Hydrogen electrical equipment

A very important issue related to the performance of the whole wind-hydrogen system is the quality of its electrical equipment. There is a strong dependence on the reliability of the power electronics used for the AC/DC conversion as well as for the sensitivity of the fault detection devices that often result in a lower overall efficiency rate. 

All electrical equipment and wiring installed in hydrogen gas transmission and distribution compressor stations shall conform to the requirements of NFPA 70, insofar as the equipment commercially available permits. Electrical installations located in hazardous areas, as defined in NFPA 70, and that are to remain in operation during compressor station emergency shutdown, as provided in para. I-1.3.2.1(a), shall be designed to conform to NFPA 70 for Class I, Division 1 requirements. 1-1.3 Compressor Station Equipment... 

Electronic control enclosures as well as other electrical equipment are best placed at a lower level, and away from gas generating units, process lines and storage containers. This is because hydrogen rises rapidly away from the ground and normally disperses quite quickly. Such placement is, however, not a substitute for appropriate enclosures since a slight breeze or draft can blow a hydrogen emission sideways and/or downwards, even when adequate ventilation has been provided for the gas to escape upwards and not collect. 

In 1973, Siemens, a German maker of electrical equipment, announced a crack carburetor that was to use a catalytic process to break down gasoline into methane, hydrogen, and carbon monoxide. The project was dropped two years later because Siemens couldn t find any takers. 

It is thus probable that the hydrogen concentration is no longer explosive at electrical equipment level. Hydrogen leakage in the network due to equipment failure can however stiU be envisaged. 

Equip motor-driven electrical equipment used in a laboratory where volatile flammable materials may be present (e.g., a hydrogenation room) with either nonsparking induction motors that meet Class 1, Division 2, Group C-D electrical standards (U.S. DOC, 1993) or air motors instead of series-wound motors that use carbon brushes, such as those generally used in vacuum pumps, mechanical shakers, stirring motors,... 

A Hydrogen Gas Meter Unit with Remote Totalization of Flow (1) 131 The Application of Commercial Electrical Equipment to Locations where Hydrogen Gas May Exist in Quantities Sufficient to Produce Explosive or Ignitable Mixtures... 

Nickel/metal hydride (Ni/MH) battery is a secondary battery using hydrogen storage alloy for the negative electrode, Ni(OH)2 for the positive electrode, and alkaline solution for the electrolyte. Polypropylene nonwoven fabric is usually selected for the separator. The theoretical voltage is about 1.32 V, and the operating voltage is about 1.2 V which is almost the same as that of Ni/Cd battery [1]. The Ni/MH battery has been put to practical use for portable electric equipments in 1990 and for HEV (hybrid electric vehicle) in 1997 [2, 3]. 

Hydrogen bromide should be used in a well-ventilated area. Electrical equipment should be weather-tight to resist the corrosive effects of the gas when wet. Personnel should be equipped with chemically resistant gloves, full face shields and chemical goggles, and chemically resistant aprons. Arms and legs should be fully covered, and open or fabric shoes should not be permitted [5]. 

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