Vertical oil-gas separator for oil-injection natural gas screw expander

Abstract

The utility model relates to a vertical oil-gas separator for an oil-injection natural gas screw expander. The vertical oil-gas separator comprises a base, a shell, a gas inlet pipe, a cyclone separation barrel, a blade separator assembly, a precise oil-gas separation filter element assembly, an exhaust pipe, a flange cover, a secondary oil sight glass, a main oil level indicator, an oil baffle plate, a main oil return pipe and a secondary oil return pipe. According to the vertical oil-gas separator, the first-stage cyclone separation section, the second-stage gravity settling section, the third-stage blade separation section and the fourth-stage condensation type separation filter element section are combined, efficient separation and recovery of an oil-gas mixture of an oil-injected natural gas screw expander system in a low-temperature environment are achieved, and the oil leakage problem of the oil-injected natural gas screw expander can be effectively solved.

Description

Technical Field

[0001] The present application belongs to the field of new energy technology, and in particular, relates to a vertical oil-gas separator for an oil-injected natural gas screw expander. Background Art

[0002] Natural gas is mainly transported to users at all levels through national pipelines, provincial pipelines and urban pipelines. Its pressure level is generally reduced from 10MPa in the national pipeline to 4.0MPa in the provincial pipeline, and then to 0.8MPa in each urban pipeline for delivery to end users. In order to effectively utilize the problem of pressure energy recovery between natural gas pipelines, an oil-injected natural gas screw expander is used to directly recover pressure energy for power generation. The oil-injected natural gas screw expander requires lubricating oil to lubricate and seal the male and female rotors of the expander. The high-pressure natural gas enters the expansion chamber of the natural gas screw expander to expand. The expanded natural gas and lubricating oil are discharged together and enter the oil-gas separator for oil-gas separation. The separated natural gas enters the lower-level natural gas pipeline network, and the separated lubricating oil re-enters the natural gas screw expander. Due to the low temperature of the natural gas after expansion, the viscosity of the lubricating oil increases. It is difficult for a general oil-gas separator to effectively separate natural gas and high-viscosity lubricating oil, resulting in the lubricating oil entering the lower-level natural gas pipeline network with the natural gas, which brings harm to the safe operation of the natural gas pipeline network. At the same time, the natural gas screw expander will lack oil after a long period of operation, causing the expander to fail and shut down, posing a safety hazard to the operation of the entire system. Utility Model Content

[0003] The utility model solves the oil leakage problem caused by low oil-gas separation efficiency of an oil-injected natural gas screw expander system and proposes a vertical oil-gas separator for an oil-injected natural gas screw expander.

[0004] The technical solution adopted by the utility model to solve its technical problems is:

[0005] A vertical oil-gas separator for an oil-injected natural gas screw expander, comprising a base, a shell located on the base, and the shell is provided with, from bottom to top, a main oil return pipe for guiding the lubricating oil in the shell, an oil retaining assembly for suppressing the fluctuation of the lubricating oil at the bottom of the shell, an air inlet pipe, a cyclone separation cylinder, a blade separator assembly, a precision oil-gas separation filter element assembly for multiple depth filtration, an exhaust pipe, and a flange cover; the flange cover is used for installing and removing the precision oil-gas separation filter element;

[0006] The cyclone separation cylinder is installed at the bottom of the blade separator assembly as a whole. A cyclone separation channel is formed between the outer wall of the cyclone separation cylinder and the inner wall of the shell. The air inlet pipe is tangentially connected to the cyclone separation channel section on the shell, and its airflow direction is tangential to the circumferential direction of the shell. The blade separator assembly separates the gas in the shell and sends it into the precision oil and gas separation filter element assembly. The gas is filtered by the precision oil and gas separation filter element assembly and then discharged through the outlet pipe. A secondary oil return pipe for leading the lubricating oil is provided on the shell.

[0007] Furthermore, the oil baffle assembly includes two oil baffles spaced apart from each other, with the ends of the oil baffles farther away being fixed in the shell, and the ends closer to each other extending to the top of the other oil baffle, with the gap therebetween forming an oil-gas mixture channel, and the oil baffles suppress the fluctuation of the lubricating oil at the bottom of the shell, thereby preventing the natural gas from carrying the lubricating oil into the blade separation channel.

[0008] Furthermore, the blade separator assembly includes a blade separator, a frame, a base plate, and an oil return pipe. The blade separator has several groups, which are respectively installed on the outer surface of the frame, the frame is installed on the base plate, and the base plate is installed on the inner wall of the shell; the oil return pipe is composed of several pipes evenly welded at the bottom of the base plate and inserted into the bottom of the shell to return the lubricating oil at the bottom to the bottom of the shell.

[0009] Furthermore, each set of blade separators is composed of multiple baffles, forming multiple sets of inertial collision separation channels. Small oil droplets hit the baffle surface due to inertial collision in the channel, and settle to the bottom of the channel in the vertical direction and flow out.

[0010] Furthermore, the precision oil-gas separation filter element assembly includes a mounting base plate, a support rod, and a precision oil-gas separation filter element. The base plate is mounted to the inner wall of the shell, the support rod is inserted into the precision oil-gas separation filter element, and the bottom is mounted on the base plate.

[0011] Furthermore, the precision oil and gas separation filter element adopts ultra-fine glass fiber to form multiple deep condensation filter layers. Tiny oil smoke condenses to produce large oil droplets under the action of condensation separation, and settles along the interception filter layer to the installation base plate including the condensation filter layer and the interception filter layer under the action of gravity. The condensation filter layer is formed by multiple layers of ultra-fine glass fiber filter layers folded into a wavy structure, and the interception filter layer is formed by winding a layer of ultra-fine glass fiber filter cotton.

[0012] Furthermore, the support rod extends out of one end of the precision oil-gas separation filter element, and the sealing cover plate is fixed to the support rod by a locking nut.

[0013] Furthermore, a secondary oil sight glass is provided outside the shell to display the oil level of the mounting base plate 0601.

[0014] Furthermore, it also includes a main oil level gauge provided at the bottom of the shell, and the main oil level gauge displays the oil level at the bottom of the shell.

[0015] The beneficial effects of the utility model are:

[0016] By utilizing the combined effects of cyclone separation, gravity sedimentation, inertial collision and condensation separation principles, efficient oil and gas separation and recovery of the oil-injected natural gas screw expander system is achieved. It has the advantages of simple structure, high efficiency and low cost, and can effectively solve the oil leakage problem of the oil-injected natural gas screw expander. Therefore, it has a huge promoting significance for improving the economy and safety of the operation of the oil-injected natural gas screw expander. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The technical solution of the present application is further described below in conjunction with the accompanying drawings and embodiments.

[0018] Figure 1 This is a schematic diagram of the main structure of a natural gas screw expander for oil injection in the present application;

[0019] Figure 2 The present invention is a kind of natural gas screw expander for oil injection Figure 1 AA cross-sectional structural diagram;

[0020] Figure 3 The present invention is a kind of natural gas screw expander for oil injection Figure 1 BB cross-sectional structure diagram;

[0021] The reference numerals in the figure are:

[0022] 01. Base; 02. Shell; 03. Inlet pipe; 04. Cyclone separation cylinder; 05. Blade separator assembly; 06. Precision oil-gas separation filter element assembly; 07. Exhaust pipe; 08. Flange cover; 09. Secondary oil sight glass; 10. Oil baffle; 11. Main oil level gauge; 12. Main oil return pipe; 13. Secondary oil return pipe. DETAILED DESCRIPTION

[0023] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0024] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the invention of the present utility model, unless otherwise specified, "multiple" means two or more.

[0025] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood by specific circumstances.

[0026] The technical solution of the present application will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0027] Example

[0028] The present embodiment provides a vertical oil-gas separator for an oil-injected natural gas screw expander, comprising a base 01, a shell 02, an air inlet pipe 03, a cyclone separation cylinder 04, a blade separator assembly 05, a precision oil-gas separation filter element assembly 06, an exhaust pipe 07, a flange cover 08, a secondary oil sight glass 09, an oil baffle 10, a main oil level gauge 11, a main oil return pipe 12 and a secondary oil return pipe 13.

[0029] The air inlet pipe 03 is welded to the shell 02 along the tangential direction, and its air flow direction is tangential to the circumferential direction of the shell 02.

[0030] The inner wall of the shell 02 and the outer wall of the cyclone separation cylinder 04 form a cyclone separation section. The air inlet pipe 03 is tangentially welded to the cyclone separation section on the shell 02. The inlet flow rate of the cyclone section is set to 15m / s.

[0031] The blade separator assembly 05 is composed of a blade separator 0501, a frame 0502, a bottom plate 0503 and an oil return pipe 0504. The blade separator 0501 uses multiple baffles to form multiple groups of inertial collision separation channels. The small oil droplets collide with the baffle surface in the channel due to inertial collision, and settle to the bottom of the channel and flow out in the vertical direction. The oil return pipe 0504 consists of 4 pipes evenly welded at the bottom of the bottom plate 0503 and inserted into the bottom of the shell 02 to return the lubricating oil at the bottom to the bottom of the shell 02.

[0032] The precision oil and gas separation component 06 consists of a mounting base plate 0601, a support rod 0602, a precision oil and gas separation filter element 0603, a sealing cover plate 0604 and a locking nut 0605. The precision oil and gas separation filter element 0603 uses ultra-fine glass fiber filter layers to form multiple deep condensation filter layers. Tiny oil smoke condenses to produce large oil droplets under the action of condensation separation, and settles to the mounting base plate 0601 along the interception filter layer under the action of gravity.

[0033] The ultra-fine glass fiber filter layer is formed by folding 4 layers of ultra-fine glass fiber filter layers into a wavy structure. The interception filter layer is formed by winding 1 layer of ultra-fine glass fiber filter cotton.

[0034] The oil baffle 10 suppresses the fluctuation of the lubricating oil at the bottom of the shell 02 , thereby preventing the natural gas from carrying the lubricating oil into the separation channel of the blade separator 0501 .

[0035] The base 01 is welded to the bottom of the housing 02 to fix the separator. The cyclone separator 04 is welded to the bottom plate 0503 of the blade separator assembly 05 to form a whole, and then welded to the inner wall of the housing 02 all around. The mounting base plate 0601 of the precision oil and gas separation filter element assembly 06 is welded to the inner wall of the housing 02 all around. The flange cover 08 is installed on the top of the housing 02 for installing and removing the precision oil and gas separation filter element 0603.

[0036] During the specific implementation of the utility model, the oil-gas mixture discharged from the oil-injected natural gas screw expander enters the channel between the inner wall of the shell 02 and the outer wall of the cyclone separation cylinder 04 through the air inlet pipe 03 for cyclone separation. The large oil droplets of more than 1 mm in the low-temperature natural gas hit the inner wall of the shell 02 under the action of centrifugal force and settle to the bottom of the shell 02 in the vertical direction. After cyclone separation, the oil-gas mixture hits the oil baffle plate 10 at the bottom of the shell 02 and then changes direction to enter the cyclone separation cylinder 04 upward. The medium and large oil droplets of more than 50 microns settle on the oil baffle plate 10 in the vertical direction under the action of gravity and then flow to the bottom of the shell 02. The oil-gas mixture after gravity sedimentation enters the channel of the blade separator 0501. The small oil droplets of more than 10 microns hit the wall of the blade separator 0501 under the inertial force, settle to the bottom of the channel in the vertical direction, flow out to the bottom plate 0503 for collection, and the lubricating oil of the bottom plate 0503 flows to the bottom of the shell 02 along the return oil pipe 0504. After inertial collision sedimentation, the oil-gas mixture enters the interior of the precision oil-gas separation filter element 0603 in the vertical upward direction. The tiny oil droplets below 10 microns condense and grow into medium and large oil droplets above 50 microns under the condensation and separation effect of the filter layer and enter the interception layer. The fibers of the interception layer intercept the oil droplets and then settle vertically to the installation base plate 0601 under the action of gravity sedimentation. The secondary oil mirror 09 shows the oil level of the installation base plate 0601, and the main oil level gauge 11 shows the oil level at the bottom of the shell 02. The oil retaining assembly 12 and the secondary oil return pipe 13 guide the lubricating oil at the bottom of the shell back to the oil-injected natural gas screw expander, thereby realizing the circulation of the lubricating oil. The oil content of the lubricating oil in the natural gas after precision separation by the precision oil-gas separation filter element 0603 is less than 3mg / Nm3 and is discharged through the exhaust pipe 07.

[0037] Based on the above ideal embodiments of this application, the relevant staff can make various changes and modifications without departing from the technical concept of this application through the above description. The technical scope of this application is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A vertical oil-gas separator for an oil-injected natural gas screw expander, comprising a base and a shell located on the base, characterized in that: The housing is provided with a main oil return pipe for guiding the lubricating oil in the housing, an oil retaining assembly for suppressing the fluctuation of the lubricating oil at the bottom of the housing, an air intake pipe, a cyclone separation cylinder, a blade separator assembly, a precision oil-gas separation filter element assembly for multiple depth filtration, an exhaust pipe, and a flange cover in sequence from bottom to top; The cyclone separation barrel is installed at the bottom of the blade separator assembly to form a whole. A cyclone separation channel is formed between the outer wall of the cyclone separation barrel and the inner wall of the shell. The air inlet pipe is tangentially connected to the cyclone separation channel section on the shell, and its air flow direction is tangential to the circumferential direction of the shell. The blade separator assembly separates the gas in the shell and sends it into the precision oil and gas separation filter element assembly. The gas is filtered by the precision oil and gas separation filter element assembly and discharged through the outlet pipe. A secondary oil return pipe for leading the lubricating oil is provided on the shell.

2. A vertical oil-gas separator for an oil-injected natural gas screw expander according to claim 1, characterized in that: The oil baffle assembly includes two oil baffles spaced up and down, wherein the ends of the oil baffles that are far away from each other are fixed in the shell, and the ends that are close to each other extend above the other oil baffle, and the gap between them forms an oil-gas mixture channel.

3. A vertical oil-gas separator for an oil-injected natural gas screw expander according to claim 1, characterized in that: The blade separator assembly includes a blade separator, a frame, a base plate, and an oil return pipe. The blade separator has several groups, which are respectively installed on the outer side of the frame, the frame is installed on the base plate, and the base plate is installed on the inner wall of the shell; the oil return pipe is composed of several pipes evenly welded to the bottom of the base plate and inserted into the bottom of the shell to return the lubricating oil at the bottom to the bottom of the shell.

4. A vertical oil-gas separator for an oil-injected natural gas screw expander according to claim 3, characterized in that: Each group of blade separators is composed of multiple baffles.

5. The vertical oil-gas separator for an oil-injected natural gas screw expander according to claim 1, characterized in that: The precision oil-gas separation filter element assembly comprises a mounting base plate, a support rod, and a precision oil-gas separation filter element. The base plate is mounted to the inner wall of the shell, the support rod is inserted into the precision oil-gas separation filter element, and the bottom is mounted on the base plate.

6. A vertical oil-gas separator for an oil-injected natural gas screw expander according to claim 5, characterized in that: The precision oil and gas separation filter element adopts ultrafine glass fibers to form multiple depth condensation filter layers, including a condensation filter layer and an interception filter layer. The condensation filter layer is formed by folding multiple layers of ultrafine glass fiber filter layers into a wavy structure, and the interception filter layer is formed by winding a layer of ultrafine glass fiber filter cotton.

7. The vertical oil-gas separator for an oil-injected natural gas screw expander according to claim 5, characterized in that: It also includes a sealing cover plate provided on the top of the precision oil and gas separation filter element. The support rod extends out of one end of the precision oil and gas separation filter element, and the sealing cover plate is fixed to the support rod by a locking nut.

8. The vertical oil-gas separator for an oil-injected natural gas screw expander according to claim 5, characterized in that: A secondary oil mirror is provided outside the shell to display the oil level of the mounting base plate.

9. The vertical oil-gas separator for an oil-injected natural gas screw expander according to claim 1, characterized in that: The main oil level gauge is also provided at the bottom of the shell body, and the main oil level gauge displays the oil level at the bottom of the shell body.

Images