CN102818654A - Continuous temperature-measuring device and method of aluminum electrolytic cell based on acoustic technique - Google Patents

Abstract

The invention belongs to the technical field of an aluminum groove temperature measuring device and method with an industrial electrolytic method, in particular to a continuous temperature-measuring device and method of an aluminum electrolytic cell based on an acoustic technique. In the device, a plurality of acoustic waveguide tubes are respectively and uniformly installed on the same horizontal plane of the middle part around the aluminum electrolytic cell, and one acoustic wave receiver and one acoustic wave generator are respectively arranged on each acoustic waveguide tube. Each acoustic wave generator generates acoustic signals, and the acoustic signals are detected by each acoustic wave receiver through each acoustic waveguide tube. The acoustic signals are converted into voltage signals through the acoustic wave receiver, and the voltage signals are received by a double-channel data collecting card. The signals of two channels are subjected to bi-spectral estimation through software in a host to obtain time of acoustic wave flying, and then the temperature of aluminum electrolyte is obtained through calculation. The temperature of the aluminum electrolytic cell can be monitored by the device in real time, the running state of the aluminum electrolytic cell is favorably and comprehensively analyzed and controlled, so that various technical indexes of the aluminum electrolytic cell achieve the optimum values, the efficiency of aluminum electrolysis is enabled to be in a higher level, and the industrial aluminum manufacturing efficiency is increased.

Description

A kind of aluminium cell continuous temperature measurement device and method based on acoustic technique

Technical field

The invention belongs to industrial electrolysis legal system aluminium groove temperature measuring equipment and method and technology field, particularly a kind of aluminium cell continuous temperature measurement device and method based on acoustic technique.

Background technology

The continuous coverage of aluminium cell temperature for real-time monitoring electrolytic tank operation conditions, is carried out analysis-by-synthesis to its operation conditions and also controlled, thereby make electrolytic tank each item technical indicator reach optimum value, and is significant.Yet the continuous temperature measurement of aluminium cell is an international difficult problem, and main cause has two: electrolyte presents severe corrosive in the first, electrolytic tank; It two is, the electrolytic tank internal temperature is high, greatly between 940 ℃ ~ 970 ℃, possibly reach 1000 ℃ ~ 1200 ℃ when " effect " occurring during operate as normal.

In contact measuring method, adoptable temperature sensor has thermopair and optical fiber etc., yet metal active strengthens under the high temperature, and electrolyte has very strong corrosive attack to thermopair, is difficult to be used for continuous temperature measurement; And the optical fiber rupture strength is low, because the aluminium oxide slagging scorification is constantly arranged above the aluminium cell, seals charging aperture, beats the impact that aluminium oxide slagging scorification layer brings in the time of can not resisting charging, also is difficult to be used for continuous temperature measurement; Noncontact measuring method such as infrared measurement of temperature etc. are influenced by environment temperature, measuring accuracy, cost etc., also are difficult to obtain practical application; At present, practical remaining is interrupted thermometric in factory, promptly carries out one-shot measurement with thermopair at set intervals, generally is 1 time weekly ~ 2 times.Nonetheless, the serviceable life of thermopair is still very short, and only tens electrolytic tanks of energy measurement are bad with regard to corroding for a thermopair, and all there are hundreds of electrolytic tanks in general aluminium manufacturer.

Summary of the invention

Not enough to prior art, the invention provides a kind of aluminium cell continuous temperature measurement device and method based on acoustic technique.

A kind of aluminium cell continuous temperature measurement device based on acoustic technique is characterized in that: this device is on average installed a plurality of acoustic waveguide tubes through flange respectively on the same surface level in middle part around aluminium cell; 1 acoustic receiver and 1 sonic generator are set respectively on each acoustic waveguide tube; Signal conditioner links to each other with a plurality of acoustic receivers with data collecting card respectively; Power amplifier links to each other with a plurality of sonic generators with sound card respectively; Main frame links to each other with sound card with data collecting card respectively.

The quantity of said acoustic waveguide tube is at least 2.

A kind of aluminium cell continuous temperature measurement method based on acoustic technique is characterized in that the concrete steps of this method are following:

Main frame makes the sound wave acoustical generator produce acoustical signal through sound card through power amplifier, and through acoustic waveguide tube, a part of acoustical signal is detected by the acoustic receiver of homonymy, and another part acoustical signal is detected by the acoustic receiver of offside through aluminium cell; Acoustic receiver converts acoustical signal into voltage signal, and through signal conditioner filtering and amplification, by the double channel data acquisition card receiver; Through the software in the main frame signal of two passages is carried out two spectrums and estimate, draw sound wave and fly over the time, because transaudient fixed distance and known, and then calculate the velocity of propagation of sound wave, calculate the temperature of aluminium electrolyte then;

Can release velocity of propagation and the relation of medium temperature of sound wave in the aluminium electrolyte medium according to thermodynamic principles and Acoustic Wave-equation is: $c=f(\mathrm{\ρ}{,t,\mathrm{\β}}_s,k)=Z\sqrt{(t+273.15)}=\frac{L}{\mathrm{\τ}}$

In the formula, τ is the time of flying over, and unit is s; L is the measuring point distance, and unit is m; C is the velocity of propagation of sound wave in the aluminium electrolyte, and unit is m/s; T is the aluminium electrolyte temperature, and unit is ℃; Z is the aluminium electrolyte dielectric constant; ρ is an aluminium electrolyte density, and unit is kg/m ³β _sBe aluminium electrolyte medium adiabatic exponent;

Can draw by following formula: $t={\left(\frac{L}{\mathrm{\τ\; Z}}\right)}^2-273.15$

For given aluminium electrolyte, measuring point distance L, medium adiabatic exponent β _s, Media density ρ, dielectric constant z are known, through the measurement of sound time τ that flies over, obtain medium temperature thereby calculate SVEL c;

Adopting two spectrums to estimate to calculate sound wave flies over the time; Be measured as research object with single path;

For discrete system, the signal model of passage 1 and passage 2 is:

x ₁(n)=s(n)+n ₁(n)，

x ₂(n)=As(n-τ)+n ₂(n)；

In the formula: s (n) is a signal; n ₁(n) and n ₂(n) be noise; τ is the time of flying over; A is an attenuation coefficient;

Represent that with P greatest hope flies over the time, and suppose that time τ at full speed is an integer, the time model formula that then flies over is:

$x_2\left(n\right)=\underset{i=-P}{\overset{P}{\mathrm{\Σ}}}a\left(i\right)x_1(n-i)+n\left(n\right)$ ；

In the formula: a (n)=0, n ≠ τ, and a (τ)=1, three rank accumulation formula is following:

$C_{x_2,x_1,x_1}(\mathrm{\τ},\mathrm{\ρ})=E\left[x_2^{*}\left(n\right)x_1(n+\mathrm{\τ})x_1(n+\mathrm{\ρ})\right]$ ，

$C_{x_1,x_1,x_1}(\mathrm{\τ},\mathrm{\ρ})=E\left[x_1^{*}\left(n\right)x_1(n+\mathrm{\τ})x_1(n+\mathrm{\ρ})\right]$ ；

Bring into and obtain:

$C_{x_2,x_1,x_1}=\underset{i=-P}{\overset{P}{\mathrm{\Σ}}}a\left(i\right)C_{x_1,x_1,x_1}(\mathrm{\τ}+i,\mathrm{\ρ}+i)$ ；

For different ρ and τ, obtain linear equation and be:

$C_{x_1,x_1,x_1}a=C_{x_2,x_1,x_1}$ ；

The sound wave time τ=n=arg [max (| a (n) |)] that flies over so;

Beneficial effect of the present invention is:

The present invention can monitor the aluminium cell temperature in real time, helps that its operation conditions is carried out analysis-by-synthesis and also controls, thereby make electrolytic tank each item technical indicator reach optimum value, guarantees aluminium electroloysis efficient in higher level, improves industry system aluminium efficient.

Description of drawings

Fig. 1 is a kind of structural representation of the aluminium cell continuous temperature measurement device based on acoustic technique;

Label among the figure: 1-main frame; The 2-data collecting card; The 3-sound card; The 4-power amplifier; The 5-sonic generator; The 6-acoustic waveguide tube; The 7-acoustic receiver; The 8-signal conditioner; The 9-aluminium cell; The 10-flange.

Embodiment

The invention provides a kind of aluminium cell continuous temperature measurement device and method, the present invention is further specified below in conjunction with accompanying drawing and embodiment based on acoustic technique.

A kind of aluminium cell continuous temperature measurement device based on acoustic technique is characterized in that: this device is on average installed a plurality of acoustic waveguide tubes 6 through flange 10 respectively on the same surface level in middle part around the aluminium cell 9; 1 acoustic receiver 7 and 1 sonic generator 5 are set respectively on each acoustic waveguide tube 6; Signal conditioner 8 links to each other with a plurality of acoustic receivers 7 with data collecting card 2 respectively; Power amplifier 4 links to each other with a plurality of sonic generators 5 with sound card 3 respectively; Main frame 1 links to each other with sound card 3 with data collecting card 2 respectively.

The quantity of said acoustic waveguide tube 6 is at least 2.

A kind of aluminium cell continuous temperature measurement method based on acoustic technique is characterized in that the concrete steps of this method are following:

Main frame 1 makes sound wave acoustical generator 5 produce acoustical signal through sound card 3 through power amplifier 4, and through acoustic waveguide tube 6, a part of acoustical signal is detected by the acoustic receiver 7 of homonymy, and another part acoustical signal is detected by the acoustic receiver 7 of offside through aluminium cell 9; Acoustic receiver 7 converts acoustical signal into voltage signal, and through signal conditioner 8 filtering and amplification, is received by double channel data acquisition card 2; Through the software in the main frame 1 signal of two passages is carried out two spectrums and estimate, draw sound wave and fly over the time, because transaudient fixed distance and known, and then calculate the velocity of propagation of sound wave, calculate the temperature of aluminium electrolyte then;

Can release velocity of propagation and the relation of medium temperature of sound wave in the aluminium electrolyte medium according to thermodynamic principles and Acoustic Wave-equation is: $c=f(\mathrm{\ρ}{,t,\mathrm{\β}}_s,k)=Z\sqrt{(t+273.15)}=\frac{L}{\mathrm{\τ}}$

In the formula, τ is the time of flying over, and unit is s; L is the measuring point distance, and unit is m; C is the velocity of propagation of sound wave in the aluminium electrolyte, and unit is m/s; T is the aluminium electrolyte temperature, and unit is ℃; Z is the aluminium electrolyte dielectric constant; ρ is an aluminium electrolyte density, and unit is kg/m ³β _sBe aluminium electrolyte medium adiabatic exponent;

Can draw by following formula: $t={\left(\frac{L}{\mathrm{\τ\; Z}}\right)}^2-273.15$

For given aluminium electrolyte, measuring point distance L, medium adiabatic exponent β _sTherefore, Media density ρ, dielectric constant z are known, can obtain medium temperature thereby calculate SVEL c through the measurement of sound time τ that flies over;

Adopt two spectrums to estimate that (three rank semi-invariants) calculating sound wave flies over the time; Be measured as research object with single path;

For discrete system, the signal model of passage 1 and passage 2 is:

x ₁(n)=s(n)+n ₁(n)，

x ₂(n)=As(n-τ)+n ₂(n)；

In the formula: s (n) is a signal; n ₁(n) and n ₂(n) be noise; τ is the time of flying over; A is an attenuation coefficient;

Represent that with P greatest hope flies over the time, and suppose that time τ at full speed is an integer, the time model formula that then flies over is:

$x_2\left(n\right)=\underset{i=-P}{\overset{P}{\mathrm{\Σ}}}a\left(i\right)x_1(n-i)+n\left(n\right)$ ；

In the formula: a (n)=0, n ≠ τ, and a (τ)=1, three rank accumulation formula is following:

$C_{x_2,x_1,x_1}(\mathrm{\τ},\mathrm{\ρ})=E\left[x_2^{*}\left(n\right)x_1(n+\mathrm{\τ})x_1(n+\mathrm{\ρ})\right]$ ，

$C_{x_1,x_1,x_1}(\mathrm{\τ},\mathrm{\ρ})=E\left[x_1^{*}\left(n\right)x_1(n+\mathrm{\τ})x_1(n+\mathrm{\ρ})\right]$ ；

Bring into and obtain:

$C_{x_2,x_1,x_1}(\mathrm{\τ},\mathrm{\ρ})=\underset{i=-P}{\overset{P}{\mathrm{\Σ}}}a\left(i\right)C_{x_1,x_1,x_1}(\mathrm{\τ}+i,\mathrm{\ρ}+i)$ ；

For different ρ and τ, obtain linear equation and be:

$C_{x_1,x_1,x_1}a=C_{x_2,x_1,x_1}$ ；

The sound wave time τ=n=arg [max (| a (n) |)] that flies over so.

Claims (3)

1. aluminium cell continuous temperature measurement device based on acoustic technique is characterized in that: this device is on average installed a plurality of acoustic waveguide tubes (6) through flange (10) respectively on the same surface level in middle part all around at aluminium cell (9); 1 acoustic receiver (7) and 1 sonic generator (5) are set respectively on each acoustic waveguide tube (6); Signal conditioner (8) links to each other with a plurality of acoustic receivers (7) with data collecting card (2) respectively; Power amplifier (4) links to each other with a plurality of sonic generators (5) with sound card (3) respectively; Main frame (1) links to each other with sound card (3) with data collecting card (2) respectively.

2. a kind of aluminium cell continuous temperature measurement device based on acoustic technique according to claim 1, it is characterized in that: the quantity of said acoustic waveguide tube (6) is at least 2.

3. a kind of aluminium cell continuous temperature measurement method based on acoustic technique as claimed in claim 1 is characterized in that the concrete steps of this method are following:

Main frame (1) is through sound card (3); Make sound wave acoustical generator (5) produce acoustical signal through power amplifier (4); Through acoustic waveguide tube (6); Part acoustical signal is detected by the acoustic receiver of homonymy (7), and another part acoustical signal is detected by the acoustic receiver of offside (7) through aluminium cell (9); Acoustic receiver (7) converts acoustical signal into voltage signal, and through signal conditioner (8) filtering and amplification, is received by double channel data acquisition card (2); Through the software in the main frame (1) signal of two passages is carried out two spectrums and estimate, draw sound wave and fly over the time, because transaudient fixed distance and known, and then calculate the velocity of propagation of sound wave, calculate the temperature of aluminium electrolyte then;

Can release velocity of propagation and the relation of medium temperature of sound wave in the aluminium electrolyte medium according to thermodynamic principles and Acoustic Wave-equation is: $c=f(\mathrm{\ρ}{,t,\mathrm{\β}}_s,k)=Z\sqrt{(t+273.15)}=\frac{L}{\mathrm{\τ}}$

In the formula, τ is the time of flying over, and unit is s; L is the measuring point distance, and unit is m; C is the velocity of propagation of sound wave in the aluminium electrolyte, and unit is m/s; T is the aluminium electrolyte temperature, and unit is ℃; Z is the aluminium electrolyte dielectric constant; ρ is an aluminium electrolyte density, and unit is kg/m ³β _sBe aluminium electrolyte medium adiabatic exponent;

Can draw by following formula: $t={\left(\frac{L}{\mathrm{\τ\; Z}}\right)}^2-273.15$

For given aluminium electrolyte, measuring point distance L, medium adiabatic exponent β _s, Media density ρ, dielectric constant z are known, through the measurement of sound time τ that flies over, obtain medium temperature thereby calculate SVEL c;

Adopting two spectrums to estimate to calculate sound wave flies over the time; Be measured as research object with single path;

For discrete system, the signal model of passage 1 and passage 2 is:

x ₁(n)=s(n)+n ₁(n)，

x ₂(n)=As(n-τ)+n ₂(n)；

In the formula: s (n) is a signal; N1 (n) and n2 (n) are noise; τ is the time of flying over; A is an attenuation coefficient;

Represent that with P greatest hope flies over the time, and suppose that time τ at full speed is an integer, the time model formula that then flies over is:

$x_2\left(n\right)=\underset{i=-P}{\overset{P}{\mathrm{\Σ}}}a\left(i\right)x_1(n-i)+n\left(n\right)$ ；

In the formula: a (n)=0, n ≠ τ, and a (τ)=1, three rank accumulation formula is following:

$C_{x_2,x_1,x_1}(\mathrm{\τ},\mathrm{\ρ})=E\left[x_2^{*}\left(n\right)x_1(n+\mathrm{\τ})x_1(n+\mathrm{\ρ})\right]$ ，

$C_{x_1,x_1,x_1}(\mathrm{\τ},\mathrm{\ρ})=E\left[x_1^{*}\left(n\right)x_1(n+\mathrm{\τ})x_1(n+\mathrm{\ρ})\right]$ ；

Bring into and obtain:

$C_{x_2,x_1,x_1}(\mathrm{\τ},\mathrm{\ρ})=\underset{i=-P}{\overset{P}{\mathrm{\Σ}}}a\left(i\right)C_{x_1,x_1,x_1}(\mathrm{\τ}+i,\mathrm{\ρ}+i)$ ；

For different ρ and τ, obtain linear equation and be:

$C_{x_1,x_1,x_1}a=C_{x_2,x_1,x_1}$ ；

The sound wave time τ=n=arg [max (| a (n) |)] that flies over so.

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