Through theoretical analysis of R290/CO2 natural refrigerants cascaded refrigeration cycle, an optimum mass flow rate ratio and an optimum condensation temperature of low temperature cycle part are calculated at a definite evaporation temperature and heat-transfer temperature difference of condenser-evaporator.
介绍了低温环境下采用自然工质R290和CO_2的复叠式制冷循环,分析了R290和CO_2的物性特征,通过对R290／CO_2式制冷循环的理论分析,在一定的蒸发温度和冷凝蒸发器传热温差下,计算出循环存在最优的低温循环冷凝温度和最优质量流量比;为提高循环效率和保证循环的安全运行,应尽可能地升高蒸发温度、降低冷凝温度和减少冷凝蒸发器的传热温差,可以看出R290／CO_2的复叠式制冷循环在低温制冷条件下有很好的发展前景。
Droplet size of two-fluid airblast atomizer with lar ge water/air mass flux ratio;
大液气质量流量比双通道气流式喷嘴雾化滴径
The velocity profiles of spray are similar at all experimental conditions,but the cone angle becomes slightly smaller under high liquid mass flow rate and low air/liquid mass flow rate(RAL).
利用Dual PDA对气泡雾化喷嘴出口下游的喷雾两相流场进行了诊断与分析,发现气液质量流量比对液雾颗粒群速度分布的影响不大,只是轻微地改变了雾化锥角,但是随着气液质量流量比的减小,雾化颗粒平均直径却有所增大。
Reducing the quality fluctuation of PVC resin produced by calcium carbide method among each production batch;
缩小电石法PVC树脂批次间的质量波动
Study on Technology of Quality Control of Micron Wood Fiber Mould Product;
微米木纤维模压制品质量控制工艺方法研究
Effect of Carbonization Time on Blast Furnace Coke Quality;
结焦时间对冶金焦质量影响
Main quanlity defect and control on product of internal CSP plants;
国内CSP产品质量与控制
On relation between quantity and quanlity in economy growing;
关于经济增长数量与质量的关系
Quantity Prepared Control of Engineering Construction Item;
浅谈工程施工项目的质量预控
Some measure to increase external appearance quantity of T beam;
提高T梁外观质量的几点措施
Miscellaneous to Hand Over the Corn Seed Quantity Control Technique Application;
杂交玉米种子质量控制技术应用