Steam Powered Ceiling Fan

Introduction:
Countless number of villages have been facing electricity scarcity for ages. This problem is prominent in summers. Lack of electricity and hot weather make rural life miserable in summers. Given the availability of adequate space and domestic burning fuels in rural households, an idea of using miniature steam turbine along with rankine steam cycle as substitute to electric motor is proposed.

Details of Conventional Fan:

• Specifications of conventional fan [Parker et. al.]:

1. Operating speed: 50-200 RPM
2. Avg. power consumption: 75 W
   
3. Total flow : ~3000 cfm
4. Total useful power output at motor shaft: ~8-10 W
5. Typical number of blades: 3/4
   

It can be seen form the above data that AC motor delivers less than 15 % of the total electrical power input to fan blades. Also, it can be observed that energy efficiency of fan blades in terms of amount of air displaced to useful power drawn from motor shaft, is similarly low.

Proposed Design Concept:
As burning fuels and working fluid is readily available, following is proposed:

1. A rankine steam cycle between appropriate operating points can be utilized to generate required energy output for rotating fan blades.
   
2. With the help of household cooking system required amount of water can be heated to generate pressurized vapour.
   
3. Output shaft of miniature steam turbine [2] can be coupled directly to celing fan blades.
4. Readily available heat resistant pipes can be used as ducts for making connections.
   
5. Overall efficiency of rankine heat cycle would be appx. 25-30 %.