The 890C, 890CL, 890e, 850C, and 850e model instruments support the use of a Gilson Minipuls 3 peristaltic pump for supplying anode liquid fuel to a DMFC or similar type of fuel cell. Before using this pump, the system needs to be configured and the user needs to understand issues involved with the use of this pump.
These instructions assume that the user has successfully installed the instrument and FuelCell software and configured the unit for normal operation with a PEM fuel cell using anode and cathode gases.
Pump Flow Rates:
The Minipuls 3 pump operates at a maximum pump head speed of 48 RPM. The resulting maximum flow rate is determined by the type of tubing used and the pump head that the pump is equipped with. Consult the Minipuls3 manual for information for flow rates with various pump head, pump speed, and tubing type combinations.
Determination of Flow Rate:
After selecting a pump head and tubing, determine the flow rate when the pump is running at maximum speed (48 RPM). This can be done by filling a graduated cylinder from a water container and timing with a stopwatch or by connecting a commercial precision flow meter to the pump. Note that any back pressure on the pump outlet presented by the fuel cell may affect the flow rate, so the flow should be measured under conditions as close to the actual cell setup as possible.
Configuring FuelCell software:
Make a copy of the file “fuelcell.ini” in the FuelCell working folder (usually “C:\fuelcell”). Name this copy “PEM fuelcell.ini”. This file will contain the previous instrument configuration when used with anode and cathode gases and can be used to restore the test system to this configuration later. Start the FuelCell software. Enter the “File>Instrument Configuration” menu and specify the instrument’s serial number when prompted. In the “Fuel Configuration” tab, select “Liquid Pump” for Anode Fuel Flow Control Type. For “Full Flow of Controller”, enter the flow rate (in liters per minute) from the previous step. See Figure P1. Set the Offset Control Signal and Minimum Control Signal values to zero. Set “Controller Channel” to “Reform #1”. Click OK and select the option to save the settings. Close and restart the FuelCell software.
Setting Up the Pump:
Turn on the pump’s power switch. Ensure that both ends of the tubing are in a container of water and press the forward button on the pump. Ensure that the display reads “48.0”, indicating that the pump is operating at full speed and that the pump head is turning. Press the Stop button and ensure that the pump stops turning.
Connecting Hardware:
For 850C and 850e models, connect the included cable from the 850C/850e Auxiliary Signals connector to the green connector on the rear panel of the pump. For 850C/850e models with an Interface Box option or 890C/890CL/890e models, connect the included cable from the “MFC R1” connector on the interface box to the green connector on the rear panel of the pump. Note that these are two different cable assemblies based on the instruments used and the correct cable must be specified when the equipment is ordered.
Figure 1 – Fuel Configuration Menu (22mL/min flow shown)
Using FuelCell with the Pump:
In the FuelCell software, click the Setup Fuel menu. Set the Anode Minimum Flow parameter to the flow rate measured with the pump operating at 48 RPM. Set the Anode Load Based Flow parameters to zero. See Figure P2. If the Enhanced Setup Fuel menu appears, click Fixed Flow for the Anode side and set it to the measured flow at 48 RPM. Note that depending on the software configuration, this will be either units of “cc/min” or “L/min”. Click OK. Click Apply Fuel and verify that the pump runs at full speed (48 RPM). Enter the Setup Fuel menu and set the Anode Minimum Flow parameter to ½ of the flow rate measured with the pump operating at 48 RPM. Click OK. Verify that the pump runs at a reduced speed and that the display on the pump reads between 23.0 and 25.0. Click Stop Fuel and verify that the pump stops. Change the Setup Fuel menu parameters as needed for the experiment performed. When finished with the test station after closing the software, turn off the power switch on the rear of the pump.
Figure 2 – Setup Fuel Menu (Standard menu shown)