possible to have the desired pressure (for example 3 bars) at the draw-off point. The problem is that pressure reducers generate annoying noise pollution for users. This noise pollution has two distinct origins: on the one hand, it comes from the pressure reducer (9) which emits an unpleasant whistling sound near the user, due to the strong restriction of the fluid passage. On the other hand, because the small section pipe (3) is constantly subjected to maximum pressure, it remains rigid and transmits well the sounds and vibrations emitted by the pump and by the motor, and more particularly the pulsations of the pump (the variations in flow rate) when it is a piston pump.When the pipe is in contact with the building's walls, the sound is amplified. It is then perceptible to those around the user and can easily exceed a maximum threshold set by standards and regulations.

[0005] To remedy this, it is tempting to install the pressure reducers upstream of the small section circuit (3), far from the draw-off points. It is then necessary to significantly increase the set pressure of the internally piloted reducer, to take into account the pressure losses in the small section circuit between the reducer and the draw-off point, in order to have the required pressure (3 bars) at the draw-off points. However, this solution does not guarantee the same pressure (3 bars) at the draw-off point in all cases of use because the pressure losses in the small section circuit (3) depend in particular on the length of the pipes but also on the flow rate. Therefore, moving these conventional pressure reducers upstream would prevent satisfactory operation of the installation for users. Description of the invention.

[0006] According to the invention, the device for regulating the pressure of a domestic hot water circuit and consequently a flow of hot water leaving at least one draw-off point forming part of a domestic hot water distribution installation comprising at least one source of hot water pressurized by a pump, at least one circuit of small-section pipes bringing the hot water under pressure to at least one draw-off point, and a regulation system is characterized in that the regulation system comprises a pressure reducer placed upstream of each small-section hot water circuit and in that the device comprises means for determining the pressure in each small-section pipe at the draw-off point(s) and for transmitting this pressure information to the pressure reducer corresponding to the draw-off point(s).

[0007] For greater precision, the term "upstream of each small-section hot water circuit" means downstream of the pump, in series on each small-section distribution circuit and far from the draw-off point. When there are several small-section circuits, the pressure reducers are ideally grouped and assembled together. The regulation system comprises several components ideally grouped together, forming a component called a regulation module.

[0008] The set value of the domestic water pressure at each draw-off point is preferably around three bars, regardless of the number of draw-off points in service.

[0009] The first advantages of the device according to the invention are multiple. In particular, when several small-section circuits are used at the same time, several users can obtain domestic hot water quickly at the draw-off points regardless of the required flow rate, without energy waste and without noise pollution.

[0010] The means for determining the pressure in each small-section pipe at each draw-off point and for transmitting this pressure information to the pressure reducer corresponding to the draw-off point(s) can be achieved in different ways: the pressure information at each draw-off point is either detected by a pressure sensor which sends an electrical signal via a wire or any other electronic means to the corresponding pressure reducers, or by a pipe full of water which transmits the pressure from the draw-off point to the corresponding pressure reducer. This second solution will be preferred in installations already equipped with traditional pipes of larger section in which or outside of which the small-section pipes run.These larger section pipe circuits, full of water, transmit pressure information from the draw-off points to the corresponding pressure reducers upstream of each small section hot water circuit.

[0011] According to an improvement, these traditional pipes of larger cross-section are each provided with a solenoid valve connected in bypass. When these solenoid valves are open, part of the sanitary water at the draw-off points returns from the draw-off points to the upstream, which makes it possible, firstly, to supply hot water even more quickly to the draw-off point regardless of the flow rate requested by the user, and secondly to recover the thermal energy contained in the pipes after each use according to a process described below.

[0012] The invention also relates to a method implementing the above device. It comprises the following steps: Opening of the draw-off point, detection of the demand for hot water at the draw-off point, automated opening of the solenoid valve causing a pressure drop in the traditional pipe of larger section, complete opening of the pressure reducer allowing the transfer of a maximum hot water flow rate into the small section pipe, arrival of the hot water at the draw-off point and return of part of the flow rate via the larger section pipe to the hot water source, automated closing of the solenoid valve, regulation of the flow rate in the pressure reducer throughout the use phase as a function of the demand at the draw-off point, closing of the draw-off point which causes a pressure increase completely closing the pressure reducer.

[0013] According to a variant of the device and the associated method, presented in the detailed description below, the calories of the domestic hot water contained in the pipes after closing the draw-off points are recovered, which further improves energy savings and reduces the risk of proliferation of bacteria in the domestic hot water pipes. Brief description of the drawings

[0014] [ Fig. 1 ] is a schematic view of the domestic hot water distribution installation equipped with the regulation device according to the invention. [ Fig.2 ] is a schematic view of a variant of the domestic hot water distribution device, equipped with three regulation modules (5) according to the invention. [ Fig.3 ] is a diagram of the hydraulic functions of the regulation module (5), also visible on the [ Fig.2 ]. [ Fig.4 ] is a sectional view of the pressure reducer (90) according to the invention. Description of the embodiments.

[0015] The device according to the invention, shown diagrammatically on the [ Fig. 1 ], uses specific pressure reducers (90) placed upstream of the small-section pipes (5.2). Their function is not to directly reduce the pressure as conventional pressure reducers would do. The pressure reducers (90) according to the invention use external downstream control to vary the flow rate in the small-section pipes (5.2), in order to obtain a predetermined adjustable pressure (e.g. 3 bars) at their other ends, at the level of the draw-off point(s) (41).

[0016] The pressure reducer (90) has the role of transforming the pressure information into flow rate. When the pressure at the draw-off point (41) is below the set pressure, the flow rate increases, and conversely when the pressure is above the set pressure the flow rate decreases. The pressure reducer (90) is an integral part of the regulation module (5)

[0017] The order of the elements according to the invention is as follows: at least one hot water source (20) pressurized by a pump (2), at least one regulation module (5) comprising at least one pressure reducer (90), at least one small section pipe (5.2), at least one draw-off point (41).

[0018] Each circuit must include a means (5.1) which takes pressure information from the draw-off point (41) and transmits it instantly to the pressure reducer (90) to control its flow rate. This means is shown on the figures 2 , 3 And 4by a control pipe (5.1) filled with water.

[0019] According to a variant of the invention not detailed in this description, the pressure information can be transmitted by another means (example: hertzian, mechanical, hydraulic or electrical, etc.).

[0020] This new arrangement provides the following technical advantages: a. The whistling and vibrations emitted by the pressure reducers (90) located in the boiler room do not disturb users. b. The pressure in the small-section pipe is first reduced at the pressure reducer (90), then it gradually decreases along the entire route to reach a predetermined standard pressure (e.g.: 3 bars) at the draw-off point(s). There is therefore never high pressure near the draw-off point(s) (41), and therefore less danger for users and workers. c. The small-section pipe (5.2), which is subjected to less pressure, remains more flexible. It therefore more easily absorbs sounds, vibrations and / or pump pulsations heard or felt in contact with the pipe. d. Connection to the draw-off point(s) is traditionally carried out by the plumber without worrying about the high pressure upstream. e.The metal volume of the regulator (9) of the prior art cools the hot water on contact before reaching the user. This is detrimental to the main function of the device (comfort & water and energy saving). According to the invention, the centralized regulation modules (5) located near the pump are kept hot, as is the pump, so as not to cool the water during the next use. f. The sandwich stacking of the regulation modules (5) is practical for the installer and for carrying out maintenance. Their production cost is also lower than that of the regulators (9) of the prior art. g. Due to their proximity to the conveniences of the boiler room and the pump control box, the regulation modules (5) easily accommodate the other functionalities described below.

[0021] The centralized regulation modules (5) developed specifically for this application preferably contain four components, each of which fulfills a function, namely:

[0022] The pressure reducer (90).

[0023] A solenoid valve (5.40) that provides hot water quickly at the draw-off point, regardless of the flow rate requested by the user. And which allows the thermal energy contained in the pipes to be recovered after each use.

[0024] A flow sensor (5.15).

[0025] A safety valve (5.36) which prevents high pressure from damaging the components of the low pressure circuit (5.1 and 41) in the event of a malfunction.

[0026] The solenoid valve (5.40) is connected on one side to the control circuit (5.1) and on the other to the hot water source (20). Its opening produces two effects: First, it allows the water coming from the small section pipe (5.2) to return to the source (20), via the pipe (5.1) (see details C1 and C3 [ Fig.2 ]). Secondly, the resulting pressure drop in the control pipe (5.1) fully opens the passage of the pressure reducer (90), thus allowing a maximum flow rate in the small-section pipe (5.2), the maximum flow rate being a function of the supply pressure of the pump (2) and the pressure losses in the pipe (5.2).

[0027] The small section pipe (5.2) must therefore have a section suitable for passing a maximum flow rate without causing too many pressure losses.

[0028] It should be noted that for practical and economic reasons, the method uses the control pipe (5.1) to return the water to the source (20). However, according to a variant not shown which produces the same effect, the method uses a circuit connected on one side upstream and close to the draw-off point(s), and on the other to the hot water source, accommodating in series the solenoid valve (5.40).

[0029] The operation of the regulation module includes the following steps: a. When a draw-off point is requested, the pressure drop transmitted by the control pipe (5.1) partially opens the passage of the pressure reducer (90). b. The flow sensor (5.15) of the requested circuit detects the flow of water. c. In order for the hot water pressurized by the pump (2) to circulate quickly in the small-section pipe (5.2) and thus supply the user with hot water more quickly, the solenoid valve (5.40) opens for several seconds. d. This has the consequence of fully opening the passage of the pressure reducer (90), allowing a maximum flow of hot water towards the source (20). e. Part of the flow reaches the user according to his request and the other part returns to the hot water source (see detail C1 [ Fig.2]) via the pipe (5.1). f. After a sufficient time for the hot water to reach the user (for example three seconds, set according to the length of the circuit), the solenoid valve (5.40) closes. g. Then during the use phase, the pressure reducer (90) regulates the flow rate (see detail C2 [ Fig.2 ]) in the small section pipe (5.2), depending on the user's request. h. The end of the usage phase is the closing of the tap (drawing point) which generates a pressure increase completely closing the pressure reducer (90).

[0030] Sanitary installations using a pump and small-section pipes to quickly deliver domestic hot water to draw-off points allow substantial energy savings to be made compared to traditional installations. However, it is possible to optimize these savings by recovering calories during and just after the draw-off phase. The [ Fig.2 ] presents an example. According to this embodiment, the small section pipe (5.2) runs inside the traditional pipe (5.1), it thus transmits its calories to the water contained in the pipe (5.1) during the use phase. In addition, the installation includes additional means, in particular a sanitary vessel or reserve (17), in order to recover the hot water contained in the pipes after the use phase, according to a method described following the nomenclature below.

Claims

1. A device allowing the pressure in a domestic hot water circuit to be regulated and consequentially a hot water flow-rate leaving at least one draw-off point being part of the installation for the distribution of domestic hot water, said device including at least one source of hot water pressurized by a pump (2), at least one small cross-section pipe circuit (5.2) bringing water to at least one draw-off point (41), and a regulating system characterized in that the regulating system includes a pressure reducer (90) placed upstream of each small-cross section hot water circuit and in that the device includes means for determining the pressure in each small cross-section pipe (5.2) at one or a plurality of draw-off points and for transmitting the pressure information to the pressure reducer (90) corresponding to the draw-off point(s).

2. The device according to claim 1 characterized in that the means for determining the pressure and for transmitting information are pipes (5.1) full of domestic water.

3. The device according to claim 2 characterized in that the pressure reducer (90) includes an injection needle (5.16) moved by the water pressure present in the pipe (5.1), by means of a piston (5.38) or a membrane, said needle (5.16) regulating the opening or passage of fluid at an injector (5.20) depending on the demand at the draw-off point(s).

4. The device according to claim 3 characterized in that each pressure reducer (90) includes a housing (5.14) receiving and guiding the needle (5.16) so as to prevent the high pressure of the fluid at the outlet of the regulator exercising an axial pressure on the end thereof, detrimental to the proper operation of the regulator, a gasket (5.18) ensuring the leak-tightness between the housing (5.14) and the needle (5.16).

5. The device according to claim 3 characterized in that the pressure reducer (90) includes a brake that slows the translation of the needle (5.16) at each change of flow-rate, allowing the pressure and the flow-rate at the draw-off point to be stabilized more quickly.

6. The device according to claim 1, 2, 3, 4 or 5 characterized in that the regulation module includes a solenoid valve (5.40) connected on one side upstream and close to the draw-off point(s) and on the other side to the hot water source allowing the domestic water to return to the hot water-source or a tank (17) connected to the hot water source.

7. The device according to any of claims 2 to 6 characterized in that said device comprises safety valves (5.36) to prevent, in case of malfunction, the high pressure from damaging the components of the low-pressure circuit (5.1) and (41).

8. A method implementing the device according to claim 6 in combination with claim 2 characterized by the detection of a demand for hot water at the draw-off point, the automated opening of the solenoid valve (5.40) leading to a low pressure in the pipe (5.1), the complete opening of the pressure reducer (90) allowing the maximum flow-rate of hot water to be transferred into the small cross-section pipe (5.2), the hot water inlet at the draw-off point and the return of a part of the flow-rate via the pipe (5.1) to the hot water source (20), the automated closing of the solenoid valve (5.40), the regulation of the flow-rate in the pressure reducer (90) throughout the usage phase depending on the demand at the draw-off point, the closing of the draw-off point that leads to a high pressure completely closing the pressure reducer (90).

9. The method according to claim 8 characterized in that after the closing of the draw-off points, the hot water contained in the pipes (5.1) and (5.2) is automatically replaced by cold water to be fed back into the tank (17) which limits the waste of energy and the proliferation of bacteria.