How to Numerical Simulation and Test of Airflow in ISO 14644 Cleanroom Single Side Downdraft Cleanroom.
The development of modern science and industrial technology has made ISO 14644 clean room air cleaning technology increasingly widely used. Whether the purification workshop can achieve a certain degree of air cleanliness, effectively control and eliminate particulate pollution, involves many factors, among which the indoor airflow organization has a greater impact. Reasonable airflow organization is to make the indoor airflow flow in a certain direction to prevent disturbance and avoid vortex.
According to the flow direction of the air flow, the air flow in the ISO 14644 clean room purification workshop can be divided into two types: unidirectional flow and non-unidirectional flow. When the cleanliness level of the purification workshop is designed to be 1-5, the airflow organization requires the use of unidirectional flow, and when the cleanliness level is 6 to 9, non-unidirectional airflow is used. When the vertical one-way flow purification workshop adopts the traditional ceiling air supply and floor grille air return method, the purification effect is the best, and the highest level of cleanliness can be achieved, but the ceiling and floor structures are complex and the cost is high; while the fan filter is used The Fan Filter Unit (FFU for short) adopts the form of lower and return air on both sides of the supply air, which can not only simplify the sealing of the ceiling of the purification workshop, but also save the area of the air-conditioning room and reduce the size of the supply and return air ducts, thereby saving the initial investment and operating costs.
However, in the design of the ISO 14644 clean room purification workshop, when the process requires that the return air vents of the air conditioning system cannot be arranged on both sides of the wall at the same time, the return air vents can only be arranged at the lower part of the single side wall, which leads to the one-sided return air form. One-way flow purification workshop. What is the airflow organization of the one-way flow purification workshop using fan filter unit (FFU) air supply and single-side down return air? How different is it from the traditional airflow organization? Can its airflow organization meet the requirements of one-way flow ?The research and solution of these problems have very important theoretical value and engineering application value for the design of this kind of purification workshop.
Computational fluid dynamics (Computational Fluid Dynamics, CFD for short) is more and more widely used, and it has also been applied in ISO 14644 clean room ventilation and air conditioning purification engineering and has achieved many results. Applying computational fluid dynamics to analyze the three-dimensional airflow distribution in the purification workshop and find out the internal laws can provide sufficient basis for the rational design of the airflow in the purification workshop. In this paper, the numerical simulation of the airflow in the purification workshop in the form of single-side return air is carried out, and the field test is carried out on an actual project. Verify the correctness and reliability of numerical calculation methods and results.
On this basis, the turbulence parameters of the working area of the ISO 14644 clean room purification workshop were further programmed and calculated, and the airflow organization of the purification workshop was evaluated, providing a reference for the engineering design and application of this type of purification workshop.