Nitrogen purging device based on natural gas compressor unit

Abstract

The utility model discloses a nitrogen gas purging device based on natural gas compressor unit relates to natural gas compressor technical field, including the nitrogen making system, pressure reducing valve, flowmeter, filler box, discharge pipeline that connect gradually, nitrogen making system is used to produce pure nitrogen, pressure reducing valve is used for adjusting pressure, flowmeter is used for real -time display nitrogen flow, and filler box is connected with pressure difference control valve, temperature transmitter and pressure transmitter, and temperature transmitter and pressure transmitter are used for monitoring the cavity pressure of filler box, and pressure difference control valve is used for real -time monitoring the cavity pressure of filler box and the pressure of discharge pipeline, and maintain the pressure of former is higher than the pressure of latter 0.05MPa 0.2MPa, and filler box still is connected with compressor crankcase and compression cylinder. The mode of constant differential pressure control can ensure that the sealing reliability under extreme working condition, and the nitrogen flow control is optimized, and the loss is reduced and the filler life is prolonged, adopts the modular design, simplifies the installation and maintenance process, and is suitable for old unit reconstruction.

Description

Technical Field

[0001] This utility model relates to the field of natural gas compressor technology, and in particular to a nitrogen purging device based on a natural gas compressor unit. Background Technology

[0002] In the oil and gas industry, reciprocating compressors are core equipment, and their packing seal performance directly affects safety and environmental protection. With increasing operating years, older units experience accelerated packing wear, coupled with issues such as decreased coalbed methane inlet pressure and sulfur content in the gas, making traditional sealing structures insufficient. Nitrogen purging, as a commonly used auxiliary sealing method, requires solutions to issues such as leak control, real-time monitoring, and energy consumption optimization.

[0003] Traditional nitrogen purging systems employ a simple nitrogen injection method, injecting nitrogen into the packing chamber at a fixed pressure, lacking dynamic differential pressure control. A typical structure includes a nitrogen source, a pressure reducing valve, and simple piping connections, achieving only basic gas sealing functionality.

[0004] Monitoring and control methods: Relies on manual periodic monitoring of pressure and flow, lacks real-time alarm devices, and cannot respond promptly to abnormal operating conditions.

[0005] Packing structure: The single-body packing box design leads to increased leakage rate after the sealing ring wears out, and the lack of integrated visual monitoring components means that maintenance relies on experience-based judgment.

[0006] Disadvantages of existing technology:

[0007] Poor sealing performance: Existing packing sealing structures cannot prevent gas leakage, resulting in a high risk of process gas leakage, which not only wastes resources but may also cause safety and environmental problems.

[0008] Low safety: The discharged process gases are directly released into the atmosphere. If the gases contain flammable or toxic components, such as natural gas containing hydrogen sulfide, they can easily cause explosions and fires, endangering personnel safety and the environment.

[0009] Inconvenient operation and maintenance: The simple nitrogen injection method lacks real-time monitoring, making it difficult for operators to understand the system's operating status in a timely manner. When problems occur, they cannot be dealt with quickly, increasing maintenance difficulty and costs.

[0010] Short equipment lifespan: Harmful substances in natural gas, such as hydrogen sulfide, can corrode compressor components when gas leaks, shortening equipment lifespan and increasing equipment replacement and maintenance costs.

[0011] High nitrogen consumption: Traditional nitrogen injection methods have not been optimized to meet actual needs, resulting in excessive nitrogen injection, which wastes resources and increases operating costs. Utility Model Content

[0012] To address the shortcomings of existing technologies, this utility model provides a nitrogen purging device based on a natural gas compressor unit, which can improve sealing performance and extend the device's lifespan.

[0013] In order to achieve the purpose of this utility model, the following solution is proposed:

[0014] A nitrogen purging device based on a natural gas compressor unit includes a nitrogen generation system, a pressure reducing valve, a flow meter, a stuffing box, and a discharge pipeline connected in sequence.

[0015] The nitrogen generation system is used to produce pure nitrogen gas;

[0016] Pressure reducing valves are used to regulate pressure;

[0017] The flow meter is used to display the nitrogen flow rate in real time;

[0018] The stuffing box is connected to a differential pressure control valve, a temperature transmitter, and a pressure transmitter. The temperature transmitter and pressure transmitter are used to monitor the pressure inside the stuffing box. The differential pressure control valve is used to monitor the pressure inside the stuffing box and the pressure in the discharge pipeline in real time, and to maintain the former pressure 0.05MPa-0.2MPa higher than the latter.

[0019] The stuffing box is also connected to the compressor crankcase and the compressor cylinder.

[0020] Furthermore, the differential pressure control valve model selected is SMC's IR2000.

[0021] Furthermore, both the temperature transmitter and the pressure transmitter are connected to a distributed control system.

[0022] Furthermore, the differential pressure control valve is used to maintain the pressure inside the stuffing box 0.1 MPa higher than that in the discharge line.

[0023] The beneficial effects of this utility model are as follows:

[0024] 1. Reduce gas leakage: Add a nitrogen sealing system to form an effective gas seal, reduce the amount of process gas leakage, reduce the frequency of contact between sulfur in the process gas and metal parts, and prevent corrosion of components such as piston rods, crossheads, and connecting rods.

[0025] 2. Improve safety: Ensure safe system operation by collecting and transporting leaked gas to a flare or high-altitude venting treatment to prevent dangerous gases from accumulating on site and causing safety accidents.

[0026] 3. Optimized operation and maintenance: Easy to install and maintain, equipped with a visual flow meter, flow abnormality alarm, temperature transmitter and pressure transmitter, etc., to monitor the nitrogen purging status in real time and promptly detect and handle abnormal situations.

[0027] 4. Extend equipment life: Reduce leakage, monitor pressure and temperature changes through instruments, and issue abnormal alarms to extend the service life of compressor-related components and save operating costs.

[0028] 5. Reduce nitrogen consumption: Reduce the amount of nitrogen injected while ensuring sealing and purging effects. Theoretical calculations show that nitrogen consumption can be reduced by about 50%, achieving energy conservation and emission reduction. Attached Figure Description

[0029] Figure 1 A schematic diagram of the nitrogen purging device is shown. Detailed Implementation

[0030] like Figure 1 As shown, this embodiment provides a nitrogen purging device based on a natural gas compressor unit, including a nitrogen generation system 1, a pressure reducing valve 2, a flow meter 3, a differential pressure control valve 4, a stuffing box 5, a temperature transmitter 6, a pressure transmitter 7, a discharge pipeline 8, a compressor crankcase 9, and a compression cylinder 10.

[0031] Nitrogen generation system 1 is existing technology used to generate pure nitrogen gas.

[0032] Pressure reducing valve 2 is existing technology used to regulate the initial pressure of nitrogen, reducing it to 0.3MPa-0.5MPa. Nitrogen passes through a filter to remove impurities, ensuring a clean gas supply.

[0033] Flow meter 3 is used to display the nitrogen flow rate in real time. Flow meter 3 is an existing technology and is a glass rotor flow meter. For example, the LZB-4WB(F) from Changzhou Shuanghuan Thermal Instrument Co., Ltd. can be selected. When the nitrogen flow rate is too high, flow meter 3 can trigger the alarm limit.

[0034] The stuffing box 5 is an existing technology, except that a nitrogen injection port and a temperature monitoring port have been added. The differential pressure control valve 4, the temperature transmitter 6, and the pressure transmitter 7 are all existing technologies. For example, the differential pressure control valve 4 is model SMC IR2000.

[0035] The stuffing box 5 is connected to the differential pressure control valve 4, the temperature transmitter 6, and the pressure transmitter 7. The temperature transmitter 6 and the pressure transmitter 7 are used to monitor the pressure inside the stuffing box 5. Both the temperature transmitter 6 and the pressure transmitter 7 are connected to a distributed control system. The distributed control system is existing technology, referred to as a DCS system, which can realize remote monitoring.

[0036] The differential pressure control valve 4 is used to monitor the pressure inside the stuffing box 5 and the pressure in the discharge pipeline 8 in real time, and maintain the former pressure 0.05MPa-0.2MPa higher than the latter to ensure the stability of the gas seal. Preferably, the pressure difference between the two is 0.1MPa, which can still maintain purging when the flare system is pressurized under extreme or abnormal conditions.

[0037] The stuffing box 5 is also connected to the compressor crankcase 9 and the compression cylinder 10. One stuffing box 5 corresponds to one compression cylinder 10. Generally, the compression cylinder 10 is often set to two, four or six rows.

[0038] This solution has the following advantages:

[0039] ① Provides a nitrogen purging device with constant differential pressure control to ensure sealing reliability under extreme operating conditions;

[0040] ②Integrates real-time monitoring and alarm functions to enhance the early warning capability of leakage risks;

[0041] ③ Optimize nitrogen flow control to reduce losses and extend packing life;

[0042] ④ Adopting a modular design simplifies the installation and maintenance process and adapts to the retrofitting of older units.

[0043] The above embodiments are only used to illustrate the technical concept and features of this utility model, and are not intended to be unique or to limit this utility model. Those skilled in the art should understand that various changes or equivalent substitutions made to this utility model without departing from its scope are all within the protection scope of this utility model.

Claims

1. A nitrogen purging device based on a natural gas compressor unit, characterized in that, It includes a nitrogen generation system (1), a pressure reducing valve (2), a flow meter (3), a stuffing box (5), and an exhaust pipe (8) connected in sequence. The nitrogen generation system (1) is used to generate pure nitrogen gas; The pressure reducing valve (2) is used to regulate pressure; The flow meter (3) is used to display the nitrogen flow rate in real time; The stuffing box (5) is connected to a differential pressure control valve (4), a temperature transmitter (6) and a pressure transmitter (7). The temperature transmitter (6) and the pressure transmitter (7) are used to monitor the pressure inside the stuffing box (5). The differential pressure control valve (4) is used to monitor the pressure inside the stuffing box (5) and the pressure of the discharge pipeline (8) in real time, and maintain the former pressure 0.05MPa-0.2MPa higher than the latter. The stuffing box (5) is also connected to the compressor crankcase (9) and the compressor cylinder (10).

2. The nitrogen purging device based on a natural gas compressor unit according to claim 1, characterized in that, The differential pressure control valve (4) is model SMC IR2000.

3. The nitrogen purging device based on a natural gas compressor unit according to claim 1, characterized in that, Temperature transmitter (6) and pressure transmitter (7) are both connected to the distributed control system.

4. The nitrogen purging device based on a natural gas compressor unit according to claim 1, characterized in that, The differential pressure control valve (4) is used to maintain the pressure inside the stuffing box (5) 0.1 MPa higher than that in the discharge line (8).

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