Measurements of forced convection condensing potassium heat transfer
Apparatus for temperature and pressure drop measurements of forced convection condensing potassium heat transfer
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Apparatus for temperature and pressure drop measurements of forced convection condensing potassium heat transfer
We present thermophysical properties of aqueous potassium acetate solutions relevant to their application as a liquid desiccant in air-conditioning systems. Liquid desiccant air conditioners could provide up to 80% energy savings compared to high-efficiency vapor compression air conditioners. However, the commonly used liquid desiccants, particularly chloride salt solutions, are highly corrosive. This precludes the use of metallic components, necessitating specialized plastics and thereby driving up cost, weight, and limiting operational temperature and pressure ranges. Potassium acetate has been identified as a less corrosive alternative, potentially enabling broader material compatibility in LDAC components. In this study we systematically measured and modelled key thermophysical properties of KAc solutions density, vapor pressure, viscosity, specific heat capacity, phase behavior, and diffusion coefficient across a range of concentrations (10 - 70wt%) and temperatures. For instance, KAc exhibits a vapor pressure of 3.1 kPa at 50wt% and 40degrees C, demonstrating dehumidification capability comparable to chloride salts. By providing an extended dataset and associated models, this work advances the understanding needed to design energy-efficient, corrosion mitigating LDAC system.
Equilibrium solubilities of niobium and tantalum in molten potassium
Pressure drop with forced convection boiling potassium
Computer codes for thermal design of multiple tube potassium condensers and boilers
Nonequilibrium, inverse temperature profile in boiling two-phase potassium flow
Potassium lubricated journal bearings for use in space system turbogenerators
Heat transfer and pressure drop measurements for high temperature boiling potassium in forced convection
Lithium-boiling potassium refractory metal loop facility
Measuring apparatus and techniques for heat transfer and pressure drop data in forced convection boiling potassium
High-performance once-through boiling of potassium in single tubes at saturation temperatures of 1500 deg to 1750 deg F - application to design of large power boiler
Initial operations of lithium-boiling potassium Rankine cycle test loop, and operating characteristics
Potassium condensing tests of horizontal multitube convective and radiative condensers operating at vapor temperatures from 1250 to 1500 degrees F
Thermodynamic, transport, and nuclear properties of saturated liquid and vapor potassium
The feasibility of fabricating and processing liquid metal heat pipes in a low mass honeycomb sandwich panel configuration for application on the NASA Langley airframe-integrated Scramjet engine was investigated. A variety of honeycomb panel facesheet and core-ribbon wick concepts was evaluated within constraints dictated by existing manufacturing technology and equipment. The chosen design consists of an all-stainless steel structure, sintered screen facesheets, and two types of core-ribbon; a diffusion bonded wire mesh and a foil-screen composite. Cleaning, fluid charging, processing, and process port sealing techniques were established. The liquid metals potassium, sodium and cesium were used as working fluids. Eleven honeycomb panels 15.24 cm X 15.24 cm X 2.94 cm were delivered to NASA Langley for extensive performance testing and evaluation; nine panels were processed as heat pipes, and two panels were left unprocessed.
As a step towards development of Stirling power conversion for potential use in Fission Surface Power (FSP) systems, a pair of commercially available 1-kW-class free-piston Stirling convertors were modified to operate with a NaK (sodium (Na) and potassium (K)) liquid metal pumped loop for thermal energy input. This was the first-ever attempt at powering a free-piston Stirling engine with a pumped liquid metal heat source and is a major FSP project milestone towards demonstrating technical feasibility. The convertors were successfully tested at the Marshall Space Flight Center (MSFC) from June 6 through July 14, 2009. The convertors were operated for a total test time of 66 hr and 16 min. The tests included (a) performance mapping the convertors over various hot- and cold-end temperatures, piston amplitudes, and NaK flow rates and (b) transient test conditions to simulate various startup (i.e., low-, medium-, and high-temperature startups) and fault scenarios (i.e., loss of heat source, loss of NaK pump, convertor stall, etc.). This report documents the results of this testing
Thermal conductivity, viscosity, pressure, volume, and temperature measurements of liquid and vapor potassium