Theoretical Model for Predicting Axial Fans/Blowers Performance Characteristics
Next to pumps, Fans/Blowers are the most energy consuming motor driven machineries in Nigeria today. Every home and office rooms in Nigeria have at least one Fan/Blower used for the purpose of ventilation and space conditioning. Unfortunately, most of the more than 170million Fans/Blowers sold in Nigeria are not accompanied by the Fans/Blowers’ performance characteristics curves. Hence, the Fans/Blowers are improperly matched to systems requiring them, which usually results to inefficient operation of the Fans/Blowers, excessive energy consumption, dissatisfaction of end users and Fans/Blowers failure. This work aims are developing a simplified theoretical model for predicting the performance characteristics of axial Fans/Blowers using a combination of aerodynamics involving through-flow analysis and a simplified classical one dimensional momentum theory. The model was developed using the geometric and basic operating particulars of the Fans/Blowers to evaluate the interaction of the Total Pressure developed, Power required and efficiency of the blower for a range of flow volumes. The model developed in this work was validated against several Fans/Blowers models in the T35 Fans/Blowers series performance data provided by NanFang Ventilator Factory. The flow volume, total Pressure, air power and efficiency predicted by the model is in reasonable agreement with those of the manufacturer’s to a mean percentage of 97.68%, 96.71%, 85.7% and 96.6% respectively. The theoretical model can be used by ventilation systems designers and Fans/Blowers end users to generate axial Fans/Blowers performance characteristic curves not supplied by Fans/Blowers manufacturers and thus, effectively specify axial Fans/Blowers for existing or newly designed systems.
Keywords- Axial Fans/Blowers, One Dimensional Momentum Theory, Performance Characteristics Curves (Efficiency, Total Pressure, Flow Volume and Required Power), Validated.