Marine ethanol fuel supply system and operation control method

Abstract

The invention provides a marine ethanol fuel supply system and an operation control method.The supply system at least comprises a first heat exchanger and a second heat exchanger, a first flow channel and a second flow channel which are not communicated with each other are arranged in the first heat exchanger, the inlet end of the first flow channel is connected with an ethanol storage tank, and the outlet end of the first flow channel is connected with an ethanol consumption unit; the inlet end of the second flow channel is connected with the second heat exchanger, the outlet end of the second flow channel is connected with the water glycol solution expansion water cabinet, a third flow channel and a fourth flow channel which are not communicated are arranged in the second heat exchanger, and the inlet end of the third flow channel is connected with the water glycol solution expansion water cabinet, and the outlet end of the third flow channel is connected with the first heat exchanger. The inlet end of the fourth runner is connected with the water source inlet, and the outlet end is connected with the water source outlet. The low-temperature ethanol fuel can utilize part of heat of water, the water glycol solution and inlet water conduct heat exchange in the second heat exchanger, the heat lost by the water glycol solution in the first heat exchanger is supplemented, and the temperature requirement of the ethanol fuel in the supply system is met.

Description

Technical Field

[0001] This invention relates to the field of marine fuel supply technology, and more specifically, to a marine ethanol fuel supply system and its operation control method. Background Technology

[0002] The global shipping industry is facing severe pressure to reduce emissions. The International Maritime Organization (IMO) has explicitly required that shipping carbon emissions be reduced by 70% by 2050 compared to 2008 levels. Traditional ship fuels (diesel and heavy oil) are no longer able to meet environmental regulations due to their high carbon and sulfur oxide emissions (sulfur content typically exceeds 1000 ppm). Ethanol fuel, as a renewable biofuel, has advantages such as low sulfur content (<10 ppm), a 40% reduction in particulate matter emissions, and a near-carbon-neutral life cycle (CO2 is absorbed during the feedstock growth process). Furthermore, it requires no special storage equipment, making it an important potential option for shipping decarbonization.

[0003] Collaborative tests by Wärtsilä and Raízen of Brazil have shown that ethanol fuel can reduce carbon emissions by up to 80%, and DNV predicts that ethanol will account for 11% of shipping biofuels by 2050. However, existing ship ethanol fuel supply systems suffer from several technical bottlenecks: First, the poor design of the bottom of ethanol storage tanks easily leads to fuel residue, incomplete delivery, and fuel waste; second, heat exchange systems mostly use single-stage heat exchange, relying on a single heat source, resulting in low heat exchange efficiency and poor temperature stability, making it difficult to meet the precise fuel temperature requirements of ship propulsion units; third, fuel transfer pumps mostly use mechanical seals, posing a risk of leakage and lacking the ability to adapt to different pressure requirements; fourth, the system does not consider the replenishment and monitoring mechanism of water-glycol heat exchange medium, and long-term operation is prone to heat exchange failure due to medium loss. Furthermore, the shipping industry currently pays less attention to ethanol fuel than to alternative fuels such as methanol and ammonia, and the technical standards and industrial applications of related supply systems are still in their infancy. There is an urgent need to improve the reliability, applicability, and intelligence of ethanol fuel supply systems through structural optimization, functional improvement, and electrical control upgrades. Summary of the Invention

[0004] In view of this, the present invention aims to propose a marine ethanol fuel supply system and operation control method to solve the problems of low heat exchange efficiency and low temperature of ethanol fuel after heat exchange in the prior art marine ethanol fuel supply system.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] A marine ethanol fuel supply system includes an ethanol storage tank, an ethanol fuel supply unit, a water glycol solution expansion tank, and an electrical control unit. The ethanol fuel supply unit includes at least a first heat exchanger and a second heat exchanger. The first heat exchanger has a first flow channel and a second flow channel that are not interconnected. The inlet end of the first flow channel is connected to the ethanol storage tank, and the outlet end of the first flow channel is connected to the ethanol consumption unit. The inlet end of the second flow channel is connected to the second heat exchanger, and the outlet end of the second flow channel is connected to the water glycol solution expansion tank. The second heat exchanger has a third flow channel and a fourth flow channel that are not interconnected. The inlet end of the third flow channel is connected to the water glycol solution expansion tank, and the outlet end of the third flow channel is connected to the first heat exchanger. The inlet end of the fourth flow channel is connected to a water source inlet, and the outlet end of the fourth flow channel is connected to a water source outlet. This application enables the low-temperature ethanol fuel to utilize some of the heat from the ship's inlet water by setting up a first heat exchanger and a second heat exchanger. The water-glycol solution and the inlet water exchange heat in the second heat exchanger, making up for the heat lost by the water-glycol solution in the first heat exchanger, so as to ensure the temperature requirements of the ethanol fuel in the supply system.

[0007] Furthermore, the ethanol storage tank is connected to an electric centrifugal transfer pump to control the flow rate of fuel flowing out of the ethanol storage tank.

[0008] Furthermore, an ethanol fuel day tank is connected between the ethanol storage tank and the first heat exchanger. The input end of the ethanol fuel day tank is connected to the output end of the electric centrifugal transfer pump, and the output end of the ethanol fuel day tank is connected to the first heat exchanger via a first pipeline. The ethanol fuel day tank is used to store the ship's daily ethanol fuel consumption, avoiding frequent start-ups and shutdowns of the electric centrifugal transfer pump from the ethanol storage tank, thus helping to improve system stability.

[0009] Furthermore, the first pipeline is equipped with a first pump body and a first regulating valve. The first pump body is used to pressurize the low-temperature ethanol fuel and deliver it to the first flow channel of the first heat exchanger for heating and heat exchange. The first regulating valve is used to adjust the flow rate of the low-temperature ethanol fuel entering the first flow channel by adjusting the valve opening.

[0010] Furthermore, the first heat exchanger and the second heat exchanger are connected by a second pipeline, the second heat exchanger and the water glycol solution expansion tank are connected by a third pipeline, the water glycol solution expansion tank and the first heat exchanger are connected by a fourth pipeline, and the third pipeline is equipped with an ethylene glycol circulation pump and a second regulating valve to form a closed loop of "water glycol solution expansion tank → water glycol solution circulation pump → second heat exchanger → first heat exchanger → water glycol solution expansion tank".

[0011] Furthermore, an oil suction well is provided at the center of the bottom of the ethanol storage tank, and the bottom of the tank is sloped at 3° to 8° towards the oil suction well. This ensures that the ethanol fuel in the tank can be completely collected into the oil suction well by gravity, minimizing the residue of ethanol fuel, and the residue level can be controlled to below 0.5%.

[0012] Furthermore, a fourth temperature sensor and a fourth pressure sensor are installed at the outlet end of the first flow channel. The fourth temperature sensor is used to detect the temperature of the ethanol fuel entering the ethanol consumption unit in real time, and the fourth pressure sensor is used to detect the pressure of the ethanol fuel entering the ethanol consumption unit in real time.

[0013] The present invention also proposes an operation control method for the above-mentioned marine ethanol fuel supply system, the operation control method comprising the following steps:

[0014] S1. The electrical control unit first performs a self-test;

[0015] S2. After the self-test is passed, the central controller sends a start command to the water glycol solution circulation pump. After the water glycol solution entering the second heat exchanger is stable, the first pump body is started and the pressure of the low-temperature ethanol fuel entering the first heat exchanger is adjusted to the required pressure.

[0016] S3. Real-time detection and acquisition of detection data from each sensor;

[0017] S4. Determine whether the real-time temperature data T detected by the fourth temperature sensor is greater than A. If yes, proceed to step S5; otherwise, proceed to step S7.

[0018] S5. Determine whether the real-time temperature data T detected by the fourth temperature sensor satisfies A < T < B. If yes, the second regulating valve maintains its current opening, and the water glycol solution circulation pump maintains its current speed. If no, proceed to step S6.

[0019] S6. Reduce the opening of the second regulating valve and the speed of the water glycol solution circulation pump;

[0020] S7. Determine whether the load on the ship's main engine has increased. If so, increase the speed of the first pump and the opening of the first regulating valve, and at the same time, increase the opening of the second regulating valve and the speed of the water glycol solution circulation pump. If not, only increase the opening of the second regulating valve and the speed of the water glycol solution circulation pump.

[0021] Furthermore, A = 30 ± 2℃, and B = 45 ± 2℃.

[0022] Furthermore, during a normal shutdown of the supply system, the electric centrifugal transfer pump is first shut down. After the ethanol fuel level in the daily use tank drops below 10%, the first pump is shut down, and finally the water glycol solution circulation pump is shut down. Simultaneously, the drain valves of each pipeline are opened to discharge any remaining ethanol fuel and water glycol solution. In case of an emergency shutdown due to a malfunction, the power supply to all pumps is immediately cut off, the first and second regulating valves are closed, and the emergency pressure relief valve on the fourth pipeline is opened to prevent overpressure damage to the pipeline.

[0023] Compared with existing technologies, the marine ethanol fuel supply system and operation control method described in this invention have the following advantages:

[0024] (1) By setting up a first heat exchanger and a second heat exchanger, the low-temperature ethanol fuel can utilize part of the heat from the ship's inlet water. The water glycol solution and the inlet water exchange heat in the second heat exchanger to make up for the heat lost by the water glycol solution in the first heat exchanger, so as to ensure the temperature requirements of the ethanol fuel in the supply system.

[0025] (2) It can reasonably regulate and ensure that the temperature of ethanol fuel entering the ethanol consumption unit meets the requirements.

[0026] (2) An oil suction well is set in the center of the bottom of the ethanol storage tank, and the bottom of the tank is sloped towards the oil suction well to ensure that the ethanol fuel in the tank can be completely collected to the oil suction well by gravity, so as to avoid the residue of ethanol fuel to the greatest extent.

[0027] (4) This application applies to the supply of ethanol fuel for ships, including the storage, transshipment, pressurization, and heat exchange of ethanol fuel. Compared to zero-carbon fuels such as hydrogen and ammonia, which require entirely new engine technologies and a large infrastructure system, ethanol, as a liquid fuel, can utilize most of the existing petroleum infrastructure (with appropriate modifications) in terms of storage, transportation, and refueling, greatly reducing the application threshold and initial investment costs. This makes ethanol a very realistic transitional solution, helping the shipping industry achieve significant and immediate emission reductions at a lower cost on the road to a future of zero-carbon fuels. Attached Figure Description

[0028] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0029] Figure 1 This is a schematic diagram of the marine ethanol fuel supply system described in this invention.

[0030] Explanation of reference numerals in the attached figures:

[0031] 1. Ethanol storage tank; 2. Electric centrifugal transfer pump; 3. Ethanol fuel daily use compartment; 4. Ethanol fuel supply unit; 41. First pump body; 42. First heat exchanger; 43. Second heat exchanger; 44. Water glycol solution circulation pump; 45. First regulating valve; 46. Second regulating valve; 5. Water glycol solution expansion tank; 6. Electrical control unit; 7. Ethanol consumption unit; 8. Water source inlet; 9. Water source outlet; 10. First pipeline; 11. Second pipeline; 12. Third pipeline; 13. Fourth pipeline; 14. Fifth pipeline; 15. Filling port. Detailed Implementation

[0032] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In addition, the orientations involved in the following specific embodiments are briefly explained: the directions or positional relationships indicated by "front", "rear", "up", "down", "left", "right", "top", "bottom", etc. mentioned in the embodiments refer to the orientations or positional relationships shown in the accompanying drawings, and the term "on" means directly or indirectly supported by the element.

[0033] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0034] like Figure 1 As shown, a marine ethanol fuel supply system includes an ethanol storage tank 1, an ethanol fuel supply unit 4, a water glycol solution expansion tank 5, and an electrical control unit 6. The ethanol fuel supply unit 4 includes at least a first heat exchanger 42 and a second heat exchanger 43. The first heat exchanger 42 has a first flow channel and a second flow channel that are not interconnected. The inlet end of the first flow channel is connected to the ethanol storage tank 1, and the outlet end of the first flow channel is connected to the ethanol consumption unit 7. The inlet end of the second flow channel is connected to the second heat exchanger 43, and the outlet end of the second flow channel is connected to the water glycol solution expansion tank 5. The second heat exchanger 43 has a third flow channel and a fourth flow channel that are not interconnected. The inlet end of the third flow channel is connected to the water glycol solution expansion tank 5, and the outlet end of the third flow channel is connected to the first heat exchanger 42. The inlet end of the fourth flow channel is connected to a water source inlet 8, and the outlet end of the fourth flow channel is connected to a water source outlet 9.

[0035] The ethanol storage tank 1 is used to store low-temperature ethanol fuel, the water-glycol solution expansion tank 5 is used to store water-glycol solution, and the water source inlet 8 is used to provide a water source. The water-glycol solution from the water-glycol solution expansion tank 5 enters the third flow channel of the second heat exchanger 43, and the inlet water from the water source inlet 8 enters the fourth flow channel of the second heat exchanger 43. The lower-temperature water-glycol solution and the higher-temperature inlet water exchange heat within the second heat exchanger 43. After absorbing some of the heat from the inlet water, the water-glycol solution enters the second flow channel of the first heat exchanger 42. The inlet water transfers some of its heat to the water-glycol solution, becoming cooler water, and then flows out from the water source outlet 9.

[0036] Low-temperature ethanol fuel from ethanol storage tank 1 enters the first flow channel of the first heat exchanger 42 and exchanges heat with the water glycol solution that absorbs heat within the first heat exchanger 42. Heat is transferred to the ethanol fuel via the water glycol solution. After the heat exchange is completed in the first heat exchanger 42, the temperature of the ethanol fuel increases, making it available for use in the downstream ethanol consumption unit 7. The temperature of the water glycol solution decreases, and it re-enters the water glycol solution expansion tank 5 to participate in the next heat exchange cycle.

[0037] This application enables low-temperature ethanol fuel to utilize some of the heat from the ship's inlet water by setting up a first heat exchanger 42 and a second heat exchanger 43. The water-glycol solution and the inlet water exchange heat in the second heat exchanger 43, making up for the heat lost by the water-glycol solution in the first heat exchanger 42, so as to ensure the temperature requirements of the ethanol fuel in the supply system.

[0038] As a specific example of this application, the ethanol consumption unit 7 is a ship's dual-fuel main engine, generator, boiler, etc.

[0039] Before a ship uses ethanol fuel for the first time, it needs to add ethylene glycol solution through the filling port 15 of the ethylene glycol solution expansion tank 5 to meet the system's heat exchange requirements. During operation, if the ethylene glycol solution decreases or is lost, it can be continuously replenished to ensure the system's heat exchange needs are met.

[0040] An external fixed pump compartment is installed around the ethanol storage tank 1 to house an electric centrifugal transfer pump 2. The electric centrifugal transfer pump 2 is connected to the ethanol storage tank 1 and is used to control the flow rate of fuel flowing out of the ethanol storage tank 1. The flow rate range of the electric centrifugal transfer pump 2 can be selected according to different ship types and operating conditions. The pump compartment is equipped with ventilation openings and explosion-proof lighting to meet the requirements of safe operation.

[0041] As a preferred example of this application, an ethanol fuel day tank 3 is connected between the ethanol storage tank 1 and the first heat exchanger 42. The input end of the ethanol fuel day tank 3 is connected to the output end of the electric centrifugal transfer pump 2, and the output end of the ethanol fuel day tank 3 is connected to the first heat exchanger 42 through a first pipeline 10. The ethanol fuel day tank 3 is used to store the ship's daily ethanol fuel consumption, avoiding frequent start-stop of the electric centrifugal transfer pump 2 from the ethanol storage tank 1, which helps improve system stability.

[0042] The first pipeline 10 is equipped with a first pump body 41 and a first regulating valve 45. The first pump body 41 is used to pressurize the low-temperature ethanol fuel and deliver it to the first flow channel of the first heat exchanger 42 for heating and heat exchange. The first regulating valve 45 is used to adjust the flow rate of the low-temperature ethanol fuel entering the first flow channel by adjusting the opening of the valve.

[0043] The first heat exchanger 42 and the second heat exchanger 43 are connected by a second pipeline 11. The second heat exchanger 43 and the water glycol solution expansion tank 5 are connected by a third pipeline 12. The water glycol solution expansion tank 5 and the first heat exchanger 42 are connected by a fourth pipeline 13. The third pipeline 12 is equipped with a water glycol solution circulation pump 44 and a second regulating valve 46, forming a closed loop of "water glycol solution expansion tank 5 → water glycol solution circulation pump 44 → second heat exchanger 43 → first heat exchanger 42 → water glycol solution expansion tank 5". The glycol circulation pump 44 is an explosion-proof centrifugal pump.

[0044] The ethylene glycol solution in the water-glycol solution expansion tank 5 is pressurized by the ethylene glycol solution circulation pump 44 and delivered to the second heat exchanger 43 for heat exchange. The second regulating valve 46 is used to adjust the flow rate of the ethylene glycol solution entering the third flow channel by adjusting the valve opening.

[0045] For the ethanol storage tank 1, the ethanol storage tank 1 is a structurally sealed tank, made of Q345R low carbon steel, and the inner wall is coated with a polytetrafluoroethylene corrosion-resistant coating to prevent the ethanol added from chemically corroding the tank.

[0046] An oil suction well is set in the center of the bottom of the ethanol storage tank 1, and the bottom of the tank is sloped at 3°~8° towards the oil suction well to ensure that the ethanol fuel in the tank can be completely collected to the oil suction well by gravity, so as to minimize the residue of ethanol fuel and control the residue to below 0.5%.

[0047] The ethanol storage tank 1 is equipped with a first liquid level sensor, a first temperature sensor, and a first pressure sensor, which are used to detect the liquid level, temperature, and pressure of the fuel inside the ethanol storage tank 1, respectively. These sensors are connected to the electrical control unit 6 via cables and transmit the detected data to the electrical control unit 6 in real time. When the liquid level, temperature, or pressure is too low or too high, the electrical control unit 6 triggers an alarm.

[0048] As a specific example of this application, the electric centrifugal transfer pump 2 has a head of 20~30m, a protection level of IP54, and the motor is equipped with a frequency converter.

[0049] The electric centrifugal transfer pump 2 is bolted to the fixed pump compartment of the ethanol storage tank 1. Its input end is connected to the bottom of the suction well via a seamless steel pipe, and its output end is connected to the ethanol fuel day tank 3 via a seamless steel pipe. To prevent heat loss, the seamless steel pipe is covered with an insulation layer.

[0050] The seamless steel pipe is equipped with a manual shut-off valve, an emergency pneumatic shut-off valve, an electromagnetic flowmeter, and a check valve. The electromagnetic flowmeter is electrically connected to the electrical control unit 6 for real-time monitoring of the transport flow. The check valve is used to prevent fuel backflow, the manual shut-off valve is used to cut off the pipeline during maintenance, and the emergency pneumatic shut-off valve is used to automatically cut off the ethanol supply pipeline in emergency situations such as leaks during normal operation.

[0051] The volume of the ethanol fuel day tank 3 is determined based on the ethanol supply volume of different ship types. The inner wall of the ethanol fuel day tank 3 is coated with a corrosion-resistant coating, and a breather valve, a second liquid level sensor, a second temperature sensor, and a second pressure sensor are installed at the top. These sensors are electrically connected to the electrical control unit 6, providing data support for the control of the electric centrifugal transfer pump 2, and simultaneously monitoring the liquid level, temperature, and pressure data of the ethanol fuel day tank 3. A drain valve is installed at the bottom of the ethanol fuel day tank 3.

[0052] When the liquid level in the ethanol fuel daily use tank 3 is below 30%, start the electric centrifugal transfer pump 2 and adjust it to its rated speed. When the liquid level in the ethanol fuel daily use tank 3 reaches 80%, reduce the speed of the electric centrifugal transfer pump 2 to 10~15% of the rated speed, maintain a small flow rate for feeding, and avoid frequent start-stop.

[0053] The ethanol fuel supply unit 4 is located in the ship's fuel preparation room, has good ventilation, and is equipped with explosion-proof equipment.

[0054] As a specific example of this application, the first pump body 41 is a magnetic centrifugal supply pump. The magnetic centrifugal supply pump is a magnetically coupled leak-free centrifugal pump, and its motor is frequency-controlled. The output pressure can be adjusted according to the needs of downstream consumption units. The magnetic coupling design avoids the risk of mechanical seal leakage and better adapts to the volatile characteristics of ethanol fuel.

[0055] A third pressure sensor is installed in the outlet pipe of the first pump body 41. The third pressure sensor is electrically connected to the electrical control unit 6. Based on the data of the third pressure sensor, the pump speed is adjusted in real time by the frequency converter to ensure that the outlet pressure is stable at the set value.

[0056] The first heat exchanger 42 is made of 316L stainless steel. A fourth temperature sensor and a fourth pressure sensor are installed at the outlet end of the first flow channel. The fourth temperature sensor is used to detect the temperature of the ethanol fuel entering the ethanol consumption unit 7 in real time, and the fourth pressure sensor is used to detect the pressure of the ethanol fuel entering the ethanol consumption unit 7 in real time. The inlet end of the first flow channel of the first heat exchanger 42 is connected to the outlet end of the first pump body 41, and the inlet end of the second flow channel is connected to the outlet end of the third flow channel.

[0057] The second heat exchanger 43 is made of 316L stainless steel. The inlet end of the third flow channel is connected to the output end of the water glycol solution circulation pump 44, and the inlet end of the fourth flow channel is connected to the water source inlet 8 through the fifth pipe 14. The electrical control unit 6 controls the opening degree of the second regulating valve 46 and the rotation speed of the water glycol solution circulation pump 44 based on the real-time temperature data T detected by the fourth temperature sensor at the outlet end of the first flow channel.

[0058] The volume of the water-glycol solution expansion tank 5 needs to be determined according to the size of the supply system, and the material is 304 stainless steel. The top is equipped with a filling port 15 with a threaded cap, a safety valve, and a sixth liquid level sensor, while the bottom is equipped with a drain valve. The sixth liquid level sensor is connected to the electrical control unit 6. When the liquid level in the water-glycol solution expansion tank 5 is too low, the electrical control unit 6 issues a replenishment warning via an audible and visual alarm.

[0059] The electrical control unit 6 is the intelligent control core of the marine ethanol fuel supply system. It can be installed in the control cabinet of the ship's control room and includes a central controller. It has digital inputs, digital outputs, analog inputs, and analog outputs, supports ship-related communication protocols, data acquisition modules, execution control modules, alarm modules (including audible and visual alarms, alarm indicator lights, and alarm relays), and a human-machine interface. All modules are connected to the central controller via a backplane bus to form a unified control network.

[0060] The central controller has a built-in control program written based on the PLCopen motion control standard. It includes a data processing module, a logic judgment module, a parameter adjustment module, and a fault diagnosis module, and has four core functions: data processing, logic judgment, parameter adjustment, and fault diagnosis.

[0061] The data processing module is used to implement data processing functions. It receives signals from various sensors (including liquid level, temperature, pressure, and flow rate) transmitted by the data acquisition module in real time through the electrical control unit 6, eliminates signal fluctuations caused by ship turbulence through digital filtering algorithms, converts the processed parameters into physical quantities, and stores them in the internal register of the central controller.

[0062] The logic judgment module is used to implement the logic judgment function. It is based on multiple sets of control logic preset by the electrical control unit 6, including normal operation logic, emergency switching logic, and maintenance mode logic.

[0063] The maintenance mode logic allows for individual control of a pump or valve's start / stop after a password is entered through the human-machine interface, facilitating equipment maintenance and debugging. During this time, the marine ethanol fuel supply system automatically shuts off or switches to emergency mode to prevent accidental triggering. Password entry allows for tiered access control, categorized into operator and administrator levels.

[0064] The parameter adjustment module supports PID (proportional-integral-derivative) closed-loop control, and sets independent PID controllers for the pressure at the outlet of the first pump body 41 and the ethanol temperature at the outlet of the first heat exchanger 42, including a pressure PID controller and a temperature PID controller.

[0065] The fault diagnosis function has three types of diagnostic capabilities: sensor faults, pump body faults, and pipeline faults.

[0066] The sensor fault diagnosis is performed when any sensor signal exceeds the measurement range for 10-12 seconds or when the signal fluctuation exceeds 10-15 seconds. If this occurs, a sensor fault is identified, and the electrical control unit 6 issues a "sensor abnormality" alarm. The unit automatically uses historical data from adjacent time points as a temporary replacement to maintain the basic operation of the supply system. The historical data from adjacent time points refers to the average of the sensor fault occurrence time and 4-5 adjacent data sets.

[0067] The pump body fault diagnosis is performed by detecting the pump motor current and speed feedback signals. If the current exceeds 120% of the rated current for 10-12 seconds, or if the real-time speed deviates from the set speed by more than ±10%, a pump body fault is determined. The electrical control unit 6 issues a "pump body abnormality" alarm and automatically triggers emergency switching or automatic switching to the standby pump. Automatic switching to the standby pump requires that a standby pump be configured in the supply system.

[0068] The pipeline fault diagnosis is performed by comparing the outlet flow rate of the electric centrifugal transfer pump 2 with the change in the liquid level of the ethanol fuel daily use tank 3, or by detecting the pressure difference between the inlet and outlet of either the first heat exchanger 42 or the second heat exchanger 43, to determine whether the pipeline is blocked or leaking. If the pipeline is determined to be blocked or leaking, the electrical control unit 6 issues a "pipeline abnormality" alarm and shuts down the relevant pumps to prevent the fault from escalating.

[0069] The operation control method for the marine ethanol fuel supply system of this application includes the following steps:

[0070] S1. Electrical control unit 6 first performs a self-test;

[0071] Specifically, in step S1, the self-test is passed if all sensors, pumps, and valves are functioning properly.

[0072] S2. After the self-test is passed, the central controller sends a start command to the water glycol solution circulation pump 44. After the water glycol solution entering the second heat exchanger 43 is stable, the first pump body 41 is started and the pressure of the low-temperature ethanol fuel entering the first heat exchanger 42 is adjusted to the required pressure.

[0073] Specifically, in step S2, the pressure of the cryogenic ethanol fuel entering the first heat exchanger 42 is controlled by adjusting the rotational speed of the first pump body 41. The required pressure is determined empirically by those skilled in the art, taking into account the capacity of the ethanol storage tank 1 and the load of the ship's main engine.

[0074] S3. Real-time detection and acquisition of detection data from each sensor;

[0075] S4. Determine whether the real-time temperature data T detected by the fourth temperature sensor is greater than A. If yes, proceed to step S5; otherwise, proceed to step S7.

[0076] S5. Determine whether the real-time temperature data T detected by the fourth temperature sensor satisfies A < T < B. If yes, the second regulating valve 46 maintains its current opening and the water glycol solution circulation pump 44 maintains its current speed. If no, proceed to step S6.

[0077] S6. Reduce the opening of the second regulating valve 46 and the speed of the water glycol solution circulation pump 44;

[0078] S7. Determine whether the load on the ship's main engine has increased. If so, increase the speed of the first pump body 41 and the opening of the first regulating valve 45. At the same time, increase the opening of the second regulating valve 46 and the speed of the water glycol solution circulation pump 44. If not, only increase the opening of the second regulating valve 46 and the speed of the water glycol solution circulation pump 44.

[0079] Specifically, in step S5, the real-time temperature data T detected by the fourth temperature sensor satisfies A < T < B, indicating that the ethanol fuel after heat exchange meets the operating temperature of the ethanol consumption unit 7. In this case, the second regulating valve 46 maintains its current opening, and the water glycol solution circulation pump 44 maintains its current speed, without the need for adjustment.

[0080] In step S6, the real-time temperature data T≥B detected by the fourth temperature sensor indicates that the temperature of the ethanol entering the ethanol consumption unit 7 is high. Therefore, it is necessary to reduce the opening of the second regulating valve 46 and the speed of the water glycol solution circulation pump 44 to reduce the flow rate of the water glycol solution entering the second heat exchanger 43, thereby reducing the temperature of the ethanol fuel after heat exchange and avoiding excessive temperature.

[0081] Normally, in step S6, the opening of the second regulating valve 46 is reduced to 10-50% of the current opening, and the speed of the water glycol solution circulation pump 44 is reduced to 5-20% of the current speed.

[0082] In step S7, the real-time temperature data T≤A detected by the fourth temperature sensor indicates that the temperature of the ethanol entering the ethanol consumption unit 7 is low. However, it is still necessary to determine the control measures based on the specific circumstances. This application considers the load of the ship's main engine. When T≤A, it is first determined whether the load of the ship's main engine has increased. If so, it indicates that the ship's sailing temperature has decreased, for example, the ship has entered a low-temperature sea area, which has also caused the ambient temperature of the ethanol storage tank 1 to decrease. It is necessary to increase the speed of the first pump body 41 and the opening of the first regulating valve 45 to increase the pressure and flow rate of the low-temperature ethanol fuel entering the heat exchanger. At the same time, the opening of the second regulating valve 46 and the speed of the water glycol solution circulation pump 44 are increased to allow more water glycol solution to enter and participate in heat exchange. These two measures work together to ensure that the supply pressure and temperature of the ethanol fuel are synchronously adapted to the changes in the load of the ship's main engine and to increase the temperature of the ethanol entering the ethanol consumption unit 7.

[0083] When T ≤ A, if the load on the ship's main engine does not increase, maintaining the current speed of the first pump 41 and the opening of the first regulating valve 45 requires increasing the opening of the second regulating valve 46 and the speed of the water-glycol solution circulation pump 44. In other words, under these conditions, the lower temperature of the ethanol can be compensated simply by increasing the pressure and flow rate of the water-glycol solution entering the second heat exchanger 43, allowing the faster-flowing and higher-volume water-glycol solution to participate in the heat exchange reaction.

[0084] Normally, in step S7, the rotation speed of the first pump body 41 and the water glycol solution circulation pump 44 is increased to 1 to 1.2 times the current rotation speed, and the opening degree of the first regulating valve 45 and the second regulating valve 46 is increased to 1 to 1.5 times the current opening degree.

[0085] As a specific example of this application, when the received load signal of the ship's main engine control system increases from 4mA (maximum 20mA), it indicates that the load of the ship's main engine has increased.

[0086] As a specific example of this application, A=30±2℃, B=45±2℃.

[0087] During the operation of the supply system, steps S3 to S7 need to be repeated.

[0088] When the supply system is shut down normally, first turn off the electric centrifugal transfer pump 2. After the liquid level in the ethanol fuel daily use tank 3 drops below 10%, turn off the first pump body 41, and finally turn off the water glycol solution circulation pump 44. At the same time, open the drain valves of each pipeline to discharge the residual ethanol fuel and water glycol solution. In case of emergency shutdown due to malfunction, immediately cut off the power to all pump bodies, close the first regulating valve 45 and the second regulating valve 46, and open the emergency pressure relief valve installed on the fourth pipeline 13 to prevent pipeline overpressure damage.

[0089] The marine ethanol fuel supply system of this application adopts the above-mentioned operation control method, and through reasonable regulation, ensures that the temperature of the ethanol fuel entering the ethanol consumption unit 7 meets the requirements.

[0090] The control program of this application supports online monitoring and offline modification, and has four major functions: parameter setting, status monitoring, fault recording, and report generation.

[0091] The parameter setting function allows administrators to modify various control parameters (such as liquid level threshold, temperature setpoint, PID parameters, and alarm delay time) through a human-machine interface. After modification, a password must be entered for confirmation. Parameter modification records are automatically stored, allowing for the tracing of nearly 100 modification records.

[0092] The status monitoring function displays a real-time system overview screen on a touchscreen (including the operating status of each unit, key parameter values, and dynamic simulation of pipeline fluid flow). It supports viewing multiple screens (tank screen, pump screen, heat exchanger screen, and electrical control screen). When parameters exceed limits or equipment malfunctions, the corresponding screen will automatically pop up and flash to indicate the problem.

[0093] The fault recording function can automatically record the time of fault occurrence, fault type, and parameter values ​​at the time of fault (such as liquid level, temperature, and pressure at the time of fault). Fault records can be queried by time (supporting daily and monthly queries) and can also be exported to Excel format via USB flash drive for easy fault analysis.

[0094] The report generation function automatically generates daily operation reports, which include statistics on ethanol fuel consumption (calculated based on the cumulative flow of the electromagnetic flowmeter), water glycol solution replenishment, operating time of each pump, and number of malfunctions. The reports can be automatically stored or manually printed.

[0095] The human-computer interaction design includes a touchscreen that can use both Chinese and English interfaces. The interface layout is divided into a title bar (displaying the system name, current time, and login permissions), a navigation bar (containing entrances to various function screens), a main display area (displaying the current screen content), and an alarm bar (displaying real-time alarm information). Operation permissions are divided into operator level (can view status, start and stop equipment, but cannot modify parameters) and administrator level (can modify parameters, view historical data, and perform system settings). A corresponding password is required to log in (a password change is required for first login). Alarm information is divided into emergency alarms (such as fuel interruption or pipeline overpressure, displayed in red with audible and visual alarms), important alarms (such as sensor malfunction or pump overload, displayed in yellow), and general alarms (such as low liquid level or temperature deviation, displayed in blue). Emergency alarms require manual confirmation to be cleared, while other alarms are automatically cleared after the fault is resolved.

[0096] The key sensors in this application, such as the first liquid level sensor installed inside the ethanol storage tank 1 and the third pressure sensor installed on the outlet pipeline of the first pump body 41, adopt a dual-sensor redundancy configuration. When the main sensor fails, it automatically switches to the backup sensor to ensure uninterrupted data acquisition. The central controller is powered by a dual-path power supply (one path is the ship's main power supply, and the other is an emergency power supply). When the main power supply is interrupted, the emergency power supply (using a 24V battery pack with a capacity of 100Ah) can maintain the controller's operation for ≥4 hours.

[0097] The control cabinet in this application adopts an IP54 protection rating. The cabinet shell is made of 304 stainless steel with a thickness of 2mm. An internal temperature and humidity controller is installed to control the temperature from 0℃ to 50℃ and the humidity from 40% to 80%. When the internal temperature exceeds 40℃, the cooling fan (airflow 200m³ / h) automatically starts; when the humidity exceeds 70%, the dehumidifier (dehumidification capacity 10L / 24h) automatically starts, ensuring stable operation of the module in the high temperature, high humidity, and salt spray environment of the ship (design life ≥ 10 years, mean time between failures (MTBF) ≥ 5000h).

[0098] The reliability of the marine ethanol fuel supply system and operation control method of this application is ensured through redundant design and environmental adaptation design.

[0099] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A marine ethanol fuel supply system comprising an ethanol storage tank (1), an ethanol fuel supply unit (4), a water glycol solution expansion water tank (5) and an electrical control unit (6), characterized in that, The ethanol fuel supply unit (4) comprises at least a first heat exchanger (42) and a second heat exchanger (43), the first heat exchanger (42) is provided with a first flow channel and a second flow channel which are not communicated with each other, the inlet end of the first flow channel is connected with the ethanol storage tank (1), the outlet end of the first flow channel is connected with the ethanol consumption unit (7), the inlet end of the second flow channel is connected with the second heat exchanger (43), the outlet end of the second flow channel is connected with the water glycol solution expansion water tank (5), the second heat exchanger (43) is provided with a third flow channel and a fourth flow channel which are not communicated with each other, the inlet end of the third flow channel is connected with the water glycol solution expansion water tank (5), the outlet end of the third flow channel is connected with the first heat exchanger (42), the inlet end of the fourth flow channel is connected with the water source inlet (8), and the outlet end of the fourth flow channel is connected with the water source outlet (9).

2. The marine ethanol fuel supply system according to claim 1, characterized in that, The ethanol storage tank (1) is connected with the electric centrifugal transfer pump (2).

3. The marine ethanol fuel supply system according to claim 2, wherein The ethanol storage tank (1) is connected with the first heat exchanger (42) through the ethanol fuel daily cabin (3), the input end of the ethanol fuel daily cabin (3) is connected with the output end of the electric centrifugal transfer pump (2), and the output end of the ethanol fuel daily cabin (3) is connected with the first heat exchanger (42) through the first pipeline (10).

4. The marine ethanol fuel supply system according to claim 3, wherein The first pipeline (10) is provided with a first pump body (41) and a first adjusting valve (45).

5. The marine ethanol fuel supply system according to claim 1, wherein The first heat exchanger (42) and the second heat exchanger (43) are connected through the second pipeline (11), the second heat exchanger (43) and the water glycol solution expansion water tank (5) are connected through the third pipeline (12), the water glycol solution expansion water tank (5) and the first heat exchanger (42) are connected through the fourth pipeline (13), and the third pipeline (12) is provided with a water glycol solution circulating pump (44) and a second adjusting valve (46).

6. The marine ethanol fuel supply system of claim 1, wherein, The inner bottom of the ethanol storage tank (1) is provided with an oil suction well, and the tank body bottom is provided with a slope of 3°-8° towards the oil suction well.

7. The marine ethanol fuel supply system of claim 1, wherein, The outlet end of the first flow channel is provided with a fourth temperature sensor and a fourth pressure sensor.

8. A method of operating a marine ethanol fuel supply system as claimed in any one of claims 1 to 7, characterised by, The operation control method comprises the following steps: S1. The electric control unit (6) is self-checked first; S2. After the self-checking is passed, the central controller sends a starting instruction to the water glycol solution circulating pump (44), the first pump body (41) is started after the water glycol solution in the second heat exchanger (43) is stabilized, and the pressure of the low-temperature ethanol fuel entering the first heat exchanger (42) is adjusted to the required pressure; S3. The detection data of each sensor is detected and acquired in real time; S4. Whether the real-time temperature data T detected by the fourth temperature sensor is greater than A is judged, if yes, step S5 is executed, and if no, step S7 is executed; S5. Whether the real-time temperature data T detected by the fourth temperature sensor meets A S6. The opening degree of the second adjusting valve (46) and the rotating speed of the water glycol solution circulating pump (44) are reduced; S7. Determine whether the ship's main engine load is increased, if yes, increase the first pump body (41) speed and the first regulating valve (45) opening, at the same time, increase the second regulating valve (46) opening and water glycol solution circulating pump (44) speed; if not, only need to increase the second regulating valve (46) opening and water glycol solution circulating pump (44) speed.

9. The operation control method according to claim 8, characterized by, Said A = 30 ± 2 ℃, said B = 45 ± 2 ℃.

10. The operation control method according to claim 8, characterized by When the supply system is normal shutdown, first close the electric centrifugal pump (2), then close the first pump body (41), and finally close the water glycol solution circulating pump (44), while opening the pipeline drain valve to discharge the residual ethanol fuel and water glycol solution. If emergency shutdown due to failure, immediately cut off the power of all pump bodies, close the first regulating valve (45) and the second regulating valve (46), and open the emergency relief valve set on the fourth pipeline (13) to prevent pipeline overpressure damage.

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