自然冷源蓄冷低温热管储粮中防止结露的方法研究

Study on preventing condensation in low temperature heat pipe for grain storage by natural cold source

为了解决自然冷源蓄冷热管储粮中管壁周围粮层结露的问题,研究提出了在热管组结构中添加电磁阀,通过热管周围粮堆孔隙空气的露点温差来控制电磁阀的开启,进而控制热管中制冷剂的运行,避免结露;设计制作了微型粮仓温湿度测定装置,研究了粮堆孔隙空气相对湿度和露点温差随温度的变化,揭示了电磁阀温控与结露的关系。结果表明:在5~20℃储粮温度范围内,粮食籽粒含水量越高,粮堆孔隙空气的露点温度越高,露点温差越小;自然冷源低温热管储粮仓(小麦仓)热管组结构中电磁阀温控设定计算公式为:y=-0.214 9x3+7.439 x2-86.384 x+343.43(其中y为电磁阀温控设定值;x为小麦籽粒含水率)。为热管技术在粮库中的应用提供依据和技术支持。

In order to solve the condensation problems between the grain around the heat pipe in grain warehouse with heat pipe by natural cold source, an electromagnetic valve was added in the heat pipe group to control operation of the refrigerant in the heat pipe according to the temperature difference between the external environment and the grain layer around the heat pipe. The micro measuring device of temperature and humidity in warehouse was designed and manufactured. The change of the air relative humidity and dew point temperature difference in porosity of grain bulk was studied ; the relationship between temperature control of electromagnetic valve and condensation was discovered. The results showed that in the range of 5 ℃ - 20 ℃ , the higher the grain moisture content, the higher the dew point temperature of the air in the barn, the smaller the dew point temperature difference. In natural cold source low temperature heat pipe group, the calculation formula for the temperature control of the electromagnetic valve was： y = -0. 214 9 x^3 ＋ 7. 439 x^2 -86. 384 x ＋ 343. 43 （the y was the temperature control of the electromagnetic valve ; x was the moisture content of wheat）. This research provides the theoretical foundation and technical support for the practical application of heat pipe technology in large grainwarehouses.