Classification and main elements Heliosystems

Sun heating systems are called systems using solar radiation as a source of thermal energy. Their characteristic difference from other low-temperature heating systems is the use of a special element - a helium, designed to capture solar radiation and transform it into thermal energy.

According to the method of using solar radiation of the solar low-temperature heating system, subdivided into passive and active.

Supported systems of solar heating, in which, as an element that perceives solar radiation and transforming it into heat, is the building itself or its individual fences (collector building, wall collector, roofing collector, etc. (Fig. 3.4)) .

Fig. 3.4. Passive low-temperature solar heating system "Wall-collector": 1 - solar rays; 2 - the beam-proximated screen; 3 - air damper; 4 - heated air; 5 - cooled air out of the room; 6 - own long-wave thermal radiation of the wall array; 7 - black emission wall surface; 8 - blinds.

The solar low-temperature heating systems are active, in which the helium is an independent separate device that is not related to the building. Active heliosystems can be divided:

- by appointment (hot water, heating systems, combined systems for heat boat supply purposes);

- by type of coolant used (liquid - water, antifreeze and air);

- by duration of work (year-round, seasonal);

- on the technical solution of the schemes (one-, two-, multi-mounted).

Air is widespread non-freezing operating parameters in the entire range of operating parameters. When using it as a coolant, it is possible to combine heating systems with ventilation system. However, air is a low-blind heat carrier, which leads to an increase in the metal consumption on the device of air heating systems compared to water systems.

Water is a heatmifted and widely available coolant. However, at temperatures below 0 ° C, it is necessary to add non-freezing fluids. In addition, it should be borne in mind that water saturated with oxygen causes corrosion of pipelines and devices. But the metal consumption in water heliosystems is much lower, which contributes to a large extent contribute to their wider use.

Seasonal hot water heliosystems are usually single-circuit and function in summer and transitional months, during periods with a positive outdoor temperature. They may have an additional heat source or do without it depending on the purpose of the served object and operating conditions.

Heliosystems of building heating are usually two-circuit or most often multi-mounted, and for different circuits, various coolants can be applied (for example, in helium-aqueous solutions of non-freezing liquids, in intermediate circuits - water, and in the consumer circuit - air).

Combined year-round heliosystems for the purposes of heat booming of buildings of multi-mounted buildings and include an additional heat source in the form of a traditional heat generator operating on organic fuel, or heat transformer.

The schematic diagram of the solar heat supply system is shown in Fig.3.5. It includes three circulation circuits:

- the first contour consisting of solar collectors 1, circulating pump 8 and liquid heat exchanger 3;

- a second outline consisting of a tank-battery 2, circulating pump 8 and heat exchanger 3;

- The third contour consisting of a tank battery 2, circulating pump 8, a water-air heat exchanger (aircraft) 5.

Fig. 3.5. Schematic diagram of the solar heat supply system: 1 - solar collector; 2 - tank battery; 3 - heat exchanger; 4 - building; 5 - calorifer; 6 - Double heating system; 7 - a double cooler system; 8 - circulating pump; 9 - fan.

The solar heat supply system is functioning as follows. The coolant (antifreeze) of the thermal circuit, heating in solar collectors 1, enters the heat exchanger 3, where the heat of antifreeze is transmitted to water circulating in the heat exchanger 3 under the action of the pump 8 of the second circuit. The heated water enters the tank battery 2. From the battery tank, water is closed by a hot water pump 8, it is brought to the desired temperature in a double 7 and enters the hot water supply system. Battery package is made from the water supply.

For heating, water from the battery-battery 2 is supplied to the third circuit pump 8 to the calorifer 5, through which the air is passed with the fan 9 and, heating, enters the building 4. In the absence of solar radiation or lack of thermal energy produced by solar collectors, to work Turns on Dubler 6.

The choice and layout of the elements of the solar heat system in each specific case are determined by climatic factors, the purpose of the object, the heat consumption mode, economic indicators.

Concentrating heliciphers

The concentrating helium and parabolic mirrors are expressed by spherical or parabolic mirrors (Fig. 3.6), made of polished metal, which are placed in the focus of which the heat-visible element (solar boiler) is placed through which the coolant circulates. Water or non-freezing fluids are used as coolant. When used as a coolant of water at night and during the cold period, the system must be emptied to prevent its freezing.

To ensure the high efficiency of the process of capturing and converting solar radiation, the concentrating helicipron must be constantly directed strictly in the sun. To this end, the helium is supplied with a tracking system, including the direction sensor in the sun, the electronic signal conversion unit, the electric motor with a gearbox for turning the design of the helium-receiver in two planes.

The advantage of systems with concentrating helicuals is the ability to generate heat with relatively high temperatures (up to 100 ° C) and even steam. The disadvantages should include a high cost of construction; the need for constant purification of reflective surfaces from dust; work only in the bright time of day, and therefore the need for large-volume batteries; Large energy consumption for the drive of the tracking of the sun, commensurate with the generated energy. These disadvantages restrain the widespread use of active low-temperature solar heating systems with concentrating heliciters. Recently, plane heliciphers are most often used for solar low-temperature heating systems.

Flat solar collectors

A flat solar collector is a device with a flat configuration absorbing panel and flat transparent insulation to absorb solar radiation energy and transform it to thermal.

Flat solar collectors (Fig. 3.7) consist of a glass or plastic coating (single, double, triple), heat-visible panel painted from the side facing the sun, black, insulation on the back side and housing (metal, plastic, glass, Wooden).

You can use any metal or plastic sheet with coolant channels as a heat dissipating panel. Drumming panels made of aluminum or steel of two types: a sheet-pipe and stamped panels (pipe in a sheet). Plastic panels due to the briefness and rapid aging under the action of sunlight, and also because of the low thermal conductivity are not widely used.

Fig. 3.6 Concentrating Helicers: A - parabolic hub; b - parabolocylindrical hub; 1 - sun rays; 2 - heat-visible element (solar collector); 3 - mirror; 4 - the mechanism of the tracking system; 5 - pipelines, applying and dischargeable heat carrier.

Fig. 3.7. Flat solar collector: 1 - sun rays; 2 - glazing; 3 - body; 4 - heat-visible surface; 5 - thermal insulation; 6 - seal; 7 - Own long-wave radiation heat-visible plate.

Under the action of solar radiation, heat-by-review panels are heated to temperatures of 70-80 ° C, exceeding the ambient temperature, which leads to an increase in the convective heat transfer of the panel to the environment and its own radiation to the sky. To achieve higher coolant temperatures, the surface of the plate is coated with spectral-selective layers, which actively absorb the shortwave radiation of the Sun and reduce its own thermal radiation in the long-wave part of the spectrum. Such structures based on "black nickel", "black chromium", copper oxide on aluminum, copper oxide and other costs (their cost is often commensurate with the cost of the heat-visible panel). Another way to improve the characteristics of flat collectors is the creation of a vacuum between the heat-visible panel and transparent insulation to reduce thermal losses (fourth-generation solar collectors).

The experience of operating solar installations based on solar collectors revealed a number of significant disadvantages of such systems. First of all, this is the high cost of collectors. Increasing the efficiency of their work through selective coatings, increasing the transparency of glazing, vacuuming, as well as the cooling system devices are economically unprofitable. A significant disadvantage is the need for frequent cleaning of glass from dust, which practically eliminates the application of the collector in industrial areas. With long-term operation of solar collectors, especially in winter conditions, there is a frequent way out of order due to the uneven expansion of the illuminated and darkened glass sections due to the violation of the intake of glazing. There is also a large percentage of failure of collectors during transportation and installation. A significant disadvantage of the system of systems with collectors is also the uneven loading during the year and day. The experience of operating collectors in the context of Europe and the European part of Russia with a high proportion of diffuse radiation (up to 50%) showed the impossibility of creating a year-round autonomous system of hot water supply and heating. All solar collectors in medium latitudes require a device of large-scale batteries and inclusion in the system of an additional energy source, which reduces the economic effect on their use. In this regard, their use is most appropriate in areas with high average intensity of solar radiation (not lower than 300 W / m 2).

Solar heat supply is a method of heating a residential building, which is becoming increasingly popular in many, mostly developed, states of the world every day. The greatest success in the field of solar thermal energy today can boast of countries in Western and Central Europe. In the territory of the European Union over the past decade, the annual growth of the renewable energy industry is 10-12%. Such a level of development is a very significant indicator.

solar collector

One of the most obvious areas of the use of solar energy is its use in order to heal water and air (as coolant). In climatic areas where cold weather prevails, the calculation and organization of heating systems of each residential building are required for comfortable residence of people. They should have a hot water supply for various needs, besides, at home it is necessary to go. Of course, the best option here will apply a scheme where automated heat supply systems work.

Large volumes of the daily arrival of hot water in the production process require industrial enterprises. As an example, Australia can be brought, where he heated the liquid coolant to a temperature not exceeding 100 o C, almost 20 percent of the entire energy consumed. For this reason, in part of the developed countries of the West, and in more extent in Israel, North America, Japan, and, of course, in Australia, the production of solar heating systems is expanding.

In the near future, the development of energy will undoubtedly be directed in favor of using solar radiation. The density of solar radiation on the earth's surface is an average of 250 W per meter square. And this is despite that, to ensure the economic needs of a person in the least industrial areas, two watts per square meter is enough.

The advantageous difference between solar energy from other industries that use fossil fuel combustion processes is the ecology of the resulting energy. The operation of solar equipment does not entail the allocation of harmful emissions into the atmosphere.

Selection of equipment for equipment, passive and active systems

There are two schemes for using solar radiation as a heating system for home. These are active and passive systems. Passive heating systems on solar radiation are those in which the element directly absorbing solar radiation and the heat generation of it, the structure of the house is served or its separate parts. These elements can serve as a fence, roof, separate parts of the building, built on the basis of a specific scheme. In passive systems, mechanical moving parts are not used.

Active systems operate on the basis of the opposite scheme of home heating, they actively use mechanical devices (pumps, engines, when they are used, it is also calculated by the required power).

The most simple in terms of its design and less costly in financial plan during the installation of the scheme are systems of passive action. Such heating schemes do not need to install additional devices for absorption and the subsequent distribution of solar radiation in the home heating system. The work of such systems is based on the principle of direct heating of the residential premises directly through the light transmitting walls located on the south side. An additional function of heating is carried out by the outer surfaces of the fence elements of the house, which are equipped with a layer of transparent screens.

To start the process of converting solar radiation to thermal energy, a system of structures based on the use of heliums with a transparent surface is used, where the main function is played by the "greenhouse effect", the possibilities of glass are used to hold heat radiation, due to which the temperature indoor increases.

It is worth noting that the use of only one of the types of systems may not be completely justified. Often, a thorough calculation shows that it is possible to achieve a significant reduction in the losses of heat and reduce the needs of the building in energy by applying integrated systems. The overall work and active, and passive system by combining positive qualities will give the maximum effect.

Typically, the cost-effective performance shows that the passive use of the radiation of the Sun will provide the needs of your home in heating by approximately 14-16 percent. Such a system will be an important component of the process of obtaining heat.

However, despite certain positive qualities of passive systems, the main opportunities for the complete provision of the needs of the building in warmth is still needed to use active heating equipment. Systems whose function is directly absorption, accumulation and distribution of solar radiation.

Planning and calculation

Calculate the possibility of mounting active heating systems that use solar energy (crystalline solar cells, solar collectors), preferably at the design stage of the building. But still this moment is not compulsory, the installation of such a system is possible and on the already existing task regardless of the year of its construction (the basis for success is the correct calculation of the whole scheme).

Installation of equipment is carried out on the south side of the house. This location creates conditions for maximum absorption of incoming solar radiation in winter. Photo cells that transform the energy of the Sun and installed on a fixed construction are most effective when they are installed relative to the surface of the Earth at an angle of equal to the geographical location of the heated building. The angle of inclination of the roof, the degree of rotation of the house to the south is significant moments that must be taken into account, producing the calculation of the entire heating scheme.

Solar cells and collectors on solar radiation must be installed as close to the energy consumption. Remember that the closer you build a bathroom and kitchen, the smaller the heat loss (in this version you can do with one solar collector, which will heat both rooms). The main evaluation criterion for the selection of the equipment you need is its efficiency.

Heating solar systems of active action are divided into the following groups according to the following criteria:

1. Application of a duplicate contour;
2. Seasonality of work (throughout the year or at a certain season);
3. Functional purposes - heating, hot water supply and combined systems;
4. Applied coolant - liquid or air;
5. The applied technical solution of the number of contours (1, 2 or more).

General economic data will serve as a major choice factor in favor of one of the types of equipment. Properly decide on the literate thermal calculation of the entire system. The calculation must be performed, given the indicators of each particular room, where the organization of solar heating and (or) hot water supply is scheduled. It is worth considering the location of the structure, climatic natural conditions, the size of the value of the outstanding energy resource. The correct calculation and successful choice of the heat supply organization scheme is the key to the economic feasibility of the use of equipment of solar energy.

Solar heat supply system

The most common from the heating schemes used is the installation of solar collectors, in which the accumulation function of absorbed energy in a special capacity is a battery.

To date, the greatest distribution was obtained by two-kinnuts for the heating of residential premises, which establishes a coercive coolant circulation system in the collector. The principle of his work is next. The supply of hot water is carried out from the upper point of the accumulative tank, the process occurs automatically according to the laws of physics. Cold flow water pressure is supplied to the lower part of the tank, this water displaces the heated tank at the top of the tank, which further enters the hot water supply system at home to meet its economic needs and the needs of heating.

For a single-family house, a tank is usually installed with a capacity with a capacity from 400 to 800 liters. To warm up thermal carrier of such volumes, depending on the natural conditions, it is necessary to correctly calculate the surface area of \u200b\u200bthe solar collector. It is also necessary to justify the use of equipment economically.

Standard set of equipment for mounting the heating system on solar radiation Next:

• Directly the solar collector itself;
• Fastener system (supports, beams, holders);
• Cumulative tank;
• Tank compensating excess extension of heat carrier;
• The pump control device;
• Pump (valve set);
• Temperature sensors;
• Heat exchange devices (used in diagrams with large volumes);
• Heat insulated pipes;
• Safety and regulatory reinforcement;
• Fitting.

System based on heat-absorbing panels. Such panels are usually used at the stage of new construction. To install them, it is necessary to build a special design called a hot roof. This means that the panels need to be mounted directly into the roof design, while using the elements of the roof as constituent elements of the equipment housing. Such an installation will reduce your costs for creating a heating system, however, it will require high-quality work on waterproofing devices and roofs. This method of installing equipment will require you careful design and planning of all stages of work. It is necessary to solve a lot of tasks on pipe wiring, placement of the accumulative tank, installation of the pump, adjusting the slopes. There are quite a lot of problems when installing will have to be solved if the building is not most successful to the south.

In general, the project of solar heating systems will be different from others to one degree or another. Only the basic principles of the system will remain unchanged. Therefore, bring the exact list of necessary parts for the full installation of the entire system is not possible, since during the installation process there may be necessary to apply additional elements and materials.

Liquid heating systems

In systems operating on the basis of a liquid coolant, conventional water is used as a accumulatory. Energy absorption occurs in solar collectors of a flat design. Energy is accumulated in the tank of the drive and is consumed as needed.

To transfer energy from the drive to the building, a water-water or water-high heat exchanger is used. The hot water supply system is equipped with an additional tank, which is called the preheating tank. Water heats up in it due to solar radiation and further enters the usual water heater.

Air heating system

Such a system as a carrier of heat uses air. The heating of the coolant is carried out in a flat solar collector, and then heated air enters heated room or into a special accumulative device, where the absorbed energy accumulates in a special nozzle, which is heated by incoming hot air. Thanks to this feature, the system continues to supply a house with warm even at night when solar radiation is not available.

Systems with Forced and Natural Circulation

The basis of the work of systems with natural circulation consists in independent movement of the coolant. Under the influence of an increase in temperature, it loses its density and therefore strive to the upper part of the device. An arising difference in pressure and makes the equipment function.

The use of "green" energy supplied by natural elements allows to significantly reduce utility costs. For example, having arranged solar heating of a private house, you will be supplied with virtually free coolant low-temperature radiators and systems of warm floors. Agree, this is already saving.

All about "green technologies" you will learn from the article we offer. With our help, you will easily figure out in the varieties of solar installations, methods of their device and the specifics of operation. Surely interest in one of the popular options intensively working in the world, but not too far in demand with us.

In presented to your attention, the constructive features of systems disassembled, described in detail the connection schemes. An example of calculating the solar heating circuit is given to evaluate the realities of its structure. Photo-selection and video attached to help independent masters.

On average, 1 m 2 of the surface of the Earth receives 161 W solar energy per hour. Of course, at the equator, this figure will be many times higher than in the plague. In addition, the density of solar radiation depends on the time of year.

In the Moscow region, the intensity of solar radiation in December is different from May-July more than five times. However, modern systems are so effective that they can work almost everywhere on Earth.

Almost half of the entire energy produced is used to heat heating. The sun shines in winter, but its radiation is usually underestimated.

December Day not far from Zurich Physicist A. Fisher generated couples; It was when the sun was in its lowest point, and the air temperature was 3 ° C. During the day later, the solar collector with an area of \u200b\u200b0.7 m2 heated 30 liters of cold water from the garden water supply to + 60 ° C.

Solar energy in winter can be easily used to heat air indoors. In the spring and autumn, when it is often sunny, but cold, solar heating of the premises will not allow the main heating. This makes it possible to save part of the energy, and accordingly money. For houses that are rarely used, or for seasonal housing (cottages, bungalows), heating solar energy is especially useful in winter, because Excludes excessive cooling of the walls, preventing destruction from condensation moisture and mold. Thus, annual operating costs are mainly reduced.

When heating houses with solar heat, it is necessary to solve the problem of thermal insulation of rooms based on architectural and structural elements, i.e. When creating an effective system of solar heating, build houses with good thermal insulation properties should be erected.

Cost of heat
Auxiliary heating

Sunny contribution to home heating
Unfortunately, the period of heat intake from the Sun does not always coincide in phase with the period of the appearance of thermal loads.

Most of the energy that is available at our disposal during the summer period is lost due to the lack of permanent demand for it (in fact, the collector system is to some extent a system of self-regulating: when the temperature of the carrier reaches an equilibrium value, the heat perception is terminated, since thermal losses from Solar collector becomes equal to perceived heat).

The amount of useful heat absorbed by the solar collector depends on 7 parameters:

1. The values \u200b\u200bof the incoming solar energy;
2. Optical losses in transparent isolation;
3. absorbing properties of the heat-visible surface of the solar collector;
4. The effectiveness of heat transfer from the heat receiver (from the heat-visible surface of the solar collector to the liquid, i.e. from the size of the thermarity efficiency);
5. transparent heat insulation transparency, which determines the level of heat losses;
6. The temperature of the heat-visible surface of the solar collector, which in turn depends on the speed of the coolant and the temperature of the coolant at the inlet in the solar collector;
7. Outdoor air temperatures.

The effectiveness of the solar collector, i.e. The ratio of used energy and incident will be determined by all these parameters. Under favorable conditions, it can reach 70%, and with unfavorable decrease to 30%. The exact value of efficiency can be obtained by pre-calculation only by completely modeling the behavior of the system, taking into account all the factors listed above. Obviously, such a task can be solved only with the use of a computer.

Since the density of the solar radiation stream is constantly changing, then for the calculated estimates, you can use the full amounts of radiation per day or even in a month.

In tab. 1 As an example, see:

the average monthly sums of the flow of solar radiation, measured on the horizontal surface;

amounts calculated for vertical walls facing south;

amounts for surfaces with an optimal tilt angle of 34 ° (for Kew, near London).

Table 1. Monthly sums of the arrival of solar radiation for Kew (near London)

From the table, it can be seen that the surface with an optimal angle of inclination receives (on average for 8 winter months) by about 1.5 times greater than the horizontal surface. If the sum of the arrival of solar radiation to the horizontal surface is known, then to recalculate on the inclined surface, they can be multiplied by the product of this coefficient (1.5) and the value of the efficiency of the solar collector, equal to 40%, i.e.

1,5*0,4=0,6

It will turn out the amount of useful energy absorbed by the inclined heat-visible surface during this period.

In order to determine the effective contribution of solar energy to the heat supply of the building, even by manual counting, it is necessary to make at least monthly balances of the needs and useful heat obtained from the Sun. For clarity, consider an example.

If you use the above data and consider the house for which the intensity of heat losses is 250 W / ° C, the location is characterized by an annual number of degree-days equal to 2800 (67200 ° C * h). And the area of \u200b\u200bsolar collectors is, for example, 40 m2, then the following distribution is obtained by months (see Table 2).

Table 2. Calculation of the effective contribution of solar energy

Month	° C * h / m	The amount of radiation on the horizontal surface, kW * h / m2	Useful heat per unit area of \u200b\u200bcollector (D * 0.6), kW * h / m2	Total useful heat (E * 40 m2), kW * h	Sunny contribution, kW * h / m2
A.	B.	C.	D.	E.	F.	G.
January	10560	2640	18,3	11	440	440
February	9600	2400	30,9	18,5	740	740
March	9120	2280	60,6	36,4	1456	1456
April	6840	1710	111	67,2	2688	1710
May	4728	1182	123,2	73,9	2956	1182
June	-	-	150,4	90,2	3608	-
July	-	-	140,4	84,2	3368	-
August	-	-	125,7	75,4	3016	-
September	3096	774	85,9	51,6	2064	774
October	5352	1388	47,6	28,6	1144	1144
November	8064	2016	23,7	14,2	568	568
December	9840	2410	14,4	8,6	344	344
Sum	67200	16800	933	559,8	22392	8358

Cost of heat
Calculating the amount of heat provided at the expense of the Sun, it is necessary to present it in monetary terms.

The cost of produced heat depends on:

the cost of fuel;

the calorific value of fuel;

overall efficiency of the system.

The operating costs obtained in this way can then be compared with capital costs for the solar heating system.

In accordance with this, if we assume that in the example above, the solar heating system is used instead of a traditional heating system that consumes, for example, gas fuel and producing heat worth 1.67 rubles / kW * h, then to determine the annual savings, it is necessary 8358 kW * h, provided at the expense of solar energy (according to the calculations of Table 2 for the collector area 40 m2), multiply by 1.67 rubles / kW * h, which gives

8358 * 1.67 \u003d 13957,86 rub.

Auxiliary heating
One of the questions most frequently asked by people who want to understand the use of solar energy for heating (or another goal) is the question: "What to do when the sun does not shine?" I understood the concept of energy of energy, they ask the following question: "What to do when in the battery does not remain more heat energy?" The issue is natural, and the need for a duplicate, often traditional system is a serious stumbling block for widespread solar energy as an alternative to existing energy sources.

If the power of the solar heat supply system is not enough to hold the building during the cold, cloudy weather, then the consequences, even once in the winter, can be quite serious, forcing it as a duplicate conventional system of heating. Most buildings heated solar energy need a full-time duplicate system. Currently, in most areas, solar energy should be considered as a means of reducing the consumption of traditional energy species, and not as a complete substitute.

Conventional heaters are suitable doubles, but there are many and other alternatives, for example:

Fireplaces;
- wood furnaces;
- wood calorifers.

Suppose, however, that we wanted to make the solar heat supply system quite large to provide a warm room in the most adverse conditions. Since the combination of very cold days and long periods of cloud weather happens rarely, then the additional dimensions of the solar energy installation (collector and battery), which will be required for these cases, will be too expensive at relatively small fuel economy. In addition, most of the time the system will operate with power below the nominal.

The system of solar heat supply, designed to provide 50% of the heating load, can give enough heat only on 1 day very cold weather. When doubling the size of the solar system, the house will be provided with heat for 2 cold cloudy days. For periods of more than 2 days, the subsequent increase in dimensions will be as unjustified as the previous one. In addition, there are periods of soft weather when the second increase will not be required.

Now, if you increase the area of \u200b\u200bthe heating system collectors by another 1.5 times to hold out 3 cold and cloud days, it is theoretically, it will be sufficient to provide 1/2 of the entire need for the house during the winter. But, of course, in practice it may not be, since sometimes there are sometimes 4 (or more) in a row in a row of cold cloud weather. To take into account this 4th day, we need a system of solar heating, which theoretically can collect 2 times more heat than it is necessary for the building during the heating season. It is clear that cold and cloud periods can be longer than provided in the project of the solar heat supply system. The larger the collector, the less intensively used every additional increment of its size, the less energy is saved per unit area of \u200b\u200bthe collector and the less the payback of investment on each additional unit of the area.

Nevertheless, bold attempts have been made to accumulate a sufficient amount of solar radiation thermal energy to cover the entire need for heating and abandon the auxiliary heating system. With the rare exception of such systems such as Sunny Hay's house, long-term accumulation of heat is perhaps the only alternative to the auxiliary system. Tomason, Tomason approached 100% solar heating in his first house in Washington; Only 5% of the heating load was covered with a standard heater on liquid fuel.

If the auxiliary system covers only a small percentage of the entire load, that is, it makes sense to use electrical installation, despite the fact that it requires the production of a significant amount of energy at a power station, which is then converted to heat for heating (10500 ... 13700 kJ for production is consumed at the power plants 1 kW * h thermal energy in the building). In most cases, the electrical heater will be cheaper than an oil or gas furnace, and a relatively small amount of electricity required to heat the building can justify its use. In addition, the electric heater is less material intensive device due to a relatively small amount of material (compared to the heater), which is on the manufacture of electrical strokes.

Since the efficiency of the solar collector increases significantly if it is operated at low temperatures, the heating system should be calculated to use as low temperatures as possible - even at 24 ... 27 ° C. One of the advantages of the Tomason system using warm air is that it continues to extract useful heat from the battery at temperatures, almost equal room temperature.

In the new construction, heating systems can be calculated on the use of lower temperatures, for example, by elongating the tubular-ribbed radiators with hot water, increasing the size of radiation panels or an increase in the air volume of a lower temperature. Designers most often stop their choice on the heating of the room with warm air or on the use of increased radiation panels. In the air heating system, low temperature is best used. Radial heating panels have long delay (between the inclusion of the system and heating airspace) and usually require higher operating temperatures of the coolant than hot air systems. Therefore, heat from the accumulating device is not fully used at lower temperatures, which are acceptable for systems with warm air, and the overall efficiency of such a system below. Excess system size from radiation panels to obtain results similar to the results when using air can entail significant additional costs.

To increase the overall efficiency of the system (solar heating and auxiliary duplicate system) and the simultaneous reduction in total costs by eliminating the idle parts, many designers elected the path of integrating a solar collector and a battery with an auxiliary system. General are composite elements as:

Fans;
- pumps;
- heat exchangers;
- management bodies;
- pipes;
- Air ducts.

In the figures of the article, the system design shows various schemes of such systems.

The trap in the design of the butt elements between systems is an increase in controls and moving parts, which increases the likelihood of mechanical breakdowns. Temptation increase by 1 ... 2% efficiency by adding another device at the junction of systems is almost insurmountable and may be the most common cause of the failure of the solar heating system. Usually an auxiliary heater should not heal the compartment of the solar heat accumulator. If this happens, the solar heat collection phase will be less efficient, since almost always this process will flow at higher temperatures. In other systems, reducing the temperature of the battery due to the use of heat by the building increases the overall efficiency of the system.

The reasons for other disadvantages of this scheme are explained by the high loss of heat from the battery due to its constantly high temperatures. In systems in which the auxiliary equipment does not heat the battery, the latter will lose significantly less heat in the absence of the Sun for several days. Even in the heat loss systems designed in such a way, 5 ... 20% of all heat absorbed by the solar heating system. With a battery, heating auxiliary equipment, heat loss will be significantly higher and can only be justified if the battery container is inside the heated room of the building

On the basis of the use of helixes, the tasks of heating, cooling and hot water supply of residential, administrative buildings, industrial and agricultural objects can be solved. Helinows have the following classification:

• for destination: hot water systems; heating systems; Combined installations for heat supply purposes;
• by type of coolant used: liquid; air;
• by duration: year-round; seasonal;
• on the technical solution of the scheme: single-circuit; dual circuit; multi-mounted.

The most frequently used heat carriers in solar heat supply systems are liquids (water, ethylene glycol, organic substances) and air. Each of them has certain advantages and disadvantages. Air does not freeze, does not create large problems associated with leaks and corrosion of equipment. However, due to the low density and heat capacity of the air, the size of air plants, power costs to pump the coolant higher than that of liquid systems. Therefore, in most exploited systems of solar heat supply, preference is given to liquids. For housing and communal needs, the main heat carrier is water.

When operating solar collectors in periods with a negative temperature of the outer air, it is necessary to either use antifreeze as a coolant, or in some way to avoid the freezing of the coolant (for example, timely drainage of water, heating it, insulation of the solar collector).

Halio-cutting hot water helplements with a duplicate heat source can be equipped with household houses, multi-storey and apartment buildings, sanatoriums, hospitals and other objects. Seasonal settings, such as, for example, shower installations for pioneering camps, boarding houses, mobile installations for geologists, builders, chapans are usually functioning in summer and transition months, during periods with a positive outdoor temperature. They may have a duplicating heat source or do without it depending on the type of object and operating conditions.

The cost of hot water helix can be from 5 to 15% of the cost of the object and depends on the climatic conditions, the cost of equipment and the degree of its development.

In helicopores intended for heating systems, both fluids and air are used as coolants. In multi-mounted helicopters in different circuits, various coolants can be used (for example, in the heliconatura - water, in the distribution room). In our country, water helicopters for heat supply received the predominant distribution.

The surface area of \u200b\u200bsolar collectors needed for heating systems is usually 3-5 times higher than the surface area of \u200b\u200bcollectors for hot water systems, therefore the utilization rate of these systems is lower, especially in the summer period of the year. The cost of the installation for the heating system may be 15-35% of the value of the object.

Combined systems can include year-round installations for heating and hot water purposes, as well as installations operating in thermal pump mode and heat pipe for heat-cooling purposes. These systems do not yet apply widely in industry.

The density of the solar radiation flow coming to the surface of the collector, largely determines the heat engineering and technical and economic indicators of solar heat systems.

The flux density of solar radiation changes throughout the day and during the year. This is one of the characteristic features of systems using solar energy, and when conducting specific engineering calculations of helixing, the question of choosing the calculated value E is decisive.

As a calculated scheme of the solar heat supply system, we consider the scheme presented in Fig.3.3, which makes it possible to take into account the features of the work of various systems. Solar collector 1 converts solar radiation energy into heat, which is transmitted to the tank battery 2 through the heat exchanger 3. The heat exchanger is possible in the battery itself. Circulation of the coolant is provided by the pump. The heated coolant enters the hot water supply and heating systems. In the event of a lack or lack of solar radiation, a duplicating heat source of hot water supply or heating 5 is included.

Fig.3.3. Solar heat supply system scheme: 1 - solar collectors; 2 - hot water tank battery; 3 - heat exchanger; 4 - building with outdoor heating; 5 - Double (source of additional energy); 6 - passive solar system; 7 - pebble battery; 8 - dampers; 9-fighter; 10 - the flow of warm air into the building; 11- Recycling air supply from the building

The solar collectors of the new generation "Rainbow" NPP "competitor" with improved heat engineers are used in the system of solar heating, due to the use of the selective coating on the heat-absorbing panel of stainless steel and the translucent coating of particularly durable glass with high optical characteristics.

In the system as a coolant, it is used: water with positive temperatures or antifreeze in the heating period (solar outline), water (second outdoor heating circuit) and air (the third air heating circuit).

Electrocotel used as a duplicate source.

Improving the efficiency of heliospheres systems can be achieved by using various methods of thermal energy accumulation, rational combination of heliosystems with heat boiler and heat-pump installations, combinations of active and passive systems for developing effective tools and automatic control methods.