Separation and discharge of low temperature liquid from vapour on mobile machines

Abstract

According to one aspect of the present disclosure, a mobile machine (102) includes an LNG fuel tank (106) that provides natural gas to a natural gas engine (104), a pressure reducing valve (202) that reduces pressure to a pressure reducing discharge line (204), and a liquid separation device (108). The liquid separation device (108) includes a tank (302) defining an interior space (304) and having a top end (306) and a bottom end (308), an LNG inlet (310) configured to receive mixed phase fluid from the pressure reducing discharge line into the tank, a separator (312) disposed within the interior space and fluidly connected to the LNG inlet, the separator configured to direct condensed liquid to the bottom end and to pass vapor to the interior space, a vapor outlet (320) disposed on the top end of the tank, and a liquid drain (322) disposed on the bottom end of the tank.

Description

Technical Field

[0001] The present invention relates generally to working machines, and more specifically to systems and methods for operating machines powered by liquefied natural gas. Background Technology

[0002] Mobile work machines can be powered by various types of engines. These machines can be, but are not limited to, dump trucks, earthmoving machines, etc. Exemplary engines include internal combustion engines and engines powered by liquid / liquefied natural gas (LNG). Sometimes, mobile machines may initially be constructed with internal combustion engines, such as diesel engines, but are later converted to LNG-powered mobile machines.

[0003] This conversion allows most of the mobile machine's structure (e.g., chassis, cab, trailer bed) to remain in place, while replacing or supplementing the initial engines with components from the LNG system, including natural gas engines and LNG fuel tanks. In this example, the initially installed gas tanks and engines associated with the mobile machine can be removed, and LNG fuel tanks and natural gas engines can be installed. Additional components, such as vaporizers and LNG pressure relief valves, can also be added during the conversion to assist in the operation of the LNG system.

[0004] When adding these new components, they are often placed around the existing structure of the mobile machinery and may be further constrained by additional rules to place or position the components in designated locations. For example, the size, capacity, and discharge location of LNG depressurization discharge pipelines are all regulated and constrained by various safety and industry-related regulations.

[0005] Even when these requirements are met in the design of various mobile machinery, such as when converting a large mining truck (LMT) from a diesel-only engine to a natural gas engine, the location of the LNG discharge line can still result in undesirable locations for discharging fluid / gas from the LNG system.

[0006] Various systems exist, such as cryogenic gas traps, for separating a component from a gas stream. For example, U.S. Patent 3,788,096A describes a cryogenic gas trap for separating at least one component from a gas stream. The exchange coefficient between the condensing surface and the cryogenic fluid cooling the surface is significantly improved by utilizing a two-phase gas-vapor fluid. This gas trap includes a first condensing surface formed by nesting vertical metal tubes arranged around and at a distance from a second condensing surface, inside which is a tank containing a cryogenic liquid. One end of the tube communicates with an annular conduit included between the housing and the tank. The other end is a manifold. However, such a cryogenic gas trap is insufficient for the operation of mobile machinery, particularly for separating and discharging cryogenic liquids from vapors on mobile machinery.

[0007] Therefore, there is a need for a system and method for removing cryogenic liquids from vapors on mobile machines powered by LNG systems. Summary of the Invention

[0008] According to one aspect of the invention, a mobile machine includes a liquefied natural gas (LNG) system. As part of the LNG system, the mobile machine may include a natural gas engine. The mobile machine further includes: an LNG fuel tank for supplying natural gas to the natural gas engine; a pressure relief valve for releasing excessive pressure from the LNG system to a pressure relief discharge line; and a liquid separation device. The liquid separation device includes a tank defining an internal space and having a top and a bottom end, configured to receive a mixed-phase fluid from the pressure relief discharge line into an LNG inlet in the tank; a separator disposed within the internal space and fluidly connected to the LNG inlet, the separator being configured to direct condensate to the bottom end and transfer vapor to the internal space; a vapor outlet disposed at the top end of the tank; and a liquid discharge port disposed at the bottom end of the tank.

[0009] In another embodiment, a liquid separation device includes: a tank defining an internal space and having a top and a bottom; a liquefied natural gas (LNG) inlet configured to receive a mixed-phase fluid into the tank; a separator disposed within the internal space and fluidly connected to the LNG inlet, the separator being configured to direct condensate to the bottom of the tank and transfer vapor to the internal space; a vapor outlet disposed at the top of the tank; and a liquid discharge port disposed at the bottom of the tank.

[0010] Another embodiment takes the form of a kit. The kit includes a tank defining an internal space, having: a liquefied natural gas (LNG) inlet located at the top of the tank, the LNG inlet configured to receive a mixed-phase fluid into the tank; a vapor outlet located at the top of the tank; and a liquid outlet located at the bottom of the tank. The kit further includes: a separator configured to guide condensate to the bottom and allow vapor to pass through the internal space; and a line configured to fluidly connect the LNG inlet to the separator, wherein the separator is disposed within the internal space when connected to the LNG inlet. Mounting connections are configured to mount the tank to a mobile machine, and the fluid discharge line is configured to fluidly connect to the liquid outlet and guide condensate from the bottom of the tank to the ground.

[0011] These and other aspects and features of the invention will be better understood when the following detailed description is read in conjunction with the accompanying drawings. Attached Figure Description

[0012] Figure 1 This is a side view of a mobile machine according to an embodiment of the present invention;

[0013] Figure 2 This is a simplified schematic diagram of a mobile LNG system according to an embodiment of the present invention;

[0014] Figure 3 This is a first cross-sectional view of a liquid separation device according to an embodiment of the present invention;

[0015] Figure 4 This is a second cross-sectional view of a liquid separation device according to an embodiment of the present invention;

[0016] Figure 5 This is a third cross-sectional view of a liquid separation apparatus according to an embodiment of the present invention; and

[0017] Figure 6 This is a view of a kit for a liquid separation apparatus according to an embodiment of the present invention. Detailed Implementation

[0018] Reference will now be made in detail to specific embodiments or features, examples of which are shown in the accompanying drawings. Where possible, corresponding or similar reference numerals are used throughout the drawings to denote the same or corresponding parts.

[0019] Figure 1 This is a side view of a mobile machine according to an embodiment of the present invention. Specifically, Figure 1A side view 100 of a mobile work machine 102 is depicted, which may be referred to throughout as a work machine, mobile machine, LNG machine, etc. The work machine 102 is exemplarily shown as a tractor or dump truck, but the teachings of the invention can be equally applied to many other types of work machines, such as, but not limited to, tracked tractors, excavators, mining equipment, automatic graders, etc. The mobile machine 102 includes an engine 104 and an LNG fuel tank 106 to supply natural gas to the engine 104. These and other components, such as a vaporizer 208, a liquid separator 108, and various connecting lines, are collectively referred to as an LNG system, which can operate on various mobile or stationary machines. The engine 104 provides power to the mobile machine 102. For example, it may provide propulsion power to its drivetrain, may be configured to power auxiliary systems such as hydraulic systems to operate the tractor bed 120, and may be used to generate electricity for various electronic and control systems associated with the mobile machine 102.

[0020] An additional component of the mobile machine 102 during LNG system conversion includes an LNG discharge line 124, shown extending upward and to the right from the engine 104 and LNG fuel tank 106 (as depicted in side view 100). The LNG discharge line 124 extends to a discharge location 126 located above the front ground engagement member 114 and near the operator's cab 118. The discharge location 126 may be specified by various safety and / or industry regulations. A liquid separator 108 is fluidly connected to the LNG discharge line 124. A fluid discharge line 110 is fluidly connected to the liquid separator 108 and is routed such that fluid discharged from the fluid discharge line 110 is directed away from the ground engagement member 114 and away from areas of the mobile machine 102 that are typically accessible to personnel. Exemplary routing locations for the fluid discharge line 110 include positioning the distal end 128 of the fluid discharge line 110 below the chassis 112 of the mobile machine, between the left front ground engagement member 114 and the right front ground engagement member 114, etc. The distal end 128 of the fluid discharge line 110 directs any fluid to the ground 122 and away from areas accessible to personnel (e.g., an outlet point near the operator's cab 118, adjacent to ground connection members 114, 116).

[0021] The mobile machine 102 is located on the ground 122, with its front ground engagement member 114 located on the right side of side view 100 and its rear ground engagement member 116 located on the left side of side view 100. There may be a pair of front ground engagement members 114 and a pair of rear ground engagement members 116, one of each pair being on the right side of the mobile machine 102 (as shown in side view 100) and the other of each pair being on the left side of the mobile machine 102.

[0022] The ground bonding components 114, 116 may include rubber, synthetic rubber, etc. When exposed to rapid temperature changes, the ground bonding components 114, 116 may experience a shortened lifespan, which can occur when liquefied natural gas is directly exposed to the rubber-based material of the ground bonding components 114, 116.

[0023] As shown in side view 100, the mobile machine 102 includes an operator's cab 118, which includes controllers for operating the mobile machine 102. Furthermore, ground engagement members 114, 116 may be higher than a normal person 130 and can be used to raise the operator's cab 118 of the mobile machine 102 approximately three to four meters above ground level 122. In some such embodiments, the mobile machine 102 is a large mining truck (LMT). A liquid separator 108 is mounted on the mobile machine 102 at a discharge location 126. The liquid separator 108 also includes a vapor outlet 132. When mounted on the mobile machine 102 located on level ground level 122, the vapor outlet 132 is at a higher height than the location where the fluid discharge line connects to the liquid separator 108. The higher height of the vapor outlet 132 further ensures that discharged vapor is not trapped below components of the mobile machine 102.

[0024] Figure 2 This is a simplified schematic diagram of an LNG system for a mobile machine according to an embodiment of the present invention. Specifically, schematic diagram 200 includes an engine 104, which may be a natural gas engine, an LNG fuel tank 106, a vaporizer 208, and a pressure reducing valve 202. A liquid LNG line 206 fluidly connects the LNG fuel tank 106 to the vaporizer 208. The vaporizer 208 converts liquefied natural gas into natural gas and supplies the natural gas to the engine 104 via a natural gas line 211. The pressure reducing valve 202 is fluidly connected to the LNG fuel tank 106 via a liquid LNG line 212 and a natural gas line 210. The pressure reducing valve 202 is designed to protect various aspects of the LNG system from overpressure conditions. The size and capacity of the pressure reducing valve 202 may be determined in part based on the operating characteristics of the LNG system (e.g., the capacity of the LNG fuel tank 106, the output limits of the engine 104, etc.). A liquid / vapor discharge line 204 fluidly connects the pressure reducing valve 202 to a liquid separator 108. Figure 1 In the side view 100, a portion of the LNG discharge line 124 may be implemented by all or some of the liquid LNG line 212, natural gas line 210, pressure reducing valve 202, and liquid / vapor discharge line 204.

[0025] In the embodiments disclosed herein, pressure reducing valve 202 is configured to release excessive pressure from the LNG system (including LNG fuel tank 106) to a liquid / vapor discharge line 204, which acts as a pressure-reducing discharge line. When pressure reducing valve 202 is raised, it can initially release natural gas in a vapor state. However, because components in the pressure-reducing path (e.g., liquid / vapor discharge line 204, liquid separator 108) are cooled by the natural gas flow in its vapor state, the flow from the pressure reducing valve is a two-phase flow (e.g., mixed-phase flow) or a fluid state. Then, as the natural gas leaves the LNG system, liquid / vapor discharge line 204 can carry two phases of natural gas, i.e., a liquid phase and a gas phase. This can be referred to as a mixed-phase flow.

[0026] In various embodiments, the liquid / vapor discharge line 204 may be implemented by a single line or multiple lines. The liquid / vapor discharge line 204 may also include any fluid connections to reduce the number of individual vent lines. For example, in an embodiment with four pressure-reducing valves 202, each of the four pressure-reducing valves 202 may have a single line that receives fluid output from one of the pressure-reducing valves 202 when the respective pressure-reducing valves 202 are raised due to overpressure conditions in the LNG system. In one embodiment, two of these lines may be fluidly connected (e.g., via a T-connection) to a first intermediate line, and the other two of these lines may be fluidly connected to a second intermediate line. The first and second intermediate lines can then be fluidly connected to the final vent pressure-reducing line and directed to the liquid separator 108. In another such embodiment with four pressure-reducing valves 202, four separate lines are directed to the liquid separator 108 without first reducing the number of lines directed to the liquid separator 108. All four lines can enter the liquid separator 108, or they can be fluidly connected to a single point just before the liquid separator 108. The liquid separator 108 also includes a fluid discharge line 110 and a vapor outlet 214 for discharging vapor from the liquid separator 108 to the atmosphere.

[0027] Figure 3 This is a first cross-sectional view of a liquid separation apparatus according to an embodiment of the present invention. Specifically, Figure 3A first cross-sectional view 300 depicts a liquid separation device 108. The liquid separation device 108 includes a tank 302 defining an internal space 304. The tank 302 also includes a top end 306 and a bottom end 308 disposed opposite to the top end 306. The terms "top" and "bottom" are used herein to describe the relative positions of the top end 306 and bottom end 308 when the liquid separation device 108 is installed within or onto a mobile machine 102 (e.g., when installed onto the mobile machine 102 via mounting connector 324). The tank 302 may be cylindrical, or in other embodiments, it may be in the shape of a rectangular prism.

[0028] The liquid separation unit 108 further includes an LNG inlet 310, which is configured to receive a mixed-phase fluid 326 into a tank 302. The mixed-phase fluid 326 can be received into the liquid separation unit 108 from a liquid / vapor discharge line 204 downstream of the pressure reducing valve 202.

[0029] Separator 312 is disposed within interior space 304 and fluidly connected (e.g., via fluid connection 314) to LNG inlet 310. Separator 312 is configured to condense liquid received from LNG inlet 310 and direct condensate 316 to bottom end 308 of tank 302. Separator 312 is also configured to deliver vapor 318 to interior space 304. In some embodiments, separator 312 includes sintered material for atomizing mixed-phase fluid 326 received from LNG system (e.g., from liquid / vapor discharge line 204).

[0030] A steam outlet 320 is located at the top 306 of tank 302, and a liquid outlet 322 is located at the bottom 308 of tank 302. The steam outlet 320 can be used as... Figure 1 The discharge location 126 is shown in the side view 100. The cross-sectional area of ​​the vapor outlet 320 can be selected at least in part based on the cross-sectional area of ​​the liquid / vapor discharge line 204. Therefore, in some embodiments, the cross-sectional area of ​​the vapor outlet 320 is equal to or greater than the cross-sectional area of ​​the liquid / vapor discharge line 204. This ensures that the liquid separation device does not restrict the pressure relief flow from the LNG system.

[0031] Figure 4 This is a second cross-sectional view of a liquid separation apparatus according to an embodiment of the present invention. Specifically, Figure 4 A second cross-sectional view 400 of the liquid separation device 108 is depicted. Figure 4 The liquid separation device 108 depicted in the image is similar to... Figure 3 The liquid separation device 108 is depicted in the first cross-sectional view 300, wherein the components with the same number have the same function, unless otherwise stated.

[0032] exist Figure 4In the liquid separation device 108, a heat insulation layer 402 is also provided on the outer surface 406 of the tank 302. The heat insulation layer 402 is used to insulate the outer surface 406 to prevent the low temperature outer surface 406 from being exposed to personnel on the mobile machine 102.

[0033] also, Figure 4 The liquid separation device 108 shown includes an inclined surface 404 on the bottom end 308 of the tank 302. Condensed liquid 316 from the separator 312 is guided to the inclined surface 404, which then directs the condensed liquid 316 to a liquid discharge port 322. Therefore, even when the mobile machine 102 is operating on a non-level ground 122, the condensed liquid 316 from the separator 312 can still be directed to the liquid discharge port 322. The inclined surface 404 may be a truncated conical surface. Figure 4 As shown, angle 408 is approximately 20 degrees, although other angles may certainly be used based on the planned operating terrain of the mobile machine 102. Furthermore, the distance between the liquid discharge port 322 and the steam outlet 320 ensures that the steam outlet 320 remains at a height above the liquid discharge port 322 even when operating on a non-horizontal ground 122.

[0034] Industrial applicability

[0035] Generally, the teachings of this invention are broadly applicable to many industries, but are not limited to mobile machines with LNG systems, large mining trucks, stationary generators, etc. In various embodiments, the liquid separation device 108 may be incorporated into the discharge system of an LNG-powered machine. Although described herein as being mounted on and fluidly connected to a mobile machine, the liquid separation device may also be mounted on and fluidly connected to a stationary machine (e.g., a generator).

[0036] In addition to being installed on machinery, various components of the liquid separation unit can be assembled as kits for installation on machinery with LNG systems. Such kits can be assembled and installed on machinery as part of the conversion of LNG-powered machinery or as replacements for existing fluid separation units already installed on LNG-powered machinery.

[0037] Figure 5 This is a third cross-sectional view of a liquid separation apparatus according to an embodiment of the present invention. Specifically, Figure 5 A third cross-sectional view 500 depicts the liquid separation device 108. (As shown in...) Figure 4 In the second cross-sectional view 400, parts with the same number have the same function, unless otherwise stated.

[0038] Liquid separation unit 108 includes an LNG inlet 310 configured to receive a mixed-phase fluid 326. In a third cross-sectional view 500, the liquid separation unit includes a plurality of separators 312 disposed within a tank 302. The plurality of separators are fluidly connected in parallel to the LNG inlet 310. The fluid connection 314 between the LNG inlet 310 and the plurality of separators 312 may further include a T-connection 502 and a plurality of elbow connections 504 to direct the flow from the LNG inlet 310 to the separators 312 in a parallel flow configuration. Branching the flow into a configuration parallel to the separators 312 reduces flow restriction to allow vapor and liquid to be discharged and vented separately from the liquid separation unit 108.

[0039] In some embodiments, the number of separators 312 in the plurality of separators is based on a planned flow rate in the pressure relief discharge line 204. The planned flow rate may be based at least in part on the operating pressure of the LNG system and the size and number of pressure relief valves 202. The planned flow rate can also account for the transition from vapor released through pressure relief valves 202 to a mixed phase, or the fluid released through pressure relief valves 202. By varying the number of separators 312, the fluid connection 314 between the LNG inlet 310 and the separators 312 can be altered to provide flow from the LNG inlet 310 to the plurality of separators 312 configured in parallel. Furthermore, the volume measurement of the internal space 304 may be based in part on the planned flow rate in the pressure relief discharge line 204.

[0040] In one embodiment, the liquid separation device 108 is mounted on a mobile machine 102, which is a large mining machine. The mobile machine 102 includes a pressure-reducing discharge line 204, sized to fit the size and number of pressure-reducing valves in the system so as not to restrict flow in the pressure-reducing line. In one such embodiment, the liquid separation device includes two separators 312. In other embodiments, different numbers of separators 312 are used to ensure unrestricted flow. For example, the liquid separation device 108 may include any one of 1 to 8 separators 312.

[0041] Separator 312 allows vapor 318 to pass through to the internal space 304 and directs condensate 316 to the bottom end 308. Vapor 318 fills the internal space 304 and exits the tank 302 via vapor outlet 320. Vapor outlet 320 is open to the atmosphere. Condensate 316 flows out through liquid drain 322 located at the bottom end 308 of tank 302. Liquid drain 322 is fluidly connected to fluid discharge line 110, which further directs condensate 316 to ground 122.

[0042] In various embodiments, the liquid separator 108 also includes a mounting connection 324 configured to mount the liquid separator 108 to an LNG machine, such as a mobile machine 102. The liquid separator 108 is mounted such that the LNG inlet 310 is fluidly connected to a pressure relief line 204 of the LNG machine (e.g., downstream of the LNG pressure relief valve 202) and the vapor outlet 320 is positioned at a height higher than the liquid discharge outlet 322. Exemplary mounting connections 324 may include head bolts or posts for receiving bolts, extension posts that can be welded or otherwise secured to the mobile machine 102, slots and / or tabs that mate with tabs and / or slots on the mobile machine 102, belts configured to hold the tank 302 of the liquid separator 108 to the mobile machine, etc.

[0043] In the various embodiments disclosed herein, the components described herein are made of materials capable of withstanding the temperature differences associated with the operation of an LNG system. Exemplary materials include materials suitable for contact with various cryogenic fluids, such as stainless steel, cryogenic carbon steel, various aluminum and brass alloys, and corrosion-resistant alloys such as 304 / 304L and 316 / 316L stainless steel.

[0044] Figure 6 This is a view of a kit for a liquid separation apparatus according to an embodiment of the present invention. Specifically, Figure 6 View 600 depicts a kit containing components of a liquid separator 108, which will be installed on a machine (e.g., mobile machine 102) with an LNG system. Mobile machine 102 can be converted from a diesel-powered machine to an LNG-powered machine, or mobile machine 102 can be manufactured to be LNG-powered. In any case, the operator of mobile machine 102 may wish to obtain a kit with different components associated with the liquid separator described herein, such as the kit depicted in view 600.

[0045] In one embodiment, the kit includes a tank 302, a separator 312, a tubing 602 that fluidly connects the LNG inlet 310 of the tank 302 to the separator 312, and a mounting connector 324.

[0046] Tank 302 can be any tank 302 described herein, and includes an LNG inlet 310 disposed at the top 306 of tank 302, wherein the LNG inlet 310 is configured to receive a mixed-phase fluid into tank 302. Tank 302 also includes a vapor outlet 320 disposed at the top 306 of tank 302 and a liquid discharge outlet 322 disposed at the bottom 308 of tank 302.

[0047] The separator 312 is configured to direct condensate to the bottom end 308 and allow vapor to pass through to the internal space 304. When the separator is located within the internal space 304, a conduit 602 fluidly connects the LNG inlet 310 to the separator 312. The conduit 602 may include various components of a fluid connection 314, including any T-connection 502 or elbow connection 504 that fluidly connects the separator to the LNG inlet 310.

[0048] Mounting connector 324 is configured to mount tank 302 onto mobile machine 102. Mounting tank 302 results in the top end 306 having a vapor outlet 320 being oriented above the bottom end 308 having a liquid discharge port 322 (e.g., at a higher height when mobile machine 102 is on a horizontal ground 122).

[0049] In some embodiments, the kit of view 600 further includes a fluid discharge line 110 configured to be fluidly connected to a liquid discharge port 322 and to guide condensate from the bottom end 308 of tank 302 to ground 122. Accordingly, the fluid discharge line 110 includes sufficient length to extend from the liquid separation device 108 to near ground 122 (e.g., 0.5 to 1.5 meters).

[0050] In yet another embodiment, the kit of view 600 further includes a plurality of separators 312, and the tubing 602 is configured to fluidly connect the LNG inlet 310 in parallel to the plurality of separators 312.

[0051] In some embodiments, tank 302 is a sealed tank, with separator 312 already disposed inside and fluidly connected to LNG inlet 310 via tubing 602. In other embodiments, tank 302 is an unsealed tank, and the internal space 304 is accessible to a technician. A technician can assemble tubing 602 to separator 312 and LNG inlet 310, and then shut down tank 302.

[0052] It should also be understood that the components of the kit shown in view 600 may include any of the various embodiments described herein. For some non-limiting examples of the various components included in the kit, tank 302 may include a sloping surface 404. Furthermore, the kit may include a thermal insulation layer 402 configured to insulate the outer surface 406 of tank 302. Additionally, separator 312 may also include a plurality of separators 312, and fluid connection 314 may include associated fluid connections to connect the plurality of separators 312 to LNG inlet 310.

[0053] While various aspects of the invention have been specifically shown and described with reference to the foregoing embodiments, those skilled in the art will understand that various additional embodiments can be contemplated through modifications to the disclosed machines, systems, and components without departing from the scope of the disclosure. Such embodiments should be understood to fall within the scope of the invention as defined by the claims and any equivalents.

Claims

1. A mobile machine (102) powered by a liquefied natural gas system, the mobile machine comprising: Natural gas engine; A liquefied natural gas fuel tank (106) that supplies natural gas to the natural gas engine; Pressure reducing valve (202) is used to release excessive pressure from the liquefied natural gas system to the pressure reducing discharge line (204); as well as A liquid separation device (108) is mounted on the mobile machine at a discharge location above the front ground engagement member and near the operator's cab. The liquid separation device (108) has the following features: A can (302) that defines an internal space (304) and has a top (306) and a bottom (308); A liquefied natural gas inlet (310) is configured to receive mixed-phase fluid from the depressurization discharge line into the tank; A separator (312) disposed within the internal space and fluidly connected to the liquefied natural gas inlet, the separator being configured to direct condensate to the bottom end and transfer vapor to the internal space; A steam outlet (320) is provided at the top of the tank; and A liquid discharge port (322) is provided at the bottom end of the tank. The liquid separation device (108) is characterized in that it further includes a fluid discharge line (110) fluidly connected to the liquid discharge port; wherein the vapor outlet is open to the atmosphere, and the fluid discharge line passes through the mobile machine to distribute the condensate below the chassis (112) of the mobile machine and between the first ground connection member and the second ground connection member of the mobile machine. The liquid separation device also includes a plurality of separators (312) disposed within the tank and fluidly connected in parallel to the liquefied natural gas inlet, the number of which is based on the planned flow rate in the depressurization discharge line.

2. The mobile machine according to claim 1, wherein, The liquid separation device is installed on the mobile machine such that the vapor outlet is positioned at a higher height than the liquid discharge outlet.

3. The mobile machine according to claim 1, wherein, The liquid separation device also includes a heat insulation layer (402) on the outer surface (406) of the tank.

4. The mobile machine according to claim 1, wherein, The bottom end of the tank includes an inclined surface (404) to guide the condensate to the liquid discharge port.

5. A liquid separation device (108) for a mobile machine, comprising: A can (302) that defines an internal space (304) and has a top (306) and a bottom (308); A liquefied natural gas inlet (310) is configured to receive a mixed-phase fluid (326) into the tank; Multiple separators (312) are disposed within the internal space and fluidly connected in parallel to the liquefied natural gas inlet. The multiple separators are configured to guide condensate (316) to the bottom end of the tank and transfer vapor (318) to the internal space. The number of separators in the multiple separators is based on the planned flow rate of the mixed phase fluid. A steam outlet (320) is provided at the top of the tank; and A liquid discharge port (322) is provided at the bottom end of the tank; The liquid separation device (108) further includes a fluid discharge line (110) fluidly connected to the liquid discharge port; wherein the vapor outlet is open to the atmosphere, and the fluid discharge line is arranged to pass through the mobile machine to direct condensate to the ground.

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