Homemade solar concentrator download in pdf. Homemade solar concentrator from a mirror film

Startup company GoSol intends to make solar energy available to everyone on a global scale. To do this, she created an initiative to develop and disseminate instructions for assembling solar concentrators from local materials that could become efficient sources of heat for cooking, washing, heating water and heating.

“The mission of GoSol.org is to eradicate energy poverty and minimize the effects of global warming by spreading our DIY technology (DIY from English. Do It Yourself - Russian “do it yourself”) and breaking down any barriers to free access to solar energy. With your help, we want to engage communities, entrepreneurs and craftsmen to use the world's most powerful source of energy. All the materials and tools needed to implement these technologies have already been produced and are in abundance in all corners of the world, ”says the GoSol website.

GoSol enthusiasts have launched a campaign with which they intend to raise $68,000 to make their goal come true. So far, the initiative has raised about $27,000 and most recently, GoSol released its first instruction manual for building a solar concentrator.

See also: Ripasso solar concentrator - the most effective method solar energy conversion?

Free step by step guide contains all the necessary information to create a 0.5 kW solar concentrator with your own hands. The reflective surface of the device will have an area of ​​about 1 square meter, and the cost of its production will cost from $79 to $145, depending on the region of residence.

Sol1, got this name solar installation from GoSol, will take approximately 1.5 cubic meters of space. Work on its manufacture will take about a week. The materials for its construction will be iron corners, plastic boxes, steel bars, and the main working element - a reflective hemisphere - is proposed to be made from pieces of an ordinary bathroom mirror.

The solar concentrator can be used for baking, frying, heating water or food preservation through dehydration. The device can also serve as a demonstration of the efficient operation of solar energy and will help many entrepreneurs in developing countries to start their own business. In addition to helping to reduce harmful emissions into the atmosphere, GoSol solar concentrators will help reduce deforestation by replacing burned wood with clean solar energy.

The GoSol instruction can be used not only for the creation and practical application, but also for the sale of solar concentrators, which will help to significantly lower the threshold for accessing solar energy, which is mainly generated today through photovoltaic solar panels. Their cost remains at an extremely high level in regions where it is often simply not possible to obtain energy in other ways.

A free solar concentrator manual is available on the GoSol website, and in order to receive it, you will need to leave your email address, to which updated information will be sent. If you want the "solar" initiative to move faster and on a larger scale, then you can support the company financially - the startup still accepts cash contributions, the reward for which will depend on the amount of the donation.

See also: Ukrainian solar concentrator "Diversity" - instructions in the public domain

Video: GoSol.org Free The Sun Campaign for Builders

ecotechnica.com.ua

Homemade solar concentrator from a mirror film

A huge amount of free energy from the sun, water and wind, and much more that nature can give, people have been using for a long time. For some, this is a hobby, but someone cannot survive without devices that can extract energy “out of thin air”. For example, in African countries, solar panels have long become a life-saving companion for people, solar-powered irrigation systems are being introduced in arid villages, “solar” pumps are being installed on wells, etc.

Solar ovens in this Chinese store.

In European countries, the sun does not shine so brightly, but the summer is quite hot, and it is a pity when the free energy of nature is wasted. There are successful developments of solar-powered ovens, but they use one-piece or prefabricated parabolic mirrors. Firstly, it is expensive, and secondly, it makes the structure heavier and therefore not always convenient to use, for example, when a light weight of the finished concentrator is required. An interesting model of a home-made parabolic solar concentrator was created by a talented inventor. will not be a heavy load on a hike.

It takes very few things to create a homemade film-based solar concentrator. All of them are sold at any clothing market.1. Self-adhesive mirror film. It has a smooth shiny surface and is therefore an excellent material for the mirror part of the solar oven.2. A chipboard sheet and a hardboard sheet of the same size.3. Thin hose and sealant.

How to make a solar oven?

First, two rings are cut from a chipboard of the size you need with an electric jigsaw, which must be glued to each other. The photo and video show one ring, but the author indicates that he later added a second ring. According to him, one could have been limited to one, but the space had to be increased to form a sufficient concavity of the parabolic mirror. Otherwise, the focus of the beam will be too far away. Under the size of the ring, a circle of hardboard is cut out to form the back wall of the solar concentrator. The ring should be glued to the hardboard. Be sure to coat everything well with sealant. The design must be completely sealed. On the side, carefully, so that there are even edges, make a small hole into which tightly insert a thin hose. For tightness, the connection of the hose and the ring can also be treated with a sealant. Stretch a mirror film over the ring. Evacuate the air from the unit body and thus form a spherical mirror. Bend the hose and clamp it with a clothespin. Make a convenient stand for the finished concentrator. The energy of this installation is enough to melt an aluminum can.

Attention! Parabolic solar reflectors can be dangerous and can cause burns and eye damage if handled carelessly! Watch the video on how to make a solar stove.

Used material from the site zabatsay.ru. How to make a solar battery - here.

izobreteniya.net

How to make a solar concentrator with your own hands (for example, parabolic)

The problem of using solar energy has occupied the best minds of mankind since ancient times. It was clear that the Sun is the most powerful source of free energy, but no one understood how to use this energy. If you believe the ancient writers Plutarch and Polybius, then the first person to practically use solar energy was Archimedes, who, using some optical devices he invented, managed to collect the sun's rays into a powerful beam and burn the Roman fleet.

In essence, the device invented by the great Greek was the first concentrator of solar radiation, which collected the sun's rays into one energy beam. And at the focus of this concentrator, the temperature could reach 300 ° C - 400 ° C, which is quite enough to ignite the wooden ships of the Roman fleet. One can only guess what kind of device Archimedes invented, although, according to modern ideas, he had only two options.

The very name of the device - a solar concentrator - speaks for itself. This device receives the sun's rays and collects them into a single energy beam. The simplest concentrator is familiar to everyone from childhood. This is an ordinary biconvex lens, which could burn out various figures, inscriptions, even entire pictures, when the sun's rays were collected by such a lens into a small dot on a wooden board, a sheet of paper.

This lens belongs to the so-called refractor concentrators. In addition to convex lenses, Fresnel lenses and prisms also belong to this class of concentrators. Long-focus concentrators based on linear Fresnel lenses, despite their low cost, are used very little in practice, since they are large. Their use is justified where the dimensions of the concentrator are not critical.

Refractory Solar Concentrator

The prismatic concentrator of solar radiation is deprived of this shortcoming. Moreover, such a device is also capable of concentrating part of the diffuse radiation, which significantly increases the power of the light beam. The trihedral prism, on the basis of which such a concentrator is built, is both a radiation receiver and a source of an energy beam. In this case, the front face of the prism receives radiation, the back face reflects, and radiation is already emerging from the side face. The operation of such a device is based on the principle of total internal reflection of rays before they hit the side face of the prism.

Unlike refractor concentrators, reflex concentrators work on the principle of collecting reflected energy into an energy beam. sunlight. According to their design, they are divided into flat, parabolic and parabolic-cylindrical concentrators. If we talk about the effectiveness of each of these types, then the highest degree of concentration - up to 10,000 - is given by parabolic concentrators. But for the construction of solar heating systems, mainly flat or parabolic-cylindrical systems are used.

Parabolic (reflector) solar concentrators

Practical application of solar concentrators

Actually, the main task of any solar concentrator is to collect the radiation of the sun into a single energy beam. And you can use this energy in various ways. It is possible to heat water with free energy, and the amount of heated water will be determined by the size and design of the concentrator. Small parabolic devices can be used as a solar cooker.

Parabolic concentrator as a solar oven

Can be used for additional lighting solar panels to increase output power. And it can be used as an external heat source for Stirling engines. The parabolic concentrator provides a focus temperature of about 300°C - 400°C. If, for example, a stand for a kettle or frying pans is placed in the focus of such a relatively small mirror, then you get a solar oven, on which you can cook food and boil water very quickly. A heater with a coolant placed at the focus will allow you to quickly heat up even running water, which can then be used for household purposes, for example, for showering, washing dishes.

The simplest circuit solar water heating

If a Stirling engine of suitable power is placed at the focus of a parabolic mirror, then a small thermal power plant can be obtained. For example, Qnergy has developed and launched the QB-3500 Stirling engines, which are designed to work with solar concentrators. In fact, it would be more correct to call them generators of electric current based on Stirling engines. This unit generates an electric current with a power of 3500 watts. The output of the inverter is a standard voltage of 220 volts 50 hertz. This is quite enough to provide electricity to a house for a family of 4, a dacha.

By the way, using the principle of operation of Stirling engines, many craftsmen make devices with their own hands that use rotational or reciprocating motion. For example, water pumps for summer cottages.

The main disadvantage of a parabolic concentrator is that it must be constantly oriented towards the sun. In industrial helium installations, special tracking systems are used that rotate mirrors or refractors following the movement of the sun, thereby ensuring the reception and concentration of the maximum amount of solar energy. For individual use, it would hardly be advisable to use such tracking devices, since their cost can significantly exceed the cost of a simple reflector on a conventional tripod.

How to make your own solar concentrator

The easiest way to make a homemade solar concentrator is to use an old satellite dish. First you need to decide for what purposes this hub will be used, and then, based on this, choose the installation site and prepare the base and fasteners accordingly. Thoroughly wash the antenna, dry it, stick a mirror film on the receiving side of the dish.

In order for the film to lie flat, without wrinkles and folds, it should be cut into strips no more than 3-5 centimeters wide. If you intend to use the concentrator as a solar oven, it is recommended to cut a hole in the center of the dish with a diameter of about 5 - 7 centimeters. Through this hole, a bracket with a support for dishes (burner) will be passed. This will ensure the immobility of the container with the cooked food when the reflector is turned to the sun.

If the plate is small in diameter, it is also recommended to cut the strips into pieces about 10 cm long. Stick each piece separately, carefully adjusting the joints. When the reflector is ready, it should be installed on the support. After that, you will need to determine the focus point, since the optical focus point at the satellite dish does not always coincide with the position of the receiving head.

Homemade solar concentrator - oven

To determine the focal point, you need to arm yourself with dark glasses, a wooden plank and thick gloves. Then you need to direct the mirror directly at the sun, catch a sunbeam on the board and, bringing the board closer or further away from the mirror, find the point where this sunbeam will have the minimum size - a small point. Gloves are needed in order to protect your hands from burns if they accidentally fall into the beam area. Well, when the focus point is found, it remains only to fix it and mount the necessary equipment.

Options self-manufacturing there are many solar concentrators. In the same way, you can make a Stirling engine from improvised materials yourself. And you can use this engine for a variety of purposes. How much imagination, desire and patience is enough.

solarb.ru

To assemble the collector, we need a few basic things: the antenna itself, the sun tracking system and the heat exchanger-collector.

parabolic antenna.

You will also need a rotary mechanism for the antenna assembly. It can be ordered on Ebay or Aliexpress.

You will need a roll of aluminum foil or lavsan mirror film used for greenhouses. Glue with which the film will be glued to the parabola.

Copper tube with a diameter of 6 mm. Fittings for connecting hot water to a tank, to a pool, or where you will use this design. The author purchased the rotary tracking mechanism on EBAY for $30.

Step 1 Modifying the antenna to focus solar radiation instead of radio waves.

All you have to do is attach a lavsan mirror film or aluminum foil to the antenna mirror.

This is almost as easy to do as it sounds. It is only necessary to take into account that if the antenna, for example, has a diameter of 2.5 m, and the film is 1 m wide, then it is not necessary to cover the antenna with a film in two passes, folds and irregularities will form, which will worsen the focusing of solar energy. Cut it into small strips and fix it to the antenna with glue. Make sure the antenna is clean before sticking the film. If there are places where the paint is swollen, clean them sandpaper. You need to smooth out all the irregularities. Please note that the LNB must be removed from its place, otherwise it may melt. After applying the film and installing the antenna in place, do not bring your hands or face near the head attachment point - you risk serious sunburn.

Step 2 tracking system.

Parts list: geliotraker.zip (downloads: 371) * U1/U2 - LM339 * Q1 - TIP42C * Q2 - TIP41C * Q3 - 2N3906 * Q4 - 2N3904 * R1 - 1meg * R2 - 1k * R3 - 10k * R4 - 10k * R5 - 10k * R6 - 4.7k * R7 - 2.7k * C1 - 10n ceramics * M - DC motor up to 1A * LEDs - 5mm 563nm

Itself can be made on the basis of the front hub of a VAZ car.

For those who are interested, the photo is taken from here: Rotary mechanism

Step 3 Creating a heat exchanger-collector

To make a heat exchanger, you will need a copper tube rolled into a ring and placed at the focus of our concentrator. But first we need to know the size of the focal point of the dish. To do this, you need to remove the LNB converter from the dish, leaving the converter mounts. Now you need to turn the plate in the sun, after fixing a piece of the board at the place where the converter is attached. Hold the board in this position for a while until smoke appears. This will take approximately 10-15 seconds. After that, unscrew the antenna from the sun, remove the board from the mount. All manipulations with the antenna, its turns, are carried out so that you do not accidentally stick your hand into the focus of the mirror - this is dangerous, you can get burned badly. Let it cool down. Measure the size of the burnt piece of wood - this will be the size of your heat exchanger.

Step 4 Putting it all together and trying it out.

From myself I will add that when using a collector in winter, measures must be taken so that the water does not freeze at night and in inclement weather. To do this, it is better to make a closed cycle - on the one hand, a collector, and on the other, a heat exchanger. Fill the system with oil - it can be heated to a higher temperature, up to 300 degrees, and it will not freeze in the cold. Source

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usamodelkina.ru

To create a water heating system using a solar reflector, the author needed the following materials: 1) parabolic satellite dish 2) mirror film 3) copper tube 4) salt 5) black heat-resistant paint 6) mullite-crystalline fiber

Consider the basics of the system and the stages of creating a solar concentrator. The main advantage of such a system is higher performance: high-quality reflectors focus high density sun rays at one point, which allows you to turn water into steam in a matter of seconds.

To demonstrate the visual power of such systems, I recommend that you familiarize yourself with the following video material:

As shown in the video, a small solar concentrator can burn wood, melt lead, that is, the temperature that occurs at the point of concentration of sunlight is quite high.

However, this system has a number of disadvantages that you need to know before deciding to build such a system.

In order for the reflector to be constantly turned towards the sun, it is necessary to install special tracking systems that will correct the reflector relative to the sun throughout the day. These trackers are quite expensive and consume a lot of energy.

The effectiveness of the concentrator is highly dependent on the cleanliness of the reflective surface, so mirrors require keeping them clean.

If these shortcomings do not scare you, then to build a concentrator you will need a parabolic satellite dish, and it is not particularly important whether it is a direct-focus or offset model. The main thing is the correct parabola, which will concentrate all the captured rays into one point. In principle, you can even make something like an antenna out of cardboard sheets, but the effectiveness of such a system depends very much on the quality of the parabola.

After cleaning the surface of the antenna, the author proceeded to pasting it with a mirror film. It is best to use a metallized film with an adhesive layer to create a mirror surface. Pasting the surface with such a film is quite simple according to the principle of self-adhesive wallpaper, but you can also use pieces of mirrors to create a reflective surface on the antenna.

Since the satellite dish itself has a curved shape, it is not entirely reasonable to try to glue a single piece of film. Therefore, before pasting, the author cut the film into thin strips. Thanks to this approach, it was possible to paste over the entire surface of the antenna quite evenly and in quality.

After the antenna acquires a mirror surface, it is necessary to determine the focus point, it will be the place of concentration of reflected sunlight from the surface of the antenna. Usually the focus point of the solar antenna is just in the area of ​​\u200b\u200bthe converter, but if you built a parabola yourself, then it is easiest to determine the focus point using the experimental method. It is necessary to take a thicker piece of plywood and gradually move it away from the concentrator until the sun spot on it decreases, as soon as it is minimal, this will be the focus point of the sun's rays. The main thing to remember is that a high temperature is concentrated in this place, so you need to be careful and wear protective equipment: leather gloves, a welding mask or sunglasses.

Next, you need to make a heat exchanger that will report the temperature to the water. For this, the author used a copper tube. He tamped salt into it, and began to wind more around the pipe. Salt inside the copper tube is needed so that the pipe does not flatten during winding.

The author notes that, in order to use the maximum energy from the sun, the heat exchanger does not hurt to be painted black. Since the heat exchanger will experience high temperatures, a heat-resistant paint must be used for painting.

Use refractory materials to insulate the heat sink, as heat will be concentrated in this place. The author of this concentrator used for these purposes a mullite-crystalline fiber, which is used in gas forges and muffle furnaces. Glass must also be tempered so as not to deform from temperature.

The heat sink was made on the principle of water cooling radiators for computers. It is made according to the spot size of the concentrator's focus point.

usamodelkina.ru

Solar thermal concentrator. Solar energy.

Alternative energy is of interest to everyone large quantity great minds. I'm not an exception. 🙂

It all started with a simple question: “Is it possible to turn a brushless motor into a generator?” - You can. Why? -Make a wind generator.

A windmill for generating electricity is not a very convenient solution. Variable wind power, chargers, batteries, inverters, a lot of cheap equipment. In a simplified scheme, the windmill does an excellent job of heating water. For the load is ten, and it is absolutely not picky about the parameters of the electricity supplied to it. You can get rid of complex expensive electronics. But the calculations showed significant construction costs in order to spin a 500-watt generator. The power carried by the wind is calculated by the formula P = 0.6 * S * V3, where: P - power, Watts S - area, m2V - wind speed, m/s

The wind blowing on 1 m2 at a speed of 2 m/s "carries" the energy of 4.8 watts. If the wind speed increases to 10 m/s, then the power will increase to 600 watts. The best wind turbines have an efficiency of 40-45%. With this in mind, for a generator with a power of 500 watts with a wind of, say, 5 m / s. It will take an area swept by the wind turbine propeller, about 12 sq.m. Which corresponds to a screw with a diameter of almost 4 meters! A lot of money - little sense. Add here the need to obtain a permit (noise limit). By the way, in some countries, the installation of a windmill must be coordinated even with ornithologists.

But then I remembered the Sun! It gives us a lot of energy. I first thought about this after flying over a frozen reservoir. When I saw a mass of ice more than a meter thick and 15 by 50 kilometers in size, I thought: “This is how much ice! How much does it need to be heated to melt!?” And all this will be done by the Sun in a dozen and a half days. In reference books, you can find the energy density that reaches the surface of the earth. The figure of about 1 kilowatt per square meter sounds tempting. But this is at the equator on a clear day. How realistic is it to utilize solar energy for household needs in our latitudes (the central part of Ukraine) using available materials?

What real power, taking into account all losses, can be obtained from this square meter?

To clarify this issue, I made the first parabolic heat concentrator out of cardboard (focus in the bowl of the parabola). I pasted over the pattern from the sectors with ordinary food foil. It is clear that the quality of the surface, and the reflective properties of the foil, are very far from ideal.

But the task was to heat a certain volume of water using “collective farm” methods in order to find out what power could be obtained, taking into account all losses. The pattern can be calculated using the Exel ParabAnt-v2.rar file, which I found on the Internet from fans of building parabolic antennas on their own. Knowing the volume of water, its heat capacity, initial and final temperature, you can calculate the amount of heat spent on heating it. And, knowing the heating time, you can calculate the power. Knowing the dimensions of the concentrator, it is possible to determine what practical power can be obtained from one square meter of the surface on which sunlight falls.

A half of an aluminum can, painted black on the outside, was taken as a volume for water.

A container of water is placed at the focus of a parabolic solar concentrator. The solar concentrator is oriented towards the sun.

Experiment #1

held around 7 am at the end of May. Morning is far from an ideal time, but just in the morning the Sun shines through the window of my “laboratory”.

With a parabola diameter of 0.31 m, calculations showed that a power of the order of 13.3 watts was obtained. Those. at least 177 watts / sq.m. It should be noted here that a round open jar is far from the most the best way to get a good result. Part of the energy is spent on heating the can itself, part is radiated into the environment, including being carried away by air currents. In general, even in such far from ideal conditions, you can at least get something.

Experiment #2

For the second experiment, a parabola with a diameter of 0.6 m was made. Metallized adhesive tape purchased at a hardware store was used as its mirror. Its reflective qualities are slightly better than aluminum food foil.

The parabola had a longer focal length (focus outside the bowl of the parabola).

This made it possible to project the rays onto one surface of the heater and obtain a high temperature at the focus. Parabola easily burns through a sheet of paper in a few seconds. The experiment was carried out at about 7 am in early June. According to the results of the experiment with the same volume of water and the same container, I received a power of 28 watts, which corresponds to approximately 102 watts / sq.m. This is less than in the first experiment. This is explained by the fact that the sun's rays from the parabola fell on the round surface of the jar not optimally everywhere. Some of the rays passed by, some fell tangentially. The jar was cooled by the fresh morning breeze on one side while warming up on the other. In the first experiment, due to the fact that the focus was inside the bowl, the jar was heated from all sides.

Experiment #3

Realizing that a decent result can be obtained by making the right heat sink, it was made next construction: a jar made of tin, painted black inside, has nozzles for supplying and discharging water. Hermetically sealed with transparent double glass. Thermally insulated.

The general scheme is as follows:

Heating occurs as follows: the rays from the solar concentrator (1) through the glass penetrate into the heat receiver jar (2), where, falling on the black surface, they heat it. Water, in contact with the surface of the jar, absorbs heat. Glass does not transmit infrared (thermal) radiation well, so heat radiation losses are minimized. As the glass heats up over time warm water, and begins to radiate heat, double glazing has been applied. Perfect option if there is a vacuum between the glasses, but this is an elusive task at home. On the reverse side of the bank is thermally insulated with foam, which also limits the radiation of thermal energy to the environment.

The heat sink (2) is connected to the tank (3) with the help of tubes (4.5) (in my case plastic bottle). The bottom of the tank is 0.3m above the heater. This design provides convection (self-circulation) of water in the system.

Ideally, the expansion tank and pipes should also be thermally insulated. The experiment was carried out at about 7 am in mid-June. The results of the experiment are as follows: Power 96.8 watts, which corresponds to about 342 watts/m.sq.

Those. system efficiency has improved more than 3 times just by optimizing the design of the heat sink!

When conducting experiments 1,2,3, aiming the parabola at the sun was done manually, "by eye". The parabola and the heating elements were held by hand. Those. the heater was not always in the focus of the parabola, because the person's hands get tired and start looking for a more comfortable position, which is not always correct from a technical point of view.

As you can see, efforts were made on my part to provide disgusting conditions for the experiment. Far from ideal conditions, namely: - not an ideal surface of the concentrators - not an ideal reflective properties of the surfaces of the concentrators - not an ideal orientation to the sun - not an ideal position of the heater - not an ideal time for the experiment (morning)

could not prevent getting a completely acceptable result for installation from improvised materials.

Experiment #4

Further a heating element was fixed motionless relative to the solar concentrator. This made it possible to increase the power to 118 watts, which corresponds to approximately 419 watts / sq.m. And this is in the morning! From 7 to 8 am!

There are other methods of heating water using solar collectors. Collectors with vacuum tubes are expensive, and flat ones have large temperature losses in the cold season. The use of solar concentrators can solve these problems, but requires the implementation of a mechanism for orientation to the Sun. Each method has both advantages and disadvantages.

One of the issues that need to be addressed on the way to the practical application of solar concentrators is to reduce its windage. Those. the concentrator must withstand wind loads. To reduce windage, you can use hubs assembled from individual segments. Such mirror concentrators can be quite flat compared to a parabola bowl, and the "perforated" structure reduces their windage.

Read also:

See also ParabolaSolar energy Solar collector

Application of solar thermal concentrators: http://ua.livejournal.com/580303.html https://www.youtube.com/watch?v=1hPmE3Swtvw https://www.youtube.com/watch?v=Rbjey5RGx3c https: //www.youtube.com/watch?v=M5OO3vCHRoI https://www.youtube.com/watch?v=CgZ0N6cg-v4

P.S. Solar energy is a resource that will remain free for all the inhabitants of the planet for a long time to come. And now everyone can freely receive it for their own purposes. Without the use of expensive technologies, but using only materials available to any person. This was confirmed by the experiments described above.

www.avislab.com

I Know: DIY Solar Concentrator - SolarNews

The main advantage of the concentrator is the high heating efficiency. The power of the reflector is capable in sunny weather at one point to focus the energy sufficient to boil water for several seconds.

The main disadvantages of such a system are the need for constant tracking of the sun (otherwise the efficiency of the concentrator drops to zero) and polishing and removing dirt from the surface.

To make a solar reflector with your own hands you will need:

1. Unnecessary parabolic antenna (you can also find instructions for making parabolic dishes yourself on the Internet).

2. Metallized mirror film with an adhesive layer (or pieces of mirrors for those who are especially enthusiastic)

3. Heat sink - a piece of copper tube twisted into a spiral - and inlet / outlet pipes.

4. Heat exchange tank (if necessary).

5. In the case of using a homemade paraboloid, a mount for a heat sink. In the case of using an antenna, the heat sink can be fixed at the place where the converter is attached.

Stages of production of a solar concentrator:

1. Clean the surface of the satellite dish or homemade paraboloid from dirt and grease. Make holes in the center for the tubes.

2. Stick the mirror film cut into thin strips. Thin strips are necessary in order to paste over the curved surface of the antenna as tightly as possible without joints, visible seams and irregularities (do not forget to make holes for the tubes).

Sticker of a mirror film on the cleaned surface of the plate

The result of gluing a paraboloid

3. Fix the heat sink painted with black heat-resistant paint at the focal point and bring the inlet and outlet tubes to it.

Fixing the heat sink in the focus of the concentrator

4. Pour liquid into the heat exchange tank and install the solar concentrator perpendicular to the sun.

Important: It must be remembered that the temperature at the point of concentration can reach 300-500 degrees, so when working with a solar parabolic concentrator, you must follow safety measures - work in protective clothing (leather or canvas gloves) and sunglasses or a welding mask.

The scheme for heating water using a homemade solar concentrator looks something like this:

Scheme of a homemade solar concentrator with a heat exchange tank

According to the materials of the site solarsistem.ru

Well, this is how the work of a home-made solar concentrator looks like on the video (very similar to the experiment with the "solar boiler", isn't it?):

solar-news.ru How to change the faucet in the bathroom with your own hands

Do-it-yourself heating from polypropylene pipes

Energy sources such as electricity, coal and gas are constantly becoming more expensive.

People need to think more about using greener systems heating.

Therefore, it was developed technical innovation in the field of alternative heat sources. Solar collectors have been used for this.

Solar collector for heating

The surface of this device has low reflectivity, due to which heat is absorbed. For space heating this mechanism uses the light of the sun and its infrared radiation.

To heat the water and heat the house, the power of a simple solar collector is enough. It depends on the design of the unit. A person can independently make the installation of equipment. For this, you do not need to use expensive tools and materials.

Reference. Coefficient useful action professional devices is 80—85% . Homemade ones are much cheaper, but their efficiency no more than 60-65%.

Design

The structure of the equipment is simple. The device is a rectangular plate consisting of several layers:

• anti-reflective cover tempered glass framed;
• absorber;
• bottom insulation;
• side insulation;
• pipeline;
• glass curtain;
• aluminum weatherproof case;
• connecting fittings.

The system includes 1-2 collectors, storage capacity and avankameru. The design is organized closed, so the sun's rays fall only into it and turn into heat.

Principle of operation

The basis of the operation of the installation is a thermosyphon. The coolant inside the equipment circulates on its own, which will help to abandon the use of the pump.

Heated water tends to rise, thereby pushing the cold water and forwarding it to heat source.

The collector is tubular radiator, which is mounted in a wooden box, one plane of which is made of glass. Pipes in the manufacture of the unit are used steel. The diversion and supply are carried out by pipes used in the plumbing device.

The structure works like this:

1. The collector converts solar energy into heat.
2. Fluid enters storage tank through the supply line.
3. The circulation of the coolant occurs independently or with the help of an electric pump. The liquid in the installation must meet several requirements: they will not evaporate at high temperatures, be non-toxic, frost-resistant. Usually take distilled water mixed with glycol in a ratio of 6:4.

solar concentrator

solar energy storage device has the function of a heat carrier. Serves to focus energy on the emitter receiver inside the product.

There are the following types:

• parabolic-cylindrical concentrators;
• concentrators on flat lenses ( fresnel lens);
• on spherical lenses;
• parabolic concentrators;
• solar towers.

Hubs reflect radiation from a large plane to a small one which helps to reach high temperatures. The liquid absorbs heat and moves to the heating object.

Important! The price of devices is not cheap, and also they require constant skilled maintenance. Such equipment is used in hybrid systems, most often in industrial scale and allows you to increase the productivity of the collector.

Types of solar collectors

Currently, there are several varieties of solar heating collectors.

Flat, do-it-yourself installation

This device consists of a panel in which the absorber plate is mounted. This type of device is the most common. The cost of the units is affordable and depends on the type of coating, manufacturer, power and heating area. Prices for equipment of this type - from 12 thousand rubles.

Photo 1. Five flat-type solar collectors installed on the roof of a private house. The appliances are tilted.

Scope of application

Similar collectors often installed in private homes for room heating and hot water supply. Appliances cope with heating water for summer shower in the country. It is appropriate to operate them in warm and sunny weather.

Attention! Collector surface cannot be obscured by other buildings, trees and houses. This has a negative impact on performance. Equipment is mounted on the roof or facade of the building, as well as on any suitable surface.

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flat collector design

The composition of the device:

• protective glass;
• copper pipes;
• thermal insulation;
• absorbent surface with a high degree of absorption;
• aluminum frame.

The collector, which has a tubular coil, is a classic option. As an alternative to makeshift designs apply: polypropylene material, aluminum beverage cans, rubber garden hoses.

The bottom and edges of the system must be thermally insulated. If the absorber is in contact with the body, then heat loss is possible. The outer part of the device is protected by tempered glass with special properties. Antifreeze is taken as a coolant.

Operating principle

The liquid is heated and enters the storage tank, from which it moves to the collector in a cooled form. The structure is available in two versions.: single-circuit and double-circuit. In the first case the liquid goes straight to the tank, in the second- passes through a thin tube through the water in the tank, warming up the volume of the room. As it moves, it cools and moves back into the collector.

Photo 2. Scheme and principle of operation of a flat-type solar collector. The arrows indicate the parts of the device.

Advantages and disadvantages

Units of this type have the following advantages:

• high performance;
• low cost;
• long-term operation;
• reliability;
• opportunity homemade installation and service.

Flat-plate collectors are suitable for operation in southern areas with a warm climate. Their downside is high windage due to the large surface, so strong winds can disrupt the structure. Performance drops in cold winter weather. Ideally, the unit should be installed on the south side of the site or house.

Vacuum

device consists of separate tubes, combined at the top and forming a single panel. In fact, each of the tubes is an independent collector. It's efficient modern look usable even in cold weather. Vacuum devices are more complex in relation to flat ones, therefore they are more expensive.

Photo 3. Vacuum-type solar collector. The device consists of many tubes fixed in one structure.

Scope of application

Apply for hot water supply and heating of large visits. Most often used in summer cottages and in private households. Mounted on the facades of buildings, pitched or flat roofs, special support structures. They function in cold climates and with short daylight hours without compromising efficiency. Due to their high efficiency, they are also used on agricultural land, industrial enterprises. This type is common in European countries.

Design

The device includes:

• thermal storage (water tank);
• circuit for the circulation of the heat exchanger;
• the collector itself;
• sensors;
• receiver.

The design of the unit is a series of tubular profiles installed in parallel. The receiver and vacuum tubes are made of copper. The glass tube block is separated from the outer circuit, so that the activity of the collector does not stop when it fails 1-2 tubes. Polyurethane insulation is used as additional protection.

Reference. hallmark collector is the composition of the alloy from which the pipes are made. This is aluminum coated and polyurethane protected copper.

Operating principle

Construction work based on zero vacuum thermal conductivity. An airless space is formed between the tubes, which reliably retains the heat generated from the sun's rays.

The vacuum manifold works like this:

• the energy of the sun is received by a tube inside a vacuum flask;
• the heated liquid evaporates and rises to the condensation area of ​​the pipe;
• the coolant flows down from the condensation zone;
• the cycle is repeated anew.

Thanks to this work much higher heat transfer and heat loss is low. Energy can be stored due to the vacuum layer, which effectively captures heat.

Photo 4. Scheme of the device of a vacuum solar collector. The components of the device are indicated by arrows.

Advantages and disadvantages

The advantages of this type of device:

• durability;
• stability in operation;
• affordable repair, it is possible to replace only one element that has failed, and not the entire structure;
• low windage, the ability to withstand gusts of wind;
• maximum absorption of solar energy.

The equipment is expensive, which can only be recouped in a few years after use. The price of components is also high, and their replacement may require the help of a professional. The system is not capable of self-cleaning from ice, snow, frost.

Types of vacuum manifolds

Products are of two types: with indirect and direct heat supply. The functioning of structures with indirect supply is carried out from the pressure in the pipes.

In devices with direct heat supply, the heat carrier container and glass vacuum devices are mounted to the frame at a certain angle, through a rubber connecting ring.

Equipment connects to the water lines through a constipation valve, and the fixing valve controls the water level in the tank.

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Air

Water has a much higher heat capacity than air. However, its use is associated with a number of everyday problems during operation (pipe corrosion, pressure control, change in aggregate state). Air collectors not so whimsical, have a simple design. Devices cannot be considered a full-fledged replacement for other types, but they are able to reduce utility costs.

Scope of application

This type of equipment is used in air heating of houses, drainage systems and for air recovery (treatment). It is used for drying agricultural products.

Design

Consists of:

• an adsorber, a heat-absorbing panel inside the case;
• external insulation made of tempered glass;
• thermal insulation between the housing wall and the absorber;
• sealed housing.

Photo 5. Air solar collector for heating a house. The device is fixed vertically on the wall of the building.

The device is located close to the heating object due to large heat losses in the air lines.

Operating principle

Unlike water collectors, air do not accumulate heat, but immediately release it into insulation. Sunlight hits the outer part of the device and heats it up, the air begins to circulate in the structure and heats the room.

You can design an air manifold yourself, using improvised materials in the manufacture: beer cans made of copper or aluminum, chipboard panels, aluminum and metal sheets.

Photo 6. Scheme of the device of an air solar collector. The drawing shows the main parts of the device.

Advantages and disadvantages

Advantages:

• low cost of the device;
• possibility self installation and repair;
• simplicity of design.

Of the shortcomings: limited scope (only heating), low efficiency. At night, the equipment will work to cool the air if it is not closed.

Choosing a set of solar collectors for the heating system

Device selection depends on the goals for which the work of the structure will be directed. The solar system is used to support air, provide hot water, heat water for the pool.

Power

To calculate the possible output of a solar system, you need to know 2 parameters: solar insolation in a certain region in right time years and the effective absorption area of ​​the collector. These numbers must be multiplied.

Is it possible to use the collector in winter

Vacuum devices cope with work in cold climates. flat show low performance in cold weather and are better suited for the southern regions.

Less suitable for functioning in the cold aerial structure as at night it is not able to heat the air.

Trouble with heavy rainfall, because in winter the equipment often falls asleep with snow and requires regular cleaning. Frosty air takes away the accumulated heat, and the collector itself can be damaged by hail.

Scope consideration

In industry, the use of solar systems is more common. Solar energy is used in the operation of power plants, steam generators, water desalination plants. For heating water, heating a summer house or a bath in domestic conditions, vacuum collectors are more often installed, less often flat ones. Air systems help reduce the cost of heating by heating the air during the day.

I finally took a vacuum manifold for 20 tubes, I will assemble a concentrator from them. 1-tube filled with water (3l.) heated from 20*C to 68.3*C (boiling water to the touch) in 2 hours 40 minutes. Outside the window on May 26, in the sun 42 * C in the shade 15 * C, the time of the experiment from 16.27 to 18.50 the sun sets ...
And in the concentrator, the measurement showed 19 minutes! up to the same 68 * C. The speed can be increased by increasing the area of ​​the concentrator, but then the windage increases and the integrity of the structure worsens ...
The area of ​​the concentrator is 1.0664 square meters (62x172 cm.)
Focal length 16cm.
You buy 1 vacuum tube, and remove from it as with 7 in my version, if you count by area. Below is a video of one of the pioneers, which prompted me to my feat.

So far I have encountered the problem of poor gluing of acrylic with glue for mirrors. Easily peeled off from the base ... Also, the mirror glue is very soft and the system "walks" you need to strengthen the structure.
said):
On the advice of FarSeer; I positioned the axis horizontally (east-west orientation for winter). This arrangement is simpler in terms of design, wind loads are less, withdrawal (coup) from precipitation is also easier.
Due to the fact that I will place my "scoops" horizontally in the east-west directions, so as not to get hung up on trackers, I had to think about how to make heat extraction more efficient, since the standard scheme with liquid condensation may not work in theory, so as there is no condensate stack down and, accordingly, steam rises up to give off its heat. I made 2 types of heat extraction from a vacuum tube.
Option-1 (on the right, in photo-1) The native tip (the thickening where the steam collects) is actively washed by the coolant.
Option-2 (average, in photo-1) 2 tubes, one 10mm, are taken. in diameter, the other 15 mm. in diameter and inserted into one another, by analogy with recuperators, the inner one does not reach the end of the couple, see. And the outer one is muffled at the end, and from above these tubes are disconnected by a tee, see photo. As experiments have shown, between a horizontal tube and one standing at 45 ° at temperatures of about 80 °, the difference was about 5 °, although I was told that this tube would not work at all in a horizontal position!
I am waiting for warmer weather to dig holes under the racks, because the ground is still frozen and it is not realistic to dig it.
As for emergency modes, everything has already been thought out, there is a 1.5 kW Smart-type uninterruptible power supply with additional batteries.
The second and, in my opinion, the most significant point in the decision emergencies, closing the mirrors or the concentrator from the sun or turning it from the focus axis, which will bring the concentrator to the minimum power of a simple vacuum tube in the hottest season, for example, according to the same principle, you can adjust the total power of the concentrators by removing some of the focus.

As a variant of the concentrator from improvised material, see photo.

Ever since the beginning of our millennium, the possibility and methods of using the energy of the sun's rays have been concerned about the most outstanding minds of mankind. Even then, people perfectly understood that the celestial body named the Sun is a source of radiation inexhaustible energy. However, no one figured out how to "tame" and use it to their advantage at that distant time. According to sources that have survived to this day, the writers of antiquity, Plutarch and Polybius, indicated that the person who first wrote the drawings with his own hand and assembled a working invention was Archimedes.

At its core, the invention of a wise Greek engineer, which he assembled with his own hands, is the first parabolic concentrator based on solar energy created on planet Earth, the principle of which was to concentrate radiation in one small beam.

In the area affected by such a beam, the temperature level could reach from 300 to 400 degrees Celsius. Such energy, concentrated on the hull of any of the ships of the Roman navy (which at that time was entirely made of wood), would have been enough to ignite a sea vessel. Today, one can only make assumptions about what specific invention Archimedes gave the world, but based on modern knowledge and ideas about technologies and achievements in this field of energy, there were only two possible options.

Let's start with the fact that the very name that the invention received is a solar concentrator, this name speaks for itself.

A lens convex on both sides is an example of a simple concentrator.

This is a device that, by capturing solar radiation by a certain bending of the surface, concentrates the rays at one point, achieving multiple indicators of an increase in energy. We all remember from our young past an ordinary lens, convex on both sides - this is an example of the simplest concentrator. In sunny weather, by adjusting the angle of incidence of the sun's radiation with your own hands, you could burn out on wooden surface or on paper everything that came to mind, any figure or inscription.

Such a lens belongs to the group of refractor concentrators. In addition to convex lenses, Fresnel lenses, which are a prism, also belong to the same group of concentrators. Long focus concentrators are assembled using so-called linear lenses. Such hubs are very inexpensive and easy to assemble with your own hands without the help of a qualified engineer (if you decide to do this, there are enough videos uploaded on the network, the request is homemade solar reflector). However, in practice they are used quite infrequently, one of the reasons for this is their rather large dimensions. Such concentrators, including home-made ones, are used in those places where the area and the space they occupy, which are not critical for its owner, allow it.

Such a disadvantage is absent in the prism concentrator of solar radiation. In addition, this equipment can partially concentrate a part of the diffusion radiation, thereby significantly increasing the power of the generated energy ray flux. The trihedral prism, with the use of which this mechanism is built, simultaneously performs the functions of both the initiator of the radiation of the point of concentration of the beam, and the reception of this radiation. In addition to everything, the rear face of the polyhedron reflects the energy flux received by the front face of solar radiation, and the side face is responsible for the emission of radiation. The principle of operation of this equipment is based on the mechanism of maximum reflective effect on the sun's rays until they hit the side face.

The reflective solar concentrator, in comparison with the refractor ones, functions by combining the energy of the beam of reflected solar radiation. Based on the shape of the structure, such concentrators are divided into subspecies and are called parabolic and parabolic. If you understand the efficiency of these devices, then the most powerful source of energy will be a parabolic concentrator, it produces up to 10 thousand units of concentration.

Parabolic concentrator delivers up to 10 thousand units of concentration

However, to create energy solar heating systems (especially for heating in winter), they resort to the installation of parabolic-cylindrical or flat devices, besides, such a system is easy to mount with your own hands.

Solar concentrators their practical use and application

In principle, the main function of solar concentrators of any design is to collect the radiation coming from the sun and concentrate it at one point. To determine the scope of this energy is the choice of the owner of this equipment. Using completely free and renewable energy, it is possible to heat water for household and hygiene needs. The amount of heated water will depend only on the size of the plate and the overall design of the concentrator. Small size parabolic concentrators can be used as a cooking oven that will operate solely on concentrated solar radiation.

In winter, concentrators can be used as additional source sunlight for photovoltaic solar panels, thereby increasing their output power in conditions of lack of solar radiation.

Parabolic concentrators can be used as an oven for food preparation

In fact, the use of crystalline batteries to increase the efficiency is a pretty good idea, given the low cost of concentrators. Moreover, you will not need a patent for such a design. It will turn out a kind of homemade solar power supply system.

It is also possible to use the device as an autonomous source of energy for the Stirling engine (a patent for such an engine was obtained by its inventor a very long time ago). Concentrators of the parabolic group create a temperature in the range from 300 to 400 °C at the point of collection of sunlight.

If you put a metal stand for dishes and place a kettle on it in the area of ​​​​concentration of rays coming from a relatively small plate, you can boil water without using electricity without any problems. By placing the heater at the point of energy concentration, you will quickly heat up running water in large enough volumes for further use in household needs. You can water the garden, wash the dishes, take a shower.

By placing a Stirling engine correctly selected in terms of power in the focus of the beam, you will get a small thermal and electric station.

Stirling engines are designed to work in tandem with a solar concentrator

For example, one company called Qnergy has developed and filed a patent, launching the QB-3500 Stirling engines, which are designed specifically to work in tandem with a solar reflector solar concentrator. At its core, such a device can be considered an electric current generator, where the Stirling engine performs the main function. Note that such a system also requires batteries to store the energy received. Such a power plant produces an electric current with a power of 3500 watts. The output inverter produces a standard voltage of 220 volts, a frequency of 50 Hz. This power of electric current is enough for you to fully meet the needs of a house in which a family of four lives. The use of such batteries is also effective for a country house. The concentrator installed on your site will have appearance satellite dish without violating the external aesthetics.

By the way, one of the manufacturers registered a patent for a device where, using the principle of the Stirling engine, you can create a system that will basically operate a reciprocating or rotational movement (does not require the installation of batteries). An example of such a system is a water pump for a well or other purposes.

The parabolic concentrator must be systematically rotated to follow the rays of the sun as the earth rotates during the day

The main disadvantage that a parabolic concentrator has is that it must be systematically monitored by turning it in the direction of the sun's rays as the earth rotates during the day. Where concentrators are used at large thermal power plants on an industrial scale, special systems for tracking the movement of the sun are additionally mounted to the battery group. Such systems rotate the mirrors following its movement. This guarantees a constant and effective reception incoming solar radiation at the most effective angle. But the use of such equipment in private, most likely, will not be very appropriate, due to the fact that the acquisition costs will be much higher than the cost of a standard tripod-mounted reflector.

How to make a solar radiation concentrator yourself?

To study this issue, one can refer to the experience of the inventor from Vladivostok, Yuri Rylov, who has a patent for the heating system. For a long time, his large country house, with a total area of ​​​​more than 400 square meters, is completely heated on the basis of a battery system, where the coolant is heated by a solar concentrator.

Yury Rylov's concentrator works more than twice as efficiently as solar panels

The entire system, for which he received a patent as a result, was developed by the craftsman himself. Its concentrator works more than twice as efficiently as solar panels.

There are a number of reasons for this, one of them is the system of concentrators, for which the inventor received a patent, it accumulates the energy of almost the entire incoming spectrum of solar radiation. The next reason is that the system was supplemented with a sun tracking mechanism (considering the scope of the equipment in this case, this may be justified).

However, problems arose with the introduction of the system into mass production. Under the created device, more than five years ago, the inventor received a patent Russian Federation, but so far it has not received wide industrial distribution. This is rather strange, since according to Rylov, his concentrator allows you to heat the entrance of a five-story house, providing it with hot water. For eight hours of operation, the equipment heats up a cubic meter of water. During the same time, the concentrator will produce 80 kW of electricity. In addition, the inventor faced the problem of protecting intellectual property in Russia. It is necessary to deal with fixing the ownership of your device in those countries where it is possible to establish such production, officials do not help to obtain a patent abroad.

Most easy way to assemble your own homemade hub - this is to make it based on an old satellite dish

So, the easiest way to build your own homemade hub is to make it based on an old satellite dish. Before assembling the mechanism, determine the purpose of its use, and then select the location of the concentrator. Thoroughly clean the antenna and attach a reflective film to the working side.

For even laying of the film and to avoid possible wrinkles, cut the film into strips no larger than fifty millimeters. If you decide to use the concentrator as a solar oven, it will be better when you make a hole about 70 millimeters in diameter in the central part of the plate. Pass the fastening of the food container through it. The device guarantees a fixed position of the container with the heated object during the turns of the device behind the sun.

If you only have a plate with a small diameter at your disposal, it is worth cutting the tape into strips of 100 millimeters. Each strip must be glued separately, carefully and accurately aligning the joints.

When you have finished pasting the reflective element, determine where the point of concentration of the rays is. This must be done because the shape of the dish often does not guarantee the coincidence of the focal point and the location of the signal receiving head.

Homemade solar concentrator oven

To begin with, it is worth identifying the place of concentration, for this, put on sunglasses. Take wooden board and thick mittens. Point the reflector towards the sun and focus the captured rays on the board, then adjust the distance until you get the most efficient, concentrated beam of energy, do this until you get its smallest size. The mittens you wear will protect your skin from sunburn if you accidentally put your hands in the focus area of ​​​​the rays. After you determine the concentration point, you will only have to fix the structure and finish its installation in optimal location. As they say in inventor circles, "The only thing left to do is get a patent." Use the results of your work, getting an inexhaustible and free source of energy.

Stirling engine can be assembled using improvised, common materials

There are many options for manufacturing concentrators based on solar radiation. In the same way, you yourself, using improvised, common materials, can assemble a Stirling engine (it is really possible, although, at first glance, it seems unattainable), and you can use the capabilities of this engine for a variety of purposes for a long time. All restrictions depend only on your patience and imagination.

Climate middle lane Russia does not indulge its inhabitants with an abundance of direct sunlight. There are few absolutely clear sunny days during the year. Basically, as a rule, partly cloudy, when the sun appears for a dozen or two minutes, and then hides behind the clouds for the same time and the intensity of solar thermal energy drops sharply.

All this has an extremely unfavorable effect on the prospects for the use of solar energy for organizing hot water supply in a country house or in country house. Solar collectors and traditional water heaters are simply not physically capable of heating water efficiently. Because they are based on the principle of continuous circulation of water from the storage tank to the solar collector and back. And a small solar collector with an area of ​​​​1-2 square meters. meter is not able to quickly heat a large volume of water of several hundred liters. This is easily proven by simple calculations.

Almost the only way to organize a really reliable hot water supply from solar energy is to build a concentrating solar collector with a small volume of water heated per unit of time. The logic here is quite simple.

For each square meter Approximately 800-1000 watts of solar energy falls on the surface. Let's take the lower value (taking into account the reflection from the solar collector itself, it is, alas, not zero). So, the calorific value of our "boiler" is 800 watts (or 2900 kJ). The heat capacity of water is 4.2 KJ/kg*deg. Now remember how long Electric kettle in 1.5 kW of power, bring those 1.5 liters of water that fits in it to a boil. In minutes! And if you make him boil a barrel of water? He will only heat it up for 3-4 hours.

On the other hand, we do not need a whole barrel of hot water at once. We need 2-3 liters of everything in every minute of time. Wash your face, wash the dishes ... And the following water heating scheme suggests itself. With a relatively low-power “kettle”, we quickly heat up 1-2 liters of water and pour it into a thermos. Then we heat the next portion and pour it into a thermos again and so on. And for our needs, we use it from a thermos. Those. do instantaneous water heater with the accumulation of the result of his work. Such it will be flow-accumulative.

Such a scheme significantly reduces the requirements for the power of the heater itself and at the same time will allow you to have a sufficiently large supply of hot water of several tens of liters.

Judge for yourself, even for 10-15 minutes when the sun is shining, we will receive about 200 watt-hours of energy from the sun. This is equivalent to 720 kJ. That will allow you to heat up to 50-60 degrees about 4-5 liters of water (almost half a bucket, by the way). In the next "exit" of the sun - another 5 liters, then another. And so on throughout the day.

Moreover, the smaller the capacity of our heater, the more efficiently it will use solar energy. It will manage to snatch the heat from the sun even if it only pops up for a few minutes! As they say, a black sheep has at least a tuft of wool. And if it is long, such a heater will turn into a boiler.

There are two ways to make such a low-capacity solar collector. The first is to make a very flat classical collector of the largest possible area. For example, with a thickness of 1-2-3 cm in total and an area of ​​​​1-1.5 square meters. meters. But its capacity will be about 20-40 liters! Don't call it too small. And it would take at least an hour of sun to heat all that water.

The second option is to make a concentrating parabolic solar collector of approximately the same area and with a capacity of 2-3 liters! Then the water in it will heat up in just 5-8 minutes! Only half an hour of sun - and we have a whole bucket of enough hot water! Moreover, the concentrating collector is able to collect scattered solar energy when the rays are scattered by haze and clouds.

Now let's move on to the design. Many people are intimidated by the word "parabolic" and think that making a parabolic concentrator is difficult. In fact, even a schoolboy can make a parabolic mirror. In addition, the concentrating collector is much simpler even in physical terms. No need to "bother" a huge and brittle flat "canister". Achieve its absolute tightness, rigidity, ensure minimal hydrodynamic resistance, etc. In a parabolic solar water heater - the collector is a simple flat finished metallic profile or pipe! It is only necessary to make plugs on the ends and cut in a couple of futons for the input and output of water. All other fittings will be the same in both cases. The parabolic mirror itself is made from ordinary plywood and pasted over with ordinary household foil for baking. Its reflection coefficient of IR rays is 90-95%!

There is a fairly simple way to construct a parabola. On a sheet of plywood, we draw a right angle. Then, on one side, we make marks through 1 unit of measurement (for example, through 100 mm, in the figure these are letters). And on the other - after 2 units (that is, after 200 mm, these are numbers in the figure). Then we connect the marks with lines a1, b2, c3, etc. The resulting intersections of the lines will give us the desired parabola. Naturally, it must be smoothed out with a pattern. And of course, this is only half of the parabola that we need. The second is a mirror image.

Now what a concentric parabolic solar water heater might look like.

Well, something like that.

Water in the collector - the heater comes under slight pressure from the pressure tank. And at the outlet of the collector there is a valve - a thermostat. Similar in action to what is installed in the cooling circuits of cars. Those. it opens when the water is heated to a certain temperature. When the portion of water in the collector is heated, the thermostat opens and the water drains into the thermos tanks. As soon as all hot water merges and cool water starts to flow, the thermostat will immediately close and the collector will begin to heat the next portion.

In order not to waste space behind the parabolic mirror, the thermos tanks are installed in free niches and carefully insulated. Although, as you know, this is just a variant of their location. They can be installed in any convenient place, but it is important to carefully insulate the pipe leading to them from the collector.

Generally speaking, a parabolic mirror has not just a focus, where all the reflected rays are directed, but the so-called focal plane. Because if the rays fall on the parabolic mirror is not perpendicular, then they will not be reflected in the center of the parabola. Therefore, solar trackers are made in devices with parabolic mirrors, which always turn the parabolic mirror directly to the sun or move the collector along the focal plane (which, in my opinion, is easier).

In gardening conditions, this, unfortunately, seriously complicates the design of a concentrating solar collector. Either you will have to install some kind of automation, or periodically, manually, unfold the parabolic mirror strictly in the sun.

A certain solution in this case may be not a horizontal, but a vertical arrangement of a parabolic mirror. After all, the sun moves quickly enough horizontally, and very slowly vertically. Therefore, if we make a sufficiently elongated parabola and place the collector in its focal plane, then for several hours in a row the entire volume of reflected solar energy will fall on the collector. And vertical adjustment will have to be done only once a week or two, depending on the angle of the sun above the horizon.

But of course, the most effective solution would be to manufacture a solar tracker that turns a parabolic mirror directly into the sun.

Attention! If you are implementing a similar project, in no case do not try the temperature in the collector area with your hand, "by touch" !!! The temperature in the heating zone reaches 200-300 degrees! It's like trying to touch the spiral of an electric stove. During my experiments, a piece of wood brought into the heating zone silently flashed almost instantly. Pretty mystical sight, by the way.

Konstantin Timoshenko

You can ask questions and discuss the design at

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