CN112554164B - Artificial stratum freezing method - Google Patents
Artificial stratum freezing method Download PDFInfo
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- CN112554164B CN112554164B CN202011235156.XA CN202011235156A CN112554164B CN 112554164 B CN112554164 B CN 112554164B CN 202011235156 A CN202011235156 A CN 202011235156A CN 112554164 B CN112554164 B CN 112554164B
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- refrigerant
- storage device
- liquid
- liquid supply
- freezer
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- 238000007710 freezing Methods 0.000 title claims abstract description 20
- 230000008014 freezing Effects 0.000 title claims abstract description 20
- 238000000034 method Methods 0.000 title claims abstract description 19
- 239000003507 refrigerant Substances 0.000 claims abstract description 80
- 239000007788 liquid Substances 0.000 claims abstract description 71
- 238000005057 refrigeration Methods 0.000 claims abstract description 33
- 239000002689 soil Substances 0.000 claims abstract description 21
- 238000011084 recovery Methods 0.000 claims abstract description 12
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 16
- 239000007789 gas Substances 0.000 claims description 14
- 238000000746 purification Methods 0.000 claims description 13
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 10
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 8
- 229910052757 nitrogen Inorganic materials 0.000 claims description 8
- 239000001301 oxygen Substances 0.000 claims description 8
- 229910052760 oxygen Inorganic materials 0.000 claims description 8
- 230000015572 biosynthetic process Effects 0.000 claims description 7
- 230000006835 compression Effects 0.000 claims description 7
- 238000007906 compression Methods 0.000 claims description 7
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 5
- 239000001569 carbon dioxide Substances 0.000 claims description 5
- 239000000498 cooling water Substances 0.000 claims description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- 229910000831 Steel Inorganic materials 0.000 claims description 3
- 229910052799 carbon Inorganic materials 0.000 claims description 3
- 238000001914 filtration Methods 0.000 claims description 3
- 238000010438 heat treatment Methods 0.000 claims description 3
- 229910001220 stainless steel Inorganic materials 0.000 claims description 3
- 239000010935 stainless steel Substances 0.000 claims description 3
- 239000010959 steel Substances 0.000 claims description 3
- 238000001704 evaporation Methods 0.000 claims 1
- 230000008901 benefit Effects 0.000 abstract description 3
- 238000009434 installation Methods 0.000 abstract description 3
- 238000001816 cooling Methods 0.000 abstract description 2
- 238000004064 recycling Methods 0.000 description 3
- 238000009835 boiling Methods 0.000 description 2
- 239000003245 coal Substances 0.000 description 2
- 230000006378 damage Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 1
- 208000027418 Wounds and injury Diseases 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 239000003673 groundwater Substances 0.000 description 1
- 230000036571 hydration Effects 0.000 description 1
- 238000006703 hydration reaction Methods 0.000 description 1
- 208000014674 injury Diseases 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
Images
Classifications
-
- 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
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
- E21D9/001—Improving soil or rock, e.g. by freezing; Injections
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21F—SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
- E21F17/00—Methods or devices for use in mines or tunnels, not covered elsewhere
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- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Soil Sciences (AREA)
- Geology (AREA)
- Geochemistry & Mineralogy (AREA)
- Environmental & Geological Engineering (AREA)
- Structural Engineering (AREA)
- Agronomy & Crop Science (AREA)
- Paleontology (AREA)
- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
- Excavating Of Shafts Or Tunnels (AREA)
Abstract
The invention discloses an artificial stratum freezing method, which utilizes a refrigerant to circulate and refrigerate in a closed-loop circulating system, directly freezes the stratum, the refrigerant is output by a refrigerating device, is distributed to a liquid supply pipe in each freezer through a refrigerant storage device, is sprayed to the inner wall of the freezer from a small hole of the liquid supply pipe, is evaporated into a gas refrigerant through heat exchange of the stratum, the gas refrigerant enters a recovery temporary storage device through an annular space between the liquid supply pipe and the freezer, flows back to the refrigerating device through a pipeline, forms the refrigerant again after cooling, freezes the stratum and repeats until a frozen soil curtain is formed outside the freezer. The invention has the advantages that: the artificial stratum freezing method adopts the refrigerant to carry out closed cycle refrigeration, and has high refrigeration effect; the frozen soil has low average temperature, high strength and low interface temperature, and can adapt to complex working conditions; the frozen soil is fast in expansion speed; the system has simple structure and convenient installation and transportation.
Description
Technical Field
The invention belongs to the technical field of artificial stratum freezing, and particularly relates to an artificial stratum freezing method.
Background
The freezing method is widely applied to domestic and foreign coal mine engineering and urban underground engineering, and the basic principle is that heat in the stratum is gradually replaced into the atmosphere through a complex artificial refrigeration system, so that the temperature of a soil body is gradually reduced to form frozen soil with certain bearing capacity, and the refrigeration system comprises three major cycles: refrigerant circulation, cooling water circulation. The refrigerant commonly used in the engineering adopts saline (CaCl 2 solution), and the refrigerant adopts Freon (R22) or liquid ammonia (R717). The traditional process has complex refrigeration and equipment system, is suitable for large-volume and long-term freezing engineering of coal mines, and has the following disadvantages when being applied to municipal freezing engineering: the refrigeration efficiency is low, heat needs to be transferred among three large circulation systems, the energy loss is serious, and the cost is high; the development speed of frozen soil is slow, and the freezing time is long; the refrigeration system is complex, and time and labor are wasted in installation and transition; the refrigeration temperature is on the high side, and for complex boundary conditions, potential safety hazards exist, such as: interface freezing, heat of hydration, groundwater flow, etc.; the leakage of the salt water has great harm to the engineering.
Disclosure of Invention
The invention aims to provide an artificial stratum freezing method according to the defects of the prior art, the artificial stratum freezing method utilizes a refrigerant to circularly refrigerate in a closed-loop circulating system, the stratum is directly frozen, the temperature of the refrigerant is increased after the refrigerant exchanges heat with the stratum through a freezer, the refrigerant flows back to a refrigerating device, the refrigerant is formed again after cooling, the stratum is frozen, and frozen soil curtains with certain thickness are formed around the freezer step by step in a circulating manner.
The purpose of the invention is realized by the following technical scheme:
a method of artificial formation freezing, the freezing method comprising the steps of:
(1) arranging a plurality of freezers in a stratum at intervals, and placing a liquid supply pipe in each freezer, wherein the pipe wall of each liquid supply pipe is provided with a plurality of small holes;
(2) the system comprises a refrigerant storage device, a refrigeration device and a temporary recovery storage device which are sequentially connected through pipelines, wherein the output end of the refrigerant storage device is connected with a liquid supply pipe, and an annular space between the liquid supply pipe and a freezer is communicated with the input end of the temporary recovery storage device to form a closed circulation system;
(3) liquid refrigerant produced by the refrigeration equipment is distributed into the liquid supply pipes through the refrigerant storage device, the liquid refrigerant is sprayed to the inner wall of the freezer from the small holes on the liquid supply pipes, and the temperature of soil around the freezer is reduced through formation heat exchange to form frozen soil cylinders; meanwhile, the liquid refrigerant is evaporated into gas refrigerant, the gas refrigerant enters the recovery temporary storage device through an annular space between the liquid supply pipe and the freezers, the gas refrigerant in the recovery temporary storage device flows back to the refrigeration equipment, the gas refrigerant is compressed and cooled through the refrigeration equipment to form the liquid refrigerant, the liquid refrigerant enters the refrigerant storage device again, circulation refrigeration is carried out, and the frozen soil cylinders of the freezers are expanded to form frozen soil curtains.
The freezer is a stainless steel tube or a low-carbon seamless steel tube.
The output end of the refrigerant storage device is sequentially provided with a cryogenic pump and a distributor, the distributor is connected with the liquid supply pipes, and the cryogenic pump pumps the liquid refrigerant from the refrigerant storage device to the distributor and pumps the liquid refrigerant to the liquid supply pipes through the distributor.
The method for preparing the liquid refrigerant by the refrigeration equipment comprises the following steps: the refrigeration equipment compresses air and removes moisture and carbon dioxide in the air; injecting nitrogen into the compressed air to reduce the oxygen content; and then the compressed air is liquefied at low temperature, and the liquid refrigerant consisting of improved liquid air is obtained.
The refrigeration equipment comprises a compression unit, a purification unit, a pressurization unit and a low-temperature unit which are connected in sequence; the compressed air is compressed by the compression unit and then sent into the purification unit, and the purification unit purifies the compressed air under the heating of the electric heater to remove moisture and carbon dioxide in the compressed air; the purified compressed air enters the pressurizing unit, and the pressurizing unit injects nitrogen into the compressed air for pressurizing so as to reduce the oxygen content; and then the compressed air enters the low-temperature unit for low-temperature liquefaction, and the liquid refrigerant consisting of improved liquid air is prepared and obtained.
And purifying water obtained by filtering the compressed air by the purification unit to be used as circulating cooling water of the refrigeration equipment.
The liquid refrigerant comprises the following components in parts by mass: 78% of nitrogen and 21% of oxygen.
The invention has the advantages that: the artificial formation freezing method realizes the recycling and recompression of the backflow low-temperature gas, greatly reduces the energy consumption, improves the energy utilization rate by about 30 percent, and has obvious economic benefit; the application range of the invention is not limited by space and region by taking the improved liquid air as a refrigerating medium, and the invention is suitable for complex boundary conditions; the circulation closed system is adopted for direct refrigeration, the refrigeration efficiency is greatly improved, the soil body can be rapidly frozen, and the frozen soil development speed is about 200 mm/d; the engineering safety reserve is improved; the refrigeration equipment is single, the transition is easy, and the installation is convenient.
Drawings
FIG. 1 is a schematic process flow diagram of the artificial formation freezing method of the present invention;
fig. 2 is a schematic diagram of the structure of the refrigeration equipment of the present invention.
Detailed Description
The features of the present invention and other related features are described in further detail below by way of example in conjunction with the following drawings to facilitate understanding by those skilled in the art:
as shown in fig. 1-2, the respective symbols in the figure are:
a freezer 1, a liquid supply pipe 2, a distributor 3, a refrigerant storage device 4, and a recovery temporary storage device 5;
frozen earth curtain 7, cryogenic pump 8.
Example (b): as shown in fig. 1-2, the present embodiment specifically relates to an artificial formation freezing method, which includes the following steps:
(1) a plurality of freezers 1 are arranged in the stratum at intervals, the freezers 1 are stainless steel pipes or low-carbon seamless steel pipes, a liquid supply pipe 2 is placed in the freezers 1, and a plurality of small holes are formed in the pipe wall of the liquid supply pipe 2.
(2) The refrigerating device is characterized in that the refrigerating device is sequentially connected with a refrigerant storage device 4, a refrigerating device 6 and a recycling temporary storage device 5 through pipelines, the output end of the refrigerant storage device 4 is connected with a liquid supply pipe 2, and the annular space between the liquid supply pipe 2 and a freezer 1 is communicated with the input end of the recycling temporary storage device 5 to form a closed circulation system. The output end of the refrigerant storage device 4 is sequentially provided with a cryogenic pump 8 and a distributor 3, the distributor 3 is connected with each liquid supply pipe 2, and the cryogenic pump 8 pumps liquid refrigerant from the refrigerant storage device 4 to the distributor 3 and pumps the liquid refrigerant to each liquid supply pipe 2 through the distributor 3. The refrigeration equipment 6 comprises a compression unit 61, a purification unit 63, a pressurization unit 64 and a low-temperature unit 65 which are connected in sequence; the compression unit 61 compresses the air and then sends the compressed air into the purification unit 63, and the purification unit 63 purifies the compressed air under the heating of the electric heater 62 to remove moisture and carbon dioxide in the compressed air; the purified compressed air enters a pressurizing unit 64, and the pressurizing unit 64 injects nitrogen into the compressed air for pressurizing so as to reduce the oxygen content; the compressed air then enters the low temperature unit 65 for low temperature liquefaction to produce a liquid refrigerant comprised of modified liquid air. The boiling point of the improved liquid air is-192 ℃, and the liquid refrigerant comprises the following components in parts by mass: 78% of nitrogen and 21% of oxygen. The improved liquid air has stable performance and small leakage, and can not cause personal injury. The water obtained by the filtration of the compressed air is purified by the purification unit 63 as the circulating cooling water of the refrigeration equipment 6.
(3) Liquid refrigerant generated by a refrigerating device 6 is distributed into each liquid supply pipe 2 through a refrigerant storage device 4, a cryogenic pump 8 and a distributor 3 in sequence, the liquid refrigerant is sprayed onto the inner wall of the freezer 1 from each small hole on the liquid supply pipe 2, the temperature of soil around the freezer 1 is rapidly reduced through stratum heat exchange, a frozen soil cylinder is formed gradually, meanwhile, the liquid refrigerant reaches a boiling point of-192 ℃, the liquid refrigerant is evaporated into gas refrigerant, the gas refrigerant enters a recovery temporary storage device 5 through an annular space between the liquid supply pipe 2 and the freezer 1, the temperature of the gas refrigerant is about-80 ℃, the gas refrigerant in the recovery temporary storage device 5 flows back to the refrigerating device 6 through a pipeline, the gas refrigerant is compressed and cooled through the refrigerating device 6 to form liquid refrigerant, and the liquid refrigerant enters the refrigerant storage device 4 again, the refrigerant cycle forms a closed system, and the frozen soil cylinders of the individual freezers 1 gradually expand to form frozen soil curtains 7.
Claims (1)
1. An artificial formation freezing method, characterized in that the freezing method comprises the following steps:
(1) arranging a plurality of freezers in a stratum at intervals, and placing a liquid supply pipe in each freezer, wherein the pipe wall of each liquid supply pipe is provided with a plurality of small holes; the freezer is a stainless steel tube or a low-carbon seamless steel tube;
(2) the system comprises a refrigerant storage device, a refrigeration device and a temporary recovery storage device which are sequentially connected through pipelines, wherein the output end of the refrigerant storage device is connected with a liquid supply pipe, and an annular space between the liquid supply pipe and a freezer is communicated with the input end of the temporary recovery storage device to form a closed circulation system; the output end of the refrigerant storage device is sequentially provided with a cryogenic pump and a distributor, the distributor is connected with the liquid supply pipes, and the cryogenic pump pumps liquid refrigerant from the refrigerant storage device to the distributor and pumps the liquid refrigerant to the liquid supply pipes through the distributor;
(3) liquid refrigerant produced by the refrigeration equipment is distributed into the liquid supply pipes through the refrigerant storage device, the liquid refrigerant is sprayed to the inner wall of the freezer from the small holes on the liquid supply pipes, and the temperature of soil around the freezer is reduced through formation heat exchange to form frozen soil cylinders; simultaneously evaporating the liquid refrigerant into gas refrigerant, enabling the gas refrigerant to enter the recovery temporary storage device through an annular space between the liquid supply pipe and the freezers, enabling the gas refrigerant in the recovery temporary storage device to flow back to the refrigeration equipment, enabling the gas refrigerant to be compressed and cooled through the refrigeration equipment to form the liquid refrigerant, enabling the liquid refrigerant to enter the refrigerant storage device again, performing circulating refrigeration, and expanding the frozen soil cylinders of the freezers to form frozen soil curtains;
the method for preparing the liquid refrigerant by the refrigeration equipment comprises the following steps: the refrigeration equipment compresses air and removes moisture and carbon dioxide in the air; injecting nitrogen into the compressed air to reduce the oxygen content; then, carrying out low-temperature liquefaction on the compressed air to obtain the liquid refrigerant consisting of improved liquid air;
the refrigeration equipment comprises a compression unit, a purification unit, a pressurization unit and a low-temperature unit which are connected in sequence; the compressed air is compressed by the compression unit and then sent into the purification unit, and the purification unit purifies the compressed air under the heating of the electric heater to remove moisture and carbon dioxide in the compressed air; the purified compressed air enters the pressurizing unit, and the pressurizing unit injects nitrogen into the compressed air for pressurizing so as to reduce the oxygen content; then the compressed air enters the low-temperature unit for low-temperature liquefaction to prepare and obtain the liquid refrigerant consisting of improved liquid air;
purifying water obtained by filtering compressed air by the purification unit to be used as circulating cooling water of the refrigeration equipment;
the liquid refrigerant comprises the following components in parts by mass: 78% of nitrogen and 21% of oxygen.
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CN202011235156.XA CN112554164B (en) | 2020-11-08 | 2020-11-08 | Artificial stratum freezing method |
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CN202011235156.XA CN112554164B (en) | 2020-11-08 | 2020-11-08 | Artificial stratum freezing method |
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CN112554164B true CN112554164B (en) | 2022-02-11 |
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Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0598882A (en) * | 1991-10-09 | 1993-04-20 | Tokyo Soil Res:Kk | Automatic feeding device for ground freezing medium |
CN101761067A (en) * | 2010-01-21 | 2010-06-30 | 北京中煤矿山工程有限公司 | Stratigraphic liquid nitrogen freezer |
CN105421334A (en) * | 2015-11-10 | 2016-03-23 | 上海市机械施工集团有限公司 | Construction method for soil freezing |
CN105908696A (en) * | 2016-06-03 | 2016-08-31 | 长春工程学院 | Foundation pit frozen soil retaining wall device and freezing method thereof |
CN106812130A (en) * | 2017-01-22 | 2017-06-09 | 山东送变电工程公司 | A kind of project of transmitting and converting electricity column foot foundation ditch freezing method |
-
2020
- 2020-11-08 CN CN202011235156.XA patent/CN112554164B/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0598882A (en) * | 1991-10-09 | 1993-04-20 | Tokyo Soil Res:Kk | Automatic feeding device for ground freezing medium |
CN101761067A (en) * | 2010-01-21 | 2010-06-30 | 北京中煤矿山工程有限公司 | Stratigraphic liquid nitrogen freezer |
CN105421334A (en) * | 2015-11-10 | 2016-03-23 | 上海市机械施工集团有限公司 | Construction method for soil freezing |
CN105908696A (en) * | 2016-06-03 | 2016-08-31 | 长春工程学院 | Foundation pit frozen soil retaining wall device and freezing method thereof |
CN106812130A (en) * | 2017-01-22 | 2017-06-09 | 山东送变电工程公司 | A kind of project of transmitting and converting electricity column foot foundation ditch freezing method |
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