Special Features 2014
Special Features SHINKA-2
Renovating for the Advent of the Hydrogen Society
Hydrogen Leak Detection Sensors Developed to Ensure Safety when Using Hydrogen*
*Hydrogen is expected to be used for fuel cell vehicles (cars and forklifts), hydrogen-filling stations, residential fuel cells and other applications.
About Hydrogen Leak Detection Sensors
Voice of our Developer
Toward development of non-degrading sensor to maintain FCV safety
Rapid and accurate detection of a hydrogen leak is one of the critical factors for the life of the driver in a fuel cell vehicle (FCV) that runs on hydrogen. Therefore, it is necessary to develop a sensor that is non-degrading at the same time as being highly precise.
NGK SPARK PLUG CO., LTD.'s hydrogen leak detection sensor is still under development, but we take pride in the facts that it uses a method of detection that is different from those of our competitors and that the durability of the sensor is superior to those of our competitors. First of all, we are aiming to develop a sensor that will be fitted to FCVs for mass production and gain the No. 1 share of the market in this area.
Ensuring Safety During Use
Hydrogen is colorless, transparent and odorless, so a driver would not be able to notice it if it leaked into the air. A highly accurate sensor that can rapidly detect even the slightest leak is essential for safe operation of FCVs.
High Sensitivity and Rapid Start-up through New Method
The new thermal conductive sensor that NGK SPARK PLUG., LTD. has developed detects the presence of hydrogen gas with great accuracy by measuring the amount of heat taken up by hydrogen through a heater (sensor element).
Hydrogen's Potential to Solve Energy Problems
Hydrogen has promise as a next-generation energy resource that will play a role in solving energy and environmental problems because it releases hardly any hazardous gases when burnt and can be manufactured from a variety of raw materials including fossil fuels, biomass and water.
The FCV, the classic example of utilizing hydrogen energy, is a clean vehicle that runs on a motor driven by electricity produced using a chemical reaction between hydrogen and oxygen, and it is believed that the spread of FCVs would have a significant effect on preventing atmospheric pollution and global warming. The leading automobile manufacturers are already promoting FCV development, and commercial models are scheduled to go on sale in 2015.
Safety management will thus be critical. Hydrogen is an extremely flammable gas with a danger of fire and explosion if it leaks into the air. Therefore, FCVs are required to be fitted with a device that will detect a hydrogen leak as well as giving an alert to inform the driver and shutting off the fuel supply in the event that a hydrogen leak is detected.
* With some exceptions
Hydrogen Leak Detection Sensor Contributing to Safe Use of Hydrogen
The hydrogen leak detection sensors that are currently in practical use mainly employ the catalytic combustion method. This is a mechanism in which the detector element (heater) is coated with a catalyst such as platinum or palladium and senses a leak via the heat generated by the chemical reaction between the leaking hydrogen and the catalyst. However, this method has the disadvantage that accurate detection is no longer possible once the catalyst degrades or separates from the element.
In contrast, NGK SPARK PLUG CO., LTD. has developed a new and unique thermal conductive method of detection. This is a method that detects the concentration of hydrogen gas by measuring the amount of heat taken up by hydrogen. The thermal conductivity of hydrogen is extremely high, so the amount of heat escaping from the heater will increase with the presence of hydrogen, and the concentration of hydrogen can be detected through changes in the volume of heat radiation.
Not only is there very little degradation with the thermal conductivity sensor, which does not use a chemical reaction, but start-up and response are also rapid. Moreover, it also withstands vehicle vibrations and impacts. Therefore, NGK SPARK PLUG CO., LTD. has been pursuing activities proposing it to automobile manufacturers as the ideal hydrogen leak detection sensor for FCVs that will be in use over long periods.
Taking Part in Development Project for Advanced Electric Vehicles
NGK SPARK PLUG CO., LTD. has also widened its approach to the field of electric vehicles (EVs). The Company is gathering and building up technical data leading into research and development on cutting edge EVs through its participation in EV projects at SIM-Drive and FOMM.
*Position and job title are as of fiscal year 2014.