A lot of money is spent on hot water supply and space heating. But there is an alternative source of energy - the vacuum solar collector. Heard about this? It allows you to significantly reduce the financial costs of maintaining comfort, providing maximum heating effect with minimal heat loss.
This device can be purchased from manufacturers of household equipment or assemble yourself at home. To select a suitable model, to study a lot of information. We will help you determine the basic criteria for the purchase.
The article will discuss the principle of operation and the device of the vacuum collector. We will talk about the structural features of various models, consider the pros and cons of these installations. In addition, we will describe in detail how to make and install a vacuum solar collector yourself.
The material is accompanied by videos, from which you will learn about the important features and principles of operation of vacuum collectors.
The content of the article:
- The principle of operation of the vacuum unit
- How is a vacuum type collector?
Constructional nuances and classification
- Characteristic of coaxial tubes
- Pen Tube Features
- The principle of operation of the heat pipe heat pipe
- Description of U-shaped straight-through heat exchanger
- Comparison of various modifications
- What should be the heat collector?
- Pros and cons of vacuum collectors
- Assembling the unit with your own hands
- How to place the device?
- Conclusions and useful video on the topic
The principle of operation of the vacuum unit
The vacuum solar collector differs from ordinary solar systems in the way solar energy recycling. A classic battery simply accepts light and converts it into electricity. The collector also consists of glass tubes with vacuum recreated inside. They are combined into a single system through special docking stations.
Inside each tube is a channel of one or two copper rods with coolant. Catching the sun's rays, the active element heats the material-coolant, thus ensuring the operation of the collector.
A vacuum solar collector placed on the roof of a private house will provide residents with hot water throughout the year, and during the cold season will allow you to comfortably heat the room without spending large financial assets
Due to this design, the level of energy efficiency increases significantly, and heat losses are significantly reduced, since the vacuum layer allows you to save about 95% of the captured solar energy.
In addition, the dependence of reservoir productivity on seasonality, ambient temperature environment and various weather conditions, such as: gusts of wind, partly cloudy weather, precipitation, etc.
How is a vacuum type collector?
Modern vacuum devices that provide rooms with heat and hot water due to solar energy are technologically different.
Collectors are divided into these types:
- tubular without glass protective coating;
- module with reduced conversion;
- standard flat option;
- device with transparent insulation;
- air unit;
- flat vacuum collector.
Vacuum solar collector is able to provide hot water and heating at any time of the year, and in any weather (+)
They all have a common structural similarity, so they consist of:
- outer transparent tubefrom where the air is completely exhausted;
- heated pipelocated in a large pipe, where the liquid or gaseous coolant moves;
- one or two prefabricated distributorsjoined to the pipe of a larger caliber and includes a circulation circuit of thin tubes placed inside.
The whole construction is somewhat reminiscent of a thermos with transparent walls, in which an unprecedented high level of thermal insulation is maintained. Due to this feature, the inner tube body acquires the ability to warm up well and to fully release the energy resource to the circulating coolant.
Constructional nuances and classification
Vacuum-type collectors are classified by the type of glass tubes installed in the structure or by the characteristics of the heat ducts. The tubes are usually coaxial and feather, and the heat channels are U-shaped straight-through and heat pipe types. .
Characteristic of coaxial tubes
Coaxial tubes are a double glass thermos flask with vacuum space created artificially between the walls. The inner surface of the tube has a layer of special heat-absorbing coating, so the actual transfer of heat occurs directly from the walls of the glass bulb.
Coaxial tubes are made of high-strength glass based on borosilicates, which has a high light transmission ability. Elements, depending on the manufacturer, have up to three layers of magnetron sputtering, demonstrate excellent strength and resistance to various atmospheric manifestations (rain, hail, etc.), withstand a pressure of 1 Mpa and reliably serve for 15 years
As an absorbing element, a copper tube containing the ether composition is soldered into the glass tube. In the process of heating, it evaporates, effectively releases its heat, condenses and flows to the bottom of the tube. Then the cycle is repeated, thus creating a continuous process of heat exchange.
Pen Tube Features
Vacuum feather tubes have a greater wall thickness than coaxial ones, and consist not of two, but of one flask. The internal absorption element made of copper is supplied along the entire length with a durable amplifier - a corrugated plate with a high-energy absorbing coating.
Due to this structural feature, the vacuum is located directly in the heat channel, part of which, together with the absorbent, is integrated directly into the flask.
Inside the vacuum tube contains a plate, its shape resembles a feather. In terms of efficiency, it exceeds the capabilities of its coaxial counterpart, but has a significantly higher cost and difficult to replace in case of violation of the integrity of the flask or failure of the heating element
The collectors, made on the basis of feather vacuum tubes, are considered the most effective in their class, they perfectly cope with the tasks and reliably serve for many years.
The principle of operation of the heat pipe heat pipe
Heat pipes heat pipe consists of closed tubes containing an easily evaporating liquid composition. Under the influence of sunlight, it warms up, passes into the upper region of the channel and concentrates there in a special heat collector (manifold).
The working fluid at this moment gives up all the accumulated heat and goes down again to resume the process.
The heat-pipe heat exchanger sleeve is connected to the manifold’s heat exchanger through a special socket, sealed into the 1-pipe heat exchanger itself, or around a 2-pipe heat exchanger.
The working element of the heat channel heat pipe is made of copper, in more rare cases, of aluminum. It exhibits high resistance to operational loads, reliably serves for 15 years, has a reasonable cost and is one of the most popular elements of modern vacuum heliosystems of tubular type
The released energy from the heat reservoir draws the coolant and transfers it further along the system, thus ensuring the presence of hot water in the taps and radiators. The heat pipe system is easy to install and demonstrates high performance.
Collectors equipped with heat pipe vacuum tubes are distinguished by a good level of reliability and are suitable for use not only in everyday life, but also in high-pressure solar thermal systems
In the event of a breakdown or failure without any difficulty, it is possible to replace a damaged node with a new one without resorting to the reconstruction of the entire system.
Repair work can be easily carried out right on the site of the collector, without dismantling the unit and not putting unnecessary effort to the work.
Description of U-shaped straight-through heat exchanger
The tube heat exchanger is shaped like a U. Water or working coolant of the heating system circulates inside. One part of the element is intended for cold coolant, and the second correctly removes the already heated.
During glowing, the active compound expands and enters the accumulation tank, thus creating the natural circulation of fluid in the system. A special selective coating applied to the inner walls increases the heat absorption capacity and increases the efficiency of the system as a whole.
Compared to heat-pipe type pipes, U-shaped products have a greater hydraulic resistance, impose increased demands on the coolant and are much more expensive. Collectors operating on straight-through U-tubes cannot operate under high pressure and provide high-quality heat transfer only during the warm season.
U-type tubes exhibit high performance and give a solid heat transfer, but they have one significant drawback. They constitute one holistic construction with a manifold’om and are always mounted with it.
Replace a single single tube that failed, will not work. For repair, it will be necessary to dismantle the entire complex completely and put a new one in its place.
Comparison of various modifications
In the manufacture of helioaggregates, thermal channels and vacuum glass tubes for solar collectors are combined in various combinations.
Coaxial models with a heat pipe heat pipe are the most popular among consumers. Buyers are attracted by the loyal price of the devices and the very simple, affordable service throughout the life cycle.
Vacuum solar collector with a working pipe heat pipe perfectly repaired. Replacement of damaged tubes is carried out on site and does not provide for dismantling the system or moving it to another location. However, the heat transfer in these models is difficult, due to which the efficiency at the output is not more than 65%
Vacuum devices with heat pipe channels demonstrate high reliability and have no restrictions on use even in high-pressure solar thermal complexes.
Devices with a coaxial flask containing straight-through U-shaped channels are also included in the list of sought-after ones. They are characterized by such parameters as low heat loss and efficiency of 70% and above.
For correct operation, a vacuum device with a U-channel must be properly installed. It is desirable that the minimum angle of inclination is at least 20⁰. Only in this embodiment will provide maximum return.
The situation is somewhat spoiled: the complex process of repair, specific maintenance during operation and the inability to replace a single damaged node. If something happens to the device, it is dismantled and an absolutely new collector is put in place.
Feather tubes are structurally a single cylinder made of glass with thick, strong walls (depending on the manufacturer from 2.5 mm and above). The inside of the pen absorbent insert fits tightly to the working channel made of heat-conducting metal.
An almost perfect insulation creates a vacuum space inside the glass container. Absorbent transfers the absorbed heat without loss and provides the system efficiency up to 77%.
In the event of a fault, collectors with feather tubes are repairable. It is not required to change the whole system, it is enough to detect the damaged unit, dismantle it and put a new one in this place.
Models with a feather element are somewhat more expensive than coaxial ones, but due to the high efficiency they provide complete comfort indoors and quickly pay for themselves.
The most effective and productive are feather flasks with internal direct-flow channels. Their actual efficiency sometimes reaches record levels of 80%.
When mounting the feather tubes in the frame on the core of each part, wear a strong compression nut with ring and heat-resistant gasket. This ensures the integrity of the entire structure and allows the collector to fully function in any conditions.
The price of the products is quite high, and when carrying out repairs, it is imperative to drain the entire coolant from the system and only then begin troubleshooting.
What should be the heat collector?
The heat collector is another very important working element of the vacuum collector. Through this node the accumulated heat is transferred from the tubes to the coolant.
The heat collector is placed at the top of the device. One of its components, the copper core, receives energy and transfers it to the main coolant circulating in the closed system “heat exchanger of the collector tank”.
Correct work is guaranteed connected to the system. circulation pump. The automation controlling the heating complex clearly follows the temperature level in the channels and, in case of its falls below the permissible critical minimum (for example, at night), stops working the pump.
This allows you to avoid reverse heating when the coolant begins to pick up the heat of hot water collected in the storage tank.
Pros and cons of vacuum collectors
The main advantage of the units is called the almost complete absence of heat losses during operation. This provides a vacuum environment, which is one of the highest quality natural insulators. But the list of benefits does not end there.
The devices have other distinct advantages:
- performance at low temperatures (up to -30 ° C);
- ability to accumulate temperatures up to 300 ° C;
- the maximum possible absorption of thermal energy, including the invisible spectrum;
- operational stability;
- low susceptibility to aggressive atmospheric manifestations;
- low sail, due to the structural features of tubular systems that can pass through the air masses of different densities;
- high level of efficiency in regions with a temperate and cool climate with few clear and sunny days;
- durability in compliance with the basic rules of operation;
- availability for repair and the ability to change not the whole system, but only one broken fragment.
The solar collector is an effective device that allows virtually without loss to convert solar energy into heat
The disadvantages include the inability of collectors for self-cleaning from frost, ice, snow, and the high price of the components needed to assemble the unit at home.
Assembling the unit with your own hands
The process of assembling a vacuum collector begins with the manufacture of a frame-substrate for work items. It is mounted immediately in the place that is allocated for the unit.
The size and dimensions of the frame depend entirely on the model that is planned to be made, and are usually prescribed in the instruction located among the accompanying documents for the components.
The finished frame under the collector is fixed on the roof so that it occupies a clear position and does not swing. If the roof of the building is slate, obrestotochny beam and large-caliber thick screws are used. Conventional anchors are used for other roofing materials.
The places where the frame fits to the roof surface are additionally fixed with sealant so that in the future no water gets into the house through the holes. Then an accumulation tank is delivered to the installation site and it is fastened with screws to the top of the frame.
In the next step, the heater, temperature sensor and automated air vent are collected. All auxiliary units and related parts are put on the included softening pads. A socket wrench is used to fix the temperature sensor.
Next, equip the supply of water communications. For this purpose, pipes from any material resistant to low temperature parameters and capable of withstanding up to 95 ° C are taken. Well proven polypropylene pipes and fittings.
Pipes made of polypropylene are ideal for organizing the connection of the solar collector with the plumbing system of the dwelling. The armature has good physical performance and operational endurance, serves reliably for many years and is easily replaced in the event of cracks or tears
Having connected the water supply system, the storage tank is filled with water and tested for tightness. If leaks have been found somewhere within 3-4 hours, they are eliminated.
At the end install the heating elements. To do this, the copper tube is wrapped with an aluminum sheet and placed in a vacuum tube made of glass. From the bottom of the flask they put a fixing cup and a boot of durable, flexible rubber.
The upper copper tip of the tube is pushed into the brass capacitor until it stops. Viscous thermal contact grease is not removed from the pipes. Snap the locking mechanism onto the bracket and mount all the remaining glass tubes on the same principle.
Tubular solar collectors need regular maintenance and mandatory cleaning, especially during the period of active snowfall. If you follow these simple rules, they will work for a long time and maintain a high level of efficiency throughout the entire operational life.
A mounting block is put on the structure, a 220-volt power supply is brought to it, and three auxiliary units are connected to the system - a heating element, an air vent and a temperature sensor.
The latter is connected to the controller, designed for the correct management of the complex. In the controller menu, make the desired operating parameters and start the system in standard mode.
Step-by-step instruction on the construction of a solar collector is given in this article.
How to place the device?
So that the vacuum collector can fully function and effectively provide the living space with the necessary energy, it is necessary to find the best place for it and correctly orient the device with respect to parts of the world.
Vacuum solar collectors are much more practical than their flat counterparts. When one of the working pipes gets damaged and fails, it is very easy to replace it with a new one. After that, the system will continue to function as before. If at once there is no possibility to put a new element in the place of the spoiled one, it does not matter. The unit will be able to perform its "duties", even with the presence of a node with a damaged element
For settlements of the northern hemisphere, it is important to place a collector in the southern part of the roof of the house or on the sunny side of the site. It is desirable to ensure for the plane of the instrument the minimum deviation.
If there is no possibility to direct the surface to the south, it is worth choosing among the west and east the most light perspective in open space.
The high working efficiency of the vacuum type collector is also due to the fact that it acts according to the mirror principle and levels its thermal power on the basis of the current height of the sun.
Energy solar complex should not be closed by chimneys, decorative fragments of roofing, sprawling tree branches and high residential or technical buildings. This will reduce the efficiency of work and reduce the level of heating of existing elements.
If the unit is positioned correctly, it will provide almost the same heat transfer throughout the year, regardless of the season.
If there is no great experience in the implementation of complex repair and assembly and plumbing work, it is irrational to evacuate the pipes at home. This process is very laborious and requires special knowledge and specialized equipment.
In addition, elements of the vacuum type, made independently, have a much lower level of efficiency than factory parts. Therefore, it is most reasonable to purchase products from the core manufacturer, and then try to assemble several sections at home.
The site has a selection of articles on the arrangement of the solar heating system, we advise you to read:
- Solar heating systems: analysis of technologies for arrangement of heating on the basis of solar systems
- Heating a private house with solar panels: the scheme and device
- Flexible solar panels: types, characteristics + connection features
Conclusions and useful video on the topic
Detailed, detailed description of the vacuum tube, the principle of its work and the features of the functioning of the solar collector as a whole. The author tells about some interesting nuances and shows that the installation can be a real alternative to the gas boiler.
Interesting information about the work of the solar collector in the winter time.
How to properly mount a vacuum solar collector with your own hands at home. All the nuances of the process, recommendations and useful tips.
Knowing the basic principle of operation of a tubular vacuum solar collector, you can assemble the unit yourself. The installation will fully meet personal individual requirements and needs.
This is not too difficult, but it requires increased attention, scrupulousness and certain skills, otherwise the risk of damaging the integrity of the flask and disrupting its integrity significantly is increasing.
Anyone interested in choosing, installing or self-assembling a solar collector is encouraged to post comments and ask questions. Contact form is located in the lower block.