摘要
研究开发了一种用于农业建筑的集中雾化蒸发降温系统，进行了实际生产条件下的夏季降温试验。降温装置内部为过风断面由下而上逐渐扩大的漏斗状，形成下高上低的变风速场，以延长雾滴与气流的接触时间，在较小的喷雾量下维持较高的雾滴密度分布。在装置内平均气流速度１．１～２．８ｍ／ｓ，喷雾压力０．０６～０．１６ＭＰａ，水气比０．０８～０．５的条件下进行了试验。试验结果表明该装置在０．１～０．２的较低水气比时其降温效率即可达８０％以上，室内平均气温低于室外气温２～５．５℃，比单纯采用机械通风时低４～７．５℃。室内相对湿度为７０％～９５％，通风总压力损失为４０．３Ｐａ。
A centralized spray cooling system for farm buildings was developed and tested under a practical production condition in summer. The inner air passage of its cooling installation was made as the shape of a funnel, gradually enlarged from the bottom to the top, so that the airflow velocity in the cooling installation decreased from the bottom to the top gradually. Higher air velocity near the air inlet at the bottom could resist most drops falling, lower velocity near the top could make the drops which were moving upward with airflow slow down and fall back to the bottom of the installation, so that the time that spray drops contact with airflow could be prolonged, and a high density of drops in airflow could be kept with a lower water flow. The tests covered the ranges of average airflow velocity from 1.1m/s to 2.8m/s, and spray pressure from 0.06MPa to 0.16MPa, water/air coefficient (the ratio of the mass of sprayed water to airflow) from 0.08 to 0.5. It was showed that the evaporative cooling efficiency of the cooling installation could attain 80 % or more even at lower water/air coefficient from 0.1 to 0.2. In fair weather, the inside air temperature of the greenhouse, in which the centralized spray cooling installation was employed, was 2￣5.5 ℃ lower than outside temperature, and 4￣7.5 ℃ lower than that by mechanical ventilation only. When the cooling installation was running, the inside air relative humidity was 70 %￣95 %. The total ventilation pressure loss was 40.3 Pa. In addition, the distribution of drops with different sizes in the cooling installation was surveyed and analyzed.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
1998年第1期158-163,共6页
Transactions of the Chinese Society of Agricultural Engineering
基金
高等学校博士学科点专项科研基金
关键词
农业建筑
蒸发降温
集中雾化
沸腾炉法
farm building, evaporative cooling, centralized spray, method of boiling bed
