DESC:FIELD OF THE INVENTION
The present invention relates to selection of fuel from multiple fuels in power generating systems like solid oxide fuel cells etc. and more particularly relates to a system and a method for using multiple fuels in fuel cells.
BACKGROUND
Solid Oxide Fuel Cells (SOFCs) are considered as one of the most promising technologies for very high-efficiency electric energy generation. SOFC is an electro-chemical device that converts chemical energy of a fuel directly into electricity without irreversible oxidation. The maximum efficiency of SOFC system can be as high as 90% depending upon the operating condition and configuration.
Another main advantage attached to the SOFC as compared to the other types of fuel cells is that it offers flexibility in using different types of fuels. However, the SOFC system being sensitive and critical for oxygen to carbon ratio (O: C) or ? for reliability and consistency, requires fuels to be pre-processed in order to break down the heavier hydrocarbons which, otherwise adversely affect the SOFC. The pre-processing is done in different catalytic reactors operating at different temperature levels indicated by the reactor manufacturers.
For the purpose of changing the fuel in the SOFC, the oxygen to carbon ratio (O: C) or ? is to be suitably maintained in order to adapt the system to the newly fed fuel.
Conventionally, gas analyzers are used for the purpose of detecting the gaseous fuel fed into the cell and also the carbon ratio (O:C) or ? present in the cell. In order to control such critical factors, a control system is known, which accommodates multiple fuesl in SOFC. In case, the fuel is changed, the system is modified, to run SOFC system on that fuel. The change in the fuel composition (gaseous fuel) changes the oxygen demand inside the reformer which is adjusted based on the results derived from the gas analyzer used for the purpose. The analyzers used for the purpose are expensive and are also specific for gases.
However, the main disadvantage of the said system is that it is restricted to the interchangeable use of gaseous fuels in the cell and not the fuels in other states. For example, Liquefied Petroleum Gas (LPG) can be fed into a cell using methane as a fuel and the system will then alter the critical factors with respect to the gaseous fuel so fed. However, petrol or diesel cannot be fed into the same cell using methane.
Also, the said known control system is not fully automatic. Although the system makes the cell adaptable to the newly fed gaseous cell, the fuel to be fed is to be manually selected and fed after analyzing various factors like economic feasibility, market conditions, availability, etc.
Therefore, there is a need for an improved solution for automatically operating the fuel cell system using multiple fuels.
SUMMARY AND OBJECTIVES OF THE INVENTION
This summary is provided to introduce a selection of concepts in a simplified format that is further described in the detailed description of the invention. This summary is not intended to identify key or essential inventive concepts of the claimed subject matter, nor is it intended for determining the scope of the claimed subject matter.
In an embodiment of the present disclosure, a fuel cell system for operating a fuel cell using multiple fuels is disclosed. The fuel cell system includes a selection unit adapted to select one of the multiple fuels to be used within the fuel cell for generating electrical energy. Further, the fuel cell system includes a control unit in communication with the selection unit. The control unit is adapted to control a value of at least one operational parameter based on the selected fuel, wherein the at least one operational parameter comprising an oxygen-carbon ratio, at least one safety temperature, at least one set-point temperature, and a mass-flow rate. Furthermore, the fuel cell system includes a reformer unit in communication with the control unit and adapted to receive a flow of air, a flow of oxygen, a flow of steam, and a flow of the selected fuel and generate an air-fuel mixture for power generation based on the at least one operational parameter controlled by the control unit.
In an embodiment of the present disclosure, a method for operating a fuel cell system for using multiple fuels. The method includesa step of selecting by a selection unti one of the multiple fuels to be used within the fuel cell for generating electrical energy. Further, the method includes a step of controlling, by a control unit, a value of at least one operational parameter based on the selected fuel, wherein the at least one operational parameter comprising an oxygen-carbon ratio, at least one safety temperature, at least one set-point temperature, and a mass-flow rate. Further, the method cincludes a step of receiving, by a reformer unit, a flow of air, a flow of oxygen, a flow of steam, and a flow of the selected fuel. Additionally the method includes a step of generating, by the reformer unit, an air-fuel mixture for power generation based on the at least one operational parameter controlled by the control unit.
One of the objective of the present disclosure is to provide at least a system and method for controlling the fuel cell system based on choice of fuel out of different gaseous/liquid fuels within the system.
Another objective of the present invention is at least to ensure reliable and smooth operation of the fuel cell system adapted to use multiple fuels.
Yet another objective of the present invention is to provide at least a control system and method for both manual and automatic operation of the fuel cell system.
To further clarify advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like characters represent like parts throughout the drawings wherein:
Figure 1 illustrates a block diagram of a fuel cell system for operating a fuel cell, according to an embodiment of the present invention;
Figure 2 illustrates a flowchart depicting a method of operating the fuel cell system for multiple fuels in a manual mode, according to an embodiment of the present disclosure;
Figure 3 illustrates a block diagram of a portion of the fuel cell systemdepicting operation of the fuel cell system in an automatic mode, according to an embodiment of the present disclosure;
Figure 4 illustrates a flowchart depicting a method of operating the fuel cell system for multiple fuels in an automatic mode, according to an embodiment of the present disclosure; and
Figure 5 illustrates a flowchart depicting a method of operating a fuel cell using multiple fuels, according to an embodiment of the present disclosure.
Further, skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have been necessarily been drawn to scale. For example, the flow charts illustrate the method in terms of the most prominent steps involved to help to improve understanding of aspects of the present invention. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.
DETAILED DESCRIPTION
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skilled in the art to which this invention belongs. The system, methods, and examples provided herein are illustrative only and not intended to be limiting.
Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
Figure 1 illustrates a block diagram of a fuel cell system 100 for operating a fuel cell, according to an embodiment of the present invention. In an embodiment, the fuel cell system 100 may be embodied as an electric generator that uses fuels, such as Hydrogen and Hydrocarbons, to generate electricity. For instance, the fuel cell system 100 may be adapted to convert chemical energy associated with the fuels into electrical energy which is further used as electricity. In an embodiment, the fuel cell system 100 may be implemented in a vehicle including, but not limited to, electric vehicles, for driving the vehicle using the generated electrical energy. In another embodiment, the fuel cell system 100 may also be implemented in other commercial applications, including but not limited to range extenders in electric vehicles, battery hybrid vehicles, and telecom towers.
In an embodiment, the fuel cell system 100 may be employed with a selection unit 101 adapted to selectone of the multiple fuels to be used within the fuel cell for generating electrical energy. The constructional and operational details of the selection unit 101 are explained in detail in the subsequent sections of the present disclosure.
In the illustrated embodiment, the fuel cell system 100 may include a control unit 102, a reformer unit 103, an after-burner unit 104, a heat exchanger 105, and a display unit 106. Each of the control unit 102, the reformer unit 103, and the after-burner unit 104 may be in communication with each other. Further, the control unit 102 may be in communication with the selection unit 101. The control unit 102 may be adapted to control a value of of at least one operational parameter based on the selected fuel, wherein the at least one operational parameter comprising an oxygen-carbon ratio, at least one safety temperature, at least one set-point temperature, and a mass-flow rate, to inturn control the operation of the fuel cell system 100 based on the fuel selected through the selection unit 101.
In the illustrated embodiment the selection unit 101 may be externally disposed with respect to the fuel cell system. In another embodiment, the selection unit 101 may be disposed within the fuel cell system 100, without departing from the scope of the present disclosure.
Further, as illustrated the reformer unit 103 may be adapted to receive a flow of air, a flow of oxygen, a flow of steam, and a flow of the selected fuel; and generate an air-fuel mixture for power generation based on the at least one operational parameter controlled by the control unit 102. Furthermore, the after-burner unit 104 adapted to receive a flow of cathode off-gas from a cathode exhaust of a fuel cell module (not shown in figure) for oxidization. The cathode off-gas is residual of the power generation. As depicted in Figure 1, the heat exchanger 105 may be in communication with the after-burner unit 104. The heat exchanger 105 may be adapted to receive the oxidized cathode off-gas and supply a flow of preheated air to the fuel cell module.
In one of the embodiments according to the present disclosure, the selection unit 101 is a manual selection unit 101. In such an embodiment, the selection unit 101 may interchangeably be referred to as the manual selection unit 101, without departing from the scope of the present disclosure. In the manual selection unit 101, the fuel to be fed into the fuel cell from the available fuels is decided manually. In such embodiemnts a user is allowed to select a type of fuel from different types of fuels available to the fuel cell. In one of the embodiments, the available fuel may be all the fuels that the fuel cell is adaptable to accommodate. In another embodiment, the available fuel may be the fuel(s) available to the fuel cell at the time of selecting the fuel to be fed into the fuel cell.
Further, in the illustrated embodiment, the manual selection unit 101 may include, but is not limited to, a switching unit 101-1. In such embodiments, the switching unit 101-1 may be embodied as mechanical switches including, but not limited to, knobs, switches, or the like. In another embodiment, the switching unit may be embodied as a touch-sensitive panel, without departing from the scope of the present disclosure. The switching unit 101-1 may be adapted to be operated by a user for selecting one of the multiple fuels to be used within the fuel cell for generating the electrical energy. In one of the embodiments of the present disclosure, the switching unit 101-1 may be positioned on a dashboard of the vehicle employed with the fuel cell.
However, it should be appreciated by a person skilled in the art that it should not be construed as limiting, and the switching unit 101-1 may be positioned at different locations within the vehicle, without departing from the scope of the present disclosure. In one instance, the switching unit 101-1, such as the knob, may be positioned on the dashboard of the vehicle. In such an instance, the user may rotate and adjust the knob in such a position so as to actuate the supply of one of the fuels from the available fuels to be fed into the fuel cell.
Figure 2 illustrates a flowchart depicting a method 200 of operating the fuel cell system 100 for multiple fuels in a manual mode, according to an embodiment of the present disclosure;
At step 201, the fuel, such as gaseous or liquid fuel, from among the plurality of fuels may be selected by the user through the selection unit 101. For instance, the display unit 106 may display a list of fuels, such as Fuel 1, Fuel 2, Fuel 3, …, and Fuel N. Subsequently, the switching unit 101-1 may be operated by the user for selecting one of the Fuel 1, Fuel 2, Fuel 3, …, and Fuel N.
At step 202, the control unit 102 may receive information indicative of selection of the fuel from the selection unit 101. Based on the received information, the control unit 102 may control the operation of the fuel cell system 100.
The control unit 102 comprising a control feedback system (not shown in the figure) senses the fuel and controls the system based on the type of fuel in order to run the fuel cell. The control unit 102 sets certain parameters including but not limited to the set points of ? or the oxygen to carbon ratio (O:C) for the fuel so selected. The control unit 102 further uploads safety limits and set-points of temperature in Total Oxidation (ToX), Partial Oxidation (PoX), and flow rate.
There may be pre-set parameters for the different types of fuels in the fuel cell. The change in the fuel leads to a change in the hydrocarbons associated with the fuel and so the oxygen demand inside the reformer unit 103 also changes.
The control unit 102 accordingly selects the appropriate pre-set parameter, once the type of fuel is selected by the user through the selection unit 101. The control unit 102 may be configured to detect hydrocarbon changes in the fuel owing to the fuel selected. The control unit 102 may be configured to control a value (not shown in the figure) of oxygen/carbon ratio supplied to the reformer unit 103 based on the type of fuel. Further, the control unit 102 suitably sets the safety limits and set-points of temperature in ToX, PoX, and flow rate based on the type of the fuel selected. Accordingly, the control unit 102 supplies required oxygen to the fuel cell for reforming as is required by the reformer unti 103 and thus, prevents deposition of carbon and degradation in the reformer unit 103 and an SOFC stack.
At step 203, the reformer unit 103 in communication with the control unit 102, receives the fuel and oxygen. The reformer unit 103 may be in communication with a steam generator to receive the flow of steam. In an embodiment, the reformer unit 103 may be embodied as one of a partial oxidation reformer (POX), or an auto thermal reformer (ATR), or a steam methane reformer (SMR). A type of the reformer unit 103, such as POX, ATR, and SMR, may be selected based on a type of fuel(s) to be used.
In an embodiment, the reformer unit 103 may be connected to the SOFC stack on one of the sides. The SOFC stack may be in communication with the Air Pre-Heater (hereinafter referred to as APH) on a other than the side in connection with the reformer unit 103. The APH may be adapted to receive ambient air and preheat the received ambient air. Subsequently, the preheated air is supplied to the SOFC stack. The flow of preheated air received at the cathode side of the SOFC stack may act as a reactant for the electrochemical reaction and a carrier for heat to the SOFC stack.
Upon receiving the flow of preheated air at the cathode side of the SOFC stack, the SOFC stack may perform the electrochemical reaction. Thereafter, on completion of the electrochemical reaction within the SOFC stack, the cathode off-gas from the SOFC stack is supplied to the after-burner unit 104.
In one of the embodiments, the after-burner unit 104 is in communication with the with the SOFC stack. Further, the after-burner unit 104 is in communication with the APH. The after-burner unit 104 may be adapted to receive the flow of cathode off-gas from the SOFC stack. The cathode off-gas may be associated with the fuel which remains unreacted during the electrochemical reaction within the SOFC stack. The after-burner unit 104 may be adapted to oxidize the flow of cathode off-gas received from the SOFC stack. The oxidized cathode off-gas from the after-burner unit 104 is then supplied to the APH as exhaust air. The APH receiving the oxidized off-gas from the after-burner unit 104 may be adapted to use heat from the oxidized cathode off-gas to increase temperature of the ambient flow of air received drom the surroundings at the APH, and thereby generating the flow of preheated air. As explained earlier, the air preheater may also be adapted to supply the flow of preheated air to the SOFC stack where the reaction occurs.Once the selected fuel is consumed in the reaction taking place in the SOFC stack, the user can then reselect another fuel from the available fuels with the selection unit 101. Subsequently, the control unit 102 may detect the change in the hydrocarbons and based on the change in the hydrocarbons, the control unit 102 will select parameters for another fuel from among the pre-set parameters of different type of fuels.
Figure 3 illustrates a block diagram of a portion of the fuel cell system 100 depicting operation of the fuel cell system 100 in an automatic mode, according to an embodiment of the present disclosure. As illustrated the fuel cell system 100 may include a determining unit 101-2 and a selection 101. In the present embodiment, the determining unit 101-2 may be adapted to determine at least one selection parameter and the selection unit 101 may be embodied as an automatic selection unit 101 with the fuel cell system 100. Therefore, the selection unit 101 may interchangeably be referred to as the automatic selection unit 101, without departing from the scope of the present disclosure. The automatic selection unit 101 is in communication with the determining unit 101-2 and may be adapted to select one of the multiple fuels available to the fuel cell. The automatic selection unit 101 selects the fuel based on at selection parameters determined by the determining unit 101-2.
Futrher, the at least one selection parameter determined by the determining unit 101-2 may include but not limited to a rail pressure, a differential pressure related to the selected fuel, a cost of operating the fuel cell using the selected fuel, a cost of operating the fuel cell using other available fuels, a volume of each fuel available in the vehicle, and availability of each fuel in the vicinity of the vehicle for refilling;
As illustrated in Figure 3, the determining unit 101-2 may include, but is not limited to, a pressure determining unit 301, a cost conversion unit 302, and a compiling unit 303. In an embodiment, the pressure determining unit 301 may be adapted to determine a rail pressure and/or differential pressure related to the selected fuel. The pressure determining unit 301 may comprise a plurality of pressure measuring devices placed in each of the fuel tanks having a fuel filled therein. The rail pressure is the pressure inside the rail which is determined by placing a fuel pressure sensor on the end of a rail. The effective pressure is the actual applied pressure for the unit. In another embodiment, one or more pressure sensor can be placed at the bottom of the respective fuel tanks.
For example, a fuel cell with multiple fuels comprising four fuel tanks having petrol, diesel, methane, and LPG filled therein may have pressure sensors placed at the bottom of each of the fuel tanks. The pressure sensors sense the pressure inside the fuel tanks and based on the determined pressure, calculate the volume of the fuel in the fuel tanks. The determined pressure may be relative pressure with regard to the different fuel tanks and accordingly the volume calculated may be relative volume with regard to the different fuel tanks. For example, a fuel cell for multiple fuels comprising four fuel tanks having petrol, diesel, methane, and LPG filled therein and having pressure sensors placed inside each of the fuel tanks calculate the relative volume of the fuels in the respective fuel tanks. The results may be projected in an ascending or descending order of the volume of the fuels in the fuel tanks.
Again referring to Figure 3, the cost conversion unit 302 may be adapted to determine the cost of operating the fuel cell using the selected fuel and the cost of operating the fuel cell using other available fuels based on at least one of a standard unit price of each fuel, a heat content of each fuel, an efficiency of each fuel, and availability of each fuel in the vehicle. The cost conversion unit 302 may also consider parameters including increase or decrease in the price of the fuel being considered. The compiling unit 303 then compiles at least the parameters above-mentioned and provides a compiled result in terms of cost. In an embodiment, the compiling unit 303 may, first consider Fuel 1 and compare the data regarding the availability of Fuel 1 to that of the availability of other fuels in the fuel cell system 100. Subsequently, the compiling unit 303 compares the equivalent cost of Fuel 1 to the equivalent cost of other fuels in the fuel cell.
Figure 4 illustrates a flowchart depicting a method of operating the fuel cell system 100 for multiple fuels in an automatic mode, according to an embodiment of the present disclosure.
The selection of fuel from the available fuels is done automatically by the fuel cell system 100. At step 401, the pressure determining unit 301 checks the availability of the fuels. The actual or the relative pressure as determined by the pressure determining unit 301 yields a corresponding value regarding the volume of the fuels.
At step 402, the cost conversion unit 302 in the determining unit 101-2 calculates the cost of the fuels available to the fuel cell system 100.
At step 403, the compiling unit 303 compiles the volume data of fuels derived from the pressure determining unit 301 and the cost data of fuels derived from the cost conversion unit 302. The compiled data from the determining unit 101-2 acts as an input for the selection unit 101 which selects the fuel among the plurality of fuels based on the compiled data. However, another embodiment may include checking the availability of the fuel and calculating the equivalent cost of the fuel simultaneously and the compiling the data. It is to be noted that the selection unit 101 may consider other parameters as well while selecting a fuel for a fuel cell having multiple fuels.
At step 404, the control unit 102 may receive information indicative of selection of the fuel from the selection unit 101. Based on the received information, the control unit 102 may control the operation of the fuel cell system 100.
The control unit 102 comprising control feedback system further senses the fuel and controls the system based on the type of fuel in order to run the fuel cell. The control unit 102 sets certain parameters including but not limited to the set points of ? or the oxygen to carbon ratio (O: C) for the fuel so selected. The control unit 102 further uploads safety limits and set-points of temperature in ToX, PoX and flow rate.
There may be pre-set parameters for the different types of fuels in the fuel cell. The change in the fuel leads to a change in the hydrocarbons associated with the fuel and so the oxygen demand inside the reformer also changes.
The control unit 102 accordingly selects the appropriate pre-set parameter, once the type of fuel is selected by the selection unit 101 based on at least the cost and availability of the fuel. The control unit 102 may be configured to detect hydrocarbon changes in the fuel owing to the fuel selected. The control unit 102 may be configured to control a value (not shown in the figure) of oxygen/carbon ratio supplied to the reformer unit 103 based on the type of fuel. Further, the control unit 102 suitably sets the safety limits and set-points of temperature in ToX, PoX and flow rate based on the type of the fuel selected. Accordingly, the control unit 102 supplies required oxygen to the fuel cell for reforming as is required by the reformer and thus, prevents deposition of carbon and degradation in reformer and stack.
Once the selected fuel is consumed, the pressure determining unit 301 determines the volume data of the available fuels. Subsequently, the cost conversion unit 302 calculates the equivalent cost of the available fuels and the selection unit 101 reselects another fuel after input of information from the determining unit 101-2. The reselection of the fuel is based on the compiled data generated by the compiling unit 303. The control unit 102 may detect any change in the hydrocarbons and based on the change in the hydrocarbons, the control unit 102 will set parameters from the pre-set parameters. The user can also consider refilling the fuel tank with the same fuel if the user desires to run the fuel cell on the same fuel.
As mentioned earlier, referring to Figure 1 and 3 the fuel cell system 100 may includes the display unit 106 in communication with the selection unit 101. The display unit 106 may render information associated with the fuels available for use within the fuel cell system 100.
The display unit 106 may be embodied as a Liquid Crystal Display (LCD) panel, without departing from the scope of the present disclosure. In one of the embodiments of the present disclosure, the display unit 106 may display details including at least one of the selected fuel, other available fuels in the vehicle, a volume of each fuel available in the vehicle, availability of each fuel in the vicinity of the vehicle for refilling, a rail pressure, a differential pressure related to the selected fuel, a cost of operating the fuel cell using the selected fuel, and a cost of operating the fuel cell using other available fuels. For example, the display unit 106 displays that the multiple fuels available for use within the fuel cell system 100 may include, but not limited to LPG, Petrol, Diesel, and Methane.
In one of the embodiments, the display unit 106 displays the selected fuel that is being consumed by the fuel cell system 100 at a particular instance. In another embodiment, apart from displaying the selected fuel being consumed by the fuel cell system 100 at a particular instance, the display unit 106 also displays the other fuels out of the multiple fuels available to the fuel cell system 100 at the same instance. In yet another embodiment, the display unit 106 displays parameters including, but not limited to, availability of each of the multiple fuels, volume of each of the multiple fuels, and equivalent cost of each of the multiple fuels.
Referring back to Figure 1, the control unit 102 further provides output to the reformer unit 103 and the after-burner unit 104 coupled to the control unit. The reformer unit 103 and the after-burner unit 104 may be a part of the fuel cell system 100 in one of the embodiments of the present invention.
Further referring to Figure 1, the control unit 102 modifies the control recipes so as to run the fuel cell on the fuel being selected manually by the user or being selected automatically. The control recipes may include, but not limited to, oxygen to carbon ratio or ? ratio, safety temperatures, set-point temperatures, mass flow rates, etc. The control unit 102 is adapted to change such control recipes in response to the change in the fuel being fed manually by the user or automatically.
In an embodiment, the reformer unit 103 may be embodied as one of a partial oxidation reformer (POX), or an auto thermal reformer (ATR), or a steam methane reformer (SMR). A type of the reformer unit, such as POX, ATR, and SMR, may be selected based on a type of fuel so selected either manually or automatically. The reformer unit 103 may be adapted to receive a flow of air, a flow of oxygen, a flow of steam, and a flow of the selected fuel.
The reformer unit 103 may be in communication with the after-burner unit 104. The after-burner unit 104 may be adapted to receive a flow of cathode off-gas from a fuel cell module.The fuel cell module may include a plurality of fuel cells arranged within the fuel cell module. In an embodiment, the plurality of fuel cells may interchangeably be referred to as the fuel cells, without departing from the scope of the present disclosure. Each of the fuel cells may include a cathode end and an anode end distal to the cathode end. In an embodiment, each of the fuel cells may be embodied as a Solid Oxide Fuel Cell (SOFC), without departing from the scope of the present disclosure. Therefore, the fuel cell module may interchangeably be referred to as the SOFC stack. The after-burner unit 104 may be adapted to oxidize the flow of cathode off-gas received from the SOFC stack. During oxidation of the flow of cathode off-gas within the after-burner unit 104, heat may be generated which is supplied from the after-burner unit 104 to a heat exchanger 105.
Figure 5 illustrates a flowchart depicting a method 500 of operating a fuel cell using multiple fuels, according to an embodiment of the present disclosure. For the sake of brevity, features of the present disclosure that are explained in details in the description of Figure 1, Figure 2, Figure 3, and Figure 4 are not explained in detail in the description of Figure 5.
At a block 501, the method 500 includes selecting, by a selection unit 101, one of the multiple fuels to be used within the fuel cell for generating electrical energy;
At a block 502, the method 500 includes controlling, by a control unit 102 , a value of at least one operational parameter based on the selected fuel. The at least one operational parameter may include, but is not limited to, an oxygen-carbon ratio, at least one safety temperature, at least one set-point temperature, and a mass-flow rate;
At a block 503, the method 500 includes receiving, by a reformer unit 103 a flow of air, a flow of oxygen, a flow of steam, and a flow of the selected fuel; and
At a block 504, the method 500 includes generating, by the reformer unit 103, an air-fuel mixture for power generation based on the at least one operational parameter controlled by the control unit 102.
In an embodiment, the method 500 may include determining, by a determining unit 101-2, at least one selection parameter including one of a rail pressure, a differential pressure related to the selected fuel, a cost of operating the fuel cell using the selected fuel, a cost of operating the fuel cell using other available fuels, a volume of each fuel available in the vehicle, and availability of each fuel in the vicinity of the vehicle for refilling. Based on the at least one selection parameter, the method 500 may include selecting, by the selection unit 101, one of the multiple fuels to be used within the fuel cell.

In an embodiment, the method 500 may include receiving, by an after-burner unit 104, a flow of cathode off-gas from a cathode exhaust of a fuel cell module for oxidization, In such embodiment the cathode off-gas is residual of the power generation.
While specific language has been used to describe the present subject matter, any limitations arising on account thereto, are not intended. As would be apparent to a person in the art, various working modifications may be made to the system and method in order to implement the inventive concept as taught herein. The drawings and the foregoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment.
,CLAIMS:1. A fuel cell system for operating a fuel cell using multiple fuels, the fuel cell system comprising:
a selection unit adapted to select one of the multiple fuels to be used within the fuel cell for generating electrical energy;
a control unit in communication with the selection unit and adapted to control a value of at least one operational parameter based on the selected fuel, wherein the at least one operational parameter comprising an oxygen-carbon ratio, at least one safety temperature, at least one set-point temperature, and a mass-flow rate; and
a reformer unit in communication with the control unit and adapted to:
receive a flow of air, a flow of oxygen, a flow of steam, and a flow of the selected fuel; and
generate an air-fuel mixture for power generation based on the at least one operational parameter controlled by the control unit.

2. The fuel cell system as claimed in claim 1, comprising a switching unit adapted to be operated by a user for selecting one of the multiple fuels to be used within the fuel cell for generating the electrical energy.

3. The fuel cell system as claimed in claim 1, comprising:
a determining unit adapted to determine at least one selection parameter including one of a rail pressure, a differential pressure related to the selected fuel, a cost of operating the fuel cell using the selected fuel, a cost of operating the fuel cell using other available fuels, a volume of each fuel available in the vehicle, and availability of each fuel in the vicinity of the vehicle for refilling; and
the selection unit in communication with the determining unit and adapted to select one of the multiple fuels to be used within the fuel cell based on the at least one selection parameter.

4. The fuel cell system as claimed in claim 3, wherein the determining unit comprising:
a pressure determining unit adapted to determine the rail pressure and the differential pressure related to the selected fuel;
a cost conversion unit adapted to determine the cost of operating the fuel cell using the selected fuel and the cost of operating the fuel cell using other available fuels based on at least one of a standard unit price of each fuel, a heat content of each fuel, an efficiency of each fuel, and availability of each fuel in the vicinity of the vehicle, and
a compiling unit adapted to provide a compiled result in form of equivalent operating cost of the selected fuel and other available fuels.

5. The fuel cell system as claimed in claim 3, comprising a display unit adapted to display details including at least one of the selected fuel, other available fuels in the vehicle, a volume of each fuel available in the vehicle, availability of each fuel in the vicinity of the vehicle for refilling, a rail pressure, a differential pressure related to the selected fuel, a cost of operating the fuel cell using the selected fuel, and a cost of operating the fuel cell using other available fuels.

6. The fuel cell system as claimed in claim 1, comprising an after-burner unit adapted to receive a flow of cathode off-gas from a cathode exhaust of a fuel cell module for oxidization, wherein the cathode off-gas is residual of the power generation.

7. The fuel cell system as claimed in claim 6, comprising a heat exchanger in communication with the after-burner unit and adapted to receive the oxidized cathode off-gas and supply a flow of preheated air to the fuel cell module.

8. A method for operating a fuel cell system using multiple fuels, the method comprising:
selecting, by a selection unit, one of the multiple fuels to be used within the fuel cell for generating electrical energy;
controlling, by a control unit, a value of at least one operational parameter based on the selected fuel, wherein the at least one operational parameter comprising an oxygen-carbon ratio, at least one safety temperature, at least one set-point temperature, and a mass-flow rate; and
receiving, by a reformer unit, a flow of air, a flow of oxygen, a flow of steam, and a flow of the selected fuel; and
generating, by the reformer unit, an air-fuel mixture for power generation based on the at least one operational parameter controlled by the control unit.

9. The method as claimed in claim 8, comprising:
determining, by a determining unit, at least one selection parameter including one of a rail pressure, a differential pressure related to the selected fuel, a cost of operating the fuel cell using the selected fuel, a cost of operating the fuel cell using other available fuels, a volume of each fuel available in the vehicle, and availability of each fuel in the vicinity of the vehicle for refilling; and
selecting, by the selection unit, one of the multiple fuels to be used within the fuel cell based on the at least one selection parameter.

10. The method as claimed in claim 8, comprising receiving, by an after-burner unit, a flow of cathode off-gas from a cathode exhaust of a fuel cell module for oxidization, wherein the cathode off-gas is residual of the power generation.