| With the increasing demand for rubber products in China,the emissions of volatile organic compounds(VOCs)generated during the production of the rubber industry have also increased year by year,and the national and local VOCs emissions from the rubber industry have made more stringent specifications.At present,some rubber workshops have low VOCs exhaust gas collection efficiency,serious pollution and poor sanitary conditions in the workshop working area.To address this issue,a rubber enterprise rubber processing workshop is selected as the research object in this paper.The workshop is divided into six sets of exhaust gas collection systems and six sets of ventilation systems according to different production equipment and equipment areas internally.The BIM coupled with CFD method is used to numerically analyze and optimize the design parameters of the exhaust gas collection system in the rubber processing workshop,to fully balance the air volume and resistance of the exhaust gas collection system,and to ensure that the exhaust gas collection rate of each closed hood meets the standard and the air volume is evenly distributed;meanwhile,the ventilation system in the workshop is analyzed by flow field and air age to ensure the labor hygiene conditions and air quality of the workshop.The main conclusions of this paper are as follows:(1)Numerical simulation combined with field measurement was used to analyze the VOCs exhaust gas distribution in the glue processing workshop,and the simulated VOCs exhaust gas concentration inside the closed hood was 0.8～1.2 mg/m~3,the field measured VOCs exhaust gas concentration was 0.73～0.94 mg/m~3,which verified the reliability of numerical simulation.The numerical analysis of the flow field inside the closed hood of the exhaust gas collection system shows that the air volume of system I,III,IV and V air volumes meet the design criteria but the design air volume is large,waste of fan air volume;system II meets the standard but the flow field distribution of the closed hood is uneven;the pressure at the gap between the hood opening and the ground of the closed hoods M6-1,M6-2,M6-7 and M6-8 in system VI is-0.4 Pa,-0.8 Pa,-0.01 Pa and-0.9 Pa;the wind speed at the hood opening is 0.28 m/s,0.3 m/s,0.27 m/s and 0.1m/s,which does not meet the design standard.(2)For the six sets of exhaust gas collection systems in the workshop,four sets of large air volume and two sets of uneven air volume,through numerical simulation and full balance negative pressure adjustment method,the parameters of exhaust gas collection systems one,three,four and five were optimized,the air volume of each system was reduced to 7000 m~3/h to meet the design standard,which can effectively reduce the energy consumption of the system;additional valves and grilles were installed in the ducts of systems two and six for resistance balancing to ensure that the optimized systems two and six have uniform negative pressure and meet the standard requirements.After the optimization,the negative pressure value of system two and six closed hoods is uniform and meets the standard requirements.After optimization,the absolute values of negative pressure at the hood opening of system II are 13.3 Pa～21.06 Pa,and the velocity is 1.7m/s～2.145 m/s;the absolute values of negative pressure at the hood opening of system VI are 4.1 Pa～14.6 Pa,and the velocity is 1.2 m/s～2.16 m/s.At the same time,in order to facilitate the equipment management and operation monitoring of the collection system,the exhaust gas collection system is combined.After numerical simulation analysis,the pressure and speed of the combined systems meet the design specifications,which provides a reference basis for the optimization of the design of the fully balanced negative pressure system and the combination of the exhaust gas collection system in the rubber workshop.(3)According to the heating,ventilation and air conditioning design code,the flow velocity and air age in the working area of the workshop are analyzed.In which the workshop is divided into light colored rubber and dark colored rubber area,the wind speed at Z=1.35 m section of area I is 1.6 m/s～2.2 m/s,the wind speed at Z=2 m section is 1.9 m/s～2.5 m/s.The wind speed at Z=1.35 m section of area II is 1.3 m/s～2.3 m/s,the wind speed at Z=2 m section is 1.4 m/s～3 m/s,which is more than The air age at Z=1.35m is 216～274 s and at Z=2 m is 180～200 s.The air age at Z=1.35 m is 216～280 s and at Z=2 m is 180～260 s.It is lower than the design air age of the workshop and can meet the requirements of workshop ventilation quality.The air age at Z=1.35 m is 216～280 s,and the air age at Z=2 m is 180～260 s.It is lower than the design air age of the workshop,which can meet the requirements of the workshop ventilation quality. |
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