Low temperature separation device and separation method

Abstract

The present invention provides a low-temperature separation device and a separation method, the low-temperature separation device comprising: a separation container, wherein the separation container is provided with a first-stage separation chamber, a second-stage separation chamber and a third-stage separation chamber which are interconnected in sequence along the flow direction of natural gas; wherein an inertial separator is provided in the first-stage separation chamber, a centrifugal separator is provided in the second-stage separation chamber, and a separator assembly is provided in the third-stage separation chamber, wherein the separator assembly comprises a coalescer and a baffle separator which are arranged in sequence along the flow direction of natural gas, and the natural gas is used to flow through the inertial separator, the centrifugal separator, the coalescer and the baffle separator in sequence, so as to separate the gas phase and the liquid phase in the natural gas. The low-temperature separation device and the separation method provided in this embodiment of the present invention achieve the purpose of gas-liquid separation of waxy natural gas, and solve the technical problem that the existing vertical separator has poor separation performance when processing waxy natural gas.

Description

Technical Field

[0001] The present invention relates to the technical field of gas-liquid separation, and in particular to a low-temperature separation device and a separation method suitable for waxy natural gas. Background Art

[0002] Due to natural conditions, natural gas extracted from natural gas fields contains certain impurities, such as hydrocarbons, alcohols and water. These impurities in natural gas have an adverse effect on both the use and transportation of natural gas. Therefore, impurities in natural gas extracted from natural gas fields must be removed.

[0003] At present, natural gas is processed through low-temperature (i.e., temperature at or below -15°C) processing technology, such as low-temperature sedimentation, to make impurities contained in natural gas become liquid, and then the liquid is separated from the natural gas by gas-liquid separation in the low-temperature processing process. In the low-temperature processing process of natural gas, the gas-liquid separator generally adopts a vertical separator, and a blade distributor, a coalescer and a cyclone are generally arranged in the vertical separator along the flow direction of natural gas. After the blade distributor evenly distributes the natural gas, the vertical separator uses a coalescer to accumulate the small condensed droplets contained in the natural gas to form large droplets, and finally uses a cyclone to separate the gas and liquid. The separated liquid is dropped to the lower end liquid storage space of the vertical separator through the downcomer, and the separated gas enters the subsequent pipeline.

[0004] However, when such a vertical separator is used to process high-wax natural gas, since the wax precipitated through the vertical separator has high viscosity, as the production time increases, the precipitated high-viscosity wax will adhere to the coalescing screen in the coalescer, causing blockage of the coalescing screen, and gradually increasing the pressure drop of the gas through the coalescer, resulting in the inability of the separated liquid to pass through the coalescing screen to descend. In severe cases, the downcomer will be blocked, seriously affecting the separation performance of the vertical separator, resulting in poor separation performance of the vertical separator for high-wax natural gas. Summary of the invention

[0005] The present invention provides a low-temperature separation device and a separation method, which solve the technical problem that the existing vertical separator has poor separation performance when processing high-wax natural gas.

[0006] In a first aspect, the present invention provides a low-temperature separation device suitable for gas-liquid separation of waxy natural gas, the low-temperature separation device comprising a separation container, wherein a first-stage separation chamber, a second-stage separation chamber and a third-stage separation chamber which are interconnected are sequentially arranged in the separation container along the flow direction of the natural gas;

[0007] An inertial separator is provided in the first-stage separation chamber, a centrifugal separator is provided in the second-stage separation chamber, and a separator assembly is provided in the third-stage separation chamber, wherein the separator assembly comprises a coalescer and a baffle separator which are sequentially arranged along the flow direction of the natural gas, and the natural gas is used to flow through the inertial separator, the centrifugal separator, the coalescer and the baffle separator in sequence to separate the gas phase and the liquid phase in the natural gas.

[0008] As described above, the low-temperature separation device, optionally, the inertial separator comprises a baffle plate and a plurality of baffles, and the plurality of baffles are arranged on one side or both sides of the baffle plate along the flow direction of the natural gas;

[0009] Wherein, a plurality of the blocking members are staggeredly arranged on the baffle group according to preset row spacing and column spacing, so as to separate the liquid phase and the gas phase in the natural gas.

[0010] As described above, in the low-temperature separation device, optionally, the barrier is a bent structure, comprising an air inlet end, a guide portion, and a bent end arranged opposite to the air inlet end and blocking the natural gas; the guide portion is connected between the air inlet end and the bent end, and is used to guide the flow of the natural gas between the air inlet end and the bent end.

[0011] As described above, in the low-temperature separation device, optionally, the width of the barrier gradually decreases in the direction from the air inlet end to the bending end.

[0012] As described above, the low-temperature separation device may optionally have bending portions bent toward the inside of the barrier member on both sides of the air inlet end, and the bending portions are used to block the natural gas that rebounds to the air inlet end after being blocked by the bending ends.

[0013] As described above, in the low-temperature separation device, optionally, a sprayer is provided in the second-stage separation chamber, and the sprayer is used to flush the wax blocked on the centrifugal separator.

[0014] In the low-temperature separation device as described in any one of the above items, optionally, the baffle separator is a corrugated plate separator arranged at the gas outlet end of the agglomerator, and the corrugated plate separator is used to separate the liquid phase formed by agglomeration in the agglomerator from the gas phase in the natural gas, so that the gas phase is discharged from the separation container.

[0015] A low-temperature separation device as described in any of the above items, optionally, an air inlet chamber is provided in the separation container, the air inlet chamber is located on the side of the first-stage separation chamber away from the second-stage separation chamber, an air inlet and a distributor connected to the air inlet are provided in the air inlet chamber, wherein the distributor is obliquely arranged in the separation container and opposite to the inertial separator.

[0016] The low-temperature separation device as described in any one of the above items, optionally, further comprises a liquid storage container located at the bottom of the separation container and connected to the separation container, wherein the liquid storage container comprises three independent liquid storage chambers;

[0017] Among them, the three independent liquid storage chambers include a first liquid storage chamber connected to the first-stage separation chamber, a third liquid storage chamber connected to the second-stage separation chamber, and a third liquid storage chamber connected to the third-stage separation chamber.

[0018] In a second aspect, the present invention provides a separation method applicable to waxy natural gas, comprising the following steps:

[0019] The natural gas enters an inertial separator in a separation container, and the natural gas is subjected to a first-stage gas-liquid separation by the inertial separator;

[0020] The natural gas after the first stage gas-liquid separation enters the centrifugal separator in the separation container, and the natural gas is subjected to a second stage gas-liquid separation by the centrifugal separator;

[0021] The natural gas after the second-stage gas-liquid separation enters the separator assembly in the separation container, and after the liquid phase in the natural gas is coalesced by the coalescer in the separator assembly, the natural gas is subjected to a third-stage gas-liquid separation to obtain the gas phase in the natural gas;

[0022] discharging the gas phase from the separation vessel;

[0023] The liquid phases after the first stage gas-liquid separation, the second stage gas-liquid separation and the third stage gas-liquid separation are collected respectively.

[0024] The present invention provides a low-temperature separation device and a separation method. By arranging an inertial separator, a centrifugal separator and a separator assembly in a separation container, since the waxy natural gas needs to be processed by a low-temperature treatment process before entering the low-temperature separation device, so that the impurities contained in the waxy natural gas become liquid, the present invention first effectively separates the gas phase and liquid phase of the natural gas through the inertial separator when the waxy natural gas after low-temperature treatment flows through the inertial separator, the centrifugal separator and the separator assembly, and then separates the heavy hydrocarbons (such as wax), alcohol and water in the liquid phase of the natural gas. Separation; then the natural gas is subjected to a second gas-liquid separation through a centrifugal separator to separate the light hydrocarbons, a small amount of alcohol and water in the liquid state of the natural gas; finally, the natural gas is subjected to a third gas-liquid separation through a separator assembly. On the basis of achieving gas-liquid separation of the natural gas, since the wax has been separated during the first gas-liquid separation and the second gas-liquid separation, there are only a small amount of light hydrocarbons, a small amount of alcohol and water in the natural gas entering the coalescer, thereby avoiding the risk of the coalescing wire mesh in the coalescer being blocked by wax. Therefore, while achieving gas-liquid separation of the natural gas, the coalescing wire mesh in the coalescer will not be blocked. Therefore, the low-temperature separation device and separation method provided in this embodiment achieve the purpose of gas-liquid separation of waxy natural gas, and solve the technical problem that the existing vertical separator has poor separation performance when processing high-wax natural gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0026] Figure 1 It is a structural schematic diagram of a neutral separator in the prior art;

[0027] Figure 2 is a schematic structural diagram of a low-temperature separation device provided in Embodiment 1 of the present invention;

[0028] Figure 3 is a schematic structural diagram of an inertial separator provided in Embodiment 1 of the present invention;

[0029] Figure 4 is a schematic structural diagram of a barrier member provided in Embodiment 1 of the present invention;

[0030] Figure 5 is a structural schematic diagram of a centrifugal separator provided in Embodiment 1 of the present invention;

[0031] Figure 6is a schematic structural diagram of a baffle separator provided in Embodiment 1 of the present invention;

[0032] Figure 7 is a schematic structural diagram of a corrugated plate provided in Embodiment 1 of the present invention;

[0033] Figure 8 It is a schematic diagram of the separation method provided in Example 2 of the present invention.

[0034] Description of reference numerals:

[0035] Separation container-1; air inlet cavity-11; first-stage separation chamber-12; inertial separator-121; baffle-1211; barrier-1212; air inlet end-12121; guide-12122; bent end-12123; bent portion-12124; second-stage separation chamber-13; centrifugal separator-131; cyclone element-1311; sprayer-132; third-stage separation chamber-14; separator assembly-141; coalescer-1411; baffle separator -1412; corrugated plate-14121; air inlet-15; air outlet-16; distributor-17; inspection port-18; liquid storage container-2; first liquid storage chamber-21; first liquid outlet-211; second liquid storage chamber-22; second liquid outlet-221; third liquid storage chamber-23; third liquid outlet-231; first connecting pipe-3; second connecting pipe-4; third connecting pipe-5; inner pipe-6; regulating valve-7; cyclone-8; downcomer-9; blade distributor-10. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] As described in the background technology, the gas-liquid separator in the natural gas cryogenic processing process generally adopts a vertical separator. Figure 1As shown, after the blade distributor 10 evenly distributes the natural gas in the vertical separator, the gas rises and passes through the coalescing screen in the coalescer 1411 to accumulate the small condensed liquid droplets in the natural gas to form large droplets, and then passes through the cyclone element and the separation screen in the cyclone 8 for gas-liquid separation. The separated liquid is dropped to the lower liquid storage space of the vertical separator through the downcomer 9, and the separated gas enters the subsequent pipeline. In the vertical separator, it is necessary to ensure that the separated liquid reaches the lower liquid storage space through the downcomer, and the pressure drop of the coalescing screen must not be too large. However, when using this vertical separator to process high-wax natural gas, since the wax precipitated through the vertical separator has high viscosity, as the production time increases, the precipitated high-viscosity wax will adhere to the coalescing screen in the coalescer 1411, causing the coalescing screen to be blocked, so that the pressure drop of the gas through the coalescer 1411 gradually increases, resulting in the separated liquid being unable to pass through the coalescing screen to be dropped. In severe cases, the bottom liquid will rise through the downcomer 9 under the action of the pressure difference, and the gas-liquid separation will fail, which will seriously affect the separation performance of the vertical separator, making the separation performance of the vertical separator for high-wax natural gas poor.

[0038] It should be noted that the high wax content natural gas in this embodiment refers to the waxy natural gas whose wax content in the natural gas will cause the above-mentioned influence on the existing vertical separator. In this embodiment, the wax content in the high wax content natural gas is not further limited.

[0039] In view of this, the present invention provides a low-temperature separation device and a separation method to solve the technical problem that the existing vertical separator has poor separation performance when processing high-wax natural gas.

[0040] Embodiment 1

[0041] Figure 2 is a schematic structural diagram of a low-temperature separation device provided in Example 1 of the present invention, Figure 3 is a schematic structural diagram of an inertial separator provided in Embodiment 1 of the present invention, Figure 4 is a schematic diagram of the structure of the barrier provided by the first embodiment of the present invention, Figure 5 is a schematic structural diagram of a centrifugal separator provided in Embodiment 1 of the present invention, Figure 6 is a schematic structural diagram of a baffle separator provided in Embodiment 1 of the present invention, Figure 7 It is a schematic diagram of the structure of the corrugated plate provided in the first embodiment of the present invention.

[0042] refer to Figures 2 to 7As shown, an embodiment of the present invention provides a low-temperature separation device, which is suitable for gas-liquid separation of waxy natural gas. The low-temperature separation device includes a separation container 1. The separation container 1 is provided with a first-stage separation chamber 12, a second-stage separation chamber 13 and a third-stage separation chamber 14 which are interconnected in sequence along the flow direction of the natural gas, so that the natural gas passes through the first-stage separation chamber 12, the second-stage separation chamber 13 and the third-stage separation chamber 14 in sequence; wherein, an inertial separator 121 is provided in the first-stage separation chamber 12, a centrifugal separator 131 is provided in the second-stage separation chamber 13, and a separator assembly 141 is provided in the third-stage separation chamber 14, wherein the separator assembly 141 includes a coalescer 1411 and a baffle separator 1412 which are arranged in sequence along the flow direction of the natural gas, and the natural gas is used to flow through the inertial separator 121, the centrifugal separator 131, the coalescer 1411 and the baffle separator 1412 in sequence, so that the gas phase and the liquid phase in the natural gas are separated.

[0043] It should be noted that the waxy natural gas in this embodiment needs to be processed by a low-temperature treatment process before being processed by the low-temperature separation device to convert the impurities in the waxy natural gas into liquid form. The low-temperature treatment process can generally be understood as a treatment performed at a temperature of less than or equal to minus 15°C, such as low-temperature sedimentation. Accordingly, the low-temperature separation device in this embodiment belongs to the separation process in the low-temperature treatment process. Therefore, the processing temperature of the low-temperature separation device in this embodiment should be less than or equal to minus 15°C, that is, the low temperature is a temperature less than or equal to minus 15°C.

[0044] Specifically, refer to Figure 2 As shown, the natural gas first passes through the inertial separator 121 and collides with the inertial separator 121, and the heavier liquid phase substances (such as wax) in the natural gas are separated from the gas phase, thereby realizing the first gas-liquid separation of the gas phase and liquid phase substances of the natural gas; the separated natural gas passes through the centrifugal separator 131, and the natural gas after the first separation can be cycloned to generate centrifugal motion. By utilizing the density difference between the liquid crystal and the gas phase in the natural gas, the gas phase with a smaller density moves upward in the centrifugal tube of the centrifugal separator 131, and the liquid phase with a relatively larger density moves downward in the centrifugal tube, thereby realizing the centrifugal separation of gas and liquid, and separating liquid phase particles with a size of 10-20 μm. The tiny liquid particles in the natural gas after the second gas-liquid separation pass through the coalescing wire mesh in the coalescer 1411, and the tiny liquid particles coalesce on the coalescing wire mesh to form larger liquid particles, and finally pass through the baffle separator 1412 in the separator assembly 141 to separate the larger liquid particles (with a particle size of 3 μm-5 μm or more) formed by coalescing through the coalescing wire mesh, thereby finally realizing the efficient separation of waxy natural gas.

[0045] refer to Figure 2As shown, the present application can separate the gas phase and liquid crystal in the natural gas step by step by setting a three-stage separation chamber in the separation container 1, thereby achieving a better separation effect. Since the natural gas is waxy natural gas, wherein the waxy natural gas can be high-wax natural gas, considering the high viscosity of the wax precipitated during the separation process, the first-stage separation chamber 12 and the second-stage separation chamber 13 are set before the separator assembly 141 of the third-stage separation chamber 14, and the gas phase and liquid crystal in the natural gas are separated for the first and second time by the inertial separator 121 of the first-stage separation chamber 12 and the centrifugal separator 131 of the second-stage separation chamber 13, and the large particles (such as wax) in the natural gas are separated from the natural gas, so that when the natural gas reaches the separator assembly 141 in the third-stage separation chamber 14, the gas phase of the natural gas contains only tiny particles of liquid phase, thereby avoiding the risk of wax blocking the coalescing wire mesh of the coalescer 1411 in the vertical separator, and finally the low-temperature separation device of this embodiment realizes the efficient separation of wax-containing natural gas.

[0046] It should be noted that, in the present embodiment, the centrifuge 131 may be a cyclone separator suitable for gas-liquid separation in the prior art or other centrifuges suitable for gas-liquid separation, that is, the centrifuge 131 in the present embodiment includes but is not limited to a cyclone separator. Among them, the cyclone separator may be a gas-liquid cyclone separator. Correspondingly, the coalescer 1411 may be a coalescer suitable for gas-liquid separation in the prior art, such as a gas-liquid coalescer. Among them, the coalescing wire mesh is a structure in the coalescer 1411 that can remove trace liquid crystals (such as water droplets, oil droplets, etc.) in the gas phase, that is, solid particles, such as a filter element of the coalescer 1411. In the present embodiment, the structure and model of the centrifuge 131, the coalescer 1411 and the baffle separator 1412 are not further limited.

[0047] Specifically, in this embodiment, the baffle separator 1412 may be a corrugated plate separator or other baffle separation structures capable of performing gas-liquid separation. That is, in this embodiment, the baffle separator 1412 includes but is not limited to a corrugated plate separator. Figure 6 and Figure 7 As shown, the corrugated plate separator can be composed of many parallel corrugated plates 14121, and a certain spacing (such as 10mm) is set between the corrugated plates 14121, and fixed by a frame. The natural gas after being coalesced by the coalescer 1411 flows in a zigzag manner between the thin plates of the corrugated plate separator. The larger liquid particles in the gas phase condensed by the coalescer 1411 are thrown onto the plate wall under the action of gravity, inertia and gravity. Under the action of adhesion, the water droplets adhere to the corrugated plate to form a water film. The water film settles under the action of gravity, so that the liquid phase and the gas phase are further separated to separate the larger (3-5μm or more) liquid particles formed by the coalescing wire mesh, and finally achieve efficient separation of waxy natural gas.

[0048] As a possible implementation manner, in order to interconnect the first-stage separation chamber 12, the second-stage separation chamber 13 and the third-stage separation chamber 14 in the separation container 1, in this embodiment, through holes (not shown in the figure) through which natural gas can flow can be provided in the first-stage separation chamber 12, the second-stage separation chamber 13 and the third-stage separation chamber 14. The size and shape of the through holes must be sufficient to allow the natural gas to pass through and enter the next stage of separation operation. In this embodiment, the size and shape of the through holes will not be further elaborated.

[0049] Among them, reference Figure 1 As shown, in this embodiment, the inertial separator 121 and the centrifugal separator 131 can be fixed to the first-stage separation chamber 12 and the second-stage separation chamber 13 respectively by fixing brackets, so that there is a certain gap between the inertial separator 121 and the centrifugal separator 131 and the bottom of the separation container 1, that is, the inertial separator 121 and the centrifugal separator 131 can be arranged as close to the middle of the natural gas flow direction as possible by fixing the brackets, so that more natural gas can enter the inertial separator 121 and the centrifugal separator 131, so as to increase the gas-liquid separation effect of the natural gas.

[0050] It should be understood that the greater the speed at which the natural gas collides with the inertial separator 121, the better the effect of the first gas-liquid separation. Therefore, in order to obtain a better effect of the first gas-liquid separation, in this embodiment, the natural gas can collide with the inertial separator 121 at a preset speed, wherein the greater the preset speed, the better the separation effect, for example, the preset speed is greater than 0m / s and less than or equal to 200m / s. In practical applications, the preset speed of the natural gas entering the inertial separator 121 can be adjusted within the above range, and in this embodiment, it is not further limited.

[0051] In the embodiment of the present invention, an inertial separator 121, a centrifugal separator 131 and a separator assembly 141 are arranged in the separation container 1, wherein the separator assembly 141 includes a coalescer 1411. When the waxy natural gas flows through the inertial separator 121, the centrifugal separator 131 and the separator assembly 141 in sequence, the gas phase and the liquid phase of the natural gas are firstly effectively separated by the inertial separator 121, and the heavy hydrocarbons (such as wax), alcohol and water in the natural gas are separated; then, the natural gas is subjected to a second gas-liquid separation by the centrifugal separator 131. Gas-liquid separation, light hydrocarbons, a small amount of alcohol and water in natural gas are separated; finally, the natural gas is subjected to a third gas-liquid separation through the separator assembly 141. On the basis of achieving gas-liquid separation of natural gas, since the wax has been separated in the first gas-liquid separation and the second gas-liquid separation, there are only a small amount of light hydrocarbons, a small amount of alcohol and water in the natural gas entering the coalescer 1411, thereby avoiding the risk of the coalescing wire mesh in the coalescer 1411 being blocked by wax. Therefore, while achieving gas-liquid separation of natural gas, the coalescing wire mesh in the coalescer 1411 will not be blocked. Therefore, the low-temperature separation device and separation method provided in this embodiment achieve the purpose of gas-liquid separation of wax-containing natural gas, and solve the technical problem that the existing vertical separator has poor separation performance when processing wax-containing natural gas.

[0052] Specifically, refer to Figure 3 and Figure 4 As shown, in this embodiment, the inertial separator 121 includes a blocking plate 1211 and a plurality of blocking members 1212, and the plurality of blocking members 1212 are arranged on one side or both sides of the blocking plate 1211 along the flow direction of the natural gas, so as to have a better blocking effect on the natural gas; wherein, in this embodiment, the group baffle can be vertically arranged in the first-stage separation chamber 12 and parallel to the flow direction of the natural gas, so as to collide with the blocking member 1212 during the flow of the natural gas and block the natural gas through the blocking member 1212, so as to effectively separate the heavier liquid phase material from the gas phase material. The plurality of blocking members 1212 are staggeredly arranged on the group baffle according to the preset row spacing and column spacing, so as to improve the flow effect of the natural gas, increase the probability of collision with the natural gas, enhance the blocking effect on the natural gas, so that the natural gas must pass through the blocking member 1212 to separate the liquid phase and the gas phase through collision, avoid omission, and enhance the separation effect.

[0053] It should be understood that reference Figure 3 and Figure 4As shown, the staggered arrangement of the plurality of barrier members 1212 on the group baffle according to the preset row spacing and column spacing can be understood as taking the column as the unit, and the staggered arrangement of the barrier members 1212 is described. Exemplarily, the second column of barrier members 1212 on the baffle plate 1211 is located between the first column of barrier members 1212 and the third column of barrier members 1212, and the second column of barrier members 1212 is slightly higher than the first column of barrier members 1212 and the third column of barrier members 1212, so as to fill the blank area between the first column of barrier members 1212 and the third column of barrier members 1212. Specifically, in practical applications, the preset row spacing and column spacing can be adjusted according to actual needs. In this embodiment, no further limitation is made, as long as the natural gas must pass through the barrier member 1212 to separate the liquid phase and the gas phase through collision.

[0054] For further reference, Figure 3 and Figure 4 As shown, the barrier 1212 is a bent structure, and the barrier 1212 includes an air inlet end 12121, a guide portion 12122, and a bent end 12123 arranged opposite to the air inlet end 12121 and blocking the natural gas; the guide portion 12122 is connected between the air inlet end 12121 and the bent end 12123, and is used to guide the flow of natural gas between the air inlet end 12121 and the bent end 12123. In this embodiment, the directions of the opening end and the bent end 12123 of the barrier 1212 are arranged according to the flow direction of the natural gas, so that the natural gas collides with the barrier 1212 when it flows in the inertial separator 121 under the action of the inertial force, thereby separating the heavier liquid phase material (such as wax) from the gas phase material. Specifically, in this embodiment, the barrier 1212 includes but is not limited to an integrated structure.

[0055] refer to Figure 3 and Figure 4 As shown, in this embodiment, the width of the barrier 1212 gradually decreases in the direction from the air inlet end 12121 to the bent end 12123, that is, the width of the barrier 1212 is larger at the air inlet end 12121 and smaller at the bent end 12123, so that when the natural gas flows in the inertial separator 121, it is easier to collide with the barrier 1212, so as to effectively separate the heavier liquid phase material (such as wax) from the gas phase material. Exemplarily, the barrier 1212 can be a bent plate in a V shape or other shapes, that is, in this embodiment, the barrier 1212 includes but is not limited to a V-shaped bent plate.

[0056] In order to enhance the collision effect between natural gas and barrier 1212, refer to Figure 3 and Figure 4As shown, in this embodiment, both sides of the air inlet end 12121 are respectively provided with bending portions 12124 bent toward the inside of the barrier 1212, and the bending portions 12124 are used to block the natural gas that rebounds to the air inlet end 12121 after being blocked by the bending end 12123, so that the natural gas collides with the bending portion 12124 again, and further separates the liquid phase material in the natural gas after the first gas-liquid separation, so that the liquid phase adheres to the barrier 1212, and is agglomerated, and descends along the vertical flow direction, thereby effectively improving the effect of the first gas-liquid separation of the natural gas.

[0057] refer to Figure 5 As shown, after the first gas-liquid separation, a large amount of heavy hydrocarbons, alcohol and water in the natural gas have been separated from the gas phase in the natural gas, but there is still a very small amount of heavy hydrocarbons (such as wax) in the natural gas after the first gas-liquid separation. As the processing time increases, the very small amount of wax in the natural gas after the first gas-liquid separation may clog the cyclone element 1311 (such as cyclone blades) in the centrifugal separator 131, causing the cyclone separation to fail, thereby reducing the gas-liquid separation effect of the low-temperature separation device on the natural gas.

[0058] For this purpose, refer to Figure 2 and Figure 5 As shown, in this embodiment, a sprayer 132 is provided in the second-stage separation chamber 13, and the sprayer 132 is used to flush the wax blocked on the centrifugal separator 131 to avoid the wax blockage of the cyclone element 1311 in the centrifugal separator 131, which causes the cyclone separation failure. Exemplarily, in this embodiment, the sprayer 132 can be a light hydrocarbon sprayer 132 or a spray device that can clean the wax blocked on the centrifugal separator 131 with gas, that is, in this embodiment, the sprayer 132 includes but is not limited to the light hydrocarbon sprayer 132. Among them, the sprayer 132 can be fixed to the top of the second-stage separation chamber 13 by a fastener (not shown in the figure) and is arranged opposite to the centrifugal separator 131. When the centrifugal separator 131 needs to be cleaned, the opening of the centrifugal separator 131 can be opened (not shown in the figure) so that the sprayer 132 can clean the wax blocked on the centrifugal separator 131.

[0059] It should be noted that after the natural gas is processed by the centrifugal separator 131 in the second-stage separation chamber 13, the 10-20 μm liquid particles in the natural gas can be separated from the gas phase. The 10-20 μm liquid particles may include light hydrocarbons, alcohols and water in the natural gas.

[0060] As we all know, light hydrocarbons and heavy hydrocarbons are often distinguished according to the number of carbon atoms. The case with more carbon atoms is called heavy, and vice versa, the case with fewer carbon atoms is called light. Generally speaking, hydrocarbons with less than 11 carbon atoms are called light hydrocarbons, such as ethane, and hydrocarbons with more than 11 carbon atoms are called heavy hydrocarbons, such as wax.

[0061] refer to Figure 2 , Figure 6 and Figure 7 As shown, in this embodiment, the baffle separator 1412 can be a corrugated plate separator arranged at the gas outlet end of the coalescer 1411. The corrugated plate separator is used to separate the liquid phase formed by coalescing in the coalescer 1411 from the gas phase in the natural gas, so that the gas phase is discharged from the separation container 1, and the liquid particles larger than 3-5 μm in the natural gas are separated by the corrugated plate separator.

[0062] For further reference, Figure 2 As shown, in this embodiment, an air inlet chamber 11 is provided in the separation container 1, and the air inlet chamber 11 is located on the side of the first-stage separation chamber 12 away from the second-stage separation chamber 13. An air inlet 15 and a distributor 17 connected to the air inlet 15 are provided in the air inlet chamber 11, which is used to evenly distribute the gas-liquid phase fluid of the input natural gas, which is conducive to improving the gas-liquid separation effect in the later stage. Among them, the distributor 17 is tilted in the separation container 1 and arranged relative to the inertial separator 121, so as to increase the effective length of the distributor 17, so that the gas-liquid mixing reaches the best uniform state. Exemplarily, the distributor 17 is arranged at an acute angle in the air inlet chamber 11, such as 45 degrees. The distributor 17 in this embodiment can refer to the distributor 17 in the prior art that can be used for uniform distribution of gas and liquid. In practical applications, the connection angle between the distributor 17 and the air inlet 15 can be set according to the specific situation, so that the gas-liquid mixing reaches the best uniform state. In this embodiment, the tilt angle of the distributor 17 is not further limited.

[0063] For further reference, Figure 2 As shown, in this embodiment, it also includes a liquid storage container 2 located at the bottom of the separation container 1 and connected to the separation container 1, and the liquid storage container 2 includes three independent liquid storage chambers; wherein, the three independent liquid storage chambers respectively include a first liquid storage chamber 21 connected to the first-stage separation chamber 12, a third liquid storage chamber 23 connected to the second-stage separation chamber 13, and a third liquid storage chamber 23 connected to the third-stage separation chamber 14, so as to classify, recycle and reuse the liquid phase after the step-by-step gas-liquid separation.

[0064] After the high-wax natural gas enters the multiple separators in the separation container 1, a large amount of heavy components and wax components are separated out by the separators at each level and under the action of gravity. The liquid phase substances separated by the separators in the three separation chambers flow downward due to the action of gravity and are respectively gathered in the corresponding three liquid storage chambers. The three liquid storage chambers correspond to the three separation stages respectively, and the liquid separated in each stage is stored, so that the discharge of each stage does not affect each other, avoiding the impact on the subsequent separation elements, ensuring the smooth discharge process, and avoiding the continued forward movement of larger particles of liquid phase, thereby ensuring the normal and efficient separation of the subsequent separators, and finally achieving efficient separation of gas and liquid.

[0065] Specifically, in this embodiment, the natural gas that has undergone the first gas-liquid separation by the inertial separator 121 continues to flow to the second-stage separation chamber 13 through the first connecting pipe 3 inertial separator 121, and the separated liquid phase material flows into the first liquid storage chamber 21 after coalescence. The first liquid storage chamber 21 contains a large amount of heavy hydrocarbons, alcohol, water and other mixtures. The natural gas that has undergone the second gas-liquid separation by the centrifugal separator 131 continues to flow to the third-stage separation chamber 14 through the cyclone separator, and the separated liquid phase material flows into the second liquid storage chamber 22 through the second connecting pipe 4 after coalescence. The second liquid storage chamber 22 contains light hydrocarbons and a small amount of alcohol and water mixture. The natural gas that has undergone the third gas-liquid separation by the coalescing wire mesh and corrugated plate separator in the coalescer 1411 is discharged through the gas outlet 16 of the separation container 1, and the separated liquid phase material flows into the third liquid storage chamber 23 through the third connecting pipe 5 after coalescence. The third liquid chamber contains a small amount of light hydrocarbons and a small amount of alcohol and water mixture.

[0066] In this embodiment, reference Figure 2 As shown, the gas inlet 15 and the gas outlet 16 on the separation container 1 are respectively arranged at both ends of the separator, and the natural gas is sent into the separator through the gas inlet 15 at a certain pressure, so as to facilitate the circulation of the natural gas in the separation container 1. On this basis, the gas outlet 16 is used to connect the subsequent pipeline, so that the product gas that meets the requirements is sent to the subsequent pipeline.

[0067] Preferably, reference Figure 2 As shown, in this embodiment, the second liquid storage chamber 22 is connected to the liquid outlet of the centrifugal separator 131 through the second connecting pipe 4, so that the liquid phase material effectively flows into the second liquid storage chamber 22 through the second connecting pipe 4, avoiding the liquid phase material from remaining in the second-stage separation chamber 13, and effectively realizing the collection of the liquid phase material after the second gas-liquid separation. The gas phase separated by the centrifugal separator 131 is discharged from the centrifugal separator 131 through another outlet and enters the coalescer 1411 of the third-stage separation chamber 14.

[0068] For further reference, Figure 2As shown, in this embodiment, the third liquid storage chamber 23 is connected to the third-stage separation chamber 14 through the third connecting pipe 5, and an inner insert pipe 6 is provided in the third connecting pipe 5, one end of the inner insert pipe 6 is connected to the baffle separator 1412 (such as a corrugated plate separator), and the other end is inserted into the third liquid storage chamber 23. After the liquid phase substance in the natural gas flows into the third liquid storage chamber 23 through the third connecting pipe 5 through the separation of the coalescing wire mesh in the coalescer 1411, the liquid phase substance after the gas-liquid separation of the natural gas in the corrugated plate separator directly flows into the third liquid storage chamber 23 through the inner insert pipe 6, which effectively realizes the collection of the liquid phase substance.

[0069] Specifically, refer to Figure 2 As shown, in this embodiment, a first liquid outlet 211 is provided on the cavity wall of the first liquid storage chamber 21; a second liquid outlet 221 is provided on the cavity wall of the second liquid storage chamber 22; and a third liquid outlet 231 is provided on the cavity wall of the third liquid storage chamber 23, so that the liquid phase in each liquid storage chamber can be discharged through the first liquid outlet 211, the second liquid outlet 221 and the third liquid outlet 231 for reuse. Specifically, the first liquid outlet 211, the second liquid outlet 221 and the third liquid outlet 231 are all provided with a regulating valve 7, and the pressure-regulated delivery of the liquid in each liquid storage chamber is realized through the three regulating valves 7.

[0070] In order to facilitate the daily maintenance of the separation container 1, refer to Figure 2 As shown, in this embodiment, a maintenance valve is provided at the end of the third-stage separation chamber 14, which is conducive to daily maintenance of the separation container 1 and ensures the normal operation of the low-temperature separation device.

[0071] Specifically, the low-temperature separation device in this embodiment can adopt an upper and lower double-layer horizontal structure, that is, the liquid storage container 2 is located in the lower layer of the separation container 1, so that the separated liquid phase can enter the corresponding liquid storage chamber under the action of gravity to achieve the collection of liquid phase substances.

[0072] The low-temperature separation device provided by the present invention arranges an inertial separator, a centrifugal separator and a separator assembly in a separation container. First, the gas phase and liquid phase of the natural gas treated at low temperature are subjected to a first gas-liquid separation and a second gas-liquid separation in sequence by the inertial separator and the centrifugal separator, and the heavy hydrocarbons (such as wax), light hydrocarbons, alcohol and water in the natural gas are separated from the gas phase of the natural gas. Then, the gas phase in the natural gas is allowed to enter the coalescer in the separator assembly, thereby achieving gas-liquid separation of the natural gas without causing clogging of the coalescing wire mesh in the coalescer.

[0073] Embodiment 2

[0074] Figure 8 A schematic flow chart of the separation method provided in Embodiment 2 of the present invention.

[0075] Further, based on the low temperature separation device of the above embodiment, refer to Figure 8 As shown, in this embodiment, the present invention provides a separation method applicable to waxy natural gas, comprising the following steps:

[0076] S100: The natural gas enters the inertial separator 121 in the separation container 1, and the natural gas is subjected to the first-stage gas-liquid separation by the inertial separator 121. The particles and liquid in the natural gas collide with the inertial separator 121 at a preset speed, and adhere to the inertial separator 121 and accumulate continuously. Under the action of gravity, the mixed liquid of heavy hydrocarbons, alcohol and water enters the first liquid storage chamber 21 through the first connecting pipe 3.

[0077] S200: The natural gas after the first-stage gas-liquid separation enters the centrifugal separator 131 in the separation container 1, and the natural gas is subjected to the second-stage gas-liquid separation by the centrifugal separator 131; under the action of the centrifugal force of the centrifugal separator 131, the 10-20 μm liquid particles in the natural gas are separated from the gas phase, and the light hydrocarbons and the alcohol-water mixed liquid particles are accumulated and enter the second liquid storage chamber through the second connecting pipe 4 under the action of gravity.

[0078] Furthermore, when the centrifugal separator 131 is blocked by condensed wax, the sprayer 132 is started to flush the wax blocking the centrifugal separator 131 to ensure the normal operation of the centrifugal separator 131 .

[0079] S300: After the second-stage gas-liquid separation, the natural gas enters the separator assembly 141 in the separation container 1. After the liquid phase in the natural gas is agglomerated by the agglomerator 1411 in the separator assembly 141, the natural gas is subjected to the third-stage gas-liquid separation by the corrugated plate separator in the separator assembly 141 to obtain the gas phase in the natural gas. After separation, the liquid particles larger than 3-5 μm enter the third liquid storage chamber through the inner insert tube 6 under the action of gravity.

[0080] S400: The gas phase is discharged from the separation container 1, and the natural gas (ie, the gas phase) after the gas-liquid separation through the first-stage separation chamber 12, the second-stage separation chamber 13 and the third-stage separation chamber 14 is discharged through the exhaust port.

[0081] S500: Collect the liquid phase after the first gas-liquid separation, the second gas-liquid separation and the third gas-liquid separation respectively. Specifically, the liquid storage container 2 is separated into three independent liquid storage chambers, which are used for separation and isolation of liquids with different densities in the low-temperature separator. The first liquid storage chamber 21 contains a large amount of heavy hydrocarbons, alcohol, water and other mixtures, the second liquid storage chamber 22 contains light hydrocarbons and a small amount of alcohol and water mixtures; the third liquid storage chamber 23 contains a small amount of light hydrocarbons and a small amount of alcohol and water mixtures.

[0082] Among them, after the high-wax natural gas enters the first-stage separation chamber 12 of the above-mentioned separation container 1, a large amount of heavy components and wax components are separated under the action of the inertial separator 121 and gravity, and enter the first liquid storage chamber 21, avoiding the impact on the subsequent separators. Therefore, the normal and efficient separation of the subsequent separators can be guaranteed, and finally the efficient separation of gas and liquid can be achieved.

[0083] Specifically, high-wax natural gas (i.e., a gas-liquid mixture of low-temperature natural gas) enters the separation container 1 from the gas inlet, and the natural gas first passes through the distributor 17 for rectification, and then enters the inertial separator 121 after the gas and liquid are evenly distributed. The natural gas collides with the inertial separator 121 at a certain speed to achieve the first gas-liquid separation, and large particles and liquid (mainly wax and heavy components) in the natural gas adhere to the inertial separator 121 and accumulate continuously. Under the action of gravity, the liquid enters the first liquid storage chamber 21 through the first connecting pipe 3, and the separated gas continues to move to the second separation chamber through the channel of the inertial separator 121 (i.e., the gap between the barrier members 1212).

[0084] The natural gas after the first gas-liquid separation enters the centrifugal separator 131. Under the action of centrifugal force, the 10-20μm liquid particles of the gas-liquid mixture are separated from the gas phase. After the liquid particles accumulate, they pass through the centrifugal separator 131 and the second connecting pipe 4 under the action of gravity into the second liquid storage chamber 22; the separated natural gas containing trace amounts of liquid droplets enters the third-stage separation chamber 14.

[0085] After the second gas-liquid separation, the natural gas is subjected to the third gas-liquid separation through the coalescing screen in the coalescer 1411, wherein the extremely fine liquid particles are coalesced on the coalescing screen and liquid particles larger than 3-5 μm are separated by the corrugated plate separator. Liquid particles larger than 3-5 μm enter the third liquid storage chamber 23 through the inner insert tube 6 under the action of gravity.

[0086] The separation method provided by the present invention first performs a first gas-liquid separation and a second gas-liquid separation on the gas phase and liquid phase of natural gas in sequence through an inertial separator and a centrifugal separator, and after separating the heavy hydrocarbons (such as wax), light hydrocarbons, alcohol and water in the natural gas from the gas phase of the natural gas, the gas phase in the natural gas is allowed to enter the coalescer in the separator assembly, thereby achieving gas-liquid separation of the natural gas without causing clogging of the coalescing wire mesh in the coalescer.

[0087] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0088] In the description of the present invention, it should be understood that the terms "including" and "having" and any variations thereof used herein are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0089] Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense, for example, it can be fixedly connected, detachably connected, or integrated; it can be directly connected, or indirectly connected through an intermediate medium, so that the internal connection of two elements or the interaction relationship between the two elements can be achieved. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. In addition, the terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low temperature separation device, suitable for gas-liquid separation of waxy natural gas, characterized in that: The separation container comprises a first-stage separation chamber, a second-stage separation chamber and a third-stage separation chamber which are interconnected and arranged in sequence along the flow direction of the natural gas; Wherein, an inertial separator is provided in the first-stage separation chamber, a centrifugal separator is provided in the second-stage separation chamber, and a separator assembly is provided in the third-stage separation chamber, wherein the separator assembly comprises a coalescer and a baffle separator which are sequentially arranged along the flow direction of the natural gas, and the natural gas is used to flow through the inertial separator, the centrifugal separator, the coalescer and the baffle separator in sequence, so as to separate the gas phase and the liquid phase in the natural gas; the inertial separator comprises a baffle plate and a plurality of baffles, and the plurality of baffles are arranged on one side or both sides of the baffle plate along the flow direction of the natural gas; wherein the baffle plate is vertically arranged in the first-stage separation chamber and parallel to the flow direction of the natural gas; the plurality of baffles are staggeredly arranged on the baffle plate according to preset row spacing and column spacing, so as to separate the liquid phase and the gas phase in the natural gas; a sprayer is provided in the second-stage separation chamber, and the sprayer is used to flush the wax blocked on the centrifugal separator.

2. The low temperature separation device according to claim 1, characterized in that: The barrier is a bent structure, comprising an air inlet end, a guide portion and a bent end arranged opposite to the air inlet end and blocking the natural gas; the guide portion is connected between the air inlet end and the bent end, and is used to guide the flow of the natural gas between the air inlet end and the bent end.

3. The low temperature separation device according to claim 2, characterized in that: In the direction from the air inlet end to the bending end, the width of the blocking member gradually decreases.

4. The low temperature separation device according to claim 3, characterized in that: The two sides of the air inlet end are respectively provided with bending parts bent toward the inside of the blocking member, and the bending parts are used to block the natural gas that rebounds to the air inlet end after being blocked by the bending ends.

5. The low temperature separation device according to any one of claims 1 to 4, characterized in that: The baffle separator is a corrugated plate separator arranged at the gas outlet end of the coalescer, and the corrugated plate separator is used to separate the liquid phase formed by coalescing in the coalescer from the gas phase in the natural gas, so that the gas phase is discharged from the separation container.

6. The low temperature separation device according to any one of claims 1 to 4, characterized in that: An air inlet chamber is provided in the separation container, and the air inlet chamber is located on the side of the first-stage separation chamber away from the second-stage separation chamber. An air inlet and a distributor connected to the air inlet are provided in the air inlet chamber, wherein the distributor is obliquely arranged in the separation container and opposite to the inertial separator.

7. The low temperature separation device according to any one of claims 1 to 4, characterized in that: Also included is a liquid storage container located at the bottom of the separation container and in communication with the separation container, the liquid storage container comprising three independent liquid storage chambers; Among them, the three independent liquid storage chambers include a first liquid storage chamber connected to the first-stage separation chamber, a second liquid storage chamber connected to the second-stage separation chamber, and a third liquid storage chamber connected to the third-stage separation chamber.

8. A separation method for waxy natural gas, characterized in that: The method is implemented by using the low temperature separation device according to any one of claims 1 to 7, comprising the following steps: The natural gas enters an inertial separator in a separation container, and the natural gas is subjected to a first-stage gas-liquid separation by the inertial separator; The natural gas after the first stage gas-liquid separation enters the centrifugal separator in the separation container, and the natural gas is subjected to a second stage gas-liquid separation by the centrifugal separator; The natural gas after the second-stage gas-liquid separation enters the separator assembly in the separation container, and after the liquid phase in the natural gas is coalesced by the coalescer in the separator assembly, the natural gas is subjected to a third-stage gas-liquid separation to obtain the gas phase in the natural gas; discharging the gas phase from the separation vessel; The liquid phases after the first stage gas-liquid separation, the second stage gas-liquid separation and the third stage gas-liquid separation are collected respectively.

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