Ullage

About: Ullage is a research topic. Over the lifetime, 501 publications have been published within this topic receiving 4704 citations. The topic is also known as: headspace.

A fuel tank assembly

Abstract: A fuel tank assembly wherein a sensing tube 3 connects with an enclosure 7 within fuel tank 1. The enclosure 7 permits vapours to escape through sensing tube 3 until the base of enclosure 7 is sealed by fuel added through filler pipe 2. The enclosure 7 is so designed that point 13 is the last part to be sealed by fuel. Point 13 defines the ullage space and is located at the point where the fuel level does not depend on the attitude of the fuel tank.

Zero Gravity Cryogenic Vent System Concepts for Upper Stages

Abstract: The capability to vent in zero gravity without resettling is a technology need that involves practically all uses of sub-critical cryogenics in space Venting without resettling would extend cryogenic orbital transfer vehicle capabilities However, the lack of definition regarding liquid/ullage orientation coupled with the somewhat random nature of the thermal stratification and resulting pressure rise rates, lead to significant technical challenges Typically a zero gravity vent concept, termed a thermodynamic vent system (TVS), consists of a tank mixer to destratify the propellant, combined with a Joule-Thomson (J-T) valve to extract thermal energy from the propellant Marshall Space Flight Center's (MSFC's) Multipurpose Hydrogen Test Bed (MHTB) was used to test both spray bar and axial jet TVS concepts The axial jet system consists of a recirculation pump heat exchanger unit The spray bar system consists of a recirculation pump, a parallel flow concentric tube, heat exchanger, and a spray bar positioned close to the longitudinal axis of the tank The operation of both concepts is similar In the mixing mode, the recirculation pump withdraws liquid from the tank and sprays it into the tank liquid, ullage, and exposed tank surfaces When energy is required a small portion of the recirculated liquid is passed sequentially through the J-T expansion valve, the heat exchanger, and is vented overboard The vented vapor cools the circulated bulk fluid, thereby removing thermal energy and reducing tank pressure The pump operates alone, cycling on and off, to destratify the tank liquid and ullage until the liquid vapor pressure reaches the lower set point At that point the J-T valve begins to cycle on and off with the pump Thus, for short duration missions, only the mixer may operate, thus minimizing or even eliminating, boil-off losses

Gas blanketing system for low-pressure hydocarbon tanks

Abstract: A hydrocarbon tank system environment corrosion inhibitor includes use of inert gas, preferably Nitrogen, to blanket ullage and interstice through the tank system. Blanket gas is provided via controller into coupling to access ullage. Blanket gas is provided upon fueling events to stabilize the pressure in the system and prevent entry of atmospheric air and water (vapor). Blanket gas may be continuously run into the ullage and/or other spaces in tank system. A controlled system allows for monitoring of pressures in the tank, and thereby identifies pressure events and even leaks in system due to unusual events, or general loss of pressure.

Marine fuel tank ullage system

Abstract: A ullage system for a marine fuel tank that maintains an exact ullage space in all marine refueling situations including refueling in moving or pitching and rolling situations. The invention includes two ball valve assemblies that are inserted into a fuel tank at approximately the same level. The two assemblies typically are at opposite ends of the tank. One of the ball valves is smaller than the other in diameter. The smaller valve is coupled to an air vent; the larger valve is coupled to the filler tube. An important feature of the present invention is that it can typically be made to fit any marine fuel tank simply by changing the length of a vent tube to reach the correct ullage level for the tank at hand. The components of the present invention can be made from standard fuel valve materials.