Gas/Liquid Handling

Input Gas Handling

The Input Gas Handling module controls flowrate at 1% of full-scale accuracy with a turn down ratio of 50:1 using standard analog mass flow controllers. Digital mass flow controllers with improved accuracy and turndown are also available as an option. The flow rate change can be ramped at adjustable rates during the test procedure. 

Unlimited gas inlets can be added for reformate gas simulation.  Programmable mass flow controllers are used for reactant gases.  These controllers can be automatically adjusted according to the load. The Input Gas Handling module also includes a gas mixing facility and stoicheometric flow control as standard features.

Gas Humidification and Heating

This module is composed of gas humidification, gas heating. It employs Arbin's proprietary dew point humidification technology which has been proven to provide precise dew point temperature control and very short response time.  The dew point humidifier (DPH) accurately, quickly, and automatically provides the supplied gas to the fuel cell at the desired programmed dew point and temperature. Additionally, the water level in the DPH is automatically monitored and maintained. No external boiler, condenser or chiller is necessary for the humidification process.

The DPH operates at >90% energy efficiency.  Condensed water and heat released from condensation are recycled for humidification and temperature control.  Fully automatic features facilitate long-term operation with very little user intervention.

The DPH humidifies passing gas streams to 100% humidity at a set dew point temperature. It then further heats the gas to the desired supply gas temperature. With these two temperatures, any RH% can be programmed.  Control range for dew point temperature is from ~ambient up to 95^oC (or higher upon special request), and ~ambient to 120°C for supply gas temperature (supply temperatures up to 180°C are available upon request). 

Upon temperature setpoint change, the temperature transition achieves 3~5^oC per minute with an overshoot of less than 20% of the temperature change.  A humidity sensor device is not required for the reading and control of the dew point temperature in this process. 

Finally, the DPH module has a fantastic turndown ratio of 100:1 and performs relatively well at turndown ratios approching 1000:1. For this reason, the DPH is rarely the limiting factor in test systems that need to test fuel cells in a wide range of power.

Exhaust Treatment and Pressure Regulation

The exhaust gas from the fuel cell is first cooled through a heat exchanger.  Condensed water is separated from the gas and purged automatically and smoothly without pressure interruption to the system.  Back pressure control is completely automatic and programmable.

Liquid Reactant Handling

The liquid reactant handling module accomodates liquid reactants such as methanol or bio-fuels.  The desired temperature, pressure, and flow rate of the solution is controlled and programmed in the softwarel. The user also has the ability to select "single pass" or "recirculation" mode for the liquid fuel.  This module also includes the capability to separate and release the gaseous products, such as CO2, from the liquid solution.