Anyone you share the following link with will be able to read this content:. Sorry, a shareable link is not currently available for this article. Provided by the Springer Nature SharedIt content-sharing initiative. Skip to main content.
Search SpringerLink Search. Bibliography 1 Pregl, F. Google Scholar 2 Benedetti-Pichler, A. Google Scholar 3 Lieb, H. Google Scholar 4 Emich, F. Google Scholar 5 Weygand, C. Google Scholar 6 Barger, G. Google Scholar 7 East, K. Google Scholar 8 Rieche, A. Google Scholar 9 Berl, E. Article Google Scholar 12 Friedrich, A. Article Google Scholar 13 Smith, J. Article Google Scholar 14 Houben, J.
Google Scholar 18 Sanchez, J. Article Google Scholar 21 Meyer, V. Google Scholar 22 Biltz, H. Google Scholar 23 Lunge, G. Google Scholar 24 La Coste, W. Google Scholar 25 Bleier, P. Article Google Scholar 26 Henderson, W. Google Scholar 28 Porter, C. Article Google Scholar 29 Blackman, Ph. Google Scholar 31 Ostwald, W.
Google Scholar 33 Biltz, H. Google Scholar 34 Habermann, J. Google Scholar 35 Routh, I. Google Scholar 37 Emich, F. Joseph B. Sign In. Skip Nav Destination Article Navigation. Close mobile search navigation Article navigation. Volume 3, Issue Previous Article Next Article. Article Navigation. November 01 Harmon ; Richard A. This Site. Google Scholar. Reid B. Grigg Reid B. SPE Res Eng 3 04 : — Society of Petroleum Engineers. You can access this article if you purchase or spend a download.
View full article. Sign in Don't already have an account? Personal Account. You could not be signed in. Please check your username and password and try again. Sign In Reset password. Sign in via OpenAthens. Pay-Per-View Access. Buy This Article. The absolute value of the pressure drop across the measuring system does assume a consistent average velocity of steam through the pipe.
If the steam generator reduces its output unpredictably, the differential pressure drop across the measuring system would also reduce as the velocity of the mixture through the narrow passage declined. This would look like a density decrease when, in fact, the cause is actually reduced average velocity of steam from the generator. To avoid this source of error, the present invention also contemplates a velocity measuring means downstream of the measurement area, but still in the pseudo-single phase region, to measure the true velocity of the steam and water droplet mixture.
The pressure drop can be compared to the velocity measurement to cancel out pressure changes that are the result of velocity changes due to external causes.
Other benefits and advantages will become apparent upon consideration of the following detailed description and the drawing referenced thereby. In FIG. The steam is conveyed through a pipe 12, shown partly with schematic arrows, and partly in section in the desired measurement area.
The steam is delivered to a desired destination 13, which could comprise, for example, an enhanced recovery oil well head. Any vapor phase steam 14 will generally be above liquid phase water Also, in general, the vapor, being lighter and less viscous, moves downstream faster than the water, which, in FIG.
Vapor 14 and liquid 16 are intermixed and homogenized by a suitable mixing means, which, in FIG. This creates a simulated single phase mixture of atomized fluid droplets and vapor 20 that behaves like a gaseous fluid, or pseudo-single phase vapor, for approximately ten pipe diameters downstream of the mixing means The homogeneous mixture 20 passes through a narrower passage or constriction 22 and, accordingly, is caused to speed up. This is the very well known venturi effect.
The accelerated mixture has a higher velocity and a lower pressure. This lower pressure is measured with a suitable tap 24 and a sensor The original pressure in pipe 12 is measured with a tap 28 and a pressure sensor 30 at a location before the mixing means Sensors 26 and 30 are well known and readily available devices that generate an output proportional to the measured pressure.
These two outputs are compared by a differential detector 32, whose output 34 is proportional to the pressure difference across the measuring area from tap 28 to tap This output 34 is also indicative of the relative density of the mixture For a given steady supply of steam from generator 10 at a constant pressure, the pressure drop across the measuring area, for pure steam, is always the same.
Hence, if desired, output 34 could drive a meter and the reading for pure steam calibrated. If pipe 12 starts to accumulate some condensed water 16, so that pure steam is no longer present, mixing means 18 will mix the water into mixture 20 increasing the mass and density of mixture The heavier mixture is harder to accelerate by the pressure force from generator This is a consequence of Newton's second law of motion.
Thus, the denser mixture 20 does not increase velocity as much through constriction 22 and the pressure at pressure tap 24 is lowered.
The difference in pressure detected by detector 32 is accordingly greater. Therefore, greater outputs 34 correspond to denser lower quality steam with more water content. In summary, more liquid means more mass, which means more pressure difference. The output 34 is, by itself, an indication of the relative density of the vapor and liquid combination in pipe But the pressure drop across the measuring system not only becomes greater with increased mass from increased liquid and increased density, but it also becomes greater with an increase in the average velocity of steam through pipe This is because the change in velocity across the constriction 22 is a percentage or fraction of the overall average velocity.
If the overall average velocity is cut in half, the change in velocity across passage 22 is cut in half. This means that any alteration of the output of generator 10, or destination 13, that reduces the flow of steam through the system will produce a reduced pressure drop across the measuring system that looks like a density decrease, when, in fact, it originates from a flow reduction. To avoid this source of error, the present invention also contemplates an average velocity measuring means which comprises a turbine 36 that produces an output signal 37 proportional to the average velocity of the steam.
This output 37 can be referenced to determine that there is a normal flow of steam during the time that pressure output 34 is relied upon. Or, alternatively, a comparing means 38 may be connected to automatically compensate for changes in average steam velocity and generate a true output 40 that represents absolute density.
Turbine 36 is an off the shelf velocity sensor well known to those skilled in the art. It should be located far enough downstream from passage 22 to sample the reestablished average steam velocity rather that the temporarily accelerated steam through passage However, velocity sensing turbine 36 should still be within ten diameters of mixing means 18 where mixture 20 persists.
When the higher speed vapor 14 encounters cone 42, it swirls down and around cone 42 as generally indicated by arrows The vapor turbulence picks up and mixes in liquid 16 and simultaneously speeds up in accordance with the-venturi effect. The pressure is sensed before the mixing by a tap 46 and downstream of the mixing cone by a tap 48 located in the center of the cone As before, the difference in pressure is detected by a detector A different velocity measuring means is depicted as well.
A device well known to those skilled in the art, and known as a vortex shedding flowmeter, is schematically illustrated in FIG.
A flowmeter 52 comprises a blunt sharp edged member that extends from wall to wall in pipe
0コメント