CN105974876A

CN105974876A - Industrial gas temperature control method

Info

Publication number: CN105974876A
Application number: CN201610325386.2A
Authority: CN
Inventors: 王青川; 苟宏叶
Original assignee: Shannxi Diesel Engine Heavy Industry Co Ltd
Current assignee: Shannxi Diesel Engine Heavy Industry Co Ltd
Priority date: 2016-05-17
Filing date: 2016-05-17
Publication date: 2016-09-28

Abstract

The invention relates to an industrial gas temperature control method, and solves technical problems that a conventional industrial gas temperature control system frequently has a flameout fault, and cannot be ignited again. The method achieves re-ignition in a mode of big-fire time sequence control and small-fire continuous burning, avoids a bottleneck that re-ignition cannot be achieved, carries out temperature compensation through the big-fire time sequence ignition, and achieves the precise control of the furnace temperature. The method is widely used in the technical field of industrial gas temperature control.

Description

A kind of industrial gas temperature-controlled process

Technical field

The present invention relates to a kind of temperature-controlled process, particularly relate to a kind of industrial gas temperature-controlled process.

Background technology

In the market industrial gas is realized temperature-controlled process mainly to have: the methods such as cold rolled continuous annealing stove control method, galvanization production line annealing furnace method for controlling combustion, annealing furnace system based on PLC and temperature control system based on fuzzy-adaptation PID control.

Because moisture content in industrial gas, ash grade, impurity is the most, and calorific value is low, uses conventional temp. control method to there is combustion process unstable, frequently occur flame-out fault, also can not again light a fire, need blow-on again, clear up, the fault such as igniting, he system failure rate is the highest, thus causes parts frequently to interrupt in performing heat treatment process, form repeatedly heat treatment, process curve is imperfect, does not reaches technological requirement, even causes parts to scrap.

Summary of the invention

The present invention is to solve that the existing control system for industrial gas temperature frequently occurs flame-out fault, the technical problem that can not again light a fire, it is provided that a kind of combustion system of stopping is frequently flame-out and can not the industrial gas temperature-controlled process that occurs of ignition problem.

The technical scheme is that

Step one: place mat multilamellar asbestos cloth bottom the crane span structure of bogie type gas heat treatment furnace, fills crane span structure sealed bottom position, extension chassis tow cable support with asbestos fibre；

The burner of some spray big fire system uses ceramic material；

Step 2, inputs the design temperature in each district of stove on host computer；

Step 2, the actual temperature in 8 districts in the stove detected by thermocouple, by host computer by design temperature compared with actual temperature, the size of the output valve after Bi compare is the real number of a corresponding 0-100%, these real numbers produce a series of time series pulse signals through PLC, PLC calculates the dutycycle of time series pulse signals according to the size of 8 real number signals of input, and then control eight burner controllers, burner combustion is controlled again by burner controller, burner controls size or the extinguishing of flame in tempering furnace according to the size of actual temperature Yu established temperature；

PLC, by the calculating to heating-up time and speed, controls little fire insulation, and big fire heats up.When in-furnace temperature reaches the technique lower limit set value of temperature in technology requires, PLC trigger point spray big fire system, carry out double-flame burning；When in-furnace temperature reaches the technique upper limit set value of temperature in technology requires, PLC controls to stop big fire burning, owing to controlling the contact always Guan Bi of the catalyst of little fire, so it can burn always, thus plays insulation effect.

Preferably, host computer is by the sampling to actual temperature with thermocouple detection temperature, and calculates deviation value according to PI algorithm, the size of deviation value export the current signal of a 4-20MA, this current signal through A after D transducer changes into digital quantity, give PLC.

The invention has the beneficial effects as follows, the present invention sets out based on solving practical problems, redesign control mode and systematic parameter, traditional size flame time sequential pulse is controlled is changed into big fire time sequential pulse and controls, little fire continuous burning mode, guarantee that the annealing furnace heating-up time is fast, shorten the process-cycle, improve heat treatment precision, significantly reduce fault rate, natural gas stove can be substituted, reduce energy cost.Combustion system dual fail-safe, thoroughly solves the fault fatal weakness that combustion system is frequently flame-out and can not light a fire, achieves extraordinary practical application effect, and this is that additive method institute is irrealizable.

Further aspect of the present invention, by the description of detailed description below, is clearly stated that.

Accompanying drawing explanation

Fig. 1 control system schematic diagram；

Fig. 2 is to control process schematic.

Symbol description in figure:

1. burner controller, PL1 represents that button ignition switch, PB1 represent that SR, TR1 represent that ignition transformer, YV1 represent gas valve.2. host computer, 3. siemens PLC system, 4. burner controller, 5. burner, 6. tempering furnace, 7. thermocouple.

Detailed description of the invention

As it is shown in figure 1, burner controller 1 is used for igniting and the monitoring of burner.Various control requirements are swift in response by the Electronic Design of its advanced person, are therefore more suitable for frequent pulse operation, may be used for the direct-fire of Industrial Burner, continuous or Pulse Width Control operating mode.

Button ignition switch PL1 is green light locking press button, and SR PB1 is general button.

Use big fire sequencing contro, little fire continuous burning mode to realize regnition, evaded cannot the bottleneck of regnition, big fire sequential ignition carries out temperature-compensating, it is achieved that the accurate control of furnace temperature.

As a example by DL09-1144 type bogie type gas heat treatment furnace, control method is:

Step one: rearrange the test signal monitoring cable of bogie type gas heat treatment furnace, place mat multilamellar asbestos cloth bottom the crane span structure of bogie type gas heat treatment furnace, to completely cut off the heat given out bottom stove, it is to avoid burn cable.On the other hand, fill crane span structure sealed bottom position with asbestos fibre, reduce thermal losses and the steam barbecue to cable.

Extension chassis tow cable support, avoids stove heat spreader district.

The burner of some spray big fire system uses ceramic material, heatproof 1200 DEG C.Every burner joins size burning things which may cause a fire disaster, can alternately light a fire and reset.

Step 2, inputs the design temperature T in each district of stove on host computer.

Step 3, with reference to Fig. 2, in the stove of thermocouple detection, the actual temperature (in order to detect temperature uniformity) in 8 districts is that t1, t2, t3, t4, t5, t6, t7 and t8 pass to actuator with the form of magnitude of voltage, actuator is after PID arithmetic, the signal of output 4-20MA, to electropneumatic transducer or electrical valve, is then converted into air pressure signal and controls operated pneumatic valve to regulate gas discharge instrument to reach temperature control effect.

The burning time of burner is controlled by time series pulse signals, and in time series pulse combustion control system, when burner burns, and namely inclined mathematic interpolation output valve PID of design temperature T with actual temperature t is determined by host computer 2.By the sampling to actual temperature with thermocouple detection temperature, and calculate deviation value according to PI algorithm (i.e. ratio, integral algorithm), the current signal of a 4-20MA is exported by the size of deviation value, this current signal through A after D transducer changes into digital quantity, give siemens PLC control system.(size of the output valve after PID calculating is the real number of a corresponding 0-100%) these real numbers produce a series of time series pulse signals through the PLC of siemens PLC control system 3, PLC the size according to in-real signal calculate the dutycycle of time series pulse signals, and then control burner controller 4, controlled burner 5 by burner controller 4 again to burn, and then control different burner controllers, controlled burner combustion by burner controller again, thus reach to control them and light the purpose of fire extinguishing stove temperature according to certain sequential.

The PLC of siemens PLC control system is by the calculating to heating-up time and speed, control little fire insulation, big fire heats up, (in electrical hardware, a point two-way realizes, one tunnel controls big fire burning, and a road controls little fire insulation, and the catalyst that only button of little fire insulation and PLC need to be controlled connects long closed contact, and programmed in cyclelog), to meet technological requirement.When in-furnace temperature reaches the technique lower limit set value of temperature in technology requires, the length of PLC touch-control opens the closing of contact, trigger point spray big fire system, carries out double-flame burning.When in-furnace temperature reaches the technique upper limit set value of temperature in technology requires, PLC sends instruction, and the length controlling big fire opens contact disconnection stopping big fire burning, and the long closed contact of catalyst controlling little fire burning is to close, so it can burn by the least fire, play the effect of insulation.

Big fire burning dual fail-safe is (when needing to carry power, with little fire as kindling material, ignite big fire), do not have because big fire lighter is malfunctioning or cannot light, cause and be forced blowing out, even cause workpiece to scrap, solve combustion system fault fatal weakness at one stroke, evaded and restricted normal combustion phenomenon because of the own physical characteristic of coal gas (burning-point is high, include tar, moisture).

The above, only to the preferred embodiments of the present invention, is not limited to the present invention, and for a person skilled in the art, the present invention can have various modifications and variations.In the range of every claim in the present invention limits, any modification, equivalent substitution and improvement etc. done, all should be within protection scope of the present invention.

Claims

1. an industrial gas temperature-controlled process, it is characterised in that comprise the following steps:

The burner of some spray big fire system uses ceramic material；

PLC, by the calculating to heating-up time and speed, controls little fire insulation, and big fire heats up, when in-furnace temperature reaches the technique lower limit set value of temperature in technology requires, and PLC trigger point spray big fire system, carry out double-flame burning；When in-furnace temperature reaches the technique upper limit set value of temperature in technology requires, PLC controls to stop big fire burning, owing to controlling the contact always Guan Bi of the catalyst of little fire, so it can burn always, thus plays insulation effect.

2.According to claimIndustrial gas temperature-controlled process described in 1, it is characterized in that, host computer is by the sampling to actual temperature with thermocouple detection temperature, and calculate deviation value according to PI algorithm, the current signal of a 4-20MA is exported by the size of deviation value, this current signal through A after D transducer changes into digital quantity, give PLC.