Chang Huang, Shuzhan Bai, Guoxiang Li^*, Ke Sun^*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.1, pp. 83-93, 2023, DOI:10.32604/fdmp.2022.021662

Abstract The influence of heterogeneous flow injection of urea at different velocities and temperatures on NOx conversion efficiency, ammonia storage and ammonia leakage is investigated experimentally. A diesel engine employing a selective catalytic reduction (SCR) technology is considered. It is found that for a fixed injection velocity, the degree of ammonia leakage changes depending on the temperature. The higher the temperature, the faster the catalytic reduction reaction and the smaller the degree of ammonia leakage. The temperature has a great influence on the catalytic reduction reaction rate. At an injection velocity of 10000/h, the average reaction rate at 420 C is… More >

Jianlu Cheng¹, Kaiyong Hu^1,*, Jiang Shen¹, Lu Jia^1,2, Rui Niu¹, Zhaoxian Yang³

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.4, pp. 1049-1066, 2022, DOI:10.32604/fdmp.2022.019007

Abstract The use of ammonia in large-scale refrigeration systems (such as those used for a stadium) requires adequate ammonia leakage prevention mechanisms are put in place. In the present study, numerical simulations have been conducted to study the dispersion law in the ammonia machinery room of the refrigeration system for the 2022 Beijing Winter Olympics. The wind speed, and release location have been varied to investigate their effects on the dispersion profile. Different positions of the leakage points in the ammonia storage tank have been found to lead to different areas affected accordingly. In general, the dangerous region area decreases with… More >