CN1223371A - Heavy oil flowmeter and measuring method thereof - Google Patents

Abstract

The present invention belongs to a measuring meter for measuring fluid flow, consisting of flow sensor, teletransmission differential pressure transmitter, resistance thermometer and flow calculating display instrument. It is characterized by that the flow sensor is equipped with a wedge-shaped throttle piece, and after two ends of measuring tube are respectively connected with pressure devices, they are communicated with oil transmission pipeline by means of connecting flanges, and then the flow calculating display instrument is used to implement the application of heavy oil flow calculation formula to automatically control the flow rate of heavy oil. Said invention is simple in structure, firm and durable, and under the condition of low Reynolds number, it can accurately implement measurement of flow rate, and can be suitable for specific requirements of high-viscosity heavy oil and residual oil.

Description

Heavy oil flowmeter and measuring method thereof

The invention belongs to high viscosity, contain the flow measurement instrument of granule foreign fluid.It is by flow sensor A, teletransmission differential pressure transmitter B, compositions such as resistance thermometer C and flow routing display instrument D.

Heavy oil flux is measured and is still generally adopted oval gear flowmeter at present, because the viscosity height of heavy oil is mobile poor, and carry impurity secretly, easily be worn, be out of shape, even stuck stall to cause movable members such as elliptic gear, influence measuring accuracy and serviceable life, to its maintenance cost height.

The objective of the invention is to:, and provide a kind of simple in structure, sturdy and durable, working stability, measurement is accurate, maintenance load is little flowmeter at the weak point of oval gear flowmeter; And can be at Reynolds number (Re _D) very low (less than 500), under the viscosity of medium and the condition of temperature variation, still can carry out flow measurement exactly, to adapt to heavy oil with residual oil viscosity height and with the different specific (special) requirements that change of temperature with composition.

The technical solution used in the present invention is:

1. flow sensor is designed and manufactured into: perforate on measuring tube 1 tube wall, a wedge shape throttling element 3 is installed then; The two ends of measuring tube 1 with after pressure obtaning device 2,4 is connected, are connected with connecting flange 8,15 respectively again; Remote transmission device diaphragm 10 is packed between pressure obtaning device flange 9 and the blind flange 12, and is fixing by bolt 13; Equally, remote transmission device diaphragm 6 is packed between pressure obtaning device flange 5 and the blind flange 7, passes through bolt.

Its major parameter is:

Wedge shape throttling element 3: included angle=80～110 °, can be solid or hollow body wedge directly than $\frac{h}{D}=0.2~0.5$ Pressure obtaning device 2,4: ways of measure pressure: "T"-shaped flange pressure

Pressure distance: L ₁=L ₂=65～150mm

The internal diameter of pressure obtaning device: D ₁=D ₂=25～50mm measuring tube 1: inside diameter D=6～75mm

Length L=400～800mm is the measuring method of above-mentioned flowmeter 2., it is characterized in that: heavy oil flux calculates formula: $Q=C{K}_{\mathrm{\α}}{K}_v{K}_t{K}_{\mathrm{\ρ}}\sqrt{\mathrm{\ΔP}}------\left(1\right)$ In the formula: the heavy oil flux (l/h of Q-flows through sensor; Kg/h);

Fluid pressure difference (the KPa that Δ P-throttling element is forward and backward; MmH ₂O);

The C-scale-up factor, relevant with factors such as measuring tube internal diameter, actual internal area, fluid density, measurement units;

K _α-coefficient of flow, relevant with Reynolds number, sensor construction parameter etc.;

K _vThe correction factor that-furol viscosity changes;

K _tThe correction factor of-heavy oil temperature change;

K _ρThe correction factor of-heavy oil variable density.

Its medium viscosity correction factor scope K _v=5.5～27 ° of E (Engler's degree), temperature correction coefficient scope K _t=80～130 ℃, density correction factor scope K _ρ=0.88～0.98g/cm ³

Be further described below in conjunction with accompanying drawing:

Fig. 1: the one-piece construction synoptic diagram of the flow sensor of heavy oil flowmeter of the present invention.

Fig. 2: be the measuring tube 1 and the wedge shape throttling element 3 assembling synoptic diagram of flow sensor of the present invention.

Fig. 3: be the A-A cut-open view of Fig. 2.

Fig. 4: be heavy oil flowmeter measuring principle figure of the present invention.

Accompanying drawing has been described the Measurement situation of heavy oil flowmeter of the present invention. With flow sensor A Be communicated with oil pipeline by end flanges 8 and 15; In throttling element 3 lower edge and the pipeline Form an arc flow area (seeing the A-A cutaway view) between the wall, when heavy oil passes through, Front (entrance side) and rear (outlet side) at throttling element 3 produces pressure (power) difference Δ P=P₁- P ₂, the flow Q of fluid with

Proportional relation; Remote transmission device diaphragm 6,10 is felt respectively Survey the forward and backward fluid pressure of throttling element 3, and be delivered among the differential pressure transmitter B, obtain to press Difference Δ P, and be transformed into standard current signal I_ΔPExport to flow routing display instrument D; Heavy oil Operating temperature t is measured by resistance thermometer D, and is transformed into normalized current I_t, also export to Flow routing display instrument C; Dynamic parameter I_ΔPWith I_tWith the non-linear adjusted coefficient K of discharge coefficient_αThe furol viscosity adjusted coefficient K_v, the heavy oil temperature adjusted coefficient K_tAnd heavy oil density revision COEFFICIENT K_ρAll by flow routing display instrument D, finish the computing that heavy oil flux calculates formula (1), show the parameters such as heavy oil instantaneous delivery, integrated flow with numeral, and export the standard current signal I of corresponding heavy oil instantaneous delivery_QGive control system, automatically control heavy oil Flow; The flow measurement precision is range ± 1.5～2%.

Heavy oil flux calculates formula: $Q=C{K}_{\mathrm{\α}}{K}_v{K}_t{K}_{\mathrm{\ρ}}\sqrt{\mathrm{\ΔP}}------\left(1\right)$ In the formula: the heavy oil flux (l/h of Q-flows through sensor; Kg/h);

Fluid pressure difference (the KPa that Δ P-throttling element is forward and backward; MmH₂O)；

The C-proportionality coefficient is with measuring tube internal diameter, actual internal area, fluid density, metering list The factors such as position are relevant;

  K _α-discharge coefficient, relevant with Reynolds number, sensor construction parameter etc.;

  K _vThe correction factor that-furol viscosity changes, its extent of amendment is 5.5～27 ° of E (grace Family name's degree);

  K _tThe correction factor of-heavy oil temperature change, its extent of amendment be 80～130 ℃;

  K _ρThe correction factor of-heavy oil variable density, its extent of amendment are 0.88～0.98g/ cm²。

Heavy oil flowmeter of the present invention compared with prior art has following advantage and good effect:

1. owing to simple in structure, there is not again movable member, thus sturdy and durable, maintenance work Measure little.

2. owing to adopt the structure of wedge shape throttling element, can avoid fluid by the time produce and stagnate Stay and clogging.

3. when in the situation of Reynolds number very low (less than 500), measuring, adopt discharge coefficient non-The method of linear revise changes the nonlinearity erron that produces to discharge coefficient with Reynolds number and advances Row is revised automatically, keeps the accuracy of measuring. So can adapt to high viscosity medium (heavy oil, residual oil, Miscella) measurement requirement.

4. can the counterweight oil viscosity, the variation of temperature and density revises. When heavy oil When viscosity, temperature, density depart from its set-point, introduce respectively adjusted coefficient K_v、K _tAnd K_ρCarry out computing, can substantially overcome their variation to the impact of flow measurement. So can adapt to heavily The requirement that the kind of oil, composition, oily temperature etc. change.

Embodiment:

The heavy oil flowmeter application example is as follows:

1. flow measurement initial condition: (1) flow range: heavy oil 50～200l/h; (2) furol viscosity: the viscosity in the time of 105 ℃ is 7.96 ° of E (Engler viscosity); (3) heavy oil temperature: 105 ℃ of normal temperatures, 85～130 ℃ of variation ranges; (4) heavy oil density: the density in the time of 105 ℃ is 0.937g/cm ³(5) heavy oil working pressure: 0.3～0.7MPa; (6) petroleum pipeline internal diameter: 25mm.

2. flow sensor is a major parameter: according to given initial condition, result of calculation is: (1) measuring tube inside diameter D=8mm, long 400mm; (2) the high h of wedge is 3.42mm; (3) maximum differential pressure Δ P _Max=8.5KPa; (4) reynolds number range: 37～150; (5) ways of measure pressure: adopt "T"-shaped flange pressure and the pressure measurement of remote transmission device diaphragm.

3. the composition of measuring system and adjustment: flow sensor reinstalls in the pipeline road and uses after process verification on the heavy oil flux standard set-up.Data such as the flow that verification obtains, pressure reduction, coefficient of flow, and the correction factor K of furol viscosity, temperature and density _v, K _tAnd K _ρ, all import intelligent flow calculation display instrument.After the instrument of a whole set of measuring system puts into operation, suitably debug,, show that at last parameter such as heavy oil flux finished the calculation function of formula (1), change normal operation over to after satisfied to use through configuration and calculation by the heavy oil flux demonstration situation at scene.The flow measurement precision is range ± 1.5～2%.

Claims (6)

1. heavy oil flowmeter belongs to high viscosity, the flow measurement instrument that contains the granule foreign fluid, it is made up of flow sensor, teletransmission differential pressure transmitter, resistance thermometer, flow routing display instrument, it is characterized in that perforate on measuring tube 1 tube wall of flow sensor, and a wedge shape throttling element 3 is installed then; The two ends of measuring tube 1 with after pressure obtaning device 2,4 is connected, are connected with connecting flange 8,15 respectively again; Remote transmission device diaphragm 10 is packed between pressure obtaning device flange 9 and the blind flange 12, and is fixing by bolt 13; Equally, remote transmission device diaphragm 6 is packed between pressure obtaning device flange 5 and the blind flange 7, passes through bolt.

2. according to the described flowmeter of claim 1, it is characterized in that: included angle=80～110 of wedge shape throttling element 3 ° in the flow sensor, wedge directly than $\frac{h}{D}=0.2~0.5$ Throttling element 3 can be made solid or hollow body.

3. according to the described flowmeter of claim 1, it is characterized in that the forward and backward pressure obtaning device 2,4 of throttling element 3 of flow sensor, adopt "T"-shaped flange to connect pressure, both sides, front and back pressure distance L ₁=L ₂=65～150mm, the inside diameter D of pressure obtaning device ₁=D ₂=25～50mm.

4. according to the described flowmeter of claim 1, it is characterized in that the measuring tube 1 of flow sensor, inside diameter D=6～75mm, the length L of pipe=400～800mm.

5. the measuring method of the described flowmeter of claim 1 is communicated with by end flanges 8 and 15 flow sensor A with oil pipeline, when heavy oil flux Q passes through, promptly produces pressure reduction in throttling element 3 front and back; This pressure reduction is measured by pressure obtaning device and teletransmission differential pressure transmitter B, and is transformed into normalized current signal I _{Δ P}, be defeated by flow routing display instrument C; Heavy oil working temperature t measures and is transformed into normalized current signal I by resistance thermometer _t, also be defeated by flow routing display instrument C; Dynamic parameter I _{Δ P}With I _tWith the non-linear correction factor K of coefficient of flow _α, furol viscosity correction factor K _v, heavy oil temperature correction factor K _tAnd heavy oil density correction factor K _ρAll, finish the computing that heavy oil flux calculates formula (1), show parameters such as heavy oil instantaneous delivery, integrated flow with numeral, and export the normalized current signal I of corresponding heavy oil instantaneous delivery by flow routing display instrument C _QGive control system, control the flow of heavy oil automatically; It is characterized in that:

Heavy oil flux calculates formula: $Q=C{K}_{\mathrm{\α}}{K}_v{K}_t{K}_{\mathrm{\ρ}}\sqrt{\mathrm{\ΔP}}------\left(1\right)$ In the formula: the heavy oil flux (l/h of Q-flows through sensor; Kg/h);

Fluid pressure difference (the KPa that Δ P-throttling element is forward and backward; MmH ₂O);

The C-scale-up factor, relevant with factors such as measuring tube internal diameter, actual internal area, fluid density, measurement units;

K _α-coefficient of flow, relevant with Reynolds number, sensor construction parameter etc.;

K _vThe correction factor that-furol viscosity changes;

K _tThe correction factor of-heavy oil temperature change;

K _ρThe correction factor of-heavy oil variable density.

6. measuring method according to claim 5 is characterized in that: its medium viscosity correction factor scope of the parameter of formula (1) K _v=5.5～27 ° of E (Engler's degree), temperature correction coefficient scope K _t=80～130 ℃, density correction factor scope K _ρ=0.88～0.98g/cm ³

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