An explosion at a coal-fired power plant killed one person and injured 10 others. The blast killed the delivery truck driver who was unloading compressed hydrogen gas, which is used to cool the plant's steam generators. Hydrogen deliveries are routine at the plant, occurring about once a week. Evidence pointed to the premature failure of a pressure-relief device (PRD) rupture disk, which had been repaired by the vendor six months prior to the explosion.
The subject needle valve was used primarily for manual filling to control the flow rate of hydrogen from storage banks to the 70MPa test system. The valve was installed on the exterior of the thermal chamber in ambient temperatures of -5C to +30C. The gas flowing through the valve was at conditioned temperatures of -40C to +50C. The valve was in service for approximately two years and 400 fill operations.
Two fitting failures were experienced for fueling equipment filling systems. Both fittings were installed in the system thermal chamber experiencing ambient temperatures of -40C to +50C. They were connected in high-pressure lines used for 70MPa hydrogen fueling.
A single-stage diaphragm compressor failed during boosting of high-pressure hydrogen ground storage banks. The compressor sources hydrogen from a 44 MPa storage bank as suction and discharges it at a stop set point of 85 MPa. The compressor capacity is 0.71 m3/min (25 scfm).
The over-pressurization of a laboratory ball mill reactor designed for operation under slightly elevated pressures resulted in a serious injury. The apparatus had been routinely operated under argon and hydrogen pressures of 5-10 atmospheres for nearly two years. The apparatus had not been tested for operation at pressures greater than 10 atm.
A sidewall burst failure of a high-pressure polytetrafluoroethylene-lined hose was experienced. The 4.0-m hose was in service for approximately two years, primarily for 70 MPa fueling of hydrogen at ambient conditions ranging from -40 C to +50 C. The total number of fills during its service life was estimated to be 150. In addition to the high-volume fill events, pressure cycling occurred as part of the routine test procedures and operational protocols. These additional pressure-cycling occurrences were approximated to be 200-250 cycles.
A five-pound CO2 cylinder being stored in a compressed gas storage cage at a power plant failed catastrophically and became a missile. The cylinder destroyed the storage cage, then struck one of six stationary hydrogen storage cylinders used as emergency make-up for the hydrogen supply system. One of the hydrogen cylinders was broken away from its mounts and moved 10 feet from its original location. The loss of this cylinder severed the manifold tubing, creating a leak path to the atmosphere for the remaining five hydrogen cylinders.
DESCRIPTION: On a Friday afternoon in 2007 a traffic accident occurred at the corner of two urban streets. Two vehicles were involved. Each vehicle contained a single driver (no passengers). Vehicle 1 was a Fuel Cell Vehicle. Vehicle 2 was a conventional Toyota Camry. Vehicle 1 was traveling west, approaching an intersection with a green light, and proceeded into the intersection. Vehicle 2 was traveling north on a cross street. The driver of Vehicle 2 incorrectly perceived a green light and proceeded into the intersection. The vehicles collided in the intersection.
A fire began in the compression skid for a high-pressure hydrogen fueling station. The initial source of fire was likely a release of hydrogen from a failed weld on a pressure switch. The initial fire cascaded to three stainless steel line failures, release of glycol coolant, and release/combustion of compressor oil. Non-metallic seals and hoses containing hydraulic fluid and coolant melted/burned and caused leakage of the fluid, which was mostly consumed by the fire.
During a refueling event, the operator activated the fueling lever in the wrong sequence. The vehicle filled to proper pressure, but filled faster than normal. Under different circumstances, this could have resulted in overheating of the receiving fuel tank.