Abstract: A method and system are provided for measuring impedance and voltage characteristics of individual cells of multi-cell electrochemical devices, for example a battery or a fuel cell stack. The electrochemical system comprises a plurality of cells; a measuring device including a plurality of inputs connected across the plurality of cells to generate voltage and current signals indicative of voltage and current characteristics of the plurality of cells; a current supply/draw means for superimposing modulated current values through the plurality of cells; and a controller for controlling at least one system operating condition based on the voltage and current characteristics received from the measuring device, the controller being connected to the measuring device.

Abstract: Fuel cell modules usually have an inherently limited load slew rate, which is adequate for some applications but insufficient where close load following is desired. An example of where the inherent lack of dynamic response, of a typical fuel cell module, has proven to be insufficient is within a standalone AC power generation system in which the fuel cell module does not, or cannot, possibly, receive a priori knowledge of current demand changes by load. In contrast, the present invention aims to provide a current controller for use in a fuel cell system, a fuel cell system with adaptive current control and a method of operating a fuel cell system that employs an adaptive current controller that enables a relatively fast dynamic response to abrupt increases in current demand whilst also providing a controlled adjustment to the output current provided by a fuel cell module included in the system.

Abstract: A method for humidifying and controlling the temperature of a process gas stream comprising the steps of super-saturating and heating the process gas stream with steam until it reaches a first pre-set temperature; cooling the process gas stream until it reaches a second pre-set temperature; removing excess condensed water from the process gas stream; and heating the process gas stream until it reaches a third pre-set temperature. An apparatus for implementing this method is also disclosed.

Abstract: A system and method in a data processor for controlling a controllable condition of a fuel cell via a control device is provided. The system and method involve (a) providing a script language comprising a control command type having an operating level field for receiving a selected operating level of the control device; (b) deriving a control command from the control command type by inserting the selected operating level of the control device into the operating level field of the control command; (c) writing a test script using the script language such that the test script includes the control command; (d) compiling the test script to provide a test program; and, (e) controlling the control device according to the test program.

Abstract: A system and method for monitoring cell voltages for a plurality of electrochemical cells connected in series forming a cell stack. The method includes dividing the cells into at least two cell groups, measuring the voltage across each cell group and estimating the minimum cell voltage for each group based on the average cell stack voltage and an estimated number of deficient cells in each group. The lowest minimum cell voltage for the entire cell stack is then determined.

Abstract: A regenerative energy and/or mass exchange assembly has: an exchange media; a first flow path to pass a fluid stream through the exchange media; at least a second flow path to pass a further fluid stream through the exchange media; and at least one fluid stream diverter to divert the different flow paths to pass the respective fluid streams through different regions of the exchange media. A method for operating the regenerative assembly is also provided.

Abstract: An apparatus for humidifying and controlling the temperature of a process gas stream; has a first humidification unit for super-saturating and heating the process gas stream at a first pre-set temperature; and a first heat exchanger for cooling the process gas stream until it reaches a second pre-set temperature, and for removing excess condensed water from the process gas stream. The apparatus can include a heater for heating the process gas stream until it reaches a third pre-set temperature.

Abstract: A method for humidifying and controlling the temperature of a process gas stream comprising the steps of super-saturating and heating the process gas stream with steam until it reaches a first pre-set temperature; cooling the process gas stream until it reaches a second pre-set temperature; removing excess condensed water from the process gas stream; and heating the process gas stream until it reaches a third pre-set temperature. An apparatus for implementing this method is also disclosed.

Abstract: Some embodiments of the present invention provide a system and method that incorporates a call to an alarm recovery sequence into a safety system for use within a fuel cell testing system. In other embodiments of the present invention there is provided a safety system and method, for use within a fuel cell testing system, which is able to suspend a fuel cell testing trail and initiate an alarm recovery sequence upon detecting that a corresponding alarm threshold has been violated. The safety system and method is then able to restart the trail if it is determined that the alarm recovery sequence was successful, in that the process and operating parameters that violated the particular alarm threshold have been brought back to within a safe operating range.

Abstract: Moisture recovery and humidification in a fuel cell system involving (i) intermittently switching each dryer in a plurality of dryers into and out of one of a first mode of operation for recovering moisture from an outgoing oxidant stream and a second mode of operation for humidifying an incoming oxidant stream such that during use at least one dryer is in the first mode of operation and at least one dryer is in the second mode of operation; (ii) directing the outgoing oxidant stream from the cathode through at least one dryer in the first mode of operation to recover moisture from the outgoing oxidant stream; and (iii) directing the incoming oxidant stream through at least one dryer in the second mode of operation to humidify the incoming oxidant stream with moisture.

Abstract: Some embodiments of the present invention provide a system and method that incorporates a call to an alarm recovery sequence into a safety system for use within a fuel cell testing system. In other embodiments of the present invention there is provided a safety system and method, for use within a fuel cell testing system, which is able to suspend a (fuel cell testing) trial and initiate an alarm recovery sequence upon detecting that a corresponding alarm threshold has been violated. The safety system and method is then able to restart the trial if it is determined that the alarm recovery sequence was successful, in that the process and operating parameters that violated the particular alarm threshold have been brought back to within a safe operating range. Various embodiments of the present invention may be advantageously integrated into various embodiments of the testing system disclosed in U.S. application Ser. No. 10/244,609.

Abstract: A method and apparatus are provided for measuring impedance and voltage characteristics of cells of multi-cell electrochemical devices, for example a battery or a fuel cell stack. Voltages are measured across individual cells, or groups of cells. At the same time, a load is connected in series with the electrochemical device. Both the device for measuring the voltages and the load are controlled together, preferably by means of a controller, which can include some form of microprocessor. This enables the load to be controlled to provide a desired combination of DC and AC current characteristics. By setting appropriate DC and AC current characteristics, desired characteristics of the impedance of individual cells can be measured.

Abstract: A method and system are provided for measuring impedance and voltage characteristics of individual ceils of multi-cell electrochemical devices, for example a battery or a fuel cell stack. The electrochemical system comprises a plurality of cells; a measuring device including a plurality of inputs connected across the plurality of cells to generate voltage and current signals indicative of voltage and current characteristics of the plurality of cells; a current supply/draw means for superimposing modulated current values through the plurality of cells; and a controller for controlling at least one system operating condition based on the voltage and current characteristics received from the measuring device, the controller being connected to the measuring device.

Abstract: A method for humidifying and controlling the temperature of a process gas stream comprising the steps of super-saturating and heating the process gas stream with steam until it reaches a first pre-set temperature; cooling the process gas stream until it reaches a second pre-set temperature; removing excess condensed water from the process gas stream; and heating the process gas stream until it reaches a third pre-set temperature. An apparatus for implementing this method is also disclosed.

Abstract: A system and method for monitoring cell voltages for a plurality of electrochemical cells connected in series forming a cell stack. The method includes dividing the cells into at least two cell groups, measuring the voltage across each cell group and estimating the minimum cell voltage for each group based on the average cell stack voltage and an estimated number of deficient cells in each group. The lowest minimum cell voltage for the entire cell stack is then determined.

Abstract: ABSTRACT An apparatus for humidifying and controlling the temperature of a process gas stream; has a first humidification unit for super-saturating and heating the process gas stream at a first pre-set temperature; and a first heat exchanger for cooling the process gas stream until it reaches a second pre-set temperature, and for removing excess condensed water from the process gas stream. The apparatus can include a heater for heating the process gas stream until it reaches a third pre-set temperature.

Abstract: A condenser, for cooling a gas flow containing a vapor to promote condensation of the vapor, has a generally cylindrical chamber. Gas is admitted at one end of the chamber and is given a swirl component of velocity. The gas then travels axially along the length of the chamber, and passes radially through poles into the bore of a separator. The swirl velocity of the gas flow tends to through water droplets radially outwards, where they can drain down the inside of a casing defining the chamber. The separator can include a skirt portion separating the main chamber from a water collection compartment. Cooling to cause condensation is provided by an external jacket, preferably having a coolant flowing through it in a helical fashion.

Abstract: A regenerative energy and/or mass exchange assembly is provided. The regenerative assembly comprises: an exchange media; a first flow path to pass a fluid stream through the exchange media; at least a second flow path to pass a further fluid stream through the exchange media; and at least one fluid stream diverter to divert the different flow paths to pass the respective fluid streams through different regions of the exchange media. A method for operating the regererative assembly is also provided.

Abstract: The invention regards a fuel cell system and method for recovering moisture from an outgoing oxidant stream and humidifying an incoming oxidant stream in a fuel cell. A plurality of dryers is used to recover moisture from an outgoing oxidant stream from the fuel cell and to humidify an incoming oxidant stream for the fuel cell. The fuel cell comprises an anode for receiving fuel and a cathode for receiving the incoming oxidant stream and discharging the outgoing oxidant stream, and an electrolyte between the anode and the cathode.

Abstract: This invention discloses a self-contained, portable, cost-effective apparatus for measuring the real and imaginary components of a fuel cell's complex impedance at discrete frequencies. The apparatus comprises a CPU, a signal generation device, a fuel cell, a load bank, current and voltage sensing circuitry and a waveform acquisition device. The measurements can be done in real time and automated. The fuel cell's internal resistance can be calculated thereby providing an indication of the electrical efficiency of the fuel cell.