EP0165161A1 - Method and plant for freezing soils by means of a cryogenic liquid - Google Patents

Method and plant for freezing soils by means of a cryogenic liquid Download PDF

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Publication number
EP0165161A1
EP0165161A1 EP85401054A EP85401054A EP0165161A1 EP 0165161 A1 EP0165161 A1 EP 0165161A1 EP 85401054 A EP85401054 A EP 85401054A EP 85401054 A EP85401054 A EP 85401054A EP 0165161 A1 EP0165161 A1 EP 0165161A1
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EP
European Patent Office
Prior art keywords
probe
cryogenic liquid
temperature
injection
soil
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP85401054A
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German (de)
French (fr)
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EP0165161B1 (en
Inventor
Pierre Karinthi
Maurice Gardent
Colette Regnier
Jean Tuccella
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Air Liquide SA
LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
Original Assignee
Air Liquide SA
LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
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Application filed by Air Liquide SA, LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude filed Critical Air Liquide SA
Priority to AT85401054T priority Critical patent/ATE36181T1/en
Publication of EP0165161A1 publication Critical patent/EP0165161A1/en
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Publication of EP0165161B1 publication Critical patent/EP0165161B1/en
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    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D3/00—Improving or preserving soil or rock, e.g. preserving permafrost soil
    • E02D3/11—Improving or preserving soil or rock, e.g. preserving permafrost soil by thermal, electrical or electro-chemical means
    • E02D3/115—Improving or preserving soil or rock, e.g. preserving permafrost soil by thermal, electrical or electro-chemical means by freezing
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D19/00—Keeping dry foundation sites or other areas in the ground
    • E02D19/06—Restraining of underground water
    • E02D19/12—Restraining of underground water by damming or interrupting the passage of underground water
    • E02D19/14—Restraining of underground water by damming or interrupting the passage of underground water by freezing the soil

Definitions

  • the present invention relates to the technique of freezing soils by injecting a cryogenic liquid, in particular liquid nitrogen, into at least one freezing probe embedded in the soil.
  • cryogenic liquid such as liquid nitrogen
  • This direct injection of liquid nitrogen has several drawbacks, in particular the difficulty of controlling the heat exchange coefficients with the soil. Indeed, by yielding from the cold, the nitrogen vaporizes, and the exchange coefficients between the probe and the pure liquid nitrogen first, then the liquid and gas mixtures in variable proportions, then the cooled gas alone are very different. This results in a large heterogeneity in the thickness of the frozen soil around the probe and a loss of time and energy so that the less frozen areas join to form the consolidated wall, while the most frozen areas are unnecessarily sub-cooled and oversized.
  • the soils being generally heterogeneous, certain parts freeze faster than others; this heterogeneity of the soil further increases the extent of unnecessarily frozen and sub-cooled areas.
  • the invention aims to make the process more. economical by ensuring a more homogeneous cooling of the soil.
  • the subject of the invention is a process for freezing soil by injecting a cryogenic liquid, in particular liquid nitrogen, into at least one freezing probe embedded in the soil, characterized in that the injection of the cryogenic liquid so as to maintain the temperature of the soil in the vicinity of the probe, over the entire length thereof, above a predetermined limit value, this limit value being at least 35 ° C higher approximately at the boiling temperature of the cryogenic liquid.
  • a cryogenic liquid in particular liquid nitrogen
  • said limit value is preferably between -140 ° C and approximately -160 ° C.
  • the flow rate of cryogenic liquid is adjusted, during the injection periods, so as to obtain a temperature of the gas at its outlet from the probe close to a predetermined value, this value preferably being equal to approximately -70 ° C. in the case of liquid nitrogen.
  • the homogeneity of the cooling is further improved when, the probe comprising a central passage and an annular passage, alternating periods of injection of the cryogenic liquid in the central passage and periods of injection of the cryogenic liquid in the annular passage.
  • the invention also relates to a soil freezing installation intended for the implementation of a method as defined above.
  • This installation of the type comprising at least one freezing probe and means for injecting into this probe a cryogenic liquid such as nitrogen to be liquidated is characterized in that the probe comprises at least a temperature sensor on its outer wall , in the vicinity of one of its ends.
  • the freezing installation shown in FIG. 1 essentially comprises a tank 1 for storing liquid nitrogen and a series of freezing probes 2, of which only one has been shown and which are all identical.
  • the probe 2 assumed to be driven vertically into the ground, comprises three concentric tubes 3 to 5.
  • the outer tube 3 is closed at its lower end by a bottom 6 and defines with this latter the heat exchange surface of the probe with the ground surrounding 7.
  • the intermediate 4 and inner 5 tubes extend from the upper orifice of the probe to a short distance from the bottom 6, and they are connected at this location by a horizontal annular wall 8.
  • a central passage 9 defined by the inner tube 5 and opening onto the bottom 6; an intermediate annular space 10, delimited by the tubes 4 and 5 and the wall 8, which can be filled with a thermally insulating material such as perlite; and an outer annular passage 11 delimited between the tubes 3 and 4 and opening onto the bottom 6.
  • the installation also includes means for injecting liquid nitrogen into the passages 9 and 11.
  • These injection means comprise two pipes 12 and 13 opening respectively into these two passages, connected to the lower part of the tank 1 and equipped with respective shut-off valves 14 and 15.
  • a common shut-off and flow control valve 16 is also provided at the outlet of the tank.
  • passages 9 and 11 are also provided with gas discharge means, shown diagrammatically by respective conduits 17, 18 equipped with respective stop valves 19, 20.
  • valves 14, 15, 18 and 19 are provided with a simultaneous actuation device with two positions (not shown) In one position, the valves 14 and 20 are open while the valves 15 and 19 are closed; the other position reverses the state of the four valves.
  • the valve 16 makes it possible to interrupt and restore the flow of liquid nitrogen.
  • the probe 2 On the outer face of the outer tube 3, the probe 2 carries three temperature sensors 21, constituted for example by thermocouples, which are adapted to measure the temperature of the ground in the immediate vicinity of the probe, at depths of 2 m, 10 m and 18 m respectively (temperatures T 2 , T10 and T 18 respectively). It is also planned. a temperature sensor 22 connected to each of the lines 17 and 18 and adapted to measure the temperature T G of the nitrogen gas leaving the probe.
  • the installation comprises a series of probes 2 arranged along a line which defines the frozen wall to be produced. All the probes which are connected in parallel to the tank 1 in the manner described above, each probe having its own set of valves 14, 15, 16, 18 and 19.
  • Each probe has an outside diameter of 150 mm and is composed of three concentric tubes 3 to 5 with respective diameters 150, 128 and 68 mm.
  • the central annular space between the 128 mm tube 4 and the 68 nm tube 5 is filled with perlite.
  • the diameters are chosen so that the free cross section of the central passage 9 and that of the outer annular passage 11 are equal.
  • Freezing begins with the injection of liquid nitrogen into the central tubes 5.
  • the temperatures in the vicinity of the probes are all initially of the order of 14 ° C.
  • the nitrogen vaporizes, yielding cold to the ground and rising through the outer annular passage.
  • the liquid nitrogen flow rate D per probe is the maximum flow rate of 15 1 / min (or 750 1 / min for the fifty probes), adjusted by means of the valves 16.
  • the temperature of the nitrogen gas leaving the probe drops during the first hour from -10 ° C to -70 ° C. Meanwhile, external temperatures reach -140 ° C at 18 m, -100 ° C at 10 m and -62 ° C at 2 m deep. As the transient cooling phenomena are still felt, the injection of liquid nitrogen is continued with the same flow for an additional 10 min, during which the outlet temperature of the nitrogen gas reaches -78 ° C and the outside temperature at 18 m reaches -145 ° C.
  • This alternation of injections and stops is continued by reducing the flow rate as long as the temperature of the gases drops below -70 ° C.
  • the flow rate is kept constant when this temperature stabilizes in a range of -68 ° C to -72 ° C. it is increased if this temperature rises above -68 ° C, and decreased if it drops below -72 ° C.
  • the flow rate is then fixed at 8 1 / min.
  • the gas initially comes out very cold at -120 ° C; it is a transient regime which comes from the passage of nitrogen against the current of the soil temperature.
  • the gas outlet temperature rises to -70 ° C and the external temperatures are: -100 ° C at 2 m, -100 ° C at 10 m, -65 ° C at 18 m ; 20 minutes later, the external temperature at 2 m is at -145 ° C and the gas comes out at -75 0 C.
  • the nitrogen flow is cut, and it is restored to 7 1 / nn when the temperature at 2 m rises to -138 ° C, which occurs after about 5 minutes.
  • the regulation thus defined is continued by reversing the flow rates every 5 hours.
  • the soil is consolidated by freezing on a thickness of 1 m in around 50 hours, with very satisfactory temperature uniformity.

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  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Structural Engineering (AREA)
  • Environmental & Geological Engineering (AREA)
  • Hydrology & Water Resources (AREA)
  • Mining & Mineral Resources (AREA)
  • Paleontology (AREA)
  • Civil Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Agronomy & Crop Science (AREA)
  • Soil Sciences (AREA)
  • Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
  • Excavating Of Shafts Or Tunnels (AREA)
  • Filling Or Discharging Of Gas Storage Vessels (AREA)

Abstract

The injection of liquid nitrogen into the probe (2) is regulated in an on-off manner so as to maintain the temperature of the ground at the coldest point above a value within the range of between -140 DEG C. and -160 DEG C. so as to cause calefaction of the liquid nitrogen. The liquid nitrogen is alternately injected into the central passage (9) and into the annular passage (11) of the probe, these passages being thermally insulated from each other.

Description

La présente invention est relative à la technique de congélation des sols par injection d'un liquide cryogénique, notamment d'azote liquide, dans au moins une sonde de congélation enfoncée dans le sol.The present invention relates to the technique of freezing soils by injecting a cryogenic liquid, in particular liquid nitrogen, into at least one freezing probe embedded in the soil.

On sait que la consolidation des sols par congélation permet l'ouverture de chantiers de travaux publics dans des sols humides et instables. Elle est pratiquée par injection d'un liquide réfrigérant dans des sondes introduites de place en place dans le sol. Ce refroidissement congèle le sol de proche en proche, jusqu'à former un mur continu quand les zones de congélation de chaque sonde ont rejoint leurs voisines.We know that consolidation of soils by freezing allows the opening of public works sites in damp and unstable soils. It is performed by injecting a coolant into probes introduced from place to place in the ground. This cooling freezes the soil step by step, until forming a continuous wall when the freezing zones of each probe have joined their neighbors.

Il est connu d'injecter dans les sondes un liquide cryogénique tel que l'azote liquide. Cette injection directe d'azote liquide présente plusieurs inconvénients, notamment la difficulté de maîtriser les coefficients d'échange thermique avec le sol. En effet, en cédant du froid, l'azote se vaporise, et les coefficients d'échange entre la sonde et l'azote liquide pur d'abord, puis les mélanges de liquide et de gaz en proportions variables, puis le gaz refroidi seul sont très différents. Il en résulte une forte hétérogénéité de l'épaisseur du sol congelé autour de la sonde et une perte de temps et d'énergie pour que les zones les moins congelées se rejoignent pour former le mur consolidé, tandis que les zones les plus congelées sont inutilement sous-refroidies et sur- dimensionnées. De plus, les sols étant généralement hétérogènes, certaines parties se congèlent plus vite que d'autres ; cette hétérogénéité du sol augmente encore l'étendue des zones inutilement congelées et sous-refroidies.It is known to inject cryogenic liquid such as liquid nitrogen into the probes. This direct injection of liquid nitrogen has several drawbacks, in particular the difficulty of controlling the heat exchange coefficients with the soil. Indeed, by yielding from the cold, the nitrogen vaporizes, and the exchange coefficients between the probe and the pure liquid nitrogen first, then the liquid and gas mixtures in variable proportions, then the cooled gas alone are very different. This results in a large heterogeneity in the thickness of the frozen soil around the probe and a loss of time and energy so that the less frozen areas join to form the consolidated wall, while the most frozen areas are unnecessarily sub-cooled and oversized. In addition, the soils being generally heterogeneous, certain parts freeze faster than others; this heterogeneity of the soil further increases the extent of unnecessarily frozen and sub-cooled areas.

L'invention a pour but de rendre le procédé plus. économique en assurant un refroidissement plus homogène du sol.The invention aims to make the process more. economical by ensuring a more homogeneous cooling of the soil.

A cet effet, l'invention a pour objet un procédé de congélation de sol par injection d'un liquide cryogénique, notamment d'azote liquide, dans au moins une sonde de congélation enfoncée dans le sol, caractérise en ce qu'on régule l'injection du liquide cryogénique de manière à maintenir la temgérature du sol au voisinage de la sonde, sur toute la longueur de celle-ci, au-dessus d'une valeur limite prédéterminée, cette valeur limite étant supérieure d'au moins 35°C environ à la température d'ébullition du liquide cryogénique.To this end, the subject of the invention is a process for freezing soil by injecting a cryogenic liquid, in particular liquid nitrogen, into at least one freezing probe embedded in the soil, characterized in that the injection of the cryogenic liquid so as to maintain the temperature of the soil in the vicinity of the probe, over the entire length thereof, above a predetermined limit value, this limit value being at least 35 ° C higher approximately at the boiling temperature of the cryogenic liquid.

Ainsi, on garantit que l'écart de température entre la paroi de la sonde et le liquide cryogénique est suffisant pour provoquer en permanence la caléfaction du liquide cryogénique au contact de cette paroi. Par suite, l'échange de chaleur entre le liquide et la paroi de la sonde a toujours lieu par l'intermédiaire d'une couche gazeuse de caléfaction. On évite ainsi le transfert excessif de froid à la paroi qu'occasionnerait le contact franc liquide-paroi si la température de la paroi de la sonde descendait trop près du point d'ébullition du liquide. Ces conditions, que l'on rencontre habituellement dans les procédés de l'art antérieur, permettent un transfert de froid très rapide mais que l'on ne peut assurer que sur une hauteur de sonde très limitée.This guarantees that the temperature difference between the wall of the probe and the cryogenic liquid is sufficient to permanently cause the cryogenic liquid to heat up on contact with it. wall. As a result, the exchange of heat between the liquid and the wall of the probe always takes place by means of a gaseous heating layer. This avoids the excessive transfer of cold to the wall that would cause the frank liquid-wall contact if the temperature of the wall of the probe dropped too close to the boiling point of the liquid. These conditions, which are usually encountered in the processes of the prior art, allow a very rapid cold transfer but which can only be ensured over a very limited probe height.

En particulier, lorsque le liquide cryogénique est de l'azote liquide, ladite valeur limite est de préférence comprise entre -140°C et -160°C environ.In particular, when the cryogenic liquid is liquid nitrogen, said limit value is preferably between -140 ° C and approximately -160 ° C.

Dans un mode de mise en oeuvre avantageux qui assure une bonne utilisation des frigories disponibles, on règle le débit de liquide cryogénique, pendant les périodes d'injection, de manière à obtenir une température du gaz à sa sortie de la sonde voisine d'une valeur prédéterminée, cette valeur étant de préférence égale à -70°C environ dans le cas de l'azote liquide.In an advantageous embodiment which ensures good use of the available frigories, the flow rate of cryogenic liquid is adjusted, during the injection periods, so as to obtain a temperature of the gas at its outlet from the probe close to a predetermined value, this value preferably being equal to approximately -70 ° C. in the case of liquid nitrogen.

L'homogénéité du refroidissement est encore améliorée lorsque, la sonde comportant un passage central et un passage annulaire, on alterne des périodes d'injection du liquide cryogénique dans le passage central et des périodes d'injection du liquide cryogénique dans le passage annulaire.The homogeneity of the cooling is further improved when, the probe comprising a central passage and an annular passage, alternating periods of injection of the cryogenic liquid in the central passage and periods of injection of the cryogenic liquid in the annular passage.

L'invention a également pour objet une installation de congélation de sol destinée à la mise en oeuvre d'un procédé tel que définit ci-dessus. Cette installation, du type comprenant au moins une sonde de congélation et des moyens d'injection dans cette sonde d'un liquide cryogénique tel que l'azote liquider est caractérisée en ce que la sonde comporte au mins un capteur de température sur sa paroi extérieure, au voisinage d'une de ses extrémités.The invention also relates to a soil freezing installation intended for the implementation of a method as defined above. This installation, of the type comprising at least one freezing probe and means for injecting into this probe a cryogenic liquid such as nitrogen to be liquidated is characterized in that the probe comprises at least a temperature sensor on its outer wall , in the vicinity of one of its ends.

Un exemple de réalisation de l'invention va maintenant être décrit en regard des dessins annexés, sur lesquels :

  • - la figure 1 est un schéma d'une partie d'une installation de congélation conforme à l'invention ; et
  • - la figure 2 est un diagramme qui illustre le fonctionnement de cette installation.
An exemplary embodiment of the invention will now be described with reference to the accompanying drawings, in which:
  • - Figure 1 is a diagram of part of a freezing installation according to the invention; and
  • - Figure 2 is a diagram which illustrates the operation of this installation.

L'installation de congélation représentée à la figure 1 comprend essentiellement un réservoir 1 de stockage d'azote liquide et une série de sondes de congélation 2, dont une seule a été représentée et qui sont toutes identiques.The freezing installation shown in FIG. 1 essentially comprises a tank 1 for storing liquid nitrogen and a series of freezing probes 2, of which only one has been shown and which are all identical.

La sonde 2, supposée enfoncée verticalement dans le sol, comprend trois tubes concentriques 3 à 5. Le tube extérieur 3 est fermé à son extrémité inférieure par un fond 6 et définit avec ce dernier la surface d'échange thermique de la sonde avec le sol environnant 7. Les tubes intermédiaire 4 et intérieur 5 s'étendent de l'orifice supérieur de la sonde jusgu'à une faible distance du fond 6, et ils sont reliés à cet emplacement par une paroi annulaire horizontale 8.The probe 2, assumed to be driven vertically into the ground, comprises three concentric tubes 3 to 5. The outer tube 3 is closed at its lower end by a bottom 6 and defines with this latter the heat exchange surface of the probe with the ground surrounding 7. The intermediate 4 and inner 5 tubes extend from the upper orifice of the probe to a short distance from the bottom 6, and they are connected at this location by a horizontal annular wall 8.

Ainsi sont délimités dans la sonde 2 : un passage central 9 défini par le tube intérieur 5 et débouchant sur le fond 6 ; un espace annulaire intermédiaire 10, délimité par les tubes 4 et 5 et la paroi 8, qui peut être empli d'une matière thermiquement isolante telle que de la perlite; et un passage annulaire extérieur 11 délimité entre les tubes 3 et 4 et débouchant sur le fond 6.Thus are delimited in the probe 2: a central passage 9 defined by the inner tube 5 and opening onto the bottom 6; an intermediate annular space 10, delimited by the tubes 4 and 5 and the wall 8, which can be filled with a thermally insulating material such as perlite; and an outer annular passage 11 delimited between the tubes 3 and 4 and opening onto the bottom 6.

L'installation comporte également des moyens pour injecter de l'azote liquide dans les passages 9 et 11. Ces moyens d'injection comprennent deux conduites 12 et 13 débouchant respectivement dans ces deux passages, reliées à la partie inférieure du réservoir 1 et équipées de vannes d'arrêt respectives 14 et 15. Une vanne commune 16 d'arrêt et de réglage de débit est également prévue à la sortie du réservoir.The installation also includes means for injecting liquid nitrogen into the passages 9 and 11. These injection means comprise two pipes 12 and 13 opening respectively into these two passages, connected to the lower part of the tank 1 and equipped with respective shut-off valves 14 and 15. A common shut-off and flow control valve 16 is also provided at the outlet of the tank.

L'extrémité supérieure des passages 9 et 11 est munie par ailleurs de moyens d'évacuation de gaz, schématisés par des conduites respectives 17, 18 équipées de vannes d'arrêt respectives 19, 20.The upper end of passages 9 and 11 is also provided with gas discharge means, shown diagrammatically by respective conduits 17, 18 equipped with respective stop valves 19, 20.

Les vannes 14, 15, 18 et 19 sont munies d'un dispositif d'actionnement simultané à deux positions (non représenté) Dans une position, les vannes 14 et 20 sont ouvertes tandis que les vannes 15 et 19 sont fermées ; l'autre position inverse l'état des quatre vannes. La vanne 16 permet d'interrompre et de rétablir le débit d'azote liquide.The valves 14, 15, 18 and 19 are provided with a simultaneous actuation device with two positions (not shown) In one position, the valves 14 and 20 are open while the valves 15 and 19 are closed; the other position reverses the state of the four valves. The valve 16 makes it possible to interrupt and restore the flow of liquid nitrogen.

Sur la face extérieure du tube extérieur 3, la sonde 2 porte trois capteurs de température 21, constitués par exemple par des thermocouples, qui sont adaptés pour mesurer la température du sol au voisinage immédiat de la sonde, à des profondeurs de 2 m, 10 m et 18 m respectivement (températures T2, T10 et T18 respectivement). Il est de plus prévu. un capteur de température 22 relié à chacune des conduites 17 et 18 et adapté pour mesurer la température TG de l'azote gazeux sortant de la sonde.On the outer face of the outer tube 3, the probe 2 carries three temperature sensors 21, constituted for example by thermocouples, which are adapted to measure the temperature of the ground in the immediate vicinity of the probe, at depths of 2 m, 10 m and 18 m respectively (temperatures T 2 , T10 and T 18 respectively). It is also planned. a temperature sensor 22 connected to each of the lines 17 and 18 and adapted to measure the temperature T G of the nitrogen gas leaving the probe.

En fait, l'installation comporte une série de sondes 2 disposée suivant une ligne qui définit le mur congelé à réaliser. Toutes les sondes qui sont branchées en parallèle sur le réservoir 1 de la manière décrite ci-dessus, chaque sonde comportant son propre jeu de vannes 14, 15, 16, 18 et 19.In fact, the installation comprises a series of probes 2 arranged along a line which defines the frozen wall to be produced. All the probes which are connected in parallel to the tank 1 in the manner described above, each probe having its own set of valves 14, 15, 16, 18 and 19.

Le fonctionnement de cette installation, illustré à la figure 2, est basé sur une double régulation de l'injection d'azote liquide dans les sondes, chaque sonde étant régulée indépendamment des autres pour tenir compte de l'hétérogénéité du terrain :

  • - d'une part, l'admission d'azote liquide est régulée en tout ou rien, au moyen de la vanne 16, de manière que la température du sol au point le plus froid reste en permanence comprise entre deux valeurs limites prédéterminées, à partir des indications fournies par les capteurs de température 21 de la sonde considérée. Comme expliqué plus haut, la limite inférieure est au moins égale à -160°C afin d'assurer la présence permanente d'une couche gazeuse de caléfaction entre l'azote liquide et le tube 3, de sorte que la totalité de l'échange thermique entre l'azote et la sonde est un échange gaz-métal.
  • - d'autre part, pendant les périodes d'injection de l'azote liquide, une fois terminée la phase transitoire de mise en froid, le débit de liquide est réglé, au moyen de la vanne 16, de manière que le gaz résultant de la vaporisation de l'azote liquide ait à sa sortie de la sonde une température voisine d'une température de consigne prédéterminée choisie de manière à optimiser l'utilisation de frigories. Une température de consigne de l'ordre de -70 °C s'est révélée satisfaisante.
The operation of this installation, illustrated in FIG. 2 , is based on a double regulation of the injection of liquid nitrogen into the probes, each probe being regulated independently of the others to take account of the heterogeneity of the terrain:
  • on the one hand, the admission of liquid nitrogen is regulated in all or nothing, by means of the valve 16, so that the temperature of the soil at the coldest point remains permanently between two predetermined limit values, at from the indications provided by the temperature sensors 21 of the probe in question. As explained above, the lower limit is at least equal to −160 ° C. in order to ensure the permanent presence of a gaseous caulking layer between the liquid nitrogen and the tube 3, so that the entire exchange thermal between nitrogen and the probe is a gas-metal exchange.
  • - on the other hand, during the periods of injection of liquid nitrogen, once the transient cooling phase has ended, the liquid flow rate is adjusted, by means of the valve 16, so that the gas resulting from the vaporization of liquid nitrogen has at its exit from the probe a temperature close to a predetermined set temperature chosen so as to optimize the use of frigories. A set temperature of the order of -70 ° C has been found satisfactory.

Cette manière de procéder améliore nettement l'homogénéité du refroidissement du sol par rapport au cas où, suivant la technique antérieure, on se contente de régler le débit d'azote liquide en fonction de la température du gaz sortant de la sonde. Toutefois, on ne peut éviter par les seules régulations ci-dessus d'obtenir un fort gradient de température entre le bas et le haut des sondes. Pour supprimer en grande partie cette hétérogénéité, on inverse périodiquement les vannes 14, 15, 19 et 20 de toutes les sondes.This way of proceeding clearly improves the homogeneity of the cooling of the soil compared to the case where, according to the prior art, we are content to regulate the flow of liquid nitrogen as a function of the temperature of the gas leaving the probe. However, it cannot be avoided by the above regulations alone to obtain a strong temperature gradient between the bottom and the top of the probes. To largely eliminate this heterogeneity, the valves 14, 15, 19 and 20 of all the probes are periodically reversed.

Ainsi, en supposant que l'on a commencé par injecter pendant quelques heures l'azote liquide par le passage central 9. en évacuant l'azote gazeux par le passage périphérique 11, l'inversion a pour résultat que l'azote liquide est injecté dans le passage 11 tandis que l'azote gazeux est évacué par le passage central 9.Thus, assuming that we started by injecting liquid nitrogen for a few hours through the central passage 9. while evacuating the gaseous nitrogen through the peripheral passage 11, the inversion has for result that the liquid nitrogen is injected into the passage 11 while the gaseous nitrogen is evacuated through the central passage 9.

On atteint de cette façon au bout de quelques heures un nouvel équilibre inversé dans lequel le point le plus froid, régulé entre les deux températures limites précitées, est situé en haut de la sonde et le point le moins froid en bas. On comprend qu'en inversant périodiquement les courants d'azote, on obtient une bonne homogénéité thermique dans le sol.In this way, a new inverted equilibrium is reached after a few hours in which the coldest point, regulated between the two aforementioned limit temperatures, is located at the top of the probe and the least cold point at the bottom. It is understood that by periodically reversing the nitrogen streams, good thermal uniformity is obtained in the soil.

L'exemple numérique suivant illustrera le procédé décrit ci-dessus :

  • On désire consolider le plus rapidement possible par congélation un mur de 1 m d'épaisseur dans un sol sableux humide sur une profondeur de 20 m et une largeur de 50 m. Pour cela, on enfonce dans le sol cinquante sondes 2 espacées de 1 m les unes des autres.
The following numerical example will illustrate the process described above:
  • We want to consolidate as quickly as possible by freezing a wall 1 m thick in moist sandy soil to a depth of 20 m and a width of 50 m. To do this, fifty probes 2 are inserted into the ground 2 spaced 1 m apart.

Chaque sonde a un diamètre extérieur de 150 mm et est composée de trois tubes concentriques 3 à 5 de diamètres respectifs 150, 128 et 68 mm. L'espace annulaire central entre le tube 4 de 128 mm et le tube 5 de 68 nm est rempli de perlite. Les diamètres sont choisis de façon que la section libre du passage central 9 et celle du passage annulaire extérieur 11 soient égales.Each probe has an outside diameter of 150 mm and is composed of three concentric tubes 3 to 5 with respective diameters 150, 128 and 68 mm. The central annular space between the 128 mm tube 4 and the 68 nm tube 5 is filled with perlite. The diameters are chosen so that the free cross section of the central passage 9 and that of the outer annular passage 11 are equal.

La congélation commence par l'injection d'azote liquide dans les tubes centraux 5. Les températures au voisinage des sondes sont toutes initialement de l'ordre de 14°C. Dans chaque sonde, l'azote se vaporise en cédant du froid au sol et en remontant par le passage annulaire extérieur. Le débit d'azote liquide D par sonde est le débit maximal de 15 1/mn (soit 750 1/mn pour. les cinquantes sondes) , réglé au moyen des -vannes 16.Freezing begins with the injection of liquid nitrogen into the central tubes 5. The temperatures in the vicinity of the probes are all initially of the order of 14 ° C. In each probe, the nitrogen vaporizes, yielding cold to the ground and rising through the outer annular passage. The liquid nitrogen flow rate D per probe is the maximum flow rate of 15 1 / min (or 750 1 / min for the fifty probes), adjusted by means of the valves 16.

Dans la suite, on décrira à titre d'exemple numérique, en regard de la figure 2, le comportement d'une seule sonde, étant entendu que chacune des sondes est régulée indépendamment des autres. Les valeurs limites de la température la plus froide du sol sont choisies à -145°C et -138°C, et la valeur de consigne de sortie de l'azote gazeux à -70°C.In the following, a numerical example will be described, with reference to FIG. 2, the behavior of a single probe, it being understood that each of the probes is regulated independently of the others. The limit values for the coldest soil temperature are chosen at -145 ° C and -138 ° C, and the nitrogen gas output setpoint at -70 ° C.

La température de l'azote gazeux en sortie de sonde s'abaisse durant la première heure de -10°C à -70°C. Pendant ce temps, les températures externes atteignent -140°C à 18 m, -100°C à 10 m et -62°C à 2 m de profondeur. Comme les phénomènes transitoires de mise en froid se font encore sentir, on poursuit l'injection d'azote liquide avec le même débit pendant 10 mn supplémentaires, durant lesquelles la tenpérature de sortie de l'azote gazeux atteint -78°C et la température extérieure à 18 m atteint -145°C.The temperature of the nitrogen gas leaving the probe drops during the first hour from -10 ° C to -70 ° C. Meanwhile, external temperatures reach -140 ° C at 18 m, -100 ° C at 10 m and -62 ° C at 2 m deep. As the transient cooling phenomena are still felt, the injection of liquid nitrogen is continued with the same flow for an additional 10 min, during which the outlet temperature of the nitrogen gas reaches -78 ° C and the outside temperature at 18 m reaches -145 ° C.

On coupe alors l'injection d'azote liquide. En 10 mn, la température extérieure à 18 m remonte à -138°C. On rétablit un débit de 10 1/mn d'azote liquide. Ce débit est plus faible que précédemment puisque la température froide de -145°C n'avait été atteinte que pour une température trop basse de l'azote gazeux sortant de la sonde.The injection of liquid nitrogen is then cut off. In 10 minutes, the outside temperature at 18 m rises to -138 ° C. A flow rate of 1 0 1 / min of liquid nitrogen is restored. This flow rate is lower than previously since the cold temperature of -145 ° C had been reached only for a too low temperature of the nitrogen gas leaving the probe.

En 20 mn, la température extérieure à 18 m s'abaisse de nouveau à -145°C et la température de sortie des gaz à -75°C. On coupe de nouveau le débit d'azote, puis on le rétablit à 8 1/nn - (pour la même raison que ci-dessus) quand la température à 18 m remonte à -138°C.In 20 minutes, the outside temperature at 18 m drops again to -145 ° C and the gas outlet temperature at -75 ° C. The nitrogen flow is again cut off, then restored to 8 1 / nn - (for the same reason as above) when the temperature at 18 m rises to -138 ° C.

On poursuit cette alternance d'injections et d'arrêts en réduisant le débit tant que la température des gaz descend au-dessous de -70°C. Le débit est gardé constant quand cette température se stabilise dans une fourchette de -68°C à -72°C. il est augmenté si cette température remonte au-dessus de -68°C, et diminué si elle redescend au-dessous de -72°C.This alternation of injections and stops is continued by reducing the flow rate as long as the temperature of the gases drops below -70 ° C. The flow rate is kept constant when this temperature stabilizes in a range of -68 ° C to -72 ° C. it is increased if this temperature rises above -68 ° C, and decreased if it drops below -72 ° C.

Au bout de 5 heures de congélation, on inverse les débits de toutes les sondes en injectant l'azote liquide par le passage annulaire extérieur 11, le gaz ressortant par le passage central 9.After 5 hours of freezing, the flow rates of all the probes are reversed by injecting liquid nitrogen through the external annular passage 11, the gas emerging through the central passage 9.

Le débit est alors fixé à 8 1/mn. Le gaz ressort initialement très froid à -120°C ; c'est un régime transitoire qui provient du passage de l'azote à contre-courant de la température du sol. Au bout de 10 mn, la température de sortie du gaz remonte à -70°C et les températures externes s'établissent à : -100°C à 2 m, -100°C à 10 m, -65°C à 18 m ; 20 mn plus tard, la température externe à 2 m se trouve à -145°C et le gaz sort à -750C.The flow rate is then fixed at 8 1 / min. The gas initially comes out very cold at -120 ° C; it is a transient regime which comes from the passage of nitrogen against the current of the soil temperature. After 10 min, the gas outlet temperature rises to -70 ° C and the external temperatures are: -100 ° C at 2 m, -100 ° C at 10 m, -65 ° C at 18 m ; 20 minutes later, the external temperature at 2 m is at -145 ° C and the gas comes out at -75 0 C.

On coupe le débit d'azote, et on le rétablit à 7 1/nn quand la température à 2 m remonte à -138°C, ce qui se produit au bout de 5 mn environ.The nitrogen flow is cut, and it is restored to 7 1 / nn when the temperature at 2 m rises to -138 ° C, which occurs after about 5 minutes.

On poursuit cette succession d'injections et d'arrêts pendant 5 heures, en modifiant éventuellement le débit d'azote liquide de la manière indiquée plus haut. On inverse de nouveau les débits à l'issue de cette période.This succession of injections and stops is continued for 5 hours, possibly modifying the flow of liquid nitrogen as indicated above. The flows are again reversed at the end of this period.

On poursuit la régulation ainsi définie en inversant les débits toutes les 5 heures. Le sol est consolidé par congélation sur une épaisseur de 1 m en 50 heures environ, avec une homogénéité de température très satisfaisante.The regulation thus defined is continued by reversing the flow rates every 5 hours. The soil is consolidated by freezing on a thickness of 1 m in around 50 hours, with very satisfactory temperature uniformity.

Claims (11)

1. Procédé de congélation de sol par injection d'un liquide cryogénique, notamment d'azote liquide, dans au moins une sonde de congélation (2) enfoncée dans le sol, caractérisé en ce qu'on régule l'injection du liquide cryogénique de manière à maintenir la température du sol au voisinage de la sonde, sur toute la longueur de celle-ci, au-dessus d'une valeur limite prédéterminée, cette valeur limite étant supérieure d'au moins 35°C environ à la température d'ébullition du liquide cryogénique.1. A method of freezing soil by injecting a cryogenic liquid, in particular liquid nitrogen, into at least one freezing probe (2) embedded in the soil, characterized in that the injection of the cryogenic liquid is regulated so as to maintain the temperature of the soil in the vicinity of the probe, over the entire length of the latter, above a predetermined limit value, this limit value being at least 35 ° C higher than the temperature of boiling of the cryogenic liquid. 2. Procédé suivant la revendication 1, dans leguel le liquide cryogénique est de l'azote liquide, caractérisé en ce que ladite valeur limite est comprise entre -140°C et -160°C environ.2. Method according to claim 1, in leguel the cryogenic liquid is liquid nitrogen, characterized in that said limit value is between -140 ° C and -160 ° C approximately. 3. Procédé suivant l'une des revendications 1 et 2, caractérisé en ce qu'on interrompt l'injection de liquide cryogénique lorsque ladite valeur limite est atteinte, et on la rétablit lorsque la température du sol au point le plus froid est remontée jusqu'à une seconde valeur limite.3. Method according to one of claims 1 and 2, characterized in that the injection of cryogenic liquid is interrupted when said limit value is reached, and it is restored when the temperature of the soil at the coldest point is raised to 'to a second limit value. 4. Procédé suivant l'une quelconque des revendications 1 à 3, caractérisé en ce qu'on règle le débit de liquide cryogénique, pendant les périodes d'injection, de manière à obtenir une température du gaz (TG) à sa sortie de la sonde voisine d'une valeur prédéterminée.4. Method according to any one of claims 1 to 3, characterized in that the flow rate of cryogenic liquid is adjusted, during the injection periods, so as to obtain a temperature of the gas (T G ) at its outlet from the probe close to a predetermined value. 5. Procédé suivant la revendication 4, dans leauel le liquide cryogénique est de l'azote liquide, caractérisé en ce que ladite valeur prédéterminée est égale à -70°C environ.5. Method according to claim 4, in leauel the cryogenic liquid is liquid nitrogen, characterized in that said predetermined value is equal to about -70 ° C. 6. Procédé suivant l'une quelconque des revendications 1 à 5, dans lequel on utilise une sonde (2) comportant un passage central et un passage annulaire, caractérisé en ce qu'on alterne des périodes d'injection du liquide cryogénique dans le passage central (9) et des périodes d'injection du liquide cryogénique dans le passage annulaire (11).6. Method according to any one of claims 1 to 5, in which a probe (2) is used comprising a central passage and an annular passage, characterized in that alternating periods of injection of the cryogenic liquid into the passage central (9) and periods of injection of the cryogenic liquid into the annular passage (11). 7. Installation de congélation de sol, du type comprenant au moins une sonde de congélation (2) et des moyens (12 à 15) d'injection dans cette sonde d'un liquide cryogénique tel que l'azote liquide, caractérisée en ce que la sonde (2) comporte au mins un capteur de température (21) sur sa paroi extérieure (3), au voisinage d'une de ses extrémités.7. Soil freezing installation, of the type comprising at least one freezing probe (2) and means (12 to 15) for injecting into this probe a cryogenic liquid such as liquid nitrogen, characterized in that the probe (2) comprises at least a temperature sensor (21) on its outer wall (3), in the vicinity of one of its ends. 8. Installation suivant la revendication 7, caractérisée en ce que la sonde (2) comprend également un capteur (22) de la température (TG) du gaz sortant de la sonde.8. Installation according to claim 7, characterized in that the probe (2) also comprises a sensor (22) of the temperature (T G ) of the gas leaving the probe. 9. Installation suivant l'une des revendications 7 et 8, dans laquelle la sonde comporte un passage central et un passage annulaire, caractérisée en ce que lesdits moyens d'injection (12 à 15) sont adaptés pour injecter le liquide cryogénique soit dans le passage central (9), soit dans le passage annulaire (11) de la sonde.9. Installation according to one of claims 7 and 8, in which the probe has a central passage and an annular passage, characterized in that said injection means (12 to 15) are adapted to inject the cryogenic liquid either into the central passage (9), or in the annular passage (11) of the probe. 10. Installation suivant la revendication 9, caractérisée en ce que la sonde (2) porte sur sa paroi extérieure (3) au moins un capteur de température (21) à chaque extrémité.10. Installation according to claim 9, characterized in that the probe (2) carries on its outer wall (3) at least one temperature sensor (21) at each end. 11. Installation suivant l'une des revendications 9 et 10, caractérisée en ce que la sonde (2) comprend des moyens d'isolation thermique (10) interposés entre le passage central (9) et le passage annulaire (11).11. Installation according to one of claims 9 and 10, characterized in that the probe (2) comprises thermal insulation means (10) interposed between the central passage (9) and the annular passage (11).
EP85401054A 1984-06-01 1985-05-29 Method and plant for freezing soils by means of a cryogenic liquid Expired EP0165161B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT85401054T ATE36181T1 (en) 1984-06-01 1985-05-29 METHOD AND APPARATUS FOR FREEZING SOIL BY MEANS OF CRYOUS LIQUID.

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FR8408647 1984-06-01
FR8408647A FR2565274B1 (en) 1984-06-01 1984-06-01 METHOD AND INSTALLATION FOR FREEZING SOILS USING A CRYOGENIC LIQUID

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EP0165161B1 EP0165161B1 (en) 1988-08-03

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EP (1) EP0165161B1 (en)
JP (1) JPS6117625A (en)
AT (1) ATE36181T1 (en)
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DE (1) DE3564142D1 (en)
ES (1) ES8608086A1 (en)
FR (1) FR2565274B1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT396881B (en) * 1990-08-17 1993-12-27 Proterra Umwelttechnik Method for the treatment of material, such as waste material, tip material, contaminated soil or the like

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2578060B1 (en) * 1985-02-28 1987-03-20 Inst Francais Du Petrole METHOD FOR IMPROVING THE SOIL COUPLING OF EARTHQUAKE SEISMIC SOURCES
US4998848A (en) * 1989-03-27 1991-03-12 R. G. Hansen & Associates Method and apparatus for removing ground contaminants
US5066166A (en) * 1989-03-27 1991-11-19 R. G. Hansen & Associates Apparatus for removing ground contaminants
US5050386A (en) * 1989-08-16 1991-09-24 Rkk, Limited Method and apparatus for containment of hazardous material migration in the earth
US5667339A (en) * 1993-02-18 1997-09-16 University Of Washington Cryogenic method and system for remediating contaminataed earth
CN103669376B (en) * 2013-11-19 2015-07-08 河南化工职业学院 Design method of unsteady state temperature field artificially frozen soil curtain
JP6756512B2 (en) * 2016-03-31 2020-09-16 清水建設株式会社 Freezing expansion pressure calculation method of freezing method

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB642058A (en) * 1947-06-23 1950-08-23 Jean Pierre Daxelhofer Method of and apparatus for freezing ground
US3220470A (en) * 1962-10-08 1965-11-30 Joseph C Balch Soil refrigerating system
FR2041356A5 (en) * 1969-04-22 1971-01-29 Air Liquide Refrigeration probes for sols
FR2113980A1 (en) * 1970-11-16 1972-06-30 Union Carbide Canada Ltd
DE3112291A1 (en) * 1981-03-27 1982-10-07 Linde Ag, 6200 Wiesbaden Soil-freezing arrangement

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB959945A (en) * 1963-04-18 1964-06-03 Conch Int Methane Ltd Constructing a frozen wall within the ground
US4403459A (en) * 1981-01-27 1983-09-13 Atlantic Richfield Co. Benchmark for use in arctic regions

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB642058A (en) * 1947-06-23 1950-08-23 Jean Pierre Daxelhofer Method of and apparatus for freezing ground
US3220470A (en) * 1962-10-08 1965-11-30 Joseph C Balch Soil refrigerating system
FR2041356A5 (en) * 1969-04-22 1971-01-29 Air Liquide Refrigeration probes for sols
FR2113980A1 (en) * 1970-11-16 1972-06-30 Union Carbide Canada Ltd
DE3112291A1 (en) * 1981-03-27 1982-10-07 Linde Ag, 6200 Wiesbaden Soil-freezing arrangement

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT396881B (en) * 1990-08-17 1993-12-27 Proterra Umwelttechnik Method for the treatment of material, such as waste material, tip material, contaminated soil or the like

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CA1269852A (en) 1990-06-05
DE3564142D1 (en) 1988-09-08
FR2565274B1 (en) 1986-10-17
ES543739A0 (en) 1986-06-01
US4676694A (en) 1987-06-30
EP0165161B1 (en) 1988-08-03
FR2565274A1 (en) 1985-12-06
JPS6117625A (en) 1986-01-25
ATE36181T1 (en) 1988-08-15
ES8608086A1 (en) 1986-06-01

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