摘  要

 

本系统是针对糖厂中蔗糖溶液PH中和微机控制系统的设计，并且把对于这一过程的控制归结为非线性并不严重的PH值控制问题。在此基础上提出了用单片机及自动化仪表组成自动控制系统来控制该工段生产。

设计中采用串级控制来实现对系统主要被控参数——蔗汁中和值的控制。在串级系统中，主调节器的任务主要是克服在副环的以外的扰动减少静差，保持中和值在工艺要求的范围内，副环中副调节器是用来克服在副环以内的扰动，保持流量恒定。采用串级控制方式，可以改善对象特性，提高系统的工作，加快过渡过程，增强抗干扰能力。

根据工艺及技术要求选择系统总体设计方案后，通过8031单片机的系统扩展（ROM2764、RAM6264、I/O8255等）及外用设备的配置（ADC0809、DAC0832、LED显示器等）构成了实用性强的硬件电路、结合硬件电路和控制过程慢时变的特点，设计了以PID控制办法为核心的软件方案，对于一些的化工过程具有一定的实用价值。

 

关键词  PH值控制，中和过程，串级控制，PID控制

 

There is a design which relates PH neutralization of sucrose solution in sugar-refinery. It’s controlled by the PH value, which is an uncritical nonlinear parameter. Then based on it, the Single-Chip Microcomputer, other automatic instrument and meter are used in the control procedure as the automation control system.

The control of two-closed loop used for sucrose solution PH value of the parameter. In the system of two-closed loop, the main mission of two-closed loop is conquering the disorder of subsidiary loop, reducing the static error, and keeping neutralization in the rage of the technique request. In the subsidiary loop, subsidiary adjuster is used to conquering the disorder in the subsidiary loop, keeping the flux invariableness. Using the control of two-closed loop can ameliorate the idiosyncrasy of object, advance the work of system, quickening the process of transition, strengthening the ability of anti-jamming.

According to the request of the technology and technique, the survey of system’s design is finished. The extend system’s installation of Single-Chip Microcomputer(ROM2764、RAM6264、I/O8255 etc)make up of the practical hardware（ADC0809、DAC0832、LED etc）. The software design is revolved round PID method, because the hardware and its controlled procedure slowly lag. This design will be some practical valuable to the procedure of chemical control that changes slowly.

 

 

KEYWORDS  PH control, process of neutralization, control of two-closed, PID control

该中和与澄清过程pH值计算机综合了系统由九个部分组成，其结构框图如下：