Power Generation in a Fuel Cell: Oper. Conds Tab

Variable Definitions, Ranges and Default Values

The following table shows a brief description of the variables appearing in this tab. The table also displays their default values and their generally acceptable range:

Variable	Default Value	Range

◙ Final Temperature (^oC) The final temperature of equipment contents after the end of the operation.	35.0	Positive
◙ Cooling Duty (kcal/h) The cooling duty of the heat transfer agent.	0.0	Positive
○ Heat Transfer Agent Indicates the heat transfer agent used by the operation. Click on the list box to bring up a list of available heat transfer agents in order to select one.	<Cooling Water>	Any Heat Transfer Agent
● Inlet Temp. (^oC) The inlet temperature of the heat transfer agent.	5.0	Positive
● Outlet Temp. (^oC) The outlet temperature of the heat transfer agent.	10.0	Positive
● Rate (kg/h) The mass flow rate of the heat transfer agent.	0.0	Positive
○ Power Type Indicates the power type that is used by the operation. Click on the list box to bring up a list of available power types in order to select one.	<Std Power>	Any Power Type
● Electric Power (kW) The total power output of the operation (note that if the host procedure is operated in batch mode, then the returned value will be per cycle).	0.0	Positive
● Operating Throughput (kg/h) The mass flow rate of inlet fuel.	0.0	Positive
○ Setup Time (min) The amount of time (per cycle) spent before each operation is carried in preparation for the actual execution of the operation. It may involve actions like cleaning, vacuuming, setting up of equipment, etc. which the user opted not to model explicitly.	0.0	Positive
◙ Process Time (min) The actual duration of the operation.	60.0	Positive
○ Ignore Labor? Check this box to ignore labor for this operation. This option is used only if the process time is set by a master-slave relationship.	Yes	Yes/No

Symbol Key: ○ User-specified value (always input); ● Calculated value (always output); ◙ Sometimes input, sometimes output

Specification Choices / Comments

The following list describes the available specification choices in this tab; for more details on how these are implemented, see Power Generation in a Fuel Cell: Modeling Calculations.

•If you select the ‘Negative Ion Transfer (from Anode to Cathode)’ option...

Positive ions travel from the fuel stream (anode) to the oxidant stream (cathode) through the electrolyte. At the cathode, the positive ions react with the oxidant and the reaction products leave the fuel cell through the Oxidant Outlet stream. For example, if the fuel is hydrogen and the oxidant is oxygen, then hydrogen ions travel from the anode to the cathode, where they react with oxygen to produce water, which leaves the fuel cell through the Oxidant Outlet stream. This is similar to what happens in a PEM fuel cell.

•If you select the ‘Negative Ion Transfer (from Cathode to Anode)’ option...

Negative ions travel from the oxidant stream (cathode) to the fuel stream (anode) through the electrolyte. At the anode, the negative ions react with the fuel and the reaction products leave the fuel cell through the Fuel Outlet stream. For example, if the fuel is hydrogen and the oxidant is oxygen, then oxygen ions travel from the cathode to the anode, where they react with hydrogen to produce water, which leaves the fuel cell through the Fuel Outlet stream.