A solar-thermal water pump.
Solar-powered water pumping is an inherently sensible proposition due to the pump being able to supply water at times when it is most in demand. In general small solar-thermal water pumps hold some promise for low technology applications in developing countries. The aim of this study was to model th...
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| Language: | en |
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University of Canterbury. Department of Mechanical Engineering
2010
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| Online Access: | http://hdl.handle.net/10092/3936 |
| Summary: | Solar-powered water pumping is an inherently sensible proposition due to the pump
being able to supply water at times when it is most in demand. In general small
solar-thermal water pumps hold some promise for low technology applications in
developing countries. The aim of this study was to model the characteristics of an
appropriate technology water pump and build a concept-proving pump.
A detailed computer model of the pump and flat plate collector gave the ability to
optimise the pump's dimensions and predict the output for any average day in any
location. An exergy analysis showed that the major losses in the system were due to wasteful processes within the pump's operating cycle. The pump took the form of
a 450mm diameter double diaphragm suction unit with a predicted operating
efficiency of approximately 1% when operating at 68°C. The concept-proving pump
was set up using compressed air and preliminary runs on pentane gave an efficiency
of 0.3%. The pump takes water from 7 metres below to 1.5 metres above the pump
at a rate of 3 litres every 10 seconds.
A financial analysis highlighted the fact that the solar pump has higher capital but
lower running costs than some of its competitors, and as such would suit certain niche
applications. Recommendations are to improve the physical lay-out of the pump and
improve the design of several components to enable better performance of the pump
operating on the same principle. |
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