Assembly for generating electrical and thermal energy

An assembly for generating electrical and thermal energy has a structure that supports a cogeneration device provided with a combustion engine supplied with fuel, an electric generator driven by the combustion engine, and at least one heat exchanger to heat a fluid for a thermal appliance using the heat produced by the combustion engine; the assembly also has a plurality of storage batteries, which guarantee the continuity of the flow of electrical energy during start-up of the electric generator and during load transients and are housed in a base of the structure.

TECHNICAL FIELD

The present invention relates to an assembly for generating electrical and thermal energy, generally referred to as a cogeneration assembly, or a trigeneration assembly if the thermal energy can be produced in two usable forms, namely high-temperature energy which can be used for example for heating and/or for services, and low-temperature energy which can be used for example for air-conditioning rooms and/or services.

BACKGROUND ART

EP1881177 describes a modular power generation assembly comprising a main cogeneration module, which can be supplied with fuel and is able to generate electrical energy for user appliances, connected in parallel to an external electrical power network or operating in isolation.

The main module also generates thermal energy in the form of a flow of hot water. The thermal energy produced by the main module can supply an auxiliary module able to supply thermal energy at a lower temperature, in the form of a flow of a chilled fluid.

The main module comprises: an electrical energy generation assembly, consisting of an internal combustion engine coupled to an alternating-current rotary electric generator; a heat exchanger coupled to the internal combustion engine; and an electronic converter unit which, in turn, comprises:an ac/dc converter connected to the output of the electric generator;a dc/ac converter connected, on one side, to the electrical output terminal of the main module via a filter and, on the other side, to the output of the ac/dc converter via a dc link, andan electrical energy storage module coupled to the dc link via a bi-directional dc/dc converter, which allows a flow of electrical energy from the storage module to the dc link and vice versa.

The main module and auxiliary module are managed according to predefined procedures by a control unit. Said control unit is able to detect an interruption in the service of the external electrical power network, and ensure the continuity of electrical power supply to the user appliances, with electrical energy supplied by the storage module for long enough to start the electrical energy generation assembly.

Moreover, the control unit is preset to implement a function involving elimination or “smoothing” of the voltage “drops” by means of continual analysis of the value of the output voltage and drawing, as required, power from the electrical energy storage module, which is used as a buffer.

In other words, the electrical energy storage module ensures the continuity of the power supply during start-up of the electrical energy generation assembly and during the inevitable load transients.

In practice, the electrical energy storage module is defined by storage batteries that are arranged in separate rooms some distance from the other components of the electronic converter and are connected to said components by means of high voltage cables (approx. 600 V).

This solution is not satisfactory, with regard to overall dimensions and ease of maintenance, due to the distance between the batteries and the other components of the main module, and with regard to safety, due to the presence of high-voltage cables around said main module.

DISCLOSURE OF INVENTION

The purpose of the present invention is to provide an assembly for generating electrical and thermal energy, which overcomes the drawbacks described above in a simple and cost-effective manner.

According to the present invention there is provided an assembly for generating electrical and thermal energy, comprising:a supporting structure;a cogeneration device carried by said supporting structure and comprising:a) a combustion engine supplied with fuel;b) an electric generator driven by said combustion engine;c) at least one heat exchanger to heat a fluid for a thermal appliance using the heat produced by said combustion engine;electrical energy storage means to guarantee the continuity of the electrical power supply during start-up of said electric generator and during load transients;
characterized in that said electrical energy storage means are housed in said supporting structure.

Preferably, said electrical energy storage means are housed in a base of said supporting structure.

BEST MODE FOR CARRYING OUT THE INVENTION

InFIG. 1designated as a whole by number1is an assembly for generating electrical and thermal energy, the latter in the form of flows of hot fluids (for example water or air), for example to heat thermal appliances, or cold, for air-conditioning of said appliances.

As regards the electrical energy, the assembly1has a first electrical output terminal (not illustrated) which can be connected directly to electrical appliances and a second electrical output terminal (not illustrated), which can be connected to an external electrical power network.

The assembly1comprises a supporting structure2, which in turn comprises a base3resting on the floor and a frame4defining a compartment5having a substantially parallelepiped shape on top of the base3.

The assembly1comprises a cogeneration device10, which is supplied with fuel, for example natural gas and has components of its own housed in the compartment5and supported by the frame4.

The device10comprises an internal combustion engine12coupled to an alternating-current rotary electric generator13. The engine12receives the combustion air from an intake line14and the gaseous fuel from a delivery line15, which has an inlet16that can be connected to an external distribution network and is provided with a compressor17. The fumes generated by the engine12are discharged through an exhaust line18that terminates in a stack19. The engine12is also provided with a liquid cooling system.

The device10also comprises at least one heat exchanger to heat a flow of fluid, in particular water, for thermal appliances using the heat generated by the combustion engine12. Numbers21and22indicate, respectively, the inlet and the outlet of a duct23that carries the water to be heated for the thermal appliance. In particular, arranged along the duct23there are: a heat exchanger24defined by a radiator coupled to the cooling system of the engine12; and a heat exchanger25coupled to a portion of the line18, in parallel to a bypass portion26for the exhaust fumes, to draw heat from the exhaust fumes.

The assembly1also comprises an electronic converter (not illustrated), which converts the electrical energy produced by the generator13, is housed in a cabinet27arranged at the side of the structure2, and comprises:an ac/dc converter connected to the output of the generator13;a dc/ac converter connected, on one side, to an electrical output terminal (not illustrated) via a filter and, on the other side, to the output of the ac/dc converter via a dc link, anda bi-directional dc/dc converter to connect the dc link to a plurality of electrical energy storage modules28(FIGS. 2-4) and allow a flow of electrical energy from the modules28to the dc link and vice versa.

An electronic unit (not illustrated) is arranged in the cabinet27or in a remote position to control the device10and manage the thermal power and electrical power output.

According to the invention, the modules28are storage batteries housed in the structure2, in particular in the base3.

With reference toFIGS. 2 and 3, the batteries28are housed in drawers30arranged along two rows, which are accessible from opposite sides of the structure2. Each drawer30comprises a U-shaped receptacle31comprising a horizontal base wall and two side walls33defining a seat34engaged by the batteries28. The walls33are provided with aeration apertures35and are coupled to the base3via guideways36, that allow the drawer30to slide along a horizontal axis37to be extracted at least partially from the base3.

The seat34is closed at the front and rear by respective vertical walls38,39, which are fixed to the receptacle31. The seat34is closed at the top by a cover40, which is removable to access the seat34from above when the drawer30has been extracted.

The lower surface of the wall32is reinforced by two bars41, which are arranged transversely to the axis37; the wall38carries, in a fixed position, an external handle42for moving the drawer30manually; and the wall39carries a vertical plate44, which is arranged in a fixed position at the bottom of the seat and supports two electrical connectors45, which define a positive pole and, respectively, a negative pole. The batteries28of each drawer30are connected electrically in series to one another and are connected to the electrical connectors45in a manner that is not illustrated and not described in detail.

With reference toFIG. 4, the electrical connectors45extend in a cantilevered manner from the plate44through an aperture46in the wall39outside the seat34. When the drawer30is fully retracted inside the base3, the electrical connectors45are connected to respective electrical contacts47provided on a vertical plate48made of an insulating material and arranged in a fixed position inside the base3. The electrical contacts47are, in turn, electrically connected to cables49that carry the electrical energy, in a manner that is not illustrated and not described in detail, towards the side of the structure2where the cabinet27is arranged, to enable the electrical connection between the batteries28of the various drawers30to the electronic converter arranged in the cabinet27.

When the drawers30are extracted, to carry out maintenance on the assembly1or to replace the batteries28, the electrical connectors45move away from the electrical contacts47so that the electrical connection is automatically disconnected.

According to an alternative embodiment that is not illustrated, instead of an electrical connection that is automatically disconnected, cables are provided between the drawers30and the plates48and are supported and guided by flexible tracks, with the possibility of disconnecting the electrical connection of said cables manually.

The position of the batteries28in the base3allows the overall dimensions available to be optimized without having high-voltage cables exposed around the structure2.

The sliding connection between the drawers30and base3is extremely simple to implement and makes maintenance and replacing the batteries28extremely convenient. The drawers30can even be extracted completely from the base3and carried elsewhere without any trouble.

Lastly, it is clear that modifications and variations may be made to the assembly1described and illustrated herein without departing from the scope of the present invention, as set forth in the appended claims.

In particular, the batteries28could be arranged in a part of the structure2other than in the base3.