Single-stage heavy oil supply system and method for marine diesel engine
By using a single-stage heavy oil supply system, a fuel supply pump and a buffer tank are combined with a bypass pressure regulating valve to achieve fuel circulation and pressure stability. This solves the problems of complexity and high cost of existing two-stage pump systems, and achieves cost reduction and ease of maintenance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA SHIPPING IND JIANGSU
- Filing Date
- 2026-03-30
- Publication Date
- 2026-05-12
AI Technical Summary
Existing ship heavy oil supply systems use a two-stage pump model, resulting in complex systems, high costs, and a large workload for maintenance.
A single-stage heavy oil supply system is adopted, which uses a fuel supply pump with ample flow and a buffer tank, combined with a bypass pressure regulating valve, to achieve fuel circulation and pressure stability, replacing the circulation pump in the dual-pump system.
It simplifies the system's power equipment, reduces costs and maintenance workload, and ensures a stable fuel supply to the diesel engine.
Smart Images
Figure CN122014468A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of marine technology, and in particular to a single-stage heavy oil supply system and method for marine diesel engines. Background Technology
[0002] The heavy fuel oil supply system of marine diesel engines is crucial for ensuring the stable operation of the main engine. Currently, existing marine heavy fuel oil supply systems generally adopt a two-stage pump supply mode. First, the fuel supply pump draws fuel from the day fuel tank and initially pressurizes it. Then, a dedicated fuel circulation pump further pressurizes it to reach the operating pressure required by the diesel engine. This traditional mode requires two sets of power equipment—one for the supply pump and one for the circulation pump—along with corresponding control boxes, valves, pipelines, etc., making the system relatively complex, costly, and requiring significant maintenance. Summary of the Invention
[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing a single-stage heavy oil supply system and method for marine diesel engines. By simplifying the system's power equipment, this invention ensures stable fuel supply to the diesel engine while reducing costs and facilitating maintenance.
[0004] To achieve the above-mentioned objectives, the present invention provides a single-stage heavy oil supply system and method for marine diesel engines, which employs the following technical solution:
[0005] A single-stage heavy oil supply system for a marine diesel engine includes a heavy oil day tank, a fuel supply pump, an atomizing heater, a fuel filter, and a diesel engine. It also includes a buffer tank and a bypass pressure regulating valve. The heavy oil day tank is sequentially connected to the fuel supply pump, the atomizing heater, and the fuel filter via a supply pipeline. After passing through the fuel filter, the supply pipeline is divided into a supply branch and a pressure regulating branch. The supply branch is connected to the diesel engine, and the pressure regulating branch is equipped with a bypass pressure regulating valve. Both the diesel engine outlet and the bypass pressure regulating valve outlet are connected to the buffer tank. The buffer tank outlet is connected to the fuel supply pump inlet via a return oil line, which is equipped with a first back pressure valve. The flow rate of the fuel supply pump is greater than the fuel consumption of the diesel engine, and the outlet oil pressure of the fuel supply pump is higher than the set pressure of the bypass pressure regulating valve.
[0006] Preferably, the buffer cabinet is equipped with an exhaust port and a safety relief port; the exhaust port has an exhaust path with an exhaust solenoid valve; the safety relief port has a relief path with a safety valve; the exhaust path and the relief path merge and are connected to the heavy oil daily use cabinet via a main pipeline, which is equipped with a second back pressure valve. This invention integrates exhaust and overpressure protection functions, enabling the system to automatically discharge gas and prevent overpressure, thus improving the system's safety and stability.
[0007] Preferably, the buffer cabinet is equipped with a liquid level switch, which is signal-connected to the exhaust solenoid valve and used to control the opening and closing of the exhaust solenoid valve according to the liquid level in the buffer cabinet.
[0008] Preferably, the upper part of the buffer cabinet retains an air cavity for pressure buffering.
[0009] Preferably, the volume of the air cavity accounts for one-quarter of the total volume of the buffer cabinet.
[0010] Preferably, a viscosity controller is installed on the fuel supply line between the atomizing heater and the fuel filter.
[0011] Preferably, the flow rate of the fuel supply pump is 3-5 times the fuel consumption of the diesel engine. Setting the flow rate of the fuel supply pump to 3-5 times the fuel consumption of the diesel engine ensures that sufficient fuel participates in the circulation.
[0012] A method for supplying heavy oil to a single-stage marine diesel engine includes the following steps:
[0013] (1) Fuel supply and pressurization: Start the fuel supply pump to pressurize the fuel in the heavy oil daily use tank. The flow rate of the fuel supply pump is greater than the fuel consumption of the diesel engine.
[0014] (2) Fuel treatment: The pressurized heavy oil is heated by an atomizing heater and then filtered by a fuel filter;
[0015] (3) Pressure regulation and diversion: The fuel filtered by the fuel filter is divided into two paths. One path is supplied to the diesel engine for combustion and consumption through the fuel supply branch, and the unconsumed fuel flows to the buffer tank; the other path flows to the buffer tank through the pressure regulation branch and the bypass pressure regulating valve.
[0016] (4) Buffering and circulation: When the pressure in the buffer tank is higher than the set pressure of the first back pressure valve, the first back pressure valve opens, and the fuel in the buffer tank returns to the inlet of the fuel supply pump through the return oil circuit, forming a circulation.
[0017] Preferably, the system also includes a level-linked venting step for the buffer tank: when the level switch indicates a level below a preset position, it controls the venting solenoid valve to open, allowing the gas accumulated in the buffer tank to enter the main pipeline; when the pressure in the main pipeline accumulates to the set pressure of the second back pressure valve, the second back pressure valve opens, venting the gas to the heavy oil daily use tank. By automatically controlling the opening and closing of the venting solenoid valve through the level switch, the accumulated gas is released, preventing gas accumulation from affecting the system pressure stability.
[0018] Preferably, the system also includes an overpressure safety relief procedure for the buffer tank: when the pressure inside the buffer tank exceeds the set pressure of the safety valve, the safety valve opens, and the overpressurized oil and gas medium inside the buffer tank is released into the heavy oil daily use tank. By setting up the safety valve, automatic release is achieved in case of abnormal pressure, effectively protecting the system equipment from damage.
[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0020] This invention employs a fuel supply pump with excess flow, in conjunction with a buffer tank and a bypass pressure regulating valve. Excess fuel flows through a pressure regulating branch into the buffer tank and back to the fuel supply pump inlet, thus achieving fuel circulation and pressure stabilization in a single-pump system, replacing the circulation pump in the original dual-pump system. This design simplifies the system's power equipment and reduces costs and maintenance workload. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the single-stage heavy oil supply system for marine diesel engines according to the present invention.
[0022] The components include: 1. Heavy oil daily use tank; 2. Main pipeline; 3. Second back pressure valve; 4. Exhaust line; 5. Exhaust solenoid valve; 6. Pressure relief line; 7. Safety valve; 8. Diesel engine; 9. Oil supply branch line; 10. Pressure regulating branch line; 11. Fuel filter; 12. Viscosity controller; 13. Bypass pressure regulating valve; 14. Atomizing heater; 15. First back pressure valve; 16. Oil supply pipeline; 17. Return oil line; 18. Buffer tank; 19. Liquid level switch; 20. Fuel supply pump. Detailed Implementation
[0023] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art will fall within the scope defined by the appended claims.
[0024] like Figure 1As shown, a single-stage heavy oil supply system for a marine diesel engine includes a heavy oil day tank 1, a fuel supply pump 20, an atomizing heater 14, a fuel filter 11, and a diesel engine 8. It also includes a buffer tank 18 and a bypass pressure regulating valve 13. The heavy oil day tank 1 is sequentially connected to the fuel supply pump 20, the atomizing heater 14, and the fuel filter 11 via a supply pipeline 16. A viscosity controller 12 is installed on the supply pipeline 16 between the atomizing heater 14 and the fuel filter 11. After passing through the fuel filter 11, the supply pipeline 16 branches into a supply branch 9 and a pressure regulating branch 10. The supply branch 9 is connected to the diesel engine 8, and the pressure regulating branch 10 is equipped with a bypass pressure regulating valve 13. The outlet of the diesel engine 8 and the outlet of the bypass pressure regulating valve 13 are both connected to the buffer tank 18. The outlet of the buffer tank 18 is connected to the inlet of the fuel supply pump 20 via a return oil line 17. A first back pressure valve 15 is provided; the flow rate of the fuel supply pump 20 is 3-5 times the fuel consumption of the diesel engine 8, and the outlet oil pressure of the fuel supply pump 20 is higher than the set pressure of the bypass pressure regulating valve 13; the upper part of the buffer cabinet 18 retains an air chamber for pressure buffering, and the volume of the air chamber occupies one-quarter of the total volume of the buffer cabinet 18; the buffer cabinet 18 is provided with an exhaust port and a safety pressure relief port; the exhaust port is provided with an exhaust path 4, and an exhaust solenoid valve 5 is provided on the exhaust path 4; the buffer cabinet 18 is provided with a liquid level switch 19, which is signal-connected to the exhaust solenoid valve 5 and is used to control the opening and closing of the exhaust solenoid valve 5 according to the liquid level in the buffer cabinet 18; the safety pressure relief port is provided with a pressure relief path 6, and a safety valve 7 is provided on the pressure relief path 6; after the exhaust path 4 and the pressure relief path 6 merge, they are connected to the heavy oil daily use cabinet 1 through the main pipeline 2, and a second back pressure valve 3 is provided on the main pipeline 2.
[0025] The specific working process and principle of this invention: After the system starts, the heavy oil at 90°C in the heavy oil daily use tank 1 is drawn in by the fuel supply pump 20 and pressurized to about 12 bar, flowing through the atomizing heater 14 to be heated to meet the preset viscosity requirement of 12-16 cSt; then the fuel passes through the fuel filter 11 and is filtered to an accuracy of 10 μm, and then splits into two paths: one path is supplied to the diesel engine 8 via the fuel supply branch 9, and the other path enters the pressure regulating branch 10; since the flow rate of the fuel supply pump 20 is 3-5 times that of the diesel engine 8, and the outlet pressure of the fuel supply pump 20 is higher than the set pressure of the bypass pressure regulating valve 13 by 10 bar, the excess fuel passes through the bypass pressure regulating valve 13, and then enters the buffer tank 18 together with the unconsumed return oil of the diesel engine 8; when the pressure in the buffer tank 18 is higher than the set pressure of the first back pressure valve 15 by 4 bar... When the pressure reaches 4 bar, fuel returns to the inlet of fuel supply pump 20 via return oil line 17, forming a continuous cycle, thereby stabilizing the inlet pressure supplied to diesel engine 8 at the set value. In addition, the upper part of the buffer cabinet 18 retains a quarter volume of air chamber for pressure buffering. When the liquid level switch 19 inside detects that the liquid level is lower than the preset position, it indicates that too much gas has accumulated. It controls the exhaust solenoid valve 5 to open for 3 seconds, and the gas enters the main pipeline 2 and accumulates pressure. When the pressure reaches the set pressure of the second back pressure valve 3 of 4 bar, the second back pressure valve 3 opens to exhaust the gas to the heavy oil daily use tank 1. If the system pressure rises abnormally and exceeds the set pressure of safety valve 7 of 15 bar, safety valve 7 opens automatically, and the second back pressure valve 3 also opens automatically, releasing the overpressurized fuel and gas mixture through the pressure relief line 6 and the main pipeline 2 to the heavy oil daily use tank 1.
[0026] A method for supplying heavy oil to a single-stage marine diesel engine includes the following steps:
[0027] (1) Fuel supply and pressurization: Start the fuel supply pump 20 to pressurize the fuel in the heavy oil daily use tank 1. The flow rate of the fuel supply pump 20 is greater than the fuel consumption of the diesel engine 8.
[0028] (2) Fuel treatment: The pressurized heavy oil is heated by the atomizing heater 14 and then filtered by the fuel filter 11;
[0029] (3) Pressure regulation and diversion: The fuel filtered by the fuel filter 11 is divided into two paths. One path is supplied to the diesel engine 8 for combustion and consumption via the fuel supply branch 9, and the unconsumed fuel flows to the buffer cabinet 18. The other path flows to the buffer cabinet 18 via the pressure regulation branch 10 and the bypass pressure regulating valve 13.
[0030] (4) Buffering and circulation: When the pressure in the buffer tank 18 is higher than the set pressure of the first back pressure valve 15, the first back pressure valve 15 opens, and the fuel in the buffer tank 18 returns to the inlet of the fuel supply pump 20 through the return oil circuit 17, forming a circulation.
[0031] When the liquid level of the liquid level switch 19 is lower than the preset position, the exhaust solenoid valve 5 is opened to allow the gas accumulated in the buffer cabinet 18 to enter the main pipeline 2; when the pressure in the main pipeline 2 reaches the set pressure of the second back pressure valve 3, the second back pressure valve 3 is opened to discharge the gas to the heavy oil daily use cabinet 1.
[0032] When the pressure inside the buffer tank 18 exceeds the set pressure of the safety valve 7, the safety valve 7 opens, and the overpressurized oil and gas medium inside the buffer tank 18 is released into the heavy oil daily use tank 1.
[0033] In the description of this invention, it should be understood that the terms "coaxial," "bottom," "one end," "top," "middle," "other end," "upper," "side," "top," "inner," "front," "center," "both ends," 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 this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.
[0034] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0035] The foregoing description illustrates and describes preferred embodiments of the present invention. As previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.
Claims
1. A single-stage heavy oil supply system for a marine diesel engine, comprising a heavy oil day tank, a fuel supply pump, an atomizing heater, a fuel filter, and a diesel engine, characterized in that: It also includes a buffer cabinet and a bypass pressure regulating valve; the heavy oil daily use cabinet is connected in sequence to a fuel supply pump, an atomizing heater, and a fuel filter via a fuel supply pipeline; the fuel supply pipeline is divided into a fuel supply branch and a pressure regulating branch after passing through the fuel filter; the fuel supply branch is connected to the diesel engine, and a bypass pressure regulating valve is installed on the pressure regulating branch; the outlet of the diesel engine and the outlet of the bypass pressure regulating valve are both connected to the buffer cabinet, and the outlet of the buffer cabinet is connected to the inlet of the fuel supply pump via a return oil line, which is equipped with a first back pressure valve; the flow rate of the fuel supply pump is greater than the fuel consumption of the diesel engine, and the outlet oil pressure of the fuel supply pump is higher than the set pressure of the bypass pressure regulating valve.
2. The single-stage heavy oil supply system for marine diesel engines according to claim 1, characterized in that: The buffer cabinet is equipped with an exhaust port and a safety pressure relief port; the exhaust port is equipped with an exhaust path and an exhaust solenoid valve; the safety pressure relief port is equipped with a pressure relief path and a safety valve; the exhaust path and the pressure relief path merge and are connected to the heavy oil daily use cabinet through a main pipeline, and a second back pressure valve is provided on the main pipeline.
3. The single-stage heavy oil supply system for marine diesel engines according to claim 2, characterized in that: The buffer cabinet is equipped with a liquid level switch, which is connected to the exhaust solenoid valve and is used to control the opening and closing of the exhaust solenoid valve according to the liquid level in the buffer cabinet.
4. The single-stage heavy oil supply system for marine diesel engines according to claim 1, characterized in that: The upper part of the buffer cabinet retains an air cavity for pressure buffering.
5. The single-stage heavy oil supply system for marine diesel engines according to claim 4, characterized in that: The volume of the air cavity accounts for one-quarter of the total volume of the buffer cabinet.
6. The single-stage heavy oil supply system for marine diesel engines according to claim 1, characterized in that: A viscosity controller is installed on the fuel supply line between the atomizing heater and the fuel filter.
7. The single-stage heavy oil supply system for marine diesel engines according to claim 1, characterized in that: The flow rate of the fuel supply pump is 3-5 times the fuel consumption of the diesel engine.
8. A method for single-stage heavy oil supply to a marine diesel engine, characterized in that, The method employing a single-stage heavy oil supply system for marine diesel engines as described in any one of claims 1-7 includes the following steps: (1) Fuel supply and pressurization: Start the fuel supply pump to pressurize the fuel in the heavy oil daily use tank. The flow rate of the fuel supply pump is greater than the fuel consumption of the diesel engine. (2) Fuel treatment: The pressurized heavy oil is heated by an atomizing heater and then filtered by a fuel filter; (3) Pressure regulation and diversion: The fuel filtered by the fuel filter is divided into two paths. One path is supplied to the diesel engine for combustion and consumption through the fuel supply branch, and the unconsumed fuel flows to the buffer tank; the other path flows to the buffer tank through the pressure regulation branch and the bypass pressure regulating valve. (4) Buffering and circulation: When the pressure in the buffer tank is higher than the set pressure of the first back pressure valve, the first back pressure valve opens, and the fuel in the buffer tank returns to the inlet of the fuel supply pump through the return oil circuit, forming a circulation.
9. The method for single-stage heavy oil supply to a marine diesel engine according to claim 8, characterized in that, It also includes a level-linked venting step for the buffer tank: when the level switch is lower than the preset position, it controls the venting solenoid valve to open, allowing the gas accumulated in the buffer tank to enter the main pipeline; when the pressure in the main pipeline reaches the set pressure of the second back pressure valve, the second back pressure valve opens, venting the gas to the heavy oil daily use tank.
10. The method for single-stage heavy oil supply to a marine diesel engine according to claim 8, characterized in that, It also includes an overpressure safety relief procedure for the buffer tank: when the pressure inside the buffer tank exceeds the set pressure of the safety valve, the safety valve opens, and the overpressured oil and gas medium inside the buffer tank is released into the heavy oil daily use tank.