The method of freezing of soil during construction of underground structures
The invention relates to the mining industry and can be used in the construction of underground structures. The method of freezing of soil during construction of underground structures includes the drilling of wells by installing them in freezing columns with liquid coolant, which connect with the tank filled with solid cases with collateral circulations chilled liquid coolant and the selection of the gas component of the refrigerating medium. What's new is that the tank is filled with liquid coolant with providing direct interaction in the reservoir of liquid coolant and solid refrigerating medium and separating a gas component from the liquid coolant. The technical result of the invention consists in reducing the temperature of the coolant and the decrease in terms of soil freezing. Il.
The invention relates to the mining industry, namely the freezing of soil during construction of underground structures.
There is a method of freezing of soil during construction of underground structures, including drilling wells, installing them in freezing columns, cooling of the coolant through the chiller and atrati energy for cooling the coolant and large periods of soil freezing.
The closest in technical essence and the achieved result to the proposed technical solution is the method of freezing of soil during construction of underground structures, including drilling wells, installing them in freezing columns with liquid coolant, which connect with the tank filled with solid cases with circulating chilled liquid coolant for freezing columns and selection of the gas component of the cases .
This method is compared with the above allows you to reduce energy costs and to lower the temperature of the coolant to -45 -50...C. However, the freeze date remain significant.
The objective of the invention is to reduce the temperature of the coolant and decreasing term soil freezing.
This is achieved in that in the method of freezing of soil during construction of underground structures, including drilling wells, installing them in freezing columns with liquid coolant, which connect with the tank filled with solid cases with circulating chilled liquid coolant and the selection of the gas component of the refrigerating medium, a reservoir of subsites and solid refrigerating medium and separating a gas component from the liquid coolant.
The drawing shows a schematic diagram of soil freezing.
Freezing the system consists of a tank 1 with two inlet holes 2, 3 for supplying coolant 4 and solid refrigerating medium 5, the ejector 6, the suction nozzle which is located in the upper part of the tank 1, and freezing the network. Freezing the network includes freezing columns 7, connected to the tank 7 through pipelines 8 and pump 9 that is installed at the outlet of the tank 7.
The method of freezing of soil during construction of underground structures is as follows.
Around underground structures at a given distance from it are drilling wells and installing them in freezing columns 7 with liquid coolant, which connect with the tank 7. Then the tank is filled with liquid coolant and solid cases. A direct result of the interaction of a solid refrigerating medium from the coolant sublimating the cases and intensive cooling of the coolant. When this gas component of the refrigerating medium is separated from the liquid coolant through the ejector 6. Then the cooled coolant is supplied by a pump 9 in freezing columns, which is by freezing the network to carry out education ledogorov fencing required thickness.
This method allows to reduce the temperature of the coolant to 70With by increasing the surface area of heat exchange of the coolant with hard cases and to ensure optimum performance of the freezing system, eliminating the presence of the gas component of the refrigerating medium in the liquid coolant. Further lowering the temperature of the coolant causes a significant increase in material costs and negative impact on the environment. By reducing the temperature of the coolant to 70With the timing of soil freezing at the same hydrogeological conditions are reduced in 2-3 times in comparison with the known methods of soil freezing with forced circulation of liquid coolant.
As an example, consider the creation of ledogorov fencing during the construction of a trunk diameter of 6 m at the initial temperature of the soil 12With its volumetric moisture content of 35% and a density of 1800 kg/m3and the heat capacity of 0.3 kcal/(kghail). The distance between the freezing columns equal to 1.1 m as the coolant used trichloroethylene (C2HCl), and as a refrigerating medium solid carbon dioxide. When p - 70Required 4 t/h of solid carbon dioxide. After the extraction of heat from the ambient array of soil and increasing the temperature of the coolant at 3-5To carry out its cooling to a temperature of 70By downloading additional quantity of solid carbon dioxide 0,220 t/h Logrotate fence thickness of 1.2 m formed within 8 days. The duration of soil freezing by known methods under similar conditions when the temperature of the coolant 45C is 17.4 per day.
Thus, using the above method of freezing of soil during construction of underground structures, the duration of soil freezing is reduced by 2.1 times.
Sources of information
1. Shoplik M. N., Meskhidze J. M., Korolev Acting and other underground Construction: a reference guide. M.: Nedra, 1990, S. 132-200.
2. Shoplik M. N., Bad C. A., Nikiforov, K. P., Kiselev Century. N. Perspective technologies of soil freezing in underground construction. // The underground space of the world, No. 4, 2001, S. 28-38 (prototype).
The method of freezing of soil during construction of underground structures, including drilling squalane hard cases, with circulating chilled liquid coolant and the selection of the gas component of the refrigerating medium, characterized in that the reservoir is filled with liquid coolant with providing direct interaction in the reservoir of liquid coolant and solid refrigerating medium and separating a gas component from the liquid coolant.
FIELD: heat engineering constructions.
SUBSTANCE: invention can be used as supports of different construction on permafrost. Proposed heated pile has reinforced concrete or metal shaft with inner or outer heated pipe in form of ribbed evaporator and condensers provided with metal strip ribbing arranged over ground surface with inclination to vertical part of shaft. Novelty is that heated pile is made T-shaped, and heated pipe in form of ribbed evaporator is made symmetrically double relative to axis of shaft with connection of some ends or its evaporators, other ends being connected with condensers. Evaporator ribbing is made in form of upward convex ring surfaces with central passes secured on inner surfaces of walls of heated pipe evaporators and uniformly distributed in height, and metal strip ribbing of condensers is element of horizontal part of T-shaped heated pile.
EFFECT: improved efficiency of heated pile, facilitated replacement of pile in case of failure.
2 cl, 4 dwg
FIELD: building heat-engineering structures, particularly for forming supports of different structures in permafrost areas.
SUBSTANCE: method involves condensing gaseous working agent in condensing chamber by cooling thereof with ambient air over ground surface; moving condensed liquid under gravity through transporting channel to evaporating chamber; evaporating thereof inside evaporating chamber and returning gaseous working agent into condensing chamber. Gaseous working agent is condensed in space having volume exceeding volume of space for working liquid evaporation. T-shaped pile for ground cooling comprises vertical reinforced concrete body with horizontal support located above ground surface, condenser part of heat pipe made of tubes and having transporting channel located inside pile body and connected to finned evaporator part along heat pipe axis. The heat pipe is also located above ground surface. Condenser part is formed of symmetrically bended tube with parts inclined towards center thereof. Condenser tube diameter exceeds that of transporting channel communicating with central area of condenser part. Transporting channel part connected with evaporator part is made as inner wall thereof and forms annular cavity defined by transporting channel and outer wall of evaporator part in cross-sectional plane thereof. Volume of the transporting channel is less than condenser part volume. Transporting channel is closed with end cap located behind the cavity and has side orifices to communicate the cavity with evaporator part. The side orifices are formed in front of the end cap.
EFFECT: increased efficiency of ground cooling around the pile.
4 cl, 1 dwg
FIELD: hydraulic building, particularly to create water-tight frozen shields having height up to 100 m or more.
SUBSTANCE: device comprises freezing column arranged in borehole, outer heat exchanger which transfers heat from liquid coolant to source of cold and pump to provide coolant circulation. Freezing column is made as two coaxial tubes, namely outer, freezing, and inner, supplying, ones. Freezing tube is formed of metal. At least part of supplying tube adjoining borehole head is formed of material with low heat conductivity or supplying tube comprises material with low heat conductivity in cross-section thereof. Outer and inner tubes define annular channel for liquid coolant circulation. Upper part of borehole and part of outer tube adjoining borehole head have the greatest diameters. Gap is created between outer tube wall and borehole wall. The gap is filled with filling material taken in the form of particles having high heat conductivity in amount corresponding to predetermined particle concentration along channel length. Particle concentration in upper part adjoining borehole head is maximal.
EFFECT: increased operational efficiency due to increased capacity of liquid coolant unit to carry away heat from ground related to tall freezing column as a whole and to separate parts thereof along with uniform distribution of heat removed from freezing column parts.
8 cl, 1 tbl, 5 dwg
FIELD: refrigeration engineering, particularly to freeze ground used for ice-ground barrier creation.
SUBSTANCE: cold accumulation device comprises casing pipe filled with coolant and including ground-submersed evaporator and condenser. Device also has condensing unit arranged over condenser and connected with line by pressure and discharge pipelines. The line is located in space defined between evaporator and shell and formed as pipe having elliptical cross-section densely wound on condenser. The space between the line and the shell is filled with heat insulation means. Cold accumulation device additionally has inlet pipeline with pressure compressor inlet and outlet pipeline. Inlet pipeline extends for the full length of casing pipe from the pressure inlet to evaporator through condensation zone. Outlet pipeline passes from pressure pipeline to casing pipe condenser.
EFFECT: increased economical efficiency, reduced casing pipe defrosting time and extended operational capabilities.
FIELD: improving or preserving soil or rock by thermal, electrical or electro-chemical means, particularly by freezing.
SUBSTANCE: cold accumulation device comprises casing pipe filled with coolant. The casing pipe includes evaporator submersed in ground and condenser comprising condensing zones A and B. Compression-and-condensing unit is arranged over condenser and connected with pipeline through pressure and discharge lines. The pipeline is made as tube of elliptic cross-section wound on tube having D1 diameter. Casing pipe has variable cross-section so that lower evaporator part L having diameter D is located in down casing pipe part and is brought in direct contact with ground. Remainder evaporator part L1 has diameter D1, wherein D>D1. Space defined by D-D1 difference is filled with air.
EFFECT: improved economical efficiency and performance, increased manufacturability and extended functional capabilities.