H About making a telescope at home in rough drafts. Efficiency-enhancing mirror concentrators for solar collectors Solar thermal concentrator

Start-up company GoSol aims to make solar energy available to everyone on a global scale. To this end, she launched an initiative to develop and distribute instructions for assembling solar concentrators from local materials that could be effective sources of heat for cooking, washing, heating water and heating.

“GoSol.org's mission is to eradicate energy poverty and minimize the impact of global warming by spreading our DIY technology (Do It Yourself) and breaking down all barriers to free access to solar energy... With your help, we want to engage communities, entrepreneurs and artisans to harness the world's most powerful energy source. All materials and tools necessary for the implementation of these technologies have already been produced and are abundant in all corners of the world, ”says the GoSol website.

GoSol enthusiasts have launched a company with which they intend to raise $ 68,000 to make their goal a reality. On this moment the initiative has raised about $ 27,000 and just recently GoSol released its first solar concentrator instruction manual.

Read also: Ripasso solar concentrator - the most efficient way to convert solar energy?

Free step by step guide contains all the information you need 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, the name given to the solar installation from GoSol, will take approximately 1.5 cubic meters space. The work on its manufacture will take about a week. The materials for its construction will be iron corners, plastic boxes, steel rods, and the main working element - a reflective hemisphere - is proposed to be made from pieces of ordinary bathroom mirrors.

The solar concentrator can be used for baking, frying, heating water or preserving food through dehydration. The device can also serve as a demo example. effective work solar energy and will help many entrepreneurs developing countries start your own business. In addition to helping to reduce harmful emissions into the atmosphere, GoSol solar concentrators will help reduce deforestation by replacing burning wood with clean energy from the sun.

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

A free solar concentrator instruction 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 advance faster and on a larger scale, then you can support the company financially - the startup is still accepting cash contributions, the reward for which will depend on the amount donated.

See also: Ukrainian solar concentrator "Diversity" - freely available instructions

Video: GoSol.org Free The Sun Campaign for Builders

ecotechnica.com.ua

Homemade solar concentrator made of mirror film

Great amount free energy of the sun, water and wind and many other things that nature can give, people have been using for a long time. For some, this is a hobby, while others cannot survive without devices that can extract energy "from the 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.

V 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 have been successful designs of solar powered stoves, 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 in operation, 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. It does not require mirrors to make it, therefore it is very light and will not be a heavy burden on a hike.

Very few things are required to create a homemade film-based solar concentrator. All of them are sold in 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 a solar oven. 2. Chipboard sheet and a sheet of hardboard of the same size. 3. Thin hose and sealant.

How to make a solar oven?

First, two rings are cut out of a chipboard of the size you need with a jigsaw, which must be glued to each other. There is one ring in the photo and video, but the author indicates that he later added a second ring. According to him, one could be limited to one, but it was necessary to increase the space to form a sufficient concavity of the parabolic mirror. Otherwise, the focus of the beam will be too far away. A circle is cut from hardboard to the size of the ring to form back wall solar concentrator. The ring should be glued to the hardboard. Be sure to coat everything well with sealant. The structure must be completely sealed. From the side, carefully so that there are even edges, make a small hole into which you can firmly insert a thin hose. For tightness, the connection of the hose and the ring can also be sealed. Pull a mirror film over the ring. Pump air from the unit body and thus form a spherical mirror. Bend the hose and clamp it with a clothespin. comfortable stand for the finished hub. 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 for making a solar stove.

Used material from the site zabatsai.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. According to the ancient writers Plutarch and Polybius, the first person to practically use solar energy was Archimedes, who, with the help of some optical devices invented by him, managed to collect the sun's rays into a powerful beam and burn the Roman fleet.

In fact, the device invented by the great Greek was the first concentrator solar radiation, which collected the sun's rays into one energy beam. And in 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 concepts, he had only two options.

The very name of the device - solar concentrator - speaks for itself. This device receives the sun's rays and collects them into a single energy beam. The simplest hub is familiar to everyone from childhood. This is a conventional biconvex lens that could be burned out various figures, inscriptions, even whole pictures, when the sun's rays were collected by such a lens into a small point on wooden board, a piece of paper.

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

Refractory Solar Concentrator

A prism concentrator of solar radiation is devoid of this drawback. Moreover, such a device is also capable of concentrating part of the diffuse radiation, which significantly increases the power of the light beam. The triangular 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 rear face reflects, and radiation is already coming out of the side face. The operation of such a device is based on the principle of total internal reflection of rays before they hit side edge prisms.

Unlike refractory, reflex concentrators work on the principle of collecting reflected sunlight into an energy beam. By 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 heat supply systems, mainly flat or parabolic-cylindrical systems are used.

Parabolic (reflex) solar concentrators

Practical application of solar concentrators

Actually, the main task of any solar concentrator is to collect the sun's radiation into a single energy beam. And you can use this energy in different 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 oven for cooking.

Parabolic concentrator as a solar oven

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

Simplest schemes water heating by solar concentrator

If a Stirling engine of a suitable power is placed in the focus of a parabolic mirror, then a small thermal power plant can be obtained. For example, Qnergy has developed and commercialized the QB-3500 Stirling engines, which are designed to work with solar concentrators. In essence, it would be more correct to call them generators of electric current based on Stirling engines. This unit produces electricity with a capacity 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 people, a summer cottage.

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 plants, special tracking systems are used that rotate mirrors or refractors to follow the movement of the sun, thereby ensuring the reception and concentration of the maximum amount of solar energy. For individual use, it will hardly be advisable to use such tracking devices, since their cost can significantly exceed the cost of a simple reflector on an ordinary 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 concentrator will be used, and then, based on this, choose an 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 plate.

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 with a diameter of about 5 - 7 centimeters in the center of the plate. A bracket with a cookware support (burner) will be passed through this hole. This will keep the food container stationary when the reflector is turned in the sun.

If the plate is small in diameter, it is also recommended to cut the strips into pieces about 10 cm long. Glue each piece separately, carefully adjusting the joints. When the reflector is ready, it should be mounted on the support. After that, it will be necessary to determine the focal point, since the optical focal 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 board and thick gloves. Then you need to direct the mirror directly to the sun, catch a sunbeam on the board and, bringing the board closer or away from the mirror, find the point where this bunny will have minimum dimensions- a small point. Gloves are needed in order to protect hands from burns if they accidentally fall into the range of the beam. Well, when the focal point is found, it only remains to fix and mount it. necessary equipment.

Options self-made solar concentrator there are many. In the same way, you can make a Stirling engine from the materials at hand. And this engine can be used for a variety of purposes. How long will there be enough imagination, desire and patience.

solarb.ru

This DIY is about how to build a solar water heater. It would be more correct to call it a parabolic solar concentrator. Its main advantage is that the mirror reflects 90% of the solar energy, and its parabolic shape concentrates this energy at one point. This installation will work effectively in most regions of Russia, up to 65 degrees N.

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

Parabolic antenna.

Any antenna can be used - iron, plastic or fiberglass. The antenna must be panel type, not mesh antenna. Antenna area and shape are important here. Remember, heating power = antenna surface area. And that the power collected by an antenna with a diameter of 1.5 m will be 4 times less than the power collected by an antenna with a mirror area of 3 m.

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. The glue with which the film will stick to the parabola.

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

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

You just need to attach a lavsan mirror film or aluminum foil to the antenna mirror.

Such a film can be ordered on Aliexpress, if suddenly you do not find the film in stores.

This is almost as easy as it sounds. You just need to take into account that if the antenna, for example, is 2.5 m in diameter, and the film is 1 m wide, then you do not need 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 out in small strips and attach it to the antenna with glue. Make sure the antenna is clean before applying tape. 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 is removed from its place, otherwise it may melt. After gluing the film and installing the antenna in place, keep your hands or face away from the head mount - you risk getting 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 Video of the solar tracker operation according to the scheme from the archive

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

Who cares the photo is taken from here: Rotary mechanism

Step 3 Create a heat exchanger-collector

To make a heat exchanger, you need a copper tube rolled into a ring and placed in the focus of our concentrator. But first we need to know the size of the focal point of the dish. To do this, remove the LNB-converter from the plate, leaving the converter mounting racks. Now you need to turn the plate in the sun, after fixing a piece of 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, turn the antenna away 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 put your hand into the focus of the mirror - this is dangerous, you can get severely burned. Let it cool down. Measure the size of the burned piece of wood - this will be the size of your heat exchanger.

The size of the focus point will determine how much copper tube you will need. The author needed 6 meters of pipe with a spot size of 13 cm.

Swivel mechanism I think that instead of a rolled tube, you can put a radiator from a car stove, there are rather small radiators. The radiator must be blackened to better absorption heat. If you decide to use a tube, you should try to bend it without kinking or kinking. Usually, for this, the tube is filled with sand, closed on both sides and bent on some mandrel of a suitable diameter. The author poured water into the tube and put it in the freezer with the open ends up to prevent the water from flowing out. The ice in the tube will create pressure from the inside to avoid kinking. This will allow the pipe to be bent with a smaller bend radius. It must be rolled up along a cone - each turn should be not much larger in diameter than the previous one. You can solder the turns of the collector together for a more rigid structure. And remember to drain the water after you are done with the manifold so that you don't get scalded by the steam or hot water after putting it back in place.

Step 4. Putting it all together and trying it out.

Installation complete You now have a mirror parabola, a sun tracker housed in a waterproof container, or plastic container, completed manifold. All that remains to be done is to reinstall the manifold and test it in operation. You can go further and improve the design by making something like a pan with insulation and putting it on the back of the manifold. The tracking mechanism must track movement from east to west, i.e. turn around during the day for the sun. And the seasonal positions of the luminary (up / down) can be manually adjusted once a week. You can, of course, add a tracking mechanism in the vertical direction - then you will get an almost automatic operation of the installation. If you plan to use the water to heat the pool or as hot water in the plumbing, you will need a pump that will pump the water through the manifold. If you will heat a container with water, you must take measures to avoid boiling water and an explosion of the tank. This can be done using an electronic thermostat, which, if the set temperature is reached, will divert the mirror from the sun using a tracking mechanism.

On my own behalf, I will add that when using the collector in winter, it is necessary to take measures 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 one side 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 will not freeze in the cold. A source

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The most popular ways to use solar energy to heat water is to create flat or vacuum solar collectors... However, there are still methods with a fairly high coefficient of efficiency, which help to use the energy of the sun to heat water. This article will discuss one such method, namely the creation of a solar concentrator for hot water supply.

To create a water heating system using a solar reflector, the author needed the following materials: 1) parabolic satellite antenna 2) mirror film 3) copper tube 4) salt 5) black heat-resistant paint 6) mullite crystal 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 next 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 where the sun's rays are concentrated 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 adjust the reflector in relation to the sun throughout the day. These trackers are quite expensive and consume a lot of energy.

The efficiency of a concentrator is highly dependent on the cleanliness of the reflective surface, so mirrors need to be kept 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 caught rays to one point. In principle, you can even make a kind of antenna yourself from sheets of cardboard, but the effectiveness of such a system depends very much on the quality of the parabola.

After cleaning the antenna surface, 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. It is quite simple to glue the surface with such a film on 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 smoothly and in quality.

After the antenna acquires mirror surface it is necessary to determine the focal point, it will be the place of concentration of reflected sunlight from the antenna surface. Usually the focal point at the solar antenna is located just in the area of the converter, but if you built the parabola yourself, then the easiest way to determine the focal point is using the experimental method. It is necessary to take a piece of plywood thicker and gradually move it away from the concentrator until sunspot it will not decrease as soon as it is minimal, this will be the focusing point of the sun's rays. The main thing is to remember that in this place is concentrated heat, therefore, you must 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. The salt inside the copper tube is needed to prevent the tube from collapsing 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, heat-resistant paint must be used for painting.

Also, to increase the efficiency, it is necessary to insulate the heat receiver so that it does not cool off from the wind. Below is a diagram of an insulated heat sink:

Use fireproof materials to insulate the heat sink, as this will concentrate the heat. The author of this concentrator used for these purposes mullite-crystalline fiber, which is used in gas forges and muffle furnaces... The 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 manufactured according to the spot size of the focusing point of the concentrator.

Below is the connection diagram of the solar concentrator:

usamodelkina.ru

Solar thermal concentrator. Solar energy.

Alternative energy interests 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?" Why? -Make a wind generator.

A wind turbine to generate electricity - not really convenient solution... Variable wind power, chargers, batteries, inverters, a lot of not a penny equipment. In a simplified scheme, the wind turbine does an excellent job of heating water. For the load is ten, and he is absolutely not picky about the parameters of the electricity supplied to it. You can get rid of complicated expensive electronics. But the calculations showed significant construction costs to spin up the 500 W generator. The power carried by the wind is calculated by the formula P = 0.6 * S * V3, where: P - power, Watt S - area, m2 V - wind speed, m / s

The wind blowing on 1 m2 at a speed of 2 m / s "carries" an 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 500 watt generator with a wind of, say, 5 m / s. An area swept by the wind turbine propeller is required, about 12 sq.m. Which corresponds to a screw with a diameter of almost 4 meters! A lot of money is of little use. Add here the need to obtain a permit (noise limitation). By the way, in some countries the installation of a windmill must be coordinated even with ornithologists.

But then I remembered about 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 it needs to be heated to melt it !? " And all this will be done by the Sun in a dozen and a half days. In reference books you can find the density of energy that reaches the surface of the earth. A 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 (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 from cardboard (focus in the parabola bowl). The pattern of the sectors was pasted over with ordinary food foil. It is clear that the surface quality and the reflectivity of the foil are very far from ideal.

But the task was to heat a certain volume of water using the “collective farm” methods in order to find out what power can be obtained, taking into account all losses. The pattern can be calculated using the Exel ParabAnt-v2.rar file that I found on the Internet from those who like to build 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 the 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 in the focus of a parabolic solar concentrator. The solar concentrator is oriented towards the Sun.

Experiment # 1

was held at about 7 am at the end of May. Morning is far from 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 about 13.3 watts was obtained. Those. at least 177 W / m2 It should be noted here that a round open can is far from the most the best way for a good result. Part of the energy is spent on heating the can itself, part is radiated into environment, including 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.Its mirror was a metallized adhesive tape purchased from hardware store... Its reflective qualities are marginally better than aluminum foil.

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

This made it possible to project the rays onto one surface of the heater and obtain a high temperature in focus. The parabola can easily burn through a sheet of paper in a matter of seconds. The experiment was carried out at about 7 a.m. in early June. According to the results of the experiment with the same volume of water and the same container, a power of 28 watts was obtained, which corresponds to approximately 102 watts / sq. This is less than in the first experiment. This is due to the fact that the sun's rays from the parabola fell on round surface banks are not always optimal. Some of the rays passed by, some fell tangentially. The jar was cooled by the fresh morning breeze on one side, while it was warmed 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 decent result can be obtained by making the correct heat sink, the following design was made: a tin can inside, painted black, has pipes for supplying and removing 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) penetrate through the glass into the can of the heat receiver (2), where, falling on the black surface, they heat it up. Water, in contact with the surface of the can, absorbs heat. Glass poorly transmits infrared (thermal) radiation, so losses due to heat radiation are minimized. As the glass warms up over time warm water, and begins to radiate heat, double glazing was applied. Ideal if there is a vacuum between the glasses, but this is an elusive task at home. On the reverse side of the can is thermally insulated with foam, which also limits the radiation of thermal energy into the environment.

The heat receiver (2) using pipes (4,5) is connected to the tank (3) (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.

Perfectly expansion tank and the tubes must also be thermally insulated. The experiment was carried out at about 7 a.m. in mid-June. The results of the experiment are as follows: Power 96.8 watts, which corresponds to approximately 342 watts / sq. M.

Those. the efficiency of the system has improved more than 3 times only due to the optimization of the design of the heat sink!

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

As you may have noticed, efforts have been made on my part to provide a disgusting environment for the experiment. Far from ideal conditions, namely: - not perfect surface concentrators - not ideal reflective properties of concentrator surfaces - not ideal orientation to the sun - not ideal position of the heater - not ideal time for experiment (morning)

could not prevent getting a completely acceptable result for installation from scrap 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 in the morning!

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

One of the issues that needs to be resolved on the way to the practical application of solar concentrators is to reduce its windage. Those. the concentrator must withstand wind loads. Hubs assembled from separate segments can be used to reduce windage. Such mirrored concentrators can be quite flat compared to a parabola bowl, and the "perforated" structure reduces their windage.

I know: DIY solar concentrator - SolarNews

The main advantage of the concentrator is its high heating efficiency. The reflector power is capable of sunny weather at one point to focus energy sufficient to boil water for a few 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. An unnecessary parabolic antenna (you can also find instructions on how to make parabolic dishes yourself on the Internet).

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

3. Heat receiver - 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 - mount for the heat sink. In the case of using an antenna, the heat sink can be fixed in the place where the converter is attached.

Solar concentrator production steps:

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

2. Stick the mirror film cut into thin strips. Thin strips are necessary in order to glue 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).

Sticking a mirror film on the cleaned surface of the plate

The result of pasting a paraboloid

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

Fixing the heat sink in the focus of the concentrator

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

Important: It must be remembered that the temperature at the concentration point can reach 300-500 degrees, therefore, when working with a solar parabolic concentrator, you must observe 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 like this:

Diagram of a homemade solar concentrator with a heat exchange tank

Based on materials from the site solarsistem.ru

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

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

DIY heating from polypropylene pipes

Do-it-yourself / DIY

Parabolic mirror for a reflector telescope with homemade CNC machine

Have you seen how much a reflector with a mirror 18 inches (almost 46 cm) in diameter costs now?
Therefore, my park of crazy engineering ideas is replenished with a new item!

To create a mirror, we need a lot of plexiglass or non-fragile (so-called tough) glass. To pick up the material - you have to be thoroughly confused, yes. You will also need three or four powerful and accurate servos with controllers, Arduino and silent radio components. Next, you need material for the bed, machine body and turning parts. And the most important thing is hand cutter suitable for processing the selected material.

The idea is to cut concentric grooves with a decreasing radius and increasing depth with each new wheel using a cutter mounted on a rotating bar. Thus, we get a stepped surface close to a paraboloid of revolution, because all changes in the position of the cutter and its immersion depth will be calculated using the parabolic function. Next, the surface is coated with epoxy resin and by rapid rotation of the workpiece is evenly distributed over the surface, filling the "steps" and bringing the surface as close to the paraboloid as possible.

The main problems that I will definitely face:

Positioning Accuracy
The choice of material and cutter, in the case of glass there will be chips, and the plexiglass is too soft and does not hold its shape
Moroka with epoxy "putty" on the steps and final sanding
Applying a reflective layer. (dusty, yeah)

Hello everyone! Vitaly Solovey with you. Today my article will be on the topic of parabolic mirrors and the energy of the sun in general. A couple of years ago, on the Internet in the United States, I came across a device that was unique at that time - a parabolic mirror, which is also called a concentrator of direct sunlight. Visually, it resembles a satellite dish with a mirrored surface inside.

The principle of operation of this dish is such that when the sun's rays hit the mirror surface, the rays are reflected and accumulated at one point. This is due to the parabolic shape of the dish and the light beam is reflected at exactly the same angle at which it hit the mirror surface.

With the correct execution of the so-called convex mirror, the temperature in the place where the rays are concentrated can reach 2000 degrees Celsius.

In support of this, I will give a video.

The surface of a parabolic mirror can be either solid, that is, without seams, or from pieces of mirrors or reflective film. In the video above, the mirror consisted of 5,800 individual small mirrors. But the difficulty lies in placing them all correctly. Place all 5800 mini mirrors under right angle.

Also, the surface can be covered with pieces of reflective silver film, which is also not gud, since due to the numerous seams, the sun's rays are slightly scattered and the effect will be much weaker.

A solution in this situation may be if the convex plate itself is made of several longitudinal parts on which the reflective film is evenly glued.

In this case, the reflected rays at the most correct angle will be focused at the point of the cluster. But the most effective way the workmanship is still natural glass mirror parabolic shape, which, of course, will cost unmeasured for the use of a mirror in everyday life.

Simplest and most effective option What I found is a method of vacuum forming a parabolic mirror.

During gluing, it is better to spread the film with the mirror side to the table top, and cover it with a glued dish and press it a little.

Now, to form a parabolic shape for the film, you need to pump out the air from the resulting vessel. To do this, we will drill a hole in any part of the plastic container and insert a bicycle valve there.

Important! The spool must be installed with the reverse side inside out, since we will pump out air, and not pump it into the vessel.

And here's what should ideally come out:

That's all for now, in subsequent articles I will talk about others, no less important applications parabolic mirror. And finally, a video on how to make a fire with toilet paper and a tablespoon:

A huge amount of free energy of the sun, water and wind and many other things that nature can give, people have been using for a long time. For some, this is a hobby, while others cannot survive without devices that can extract energy “from the 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.

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 designs of solar powered stoves, but they use one-piece or prefabricated mirrors. Firstly, it is expensive, and secondly, it makes the structure heavier and therefore it is not always convenient to use, for example, when a light weight of the finished concentrator is required.
An interesting model of a homemade parabolic solar concentrator was created by a talented inventor.
No mirrors are needed to make it, so it is very light and will not be a heavy load on a hike.

Very few things are required to create a homemade film-based solar concentrator. All of them are sold in 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 a solar oven.
2. A sheet of chipboard and a sheet of hardboard of the same size.
3. Thin hose and sealant.

How to make a solar oven?

First, two rings are cut out of a chipboard of the size you need with a jigsaw, which must be glued to each other. There is one ring in the photo and video, but the author indicates that he later added a second ring. According to him, one could be limited to one, but it was necessary to increase the space to form a sufficient concavity of the parabolic mirror. Otherwise, the focus of the beam will be too far away. A hardboard circle is cut to the size of the ring 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 structure must be completely sealed.
On the side, carefully so that there are even edges, make a small hole into which you firmly insert a thin hose. The hose-to-ring connection can also be sealed with a sealant to ensure a tight seal.
Pull the 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 comfortable stand for your finished hub. 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 roughly!
Watch the process of making a solar stove in the video.

Used material from the site zabatsai.ru. How to make a solar panel -.

How to build a solar water heater. It would be more correct to call it a parabolic solar concentrator. Its main advantage is that the mirror reflects 90% of the solar energy, and its parabolic shape concentrates this energy at one point. This installation will work effectively in most regions of Russia, up to 65 degrees N.

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

Parabolic antenna.

Any antenna can be used - iron, plastic or fiberglass. The antenna must be panel type, not mesh antenna. Antenna area and shape are important here. Remember, heating power = antenna surface area. And that the power collected by an antenna with a diameter of 1.5 m will be 4 times less than the power collected by an antenna with a mirror area of 3 m.

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. The glue with which the film will stick to the parabola.

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

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

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

Such a film can be ordered on Aliexpress, if suddenly you do not find it in stores

This is almost as easy as it sounds. You just need to take into account that if the antenna, for example, is 2.5 m in diameter, and the film is 1 m wide, then you do not need 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 out in small strips and attach it to the antenna with glue. Make sure the antenna is clean before applying tape. If there are areas where the paint is swollen, clean them with sandpaper. You need to smooth out all the irregularities. Please note that the LNB is removed from its place, otherwise it may melt. After gluing the film and installing the antenna in place, keep your hands or face away from the head mount - you risk getting serious sunburn.

Step 2 tracking system.

As stated above - the author bought a tracking system on Ebay. You can also look for rotary sun trackers. But I found a simple, penny-priced circuit that tracks the position of the sun fairly accurately.

Parts List:
(downloads: 428)
* 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 ceramic
* M - DC motor up to 1A
* LEDs - 5mm 563nm

Video of the solar tracker operation according to the scheme from the archive

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

Who cares the photo is taken from here:

Step 3 Create a heat exchanger-collector

The size of the focal point will dictate how much copper tubing you need. The author needed 6 meters of pipe with a spot size of 13 cm.

I think that it is possible, instead of a rolled tube, you can put a radiator from a car stove, there are rather small radiators. The radiator should be blackened for better heat absorption. If you decide to use a tube, you should try to bend it without kinking or kinking. Usually, for this, the tube is filled with sand, closed on both sides and bent on some mandrel of a suitable diameter. The author poured water into the tube and put it in the freezer with the open ends up to prevent the water from flowing out. The ice in the tube will create pressure from the inside to avoid kinking. This will allow the pipe to be bent with a smaller bend radius. It must be rolled up along a cone - each turn should be not much larger in diameter than the previous one. You can solder the turns of the collector together for a more rigid structure. And remember to drain the water after you are done with the manifold so that you don't get scalded by the steam or hot water after putting it back in place.

Step 4. Putting it all together and trying it out.

Now you have a mirrored parabola, a sun tracking module housed in a waterproof container, or a plastic container, a complete manifold. All that remains to be done is to reinstall the manifold and test it in operation. You can go further and improve the design by making something like a pan with insulation and putting it on the back of the manifold. The tracking mechanism must track movement from east to west, i.e. turn around during the day for the sun. And the seasonal positions of the luminary (up / down) can be manually adjusted once a week. You can, of course, add a tracking mechanism in the vertical direction - then you will get an almost automatic operation of the installation. If you plan to use the water to heat the pool or as hot water in the plumbing, you will need a pump that will pump the water through the manifold. If you will heat a container with water, you must take measures to avoid boiling water and an explosion of the tank. This can be done using

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