Water, wind and sun - the most accessible and inexhaustible source of energy that nature gives to man. It is no accident to them in recent years, re-drawn the most attention as a science and industry, and creativity enthusiasts, amateur designers. Some of them created by «home» devices using wind and solar, we have already described in our publications section KDM and «Low mechanization». Today, introduce you to the heating of solar installation designed Bulgarian engineer Stanisław Stanilovym.
Solar water heater: 1 - avankamery ball valve, 2 - drain pipe drive 3 - a pipeline to bring cold water to avankamere, 4 - heat-insulating box for storage, 5 - enter the cold water pipe, 6 - trumpet bring cold water to the mixer; 7 - trumpet a supply of hot water to the mixer, 8 - trumpet to bring hot water to drive, 9 - solar thermal, 10 - drain valve, 11 - valve system for the Gulf, 12 - «hot» tube solar collector, 13 - tube feeding drive 14 — avankamera, 15 - avankamery drainage pipe.
Hydraulic scheme of solar water heater: 1 - solar collector, 2 - «hot» tube solar collector, 3 - coarse pipe hot water to exit from the drive, 4 - sough avankamery, 5 - drainage pipe storage, 6 - avankamery ball valve, 7 — avankamera, 8 - trumpet bring cold water to avankamere, 9 - a pipeline feeding the drive, 10 - water-supply input, 11 - supply of cold water to the mixer, 12 - supply of hot water to the mixer, 13 - «cold» tube solar collector.
Solar Collector: 1 - glass, 2 - frame (steel corner), 3 - bottom (orgalit 5 mm thick), 4, 7 - the walls of the collector box (plaque cross-section 120X25 mm), 5 - steel lining (lane cross-section 2,5 X20 mm), 6 - lining corner, 8 - Strengthening the bottom (a wooden block section of 30X50 mm), 9 - Connection, 10 - tube heater, 11 - receiving pipe cooler, 12 - clamp mounting radiator, 13 - teplootrazhatel (galvanized iron roof or tin), 14 - heat insulator (polystyrene, glass or shlakovata).
Just when you thought ice cube-creation technology had peaked, a team of engineering students from San Jose State University has come up an ice maker that has zero carbon footprint. It’s more than an eco-party trick — consider it an electricity-free alternative to refrigeration and air conditioning, which is critical if you happen to be somewhere off of the electrical grid, like in the developing world or in a disaster zone.
It works like this: the solar icemaker uses a refrigerant liquid that evaporates when exposed to the sun. The vapor travels through pipes that come into contact an absorbent material, which cools when the sun goes down. Once the slow-cooling absorbent hits 104°F, the refrigerant turns back into a liquid and its temperature drops like a rock to below freezing because of pressure differences. Put some water next to the evaporator’s exterior and, presto, ice.
A typical icemaker uses electricity to run a compressor to do this work, but the solar icemaker just uses solar energy, with no moving parts. And the systems are sealed, so barring a leak, they’ll never need replenishing. The icemaker makes about 14 pounds of ice per day — more than enough for the margaritas at your end-of-summer barbecue. The students’ prototype isn’t available yet, but maybe next summer….
Via San Jose State University
Tags: pressure differences, refrigeration and air conditioning, Solar & fire
This a Stirling engine concept that I am developing as part of my Masters of engineering degree at the university of Canterbury (New Zealand).
The displacer, shown at the right, is a segment of a third of a cylinder, which is rotated back and forth by an electric motor, forcing air through the heat exchangers and regenerator (shown as red for hot exchanger, blue for cold exchanger, and green for regenerator. The heated or cooled air pushes out or sucks in the power piston which turns the crank and flywheel. Estimated power output of 1kW at temperature difference of less than 200 degrees C. It is quite large, about 2m x 1m footprint size.
Tags: heat exchangers, stirling engine
MAKING THE GENERATOR
Although you can simply wind the coil directly around the plastic film can (see picture of the first prototype) it is neater and easier to make a simple bobin to wind the coil round. Here’s how to do it:
Step 1
Find a 35mm plastic film can and remove the lid. Cut out two cardboard circles about 50mm diameter and cut out their centres (33mm diameter hole) so that they fit snugly onto the canister. Space the two circles about 1cm either side of the center of the can. Wind on a few turns of insulation tape on to the can, either side of the cardboard to hold them in place.
Step 2
Use the cardboard circles as a bobbin (or former) on which to wind the coil. Wind on 500 to 1000 turns of thin, insulated copper wire. Add a layer of sellotape to keep them from un-winding. Remember to leave about 10cm or so of wire free at each end.
Step 3
Scrape off some of the insulation (say 5mm or so) from the ends of the wire (using sandpaper) and connect to the LED (it does not matter which way round). Solder the connections if possible. Use some sellotape to secure the wire and LED to the bottom of the can.
Step 4
Pop a small (but powerful) magnet into the can and snap the lid back on. Hold the can between thumb and forefinger at the two ends of the can (with thumb or forefinger on the lid to stop it coming off !) and shake. The LED will light
HOW THE GENERATOR WORKS
A generator works by a magnetic field inducing a voltage into a coil of wire. Important points to note are that the voltage increases as the number of turns of wire on the coil becomes larger and the size of the coil and the strength of the magnetic field increase. The magnetic field (or the coil) needs to be in constant motion to produce/induce the electricity into the coil. This can be done by moving the magnet or by moving the coil - the effect is the same. The coil (or the magnet) needs to move in such a way that the coil continually passes through the magnetic field.
The type of wire in the coil is also important. For example, thick wire means there will be less power loss, but the down side is that the coil will get very large when a great number of turns is needed. In a practical generator some trade off has therefore to be found between the size of magnet, coil and the wire.
The peak voltage generated by this little device is given by:
V = A x M x N
Where A is the cross sectional area of the can (0.0008 m²), M is the rate of change of magnetic field (ca. we need to use very strong magnets having a surface field of say 1 Tesla (see magnet info. below), so shaking it say 5 times a sec we get M = 5 Tesla / sec) and N the number of turns.
If we want an LED to light brightly we need to generate peak voltages of about 4V;
rearanging the formula allows us to estimate the number of turns:
N = V / (A x M) = 4 / (0.0008 x 5) = about 1000 turns - happy winding !
AC or DC
This simple generator is called an AC generator. This means that the voltage appearing at the two wires alternates between + and -, and - and + each time the magnet goes from one end of the can to the other. As a result the generator can light a bulb or an LED without you having to worry about which way round the connections need to go (as they are effectively reversing all the time anyway). However, this simple generator is not good for running radios, calculators or other devices that need a direct current (DC) that is produced for example from a battery.
source: www.creative-science.org.uk
Tags: bobin, magnet, magnetic field
Tags: generating electricity
The Turgo turbine is an impulse type turbine; water does not change pressure as it moves through the turbine blades. The water’s potential energy is converted to kinetic energy with a nozzle. The high speed water jet is then directed on the turbine blades which deflect and reverse the flow. The resulting impulse spins the turbine runner, imparting energy to the turbine shaft. Water exits with very little energy. Turgo runners may have an efficiency of over 90%.
A Turgo runner looks like a Pelton runner split in half. For the same power, the Turgo runner is one half the diameter of the Pelton runner, and so twice the specific speed. The Turgo can handle a greater water flow than the Pelton because exiting water doesn’t interfere with adjacent buckets.
Tags: high speed, hydro generators, kinetic energy, pelton, water flow
start with some 2×4s and plywood to build a simple box.
built the box to certain dimensions. That sure was a lot of Sprite. Fifty cans in five columns of 10.
Sealed the box using adhesive caulk, just to keep any heated air from escaping the box.
So you may have already thought, “How can air climb the columns of cans when there’s no hole at the bottom of the can?” Answer: drill press and 3/4-inch bit. Times 45.
The last five cans, the bases of each column, will sit on the bottom of the box and thus will
be unable to draw air from underneath, so I poked holes in the sides of each of the five.
Stack the cans with liberal doses of adhesive caulk. Give them enough time to dry.
Once they’re dry, I painted each column with black BBQ paint. Black to best absorb the sun’s heat, BBQ paint to keep from flaking off the cans. At the top, I drilled an outlet hole. I left an inch or two of space between the tops of the columns and the top of the box to permit air to flow out of the columns.
I drilled the outlet hole based on the diameter of some wet-dry vacuum hose I picked up, about 1-1/2 inches in diameter.
At the bottom, I used another wet-dry vacuum attachement that would more evenly disperse the incoming air. Screwed it in at each end, then caulked the seal.
Then started to caulk the columns in place. At the bottom, you can see the inlet hole I drilled. At about this point, I realized that a better place for the inlet would have been through the plywood at the bases of each column. In this location, the air can simply pass over the cans (there’s about 1/2 to 3/4 of an inch between the cans and the upper edge of the 2×4 frame) and not really pick up that much heat. If I were to relocate the inlet, it would force all the air to pass through the cans and pick up the absorbed heat. Next time.
Had some red paint left over from one of Heather’s previous projects, so slapped on a couple coats to at least keep the weather off the bare wood.
The caulk is pretty strong. Kept the cans from falling out while I had the box inverted.
Also had some 3/4-inch PVC pipe from another previous project. Bought a couple elbows and T-fittings and whipped up a simple frame to keep the box off the ground and to angle it upward toward the sun. Didn’t give the exact angle too much thought.
Caulked a clear plexiglas cover on the front and sat the furnace out in the sun for a full day over the weekend to see how it would work.
Using some advanced technological
equipment, such as this precisely calibrated pyrometer, I determined the intake air temperature, which should have been the same as the ambient air temperature, to be about 80 degrees.
Using the same equipment and methods, I determined the outlet temperature to be about 95 degrees - thus a 15 degree temperature differential. Not 110 degrees, but not bad , considering I didn’t even break $50 in materials - most of that being the plexiglas window.
Tags: heather, vacuum hose, weather
The aluminum vanes are constructed from a building flashing roll utilizing the pre-existing bend of the roll in
construction. Two 16 ” sections are riveted together to make one vane. The vanes clip on the spokes of the bicycle wheel using a “bent nail” and a bend in the vane. Detailed pictures will be provided shortly. The generator is a surplus permanent magnet motor and the uv resistant endless belting is purchased to length from online sources.
Output is a respectable 2 amps at 12 mph (18-20 volts) providing a cost effective alternative to a solar photovoltaic panels (if wind is available). The total cost of the windmill was less than $80 purchasing most items new (off-the-shelf). The two most expensive items were the permanent magnet motor (around $30) and the uv resistant round belting typically used in food processing plants to drive conveyors ($3 to $5 per foot).
The windmill does have a tail (see new photo). The frame is made from PVC pipe. It is important to use only a 24 to 27 
inch rear solid axle bicycle wheel. The wheel is mounted to a PVC end cap via a hole drilled in the middle of the end cap.
The generator is a 24 volt DC permanent magnet motor. This one was surplus and used in old main frame disk drive units. DC permanent magnet motors are available through Internet surplus resources, but getting scarce.
The generator is mounted using a simple L bracket. Should be sturdy (not the typical shelf bracket) and both the motor and the bracket are secured with radiator hose clamps.
The windmill pole is electrical conduit that 1.5 inch PVC slides over. A short segment of PVC pipe is screwed into the metal conduit to create a bearing that the windmill pivots on (PVC to PVC).
Tags: Wind turbine