Abstract: On the basis of laminar and turbulent theory, mathematical model was presented about aqua ammonia falling film absorption performance, and theoretical formula of ammonia absorption rate for aqua ammonia was deduced. This formula indicated two methods which can improve ammonia absorption rate, namely sprinkle density of aqua ammonia outside tube and ammonia solubility of aqua ammonia. When sprinkle density of aqua ammonia increased from 615 kg·m^-1·h^-1 to 3191 kg·m^-1·h^-1, ammonia absorption rate rose by 220%. In winter the aqua ammonia absorption experiments using 2^# tube were carried out under absorption pressure of 0.15 MPa. When average temperature of aqua ammonia increased from 25℃ to 34℃, ammonia absorption rate decreased by 130%.In summer the aqua ammonia absorption experiments using 2^# tube were carried out under absorption pressure of 0.25 MPa. When average temperature of aqua ammonia increased from 35℃ to 50℃, ammonia absorption rate decreased by 86%.An important parameter having influence on transversally grooved tube (TGT) falling film absorption performance is comprehensive impact factor of groove size i.e.e²/pd. Choosing this comprehensive impactfactor and falling film Reynolds number as independent variable, the correlation equation of Sherwood number was established for ammonia solution falling film absorption outside tube.

Key words: aqua ammonia, absorption, diffusion, mass transfer

摘要： 建立了氨水溶液竖直降膜层流和湍流的数学模型，推导出降膜溶液氨气吸收速率的理论公式。该公式指明可以通过提高氨水溶液喷淋密度和氨水溶液的氨气溶解度来提高氨气吸收速率。当2^#横纹管管外氨水溶液喷淋密度从615 kg·m^-1·h^-1增加到3191 kg·m^-1·h^-1，氨气吸收速率提高了220%。在冬季保持吸收段吸收压力为0.15 MPa，当氨水溶液平均温度从25℃提高到34℃，则氨气吸收速率下降了130%。在夏季维持吸收段吸收压力为0.25 MPa，当氨水溶液平均温度从35℃增加到50℃，氨气吸收速率相比下降了86%。影响横纹管降膜吸收性能的一个重要参数是凹槽尺寸的综合影响因子即e²/pd。以该影响因子和管外溶液降膜Reynolds数作为自变量，建立了管外氨水溶液Sherwood数的关联式。

关键词: 氨水, 吸收, 扩散, 传质