应用环境舱研究室内混凝土墙体中氨的释放规律

Studies on the emission rule of ammonia from indoor concrete wall using environmental chamber

采用环境舱模拟研究了随温度(T)、相对湿度(RH)和空气交换率(AER)变化墙体试块中氨的释放规律,并将现场实验结果与环境舱的模拟实验结果进行对比.研究发现:T和RH一定,随着AER的增大,舱内氨气平衡浓度下降,氨气挥发速率和完全释放时间呈现出一定的规律性;AER和RH一定,舱内氨气平衡浓度和挥发速率随T升高而变大,完全释放时间减小;与AER和T相比,RH对氨气释放的影响有限;通过与现场通风实验和浓度监测结果比较,考虑到室内墙体老化时间等因素,环境舱实验与实际住宅测试得到的结论基本一致.在一般的情况下,使用含尿素防冻剂的住宅,其墙体中氨释放完全大约需要10～32年.

For the studies on ammonia emission from indoor concrete wall, the environmental chamber is adopted for the simulated study on emission rule of ammonia from the experiment pieces of indoor concrete wall with the changes of temperature (T), relative humidity (RH) and air exchange rate (AER); and the results of field experiment and that from simulated experiment of environmental chamber are compared. It is found in the study that at fixed T and RH, with increase of AER, the balance concentration of ammonia in chamber decreases, and its volatilizing rate and complete emission time have definite regularity. At fixed AER and RH, with increase of temperature, the ammonia balance concentration and volatilizing rate in chamber increase, and complete emission time decreases. In comparing with AER and T, the RH effect on ammonia emission is limited. Through comparing with the results of the field ventilation experiment and concentration monitoring, and considering the factor of indoor wall aging time, the conclusions of actual test of residence and environmental chamber experiment are basically consistent. Under general conditions, the complete emission of ammonia from the wall of residence where the antifreeze containing carbamide has been used needs about 10~32 years.