Summary of the invention
The shortcoming of prior art in view of the above, the object of the present invention is to provide a kind of control system of material drying cylinder equipment, the control system that is used for solving prior art drying cylinder equipment can't satisfy the moisture requirement of tobacco oven dry, and problem such as the temperature survey of dryer surface is inaccurate in the existing control system.
Reach other relevant purposes for achieving the above object, the invention provides a kind of control system of material drying cylinder equipment, wherein, drying cylinder equipment comprises: material outlet, material inlet, the drum-type drying cylinder that is connected with the material gateway, be used to dry the air-heater of the tobacco on the described drying cylinder, and be used to discharge the steam valve of moisture in the drying cylinder, described control system comprises at least: sampling unit, the moisture measurement value of the described material outlet that is used to sample, the moisture measurement value of material inlet, the measured temperature of described drying cylinder side surface, the leaving air temp measured value of described air-heater and air-out velocity measurement; The moisture content of outlet control module that is connected with described sampling unit, the variation that is used for the moisture measurement value of moisture measurement value, material inlet according to the material outlet of being sampled are revised air-out speed setting value, and the surface temperature of drier setting value of the leaving air temp setting value of described air-heater, air-heater; The steam valve control module that is connected with described sampling unit and moisture content of outlet control module, be used for controlling the folding size of described steam valve, to adjust the steam pressure in the drying cylinder according to the described surface temperature of drier setting value and the difference of the measured temperature of being sampled; The air-heater control module that is connected with described sampling unit and moisture content of outlet control module, be used for controlling described air-heater with the difference of the leaving air temp measured value of being sampled and change leaving air temp, and control described air-heater change air-out speed according to the air-out speed setting value and the difference of the air-out velocity measurement of being sampled according to described leaving air temp setting value.
Preferably, described sampling unit comprises:
Be used to sample at least one first temperature sampling module of described drying cylinder side surface measured temperature comprises:
Be attached at the temperature sensor of the side surface between the drying materials district of described drying cylinder bottom surface and drying cylinder side surface;
Be installed in described temperature sensor rear end and described temperature sensor be pressed in the spring assembly of described drying cylinder side surface;
The rotating speed sampling module of rotating speed measured value of described air-heater is used to sample;
The second temperature sampling module of leaving air temp measured value of described air-heater is used to sample;
The Moisture Meter of moisture measurement value of described material outlet and material inlet is used to sample.
Preferably, described temperature sensor is wired contact type temperature sensor.
Preferably, described moisture content of outlet control module comprises: the feedforward compensation module that is connected with described sampling unit, be used for utilizing the PI control algolithm to come real-time moisture measurement value to carry out the compensation budget of material in the control hysteresis of drying course to the material inlet of being sampled, and the output budget result; The moisture content of outlet control module that is connected with described sampling unit and feedforward compensation module, be used to utilize default PID control algolithm to determine the control component of material outlet moisture setting value and the pairing moisture content of outlet of difference of the moisture measurement value of the material outlet of being sampled, and according to described control component and budget result revise leaving air temp setting value, the air-heater of air-heater the air-out speed setting value, and surface temperature of drier set value.
Preferably, described moisture content of outlet control module also is used for having obtained considering according to the shared separately weight of described control component and budget result the controlled quentity controlled variable of compensation budget, and with described controlled quentity controlled variable respectively with the air-out speed setting value of the leaving air temp setting value of default air-heater, air-heater, and the amplification coefficient of surface temperature of drier setting value amplify computing, obtain air-out speed setting value, and the surface temperature of drier setting value of leaving air temp setting value, the air-heater of revised air-heater.
Preferably, described steam valve control module comprises: with first temperature transmitter that each described temperature sensor is connected, the measured temperature that is used for sampling according to each described temperature sensor is determined the measured temperature in the drying materials district of described drying cylinder side surface; The steam valve control module that is connected with described first temperature transmitter, be used for carrying out pid control computation according to the resulting a plurality of measured temperature of repeatedly sampling, obtaining the controlled quentity controlled variable of described steam valve, and control the folding degree of described steam valve according to the controlled quentity controlled variable of described steam valve.
Preferably, described air-heater control module comprises: the wind speed transmitter that is connected with described rotating speed sampling module converts the rotating speed measured value of the air-heater of being sampled to according to the corresponding relation of the rotating speed of default air-heater and air-out speed the air-out velocity measurement of described air-heater; The first air-heater control module that is connected with described wind speed transmitter, be used for carrying out pid control computation according to the resulting a plurality of described air-out velocity measurement of repeatedly sampling, obtaining the controlled quentity controlled variable of the air supply motor in the described air-heater, and control the power output of described air supply motor according to the controlled quentity controlled variable of described air supply motor.
Preferably, described air-heater control module comprises: with second temperature transmitter that the described second temperature sampling module is connected, the leaving air temp measured value that is used for the air-heater of will be sampled carries out digitlization and amplification; The second air-heater control module that is connected with described second temperature transmitter, be used for carrying out pid control computation according to the resulting a plurality of leaving air temp measured value of repeatedly sampling, obtaining the controlled quentity controlled variable of the heater in the described air-heater, and control the power output of described heater according to the controlled quentity controlled variable of described heater.
As mentioned above, the control system of material drying cylinder equipment of the present invention, has following beneficial effect: each measured value relevant in the real-time sampling drying cylinder equipment with moisture content of outlet, and by the moisture content of outlet control module according to measured value and default control model and control circuit to the air-heater control module, the steam valve control module provides corresponding setting value, and by the air-heater control module, the steam valve control module is controlled corresponding air-heater and steam valve according to the difference of measured value of being sampled and setting value separately, so simultaneously the multiple arrangement in the drying cylinder equipment relevant with drying materials moisture is controlled, guaranteed that the maximum deviation of material outlet moisture is controlled in 1.5%.
The specific embodiment
Below by particular specific embodiment explanation embodiments of the present invention, person skilled in the art scholar can understand other advantages of the present invention and effect easily by the disclosed content of this specification.
See also Fig. 1 to Fig. 3.Notice, the appended graphic structure that illustrates of this specification, ratio, size etc., all only in order to cooperate the content that specification disclosed, understand and reading for person skilled in the art scholar, be not in order to limit the enforceable qualifications of the present invention, event is the technical essential meaning of tool not, the adjustment of the modification of any structure, the change of proportionate relationship or size, not influencing under effect that the present invention can produce and the purpose that can reach, all should still drop on disclosed technology contents and get in the scope that can contain.Simultaneously, quoted in this specification as " on ", D score, " left side ", " right side ", " centre " reach the term of " " etc., also only for ease of understanding of narrating, but not in order to limit the enforceable scope of the present invention, the change of its relativeness or adjustment, under no essence change technology contents, when also being considered as the enforceable category of the present invention.
The invention provides a kind of control system of material drying cylinder equipment.Described control system is used for controlling the moisture of the tobacco that drying cylinder equipment dried, and the moisture of the tobacco after the oven dry is remained in the specified scope, to improve the quality of tobacco.Wherein, as shown in Figure 1, described drying cylinder equipment comprises: material outlet 23, material inlet 21, go out/enter the mouth the drum-type drying cylinder 22 that is connected, the steam valve 24 that is used to dry the air-heater 25 of the tobacco on the described drying cylinder and is used to discharge dryer surface moisture with material.Wherein, described air-heater comprises heater and air supply motor.As shown in Figure 2, described control system comprises: sampling unit 11, moisture content of outlet control module 12, air-heater control module 14, steam valve control module 13.
Described sampling unit 11 be used to the sample measured temperature of the moisture measurement value of described material outlet 23, the moisture measurement value of material inlet 21, described drying cylinder 22 side surfaces, the leaving air temp measured value and the air-out velocity measurement of described air-heater 25.
Particularly, described sampling unit 11 comprises: the first temperature sampling module, rotating speed sampling module, second temperature sampling module and the Moisture Meter.
The described first temperature sampling module described drying cylinder side surface measured temperature that is used to sample.It also can be a plurality of that its quantity can be one.As shown in Figure 3.The described first temperature sampling module comprises: temperature sensor 111 and spring assembly 112.
Particularly, described temperature sensor 111 is attached at the side surface between the drying materials district of described drying cylinder bottom surface and drying cylinder side surface.Described temperature sensor 111 is mainly contact type temperature sensor.Described contact type temperature sensor is preferably wired contact type temperature sensor.
Described spring assembly 112 is installed in described temperature sensor 111 rear ends and described temperature sensor 111 is pressed in described drying cylinder side surface.Wherein, described spring assembly 112 can comprise spring or spring leaf.
Particularly, described spring assembly 112 is fixed on the support of described drying cylinder, and the spring in the described spring assembly 112 is by described temperature sensor 111 crimps, and described temperature sensor 111 is subjected to the active force of spring to be close to the side surface of drying cylinder 22.When described drying cylinder 22 rotates, the side surface of described temperature sensor 111 and described drying cylinder 22 is to friction, therefore described temperature sensor 111 can be worn, but because the active force of spring, can not produce the slit between the side surface of temperature sensor 111 and described drying cylinder 22, so can measure the measured temperature of described side surface exactly.
Described rotating speed sampling module be used to the to sample rotating speed measured value of described air-heater.
Particularly, described rotating speed sampling module is connected with the air supply motor of described air-heater, calculates the current rotating speed of described air supply motor by the parameters such as power output of obtaining air supply motor.The hardware of described rotating speed sampling module comprises: be connected and be used to obtain the sampling resistor of the air supply motor output signal of telecommunication with air supply motor, be connected with sampling resistor and be used for the DSP according to the current rotating speed of default formula calculating air supply motor.
The described second temperature sampling module be used to the to sample leaving air temp measured value of air-heater.Particularly, the described second temperature sampling module is positioned at the air outlet of described air-heater, with the leaving air temp measured value of the air outlet that obtains air-heater.The described second temperature sampling module can be non-contact temperature sensor.
Described Moisture Meter lays respectively at material outlet and material inlet, the moisture measurement value of be used to sample described material outlet and material inlet.
Described moisture content of outlet control module 12 is connected with described sampling unit 11, and air-out speed setting value, and the surface temperature of drier setting value of the leaving air temp setting value of described air-heater, air-heater revised in the variation that is used for the moisture measurement value of moisture measurement value, material inlet according to the material outlet of being sampled.
Particularly, described moisture content of outlet control module 12 is done difference with the moisture measurement value of the moisture measurement value of the material inlet of described Moisture Meter sampling, material outlet respectively with default material inlet, material outlet moisture setting value and is calculated, again according to default corresponding difference interval respectively with the segmentation corresponding relation of leaving air temp setting value, air-out speed setting value and surface temperature of drier setting value, determine resulting difference pairing each set value.
Preferably, described moisture content of outlet control module 12 comprises: feedforward compensation module, moisture content of outlet control module.
Described feedforward compensation module is connected with the Moisture Meter of described material inlet, is used for utilizing the PI control algolithm to come real-time moisture measurement value to the material inlet of being sampled to carry out the compensation budget of material in the control hysteresis of drying course, and the output budget result.Wherein, the module of described feedforward compensation module for carrying out big numerical quantity, logical operation according to default program, it includes but not limited to: processor, FPGA, DSP etc.
Particularly, described feedforward compensation module is utilized formula (1):
Compensate budget, wherein, T
InBe the moisture measurement value of material inlet, preferably, T
InBe the matrix of the moisture measurement value that comprises material inlet, drying cylinder rotating speed, gas hood hot blast temperature, gas hood hot blast wind speed,
The inertial element of representing described feedforward compensation module, e
-τ sRepresent hysteresis (delay) link of described feedforward compensation module, Kp represents proportional component (being proportionality coefficient), Y
1(s) be the result of budget, described feedforward compensation module is with Y
1(s) exported.
Described moisture content of outlet control module is connected with the Moisture Meter of described feedforward compensation module and described material outlet, be used to utilize default PID control algolithm to determine the control component of material outlet moisture setting value and the pairing material outlet moisture of difference of the moisture measurement value of the material outlet of being sampled, and according to described control component and budget result revise leaving air temp setting value, the air-heater of air-heater the air-out speed setting value, and surface temperature of drier set value.Wherein, described moisture content of outlet control module comprises subtracter and the processor that is connected with described subtracter output, described processor is mainly a kind of module that can carry out big numerical quantity, logical operation according to default program, and it includes but not limited to: FPGA, single-chip microcomputer etc.
Particularly, described moisture content of outlet control module is utilized formula (2):
Calculate the control component of material outlet moisture, wherein,
Be the PID control coefrficient, △ T
OutPoor for the moisture measurement value of material outlet moisture setting value and the material outlet of being sampled, Y
2(s) be the control component;
Then, the shared separately weight of control component that described moisture content of outlet control module basis is default and budget result has obtained considering the controlled quentity controlled variable of compensation budget, and with described controlled quentity controlled variable respectively with the air-out speed setting value of the leaving air temp setting value of default air-heater, air-heater, and the amplification coefficient of surface temperature of drier setting value amplify computing, obtain air-out speed setting value, and the surface temperature of drier setting value of leaving air temp setting value, the air-heater of revised air-heater.
For example, the weight of described control component is 0.7, the weight of budget result is 0.3, the controlled amount Y of then described moisture content of outlet control module (s) is 0.7*Y2 (s)+0.3*Y1 (s), amplification coefficient according to the leaving air temp setting value of default air-heater is 5.3 again, the leaving air temp setting value that obtains air-heater is Y (s) * 5.3, similarly, the amplification coefficient of the air-out speed setting value of default air-heater is 0.5, the air-out speed setting value that obtains air-heater is Y (s) * 0.5, the amplification coefficient of default surface temperature of drier setting value is 20, obtains the surface temperature of drier setting value and is Y (s) * 20.
Described steam valve control module 13 is connected with described sampling unit 11 and moisture content of outlet control module 12, be used for controlling the folding size of described steam valve, to adjust the steam pressure in the drying cylinder according to the described surface temperature of drier setting value and the difference of the measured temperature of being sampled.
Particularly, the corresponding relation of described steam valve control module 13 default described surface temperature of drier differences intervals and described steam valve folding degree, and the difference of determining resulting described surface temperature of drier setting value and the measured temperature of being sampled is in which temperature gap interval range, determine the interval pairing steam valve folding degree of relevant temperature difference again, and send control corresponding to described steam valve and instruct, for example, when described steam valve when the folding degree becomes big under control instruction, steam pressure in the described drying cylinder so can discharge more moisture in the drying cylinder from large to small.
Preferably, described steam valve control module 13 comprises: first temperature transmitter, steam valve control module.
Described first temperature transmitter is connected with each described first temperature sensor, is used for determining according to the measured temperature that each described first temperature sensor is sampled the measured temperature in the drying materials district of described drying cylinder side surface.
Particularly, described first temperature transmitter obtains the measured temperature that first temperature sensor of described drying cylinder side surface diverse location is sampled, and all measured temperatures of being sampled are carried out modeling according to the temperature model of default drying cylinder side surface, covered the measured temperature in the oven dry zone of material with simulation.
Described steam valve control module is connected with described first temperature transmitter, be used for carrying out pid control computation according to the resulting a plurality of measured temperature of repeatedly sampling, obtaining the controlled quentity controlled variable of described steam valve, and control the folding degree of described steam valve according to the controlled quentity controlled variable of described steam valve.
Particularly, described steam valve control module is with the continuous three times resulting measured temperature substitution formula (3) of sampling:
Obtain the controlled quentity controlled variable of described steam valve, and according to the corresponding relation of the folding degree of default controlled quentity controlled variable and steam valve, convert described controlled quentity controlled variable to corresponding control instruction to described steam valve, to control the switching degree of described steam valve, so that the water vapour content in the drying cylinder keeps stable.Wherein, Y (t)
K1Be the controlled quentity controlled variable of current described steam valve control module output, Y (t)
K1-1Be the controlled quentity controlled variable of described steam valve control module output of last cycle, E
1Be the error of representing with the range of temperature percentage of being sampled, particularly, E
1=(k1 measured temperature-desired temperature)/desired temperature-((k1-1) individual measured temperature-desired temperature)/desired temperature, Δ E
1Be (E
K1-E
K1-1), Δ t
1Be circuit controls update time, K
P1Be proportional gain factor, K
I1Be integration gain factor, K
D1Be differential gain coefficient.Wherein, K
P1=0.8, K
I1=90, K
D1=5.
Described air-heater control module 14 is connected with described sampling unit 11 and moisture content of outlet control module 12, be used for controlling described air-heater with the difference of the leaving air temp measured value of being sampled and change leaving air temp, and control described air-heater change air-out speed according to the air-out speed setting value and the difference of the air-out velocity measurement of being sampled according to described leaving air temp setting value.
Particularly, described air-heater control module 14 prestores the corresponding relation of the heating power of the excursion of leaving air temp and air-heater, and the corresponding relation of the power output of the air supply motor of the excursion of air-out speed and air-heater, the pairing heating power of difference of the leaving air temp measured value of then determining described leaving air temp setting value and being sampled according to the excursion of the leaving air temp that prestores, and send temperature control instruction to described air-heater, so that described air-heater changes heating power; Simultaneously, described air-heater control module 14 is determined the power output of described air-out speed setting value and the pairing air supply motor of difference of the air-out velocity measurement of being sampled according to the excursion of the air-out speed that prestores, and send power control instruction to described air-heater, so that described air-heater changes the power output of air supply motor.
Described air-heater control module 14 preferably includes: wind speed transmitter, the first air-heater control module, second temperature transmitter, the second air-heater control module.
Described wind speed transmitter is connected with described rotating speed sampling module, is used for according to the corresponding relation of the rotating speed of default air-heater and outlet wind speed the rotating speed measured value of the air-heater of being sampled being converted to the outlet measuring wind speed value of described air-heater;
For example, prestore in the described wind speed transmitter four groups of rotating speed intervals respectively with the corresponding relation of the outlet wind speed of described air-heater, and determine resulting rotating speed measured value in which rotating speed interval, determine the interval pairing outlet measuring wind speed value of corresponding rotating speeds again.
And for example, the linear relation of described wind speed transmitter preset rotation speed and outlet measuring wind speed value, and the rotating speed measured value of the air-heater of being sampled is converted to the outlet measuring wind speed value of described air-heater according to described relational expression.
The described first air-heater control module is connected with described wind speed transmitter, be used for carrying out pid control computation according to the resulting a plurality of described air-out velocity measurement of repeatedly sampling, obtaining the controlled quentity controlled variable of the air supply motor in the described air-heater, and control the power output of described air supply motor according to the controlled quentity controlled variable of described air supply motor.
Particularly, the described first air-heater control module is with the continuous three times resulting air-out velocity measurement substitution formula (4) of sampling:
Obtain the controlled quentity controlled variable of the air-out speed of described air-heater, and according to the corresponding relation of the power output of air supply motor in default controlled quentity controlled variable and the air-heater, convert described controlled quentity controlled variable to corresponding control instruction, to control the power output of described air supply motor to described air supply motor.Wherein, Y (t)
K2Be the controlled quentity controlled variable of current described first air-heater control module output, Y (t)
K2-1Be the controlled quentity controlled variable of described first air-heater control module output of last cycle, E
2Be the error of representing with the air-out velocity variations range percentage of being sampled, particularly, E
2=(k2 air-out velocity measurement-air-out speed setting value)/air-out speed setting value-((k2-1) individual air-out velocity measurement-air-out speed setting value)/air-out speed setting value, Δ E
2Be (E
K2-E
K2-1), Δ t
2Be circuit controls update time, K
P2Be proportional gain factor, K
I2Be integration gain factor, K
D2Be differential gain coefficient.Wherein, K
P2=0.4, K
I2=10, K
D2=2.
Described second temperature transmitter is connected with the described second temperature sampling module, and the leaving air temp measured value that is used for the air-heater of will be sampled carries out digitlization and amplification.
Particularly, the leaving air temp measured value that the described second temperature sampling module is sampled is an analog signal, then described second temperature transmitter becomes data signal with described analog signal conversion, and amplifies, the data signal that requires with the input that is met the second air-heater control module.
The described second air-heater control module is used for carrying out pid control computation according to the resulting a plurality of leaving air temp measured value of repeatedly sampling, obtaining the controlled quentity controlled variable of the heater in the described air-heater, and control the power output of described heater according to the controlled quentity controlled variable of described heater.
Particularly, the described second air-heater control module is with the continuous three times resulting leaving air temp measured value substitution formula (5) of sampling:
Obtain the controlled quentity controlled variable of the leaving air temp of described air-heater, and according to the corresponding relation of the power output of heater in default controlled quentity controlled variable and the air-heater, convert described controlled quentity controlled variable to corresponding control instruction, to control the power output of described heater to described heater.Wherein, Y (t)
K3Be the controlled quentity controlled variable of current described second air-heater control module output, Y (t)
K3-1Be the controlled quentity controlled variable of described second air-heater control module output of last cycle, E
3Be the error of representing with the leaving air temp excursion percentage of being sampled, particularly, E
3=(k3 leaving air temp measured value-leaving air temp setting value)/leaving air temp setting value-((k3-1) individual leaving air temp measured value-leaving air temp setting value)/leaving air temp setting value, Δ E
3Be (E
K3-E
K3-1), Δ t
3Be circuit controls update time, K
P3Be proportional gain factor, K
I3Be integration gain factor, K
D3Be differential gain coefficient.Wherein, K
P3=0.5, K
I3=25, K
D3=3.
The course of work of described control system is as follows:
Described sampling unit sample the leaving air temp measured value and the air-out velocity measurement of the moisture measurement value of described material outlet, the moisture measurement value of material inlet, the measured temperature of described drying cylinder side surface, described air-heater, and each measured value of being sampled is packaged together, be defeated by moisture content of outlet control module, steam valve control module and air-heater control module;
Feedforward compensation module in the described moisture content of outlet control module is with the moisture measurement value substitution formula (1) of the material inlet of the being sampled result with the compensation budget that obtains being used for control hysteresis, and described budget result offered the moisture content of outlet control module, described moisture content of outlet control module is earlier with the moisture measurement value substitution formula (2) of the material outlet of being sampled, controlled component, and according to the weight relationship of controlling component and budget result, obtained considering the controlled quentity controlled variable of budget result, simultaneously, according to steam valve in the dryer, heater in the air-heater, rise to such an extent that effect is big or small in each comfortable oven dry material of air supply motor in the air-heater, described controlled quentity controlled variable is amplified in default ratio, to obtain the leaving air temp setting value of air-heater respectively, the air-out speed setting value of air-heater, and surface temperature of drier setting value, and with the leaving air temp of air-heater setting value, the air-out speed setting value of air-heater is transported to the air-heater control module, and the surface temperature of drier setting value is transported to the steam valve control module;
The temperature sensor that is attached to the drying cylinder side surface in the described steam valve control module is given first temperature transmitter with measured measured temperature by wire transmission, calculate the measured temperature in oven dry material zone in the drying cylinder side surface according to pre-established temperature model by first temperature transmitter, and resulting measured temperature offered the steam valve control module, come the controlled quentity controlled variable of controlled steam valve folding degree by described steam valve control module according to measured temperature that repeatedly obtains and formula (3), and control the folding degree of steam valve in real time;
Wind speed transmitter in the described air-heater control module converts the rotating speed measured value of air supply motor in the air-heater of being sampled to the air-out velocity measurement, and come the controlled quentity controlled variable of the power output of controlled air supply motor according to the air-out velocity measurement that repeatedly obtains and formula (4), and control the power output of air supply motor in real time by the first hot blast control module;
Simultaneously, second temperature transmitter in the described air-heater control module carries out digitlization and amplification with the leaving air temp measured value of the air-heater of being sampled, to be met the leaving air temp measured value that the subtracter input requires in the second air-heater control module, and by the controlled quentity controlled variable of the second air-heater control module, and the power output of real-time control heater according to the power output of leaving air temp measured value that repeatedly obtains and the next controlled heater of formula (5).
In sum, the control system of material drying cylinder equipment of the present invention, each measured value relevant in the real-time sampling drying cylinder equipment with moisture content of outlet, and by the moisture content of outlet control module according to measured value and default control model and control circuit to the air-heater control module, the steam valve control module provides corresponding setting value, and by the air-heater control module, the steam valve control module is controlled corresponding air-heater and steam valve according to the difference of measured value of being sampled and setting value separately, so simultaneously the multiple arrangement in the drying cylinder equipment relevant with drying materials moisture is controlled, guaranteed that the maximum deviation of material outlet moisture is controlled in 1.5%; In addition, in the moisture content of outlet control module, add feedforward compensation mechanism, can predict the lag factor of control system in the drying course, each setting value thus upgrades in time, so that in time change the control instruction of air-heater control module, the output of steam valve control module, so further increase the stability of material moisture content of outlet; In addition, temperature sensor in the first temperature sampling module is positioned over the side surface between the drying materials district of described drying cylinder bottom surface and drying cylinder side surface, can measure the temperature of side surface accurately, the simultaneous temperature sensor adopts wired temperature sensor, can avoid because of drying environment abominable, the shortcoming that the signal of radio temperature sensor can't accurately obtain.So the present invention has effectively overcome various shortcoming of the prior art and the tool high industrial utilization.
The foregoing description is illustrative principle of the present invention and effect thereof only, but not is used to limit the present invention.Any person skilled in the art scholar all can be under spirit of the present invention and category, and the foregoing description is modified or changed.Therefore, have in the technical field under such as and know that usually the knowledgeable modifies or changes not breaking away from all equivalences of being finished under disclosed spirit and the technological thought, must be contained by claim of the present invention.