Research supervisor, Ph.D., Sapa Vladimir, student, Assylkhanov Azamat

Kostanay State University A. Baitursynov, Kazakhstan

The possibility of using solar dryers in agriculture

One of the main reasons for the decline of profitability of agricultural industries in recent years, is to increase the price of fossil fuels - oil, gas, coal, electricity. Work to reduce energy costs, the development and use of alternative sources of heat, are now very relevant.

First of all, reduce energy costs, it is necessary to create processes of climate and water heating in livestock buildings, greenhouses, cleaning equipment and milking equipment, when Rearing silkworm cocoon drying and marinating and others. Therefore, should create the technical means for heating air and water using solar energy.

Developed the basic design of electrical installations helio obtained theoretical and experimental data supporting their effectiveness. Solar systems for heating water and air (generators solar power) - a container with thermal insulation, facing south to capture the maximum energy from the sun.

In agricultural production choices drying method determined by the scale of production, climatic features of the area, overlooking the material being dried and the cost of additional energy. The supply of heat to the material from the drying agent can be by convection or by radiation. Distinguish between convective and radiative dryers. In convective dryers the product is contacted with air, heated by solar energy. In radiation dryers product directly irradiated by the Sun, the temperature in the dryer of this type is 60 ... 75 °C. Can also be used combined dryers. In these involved both types of heat transfer, but is dominated by convection, and the installation consists of a heater and the drying chamber with transparent walls.

Natural drying of agricultural products used everywhere and for a long time. In this case, the products spread out on the ground, under a canopy suspended or placed on pallets. When drying in the air unprotected agricultural products have huge losses due to incomplete drying, pollution as mold, eating birds, insect damage, acts of precipitation.

The use of solar installations of the "hot box" increases the drying efficiency and reduces product loss. Significantly reduces the drying time and improves the quality of the product, including the preservation of vitamins. However, the utilization rate helio dryers for agriculture is low. In some cases, a year may be used only a few weeks. This is not conducive to the achievement of high economic performance of solar dryers. Currently economically feasible to use helio dryers for drying hay. The situation is quite favorable when drying fish.

Solar drying chamber with forced draft is shown in Figure 1. It includes: the heater, an oven, a fan.

Fig. 4. Chamber solar dryer with a fan and heater corrugated absorber: 1 - heater; 2 - drying chamber; 3 - fan; 4 - insulated housing; 5 - light transparent insulation; 6 - absorber; 7 - the air; 8 - Bearing; 9 - visor.

In heat-insulated casing of the heater with a light transparent insulation is blackened surface absorbs the rays of corrugated metal. Hot air for air ducts fed into the drying chamber with perforated trays for drying material, which is mounted on bearings and top covered with a visor.

Energy consumption during drying of hay using solar energy is less than when using the dryer on liquid fuel. Flow is approximately equal to the power consumption when drying air is not preheated. The system is a solar air collector in which the air temperature rises to 20 °C on a bright sunny day and 1 °C on an overcast cloudy day. At the same time the humidity of hay is reduced by 5% on a cloudy day. As a collector of solar energy can be used conventional glazed solar collector or roof construction itself, which is mounted under the bottom of the solar collector and a fan blows air.

The use of solar installations not only replaces scarce fuel, but also prevents contamination of the environment with harmful emissions using fuel plants. In remote areas from energy sources solar energy (along with wind energy) is virtually the only alternative, and can significantly improve the living conditions.

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.