| With the development of society and economy and the rapid development of traditional industry,computer network,communication network,electronic industry,medical industry and military industry,people pay more and more attention to the requirement of high precision machining.In the actual manufacturing process,improving the machining accuracy is of great significance to improve the assembly performance of mechanical equipment,improve the interchangeability of parts and components,and control the rejection rate of products.Taking an engineering example of Hebei Styrene Chemical Co.,Ltd.with an annual output value of 80,000 tons as the research object,this paper studies the constant temperature and humidity in the central control room of the petrochemical plant by means of literature collection,theoretical research,simulation research,optimization design and scheme comparison with the computer numerical simulation as the technical support.The status and characteristics of the air conditioning system are studied.By means of mathematical modeling and CFD numerical simulation.the internal and external disturbance characteristics,the temperature uniformity and stability in the working area,and the air distribution in the central control room are simulated and optimized.Different air distribution patterns were selected for comparative analysis.Through the real-time monitoring of temperature and humidity in the central control room of petrochemical plant,it is concluded that the temperature of the cabinet in the central control room in winter and summer is higher than that in the engineer's room,and the temperature of the cabinet in winter is close to the relevant regulations of the current national standard GB50019-2015.The temperature in summer has obviously exceeded the national standard.CFD numerical simulation technology is used to simulate and analyze the important room(engineer room and cabinet room)in the central control room.It is concluded that the ventilation mode of upward feeding and upward returning is better than that of upward feeding and upward returning in the cabinet room with fewer high-power equipments,but it is not suitable for the cabinet room with more high-power equipments.It can only reduce the temperature of the area below the air supply outlet.Cold air can not diffuse to the equipment display area.The cabinet temperature in winter and summer is on the high side.The average temperature of the cabinet in summer is 32.5 ? degrees centigrade.Under the condition of the original up-supply and up-return ventilation mode,the air supply is increased to 350m3/h,400 m3/h and 450 m3/h.When the air supply is 350m3/h and 400 m3/h,the temperature below the air supply outlet in the cabinet is about 28?,and the temperature in the equipment area is about 32?,which is basically the same as that in the previous 300m3/h,and is raised to 450m3/h,the temperature of the equipment placed area is reduced to 30.5? degrees,and the improvement effect is not obvious.The average temperature below the air supply outlet in the cabinet room can not effectively reduce the temperature in the cabinet room,because the air flow in the air supply and return mode is poor,it can not effectively diffuse the air flow to the whole room,so that the heat generated by the equipment can not be discharged from the room.By CFD numerical simulation technology,the ventilation mode of the cabinet is changed into two different air distribution modes,i.e.up-feed,down-feed and up-feed.The average temperature in the vertical area near the air supply outlet is 26?,but the temperature in the equipment area is still maintained at about 30?.The average indoor temperature of the cabinet is about 29.5?,while the temperature of the equipment is reduced to 28.5?.It is concluded that the ventilation mode is the best way.Through this study,it can provide reference for the optimization of air conditioning system in the central control room of petrochemical plant. |
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