差压预冷外部遮挡最佳开孔方式的实验研究  

Experimental study for the optimal vent-hole type of external cover on differential pressure cooling

作　　者：王艳红[1] 刘斌[1] 牛建会[2] 

机构地区：[1]天津市制冷技术重点实验室,天津商业大学,天津300134 [2]河北建筑工程学院,张家口075024

出　　处：《食品科技》2010年第11期135-140,共6页Food Science and Technology

基　　金：天津市教委资助项目(2006ZY08);天津市教委资助项目(06YFGZNC01900)

摘　　要：果蔬差压通风预冷外部开孔方式是影响预冷效果的重要参数之一。设计了5种开孔方式依次为:8列4排半径为40 mm的32个均匀孔,开孔率28.7%;靠近差压风机侧的3列和最下面1排的孔径均为30 mm,其余为40 mm的8列4排32个非均匀孔,开孔率22.03%;最下面1排孔径均为40 mm,其为30 mm的7列4排共28个孔,开孔率18.9%;最下面2排孔径均为30mm,其余为40 mm的8列5排共40个孔,开孔率29.6%;靠近差压风机侧的3列和最下面1排孔的孔径均为30 mm,其余为40 mm的10列5排共50个孔,开孔率36.2%,两个相对侧面开孔方式相同。以土豆,西兰花为实验对象进行了同条件下的不同开孔方式的预冷实验。根据实验数据,分析不同开口方式下预冷的蔬菜的中心温度、周转箱内风速和压差,比较得出了均匀孔开孔方式对预冷效果的影响最差;对预冷均匀性的影响最大的因素是孔的排列方式;第2种开孔方式是5种方式中最好的。提出了如何进一步改进,为以后差压预冷外部遮挡开孔优化设计提出了方案建议。The type of the vent-hole is one of the most important parameters affecting the cooling effect in the pressure pre-cooling of fruits and vegetables.Five vent-hole types were designed.The fist type had 32 uniform vent-holes with a radius of 40 mm arranged in 8 arrays and 4 rows and the aperture area ratio was 28.7%;the second type had 32 non-uniform vent-holes arranged in 8 arrays and 4 rows,the radius of the vent-holes of 3 rows near to the differential pressure blower and the last array was 30 mm,the radius of other holes was 40 mm and the aperture area ratio was 22.03%;the third type had 28 non-uniform vent-holes arranged in 7 arrays and 4 rows,the radius of the holes in the last row was 40 mm,the radius of other holes was 30 mm,and the aperture area ratio was 18.9%;the fourth type had 40 non-uniform vent-holes arranged in 8 arrays and 5 rows,the radius of the holes in last two arrays was 30mm,the radius of other holes was 40 mm and the aperture area ratio was 29.6%;the fifth type had 50 vent-holes arranged in 10 arrays and 5 rows,the radius of the vent-holes of 3 rows near to the differential pressure blower and the last array was 30 mm,the radius of other holes was 40 mm and the aperture area ratio was 36.2%.The precooling experiments of potatoes and broccolis were carried out to study the effect of external cover with different vent-hole types According to the large number of experimental data,the center temperature,and the air velocity and thepressure difference in turnover container were analyzed.The results show that the effect of uniform vent-hole on cooling uniformity was the worst,the most important factor affecting the cooling uniformity was the arrangement mode of vent-hole and the second type was best.At last the improvement was suggested which is helpful for the design of precooling.

关 键 词：差压预冷 开孔方式 冷却速度 冷却均匀性 

分 类 号：TS255.3[轻工技术与工程—农产品加工及贮藏工程]