Air blowing device and ground freezing system

Abstract

To provide an air blowing device and a ground freezing system, which can suppress reduction in efficiency of freezing cycle of a freezer caused by air temperature around an intake side of a heat discharge device exceeding an appropriate temperature range of the heat discharge device.SOLUTION: An air blowing device 100 comprises: a duct 110, which has a first end 112 positioned on an intake side of a heat discharge device 80 installed on the ground in order to discharge heat of a freezing cycle of a freezer 10 to the outside of a system, and a second end 114 positioned in a pit 5 in which a freezing pipe 70 is installed; and a fan 120 to introduce air in the pit 5 to the intake side of the heat discharge device 90 through the duct 110.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present disclosure relates to a blower and a ground freezing system. [Background technology]

[0002] A ground freezing method has been known for some time, in which the area around the ground to be excavated is frozen before excavation work begins. In this method, the ground is frozen by sending a refrigerant cooled by a refrigeration cycle in a refrigerator to a freezing pipe installed in the ground. In the refrigeration cycle, the heat removed from the refrigerant used for freezing the ground must be released outside the system, so a heat dissipation device is installed.

[0003] For example, Patent Document 1 describes a ground freezing method that uses CO2 as a refrigerant, and uses a cooling device that includes a CO2 liquefier and a condenser as refrigeration cycle components, and a cooling tower (heat dissipation device) that cools water (cooling water) that has absorbed heat from the refrigeration cycle in the condenser. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-148104 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, heat dissipation devices such as the cooling tower of Patent Document 1 cool the cooling water heated in the condenser of the refrigerator using air taken into the heat dissipation device and return the cooled cooling water to the condenser. If the temperature of the air taken into the heat dissipation device is within a temperature range suitable for cooling the cooling water, the cooling water is appropriately cooled as it passes through the heat dissipation device.

[0006] However, if the temperature of the air around the intake side of the radiator exceeds the appropriate temperature range, the radiator will not be able to cool the coolant sufficiently, hindering the heat dissipation of the refrigeration cycle of the chiller, leading to an increase in the high-pressure side pressure of the chiller.When the high-pressure side pressure of the chiller increases, not only does the efficiency (COP) of the refrigeration cycle decrease due to an increase in compression power (power consumption), but the increase in high-pressure side pressure can also cause the chiller to stop.

[0007] In view of the above circumstances, at least some embodiments of the present invention aim to provide a blower device and a ground freezing system that can suppress a decrease in the efficiency of the refrigeration cycle of a refrigerator caused by the temperature of the air around the intake side of the heat dissipation device exceeding the appropriate temperature range of the heat dissipation device. [Means for solving the problem]

[0008] In some embodiments, the blower device A blower for a ground freezing system that supplies refrigerant from a refrigerator installed on the ground to a freezing pipe in a tunnel to freeze the ground. a duct having a first end located on the intake side of a heat dissipation device installed on the ground to release heat from the refrigeration cycle of the refrigerator to the outside of the system, and a second end located inside the tunnel where the freezing pipe is installed; A fan that guides the air inside the mine to the intake side of the heat dissipation device through a duct; Equipped with.

[0009] In some embodiments, the ground freezing system includes: A freezing pipe that freezes the ground inside the tunnel; a refrigeration machine installed on the ground and supplying a refrigerant to the freezing pipe; a heat dissipation device that is installed on the ground and that dissipates heat from the refrigeration cycle of the refrigerator to the outside of the system; The above-mentioned blower device; Equipped with. [Effects of the Invention]

[0010] The air drawn into the radiator is cooled by the low-temperature underground air guided by the blower, making it less likely to exceed the appropriate temperature range for the radiator, thereby preventing a decrease in the efficiency of the refrigeration cycle of the refrigerator due to an increase in the high-pressure side of the refrigerator. [Brief explanation of the drawings]

[0011] [Figure 1A] 1 is a diagram showing the overall configuration of a ground freezing system according to one embodiment. FIG. [Figure 1B] FIG. 10 is a diagram showing the overall configuration of a ground freezing system according to another embodiment. [Figure 2A] 1 is a diagram illustrating a configuration of a heat dissipation device according to an embodiment. [Figure 2B] 10A and 10B are diagrams illustrating a configuration of a heat dissipation device according to another embodiment. [Figure 3] 1 is a diagram illustrating a heat dissipation device, a blower, and the air around them according to an embodiment; [Figure 4A] 2 is a perspective view showing the relationship between an intake port of a heat dissipation device and an outlet port of a blower device according to an embodiment; FIG. [Figure 4B] 4B is a schematic diagram showing the relationship between the intake port of the heat dissipation device and the outlet port of the blower device of FIG. 4A according to one embodiment. FIG. [Figure 5A] FIG. 10 is a perspective view showing the relationship between an intake port of a heat dissipation device and an outlet port of a blower device according to another embodiment. [Figure 5B] 5B is a schematic diagram showing the relationship between the intake port of the heat dissipation device and the outlet port of the blower device of FIG. 5A according to one embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, several embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present invention.

[0013] Hereinafter, a blower device and a ground freezing system according to several embodiments will be described with reference to the drawings.

[0014] Fig. 1A is a diagram showing the overall configuration of a ground freezing system according to one embodiment, and Fig. 1B is a diagram showing the overall configuration of a ground freezing system according to another embodiment. Fig. 2A is a diagram showing the configuration of a heat dissipation device according to one embodiment, and Fig. 2B is a diagram showing the configuration of a heat dissipation device according to another embodiment. FIG. 3 is a diagram schematically illustrating a heat dissipation device, a blower, and the air around them according to one embodiment.

[0015] In some embodiments, as shown in Figures 1A and 1B, the ground freezing system 1 (1A, 1B) includes a refrigerator 10, a freezing pipe 70 that receives a refrigerant supply from the refrigerator 10, a heat dissipation device 80 connected to the refrigerator 10, and a blower 100 (100A, 100B) for directing air to the heat dissipation device 80. The refrigerator 10 and the heat dissipation device 80 are installed in the above-ground space 3. The above-ground space 3 is a space where the temperature around the heat dissipation device 80 is high (for example, 30 degrees Celsius or higher), and may be, for example, outdoors in summer or inside a soundproof house where ventilation is likely to be insufficient.

[0016] The refrigerator 10 has a refrigeration cycle for cooling the refrigerant supplied to the freezing pipe 70 . In some embodiments, the refrigerator 10 is an indirect cooling refrigerator having a system in which the refrigerant circulating in the refrigeration cycle (hereinafter referred to as the "primary refrigerant") and the refrigerant supplied to the freezing pipe 70 (hereinafter referred to as the "secondary refrigerant") are different systems. The refrigerator 10 includes, as refrigeration cycle components, a primary refrigerant line 12 that circulates a primary refrigerant that exchanges heat with a secondary refrigerant, and a compressor 14, a condenser 16, an expansion valve 18, and an evaporator 20 that are provided in the primary refrigerant line 12. The compressor 14 compresses the primary refrigerant and discharges it into the primary refrigerant line 12. The condenser 16 cools the primary refrigerant by heat exchange between the cooling water (described below) guided from the heat dissipation device 80 and the primary refrigerant discharged from the compressor 14. The primary refrigerant that passes through the condenser 16 is decompressed by the expansion valve 18. The evaporator 20 exchanges heat between the decompressed primary refrigerant and the secondary refrigerant. The secondary refrigerant is cooled by the heat exchange in the evaporator 20. The primary refrigerant may be, for example, an NH3 refrigerant, while the secondary refrigerant may be, for example, a CO2 refrigerant.

[0017] The secondary refrigerant cooled by the refrigerator 10 is stored in the receiver 30 via a secondary refrigerant re-liquefaction line 32 .

[0018] In addition to the secondary refrigerant reliquefaction line 32, a secondary refrigerant line 40 is also connected to the receiver 30. The secondary refrigerant line 40 includes an outgoing path 40A provided with a secondary refrigerant supply pump 42, and a returning path 40B. The outgoing path 40A of the secondary refrigerant line 40 is connected to a feed header 50A for branching the secondary refrigerant to multiple freezing pipes 70, and multiple feed pipes 60A are provided between the feed header 50A and the multiple freezing pipes 70. In this way, the outgoing path 40A of the secondary refrigerant line 40 communicates with the freezing pipes 70 via the feed header 50A and the feed pipes 60A. The secondary refrigerant in the receiver 30 is sent from the receiver 30 to the freezing pipes 70 by a secondary refrigerant supply pump 42. Similarly, the return path 40B of the secondary refrigerant line 40 communicates with the freezing pipe 70 via a return header 50B and a return pipe 60B. The secondary refrigerant that has passed through the freezing pipe 70 returns to the receiver 30 via the return path 40B of the secondary refrigerant line 40. In this way, the secondary refrigerant circulates between the freezing pipe 70 and the receiver 30.

[0019] Freezing pipe 70 is installed in ground 7 inside tunnel 5, and includes an outer cylinder 72 and refrigerant piping 74 provided inside outer cylinder 72. Refrigerant piping 74 is formed so as to be folded back inside outer cylinder 72, with one end of refrigerant piping 74 connected to delivery piping 60A and the other end of refrigerant piping 74 connected to return piping 60B. The freezing pipe 70 also has a space 76 between the outer cylinder 72 and the refrigerant pipe 74. The space 76 may be filled with a fluid (e.g., water) that has a higher thermal conductivity than air. When water is used as the fluid filling the space 76, the water in the space 76 is frozen by the refrigerant flowing through the refrigerant pipe 74. The water (ice) in the frozen space 76 cools and freezes the ground 7. In the embodiment shown in FIGS. 1A and 1B, the freezing pipe 70 is buried in the ground 7 within the well 5 . In another embodiment, the freezing pipe 70 may be installed on the surface of the ground 7 inside the tunnel 5. When the freezing pipe 70 is installed on the surface of the ground 7 inside the tunnel 5, the freezing pipe 70 may not include the outer casing 72 and may be attached to the surface of the ground 7 inside the tunnel 5 as a refrigerant pipe 74. The pit 5 may be, for example, a vertical shaft, or may be a shaft including a vertical shaft and an adit.

[0020] The radiator 80 is connected to the condenser 16 of the chiller 10 via a heat radiation line 82 provided with a cooling water pump 84. Cooling water flows through the heat radiation line 82. The cooling water removes heat from the primary refrigerant in the condenser 16. The cooling water that passes through the condenser 16 is cooled by heat exchange with intake air drawn in from around an intake port 86 of the radiator 80. The cooling water cooled by the radiator 80 is returned to the condenser 16 via the heat radiation line 82. Meanwhile, the air that has removed heat from the cooling water is discharged from an exhaust port 88 of the radiator 80. In this way, the radiator 80 releases heat from the refrigeration cycle of the chiller 10 to the outside of the refrigeration cycle system. 1A and 1B, openings provided in the casing of the heat dissipation device 80 form the intake port 86 and the exhaust port 88 of the heat dissipation device 80. In other embodiments, the intake port 86 of the heat dissipation device 80 is formed by an intake guide member connected to the surface of the casing of the heat dissipation device 80 where the intake side opening is formed. The intake guide member may be an extension pipe, an intake chamber, or a hood that connects the intake side opening of the casing of the heat dissipation device 80 and the intake port 86.

[0021] In some embodiments, the heat dissipation device 80 is a cooling tower 80A that uses water evaporation to dissipate heat from cooling water. In the embodiment shown in FIG. 2A, the cooling tower 80A is an open-type cooling tower that utilizes the evaporation of the cooling water itself, and includes a spray section 90 that discharges the cooling water that has passed through the condenser 16 of the chiller 10 from the heat dissipation line 82, a water tank 92 that returns the cooling water discharged from the spray section 90 to the heat dissipation line 82, and an exhaust fan 94 that directs intake air from the intake port 86 of the cooling tower 80A to the exhaust port 88. Although Figure 2A shows an example in which cooling tower 80A is an open-type cooling tower, cooling tower 80A is not limited to this example and may be, for example, a closed-type cooling tower that includes a spray device for bringing water (spray water) from a system separate from the cooling water into contact with the surface of heat dissipation line 82, and dissipates heat from the cooling water by utilizing the evaporation of the spray water.

[0022] In the embodiment shown in FIG. 2B, the heat dissipation device 80 is a dry cooler 80B that dissipates heat from the cooling water by heat exchange between the intake air and the cooling water, in contrast to the cooling tower 80A, without using water evaporation. The dry cooler 80B includes an exhaust fan 94 that guides intake air from an intake port 86 of the dry cooler 80B to an exhaust port 88, and a heat transfer tube 96 that forms part of the heat dissipation line 82. The dry cooler 80B exchanges heat between the cooling water flowing inside the heat transfer tube 96 and the intake air flowing outside the heat transfer tube 96.

[0023] In some embodiments, as shown in FIGS. 1A and 1B, a blower device 100 (100A, 100B) includes a duct 110 and a fan 120 (120A, 120B) that directs air through the duct 110.

[0024] The duct 110 has a first end 112 located near the intake port 86 of the heat dissipation device 80 and a second end 114 located in the underground space 9 in which the freezing pipe 70 is installed. The duct 110 has an opening at each of a first end 112 and a second end 114, and the aboveground space 3 and the underground space 9 communicate with each other via the duct 110. In the embodiment shown in FIGS. 1A and 1B, the opening at the first end 112 of the duct 110 forms the outlet 102 of the blower 100, and the opening at the second end 114 of the duct 110 forms the inlet 104 of the blower 100. In other embodiments, the outlet 102 or the inlet 104 of the blower 100 is formed by an extension pipe connected to the first end 112 or the second end 114 of the duct 110. As will be described in detail later, the outlet 102 of the blower 100 is positioned to face the intake port 86 of the heat dissipation device 80, as shown in FIGS. 1A and 1B. The second end 114 of the duct 110 is installed at a depth Z from the ground surface 4. It is known that the temperature of the ground 7 is not affected by the temperature of the aboveground space 3 at a depth of 10 to 20 meters (constant temperature layer) from the ground surface 4 and remains almost constant (for example, approximately 18 to 20 degrees Celsius). If the depth Z is set to a depth of 10 meters or more, preferably 20 meters or more, the temperature of the air in the underground space 9 introduced into the duct 110 from the second end 114 of the duct 110 remains almost constant regardless of the depth Z of the second end 114. The duct 110 is not particularly limited, but may be, for example, a flexible duct, a round duct, or a square duct.

[0025] The fans 120 (120A, 120B) guide the air in the underground space 9 through the duct 110 to the vicinity of the intake port 86 of the heat dissipation device 80. The fans 120 (120A, 120B) may be provided inside the duct 110, or may be assembled to the duct 110 by connecting the casing of the fans 120 (120A, 120B) to the duct 110 body.

[0026] In the embodiment shown in FIG. 1A, the fan 120 is a suction fan 120A that is provided within the duct 110 at the first end 112 of the duct 110. Air in the underground space 9 is drawn into the duct 110 from the second end 114 of the duct 110 by the suction fan 120A. The air drawn into the duct 110 is discharged from the first end 112 of the duct 110 and is drawn into the heat dissipation device 80 through the air inlet 86 of the heat dissipation device 80 together with the air around the air inlet 86 of the heat dissipation device 80.

[0027] In the embodiment shown in FIG. 1B, the fan 120 is a forced draft fan 120B that is provided within the duct 110 at the second end 114 of the duct 110. Air in the underground space 9 is forced into the duct 110 from the second end 114 of the duct 110 by the forced draft fan 120B. The air forced into the duct 110 is discharged from the first end 112 of the duct 110 and, together with the air around the intake port 86 of the heat dissipation device 80, is sucked into the heat dissipation device 80 through the intake port 86 of the heat dissipation device 80.

[0028] In some embodiments, as shown in FIG. 3, the blower device 100A (100) includes a control device 130 for controlling the airflow rate of the fan 120A (120) based on the temperature of the intake side of the heat dissipation device 80. Air A1 guided to the vicinity of the intake port 86 of the heat dissipation device 80 by the fan 120A (120) under the control of the control device 130 is taken into the heat dissipation device 80 from the intake port 86 as intake air A3 together with air A2 around the heat dissipation device 80 on the intake side. 2, the blower 100A (100) includes a temperature measuring unit 98 for detecting the temperature of the air A2 around the heat dissipation device 80 on the intake side as the temperature of the intake side of the heat dissipation device 80, and the detection result of the temperature measuring unit 98 is used for control in the control device 130. In other embodiments, the temperature measuring unit 98 detects the temperature of the intake air A3 as the temperature of the intake side of the heat dissipation device 80. Furthermore, the temperature on the intake side of the heat dissipation device 80 measured by the temperature measurement unit 98 may be either a dry-bulb temperature or a wet-bulb temperature. For example, if the heat dissipation device 80 is a cooling tower 80A, the performance of the cooling tower 80A depends on the wet-bulb temperature on the intake side. Therefore, the temperature measurement unit 98 may be a wet-bulb thermometer, or may include a dry-bulb thermometer and a hygrometer.

[0029] As described above, in order to promote the intake of air A1 from the blower 100 into the intake port 86, the outlet 102 of the blower 100 is disposed opposite the intake port 86 of the heat dissipation device 80. The relative positions and dimensional relationship between the outlet 102 of the blower 100 and the intake port 86 of the heat dissipation device 80 will be described in detail below with reference to Figures 4A to 5B.

[0030] Fig. 4A is a perspective view showing the relationship between the intake port of a heat dissipation device and the outlet of a blower according to one embodiment. Fig. 4B is a schematic view showing the relationship between the intake port of the heat dissipation device of Fig. 4A and the outlet of a blower according to one embodiment. Fig. 5A is a perspective view showing the relationship between the intake port of a heat dissipation device and the outlet of a blower according to another embodiment, and Fig. 5B is a schematic view showing the relationship between the intake port of the heat dissipation device of Fig. 5A according to one embodiment and the outlet of a blower. 4B and 5B, for the sake of convenience, the device configuration is omitted, and only the outlet 102 of the blower device 100, the intake port 86 of the heat dissipation device 80, and the virtual area 87 obtained by projecting the intake port 86 onto the plane on which the outlet 102 exists are shown. The intake port 86 of the heat dissipation device 80 in FIG. 5B is a partial illustration of the intake port 86 of the heat dissipation device 80 in FIG. 5A.

[0031] In the embodiment shown in FIG. 4A, the heat dissipation device 80 is a rectangular heat dissipation device 80C having a casing in the shape of a rectangular parallelepiped. In contrast, in the embodiment shown in FIG. 5A, the heat dissipation device 80 is a cylindrical (round) heat dissipation device 80D having a cylindrical casing.

[0032] In some embodiments, as shown in FIGS. 4A and 5A, the blower device 100 has a plurality of outlets 102 disposed opposite the intake port 86 of the heat dissipation device 80. 4A, the air intake ports 86 of the rectangular heat dissipation device 80C are provided on a pair of opposing side surfaces of the casing of the rectangular heat dissipation device 80C. A pair of outlets 102 of the air blower 100 face the pair of air intake ports 86 of the rectangular heat dissipation device 80C, respectively. 5A is provided around the entire circumference of the casing of the cylindrical heat dissipation device 80D. The outlets 102 of the air blower 100 face the intakes 86 of the cylindrical heat dissipation device 80D at multiple positions in the circumferential direction of the heat dissipation device 80, respectively.

[0033] In addition, when the blower device 100 has multiple outlets 102, the duct 110 may include an upstream duct having a second end 114 and multiple downstream ducts branching off from the upstream duct, and multiple outlets 102 may be formed corresponding to the downstream ducts, each having a first end 112. Alternatively, the blower device 100 may include a plurality of ducts 110 each having a first end 112 and a second end 114, and a plurality of outlets 102 may be formed corresponding to the plurality of ducts 110, respectively.

[0034] In some embodiments, the intake port 86 of the heat dissipation device 80 (80C, 80D) at least partially overlaps with the outlet 102 of the blower 100 in a virtual area 87 obtained by projecting the intake port 86 onto a plane on which the outlet 102 of the blower 100 exists, as shown in Figures 4B and 5B. In one embodiment, the entire outlet 102 of the blower 100 overlaps with the virtual region 87. In another embodiment, the outlet 102 of the blower 100 partially overlaps with the virtual region 87, with a portion of the outlet 102 being outside the virtual region 87. In addition, considering that the low-temperature air flowing out from the outlet 102 of the blower device 100 tends to stagnate near the installation surface of the heat dissipation device 80, the centroid P of the outlet 102 of the blower device 100 may be located higher than the centroid O of the intake port 86.

[0035] In some embodiments, as shown in Figures 4B and 5B, the distance L between the outlet 102 of the blower device 100 and the intake 86 of the heat dissipation device 80 satisfies at least one of the conditions 0 < L < 2W0 or 0 < L < 2H0. Here, distance L is the shortest distance between the centroid P of the outlet 102 of the blower device 100 and the intake port 86 of the heat dissipation device 80, W0 is the width (or circumferential length) of the intake port 86 of the heat dissipation device 80, and H0 is the height of the intake port 86 of the heat dissipation device 80.

[0036] In some embodiments, the air inlet 86 of the heat dissipation device 80 and the air outlet 102 of the blower device 100 satisfy at least one of the conditions 0.8W0≦W1≦1.2W0 or 0.8H0≦H1≦1.2H0. Here, W1 is the horizontal length (width) of outlet 102 of blower device 100, and H1 is the vertical length (height) of outlet 102 of blower device 100.

[0037] The angle α (see FIG. 4B) formed between the outlet 102 of the blower 100 and the intake 86 of the heat dissipation device 80 may be between 0 and 45 degrees. The angle α is defined as the angle formed between the normal to the intake 86 and the normal to the outlet 102. FIG. 4A shows an example in which the outlet 102 of the blower 100 is parallel to the intake 86 of the heat dissipation device 80 (α=0°).

[0038] The characteristic configurations of the air blower and ground freezing system according to the above-described several embodiments can be summarized as follows.

[0039] [1] In some embodiments, the blower device (100) includes: A blower (100) for a ground freezing system (1) that freezes the ground by supplying a refrigerant cooled by a refrigerator (10) installed on the ground to a freezing pipe (70) in a tunnel (5), a duct (110) having a first end (112) located on the intake side of a heat dissipation device (80) installed on the ground to dissipate heat from the refrigeration cycle of the refrigerator (10) to the outside of the system, and a second end (114) located in a tunnel (5) in which a freezing pipe (70) is installed; a fan (120 (120A, 120B)) that guides the air (A1) in the well (5) through a duct (110) to the intake side of the heat dissipation device (80); Equipped with.

[0040] When the temperature of the air (A2) around the intake side of the heat dissipation device (80) is high, heat is prevented from being released from the refrigeration cycle to the outside, which leads to an increase in the high-pressure side pressure of the refrigerator (10). When the high-pressure side pressure of the refrigerator (10) increases, not only does the efficiency (COP) of the refrigeration cycle decrease due to an increase in compression power (power consumption), but the increase in the high-pressure side pressure can also cause the refrigerator (10) to stop. In this regard, according to the configuration [1], the air (A3) drawn into the heat dissipation device (80) is cooled by the low-temperature air (A1) in the well (5) guided by the blower (100), and the temperature of the air (A3) falls within a suitable temperature range for the heat dissipation device (80). This makes it possible to prevent a decrease in the efficiency of the refrigeration cycle of the refrigerator (10) due to an increase in the high-pressure side pressure.

[0041] [2] In some embodiments, in the configuration of [1] above, The fan (120) is a suction fan (120A) provided on the first end (112) side of the duct (110).

[0042] According to the configuration [2] above, the fan (120 (120A)) is connected to the first end (112) of the duct (110) located on the ground side, so that installation space for the fan (120 (120A)) can be easily secured.

[0043] [3] In some embodiments, in the configuration of [1] or [2] above, The fan (120) is a forced draft fan (120B) provided on the second end (114) side of the duct (110).

[0044] According to the configuration [3], the fan (120 (120B)) pushes air into the duct (110), thereby preventing deformation of the duct (110) due to negative pressure in the duct (110). This increases the options for the duct (110) that can be used, and increases the degree of freedom in designing the air blower (100B). Furthermore, since the forced draft fan (120B) is installed in the well (5) away from the heat dissipation device (80), an increase in the intake air temperature of the heat dissipation device (80) due to the exhaust heat of the forced draft fan (120B) is prevented, and a decrease in the efficiency of the refrigeration cycle of the refrigerator (10) can be suppressed.

[0045] [4] In some embodiments, in any of the configurations [1] to [3] above, The heat dissipation device (80) is a cooling tower (80A) configured to dissipate heat of the refrigeration cycle to intake air (A3) including air (A1) in the well (5) supplied through a duct (110).

[0046] According to the above configuration [4], the intake air (A3) containing the low-temperature air (A1) in the well (5) is taken into the cooling tower (80A), thereby promoting heat dissipation in the cooling tower (80A) and suppressing a decrease in the efficiency of the refrigeration cycle of the refrigerator (10).

[0047] [5] In some embodiments, in the configuration of [4] above, The fans (120 (120A, 120B)) are configured so that the air volume is controlled based on the wet-bulb temperature on the intake side of the cooling tower (80A).

[0048] According to the configuration [5] above, the heat dissipation performance of the cooling tower (80A) is determined by the wet-bulb temperature on the intake side of the cooling tower (80A). Therefore, by appropriately controlling the airflow rate of the fan (120 (120A, 120B)) in accordance with the wet-bulb temperature of the air (A2) around the intake side of the cooling tower (80A) and supplying a necessary and sufficient amount of low-temperature air (A1) to the intake side of the cooling tower (80A), it is possible to both suppress a decrease in the efficiency of the refrigeration cycle and reduce the energy required for blowing air.

[0049] [6] In some embodiments, in any of the configurations [1] to [3] above, The heat dissipation device (80) is a dry cooler (80B) configured to radiate heat of a refrigeration cycle to intake air (A3) containing air (A1) in the well (5) supplied through a duct (110).

[0050] According to the above configuration [6], by taking in the intake air (A3) containing the low-temperature air (A1) in the well (5) into the dry cooler (80B), heat dissipation in the dry cooler (80B) is promoted, and a decrease in the efficiency of the refrigeration cycle of the refrigerator (10) can be suppressed.

[0051] [7] In some embodiments, the ground freezing system (1) includes: a freezing pipe (70) for freezing the ground (7) inside the tunnel (5); a refrigerator (10) installed on the ground for cooling a refrigerant to be supplied to a freezing pipe (70); a heat dissipation device (80) installed on the ground for dissipating heat generated in the refrigeration cycle of the refrigerator (10) to the outside of the system; The blower (100) according to any one of [1] to [6] above; Equipped with.

[0052] When the temperature of the air (A2) around the intake side of the heat dissipation device (80) is high, heat is prevented from being released from the refrigeration cycle to the outside, which leads to an increase in the high-pressure side pressure of the refrigerator (10). When the high-pressure side pressure of the refrigerator (10) increases, not only does the efficiency (COP) of the refrigeration cycle decrease due to an increase in compression power (power consumption), but the increase in the high-pressure side pressure can also cause the refrigerator (10) to stop. According to the configuration [7], the air (A3) drawn into the heat dissipation device (80) is cooled by the low-temperature air (A1) in the well (5) guided by the blower (100), and the temperature of the air (A3) falls within a suitable temperature range for the heat dissipation device (80). This prevents a decrease in the efficiency of the refrigeration cycle of the refrigerator (10) due to an increase in the high-pressure side pressure.

[0053] Although several embodiments of the present invention have been described above, it is of course possible to add modifications to the above-described embodiments without departing from the spirit of the present invention. For example, Figures 1 to 5B show an example in which the outlet 102 of the blower 100 is positioned opposite the intake 86 of the heat dissipation device 80, but since the low-temperature air flowing out from the outlet 102 of the blower 100 tends to stagnate near the installation surface of the heat dissipation device 80, the outlet 102 may also be positioned above the intake 86.

[0054] In this specification, expressions expressing relative or absolute arrangement such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" not only express such an arrangement strictly, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions such as "identical," "equal," and "homogeneous" that indicate that something is in an equal state not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. Furthermore, in this specification, expressions representing shapes such as a rectangular shape or a cylindrical shape not only represent rectangular shapes or cylindrical shapes in the strict geometric sense, but also represent shapes including uneven portions, chamfered portions, etc., to the extent that the same effect can be obtained. Furthermore, in this specification, the expressions "comprise," "include," or "have" a component are not exclusive expressions that exclude the presence of other components. [Explanation of symbols]

[0055] 1: Ground freezing system 5: Pit 7: Ground 10: Freezer 70: Freezing tube 80: Heat dissipation device 80A: Cooling tower 80B: Dry cooler 100: Air blower 110: Duct 112: 1st end 114: 2nd end 120: Fan 120A: Intake fan 120B: Push-in fan

Claims

1. A blower for a ground freezing system that supplies refrigerant cooled by a refrigerator installed on the ground to a freezing pipe in a tunnel to freeze the ground. a duct having a first end located on the intake side of a heat dissipation device installed on the ground to dissipate heat from the refrigeration cycle of the refrigerator to the outside of the system, and a second end located inside the tunnel where the freezing pipe is installed; a fan that guides the air inside the tunnel through the duct to the intake side of the heat dissipation device; Equipped with Blower.

2. The fan is a suction fan provided on the first end side of the duct. The blower device according to claim 1 .

3. The fan is a forced draft fan provided on the second end side of the duct. The blower device according to claim 1 .

4. The heat dissipation device is a cooling tower configured to release heat of the refrigeration cycle to intake air containing the air in the mine supplied through the duct. The blower device according to any one of claims 1 to 3.

5. The fan is configured so that the air volume is controlled based on the wet bulb temperature on the intake side of the cooling tower. The blower device according to claim 4.

6. The heat dissipation device is a dry cooler configured to radiate heat of the refrigeration cycle to intake air containing the air in the mine that is supplied through the duct. The blower device according to any one of claims 1 to 3.

7. A freezing pipe that freezes the ground inside the tunnel; a refrigerator installed on the ground for cooling the refrigerant supplied to the freezing pipe; a heat dissipation device that is installed on the ground and that dissipates heat from the refrigeration cycle of the refrigerator to the outside of the system; The blower device according to any one of claims 1 to 3; Equipped with Ground freezing system.

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