Bronkhorst thermal mass flow controllers take an essential role in fuel cell research projects: these units have been used to check the fuel consumption on the BOC Ech2o fuel cell powered vehicle.

Bronkhorst thermal mass flow controllers are taking an essential role in the many current fuel cell research projects. These power sources typically use hydrogen gas as the fuel and produce an electrical power output. Bronkhorst El-Flow and IQ+Flow systems are ideally suited to accurate measurement of the low gas flows needed, and with the integral valve can accurately control the flow of gas at the required rate - as defined by an analogue or digital signal from the fuel cell control system.

Recently displayed at the I Chem E Congress in Glasgow, the BOC Ech2o hydrogen fuel cell powered vehicle has been designed to demonstrate fuel efficiency.

Ech2o is a joint development project to make an attempt to break the world fuel efficiency record, currently held by a Swiss vehicle at the equivalent of over 10,000mpg (5385 Km/Litre).

Several UK organisations are involved: BOC designed the hydrogen storage system; OSCar Automotive designed the body and running gear; and the electric power train has been developed by Oxford University.

The Bronkhorst involvement in this project has been to provide the light-weight, battery powered hydrogen mass flow meter with digital totaliser.

This system will be used by the trials assessors to determine the actual hydrogen consumption as the totaliser can easily be re-set to zero by the adjudicator before the start of each phase of the test.

Hydrogen gas flow can be determined accurately over a wide flow range and, being a mass flow measurement, it is an absolute consumption measurement, unaffected by gas density changes resulting from pressure or temperature variations.

Bronkhorst have designed the widest range of mass flow instruments available in the market today and utilise by-pass, direct measurement and chip sensor techniques as well as the Coriolis principle.

Their strengths have been proven in over 300,000 field installations whereby flows are controlled from as low as 0.02 mln/min up to 11,000 m3/hour, air equivalent.

Bronkhorst has a full database and downloadable software programme that can provide accurate meter calibrations on other gases and gas mixtures.

The sensors, with no moving parts, are inherently safe and reliable in operation, typically supplied as intrinsically safe units for use on hazardous or potentially explosive gases.

Engineered solutions ensure that pressure drop across the instrument can be significantly less than 1 mbar.