IT202100028289A1 - "FUEL CELL STORAGE SYSTEM" - Google Patents

Description

Description of the invention with TITLE:

?Fuel cell storage system?

TECHNICAL FIELD

This invention? relating to an electrochemical equipment for the accumulation of electrical energy, mainly from renewable sources. This device, in appropriate variations, is used for the supply of energy in residential homes, making them independent from the conventional connection to the electrical distribution network

STATE OF THE TECHNIQUE

The renewable energy sector? in strong ferment and is obtaining constant support from Government bodies, which intentionally stimulate its development to reduce the unwanted environmental impacts caused by a pressing and unstoppable increase in global energy demand, which, if it remains mainly supported by fossils, would produce, with now known certainty, enormous damage to the planet, what? tickling the conscience of every industrialized country.

Being able to make homes autonomous from the current connection to the electricity distribution network, feeding them mainly with renewable energy would, equally certainly, be an enormous contribution to this objective

Not by chance, ? There is an authentic revolution underway in this sector which ranges from expanding the use of renewables to creating renewable energy units. storage rooms for these energies, together with making homes increasingly energy efficient.

Renewable energy production? has been at the center of government incentives for some time but lately, there has been an accentuated interest in making civil homes increasingly autonomous from an energy point of view, encouraging the installation of solar panels and/or wind turbines but also the installation of units? of accumulation, designed to store surpluses during low consumption hours to make them available at peak times.

A further government incentive? also that of the obligation (commitment) on the part of the electricity distribution company to purchase "green" electricity, for example by issuing credit certificates or using the so-called "net metering".

The vast majority of these storage systems? based on conventional batteries which, through appropriate electronic equipment, are able to absorb and store renewable electricity when not needed and make it available when needed. Generally, they are also already? able to ?transfer? energy on the grid and actually selling energy

Even the installation of these units? of accumulation? incentivized as the possibility? of accumulating energy effectively creates a lung that reduces the power commitments of the electricity grid overall, in fact it is enough to think about the possibility? to program these systems to be able to purchase electricity at night and make it available to cover peak needs, making the public body in better conditions. favorable when usage peaks occur

A limitation of these systems is that the batteries have a capacity limited and can become cumbersome and expensive, if you want to considerably increase said capacity.

Recently, although not yet very widespread, but with sharply increasing rates, the use of hydrogen fuel cells is becoming established - as a valid alternative to batteries.

These systems are reversible and are essentially able to absorb electrical energy by splitting demineralised water into hydrogen and oxygen in the gaseous state, then compressed and accumulated in cylinders, but also fully reversible, that is? capable of producing electricity and water resulting from the controlled combustion of hydrogen and oxygen fed into the cell in the gaseous state.

SCOPE

The main purpose of the pi (this invention) is the creation of a completely autonomous and integrated system, capable not only of providing for the accumulation of renewable energy but of allowing the taking charge of the entire electricity supply to the home, with various additional functions, all managed by a single process controller.

A further purpose of the pi? that of being able to recycle the heat produced during energy conversion and making it easily and efficiently available as a winter heat source

An additional purpose? that of being able to store high capacities? energy in modest spaces, including the possibility? to transport the units? to accumulate charges elsewhere when and if necessary or convenient, as well as being able to easily pour them into the network.

LIST OF FIGURES

Further characteristics and advantages of the present invention will appear clearer from the indicative, and therefore non-limiting, description of the preferred but not exclusive embodiments of an innovative system for the accumulation and management of renewable energy sources, as illustrated in the attached drawings in which:

- the fig. 1 depicts a block diagram of the system according to the present invention, in its most basic form. complete form of execution;

- the fig. 2 depicts the diagram of figure 1 in a further expanded embodiment (configuration).

- the fig. 3 depicts the scheme of figure 1 in a further embodiment, called basic

DESCRIPTION of the main components

The fig. 1 schematically represents the block diagram of the storage and management system according to the present invention in a typical configuration in which block 1 represents the electrical cabinet in which the system is enclosed, block 2 represents the house powered by system 1, block 3 represents the existing electricity distribution network, block 4 represents a source of alternative wind energy and group 5 represents a photovoltaic system, typically including a plurality of of individual solar panels, composed of silicon cells, essentially a photosensitive material, capable of converting the solar energy of ultraviolet rays into electrical energy delivered in direct current.

Still in the same figure, block 6 represents a modern fuel cell capable of absorbing electrical energy, producing hydrogen and oxygen in the gaseous state and reversing - without interruptions - the reverse process, that is, activate the combustion of hydrogen by providing electricity. Inside the fuel cell 6 there is the combustion chamber which contains the electrodes 7a and 7b (anode and cathode), the catalysts 7c and 7d and an electrolyte, which instead of being liquid, is made up of a thin polymeric membrane 7e which allows the passage of only positive ions (hydrogen protons), commonly called PEM. The fuel in this system? hydrogen and the oxidizer? oxygen, both supplied or stored in the gaseous state in appropriate cylinders 17 and 18. Basically, by feeding the anode with hydrogen, thanks to a first catalyst (usually made of platinum), the ionization of the gas and the positive ions (the protons of the ?hydrogen) migrate through the PEM polymeric membrane towards the cathode while the electrons, blocked by the membrane, through an appropriate electrical connection, generate a removable electrical power while the cathode, fed with oxygen and receiving the hydrogen protons through the electrolyte, triggers a chemical reaction that produces pure water. This process lasts until you fuel the device with hydrogen and ? perfectly reversible, in particular the chemical energy is actually transformed into electrical energy producing electrical energy and pure water but also, vice versa, the cell? capable of absorbing electrical energy and splitting pure water molecules into its two elementary components. For the system being described, the ?PEM? type fuel cells (Proton exchange fuel cells) have proven to be optimal in terms of power output and efficiency. Are these types of cells commercially available, for example produced by the Company? HORIZON.

AND? It is important to point out that one of the characteristics of this system is that of being able to reverse the process without the house seeing any discontinuity? of supply, a feature that this system intrinsically offers without the need to integrate uninterruptible power supplies, which is instead indispensable in conventional battery storage groups

Still in the same fig. 1, the pipes 8 and 9 are indicated which connect and transport the gaseous hydrogen from the main internal containment cylinder 17 to the cell 6. And? It is important to point out that the hydrogen gas that enters or leaves cell 6 is at low pressure (2 bar) while in order to obtain a good capacity? of accumulation, it is advisable to compress the gas (200 bar) to accumulate it and decompress it when you want to use it. For this purpose, the compressor 12 and the valve 16 are provided. In the same way, the oxygen gas is transported in the pipes 10 and 11, compressed by the compressor 13 and decompressed by the valve 15. The component 19, 20, 21, 22 and 23 represent, respectively, the electrical connection cables between the converter 24 and the cell 6, the system photovoltaic 5, the wind system 4, the distribution network 3 and the house 2, which receives them in a connection box 33 which, is not? more? the connection point of home 2 to network 3.

The two components 24 and 25 represent the electrical energy converter and the system controller respectively and represent, together with the fuel fluid cell 6, the most important components of the system being described. The converter 24 ? an apparatus presenting a plurality? of electrical energy input and output lines. Since each energy source supplies or absorbs electrical energy with different parameters, the purpose of the converter is? that of transforming these parameters to be able to sort them according to the instructions sent by the process controller. In particular, electricity in transit can be supplied - or requested - in direct current DC rather than in alternating AC and, in turn, at different voltage and/or frequency values. Just think that the mains voltage, like this? like the home, it typically requires 240 Volt alternating current and a frequency of 50 Hertz, while solar panels, but also the fuel cell, provide DC current but at different voltages

The controller 25, together with the related management application software, represents par excellence one of the most innovative of the present invention as it manages:

- The traffic of each single energy flow in transit (incoming and outgoing) - Diagnostics

- All the securities

- Memorize each menu

- Receives and processes inputs provided from outside (keyboard or mobile phone)

- Directs the entire concert of each individual component within the equipment (system) in order to implement and control the process in real time

The controller 25 ? programmable and can? operate different modes? of work which are stored and accessible by the operator, who can? also select them by location? remote thanks to the possibility? of a modern telephone interface

- Can you? offer memory spaces and men? auxiliary applications, designed to carry out additional functions completely unrelated to the energy management of the home, such as alarms, lighting and more, with the aim of grouping - in a single summary table, the global monitoring of the home, making it visible in a single telephone connection through the system of reception 26

The exchanger 27 performs the function of removing the heat produced during energy conversion from the fuel cell and preferably works by recirculating the heat transfer fluid operating in a closed circuit created in such a way as to be able to selectively direct said heat to its own radiator 45 rather than to a radiator inside the house 32, allowing energy recovery during the winter periods. For this purpose, the system has integrated a circulation pump 28 and at least one pair of directional solenoid valves 29 and 30, by activating which, the controller allows heat to be transferred to the radiator 45 rather than to 32 through the pipes 31.

Still in fig. 1, ? Also shown is the distilled water tank 42 with its connection pipes 40 and 41 to the fuel cell 6 respectively dedicated to feeding water or returning it to the tank depending on the mode. of operation of the cell 6. In the same figure, 43 indicates the cap for topping up demineralised water in the tank 42, while 44 and 45 respectively indicate a reverse osmosis system and the relative domestic water supply hose, a useful accessory to make the system is autonomous and works with normal water and does not require topping up.

In fig. 2, using a block diagram, ? an alternative form of execution of the system in figure 1 is illustrated in which the presence of groups 36 and 39 can be seen which represent a pack of cylinders, with high storage capacity, which can be connected to the system, respectively for hydrogen and oxygen. This feature, to be considered as one of the various options available, is very important because? it allows hydrogen to be used as a primary energy source to be converted into electricity for the home but additionally as clean energy, generated from renewable energy, transportable and with a marketable commercial value, for example for transport. In fact, when the tanks 17 and 18 are full, the controller can activate the valves 34 and 37 to divert the gaseous flow from or towards the packs of cylinders through the pipes 35 and 38 also offering the additional mode? of use of the system in which the hydrogen is converted into electrical energy transferred to the grid if economically convenient or the possibility? to convert electricity taken from the grid at night and then return it during peak hours, always providing for the needs of the home

In fig. 3 ? instead, a further embodiment of the system of fig. is illustrated. 1, illustrated here in its elementary configuration in which, compared to fig. 1, the wind power plant 4, the auxiliary cylinder pack 36, 39 and the reverse electrolysis plant 44 are respectively absent. furthermore note how the heat disposal system developed by the cell 6 occurs by integrating a single exchanger 46 of the forced air type by a motorized fan 47 inside the cell 6.

OPERATION

As previously mentioned, the controller allows the equipment to replace the electrical network as the main source of energy, which in system management is reduced to being one of the energy sources to which the system supplies or requests energy. As better specified below, if the system has sufficient capacity? of hydrogen accumulation - for example if the system includes an auxiliary cylinder pack - the system preferably uses renewable energy as the main source and uses gaseous hydrogen as a secondary energy source to satisfy the needs of the home when consumption is ? higher than available renewable energy. In other words, does the connection to the network become necessary solely to sell electricity or serve as an emergency in the event of system failure to avoid discontinuity? of electricity supply to the home, there? effectively creating the foundations for homes capable of functioning autonomously, without drawing energy from the electricity grid

Due to its intrinsic functions, ? It is useful to note that the present system can obviously also, potentially, serve as a storage system capable of using electricity from the network at night and returning it to the network during peak hours, while not distracting from the main task of satisfying the needs of the home to which it is connected. connected or even power several simultaneously? of a house. To better understand the inventive content of the present invention? It is important to consider the management software that allows the operator to select one of different modes? operational among which stand out:

- The possibility? to receive renewable energy and supply the needs of the home by integrating said energy coming from the combustion of hydrogen gas;

- The possibility? to receive renewable energy, appropriately transformed into hydrogen and oxygen gas, and feed the needs of the home by integrating it with energy taken from the electricity grid or, on the contrary, by pumping energy on consignment if the power of renewable energy is in excess of the needs of the home ?dwelling;

The possibility? to accumulate renewable energy, appropriately transformed into hydrogen and oxygen gas, filling both internal and external tanks, and therefore offering the possibility to sell valuable gaseous fuel

- The possibility? to withdraw energy from the electricity grid at night and then return it to the grid during working hours, speculating on a substantial difference between the purchase cost and the selling price.

- The possibility? to withdraw energy from the electricity grid at night and convert it, together with the available renewable energy, into marketable gaseous fuel

- Manage all system security

- Change, depending on the time and the needs of the home, the operating strategy considered optimal, including the zero home consumption condition, for example if the house is empty

- Offer the possibility? to control additional utilities external to the storage system described, to allow the user to keep the home under control in all its functions? such as heating, lights, security and more

ADVANTAGES

The accumulation and intelligent management of renewable energy, which operate in concert with the fuel cell described above thanks to the system's process controller, allow the home to become autonomous from the connection to the electrical distribution network which becomes a source of energy secondary, however mainly designed to receive energy or cover emergencies.

The system actually allows you to

- Work without network

- Sell energy (put energy into the grid)

- Selling hydrogen

But above all, satisfy the needs of residential homes using alternative sources

From what has been described above it is clear how the system created according to the present invention achieves the intended purposes and offers a considerable series of advantages

Claims (6)

1. Integrated system for the accumulation and management of renewable electrical energy for civil homes, of the type using a fuel cell operating with hydrogen and oxygen in the gaseous state respectively as fuel and oxidizer and using a cycle proton exchange membrane reversible operation, characterized by the fact that it includes: - at least one renewable energy source such as for example a solar panel (5) or a wind generator (4); - at least one reversible fuel cell (6), operating with hydrogen and oxygen in the gaseous state and a proton exchange membrane (PEM) with a power typically between 3 and 7 KVA; - an electrical energy converter (24) having at least one input line, for direct or alternating current, connectable to said renewable energy generator, at least one single-phase and/or three-phase alternating current output line, connectable to the home (2) and a bidirectional direct current electrical line, connectable to said reversible cycle fuel cell (6), capable of delivering direct current electrical energy to the cell, converting the incoming renewable electrical energy or receiving direct current electrical energy from it , and transform it into alternating electrical energy supplied to the home made available to the output line when the cell (6) operates in reverse cycle, according to the instructions provided by the controller (25); - an accumulation system for the two gases, fuel (hydrogen) and oxidising agent (oxygen) comprising at least two cylinders capable of containing pressurized gas, typically up to a maximum pressure of 200 bar (18); - two compressors (12, 13) capable of raising the pressure of the gases produced by the cell (6) from ambient pressure up to a maximum pressure of 200 bar, said compressors operating when the cell absorbs electrical energy supplied by the converter (24); - Low pressure connection pipes between said cell and said compressor and high pressure connection pipes between said compressor and said storage cylinders - a pressure reducer (15, 16), and related connection pipes to reduce the pressure of the gases from the pressure of the accumulation cylinders to the operating pressure of the fuel cell, generally operating at ambient pressure, said pressure reducer operating when the cell (6) works in reverse cycle, consuming gases to convert them into electricity; - an integrated heat exchange system (27) for the controlled removal of the heat generated inside the fuel cell (6) during its operation regardless of whether it is in mode? normal or reverse; - a buffer tank of demineralised water (42) connected to the fuel cell (6) intended to supply or receive water to or from the cell, depending on the mode? of operation; - A control system (25), capable of controlling the flow of energy entering and exiting the system, controlling the energy converter (24) according to the needs of the home (2) and the energy supplied by alternative sources ; this system allows you to make the home autonomous from an energy point of view. 2. System according to claim 1 characterized by the fact that the converter (24) of said system provides an additional input electrical line, in alternating current, connectable to the public distribution network (3); 3. System according to claim 1 characterized by the fact that said gas accumulation system produced by the cell (6) also includes a pack of remote external cylinders (53 and 57), related connection pipes and three-way flow diverter valves (50 , 54) controlled by the process controller (25) to allow the capacity to be considerably increased? of accumulation of the two process gases, making them transportable. 4. System according to claim 1 characterized in that the system comprises a unit? for the production of demineralised water intended for the automatic topping up of said buffer tank; 5. System according to claim 1 characterized by the fact that said heat exchange system includes an internal radiator (27), a circulation pump (28) and a pair of three-way valves (29, 30) managed by the control system ( 25), which allow you to selectively direct the heat transfer fluid produced by the cell (6) during its operation towards the home (2) instead of? the radiator (45), allowing for appreciable energy savings through winter district heating. 6. System according to claim 2 characterized by the fact that the system includes a wireless modem (26), connected to said controller (25), which allows the user to communicate with the controller via a mobile phone.