SU1597588A1 - Apparatus for determining mass of petroleum product being dispensed - Google Patents

Abstract

The invention provides for the determination of the mass of petroleum products when they are stored in tanks and when all types of commodity operations are carried out, and it allows to increase the accuracy of the weight dosing. This is achieved through the use of an intermediate tank 3, the internal diameter of which is in a certain way correlated with the upper limit of the density of the monitored oil product, the maximum undercompensation value of the hydrostatic pressure compensation meter 5 used and the minimum dose of volume output of the oil product. The switching device allows to measure the hydrostatic pressure by means of a compensation meter in the tank or an intermediate tank, depending on the type of commodity operation performed. The mass of the oil product is determined by the calculated formula. 2 Il.

Description

The invention relates to measuring technology, in particular, to measuring the mass of petroleum products in the implementation of commodity (take-off) operations, and can be used to determine the mass of petroleum products stored in tanks or discharged from tanks to road and rail tanks in various fields. national households.

The purpose of the invention is to improve accuracy by reducing the effect of measurement error of a change in hydrostatic pressure,

Fig. 1 schematically shows a device for determining the mass of the released oil product; figure 2 - the same, with simultaneous dispensing of the oil product to several consumers.

The device (Fig. 1) contains measuring instruments for the temperature of the oil product in the tank 1 and ambient air 2, as well as a unit for measuring the released oil product, made in the form of a tank 3 equipped with an additional meter 4 for the temperature of the released oil product. The hydrostatic pressure meter 5 is connected via a switching unit 6 by one input to pipelines 7 and 8 for supplying gas pressure, respectively, in tank 9 and tank 3, and a second input to pipelines 10 and 11 for supplying oil product pressure, respectively, in tank 9 and tank 3. Pressure pipelines gas and oil products contain separation vessels 12. Temperature meters of oil products 1 and 4, ambient air temperature 2 and hydrostatic pressure 5 are connected to the processing and display unit 13. The container 3 is connected to the tank 9 by means of a process pipe 14, equipped with a valve 15. The release of petroleum product from the tank 3 is carried out through the drain node 16.

The device works as follows.

After the hydrostatic pressure meter 5 inputs are properly connected to the gas supply pressure lines 8 and oil product 11 in vessel 3, meter 5 measures hydrostatic pressure of oil product Pi, and temperature meters 4 and 2 measure respectively the average oil temperature tHi in the vessel 3 and ambient air tbi before the release of the oil product from the tank 3. Then the measurement results are processed by the processing and display unit 13, which is used to determine the level

pco (zo-tHi) Jg

where RSO - the average density of the controlled oil product,

/ C-temperature temperature correction of oil with a density of / Oto1 / ° C;

Q - free fall acceleration,

m / s, and the actual volume of oil in

tanks 3 before release

15

(n) 1 + (ws) f;

ZOtHI + tb1

(2)

where V (H) is the volume of the filled part of the tank

0 3 determined from the calibration table of capacity,

US, and - coefficients, respectively, of the volume expansion of the oil product and the linear expansion of steel, 1 / ° C,

5 as well as its mass

Mi SiPi / g, (3)

where Si Uf1 / H1 is the average cross-section of the filled part of the tank 3, m.

According to the obtained mass values Mi and

 the actual volume of the oil product Vfl in the tank 3, before the oil product leaves it, the actual value of the oil product density p is determined and the values Hi, / F1 and Mi are specified. Given the known density of the product being dispensed and the internal diameter of that part of the tank 3 from which the oil product is dispensed, a predetermined volume of oil product from the tank 3 can be dispensed (through the drain

0 node 16) for changing the readings of the hydrostatic pressure meter 5;

At the end of the oil supply, the hydrostatic pressure P2 of the oil product is measured in the tank 3 and

 its average temperature tH2, as well as the ambient temperature gh2. The measurement results are processed as described, and the level of H2, the actual volume of UV2 and the mass M2 of the oil product in the tank 3 after the specified volume of oil product has been discharged are determined.

The mass of the released oil product is determined by the formula 55m MI - M2. (4)

In order to influence the measurement error of the change in hydrostatic pressure during the tempering of oil from the tank 3 on the accuracy of determining the mass of the released

oil was the smallest, it is necessary that the change in hydrostatic pressure caused by the release of a given volume of oil to be close to the upper limit of the measuring range of the hydrostatic pressure meter. Then the measurement error of the change in hydrostatic pressure during the tempering of the oil product will be close to the accuracy class of the meter. Under these conditions, the most rational use is to use a compensating type hydrostatic pressure gauge, the under-compensation measurement range of which is chosen so that the smallest predetermined amount of oil supplied is dispensed (for 5 m tank trucks. 73.1 m for rail tank cars. Within this range. must be performed with an inner diameter d. satisfying the relation

(five)

where RT is the upper limit of the density of the controlled oil product, kg / m:

DPm is the upper limit of undercompensation of the hydrostatic pressure meter. Pa;

V6T - the minimum dose of supplied petroleum products, m.

The device (Fig. 2), which provides simultaneous delivery of oil to several consumers, contains a unit for measuring the volume of oil sold, made, for example, in the form of liquid meters 17 connected in parallel to the pipeline 14. Oil product is discharged from reservoir 9 through liquid meters 17 by means of drain nodes 16.

The device works as follows.

Prior to the release of the oil from the tank, the relevant temperature is measured by 9 appropriate meters.

air tb. the average temperature Tn and the hydrostatic pressure P of the oil product in the reservoir, the level H is determined using the formulas (1N3). Actual volume UV and mass M.

of the oil product in tank 9 and the density p is calculated (by the value of which the value of the level H obtained using the RRN can be specified), the value of which is brought to a temperature of 20 ° C. The flow of oil from tank 9 is carried out through drain nodes 16 and liquid counters 17, and the mass of the released oil product is determined by the formula

mi / vt vi. (6)

where / bt is the density of the released oil product, reduced to the tempering temperature toT, measured by the additional temperature gauge 4;

Vi is the volume of petroleum product sold to the ith consumer (as measured by the ith counter), m.

Claims (1)

Invention Formula A device for determining the mass of dispensed petroleum product, comprising reservoir temperature meters for the petroleum product, ambient air temperature and hydrostatic oil pressure connected to the processing and display unit, and a drain unit, characterized in that, in order to increase accuracy by reducing the effect of measurement error of the change in hydrostatic pressure, it is equipped with an oil product volume measuring unit connected through the injected pipeline to the tank, and an additional oil product temperature gauge associated with a unit for measuring the volume of oil product. a unit for measuring the volume of oil product and an additional oil temperature meter odukta connected to the processing unit and displaying information, and a drain assembly secured to measure the oil volume unit. 1