Determining the efficiency of functioning of systems of temperature stabilization of soils with horizontal evaporator filled with different refrigerants

Abstract

The construction of buildings and structures in the zones of distribution of frozen soils follows the principle I. The bearing capacity of frozen soils significantly depends on their value of negative temperature. When thawed, such soils shrink, which negatively affects the objects built on them. To prevent this, temperature stabilization systems for frozen soils are used. Simultaneous accounting of the thermal effect on the frozen soil of an engineering object, as well as the temperature stabilization system of soils, is a difficult task, the accuracy of determining the strength characteristics of the soil will depend on the correctness of its solution. This paper presents calculations of the temperature fields of frozen soils with simultaneous exposure to an object with intense heat (RVS with hot oil) and soil temperature stabilization system of the horizontal natural-acting tubular system (GET) type. The calculations follow the previously developed mathematical model of the temperature stabilization system with a horizontal evaporator. The authors consider the efficiency of the operation of the GET system charged with different refrigerants (ammonia and carbon dioxide) for different geocryological subzones of Western Siberia. Particular attention should be paid to the fact that the soil was initially at a close to positive temperature (−0,1 °C), but after calculating for 10 years, the entire soil mass around the evaporation part of the temperature stabilization system froze because of the soil temperature stabilization system. Systems charged with carbon dioxide showed better work efficiency. This is due to two factors: a lower value of the lower critical heat load, which gives more working days per year relative to the system charged with ammonia; and the evaporative part of the system on carbon dioxide, which has the average temperature 1 °C lower than ammonia systems. The results show that carbon dioxide as the heat carrier for the GET system is the most effective.