CN102080767A - Method and device for detecting oil mixing interface in sequential oil transportation - Google Patents

Abstract

The invention discloses a method and a device for detecting an oil mixing interface in sequential oil transportation, belonging to the technical field of oil-gas storage and transportation engineering. A detection device of the invention comprises a V-cone flow sensor, a temperature sensor, a data acquisition module and a computer. The V-cone flow sensor and the temperature sensor are used for obtaining pressure, pressure difference and a temperature signal of a sequential oil transportation section, and concrete position of the oil mixing interface is determined according to pressure difference of one kind of oil having certain density under certain pressure and at temperature, so that accurate cutting of the sequential oil transportation section can be implemented. In the method and the device of the invention, the simple V-cone flow sensor, the temperature sensor and the data acquisition module are used for properly solving the problem of mixing oil cutting in the sequential oil transportation through a program set by the computer; simultaneously, the device has the advantages of high measurement accuracy, high degree of automation, low cost, small volume and the like, and can be used for detection of oil mixing interfaces in the sequential oil transportation of industries, such as oil industry, petrochemicals industry, oil field industry and the like.

Description

A kind of oil product sequential delivery batching interface detecting method and device

One, technical field

The invention belongs to oil gas and store and the Transportation Engineering technical field, be specifically related to a kind of detecting method and device of oil product sequential delivery batching interface.

Two, background technique

The batch tracing monitoring is the distinctive work of processed oil pipeline, because what carried is final products, if ignored the tracking at mixed contamination plug interface, contaminated product being used as pure oil being defeated by the defeated station of branch, will be very big accident, therefore must trace and monitor the position, interface closely, and before the establishment working procedure, just should predict that a certain batch should arrive certain sales depot emptying somewhat in certain month some time, when assigning working procedure, each sales depot of prior notice prepares to receive when the time comes oil.By the requirement of pipeline, running precision should be accurate to the sales depot that arrives appointment what time somewhat.Specifically in service, when this batch oil will arrive certain station, notify this station to prepare earlier by the operator, given this station flowmeter of remote control unloads oil mass then, to be monitored when pure oil has entered this station, the aperture of oil drain valve and control oil drain valve is opened in remote control, and purpose is a control discharge velocity, wait to reach given unload oil mass after, flowmeter cuts out automatically.On large-scale pipeline, be provided with a plurality of unloading Stations along the line, all have all the time else to stand in emptying.The flow in each unloading Stations downstream is all changing simultaneously, and the difficulty of therefore following the tracks of the interface is also increasing.

Measure the accurate position of each batch oil product, rely on the densitometric monitoring of respectively standing, and to the oil inlet quantity of pipeline with unload the monitoring of oil mass, calculate and the comprehensive judgement of the multinomial means such as batch tracing strip-chart of total activation chamber by the precision of computer, realize tracking and monitoring to batching interface.The disturbing factor that every batch conveying oil product is in operation is a lot, when temperature or variation in pressure, its position, interface will produce very big displacement, wherein temperature is a key factor, but be difficult to record the mean temperature of oil product, therefore adopt the multiple means monitoring very necessary, multimedia employing makes the automatic monitoring system of processed oil pipeline complicated more.Density of medium is directly related with its composition in addition.Entrained moisture etc. all can make its density change in ducted mechanical admixture and the medium, and the on-line densimeter indicating value departs from the prefect dielectric corresponding density, causes difficulty for the cutting operation of contaminated product.If once monitoring error just might cause pipeline accident, so tight tracking and monitoring batching interface is crucial.

The mark detecting method has safety, characteristics easily, and tracer generally can not lag behind, and particularly it is also more stable behind the pipeline shutdown, is convenient to confirm the mixed contamination plug of oil product, and can be according to actual needs have protection ground cut and select to trailing oil product in advance.But the tracer that is to use must strictly be selected, because the partial pigment dyestuff can reduce the commodity value of oil product.Abroad do not re-use at present for this tracer of colouring substance.

In order to follow the trail of and detect the position of batching interface as early as possible exactly, must seek a kind of new batching interface detecting method, overcome the deficiency of above-mentioned detecting method.

The V prick flow transducer is a kind of new throttling arrangement.Cone as throttling element is hung in the pipeline by a circular section strut, adopts the mode of center throttling to obtain poor defeating.High pressure is taken from the cone pipeline wall of a segment distance before, and low pressure is taken from the cone afterbody, draws via the pressure inlet tube that passes cone and strut.The major advantage of V prick flow transducer has: cone can be adjusted the velocity distribution of incoming flow, thereby has good incoming flow adaptive capacity, and the length requirement of upstream straight length is shortened to 0-3D; The pressure pulsation frequency ratio orifice plate height of low pressure point, amplitude is littler than orifice plate, the signal to noise ratio height, thus can obtain higher repeatability of measurement; High s/n ratio allows to reduce the size that required difference is defeated under the condition that guarantees certain precision, thereby reduces the permanent pressure loss; It is not easy to wear owing to the protection that the boundary layer is arranged to separate angle point, has improved long-term reliability.

The V prick flow transducer is used for oil product sequential delivery batching interface detects, can directly read force value and V cone pressure at two ends is poor, calculate the total volumetric flow rate of oil product.Facts have proved that the V prick flow transducer can detect batching interface exactly.

Three, summary of the invention

The object of the invention provides a kind of more accurate oil product sequential delivery batching interface detecting method, and the detection device that adopts the method is provided.

The oil product sequential delivery batching interface detecting method that the present invention proposes may further comprise the steps:

1) utilizes the V prick flow transducer to obtain the pressure P of oil product Batch Transportation Pipeline and the pressure difference Δ P of V centrum, utilize temperature transducer to obtain the temperature T of oil product;

2) under pipeline pressure P and oil product temperature T, the density of measuring oil product A is ρ ₁, the density of oil product B is ρ ₂, oil product A is oil product in advance, and oil product B is a trailing oil product, and oil product B heads on oil product A and flows forward in pipeline, and according to the qualitative potential of oil product A and oil product B, the density of correspondence is ρ when measuring oil product A and allowing to sneak into the Cmax of oil product B ₃The density of correspondence was ρ when oil product B allowed to sneak into the Cmax of oil product A ₄

3) calculate the total volumetric flow rate q of oil product according to the data Δ P of computer acquisition _v, calculate right 2 then respectively) in four pairing pressure differences of density being mentioned ${\mathrm{\ΔP}}_i=\frac{8{\mathrm{\ρ}}_i{q_v}^2(1-{{\mathrm{\β}}_v}^4)}{{\mathrm{\π}}^2{C}^2{D}^4{{\mathrm{\β}}_v}^4},$ (i=1,2,3,4), wherein: C is a discharge coefficient; D is an internal diameter of the pipeline; β _vBe the equivalent diameter ratio;

4) if ρ during the oil product sequential delivery ₁＞ρ ₂, as Δ P ₃＜Δ P≤Δ P ₁, oil product A is transported to oil tank 1; As Δ P=Δ P ₃, batching interface appears in pipeline, and oil product begins cutting, and contaminated product is transported to slop tank 2, Δ P ₄≤ Δ P≤Δ P ₃, be mixed contamination plug; As Δ P=Δ P ₄, mixed contamination plug finishes, and batching interface occurs once more, and Δ P is finished in the oil product cutting ₂≤ Δ P＜Δ P ₄, oil product B is transported to oil tank 3.If ρ ₁＜ρ ₂, as Δ P ₁≤ Δ P＜Δ P ₃, oil product A is transported to oil tank 4; As Δ P=Δ P ₃, batching interface appears in pipeline, and oil product begins cutting, and contaminated product is transported to slop tank 5, Δ P ₃≤ Δ P≤Δ P ₄, be mixed contamination plug; As Δ P=Δ P ₄, mixed contamination plug finishes, and batching interface occurs once more, and Δ P is finished in the oil product cutting ₄＜Δ P≤Δ P ₂, oil product B is transported to oil tank 6.

The present invention provides a kind of oil product sequential delivery batching interface detection device that adopts said method simultaneously, V prick flow transducer and temperature transducer are arranged on oil transport pipeline, the V prick flow transducer is connected data acquisition module with temperature transducer, and data acquisition module is connected to computer by datawire again.

The present invention utilizes V prick flow transducer and temperature transducer to obtain pressure, pressure difference and the temperature signal of oil product sequential delivery mixed contamination plug, the pressure difference difference of a certain density oil product of foundation under certain pressure, uniform temperature determined the particular location of batching interface, realizes that oil product sequential delivery mixed contamination plug accurately cuts.Not destroying and not disturbing under the mobile situation of fluid, obtain the data such as pressure, pressure difference and temperature of oil product mixed contamination plug in the pipeline; And adopt the measurment technique of V cone as throttling element, can realize more accurate pressure difference signals collecting with wideer range ratio to clean or dirty fluid under the shorter straight length condition and seldom destroy under the situation that fluid flows; The present invention utilizes simple V prick flow transducer, temperature transducer and data acquisition module, program by computer settings, can solve the contaminated product cutting problem in the oil product sequential delivery well, this device has the measuring accuracy standard simultaneously, the automaticity height, advantages such as cost is low, and device volume is little can be used for the detection of oil product sequential delivery batching interface in the industries such as oil, petrochemical industry, oil field.

Four, description of drawings

Fig. 1 is the structured flowchart of apparatus of the present invention;

Fig. 2 is the program flow diagram of the inventive method, and program begins, and behind oil product process V prick flow transducer and the temperature transducer, computer reads parameter P/ Δ P/T, input ρ ₁/ ρ ₂/ ρ ₃/ ρ ₄, calculate q then _v/ Δ P ₁/ Δ P ₂/ Δ P ₃/ Δ P ₄If ρ ₁＞ρ ₂, as Δ P ₃＜Δ P≤Δ P ₁, oil product A is transported to oil tank 1; As Δ P=Δ P ₃, batching interface appears in pipeline, and oil product begins cutting, and contaminated product is transported to slop tank 2, Δ P ₄≤ Δ P≤Δ P ₃, be mixed contamination plug; As Δ P=Δ P ₄, mixed contamination plug finishes, and batching interface occurs once more, and Δ P is finished in the oil product cutting ₂≤ Δ P＜Δ P ₄, oil product B is transported to oil tank 3.If ρ ₁＜ρ ₂, as Δ P ₁≤ Δ P＜Δ P ₃, oil product A is transported to oil tank 4; As Δ P=Δ P ₃, batching interface appears in pipeline, and oil product begins cutting, and contaminated product is transported to slop tank 5, Δ P ₃≤ Δ P≤Δ P ₄, be mixed contamination plug; As Δ P=Δ P ₄, mixed contamination plug finishes, and batching interface occurs once more, and Δ P is finished in the oil product cutting ₄＜Δ P≤Δ P ₂, oil product B is transported to oil tank 6, EOP end of program;

Fig. 3 is the circuit theory diagrams of apparatus of the present invention, and after circuit breaker Q S1 and the QS2 closure, by control panel switch S N1 and HL0, the display lamp on the panel is normally luminous, and computer begins proper functioning.After oil product was through V prick flow transducer and temperature transducer, signal began to read.In the V prick flow transducer, (0～20mA) through behind the precision resistance R1 for the current signal of pressure transmitter, convert voltage signal (1～5V) to, corresponding pressure is (0～1.6MPa), (0～20mA) through behind the precision resistance R2 for the current signal of differential pressure transmitter, (1～5V), corresponding pressure difference is that (0～50KPa), the voltage signal of pressure transmitter and the voltage signal of differential pressure transmitter are transferred to pressure and pressure reduction acquisition module ADAM4017 to convert voltage signal to.The millivolt value signal that temperature transducer reads temperature is transferred to temperature collect module ADAM4018.Three groups of signals are transferred to communication modular converter ADAM4520 through RS485.After ADAM4520 and computer carry out the RS232 communication, three groups of signal datas are sent into computer, signals collecting finishes.

Five, embodiment

Apparatus of the present invention have oil transport pipeline, and V prick flow transducer and temperature transducer are arranged on oil transport pipeline, and the signal output of V prick flow transducer and temperature transducer inserts data acquisition module, and data acquisition module is connected to computer by datawire again.

After oil product enters oil transport pipeline, flow through V prick flow transducer and temperature transducer, pressure, pressure difference signal and temperature signal are sent to data acquisition module, data capture, pass to computer after handling, by the program of computer settings, obtain mixed contamination plug parameter separately respectively.

Vin0+, the Vin0-of the pressure signal of V prick flow transducer and pressure difference signal difference cut-in pressure and pressure reduction acquisition module and Vin3+, Vin3-end; Output signal cut-in temperature acquisition module Vin0+, the Vin0-end of temperature transducer; Pressure is connected with the communication modular converter by datawire with temperature collect module with the pressure reduction acquisition module, and the communication modular converter is connected with computer through datawire again; Ac power supply is given the power supply of computer and DC power supplier respectively; DC power supplier is respectively V prick flow transducer, pressure and pressure reduction acquisition module, temperature collect module and communication modular converter 24 volts of DC electrical source is provided.

The volume flowrate general-purpose computations formula of oil product is:

$q_v=\frac{C}{\sqrt{1-{{\mathrm{\β}}_v}^4}}\frac{\mathrm{\π}}{4}{D}^2{{\mathrm{\β}}_v}^2\sqrt{2\mathrm{\ΔP}/\mathrm{\ρ}}---\left(1\right)$

${\mathrm{\β}}_v=\sqrt{1-\frac{d^2}{D^2}}$ D is a V cone maximum cross section diameter of a circle (2)

The pressure difference of a certain definite density oil product is calculated by (1) Shi Kede:

${\mathrm{\ΔP}}_i=\frac{{8\mathrm{\ρ}}_i{q_v}^2(1-{{\mathrm{\β}}_v}^4)}{{\mathrm{\π}}^2{C}^2{D}^2{{\mathrm{\β}}_v}^4},$ i＝1，2，3，4(3)

The calculating formula of discharge coefficient is by (1) Shi Kede:

$C=\frac{4q_v\sqrt{1-{{\mathrm{\β}}_v}^4}}{{\mathrm{\πD}}^2{{\mathrm{\β}}_v}^2\sqrt{2\mathrm{\ΔP}/\mathrm{\ρ}}}---\left(4\right)$

Discharge coefficient C is an important parameter of V prick flow transducer, because V centrum throttle element is not a standard knot fluid element, so discharge coefficient C needs to demarcate by experiment.Demarcate with oil product A and oil product B respectively, analytical error is got the discharge coefficient that its mean value is demarcated as reality then.

Claims (3)

1. oil product sequential delivery batching interface detecting method is characterized in that the step of method is:

1) utilizes the V prick flow transducer to obtain the pressure P of oil product Batch Transportation Pipeline and the pressure difference Δ P of V centrum, utilize temperature transducer to obtain the temperature T of oil product;

2) under pipeline pressure P and oil product temperature T, the density of measuring oil product A is ρ ₁, the density of oil product B is ρ ₂, oil product A is oil product in advance, and oil product B is a trailing oil product, and oil product B heads on oil product A and flows forward in pipeline, and according to the qualitative potential of oil product A and oil product B, the density of correspondence is ρ when measuring oil product A and allowing to sneak into the Cmax of oil product B ₃The density of correspondence was ρ when oil product B allowed to sneak into the Cmax of oil product A ₄

3) calculate the total volumetric flow rate q of oil product according to the data Δ P of computer acquisition _v, calculation procedure 2 respectively then) in four pairing pressure differences of density being mentioned ${\mathrm{\ΔP}}_i=\frac{{8\mathrm{\ρ}}_i{q_v}^2(1-{{\mathrm{\β}}_v}^4)}{{\mathrm{\π}}^2{C}^2{D}^4{{\mathrm{\β}}_v}^4},$ I=1,2,3,4, wherein: C is a discharge coefficient; D is an internal diameter of the pipeline; β _vBe the equivalent diameter ratio;

4) if ρ during the oil product sequential delivery ₁＞ρ ₂, according to the pressure difference signal delta P of V prick flow transducer, as Δ P ₃＜Δ P≤Δ P ₁, oil product A is transported to oil tank 1; As Δ P=Δ P ₃, batching interface appears in pipeline, and oil product begins cutting, and contaminated product is transported to slop tank 2, Δ P ₄≤ Δ P≤Δ P ₃, be mixed contamination plug; As Δ P=Δ P ₄, mixed contamination plug finishes, and batching interface occurs once more, and Δ P is finished in the oil product cutting ₂≤ Δ P＜Δ P ₄, oil product B is transported to oil tank 3; If ρ ₁＜ρ ₂, as Δ P ₁≤ Δ P＜Δ P ₃, oil product A is transported to oil tank 4; As Δ P=Δ P ₃, batching interface appears in pipeline, and oil product begins cutting, and contaminated product is transported to slop tank 5, Δ P ₃≤ Δ P≤Δ P ₄, be mixed contamination plug; As Δ P=Δ P ₄, mixed contamination plug finishes, and batching interface occurs once more, and Δ P is finished in the oil product cutting ₄＜Δ P≤Δ P ₂, oil product B is transported to oil tank 6.

2. oil product sequential delivery batching interface detection device, it is characterized in that: V prick flow transducer and temperature transducer are arranged on oil transport pipeline, the V prick flow transducer is connected data acquisition module with temperature transducer, and data acquisition module is connected to computer by datawire again.

3. oil product sequential delivery batching interface detection device according to claim 2 is characterized in that: the Vin0+ of the pressure signal of V prick flow transducer and pressure difference signal difference cut-in pressure and pressure reduction acquisition module, Vin0-end and Vin3+, Vin3-end; Vin0+, the Vin0-end of the output signal cut-in temperature acquisition module of temperature transducer; Pressure is connected with the communication modular converter by datawire with temperature collect module with the pressure reduction acquisition module, and the communication modular converter is connected with computer through datawire again; Ac power supply is given the power supply of computer and DC power supplier respectively; DC power supplier is respectively V prick flow transducer, pressure and pressure reduction acquisition module, temperature collect module and communication modular converter 24 volts of DC electrical source is provided.

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