仔猪配合料比热预测模型的构建  

Establishment of specific heat prediction model for weaned piglet mash feed

作　　者：孔丹丹[1] 陈啸[1] 杨洁[1] 张国栋[1] 彭飞[1] 王红英[1] 

机构地区：[1]中国农业大学工学院,国家农产品加工技术装备研发中心,北京100083

出　　处：《农业工程学报》2016年第18期307-314,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：公益性行业(农业)科研专项(201203015)

摘　　要：为探究调质、制粒等热处理过程中仔猪配合粉料传热的基本特性,有效控制热量供给并实现调质温度、时间等工艺参数的优化评估,该文以4种粉碎粒度(粉碎筛片孔径:Φ1.0、Φ1.5、Φ2.0和Φ2.5 mm)的仔猪配合粉料为研究对象,采用DSC(differential scanning calorimetry,差示扫描量热法)的方法测定了其在不同含水率范围(10%~18%,湿基)和不同温度范围(25~100℃)的比热,并分析了3个变量对比热的影响规律,构建了比热关于研究变量的预测模型。结果显示:仔猪配合粉料的比热受含水率、温度、粉碎粒度的显著影响,其中含水率的影响最为显著,温度及粉碎粒度次之;比热亦受含水率与粉碎粒度及其与温度的交互作用影响。比热随含水率和温度的增加在1.533~2.881 k J/(kg·K)范围内升高,且与含水率呈线性关系,与温度呈非线性关系。粉碎过Φ2.5和Φ2.0 mm的仔猪料比热较粉碎过Φ1.5和Φ1.0 mm的大,在高温(60~100℃)和高含水率(18%)时表现尤为明显。基于试验数据建立了比热关于含水率、温度、粉碎粒度的多元回归模型(R^2>0.993),可以有效预测仔猪配合料在此研究变量范围内的比热。研究结果为仔猪配合料调质过程传热方程的建立提供基础数据,并为其热处理工艺参数的优化提供理论依据。Weaned piglet＇s pellet feeds are designed for healthy growth of weaned piglet. Conditioning is a key factor affecting pellet feed quality and pellet mill throughput, which can be defined as the process of transforming the physical state of the mixed mash with the addition of saturated steam to facilitate the compaction of the feed mash. Knowledge of the thermal properties of mash feed is required to perform the heat transfer calculations that are involved in the optimal design of conditioner and evaluation of operating parameters. Specific heat is an important thermodynamic parameter used in heat transfer and energy balance calculations. Conditioning processing involves broad temperature（25-95 ℃） and moisture content（12%-16.5%, wet base） ranges. The objectives of this investigation were to determine the specific heat of mash feeds for weaned piglet as affected by moisture content, temperature and grinding particle size. In this work, the specific heat of mash feeds for weaned piglet in 4 grinding particle sizes（geometric mean diameter of 346.34, 364.57, 388.93 and 404.25 μm, and sieve aperture of Φ1.0, Φ1.5, Φ2.0 and Φ2.5 mm） was measured as a function of moisture content（10%-18%） and temperature（25-100 ℃） by differential scanning calorimetry（DSC）. The mash feeds were processed in Xinsanfeng feed mill in Miyun District, Beijing, while the determination of specific heat was conducted in China Agriculture University from April to November in 2015. As for the experiment design, the method of total experiment with full randomization was applied with 3 factors which included 4 kinds of grinding particle sizes（346.34, 364.57, 388.93 and 404.25 μm）, 16 levels of temperatures（25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 and 100 ℃） and 5 levels of moisture contents（10%, 12%, 14%, 16% and 18%）. The influences of these variables on the specific heat were analyzed and a prediction model of specific heat concerning these variables was established. The specific he

关 键 词：比热 温度 模型 仔猪配合料 含水率 粉碎粒度 

分 类 号：S816.8[农业科学—饲料科学]