Technical Field

The invention relates to a plant for supplying electrical supply at low power, preferably single-phase, to residential and non-residential buildings.

In other terms the plant of the present invention enables supply to all users with only electrical energy, thus eliminating the need for other forms of energy supply.

Background Art

In modern-type civil buildings, whether for residential or non-residential use, a certain number of energetic systems are present, which enable activating of various types of services on the part of the occupants, The services normally present in these buildings are: lighting; production of clean hot water; heating; use of small/large domestic electrical appliances and other electrically- functioning users (electrical/electronic users); oven and stove (burners, oven, electric hotplates, etc); other users consuming electricity.

Heating, production of clean hot water and the oven, which require quite high-level power to meet the needs of the users, are usually managed by devices, such as boilers, ovens and burners, supplied by gas, liquid, coal or wood fossil fuels, substantially to limit the use of electric power. The actuation of all the listed services with only electrical energy requires the use of rather high level of electrical power which, normally, is not available in single phase on the supplier's grid. In any case, the electrical power required is supplied with some difficulty even in three-phase and is even more difficult to obtain for dwellings. For these reasons, there has , traditionally been a combination of electrical energy and other forms of energy in supply to civil constructions.

The relatively lower costs for gas supply, together with the fact that gas boilers can make clean hot water available instantaneously, have led to gas being widely chosen as main energy source for boilers, instead of electric, for the production of clean hot water.

As is known, the use of fossil fuels leads to considerable problems of an environmental character, which, on the basis of the most recent standards for pollution control and the battle against global climate change, are measured according to the amount of carbon dioxide and greenhouse gases which are emitted into the atmosphere. All modern environmental standards impose limitations on users' carbon dioxide emission (CO2 and greenhouse gases) in the battle against climate change. The clear intention of the modern environmental standards is thus to encourage all users, whether civil, industrial or commercial, to favour the use of electrical energy produced by renewable sources with respect to that produced using fossil fuels, such as to limit production and atmospheric emission of carbon dioxide and greenhouse gas, and therefore to limit global heating. The main aim of the present invention is to provide a plant for low-power electrical supply, preferably in single-phase, to residential and non- residential buildings which enables the consumption of fossil fuels to be considerably reduced. A further aim of the present invention is to provide a plant which enables the consumption of electrical energy to be reduced on the part of all devices and users in residential and non-residential constructions, such that the electrical energy need can be covered by the use of renewable energy sources, both self-produced and bought. Disclosure of Invention

Further characteristics and advantages of the invention will better emerge from the detailed description that follows, with reference to the accompanying figure of the drawing, provided purely by way of non- limiting example, which is a schematic representation of the plant of the present invention.

The plant of the present invention comprises a source of electrical power 2, preferably low-power and single-phase or three-phase. The source of electrical power 2 can be constituted, for example: by the urban electrical energy grid; electrical energy plants constituted by stand-alone renewable sources; electrical energy plants using renewable grid-connected sources; a combination of the above-listed solutions.

In the preferred embodiment of the plant, connection can be made both to the electric grid by means of a bi-directional counter, of known type, which enables both the taking from and the giving of self-produced electrical energy to the grid, as shown for example by the Italian norm relating to "exchange", and direct consumption of electrical energy produced by stand-alone plants before it is sent to the grid. The plant further comprises a plurality of electrical connections 3, supplied by the source 2 by means of a supply circuit, which are predisposed to enable connection to the source 2 and the supply of electrical users 4 of various types. The plant comprises a control device 5, for example an electronic processor such as a computer, which is predisposed to continuously measure overall absorption of electrical power on the part of electric users in order to compare overall absorption measured using a predetermined maximum value of available electrical power. As will be more clearly described herein below, the control device 5 is predisposed automatically to adopt some programmed control procedures.

The maximum predetermined power value is dictated by the supply on the part of the distributor of electrical power. In Italy, for example, the maximum electrical power value available for a dwelling is subdivided into levels of 3 kW, 4.5 kW, 6 kW up to 10 kW in single-phase with supply voltage at 220V. For higher powers three-phase supply is 380V. With the invention, though supplying all the users with electrical energy, the functioning of all users is ensured, with a drop in consumption, with supply in single-phase within 10Kw for residential constructions of a standard type (up to about 150 square metres area). Buildings having three- phase power above 10Kw are also supplied with considerably lower supply levels than is normally necessary. The control device 5 is further predisposed to block or limit the supply of electrical power to certain electrical connections 3 if the overall absorption of electrical power measured exceeds the maximum predetermined value. This function is performed by the control device 5 by means of a first main operating algorithm which comprises: assigning to the electrical connections 3 predetermined indices of importance which overall define a scale of importance of the electrical connections 3; if the overall absorption of electrical power exceeds the maximum predetermined value, the first operating algorithm blocks or limits supply of electrical power to an electrical connection 3 on the basis of its index of importance, i.e. by - S -

blocking or limiting the supply of electrical power starting from the less important electrical connections and proceeding to those having greater importance up to when the total absorption of power returns below the maximum predetermined amount. In a preferred embodiment of the plant, the operating algorithm includes at least three indices of importance for electrical connections. A first index of importance corresponds to a constant and unconditioned supply of electrical power. This first index of importance can be assigned to the connections destined to supply the electrical users which if deprived of electrical energy lead to considerable drawbacks, such as for example freezers, refrigerators, alarm plants or fire alarm plants, internal lighting and others.

A second index of importance corresponds to a supply of electrical power subordinated to a comparison, to be done before turning the electrical user on, between the nominal power absorbed by the electrical user and the power available on reaching the maximum predetermined value. The electrical power available on reaching the maximum predetermined value corresponds to the difference between the maximum electrical power available at the source of electrical power and the overall absorption of electrical power at present in use. If the available electrical power on reaching the maximum predetermined value is sufficient, the supply of electrical power to the connection is allowed and, once started up, cannot then be blocked or limited. This second index of importance can be assigned to the connections destined to supplying the electrical users in which a shutdown in functioning, once started up, might cause problems, such as for example happens with ovens and cooking burners. While the start of a cooking process can be spread over time, its halting usually causes irreparable deterioration of the foodstuffs. A third index of importance corresponds to a continuously-controlled supply of electrical power which can be limited or blocked if the overall absorption of electrical power exceeds the maximum predetermined value. The third index of importance can be assigned to the connections destined to supply the electrical users which can be started off and stopped at any moment without causing particular problems, such as for example heating, clean hot water, dish-washers and other electrical domestic appliances. The first operating algorithm can also include further indices of intermediate importance for electrical users of different type. A further possibility of operating management by means of the first operating algorithm can include integration between the scale of the indices of importance and a temporal scheme of control of the supply of electrical power towards some electrical connections. With the exception of the electrical connections 3 to which the first index of importance is assigned, for the other electrical connections it is possible, in order to limit the overall absorption of electrical power, to supply electrical power only in certain time zones, for example during the night, as the overall absorption of electrical power is in any case low. In this way an attempt is made to limit peaks of absorption of electrical power. The management of the supply of electrical power towards the electrical connections operated by the plant of the present invention enables considerably limiting overall absorption of electrical power and the consumption of electrical energy and maintaining it below a predetermined value. In this way, the energy requirement of a dwelling can be entirely covered by the use of renewable energy sources, for example solar panels, wind generators or the like. The electrical energy produced by the renewable sources can be sent into the grid via a bi-directional counter. The electrical energy required for the functioning of the various electrical users is taken from the grid also via the bi-directional counter. In this way, any peaks of electrical power which are not covered by the electrical power produced by renewable sources can be covered by the grid, and in any case the overall balance between the energy produced by the renewable sources and the energy consumed by the plant of the invention is substantially neutral or characterised by a prevalence of the energy produced by the renewable sources with respect to the grid supply.

The plant of the present invention comprises a heating device 6 predisposed to produce clean hot water comprising an instantaneous electric heater 7, able to raise the temperature of the water to a programmed temperature according to the available electrical power, functionally coupled to a small electric boiler 8 able to maintain the water at a constant temperature of or above 65°. The heated water in the electric boiler 8 can be removed in addition to the water coming from the instant heater 7 by means of a mixer 9, which is controlled in real-time by the control device 5, which is connected to one of the electrical connections 3 and is predisposed to mix the water at the desired temperature by combining the two solutions. The heating device 6 comprises an electric heater 7, of the instant type, connected to one of the electrical connections 3, which is predisposed to heat a flow rate at a first temperature. The heating device 6 further comprises a boiler 8 provided with a heater connected to another of the electric connections 3, which is predisposed to heat a determined quantity of water to a second temperature of 65° or more, which is higher than the first temperature. The electric heater 7 and the boiler 8 are supplied by a single conduit connected to a general hydraulic plant. A mixer 9 is predisposed to receive in inlet a flow of water coming from the boiler and a flow of water coming from the electric heater, and to produce in outlet a mixture between the two flows at a desired temperature which is intermediate between the first and the second temperature. This obviates the installing problem in traditional plants. The hot water pipes can be eliminated as the heating device can be connected directly at the point of use. In the preferred embodiment of the plant, the heating device 6 comprises at least a first thermometer 10, predisposed to measure the temperature of the water in outlet from the mixer 9, and a flow-meter 11, predisposed to detect the presence of a water flow in outlet from the mixer 9. The instant electric heater 7, the heater of the boiler 8, the mixer 9, the first thermometer 10 and the flow-meter 11 are connected to the control device 5. In particular the control device 5 commands switching-on of the electric heater 7 and the heater of the boiler 8 and regulates the electric mixer 7 such as to vary the water flow which is removed from the boiler and mixed with the flow of water coming from the electric heater 7 on the basis of the temperature measured by the first thermometer 10. To this end the control device 5 works by means of a second algorithm on the basis of which, in the presence of a water flow detected by the flow meter 11 , the electric heater 7 is switched on. The presence of a water flow can be determined for example by a user's opening a hot water tap. If the temperature measured by the first thermometer 10 is lower than a requested temperature value, settable for example by means of the specially-programmed control device 5, the mixer 9 is regulated such as to increase the water flow rate from the boiler 8 which, as described above, is at the second temperature, corresponding substantially to the maximum temperature at which the water can be dispensed from the heating device 6. If the temperature measured by the first thermometer 10 is greater than or equal to the requested temperature, the mixer 9 is regulated such as to reduce or annul the flow of water removed from the boiler 8. The functioning of the heating device 6 is extremely efficient and rational. The functional integration between the electrical heater 7 and the boiler 8 enables the electrical power required by the heater 7 to be reduced, as the heater 7 can be of such a size as to produce a predetermined flow of water at a variable temperature according to the availability of electrical energy with a maximum increase with respect to the temperature value of the water in inlet, which normally varies between 10 ⁰ C and 15 ⁰ C, of about 25°C, or in any case such as to enable a temperature of about 40 ⁰ C to be reached, at maximum power, sufficient to cover the normal domestic needs while respecting Italian standards in the sector. If a higher water temperature is required, the removal of the water from the boiler 8, which is at a higher temperature than the water coming from the electric heater 7, adds to the flow of water coming from the electric heater 7 and raises the temperature thereof. In this way, as the boiler 8 does not have to supply the whole flow of hot water, it can be dimensioned in terms of both capacity and power, for example with a capacity of 60 litres to 80 litres and with a power of 1.5 Kw, very much lower than with normal domestic installations and thus with a lower electrical energy consumption. Further, the switching-on of the boiler 8,. adequately insulated such as to limit heat loss, can be programmed by the control device 5 such as to intervene when overall absorption of electrical energy is lower, such as for example during the night-time hours. A second thermometer 18, connected to the control device 5, measures the temperature of the water contained in the boiler 8 in order to activate the requests at the control device 5 for switching on the heater of the boiler. A third thermometer 17 can further be connected to the control device 5 in order to measure the temperature of the water in outlet from the electric heater 7. The heating device 6 can also be autonomously functioning and thus replace the usual boilers using gas or other fuel. In this case the control device 5 is integrated internally of the heating device 6 itself.

The second algorithm performed by the control device is integrated in the first operating algorithm performed by the control device 5 by the attribution of the second index of importance to the electric heater 7 and the third index of importance to the heater of the boiler 8. The dispensing of hot water by the instant electric heater 7, once started, is thus guaranteed at a minimum temperature value. The increase of this temperature, with a removal of water from the boiler 8, is subordinated to the availability of electric power on reaching the maximum predetermined value. To this end the electric heater 7 can be realised such as to enable a regulation of the absorbed power between a minimum value and a maximum value which corresponds to a minimum value and a maximum value of the temperature to which the electric heater 7 can heat the water. If the maximum temperature reached is not sufficient to satisfy the desired temperature level, repair is made by removing hot water from the boiler 8, which is always available. The regulation of the power absorbed by the electric heater 7 can therefore be linked to the temperature requested for the water, but also the availability of electric power on reaching the maximum predetermined value: if the electrical power absorbed lowers or is annulled, the control device 5 reduces the electric power supply to the electric heater 7 to the minimum value.

The plant of the present invention further comprises a plurality of electric heating elements 12, predisposed to be located in various zones or rooms in the dwelling in which the plant is installed. The electric heating elements 12 are preferably radiating elements, locatable on the floor, on the ceiling or on the wall, which enable the zone or room in which they are installed to be heated by radiation. Each electric heating element 12 is connected to an electrical connection 3 and is controlled by the control device 5 by means of the first operating algorithm by attributing the third index of importanceto to the electric heating elements 12. The electric heating elements 12 overall define the dwelling's heating plant. The overall functioning of the heating plant is controllable by the control device 5 on the basis of the normal parameter controlling usual gas-boiler or diesel heating plants, i.e. time-programming of the functioning of the plant and the temperature to which the dwelling is to be heated. The control of the electric heating elements 12 is done by means of a third operating algorithm, integrated in the first operating algorithm, on the basis of which, if the electric power available on reaching the maximum predetermined value is not sufficient for contemporaneous supply of all the electric heating elements, the control device 5 commands a temporary switching-off of at least an electric heating element 12 according to a predetermined time cycle such as to limit the total electric power absorbed by the electric heating elements at a lower or equal value to the power available in that instant on reaching the maximum predetermined value. In other words the heating of the dwelling or rooms or zones thereof to a determined temperature requires the switching-on of one or more electric heating elements 12 and thus supply of electric power to the electric heating elements 12. If the electric power available on reaching the maximum predetermined value does not allow dispensing of power towards one of the heating elements, one or more heating elements are switched off at predetermined time intervals such as to reduce the overall electric power absorbed. It is possible to have a scale of importance of the electric heating elements 12 on the basis of which some elements 12 cannot be switched off (for example those located in bathrooms), others can be unconditionally switched off, others besides can be turned off at each control cycle of the control device, or every two control cycles, every three cycles and so on. The switching-on and off of the various heating elements 12 can thus be regulated for example according to the type of room and the presence of people internally of the rooms such as to limit the instantaneous electric power absorbed overall by all the users and not to exceed the power available.

The plant of the present invention can also be provided with cooling devices which can be controlled by the third operating algorithm in an entirely similar way to the heating elements. A special cooling device which is integrated very efficiently into the plant of the present invention is constituted by geothermal heat pumps.

To limit absorption of the electric power on the part of the cooling devices the plant of the present invention can be provided with means for controlling the solar radiation. These means for controlling the solar radiation comprise, for example, curtains, shutters and/or blinds provided with motors which cause opening and closure thereof and are controlled by the control device 5. The management of the means for controlling the radiation by the control device 5 can be actuated via a timing program or by means of radiation sensors positioned externally of the dwelling. The plant is advantageously provided with at least a rechargeable battery 13 which can dispense an electric power which is lower than that of the main source of electric power. The battery 13 preferably exhibits a supply voltage of 12V in direct current. The battery 13 is connected to the main source of electric power and is constantly supplied thereby. By means of suitable cables and connections the battery 13 supplies a plurality of low- power electric users 14. The low-power electric users 14 comprise, for example, lighting, the control device 5, domotic controllers 15, burglar alarm and fire alarm and in general the devices which, even in the case of a black-out, have to stay functional at least for a determined period of time. In order to limit the total absorption of electric power, the lighting devices are constituted by light sources having LED technology. An example of light sources that are particularly suitable to be integrated in the plant of the present invention is constituted by a bulb comprising a transparent or semi- transparent covering internally of which a determined number of LEDs are grouped in a bulb-fashion. The rechargeable battery 13 also supplies a plurality of domotic controllers 15, each of which is interposed between at least an electric connection 3 and the electric source 2. The domotic controllers 15 are further connected to the control device 5 which, via them, controls the electric power supply to the electric connections 3. An important advantage of the plant of the present invention is that in the case of a black out of the electric grid the building provided with the invention continues to provide light for an overall period of not less than 12 hours thanks to the batteries which are always on charge and which will continue to dispense electrical energy even in the absence of a primary source. The control device 5 can be provided with a communication peripheral, for example a keyboard or touch-screen monitor, which enables the users to change certain functioning parameters of the operating algorithms. It is possible for example to modify the attribution of the indices of importance to the electric connections 3, to change the timing program of the supply of electric power to the electric connections 3, to change the temperature at which it is desired to maintain the single rooms into which the construction is subdivided, and so on. The plant of the present invention thus enables production of hot water for clean-water use, use of electric energy for cooking needs and obtaining heating of rooms by the use of only electric energy. The instantaneous control and management of the overall electric power absorbed for the production of hot water and for heating and other users enables a limiting of the overall electric power absorbed below the normally available electric power for buildings for civil use. The instantaneous control and management of the overall electric power absorbed thus enables actuating all services that are normally present in civil-use buildings via electric users, completely eliminating the use of fossil fuels.

This control means that electric energy can be used at moment of need and the level of consumption can be constantly verified with the aim of determining the correspondence thereof to the projected profile and with lower consumption than the use thereof without the invention.