Total CO2 refrigeration device arranged in tunnel and capable of shortening construction period

Abstract

The utility model relates to a total CO2 refrigeration device which is arranged in a tunnel and can shorten the construction period. The problems that in the background technology, due to the fact that a refrigerating medium and a refrigerant adopt different working media, a system is complex, the size of equipment is too wide and too high, when the equipment is placed in a tunnel, synchronous construction with other working procedures cannot be achieved, the construction period of a whole project is prolonged, and the construction cost is increased are solved. According to the technical scheme for solving the technical problem, the device is divided into two or more than two modules, and the modules are connected through a plurality of pipelines; the plurality of modules comprise a CO2 compressor unit and a low-pressure-stage CO2 compressor, a high-pressure-stage CO2 compressor, a parallel compressor, an oil separator, an air cooler, an expansion valve I, a gas-liquid separator and a gas bypass valve in accessory equipment of the CO2 compressor unit; the multiple modules further comprise a CO2 low-pressure circulating barrel, a second expansion valve and a refrigerating pump in a CO2 barrel pump unit and accessory equipment of the CO2 barrel pump unit. The method is suitable for stratum freezing construction in tunnels.

Description

Technical Field

[0001] The utility model belongs to the refrigeration technology, and specifically relates to a full CO₂ refrigeration device that can be placed in a tunnel to shorten the construction period. 2 Refrigeration device. Background Technique

[0002] At present, the existing ground freezing technologies in the industry are divided into three types: brine freezing, liquid nitrogen freezing, and low-temperature carbon dioxide freezing. Among them, at similar costs, the freezing efficiency of low-temperature carbon dioxide is the highest. In the ground freezing of tunnels, the invention patent with the application number 202210450347.0 discloses "A carbon dioxide secondary refrigerant unit for an artificial ground freezing system". The problems of this secondary refrigerant unit are as follows: First, it is an integral device, and the compressor, water-cooled condenser, and carbon dioxide liquid storage tank are arranged side by side in the width direction of the device, so the overall device is too wide. Second, the used condensation evaporator and carbon dioxide liquid storage tank are two separate devices. Due to the need for gravity liquid drainage, the condensation evaporator must be placed above the carbon dioxide liquid storage tank, so the device will be very tall. If the height is reduced, only the height between the CO₂ refrigeration pump and the CO₂ liquid storage tank can be reduced, which will greatly reduce the safe net positive suction head of the pump, and the pump is very likely to generate cavitation phenomenon, posing a great safety hazard to the CO₂ refrigeration pump; the above-mentioned patent is a carbon dioxide secondary refrigerant unit. Because the refrigerant and secondary refrigerant are different working media, there are many devices used in the system, the system is complex, and when the whole is placed in the tunnel, it will occupy a very wide passage, which will affect the construction of other processes and cannot be constructed synchronously with other processes. Only after other processes in the tunnel are completed, the ground freezing can be carried out finally. Generally, the time for ground freezing is very long, which will cause problems such as the extension of the entire project construction period and the increase of construction costs. 2 Refrigeration pump and CO₂ 2 Between the liquid storage tank, this will cause the safe net positive suction head of the pump to be greatly reduced, and the pump is very likely to generate cavitation phenomenon, making the CO₂ 2 Refrigeration pump has a great safety hazard; the above-mentioned patent is for the CO₂ 2 Secondary refrigerant unit. Because the refrigerant and secondary refrigerant are different working media, there are many devices used in the system, the system is complex, and when the whole is placed in the tunnel, it will occupy a very wide passage, which will affect the construction of other processes and cannot be constructed synchronously with other processes. As a result, the entire project construction period is extended and the construction cost is increased. Content of the Utility Model

[0003] The purpose of the utility model is to propose a full CO₂ refrigeration device that can be placed in a tunnel to shorten the construction period, so as to solve the problems in the background technique: the system is complex due to different working media for the secondary refrigerant and the refrigerant, the device size is too wide and too high, when placed in the tunnel, it will occupy a very wide passage, affecting the construction of other processes and unable to be constructed synchronously with other processes, resulting in problems such as the extension of the entire project construction period and the increase of construction costs. The technical solution adopted to solve this technical problem is: a full CO₂ refrigeration device that can be placed in a tunnel to shorten the construction period, wherein the refrigeration system is: the exhaust port of the low-pressure stage CO₂ compressor is connected in sequence through a pipeline to the high-pressure stage CO₂ compressor, oil separator, air cooler, expansion valve 1, A port and B port of the gas-liquid separator, expansion valve 2, CO₂ 2 Refrigeration device, to solve the problems in the background technology: the system is complex due to different working media for the secondary refrigerant and the refrigerant, the equipment size is too wide and too high, when placed in the tunnel, it will occupy a very wide passage, affecting the construction of other processes, unable to be constructed synchronously with other processes, and resulting in problems such as the extension of the entire project construction period and the increase of construction costs. The technical solution adopted to solve this technical problem is: a full CO₂ 2 Refrigeration device, wherein the refrigeration system is: the low-pressure stage CO₂ 2 The compressor exhaust port is connected in sequence through a pipeline to the high-pressure stage CO₂ 2 Compressor, oil separator, air cooler, expansion valve 1, A port and B port of the gas-liquid separator, expansion valve 2, CO₂2 The D port and E port of the low-pressure circulating drum, the refrigeration pump, the end evaporator outside this device, CO 2 The F port and G port of the low-pressure circulating drum return to the low-pressure stage CO 2 The suction port of the compressor, the C port of the gas-liquid separator and the high-pressure stage CO 2 A gas bypass valve is provided between the intake port of the compressor, the C port of the gas-liquid separator and the high-pressure stage CO 2 A parallel compressor is provided between the outlet port of the compressor; the oil circulation is: the oil outlet of the oil separator is connected to the oil inlet of the parallel compressor, the high-pressure stage CO 2 The oil inlet of the compressor and the low-pressure stage CO 2 The oil inlet of the compressor; characterized in that: this device is divided into two or more modules, and the modules are connected by a number of pipelines. The number of modules includes: CO 2 The low-pressure stage CO in the compressor unit and its auxiliary equipment 2 The compressor, the high-pressure stage CO 2 The compressor, the parallel compressor, the oil separator, the air cooler, the first expansion valve, the gas-liquid separator, the gas bypass valve; the number of modules also includes: CO 2 The CO in the barrel pump unit and its auxiliary equipment 2 The low-pressure circulating drum, the second expansion valve, the refrigeration pump. Among them, the width of each module is 1-2 meters, and the height is 2-3 meters. The air cooler is water-cooled. The first expansion valve is a ejector. The parallel compressor, the high-pressure stage CO 2 The compressor, the low-pressure stage CO 2 The number of compressors is single or multiple. Each module in this refrigeration device is arranged horizontally or vertically in a horizontal well or a vertical well.

[0004] The A port of the gas-liquid separator is the liquid inlet pipe port, the B port of the gas-liquid separator is the liquid outlet pipe port, and the C port of the gas-liquid separator is the gas outlet pipe port. CO 2 The D port of the low-pressure circulating drum is CO 2 The liquid inlet port, CO 2 The E port of the low-pressure circulating drum is located in the liquid phase area, CO 2 The F port of the low-pressure circulating drum is located in the gas phase area at the intake end, CO 2 The G port of the low-pressure circulating drum is located in the gas phase area at the outlet end.

[0005] The beneficial effects of the present utility model compared with the prior art are: adopting the above technical solution for the construction of ground freezing in tunnels. On the one hand, the number of modules includes: CO 2 The low-pressure stage CO in the compressor unit and its auxiliary equipment 2 The compressor, the high-pressure stage CO 2 The compressor, the parallel compressor, the oil separator, the air cooler, the first expansion valve, the gas-liquid separator, the gas bypass valve; the number of modules also includes: CO2 CO₂ in the barrel pump unit and its auxiliary equipment 2 Low-pressure circulating barrel, expansion valve II, refrigeration pump. Several modules are connected by several pipelines, making the device modular on the premise of complete equipment. The width of each module is not more than 2 meters. Since the cross-section of the tunnel is circular, when the equipment is placed on one side, the height of the equipment is also limited. Now, the overall height of each module is made not higher than 3 meters. When it is placed on one side of the tunnel, the remaining passage width can reach 3.5 meters, greatly reducing the floor area of the equipment on one side of the tunnel. The ground freezing can be carried out synchronously with other processes in the tunnel without mutual influence, ultimately achieving the purpose of shortening the construction period of the entire project and reducing the construction cost; on the other hand: using CO₂ as a single refrigerant solves the problem of 2 the complex system with multiple devices used in the refrigeration system due to different refrigerants and secondary coolants in the secondary coolant unit; on the other hand: the gas cooler uses water cooling, solving the problem that air-cooled gas coolers cannot be used in the tunnel; on the other hand: when there are multiple parallel compressors, high-pressure stage CO₂ 2 compressors, and low-pressure stage CO₂ 2 compressors, when one compressor fails, there are still compressors that can continue to work, and the on-site freezing equipment does not need to stop, and the ground freezing work can continue; on the other hand, this refrigeration device can be applied in different fields. According to the actual application occasion and the on-site installation size, it can be selected to be arranged horizontally or vertically in the cross shaft or the vertical shaft Description of the Drawings

[0006] Figure 1 is a schematic structural view of two modules of the present invention Figure 2 is Figure 1 the left view of Figure 3 is a schematic pipeline view of two modules of the present invention Figure 4 is an in-position view of the equipment of the present invention in the tunnel Detailed Embodiment

[0007] Embodiment: Refer to Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 A full CO₂ 2 refrigeration device placed in a tunnel that can shorten the construction period, wherein the refrigeration system is: the exhaust port of the low-pressure stage CO₂ 2 compressor 5 is connected in sequence through pipelines to the high-pressure stage CO₂ 2 compressor 3, oil separator 1, gas cooler 6, expansion valve I 7, gas-liquid separator 8 A port and B port, expansion valve II 9, CO₂ 2 low-pressure circulating barrel 10 D port and E port, refrigeration pump 11, end evaporator 12 outside this device, CO₂ 2 low-pressure circulating barrel 10 F port and G port and returns to the low-pressure stage CO₂2 The suction port of compressor 5, port C of the gas-liquid separator 8, and high-pressure stage CO 2 A gas bypass valve 4 is provided between the intake port of compressor 3 and port C of the gas-liquid separator 8 and high-pressure stage CO 2 A parallel compressor 2 is provided between the outlet port of compressor 3; The oil circulation is as follows: The oil outlet of the oil separator 1 is connected to the oil inlet of the parallel compressor 2, high-pressure stage CO 2 The oil inlet of compressor 3 and low-pressure stage CO 2 The oil inlet of compressor 5, characterized in that: the device is divided into two modules, A and B. Module A contains: CO 2 The low-pressure stage CO in the compressor unit and its auxiliary equipment 2 Compressor 5, high-pressure stage CO 2 Compressor 3, parallel compressor 2, oil separator 1, air cooler 6, expansion valve 1 7, gas-liquid separator 8, gas bypass valve 4. Module B contains: CO 2 The CO in the barrel pump unit and its auxiliary equipment 2 Low-pressure circulation barrel 10, expansion valve 2 9, refrigeration pump 11. Module A and module B are arranged left and right in the cross well and connected by several pipelines, enabling the device to achieve modularization on the premise of complete equipment; The width of each module is 1.2 meters and the height is 2.5 meters. Placing it on one side of the tunnel, the remaining passage width can reach 3.5 meters, and the ground freezing can be synchronized with other processes in the tunnel without mutual influence; The air cooler 6 is water-cooled; There is 1 parallel compressor 2, high-pressure stage CO 2 There are two compressor 3s, low-pressure stage CO 2 There are two compressor 5s.

Claims

1. A full CO2 refrigeration device placed in a tunnel to shorten the construction period, wherein the refrigeration system is: the exhaust port of a low-pressure CO2 compressor (5) is connected in sequence through a pipeline to a high-pressure CO2 compressor (3), an oil separator (1), an air cooler (6), an expansion valve 1 (7), ports A and B of a gas-liquid separator (8), an expansion valve 2 (9), ports D and E of a CO2 low-pressure circulation barrel (10), a refrigeration pump (11), an end evaporator (12) outside the device, ports F and The G port returns to the air intake port of the low-pressure CO2 compressor (5), a gas bypass valve (4) is provided between the C port of the gas-liquid separator (8) and the air intake port of the high-pressure CO2 compressor (3), and a parallel compressor (2) is provided between the C port of the gas-liquid separator (8) and the air outlet port of the high-pressure CO2 compressor (3); the oil circulation is as follows: the oil outlet of the oil separator (1) is connected to the oil inlet of the parallel compressor (2), the oil inlet of the high-pressure CO2 compressor (3) and the oil inlet of the low-pressure CO2 compressor (5) through pipelines; the characteristics are as follows: The device is divided into two or more modules, and the modules are connected by a number of pipelines. The modules include: a low-pressure CO2 compressor (5) in the CO2 compressor unit and its ancillary equipment, a high-pressure CO2 compressor (3), a parallel compressor (2), an oil separator (1), an air cooler (6), an expansion valve 1 (7), a gas-liquid separator (8), and a gas bypass valve (4); the modules also include: a CO2 low-pressure circulation barrel (10), an expansion valve 2 (9), and a refrigeration pump (11) in the CO2 barrel pump unit and its ancillary equipment.

2. According to claim 1, a full CO2 refrigeration device placed in a tunnel to shorten the construction period is characterized by: Each module is 1 to 2 meters wide and 2 to 3 meters high.

3. A full CO2 refrigeration device placed in a tunnel to shorten the construction period according to claim 1 or 2, characterized in that: The air cooler (6) is water-cooled.

4. A full CO2 refrigeration device placed in a tunnel to shorten the construction period according to claim 1 or 2, characterized in that: Expansion valve one (7) is an ejector.

5. The all-CO2 refrigeration device placed in a tunnel to shorten the construction period according to claim 3 is characterized by: Expansion valve one (7) is an ejector.

6. A full CO2 refrigeration device placed in a tunnel to shorten the construction period according to claim 1 or 2, characterized in that: The number of the parallel compressor (2), the high-pressure CO2 compressor (3), and the low-pressure CO2 compressor (5) is one or more.

7. The all-CO2 refrigeration device placed in a tunnel to shorten the construction period according to claim 3 is characterized by: The number of the parallel compressor (2), the high-pressure CO2 compressor (3), and the low-pressure CO2 compressor (5) is one or more.

8. The all-CO2 refrigeration device placed in a tunnel to shorten the construction period according to claim 4 is characterized in that: The number of the parallel compressor (2), the high-pressure CO2 compressor (3), and the low-pressure CO2 compressor (5) is one or more.

9. A full CO2 refrigeration device placed in a tunnel to shorten the construction period according to claim 1 or 2, characterized in that: Each module in this refrigeration device is either arranged left and right in a horizontal shaft, or arranged up and down in a vertical shaft.

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