High-pressure plunger pump packing seal leakage oil automatic recovery system

Abstract

The application discloses a kind of high-pressure plunger pump packing seal leakage oil automatic recovery system, including recovery tank collection unit and with the recovery tank collection unit connection flow guide unit, pumping unit and nitrogen seal protection unit;The flow guide unit includes oil pipe, oil pipe one end is connected with the oil outlet of pump body oil collection pool bottom, the other end is connected with recovery tank;The recovery tank collection unit includes recovery tank, recovery tank is equipped with liquid level gauge, pressure gauge and breather valve;The pumping unit includes recovery pump, the inlet of recovery pump is connected with the bottom of recovery tank by oil suction pipe, and outlet is connected by oil return pipe into plunger pump main system;The nitrogen seal protection unit is connected with the top of recovery tank by nitrogen pipeline, and pressure reducing valve, nitrogen seal valve and check valve are arranged on nitrogen pipeline, and pressure transmitter is arranged on the top of recovery tank.The application integrates flow guide, closed collection, pumping and nitrogen seal protection function as a whole, and has important significance for improving equipment operation safety, reducing operation and maintenance cost and realizing clean production.

Description

Technical Field

[0001] This invention relates to the field of high-pressure reciprocating pumps, and in particular to an automatic oil recovery system for leakage from the packing seal of a high-pressure plunger pump. Background Technology

[0002] High-pressure plunger pumps are reciprocating pumps that operate on the principle of volume change. The reciprocating motion of the plunger alters the pump chamber volume, thereby facilitating fluid intake and discharge under high-pressure conditions. They are widely used in high-pressure fluid transport applications in petrochemical, energy, and other fields. In existing technologies, the moving parts of plunger pumps are typically sealed using a packing wet seal structure. This relies on preload to tighten the packing around the plunger, forming a lubricating film on the contact surface. The tight fit between the packing and the plunger seals the gaps, preventing leakage of the high-pressure medium. However, during long-term operation, the packing's sealing performance gradually declines due to continuous friction with the reciprocating plunger. The leakage rate increases with operating time, eventually leading to seal failure and significant media leakage. Especially under high-pressure conditions, the significant pressure difference between the inside and outside of the sealing chamber exacerbates leakage, further shortens the effective service life of the packing, and significantly increases the leakage rate.

[0003] The current industry standard for handling leaking oil is as follows: after the leaking oil is collected by gravity in the pump's oil collection tank, the drain valve needs to be manually opened periodically to transfer the oil to temporary storage facilities such as tonnes or portable containers. Once a certain volume is reached, the oil is then transferred to a waste oil treatment system for recycling. This method has the following significant drawbacks: 1. Manual operation is inefficient and poses safety hazards: Fixed-cycle inspections and manual cleaning modes result in delays in handling leaked oil (the longest storage time can be up to 8 hours), requiring an average of 2-3 man-hours per pump per day. This problem is particularly prominent in large-scale plants with multiple pump sets.

[0004] 2. Functional defects of temporary storage facilities: Existing oil collection facilities lack liquid level monitoring and intelligent emission control. Oil spill pollution is likely to occur when the liquid level is high, and long-term exposure of oil at low liquid levels leads to excessive emissions of volatile organic compounds, which does not meet the requirements of environmental protection standards such as GB31571-2015 "Emission Standard of Pollutants for Petrochemical Industry".

[0005] 3. The quality of the leaked oil is severely deteriorated: Open temporary storage causes the oil to come into full contact with air, resulting in oxidation and deterioration, as well as the introduction of moisture. This degrades the originally reusable leaked oil into waste oil, significantly increasing the treatment cost.

[0006] Therefore, developing an integrated leaked oil recovery system that combines diversion, sealed collection, pumping, and nitrogen sealing protection is of great significance for improving equipment operation safety, reducing operation and maintenance costs, and achieving cleaner production. Summary of the Invention

[0007] To address the technical problems of low efficiency, high safety risks, and poor environmental performance in the manual handling of leaking oil from the packing seal of high-pressure plunger pumps, this invention provides an automatic oil recovery system for leaking oil from the packing seal of high-pressure plunger pumps.

[0008] The present invention is achieved by the following technical solution.

[0009] An automatic recovery system for leaking oil from the packing seal of a high-pressure plunger pump includes a recovery tank collection unit and a flow guiding unit, a pumping unit, and a nitrogen sealing protection unit connected to the recovery tank collection unit. The flow guiding unit includes an oil guide pipe, one end of which is connected to the oil outlet at the bottom of the oil collection tank of the pump body, and the other end is connected to the recovery tank. The oil guide pipe is equipped with a switch valve, a check valve and a flow meter. The recovery tank collection unit includes a recovery tank, which is equipped with a level gauge, a pressure gauge and a breather valve; The pumping unit includes a recovery pump, the inlet of which is connected to the bottom of the recovery tank via a suction pipe, and the outlet is connected to the plunger pump main system via a return pipe; the suction pipe is equipped with a gate valve and a filter. The nitrogen sealing protection unit is connected to the top of the recovery tank via a nitrogen pipeline. The nitrogen pipeline is equipped with a pressure reducing valve, a nitrogen sealing valve, and a check valve. A pressure transmitter is installed on the top of the recovery tank.

[0010] Furthermore, the switching valve is a pneumatic ball valve, which is interlocked with the ultrasonic level gauge in the oil collection tank. The switching valve opens when the liquid level reaches 80% of the effective volume of the oil collection tank and closes when the liquid level drops to 20%.

[0011] Furthermore, the flow meter employs an electromagnetic or turbine flow sensor with a measurement accuracy of not less than 1.0 class.

[0012] Furthermore, the recovery tank adopts a vertical cylindrical structure with an effective volume of 500-2000L, a design pressure of 0.1-0.2MPa, a magnetic level gauge installed on the side wall, and a breather valve installed on the top.

[0013] Furthermore, the recovery pump is selected as a screw pump or gear pump, which is interlocked with the liquid level gauge of the recovery tank. The recovery pump starts when the liquid level reaches 60-70% and stops when the liquid level drops to 20-30%.

[0014] Furthermore, the nitrogen sealing protection unit maintains the pressure inside the recovery tank in a slightly positive pressure range of 0.02-0.05 MPa.

[0015] This application has the following beneficial effects: 1. This invention can realize the entire process from oil spill collection to transportation, reducing the degree of manual intervention and saving more than 85% of labor costs; this invention can realize automatic recovery, effectively solving the shortcomings of low efficiency, low safety risk and prominent environmental problems of manual handling; 2. Optimized safety and environmental performance: Through closed-loop recovery and nitrogen sealing protection, VOC emissions are reduced by 90%, eliminating the risk of oil spills and meeting the latest environmental emission standards; 3. Improved oil reuse rate: Nitrogen sealing protection reduces the degree of oil oxidation to below 0.1 mg KOH / g and controls the moisture content to below 50 ppm, increasing the reuse rate to 95% and reducing waste oil treatment costs by approximately RMB 120,000 per pump per year. 4. Enhanced system reliability: Multiple interlock protections (level, pressure, flow) are adopted, and the mean time between failures (MTBF) reaches more than 8,000 hours. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention (the arrows in the figure indicate the flow paths of leaking sealing oil and nitrogen, and the area within the dashed box is the recovery system of the present invention).

[0017] Among them, 1. oil guide pipe, 2. switch valve, 3. flow meter, 4. recovery tank, 5. level gauge, 6. breather valve, 7. pressure transmitter, 8. suction pipe, 9. gate valve, 10. filter, 11. recovery pump, 12. return pipe, 13. check valve, 14. nitrogen sealing valve, 15. pressure reducing valve. Detailed Implementation

[0018] The present patent application will be further described below with reference to the embodiments. Unless otherwise specified, the materials used in the preparation process in the following embodiments have not undergone further processing and have been commercially available.

[0019] like Figure 1 As shown, an automatic oil recovery system for leakage from the packing seal of a high-pressure plunger pump includes: The flow guiding unit is connected to the oil outlet at the bottom of the oil collection tank of the pump body, and includes an oil guide pipe 1, a switch valve 2, a check valve and a flow meter 3; Recovery tank collection unit: used to receive leaked oil delivered by the diversion unit, equipped with a level gauge 5, a pressure gauge and a breather valve 6; Pumping unit: includes recovery pump 11, suction pipe 8, return pipe 12 and control valve group, to realize the delivery of oil to the main system; Nitrogen blanketing protection unit: connected to the top of recovery tank 4 via nitrogen pipeline, and equipped with nitrogen blanketing valve 14 and pressure transmitter 7.

[0020] In the flow guiding unit, the oil guide pipe 1 is made of 316L stainless steel or Q345R carbon steel, with the inner wall subjected to pickling and passivation treatment, and has a pipe diameter of DN50; the switching valve 2 is a pneumatic ball valve (response time ≤1 second), which is interlocked with the ultrasonic level gauge (measurement accuracy ±1mm) installed in the oil collection tank. It opens when the liquid level reaches 80% of the effective volume of the oil collection tank and closes when the liquid level drops to 20%; the check valve adopts a spring structure with an opening pressure ≤0.02MPa; the flow meter 3 has a measurement range of 0.1-10m. 3 / h, with an accuracy class of 0.5.

[0021] The recovery tank 4 in the recovery tank collection unit adopts a vertical cylindrical structure with an effective volume of 1000L, a design pressure of 0.1MPa, and is made of Q345R material. A magnetic float level gauge 5 (range 0-1200mm) is installed on the side wall to achieve level interlocking with the pumping unit; a pressure gauge (measuring range 0-0.16MPa) and a spring-loaded breather valve 6 (set pressure 0.05 / -0.02MPa) are installed on the top; the bottom of the tank is sloped at 1° towards the pump inlet to ensure complete drainage.

[0022] The pumping unit includes a recovery pump 11, which is a 220V single-phase screw pump (flow rate 1.5m³ / h). 3 The pump operates at a flow rate of 100 m / h and a head of 30 m. An inlet Y-type filter 10 (100 μm filtration accuracy) and a gate valve 9 are installed. The outlet is equipped with a check valve and a pressure transmitter (range 0-1 MPa). The recovery pump 11 starts when the liquid level in the recovery tank 4 reaches 600 mm and stops when the liquid level drops to 200 mm. It features manual / automatic switching functionality.

[0023] The nitrogen sealing protection unit is connected to the main nitrogen pipeline in the plant area (pressure 0.6-0.8MPa). A pressure reducing valve 15 (outlet pressure 0.1MPa), a nitrogen sealing valve 14 (control accuracy ± 0.002MPa), and a check valve 13 are installed sequentially on the nitrogen pipeline. The nitrogen sealing valve 14 and the pressure transmitter 7 at the top of the recovery tank (measuring range 0-0.1MPa, accuracy class 0.2) form a closed-loop control to maintain the pressure inside the tank in a slightly positive pressure range of 0.02-0.03MPa.

[0024] Example 1

[0025] The high-pressure plunger pump (model 3DS-25 / 160) of a hydrogenation unit in a certain refining and chemical enterprise uses the system of this invention, with the specific configuration as follows: Flow guiding unit: Oil guide pipe 1 is made of Φ57×3.5mm 316L stainless steel pipe; switch valve 2 is a DN50 pneumatic ball valve (with handwheel operating mechanism), which is interlocked with the ULM-800 ultrasonic level gauge in the oil collection tank. It is set to open when the liquid level is 80% (400mm) and close when the liquid level is 20% (100mm); the flow meter is an LDG-50 electromagnetic flow meter.

[0026] Recovery tank collection unit: Vertical storage tank with specifications of Φ800×1800mm, effective volume of 1000L, design pressure of 0.1MPa, level gauge 5 is a UHZ-58 / CFPP type magnetic float level gauge; pressure gauge is a YTZ-150 type resistance remote transmission pressure gauge; breather valve 6 is a ZFQ-150 type.

[0027] Pumping unit: The recovery pump 11 is a 1.5GC-5×2 type screw pump, equipped with a Y-type filter 10 (DN50, 100 mesh), and the outlet check valve is an H41W-16P type check valve.

[0028] Nitrogen sealing protection unit: The nitrogen pipeline uses Φ20×3mm stainless steel pipe, the nitrogen sealing valve 14 is a ZZDQ-50 type regulating valve, and the pressure transmitter 7 is a Rosemount 3051TG type.

[0029] System operating parameters: flow response time ≤ 15 seconds; pressure control accuracy of recovery tank ± 0.003 MPa; liquid level control deviation of pumping unit start / stop ≤ 5 mm; average daily recovery of leaked oil by a single pump is 180 L; acid value change after oil reuse ≤ 0.05 mg KOH / g.

[0030] Operational results show that the system of the present invention can achieve 100% recovery of leaked oil, reduce labor costs by about 60,000 yuan per year, and generate economic benefits of about 150,000 yuan per year through oil reuse, while meeting the requirements of GB 31571-2015 "Emission Standard of Pollutants from Petrochemical Industry".

[0031] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An automatic oil recovery system for leakage from the packing seal of a high-pressure plunger pump, characterized in that: It includes a recovery tank collection unit, as well as a flow guiding unit, a pumping unit, and a nitrogen blanketing protection unit connected to the recovery tank collection unit; The flow guiding unit includes an oil guide pipe (1), one end of which is connected to the oil outlet at the bottom of the oil collection tank of the pump body, and the other end is connected to the recovery tank (4). The oil guide pipe (1) is equipped with a switch valve (2), a check valve and a flow meter (3). The recycling tank collection unit includes a recycling tank (4), which is equipped with a level gauge (5), a pressure gauge and a breather valve (6). The pumping unit includes a recovery pump (11), the inlet of which is connected to the bottom of the recovery tank (4) through an oil suction pipe (8), and the outlet is connected to the plunger pump main system through an oil return pipe (12); the oil suction pipe (8) is equipped with a gate valve (9) and a filter (10). The nitrogen sealing protection unit is connected to the top of the recovery tank (4) via a nitrogen pipeline. A pressure reducing valve (15), a nitrogen sealing valve (14), and a check valve (13) are installed on the nitrogen pipeline. A pressure transmitter (7) is installed on the top of the recovery tank (4).

2. The automatic oil recovery system for high-pressure plunger pump packing seal leakage according to claim 1, characterized in that: The switching valve (2) is a pneumatic ball valve, which is interlocked with the ultrasonic level gauge in the oil collection tank. When the liquid level reaches 80% of the effective volume of the oil collection tank, the switching valve (2) opens, and when the liquid level drops to 20%, the switching valve (2) closes.

3. The automatic oil recovery system for high-pressure plunger pump packing seal leakage according to claim 1, characterized in that: The flow meter (3) uses an electromagnetic or turbine flow sensor with a measurement accuracy of not less than 1.

0.

4. The automatic oil recovery system for high-pressure plunger pump packing seal leakage according to claim 1, characterized in that: The recovery tank (4) adopts a vertical cylindrical structure with an effective volume of 500-2000L and a design pressure of 0.1-0.2MPa. A magnetic level gauge is installed on the side wall, and a breather valve (6) is installed on the top.

5. The automatic oil recovery system for high-pressure plunger pump packing seal leakage according to claim 1, characterized in that: The recovery pump (11) is a screw pump or gear pump, which is interlocked with the liquid level gauge (5) of the recovery tank. When the liquid level reaches 60-70%, the recovery pump (11) starts and when it drops to 20-30%, the recovery pump (11) stops.

6. The automatic oil recovery system for high-pressure plunger pump packing seal leakage according to claim 1, characterized in that: The nitrogen sealing protection unit maintains the pressure inside the recovery tank (4) in a slightly positive pressure range of 0.02-0.05 MPa.

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