Chemical to Mechanical Energy
Initial brainstorm and construction:
During my visit to India in 2011, I collected a few spare parts from the local garage like the cup shaped-tin fins, PVC pipes, discarded electronic hot plate, spare pressure cooker, ball bearings and a tin funnel (later converted into a nozzle). Using these household discarded items, I worked along the
principles of a heat engine (about which I was specifically enlightened in my junior year) to create an energy converter without the cold reservoir. The discarded electronic hot plate and spare pressure cooker were used for the heat source and tap water as the working substance. I had the tin funnel shaped in the form of a nozzle and welded onto the lid of the pressure cooker, during my visit to the nearby industrial area. Finally 8 small metal rods contributed to the spokes of the rotor blades attached to the ball bearing on one side and tin cups on the other.
AIM: To apply my knowledge, of physical sciences, attained from my school resources about:
i)The elevation in boiling point of a solution containing a non volatile solute (direct consequence of Raoult’s Law)
ii)Change in physical state of water from liquid to water vapour (vaporisation).
iii)Rotational analogues of motion.
iv)Work energy theorem.
v)Law of conservation of energy
vi)Calculation of efficiency of the energy converter
vii)Carnot’s theorem (for efficiency)
and demonstrate the conversion of heat energy to mechanical energy.
APPARATUS
Tap water (our working substance), spare pressure cooker, tin funnel, metal fins, electronic hot plate, PVC pipes and ball bearing.
BLOCK DIAGRAM
Hence the working of this energy converter resembles that of the heat engine; the difference in this case is the absence of a sink (cold reservoir).
Figure-1
PROCEDURE
1. Calculate the elevation in boiling point of water due to impurities.
2. Take this water in a container (pressure cooker); this water is our working substance.
3. Heat the water to its elevated boiling point (373.15 K). Here the heat energy is derived from the chemical energy stored in the fuel.
4. Latent Heat of vaporisation is then used to convert water at boiling point to steam at the
same temperature.
5. This steam is later converted into saturated steam by restriction on its discharge from the
container.
6.At appropriate temperature, this steam is released with great pressure and impinges on the
metallic fins.
7. Hence the heat energy consumed to produce saturated steam is converted into mechanical
energy (which is used to do the mechanical work of rotating the fins).