摘要
机械式蒸汽再压缩浓缩技术(MVR)利用浓缩过程中二次蒸汽的机械式加热加压,实现了热能的充分利用,具有蒸汽用量少、能耗低的优势而被广泛应用于制药、食品和污水处理领域,其关键技术之一是对二次蒸汽压缩过程中的温度的实时控制.在对MVR系统进行系统研究的基础上,采用西门子S7-200PLC控制器对二次蒸汽压缩前后的温度实施在线监测和数据的优化处理,在设计的计算机软件驱动下,运用比例积分微分控制法对采集到的二次蒸汽实时温度值进行判断,实时温度低于设定温度值时,控制器发出指令提高压缩机转速增加压缩机对二次蒸汽的升温值,并通过上位机监视与控制通用系统软件与可编程逻辑控制器进行连接通讯,从而实现系统参数的设置和二次蒸汽温度的实时监控.研究结果表明,该系统能实现二次蒸汽温度的实时在线监测和快速调节,并绘制实时温度曲线和温度数值的显示,降低了人工劳动力,确保MVR系统的自动化运行.
Mechanical vapor recompression technology （MVR） makes the best use of heat by mechanical heating and pressurizing the secondary steam in the enrichment process,which has advantages of less use of raw steam and low energy consuming.This technology was widely used in fields of pharmacy and food and wastewater treatment processing.The control of real-time temperature values of secondary steam in compression process is one of the key points to this technology.Based on the systematic study of MVR system,this paper is aimed to realize the online monitoring and data optimization by using the Siemens S7-200PLC controller to the secondary steam temperature before and after compression.Driven by designed computer software,the real time secondary steam temperature is collected and judged by using proportion integration differentiation method.When real time temperature is lower than the setting value,the secondary steam is heated up to setting value by frequency converter which can increase the compressor speed of rotation.The communication of monitor and control generated system software and programmable logic controllers through the upper machine can achieve real-time monitoring of parameter settings and secondary steam temperature.The results of this research have shown the system can realize real-time online monitoring of secondary steam temperature and rapid adjustment,as well as draw temperature curves and display temperature values in real time,which reduces labor workforce and ensures the automatic running of MVR system.
出处
《武汉工程大学学报》
CAS
2014年第1期63-68,68+67,共6页
Journal of Wuhan Institute of Technology
