Numerical Simulation And Parameter Optimization Of Residential Negative Pressure Air System Airflow Organizations

In the past several decades, a series of outdoor environmental problems, such as global warming, soil desertification, water pollution, air pollution and so on have always been concerned by people. However, indoor environmental problems, especially the fresh air problem, arise people's concerns with the rapid development of economy and the constant improvement of people's living standard. Meanwhile, one of the Chinese Academy of Science investigations shows that China is one of the countries where Natural resources are the most seriously wasted in the world, and the utility of energy in china is only 26.9% of the United States, 11.5% of Japan, therefore, it is very imminent to promote energy saving and emission reduction.Residential negative pressure fresh air system has characteristics, including ventilation uniform, simple system, no need to install indoor air duct, impropriating small space, constantly supplying air and so on. Reasonable air flow has effects on not only indoor air environment, but also energy consumption. It is very significant for energy saving to organize optimal ventilation while ensuring the indoor air quality in order to has minimum ventilation fresh air volume. Thus, the study based on air flow, on negative pressure fresh air system as one of effective methods resolving indoor fresh air problem to improve indoor air environment has practical significance, but also can provide references for design of residential ventilation.3D numerical simulation and optimization study on residential indoor air distribution environment with negative pressure fresh air system is carried out in this paper by FLUENT software. The simulations are founded on k -εtwo-equation turbulence model, SIMPLEC method as well as the wall function. And test on residential indoor air distribution with negative pressure fresh air system in Yangzhou is done to verify the correctness and reliability of models. Finally, with taking a typical bedroom in winter as the simulation object, simulation optimal calculation, based on air flow, on indoor air distribution environment using negative pressure fresh air system and radiant floor heating in total of 36 cases is done, and comparative analysis are also done. From the comparative analysis, it is obtained that the fresh air ventilation plan when the ratio of length to width of inlet below the window is 0.3 and exhaust velocity is 3.5 m/s can get the optimal indoor air distribution environment, which can ensure indoor air quality requirements, but also not waste energy.