Portable receiver of soil freezing system, and soil freezing system

Abstract

To provide a portable receiver of a soil freezing system and a soil freezing system that can be easily carried into small spaces.SOLUTION: A portable receiver of a soil freezing system comprises a cradle, a receiver tank mounted on the cradle, one or more first pipes connected to a liquid phase portion of the receiver tank, and one or more second pipes connected to a gas phase portion of the receiver tank. The first pipe has a first connector portion at an end to which another pipe can be connected. The second pipe has a second connector portion at an end to which another pipe can be connected.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a portable receiver for a soil freezing system and to a soil freezing system. [Background technology]

[0002] A method for freezing soil in a specified area is known for the purposes of stabilizing the construction ground, blocking water, etc. In this method, a soil freezing pipe is placed in the soil to be frozen, and a refrigerant is passed through the soil freezing pipe, thereby removing heat from the soil and freezing the target soil (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-148104 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the soil freezing pipe and the refrigerator are relatively far apart, the amount of liquid refrigerant in the return pipe that returns the refrigerant from the soil freezing pipe to the refrigerator increases, which increases the total amount of refrigerant. Therefore, in order to place the refrigerant receiver tank away from the refrigerator and near the location of the soil freezing pipe, it is possible to consider transporting the receiver tank into a tunnel or the like.

[0005] However, if the receiver tank, along with the liquid pump, liquid supply valve, strainer, etc., is mounted on a common platform and then transported into a narrow space such as a tunnel, it becomes difficult to transport the tank.

[0006] In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a portable receiver for a soil freezing system and a soil freezing system that can be easily transported into small spaces. [Means for solving the problem]

[0007] (1) A portable receiver of a soil freezing system according to at least one embodiment of the present disclosure includes: A stand and a receiver tank provided on the frame; One or more first pipes connected to the liquid phase portion of the receiver tank; One or more second pipes connected to the gas phase portion of the receiver tank; Equipped with the first pipe has a first connector portion at an end thereof to which another pipe can be connected; The second pipe has a second connector portion at an end thereof to which another pipe can be connected.

[0008] (2) A soil freezing system according to at least one embodiment of the present disclosure, A portable receiver for the soil freezing system having the configuration (1) above; a supply valve unit for supplying a refrigerant from a refrigerator to the liquid phase portion of the portable receiver; a pump unit for sending the refrigerant from the liquid phase portion to the freezing tube; a strainer unit connected to the gas phase portion of the portable receiver via the second pipe for removing foreign matter in the refrigerant from the freezing pipe; Equipped with The first pipe includes an inlet-side first pipe connected to the supply valve unit, and an outlet-side first pipe connected to the pump unit. [Effects of the Invention]

[0009] At least one embodiment of the present disclosure facilitates transporting a portable receiver and soil freezing system into tight spaces. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating the overall configuration of a soil freezing device as an example of a refrigerant supply system according to some embodiments. [Figure 2]FIG. 2 is an isometric view of a receiver unit. [Figure 3] FIG. 2 is an isometric view showing the connection state of each unit. [Figure 4] FIG. 2 is a schematic plan view showing the connection state of each unit. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, several embodiments of the present disclosure 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 disclosure. For example, 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 exactly, 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. For example, expressions representing shapes such as a square shape or a cylindrical shape not only represent shapes such as a square shape or a cylindrical shape 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. On the other hand, the expressions "comprise," "include," "have," "includes," or "have" of one element are not exclusive expressions that exclude the presence of other elements.

[0012] (Overall configuration of soil freezing device 1) FIG. 1 is a diagram illustrating the overall configuration of a soil freezing device as an example of a refrigerant supply system according to some embodiments. In some embodiments, the soil freezing device 1 includes a refrigerator 5 having a primary refrigerant circulation system 3 and a secondary refrigerant circulation system 10 connected to the primary refrigerant circulation system 3 via a heat exchanger 4. In the secondary refrigerant circulation system 10 according to some embodiments, the refrigerant (secondary refrigerant) is, for example, a CO2 refrigerant.

[0013] In some embodiments, the secondary refrigerant circulation system 10 includes a refrigerant circulation path 20 of the secondary refrigerant circulation system 10, which includes a plurality of soil freezing pipes 15 (hereinafter simply referred to as freezing pipes 15) buried in the soil 9 to freeze the soil 9, a first receiver 11 installed lower than the refrigerator 5 and storing the refrigerant supplied to the plurality of freezing pipes 15, a feed pipe 21 that sends the refrigerant liquefied in the refrigerator 5 to the first receiver 11, and a return pipe 51 that returns the gaseous refrigerant from the gas phase portion of the first receiver 11 to the refrigerator 5 side. In some embodiments, the secondary refrigerant circulation system 10 is provided with a liquid supply pump 13 (hereinafter also referred to as an underground pump 13) for supplying the liquid refrigerant stored in the first receiver 11 to multiple soil freezing pipes 15, a liquid header 17 for distributing the liquid refrigerant to the multiple freezing pipes 15, and a gas header 19 for collecting gaseous and liquid refrigerant from the multiple freezing pipes 15. In some embodiments of the secondary refrigerant circulation system 10, the first receiver 11, the underground pump 13, the liquid header 17, and the gas header 19 are arranged in the underground space 8. The first receiver 11 is included in the receiver unit 100, which will be described later.

[0014] In some embodiments, the secondary refrigerant circulation system 10 includes a second receiver 12 that is positioned higher than the first receiver 11 and stores the refrigerant to be supplied to the first receiver 11, and a liquid supply pump 14 (hereinafter also referred to as the ground pump 14) that supplies the liquid refrigerant stored in the second receiver 12 to the first receiver 11. In some embodiments of the secondary refrigerant circulation system 10, the second receiver 12 and the ground pump 14 are located on the ground 7.

[0015] (Feed pipe 21) In some embodiments of the secondary refrigerant circulation system 10, the feed pipe 21 includes an above-ground pipe 21a arranged above ground 7, an underground pipe 21b arranged in the underground space 8, and a vertical pipe 21c that connects the above-ground pipe 21a and the underground pipe 21b and extends vertically.

[0016] In the secondary refrigerant circulation system 10 shown in Figure 1, the above-ground piping 21a includes a piping 22 that connects the heat exchanger 4 and the liquid phase portion of the second receiver 12, and a pump piping 23 that connects the liquid phase portion of the second receiver 12 and the upper end of the vertical pipe 21c, and has an above-ground pump 14 installed in the middle. In some embodiments of the secondary refrigerant circulation system 10, the underground pipe 21b connects the lower end of the vertical pipe 21c to a supply valve unit 200 described later for connecting the underground pipe 21b to the first receiver 11.

[0017] (Return piping 51) In some embodiments of the secondary refrigerant circulation system 10, the return pipe 51 includes an underground pipe 51b arranged in the underground space 8, an above-ground pipe 51a arranged above ground 7, and a vertical pipe 51c that connects the underground pipe 51b and the above-ground pipe 51a and extends vertically.

[0018] In the secondary refrigerant circulation system 10 shown in FIG. 1, the underground pipe 51b connects the gas phase portion of the first receiver 11 to the lower end of the vertical pipe 51c.

[0019] In some embodiments of the secondary refrigerant circulation system 10, the above-ground piping 51a includes a piping 52 connecting the upper end of the vertical pipe 51c to the gas phase portion of the second receiver 12, and a piping 53 connecting the gas phase portion of the second receiver 12 to the heat exchanger 4.

[0020] (Configuration for controlling each part of the soil freezing device 1) The secondary refrigerant circulation system 10 according to some embodiments is provided with a control valve 31 connected to the underground pipe 21b of the feed pipe 21 for adjusting the liquid level of the liquid refrigerant stored in the first receiver 11, and a level sensor 41 for detecting the liquid level of the liquid refrigerant stored in the first receiver 11. The secondary refrigerant circulation system 10 according to some embodiments is provided with a pressure sensor 44 for detecting the pressure in the first receiver 11, and a pressure sensor 45 for detecting the discharge pressure of the underground pump 13.

[0021] In some embodiments, the secondary refrigerant circulation system 10 is provided with a level sensor (not shown) for detecting the liquid level of the liquid refrigerant stored in the second receiver 12, a pressure sensor (not shown) for detecting the pressure within the second receiver 12, and a pressure sensor (not shown) for detecting the discharge pressure of the ground pump 14.

[0022] (Control device 90) The soil freezing apparatus 1 according to some embodiments includes a control device 90 for controlling the soil freezing apparatus 1. In the soil freezing apparatus 1 according to some embodiments, the control device 90 includes an underground control device 92 provided in an underground control panel 91 located in the underground space 8, and an above-ground control device 94 provided in an above-ground control panel 93 located above ground 7. The underground control device 92 and the ground control device 94 each include a processor (not shown) that executes various types of arithmetic processing, and a memory (not shown) that stores various types of data processed by the processor either non-temporarily or temporarily. The processor may be implemented by a CPU, GPU, MPU, DSP, or other types of arithmetic devices, or a combination of these. The memory may be implemented by a ROM, RAM, flash memory, or a combination of these. The control details of the underground control device 92 and the ground control device 94 will be explained later.

[0023] (Regarding the flow of secondary refrigerant in the secondary refrigerant circulation system 10) In the soil freezing device 1 according to some embodiments configured as described above, the gaseous refrigerant (secondary refrigerant) stored in the second receiver 12 is cooled by the refrigerator 5 via the heat exchanger 4 to become a liquid refrigerant, which is then stored in the second receiver 12. The liquid refrigerant stored in the second receiver 12 is supplied to the first receiver 11 by the above-ground pump 14. Furthermore, for example, if the first receiver 11 is located relatively deep underground, the head difference between the second receiver 12 and the first receiver 11 is relatively large, so by utilizing the head difference, the liquid refrigerant stored in the second receiver 12 can be supplied to the first receiver 11 without using the above-ground pump 14.

[0024] In the soil freezing device 1 shown in Figure 1, the amount of liquid refrigerant stored in the first receiver 11 is maintained at a specified liquid level by the underground control device 92 controlling the opening of the control valve 31 based on the liquid level in the first receiver 11 detected by the level sensor 41. In the soil freezing device 1 according to some embodiments, the regulating valve 31 also serves as an expansion valve.

[0025] In the soil freezing device 1 shown in FIG. 1, the liquid refrigerant stored in the first receiver 11 is supplied to the liquid header 17 by the underground pump 13, and is supplied from the liquid header 17 to the plurality of freezing pipes 15. When the refrigerant supplied to the freezing pipes 15 evaporates in the freezing pipes 15, it absorbs heat from the soil around the freezing pipes 15. As a result, the soil around the freezing pipes 15 freezes. The gaseous refrigerant that has evaporated in the plurality of freezing pipes 15 and the liquid refrigerant that has not completely evaporated in the plurality of freezing pipes 15 are collected in the gas header 19 and returned to the first receiver 11.

[0026] In some embodiments of the soil freezing device 1, the liquid phase refrigerant in the first receiver 11 remains in the first receiver 11, and the gas phase refrigerant in the first receiver 11 returns to the second receiver 12, where it is cooled and liquefied in the heat exchanger 4 and returns to the second receiver 12 as liquid refrigerant.

[0027] (Regarding the transport of the first receiver 11, etc. into the underground space 8) As described above, in the soil freezing device 1 according to some embodiments, the first receiver 11, the control valve 31, and the underground pump 13 are placed in the underground space 8. However, if the first receiver 11 is installed on a common frame together with the control valve 31, the underground pump 13, etc., and is then transported into a narrow space such as a tunnel within the underground space 8, the transport becomes difficult. Therefore, in the soil freezing device 1 according to some embodiments, the first receiver 11, the control valve 31, the underground pump 13, and the strainer 35 described below are each mounted on separate frames as units, and each unit can be carried into the underground space 8. In the soil freezing device 1 according to some embodiments, each unit is placed in the underground space 8, and the units are connected to each other by piping or flexible piping. Each of these units will be described below.

[0028] FIG. 2 is an isometric view of the receiver unit 100. FIG. 3 is an isometric view showing the connection state of each unit. FIG. 4 is a schematic plan view showing the connection state of each unit. The soil freezing device 1 according to some embodiments includes a receiver unit 100, a supply valve unit 200, a pump unit 300, and a strainer unit 400.

[0029] (Receiver unit 100) As shown in FIG. 2, the receiver unit 100 of the soil freezing device 1 according to some embodiments includes the above-described first receiver 11, a stand 101 that supports the first receiver 11, and a receiver unit control panel 911. In the receiver unit 100 shown in Fig. 2, the first receiver 11 is supported on the mount 101 by four support pillars 102 extending upward from the mount 101. For ease of illustration, the upper part of the support pillar 102 located closest to the viewer in Fig. 2 is omitted. The first receiver 11 has a cylindrical shape that extends horizontally along a central axis AX (see FIG. 4), and has end plates on both ends.

[0030] The first receiver 11 is provided with one or more first pipes 110 connected to a liquid phase part of the first receiver 11, and one or more second pipes 120 connected to a gas phase part of the first receiver 11. In the example shown in Figures 2 to 4, two first pipes 110 and two second pipes 120 are provided.

[0031] (First piping 110) In the receiver unit 100 shown in FIG. 2, the first pipe 110 includes an inlet side first pipe 110A connected to the supply valve unit 200 described later, and an outlet side first pipe 110B connected to the pump unit 300 described later.

[0032] The inlet-side first pipe 110A has a base end connected to, for example, the bottom of the first receiver 11, and a tip end branched to one side and the other side of the first receiver 11 in the longitudinal direction.

[0033] The base end of the outlet-side first pipe 110B is connected to, for example, a cylindrical liquid reservoir 11a with a bottom provided at the bottom of the first receiver 11. In the receiver unit 100 shown in Fig. 2, the outlet-side first pipe 110B includes a pipe 110B1 having a tip extending toward one side in the longitudinal direction (extension direction) of the first receiver 11 and a pipe 110B2 having a tip extending toward the other side in the longitudinal direction of the first receiver 11, but the base end of one pipe may be connected to the liquid reservoir 11a, and the tip side of the pipe may branch out toward one side and the other side in the longitudinal direction of the first receiver 11.

[0034] Each first pipe 110 has a first connector portion 111 at its end (tip) to which the flexible pipe 71 or another pipe 72 with little flexibility can be connected. That is, each first pipe 110 has two first connector portions 111 arranged toward one side and the other side of the first receiver 11 in the longitudinal direction. Each first connector portion 111 is a joint for connecting to the flexible pipe 71 or another pipe 72, for example, a flange joint.

[0035] In the receiver unit 100 shown in Figure 2, when the receiver unit 100 is viewed from above as shown in Figure 4, the inlet side first piping 110A is configured so that the two first connector portions 111 of the inlet side first piping 110A are located on one side of the central axis AX of the first receiver 11 extending in the longitudinal direction of the first receiver 11 (one side in the short direction perpendicular to the longitudinal direction of the first receiver 11: the left side in Figure 4). Similarly, in the receiver unit 100 shown in Figure 2, when the receiver unit 100 is viewed from above as shown in Figure 4, the outlet side first piping 110B is configured so that the two first connector parts 111 of the outlet side first piping 110B are located on the other side of the central axis AX of the first receiver 11 (the other side in the short direction of the first receiver 11: the right side in Figure 4).

[0036] In addition, the inlet side first piping 110A may be configured so that, when the receiver unit 100 is viewed from above as shown in Figure 4, the two first connector portions 111 of the inlet side first piping 110A are located on the other side (the right side in Figure 4) of the central axis AX of the first receiver 11. Similarly, the outlet side first piping 110B may be configured so that, when the receiver unit 100 is viewed from above, the two first connector portions 111 of the outlet side first piping 110B are located on one side (the left side in Figure 4) of the central axis AX of the first receiver 11.

[0037] In the receiver unit 100 shown in Figure 2, when the receiver unit 100 is viewed from above as shown in Figure 4, the first connector portion 111 of the pipe 110B1 whose tip faces one side of the longitudinal direction (extension direction) of the first receiver 11 and the first connector portion 111 of the pipe 110B2 whose tip faces the other side of the longitudinal direction of the first receiver 11 may be configured to be located in opposite directions across the central axis AX of the first receiver 11.

[0038] Furthermore, in the receiver unit 100 shown in Figure 2, the inlet side first piping 110A is provided on one side of the first receiver 11 in the longitudinal direction (the right side in the figure) relative to the liquid reservoir portion 11a, but it may also be provided on the other side of the first receiver 11 in the longitudinal direction (the left side in the figure).

[0039] The first connector portion 111 that is not connected to other units, etc., is fitted with a member for closing the first connector portion 111. If the first connector portion 111 is a flange joint, a closing flange is fitted to the first connector portion 111 that is not connected to other units, etc.

[0040] (Second piping 120) In the receiver unit 100 shown in Figure 2, the second piping 120 includes an inlet side second piping 120A connected to the strainer unit 400 described later, and an outlet side second piping 120B connected to the underground piping 51b of the return piping 51 directly or via a flexible piping 71 or another piping 72. The inlet side second pipe 120A and the outlet side second pipe 120B have their respective base ends connected to, for example, the upper part of the first receiver 11, and their respective tip ends branching out to one side and the other side of the first receiver 11 in the longitudinal direction.

[0041] Each second pipe 120 has a second connector portion 121 at its end (tip) to which the flexible pipe 71 or another pipe 72 with little flexibility can be connected. That is, each second pipe 120 has two second connector portions 121 arranged toward one side and the other side of the first receiver 11 in the longitudinal direction. Each second connector portion 121 is a joint for connecting to the flexible pipe 71 or another pipe 72, for example, a flange joint.

[0042] In the receiver unit 100 shown in Figure 2, when the receiver unit 100 is viewed from above as shown in Figure 4, the inlet side second piping 120A is configured so that the two second connector portions 121 of the inlet side second piping 120A are located on one side of the central axis AX of the first receiver 11 (one side in the short direction of the first receiver 11: the left side in Figure 4). Similarly, in the receiver unit 100 shown in Figure 2, when the receiver unit 100 is viewed from above as shown in Figure 4, the outlet side second piping 120B is configured so that the two second connector portions 121 of the outlet side second piping 120B are located on the other side of the central axis AX of the first receiver 11 (the other side in the short direction of the first receiver 11: the right side in Figure 4).

[0043] In addition, the inlet side second piping 120A may be configured so that, when the receiver unit 100 is viewed from above as shown in Figure 4, the two second connector portions 121 of the inlet side second piping 120A are located on the other side (the right side in Figure 4) of the central axis AX of the first receiver 11. Similarly, the outlet side second piping 120B may be configured such that, when the receiver unit 100 is viewed from above, the two second connector portions 121 of the outlet side second piping 120B are located on one side (the left side in Figure 4) of the central axis AX of the first receiver 11.

[0044] Furthermore, in the receiver unit 100 shown in Figure 2, the inlet side second piping 120A is provided on the other longitudinal side (left side in the figure) of the first receiver 11, and the outlet side second piping 120B is provided on one longitudinal side (right side in the figure) of the first receiver 11, but the inlet side second piping 120A may be provided on one longitudinal side (right side in the figure) of the first receiver 11, and the outlet side second piping 120B may be provided on the other longitudinal side (left side in the figure) of the first receiver 11.

[0045] The second connector portion 121 that is not connected to other units, etc., is fitted with a member for closing the second connector portion 121. If the second connector portion 121 is a flange joint, a closing flange is fitted to the second connector portion 121 that is not connected to other units, etc.

[0046] When the first receiver 11 is installed on a common frame together with the underground pump 13, the control valve 31, and the strainer 35, it is difficult to transport it into a narrow space such as a tunnel. 2, the receiver unit 100 can be carried alone into a small space and connected to other units 200, 300, and 400 within the small space. This makes it easy to carry the first receiver 11 into the small space.

[0047] In the receiver unit 100 shown in FIG. 2, at least a portion of the first connector portion 111 and the second connector portion 121 may be located outside the area occupied by the base 101 of the receiver unit 100 in a plan view. This makes it easy to arrange the receiver unit 100 and the other units 200, 300, 400 connected via the first connector portion 111 and the second connector portion 121 so that they overlap in the height direction, thereby making it possible to keep the height of the entire device, including the other units 200, 300, 400 connected to the first receiver 11, relatively low. This makes it possible to arrange the entire device, including the other units 200, 300, 400, in a relatively low, narrow space such as a mine. Furthermore, the positions of the other units 200, 300, 400 relative to the receiver unit 100 can be set relatively freely in both the longitudinal and lateral directions.

[0048] In the receiver unit 100 shown in Fig. 2, each first pipe 110 has two first connector portions 111 arranged toward one side and the other side in the longitudinal direction of the first receiver 11. In the receiver unit 100 shown in Fig. 2, each second pipe 120 has two second connector portions 121 arranged toward one side and the other side in the longitudinal direction of the first receiver 11. This makes it easier to place the other units 200, 300, 400 connected to the first receiver 11 on either side of the first receiver 11 in the longitudinal direction, thereby improving the freedom of placement of the other units 200, 300, 400 in a small space.

[0049] In the receiver unit 100 shown in Fig. 2, the first pipe 110 includes an inlet-side first pipe 110A and an outlet-side first pipe 110B, which are two first pipes 110 connected to the lower part of the first receiver 11 and provided at different positions in the longitudinal direction of the first receiver 11. In the receiver unit 100 shown in Fig. 2, the second pipe 120 includes an inlet-side second pipe 120A and an outlet-side second pipe 120B, which are two second pipes 120 connected to the upper part of the first receiver 11 and provided at different positions in the longitudinal direction of the first receiver 11. This makes it easy to arrange the supply valve unit 200 and the pump unit 300, which are two external devices connected to the two first pipes 110 (the inlet side first pipe 110A and the outlet side first pipe 110B), on one side and the other side in the longitudinal direction of the first receiver 11. Also, it makes it easy to arrange the strainer unit 400 and the underground pipe 51b, which are two external devices connected to the two second pipes 120 (the inlet side second pipe 120A and the outlet side second pipe 120B), on one side and the other side in the longitudinal direction of the first receiver 11. In addition, it becomes easier to stagger the height positions of the two external devices, the supply valve unit 200 and the pump unit 300, which are connected to the two first pipes 110 (the inlet side first pipe 110A and the outlet side first pipe 110B), and the two external devices, the strainer unit 400 and the underground pipe 51b, which are connected to the two second pipes 120 (the inlet side second pipe 120A and the outlet side second pipe 120B), making it possible to arrange multiple external devices compactly.

[0050] (Receiver unit control panel 911) In the soil freezing apparatus 1 according to some embodiments, the underground control panel 91 includes a receiver unit control panel 911. In the soil freezing apparatus 1 according to some embodiments, the underground control device 92 includes a receiver unit control device 921 provided in the receiver unit control panel 911. The receiver unit control device 921 includes a processor (not shown) that executes various arithmetic processes, and a memory (not shown) that non-temporarily or temporarily stores various data processed by the processor. The control details of the receiver unit control device 921 will be described later.

[0051] (Supply valve unit 200) The supply valve unit 200 of the soil freezing device 1 according to some embodiments is for supplying the refrigerant from the refrigerator 5 to the liquid phase part of the first receiver 11. As shown in FIG. 3, the supply valve unit 200 of the soil freezing device 1 according to some embodiments includes the above-mentioned regulating valve 31, a stand 201 that supports the regulating valve 31, and a supply valve unit control panel 912. In the supply valve unit 200 shown in FIG. 3, connector portions 211 are provided at the ends of the upstream and downstream pipes of the regulator valve 31, respectively. The underground pipe 21 b of the feed pipe 21 is connected to a connector portion 211 of the pipe upstream of the control valve 31 directly or via a flexible pipe 71 or another pipe 72 . A first connector portion 111 of the inlet side first pipe 110A is connected to a connector portion 211 of the pipe downstream of the regulator valve 31 via a flexible pipe 71 and another pipe 72. In Figure 3, the connector portion 211 of the piping downstream of the control valve 31 is connected to the first connector portion 111 on one side of the longitudinal direction of the first receiver 11 (right side in the figure) of the two first connector portions 111 of the inlet side first piping 110A via a flexible piping 71 or another piping 72, but it may also be connected to the first connector portion 111 on the other side of the longitudinal direction of the first receiver 11 (left side in the figure) of the two first connector portions 111 of the inlet side first piping 110A.

[0052] (Supply valve unit control panel 912) In the soil freezing apparatus 1 according to some embodiments, the underground control panel 91 includes a supply valve unit control panel 912. In the soil freezing apparatus 1 according to some embodiments, the underground control device 92 includes a supply valve unit control device 922 provided on the supply valve unit control panel 912. The supply valve unit control device 922 includes a processor (not shown) that executes various arithmetic processes, and a memory (not shown) that non-temporarily or temporarily stores various data processed by the processor. The control content of the supply valve unit control device 922 will be described later.

[0053] (Pump unit 300) The pump unit 300 of the soil freezing device 1 according to some embodiments is for sending the refrigerant from the liquid phase portion of the first receiver 11 to the freezing pipe 15. As shown in FIG. 3, the pump unit 300 of the soil freezing device 1 according to some embodiments includes the above-mentioned underground pump 13, a stand 301 that supports the underground pump 13, and a pump unit control panel 913. In the pump unit 300 shown in FIG. 3, connector portions 311 are provided at the ends of the upstream and downstream pipes of the pump unit 300, respectively. The first connector portion 111 of the outlet side first pipe 110B is connected to the connector portion 311 of the pipe upstream of the underground pump 13 via a flexible pipe 71 and another pipe 72. The upstream end of the refrigerant liquid piping 26 (see Figure 1), whose downstream end is connected to the liquid header 17, is connected to the connector portion 311 of the piping downstream of the underground pump 13, either directly or via a flexible piping 71 or another piping 72. In Figure 3, the connector portion 311 of the piping upstream of the underground pump 13 is connected to the first connector portion 111 of the piping 110B1 of the outlet side first piping 110B, the tip of which extends toward one side of the longitudinal direction of the first receiver 11, via a flexible piping 71 or another piping 72, but it may also be connected to the first connector portion 111 of the piping 110B2 of the outlet side first piping 110B, the tip of which extends toward the other side of the longitudinal direction of the first receiver 11.

[0054] (Pump unit control panel 913) In the soil freezing apparatus 1 according to some embodiments, the underground control panel 91 includes a pump unit control panel 913. In the soil freezing apparatus 1 according to some embodiments, the underground control device 92 includes a pump unit control device 923 provided in the pump unit control panel 913. The pump unit control device 923 includes a processor (not shown) that executes various arithmetic processes, and a memory (not shown) that non-temporarily or temporarily stores various data processed by the processor. The control contents of the pump unit control device 923 will be described later.

[0055] (Strainer Unit 400) The strainer unit 400 of the soil freezing device 1 according to some embodiments is for removing foreign matter in the refrigerant from the freezing pipe 15. As shown in FIG. 3, the strainer unit 400 of the soil freezing device 1 according to some embodiments includes a strainer 35 for removing foreign matter in the refrigerant from the freezing pipe 15, and a stand 401 for supporting the strainer 35. In the strainer unit 400 shown in FIG. 3, connector portions 411 are provided at the ends of the pipes on the upstream side and downstream side of the strainer 35, respectively. The downstream end of the refrigerant return pipe 27 (see Figure 1), whose upstream end is connected to the gas header 19, is connected to the connector portion 411 of the pipe upstream of the strainer 35, either directly or via a flexible pipe 71 or another pipe 72. A second connector 121 of the second inlet pipe 120A is connected to a connector 411 of the pipe downstream of the strainer 35 via a flexible pipe 71 and another pipe 72. In Figure 3, the connector portion 411 of the piping downstream of the strainer 35 is connected to the second connector portion 121 of the two second connector portions 121 of the inlet side second piping 120A on the other side of the longitudinal direction of the first receiver 11 (left side in the figure) via a flexible piping 71 or another piping 72, but it may also be connected to the second connector portion 121 of the two second connector portions 121 of the inlet side second piping 120A on one side of the longitudinal direction of the first receiver 11 (right side in the figure).

[0056] A soil freezing device 1 according to some embodiments includes a receiver unit 100, a supply valve unit 200 for supplying refrigerant from a refrigerator 5 to a liquid phase portion of a first receiver 11, a pump unit 300 for sending the refrigerant from the liquid phase portion to a freezing pipe 15, and a strainer unit 400 connected to a gas phase portion of the first receiver 11 via a second pipe 120 for removing foreign matter in the refrigerant from the freezing pipe 15. The first pipe 110 includes an inlet side first pipe 110A connected to the supply valve unit 200 and an outlet side first pipe 110B connected to the pump unit 300. This allows the receiver unit 100, the supply valve unit 200, the pump unit 300, and the strainer unit 400 to be carried into a small space, and the receiver unit 100 can be connected to the other units 200, 300, 400 within the small space.

[0057] In some embodiments, the soil freezing device 1 includes a supply valve unit 200, a pump unit 300, and a strainer unit 400, each of which includes a base 201, 301, 401 specific to each unit 200, 300, 400, and equipment consisting of a control valve 31, an underground pump 13, or a strainer 35 mounted on the base 201, 301, 401. As a result, each unit 200, 300, 400 is a single unit with its respective equipment (control valve 31, underground pump 13, strainer 35) mounted on a stand 201, 301, 401, making it easy to transport into and out of small spaces.

[0058] (Refrigerant flow in each unit 100, 200, 300, 400) The refrigerant flows through each of the units 100, 200, 300, and 400 configured as described above as follows. The liquid refrigerant stored in the second receiver 12 is supplied to the supply valve unit 200 via the feed pipe 21, and then supplied from the supply valve unit 200 to the first receiver 11 of the receiver unit 100 via the inlet side first pipe 110A. The amount of liquid refrigerant stored in the first receiver 11 is maintained at a specified liquid level by controlling the opening of the adjustment valve 31 of the supply valve unit 200 based on the liquid level of the first receiver 11 detected by the level sensor 41 (Figure 1).

[0059] The liquid refrigerant supplied to the first receiver 11 is sent from the first receiver 11 to the pump unit 300 via the outlet side first piping 110B, supplied to the liquid header 17 by the underground pump 13 of the pump unit 300, and supplied from the liquid header 17 to multiple freezing pipes 15.

[0060] The gaseous refrigerant that has evaporated in the multiple freezing pipes 15 and the liquid refrigerant that has not completely evaporated in the multiple freezing pipes 15 are collected in the gas header 19 and sent to the strainer unit 400, and after foreign matter in the refrigerant is removed by the strainer 35 of the strainer unit 400, the refrigerant returns to the first receiver 11 via the inlet side second piping 120A. The liquid phase refrigerant in the first receiver 11 remains in the first receiver 11, and the gas phase refrigerant in the first receiver 11 is discharged from the outlet side second piping 120B and returns to the second receiver 12 through the return piping 51.

[0061] (Regarding delivery and assembly of each unit 100, 200, 300, and 400) Each of the units 100, 200, 300, 400 configured in this manner is individually carried in and placed near the installation position of the freezing pipe 15, for example, in the underground space 8. Then, as described above, the receiver unit 100 and the supply valve unit 200 are connected, the receiver unit 100 and the pump unit 300 are connected, and the receiver unit 100 and the strainer unit 400 are connected.

[0062] Furthermore, the receiver unit control panel 911 and the supply valve unit control panel 912 are connected to be able to exchange control signals, and the receiver unit control panel 911 and the pump unit control panel 913 are connected to be able to exchange control signals. Although not described in detail, a cable (not shown) that transmits an output signal from a pressure sensor (not shown) provided in the strainer unit 400 is connected to the receiver unit control panel 911.

[0063] (Regarding the control contents of the underground control device 92 and the ground control device 94) In the soil freezing device 1 shown in FIG. 1, when soil freezing is performed, the ground control device 94 controls each part of the refrigerator 5 to operate the refrigerator 5. As a result, the refrigerator 5 cools and liquefies the gaseous refrigerant from the second receiver 12 in the heat exchanger 4. The liquefied refrigerant is sent to the second receiver 12. In the soil freezing apparatus 1 according to some embodiments, the operation of the refrigerator 5 is continued when soil freezing is performed.

[0064] In some embodiments of the soil freezing device 1, after the soil freezing device 1 starts operating, the underground control device 92 controls the control valve 31 to open at a specified opening until the liquid level in the first receiver 11 detected by the level sensor 41 reaches a specified liquid level. That is, the receiver unit control device 921 outputs a control signal to the supply valve unit control device 922 to open the adjustment valve 31 at a specified opening until the liquid level in the first receiver 11 detected by the level sensor 41 reaches a specified liquid level. The supply valve unit control device 922 outputs a drive signal to a drive section (not shown) of the adjustment valve 31 based on the control signal from the receiver unit control device 921.

[0065] Then, when the underground control device 92 determines that the liquid level in the first receiver 11 detected by the level sensor 41 has reached a specified liquid level, it controls the opening of the control valve 31 using feedback control based on PID control so that the liquid level falls within a specified range. That is, when the receiver unit control device 921 determines that the liquid level in the first receiver 11 detected by the level sensor 41 has reached a specified liquid level, it outputs a control signal for PID feedback control of the opening of the adjustment valve 31 so that the liquid level falls within a specified range. The supply valve unit control device 922 outputs a drive signal to a drive section (not shown) of the adjustment valve 31 based on the control signal from the receiver unit control device 921.

[0066] In some embodiments of the soil freezing device 1, the underground control device 92 controls the underground pump 13 to stop the underground pump 13 after the soil freezing device 1 starts operating until the liquid level in the first receiver 11 detected by the level sensor 41 reaches a specified liquid level. That is, after the soil freezing device 1 starts operating, the receiver unit control device 921 outputs a signal to the pump unit control device 923 to control the underground pump 13 so as to stop the underground pump 13 until the liquid level in the first receiver 11 detected by the level sensor 41 reaches a specified liquid level. Based on the control signal from the receiver unit control device 921, the pump unit control device 923 does not output a drive signal to the underground pump 13.

[0067] Then, when the underground control device 92 determines that the liquid level in the first receiver 11 detected by the level sensor 41 has reached a specified liquid level, it controls the underground pump 13 to operate and stop the underground pump 13 based on the pressure in the first receiver 11 detected by the pressure sensor 44 and the discharge pressure of the underground pump 13 detected by the pressure sensor 45, for example, as described below.

[0068] When the receiver unit control device 921 determines that the liquid level in the first receiver 11 detected by the level sensor 41 has reached a specified liquid level, it outputs a signal to the pump unit control device 923 to control the underground pump 13 to operate the underground pump 13. The pump unit control device 923 outputs a drive signal to the underground pump 13 based on the control signal from the receiver unit control device 921.

[0069] For example, at a relatively early stage after the soil starts to freeze, the temperature of the soil 9 around the freezing pipe 15 is relatively high, so that the freezing pipe 15 is likely to be overloaded, and the pressure inside the first receiver 11 is likely to rise. Therefore, when the pressure in the first receiver 11 detected by the pressure sensor 44 exceeds a specified pressure range, the receiver unit control device 921 outputs a signal to the pump unit control device 923 to control the underground pump 13 to stop the underground pump 13. The pump unit control device 923 stops outputting the drive signal to the underground pump 13 based on the control signal from the receiver unit control device 921. Thereafter, the receiver unit control device 921 outputs a signal to the pump unit control device 923 to control the underground pump 13 so as to operate the underground pump 13 when the pressure in the first receiver 11 detected by the pressure sensor 44 falls below a specified threshold. The pump unit control device 923 outputs a drive signal to the underground pump 13 based on the control signal from the receiver unit control device 921.

[0070] For example, if the liquid level in the first receiver 11 drops undesirably and the underground pump 13 experiences cavitation, the pressure difference between the pressure inside the first receiver 11 detected by the pressure sensor 44 and the discharge pressure of the underground pump 13 detected by the pressure sensor 45 will decrease. Therefore, when the differential pressure between the pressure in the first receiver 11 detected by the pressure sensor 44 and the discharge pressure of the underground pump 13 detected by the pressure sensor 45 falls below a specified value, the receiver unit control device 921 outputs a signal to the pump unit control device 923 to control the underground pump 13 to stop the underground pump 13. The pump unit control device 923 stops outputting the drive signal to the underground pump 13 based on the control signal from the receiver unit control device 921. Thereafter, when the receiver unit control device 921 determines that the liquid level in the first receiver 11 detected by the level sensor 41 has reached a specified liquid level, it outputs a signal to the pump unit control device 923 to control the underground pump 13 to operate the underground pump 13. The pump unit control device 923 outputs a drive signal to the underground pump 13 based on the control signal from the receiver unit control device 921. In addition, when the receiver unit control device 921 determines that the pressure in the first receiver 11 detected by the pressure sensor 44 has become lower than the specified pressure, it outputs a signal to the pump unit control device 923 to control the underground pump 13 to operate it. When the receiver unit control device 921 determines that the pressure in the first receiver 11 detected by the pressure sensor 44 has become higher than the specified pressure, it outputs a signal to the pump unit control device 923 to control the underground pump 13 to stop the underground pump 13.

[0071] Thus, in some embodiments of the soil freezing device 1, the ground control device 94 controls the chiller 5 and ground pump 14, which are devices to be controlled and installed on the ground 7, and the underground control device 92 controls the control valve 31 and underground pump 13, which are devices to be controlled and located in the underground space 8.

[0072] The present disclosure is not limited to the above-described embodiments, but also includes modifications to the above-described embodiments and appropriate combinations of these modifications. For example, in the receiver unit 100 shown in Figure 2, the first pipe 110 includes two pipes, the inlet side first pipe 110A and the outlet side first pipe 110B, but it may also include another first pipe 110 provided at a different position in the longitudinal direction of the first receiver 11, or there may be only one first pipe 110. Similarly, in the receiver unit 100 shown in Figure 2, the second pipe 120 includes two pipes, the inlet side second pipe 120A and the outlet side second pipe 120B, but it may also include another second pipe 120 provided at a different position in the longitudinal direction of the first receiver 11, or there may be only one second pipe 120.

[0073] For example, in the receiver unit 100 described above, each first pipe 110 has two first connector portions 111 arranged toward one side and the other side in the longitudinal direction of the first receiver 11. However, it is sufficient that at least one first pipe 110 has two first connector portions 111 arranged toward one side and the other side in the longitudinal direction of the first receiver 11. Similarly, in the receiver unit 100 described above, each second pipe 120 has two second connector portions 121 arranged toward one side and the other side in the longitudinal direction of the first receiver 11. However, it is sufficient that at least one second pipe 120 has two second connector portions 121 arranged toward one side and the other side in the longitudinal direction of the first receiver 11.

[0074] The contents described in each of the above embodiments can be understood, for example, as follows. (1) A portable receiver (receiver unit 100) of a soil freezing system (soil freezing device 1) according to at least one embodiment of the present disclosure includes a base 101, a receiver tank (first receiver 11) provided on the base 101, one or more first pipes 110 connected to a liquid phase portion of the receiver tank (first receiver 11), and one or more second pipes 120 connected to a gas phase portion of the receiver tank (first receiver 11). The first pipe 110 has a first connector portion 111 at its end to which other pipes (flexible pipe 71, other pipes 72) can be connected. The second pipe 120 has a second connector portion 121 at its end to which other pipes (flexible pipe 71, other pipes 72) can be connected.

[0075] If the receiver tank (first receiver 11) is installed on a common frame together with the liquid pump (underground pump 13), liquid supply valve (control valve 31), and strainer 35, it is difficult to transport it into a narrow space such as a tunnel. In this regard, according to the configuration (1) above, the portable receiver (receiver unit 100) can be carried alone into a small space and connected to other devices (units 200, 300, 400) within the small space, making it easy to carry the portable receiver (receiver unit 100) into a small space.

[0076] (2) In some embodiments, in the configuration of (1) above, at least a portion of the first connector portion 111 and the second connector portion 121 may be located outside the area occupied by the pedestal 101 in a plan view.

[0077] According to the configuration (2) above, it is easy to arrange the other devices (units 200, 300, 400) connected via the first connector portion 111 and the second connector portion 121 and the portable receiver (receiver unit 100) so that they overlap in the height direction, so that the height of the entire apparatus including the other devices (units 200, 300, 400) connected to the receiver tank (first receiver 11) can be kept relatively low. This allows the entire apparatus including the other devices (units 200, 300, 400) to be arranged in a narrow space with a relatively low height, such as a mine. Furthermore, according to the configuration (2) above, the positions of the other units 200, 300, 400 relative to the receiver unit 100 can be set relatively freely in both the longitudinal and lateral directions.

[0078] (3) In some embodiments, in the configuration of (1) or (2) above, at least one of the first pipes 110 may have two first connector portions 111 arranged toward one side and the other side of the receiver tank (first receiver 11) in the longitudinal direction.

[0079] According to the configuration (3) above, other devices (units 200, 300) connected to the receiver tank (first receiver 11) can be easily arranged on either one side or the other side of the receiver tank (first receiver 11) in the longitudinal direction, thereby improving the freedom of arrangement of other devices (units 200, 300) in a small space. Furthermore, according to the configuration (3) above, it becomes easy to place other devices (units 200, 300) on either side of the receiver tank (first receiver 11) in the longitudinal direction, so even if it is difficult to rotate the receiver tank (first receiver 11) horizontally in a small space because the longitudinal length of the receiver tank (first receiver 11) is relatively long, it becomes easy to connect other devices (units 200, 300) to the receiver tank (first receiver 11).

[0080] (4) In some embodiments, in any of the configurations (1) to (3) above, at least one of the second pipes 120 may have two second connector portions 121 arranged toward one side and the other side of the receiver tank (first receiver 11) in the longitudinal direction.

[0081] According to the configuration (4) above, other devices (strainer unit 400, underground piping 51b) connected to the receiver tank (first receiver 11) can be easily placed on either one side or the other of the longitudinal direction of the receiver tank (first receiver 11), thereby improving the freedom of placement of other devices (strainer unit 400, underground piping 51b) in a small space. Furthermore, according to the configuration (4) above, it becomes easy to place other devices (strainer unit 400, underground piping 51b) on either side of the receiver tank (first receiver 11) in the longitudinal direction, so even if it is difficult to rotate the receiver tank (first receiver 11) horizontally in a narrow space because the longitudinal length of the receiver tank (first receiver 11) is relatively long, it becomes easy to connect other devices (strainer unit 400, underground piping 51b) to the receiver tank (first receiver 11).

[0082] (5) In some embodiments, in any of the configurations (1) to (4) above, the plurality of first pipes 110 may include two first pipes 110 (an inlet-side first pipe 110A and an outlet-side first pipe 110B) connected to a lower portion of the receiver tank (first receiver 11) and provided at different positions in the longitudinal direction of the receiver tank (first receiver 11). The plurality of second pipes 120 may include two second pipes 120 (an inlet-side second pipe 120A and an outlet-side second pipe 120B) connected to an upper portion of the receiver tank (first receiver 11) and provided at different positions in the longitudinal direction.

[0083] According to the above configuration (5), it becomes easier to arrange two external devices (supply valve unit 200, pump unit 300) connected to two first pipes 110 (inlet side first pipe 110A, outlet side first pipe 110B) on one side and the other side of the longitudinal direction of the receiver tank (first receiver 11), and it becomes easier to arrange two external devices (strainer unit 400, underground pipe 51b) connected to two second pipes 120 (inlet side second pipe 120A, outlet side second pipe 120B) on one side and the other side of the longitudinal direction of the receiver tank (first receiver 11). In addition, it becomes easier to stagger the height positions of two external devices (supply valve unit 200, pump unit 300) connected to two first pipes 110 (inlet side first pipe 110A, outlet side first pipe 110B) and two external devices (strainer unit 400, underground pipe 51b) connected to two second pipes 120 (inlet side second pipe 120A, outlet side second pipe 120B), allowing multiple external devices to be arranged compactly.

[0084] (6) In some embodiments, in any of the configurations (1) to (5) above, at least one of the other pipes (flexible pipe 71, other pipe 72) connectable to the first connector portion 111 or the other pipes (flexible pipe 71, other pipe 72) connectable to the second connector portion 121 may be a flexible pipe (flexible pipe 71).

[0085] According to the configuration (6) above, even if the position of an equipment connected to the first pipe 110 (inlet side first pipe 110A, outlet side first pipe 110B) via a flexible pipe (flexible pipe 71), or the position of an equipment connected to the second pipe 120 (inlet side second pipe 120A, outlet side second pipe 120B) via a flexible pipe (flexible pipe 71) is shifted to some extent relative to the portable receiver (receiver unit 100), it can be easily connected to the portable receiver (receiver unit 100).

[0086] (7) A soil freezing system (soil freezing device 1) according to at least one embodiment of the present disclosure includes a portable receiver (receiver unit 100) of the soil freezing system (soil freezing device 1) according to any one of (1) to (6) above, a supply valve unit 200 for supplying refrigerant from a refrigerator to a liquid phase portion of the portable receiver (receiver unit 100), a pump unit 300 for sending the refrigerant from the liquid phase portion to a freezing pipe 15, and a strainer unit 400 connected to a gas phase portion of the portable receiver (receiver unit 100) via a second pipe 120 for removing foreign matter in the refrigerant from the freezing pipe 15. The first pipe 110 includes an inlet-side first pipe 110A connected to the supply valve unit 200 and an outlet-side first pipe 110B connected to the pump unit 300.

[0087] According to the configuration (7) above, the portable receiver (receiver unit 100), the supply valve unit 200, the pump unit 300, and the strainer unit 400 can be carried into a small space, and the portable receiver (receiver unit 100) can be connected to the other units 200, 300, and 400 within the small space.

[0088] (8) In some embodiments, in the configuration of (7) above, each of the supply valve unit 200, pump unit 300, and strainer unit 400 may include a stand 201, 301, 401 specific to each unit 200, 300, 400, and equipment consisting of a valve (control valve 31), a pump (underground pump 13), or a strainer 35 provided on the stand 201, 301, 401.

[0089] According to the configuration (8) above, each unit 200, 300, 400 is a single unit with each piece of equipment (control valve 31, underground pump 13, strainer 35) mounted on a stand 201, 301, 401, making it easy to transport into and out of small spaces. [Explanation of symbols]

[0090] 1. Soil freezing device 4 Heat exchanger 5. Freezer 7 Ground 8 Underground space 9. Soil 10 Secondary refrigerant circulation system 11 First Receiver 11a Liquid reservoir 12 Second Receiver 13 Liquid transfer pump (underground pump) 14 Liquid transfer pump (ground pump) 15 Soil freezing tube (freezing tube) 17 Liquid header 19 Gas Header 20 Refrigerant circuit 21 Feed piping 21a Aboveground piping 21b Underground piping 21c vertical tube 26 Refrigerant liquid piping 27 Refrigerant return pipe 31 Control valve 35 Strainer 51 Return pipe 51a Aboveground piping 51b Underground piping 51c vertical tube 71 Flexible piping 72 Other piping 90 Control device 91 Underground control panel 92 Underground Control Device 93 Ground Control Panel 94 Ground Control Device 100 receiver unit 101 Mounting stand 102 Post 110 First Pipe 110A Inlet side first pipe 110B Outlet side 1st piping 110B1 Piping 110B2 Piping 111 First connector part 120 Second Pipe 120A Inlet side second piping 120B Outlet side 2nd piping 120B1 Piping 120B2 Piping 121 Second connector part 200 Supply valve unit 201 Mounting stand 211 Connector part 300 Pump Unit 301 Mounting stand 311 Connector part 400 strainer unit 401 Mounting stand 411 Connector part 911 receiver unit control panel 912 Supply valve unit control panel 913 Pump unit control panel 921 Receiver unit control device 922 Supply valve unit control device 923 Pump unit control device

Claims

1. A stand and a receiver tank provided on the frame; One or more first pipes connected to a liquid phase portion of the receiver tank; One or more second pipes connected to the gas phase portion of the receiver tank; Equipped with the first pipe has a first connector portion at an end thereof to which another pipe can be connected; The second pipe has a second connector portion at an end thereof to which another pipe can be connected. Portable receiver for soil freezing systems.

2. At least a portion of the first connector portion and the second connector portion is located outside an area occupied by the base in a plan view.

10. The portable receiver of claim 1, wherein the soil freezing system comprises:

3. At least one of the first pipes has two first connector portions arranged toward one side and the other side in the longitudinal direction of the receiver tank, respectively.

3. A portable receiver for a soil freezing system according to claim 1 or 2.

4. At least one of the second pipes has two second connector portions arranged toward one side and the other side in the longitudinal direction of the receiver tank, respectively.

3. A portable receiver for a soil freezing system according to claim 1 or 2.

5. the first pipe includes two first pipes connected to a lower portion of the receiver tank and provided at different positions in a longitudinal direction of the receiver tank; the second piping includes two second pipings connected to an upper portion of the receiver tank and provided at different positions in the longitudinal direction; 3. A portable receiver for a soil freezing system according to claim 1 or 2.

6. At least one of the other pipe connectable to the first connector portion and the other pipe connectable to the second connector portion is a flexible pipe.

3. A portable receiver for a soil freezing system according to claim 1 or 2.

7. A portable receiver of the soil freezing system according to claim 1 or 2; a supply valve unit for supplying a refrigerant from a refrigerator to the liquid phase portion of the portable receiver; a pump unit for sending the refrigerant from the liquid phase portion to the freezing tube; a strainer unit connected to the gas phase portion of the portable receiver via the second pipe for removing foreign matter in the refrigerant from the freezing pipe; Equipped with the first piping includes an inlet-side first piping connected to the supply valve unit and an outlet-side first piping connected to the pump unit; Soil freezing system.

8. Each of the supply valve unit, the pump unit, and the strainer unit comprises: a stand specific to each of the units; a device configured by a valve, a pump, or a strainer provided on the frame; Including, 8. The soil freezing system of claim 7.

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