Scientists propose to heat greenhouses with the Earth's heat

Scientists from the Institute of Engineering and Technology of South Ural State University have proposed using the heat of the earth to increase the quality of energy supply to greenhouses. It will reduce the cost of heating these facilities. The Government supported the study. The research was published in the IOP Conference Series: Materials Science and Engineering.

Konstantin Osintsev, Ph.D., Associate Professor, Head of the Department of Thermal Power Engineering at the Faculty of Energy and Power Engineering of SUSU, proposed a new economically viable technology for heating greenhouses in cold seasons.

Agricultural enterprises use greenhouses for producing crop products in a subcontinental climate. Greenhouses are industrial facilities for growing vegetables and flowers. They are protected from external influences by a transparent roof and walls. The main elements of such structures are the soil on which the plants are grown and engineering networks for heating the premises. In greenhouses, the energy consumption falls on supplementary lighting of plants and heating of greenhouses in winter.

It is necessary to correctly determine the optimal composition of heating units and engineering networks—not an easy task. The main difficulty lies in the fact that agricultural enterprises are diversified farms, where many crops are grown with different needs for light and heat thus, the conditions for making production decisions are diverse.

"Almost all types of heating units and devices can be most effectively used only in a certain range of natural production conditions. Therefore, from a wide variety of units, only the minimum required quantity is selected, which will ensure the best economic effect. It is advisable to start the choice with energy resources, which account for the largest share of operating costs. These options include the use of an organic Rankine cycle. In this case, fuel costs sharply reduced in the face of the constant growth of electricity prices," Konstantin Osintsev says.

The organic Rankine cycle is a thermodynamic cycle of converting heat into work using water vapor. It is needed to generate heat in the form of hot water as well as electricity. Hot water can heat the air in the heaters and maintain the required air temperature in the greenhouses themselves. Electricity production is possible with a microturbine.

The scientist assumes that heating greenhouses using the proposed technology will significantly reduce the heating costs of greenhouses in winter and autumn. This idea is useful for our country with its harsh climate.

More information:
K V Osintsev. Using the organic Rankine cycle for heat supply of greenhouses at agricultural enterprises, IOP Conference Series: Materials Science and Engineering (2020). DOI: 10.1088/1757-899X/941/1/012056

Provided by South Ural State University