RU178615U1 - OIL PRODUCT LEVEL AND DENSITY MEASUREMENT DEVICE - Google Patents

Abstract

The device can be used to measure the level and density of petroleum products in tanks. The device contains a generator 6, forming a probing signal, which with the help of an electro-acoustic transducer 3 is converted into acoustic waves. The acoustic signal is reflected from the reflector 4, then passes through the waveguide 2 to the boundaries of the media, the reflection from which passes back to the transducer 3, the electric signal from which enters the microprocessor processing unit 7. In addition to reflections from the media boundary, reflections from the microprocessor processing unit reference holes 5. These holes in the wall of the waveguide create an inhomogeneity of acoustic resistance, as a result of which part of the wave is reflected to the transducer 3. In addition, the holes allow different layers of liquid get into waveguide 2, an additional fluid mixing generator is used to increase the exchange efficiency 8. The use of mixing pulses as reference holes together with a stirring pulse generator allows for efficient fluid exchange between the reservoir and the waveguide cavity, thus not only a heavy fraction of liquid enters the waveguide settling at the bottom of the tank. This device provides high accuracy in measuring the level and density of liquids in tanks. 1 ill.

Description

The device relates to measuring technique and can be used to measure the level and density of petroleum products in tanks.

Known acoustic devices for measuring the level of liquids, based on fixing the propagation time of the probe and reflected acoustic pulses in the direction of the media boundary (patent RU 1757304 C G01F 23/28 publ. 08/30/1994, utility model RU 16313 U1 G01F 23/28 publ. 20.12. 2000, utility model RU 48629 U1 G01F 23/28, RU publ. 10.27.2005).

The prototype of the claimed utility model is a device for measuring the level and density of petroleum products (utility model RU 150171 U1 G01F 23/28, RU publ. September 16, 2014), containing an excitation pulse generator, an acoustic measuring channel made in the form of a L-shaped pipe, consisting of a vertical and a horizontal section with an opening in the lower part to remove deposits, and in the horizontal section of the pipe there is a transducer, the emitting surface of which is located vertically, and the reflector oriented at an angle of 45 ° to the top awns converter, wherein the acoustic part in the measuring channel added disposed at a fixed distance along the length of the riser intermediate acoustic reflectors. The electrical signal processing circuit consists of an excitation pulse generator and a microprocessor signal processing unit connected in parallel to the electro-acoustic transducer of the measuring channel.

The main disadvantage of this device is the large error in measuring the level and density arising from the lack of mixing of the liquid between the volume inside the tank and the vertical part of the acoustic measuring channel. When filling the tank, the liquid enters the measuring channel through the lower hole, thus, a heavy fraction appears in the waveguide, the level and density of which does not correspond to the level of the liquid in the rest of the tank. In particular, during storage of crude oil, exfoliated commercial water has a density of 20% higher than the rest of the oil, and since the measuring channel is filled with a heavy lower fraction, the measurement error will also be about 20%.

The task is to increase the accuracy of the device for measuring the level and density of petroleum products.

This object is achieved in that in a device containing an acoustic measuring channel, made in the form of a L-shaped pipe, consisting of a vertical and horizontal section with an opening in the lower part for removing deposits, in the horizontal section of the pipe is placed an electro-acoustic transducer, the emitting surface of which is located vertically , and a reflector oriented at an angle of 45 ° to the surface of the transducer, a circuit for processing electrical signals consisting of a pulse generator of the microprocessor processing unit of signals connected in parallel to the electro-acoustic transducer according to the utility model, characterized in that reference holes located at a fixed distance along the length of the vertical pipe are added to the acoustic part of the measuring channel, and a liquid mixing pulse generator is additionally connected to the electro-acoustic transducer.

The essence of the utility model is illustrated in the drawing (Fig. 1), which shows a structural diagram of the proposed device. The circuit contains horizontal 1 and vertical 2 waveguide tubes, an electro-acoustic transducer 3, an acoustic signal reflector 4 located at a fixed distance along the length of the vertical tube, reference holes 5, an excitation pulse generator 6. a microprocessor signal processing unit 7 and a liquid mixing pulse generator 8.

The device operates as follows. At the input of the electro-acoustic transducer, a sounding signal is generated by the generator 6 in the frequency range 50-200 kHz. The acoustic signal passes through the horizontal waveguide 1, is reflected from the reflector 4, then along the waveguide 2 passes to the boundaries of the media, the reflection from which passes back to the electro-acoustic transducer 3, the electric signal from which enters the microprocessor-based signal processing unit 7. In addition to reflections from the media boundary the microprocessor processing unit receives reflections from the reference holes 5. These holes in the waveguide wall create an inhomogeneity of acoustic resistance, as a result of which part of the waves s is reflected to the acoustic transducer 3. The signal from the intermediate reflectors and from the boundary of the media is distinguished by amplitude. In addition, the reference holes allow different layers of liquid to enter the waveguide 2. For efficient exchange between the reservoir and the cavity of the waveguide by viscous media, an additional liquid mixing generator 8 is used, which generates a signal of maximum amplitude on the existing electro-acoustic transducer 3 and lasts from a second to several minutes.

The speed of sound propagation varies along the height of the tank, since in practice there is a temperature gradient and stratification of oil products. Reference holes solve this problem, because with their known coordinates, the real speed of sound in any area between the reflectors is calculated and then the resulting sound speed is used to more accurately calculate the liquid level. In the device, reference holes with a diameter of 1-5 millimeters are arranged in increments of 0.5 m. The horizontal pipe section has a length of 0.2 m and serves to reduce the dead zone of the device, which also solves the problem of clogging of the electro-acoustic transducer by heavy fractions.

In the reflected signal, reflection of the bottom water / oil product from the media boundary is recorded, which makes it possible to determine the bottom water level. The reflection from this boundary of the media is distinguished by an amplitude that is less than the reflection of the oil / air, but exceeds the amplitudes from the reference holes.

The use of a microprocessor signal processing unit allows measurements of the density of controlled media according to the spectral characteristics of the probing and reflected signals according to the method specified in the prototype (utility model RU 150171 U1 G01F 23/28, RU publ. September 16, 2014).

The use of mixing pulses as a benchmark with a pulse generator allows an efficient exchange of fluid between the reservoir and the waveguide cavity where measurements are made. A power of 2-5 W of generator 8 at a frequency of 50 kHz is sufficient for fluid exchange, while mixing of various fractions along the height of the waveguide does not occur.

It should be noted that in practice, blocks 6 and 8 can be made in the form of a single generator on a microprocessor device.

Compared with analogues, this device provides high accuracy of measuring the level and density of liquids in tanks by increasing the efficiency of the exchange of liquid medium between the tank and the measuring waveguide.

Claims (1)

A device for measuring the level and density of petroleum products, containing an acoustic measuring channel made in the form of a L-shaped pipe, consisting of a vertical and horizontal section with an opening in the lower part for removing deposits, in the horizontal section of the pipe there is an electro-acoustic transducer, the emitting surface of which is located vertically, and reflector oriented at an angle of 45 ° to the surface of the transducer, a circuit for processing electrical signals, consisting of an excitation pulse generator a unit and a microprocessor processing unit for signals connected in parallel to an electro-acoustic transducer according to a utility model, characterized in that reference holes located at a fixed distance along the length of the vertical pipe are added to the acoustic part of the measuring channel, and a liquid mixing pulse generator is additionally connected to the electro-acoustic transducer.

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