【作者】 侯晓鹏；

【导师】 周玉成；

【作者基本信息】 中国林业科学研究院 ， 木材科学与技术， 2010， 博士

【摘要】 木材干燥是木材加工过程中的重要环节,木材干燥质量的优劣直接影响木材的出材率和木制品的加工质量。面对木材资源严重短缺的情况,保证干燥质量、降低能耗、缩短干燥周期、减少环境污染、提高生产率、增加优质干燥材数量已成为现阶段木材干燥技术发展的要求。木材干燥在木材加工企业中通常是能耗最大的工序,我国木材干燥行业中,常规干燥设备仍占主导地位,约占干燥设备市场的80%。这些常规干燥设备热效率低,干燥热效率仅为30～40%。同时,现有大量的木材干燥设备还处于手动、半自动控制状态。虽然有一些干燥设备实现了全自动控制,但其控制系统和控制设备的可靠性、稳定性、控制精度与发达国家相比还有一定的差距。针对常规干燥过程中能耗大、污染严重的问题,论文设计、制造了一种新型节能、环保的木材干燥设备。该设备除实现常规干燥功能外,还具有废气热能回收、废气清洁和自循环功能。将废弃的热能进行重复利用,又对VOC等气体进行清洁处理,真正达到节能、减排的效果,相比常规干燥节能10～15%。研发出适用于木材干燥过程控制的控制器,该控制器以ATmega1280微处理器为核心,具有16路数字量输入、16路数字量输出、16路模拟量输入、4路模拟量输出、4路PWM输出、4路RS232串行接口、16M的实验数据存储;针对木材干燥过程中木材含水率的变化特点,进行木材含水率实时采集模块电路设计,测量范围为6~90%,精度为±1%;人机交互系统以单片机为控制核心、液晶显示触摸屏为显示界面,该系统使复杂控制过程变得简单、可靠,替代上位计算机与下位机繁冗昂贵的控制方式,取消了计算机、键盘及鼠标等操作部件,也可以替代设备上的按钮、旋钮、显示仪表及状态指示灯等部件。完成木材干燥智能控制系统软件程序设计与实现。其中包括:时间基准和含水率基准的程序设计与实现;干球温度+湿球温度、干球温度+相对湿度、干球温度+平衡含水率三种控制方式的设计与实现;木材干燥专家系统的设计与实现,对常见树种提供最佳解决方案,并能够保存最优干燥配方;木材含水率实时采集模块的程序设计;网络拓扑结构的设计和通信协议的制定,利用RS232串口和RS485总线实现计算机、触摸屏与木材含水率实时采集模块的实时或分时通信。研发的新型木材干燥设备及其智能控制设备已在内蒙古农业大学和中国林科院木材工业研究所使用,由于其比传统的常规木材干燥设备干燥质量好,实现了废气热能回收利用和废气清洁过滤,达到了节能、减排的效果,受到使用单位的好评。因此本研究成果对于我国木材干燥行业的技术升级与改造将会起到借鉴与推动作用。更多还原

【Abstract】 Wood drying is the important section in wood processing, whose quality directly affected the recovery and processing quality of wooden products. Facing the serious shortage of wood resources, drying quality assurance, reduce energy consumption, shorten the drying cycle, reduce environmental pollution, improve productivity, increase the number of high-quality dried wood, whole were necessary to the development of wood drying technology at the present stage.Wood drying is the most energy consumption process in wood processing. In domestic industry of wood drying, conventional drying devices still play a leading role, which takes up 80%. These conventional drying devices have a low drying thermal efficiency about 30~40%. At the same time, most devices are still under manual and semi-automatic control status. Even though automatic control is realized in some devices, the reliability, stability and control precision of its control system and equipment have a great gap comparing to developed countries.According to high energy consumption and serious pollution, a new energy saving and environmental protective wood drying device was designed and manufactured by author who worked as a key technician. Based on conventional drying function, the waste heat recovery, waste gas cleaner and humidity generator were added. Therefore, the system utilized waste heat energy to do secondary work, and the toxic gases such as VOC were carried out cleaning process. Thus, the effects of energy conservation and emission reduction are reached genuinely. Comparing to the conventional drying, 10~15% amount of energy is saved.The controller, suitable for wood drying processing control, used ATmega1280 microcontroller as the core which has 16 digital inputs, 16 digital outputs, 16 analog inputs, 4 analog outputs, 4 PWM outputs, 4 RS232 serial interface vectors and 16M data storage; Based on the varying character of moisture content in wood drying process, real-time moisture content acquisition module was developed which has a measuring range of 6~90% with a precision of±1%; User Interface based on simple MCU control and liquid crystal display touch screen which makes the complex control easier and more reliable.At the same time, the program design and implement of wood drying intelligent control system software was completed. The control system with time benchmark and moisture content benchmark,of two kinds wood drying schedule, would achieved three control methods, which were dry bulb temperature + wet bulb temperature, dry bulb temperature + relative humidity, and dry bulb temperature + equal moisture content. The program of the acquisition of wood moisture content module is designed. The wood drying expert system could provide an optimum solution to common tree species and save the best drying formula. Network topology structures and communication protocol were designed. The real-time and time sharing communication with computer, touch screen and the acquisition of wood moisture content module were implemented by RS232 serial port and RS485 bus.The new wood drying devices and its intelligent control devices are now using in Inner Mongolia Agriculture University and Research Institute of Wood Industry, Chinese Academy of Forestry. Compared to conventional wood drying devices, they have the advantages such as high drying quality, waste heat energy recovery, zero gas emission and reach the affects of energy conservation and emission reduction. As a result, the research achievement plays reference and pushing effects to domestic technical reform and upgrade of wood drying field.更多还原