The contents
The abundance of sunlight and heat in summer, desire or need to achieve real savings in heating and hot water supply forced many craftsmen to invent and implement in metal most interesting from their point of view, the project solar water collector.
But, as always, smart people suggest – before taken over the production of a water solar collector with their hands, learn with ready-made designs, incarnate in reality. It is difficult to tell if you have achieved the main goal, and obtained the desired effect of conversion of solar heat into the water. Typically, this information is missing from the masters.
Therefore, before the production of a water solar collector analyze and answer yourself a simple question:
- What is the amount of hot water needed and for what purpose it is supposed to use it.
- What are the water parameters of the solar collector to satisfy the consumer;
- Justify whether money and time spent on the goal.
Goals and objectives the manufacture of a water solar collector ↑
It is worth Recalling that the solar flux maximum incident thermal energy in average 800W/h per meter squared in the summer. For hot water heating systems a modern house or apartment is not enough. For example, if the heated area is 50 mTwo minimum thermal requirements will be at least 7-8kW/h, depending on the condition of housing, so at 100% efficiency, the device will need at least 10mTwo solar collector.
But as an alternative electric boiler system water solar collector is quite pull. Subject to the availability of system storage tank and water pump.
Select the design water solar collector ↑
As a working model use of standard and proven design using a set of parallel heated tubes. The most difficult question – materials. Among the many options the solar water Amateur designs you can choose the most appropriate scheme, subject to:
- A single length of heated tube from the common inlet pipe to the drainage pipe must not exceed 70cm schemes for horizontal and for vertical 200cm. The size of the practical selection.
- Step theproprietary between tubes should not exceed 10 times the diameter for copper of performance and 5 diameters for aluminum. This is due, primarily, with the need to efficiently collect heat from the surface of the heat-screen-absorber of solar heat. At higher step deteriorates the heat removal and increased losses, a lower step, rising costs for materials without a significant increase of the efficiency of the water collector.
- Complete with a solar water collector you need to connect the boiler with an internal heat exchanger and pump performance in the range of 100-150лч hot water.
Quite often there are construction of water reservoirs using a variety of heat exchangers from old refrigerators and similar devices. By itself, such a heat exchanger is soldered to the sheet copper and mounted on the heat shield will give a Sunny day a maximum of half a litre of boiling water per hour. More efficient use of its copper tube for the manufacture of the water heater tube solar collector.
For solar water collector will require a certain amount of copper pipes, flux and tin-lead solder, copper sheet.
Collector size 200х70см should:
- Copper tube, diameter 12-15mm – 4.2 m, the cost is estimated in 20-25дол.;
- The tube is heated, copper, diameter 8mm – 30m, the cost – 90дол;
- Copper sheet, width 100mm and thickness 1mm – 20m, price – to 20dol;
- Solder POS-9 and alcohol-rosin flux 300 and 100g respectively-5дол.
The result: the average cost of materials is estimated at 140-150дол., which is approximately comparable with the requirements to the cost of the project water collector sunlight.
We manufacture heat exchanger water solar collector ↑
Before soldering and Assembly will be required to undertake the layout and cutting of the material. Places drilling note blow sharpened punch.
The drill holes executed only on a drill press, carefully remove the burrs.
Before assembling and soldering of the heated soldering gas burner treated obslujivaem flux and solder all the soldering points. A thin heated tube Ludim along the entire length in the places of the future rear-absorber.
In the process the soldered places wrap a wet cloth to avoid melting the junction due to overheating of the heat exchanger.
The second time we cut out strips of copper so that they form a continuous sheet. Do not attempt to solder one solid sheet, it’s harder than you think, and will require special equipment.
At the ends of the submarine and into the discharge pipe sealed fittings for fixing the pipes connecting the solar collector with the boiler or water storage tank.
To avoid possible structural deformation of the manifold heat exchanger can be placed in a box or on the hinged frame. As a rule, the bottom of the box is lined with insulating Mat and additionally blow out of construction foam.
Before mounting in the box it was necessary to check the tightness of the soldering. To do this, one of the fittings to jam with threaded plugs for sealing of a fluoroplastic tape. The second fitting is supplied pressure from the construction or automotive compressor. Soldering each joint sequentially coated with soapy water, like checking for a gas leak. In the case of bubbles, the marriage needs to be resolder.
Coating for water solar collector ↑
A separate issue is the coating than usual trumps all sellers water solar collectors, industrial manufacturing. For the application of a black coating uses lacquer in aerosol cans and a piece of rubber. Before the surface of the heat exchanger must be treated with alcohol or acetone.
All work is performed outdoors, in the draft, using a respirator. Before coating the disposable collector so that the heated tube was vertical, and light rubber. Consistently spray the lacquer, and a second offer aptasia flame rubber at a distance, providing a soot deposition on thin layer of varnish. It is better to run a few passes until you get the solid black particle coating. After the final drying of the lacquer coating well-kept on the copper surface. In an experiment to apply a re-coat of varnish, but often it is not needed.
Ready water collector is mounted in a box and is closed by a sheet of transparent polycarbonate. It is better and easier glass, is not afraid of heat overload from sunlight, bumps, thanks to a special protective film more durable in use, even in the sun. But, unlike mineral glass, polycarbonate has a high coefficient of thermal expansion of approximately 1m the amount of change is 3mm. So the sheet is attached to the surface of the water manifold, using a special teplogenerirujushchej linings and washers, sealant, resistant to sunlight.
Before hermetic packing of the collector housing at the bottom part you can put a couple of bags of silica gel or brand of the sinks of moisture and water vapor.
