Multi-mode interlocking control system for wind machines and roll-on equipment at a ship roll-on area

Abstract

The application discloses a kind of ship roll-on / roll-off place fan and the multi-mode interlocking control system of roll-on / roll-off equipment, it is related to ship ventilation and roll-on / roll-off equipment linkage control technical field, including mode selection unit, according to received navigation state signal, ramp state signal, fan fault state signal and emergency bypass trigger signal, between economic mode, navigation mode, port mode, loading and unloading mode and emergency bypass mode switch, send operation instruction to other unit;Ventilation control unit controls fan start-stop, frequency, ventilation frequency and steering;Ramp state monitoring unit outputs ramp state signal;Roll-on / roll-off equipment management unit executes the power-on, power-off, start locking and unlocking of roll-on / roll-off equipment;Emergency bypass unit contains independent physical bypass device, for closing roll-on / roll-off equipment start loop when fan fails.The application realizes the intelligent interlocking control of ventilation and roll-on / roll-off equipment under different working conditions, and improves safety and operation efficiency.

Description

Technical Field

[0001] This invention relates to the field of ship ventilation and roll-on / roll-off equipment linkage control technology, and in particular to a multi-mode interlocking control system for ship roll-on / roll-off space fans and roll-on / roll-off equipment. Background Technology

[0002] Cargo holds (vehicle decks) on roll-on / roll-off (Ro-Ro) vessels (including car carriers, passenger Ro-Ro ships, and cargo Ro-Ro ships) are considered potentially explosive controlled non-hazardous areas, with the primary risk stemming from the accumulation of vehicle fuel vapors. The ventilation system in Ro-Ro spaces must meet the following basic requirements: ventilation capacity must provide at least 6 air changes per hour to maintain basic safety; if power is supplied to non-explosion-proof electrical equipment in the controlled non-hazardous area, the air change rate must reach 10 times per hour; during loading and unloading operations, due to frequent vehicle entry and exit and increased fuel vapor release caused by door openings, the air change rate typically needs to be increased to 20 times per hour.

[0003] In practical engineering, the ventilation systems of ro-ro ships often employ variable frequency speed-regulating fans, and are equipped with both supply fans and reversible exhaust fans (which can switch between supply and exhaust). Existing control technologies include: automatically determining the ventilation mode based on the opening status of midship doors, stern doors, or ramps; interlocking control of fans and fire dampers; remote control and multi-signal linkage through integrated control systems; and independent control of multiple deck zones, etc.

[0004] However, existing technologies for the linkage control of ventilation and roll-on / roll-off equipment still have the following technical problems: First, there is a lack of ventilation and equipment control modes during the berthing and waiting-for-operation phase. Between the ship's transition from navigation to loading / unloading, there is a berthing and waiting-for-operation phase. At this time, the ship is docked but has not yet begun formal loading / unloading, requiring personnel to enter the cargo hold to untie vehicle lashings, check cargo condition, and activate ramps, among other preparatory work. Current technology typically only sets up a navigation mode (10 times / hour) and a loading / unloading mode (20 times / hour): in navigation mode, roll-on / roll-off equipment is electrically locked and cannot be started; the loading / unloading mode requires ramps to be open and operates at high ventilation (20 times / hour), resulting in high energy consumption, and cannot be used if the ramps are not open. Operators are either restricted to working in navigation mode or directly switch to the high-energy-consuming loading / unloading mode, which is both inconvenient and uneconomical.

[0005] Second, the management of non-explosion-proof equipment in controlled non-hazardous areas is lax under the economic model. The economic model only maintains basic ventilation of 6 times per hour. According to regulations, non-explosion-proof electrical equipment cannot be used in controlled non-hazardous areas under this ventilation condition. Existing systems lack the ability to automatically identify the explosion-proof properties of roll-on / roll-off equipment, often adopting a "one-size-fits-all" strategy—either cutting off power to all equipment (including explosion-proof types), causing unnecessary interruptions to explosion-proof equipment; or leaving power on, creating a significant hidden danger of electrical sparks igniting flammable gases.

[0006] Third, the electrical locking mechanism is unreliable in navigation mode. Navigation mode requires ventilation of 10 times per hour, and roll-on / roll-off equipment can be powered on but should not be started to move. Existing solutions mostly rely on manual operation of mechanical locking pins, hanging warning signs, or operator self-discipline, which makes it very easy for the equipment to move unexpectedly during navigation due to forgetfulness, misoperation, or human error, causing safety accidents.

[0007] Fourth, the positive pressure risk caused by switching from exhaust to forced-flow ventilation during loading and unloading modes is not effectively controlled. Loading and unloading modes require high-intensity ventilation of 20 times per hour. To quickly dilute oil and gas, exhaust fans need to be switched to forced-flow fans, creating a fully supplied-airflow system with no exhaust. If this mode is switched to before the ramp is open, the cargo hold will experience a rapid pressure increase, leading to decreased ventilation efficiency, inability to expel harmful gases, additional loads on the bulkhead structure, and personnel being impacted by the positive pressure airflow. Current technology does not establish a mandatory pre-locking mechanism for the "exhaust-to-force-flow ventilation" mode, requiring that switching only be done after the ramp is open.

[0008] Fifth, the emergency operation issue of roll-on / roll-off equipment failing to start interlocked under abnormal operating conditions such as fan failure. When the fan system fails and cannot maintain normal ventilation, existing technology cannot supply power to the roll-on / roll-off equipment and unlock it without relying on the fan's operating signal. The existing "emergency overpass switch" is only used to forcibly start the fan or close the damper.

[0009] In summary, existing technologies suffer from several problems, including the lack of berthing modes, lax management of equipment in controlled non-dangerous areas, unreliable navigation locks, uncontrollable positive pressure risks during loading and unloading, and difficulties in emergency operations during wind turbine failures. Summary of the Invention

[0010] This invention provides a multi-mode interlocking control system for the fan and roll-on / roll-off equipment at a ship's roll-on / roll-off terminal, in order to overcome the aforementioned technical problems.

[0011] To achieve the above objectives, the technical solution of the present invention is as follows: A multi-mode interlocking control system for the fan and ro-ro equipment at a ship's ro-ro loading area includes: a mode selection unit, a ventilation control unit, a ramp status monitoring unit, a ro-ro equipment management unit, and an emergency bypass unit; The mode selection unit is used to switch the working mode according to the received ship navigation status signal, ramp status signal, fan fault status signal and emergency bypass trigger signal, using a preset multi-mode switching architecture that includes economic mode, navigation mode, berthing mode, loading and unloading mode and emergency bypass mode, and sends the corresponding working mode operation command to the ventilation control unit and roll-on / roll-off equipment management unit during the switching. The ventilation control unit includes a blower and a reversible fan, and is used to control the start and stop, operating frequency, number of air changes per unit time, and direction of the reversible fan according to the operation instructions of the corresponding working mode output by the mode selection unit. The ramp status monitoring unit includes a limit switch and an tilt sensor, which are used to monitor the opening status of the ramp in real time and output the ramp status signal. The roll-on / roll-off equipment management unit includes an explosion-proof and non-explosion-proof identification module and a positioning module, which are used to identify the explosion-proof attributes of the roll-on / roll-off equipment and its location in a controlled non-hazardous area, and to perform power-on, power-off, start-up locking and unlocking of the roll-on / roll-off equipment according to the current working mode. The emergency bypass unit includes an independent physical bypass device, which is used to close the starting circuit of the roll-on / roll-off equipment when the wind turbine fails and an emergency bypass mode operation command is received.

[0012] Furthermore, the ventilation control unit controls the start / stop, operating frequency, air exchange rate per unit time, and direction of rotation of the supply fan and reversible fan according to the operating mode command output by the mode selection unit, including: In the economic mode, the blower and the reversible blower are controlled to operate at a first frequency, the reversible blower is controlled to turn to exhaust, and the number of air changes per unit time is maintained. In the navigation mode and the berthing mode, the blower and the reversible blower are controlled to operate at a second frequency, the reversible blower is controlled to turn to exhaust, and the number of air exchanges per unit time is maintained. In the loading and unloading mode, the blower is controlled to operate at the third frequency, the reversible blower is controlled to switch to air supply, and the number of air changes per unit time is maintained.

[0013] Furthermore, the roll-on / roll-off equipment management unit executes power-on, power-off, start-up locking, or unlocking of the roll-on / roll-off equipment according to the current operating mode, including: In the economic mode, interlocked automatic power-off is performed on non-explosion-proof roll-on / roll-off equipment located in a controlled, non-hazardous area; In the navigation mode, non-explosion-proof roll-on / roll-off equipment located in a controlled, non-hazardous area remains powered on; In the docking mode, a drive signal is output to the hardware relay in the start-up circuit to energize the relay coil and close the normally open contact. At the same time, the start-up control circuit of the roll-on / roll-off equipment is activated, the electrical lock is released, and the roll-on / roll-off equipment is granted start-up permission. In the loading and unloading mode, the start-up permission of the roll-on / roll-off equipment remains unchanged; In the emergency bypass mode, the starting circuit of the roll-on / roll-off equipment is directly closed through the contacts of the physical bypass device, allowing for normal startup.

[0014] Furthermore, the ramp status monitoring unit outputs ramp status signals according to the working mode command output by the mode selection unit, including: In the economic mode and the navigation mode, the ramp status monitoring unit is in standby mode and outputs a ramp standby signal; In the berthing mode, the ramp status monitoring unit continuously monitors the ramp limit switch signal and the tilt sensor reading. When the ramp limit switch signal is 2 or the tilt sensor reading is greater than or equal to the preset value, the ramp opening signal is output. In the loading and unloading mode, the ramp limit switch signal and the tilt sensor reading are continuously monitored. When the ramp limit switch signal is detected to be 0 or the tilt sensor reading is less than the preset value, the delay timer T is triggered. If T reaches the specified time and the ramp status is not restored, the ramp closure signal is output.

[0015] Furthermore, the mode selection unit switches the operating mode according to the received signal, including: When a normal wind turbine signal and a preset navigation condition signal are received, the system switches to either the economic mode or the navigation mode. The preset navigation condition signals include an energy-saving navigation status signal and a navigation status signal that requires equipment monitoring and emergency response. The energy-saving navigation status signal corresponds to the economic mode, and the navigation status signal that requires equipment monitoring and emergency response corresponds to the navigation mode. When the navigation status signal indicates that the ship’s speed over land is zero, the ship switches from the navigation mode or the economic mode to the berthing mode. When the status signal of the ramp is received as a ramp opening signal, switch from the berthing mode to the loading and unloading mode. When a wind turbine fault signal and an emergency bypass trigger signal are received, and the loading / unloading mode is currently in effect, and the ramp is fully open, switch to the emergency bypass mode. When a fan fault signal and an emergency bypass trigger signal are received, but the current loading / unloading mode is not in effect, the current ramp is not fully open, or there is a risk of positive pressure, the switch to the emergency bypass mode is refused, the current mode is maintained, and a bypass prohibition alarm signal is output.

[0016] Furthermore, the mode selection unit is also used to maintain the current mode and output a ramp not open alarm signal when it does not receive the ramp opening status signal but receives the loading / unloading mode selection signal.

[0017] Furthermore, monitoring the fault status of the wind turbine includes: The wind speed sensor monitors the actual number of air changes per unit time in real time, and obtains the deviation between the target number of air changes per unit time and the actual number of air changes per unit time in the current mode. When the deviation is greater than the preset value, an abnormal ventilation alarm signal is triggered. When the fan stops or the actual number of air changes per unit time is less than the preset number and continues to exceed the set time, a fan fault status signal and an emergency bypass trigger signal are output.

[0018] Furthermore, the handling methods for wind turbine failure include: When the mode selection unit receives a fan fault signal, if it is in the economy mode or the navigation mode, the mode selection unit will maintain the current mode and output a ventilation abnormality alarm signal to the roll-on / roll-off equipment management unit. The roll-on / roll-off equipment management unit will maintain the start-up lock state of the roll-on / roll-off equipment. When the mode selection unit receives a fan fault signal, and is in the berthing mode, the mode selection unit maintains the current mode and outputs a ventilation abnormality alarm signal, and the roll-on / roll-off equipment management unit cuts off the start control circuit of the roll-on / roll-off equipment.

[0019] Furthermore, the first unit time air exchange rate is 6 times / hour; the second unit time air exchange rate is 10 times / hour; and the third unit time air exchange rate is 20 times / hour.

[0020] Beneficial effects: This invention provides a multi-mode interlocking control system for the fan and roll-on / roll-off equipment at a ship's roll-on / roll-off terminal, which has the following advantages: 1. This invention sets up a roll-on / roll-off equipment management unit, which identifies the explosion-proof attributes of the roll-on / roll-off equipment and its location in a controlled non-hazardous area through an explosion-proof and non-explosion-proof identification module and a positioning module. It then performs power-on, power-off, lock-on, and unlocking according to the current working mode, solving the problem of crude equipment management in controlled non-hazardous areas in the prior art. It also achieves equipment locking from the control logic level, effectively solving the problem of unreliable navigation locking.

[0021] 2. The present invention adds a port berthing mode as a transitional mode between the navigation mode and the loading and unloading mode, filling the gap in the existing technology where a port berthing mode is missing, and making the coverage of working modes more complete.

[0022] 3. In loading and unloading mode, the system continuously monitors the ramp opening status through the ramp status monitoring unit, and the ventilation control unit controls the blower and reversible fan, eliminating the risk of positive pressure accumulation from the root and solving the problem of uncontrolled positive pressure risk during loading and unloading.

[0023] 4. The present invention provides an emergency bypass unit, which includes an independent physical bypass device. When the fan fails and is triggered, it bypasses the ventilation status detection logic and directly closes the start-up circuit of the roll-on / roll-off equipment, thus solving the problem of difficult emergency operation when the fan fails. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A system block diagram of a multi-mode interlocking control system for a ship roll-on / roll-off (Ro-Ro) terminal fan and Ro-Ro equipment provided by the present invention; Figure 2 The working mode and interlocking logic flowchart provided by this invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] This embodiment provides a multi-mode interlocking control system for the fan and roll-on / roll-off equipment at a ship's roll-on / roll-off terminal, such as... Figure 1 As shown, it includes: a mode selection unit, a ventilation control unit, a ramp status monitoring unit, a roll-on / roll-off equipment management unit, and an emergency bypass unit; The mode selection unit is used to switch the working mode according to the received ship navigation status signal, ramp status signal, fan fault status signal and emergency bypass trigger signal, using a preset multi-mode switching architecture that includes economic mode, navigation mode, berthing mode, loading and unloading mode and emergency bypass mode. During the switching, it sends the corresponding working mode operation command to the ventilation control unit and the roll-on / roll-off equipment management unit. In this embodiment, the signal received by the mode selection unit is sent by the operator through the human-machine interface or control panel, or is automatically detected and generated by the system.

[0028] The specific switching logic is as follows: When a normal wind turbine signal and a preset navigation condition signal are received, the system switches to either the economic mode or the navigation mode. The preset navigation condition signals include an energy-saving navigation status signal and a navigation status signal requiring equipment monitoring and emergency response. The energy-saving navigation status signal corresponds to the economic mode, and the navigation status signal requiring equipment monitoring and emergency response corresponds to the navigation mode. That is, if an energy-saving navigation status signal is received, the system switches to the economic mode; if a navigation status signal requiring equipment monitoring and emergency response is received, the system switches to the navigation mode. When the navigation status signal indicates that the ship's speed over land is zero, it can switch from the navigation mode or the economic mode to the berthing mode. When the status signal of the ramp is received as a ramp opening signal, it can switch from the berthing mode to the loading and unloading mode. When a wind turbine fault signal and an emergency bypass trigger signal are received, and the loading / unloading mode is currently in effect, and the ramp is fully open, switch to the emergency bypass mode. When a fan fault signal and an emergency bypass trigger signal are received, but the current loading / unloading mode is not in effect, the current ramp is not fully open, or there is a risk of positive pressure, the switch to the emergency bypass mode is refused, the current mode is maintained, and a bypass prohibition alarm signal is output.

[0029] Monitoring the fault status of the wind turbine includes: The wind speed sensor monitors the actual number of air changes per unit time in real time, and obtains the deviation between the target number of air changes per unit time and the actual number of air changes per unit time in the current mode. When the deviation is greater than the preset value, an abnormal ventilation alarm signal is triggered. When the fan stops or the actual number of air changes per unit time is less than the preset number and continues to exceed the set time, a fan fault status signal and an emergency bypass trigger signal are output.

[0030] The procedures for handling fan malfunctions include: When the mode selection unit receives a fan fault signal, if it is in the economy mode or the navigation mode, the mode selection unit will maintain the current mode and output a ventilation abnormality alarm signal to the roll-on / roll-off equipment management unit. The roll-on / roll-off equipment management unit will maintain the start-up lock state of the roll-on / roll-off equipment.

[0031] When the mode selection unit receives a fan fault signal, and is in the berthing mode, the mode selection unit maintains the current mode and outputs a ventilation abnormality alarm signal, and the roll-on / roll-off equipment management unit cuts off the start control circuit of the roll-on / roll-off equipment.

[0032] The ventilation control unit includes a supply fan and a reversible fan. It is used to control the start / stop, operating frequency, air exchange rate per unit time, and direction of the reversible fan of the supply fan and the reversible fan according to the operation commands of the corresponding working mode output by the mode selection unit. Specifically: In the economic mode, the blower and the reversible blower are controlled to operate at a first frequency, the reversible blower is controlled to turn to exhaust, and the number of air changes per unit time is maintained. In the navigation mode and the berthing mode, the blower and the reversible blower are controlled to operate at a second frequency, the reversible blower is controlled to turn to exhaust, and the number of air exchanges per unit time is maintained. In the loading and unloading mode, the blower is controlled to operate at a third frequency, the reversible blower is controlled to switch to air supply, and the air exchange rate is maintained at a third unit time. Wherein, the first unit time air exchange rate is 6 times / hour; the second unit time air exchange rate is 10 times / hour; and the third unit time air exchange rate is 20 times / hour. The ramp status monitoring unit includes a limit switch and a tilt sensor, used to monitor the ramp's opening status in real time and output the ramp's status signal, specifically: In the economic mode and the navigation mode, the ramp status monitoring unit is in standby mode and outputs a ramp standby signal; In the berthing mode, the ramp status monitoring unit continuously monitors the ramp limit switch signal and the tilt sensor reading. When the ramp limit switch signal is 2 or the tilt sensor reading is greater than or equal to the preset value, the ramp opening signal is output. In the loading and unloading mode, the ramp limit switch signal and the tilt sensor reading are continuously monitored. When the ramp limit switch signal is detected to be 0 or the tilt sensor reading is less than the preset value, the delay timer T is triggered. If T reaches the specified time and the ramp status is not restored, the ramp closure signal is output.

[0033] The roll-on / roll-off (Ro-Ro) equipment management unit includes an explosion-proof / non-explosion-proof identification module and a positioning module. These modules are used to identify the explosion-proof properties of the Ro-Ro equipment and its location within a controlled, non-hazardous area. Based on the current operating mode, the module performs power-on, power-off, start-up locking, and unlocking of the Ro-Ro equipment. Specifically: Specifically: In the economic mode, interlocked automatic power-off is performed on non-explosion-proof roll-on / roll-off equipment located in a controlled, non-hazardous area; In the navigation mode, non-explosion-proof roll-on / roll-off equipment located in a controlled, non-hazardous area remains powered on; In the docking mode, a drive signal is output to the hardware relay in the start-up circuit to energize the relay coil and close the normally open contact. At the same time, the start-up control circuit of the roll-on / roll-off equipment is activated, the electrical lock is released, and the roll-on / roll-off equipment is granted start-up permission. In the loading and unloading mode, the start-up permission of the roll-on / roll-off equipment remains unchanged; In the emergency bypass mode, the starting circuit of the roll-on / roll-off equipment is directly closed through the contacts of the physical bypass device, allowing for normal startup.

[0034] The emergency bypass unit includes an independent physical bypass device, which is used to close the starting circuit of the roll-on / roll-off equipment when the wind turbine fails and an emergency bypass mode operation command is received.

[0035] It should be noted that the sensors, positioning modules, identification modules, PLCs, relays, contactors, frequency converters, HMIs, etc., used in this embodiment to obtain the ramp status, fan status, equipment explosion-proof attributes, and equipment location are all mature hardware or common components in the field of marine and industrial control. For example, obtaining the ramp opening status through limit switches and tilt sensors, calculating the number of air changes per unit time through wind speed sensors, distinguishing equipment attributes through explosion-proof and non-explosion-proof identification modules, and determining the area where the equipment is located through positioning modules are all existing technologies.

[0036] In this embodiment, device identification and area positioning can be achieved by collecting data through sensors, identifying attributes through modules, and obtaining location through positioning devices. The specific sensing principles, communication protocols, and identification algorithms can adopt common methods in the field and belong to the prior art. Therefore, this application will not elaborate on them in detail. Those skilled in the art can choose the appropriate specific implementation method according to actual needs.

[0037] Specifically, the working process and definitions of each working mode in this solution are as follows: In economic mode, the turbine operates at 6 cycles per hour (corresponding to the inverter speed). During ocean voyages, this mode can significantly reduce shipowner operating costs by decreasing the turbine's operating power.

[0038] The equipment is located in a controlled, non-hazardous area: Non-explosion-proof equipment: The roll-on / roll-off equipment management unit immediately cuts off the main power contactor (power and control power) to ensure that no ignition source is generated under insufficient ventilation conditions.

[0039] Explosion-proof equipment: The roll-on / roll-off equipment management unit is kept powered on and allowed to continue operating (such as explosion-proof probes, explosion-proof monitoring, explosion-proof lighting, etc.) because it has an explosion-proof enclosure, intrinsically safe circuit or pressurized enclosure design, and can work safely in explosive environments.

[0040] Equipment located in non-hazardous areas: Both types of equipment can remain powered on, but the permission to start moving equipment is determined by the current mode (roll-on / roll-off operations are not performed in economy mode).

[0041] This differentiation strategy satisfies the requirement that non-explosion-proof equipment must not be powered on under 6 times / hour ventilation, while avoiding unnecessary shutdown of explosion-proof equipment.

[0042] In navigation mode, the wind turbine operates at 10 cycles per hour. The roll-on / roll-off equipment management unit is electrically locked, and operation of the roll-on / roll-off equipment is not permitted. In this mode, non-explosion-proof equipment in controlled, non-hazardous areas is powered on, allowing crew members to enter the area for inspections to ensure personnel safety.

[0043] The roll-on / roll-off equipment management unit closes the main power contactor of all non-explosion-proof equipment to keep it powered on (lighting, probes, monitoring and other functions are available).

[0044] The roll-on / roll-off equipment management unit disconnects the normally open relay contacts in the series of all roll-on / roll-off equipment start-up circuits (hardware lock), while the PLC internal logic disables the output of start-up commands (software lock), providing double redundancy.

[0045] The human-machine interface prominently displays "Navigation mode locked - the device is powered on but cannot be started".

[0046] In this mode, even if the operator presses the start button or simulates a short circuit signal, the equipment cannot obtain starting current, thus fundamentally preventing accidental movement during navigation.

[0047] The berthing mode is a key new mode added to this invention. The wind turbine operates normally at 10 cycles per hour (the same as the sailing mode), but the control logic for the roll-on / roll-off equipment is completely different. To switch to berthing mode, the ship can only be switched to when it is stationary relative to the ground to prevent accidental operation by the crew during movement. This is achieved by the DGPS system sending a 0-knot speed signal to the mode selection unit. Upon receiving this contact signal, the mode selection unit can switch to berthing mode, and the roll-on / roll-off equipment management unit will be unlocked.

[0048] Release condition: The mode selection unit receives a speed signal of 0 knots from the DGPS output.

[0049] Release electrical lockout: The roll-on / roll-off equipment management unit closes the relay contacts in the start-up circuit, and the PLC resumes the output of the start-up command.

[0050] In berthing mode, the roll-on / roll-off equipment has been restored to start-up permission, and ventilation is 10 times / hour.

[0051] The docking mode fills the functional gap between navigation (non-startable) and loading / unloading (high ventilation, requiring ramps), allowing personnel to safely and legally enter the cargo hold for operations before the ramps are opened.

[0052] The roll-on / roll-off equipment can be powered on and started normally: the stern / side doors, ramps, vehicles, etc. can all be operated normally by the operator for tasks such as lashing and unlashing, cargo inspection, and preparation before ramp opening.

[0053] During loading and unloading, the system implements extraction-to-supply ventilation and positive pressure interlock. (1) Fan supply / exhaust switching logic In loading and unloading mode, the ventilation control unit controls the fan to operate normally at 20 times / hour. To achieve high-intensity dilution ventilation, the mode selection unit sends a command to the ventilation control unit to switch the reversible exhaust fan to a supply fan (by reversing the frequency converter or switching the air valve), while the original supply fan continues to supply air, forming a state of full supply air with no exhaust.

[0054] (2) The opening of the ramp is a mandatory prerequisite for switching. To prevent the hazards of positive pressure, the mode selection unit stipulates that the switch from berthing mode (or navigation mode) to loading and unloading mode is only allowed when the ramp status monitoring unit detects that the ramp of the corresponding ventilation path has been fully opened to the working position (double confirmation by limit switch and tilt sensor) and outputs a ramp opening signal, and then the operation of supplying and exhausting air 20 times / hour is performed.

[0055] If the operator attempts to select the loading / unloading mode when the ramp is not open, the system will refuse to switch, maintain the current mode, and issue an audible and visual alarm: "Please open the ramp corresponding to the ventilation path first."

[0056] (3) Protection against positive pressure abnormalities If the ramp is accidentally closed during loading and unloading (sensor signal loss or angle <85°): Immediately trigger audible and visual alarm: "Slope abnormality, positive pressure risk, downgrade in 30 seconds."

[0057] A 30-second processing window is provided for equipment that is currently on the ramp to pass through.

[0058] If the ramp still does not open after 30 seconds, the fan frequency will be automatically reduced to 10 times / hour. The ventilation control unit will control the exhaust fan to restore the exhaust direction, and the roll-on / roll-off equipment management unit will relock the roll-on / roll-off equipment start circuit (keeping power on but preventing new equipment from entering).

[0059] In emergency bypass mode, power is forcibly supplied to the roll-on / roll-off unit in case of fan failure. The core design principle of the emergency bypass mode is: when the fan system malfunctions (such as inverter failure, motor stoppage, duct blockage, or control circuit power failure) and normal ventilation cannot be maintained, operators are allowed to bypass all ventilation interlocks, forcibly power on the roll-on / roll-off equipment, and release the start-up lock in order to complete emergency operations.

[0060] (1) Emergency bypass triggering conditions Install an independent physical bypass device (key switch or button with protective cover) and add a "fan failure confirmation" signal.

[0061] Manual trigger: After confirming that the fan has malfunctioned (e.g., by observing the fan current, speed feedback, air volume sensor readings, or local alarms), the operator can turn the emergency bypass key or press the button with the protective cover.

[0062] Automatic trigger (optional): When the PLC detects a serious fan fault (such as inverter overload fault, motor thermal overload trip, air volume sensor readings below 2 times / hour and mode requirement ≥6 times) for more than 10 seconds, the system will automatically prompt "It is recommended to enable emergency bypass", but manual confirmation is still required for activation.

[0063] (2) Emergency bypass execution logic After the emergency bypass signal is activated, the mode selection unit determines whether it is currently in loading / unloading mode and whether the ramp is fully open. If the conditions are met, it switches to emergency bypass mode and performs the following operations: The requirement for wind turbine operation is abandoned: The "wind turbine in normal operation" signal is no longer sent to the roll-on / roll-off equipment management unit as a prerequisite. The main power supply and starting circuit of the roll-on / roll-off equipment are directly and forcibly closed by the emergency bypass unit, completely decoupled from the actual operating status of the wind turbine. This means that even if the wind turbine stops, is damaged, or completely fails, the roll-on / roll-off equipment can still be powered on and started.

[0064] Forced fan start: Considering the fan is already faulty, forcibly sending a fan start command would not only be ineffective but could also damage the inverter or motor. Therefore, in emergency mode, the mode selection unit no longer sends any control commands to the ventilation control unit, maintaining the fan's current state (shutdown or fault state). The operation interface clearly displays "Emergency bypass activated—Fan fault, ventilation lost, roll-on / roll-off equipment forcibly powered on."

[0065] Positive pressure risk alarm (only for loading and unloading scenarios): If the emergency bypass is activated and the vessel is currently in a loading / unloading state (i.e., the ramp may not be open), and the blower was originally set to full ventilation mode (exhaust to supply), the mode selection unit automatically determines the positive pressure risk. A high-frequency audible and visual alarm is issued, and the screen displays "Emergency bypass mode – blower malfunction, roll-on / roll-off power on, note the loss of ventilation and positive pressure risk (if the ramp is not open)". The local control cabinet has an "Emergency Risk Confirmation" button. After operator confirmation, the mode selection unit receives the risk confirmation signal and clears the alarm (without interrupting roll-on / roll-off power supply).

[0066] Recording and Indication: After emergency bypass is activated, the PLC records the action time, cause (manual / automatic), and current fan fault code. The indicator lights on the control panel and local area remain constantly lit, indicating that the system is in bypass mode.

[0067] (3) Emergency bypass exit The emergency bypass mode must be manually reset by authorized personnel. After the fan malfunction is repaired and normal ventilation capacity is restored, the operator turns the emergency key back to the "normal" position. The mode selection unit then exits bypass mode, reverts to the operating mode before the malfunction (economy / navigation / berthing / loading / unloading), and re-executes the corresponding ventilation-roll-off interlock logic.

[0068] Fan status closed loop and fault tolerance An air velocity / air volume sensor is installed inside the air duct to monitor the actual number of air changes in real time. An alarm is triggered when the deviation from the target value exceeds ±15%.

[0069] In normal mode, if the fan stops due to a malfunction or the actual ventilation frequency is less than 3 times / hour and lasts for 5 seconds, immediately cut off the main power supply to the non-explosion-proof equipment.

[0070] In emergency bypass mode, the above power outage logic is completely bypassed; however, the system continuously monitors the fan status. If the fan unexpectedly resumes operation during emergency bypass, the system will issue a prompt but will not automatically exit the bypass (manual intervention is required).

[0071] Working mode and interlocking logic flow as follows Figure 2 As shown, the system has five operating modes: Economy Mode, Navigation Mode, Port Call Mode, Loading / Unloading Mode, and Emergency Bypass Mode. Arrows in the diagram indicate the direction of mode switching, and diamonds represent decision conditions.

[0072] The specific logic is as follows: the economic mode and navigation mode can be switched according to the navigation status; after the ship berths, it enters the berthing mode and the electrical lock is released; in the berthing mode, it can only switch to the loading / unloading mode when the ramp opening signal is valid (verified by both limit switches and tilt sensors); if the ramp is accidentally closed in the loading / unloading mode, it will automatically downgrade back to the berthing mode after a 30-second delay. The emergency bypass mode can be activated in any mode via an independent emergency key. After activation, it bypasses all ventilation interlocks and forcibly powers on the roll-on / roll-off equipment; manual reset is required to exit.

[0073] Example 1: The specific implementation is illustrated using a 4,000-vehicle roll-on / roll-off ship (equipped with three vehicle decks) as an example.

[0074] Hardware configuration: Main controller: Siemens S7-1515F safety PLC (redundant CPU), equipped with digital I / O, analog input, and communication modules.

[0075] Fan system: There are 6 air supply fans (variable frequency), 2 on each deck; Three reversible exhaust fans (frequency conversion, capable of forward and reverse rotation), one for each deck.

[0076] Fan fault detection: inverter fault relay output, motor thermal overload relay, duct wind speed sensor (low flow alarm).

[0077] Ramps: 1 stern ramp and 1 side ramp; each ramp is equipped with a limit switch (open in position) and an tilt sensor (dual redundancy).

[0078] Roll-on / roll-off equipment: 4 roll-on / roll-off ramps.

[0079] Controlled non-hazardous areas: Space within the cargo hold at least 450mm above the deck surface.

[0080] Emergency bypass: The driver's cab and the local control box are each equipped with a key-type selector switch (normal / emergency) and connected in series with a "fan failure confirmation" button (which allows activation when pressed).

[0081] Human-Machine Interface (HMI): 15-inch touchscreen, displaying mode, actual air exchange rate, ramp status, equipment power supply status, and fan fault codes.

[0082] Operating procedures: 1. Economic Model (Energy-Saving Navigation at Sea) The captain selects "Economy Mode" via the human-machine interface, and the system receives the economy mode selection signal. The PLC controls the blower to operate at 25Hz (calibrated to 6 times / hour), and the exhaust fan stops (maintaining basic air exchange). Non-explosion-proof equipment in this area is powered off.

[0083] 2. Navigation Mode (Normal Navigation) The ship enters a busy channel, and the captain selects "navigation mode" via the human-machine interface (HMI). The system receives the navigation mode selection signal. The fan frequency increases to 35Hz (10 times / hour). The PLC closes the main power contactor for all non-explosion-proof equipment in the area (keeping it energized). The operator presses the ramp opening button, but there is no response; the HMI displays "Navigation mode locked - power on only, cannot start." Even if the start signal line is manually shorted, the circuit remains closed because the relay contacts are open.

[0084] 3. Dock berthing mode (after arrival, before loading and unloading) The DGPS outputs a 0 knot speed signal. Upon receiving this signal, the operator selects "berthing mode" via the HMI, and the system receives the berthing mode selection signal. The fans continue operating at 10 breaths per hour (pre-ventilation begins). The PLC closes the start-up circuit relay, and the internal logic resumes startup permission. All roll-on / roll-off equipment can be powered on and started normally. The operator drives a forklift into the cargo hold, unties the vehicle lashings, checks the cargo's securing status, and simultaneously activates the hydraulic system of the stern ramp, ready for operation. The HMI displays "berthing mode—roll-on / roll-off equipment can start normally, ventilation 10 breaths per hour." At this time, the ramp is not yet open, but ventilation continues, and hazardous gases in the cargo hold are constantly being replaced.

[0085] 4. Loading and unloading mode (formal operation) Once ready, the operator fully opens the stern door, side doors, and the roll-on / roll-off ramps required for the corresponding area's fans. Limit switches close, tilt sensors report 90.5°, and the system receives the ramp opening signal. The operator selects "Loading / Unloading Mode" on the HMI, and the system receives the loading / unloading mode selection signal. The system executes: The fan speeds up from 35Hz to 50Hz (20 times / hour); The reversible exhaust fan reverses and accelerates to 50Hz (from exhaust to supply air); With the full air supply mode established, the positive pressure in the cargo compartment is released due to the opening of the ramp, posing no safety risk.

[0086] The HMI displays "Loading / Unloading Mode - Full Ventilation Operation, Roll-on / Roll-off Loading Can Operate Normally." Loading and unloading operations proceeded smoothly.

[0087] If the ramp closes unexpectedly during operation (hydraulic failure), the tilt sensor reports 80° and the limit switch is lost. The PLC immediately issues an audible and visual alarm: "Ramp abnormality, positive pressure risk, downgrade after 30 seconds." If the ramp is not restored within 30 seconds, the system automatically reduces its frequency to 35Hz, the exhaust fan resumes its exhaust direction, and the start-up circuit is relocked. Equipment already inside the cargo hold remains powered but cannot be restarted.

[0088] 5. Emergency bypass mode (activated in case of wind turbine failure) Scenario Description: During loading and unloading operations, a main blower inverter suddenly malfunctioned (reporting an overcurrent trip), causing the blower to stop. The duct speed sensor showed that the actual air exchange rate had dropped to 1 time per hour. According to normal logic, the PLC should cut off the main power supply to non-explosion-proof equipment after 5 seconds. However, some vehicles are still parked on the ramp at this time. A power outage would prevent the vehicles from moving, causing congestion or even causing them to roll back down the ramp.

[0089] Operating steps: The operator on the control panel observed the fan malfunction alarm and low wind speed alarm, confirming that the fan could no longer operate.

[0090] The chief engineer or captain uses the emergency bypass key (insert and turn it to the "emergency" position) and simultaneously presses the adjacent "wind turbine failure confirmation" button (to ensure that the operator is aware of the wind turbine failure status).

[0091] After the PLC detects the emergency bypass signal: Instead of executing the logic of "cutting off the power supply to the roll-on / roll-off equipment due to insufficient ventilation", the main power contactor and starting circuit relay of all roll-on / roll-off equipment are forcibly closed through hard-wired bypass relays.

[0092] Do not send any start commands to the faulty fan (to avoid further damage), and keep the fan in a stopped state.

[0093] High-frequency audible and visual alarms are issued simultaneously from the control panel and the local station. The HMI flashes red and displays: "Emergency bypass mode - fan failure and stoppage, roll-on / roll-off has been forcibly powered on, ventilation lost! Positive pressure risk (if the ramp is not open) Please be aware." After the on-site commander pressed the "emergency risk confirmation" button, the alarm stopped, but the red light remained on.

[0094] The operator immediately started the roll-on / roll-off equipment to evacuate all vehicles that were stuck on the ramp and in the cargo hold to a safe area on the dock.

[0095] After the evacuation was completed, maintenance personnel repaired the frequency converter. Once the wind turbine was back to normal operation, the chief engineer turned the emergency key back to the "normal" position, the system exited emergency bypass, and re-entered loading and unloading mode (or, depending on the ramp status, entered berthing mode).

[0096] Supplementary test: In emergency bypass mode, if the fan suddenly resumes operation due to some unexpected reason (such as the inverter automatically resetting), the system will only prompt "The fan has resumed operation, please pay attention" on the HMI, and will not automatically exit the bypass. Manual confirmation is required before resetting to prevent accidental power outages.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multimode interlock control system for a ship roll-on / roll-off ramp air fan and roll-on / roll-off equipment, characterized by, include: Mode selection unit, ventilation control unit, ramp status monitoring unit, roll-on / roll-off equipment management unit, and emergency bypass unit; The mode selection unit is used to switch the working mode according to the received ship navigation status signal, ramp status signal, fan fault status signal and emergency bypass trigger signal, using a preset multi-mode switching architecture that includes economic mode, navigation mode, berthing mode, loading and unloading mode and emergency bypass mode, and sends the corresponding working mode operation command to the ventilation control unit and roll-on / roll-off equipment management unit during the switching. The ventilation control unit includes a blower and a reversible fan, and is used to control the start and stop, operating frequency, number of air changes per unit time, and direction of the reversible fan according to the operation instructions of the corresponding working mode output by the mode selection unit. The ramp status monitoring unit includes a limit switch and an tilt sensor, which are used to monitor the opening status of the ramp in real time and output the ramp status signal. The roll-on / roll-off equipment management unit includes an explosion-proof and non-explosion-proof identification module and a positioning module, which are used to identify the explosion-proof attributes of the roll-on / roll-off equipment and its location in a controlled non-hazardous area, and to perform power-on, power-off, start-up locking and unlocking of the roll-on / roll-off equipment according to the current working mode. The emergency bypass unit includes an independent physical bypass device, which is used to close the starting circuit of the roll-on / roll-off equipment when the wind turbine fails and an emergency bypass mode operation command is received.

2. The multi-mode interlocking control system for the ship roll-on / roll-off (Ro-Ro) terminal fan and Ro-Ro equipment according to claim 1, characterized in that, The ventilation control unit controls the start / stop, operating frequency, air exchange rate per unit time, and direction of rotation of the supply fan and reversible fan according to the operating mode command output by the mode selection unit, including: In the economic mode, the blower and the reversible blower are controlled to operate at a first frequency, the reversible blower is controlled to turn to exhaust, and the number of air changes per unit time is maintained. In the navigation mode and the berthing mode, the blower and the reversible blower are controlled to operate at a second frequency, the reversible blower is controlled to turn to exhaust, and the number of air exchanges per unit time is maintained. In the loading and unloading mode, the blower is controlled to operate at the third frequency, the reversible blower is controlled to switch to air supply, and the number of air changes per unit time is maintained.

3. The multi-mode interlocking control system for the ship roll-on / roll-off (Ro-Ro) terminal fan and Ro-Ro equipment according to claim 1, characterized in that, The roll-on / roll-off equipment management unit executes power-on, power-off, start-up locking, or unlocking of the roll-on / roll-off equipment according to the current working mode, including: In the economic mode, interlocked automatic power-off is performed on non-explosion-proof roll-on / roll-off equipment located in a controlled, non-hazardous area; In the navigation mode, non-explosion-proof roll-on / roll-off equipment located in a controlled, non-hazardous area remains powered on; In the docking mode, a drive signal is output to the hardware relay in the start-up circuit to energize the relay coil and close the normally open contact. At the same time, the start-up control circuit of the roll-on / roll-off equipment is activated, the electrical lock is released, and the roll-on / roll-off equipment is granted start-up permission. In the loading and unloading mode, the start-up permission of the roll-on / roll-off equipment remains unchanged; In the emergency bypass mode, the starting circuit of the roll-on / roll-off equipment is directly closed through the contacts of the physical bypass device, allowing for normal startup.

4. The multi-mode interlocking control system for the ship roll-on / roll-off (Ro-Ro) terminal fan and Ro-Ro equipment according to claim 1, characterized in that, The ramp status monitoring unit outputs ramp status signals according to the working mode command output by the mode selection unit, including: In the economic mode and the navigation mode, the ramp status monitoring unit is in standby mode and outputs a ramp standby signal; In the berthing mode, the ramp status monitoring unit continuously monitors the ramp limit switch signal and the tilt sensor reading. When the ramp limit switch signal is 2 or the tilt sensor reading is greater than or equal to the preset value, the ramp opening signal is output. In the loading and unloading mode, the ramp limit switch signal and the tilt sensor reading are continuously monitored. When the ramp limit switch signal is detected to be 0 or the tilt sensor reading is less than the preset value, the delay timer T is triggered. If T reaches the specified time and the ramp status is not restored, the ramp closure signal is output.

5. The multi-mode interlocking control system for the ship roll-on / roll-off (Ro-Ro) terminal fan and Ro-Ro equipment according to claim 4, characterized in that, The mode selection unit switches the operating mode according to the received signal, including: When a normal wind turbine signal and a preset navigation condition signal are received, the system switches to either the economic mode or the navigation mode. The preset navigation condition signals include an energy-saving navigation status signal and a navigation status signal that requires equipment monitoring and emergency response. The energy-saving navigation status signal corresponds to the economic mode, and the navigation status signal that requires equipment monitoring and emergency response corresponds to the navigation mode. When the navigation status signal indicates that the ship’s speed over land is zero, the ship switches from the navigation mode or the economic mode to the berthing mode. When the status signal of the ramp is received as a ramp opening signal, switch from the berthing mode to the loading and unloading mode. When a wind turbine fault signal and an emergency bypass trigger signal are received, and the loading / unloading mode is currently in effect, and the ramp is fully open, switch to the emergency bypass mode. When a fan fault signal and an emergency bypass trigger signal are received, but the current loading / unloading mode is not in effect, the current ramp is not fully open, or there is a risk of positive pressure, the switch to the emergency bypass mode is refused, the current mode is maintained, and a bypass prohibition alarm signal is output.

6. The multi-mode interlocking control system for the ship roll-on / roll-off (Ro-Ro) terminal fan and Ro-Ro equipment according to claim 3, characterized in that, The mode selection unit is also used to maintain the current mode and output a ramp not open alarm signal when it does not receive the ramp opening status signal and receives the loading / unloading mode selection signal.

7. The multi-mode interlocking control system for the ship roll-on / roll-off (Ro-Ro) terminal fan and Ro-Ro equipment according to claim 1, characterized in that, Monitoring the fault status of the wind turbine includes: The wind speed sensor monitors the actual number of air changes per unit time in real time, and obtains the deviation between the target number of air changes per unit time and the actual number of air changes per unit time in the current mode. When the deviation is greater than the preset value, an abnormal ventilation alarm signal is triggered. When the fan stops or the actual number of air changes per unit time is less than the preset number and continues to exceed the set time, a fan fault status signal and an emergency bypass trigger signal are output.

8. The multi-mode interlocking control system for the ship roll-on / roll-off (Ro-Ro) terminal fan and Ro-Ro equipment according to claim 7, characterized in that, The procedures for handling fan malfunctions include: When the mode selection unit receives a fan fault signal, if it is in the economy mode or the navigation mode, the mode selection unit will maintain the current mode and output a ventilation abnormality alarm signal to the roll-on / roll-off equipment management unit. The roll-on / roll-off equipment management unit will maintain the start-up lock state of the roll-on / roll-off equipment. When the mode selection unit receives a fan fault signal, and is in the berthing mode, the mode selection unit maintains the current mode and outputs a ventilation abnormality alarm signal, and the roll-on / roll-off equipment management unit cuts off the start control circuit of the roll-on / roll-off equipment.

9. The multi-mode interlocking control system for the ship roll-on / roll-off (Ro-Ro) terminal fan and Ro-Ro equipment according to claim 2, characterized in that, The first unit time air exchange rate is 6 times / hour; the second unit time air exchange rate is 10 times / hour; and the third unit time air exchange rate is 20 times / hour.

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