Numerical Simulation Study Of The Spray System On The Control Of Ammonia Leakage Accident

As the country's request to ammonia enterprise becomes stricter and stricter,these enterprises have to do the safety transformation. The notice of the State Council safety Commission on the development of Liquid ammonia Usage Special treatment of the Ammonia Refrigeration Enterprise(State Council safety production Committee) pointed that the water spraying system should be established above the ammonia storage tank, which at present make the water spraying system becomes the primary choice of domestic ammonia enterprise,and the water spraying system as emergency equipment of the ammonia gas leakage accidents, its absorption effect directly relate to the person and property security, meanwhile it has decided severity of environmental pollution. At current the main reference of water spraying system design and installment in ammonia enterprise is the extinguishment and related standard in desulfuration field, which means its use also stays in the experimental phase, therefore some questions have generally existed in the ammonia enterprise such as the unordered spray nozzle arrangement, the slow response speed, lower effect and so on. This will provide the hidden danger in the steady operation of this kind of enterprise. In order to raise the absorption efficiency of ammonia gas and to further enhance the control effect of the ammonia enterprise on the ammonia gas leakage accidents, in this paper, the author uses the water spraying system as the object of study, simplifies the physical prototype of the ammonia gas absorption, and analyzes the factors that influence the absorption efficiency of ammonia gas. The following work has been done1.The author summarizes the current research of the ammonia gas leakage in home and abroad and the development process of the spray system, and ensures the main content and method of this paper;2.The author studies the mechanism of liquefied gas leakage diffusion,compares general theory model of gas-liquid reaction, then combines the basic reaction theory to analyze the mass transfer theory of gas and liquid two phases,and gets the balance conditions that ammonia gas react with water when the ammonia leakage accidents occur;3.The author simplifies the actual production environment and the environmental conditions of the ammonia storage room,then makes the simplified model as the research object, using the GAMBIT to do physical model for modeling and meshing. In accordance with the actual situation to determine the working parameters of spray system, the author sets the environmental conditions that fit with the actual situation in order to lay a foundation for accurate numerical simulation;4.Simulating the absorption of ammonia gas in spray system under the simplified model by FLUENT, the author gets the variation of ammonia concentration in a certain time in the absorption field of the spray system and the variation of ammonia concentration in different working parameters with the change of time, and changes some condition parameters such as working pressure of the nozzle, the PH value of absorbing liquid and nozzle spray angle and so forth, which is to conclude the influence on the change of working parameters of the spray system for the control effect of ammonia leakage accidents.