A kind of thermocouple dynamic response test system and its method of testing
Technical field
The present invention designs a kind of thermocouple dynamic response test system and its method of testing, belongs to power system technology neck
Domain.
Background technology
" temperature " as one of most important thermal parameter in thermal power plant, its accurate measurement is directly related to the peace of unit
Full stable operation, tripping, malfunction to preventing unit, and timely temperature protection suffers from vital effect.
Thermocouple temperature sensor is also very extensive as one of main temperature element, its application in thermal power plant.
Understand its performance characteristics, grasp the factor for influenceing temperature measurement accuracy and thermal response time, be advantageous to more reasonably carry out technology to it
Specification.When preventing the failures such as high temperature alarm, high temperature tripping operation, the sequential control of unit can be realized in time and is automatically adjusted, it is right
The safety and stability for improving unit suffers from profound significance.
The content of the invention
The present invention is in order to solve drawbacks described above present in prior art and deficiency, there is provided a kind of thermocouple dynamic response
Test system and its method of testing, can be that power plant and grid equipment carry by studying thermocouple temperature sensor dynamic characteristic
For " temperature signal bad value criterion ", the threshold value for avoiding temperature signal sets unreasonable, and makes under temperature discrimination function accuracy
Drop, cause false protection or tripping and then cause unit or capital equipment to trip, cause that unit is unplanned to subtract output, to electric power
System brings unnecessary loss.
In order to solve the above technical problems, the present invention provides a kind of thermocouple dynamic response test system, including dry type stove, heat
Galvanic couple, thermocouple signal acquisition module, modular converter, power supply and industrial computer, the industrial computer respectively with the dry type stove, described
Modular converter is connected, and the thermocouple is connected with the dry type stove, thermocouple signal acquisition module respectively, the thermocouple signal
Acquisition module is connected with the modular converter.
Preferably, the thermocouple is K-type or E types.
Preferably, the length of the K-type thermocouple is 15cm, a diameter of 1-5mm.
Preferably, the length of the E types thermocouple is 15cm, a diameter of 2-5mm.
Preferably, the model I-7018 of the thermocouple signal acquisition module.
Preferably, the model I-7520 of the modular converter.
Preferably, the industrial computer is connected by RS-232 serial ports with the modular converter.
Preferably, the industrial computer is connected by RS-232 serial ports with the dry type stove.
Preferably, the power supply is DR-75-24 Switching Power Supplies.
A kind of method of testing of thermocouple dynamic response test system, comprises the following steps:
Step 1, founding mathematical models;
1) turn on the power, connection line, start computer, check whether equipment is normal, and heat up to dry type stove;Meanwhile
Application program is run, sets dut temperature and acquisition time, selects receiving port and collection period;When dry type stove is warming up to setting
When temperature and stabilization, thermocouple is inserted in dry type stove, while clicks on " starting to gather " button on industrial computer interface, experiment is opened
Begin;
2) in experimentation, keep thermocouple to fix, until response curve is steady, clicks on and " stop on industrial computer interface
Only gather " button, thermocouple is taken out, is put into mixture of ice and water and cools down, " the preservation data " clicked on industrial computer interface are pressed
Button, preserve experimental data and image;
3) after thermocouple is cooled to room temperature, the setting of the depth, dry type stove in thermocouple insertion dry type stove is changed respectively
The diameter of temperature and thermocouple, repeat step 1) and step 2), the step for obtaining the insertion depth of thermocouple, temperature and diameter rings
Answer curve, establish under the conditions of different thermoelectricity dual diameters, relationship between relative error and insertion depth and temperature, when
Between relationship between constant and insertion depth and temperature;
Step 2, thermocouple dynamic analysis to be measured;
Repeat step 1) and step 2) collection thermoelectricity even data to be measured, data are substituted into mathematical modeling, calculated to be measured
The relative error and time constant of thermocouple, dynamic characteristic is analyzed, and verify that the precision of thermocouple to be measured is according to analysis result
It is no to meet required precision, determine choosing whether rationally for thermometric position.
The advantageous effects that the present invention is reached:The present invention simulates the steady of thermocouple temperature measurement by founding mathematical models
Step response, and the influence of thermoelectricity dual diameter, temperature, insertion depth to its precision and dynamic response is obtained, thermocouple is made,
Choose and thermometric has directive significance., can be by this meanwhile the mathematical modeling established and fitting experimental data degree are higher
Based on model, obtain under different conditions, a certain specific performance parameter value of thermocouple, to improve its steady-state characteristic and dividing
The amendment of analysis result provides foundation.
Brief description of the drawings
The thermocouple dynamic response test system building block of Fig. 1 present invention and each part connection relationship diagram;
Fig. 2 specific embodiment of the invention modeling process schematic flow sheets;
Embodiment
In order to be better understood by technical characteristic, technology contents and its technique effect reached of the present invention, now this is sent out
Bright accompanying drawing is described in detail in conjunction with the embodiments.
Patent of the present invention is further illustrated with reference to the accompanying drawings and examples.
As shown in figure 1, the present invention provides a kind of thermocouple dynamic response test system, including dry type stove, thermocouple, thermoelectricity
Even signal acquisition module, modular converter, power supply and industrial computer, the industrial computer respectively with the dry type stove, the modular converter
It is connected, the thermocouple is connected with the dry type stove, thermocouple signal acquisition module respectively, the thermocouple signal acquisition module
It is connected with the modular converter.The thermocouple is K-type or E types.Because the temperature in use of thermocouple is by material specification and diameter
Influence, therefore, the length of the K-type thermocouple is 15cm, a diameter of 1-5mm, and positive pole uses nickel chromium triangle, and negative pole uses nisiloy;
The length of the E types thermocouple is 15cm, a diameter of 2-5mm, and positive pole uses nickel chromium triangle, and negative pole uses cupro-nickel.The thermocouple letter
The model I-7018 of number acquisition module.The model I-7520 of the modular converter.The industrial computer passes through RS-232 serial ports
It is connected with the modular converter.The industrial computer is connected by RS-232 serial ports with the dry type stove.The power supply is DR-75-
24 Switching Power Supplies.Wherein, I-7018 modules are 8 path thermocouple input modules, and its parameter is as shown in table 1;I-7520 moduluss of conversion
Block is used to RS-232 being converted to RS-485, and its pin assignment and specification are as shown in table 2;Power supply uses dc source, power supply model
Enclose and be more than the summation of the consumption power of whole system for 10V~30V, the rated power of power supply unit.
Table 1:The parameter of I-7018 modules
Table 2:I-7520 modular converters pin assignment and specification
As shown in Fig. 2 a kind of method of testing of thermocouple dynamic response test system, comprises the following steps:
Step 1, founding mathematical models;
1) turn on the power, connection line, start computer, check whether equipment is normal, and heat up to dry type stove;Meanwhile
Application program is run, sets dut temperature and acquisition time, selects receiving port and collection period;When dry type stove is warming up to setting
When temperature and stabilization, thermocouple is inserted in dry type stove, while clicks on " starting to gather " button on industrial computer interface, experiment is opened
Begin;
2) in experimentation, keep thermocouple to fix, until response curve is steady, clicks on and " stop on industrial computer interface
Only gather " button, thermocouple is taken out, is put into mixture of ice and water and cools down, " the preservation data " clicked on industrial computer interface are pressed
Button, preserve experimental data and image;
3) after thermocouple is cooled to room temperature, the setting of the depth, dry type stove in thermocouple insertion dry type stove is changed respectively
The diameter of temperature and thermocouple, repeat step 1) and step 2), the step for obtaining the insertion depth of thermocouple, temperature and diameter rings
Answer curve, establish under the conditions of different thermoelectricity dual diameters, relationship between relative error and insertion depth and temperature, when
Between relationship between constant and insertion depth and temperature;So as to intuitively find out very much thermocouple insertion depth, diameter pair
The influence of thermocouple temperature measurement performance, rational thermocouple temperature sensor is selected to thermometric position different in thermal power plant,
To realize that the minimum of temperature lag has certain directiveness to act on.
Step 2, thermocouple dynamic analysis to be measured;
Repeat step 1) and step 2) collection thermoelectricity even data to be measured, data are substituted into mathematical modeling, calculated to be measured
The relative error and time constant of thermocouple, dynamic characteristic is analyzed, and verify that the precision of thermocouple to be measured is according to analysis result
It is no to meet required precision, determine choosing whether rationally for thermometric position.
Specific embodiment
In order to verify the feasibility of thermocouple dynamic response test system and its method of testing provided by the invention, respectively with
K-type and E types thermocouple are as standard couple founding mathematical models.
Table 3:K-type thermocouple relative error and the relational expression of dut temperature and insertion depth
Wherein, cNDuring-Ф=N (mm), relative error during K-type thermocouple measurement;
bNDuring-Ф=N (mm), dut temperature;
dNDuring-Ф=N (mm), the insertion depth of K-type thermocouple;
N=1,2,3,4, or 5.
Table 4:K-type thermocouple time constant and the relational expression of dut temperature and insertion depth
Wherein, eNDuring-Ф=N (mm), the time constant of K-type thermocouple;
bNDuring-Ф=N (mm), dut temperature;
dNDuring-Ф=N (mm), the insertion depth of K-type thermocouple;
N=1,2,3,4, or 5.
1), K-type thermocouple, under different-diameter state, obtain its relative error and time constant respectively with temperature and insert
Enter the relational expression between depth, as shown in Table 3 and Table 4, temperature is respectively 100 DEG C, 200 DEG C, 300 DEG C, 400 DEG C, insertion depth
Respectively 2cm, 6cm, 8cm, 10cm, 14cm.
For the accuracy of the mathematical modeling shown in proof list 3 and table 4, take Ф=5mm K-type thermocouple to be used as and treat
Calorimetric galvanic couple is tested, and measurement temperature is respectively 100 DEG C, 200 DEG C, 300 DEG C, 400 DEG C, insertion depth be respectively 2cm, 6cm,
8cm, 10cm, 14cm have carried out data acquisition such as table 5:
Table 5:K-type thermocouple interpretation to be measured
Bring above-mentioned data into above-mentioned corresponding mathematic(al) representation, calculate the precision of K-type thermocouple to be measured, meeting its precision will
Ask, illustrate that above-mentioned mathematical modeling can conveniently verify the relevant issues such as whether selected thermocouple reasonable, be power generation
During temperature detection provide fast and accurately measuring method.
Table 6:E type thermocouple relative errors and the relational expression of dut temperature and insertion depth
Wherein, cNDuring-Ф=N (mm), relative error during K-type thermocouple measurement;
bNDuring-Ф=N (mm), dut temperature;
dNDuring-Ф=N (mm), the insertion depth of K-type thermocouple;
N=1,2,3,4, or 5.
Table 7:E type thermocouple time constants and the relational expression of dut temperature and insertion depth
Wherein, eN--- during Ф=N (mm), the time constant of E type thermocouples;
bN--- during Ф=N (mm), dut temperature;
dN--- during Ф=N (mm), the insertion depth of E type thermocouples;
N=1,2,3,4, or 5.
2), E types thermocouple, it is deep with temperature and insertion respectively that relative error and time constant are obtained under different-diameter state
Relational expression between degree, as shown in table 6 and table 7, temperature are respectively 100 DEG C, 200 DEG C, 300 DEG C, 400 DEG C, insertion depth difference
For 2cm, 6cm, 8cm, 10cm, 14cm.
For the accuracy of the mathematical modeling shown in proof list 6 and table 7, take Ф=3mm E types thermocouple to be used as and treat
Calorimetric galvanic couple is tested, and measurement temperature is respectively 100 DEG C, 200 DEG C, 300 DEG C, 400 DEG C, insertion depth be respectively 2cm, 6cm,
8cm, 10cm, 14cm have carried out data acquisition such as table 8:
Table 8:E types thermocouple interpretation to be measured
Bring above-mentioned data into above-mentioned corresponding mathematic(al) representation, calculate the precision of E types thermocouple to be measured, meeting its precision will
Ask, illustrate that above-mentioned mathematical modeling can conveniently verify the relevant issues such as whether selected thermocouple reasonable, be power generation
During temperature detection provide fast and accurately measuring method.
The present invention is disclosed with preferred embodiment above, so it is not intended to limiting the invention, all to take equivalent substitution
Or the technical scheme that the scheme of equivalent transformation is obtained, all fall within protection scope of the present invention.