WO1992012389A1

WO1992012389A1 - Device for producing hot water for domestic use or heating

Info

Publication number: WO1992012389A1
Application number: PCT/FR1991/001062
Authority: WO
Inventors: André THEVENON
Original assignee: Thevenon Andre
Priority date: 1990-12-27
Filing date: 1991-12-24
Publication date: 1992-07-23
Also published as: EP0577606A1; JPH06507006A

Abstract

The device is characterized by the unique structure of the heating elements (8), which comprises a self-regulating heating cord coiled around the outside of the lower portion of the wall (117) of the tank (4), and composed of two electrical conductors embedded next to each other in a resistive material whose resistivity increases in proportion to the temperature. The heating tank (4) delivers luke warm water at the outlet (1) and heats water from the inlet pipe (2) which has cooled after passing through a central hot water generator.

Description

DEVICE FOR PRODUCING DOMESTIC HOT OR HEATING WATER

The present invention relates to the production of domestic hot water (DHW) or lukewarm domestic water (ETS).

An important application of the invention is the production of lukewarm sanitary water, that is to say water whose temperature is certainly lower than the boiling temperature.

The invention also finds applications for the production of hot liquids such as for example: demineralized water, thermal fluids, other hot industrial liquids. Hot water is currently produced: either with accumulation, which requires high thermal powers which cause short-term operations to compensate for the losses of the accumulator when the set temperature is reached and an oversizing of this accumulator to compensate for the losses. which leads to overkill and increased wastage;

- Either without accumulation, which requires even higher thermal powers which are generally insufficient for several simultaneous withdrawals. In most cases, the regulation of domestic hot water generation works on the All or Nothing principle.

Depending on the type of installation, the heating of domestic hot water can be done by thermosiphon.

In the current case, the opening of a tap (or drawing) of domestic hot water does not result in the immediate obtaining of hot water if the time between two drawing was sufficient for cooling. The water is initially cold, then it gradually heats up, with an effect of pure delay and time constant due to the lengths and diameters of pipes between the centralization of domestic hot water and the point of withdrawal. Too cold water not used at the draw-off point is equal in mass to cold water which enters the tank or the calorifier and represents a loss of energy and water. Known improvements have been made to this system by:

- creating a circulation of domestic hot water between the centralized hot water production tanks and the area close to the draw-off points with circulation of domestic hot water by pump, tracing the domestic hot water piping by cords electric heaters.

In a decentralized installation, gas or electric energy is generally used as the energy source, electricity being preponderant. The electrical system consists of putting a water heater with a capacity equal to a few tens of liters near the draw-off point with a relatively high immersion heater power of one to several kW.

A drawback of the centralized installation system relative to the decentralized installation system is the greater loss of water and energy.

Looping or tracing for the centralized system is expensive in investment and energy: permanent losses are increased.

The automatic heating control of liquids is generally obtained by a thermostat which allows the supply of energy in all or nothing. The thermostats are given for a determined number of cuts. They degrade over time, and are the cause of disorders.

In the event of malfunction of the thermostats and the safety groups and / or thermal valves which are generally associated with them, the domestic hot water circuit being able to be isolated by taps, there is a risk of explosion and vaporization of the water, or burns while drawing.

The safety groups must be operated periodically to improve their probability of proper operation. In practice this is rarely done, and the security group is either fleeing or blocked.

In the case of electrical energy, the immersion heaters are brought to very high surface temperatures which cause the deposit of scale, therefore an increase in thermal resistance, therefore an increase in the temperature of the heating element and a deterioration of that -this.

The tanks are generally made of surface-treated steel to slow corrosion. A bond with other metals can create electrochemical couples causing corrosion. As a result, the guarantees granted by the manufacturers of electric water heaters on the market are generally limited in time: - 5 to 10 years on the tanks,

- 5 years for immersion heaters with soapstone,

- 2 years for armored immersion heaters.

The invention makes it possible to replace the thermostat and the high-power immersion heater, which are organs with a high risk of breakdowns, by static elements, external to the capacity, self-regulating in temperature. Optimization reduces the thermal power of these static elements. Reliability is thus considerably increased. As a result, compared to conventional systems, low operating costs and significant savings in water and energy. The power demand is low, which makes it possible to reduce the cost of electricity subscriptions, the cost of the supply and protection means. It is found that the overall energy efficiency is improved.

The installed power required for a sink is a few tens of watts, the average annual power for offices with 10 people is around 20. The power at equilibrium temperature without drawing can be about 14 W. The invention makes it possible to design particular structures for heating water which avoid the risks of explosion, by the fact that all the means of heating are self-regulating and limit by themselves the maximum possible temperature. The only protection needed is that of people in relation to electricity. This is obtained by differential circuit breaker and earthing of the metal braid which envelops the heating elements or the tank.

The structure according to the invention makes it possible to provide a heating of the water just sufficient for the desired temperature at the point of withdrawal. The transmission of heat energy is distributed over a large area. Thus, the scaling is significantly reduced, and virtually all maintenance is eliminated.

Another problem proposed by the present invention is thus to produce an installation for producing sanitary hot water or lukewarm sanitary water, making it possible to very quickly obtain an appropriate temperature of water at the point of withdrawal, and not requiring a significant overall installed power for the means of heating the water in the tank or tanks. In particular, the invention aims to use the capacity of the tanks as efficiently as possible, so that, during use, the cold water gradually introduced into the tank does not mix excessively with the hot water still ready to come out of the tank towards the draw-off point.

To achieve these and other objects, a device according to the invention produces hot or lukewarm sanitary water discharging through an outlet orifice, from a flow of water available in an inlet pipe. The device comprises a means for controlling the flow of hot water, a sealed tank, provided with a water introduction port and a water extraction port, and intended to contain a quantity of water. to be heated, the water introduction orifice being connected to the inlet pipe. The water extraction port is connected by an outlet pipe to said outlet port. Heating means, connected to an external source of energy, heat the water contained in the tank to bring it to an appropriate temperature. The heating means comprise a self-regulating assembly comprising first means of electrical conductors and second means of electrical conductors intended to be permanently connected respectively to a first and a second output terminal of an external source of electrical energy, said means means of electrical conductors being arranged close to each other and separated from each other by a resistive material whose resistivity is an increasing function of its temperature, the self-regulating assembly formed by the means of electrical conductors and said resistive material being suitably electrically insulated and thermally coupled to the interior space of the tank to heat the water contained in said reser¬ see.

According to an advantageous embodiment, the self-regulating heating means are pressed around and outside the tank in the lower zone.

With a tank of relatively reduced capacity placed in the vicinity of each draw-off point, a decentralized installation is produced, suitable for intermittent drawing of hot water, giving the heating means time to heat the cold water as soon as it is introduced into the tank.

The invention is also adaptable to an installation centralized. In this case, the invention makes it possible to eliminate water losses and reduce energy losses by installing suitable volume capacities near the wells on an existing installation.

The central accumulator can be produced according to the principle of self-regulating external heating, with for example heating sheets of rectangular or circular shape.

An improvement for the central accumulator consists in placing inside an intermediate tank which makes it possible to make the best use of the available power by bringing cold water up along the self-regulating walls in temperature.

This intermediate tank must be of the lowest possible thermal resistance, and cause water displacement speeds sufficiently reduced so as not to disturb the phenomena of stratification by temperature (hot water is less dense than cold water. ).

The use of particular self-regulating heating means of the invention results in an installation cost which may be slightly increased compared to traditional heating structures. The invention aims to compensate for this increase by optimizing the position of the self-regulating heating means, in order to reduce their quantity, by using compensating capacities, by optimizing the shapes of tanks, by optimizing their orientation, and by providing heat-insulating means and means reducing water loss.

The longevity of all the equipment for producing lukewarm sanitary water according to the invention is considerably increased. The self-regulating heating element can be easily repaired.

The lukewarm sanitary water system according to the invention results in savings in material, energy and water, it operates reliably and safely. The walls of the reservoirs can advantageously be made of copper, presenting no risk of electrocorrosion because the pipes are generally made of copper or plastic.

In order to very quickly obtain the appropriate temperature of water at the draw-off point, the invention provides an installation of the decentralized type, with at least one sealed tank, heat-insulating means, heating means, an inlet pipe, a pipe outlet, water flow control means, mixing means. According to the invention:

- the mixing means are arranged in the high position, in the immediate vicinity of the upper water extraction orifice to which they are connected by a first short segment of outlet pipe, - the point of connection of the inlet pipe is in high position, and in the immediate vicinity of the mixing means to which it is connected by a short bypass pipe,

- the inlet pipe inlet segment, located between the tapping point and the lower water introduction orifice, is thermally insulated from ambient air over at least most of its length .

Thanks to such a structure, the water inlet and outlet are above the tank, with maintenance of a thermosyphon which advantageously increases the heat exchanges between the heating means and the water in the tank, thus reducing the duration of rise in water temperature.

Preferably, the inlet pipe inlet segment is disposed in the immediate vicinity of the tank, and is thermally isolated from the ambient air by the heat-insulating means of the tank itself, the pipe inlet segment d entry can be taken in the same envelope of heat insulating means. This reduces thermal losses, and decreases the thermal response time and the variations in water temperature at the drawing point.

According to a first embodiment, the mixing means comprise:

a connection T between the branch pipe, between the first outlet pipe segment and between the second outlet pipe segment,

a constant flow calibration means, interposed in the bypass line, determining a constant proportion between the flow of cooler water passing directly through the bypass line and the flow of hotter water passing through the line inlet segment inlet, the tank and the first outlet pipe segment. The constant flow calibration means can be a simple constriction of appropriate diameter made in the bypass pipe wall itself, or can be an interchangeable diaphragm allowing discontinuous adjustment, or can be a valve allowing continuous manual adjustment.

According to a second embodiment, the mixing means comprise a mixer, a first inlet of which is connected to the branch pipe, a second inlet of which is connected to the first outlet pipe segment, and the outlet of which is connected to the second outlet segment outlet pipe.

Other objects, characteristics and advantages of the present invention will emerge from the following description of particular embodiments, made in relation to the attached figures, among which:

- Figure 1 is a front sectional view of a device for producing lukewarm sanitary water or cold water according to the invention, according to an embodiment adapted to a sink;

- Figure 2 illustrates an embodiment of the heating means according to the invention; FIG. 3 is a perspective view in section, on a larger scale, of a heating cord which can be used according to the invention; FIG. 4 illustrates a heating sheet structure according to the invention; - Figure 5 illustrates the constitution of a circular heating wall according to the invention;

- Figure.6 is a schematic front view in section of a high capacity heating tank structure according to the invention;

- Figure 7 illustrates a known structure of installation for producing domestic hot water;

- Figure 8 is a schematic view of a device for producing lukewarm sanitary water according to one embodiment of the invention;

- Figure 9 illustrates a device for producing lukewarm sanitary water according to another embodiment of the invention; - Figure 10 shows an application of the device of the invention, for supplying a sink with lukewarm sanitary water and cold water with two taps with foot control;

FIG. 11 is a schematic view of a device for producing lukewarm sanitary water according to another embodiment of the invention;

FIG. 12 illustrates an application of the device according to the invention for the production of an installation with centralized water heater and cascade compensators; and FIG. 13 illustrates an application of the invention for the production of a space heating installation.

In the embodiment shown in FIG. 1, the device makes it possible to produce lukewarm sanitary water pouring out through the outlet orifice 1, or drawing point, from a flow of water available in a pipe. 2. A tap 3 allows the control of lukewarm water flow. It is preferably a foot-operated tap. The device comprises a sealed reservoir 4, provided with a water introduction orifice 5 and a water extraction orifice 6. The water extraction orifice 6 is connected to the orifice of outlet 1 by a short outlet pipe, and this connection is free, that is to say that the outlet pipe 7 is devoid of any tap. Thus, the interior space of the reservoir 4 is permanently left at atmospheric pressure. In this embodiment, to prevent the reservoir 4 from emptying of water, the outlet orifice 1 is intended to be placed in a position higher than the maximum level of water in the reservoir 4. Alternatively, , an anti-siphon system with high level air intake for example must be installed.

In the case of a sink, as shown in the figure, the tank 4 is advantageously arranged below the sink, possibly in the column of the sink.

The introduction orifice 5 is connected to the inlet pipe 2, the lukewarm water flow control valve 3 being interposed in the inlet pipe 2, upstream of the tank 4.

Heating means 8, connected to an external source of energy, heat the water contained in the tank 4 to bring it to an appropriate temperature. The heating means 8 constitute a self-regulating assembly, electrically connected to an external source of electrical energy by conductors 9 and 10.

The shape of the reservoir 4 can be arbitrary, but a cylinder with circular section seems to be more suitable. The wall of the reservoir 4 can be made of any material capable of conducting the heat produced by the heating means 8. Due to the absence of pressure at. inside the tank 4, the wall of the tank 4 does not have to be particularly mechanically resistant. A heat insulator 40 limits heat loss. An envelope 41, for example made of metal, provides mechanical protection. A high density polyurethane wall can fulfill both functions.

FIG. 2 shows an example of an embodiment of the self-regulating assembly 8 constituted by a heating cord 80 wound in a helix around the peripheral lateral wall 117 of the reservoir 4. Such a cord 80, shown on a larger scale and in section in Figure 3, consists of a first electrical conductor 81 and a second electrical conductor 82, arranged close to one another and separated from each other by a resistive material 83 such than a self-regulating semiconductor polymer whose electrical resistivity is an increasing function of its temperature. For example, the conductors 81 and 82 are two metallic wires arranged parallel to each other and embedded in the resistive material 83. The resistive material 83 is surrounded by an electrically insulating layer 87 itself surrounded by a braid 88 in tinned copper providing mechanical and electrical protection and thermal conduction. Such self-regulating heating cord structures are for example distributed by the company Raychem S.A. international in Brussels, under the brand HWAT. The cord 80 is preferably arranged around the lower zone of the reservoir 4, the water introduction orifice 5 itself being in the lower zone of the enclosure 4, the water extraction orifice 6 being in the upper zone of the enclosure. The respective ends of the conductors 81 and 82 are intended to be connected to the terminals of the external source of electrical energy by the conductors 9 and 10. A reflective coating, not shown in the figures, can be bonded around the area covered with the cord. 80, in order to improve the thermal efficiency.

In the embodiment shown in FIG. 4, the self-regulating assembly 8 comprises a heating sheet 84 comprising a first p. ne conductor 85 and a second conductive comb 86 arranged in one inside the other as shown in the figure. The conductive combs are embedded in the resistive material 83 in the form of a plate, the assembly constituting a heating sheet which can be wound around the cylindrical lateral face of the reservoir 4. The first conductive comb 85 is connected to the conductor 9 for its connection to a first electrical power source terminal, while the second conductive comb 86 is connected to the second conductor 10 for its connection to the second electrical energy source terminal.

In the embodiment of Figure 5, there is shown a self-regulating hot plate of circular shape intended to fit under the lower circular face of the enclosure 4. Two electric wires whose ends constitute the conductors 9 and 10 are arranged parallel to each other in a spiral and embedded in a circular plate of resistive material 83, as shown in the figure. In all cases, an electric protective layer such as the metal braid 88, grounded, covers the resistive material 83, to avoid any risk of electrocution.

In the embodiment of FIG. 1, the reservoir 4 is a cylinder with a substantially vertical axis. In the embodiment shown in Figure 1, the device according to the invention is sufficient in itself, from a cold water inlet pipe 2, to produce lukewarm water for intermittent use . The device is furthermore provided with a cold water control valve 13, interposed in a cold water supply pipe 14 disposed between the inlet pipe 2 and the outlet pipe 7. Thus, the pipe of outlet 7 acts as a mixing zone for the hot water leaving the tank 4 and the cold water arriving via the pipe 14.

The tap 3 is advantageously a tap controlled by the foot or by detection of the presence of the hands. This arrangement is particularly advantageous in professional premises, and it makes it possible to reduce the consumption of water and energy. The tap 13 is manually operated near the spout, or can advantageously be operated by foot. In the embodiment of FIG. 6, the reservoir 4 has a cylindrical shape with a substantially vertical axis, the water introduction orifice 5 being at the bottom of the reservoir, the water extraction orifice 6 being in the upper part of the tank. The heating means 8 are distributed on the lower part of the side wall of the tank 4, and on the bottom of the tank. The reservoir. 4 is further provided with an inner intermediate tank 11, of cylindrical shape, blind, open upwards, coaxial with the wall outer and slightly smaller in diameter than the outer wall. The intermediate tank is arranged near the lower portion of the side wall of the tank 4 and near the bottom of the tank, in the zone provided with heating means 8. For example, the intermediate tank 11 has spacing legs 99 lower, and is placed on the bottom of the tank 4. A space 12 is left between the intermediate wall 11 and the outer wall of the tank 4, for the passage of water from the water introduction orifice 5 Thus, the cold water entering the tank 4 moves in the passage 12, and remains close to the heating means 8, which accelerates its heating and, by reducing the temperature, increases the calorific power developed by the heating means. 8 when the water is drawn off. The thermal conduction of the intermediate tank 11 allows the temperature of the entire body of water to rise. This system uses the principle of hot water stratification with low speed water operations.

The volume of the tank is such that it allows a series of close successive washes, knowing that as and when drawn the thermal power of the heating elements increases. Satisfactory results have been obtained, in a professional room of 8 to 10 people, with a cylindrical tank 4 with a diameter equal to approximately 8 centimeters, a height equal to approximately 50 centimeters, and a self-regulating heating assembly providing a maximum power of 66 Watts about cold and about 14 Watts hot. These values can be optimized.

The description which follows, given in relation to FIGS. 7 to 12, relates to the means for quickly obtaining the appropriate water temperature at the withdrawal points.

FIG. 7 represents a type of traditional central water heater for producing hot water or lukewarm sanitary water.

The traditional water heater comprises a sealed tank 4, provided with a lower water inlet orifice 5 and an upper water extraction orifice 6. The tank 4 is enclosed in heat-insulating means 104, allowing to thermally isolate the tank 4 from the ambient air. Heating means 8 such as an electrical immersion heater, connected to an external source of electrical energy, make it possible to heat the water contained in the tank 4 and bring it to an appropriate temperature. Generally, the electrical immersion heaters are associated with control means for alternately establishing or interrupting the supply of electrical energy to the heating means, as a function of a thermostat placed in the tank 4 to measure the temperature of the water. This regulates the temperature in the tank by all or nothing action.

An inlet pipe 2, connected to the lower water introduction orifice 5, makes it possible to bring water into the tank 4. An outlet pipe 7, connected to the upper extraction orifice tion of water 6, makes it possible to extract the hot water from the tank 4 and bring it to drawing means not shown.

Flow control means, actuable by the user, and not shown in the figure, make it possible to control the flow of water in the outlet pipe 7. Mixing or mixing means 108 are arranged downstream in the pipe outlet 7, between a first segment 109 and a second segment 110 of outlet pipe. The mixing or mixing means 108 are connected, by a bypass line 111, to a tapping point 112 of the inlet pipe 2. The mixing or mixing means 108 realizes, in the outlet pipe 7, a mixture of appropriate proportion of cooler water from the inlet pipe and warmer water from the tank 4.

During periods of non-use, the mixing means or mixing valves 108 generally allow the passage of water between the first segment 109 of the outlet pipe and the bypass pipe 111. This results in a circulation of water, by thermosyphon, in the direction represented by the arrows 113. The hot water circulating in the first segment of the outlet pipe 109, in the bypass pipe 111 and in the inlet segment 114 of the inlet pipe located between the point of tapping 112 and the lower orifice for introducing water 5, tends to cool because these pipe parts are generally little or not insulated.

On the other hand, the appropriate temperature of the water leaving the outlet pipe is not immediately reached.

The device structure according to the present invention, shown for example in Figure 8, differs from this installation traditional by the particular arrangement of the functional elements and the pipes. In FIG. 8, the elements similar to those in FIG. 7 have been designated by the same reference numerals. Thus, the sealed reservoir 4, the lower introduction orifice 5, the upper extraction orifice 6 are found again. , the heat-insulating means 104 of the tank, the heating means 8, an inlet pipe 2, an outlet pipe 7, mixing means 108, a first segment 109 of the outlet pipe, a second segment 110 of the outlet pipe, a bypass line 111, a tapping point 112, and an inlet segment 114 of the inlet line.

According to the invention, in the embodiment shown in FIG. 8, mixing means 108 are arranged in the high position and in the immediate vicinity of the upper water extraction orifice 6. Thus, the mixing means 108 are connected to the upper water extraction orifice 6 by a first segment 109 of the outlet pipe which is as short as possible.

In addition, the tapping point 112 of the inlet pipe is in the high position, and in the immediate vicinity of the mixing means 108. The bypass pipe 111, connecting the tapping point 112 and the mixing means 108, has the length d as short as possible. The inlet pipe 2 thus arrives in the high position at the stitching point 112, and the outlet pipe 7 begins in the high position at the outlet of the mixing means 108. A first advantage of this structure is that the inlet pipe connections 2 and outlet pipe 7 are in the high position, a position more accessible to the installer.

With such a structure, the inlet pipe 2 and the outlet pipe 7 can advantageously be placed in alignment with one another. In this case, the device can be easily inserted into a pre-existing pipe, simply by cut and connection.

The inlet segment 114 of the inlet pipe, located between the stitching point 112 and the lower water introduction orifice 5, is thermally insulated from the ambient air over at least most of its length. , preferably over its entire length. The outlet pipe 7 can advantageously be insulated. According to a preferred arrangement, represented in FIG. 8, said segment inlet 114 of the inlet pipe is placed in the immediate vicinity of the tank 4, and is thermally isolated from the ambient air by the heat-insulating means 104 of the tank. A particularly compact, space-saving assembly is thus produced, which can be contained in an insulating enclosure which can be easily positioned near a drawing point such as a sink or a shower.

The same principle is adopted for large water heaters according to the invention.

According to a first embodiment as shown in FIG. 8, the mixing means 108 comprise a connection T 115 and a diaphragm 116. The connection T 115 is positioned between the branch pipe 111, the first segment 109 of the outlet pipe and the second segment 110 of outlet pipe, as shown in the figure. The diaphragm 116 is interposed in the bypass pipe 111, between the stitching point 112 and the connection T 115. The diaphragm 116 is chosen with an appropriate opening, which determines the proportion between the flow of water passing directly through the bypass pipe 111 and the water flow rate passing through the inlet segment 114 of the inlet pipe, the tank 4 and the first segment 109 of the outlet pipe. The diaphragm 116 can be interchangeable, to allow a discontinuous adjustment of the flow rate, during the manufacture of the device for producing lukewarm sanitary water. The temperature T3 of the water in the second segment

110 of outlet pipe 7 is higher than the temperature T1 of the water in the inlet pipe 2, and lower than the temperature

T2 of the water in the tank 4. The temperature T3 of the water leaving is determined by the temperatures T1 and T2 and by the proportion of the relative flow rates determined by the diaphragm 116.

According to a simplified variant, the diaphragm 116 is replaced by a simple constriction produced on the wall itself of bypass pipe 111. The constant proportion of water flow is then determined by construction, according to the shape of the constriction.

According to a more advanced variant, the diaphragm 116 is replaced by a tap, kept partially open, thus allowing continuous manual adjustment of the constant proportion of water flow.

It is thus possible to obtain, in the outlet pipe, lukewarm sanitary water at a relatively constant temperature, without the need for expensive adjustment means. Also, the water contained in the tank 4 can be at a relatively high temperature, for example between 55 and 90 ° C. This temperature prevents bacteria from forming in the tank, which could result from the stagnation of water in the tank for an extended period and at a temperature below 50 ° C. Despite the relatively high tank temperature of 55 to 90 ° C, the temperature of the water in the outlet pipe is constantly lower, and is automatically at a temperature permissible for normal use. Preferably, the reservoir 4 is limited by a peripheral wall 117 of elongated cylindrical shape, oriented along an axis I-I generally vertical. The peripheral wall 117 is connected to a bottom wall 118 and to a top wall 119. The lower water inlet orifice 5 is formed in the bottom wall 118, while the upper extraction orifice d water 6 is formed in the top wall 119. The reservoir 4 can have a relatively large height, compared to its diameter, so that, for the same volume, the diameter is relatively small. Such a reservoir, because of its reliability, can thus be • housed in a building wall, near a drawing point such as a sink. The elongated height arrangement promotes the thermosyphon process, by which a permanent circulation of hot water occurs between the tank 4, the bypass line 111 and the inlet segment 114 of the inlet line. This thermosyphon process promotes heat exchange and the gradual homogenization of the water contained in the tank 4, during periods of non-drawing.

In the embodiment shown in FIG. 8, the inlet segment 114 of the water inlet pipe further comprises, in its lower part, a bypass 120 towards a lower drain orifice 121 closed by means shutter such as a removable plug 122. According to one possibility shown, the heat-insulating enclosure 104, which encloses the reservoir 4 and the inlet segment 114, comprises feet 123 not welded to the reservoir, so that the device can rest on the ground without thermal bridge, leaving access to drain port 121.

This particular structure of water heaters according to the invention makes it possible to more quickly obtain the appropriate temperature of water for draw-off points after a period of non-consumption of water. These advantages of speed are obtained whatever the type of heating means 8 used. Thus, the heating means 8 can be of different well-known types. For example, it is possible to use heating means constituted by traditional immersion heaters, or electrical resistances which are connected to an external source of supply of electrical energy. Such heating means constituted by immersion heaters must necessarily be associated with thermal regulation means, ensuring the establishment and interruption of supply of the immersion heaters as a function of the temperature of the water inside the tank. It is not uncommon for these thermal regulation means to experience faults, which quite often lead to an exaggerated increase in temperature and pressure inside the tank 4, which can in some cases cause an accidental explosion capable of causing the death of men.

For these reasons, it may be preferred, according to the invention, a particular embodiment of the heating means of the self-regulating assembly type 8, illustrated in FIGS. 2 and 8. In this embodiment, the self-regulating heating assembly 8 comprises a cord self-regulating heater 80, suitably electrically insulated and plated around and outside the wall 117 of the tank 4, and coated with a reflective outer wall 50 in order to improve the thermal efficiency.

The heating cord is preferably arranged around the lower zone of the tank 4.

When a greater capacity for producing lukewarm sanitary water is desired, it is possible to combine several chambers similar to the reservoir 4 of the embodiment of FIG. 8. For example, FIG. 9 shows an embodiment in which the means of tank comprise several cylindrical enclosures of generally vertical axis arranged side by side in a battery. One can for example have three enclosures 127, 128 and 129, forming a relatively flat parallelepipedic assembly. Enclosures 127, 128 and 129 are connected in a TICKELMAN loop, as shown in the figure, so that the water circulation paths are the same length regardless of the enclosure they cross, without there being preferential circuit. In the embodiment shown in this FIG. 9, the mixing means 108 have a structure different from that provided in the embodiment of FIG. 13. In fact, in this case, the mixing means comprise a mixer 130, mechanical or thermostatic , a first inlet 131 of which is connected to the branch line 111, a second inlet 132 of which is connected to the first segment 109 of outlet pipe, and the outlet 133 of which is connected to the second segment 110 of outlet pipe. The mixer 130 allows variable adjustment of the proportion of outlet flow coming respectively from the reservoir means and the bypass pipe 111, in order to approach the temperature set point as closely as possible.

In this embodiment, as shown in FIG. 9, all of the enclosures 127, 128 and 129 forming the reservoir means are incorporated into the heat-insulating means 104, the inlet segment 114 of the inlet pipe, thus that the bypass line 111. Only the mixer 130 is possibly outside the heat-insulating means 104. Thus, the bypass line 111 is arranged in the immediate vicinity of the tank means, and is thermally insulated from the ambient air by the heat insulating means 104.

In the embodiments of FIGS. 8 and 9, short internal recycling of the hot water from the tank is carried out by the inlet segment 114, the bypass pipe 111 and the first segment 109 of the outlet pipe. FIG. 10 represents a possible use of the device of FIG. 8. The device for the production of lukewarm sanitary water is then placed near a drawing point constituted by a spout 134 for supplying a sink 135 schematically represented. The spout 134 is connected directly to the outlet pipe. In this case, the outlet pipe is particularly short. The device can be housed below the sink 135, vertically, along or in the sink column, or in the wall against which the sink 135 is placed.

The water inlet pipe 2 is provided with a hot water flow control valve 136, advantageously operable at the foot, as shown in the figure.

The water inlet pipe 2 comprises a water branch cold 137, connected at a connection point 138 upstream of the hot water flow control valve 136. The cold water branch 137 is provided with a cold water flow control valve 139. The branch d cold water 137 is connected downstream at an intermediate junction point 140 in the second segment 110 of the outlet pipe. The actuation of the cold water flow control valve 139 makes it possible to directly supply the spout 134 with cold water coming from the inlet pipe 2.

The actuation of the lukewarm water flow control valve 136 makes it possible to supply the spout 134 with lukewarm water coming from the device, that is to say water constituted by a mixture of water lukewarm from tank 4 and cold water from water supply line 2.

In the embodiment shown in Figure 11, the device includes the same elements as in the embodiment of Figure 8, and these same elements are identified by the same reference numerals. The difference lies in the mixed structure of the heating means 8: the heating means 8 comprise on the one hand a self-regulating assembly 80 comprising the self-regulating heating cord 51 wound in a helix around the lower part of the peripheral wall 117 of the tank, and on the other share a heating element 52 of high power such as a heating collar applied around the remaining part of the peripheral wall 117 of the tank. The heating element 52 can for example have a power of several kilowatts. It is associated with a thermostat 53 provided with a temperature probe 54. The temperature probe 54 is housed inside the tank 4, for measuring the temperature of the water contained in the tank. The thermostat 53 receives the information provided by the temperature probe 54, and controls all or nothing the electrical supply of the heating collar 52. The self-regulating heating cord 51 is continuously supplied with electrical energy. The figure schematically represents the appropriate electrical connections. The temperature probe 54 can for example be placed in the lower bypass line 120, passing through the plug 122 and possibly passing through a full-flow valve inserted in said bypass line 120, and not shown in the figure. In the presence of a full-flow valve, the valve allows the probe 54 to be removed without draining all of the water contained in the tank 4. Preferably, as shown, the probe 54 crosses the first segment 109 of the outlet pipe, which makes it more easily accessible from the top of the device, and which can allow temperature regulation. In this embodiment, the self-regulating heating cord

51, of low power, is suitable for heating the water in the tank 4 to a high temperature T5, for example around 65 ° C. The thermostat 53 is adjusted to control the supply of the heating collar 52 up to an intermediate temperature T4 of water. The high temperature T5 for regulating the self-regulating heating cord 51 is higher than the intermediate temperature T4 obtained by the heating collar 52 and the thermostat 53. For example, the intermediate temperature T4 for stabilization by the thermostat 53 may be approximately 60 °. C, or less as needed. At the start of operation, the water contained in the tank 1 is heated simultaneously by the self-regulating heating cord 51 and the heating collar 52. When a temperature of 60 ^C C is reached, the heating collar 52 is no longer powered, and the temperature regulation is ensured by the only self-regulating heating cord 51. This structure makes it possible not to stress the thermostat 53 and the heating collar 52 for short periods of time for maintaining the temperature. This appreciably prolongs the lifespan of equipment operating discontinuously. This principle can be applied to devices for producing decentralized lukewarm water, but also to devices for producing centralized hot water, or to devices for producing hot water for space heating.

Such a mixed structure of heating means 8, comprising a heating element 52 of high power associated with a thermostat 53 and a self-regulating heating cord 51, can be advantageously used in a structure according to the present invention provided with an integrated thermosyphon. However, this mixed structure of heating means 8 can also be used independently of such an integrated thermosyphon. In fact, this structure is useful each time a heating element such as the heating collar 52 is controlled by a thermostat 53. Thus, on a traditional installation of a heating balloon provided with a thermo¬ plunger or a heating collar, the immersion heater or the collar being controlled by a thermostat, it is advantageously possible to adapt a Self-regulating heating cord intended to maintain a temperature higher than that for which the thermostat is adjusted. This avoids using the thermostat and high-power heating elements for short periods of time to maintain the temperature. This considerably prolongs the life of equipment operating in disconti¬ nu.

FIG. 12 shows an example of an application of devices according to the invention, for producing an installation for producing domestic hot water or lukewarm domestic water, comprising in cascade at least one centralized high-capacity device. for producing domestic hot water, and at least one decentralized compensating device of lower capacity for producing hot or lukewarm water in the vicinity of the draw-off points.

In the embodiment shown, the installation comprises a centralized device 55, of high capacity, preferably placed below and as close as possible to the zone of high frequency use of hot water. The centralized device 55 has a structure similar to that of the embodiment of FIG. 8, preferably with a thermostatic mixer 56 at the outlet. The tank 4 is provided with heating means which advantageously comprise a high-power heating element 52 of the immersion heater type and a self-regulating assembly 80 with a heating cord. A tap 116 makes it possible to adjust the proportion of flow of cooler water and hotter water producing by mixing the flow of hot water in the outlet pipe 7. The centralized device 55 is also associated with a vessel of expansion 57 and to a safety valve 58, both arranged for example in the inlet pipe 2. A stop valve for general water inlet 59 is inserted in the general inlet of water.

The centralized device 55 is adjusted to regulate the temperature of the water in its tank to a relatively high value, for example around 70 ° C. The mixer 56 is adjusted to supply, in the outlet pipe 7, lukewarm water at a temperature known as of general use, for example around 40 ° C., which is the usual temperature at draw-off points such as sinks, showers or baths . The outlet pipe 7 is connected to at least one first decentralized compensating device 60 close to a drawing point 61. The decentralized compensating device 60 can advantageously be of the same type as the device of FIG. 8. The inlet pipe 102 is connected by the valve 3 to the outlet pipe 7 of the centralized device 55. The drawing point 61 is also connected by a tap 13 to a pipe of cold water 62 coming directly from the general water inlet shut-off valve 59. The decentralized compensating device 60 is of lower capacity, and thus receives by its inlet pipe water at general use temperature coming from of the outlet pipe 7 of the centralized device 55. The decentralized compensating device 60 can be adjusted so that the water contained in its reservoir is at a temperature of approximately 65 ° C., and so that the lukewarm water at the outlet is at a temperature of about 40 ° C. The decentralized device 60 performs the function of compensator, in order to reduce the temperature of the water leaving the drawing point to a value close to the appropriate operating temperature, for example of the order of approximately 40 ° C., compensating for the possible thermal losses in the outlet pipe 7 during the transfer between the centralized device 57 and the decentralized compensating device 60. The centralized device 55 allows a greater accumulation by hot water at higher temperature, for example from the 'around 70 ^β C. The decentralized compensating device 60 avoids the wasting of hot water, and makes it possible to reduce the volume and the power of the centralized device 55. The lowering of power of the centralized device 55 allows either continuous operation because the fixed premium surcharge for the operation during off-peak hours is no longer justified, that is, operation during off-peak hours with automatic restart below a water temperature threshold.

Such a cascade installation has the advantage of significantly saving the heat energy necessary for its operation. In fact, as soon as it leaves the mixer 56, the water sent into the outlet pipe 7 is at general use temperature, of the order of 40 ° C., which induces lower heat losses than in the case of A traditional installation in which the water present in the outlet pipe of a central storage tank is necessarily at a higher temperature.

If it is desired, at drawing point 61, a temperature close to the general use temperature, the compensating device decentralized 60 must only compensate for the loss of temperature undergone by the water in the outlet pipe 7.

If, on the other hand, it is desired to have a higher temperature of the water at the draw-off point 61, it is possible to use a decentralized compensating device 60 provided with a heating collar such as the collar 52 of the embodiment of FIG. 11, for raising the water temperature to a temperature higher than that present in outlet pipe 7, for example at 50 ° C.

By way of example, FIG. 12 also shows a drawing point 63, close to the centralized device 55, which can be devoid of a compensating device, and a drawing point 64 such as a WC hand basin, supplied only in cold water and provided with an independent water heater according to the invention, producing lukewarm water at approximately 30 or 35 ° C. Also, the drawing points 65 and 66 illustrate a bathroom assembly, with two compensating devices in series allowing the immediate drawing of hot water.

FIG. 13 represents an application of a device according to the invention with a high-power heating element associated with a self-regulating assembly, for the production of hot water for space heating. A thermostatically controlled main boiler 140 produces hot water sent into a primary circuit 141 comprising a mixing bottle 142 and a first circulator 143. The mixing bottle is also connected by an outlet orifice 148 to a secondary heating circuit 144 conventional, to a second circulator 145, for heating radiators 146 or heated floors. According to the invention, there is provided on the mixing bottle 142 a self-regulating assembly 147 such as a self-regulating heating cord. This arrangement of the self-regulating assembly in particular provides heating at a reduced temperature or for frost-free maintenance, at the voluntary or accidental shutdown of the main boiler.

Another advantageous application consists in placing a compensating device similar to that shown in FIG. 8, at the outlet of a boiler without accumulation. The compensating device appreciably increases the capacity for producing water at an appropriate temperature, and allows, for example, simultaneous drawing without significant variation in temperature of the drawn water.

The present invention is not limited to the embodiments. tion which have been explicitly described, but it includes the various variants and generalizations thereof contained in the field of claims below.

Claims

CLAIMS 1 - Device for producing hot water or lukewarm water for sanitary use or for space heating, the water discharging through an outlet orifice (1), from an available water flow in an inlet pipe (2), the device being provided with a means for controlling the flow of hot water (3), the device comprising a sealed tank (4) provided with a water introduction orifice (5) and a water extraction orifice (6) and intended to contain a quantity of water to be heated, the water introduction orifice (5) being connected to the inlet pipe ( 2), the water extraction orifice (6) being connected by an outlet pipe (7) to said outlet orifice (1), heating means (8) being able to be connected to an external source of energy for heating the water contained in the tank (4) and bringing it to an appropriate temperature, characterized in that the heating means (8) comprise a self-regulating assembly (80, 8 4) comprising first means of electrical conductors (81, 85) and second means of electrical conductors (82, 86) intended to be permanently connected respectively to a first and a second output terminal of an external source of energy electric, said means of electric conductors being arranged close to each other and separated from each other by a resistive material (83) whose resistivity is an increasing function of its temperature, the self-regulating assembly ( 80, 84) formed by the means of electrical conductors and said resistive material being suitably electrically insulated and thermally coupled to the interior space of the tank (4) to heat the water contained in said tank (4).

2 - Device according to claim 1 characterized in that the self-regulating assembly (80, 84) is arranged outside the tank (4), pressed around and outside the wall of the tank (4). 3 Device according to one of claims 1 or 2, characterized in that the self-regulating assembly (80, 84) is distributed over a large part of the wall surface of the tank (4), to widely distribute the heating surface.

4 - Device according to one of claims 2 or 3, characterized in that the heating means (8) are arranged around the lower part of the wall of the tank (4), the orifice for introducing water (5) also being located in the lower part of the wall of the tank, the water extraction orifice (6) being located in the upper part of the wall of the tank.

5 - Device according to any one of claims 2 to 4, characterized in that said electrical conductor means comprise a first electrical wire (81) and a second electrical wire (82) parallel to each other and embedded in said resistive material (83), the assembly constituting a heating cord applied helically around the reservoir (4).

6 - Device according to any one of claims 2 to 4, characterized in that said means of electrical conductors (8) comprise a heating sheet (84) comprising a first conductive comb (85) and a second conductive comb (86) arranged interlocking with each other and embedded in said resistive material (83), the assembly constituting a heating sheet wound and kept pressed by elastic means around the tank (4).

7 - Device according to any one of claims 1 to 6, characterized in that the reservoir (4) is limited by a peripheral wall (117) of elongated cylindrical shape, connecting to a bottom wall (118) and to a top wall (119), the reservoir (4) being oriented along a generally vertical axis (ll), the lower water introduction orifice (5) being formed in the bottom wall (118), the orifice upper water extraction (6) being formed in the top wall (119).

8 - Device according to any one of claims 1 to 7, characterized in that the reservoir (4) comprises an inner intermediate wall (11) of cylindrical blind coaxial shape of smaller diameter, defining an intermediate space (12) between said intermediate wall (11) and the tank wall (4), the water introduced into the tank (4) through the introduction orifice (5) traveling at low speed through the space (12) near the heating means ( 8).

9 - Device according to any one of claims 1 to 8, characterized in that:

the heating means (8) further comprise a high-power heating element (52) associated with a thermostat (53) for heating the water in the tank to an intermediate temperature T4,

The self-regulating assembly (80, 84) is suitable for heating the water in the reservoir to a high temperature T5 higher than the temperature intermediate T4.

10 - Device according to any one of claims 1 to 9, characterized in that:

the water introduction orifice (5) is in the lower position and the water extraction orifice (6) is in the upper position in the tank (4),

- heat-insulating means (104) thermally isolate the tank (4) from the ambient air, the inlet pipe (2) is connected to the lower water introduction orifice (5) by a segment d 'inlet (114), to bring water into the tank (4),

- flow control means, actuatable by the user, control the flow of water in the outlet pipe (7),

- mixing means (108), arranged downstream in the outlet pipe (7) between a first segment (109) and a second segment (110) of outlet pipe, are connected to a tapping point (112) of the inlet pipe (2) by a bypass pipe (111), in order to produce in the outlet pipe (7) a mixture in appropriate proportion of water coming from the inlet pipe (2) and water coming from the tank (4), the mixing means (108) are arranged in the high position in the immediate vicinity of the upper water extraction orifice (6), to which they are connected by a first segment (109) short of channeling outlet, - the tapping point (112) of the inlet pipe (2) is in the high position and in the immediate vicinity of the mixing means (108), to which it is connected by a short branch pipe (111), - the inlet segment (114) of inlet pipe (2), located between the stitching point (11 2) and the lower water introduction orifice (5), is thermally insulated from the ambient air over all or most of its length.

11 - Device according to claim 10, characterized in that the inlet segment (114) of inlet pipe (2) is disposed in the immediate vicinity of the tank (4), and is thermally isolated from the ambient air by said heat-insulating means (104) of the tank.

12 - Device according to one of claims 10 or 11, characterized in that the mixing means (108) comprise: a connection T (115) between the branch pipe (111), between the first segment (109) of outlet pipe and between the second segment (110) of outlet pipe,

- constant flow calibration means (116) interposed in the bypass line (111), determining the proportion between the flow of cooler water passing directly through the bypass line (111) and the flow of hotter water passing through the inlet segment inlet (114), the reservoir (4) and the first outlet segment (109). 13 - Device according to claim 12, characterized in that the means for constant calibration of flow (116) comprise a constriction of the wall of bypass pipe (111), or an interchangeable diaphragm, or a tap.

14 - Device according to one of claims 10 or 11, characterized in that the mixing means (108) comprise a mixer (130), of which a first inlet (131) is connected to the bypass pipe (111), one of which second inlet (132) is connected to the first segment (109) of outlet pipe, and the outlet (133) of which is connected to the second segment (110) of outlet pipe.

15 - Device according to any one of claims 10 to

14, characterized in that the bypass pipe (111) is arranged in the immediate vicinity of the tank, and is thermally isolated from the ambient air by said heat-insulating means (104) of the tank. 16 - Device according to any one of claims 10 to

15, characterized in that the reservoir comprises several cylindrical enclosures (127, 128, 129) of generally vertical axis arranged side by side in a battery, connected in a TICKELMAN loop.

17 - Installation for producing domestic hot water or lukewarm domestic water, characterized in that it comprises:

- at least one high capacity centralized device (55) according to any one of claims 1 to 16,

- At least one decentralized compensating device (60) of lower capacity according to any one of claims 1 to 18, disposed near a drawing point (61) to which its outlet pipe is connected, and receiving by its inlet pipe for water at general use temperature coming from the outlet (7) of the centralized device (55).