CN101093170A - Method and device for nondestructive measuring surface temperature and pressure of cylindrical pressure vessel - Google Patents

Abstract

A nondestructive measuring-method of surface temperature and pressure of cylindrical pressure container includes setting up relation model of Rayleigh wave transition time to pressure container surface temperature and pressure; utilizing measurement unit formed by four Rayleigh wave probe, ultrasonic transceiver circuit, circulation control circuit, time/digit conversion circuit and monolithic computer for calculating out surface pressure and temperature value of pressure container by measuring transition time of Rayleigh wave in transmission distance.

Description

The non-destructive measuring method of cylindrical pressure vessel surface temperature and pressure and device

Technical field

The present invention relates to the non-destructive measuring method and the device of a kind of cylindrical pressure vessel surface temperature and pressure.

Background technology

Cylindrical pressure vessel has been widely used in order to guarantee industrial normal operation, usually needing the surface temperature and the pressure of monitoring pressure container at any time in the modern industry production runes such as petrochemical industry, the energy, light industry, metallurgy.

R wave is the two-dimension elastic surface wave of propagating along material surface.It not only can be used as a kind of media of nondestructive examination, and can also reflect information such as the stress of material internal and temperature delicately.According to the relevant characteristic of stress of bearing in Rayleigh velocity of wave and the transmission medium, can set up the model of ultrasonic measurement pressure, and then the Non-Destructive Testing that realizes pressure is to overcome the various drawbacks of bringing because of the intrusive mood pressure survey.But this model is not considered Temperature Influence, therefore only is useful in the constant environment of vessel temp.When vessel temp changed, 1 ℃ of every variation changed the same order of magnitude of ultrasonic propagation time variable quantity that 1MPa causes with pressure, was about ten thousand of total travel-time/several.In the practical application, because the influence of external environment or internal tank material, the vessel surface temperature generally all changes, and therefore must consider the influence of temperature and pressure to ultrasonic propagation time simultaneously.

Existing thermometry adopts the contact method to measure more.Use the contact temperature instrument, behind the measured surface sensor installation, can cause the destruction of surface temperature field, therefore, measuring accuracy is difficult to guarantee, and there is the equipment complexity in existing contactless instrument, the more high shortcoming of price.Therefore developing a kind of method of can be simultaneously and nondestructively obtaining the Surface Pressure Vessel temperature and pressure will be significant.

Summary of the invention

The non-destructive measuring method and the device that the purpose of this invention is to provide a kind of cylindrical pressure vessel surface temperature and pressure.

The non-destructive measuring method of cylindrical pressure vessel surface temperature and pressure: utilize ultrasonic R wave in the axial and tangential propagation distance of pressure vessel transit time and the relation of Surface Pressure Vessel temperature and pressure value measure, the tangential and axial ultrasonic R wave transit time and the pressure of pressure vessel and the relational expression of surface temperature are:

$t_{\mathrm{\θ}}^{(\mathrm{\σ},T)}=k_{\mathrm{\θ}}p+g_{\mathrm{\θ}}T+h_{\mathrm{\θ}}$

T wherein _θ ^{(σ, T)}, t _ ^{(σ, T)}Be respectively the tangential and axial transit time of ultrasound wave, p is the working pressure of testing container, and T is the surface temperature of testing container, k _θ, g _θ, h _θ, k _, g _, h _Be coefficient.

Described ultrasonic R wave is to adopt four identical R wave probes to be divided into two groups to transmit and receive, the frequency of operation that transmits and receives is 1.0～5.0MHz, first group of probe is installed in the axial of cylindrical pressure vessel outside surface to be measured, and remain on the same straight line in vertical direction, the distance between two probes is 5～50 centimetres; Another group probe is installed in the tangential of testing pressure container outer surface, and remains in the horizontal direction on the same straight line, and the distance between two probes is 5～50 centimetres.

Described k _θ, g _θ, h _θ, k _, g _, h _The preparation method of coefficient is: the normal pressure and the surface temperature value that change the testing pressure container, measure the axial and tangential ultrasound wave transit time under the corresponding state, behind the multi-group data of the normal pressure that obtains the testing pressure container and surface temperature value and axial and these four values of tangential ultrasound wave transit time, the method by approximation of function obtains k _θ, g _θ, h _θ, k _, g _, h _The value of coefficient.

Single-chip microcomputer in the damage-free measuring apparatus of cylindrical pressure vessel surface temperature and pressure respectively with memory module, display module, Keysheet module, communication module, ultrasonic transmit circuit, circulating controling circuit, time-to-digital conversion circuit is connected, circulating controling circuit and ultrasonic transmit circuit, axial ultrasonic ripple receiving circuit, tangential ultrasound wave receiving circuit, time-to-digital conversion circuit is connected, ultrasonic transmit circuit and axial R wave transmitting probe, tangential R wave transmitting probe is connected, axial ultrasonic ripple receiving circuit is connected with axial R wave receiving transducer, and tangential ultrasound wave receiving circuit is connected with tangential R wave receiving transducer.

The frequency of operation of described axial R wave transmitting probe, tangential R wave transmitting probe, axial R wave receiving transducer, tangential R wave receiving transducer is 1.0～5.0MHz.

Described axial R wave transmitting probe, tangential R wave transmitting probe, axially in R wave receiving transducer, the tangential R wave receiving transducer axially the R wave transmitting probe and axially the R wave receiving transducer be installed in cylindrical pressure vessel outside surface to be measured axially, and remain on the same straight line in vertical direction, the distance between two probes is 5～50 centimetres; Tangential R wave transmitting probe and tangential R wave receiving transducer are installed in the tangential of testing pressure container outer surface, and remain in the horizontal direction on the same straight line, and the distance between two probes is 5～50 centimetres.

The present invention proposes the relational expression of axial and tangential transit time of R wave and cylindrical pressure vessel surface temperature, pressure, all kinds of potential safety hazards of not only having avoided traditional temperature and pressure measuring method to cause because of perforated container, and a kind of more convenient, Surface Pressure Vessel temperature and pressure measuring method more flexibly is provided, the newly-increased check point of inservice pressure vessel and some pressure vessel can be satisfied and should not or demand such as point for measuring temperature can't be realized installing at the direct impulse of chamber wall perforate.Measurement mechanism based on this method is simple to operate, and is with low cost, can online detected temperatures and pressure, help the safe operation of monitor force container more effectively.

Description of drawings

Fig. 1 is the cylindrical pressure vessel synoptic diagram

Fig. 2 is a structured flowchart of the present invention

Fig. 3 is a ultrasound wave receiving circuit of the present invention

Fig. 4 is a circulating controling circuit of the present invention

Fig. 5 is the measurement sequential of time-to-digital conversion circuit of the present invention

Fig. 6 is temperature and ultrasound wave transit time graph of a relation when container pressure was constant during the present invention tested

Fig. 7 is the graph of a relation that container pressure and ultrasound wave transit time changed during the present invention tested

Fig. 8 is that the present invention measures schematic flow sheet

Embodiment

Be the synoptic diagram of cylindrical pressure vessel to be measured as shown in Figure 1.Ultrasonic velocity is subjected to the common influence of stress and temperature, according to this principle, can set up the relation between velocity of wave variation and container pressure, the temperature.But velocity variations itself can not directly be measured, and the present invention is converted to the variable quantity of velocity of wave the variable quantity of ultrasonic propagation time.The R wave travel-time equals the ratio of propagation distance and velocity of propagation, therefore must consider the influence to R wave propagation distance and speed of temperature and pressure simultaneously.

1) temperature and stress are to the influence of velocity of wave

Set pressure is 0, temperature is a certain specified temp T _oThe time state be original state.Current state is compared with original state, and variation has all taken place for temperature and pressure.As a kind of mechanical wave, because influence of temperature variation, current state is compared with original state, and the Rayleigh velocity of wave propagation can change.In certain temperature range, velocity of wave and medium temperature can be similar to thinks linear relationship:

$v^{(0,T)}=v^{(0,T_o)}(1-\mathrm{\α\ΔT}).---\left(1\right)$

In the formula: temperature variation Δ T=T-T _o, T _oBe the original state temperature, T is a Current Temperatures, v ^{(0, T)}Expression pressure is 0, ultrasonic velocity when temperature is T, v ^{(0, To)}Velocity of wave during the expression original state, α is the influence coefficient of temperature to velocity of wave.

For pressure vessel as shown in Figure 1, when in container bears, pressing, only propagate at dielectric surface because of R wave, can directly get tangential stress is chamber wall surface tangential stress.Then for pressing the cylindrical pressure vessel of p to have in only being subjected to:

${\mathrm{\σ}}_{\mathrm{\θ}}=\frac{{2a}^{2}p}{b^2-a^2}---\left(3\right)$

σ in the formula _, σ _θAxial stress when representing the pressure vessel pressurized respectively and tangential stress; α is the inside radius of pressure vessel; B is the external radius of pressure vessel.

When R wave is propagated with tangential direction vertically, can get:

In the formula, A _{R } ^, A _{R } ^θ, A _{R θ} ^, A _{R θ} ^θBe second order and the relevant amount of three rank acoustic elasticity constants with material; v _ ^{(0, To)}, v _θ ^{(0, To)}Be illustrated respectively in that temperature is T under the unstress state _oThe time Rayleigh surface wave vertically and the tangential speed of propagating;

${\mathrm{\Δv}}_{\mathrm{\θ}}=v_{\mathrm{\θ}}^{(\mathrm{\σ},T_o)}-v_{\mathrm{\θ}}^{(0,T_o)};$ Wherein, v _ ^{(σ, To)}, v _θ ^{(σ, To)}Temperature was T after expression was influenced by stress σ respectively _oThe time along φ, θ direction velocity of wave

(2) formula and (3) formula substitution (4) formula can be obtained with (5) formula:

$v_{\mathrm{\θ}}^{(\mathrm{\σ},T_o)}=(K_{\mathrm{\θ}}\frac{{2a}^{2}p}{b^2-a^2}+1)v_{\mathrm{\θ}}^{(0,T_o)}---\left(6\right)$

K in the formula _φ, K _θBe and the relevant parameter of material acoustic elasticity constant.

Be subjected to temperature and stress to influence the rear surface velocity of wave propagation simultaneously to be:

$v_{\mathrm{\θ}}^{(\mathrm{\σ},T)}=v_{\mathrm{\θ}}^{(\mathrm{\σ},T_o)}(1-{\mathrm{\α}}_{\mathrm{\θ}}\mathrm{\ΔT})---\left(8\right)$

2) temperature and stress are to the influence of transonic distance

Ultrasonic propagation distance is subjected to the influence of temperature and pressure simultaneously, and temperature variation can cause expanding with heat and contract with cold of material, thereby the ultrasonic propagation distance is changed, and to be example tangentially, converted quantity can be expressed as behind the temperature influence:

${\mathrm{\ΔL}}_{\mathrm{\θ}}^{(0,T)}=\mathrm{\β\Δ}{\mathrm{TL}}_{\mathrm{\θ}}^{(0,T_o)}---\left(10\right)$

Wherein, β is a linear expansion coefficient, L _θ ^{(0, To)}The propagation distance of expression original state lower edge θ direction, Δ L _θ ^{(0, T)}Expression stress is subjected to temperature T to influence the propagation distance variable quantity of back along the θ direction when being zero.

On the other hand, pressure can cause strain at the stress that chamber wall produces, and causes the tangential propagation distance of ultrasound wave to change:

E is a Young modulus in the formula, and μ is a Poisson ratio, σ _φBe the stress of container pressure in axial generation, σ _θBe tangential stress, Δ L _θ ^{(σ, To)}The expression temperature is T _oThe time affected by force after along the strain of θ direction.

Therefore, with formula (2), (3) substitution (11), can get:

${\mathrm{\ΔL}}_{\mathrm{\θ}}^{(\mathrm{\σ},T_o)}=(1-\frac{\mathrm{\μ}}{2})\frac{{2a}^2{L}_{\mathrm{\θ}}^{(0,T_o)}p}{(b^2-a^2)E}---\left(12\right)$

The total variation of propagation distance is the coefficient result of temperature, stress:

$\mathrm{\Δ}{L}_{\mathrm{\θ}}^{(\mathrm{\σ},T)}={\mathrm{\ΔL}}_{\mathrm{\θ}}^{(0,T)}+{\mathrm{\ΔL}}_{\mathrm{\θ}}^{(\mathrm{\σ},T_o)}+{\mathrm{\β\ΔT\ΔL}}_{\mathrm{\θ}}^{(\mathrm{\σ},T_o)}---\left(13\right)$

β is very little for linear expansion coefficient, and the general order of magnitude has only 10 ^-5, therefore, β Δ T Δ L _θ ^{(σ, To)}Be no more than Δ L _θ ^{(σ, To)}Per mille, can omit, then formula (13) abbreviation is:

With formula (10), (12) substitution formula (14):

$\mathrm{\Δ}{L}_{\mathrm{\θ}}^{(\mathrm{\σ},T)}=[(1-\frac{\mathrm{\μ}}{2})\frac{{2a}^{2}p}{(b^2-a^2)E}+\mathrm{\β\ΔT}]L_{\mathrm{\θ}}^{(0,T_o)}---\left(15\right)$

In like manner can get axial propagation distance and be subjected to variable quantity after temperature and stress influence jointly:

3) temperature and pressure is to the influence in travel-time

With tangential propagation of R wave is example, the relational model of derive travel-time and temperature variation and pressure:

$t_{\mathrm{\θ}}^{(0,T_o)}=\frac{L_{\mathrm{\θ}}^{(0,T_o)}}{v_{\mathrm{\θ}}^{(0,T_o)}}---\left(17\right)$

In the formula, t _θ ^{(0, To)}The expression following travel-time of original state.

After temperature and pressure changed, the tangential travel-time of surface wave was:

$t_{\mathrm{\θ}}^{(\mathrm{\σ},T)}=\frac{L_{\mathrm{\θ}}^{(0,T_o)}+{\mathrm{\ΔL}}_{\mathrm{\θ}}^{(\mathrm{\σ},T)}}{v_{\mathrm{\θ}}^{(\mathrm{\σ},T)}}$

With formula (8), (15) substitution (18) formula, further substitution formula (6), arrangement can get:

$t_{\mathrm{\θ}}^{(\mathrm{\σ},T)}=[(\frac{2-\mathrm{\μ}}{2E}-K_{\mathrm{\θ}})\frac{2a^{2}p}{b^2-a^2}+\mathrm{\β\ΔT}+{\mathrm{\α}}_{\mathrm{\θ}}\mathrm{\ΔT}(1+\frac{2K_{\mathrm{\θ}}{a}^{2}p}{b^2-a^2})]c+t_{\mathrm{\θ}}^{(0,T_o)}---\left(19\right)$

C is a suitable constant in the formula (19).2K _θa ²P/ (b ²-a ²) be about ten thousand/several, much smaller than 1, therefore can dispense this, can get the relational expression between tangential travel-time, pressure and the temperature:

$t_{\mathrm{\θ}}^{(\mathrm{\σ},T)}=(\frac{2-\mathrm{\μ}}{2E}-K_{\mathrm{\θ}})\frac{2a^{2}c}{b^2-a^2}p+(\mathrm{\β}+{\mathrm{\α}}_{\mathrm{\θ}})\mathrm{cT}+[t_{\mathrm{\θ}}^{(0,T_o)}-\mathrm{\βc}{T}_o-{\mathrm{\α}}_{\mathrm{\θ}}c{T}_o]---\left(20\right)$

In like manner, can get the shaft orientation relation formula through deriving:

Can find out from formula (20), (21), coefficient before pressure p and the surface temperature T is made up of parameters such as Young modulus E, Poisson ratio μ, linear expansion coefficient β, these parameters are according to the difference of material and difference, even commaterial, because the difference of process also has small difference, therefore be difficult to determine separately the value of each parameter, in actual the use, each coefficient can be regarded as an integral body, be write formula as following form:

Tangentially: $t_{\mathrm{\θ}}^{(\mathrm{\σ},T)}=k_{\mathrm{\θ}}p+g_{\mathrm{\θ}}T+h_{\mathrm{\θ}}---\left(22\right)$

Axially:

Therefore the non-destructive measuring method of cylindrical pressure vessel surface temperature and pressure is: utilize ultrasonic R wave in the axial and tangential propagation distance of pressure vessel transit time and the relation of Surface Pressure Vessel temperature and pressure value measure, the tangential and axial ultrasonic R wave transit time and the pressure of pressure vessel and the relational expression of surface temperature are:

$t_{\mathrm{\θ}}^{(\mathrm{\σ},T)}=k_{\mathrm{\θ}}p+g_{\mathrm{\θ}}T+h_{\mathrm{\θ}}$

T wherein _θ ^{(σ, T)}, t _ ^{(σ, T)}Be respectively the tangential and axial transit time of ultrasound wave, p is the working pressure of testing container, and T is the surface temperature of testing container, k _θ, g _θ, h _θ, k _, g _, h _Be coefficient.

K wherein _θ, g _θ, h _θ, k _, g _, h _The preparation method of coefficient is: the normal pressure and the surface temperature value that change the testing pressure container, measure the axial and tangential ultrasound wave transit time under the corresponding state, behind the multi-group data of the normal pressure that obtains the testing pressure container and surface temperature value and axial and these four values of tangential ultrasound wave transit time, the method by approximation of function obtains k _θ, g _θ, h _θ, k _, g _, h _The value of coefficient.

As shown in Figure 2, single-chip microcomputer 15 in the damage-free measuring apparatus of cylindrical pressure vessel surface temperature and pressure respectively with memory module 6, display module 7, Keysheet module 8, communication module 9, ultrasonic transmit circuit 10, circulating controling circuit 12, time-to-digital conversion circuit 14 is connected, circulating controling circuit 12 and ultrasonic transmit circuit 10, axial ultrasonic ripple receiving circuit 11, tangential ultrasound wave receiving circuit 13, time-to-digital conversion circuit 14 is connected, ultrasonic transmit circuit 10 and axial R wave transmitting probe 2, tangential R wave transmitting probe 3 is connected, axial ultrasonic ripple receiving circuit 11 is connected with axial R wave receiving transducer 4, and tangential ultrasound wave receiving circuit 13 is connected with tangential R wave receiving transducer 5.

Axially the frequency of operation of R wave transmitting probe 2, tangential R wave transmitting probe 3, axial R wave receiving transducer 4, tangential R wave receiving transducer 5 is 1.0～5.0MHz.Axially R wave transmitting probe 2, tangential R wave transmitting probe 3, axially in R wave receiving transducer 4, the tangential R wave receiving transducer 5 axially R wave transmitting probe 2 and axially R wave receiving transducer 4 be installed in cylindrical pressure vessel outside surface to be measured axially, and remain on the same straight line in vertical direction, the distance between two probes is 5～50 centimetres; Tangential R wave transmitting probe 3 and tangential R wave receiving transducer 5 are installed in the tangential of testing pressure container outer surface, and remain in the horizontal direction on the same straight line, and the distance between two probes is 5～50 centimetres.

The R wave probe can be selected lead titanate piezoelectric ceramics (PZT) surface wave ultrasonic probe for use, and the electromechanical coupling factor of PZT probe is about 70%, and impedance operator is superior, and frequency of operation is 2.5MHz, is of a size of 13 * 13 (mm ²), can be from Changzhou big flat ultrasonic instrument company limited buys.

Time-to-digital conversion circuit (14) adopts split-second precision-digital quantizer TDC-GP2, is operated in the second range pattern.Split-second precision-digital quantizer TDC-GP2 can buy to acam company.

Single-chip microcomputer can be selected the PIC16F877A of microchip company for use

The principle of work of whole instrument is: radiating circuit produces the pulse of bearing 300 volts and excites two transmitting probes simultaneously under Single-chip Controlling, after after a while, two receiving transducers are received the R wave signal respectively, utilizing the two-way receiving circuit to carry out signal amplifies and filtering, under the control of Single-chip Controlling line and program, circulating controling circuit is at first handled axial signal, and its output signal one road is connected to radiating circuit and carries out ultrasonic exciting again; One the road is connected to single-chip microcomputer carries out cycle count; One the road is connected to time-to-digital conversion circuit.After ultrasonic cycle index reached setting value, single-chip microcomputer will change control line signal made the incoming level of ultrasound emission termination and change TDC carry out the time timing.Single-chip microcomputer reads the TDC register and obtains the axial transit time of ultrasound wave and deposit memory module in after axial measurement is finished, afterwards single-chip microcomputer revise control line and again excitation ultrasound carry out the measurement of tangential transit time of ultrasound wave.Single-chip microcomputer utilizes the computing formula of preserving in the memory to carry out the calculating of Surface Pressure Vessel temperature and pressure after obtaining the axial and tangential transit time of ultrasound wave, and carries out information interaction by display module and communication module.

As shown in Figure 3, the circuit of axial ultrasonic ripple receiving circuit 11 or tangential ultrasound wave receiving circuit 13 is: received ultrasound signal the 6th capacitor C that axial R wave receiving transducer 4 or tangential R wave receiving transducer 5 receive ₆An end, the 6th capacitor C ₆The other end receive the 14 resistance R ₁₄With the 15 resistance R ₁₅, the 14 resistance R ₁₄Other end ground connection, the 15 resistance R ₁₅The other end be connected to the negative terminal of the first amplifier A1, the positive ending grounding of the first amplifier A1, the output terminal of the first amplifier A1 is by the 16 resistance R ₁₆Be connected to the negative terminal of the first amplifier A1, the output terminal of the first amplifier A1 connects the 7th capacitor C ₇An end, the 7th capacitor C ₇The other end connect the 5th resistance R ₅With the 6th resistance R ₆, the 5th resistance R ₅Other end ground connection, the 6th resistance R ₆The other end connect and to connect the 17 resistance R simultaneously ₁₇, the 4th capacitor C ₄, the 3rd capacitor C ₃An end, the 17 resistance R ₁₇Other end ground connection, the 4th capacitor C ₄The negative terminal of another termination second amplifier A2, the 3rd capacitor C ₃The output terminal of another termination second amplifier A2, the 7th resistance R ₇Two ends be connected on negative terminal and the output terminal of the second amplifier A2 respectively, the anode of the second amplifier A2 is by the 8th resistance R ₈Ground connection, the output terminal of the second amplifier A2 connects the 5th capacitor C ₅An end, the 5th capacitor C ₅The other end connect the 9th resistance R ₉With the tenth resistance R ₁₀, the 9th resistance R ₉Other end ground connection, the tenth resistance R ₁₀The other end be connected to the negative terminal of the 3rd amplifier A3, the positive ending grounding of the 3rd amplifier A3, the output terminal of the 3rd amplifier A3 is by the 12 resistance R ₁₂With the 11 resistance R ₁₁Be connected to the negative terminal of the 3rd amplifier A3, the output terminal of the 3rd amplifier A3 is by the 13 resistance R ₁₃Be connected to circulating controling circuit 12.

The first amplifier A1 and the 3rd amplifier A3 can adopt the amplifier AD8091 of high-speed broadband band, and the second amplifier A2 can adopt wide band amplifier AD8092.Entire circuit is by the 11 resistance R ₁₁Make 1000～3000 times of total magnifications, by the 6th capacitor C ₆With the 14 resistance R ₁₄, the 7th capacitor C ₇With the 6th resistance R ₅, the 5th capacitor C ₅With the 9th resistance R ₉The passive high-pass filtering circuit cutoff frequency of forming of preposition, mid-and rearmounted RC can be set to 0.8～0.9Mhz, by the second amplifier A2, the 7th resistance R ₇, the 17 resistance R ₁₇, the 8th resistance R ₈, the 3rd capacitor C ₃, the 4th capacitor C ₄The active bandwidth-limited circuit centre frequency of forming is set to the R wave frequency of operation.

As shown in Figure 4, the circuit of circulating controling circuit 12 is: the negative terminal of the first high-speed comparator U11 and second high-speed comparator U12 coupling shaft respectively is connected identical comparative voltage to ultrasound wave receiving circuit 11 or tangential ultrasound wave receiving circuit 13, the first high-speed comparator U11 with the second high-speed comparator U12 anode; The positive output end of the first high-speed comparator U11 connects the C end of the first JK flip-flop U1, S end and the J termination power VCC of the first JK flip-flop U1, and its K end ground connection, its Q end is connected to the B end of the first monostalbe trigger U5, the first JK flip-flop U1's

End be connected respectively to the second JK flip-flop U2 C end and the 3rd with the end of a U9; Second resistance R ₂An end connect power supply VCC, the other end connects first resistance R ₁, first resistance R ₁The other end be connected to the CX/RX end and first capacitor C of the first monostalbe trigger U5 simultaneously ₁An end, first capacitor C ₁The other end be connected to the CX end of the first monostalbe trigger U5, the first monostalbe trigger U5's

End connects single-chip microcomputer the 5th control line cp5, the first monostalbe trigger U5's

End ground connection, the first monostalbe trigger U5's

End and the single-chip microcomputer first control line cp1 be connected first with two input ends of U7, first is connected the R end of the first JK flip-flop U1 with the output terminal of door U7, S end and the J termination power VCC of the second JK flip-flop U2, and its K holds ground connection, its R end connects single-chip microcomputer the 3rd control line cp3, its The end be connected to the 4th with the door U10 an input end; The positive output end of the second high-speed comparator U12 connects the C end of the 3rd JK flip-flop U3, S end and the J termination power VCC of the 3rd JK flip-flop U3, and its K end ground connection, its Q end is connected to the B end of the second monostalbe trigger U6, the 3rd JK flip-flop U3's End be connected respectively to the 4th JK flip-flop U4 C end and the 3rd with the other end of a U9; The 4th resistance R ₄An end connect power supply VCC, the other end connects the 3rd resistance R ₃, the 3rd resistance R ₃The other end be connected to the CX/RX end and second capacitor C of the second monostalbe trigger U6 simultaneously ₂An end, second capacitor C ₂The other end be connected to the CX end of the second monostalbe trigger U6, the second monostalbe trigger U6's

End connects single-chip microcomputer the 6th control line cp6, the second monostalbe trigger U6's

End ground connection, the second monostalbe trigger U6's

End and the single-chip microcomputer second control line cp2 be connected second with two input ends of U8, second is connected the R end of the 3rd JK flip-flop U3 with the output terminal of door U8, S end and the J termination power VCC of the 4th JK flip-flop U4, and its K holds ground connection, its R end connects single-chip microcomputer the 4th control line cp4, its

The end be connected to the 4th with the door U10 another input end; Be divided into two-way with the output terminal of door U9, the one road is connected to single-chip microcomputer 15, and one the road is connected to radiating circuit 10; Output terminal tie-time digital conversion circuit 14 with door U10.

High-speed comparator can be selected the MAX912 of U.S. letter company for use, and JK flip-flop can be selected 74LS112 for use, and monostalbe trigger can be selected 74LS123 for use, can select 74LS00 for use with door.The pulse width of the first monostalbe trigger U5 and the second monostalbe trigger U6 is respectively by first capacitor C ₁, first resistance R ₁, second resistance R ₂With second capacitor C ₂, the 3rd resistance R ₃, the 4th resistance R ₄Regulate, requiring its pulse width greater than whole relatively passing through the time of pulses, less than total travel-time of one way surface wave, is the 16MnR steel with the material of pressure vessel, it is example that the ultrasonic propagation distance is about 15cm, and its pulse width can be arranged on 14～28 μ s.

The principle of work of entire circuit is: after receiving through the ultrasonic signal after the amplification filtering, first high-speed comparator and second high-speed comparator meeting output pulse signal enter has the first JK flip-flop U1 and the 3rd JK flip-flop U3 that puts 1 function, and further excite the first monostalbe trigger U5 and the second monostalbe trigger U6, under the control of the first Single-chip Controlling line cp1 and second singlechip control line cp2, first with door U7 and first with U8 can be so that the first JK flip-flop U1 and the 3rd JK flip-flop U3

End is returned to high level again after producing a negative edge pulse, utilizes this pulse can impel ultrasonic transmit circuit excitation ultrasound once more by the 3rd with door U9, is connected to single-chip microcomputer simultaneously and is used for cycle count.After axial or tangential ultrasonic cycle calculations was finished, single-chip microcomputer utilized the 3rd control line cp3 and the 4th control line cp4 to change the second JK flip-flop U2 and the 4th JK flip-flop U4

End signal, and this signal is changed with door U10 by the 4th and to be used for the TDC timing.

As shown in Figure 5, time-to-digital conversion circuit 14 adopts split-second precision one digital quantizer TDC-GP2, is operated in the second range pattern, and Fig. 5 is the measurement sequential of TDC-GP2.t ₁The travel-time of expression ultrasound wave circulation primary, t _N-1Total travel-time that the expression circulation is n-1 time.TDC-GP2 will calculate the total travel-time after ultrasonic circulation n time, and single-chip microcomputer reads relevant register, calculate the back and just can obtain the required ultrasound wave transit time.

Fig. 6 is one group of experimental data figure during the present invention tests, and ultrasonic probe is selected lead titanate piezoelectric ceramics (PZT) surface wave ultrasonic probe for use, and frequency of operation is 2.5MHz.Axially the distance with tangential probe all is made as about 150mm, and the material of container is the 16MnR steel, and inside radius is 162mm, and external radius is 165mm.Pressure p=0 that keeps container, when the chamber wall surface temperature when changing for 0～100 ℃, measure the ultrasonic propagation time of axial and tangential surface temperature and correspondence respectively, do the curve match then.The slope of axial straight line is 0.0191 among Fig. 6, and intercept is 29.177; The slope of tangential straight line is 0.0197, and intercept is 30.254.Therefore, the coefficient in formula (22), (23) is:

g _φ＝1.91×10 ^-8；h _φ＝2.9177×10 ^-5

g _θ＝1.97×10 ^-8；h _θ＝3.0254×10 ^-5

Fig. 7 be during the present invention tests under different temperatures, the graph of a relation that container pressure and ultrasound wave transit time change.When tangential and axial propagation distance equates, coefficient g _φ=g _θ, h _φ=h _θFurther container is exerted pressure, tangentially to be example, when temperature is T ₁Measure travel-time and corresponding force value in the time of=5.1 ℃, the travel-time during different pressures under this temperature is deducted travel-time under the zero pressure, that is:

$\mathrm{\Δ}{t}_{\mathrm{\θ}}^{(\mathrm{\σ},T_1)}=t_{\mathrm{\θ}}^{(\mathrm{\σ},T_1)}-t_{\mathrm{\θ}}^{(0,T_1)}=k_{\mathrm{\θ}}p---\left(24\right)$

Can get coefficient k by formula (24) _θIn like manner can get coefficient k _φ

Be 5.1 ℃ in temperature respectively, 12 ℃, 25 ℃, measure axial and tangential time variation amount and corresponding pressure p in the time of 33 ℃, the curve fit result is as shown in Figure 7.

Can get the axial scale coefficient by Fig. 7 is 4.9, and tangential scale-up factor is 8.4, and then the coefficient in formula (22), (23) is:

k _φ＝4.9×10 ^-15；k _θ＝8.4×10 ^-15

With k _φ, k _θAnd the g that obtains previously _φ, g _θ, h _φ, h _θDifference substitution formula (22), (23) can get:

$t_{\mathrm{\θ}}^{(\mathrm{\σ},T)}=8.4\×{10}^{-15}p+1.97\×{10}^{-8}T+3.0254\×{10}^{-5}---\left(25\right)$

After measuring the tangential and axial travel-time, substitution formula (25) and (26), calculating can get vessel surface temperature T and pressure p.

For different vessels, structure, probe etc., its coefficient is different, but measuring process is the same.

Be that the present invention measures schematic flow sheet as shown in Figure 8.Behind the instrument coefficient of having adjusted, the measure equation of Surface Pressure Vessel temperature and pressure is kept in the memory module, after instrument powers on, under the control of Single Chip Microcomputer (SCM) program, obtain the axial and tangential ultrasound wave transit time, calculate the value of the Surface Pressure Vessel temperature and pressure of being asked then, be used for data presentation and communication.

Claims (9)

1. the non-destructive measuring method of cylindrical pressure vessel surface temperature and pressure, it is characterized in that: utilize ultrasonic R wave in the axial and tangential propagation distance of pressure vessel transit time and the relation of Surface Pressure Vessel temperature and pressure value measure, the tangential and axial ultrasonic R wave transit time and the pressure of pressure vessel and the relational expression of surface temperature are:

$t_{\mathrm{\θ}}^{(\mathrm{\σ},T)}=k_{\mathrm{\θ}}p+g_{\mathrm{\θ}}T+h_{\mathrm{\θ}}$

T wherein _θ ^{(σ, T)}, t _ ^{(σ, T)}Be respectively the tangential and axial transit time of ultrasound wave, p is the working pressure of testing container, and T is the surface temperature of testing container, k _θ, g _θ, h _θ, k _, g _, h _Be coefficient.

2. the non-destructive measuring method of a kind of cylindrical pressure vessel surface temperature according to claim 1 and pressure, it is characterized in that described ultrasonic R wave is to adopt four identical R wave probes to be divided into two groups to transmit and receive, the frequency of operation that transmits and receives is 1.0～5.0MHz, first group of probe is installed in the axial of cylindrical pressure vessel outside surface to be measured, and remain on the same straight line in vertical direction, the distance between two probes is 5～50 centimetres; Another group probe is installed in the tangential of testing pressure container outer surface, and remains in the horizontal direction on the same straight line, and the distance between two probes is 5～50 centimetres.

3. the non-destructive measuring method of a kind of cylindrical pressure vessel surface temperature according to claim 1 and pressure is characterized in that described k _θ, g _θ, h _θ, k _, g _, h _The preparation method of coefficient is: the normal pressure and the surface temperature value that change the testing pressure container, measure the axial and tangential ultrasound wave transit time under the corresponding state, behind the multi-group data of the normal pressure that obtains the testing pressure container and surface temperature value and axial and these four values of tangential ultrasound wave transit time, the method by approximation of function obtains k _θ, g _θ, h _θ, k _, g _, h _The value of coefficient.

4. the damage-free measuring apparatus of cylindrical pressure vessel surface temperature and pressure, it is characterized in that single-chip microcomputer (15) respectively with memory module (6), display module (7), Keysheet module (8), communication module (9), ultrasonic transmit circuit (10), circulating controling circuit (12), time-to-digital conversion circuit (14) is connected, circulating controling circuit (12) and ultrasonic transmit circuit (10), axial ultrasonic ripple receiving circuit (11), tangential ultrasound wave receiving circuit (13), time-to-digital conversion circuit (14) is connected, ultrasonic transmit circuit (10) and axial R wave transmitting probe (2), tangential R wave transmitting probe (3) is connected, axial ultrasonic ripple receiving circuit (11) is connected with axial R wave receiving transducer (4), and tangential ultrasound wave receiving circuit (13) is connected with tangential R wave receiving transducer (5).

5. the damage-free measuring apparatus of a kind of cylindrical pressure vessel surface temperature according to claim 4 and pressure is characterized in that the frequency of operation of described axial R wave transmitting probe (2), tangential R wave transmitting probe (3), axial R wave receiving transducer (4), tangential R wave receiving transducer (5) is 1.0～5.0MHz.

6. the damage-free measuring apparatus of a kind of cylindrical pressure vessel surface temperature according to claim 4 and pressure, it is characterized in that described axial R wave transmitting probe (2), tangential R wave transmitting probe (3), axially in R wave receiving transducer (4), the tangential R wave receiving transducer (5) axially R wave transmitting probe (2) and axially R wave receiving transducer (4) be installed in the axial of cylindrical pressure vessel outside surface to be measured, and remain on the same straight line in vertical direction, the distance between two probes is 5～50 centimetres; Tangential R wave transmitting probe (3) and tangential R wave receiving transducer (5) are installed in the tangential of testing pressure container outer surface, and remain in the horizontal direction on the same straight line, and the distance between two probes is 5～50 centimetres.

7. the damage-free measuring apparatus of a kind of cylindrical pressure vessel surface temperature according to claim 4 and pressure is characterized in that the circuit of described axial ultrasonic ripple receiving circuit (11) or tangential ultrasound wave receiving circuit (13) is: received ultrasound signal the 6th electric capacity (C that axial R wave receiving transducer (4) or tangential R wave receiving transducer (5) receive ₆) an end, the 6th electric capacity (C ₆) the other end receive the 14 resistance (R ₁₄) and the 15 resistance (R ₁₅), the 14 resistance (R ₁₄) other end ground connection, the 15 resistance (R ₁₅) the other end be connected to the negative terminal of first amplifier (A1), the positive ending grounding of first amplifier (A1), the output terminal of first amplifier (A1) is by the 16 resistance (R ₁₆) being connected to the negative terminal of first amplifier (A1), the output terminal of first amplifier (A1) connects the 7th electric capacity (C ₇) an end, the 7th electric capacity (C ₇) the other end connect the 5th resistance (R ₅) and the 6th resistance (R ₆), the 5th resistance (R ₅) other end ground connection, the 6th resistance (R ₆) the other end connect and to connect the 17 resistance (R simultaneously ₁₇), the 4th electric capacity (C ₄), the 3rd electric capacity (C ₃) an end, the 17 resistance (R ₁₇) other end ground connection, the 4th electric capacity (C ₄) the negative terminal of another termination second amplifier (A2), the 3rd electric capacity (C ₃) the output terminal of another termination second amplifier (A2), the 7th resistance (R ₇) two ends be connected on the negative terminal and the output terminal of second amplifier (A2) respectively, the anode of second amplifier (A2) is by the 8th resistance (R ₈) ground connection, the output terminal of second amplifier (A2) connects the 5th electric capacity (C ₅) an end, the 5th electric capacity (C ₅) the other end connect the 9th resistance (R ₉) and the tenth resistance (R ₁₀), the 9th resistance (R ₉) other end ground connection, the tenth resistance (R ₁₀) the other end be connected to the negative terminal of the 3rd amplifier (A3), the positive ending grounding of the 3rd amplifier (A3), the output terminal of the 3rd amplifier (A3) is by the 12 resistance (R ₁₂) and the 11 resistance (R ₁₁) being connected to the negative terminal of the 3rd amplifier (A3), the output terminal of the 3rd amplifier (A3) is by the 13 resistance (R ₁₃) be connected to circulating controling circuit (12).

8. the damage-free measuring apparatus of a kind of cylindrical pressure vessel surface temperature according to claim 4 and pressure, the circuit that it is characterized in that described circulating controling circuit (12) is: coupling shaft is to ultrasound wave receiving circuit (11) or tangential ultrasound wave receiving circuit (13) respectively for the negative terminal of first high-speed comparator (U11) and second high-speed comparator (U12), and first high-speed comparator (U11) is connected identical comparative voltage with second high-speed comparator (U12) anode; The positive output end of first high-speed comparator (U11) connects the C end of first JK flip-flop (U1), the S end and the J termination power VCC of first JK flip-flop (U1), its K end ground connection, its Q end is connected to the B end of first monostalbe trigger (U5), first JK flip-flop (U1)

End be connected respectively to second JK flip-flop (U2) C end and the 3rd with the end of (U9); Second resistance (the R ₂) an end connect power supply VCC, the other end connects the first resistance (R ₁), the first resistance (R ₁) the other end be connected to the CX/RX end and the first electric capacity (C of first monostalbe trigger (U5) simultaneously ₁) an end, the first electric capacity (C ₁) the other end be connected to the CX end of first monostalbe trigger (U5), first monostalbe trigger (U5)

End connects single-chip microcomputer the 5th control line (cp5), first monostalbe trigger (U5)

End ground connection, first monostalbe trigger (U5)

End and single-chip microcomputer first control line (cp1) be connected first with two input ends of (U7), first is connected the R end of first JK flip-flop (U1) with the output terminal of door (U7), the S end and the J termination power VCC of second JK flip-flop (U2), its K end ground connection, its R end connects single-chip microcomputer the 3rd control line (cp3), its

The end be connected to the 4th with the door (U10) an input end; The positive output end of second high-speed comparator (U12) connects the C end of the 3rd JK flip-flop (U3), the S end and the J termination power VCC of the 3rd JK flip-flop (U3), its K end ground connection, its Q end is connected to the B end of second monostalbe trigger (U6), the 3rd JK flip-flop (U3)

End be connected respectively to the 4th JK flip-flop (U4) C end and the 3rd with the other end of (U9); The 4th resistance (R ₄) an end connect power supply VCC, the other end connects the 3rd resistance (R ₃), the 3rd resistance (R ₃) the other end be connected to the CX/RX end and the second electric capacity (C of second monostalbe trigger (U6) simultaneously ₂) an end, the second electric capacity (C ₂) the other end be connected to the CX end of second monostalbe trigger (U6), second monostalbe trigger (U6)

End connects single-chip microcomputer the 6th control line (cp6), second monostalbe trigger (U6)

End ground connection, second monostalbe trigger (U6) End and single-chip microcomputer second control line (cp2) be connected second with two input ends of (U8), second is connected the R end of the 3rd JK flip-flop (U3) with the output terminal of door (U8), the S end and the J termination power VCC of the 4th JK flip-flop (U4), its K end ground connection, its R end connects single-chip microcomputer the 4th control line (cp4), its

The end be connected to the 4th with the door (U10) another input end; Be divided into two-way with the output terminal of door (U9), the one road is connected to single-chip microcomputer (15), and one the road is connected to radiating circuit (10); Output terminal tie-time digital conversion circuit (14) with door (U10).

9. the damage-free measuring apparatus of a kind of cylindrical pressure vessel surface temperature according to claim 4 and pressure is characterized in that described time-to-digital conversion circuit (14) adopts split-second precision-digital quantizer TDC-GP2, is operated in the second range pattern.

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