ITCO20100037A1 - "HYDROGEN ENERGY PRODUCTION SYSTEM, IN PARTICULAR FOR HOUSES" - Google Patents

Description

? Hydrogen energy production system, especially for homes?

Description of the invention

Field of use

The present invention relates to a hydrogen energy production system, in particular for homes, according to the preamble of claim 1.

Technological background and state of the art

As known, from hydrogen? it is possible to produce, for example for homes, thermal energy through hydrogen catalytic combustors (WO 2006/136316 A1 of the applicant) or electrical energy through fuel cells (US 2010/0164287 A1).

The applicant's catalytic combustors have been in use for several years and the fuel cells, i.e. hydrogen cells, nowadays have very advanced technologies.

In catalytic combustors, the thermal energy produced is used, through a heat exchanger, to heat the water of, for example, a home heating system and to heat sanitary water, or for other heating purposes. for example for the heating of greenhouses and so on? Street.

The hydrogen supplying the combustor is preferably produced by electrolysis, where the necessary electrical energy is advantageously produced from renewable sources, for example from a photovoltaic system. Hydrogen could also be produced via a reformer, i.e. generated from methane gas.

Various command and control components are associated with the combustor, for example a pressure reducer, a control unit, a battery with battery charger and so on. Street.

Fuel cells were developed specifically for the automotive industry, and they provide optimum levels of both efficiency and durability. They can also be used for the production of electricity in homes.

? it is also known that fuel cells during their operation produce heat, which is generally dispersed into the environment.

From the aforementioned US 2010/0164287 A1? an electric power supply system can be detected between a vehicle, comprising a fuel cell, and a house.

Summary of the invention

At the basis of the present invention? given the task of indicating a hydrogen energy production system capable of supplying, for example to a house, the necessary thermal and electrical energy in order to make said house independent from the electricity and gas connection networks, where in the same time an operational synergy between the components of the system is exploited which improves the efficiency of the system.

The indicated task is achieved, according to the invention, with a system for the production of mixed energy from hydrogen which has the characteristics of claim 1.

Further developments of the invention can be seen from the dependent claims.

Numerous and important advantages are obtained with the hydrogen energy production system according to the invention.

In the first place, the integration in the energy production system according to the invention of a catalytic combustor and a fuel cell both fueled with hydrogen, advantageously produced by electrolysis in situ, will allow? to the user to be able to use the two sources, that is the source of thermal energy and the source of electrical energy, in a completely independent way from each other, and therefore to modulate both the electrical and thermal power in order to regulate the relative consumptions according to the requirement from time to time necessary, where the use of hydrogen for both the combustor and the fuel cell allows for a totally zero emission energy production system, since? both in the fuel cell and in the combustor do not generate carbon dioxide and nitrogen oxides, but only water vapor.

Since? the two sources of energy (combustor and fuel cell) are independent of each other in operation, the production of electricity is not? subordinated to that of thermal energy, and vice versa. At the same time, several circuit components already? necessary for the combustor can be advantageously used at the same time also for the fuel cell. With the energy production system according to the invention, an improvement in the overall yield of the system is also obtained. For example, with the air used for cooling the fuel cell, available at around 40-45 ° C,? It is possible to preheat the combustor inlet air, with a consequent increase in the efficiency of the latter. There, as recalled below,? also valid for water-cooled fuel cells.

In the mixed energy production plant according to the invention, using the fuel cell, the system can also be used. operate without being connected to the electricity grid so, once started, the system sustains itself autonomously. There? constitutes an important advantage with respect to the known art of heat generators, since the known methane heat generators do not work in the absence of electric current. Having the power supply mains, a power socket for a possible mains power supply and to be able to recharge the auxiliary battery in the event of its discharge for any reason, would still be advisable. By combining a hydrogen catalytic combustor and a fuel cell in the system, the efficiency of the latter is increased as it can be achieved. recover the heat generated by the same during operation, instead of? dissipate this heat.

By associating a high efficiency heat pump with the mixed energy production system according to the invention, further advantages are obtained. With this association, using a set of highly efficient technologies, it would even be possible to recover the energy spent for the production of hydrogen by electrolysis.

In fact, in practice, a heat pump currently has a coefficient of performance (COP) normally between the values of 3 and 4, where for simplicity? a COP of 3.5 is considered. A fuel cell has a yield of about 40%, so the combination of the two systems provides an overall value of 1.4 and, therefore, greater than one unit. If we consider the production of hydrogen by electrolysis (efficiency around 75%), then the total yield would assume a value of about 1.05. There? means that this system, coupled to a heat pump and with the generation of hydrogen electrolytically, allows you to recover more? energy of that expenditure initially, which makes it extremely beneficial. If then the? Input energy? taken and stored at the right time (for example, in the case of connection to the power supply network, at night when it can cost less) or if it comes from a renewable and free source (for example solar photovoltaic), the system according to the invention becomes even more convenient and advantageous.

The numbers indicated pi? above refer to products currently normally available on the market, and more? precisely considering a qualitatively? average? range of products. Therefore you can? wait that in the future the products mentioned can be replaced by other better performing ones, so the total yield? destined to grow and exceed the indicated value pi? over.

By producing hydrogen electrolytically and using an electric heat pump, the system obtained maintains in any case a strongly? Ecological and environmental? Value. as it remains zero emissions.

According to a particular aspect of the invention, the electrical and thermal energy production system according to the invention can? constitute a? unit? autonomous suitable for the production of emergency electrical and / or thermal energy, for example in the event of a disaster? natural, earthquakes and the like. A further advantage of the invention is to be seen in the fact that the circuit parts for the two sources of thermal and electrical energy fed with hydrogen and the individual components are partly common and the resulting circuits are therefore much more common. simple and require fewer components than two independent source systems.

AND? also advantageous the particular use of a system or unit? of mixed energy production fueled with hydrogen for homes not reached by the electricity and gas distribution networks.

Brief description of the drawings

Further characteristics, advantages and details of the mixed energy production system according to the invention will appear further below with reference to some embodiments illustrated by way of example in the attached drawings, in which they schematically show:

Figure 1 shows a system for the production of electricity and / or thermal energy from hydrogen with the relative distribution and control circuits,

Figures 2, 3 and 4 show variants of execution of the energy production system according to the invention, e

figure 5 shows a mixed energy production system comprising a heat pump.

Description of the preferred embodiments

To avoid repetitions, unless otherwise specified, in the various figures identical parts have the same reference marks.

With reference to Figure 1, the system for the production of mixed thermal and / or electrical energy from hydrogen? indicated as a whole with 1 and, in the example illustrated,? housed, which unit ?, in a case 2 indicated with dotted lines. The entrance of the hydrogen? indicated by A and the hydrogen distribution circuit 3 to a catalytic combustor 4 and to a fuel cell 5 comprises a common reducer R. Downstream of the reducer R in the two branches 3A and 3B feeding respectively the combustor 4 and the cell a fuel 5? provided respectively a solenoid valve 6 and 7 of the modulating type with electronic control, which are managed by a special CPU 14 with programmable software, where said valves 6 and 7 are followed in series respectively by a fine regulation valve 8, 9, to mechanical example.

With B? indicated an input for the electrical network while with 10 and 11? indicated respectively a battery charger and a buffer battery, while with 12? indicated an inverter connected to the fuel cell 5 and to the battery charger 10. The inverter 12 transforms the direct current produced into an alternating current at a voltage at its output C of, for example, 220V and 50Hz, as usual in homes in Europe.

D and E indicate respectively the flow and return of, for example, a heat exchanger, not shown, associated with the combustor 4 and connected to a heating system, not shown.

To fuel cell 5? associated with a cooling fan 13 which can be controlled by the CPU. The hot air 15 coming from the cooling of the fuel cell 5? conveyed directly to the intake 16 of the combustor 4. Ci? it allows the heat contained in the cooling air 15 to be recovered without further means or heat exchange devices. This cooling air 15, having a temperature of about 40-45 ° C, allows to increase the temperature on the catalyst, not shown, of the catalytic combustor 4, without however? overcome the limits of the same.

The efficiency of the combustor 4 will be? maximum for water heating in particular for low temperature radiant heating systems, operating with water at a maximum of approx. 40-45? C. The combustor 4? in any case also able to bring the water temperature to about 60? C, the ideal temperature for the production of domestic hot water.

In the examples shown, input B of electricity from the mains? provided to power the auxiliary components of the system and to charge the battery 11. The battery 11? it can also be loaded from the fuel cell 5 itself when? in operation and then allows off-grid operation, ie independent, of the entire system 1, therefore also in the event of a blackout.

The dotted lines from the CPU 14 to the valves 6, 7 and to the fans 13 and 16 indicate the signals subject to control by the CPU, which can simply be of the on / off or modulated type, depending on the degree of optimization to be achieved. as well known to those skilled in the art.

For reasons of clarity of representation, in box 2 is not it? indicated the air? humid? (containing the water generated by the reaction between hydrogen and oxygen) at the output produced by the fuel cell 5 and by the catalytic combustor 4, as well as not? shown an air inlet.

The operations of both catalytic combustors and fuel cells are known from the known art, so that a more detailed description is disregarded. detailed of the same.

Example

An example of sizing of an electrical energy and thermal energy production system according to the invention is provided below. Are you supposed to build a system or unit? comprising a fuel cell 5 with a power of 1 kW and a catalytic combustor 4 formed by a 5 kW module of the applicant, ie of the type indicated in WO2006 / 136316 A1.

With these powers it is possible to satisfy the basic energy needs of a small house.

The combustor 4 requires the following hydrogen flow to provide the indicated nominal power:

5 kW / 3 kWh / Nm <3> = 1.67 Nm <3> / h

where ? divided the nominal power by the lower calorific value of hydrogen.

For the fuel cell 5 an overall efficiency of 40% is assumed (as expected with fuel cells of the PEM type currently on the market), so the consumption of hydrogen will be? equal to:

(1 kW / 3 kWh / Nm3) / 0.4 = 0.833 Nm3 / h

value foreseen by the plate data of the fuel cells currently on the market.

From the fuel cell 5 during operation develops for? also heat, which can? be quantified as follows:

(0.833 Nm3 / h * 3 kWh / Nm3)? 1 kW = 1,499 thermal kW.

This heat? usually dissipated by the fan 13 disposed in proximity? of the stack, in the case of air cooling.

To increase the efficiency of the system according to the invention, this heat, previously dissipated, is whose temperature? of the order of about 40? C, is recovered. A first solution, as illustrated in Figure 1,? that of conveying this hot air 15 directly onto the intake fan 16 of the combustor 4. In this way, a direct passage of the hot air coming from the fuel cell 5 to the fan 16 is used without an intermediate heat exchange.

It assumes a recovery of 75% of this heat by the combustor 4. Since? the latter behaves like a condensing boiler, it? able to recover part of the latent heat of the? fumes? drain. Experimental tests have indicated a yield of approximately 107% for this recovery.

The potential? overall system thermal? therefore equal to

5 kW * 1.07 1.499 kW * 0.75 = 6.474 kW.

The potential? theoretical? instead of:

(1.67 0.833) Nm <3> / h * 3 kWh / Nm <3> = 7.509 kW.

The overall efficiency of the system according to the invention will be? therefore of: (6.474 kW 1 kW) / 7.509 kW * 100 = 99.53%.

With the integration to the combustor 4 of a fuel cell 5 yes? obtained an increase in the potential? thermal system of about 16%, without reducing the efficiency of the combustor 4 per se? very high (above 100% referring to the lower calorific value). In the fuel cell 5, on the other hand, following the recovery of heat, the yield increases considerably and reaches the value of about 85%, or more than double the nominal value.

Without the heat recovery of the fuel cell 5, the grouping of the combustor 4 and the fuel cell 5 as indicated would have obtained the following total efficiency:

(0.4 * 1.07) * 100 = 42.8%.

Embodiments according to Figures 2 to 4.

The system or unit? 1, respectively 2, for the production of mixed energy from hydrogen according to the invention illustrated in Figure 1 can? advantageously be modified for use in particular applications.

For example, figure 2, for a back-up function the system according to the invention can? provide inside it a small hydrogen storage tank 18 to ensure in any case safe operation for a predetermined number of hours.

For this purpose, the most technical solution? efficient would be to provide in the system 1 the hydrogen storage tank 18 in the form of metal hydrides, inserted as shown in figure 2. This solution allows to have a good supply of hydrogen in a relatively small space, where for? this type of storage requires heat in order to deliver the hydrogen contained within it. For this purpose, according to the invention, the heat of the cooling air 15 recovered from the fuel cell 5 is used. preferable to the combustor for several reasons: the recovery heat would in any case occur with the fuel cell 5 in operation and, due to the cost of the hydrides,? preferable to have a back-up only on the electrical part rather than on the thermal one, even if this evaluation can? expire depending on the applications envisaged, or considered.

As illustrated in figure 2, the hydrogen charge in the hydride takes place directly with a branch 20 connected upstream of the reducer R, i.e. with a higher hydrogen pressure than that present downstream of the reducer R, where this value is higher can be set at about 15 bar. The release of hydrogen, on the other hand, takes place through the outlet section 21 connected to the supply branch 3B of the fuel cell 5. The hydrogen release pressure will be? therefore lower than the hydrogen charge pressure value following the hysteresis of the metal hydride 18. The two lines 20 and 21 are equipped with a non-return valve 22 and 23 to have the correct direction of the hydrogen flows in each situation.

With internal storage 18? It is possible to transport the system 1 according to the invention to a hydrogen loading point or station in the metal hydride 18 and then to transport the system to a place where electrical and / or thermal energy is needed such as a normal generator. In any case, the internal storage 18 of hydrogen could also be used for emergency operation if, for any reason, the source of hydrogen, or the electrolysis device, not shown, should suddenly fail.

The further variant illustrated in figure 3 refers to a production of direct current, for example for the power supply of a network or of a series of devices which can be fed with direct current. In this variant instead of the inverter 12 will come? a DC / DC converter 25 is provided for setting the output voltage to the desired value, where in the figure? a value of 24 Vdc is indicated on output C. In this case there are therefore no efficiency reductions due to the inverter 12 of the previous variants, which inverter reduces the fuel cell yield, in the presence of an increase in electrical efficiency.

The system 1 according to the invention illustrated in the variant of Figure 4 provides for the use of a water-cooled fuel cell 5. In this case, improvements related to heat recovery are achievable. In this case, the heat recovery? obtained by means of a heat exchanger 27, whose primary circuit 28? crossed by the cooling water of the fuel cell 5 and whose secondary circuit 29 transfers the heat flow from the water cell to the inlet E of the combustor 4, as illustrated in figure 4. In other words, the heat supplied by the cell is used. fuel 5 to preheat the return E of a heating system, not shown.

To have a better management of flows? it is preferable to have two separate water circuits. Furthermore, this variant eliminates the risk of? Polluting? the fuel cell 5 with water coming from the heating system, which could carry impurities of different kinds. The control of the temperature flows can? be performed by switching the pump 30 for circulating the water in the cooling water circuit of the fuel cell 5 on and off. precise can? also be carried out by modulating the speed? of pump 30, i.e. its flow rate.

From Figure 5? finally detectable a system 1 according to the invention, comprising a combustor 4 and a fuel cell 5, to which system 1? associated with a heat pump 31, which? fed with electrical energy supplied by the fuel cell 5 and for its part supplies thermal energy for a user 32 which also receives thermal energy from the combustor 4.

With this embodiment, therefore, the functional behavior described above is obtained with the related performance which is further improved.

From the structural and functional description of the different systems of production of mixed energy from hydrogen according to the invention? it can be seen that with them the task set at the basis of the invention is effectively solved and the mentioned advantages are achieved.

It falls within the scope of the invention to provide systems for the production of mixed energy from hydrogen using the individual characteristics of the illustrated embodiments in combinations as desired.

Those skilled in the art will be able to introduce various modifications or variants, such as for example providing a supply of hydrogen from a cylinder with a reducer, for example for systems or units. emergency, or provide internal hydrogen tanks of the pressure type, propose alternative uses to use in homes, such as for heating greenhouses, industrial warehouses and so on? away, without thereby departing from the scope of protection of the present invention, as claimed in the following claims.

? Hydrogen energy production system, especially for homes?

Claims

1. Hydrogen energy production system, in particular for dwellings, for example of thermal energy, comprising

a catalytic combustor with a hydrogen supply,

a water / water heat exchanger with primary circuit heated by the combustor and with secondary circuit feeding a user, for example a heating and / or sanitary water production system of a house or similar,

with associated control means via software with settable programs, characterized in that it further comprises a fuel cell which can also be fed with hydrogen for the production of electrical energy, with an associated cooling device and with an associated device for the production of electrical energy, And

by the fact that the vector of exhaust heat emitted by the fuel cell? used for heating purposes within the system.

2. System for the production of mixed energy from hydrogen, according to claim 1, characterized in that in the hydrogen supply circuit downstream of a reducer? a first branch is planned for

Claims (9)

? Hydrogen energy production system, especially for homes? Claims 1. Hydrogen energy production system, in particular for dwellings, for example of thermal energy, comprising a catalytic combustor with a hydrogen supply, a water / water heat exchanger with primary circuit heated by the combustor and with secondary circuit feeding a user, for example a heating and / or sanitary water production system of a house or similar, with associated control means via software with settable programs, characterized in that it further comprises a fuel cell which can also be fed with hydrogen for the production of electrical energy, with an associated cooling device and with an associated device for the production of electrical energy, And by the fact that the vector of exhaust heat emitted by the fuel cell? used for heating purposes within the system. 2. System for the production of mixed energy from hydrogen, according to claim 1, characterized in that in the hydrogen supply circuit downstream of a reducer? a first branch is provided for feeding the fuel cell and a second branch for feeding the combustor, whereas in each branch? a first electronically controlled modulating solenoid valve managed by the software control and a second valve, respectively of fine adjustment, for example of the mechanical type, is provided. 3. System for the production of mixed energy from hydrogen, according to claim 1, characterized in that the fuel cell? connected an inverter for the production of alternating electric current or a DC / DC group for the supply of direct current, where the vector / exhaust air of the heat emitted by the fuel cell? directed to the catalyst preheating fan of the catalytic combustor. 4. System for the production of mixed energy from hydrogen, according to claims 1 to 3, characterized in that in the system? a hydrogen storage container is foreseen, for example of the hydride type, inserted in the hydrogen supply circuit, where the vector / exhaust air of the heat emitted by the fuel cell? direct on the said storage container, where moreover the entrance of the said storage tank? connected to the hydrogen supply circuit upstream of said reducer while the outlet of said storage container? connected to the hydrogen supply branch to the fuel cell downstream of said reducer, and where in said inlet and outlet branches of said storage tank? respectively contained a non-return valve. 5. System of production of mixed energy from hydrogen, according to one or more? of the preceding claims 1 to 4, characterized in that with a water-cooled fuel cell the cooling water? conducted in the primary circuit of a water / water type heat exchanger whose secondary circuit? inserted in the return pipe of a heating system, for example domestic, which pipe continues in the exchanger of the combustor for its heating, whereas in said primary circuit? there is a circulation pump that can be controlled by the system software. 6. System of production of mixed energy from hydrogen, according to one or more? of the preceding claims from 1 to 4, characterized in that in the electrical circuit feeding the CPU? a battery charger is provided for charging a buffer battery on one side and connected on the other side between the fuel cell and the inverter or the DC / DC unit. 7. System of production of mixed energy from hydrogen, according to one or more? of the preceding claims from 1 to 4, characterized in that the system? housed in a box and forms a unit? for the production of electricity and / or thermal energy from hydrogen. 8. System of production of mixed energy from hydrogen, according to one or more? of the preceding claims, characterized in that to it? associated with a heat pump. 9. Mixed energy production system from hydrogen, according to claim 8, characterized in that the mixed energy production system, the heat pump and a consumer using thermal energy are connected in series in a loop circuit, where the system feeds, through the fuel cell, electrical energy to the heat pump, which feeds the user with thermal energy, which is fed with energy, it also ends up from the system through the combustor. ? Hydrogen energy production system, especially for homes? Summary of the invention A system (1) for the production of energy from hydrogen is proposed, in particular for homes, for example of thermal energy, comprising a catalytic combustor (4) with a hydrogen supply, with a water / water heat exchanger fed with thermal energy a user, for example a heating and / or sanitary water production system of a house or the like, which system (1) further comprises a fuel cell (5) that can also be fed with hydrogen for the production of electricity , and with an associated cooling device (13; 27) and an associated inverter (13) or DC / DC unit (25) for the production of alternating or direct current, where the air or the cooling water of the fuel cell (5) during operation they are used for heating purposes inside the system (1) increasing its efficiency. The efficiency is further increased by associating a heat pump to the system (1). (Figure 1)