Self-contained cooling and lubricating device for double-screw pump and using method of self-contained cooling and lubricating device

Abstract

The invention relates to the technical field of pump lubricating oil, in particular to a self-contained cooling and lubricating device for a double-screw pump and a using method thereof.The self-contained cooling and lubricating device for the double-screw pump comprises the double-screw pump and an externally-hung oil can, a pump driving shaft end cover is arranged on a driving shaft of the double-screw pump, and a pump driven shaft end cover is arranged on a driven shaft of the double-screw pump; a driving shaft end cover lower oil way pipeline is communicated between the externally-hung oil pot and the pump driving shaft end cover, a driven shaft end cover lower oil way pipeline is communicated between the externally-hung oil pot and the pump driven shaft end cover, and a driving shaft end cover upper oil way pipeline is communicated between the pump driving shaft end cover and the externally-hung oil pot. And a driven shaft end cover upper oil way pipeline is communicated between the pump driven shaft end cover and the externally-hung oil can. According to the double-screw pump, lubricating oil in the externally-hung oil can is automatically supplemented into the driving shaft end cover and the driven shaft end cover through the lower-end oil way pipeline according to the principle of a connector, the service life of the double-screw pump is prolonged, the failure rate of the double-screw pump is reduced, and stable and continuous operation of closed gathering and transportation in the super-heavy oil development process is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of pump lubricating oil, in particular to a self-contained cooling and lubricating device for a twin-screw pump and a use method thereof. Background Art

[0002] The oil industry production requires a complete set of multiphase mixed transportation technology with strong applicability to improve the development efficiency and equipment level of desert oil fields, beach oil fields, offshore oil fields, remote peripheral oil fields, and heavy oil fields. Although the multiphase mixed transportation equipment used in China has reached a certain technical level, it still cannot meet the actual needs of long life and low failure rate, especially the needs of Fengcheng's special and complex multiphase fluid media (crude oil, water, steam, associated gas, non-condensable gas, sand, high temperature, etc.), which has seriously restricted the development of multiphase mixed transportation process technology and the smooth operation of Fengcheng's closed gathering and transportation.

[0003] At present, the main oil and gas mixed transmission pump used in Fengcheng is a bimetallic screw pump. During actual operation, the average service life and maximum service life of the pump's spiral sleeve, inner casing, bearings, mechanical seals and other wearing parts did not meet the design requirements. The average service life of the mechanical seal was only 15.1% of the design life, and the service life of the four wearing parts did not exceed 28% of the design. This is quite different from the application effect of the bimetallic screw pump under other working conditions. The pump frequently suffers from mechanical seal leakage, abnormal noise from the pump body, reduced pump efficiency, local overheating, pump shaft locking and other faults, which seriously affect the smooth operation of the closed gathering and transportation process in the operating area. Summary of the invention

[0004] The present invention provides a self-contained cooling and lubricating device for a twin-screw pump and a method for using the same, which overcomes the above-mentioned deficiencies in the prior art and can effectively solve the problems of short service life, high failure rate and poor heat exchange effect of lubricating oil in the closed collection and transportation of ultra-heavy oil and high-temperature multiphase mixed transportation of twin-screw pumps.

[0005] One of the technical solutions of the present invention is achieved through the following measures: a self-contained cooling and lubrication device for a twin-screw pump, comprising a twin-screw pump and an external oil pot, a pump driving shaft end cover is arranged on the driving shaft of the twin-screw pump, a pump driven shaft end cover is arranged on the driven shaft of the twin-screw pump, an oil pipeline under the driving shaft end cover is fixedly connected between the first outlet at the bottom of the external oil pot and the pump driving shaft end cover, an oil pipeline under the driven shaft end cover is fixedly connected between the second outlet at the bottom of the external oil pot and the pump driven shaft end cover, an oil pipeline on the driving shaft end cover is fixedly connected between the pump driving shaft end cover and the first inlet on the upper part of the external oil pot, and an oil pipeline on the driven shaft end cover is fixedly connected between the pump driven shaft end cover and the second inlet on the upper part of the external oil pot.

[0006] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions: A pump driving shaft temperature transmitter is arranged on the pump driving shaft end cover, a pump driving shaft electric control valve is fixedly installed on the oil pipeline under the driving shaft end cover, and an interlock is arranged between the pump driving shaft temperature transmitter and the pump driving shaft electric control valve.

[0007] The pump driven shaft end cover is provided with a pump driven shaft temperature transmitter, the oil pipeline under the driven shaft end cover is fixedly installed with a pump driven shaft electric control valve, and an interlock is provided between the pump driven shaft temperature transmitter and the pump driven shaft electric control valve.

[0008] An oil level gauge is arranged at the lower part of the external oil pot, and an exhaust valve is arranged at the top of the external oil pot.

[0009] A first bypass pipeline is fixedly connected to the oil pipeline under the active shaft end cover before and after the above-mentioned active shaft electric control valve, and a second bypass pipeline is fixedly connected to the oil pipeline under the driven shaft end cover before and after the pump driven shaft electric control valve. Bypass valves are connected in series on the first bypass pipeline and the second bypass pipeline.

[0010] The oil pipeline under the active shaft end cover between the first bypass pipeline and the pump active shaft electric control valve, and the oil pipeline under the driven shaft end cover between the second bypass pipeline and the pump driven shaft electric control valve are fixedly installed with an electric control valve inlet valve and an electric control valve outlet valve in sequence.

[0011] The second technical solution of the present invention is achieved through the following measures: A method for using a self-contained cooling and lubrication device for a twin-screw pump is carried out according to the following steps: First, a portion of the lubricating oil in the external oil pot is automatically replenished into the driving shaft end cover of the twin-screw pump through the oil pipeline under the driving shaft end cover; then, a portion of the lubricating oil in the external oil pot is automatically replenished into the driven shaft end cover of the twin-screw pump through the oil pipeline under the driven shaft end cover.

[0012] The present invention adopts the connecting through-device principle to automatically replenish the lubricating oil in the external oil pot into the driving shaft end cover and the driven shaft end cover through the lower end oil pipeline, thereby extending the service life of the twin-screw pump, reducing the failure rate of the twin-screw pump, and ensuring the stable and continuous operation of the closed gathering and transportation in the process of super-heavy oil development. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Attached Figure 1 This is a schematic diagram of the process flow of Example 1 of the present invention.

[0014] The codes in the accompanying drawings are: 1 is an external oil pot, 2 is an exhaust valve, 3 is an oil level gauge, 4 is the oil pipeline on the driving shaft end cover, 5 is the oil pipeline under the driving shaft end cover, 6 is the oil pipeline on the driven shaft end cover, 7 is the oil pipeline under the driven shaft end cover, 8 is the pump driving shaft end cover, 9 is the pump driven shaft end cover, 10 is the pump driving shaft temperature transmitter, 11 is the pump driven shaft temperature transmitter, 12 is the pump driving shaft electric control valve, 13 is the pump driven shaft electric control valve, 14 is the first bypass pipeline, 15 is the second bypass pipeline, 16 is the bypass valve, 17 is the electric control valve inlet valve, and 18 is the electric control valve outlet valve. DETAILED DESCRIPTION

[0015] The present invention is not limited by the following embodiments, and specific implementation methods can be determined based on the technical solution of the present invention and actual conditions.

[0016] The present invention will be further described below in conjunction with embodiments: Embodiment 1: As attached Figure 1 As shown, the self-contained cooling and lubricating device for a twin-screw pump comprises a twin-screw pump and an external oil pot 1, a pump driving shaft end cover 8 is arranged on the driving shaft of the twin-screw pump, a pump driven shaft end cover 9 is arranged on the driven shaft of the twin-screw pump, an oil pipeline 5 under the driving shaft end cover is fixedly connected between the first outlet at the bottom of the external oil pot 1 and the pump driving shaft end cover 8, an oil pipeline 7 under the driven shaft end cover is fixedly connected between the second outlet at the bottom of the external oil pot 1 and the pump driven shaft end cover 9, an oil pipeline 4 on the driving shaft end cover is fixedly connected between the pump driving shaft end cover 8 and the first inlet at the top of the external oil pot 1, and an oil pipeline 6 on the driven shaft end cover is fixedly connected between the pump driven shaft end cover 9 and the second inlet at the top of the external oil pot 1.

[0017] The twin-screw pump is a key core equipment for closed gathering and transportation, and its stable operation is related to the stability of closed gathering and transportation. The present invention is used in the self-sufficient cooling and lubrication device of the twin-screw pump. The external oil pot 1 forms a communicating vessel between the oil pipeline 5 under the active shaft end cover and the pump active shaft end cover 8, and the oil pipeline 7 under the pump driven shaft end cover 9 and the pump active shaft end cover 8. By using the communicating vessel principle, on the one hand, the external oil pot 1 automatically replenishes the lubricating oil to the pump active shaft end cover 8 through the oil pipeline 5 under the active shaft end cover, and on the other hand, the external oil pot 1 automatically replenishes the lubricating oil to the pump driven shaft end cover 9 through the oil pipeline 7 under the driven shaft end cover, realizing the self-sufficient cooling and lubrication of the twin-screw pump, filling the blank of the application of bimetallic screw pumps in closed gathering and transportation technology in my country.

[0018] In the present invention, the external oil pot 1 can be an external oil pot 1 with a height of 400 mm and a diameter of 210 mm, which provides a larger lubricating oil capacity and heat dissipation area by setting a larger volume and surface area. The oil pipeline 5 under the driving shaft end cover, the oil pipeline 7 under the driven shaft end cover, the oil pipeline 4 on the driving shaft end cover, and the oil pipeline 6 on the driven shaft end cover can be φ20 mm lubricating oil circulation pipelines. The design of the larger pipe diameter not only improves the heat exchange effect, but also effectively avoids the problem of pipeline blockage due to oil deterioration.

[0019] The present invention reduces the failure rate of the closed gathering and transportation oil and gas mixed transportation pump, ensures the stable and continuous operation of the closed gathering and transportation, lays a foundation for the stable operation of the Fengcheng super-heavy oil closed gathering and transportation process, which is a key central environmental protection project, ensures that the development of Fengcheng super-heavy oil meets environmental protection requirements, ensures the continuous development of Fengcheng oilfield super-heavy oil, and also ensures Fengcheng's carbon reduction and emission reduction.

[0020] Embodiment 2: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, a pump driving shaft temperature transmitter 10 is provided on the pump driving shaft end cover 8, a pump driving shaft electric control valve 12 is fixedly installed on the oil pipeline 5 under the driving shaft end cover, and an interlock is provided between the pump driving shaft temperature transmitter 10 and the pump driving shaft electric control valve 12.

[0021] According to needs, the interlocking arrangement of the pump driving shaft temperature transmitter 10 and the pump driving shaft electric control valve 12 of the present invention enables the pump driving shaft temperature transmitter 10 to timely measure the temperature of the pump driving shaft, thereby timely adjusting the opening of the pump driving shaft electric control valve 12 and controlling the lubricating oil flow in the oil pipeline 5 under the driving shaft end cover.

[0022] Embodiment 3: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, a pump driven shaft temperature transmitter 11 is provided on the pump driven shaft end cover 9, a pump driven shaft electric control valve 13 is fixedly installed on the oil pipeline 7 under the driven shaft end cover, and an interlock is provided between the pump driven shaft temperature transmitter 11 and the pump driven shaft electric control valve 13.

[0023] As needed, the oil pipeline 4 on the driving shaft end cover of the present invention is used to balance the pressure inside the external oil pot 1 and the pump driving shaft end cover 8, and the oil pipeline 6 on the driven shaft end cover is used to balance the pressure inside the external oil pot 1 and the pump driven shaft end cover 9.

[0024] The interlocking arrangement of the pump driven shaft temperature transmitter 11 and the pump driven shaft electric control valve 13 of the present invention enables the pump driven shaft temperature transmitter 11 to timely measure the temperature of the pump driven shaft, thereby timely adjusting the opening of the pump driven shaft electric control valve 13 to control the lubricating oil flow in the oil pipeline 7 under the driven shaft end cover.

[0025] Embodiment 4: As an optimization of the above embodiment, as shown in the attached Figure 1As shown, an oil level gauge 3 is provided at the lower part of the external oil pot 1, and an exhaust valve 2 is provided at the top of the external oil pot 1.

[0026] As required, the exhaust valve 2 is used to balance the pressure between the external oil pot 1 and the outside during use, and the oil level gauge 3 is used to timely observe and judge the oil level of the lubricating oil inside the external oil pot 1.

[0027] Embodiment 5: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, a first bypass pipeline 14 is fixedly connected to the oil circuit pipeline 5 under the active shaft end cover before and after the pump active shaft electric control valve 12, and a second bypass pipeline 15 is fixedly connected to the oil circuit pipeline 7 under the driven shaft end cover before and after the pump driven shaft electric control valve 13, and bypass valves 16 are serially connected to the first bypass pipeline 14 and the second bypass pipeline 15.

[0028] Embodiment 6: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, the oil line 5 under the active shaft end cover between the first bypass line 14 and the pump active shaft electric control valve 12, and the oil line 7 under the driven shaft end cover between the second bypass line 15 and the pump driven shaft electric control valve 13 are fixedly installed with an electric control valve inlet valve 17 and an electric control valve outlet valve 18 in sequence.

[0029] Embodiment 7: As attached Figure 1 The method for using the self-contained cooling and lubrication device of the twin-screw pump shown in the figure is carried out according to the following steps: first, a part of the lubricating oil in the external oil pot 1 is automatically replenished into the driving shaft end cover 8 of the twin-screw pump through the oil pipeline 5 under the driving shaft end cover; then, a part of the lubricating oil in the external oil pot 1 is automatically replenished into the driven shaft end cover 9 of the twin-screw pump through the oil pipeline 7 under the driven shaft end cover.

[0030] As required, the pipelines and equipment of the self-contained cooling and lubricating device for the twin-screw pump may be provided with conventional valves, thermometers, pressure gauges, etc. known and used in the art according to production needs.

[0031] After the use of the present invention, the normal operating time of the twin-screw pump is twice as long as before. The average life of the spiral sleeve before the transformation is 4857h, and the life after the transformation is 5720h; the average life of the bearing before the transformation is 3568h, and the life after the transformation is 5720h; the average life of the mechanical seal before the transformation is 2395h, and the life after the transformation is 5720h; the average life of the shaft before the transformation is 4857h, and the life after the transformation is 5720h. According to the failure rate statistics in 2021, the annual maintenance cost of 18 bimetallic screw pumps for closed gathering and transportation is about 6.8 million, accounting for about 85% of the purchase cost of 18 pumps (9.588 million), which is equivalent to replacing most of the pumps. After the present invention is put into use, the bottleneck of returning to the factory (Shanghai) for maintenance is changed to local independent maintenance, which controls and reduces maintenance costs. The annual estimated cost is 2 million yuan, and the annual cost savings are 4.8 million yuan.

[0032] In summary, the present invention uses the connecting through-device principle to automatically replenish the lubricating oil in the external oil pot into the driving shaft end cover and the driven shaft end cover through the lower oil pipeline, thereby extending the service life of the twin-screw pump, reducing the failure rate of the twin-screw pump, and ensuring the stable and continuous operation of the closed gathering and transportation during the development of super-heavy oil.

[0033] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A self-contained cooling and lubrication device for a twin-screw pump, characterized in that It includes a twin-screw pump and an external oil pot. A pump driving shaft end cover is arranged on the driving shaft of the twin-screw pump, a pump driven shaft end cover is arranged on the driven shaft of the twin-screw pump, an oil pipeline under the driving shaft end cover is fixedly connected between the first outlet at the bottom of the external oil pot and the pump driving shaft end cover, an oil pipeline under the driven shaft end cover is fixedly connected between the second outlet at the bottom of the external oil pot and the pump driven shaft end cover, an oil pipeline on the driving shaft end cover is fixedly connected between the pump driving shaft end cover and the first inlet on the upper part of the external oil pot, and an oil pipeline on the driven shaft end cover is fixedly connected between the pump driven shaft end cover and the second inlet on the upper part of the external oil pot.

2. The self-contained cooling and lubricating device for a twin-screw pump according to claim 1, characterized in that A pump driving shaft temperature transmitter is arranged on the pump driving shaft end cover, a pump driving shaft electric control valve is fixedly installed on the oil pipeline under the driving shaft end cover, and an interlock is arranged between the pump driving shaft temperature transmitter and the pump driving shaft electric control valve.

3. The self-contained cooling and lubricating device for a twin-screw pump according to claim 1 or 2, characterized in that A pump driven shaft temperature transmitter is arranged on the pump driven shaft end cover, a pump driven shaft electric control valve is fixedly installed on the oil pipeline under the driven shaft end cover, and an interlock is arranged between the pump driven shaft temperature transmitter and the pump driven shaft electric control valve.

4. The self-contained cooling and lubricating device for a twin-screw pump according to claim 1, 2 or 3, characterized in that An oil level gauge is arranged at the lower part of the external oil pot, and an exhaust valve is arranged at the top of the external oil pot.

5. The self-contained cooling and lubricating device for a twin-screw pump according to claim 2, 3 or 4, characterized in that A first bypass pipeline is fixedly connected to the oil pipeline under the active shaft end cover before and after the pump active shaft electric control valve, and a second bypass pipeline is fixedly connected to the oil pipeline under the driven shaft end cover before and after the pump driven shaft electric control valve. Bypass valves are connected in series on the first bypass pipeline and the second bypass pipeline.

6. The self-contained cooling and lubricating device for a twin-screw pump according to claim 5, characterized in that The oil line under the active shaft end cover between the first bypass line and the pump active shaft electric control valve, and the oil line under the driven shaft end cover between the second bypass line and the pump driven shaft electric control valve are fixedly installed with an electric control valve inlet valve and an electric control valve outlet valve in sequence.

7. A method for using the self-contained cooling and lubricating device for a twin-screw pump according to any one of claims 1 to 6, characterized in that Proceed in the following steps: First, a portion of the lubricating oil in the external oil pot is automatically replenished into the driving shaft end cover of the twin-screw pump through the oil pipeline under the driving shaft end cover; then, a portion of the lubricating oil in the external oil pot is automatically replenished into the driven shaft end cover of the twin-screw pump through the oil pipeline under the driven shaft end cover.

Images