An underground heavy oil lifting and conveying system and method

Abstract

This invention discloses an underground heavy oil spill lifting and conveying system and method, including an underground oil spill tank, an above-ground oil spill tank, a heavy oil spill pump, and a third line for conveying nitrogen. The above-ground oil spill tank is connected to the underground oil spill tank via a first line. The heavy oil spill pump is located on the ground, with its inlet and outlet connected to the underground oil spill tank and pump outlet pipeline, respectively. A self-priming return line is connected to the pump outlet pipeline and is also connected to the underground oil spill tank. The third line is connected to the underground oil spill tank and includes a nitrogen regulating valve assembly and a check valve. The nitrogen regulating valve assembly on the third line is used to pressurize the underground oil spill tank, assisting the heavy oil spill pump in achieving self-priming, avoiding confined space operations and explosion risks, solving the problem of poor flow of atmospheric pressure waste oil into the tank, ensuring reliable intake of high-viscosity oil, and significantly improving the intrinsic safety level of the device.

Description

Technical Field

[0001] This invention belongs to the field of waste oil treatment and transportation technology in the petrochemical industry, specifically relating to an underground heavy waste oil lifting and transportation system and method, applicable to heavy oil hydrogen production, oil refining, coal-to-oil and various oil processing devices. Background Technology

[0002] The existing underground sludge tanks of petrochemical enterprises mostly use long-shaft submersible pumps to lift and transport heavy sludge oil, which has the following drawbacks: the back pressure of the flare causes the atmospheric pressure waste oil to enter the tank unimpeded; maintenance of the submersible pump requires entering the underground confined space, which poses a high safety risk; the wear of the pump body is prone to generating high-temperature sparks, which pose a fire and explosion hazard in explosion-proof areas; long-shaft submersible pumps have been listed as restricted equipment and are planned to be phased out, and the existing system cannot meet the requirements of safe production and compliance. Summary of the Invention

[0003] This invention aims to solve problems such as poor flow of atmospheric pressure waste oil into tanks, high safety risks of long-shaft submersible pumps, and difficulty in self-priming of high-viscosity waste oil in underground heavy oil transportation, and provides a safe, reliable, easy-to-maintain, and policy-compliant underground heavy oil lifting and transportation system and method.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solution: This invention discloses an underground heavy oil spill lifting and conveying system, comprising an underground oil spill tank, an above-ground oil spill tank, a heavy oil spill pump, and a third line for conveying nitrogen. The above-ground oil spill tank is connected to the underground oil spill tank via a first line. The heavy oil spill pump is located on the ground, with its inlet and outlet connected to the underground oil spill tank and the pump outlet pipeline, respectively. A self-priming return line is connected to the pump outlet pipeline and is also connected to the underground oil spill tank. The third line is connected to the underground oil spill tank and includes a nitrogen regulating valve assembly and a check valve. The nitrogen regulating valve assembly on the third line is used to pressurize the underground oil spill tank, assisting the heavy oil spill pump in achieving self-priming.

[0005] Preferably, the underground sludge tank is connected to a second line that can communicate with the outside world or a flare, and the second line is connected to a pressure regulating valve and a shut-off valve.

[0006] Preferably, the heavy oil pump is a self-priming pump, and a check valve and a shut-off valve are connected to the pump outlet pipeline at the outlet of the heavy oil pump. The inlet end of the self-priming return line is connected to the pump outlet pipeline between the check valve and the shut-off valve.

[0007] Preferably, the above-ground sludge tank is an atmospheric pressure tank, and a drain valve is installed on the No. 1 line. The No. 1 line can be used to transport pressurized waste oil generated from process drainage, venting and pipeline flushing, and directly connect to the underground sludge tank.

[0008] Preferably, it also includes a fourth line for conveying waste oil, the outlet end of which is connected to the first line at the outlet end of the drain valve.

[0009] Preferably, the design pressure of the underground sludge tank is greater than its maximum operating pressure, so as to achieve and reserve a safety margin.

[0010] Preferably, the inlet pressure of the heavy oil pump is adapted to both atmospheric pressure conditions and underground oil tank pressurization conditions.

[0011] This invention discloses an underground heavy oil spill lifting and transportation method, characterized in that the method comprises the following: The waste oil under normal pressure is collected in the above-ground sludge tank. The drain valve on line 1 is closed, and the pressure regulating valve on line 2 is opened to depressurize the underground sludge tank to near normal pressure. Then open the drain valve to allow the atmospheric pressure waste oil to enter the underground sludge tank through line number one. Pressurized waste oil is fed into Line 1 via Line 4 and then directly enters the underground sludge tank.

[0012] Preferably, when the heavy oil pump is started, the medium in the pump outlet pipeline flows back to the underground oil tank via the self-priming return line, forming a circulation to enhance the self-priming capability of the heavy oil pump and realize the continuous lifting and delivery of underground heavy oil.

[0013] Preferably, when the heavy oil pump fails to self-prime, all valves on line 2 are closed, and the nitrogen regulating valve group on line 3 is opened to pressurize the underground oil tank, pushing the waste oil in the tank into the inlet of the heavy oil pump to complete the self-priming start.

[0014] Beneficial effects: This system eliminates the need for a long-shaft submersible pump, and the heavy sludge pump is located on the ground, avoiding confined space operations and explosion risks; the use of an above-ground atmospheric pressure tank for buffer feeding solves the problem of poor flow of atmospheric pressure waste oil into the tank; the dual protection of self-priming reflux and nitrogen pressurization ensures reliable intake of high-viscosity sludge oil; the equipment is simple to maintain and operates stably, meets the policy requirements for eliminating outdated equipment, and significantly improves the intrinsic safety level of the device. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the system structure of the present invention. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] In the description of the invention, it should be noted that the terms "upper", "lower", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the invention.

[0018] In the description of the invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0019] Technical solution / principle: This invention discloses an underground heavy oil spill lifting and conveying system, comprising an underground oil spill tank 1, an above-ground oil spill tank 2, a heavy oil spill pump 3, a first line 6, a second line 7, a self-priming return line 5, a third line 10, a fourth line 11, a nitrogen regulating valve group 4, a pressure regulating valve 8, and a drain valve 9. The above-ground oil spill tank 2 is an atmospheric pressure tank, connected to the underground oil spill tank 1 via the first line 6, which is equipped with the drain valve 9. The outlet of the fourth line 11 is connected to the first line 6 for conveying pressurized waste oil. The underground oil spill tank 1 is connected to the second line 7, which is equipped with a pressure regulating valve 8 for depressurizing to a flare or external environment. The heavy oil spill pump 3 is located on the ground and is a self-priming pump, with its inlet connected to the underground oil spill tank 1 and its outlet connected to a pump outlet pipeline 12. One end of the self-priming return line 5 is connected to the pump outlet pipeline 12, and the other end is connected to the underground oil spill tank 1. Line 3 (Line 10) connects underground sludge tank 1 to a nitrogen source. A nitrogen regulating valve group 4 and a check valve are installed on the pipeline for pressurization and self-priming assistance within the tank. Underground sludge tank 1 is designed to have a pressure greater than the maximum operating pressure with a safety margin. The inlet pressure of heavy sludge pump 3 is adapted to both atmospheric pressure and pressurization conditions.

[0020] Example 1: Atmospheric pressure waste oil feeding: Atmospheric pressure waste oil is collected into the above-ground sludge tank 2 to the set liquid level, the drain valve 9 is closed, and the pressure regulating valve 8 on line 2 is opened to depressurize the underground sludge tank 1 to near atmospheric pressure; the drain valve 9 is opened, and the atmospheric pressure waste oil enters the underground sludge tank 1 through line 1 6.

[0021] Example 2: Pressurized waste oil feeding: Pressurized waste oil generated from process drainage, venting, and pipeline flushing is fed into Line 16 via Line 4 and directly enters the underground sludge tank 1.

[0022] Example 3 Normal lifting and conveying: Start the ground heavy oil pump 3. The pump outlet medium flows back to the underground oil tank 1 through the self-priming return line 5, forming a circulation to enhance the self-priming force, and stably lift and deliver the heavy oil in the underground oil tank 1.

[0023] Example 4: High viscosity emergency self-priming: When the heavy sludge pump 3 cannot self-prime due to high viscosity, close line 7 and other unnecessary valves, open the nitrogen regulating valve group 4 on line 10, pressurize the underground sludge tank 1, push the oil in the tank into the pump inlet, and quickly complete the self-priming start.

[0024] Finally, it should be noted that the present invention is not limited to the above embodiments, and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.

Claims

1. An underground heavy oil spill lifting and conveying system, characterized in that, The system includes an underground sludge tank (1), an above-ground sludge tank (2), a heavy sludge pump (3), and a third line (10) for transporting nitrogen. The above-ground sludge tank (2) is connected to the underground sludge tank (1) via a first line (6). The heavy sludge pump (3) is located on the ground. The inlet and outlet of the heavy sludge pump (3) are connected to the underground sludge tank (1) and the pump outlet pipeline (12), respectively. A self-priming return line (5) is connected to the pump outlet pipeline (12), and the self-priming return line (5) is connected to the underground sludge tank (1). The third line (10) is connected to the underground sludge tank (1), and a nitrogen regulating valve group (4) and a check valve are connected to the third line (10). The nitrogen regulating valve group (4) on the third line (10) is used to pressurize the underground sludge tank (1) to assist the heavy sludge pump (3) in achieving self-priming.

2. The underground heavy oil spill lifting and conveying system according to claim 1, characterized in that, The underground sludge tank (1) is connected to a second line (7) that can communicate with the outside world or the flare. The second line (7) is connected to a pressure regulating valve (8) and a shut-off valve.

3. The underground heavy oil spill lifting and conveying system according to claim 1, characterized in that, The heavy oil pump (3) is a strong self-priming pump. A check valve and a shut-off valve are connected to the pump outlet pipeline (12) at the outlet of the heavy oil pump (3). The inlet end of the self-priming return line (5) is connected to the pump outlet pipeline (12) between the check valve and the shut-off valve.

4. The underground heavy oil spill lifting and conveying system according to claim 1, characterized in that, The above-ground sludge tank (2) is an atmospheric pressure tank. A drain valve (9) is installed on the No. 1 line (6). The No. 1 line (6) can be used to transport pressurized waste oil generated by process drainage, venting and pipeline flushing, and directly connect to the underground sludge tank (1).

5. The underground heavy oil spill lifting and conveying system according to claim 1, characterized in that, It also includes a fourth line (11) for transporting waste oil, the outlet of which is connected to the first line (6) at the outlet of the drain valve (9).

6. The underground heavy oil spill lifting and conveying system according to claim 1, characterized in that, The design pressure of the underground sludge tank (1) is greater than its maximum operating pressure, so as to achieve and reserve a safety margin.

7. The underground heavy oil spill lifting and conveying system according to claim 1, characterized in that, The inlet pressure of the heavy oil pump (3) is adapted to both normal pressure conditions and the pressurization conditions of the underground oil tank (1).

8. A method for lifting and transporting underground heavy oil pollution, employing the system described in any one of claims 1-7, characterized in that... The method includes the following: The waste oil under normal pressure is collected in the above-ground sludge tank (2), the drain valve (9) on line 1 (6) is closed, and the pressure regulating valve (8) on line 2 (7) is opened to depressurize the underground sludge tank (1) to near normal pressure; Then open the drain valve (9) to allow the atmospheric pressure waste oil to enter the underground sludge tank (1) via line 1 (6); The pressurized waste oil flows into Line 1 (6) via Line 4 (11) and directly enters the underground sludge tank (1).

9. The underground heavy oil spill lifting and transportation method according to claim 8, characterized in that, When the heavy oil pump (3) is started, the medium in the pump outlet pipeline (12) flows back to the underground oil tank (1) through the self-priming return line (5) to form a circulation to enhance the self-priming capacity of the heavy oil pump (3) and realize the continuous lifting and delivery of underground heavy oil.

10. The underground heavy oil spill lifting and transportation method according to claim 8, characterized in that, When the self-priming of the heavy oil pump (3) fails, close all valves on line 2 (7), open the nitrogen regulating valve group (4) on line 3 (10), pressurize the underground oil tank (1), and push the waste oil in the tank into the inlet of the heavy oil pump (3) to complete the self-priming start.

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