Showing papers on "Thermal mass flow meter published in 1976"

Solar radiation collection system

Abstract: High efficiency solar radiation collectors may employ a dual flow path relative to heat transfer surfaces of the collector panel. A major air flow is confined beneath the panel, but a subsidiary (bypass) air flow at an angle to the principal air flow is also employed to suppress natural (free) flow convection at an upper side of the panel. Advantageously, the subsidiary air flow can be established by perforations in the collector panel and by creation of a suction for the bypass air. High efficiency energy collection, particularly adapted to weak and intermittent radiation environments, is further enhanced by the usage of a collector panel having a low thermal mass and providing good thermal interchange with a relatively small air mass moving beneath and above the panel, while being arranged to limit thermal conduction along the panel in the direction of air flow. Thus, a thermal gradient is established along the length of the collector panel, with a low temperature differential with the heated air mass at every position, with a fast heating response time, and with reradiation losses being minimized. By recirculating the air in a low thermal mass heat exchange system with an energy storage system in such fashion that inlet fluid is at the lowest sustainable temperature, insolation incident upon the collector is more fully utilized. The thermal energy storage most advantageously comprises what may be termed a minimum entropy system, with thermal energy in the heated air mass being interchanged in counterflow relation with a storage fluid which may be fed to different temperature level storages, dependent upon the intensity of the solar radiation available to the collector.

Density-responsive mass flow vortex type meter

Abstract: A system for measuring the mass flow of a fluid stream wherein gas is interspersed with liquid, the system providing separate mass flow readings for the gas and liquid. The system includes a mass flow vortex-type meter having a flow tube through which the stream is conducted, the meter producing an output signal whose frequency is indicative of volumetric flow and whose amplitude is indicative of mass flow. This output signal is routed either to a liquid-mass flow indicator or to a gas-mass flow indicator by a switch responsive to a density signal whose magnitude depends on the density of the fluid passing through the meter, such that when the stream is in liquid form the output signal is applied to the liquid indicator, and when in gas form to the gas indicator. The density signal is generated by a detector that in one channel converts the meter output signal to a first analog voltage representing volumetric flow and in a second channel to a second analog voltage representing mass flow, the second voltage being divided by the first to produce a third analog voltage constituting the density signal.

Engine mass air flow meter

Abstract: At Ford Motor Company, one car engineering concept that has been under development for several years is a precision engine air input measuring meter. Using both temperature and pressure sensors to normalize incoming air calculations, this vortex shedding principle meter constantly reports at a high electronic data rate to mass air inflow to the engine. Key elements of this composite device are economical, wide range, high accuracy sensors.

Experimental study of flow monitoring instruments in air-water, two-phase downflow

Abstract: The performance of a turbine meter, target flow meter (drag disk), and a gamma densitometer was studied in air-water, two-phase vertical downflow. Air and water were metered into an 0.0889-m-ID (3.5-in.) piping system; air flows ranged from 0.007 to 0.3 m/sup 3//sec (16 to 500 scfm) and water flows ranged from 0.0006 to 0.03 m/sup 3//sec (10 to 500 gpm). The study included effects of flow rate, quality, flow regime, and flow dispersion on the mean and fluctuating components of the instrument signals. Wire screen flow dispersers located at the inlet to the test section had a significant effect on the readings of the drag disk and gamma densitometer, but had little effect on the turbine. Further, when flow dispersers were used, mass flow rates determined from the three instrument readings and a two-velocity, slip flow model showed good agreement with actual mass flow rate over a three-fold range in quality; mass flows determined with the drag disk and densitometer readings assuming homogeneous flow were nearly as accurate. However, when mass flows were calculated using the turbine and densitometer or turbine and drag disk readings assuming homogeneous flow, results were scattered and relatively inaccurate compared to the actual mass flows. more » Turbine meter data were used with a two-velocity turbine model and continuity relationships for each phase to determine the void fraction and mean phase velocities in the test section. The void fraction was compared with single beam gamma densitometer results and fluid momentum calculated from a two-velocity model was compared with drag disk readings. « less