Research supervisor, Ph.D., Sapa Vladimir, student, Kuttybaev Serikbolsyn

Kostanay State University A. Baitursynov, Kazakhstan

The possibility of using solar collectors in agriculture

On average a year, depending on climatic conditions and latitude, the flow of solar radiation on the earth's surface is 100 to 250 W / m², the peak value reached in the afternoon when the sky is clear, in almost any (regardless of latitude) location, about 1 000 W / m².

The principle of operation of the solar water heater is shown in Fig. 1.

Fig. 1. Diagram of a year-round solar water heaters.

Year-round solar water heater (Fig.1) consists of a solar collector and heat exchanger-accumulator. Through the solar collector circulates coolant (antifreeze). Heat transfer fluid is heated in the solar collector energy of the sun and gives then heat the water through a heat exchanger mounted in the storage tank. In the storage tank hot water is stored until use. He must have good thermal insulation. In the first loop, where the solar collector can be used natural or forced circulation of coolant. In the storage tank can be installed electric or any other automatic. In the case of lowering the temperature in the storage tank below the (long cloudy weather or a small number of hours of sunshine in winter) heater-doubler automatically turns on and heats the water to the desired temperature.

Solar collector receives radiant energy and transmits this heat the coolant flowing through the collector. Collectors have a special selective coating surface that faces the sun. This coating allows you to absorb almost all of the visible and infrared spectrum of solar radiation. All surfaces of the collector, which are located in the shadow of a single-layer or two-layer thermal insulation. Therefore, heat loss through these surfaces are nearly 10 times less than that supplied from the surface that is aimed at the sun. Modern storage tank also try to minimize heat loss. Since the selection of the hot water storage tank is usually carried out from the upper part, to the accumulation tank in this part with a maximum temperature of water in the tank is set special devices through which inhibited the maximum vertical height of mixing water tank. Fig. 2 shows the installation of solar collectors.

Fig. 2. Solar collectors on the roof farm

Solar thermal systems and installations used for hot water and heating in households, agriculture, low-temperature heating of industrial and household processes, drying of agricultural products.

Hot water - the most common form of direct application of solar energy. Photovoltaic systems can reach 10-15% efficiency, solar thermal systems show the efficiency of 50-90%. In combination with solid furnaces (with wood) Domestic hot water demand can be met almost all year round without the use of fossil fuels.

A new approach to farming. The use of local renewable energy resources across the production chain will help to improve access to energy, to diversify the income of farmers and processing industry, to minimize food waste, reduce dependence on fossil fuels and greenhouse gas emissions and help achieve sustainable development goals.

Where there is good solar, wind, water and geothermal resources and biomass energy, they can be used as an alternative to fossil fuels in the farm.

References:

1. Yurchenko, A.V.; Savrasov F.W.; Yurchenko V. The real cost of energy - from resources to consumer // Bulletin of the Tomsk Polytechnic University. - 2009. - p. 43-46.

2. Stepanenko, N.I.; Gubin, V.E. Prospects for the use of alternative and renewable-energy sources in the conditions of Siberia // Modern Techniques and Technologies: Proceedings of IX Intern. Conf. students, graduate students and young scientists. - Tomsk, 2003. - T. 1. - P. 47-48.

3. Lukutin, B.V.; Surzhikova O.A.; Shandarova, E.B. Renewable energy in decentralized energy supply. - M .: Energoizdat, 2008. - 231 p.