Freezer-free liquid nitrogen artificial ground freezing method

Abstract

The invention provides a freezer-free liquid nitrogen artificial ground freezing method and belongs to the technical field of artificial ground freezing. According to the method, construction drilling, namely primary drilling is carried out at first, and then freezing of a drilled hole and the ground surrounding the drilled hole is carried out by inserting a liquid nitrogen injection pipe into the drilled hole; after muddy water in the drilled hole formed through primary drilling and the surrounding ground are frozen, secondary drilling construction is carried out, a stable channel is formed, and liquid nitrogen is injected continuously to achieve ground freezing; and after the range, temperature and strength of frozen soil meet design requirements, liquid nitrogen injection is stopped, and freezing is completed. According to the method, the characteristics of low temperature and quick freezing of the liquid nitrogen are fully used, the ground is frozen in a forced mode, conditions are provided for secondary drilling dry operation, a natural liquid nitrogen heat exchange space is formed in the ground after secondary drilling, the liquid nitrogen makes direct contact with the soil, and higher heat exchange efficiency and higher freezing speed can be obtained. The links of machining, producing and installing traditional freezers are omitted, material is saved, cost is reduced, and the construction progress is improved.

Description

technical field [0001] The invention relates to the technical field of artificial formation freezing, in particular to a liquid nitrogen artificial formation freezing method without a freezer. Background technique [0002] The artificial ground freezing method uses artificial refrigeration technology to replace the heat in the ground, thereby reducing the temperature of the ground until the water in the ground freezes, making the ground a frozen state. The frozen soil has a certain strength and can resist external water and soil. Pressure, to achieve the purpose of water isolation and formation reinforcement. According to different refrigeration media, the artificial formation freezing method can be divided into traditional low-temperature brine freezing and new liquid nitrogen freezing, dry ice freezing and other methods. Under standard atmospheric pressure, the vaporization temperature of liquid nitrogen is -196°C. When liquid nitrogen vaporizes, it absorbs a large amoun...

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Problems solved by technology

[0004] Liquid nitrogen artificial stratum freezing is often used for sealing water freezing and soil reinforcement in engineering rescue. The method of using traditional liquid nitrogen freezer for stratum freezing has the disadvantages of many procedures, many processed parts, time-consuming and labor-intensive, and it is easy to delay the emergency rescue opportunity.

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