CFD Analysis of Warehouse
CFD APPLICATION IN A WAREHOUSE
Warehouses store goods for considerable time. HVAC systems and distributions should be carefully designed for larger spaces as they have energy implications also. In large warehouses an under sized HVAC system makes the work environment tiresome. The areas of human movement should be comfortable. A Storage containing fabrics and related products may emit odor in lack of proper conditioning. A computational fluid dynamic study is required to determine the reach of conditioned air. At geographical locations, where temperature during a day varies a lot. A dynamic thermal modeling along with a CFD study can make an energy efficient and robust HVAC designs.
In a warehouse, humidity of air at various locations in the facility, along with temperature and velocities should be monitored. In large spaces with solar heat gains, there is a possibility of buoyancy driven flows in places where velocity of air is lesser. Forced flows will also be present where velocity of air is more (near supply diffusers). The external walls are conductive in nature to the solar heat gains. Lighting, equipment and occupants loads are added as zonal sensible loads. Navier-stokes equations with energy equation can determine velocities and temperature distributions inside warehouse. The moisture distribution is modeled by introducing additional phase equation. Gravity modeling is necessary if at much of the spaces flow velocities are negligible.
The warehouse under consideration is a furniture warehouse and located at Riyadh. It is a 1.7 lakhs ft2 facility with 30 feet high roof with 60 racks to store goods. The facility is supplied with conditioned air at 17 degree Celsius and 85% relative humidity. The total volume flow rate is 2.1 lakhs ft3/minute. The post-processing image represents temperature variations inside the establishment. It shows the temperature is higher near the walls, as the supply diffusers are located at certain distance from the wall and flow does not reach walls. At the same time major portion of the warehouse, which will be subjected to human movement is having temperature within specified limit of 300 K. There can be improvement in temperature distribution by providing supply diffusers near the walls, which will require additional ducting. Regarding the relative humidity inside this facility, it lies in the range of 40% to 55%. Hence it is under desired limits. The duct work in this warehouse is nearly at half the height of roof. The post-processing image also indicates increased temperature towards top of the duct. This can be avoided by placing the duct towards top of the racks in the modified duct layout