Triethylene glycol dehydration skid low pressure operation system

Abstract

The present application provides a kind of triethylene glycol dehydration skid low pressure operation system, including rich liquid circulation system and lean liquid circulation system, the rich liquid circulation system includes rich liquid liquefaction tank (1), rich liquid inlet pipe (2) and rich liquid outlet pipe (3);Rich liquid liquefaction tank (1) is further provided with liquid level meter (6) on;Rich liquid outlet pipe (3) is equipped with regulating valve;The lean liquid circulation system includes circulating pump (7), lean liquid inlet pipe (8) and lean liquid outlet pipe (9);Lean liquid inlet pipe (8) one end is connected with circulating pump (7), the other end is connected with the outlet of heat exchanger (10);Further including control system (11);The control system (11) is signal connected with liquid level meter (6), regulating valve and circulating pump (7).The present application can make that dehydration dehydration skid can also be normally operated in low pressure state, and can realize the remote start-stop of rich liquid circulation system and lean liquid circulation system.

Description

Technical Field

[0001] The invention relates to the technical field of dehydration skids, and in particular to a triethylene glycol dehydration skid low-pressure operation system. Background Art

[0002] Most gas fields produce gas with water, and even light hydrocarbons and condensate oil when extracting natural gas. Direct transportation will corrode the transportation pipeline. In order to ensure the safe transportation of natural gas, the natural gas needs to be dehydrated.

[0003] Currently, the most mature natural gas dehydration process is the triethylene glycol absorption method. This dehydration process takes place within a triethylene glycol absorption tower. Regenerated, water-free triethylene glycol (lean liquid) and water-containing natural gas are thoroughly mixed and contacted on the absorption tower trays. Because triethylene glycol is a hydrophilic compound, it absorbs the water from the water-containing natural gas into the triethylene glycol, converting the water-free triethylene glycol (lean liquid) into water-containing triethylene glycol (rich liquid), thereby dehydrating the natural gas.

[0004] However, in actual operation, as the pressure of the gas field booster production pipeline system decreases, the system pressure in the station will be lower than the operating pressure of the existing triethylene glycol circulation pump. When the system pressure of the dehydration skid is lower than 3Mpa, it cannot operate normally at low pressure, making it impossible for the natural gas to meet the dew point requirements for external water transmission. Summary of the Invention

[0005] The present invention aims to overcome the shortcomings of the prior art by providing a low-pressure operation system for a triethylene glycol dehydration skid. By providing a rich liquid circulation system and a lean liquid circulation system, the dehydration skid can operate normally even under low pressure. A control system can also be used to remotely start and stop the rich and lean liquid circulation systems.

[0006] The purpose of the present invention is specifically achieved through the following technical solutions:

[0007] A low-pressure operation system for a triethylene glycol dehydration skid includes a rich liquid circulation system and a lean liquid circulation system, wherein:

[0008] The rich liquid circulation system includes a rich liquid liquefaction tank, a rich liquid inlet pipe, and a rich liquid outlet pipe; one end of the rich liquid inlet pipe is connected to the rich liquid outlet of the glycol absorption tower, and the other end is connected to the rich liquid inlet of the rich liquid liquefaction tank; one end of the rich liquid outlet pipe is connected to the rich liquid outlet of the rich liquid liquefaction tank, and the other end is connected to the inlet of the flash evaporation system; the rich liquid liquefaction tank is also provided with a liquid level gauge; the rich liquid outlet pipe is provided with a regulating valve;

[0009] The lean liquid circulation system includes a circulation pump, a lean liquid inlet pipe and a lean liquid outlet pipe; one end of the lean liquid inlet pipe is connected to the circulation pump, and the other end is connected to the outlet of the heat exchanger; one end of the lean liquid outlet pipe is connected to the circulation pump, and the other end is connected to the inlet of the glycol absorption tower;

[0010] It also includes a control system; the control system is connected to the liquid level meter, the regulating valve and the circulating pump signal.

[0011] Optionally or preferably, the rich liquid circulation system further comprises a pressure balancing pipe; one end of the pressure balancing pipe is connected to the bottom of the glycol absorption tower, and the other end is connected to the top of the rich liquid liquefaction tank.

[0012] Optionally or preferably, it further includes a gas pipeline; one end of the gas pipeline is connected to the top of the rich liquid liquefaction tank, and the other end is connected to the gas gathering station.

[0013] Optionally or preferably, the gas pipeline is provided with a safety valve and a variable-diameter discharge valve connected in parallel with each other; ball valves are also provided at both ends of the safety valve.

[0014] Optionally or preferably, the liquid level gauge includes a float level gauge and a magnetic flip level gauge; the regulating valve includes an emergency shut-off valve and a start-up regulating valve; and a pressure reducing valve is further provided on the rich liquid outlet pipe.

[0015] Optionally or preferably, there are multiple circulating pumps; two circulating pumps are arranged in parallel, and the liquid inlet end of each circulating pump is provided with a Y-type filter and a stop valve in sequence; the liquid outlet end of each circulating pump is provided with a safety valve and a stop valve in sequence; the filter port end of the Y-type filter is provided with a variable diameter discharge valve.

[0016] Optionally or preferably, the lean liquid outlet pipe is further provided with a basket filter and a turbine flowmeter; the turbine flowmeter is signal-connected to the control system.

[0017] Optionally or preferably, the lean liquid outlet pipe further includes a bypass pipe; the bypass pipe is coiled at the bottom of the rich liquid liquefaction tank for heat exchange.

[0018] Based on the above technical solution, the following technical effects can be produced:

[0019] The present invention provides a triethylene glycol dehydration skid low-pressure operation system for a natural gas dehydration system, which has the following beneficial effects:

[0020] (1) The control system of the present invention can realize the start and stop of the remote control operation system;

[0021] (2) The liquid level meter, circulation pump and regulating valve in the present invention can realize interlocking protection and automatic pump stop under the signal connection of the control system;

[0022] (3) The present invention enables the dewatering skid to operate normally under low pressure conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] 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 only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0024] Figure 1 It is a structural schematic diagram of the present invention;

[0025] Figure 2 is a control logic diagram of the present invention;

[0026] In the figure: 1-rich liquid liquefaction tank, 2-rich liquid inlet pipe, 3-rich liquid outlet pipe, 4-glycol absorption tower, 5-flash system, 6-liquid level gauge, 7-circulation pump, 8-lean liquid inlet pipe, 9-lean liquid outlet pipe, 10-heat exchanger, 11-control system, 12-pressure balance pipe, 13-gas transmission pipe, 14-gas gathering station, 15-safety valve, 16-reducing discharge valve, 17-emergency shut-off valve, 18-start regulating valve, 19-pressure reducing valve, 20-Y-type filter, 21-basket filter, 22-turbine flowmeter, 23-bypass pipe, 24-upper operation station. DETAILED DESCRIPTION

[0027] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0029] Example 1:

[0030] like Figure 1 As shown:

[0031] This embodiment provides a triethylene glycol dehydration skid low-pressure operation system, including a rich liquid circulation system, a lean liquid circulation system and a control system 11, wherein:

[0032] The rich liquid circulation system includes a rich liquid liquefaction tank 1, a rich liquid inlet pipe 2 and a rich liquid outlet pipe 3; one end of the rich liquid inlet pipe 2 is connected to the rich liquid outlet of the glycol absorption tower 4, and the other end is connected to the rich liquid inlet of the rich liquid liquefaction tank 1; one end of the rich liquid outlet pipe 3 is connected to the rich liquid outlet of the rich liquid liquefaction tank 1, and the other end is connected to the inlet of the flash evaporation system 5; the rich liquid liquefaction tank 1 is also provided with a liquid level gauge 6; the rich liquid outlet pipe 3 is provided with a regulating valve; when the liquid level is low, the pumping is urgently cut off or automatically stopped.

[0033] Furthermore, the rich liquid circulation system further includes a pressure balancing pipe 12; one end of the pressure balancing pipe 12 is connected to the bottom of the glycol absorption tower 4, and the other end is connected to the top of the rich liquid liquefaction tank 1, which can balance the pressure at the bottom of the absorption tower and the rich liquid liquefaction tank 1;

[0034] Furthermore, the liquid level gauge 6 includes a float level gauge and a magnetic flip level gauge; the regulating valve includes an emergency shut-off valve 17 and a start regulating valve 18; the rich liquid outlet pipe 3 is also provided with a pressure reducing valve 19;

[0035] In this embodiment, the foamy rich liquid in the rich liquid liquefaction tank 1 stays briefly and the gas and liquid are separated. Furthermore, a gas pipeline 13 connected to a gas gathering station 14 is provided on the top of the rich liquid liquefaction tank 1, and the rich liquid triethylene glycol is discharged to the flash regeneration system through an emergency shut-off valve 17 and a start-up regulating valve 18 controlled by a liquid level meter 6.

[0036] The lean liquid circulation system includes a circulation pump 7, a lean liquid inlet pipe 8, and a lean liquid outlet pipe 9; one end of the lean liquid inlet pipe 8 is connected to the circulation pump 7, and the other end is connected to the outlet of the heat exchanger 10; one end of the lean liquid outlet pipe 9 is connected to the circulation pump 7, and the other end is connected to the inlet of the glycol absorption tower 4;

[0037] Furthermore, in this embodiment, there are multiple circulating pumps 7; two circulating pumps 7 are arranged in parallel, and the liquid inlet end of each circulating pump 7 is provided with a Y-type filter 20 and a stop valve in sequence; the liquid outlet end of each circulating pump 7 is provided with a safety valve 15 and a stop valve in sequence; the filter port end of the Y-type filter 20 is provided with a variable diameter discharge valve 16.

[0038] Furthermore, the circulation pump 7 is a plunger pump with a working pressure of 6.4 MPa and a circulation volume of 200L-2000L / h. The circulation pump 7 is equipped with a frequency converter, which can control the displacement by adjusting the speed of the three-phase asynchronous motor. Furthermore, a basket filter 21 and a turbine flowmeter 22 are provided on the lean liquid outlet pipe 9. The turbine flowmeter 22 is connected to the control system 11 for signal monitoring of the triethylene glycol circulation volume.

[0039] This embodiment has the following advantages:

[0040] (1) Compact structure, modular production, safe and reliable control system, and full automatic control;

[0041] (2) When the system pressure is lower than 3.0 MPa, the electric circulating pump 7 can ensure the water dew point requirements of the natural gas to be transported;

[0042] (3) The setting of the rich liquid liquefaction tank 1 can make the foamy rich liquid in the tank stay briefly, separate the gas and liquid, and thus adjust the pressure to be stable;

[0043] (4) The electric circulation pump 7 of the lean liquid circulation system is equipped with a frequency converter. The displacement is controlled by adjusting the speed of the three-phase asynchronous motor in the circuit control system. A flow meter is installed next to the circulation pump 7 to monitor the circulation volume of triethylene glycol.

[0044] (5) Ability to remotely adjust and control opening and closing;

[0045] (6) It has a number of safety facilities including a safety valve 15 and an emergency shut-off valve 17 to ensure the normal operation of natural gas dehydration.

[0046] The foregoing description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein and should not be construed as excluding other embodiments. Rather, the present invention can be used in various other combinations, modifications, and environments and can be modified within the scope of the concept described herein through the above teachings or techniques or knowledge in the relevant field. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention are intended to be protected by the appended claims.

Claims

1. A triethylene glycol dehydration skid low-pressure operation system, characterized by: It includes rich liquid circulation system and lean liquid circulation system, in which: The rich liquid circulation system comprises a rich liquid liquefaction tank (1), a rich liquid inlet pipe (2) and a rich liquid outlet pipe (3); one end of the rich liquid inlet pipe (2) is connected to the rich liquid outlet of the glycol absorption tower (4), and the other end is connected to the rich liquid inlet of the rich liquid liquefaction tank (1); one end of the rich liquid outlet pipe (3) is connected to the rich liquid outlet of the rich liquid liquefaction tank (1), and the other end is connected to the inlet of the flash evaporation system (5); the rich liquid liquefaction tank (1) is also provided with a liquid level gauge (6); the rich liquid outlet pipe (3) is provided with a regulating valve; The rich liquid circulation system further includes a pressure balance pipe (12); one end of the pressure balance pipe (12) is connected to the bottom of the glycol absorption tower (4), and the other end is connected to the top of the rich liquid liquefaction tank (1); The lean liquid circulation system comprises a circulation pump (7), a lean liquid inlet pipe (8) and a lean liquid outlet pipe (9); one end of the lean liquid inlet pipe (8) is connected to the circulation pump (7), and the other end is connected to the outlet of the heat exchanger (10); one end of the lean liquid outlet pipe (9) is connected to the circulation pump (7), and the other end is connected to the inlet of the glycol absorption tower (4); The lean liquid outlet pipe (9) is further provided with a basket filter (21) and a turbine flowmeter (22); the turbine flowmeter (22) is signal-connected to the control system (11); It also includes a control system (11); the control system (11) is connected to the liquid level meter (6), the regulating valve and the circulation pump (7) by signal; It also includes a gas transmission pipe (13); one end of the gas transmission pipe (13) is connected to the top of the rich liquid liquefaction tank (1), and the other end is connected to the gas gathering station (14); The gas delivery pipe (13) is provided with a safety valve (15) and a variable diameter discharge valve (16) connected in parallel with each other; ball valves are also provided at both ends of the safety valve (15); The liquid level gauge (6) includes a float level gauge and a magnetic flip level gauge; the regulating valve includes an emergency shut-off valve (17) and a start regulating valve (18); and a pressure reducing valve (19) is also provided on the rich liquid outlet pipe (3).

2. The low-pressure operation system of a triethylene glycol dehydration skid according to claim 1, characterized in that: The number of the circulating pumps (7) is multiple; two circulating pumps (7) are arranged in parallel, and the liquid inlet end of each circulating pump (7) is provided with a Y-type filter (20) and a stop valve in sequence; the liquid outlet end of each circulating pump (7) is provided with a safety valve (15) and a stop valve in sequence; the filter port end of the Y-type filter (20) is provided with a variable diameter discharge valve (16).

3. The low-pressure operation system of a triethylene glycol dehydration skid according to claim 1, characterized in that: The lean liquid outlet pipe (9) further includes a bypass pipe (23); the bypass pipe (23) is coiled around the bottom of the rich liquid liquefaction tank (1) for heat exchange.

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