U.S. patent application number 13/184923 was filed with the patent office on 2012-02-16 for system for producing energy from hydrogen, in particular for residential buildings.
This patent application is currently assigned to GIACOMINI S.p.A.. Invention is credited to Corrado GIACOMINI.
Application Number | 20120037153 13/184923 |
Document ID | / |
Family ID | 43739857 |
Filed Date | 2012-02-16 |
United States Patent
Application |
20120037153 |
Kind Code |
A1 |
GIACOMINI; Corrado |
February 16, 2012 |
SYSTEM FOR PRODUCING ENERGY FROM HYDROGEN, IN PARTICULAR FOR
RESIDENTIAL BUILDINGS
Abstract
Herein proposed is a system (1) for producing energy from
hydrogen, in particular for residential buildings, for example heat
energy, including a catalytic burner (4) with hydrogen supply, with
water/water heat exchanger power supplying a thermal unit, for
example a system for heating and/or producing domestic water for a
residential building or the like, such system (1) further including
a fuel cell (5) which can also be supplied with hydrogen for
producing electrical power, and having an associated cooling device
(13; 27) and an associated inverter (13) or DC/DC unit (25) for
producing alternating or direct current, wherein the air or water
for cooling the fuel cell (5) during operation are used for heating
within the system (1) increasing performance thereof. Performance
is increased further by associating a heat pump to the system
(1).
Inventors: |
GIACOMINI; Corrado; (Orta S.
Giulio (NO), IT) |
Assignee: |
GIACOMINI S.p.A.
San Maurizio d'Opaglio (NO)
IT
|
Family ID: |
43739857 |
Appl. No.: |
13/184923 |
Filed: |
July 18, 2011 |
Current U.S.
Class: |
126/85R |
Current CPC
Class: |
Y02E 60/50 20130101;
F23M 2900/13001 20130101; Y02B 90/10 20130101; H01M 2250/405
20130101; F23C 13/00 20130101; F23C 99/00 20130101; H01M 8/04022
20130101; F23C 2900/9901 20130101 |
Class at
Publication: |
126/85.R |
International
Class: |
F24C 3/00 20060101
F24C003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 27, 2010 |
IT |
CO2010A 000037 |
Claims
1. System for producing energy from hydrogen, in particular for
residential buildings, for example heat energy, comprising a
catalytic burner with hydrogen supply, a water/water heat exchanger
with primary circuit heated by the burner and with secondary
circuit supplying a unit, for example a system for heating and/or
producing domestic water for a residential building or the like,
with means controlled through software with settable programs
associated thereto, characterised in that it further comprises a
fuel cell which can also be supplied with hydrogen for producing
electrical energy, with a cooling device associated thereto and
with a device for producing electrical energy associated thereto,
and in that the carrier for discharging the heat emitted by the
fuel cell is used for heating purposes in the system.
2. System for producing combined energy from hydrogen, according to
claim 1, characterised in that in the hydrogen supply circuit
downstream of a reducer there is provided a first branch for
supplying the fuel cell and a second branch for supplying the
burner, where there is provided in each branch a first electronic
control modulating solenoid valve controlled by the software
control and a second valve, respectively for fine regulation, for
example of the mechanical type.
3. System for producing combined energy from hydrogen, according to
claim 1, characterised in that there is connected to the fuel cell
an inverter for producing alternating electrical current or a DC/DC
unit for supplying direct current, where the carrier/discharge air
of the heat emitted by the fuel cell is directed to the preheating
fan of the catalyst of the catalytic burner.
4. System for producing combined energy from hydrogen, according to
claim 1, characterised in that there is provided in the system a
container for storing hydrogen, for example of the hydride type,
introduced into the hydrogen supply circuit, where the
carrier/discharge air of the heat emitted by the fuel cell is
directed to said storage container, where--in addition--the inlet
of said storage tank is connected to the hydrogen supply circuit
upstream of said reducer while the outlet of said storage container
is connected to the branch for supplying hydrogen to the fuel cell
downstream of said reducer, and where there is contained in said
inlet and outlet branches of said storage tank respectively a
check-valve.
5. System for producing combined energy from hydrogen, according to
claim 1, characterised in that with a fuel cell with water cooling,
the cooling water is supplied in the primary circuit of a
water/water heat exchanger whose secondary circuit is introduced in
the return pipe of a heating system, for example of a residential
house, such pipe extending into the exchanger of the burner for
heating thereof, where there is provided in said primary circuit a
circulation pump that can be controlled by the software of the
system.
6. System for producing combined energy from hydrogen, according to
claim 1, characterised in that there is provided in the electrical
circuit supplying the CPU a battery charger 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 for producing combined energy from hydrogen, according to
claim 1, characterised in that the system is housed in a casing and
forms a hydrogen electrical and/or heat energy production unit.
8. System for producing combined energy from hydrogen, according to
claim 1, characterised that a heat pump is associated thereto.
9. System for producing combined energy from hydrogen, according to
claim 8, characterised in that the system for producing combined
energy, the heat pump and a unit using heat energy are connected in
series in a loop circuit, where the system supplies, through the
fuel cell, electrical energy to the heat pump, which supplies
energy to the unit, heat energy being supplied to the latter also
by the system through the burner.
10. System for producing combined energy from hydrogen, according
to claim 2, characterised in that there is provided in the system a
container for storing hydrogen, for example of the hydride type,
introduced into the hydrogen supply circuit, where the
carrier/discharge air of the heat emitted by the fuel cell is
directed to said storage container, where--in addition--the inlet
of said storage tank is connected to the hydrogen supply circuit
upstream of said reducer while the outlet of said storage container
is connected to the branch for supplying hydrogen to the fuel cell
downstream of said reducer, and where there is contained in said
inlet and outlet branches of said storage tank respectively a
check-valve.
11. System for producing combined energy from hydrogen, according
to claim 2, characterised in that with a fuel cell with water
cooling, the cooling water is supplied in the primary circuit of a
water/water heat exchanger whose secondary circuit is introduced in
the return pipe of a heating system, for example of a residential
house, such pipe extending into the exchanger of the burner for
heating thereof, where there is provided in said primary circuit a
circulation pump that can be controlled by the software of the
system.
12. System for producing combined energy from hydrogen, according
to claim 2, characterised in that there is provided in the
electrical circuit supplying the CPU a battery charger 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.
13. System for producing combined energy from hydrogen, according
to claim 2, characterised in that the system is housed in a casing
and forms a hydrogen electrical and/or heat energy production
unit.
14. System for producing combined energy from hydrogen, according
to claim 2, characterised that a heat pump is associated thereto.
Description
DESCRIPTION OF THE INVENTION
[0001] 1. Field of application
[0002] The present invention refers to a system for producing
energy from hydrogen, in particular for residential buildings,
according to the preamble of claim 1.
[0003] 2. Prior art
[0004] As known, hydrogen can be used to produce, for example for
residential buildings, heat energy through hydrogen catalytic
burners (WO 2006/136316 A1 of the applicant) or through electrical
energy through fuel cells (US 2010/0164287 A1).
[0005] Catalytic burners of the applicant have been used over the
years and the fuel cells, i.e. the hydrogen cells, currently have
extremely advanced technologies.
[0006] In catalytic burners, the generated heat energy is used,
through a heat exchanger, for heating the water of, for example, a
heating system of a residential building and for heating domestic
water, or for other heating purposes, for example for heating
greenhouses and so on and so forth.
[0007] The hydrogen for supplying the burner is preferably produced
through electrolysis, where the required electrical energy is
advantageously produced by renewable sources, such as for example a
photovoltaic plant. Hydrogen could also be produced by means of a
reformer, or generated by methane gas.
[0008] Different control components, for example a pressure
reducer, a control unit, a battery with battery charger and so on
and so forth are associated to the burner.
[0009] Fuel cells were developed in particular for the automotive
industry, and they provide optimal levels both in terms of
performance and duration. They can also be used for producing
electrical energy in residential buildings.
[0010] It is also known that fuel cells, during operation thereof,
produce heat, which is generally dispersed into the
environment.
[0011] From the abovementioned US 2010/0164287 A1 there is known a
system for supplying electric power between a vehicle, comprising a
fuel cell and a house.
SUMMARY OF THE INVENTION
[0012] The object of the present invention is that of providing a
system for producing energy from hydrogen capable of supplying, for
example to a residential building, the required energy whether heat
and electrical energy so as to make said residential building
independent from the electrical power and gas supply system,
wherein--at the same time--the operative synergy between the
components of the system which improves the performance of the
system is exploited.
[0013] Such object is attained, according to the invention, by
means of system for producing combined energy from hydrogen having
the characteristics of claim 1.
[0014] Further developments of the invention are observable from
the dependent claims. Numerous and significant advantages are
obtained from the system for producing energy from hydrogen
according to the invention.
[0015] Firstly, integration--in the system for producing energy
according to the invention--of a catalytic burner and a fuel cell
both of which can be supplied with hydrogen, advantageously
produced through in situ electrolysis, allows the unit to use two
sources, i.e. the source of heat energy and the source of
electrical energy, in a manner entirely independent from the other,
and thus modulate both the electric power and the heat power so as
to regulate the relative consumption depending on the contingent
needs, wherein the use of hydrogen both for the burner and for the
fuel cell allows having a system for producing entirely
zero-emission energy, given that both the fuel cell and the burner
generate water vapour alone and thus no carbon dioxide and nitrogen
oxides. Given that the two sources of energy (burner and fuel cell)
operate independently from each other, production of electrical
energy is not subordinated to that of heat energy, and vice versa.
At the same time, different circuit components already required for
the burner can be advantageously used at the same time also for the
fuel cell. The system for producing energy according to the
invention also allows improving the overall performance of the
system. For example, the air used for cooling the fuel cell,
available at about 40-45.degree. C., can be used for heating the
air entering the burner, thus boosting the efficiency of the
latter. As outlined hereinafter, same case applies also regarding
water-cooled fuel cells.
[0016] In the plant for producing combined energy according to the
invention using the fuel cell, the plant can operate without being
connected to the electrical power supply system, thus the system
operates autonomously upon starting. This constitutes an important
advantage with respect to the prior art heat generators, in that
the prior art methane-powered heat generators do not operate in
absence of electrical power. Having the electrical power supply
system, a power outlet for possible supply from the power system
and for recharging the battery of the auxiliary components in case
of discharge thereof for any reason whatsoever, is however
recommendable.
[0017] Associating--in the system--a hydrogen catalytic burner and
a fuel cell boosts the efficiency of the latter in that it can
recover the heat generated by the same during operation, instead of
dispersing such heat.
[0018] Associating--to the system for producing combined energy
according to the invention--a high efficiency heat pump allows
obtaining further advantages. Such association--using an assembly
of highly efficient technologies--would even allow recovering the
energy used for producing hydrogen by electrolysis.
[0019] Actually, in practice, currently a heat pump has a
coefficient of performance (COP) normally comprised between 3 and 4
values, wherein--for the sake of simplicity--a 3.5 COP is
considered. A fuel cell has a yield of about 40%, hence the
association of the two systems provides an overall value of 1.4
and, thus, greater than one unit. Considering that production of
hydrogen through electrolysis (performance of about 75%), then the
total performance would reach the value of about 1.05. This means
that this system, coupled with a heat pump and with generation of
hydrogen through electrolysis, allows recovering more energy with
respect to that used initially, hence making it extremely
advantageous. Then if the input energy is collected and stored at
the right time (for example, in case of connection to the power
supply system, at night when it might cost less) or if it comes
from a renewable and free source (for example photovoltaic solar),
the system according to the invention becomes even more convenient
and advantageous.
[0020] The figures indicated above refer to products currently
normally available in the market, and more precisely considering a
qualitatively "average" range of products. Therefore, it can be
expected that the abovementioned products may in future be replaced
by other more efficient ones, hence the total yield is bound to
increase and overcome the value indicated previously.
[0021] Production of hydrogen through electrolysis and using an
electric heat pump however allows the obtained system to maintain a
strongly "ecological and environmental" value in that it preserves
the zero-emission characteristic thereof
[0022] According to a particular aspect of the invention, the
system for producing electrical and heat energy according to the
invention can constitute an autonomous unit adapted for the
production of emergency electrical and/or heat energy for example
in case of natural disasters, earthquakes and the like.
[0023] A further advantage of the invention lies in the fact that
the circuit for the two sources of heat and electrical energy
supplied with hydrogen and the single components are partly shared
and thus the resulting circuits are much simpler and require fewer
components with respect to two independent source systems.
[0024] Particular use of a system or unit for producing combined
energy supplied with hydrogen for residential buildings not served
by the electrical and gas supply system is also advantageous.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Further characteristics, advantages and details of the
system for producing combined energy according to the invention
shall be clearer from the following description with reference to
some embodiments provided solely by way of example in the attached
schematic drawings, wherein:
[0026] FIG. 1 shows a system for producing electrical and/or heat
energy from hydrogen with the respective distribution and control
circuits,
[0027] FIGS. 2, 3 and 4 show variant embodiments of the system for
producing energy according to the invention, and
[0028] FIG. 5 shows a system for combined energy comprising a heat
pump.
Description of the preferred embodiments
[0029] Unless otherwise specified, identical parts have identical
reference numbers in the various figures in order to avoid
repetition.
[0030] With reference to FIG. 1 the system for combined heat and/or
electrical energy from hydrogen is indicated in its entirety with 1
and, in the illustrated example, it is housed, as a unit, in a
casing 2 indicated with dotted lines. The hydrogen inlet is
indicated with A and the circuit 3 for supplying hydrogen to a
catalytic burner 4 and to a fuel cell 5 comprises a shared reducer
R. Electronic control modulating solenoid valves 6 and 7, which are
controlled by a special CPU 14 with programmable software, wherein
said valves 6 and 7 are followed in series respectively by a fine
regulation valve 8, 9, for example of the mechanical type, are
respectively provided for downstream of the reducer R in the two
branches 3A and 3B respectively supplying the burner 4 and the fuel
cell 5.
[0031] B is used to indicate an inlet of the electrical power
supply system while 10 and 11 are used to respectively indicate a
battery charger and a buffer battery, while 12 is used to indicate
an inverter connected to the fuel cell 5 and to the battery charger
10. The inverter 12 converts the produced direct current into an
alternating current with a voltage upon exit C of, for example,
220V and 50 Hz, as usually provided for residential buildings in
Europe.
[0032] D and E are respectively used to indicate the inlet and
outlet, for example, of a heat exchanger, not illustrated,
associated to the burner 4 and connected with a heating system, not
illustrated.
[0033] A cooling fan 13 controllable by the CPU is associated to
the fuel cell 5. The hot air 15 coming from the cooling of the fuel
cell 5 is directly conveyed to the suctioning element 16 of the
burner 4. This allows recovering the heat contained in the cooling
air 15 without requiring further heat exchange means or devices.
This cooling air 15, having a temperature of about 40-45.degree.
C., allows increasing the temperature on the catalyst, not
illustrated, of the catalytic burner 4, but without exceeding the
limiyt thereof
[0034] The efficiency of the burner 4 shall be maximum for heating
water in particular for the low temperature radiant heating
systems, operating with water at a maximum of about 40-45.degree.
C. The burner 4 in any case is also capable of bringing the water
temperature to about 60.degree. C., the ideal temperature for
producing hot domestic water.
[0035] In the illustrated examples, the electrical power inlet B
from the power supply system is provided for supplying the
auxiliary components of the system and for charging the battery 11.
The battery 11 can also be charged by the fuel cell 5 when it is
operative and thus it allows an off-grid operation, i.e.
independent, of the entire system 1, thus also in case of power
failure.
[0036] The dashed lines from the CPU 14 to the valves 6, 7 and to
the fans 13 and 16 indicate the signals subjected to the control of
the CPU, which can simply be of the on/off or modulated type,
depending on the degree of optimization intended to be attained, as
well known to a man skilled in the art.
[0037] For the sake of representation clarity, the exiting "moist"
air (containing water generated by the reaction between hydrogen
and oxygen) produced by the fuel cell 5 and by the catalytic burner
4 is not illustrated in the casing 2, just like an air inlet is not
illustrated.
[0038] Both the operation of catalytic burners and fuel cells is
known from the prior art, hence a detailed description of the same
shall not be provided herein.
Example
[0039] Provided hereinafter is an example for dimensioning a system
for producing electrical energy and heat energy according to the
invention.
[0040] It is intended for providing a system or unit comprising a 1
kW fuel cell 5 and a catalytic burner 4 formed by a 5 kW module of
the Applicant, i.e. of the type indicated in WO2006/136316 A1.
[0041] Such power allows meeting basic energy needs of a small
residential buidling.
[0042] The burner 4 for providing the indicated nominal power
requires the following hydrogen flow rate:
5 kW/3 kWh/Nm.sup.3=1.67 Nm.sup.3/h
in which the nominal power is divided by the lowest calorific value
of hydrogen.
[0043] Regarding the fuel cell 5 there is assumed an overall
performance of 40% (as provided for with PEM fuel cells currently
available in the market), hence hydrogen consumption shall be
equivalent to:
(1 kW/3 kWh/Nm.sup.3)/0.4=0.833 Nm.sup.3/h
value provided for by the data on the plate of the fuel cells
currently available in the market.
[0044] However, from the fuel cell 5--during operation--there also
develops heat, which can be quantified as follows:
(0.833 Nm.sup.3/h*3 kWh/Nm.sup.3)--1 kW=1.499 thermal kW.
[0045] This heat is usually dispersed by the fan 13 arranged in
proximity to the stack, in case of air cooling.
[0046] In order to increase the efficiency of the system according
to the invention this heat, previously dispersed, and whose
temperature is in the order of about 40.degree. C., is
recovered.
[0047] A first solution, as illustrated in FIG. 1, is that of
conveying this hot air 15 directly onto the suction fan 16 of the
burner 4. This allows using the direct passage of the hot air
coming from fuel cell 5 to the fan 16 without an intermediate heat
exchange.
[0048] There is assumed a 75% recovery of such heat by the burner
4. Given that the latter behaves like a normal condensation boiler,
it is capable of recovering part of the latent heat of the exhaust
"fumes". Experimental tests indicated a performance equivalent
to
[0049] The overall thermal potential of the system is thus
equivalent to
5 kW*1.07+1.499 kW*0.75=6.474 kW.
[0050] The theoretical potential instead amounts to:
(1.67+0.833)Nm.sup.3/h*3 kWh/Nm.sup.3=7.509 kW.
[0051] The overall performance of the system according to the
invention shall thus be:
(6.474 kW+1 kW)/7.509 kW*100=99.53%.
[0052] The integration of a fuel cell 5 to the burner 4 allowed
obtaining an increase of the thermal potential of the system by
about 16%, without reducing the yield of the burner 4 per se
extremely high (exceeding 100% with reference to the lowest
calorific power). In the fuel cell 5 instead, following heat
recovery, the yield increases considerably and reaches the value of
about 85%, i.e. more than twice the nominal value.
[0053] Without the heat recovery of the fuel cell 5 the grouping of
the burner 4 and of the fuel cell 5 as indicated would have lead to
the following total performance:
(0.4*1.07)*100=42.8%.
[0054] Embodiments according to FIGS. 2 to 4.
[0055] The system or unit 1, respectively 2, for producing combined
energy from hydrogen according to the invention illustrated in FIG.
1 can advantageously be modified for use in particular
applications.
[0056] For example, FIG. 2, for a back-up function, the system
according to the invention may provided--therein--for a small tank
18 for storing hydrogen to guarantee operation in any case for a
preset number of hours.
[0057] For such purpose, the most efficient technical solution
would be that of providing--in the system 1--the tank 18 for
storing hydrogen in form of metal hydrides, inserted as observable
in FIG. 2. This solution allows having a good hydrogen reserve
within a relatively small space, this type of storage however
requiring heat so as to supply the hydrogen contained therein. For
this purpose, according to the invention, the heat of the cooling
air 15 recovered by the the fuel cell 5 is used. Such device is
preferred to the burner for various reasons: the recovery heat
would however be obtained in any case with the fuel cell 5
operating and, due to the cost of the hydrides, it is preferable to
have a back-up only on the electrical part instead of also on the
heat part, even though this argument lose its effectiveness
depending on the applications provided for, i.e. considered.
[0058] As illustrated in FIG. 2, the loading of hydrogen into the
hydride occurs directly on a branch 20 connected upstream of the
reducer R, i.e. with a higher hydrogen pressure with respect to
that present downstream of the reducer R, where such higher value
can be set at about 15 bars. Hydrogen is instead released through
the outlet section 21 connected to the branch 3B for supplying the
fuel cell 5. The hydrogen release pressure shall thus be lower than
the hydrogen loading pressure following the hysteresis of the
metallic hydride 18. The two lines 20 and 21 are provided with a
check-valve 22 and 23 so as to obtain the correct direction of the
hydrogen flows under any condition.
[0059] The internal storage 18 allows transferring the system 1
according to the invention from one point or station of loading
hydrogen into the metallic hydride 18 and then transferring the
system to a place where the electrical and/or heat energy is
required, like a normal generator. In any case, the internal
storage 18 of hydrogen could also serve for an emergency operation,
for any reason, in case of a sudden failure of the source of
hydrogen, i.e. the electrolysis device, not illustrated.
[0060] The further variant illustrated in FIG. 3 refers to a direct
current production, for example for supplying a system or several
apparatus that can be supplied in direct current. In this variant,
the inverter 12 is replaced by a DC/DC convertor 25 for setting the
output voltage to the desired value, where indicated in the figure
is a value of 24 Vdc on the output C. Thus, in this case there are
no performance drops due to the inverter 12 of the previous
variants, such inverter reducing the performance of the fuel cell,
in case of increase of the electrical performance.
[0061] The system 1 according to the invention illustrated in the
variant of FIG. 4 provides for the use of a water-cooled fuel cell
5. Heat recovery improvements can be obtained in this case. In this
case, heat recovery is obtained by means of a heat exchanger 27,
whose primary circuit 28 is traversed by the cooling water of the
fuel cell 5 and whose secondary circuit 29 transfers the thermal
flow rate from the water cell to the inlet E of the burner 4, as
illustrated in FIG. 4. In other words the heat provided by the fuel
cell 5 is used for preheating the delivery of a heating system, not
illustrated.
[0062] Two distinct water circuits are preferably provided for a
better management of the flows. Furthermore, this variant allows
eliminating the risk of "contaminating" the fuel cell 5 with water
coming from the heating system, which could contain various types
of impurities.
[0063] Temperature flows can be controlled by switching the pump
30--for circulating water in the circuit of the cooling water of
the fuel cell 5--on and off A more accurate control can be carried
out by modulating the speed of the pump 30, i.e. the flow rate
thereof FIG. 5 lastly shows a system 1 according to the invention,
comprising a burner 4 and a fuel cell 5, associated to such system
1 being a heat pump 31, which is supplied with electrical energy
provided by the fuel cell 5 and which in turn supplies thermal
energy for a unit 32 which receives--likewise--thermal energy from
the burner 4.
[0064] Thus, this embodiment allows obtaining the functional
behaviour described previously with the relative further improved
performance.
[0065] The structural and functional description of the various
systems for producing combined energy from hydrogen according to
the invention, show that the same allow efficiently attaining both
the main object of the present invention and the previously
mentioned advantages.
[0066] Providing systems for producing combined energy from
hydrogen jointly applying the single characteristics of the
illustrated embodiments at will falls within the scope of
protection of the invention.
[0067] The invention may be subjected--by those skilled in the
art--to various modifications and variants, such as for example
providing for hydrogen supply from cylinders with reducer, for
example for emergency systems and units, or providing for internal
hydrogen tanks of the pressurized type, proposing uses alternative
to the use in residential buildings, such as for example for
heating greenhouses, industrial sheds and so on and so forth,
without departing from the scope of protection of the present
invention, as claimed in the claims that follow.
* * * * *