Automatic exhaust system suitable for ship oil-water exchange tank and use method

Abstract

The present invention belongs to the field of ships and discloses an automatic exhaust system suitable for oil-water exchange tanks on ships. The system includes a medium sensor for detecting the type of medium discharged from the tank; a control box electrically connected to the medium sensor for receiving and processing the medium type signal output by the medium sensor; and an electric valve for controlling the on / off flow of medium from the tank. The control box controls the on / off flow of the electric valve based on the signal transmitted by the medium sensor. The medium sensor precisely controls the closing time of the electric valve, thereby reducing residual air in the top of the exchange tank.

Description

Technical Field

[0001] The invention belongs to the field of ships and relates to an automatic exhaust system suitable for an oil-water exchange tank of a ship. Background Art

[0002] Space utilization, stability, and endurance are important indicators of a ship's overall performance. To maintain and improve stability, ships typically have ballast tanks. For navigational purposes, fuel tanks and other compartments for carrying consumable liquids are also required. The use of ballast tanks takes up a certain amount of ship space, limiting the amount of fuel a ship can carry, thus affecting its endurance. As fuel is consumed, the ship's center of gravity shifts, potentially exposing ship stability issues. Therefore, a ship's space utilization, stability, and endurance are in a mutually restrictive and conflicting relationship. The use of an oil-water exchange system in ships is an effective technical means of resolving this contradiction.

[0003] Oil-water exchange means that during the fuel consumption process, the ship continuously injects an equal amount of seawater into the bottom of the fuel tank, so that the liquid load of the ship basically does not decrease with the fuel consumption, and ultimately maintains the overall stability without decreasing with the fuel consumption. At the same time, compared with the traditional fuel tank system, the use of the oil-water exchange system can also reduce the free liquid surface above the fuel and ballast tank, reduce the oil and gas mixing space above the fuel tank, and improve the stability and navigation safety performance of the ship.

[0004] The fuel replacement system mainly includes expansion tank, fuel replacement tank, fuel collection tank and receiving tank. Functions of each tank:

[0005] (1) Expansion tank: A compartment that holds seawater. When the system is operating, seawater first enters the expansion tank. In an open system, there is a certain height difference between the expansion tank and the replacement tank. At this time, the seawater entering the expansion tank flows into the replacement tank by gravity to replace the fuel oil. In a closed system, this height difference is not necessarily required. The replacement power can be provided by a seawater pump. In order to maintain a constant water level in the expansion tank, an overflow port is provided in the expansion tank.

[0006] (2) Fuel exchange tank: Before the system is operational, the fuel exchange tank is used to store fuel. After the system is put into operation, seawater from the expansion tank is injected into this tank to replace the fuel consumed by the power system. This type of tank is initially filled with fuel and gradually fills with seawater as the exchange proceeds.

[0007] (3) Fuel Oil Aggregation Tank: After the fuel oil from the replacement tank enters the aggregation tank, it is separated from the seawater by sedimentation due to the difference in specific gravity between the fuel oil and seawater. When the system is in operation, the fuel oil from each replacement tank first enters this tank to precipitate and separate the seawater that may be mixed with the fuel oil. The separated fuel oil is then sent to the daily fuel oil tank. To ensure the safety of the system, seawater cannot be replaced by water in this tank.

[0008] (4) Receiving tank: The fuel in the gathering tank enters the receiving tank and is then transferred to the daily fuel tank. The receiving tank can also be used as an injection tank when adding fuel.

[0009] According to the power source of the oil-water replacement system, it is divided into open and closed systems.

[0010] (1) Open system: During the replacement process, the vent valve of the expansion tank is in the open state, and the replacement pipeline uses the height difference between the liquid level in the expansion tank and the liquid level in the replacement tank to achieve oil-water replacement.

[0011] (2) Closed system: During the closed expansion chamber replacement process, the expansion chamber vent valve is in a closed state, and the replacement pipeline uses the fluid pressure generated by the oil-water replacement pump to achieve oil-water replacement.

[0012] In a closed oil-water exchange system, control valves are installed on the vent pipes of the oil-water exchange expansion tank and the fuel accumulation tank. These valves must be closed during the exchange process to maintain stable fluid pressure generated by the exchange pump. Whether using manual or remote control valves, precise control of the closing time is difficult, which can lead to air remaining in the upper chamber. During a closed exchange process, the air layer within the chamber can easily lead to localized high pressure, creating the risk of a tank explosion and compromising system safety. Furthermore, the upper chamber's air layer can easily mix with the fuel, creating an oil-gas mixture that can easily cause explosions and fires.

[0013] Relevant journals and patents, such as "Analysis of Ship Intact Stability Based on Oil-Water Exchange System" by Zhang Xiangrui et al., published in the 5th issue of Ships in October 2009, and CN213200041U "A Ship Oil-Water Exchange System", all focus on the overall design of the ship oil-water exchange system, focusing on the cabin layout and the piping connection between cabins, that is, the open and closed design of the system and the series and parallel relationship of the piping between the expansion tank, exchange tank and fuel accumulation tank. None of the above-mentioned public documents involve the residual air exhaust structure or method of the closed system.

[0014] In addition to the above-mentioned public documents, patent CN217842229U is designed for an automatic exhaust valve, while patent CN117490291A is equipped with a refill tank, which is used as a transfer point to achieve rapid exhaust. The objects and systems they are aimed at are different from this solution.

[0015] Existing oil-water exchange systems primarily monitor the liquid level using a liquid level sensor installed within the exchange tank, which determines when to close the valve on the vent pipe. However, due to constraints during sensor installation, such as the tank structure, its mounting base, and the ship's posture, there exists an unmeasured dead zone. This prevents the air from being completely vented from the top of the expansion and exchange tanks, compromising system safety and stability. In the field of oil-water exchange systems, and more specifically, within the marine industry, there is currently no design for automatic venting of liquid tanks. This present invention represents a first. Summary of the Invention

[0016] In order to solve the above technical problems, the present invention provides an automatic exhaust system suitable for ship oil-water exchange tanks, which accurately controls the closing time of the electric valve through sensors, thereby reducing the residual air on the top of the exchange tank.

[0017] In order to achieve the above-mentioned object, as a first aspect of the present invention, the technical solution of the present invention is to provide an automatic exhaust system suitable for an oil-water exchange tank of a ship, comprising:

[0018] A medium sensor is used to detect the type of medium discharged from the cabin;

[0019] a control box, electrically connected to the media sensor, and receiving and processing a signal indicating the media type output by the media sensor;

[0020] Electric valve, controlling the on and off of the medium discharged from the cabin;

[0021] The control box controls the on and off of the electric valve according to the signal transmitted by the medium sensor.

[0022] According to the present invention, further, the electric valve is an electric butterfly valve.

[0023] According to the present invention, further, the installation position of the electric butterfly valve is higher than the highest point of the replacement pipeline of the cabin.

[0024] The present invention further includes a ventilation pipe connected to the cabin at one end. The medium sensor detects the type of medium flowing through the ventilation pipe, and the electric butterfly valve controls the opening and closing of the ventilation pipe. The medium passing through the ventilation pipe is either gas or non-gaseous. When the medium sensor detects that the medium in the ventilation pipe is non-gaseous, the control box receives a signal from the medium sensor and closes the electric butterfly valve. The sensor and electric butterfly valve are located on the ventilation pipe to further control residual exhaust and improve exhaust efficiency.

[0025] According to the present invention, further, the end section of the vent pipeline is connected to an overflow pipeline provided with an electric overflow valve.

[0026] According to the present invention, further, the electric overflow valve is arranged behind the electric butterfly valve; the residual liquid in the air vent pipe behind the electric butterfly valve is discharged to the sewage collection well through the overflow pipe.

[0027] According to the present invention, further, a float-type automatic exhaust valve is provided on the ventilation pipeline.

[0028] According to the present invention, further, an overflow observation mirror is included to judge the liquid level and manually close the electric butterfly valve.

[0029] As a second aspect of the present invention, a method for using an automatic exhaust system for an oil-water exchange tank of a ship is provided, comprising the following steps:

[0030] The electric butterfly valves of all cabins are in the open state, the replacement begins, the liquid level in the cabin rises, and the medium sensor transmits the "air" signal to the medium signal acquisition module in the control box;

[0031] As the replacement continues, the medium in the ventilation pipeline changes from air to liquid. At this time, the medium sensor transmits a "liquid" signal to the medium signal acquisition module in the control box, and the control box outputs a switch quantity to control the electric butterfly valve to close. As the replacement continues, the remaining small amount of air is discharged to the atmosphere through the float exhaust valve.

[0032] The electric overflow valve of the overflow pipeline is controlled by the control box to open, so that the residual liquid in the pipe section behind the electric butterfly valve is discharged to the sewage collection well through the overflow pipeline.

[0033] Furthermore, if the sensor fails, the liquid level is observed through the overflow sight glass and the electric butterfly valve is manually closed.

[0034] The beneficial effects of the present invention are:

[0035] 1. The present invention combines the characteristics of the closed oil-water exchange process to add an automatic exhaust device, which solves the problem of air residue during the exhaust process and prevents the occurrence of problems such as cabin explosion and oil-gas mixing.

[0036] 2. The present invention can effectively improve the reliability and safety of the oil-water replacement system, and is of great significance to the promotion and application of the oil-water replacement system.

[0037] 3. In order to ensure that the automatic exhaust system can still work stably in the event of sensor failure, the present invention provides an overflow observation mirror at the highest point of the replacement pipeline. At this time, the corresponding valve can be manually closed according to the observation situation, thereby increasing the operability of the present invention and thus improving the working stability of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic diagram of the automatic exhaust device of the closed oil-water replacement system of the present invention;

[0039] Figure 2 This is a reference diagram of a scaled model of the oil-water substitution system of the present invention;

[0040] Figure 3 This is a schematic diagram of the pipeline connections of each cabin of the oil-water replacement system of the present invention.

[0041] 1- Medium sensor, 2- Electric butterfly valve, 3- Float type exhaust valve, 4- Overflow observation mirror, 5- Control box, 6- Electric overflow valve, 7- Cabin, 71- Replacement injection pipeline, 72- Replacement discharge pipeline, 8- Ventilation pipeline, 9- Overflow pipeline. DETAILED DESCRIPTION

[0042] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0043] The embodiment of the present application discloses an automatic exhaust system for oil-water exchange tanks on ships, which is applicable to the cabins of the oil-water exchange system. The cabins are divided into expansion cabins, exchange cabins, and fuel collection cabins according to their functions. The fuel collection cabin is a conventional cabin without special structural design. Figure 3 shown.

[0044] The automatic exhaust system is connected to the cabin 7 and is used to exhaust the air inside the cabin 7. The cabin 7 includes an expansion cabin and a replacement cabin connected thereto. The expansion cabin is connected to a replacement injection pipeline 71, and the replacement cabin is connected to a replacement discharge pipeline 72. The automatic exhaust system includes a medium sensor 1, an electric butterfly valve 2, a float exhaust valve 3, an overflow observation mirror 4, a control box 5, and an electric overflow valve 6. Figure 1 As shown in the figure, during the oil-water exchange process, seawater enters the expansion chamber through the inlet and is discharged from the seawater outlet into the exchange chamber as the liquid level rises, providing power for the exchange process. During the oil-water exchange system commissioning process, the air inside the chamber must be completely purged to prevent localized high pressure from developing during the exchange process. However, due to space limitations, the liquid level sensor typically installed inside the chamber has a blind spot at the top, making it difficult to accurately measure the liquid level within the chamber, which in turn prevents the air from being completely purged. To address this issue, a medium sensor 1 is installed on the vent pipe 8 connected to the chamber 7 to determine whether the medium in the vent pipe is liquid or gas. During the commissioning process, seawater is first injected into the expansion chamber at a low flow rate to initiate the venting process. Initially, the medium in the vent pipe is air. As seawater is continuously injected, the air is completely purged and the medium in the vent pipe becomes liquid. The signal from sensor 1 is transmitted via RS485 to the medium signal acquisition module in the control box 5. When the sensor signal switches to liquid, the control box 5 outputs a switching value to control the closing of the electric butterfly valve 2 installed on the vent pipe, completing the initial venting process.

[0045] Due to the swaying and posture problems of the ship, it is often difficult to completely exhaust the air through the initial exhaust. At this time, the remaining small amount of air is automatically discharged through the float-type automatic exhaust valve 3 set on the ventilation pipeline 8.

[0046] If the medium sensor 1 fails, the liquid level can still be judged by the overflow sight glass 4 provided in the automatic exhaust system and the system can be closed manually, thereby improving the operability of the automatic exhaust system.

[0047] To prevent liquid from being discharged from the end of the vent line 8 due to initial replacement pump flow fluctuations, an overflow line 9 equipped with an electric overflow valve 6 is connected to the end of the vent line 8. The end of the overflow line 9 is located in the sewage collection well. The electric overflow valve 6 is installed after the electric butterfly valve 2. Residual liquid in the pipe section after the electric butterfly valve 2 can be discharged to the sewage collection well through the overflow line 9. The electric butterfly valve 2 should be installed above the highest point of the replacement line in this cabin.

[0048] The working process of the present invention is:

[0049] 1. The electric butterfly valves 2 of all cabins are in the open state, the replacement begins, and the liquid level in the cabin rises. At this time, the medium sensor 1 transmits the "air" signal to the medium signal acquisition module in the control box 5;

[0050] 2. The replacement continues, and the medium in the ventilation pipe 8 is converted from air to liquid. At this time, the medium sensor 1 transmits a "liquid" signal to the medium signal acquisition module in the control box 5. The control box 5 outputs a switching value to control the electric butterfly valve 2 to close;

[0051] 3. As the replacement continues, a small amount of remaining air is discharged to the atmosphere through the float-type exhaust valve 3; the electric overflow valve 6 of the overflow pipe 9 is controlled by the control box 5 to open, so that the residual liquid in the pipe section after the electric butterfly valve 2 is discharged to the sewage collection well through the overflow pipe;

[0052] 4. If the sensor 1 fails, the liquid level can be observed through the overflow sight glass 4 installed on the vent pipe 8, and the electric butterfly valve 2 can be closed manually.

[0053] Comparative Example 1: Figure 2 As shown, a closed-loop replacement system replacement test was conducted using a scaled-down replacement system model. Automatic venting was not configured during the test. A magnetic flap level gauge was installed outside the chamber to monitor the liquid level. When the liquid level reached 100%, the valve on the vent pipe was manually closed, halting the replacement. The liquid level inside the chamber was then measured using a depth gauge. Three tests were conducted, with air layers at the top of the replacement chamber at heights of 13 mm, 10 mm, and 12 mm, respectively.

[0054] Comparative Example 2: A closed-loop replacement system replacement test was conducted using a scaled-down replacement system model. Automatic venting was not configured. A side-mounted liquid level sensor was installed outside the chamber to monitor the liquid level (100 mm from the top, as per sensor installation requirements). When the liquid level reached 100%, the valve on the vent pipe was manually closed, halting the replacement. The liquid level inside the chamber was then measured using a depth gauge. Three tests were conducted, with air layers at the top of the replacement chamber at heights of 93 mm, 92 mm, and 96 mm, respectively.

[0055] Comparative Example 3: A closed-loop replacement system replacement test was conducted using a scaled-down replacement system model. Automatic venting was not configured. A top-mounted liquid level sensor was installed outside the chamber to monitor the liquid level. When the liquid level reached 100%, the valve on the vent pipe was manually closed, halting the replacement. The liquid level inside the chamber was then measured using a depth gauge. Three tests were conducted, with air layers at the top of the replacement chamber at heights of 8mm, 8mm, and 9mm, respectively.

[0056] Example 1: A closed-loop replacement system replacement test was conducted using a scaled-down replacement system model. The automatic exhaust device described in this patent was configured, and no external sensors were installed to monitor the liquid level. The liquid level inside the chamber was then measured using a depth gauge. Three tests were conducted, and no air layer was observed on the top of the replacement chamber.

[0057] Effects of the present invention: By comparing Examples 1-3 with Example 1, by setting a medium sensor, it is ensured that the cabin is basically in a full state when the solenoid valve is closed. At the same time, by setting a float exhaust valve, a small amount of residual air is further discharged. By setting an overflow observation mirror, it is ensured that the device can still be used after the sensor fails. By setting an overflow pipeline, it is ensured that there is no liquid residue at the rear end of the solenoid valve.

[0058] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form or substance. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the present invention, and these improvements and supplements should also be regarded as the scope of protection of the present invention. Any equivalent changes, modifications and evolutions made by technicians familiar with this profession without departing from the spirit and scope of the present invention by using the technical content disclosed above are all equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An automatic exhaust system suitable for ship oil-water exchange tanks, characterized in that: include: A medium sensor is used to detect the type of medium discharged from the cabin; a control box, electrically connected to the media sensor, and receiving and processing a signal indicating the media type output by the media sensor; An electric valve controls the on / off of the medium discharged from the cabin; the electric valve is installed at a position higher than the highest point of the replacement pipeline of the cabin; The control box controls the on and off of the electric valve according to the signal transmitted by the medium sensor; It also includes a ventilation pipeline with one end connected to the cabin, the medium sensor detects the type of medium flowing through the ventilation pipeline, and the electric valve controls the on-off of the ventilation pipeline; The media passing through the breathable pipeline are gas and non-gas. When the medium sensor detects that the medium in the breathable pipeline is non-gas, the control box closes the electric valve after receiving the medium sensor signal.

2. The automatic exhaust system for an oil-water exchange tank of a ship according to claim 1, characterized in that: The electric valve is an electric butterfly valve.

3. The automatic exhaust system for an oil-water exchange tank of a ship according to claim 2, characterized in that: The end section of the ventilation pipeline is connected to an overflow pipeline provided with an electric overflow valve.

4. The automatic exhaust system for an oil-water exchange tank of a ship according to claim 3, characterized in that: The electric overflow valve is arranged behind the electric butterfly valve; the residual liquid in the air vent pipe behind the electric butterfly valve is discharged to the sewage collecting well through the overflow pipe.

5. The automatic exhaust system for an oil-water exchange tank of a ship according to claim 4, characterized in that: A float type automatic exhaust valve is arranged on the ventilation pipeline.

6. The automatic exhaust system for an oil-water exchange tank of a ship according to claim 5, characterized in that: It also includes an overflow sight glass to judge the liquid level and manually close the electric butterfly valve.

7. A method for using the automatic exhaust system for a ship's oil-water exchange tank according to claim 6, characterized in that: The following steps are included: The electric butterfly valves of all cabins are in the open state, the replacement begins, the liquid level in the cabin rises, and the medium sensor transmits the "air" signal to the medium signal acquisition module in the control box; As the replacement continues, the medium in the ventilation pipeline changes from air to liquid. At this time, the medium sensor transmits a "liquid" signal to the medium signal acquisition module in the control box. The control box outputs a switch value to control the electric butterfly valve to close. As the replacement continues, the remaining small amount of air is discharged to the atmosphere through the float exhaust valve. The electric overflow valve of the overflow pipeline is controlled by the control box to open, so that the residual liquid in the pipe section behind the electric butterfly valve is discharged to the sewage collection well through the overflow pipeline.

8. The method for using the automatic exhaust system for the oil-water exchange tank of a ship according to claim 7, characterized in that: If the sensor fails, observe the liquid level through the overflow sight glass and manually close the electric butterfly valve.

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