The Design And Fulfillment Of Temperature Automatic Control System For The Boiler On Vehicle Based On PLC

Many existing industrial boiler of our country, have problem of lowautomatization , the thermal efficiency of these equipments are only about 40% .Along with the economic growth mode of business enterprise change to depend onprogress of technique, the request of automatization becomes more and moreurgent, change traditional manual,semiautomatic operational manners, carry outautomatic control and manage, improve thermal efficiency of boiler , guaranteesafe running of equipment becomes quite necessary.At present situation economize energy and protect environment are beingpaid more and more attention, design of control for industrial boiler, accord withguarantee safe work, should make it work under optimal condition which minimumthe loss of combustion, pollution of environment , maximum thermal efficiency.Current it is already become the most important topic of automatic control ofindustrial boiler.The hot-oil paraffin-cleaning vehicle that used in oil industry , adopte boileron vehicle to be used to hot clean the wax in pipeline. And mainly of its controlfunction, fulfillment by manual work ,and one fuel , the adjust of boilertemperature , only depend on experience of worker , in order to get demandedtemperature , worker are used to increase fuel by manual manipulation , butsynchronously the supply of air couldn't meet in reason , then dark smoke andpoisonous gas that come from incomplete burning of fuel should pollute airseriously , at the same time the increase of fuel wastage is large , economy ofcombustion couldn't achieve.This article take reformation of the hot-oil paraffin-cleaning vehicle asbackground , study control of boiler on vehicle ,and design automatic temperaturecontrol system for it . The system can make full use of cheap ,more overabundant associated gas of oil field . The control system base on combustion theoryand control theory , betake programmable logic controller—PLC and multi-sensortechnique on special type mobile machinery shop—hot-oil paraffin-cleaningvehicle , it can realize automatic temperature control of multi-mode such as gas ,oil , mixed gas and oil , make combustion work at the optimal scale of air and fuel.The key study content is as follows:1. The system adopt sound control project on temperature control system ofboiler , including control of air supply , control of fuel supple and control ofignition process . Betake general PID control into boiler control , adopt PIDarithmetic-integral separate , solve problem of temperature overtake control inprocess of boiler combustion , make the system accord with precision of techniquerequest , engaged request in stability , precision of stabilization and dynamicprocess.2.The system make programmable logic controller—PLC as main control unit ,adopt multi-sensor ,such as temperature change and deliver sensor , gas presschange and deliver sensor, oil press change and deliver sensor , Zirconia measure ,blaze inspector , anemometry sensor etc., make multi-control processes form closedfeedback . The system can economical combustion , automatic choosecombustion mode , and combust mixed oil and gas in safety.3. The design of the system fully consider convenience and security ofmanipulation , provide economical technologic interface for worker . In term ofclosed loop feedback from sensor , inspect limit of gas and oil press, blaze,pre-blow time and ignition time ,set multi-electric mutual lock , to eliminate dangerof boiler's combustion , guarantee safety of the system .4. The system has being installed and debugged on the boiler on vehicle , aswell as work in locale of oil field . I adopt means of engineering regulation ,regulate PID parameter without test on object , confirm PID parameter throughabundant locale experiments , to make the control system attain upper controlquality , economical combustion , validate reliability and veracity of the automatictemperature control system .After put the system into use , through practical manipulation , prove thetemperature control system that design for the project , can realize automaticcontrol in fuel supply ,air supply , ignition control and anti-blast , in conditions ofdissimilar enacted temperature , mediums' velocity of flow , we could make threemodes work smoothly including gas , oil , mixed gas and oil . These design haveimportant meanings in safe fulfill producing task , make fuel and air work inoptimal mixed scale , decrease fuel consume , reduce air pollution etc.The system can automatic run, enhance control precision, simultaneous lessenwork intensity, worker could make the system run in upper control quality withoutabundant experience, it can reduce cost of worker's train for business enterprise.In a word, the automatic temperature control system in the hot-oilparaffin-cleaning vehicle in the article, fully utilize associated gas from the mouthof well in oil field, and take this gas as mostly fuel for use of the system , it cangreatly reduce cost of wax-cleaning. The vehicle with the dual-fuel burning andheating system boiler is useful and valuable in the oil fields.