Showing papers on "Ullage published in 2003"

Fueling system vapor recovery and containment performance monitor and method of operation thereof

Abstract: A method and apparatus for monitoring and determining fuel vapor recovery performance is disclosed. The dispensing of liquid fuel into a tank by a conventional gas pump nozzle naturally displaces a mixture of air and fuel ullage vapor in the tank. These displaced vapors may be recovered at the dispensing point nozzle by a vapor recovery system. A properly functioning vapor recovery system recovers approximately one unit volume of vapor for every unit volume of dispensed liquid fuel. The ratio of recovered vapor to dispensed fuel is termed the A/L ratio, which should ideally be approximately equal to one (1). The A/L ratio, and thus the proper functioning of the vapor recovery system, may be determined by measuring liquid fuel flow and return vapor flow (using a vapor flow sensor) on a nozzle-by-nozzle basis. The disclosed methods and apparatus provide for the determination of A/L ratios for individual nozzles using a reduced number of vapor flow sensors. The disclosed methods and apparatus also provide for the determination of fuel dispensing system vapor containment integrity, and the differentiation of true vapor recovery failures as opposed to false failures resulting from the refueling of vehicles provided with onboard vapor recovery systems.

Turbo compressor for use in OBIGGS application

Abstract: An on-board inert gas generating system (OBIGGS) uses a turbine in order to recover the energy of compression of the nitrogen-enriched product gas. This energy is transferred, through a shaft, to the compressor, which supplies compressed air to the separation membrane. Unlike conventional systems, where there is no means for recovering the energy of the compressed nitrogen enriched product air, the present system provides a cooled nitrogen-enriched gas to be supplied to a fuel tank ullage without losing the energy stored in the compressed nitrogen-enriched product gas.

Fuel tank safety system

Abstract: An apparatus and method for inerting the gas present in the ullage region of a storage tank for combustible liquids, e.g., a fuel tank containing a hydrocarbon liquid fuel, utilizes a molecular sieve zone (2, beds 12/14) which either (a) selectively adsorbs oxygen from the ullage gas to provide an oxygen-depleted return ullage gas, or (b) selectively adsorbs nitrogen from the ullage gas, which nitrogen is desorbed and conveyed by a purge gas to provide a nitrogen-enriched gas. The return ullage gas or the nitrogen-enriched gas is flowed to the ullage region (30, 130) in quantity sufficient to render the overall composition of gas in the ullage region (30, 130) non-combustible and non-explosive. The apparatus may include a compressor (22) or a vacuum pump to flow the ullage gas through the system, and a valving arrangement (16, 18) is used to control the flow of gases. Operation may be intermittent or continuous and may comprise pressure-swing adsorption/desorption to place one of molecular sieve beds (12, 14) on-line to adsorb oxygen or nitrogen from the ullage gas, while the other of molecular sieve beds (12, 14) is off-line being regenerated.

Aircraft fuel tank ullage safety system

Abstract: An aircraft fuel tank ullage safety system ( 10 ) that is designed to maintain the fuel tank ullage ( 94 ) of an aircraft fuel tank ( 90 ) filled with nitrogen. The nitrogen prevents the fuel tank ullage ( 94 ) from becoming filled with flammable fuel fumes which can cause an explosion. The system ( 10 ) consists of at least one flexible, resilient, air-enclosing container ( 12 ) having a container ullage ( 50 ) that is dimensioned to substantially occupy the space of the fuel tank ullage ( 94 ), a differential pressure sensor ( 30 ) that determines the internal pressure of the aircraft's fuel tank ( 90 ) and a microcontroller ( 64 ) that controls and maintains the volume of the air-enclosing container ( 12 ) as determined by the differential pressure sensor ( 30 ).

Storage tank for cryogenic liquids

Abstract: The storage tank for cryogenic liquids incorporates an ullage vessel that provides for an ullage space. The ullage vessel is in communication through an ullage line to a fill line that provides cryogen to a cryogen space. The junction where the ullage line and fill line meet is of a certain cross-sectional area. Downstream of the junction within the fill line, measured in reference to the direction of cryogen flow during a coruse of filling the cryogen space, is of a greater cross-sectional area than is the case at the junction. This creates a pressure reduction at the junction during a course of filling that causes a net flow of material from the ullage space over the course of filling. Once the cryogen tank is liquid full causing cryogen to be redirected down the ullage line, the smaller cross-sectional area of the ullage line compared to the fill line causes a reduction in flow of cryogen which is detected by the fill pump causing filling to stop providing the ullage space. A means of draining the ullage vessel prior to and during filling of the storage tank is provided.

Vapor space pressure control system for underground gasoline storage tank

Abstract: A passive pressure control method and system for controlling pressure in the ullage vapor space of a volatile liquid fuel underground storage tank (“UST”) temporarily, during periods of increasing ullage vapor space pressure, allows vapor to flow into an auxiliary vapor space of variable volume, defined at least in part by a resilient wall member, thereby to reduce the volume of vapor otherwise released to the environment.

Cryogenic vessel with an ullage space venturi assembly

Abstract: A cryogenic vessel includes a first, outer vessel assembly having an outer vessel and a liquid fill line assembly and a second, ullage space vessel having a bottom and disposed within the first, outer vessel, adjacent to the top of the first, outer vessel. The liquid fill line assembly has a venturi assembly adjacent the bottom of the ullage space vessel. The venturi assembly is structured to create a low pressure zone, relative to the ullage space vessel, during a fill procedure whereby, during a fill procedure, fluid is drawn from within the ullage space vessel into the fill line assembly.

Natural gas supply devices

Abstract: Apparatus for supplying natural gas fuel to heat the boilers 42 of an ocean-going tanker for the transport of LNG comprises a compressor 12 having an inlet communicating with the ullage space 4 of at least one LNG storage tank 2 and an outlet communicating with a conduit 22 leading from the compressor 12 to fuel burners 40 associated with the boilers 42, and a forced LNG vaporiser 24 having an inlet communicating with a liquid storage region of the said tank 2 and an outlet communicating with the same or a different conduit 22 leading to fuel burners 40 associated with the boilers 42.

Fire control system

Abstract: A system for filling the ullage of an aircraft fuel tank using inert gases produced by an aircraft engine exhaust comprises a means for regeneration of desiccation chambers and condensers. To produce an inert gas mixture of suitable temperature and moisture content the exhaust gases are passed through heat exchangers 22 and 26, water is removed by a desiccation chamber 51 or 53 and condenser 52 or 54, and the inert gas is passed to reservoir tank 32 before transfer to the ullage of the fuel tank 14. A second line 55 is connected to the engine, and pairs of condenser and desiccant chambers are used so that hot gases may be used to regenerate one set of chambers whilst inert gas conditioning continues in the other set.

Crude oil under negative pressures and hydrocarbons emission containment. Discussion. Authors'closure

Abstract: This paper presents the results of experimental and theoretical analysis of crude oil under negative (sub-atmospheric) pressures. The use of negative pressure in the ullage space of tankers has been proposed for the mitigation of cargo losses resulting from accidental hull rupture. This potential application resulted in detailed laboratory tests of various crudes over a range of temperatures and pressures. The findings were then applied to prevent and minimize VOC (volatile organic compound) emissions occurring during transport of crude oil.

Sloshing prediction in the propellant tank of reusable rocket vehicle

Abstract: For the prediction of sloshing in the propellant tank of rocket vehicle utilized in RVT (reusable rocket vehicle testing) conducted by ISAS, the flow field in the propellant tank during the coasting flight was experimentally reproduced with the sub-scale model of it. The lateral acceleration as large as about 1.0 G was provided with a mechanical exciter and the deformation of liquid surface in the vessel was visualized with a high-speed camera. The several configurations of damping devices were installed in the vessel, which should keep the ullage gas away from the outlet port, and tested to verify their performance. It was consequently suggested that the combination of a baffle plate and a perforated cylinder could be effective against the gas suction before the re-ignition of the engine. The sloshing was also simulated with the newly developed CFD code, called CIP-LSM. The numerical results showed good agreement with the corresponding data obtained in the experiment. For the appropriate assessment of liquid behavior in the flight of RVT, the flow field in the full scale tank was investigated numerically under the practical condition of acceleration.

Test Data Analysis of a Spray Bar Zero-Gravity Liquid Hydrogen Vent System for Upper Stages

Abstract: To support development of a zero-gravity pressure control capability for liquid hydrogen (LH2), a series of thermodynamic venting system (TVS) tests was conducted in 1996 and 1998 using the Marshall Space Flight Center (MSFC) multipurpose hydrogen test bed (MHTB). These tests were performed with ambient heat leaks =20 and 50 W for tank fill levels of 90%, 50%, and 25%. TVS performance testing revealed that the spray bar was highly effective in providing tank pressure control within a 7-kPa band (131-138 Wa), and complete destratification of the liquid and the ullage was achieved with all test conditions. Seven of the MHTB tests were correlated with the TVS performance analytical model. The tests were selected to encompass the range of tank fill levels, ambient heat leaks, operational modes, and ullage pressurants. The TVS model predicted ullage pressure and temperature and bulk liquid saturation pressure and temperature obtained from the TVS model were compared with the test data. During extended self-pressurization periods, following tank lockup, the model predicted faster pressure rise rates than were measured. However, once the system entered the cyclic mixing/venting operational mode, the modeled and measured data were quite similar.

Over pressure relief valve for carbonated beverage container

Abstract: A valve assembly for a carbonated beverage container includes first and second chambers (7, 8) separated by a diaphragm (9), a gas valve (28, 29) for controlling communication between a gas outlet (21) and the ullage space (13) above the liquid in the container via the first chamber (7), a liquid valve (30, 36) for controlling communication between a liquid outlet (11) and the liquid in the container via the second chamber (8), and a valve actuating button (33) operable to open the gas valve (28, 29) and the liquid valve in sequence so that the gas pressure in the ullage space is relieved before any liquid is dispensed through the liquid outlet. The gas valve member (29) is urged against its seat (28) by a spring (34) and is attached to the diaphragm (9) so that the gas valve is opened in response to a certain pressure in the container and first chamber being exceeded whereby the gas valve also functions as an overpressure relief valve.

Liquid container and valve assembly therefor

Abstract: A valve assembly for a carbonated beverage container includes first and second chambers (7, 8) separated by a diaphragm (9), a gas valve (28, 29) for controlling communication between a gas outlet (21) and the ullage space (13) above the liquid in the container via the first chamber (7), a liquid valve (30, 36) for controlling communication between a liquid outlet (11) and the liquid in the container via the second chamber (8), and a valve actuating button (33) operable to open the gas valve (28, 29) and the liquid valve in sequence so that the gas pressure in the ullage space is relieved before any liquid is dispensed through the liquid outlet. The gas valve member (29) is urged against its seat (28) by a spring (34) and is attached to the diaphragm (9) so that the gas valve is opened in response to a certain pressure in the container and first chamber being exceeded whereby the gas valve also functions as an overpressure relief valve.